How To Kill Staphylococci On The Skin

Staph Infection Secrets By Dr. Walinski

Discover a Simple 3-Step Program to Permanently Eradicate Mrsa & Staph Infections Without Using Antibiotics. Here is what's provided in Staph Infection Secrets. Get Rid of Your Staph / Mrsa Infection. Best ways to quickly get rid of the most common conditions caused by Mrsa and Staph, such as: Impetigo, Cellulitis, Folliculitis, Boils / Carbuncles and more. An easy remedy for nasal infections than can completely eradicate the presence of the bacteria in less than 7 days. How to treat internal infections using a naturally occurring powerful antibiotic with a proven success rate. Learn how to get the most out of Western medicine learn what kinds of treatment is available and how to work with your doctor for best results.

Staph Infection Secrets By Dr Walinski Overview


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Coagulasenegative staphylococci

Early prosthetic valve endocarditis is commonly caused by coagulase-negative staphylococci which are characteristically resistant to methicillin ( Wolff. etal 1995). Late endocarditis is usually caused by more susceptible organisms. Teicoplanin is less active than vancomycin against Staphylococcus hemolyticus and some strains of Staphylococcus epidermidis. Vancomycin or teicoplanin plus rifampin and or gentamicin is suitable. For methicillin-susceptible strains, flucloxacillin, nafcillin, or

Furuncles and Carbuncles

A furuncle, or boil, is an acute perifollicular staphylococcal abscess of the skin and subcutaneous tissue. Lesions appear as an indurated, dull, red nodule with a central purulent core, usually beginning around a hair follicle or a sebaceous gland. Furuncles occur most commonly on the nape, face, buttocks, thighs, perineum, breast, and axillae. B. A carbuncle is a coalescence of interconnected furuncles that drain through a number of points on the skin surface. C. The most common cause of furuncles and carbuncles is coagulase-positive S aureus. Cultures should be obtained from all suppurative lesions.

Methicillinresistant staphylococci

Staph. aureus is a well-recognized pathogen capable of causing infections virtually anywhere in the body, and Staph. epidermidis is also emerging as a pathogen of bacteremia, catheter-related infections, suppurative phlebitis), the lung and pleural space, the facial sinuses or parotid gland, and the peritoneal cavity. Infections of prosthetic devices are a particularly important subgroup of wound infections from staphylococci. Infections may be sporadic, or they may contribute to major nosocomial outbreaks. Staphylococci possess many properties that enhance their virulence. Peptidoglycans in the bacterial cell wall activate complement and cause other immune responses, and the teichoic acid moiety promotes attachment to epithelial cells. Staphylococci also produce numerous cytotoxins, including a- and b-toxins and leukocidin. Capsular antigens, such as protein A, and a glycocalyx or 'slime' (particularly for Staph. epidermidis) decrease opsonization and antigen presentation. Staph....

Staphylococcus aureus

Many strains of Staphylococcus aureus produce a toxin that, when ingested, causes nausea and vomiting. Although S. aureus does not compete well with most spoilage organisms, it thrives in moist, rich foods in which other organisms have been killed or their growth has been inhibited. For example, S. aureus can grow with little competition on unrefrigerated salty products such as ham (aw of 0.91). Creamy pastries and starchy salads stored at room temperature also offer ideal conditions for the growth of this pathogen, because the cooking of the ingredients kills most other competing organisms. The source of S. aureus is usually a human carrier who has not followed adequate hygiene procedures, such as handwashing, before preparing the food. If the organism is inoculated into a food that can support its growth, and the food is left at room temperature for several hours, S. aureus can grow and produce the toxin. Unlike most exotoxins, S. aureus toxin is heat-stable, so that cooking the...

Antistaphylococcal penicillinaseresistant Penicillins

Nafcillin, oxacillin, cloxacillin, and dicloxacillin are more resistant to bacterial p-lactamases than is penicillin G. Consequently, these antibiotics are effective against streptococci and most community-acquired penicilli-nase-producing staphylococci. Methicillin, which is no longer marketed in the United States, is another peni-cillinase-resistant antibiotic similar to nafcillin and oxacillin. For historical reasons, staphylococci resistant to oxacillin or nafcillin are labeled methicillin resistant. Many hospitals are reservoirs for MRSA and methi-cillin-resistant Staphylococcus epidermidis (MRSE). These nosocomial pathogens are resistant in vitro to all p-lactam antibiotics.

Roots In Intervention And Manipulation

For example, most people would say that research relating to HIV or genetics involves greater privacy risk than research on the common cold. This perceived difference in the risk of the research is an illusion. Assume that a single database, maintained under tight security arrangements, is made available to two different researchers under confidentiality agreements that bind the two investigators to the same obligations regarding use and protection of the data. One is studying HIV infection and the other is studying staphylococcus infection. The privacy risks in both cases are the same they stem from the adequacy of data security arrangements and the obligations imposed on the investigators. The appearance of differential risk stems from the current cultural perceptions of HIV, and the fact that people or institutions other than the researcher might misuse the information to embarrass or harm the data subject, if they were to gain access to the information. Similarly, test results...

Mechanisms of bacterial clearance

The most important process during phagocytosis is oxidative burst. Non-oxidative mechanisms include the release of enzymes such as proteases, hydrolases, and lysozymes. Lymphocytes form 10 per cent of the alveolar cell population and produce soluble mediators that stimulate alveolar macrophages. This mechanism seems to be regulated by cytokines. In addition, alveolar macrophages are able to release several mediators (e.g. interleukin 8, C5a, leukotriene B4, and platelet activating factor) with potent chemotactic activity for polymorphonuclear bodies. These cells act mainly through phagocytosis and exert their antibacterial activity in a dose-dependent manner via the release of granular enzymes. They constitude the primary defense against pathogens such as Staphylococcus aureus or fungi. Finally, natural killer cells are lymphocytes responsible for immunological surveillance of viral infections.

Transcriptomics Where We Are Now and Whats to Come

Transcriptomics is used as an indication of cellular activity at the protein level. In prokaryotes there is thought to be a high (but not an absolute) correlation between transcription and translation. Although there will always be exceptions to this, studies have been performed that assessed the relationship between tran-scriptional activities and the resulting level of biological activity at the protein level 54 . An obvious drawback becoming apparent to this kind of study is that the current technology available to analyze the proteome of a cell is far behind that used to analyze the transcriptome. For example, Scherl et al. 54 were able to identify proteins corresponding to just 23 of the Staphylococcus aureus predicted ORFs despite using a myriad of technologies to increase their detection rate. To fully unravel the story of a host and its pathogen, much more work is needed in exploring the integration of transcriptomic data with that derived from proteomic studies.

Antibiotic and Antiviral Agents

Under pathological conditions involving mucus hypersecretion and diminished mucociliary function (such as cystic fibrosis), bacterial organisms may colonize the airways and produce infection, a process that leads to pulmonary tissue damage. Antibiotics are administered to reverse the lung infection by killing the responsible bacteria, most commonly either Pseudomonas aeruginosa or Staphylococcus aureus. In general, short-term therapy involves intravenous administration of high doses of antibiotics and oral antibiotics for prophylactic therapy. Aerosol administration has been suggested for the delivery of antibiotics that are not orally active and as an alternative to the oral route of antibiotic administration because, in general, high blood levels of antibiotics (which increase the chance of systemic toxicity) are necessary to attain adequate concentrations in the sputum 88 . Aerosolized antibiotics have the advantage of delivering high concentrations directly to the site of...

The Postgenome Era of S aureus

With the long experience in Bacillus proteomics, this expertise has been transferred to a closely related pathogenic gram-positive bacterium, Staphylococcus aureus. S. aureus is a human pathogen of increasing importance, mainly as a result of the spread of antibiotic resistance. The pathogenicity of this species is very complex and involves the strongly regulated production of cell-wall-associated and extracellular proteins forming a changing set of virulence factors. Due to the great variety of these proteins, S. aureus causes a broad spectrum of infectious diseases ranging from superficial abscesses to endocarditis, osteomyelitis, and toxic shock syndrome 21 . Methicillin-resistant S. aureus (MRSA) strains are currently predominant and dangerous nosocomial pathogens, since infections caused by these strains have become difficult to treat. Vancomycin has become the drug of choice for treating MRSA infections. However, the emergence of vancomycin-resistant MRSA strains is leading to...

Infections Osteomyelitis

Infections involving bones may be a consequence of hematogenous spread or by direct inoculation following trauma or surgical intervention (secondary osteomyelitis). Hematogenous bacterial osteomyelitis results from a source elsewhere in the body and has decreased in incidence over the past 25 years. The typical case involves the metaphyseal portion of long bones in children aged 15 years or below. Staphylococcus aureus is the most common organism cultured however, Hemophilus influenza may be present in children aged less than three years (7). Other bacteria such as Group B streptococcus and coliforms may be seen in neonates. Staphylococcus epidermidis is another pathogen sometimes cultured and may follow surgical procedures or invasive techniques such as an intravenous catheter placement. Vertebral body involvement, especially in older patients with genitourinary tract infection (gram-negative rods), can occur via Batson's venous plexus. Infections involving the small bones of the...

Extracellular Proteins and Pathogenicity Networks

For the purposes of defining the structure of stimulons and regulons, transcrip-tomics provides a more complete picture than does proteomics, because - as already mentioned - many proteins still escape detection by gel-based proteomics. In many areas of application, however, proteomics can not be replaced by tran-scriptomics, because proteomics can also visualize events that never have been seen before by transcriptomics. Protein secretion is one such field of application that is crucial for Staphylococcus biology because of most of the virulence factors having signal sequences belong to the secretome. Using the dual channel technique it is possible to follow the protein secretion kinetics along the growth curve (Fig. 3.12). There are some proteins (e.g., SsaA, IsaA, Aly, Spa, SceD, LytM, and Aur) that are synthesized and secreted during exponential growth, but most are secreted only during the transient or even the stationary phase of growth 38, 39 .

Chapter References

Simmons, N.A., etal. (Working Party of the British Society for Antimicrobial Chemotherapy) (1985). Antibiotic treatment of streptococcal and staphylococcal endocarditis. Lancet, ii, 815-17. Wilson, W.R., et al. (1995). Antibiotic treatment of adults with infective endocarditis due to streptococci, enterococci, staphylococci and HACEK microorganisms. Journal of the American Medical Association, 274, 1706-13.

Transposon Mutagenesis

Most of our current understanding of the mechanisms of microbial pathogenesis comes from studies where scores of mutants, most often randomly generated by transposon mutagenesis, were monitored in suitable models of infection in search of those presenting reduced virulence 3 . For example, the individual screening of 9516 transposon mutants of Salmonella typhimurium in a macrophage culture assay led to the identification of 115 candidates with a diminished capacity for intracellular survival, of which 83 were also less virulent in vivo 9 . For example, the loss of virulence of one of the mutants, which was mutated in the phoP gene, was subsequently shown to be the result of its reduced resistance to defensins, an important microbicidal mechanism of the phagocyte 10 . The main advantages of this approach over directed mutagenesis are that (a) no a priori assumptions (which are often misleading) have to be made about the identity of the genes important for virulence, and (b) large...

Urinary Tract Infection

A microscopic bacterial count of 100 CFU mL of urine has a high positive predictive value for cystitis in symptomatic women. Ninety percent of uncomplicated cystitis episodes are caused by Escherichia coli, 10 to 20 percent are caused by coagulase-negative Staphylococcus saprophyticus and 5 percent are caused by other Enterobacteriaceae organisms or enterococci. Up to one-third of uropathogens are resistant to ampicillin, but the majority are susceptible to trimethoprim-sulfamethoxazole (85 to 95 percent) and fluoroquinolones (95 percent).

Wegeners Granulomatosis

Wegener's granulomatosis (WG) is an uncommon but distinctive form of vasculitis characterised in its classical form by necrotising granulomatous inflammation of the upper and lower respiratory tracts and segmental necrotising glomerulonephritis 76 . It is now recognised that a wide variety of other organs and tissues may be involved. Rarely, a proliferative rather than a destructive response produces tumefactions 65 . Variants of WG include a limited form, which has few extra-pulmonary manifestations, and a protracted superficial form, which is characterised by lesions restricted to the upper respiratory tract, mucosa and skin for a prolonged period, although it may eventually progress to renal involvement 58 . Wegener's granulomatosis limited to the respiratory system may respond to antibiotics such as co-trimoxazole and Staphylococcus aureus has been implicated as a triggering agent for this disease, but the evidence remains equivocal 141 .

Hemolysins Proteases and other Enzymes

The genome sequence of E.faecalis V583 shows the presence of three putative hemolysins (EF0700, EF0982, EF1685). EF0700 has its closest identity to L64811 (57.2 ) from L. lactis, while EF0982 is most similar to Lm01366 from L. monocytogenes. The third putative hemolysin, EF1685, shares 46 identity to hemolysin III from Bacillus cereus 70 . E.faecalis V583 is nonhemolytic on blood agar however, it is possible that expression of these genes could be induced in in vivo conditions. It is unknown at present whether these genes do indeed encode functional hemolysins. A putative exfoliative toxin A (EF0645) is likewise present in the chromosome. This protein shares 32 identity to Staphylococcus hyicus exfoliative toxin A and again its function in E.faecalis is unknown.

Haemophilus influenzae

5-10 year 6.0 mg kg day IV IM q8h. > 10 year 5.0 mg kg day IV IM q8h Staphylococcus aureus -Vancomycin (Vancocin) 40-60 mg kg day IV q6-8h, max 4 gm day. Staphylococcus aureus (methicillin sensitive) -Nafcillin (Nafcil) or oxacillin (Bactocill, Prostaphlin) 150 mg kg day IV IM q6h, max 12 gm day AND -Gentamicin (Garamycin) or Tobramycin (Nebcin), see dose above. Methicillin-resistant Staphylococcus aureus -Vancomycin (Vancocin) 40-60 mg kg day IV q6h, max 4 gm day. Staphylococcus epidermidis

Mechanisms of Immune Signaling to the Brain

Further evidence for a vagal immune to brain signaling pathways is provided by findings that vagal sensory neurons respond to injections of cytokines such IL-1 (Ek, Kurosawa, Lundeberg, and Ericsson 1998 Goehler, Gaykema, Hammack, Maier, and Watkins 1998 Niijima 1996), as well as LPS (Gaykema et al. 1998), staphylococcus enterotoxin B (SEB), a product of gram positive bacteria (Goehler et al. 2000), and live bacteria in the lower gut (Goehler, Gaykema, Opitz, Reddaway, Badr, and Lyte 2005). Interestingly, cells in the nodose ganglia express mRNA and protein corresponding to the TOLL-like receptor 4 (TLR4), a pathogen receptor sensitive to bacterial LPS (Hosoi, Okuma, Matsuda, and Nomura 2005). From the study it was not possible to know the cell type expressing TLR4, which could be satellite cells, resident immune cells, or vagal sensory neurons. Nonetheless, taken together these studies indicate that vagal sensory neurons are likely to be sensitive to a wide variety of pathogenic or...

Protein A chromatography

Most species of Staphylococcus aureus produce a protein known simply as protein A. This protein consists of a single polypeptide chain of molecular weight 42 kDa. Protein A binds the Fc region (the constant region) of immunoglobulin G (IgG Chapter 13) obtained from human and many other mammalian species with high specificity and affinity. Immobilization of protein A on chro-matography beads provides a powerful affinity system that may be used to purify IgG. There is, however, a considerable variation in the binding affinity of protein A for various IgG subclasses obtained from different mammalian sources. In some cases another protein, protein G, may be used instead of protein A. Most immunoglobulin molecules that bind to immobilized protein A do so under alkaline conditions, and may subsequently be eluted at acidic pH values.

Detailed Immunologic Laboratory Evaluation

To surmount these difficulties, many laboratories are now using flow cytometry assays based on the appearance on the lymphocyte plasma membrane of early activation markers such as CD69 (56). Mixed lymphocyte cultures, in which a patient's (or potential donor's) T cells are stimulated by a relative's lymphocytes that have been irradiated to prevent them from proliferating, are also used to test T-cell competence and to determine histocompatability in cases in which bone marrow transplantation is contemplated. Staphylococcal enterotoxins are also often employed as stimuli in proliferation assays because they function as superantigens, which stimulate broad families of T cells by binding to parts of their T-cell receptors other than the antigen-binding site. The response to these superantigens is thus also independent of prior antigen sensitization. The Cowen strain of Staphylococcus aureus may be used as a T-cell-independent stimulus for B-cell proliferation. T-cell proliferative...

Respiratory rate may be respiratory compensation for metabolic

Suppurative nodes are usually caused by either Staphylococcus aureus or group A streptococcus. Cat-scratch fever usually is associated with a cold lymphadenitis. Often an entry punctum can be found on skin in the anatomic area associated with the abnormal node. Generalized adenopathy directs clinician away from focal infections with considerations of certain viral, rheumatologic, or malignant processes.

Acute infectious diarrhea

Vomiting out of proportion to diarrhea is usually related to a neuroenterotoxin-mediated food poisoning from Staphylococcus aureus or Bacillus cereus, or from an enteric virus, such as rotavirus (in an infant), or a small round virus, such as Norwalk virus (in older children or adults). The incubation period for neuroenterotoxin food poisoning is less than 4 hours, while that of a viral agent is more than 8 hours.

MTMIOtreated cellulose

In order to increase washing durability of the N-halamine-treated textiles, the more stable amine N-halamine has been grafted to cellulose in a similar approach by using (MTMIO, shown in Figure 6.1) 4 . The resulting fabrics contained the more stable, and less reactive, amine N-halamine structure, thus providing slow, but durable, biocidal functions. The improved biocidal functions are summarized in Table 6.2 which compares fabrics treated by DMDMH and MTMIO separately. Both active chlorine contents and biocidal functions against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are listed in the table.

Antibacterial Screening of Tragia involucrata L Euphorbiaceae A Tribal Used Medicinal Plant

Reported the antimicrobial activity of traditional medicinal plants worldwide. Osmitopsis asteriscoides, a medicinal plant used in traditional drug preparations in South Africa, has been evaluated for antimicrobial activity against Candida albicans, Staphylococcus aureus mdPseudomonas aeruginosa 3 . The antimicrobial potential of Carpobrotus species (Aizoaceae) extracts was tested against S. aureus, P. aeruginosa, C. albicans and Mycobacterium smegmatis 4 . The efficacy of Warburgia ugandensis and Zanthoxylum chalybeum against common bacteria and fungi have also been investigated 5 . The oil obtained from the bark of Santiria trimera widely used by the traditional healers for wound healing 6 has also been investigated. Most people in South Africa with sexually transmitted diseases (STDs) first seek help from traditional healers

Screening by Immunoprecipitation and Polyacrylamide Gel Electrophoresis

In order to minimize the number of supernates to be tested, two strategies were adopted. First, all supernates were screened for IgG production by testing their ability to compete with l25I -IgG for binding to protein A-con-taining staphylococci. About 25 of wells with growth contained IgG. The second strategy involved pooling a series of horizontal rows (1-12), and pooling a series of vertical columns (A-H), with each primary well contributing 10 il supernatant. The pools were held for 1 h at 0 C with 100-200 nl 125I-labelled lysate of the immunizing cell (c. 108 c.p.m.), and then 1 mg of heat-killed and formalin-fixed protein A-bearing Staphyloccus aureus was added. (One could substitute 50 xl of 10 v v protein A-Sepharose for the intact bacteria.) The staphyloccoci, to which the immune complexes were bound, were harvested by centrifugation and washed twice. Bound antigen was released by heating the bacteria to 100 C in SDS sample buffer, and identified by SDS-polyacrylamide...

Experimental models for bloodCNSbarrier observations

The best-studied system so far is a human brain microvascular endo-thelial cell line (HBMEC) that has been derived from a brain biopsy of an adult female with epilepsy. The HBMEC were immortalized by transfection with simian virus 40 large-T antigen 90 . This cell line has proven invaluable in multiple experiments on bacterial interaction with the BBB. Many different bacterial species have been examined, e.g. S. agalactiae 91 , S. suis 92 , S. pneumoniae 83 , N. meningitidis 93 , Staphylococcus aureus 94 , and H. influenzae 95 .

Immunological properties of the bloodCNS barrier

Besides confining entry of blood-borne pathogens into the CNS by means of tightly sealed cell-to-cell interfaces, HBMECs display distinct antimicrobial properties 191 . Experiments from our laboratory demonstrated that bacteria such as Staphylococcus aureus as well as intracellular parasites such as Toxoplasma gondii were restricted in their growth in HBMECs after stimulation with interferon-y 94, 192 . Activation of indoleamine 2,3-dioxygenase (IDO) with subsequent degradation of the essential amino acid L-tryptophan has been found to be the principle antimicrobial mechanism. The in vivo relevance of this mechanism is emphasized by studies on patients suffering from bacterial meningitis 193 . For example, in children with purulent meningitis, concentrations of kynurenine, the primary meta

Functional neutrophil disorders

An increased susceptibility to infection is well recognized in conditions associated with defects in phagocytic function. These defects occur in many systemic conditions, including diabetes mellitus, uremia, malnourishment, and alcohol ingestion, and following corticosteroid therapy. There are also well-recognized but exceedingly rare inherited defects of phagocyte function, the most striking being chronic granulomatous disease in which neutrophils are unable to kill catalase-positive micro-organisms such as staphylococci, Serratia, Candida, and Aspergillus. These organisms survive intracellularly, resulting in chronic local granulomatous inflammation. The defect in chronic granulomatous disease involves an enzyme in the respiratory burst of oxidative metabolism that accompanies phagocytosis. Unless the disease has previously been recognized in the family, the diagnosis is usually made when the clinical picture of recurrent infection prompts investigation of neutrophil and immune...

Chronic airflow limitation

Many patients requiring ICU admission for a community acquired pneumonia have chronic respiratory failure. An acute exacerbation (which may or may not be infection-related) results in decompensation and symptomatic deterioration. Infections resulting in acute exacerbations include viruses, Haemophilus influenzae, Klebsiella and Staph. aureus in addition to Strep. pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila. Otherwise, patients with coincidental chronic airflow limitation (CAL) are admitted for other reasons or as a prophylactic measure in view of their limited respiratory function, e.g. for elective post-operative ventilation.

Diagnosis and initial antimicrobial treatment

Acute bronchitis is associated with cough, mucoid sputum and wheeze. In previously healthy patients a viral aetiology is most likely and there is often an upper respiratory prodrome. Symptomatic relief is usually all that is required. Likely organisms in acute on chronic bronchitis include Strep. pneumoniae, H. in. uenzae or Staph. aureus. Appropriate antibiotics include cefuroxime or ampicillin and .ucloxacillin. Viral pneumonia may be confused by the presence of bacteria in the sputum but secondary bacterial infection is common. Cavitation should alert to the possibility of anaerobic infection (sputum is often foul smelling). Staph. aureus, K. pneumoniae or tuberculosis are also associated with cavitation. Appropriate antibiotics include metronidazole or clindamycin for anaerobic infection, flucloxacillin for Staph. aureus and ceftazidime and gentamicin for K. pneumoniae. A foreign body or pulmonary infarct should also be considered where there is a single abscess. Hospital acquired...

Bacterial Tonsillitis

Bacterial suppurative tonsillitis is among the most frequent paediatric infections. Group A beta-haemolytic streptococci are the most frequent cause. Other common isolates in bacterial tonsillitis are Hemophilus influenza, Streptococcus pyogenes, Streptococcus milleri and Staphylococcus aureus 97, 202, 205 . Children with acute strep-tococcal tonsillitis are significantly older than children with viral tonsillitis. The treatment of choice is penicillin administration for 10 days. Prevention of acute rheumatic fever is the principal goal of treatment. Surgical specimens of acute tonsillitis are rarely encountered. The surface epithelium may be ulcerated, and the surface and crypt epithelium is infiltrated by neutrophilic granulo-cytes producing a cryptitis with crypt abscesses. Acute bacterial infections may advance to intraparenchymal and peritonsillar abscesses (quinsy) with a lateral extension into the parapharyngeal space, base of skull and the sheath of the carotid artery 33, 64 ....

An Outstanding Proposal

We have obtained a specimen isolated from pine soil that we believe is Streptomyces and have cross-streaked it with Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus with excellent inhibition. This technique involves streaking one-third trypticase soy agar plate with the test organism and placing cross streaks of known bacterial species in close proximity to it. A clearing on the agar between the test and known bacteria indicates antibiotic production by the test organism.

Subsequent assessment

Today, with improved wound care and earlier surgical excision, sepsis originating in the burn wound has been replaced by pulmonary sepsis associated with smoke inhalation as the leading cause of death. However, burn wound sepsis is still a major source of morbidity, including prolonged hospitalization and skin graft loss with the need for regrafting. Infection arising in the burn wound during the first 72 h postinjury usually appears as cellulitis surrounding the margins of the burn. The offending organisms are routinely either streptococci or staphylococci. Such infections may initially be difficult to distinguish from adjacent areas of first-degree burn with erythema, heat, and pain. However, serial examinations, often over only a few hours, will demonstrate progression. Such infections occur in about 30 per cent of admitted burn patients. The use of prophylactic antibiotics for 48 to 72 h remains a disputed issue. The cellulitis usually responds promptly once it is recognized and...

Qualitative Determinations

The subject organisms of qualitative tests are described as objectionable and they are all potential pathogens, although they may also be significant as indicators of product quality. Currently, the EP and USP both describe tests for the absence of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Salmonellae in selected raw materials and finished product categories, and in addition, the EP has tests for Enterobacteriaceae and Clostridia. Other organisms have been suggested as candidates for inclusion in this category7,12 and the first of these two papers lists 20 such organisms relevant in eight different dosage forms (Table 5.2). The detection of the target organism is dependent upon laboratory staff recognizing a typical colony when the only guide to appearance that they may have available is a description in a pharmacopoeia that can, at best, be described as vague, e.g., well-developed colourless colonies is the EP description of salmonellae growing upon...

Structures of Urease Mutants

Cysa319 is located on the flexible flap covering the active site of KAU. This residue is largely conserved in all urease enzymes, except for the enzyme from Staphylococcus xylosus, which has a threonine in this position 63 . Chemical modification of Cysa319 blocks enzyme activity 55,56 , indicating that this residue is somehow involved in catalysis. However, the Cysa319Ala mutant is still 50 as active as the wild-type urease 57 . Structures of this mutant were determined at pH 6.5, 7.5, 8.5, and 9.4 (PDB codes 1FWB, 1FWA, 1FWC, and 1FWD in that order, Table 1) 26 . There were no significant differences among all these structures. The most evident differences between the structure of Cysa319Ala mutant and that of the wild-type enzyme involve a much-reduced mobility of the flexible flap covering the active site, still found in a 'closed' conformation, but displaying significantly reduced mobility. In contrast, the structures of Cysa319Asp (PDB code 1FWF), Cysa319Ser (PDB code 1FWG), and...

Impaired carriage defense and the abnormal carrier state

Carriage defense is the first line of defense to fail in critically ill patients. The adherence of Gram-negative bacilli to mucosal cells is greatly increased. Stasis, an increase in gastric pH, and mucosal atrophy all lead to an explosive overgrowth of aerobic Gram-negative bacilli. The intravenous administration of broad-spectrum antibiotics excreted via saliva, bile, and mucus may eradicate both the indigenous flora and the sensitive 'community' potentially pathogenic micro-organisms. Consequently, resistant Gram-negative bacilli, Staph. aureus, and Candida species are selected, followed by overgrowth in the oropharynx and gastrointestinal tract. From a microbiological point of view, the impairment of carriage defense is associated with an abnormal carrier state. The incidence of abnormal carriage in mechanically ventilated patients is 60 to 90 per cent. High concentrations of mostly Gram-negative bacilli (> 10 8 ml), but also Staph. aureus and Candida species, can be found in...

Systemic antibiotic prophylaxis

Early-onset infections in mechanically ventilated intensive care patients are invariably caused by potentially pathogenic micro-organisms carried by the patient in the throat or gastrointestinal tract and aspirated before or during intubation (i.e. primary endogenous infections). Primary endogenous infections, occurring mainly within the first 4 days in the ICU, constitute about 50 per cent of all respiratory infections developing in intensive care when no systemic antibiotic prophylaxis is given. Primary endogenous infections in patients who have not previously been in hospital (e.g. multiple trauma patients) are mostly caused by Strep. pneumoniae, H. influenzae, Staph. aureus and E. coli, whereas species from the Klebsiella-Enterobacter group are more frequently found in patients who have been in hospital prior to admission to the ICU.

Emergence of resistance

It has been suggested that SDD may lead to a Gram-positive selection. During successful decontamination, enterococci and Staph. epidermidis, which belong to the normal indigenous flora and are intrinsically insensitive to the topical antibiotics, are the only micro-organisms isolated. Controlled trials that specifically studied enterococci and Staph. epidermidis did not show increased colonization or infection with these micro-organisms during SDD. MRSA is an inherent limitation of the PTA regimen. In an environment where MRSA is endemic, SDD may select this micro-organism. In this situation SDD should be reconsidered or vancomycin should be added to the PTA regimen.

Intracranial abscess

Subdural empyema occurs far less frequently than intracerebral abscess formation. Infection usually spreads from infected sinuses or mastoids, but may arise from any of the aforementioned sources. The responsible organism is usually Strep, pneumoniae, Strep, milleri or Staph, aureus. Clinical features match those of intracerebral abscess but since rapid extension occurs across the subdural space, overwhelming symptoms often develop suddenly. Seizures occur in 70 at onset.

Pseudomonas aeruginosa

Ps. aeruginosa causes native tissue endocarditis in intravenous drug users, and can infect prosthetic valves. Depending upon the infected valve, consequences may include septic pulmonary or systemic emboli, conduction disturbances, intractable congestive heart failure, brain abscess, cerebritis, and metastatic skin lesions. Lower respiratory tract infections are common in patients with abnormal local respiratory or systemic host defenses. Pneumonia due to Ps. aeruginosa is fulminant and usually fatal (70 per cent). Radiographs reveal a diffuse bronchopneumonia that is typically bilateral and characterized by distinctive nodular infiltrates, sometimes with small areas of radiolucency. Such a pattern can be characteristic of pneumonia caused by Staph. aureus, but is unusual with other Gram-negative pneumonias. Bacteremic pneumonia is usually seen in the neutropenic cancer patient, but can occur in children or AIDS patients.

Pneumocystis carinii pneumonitis

At CD4 counts over 200 * 106 l HIV-infected patients are susceptible to common pathogens such as Streptococcus pneumoniae, Staphylococcus aureus, and Hemophilus influenzae. At lower CD4 counts a wider range of pathogens will be found including Pseudomonas species and organisms that are uncommon in the immunocompetent (e.g. Serratia marcescens).

Advanced Concepts

The first antibiotics isolated were natural secretions from fungi and other organisms. Synthetic modifications of these natural agents were designed to increase the spectrum of activity (ability to kill more organisms) and to overcome resistance. For example, cephalosporins include first-generation agents, ceph-alothin and cefazolin active against Staphylococcus, Streptococcus, and some Enterobacteriaceae. A second generation of cephalosporins, cefamondole, cefoxitin, and cefuroxime, is active against more Enterobacteriaceae and organisms resistant to p-lactam antibiotics. A third generation, cefotaxime, ceftriaxone, and ceftazidime, is active against P. aeruginosa as well as many Enterobacteriaceae and organisms resistant to p-lactam antibiotics. The fourth generation, cefepime, is active against an extended spectrum of organisms resistant to p-lactam antibiotics.

Antibacterial Therapy

Certain bacteria are more common than others in ophthalmic practice. Examples of gram-positive organisms important in ocular infections include Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pneumoniae. Examples of gram-negative bacteria are Neisseria gonorrhea, Haemophilus influenzae, and Pseudomonas aeruginosa. It should be noted here that the treatment of certain other infections involving acanthamoeba (a protozoan) and parasites (eg, Toxoplasmosis gondii and Chlamydia trachomatis) are often treated with antibacterial drugs. These infectious organisms may share common physiologic properties with bacteria thus, antibacterial drugs are sometimes used in the management of nonbacterial infections.

Antibacterial Spectrum and Resistance

Trimethoprim exhibits broad-spectrum activity. It is most commonly used in combination with sulfamethoxazole and is active against most gram-positive and gramnegative organisms, especially the Enterobacteriaceae. There is little activity against anaerobic bacteria P. aerug-inosa, enterococci, and methicillin-resistant staphylo-cocci should be considered resistant to trimethoprim.

Medical Applications Of Iontophoresis A Archival Studies

During the 1940s in the United States, Ludwig von Sallmann, a prominent ophthalmologist, was one of the pioneers in the clinical use of ocular iontophoresis. Von Sallmann showed that transcorneal iontophoresis of penicillin was more effective than subconjunctival injection for the delivery of penicillin into the aqueous humor (24,25) and demonstrated modest success in the treatment of intraocular staphylococcal infection (26). In 1956, Witzel and his colleagues (27) published a report on the use of ocular iontophoresis as a drug delivery system for a variety of antibiotics. They found that iontophoresis was effective in the delivery of streptomycin, neo-mycin, and penicillin.

Mechanisms Of Resistance

The most important mechanism of resistance is hydrolysis of the p-lactam ring by p-lactamases (penicilli-nases and cephalosporinases). Many bacteria (Staphylococcus aureus, Moraxella Branhamella catarrhalis, Neisseria gonorrhoeae, Enterobacteriaceae, Haemophilus influenzae, and Bacteroides spp.) possess p-lactamases that hydrolyze penicillins and cephalosporins. The p-lactamases evolved from PBPs and acquired the capacity to bind p-lactam antibiotics, form an acyl enzyme molecule, then deacylate and hydrolyze the p-lactam ring. Some bacteria have chromosomal (inducible) genes for p-lactamases. Other bacteria acquire p-lactamase genes via plasmids or transposons. Transfer of p-lactamase genes between bacterial species has contributed to the proliferation of resistant organisms resulting in the appearance of clinically important adverse consequences. An additional mechanism of antibiotic resistance involves an alteration of PBPs. Resistant bacteria, usually gram-positive organisms,...

Antibacterial Spectrum

The cephalosporins are classified into generations (Table 45.2) according to their antibacterial spectrum and stability to p-lactamases. The first-generation cephalosporins have in vitro antimicrobial activity against streptococci, methicillin-sensitive S. aureus, and a few gram-negative bacilli. The second-generation cepha-losporins have greater stability against p-lactamase inac-tivation and possess a broader spectrum of activity to include gram-positive cocci, gram-negative organisms, and anaerobes. Among the second-generation cephalo-sporins, the cephamycins (cefoxitin Mefoxin , cefotetan Cefotan , and cefmetazole Zefazone ) have the most activity against Bacteroides fragilis. The extended-spectrum, or third-generation, cephalosporins possess a high degree of in vitro potency and p-lactamase stability and a broader spectrum of action against many common gram-negative bacteria and anaerobes while retaining good activity against streptococci. Third-generation cephalosporins are less...

Hydrocephalus And Shunts

The commensal skin flora is the usual source of pathogens that give rise to shunt infections with the coagulase-negative staphylococci, particularly S. epidermidis, the most commonly isolated. S. aureus is also well recognized, especially in the context of wound infection or skin breakdown. Enterococci, micrococci and coryneforms account for a significant proportion of the remainder of infecting organisms (Table 24.4). One of the principal factors which enables coagulase-negative staphylocci to colonize shunt systems is their ability to produce an extracellular slime, which aids adherence of the organisms to the surface of the silicone catheter 20 . This is also one of the main factors responsible for the resilience of these infections to treatment with the shunt in situ.

Serious Gram Negative Bacillary Infections

Gentamicin is the aminoglycoside antibiotic most commonly used to treat serious infections due to gramnegative aerobic bacilli, such as Escherichia coli and Klebsiella pneumoniae, and Proteus, Serratia, Acinetobacter, Citrobacter, and Enterobacter spp. Gentamicin also has significant activity against Staphylococcus aureus. The aminoglycosides are often used in combination with p-lactams in the initial empirical therapy of sepsis and of fever in immunocompromised patients. The combination is used both to ensure adequate antibiotic coverage in these seriously ill patients and to exploit the synergistic antibiotic activity that p-lactams and aminoglycosides have against many species. These drugs should not, however, be injected simultaneously, since the p-lactams can chemically inactivate the aminoglycosides.

Supplemental Reading

The emergence of decreased susceptibility to vancomycin in Staphylococcus epider-midis. Infect Control Hosp Epidemiol1999 20 167-170. Robinson-Dunn B et al. Emergence of vancomycin resistance in Staph aureus. Glycopeptide-Intermediate S. aureus Working Group. N Engl J Med 1999 340 493-501. Srinivasan A, Dick JD, and Perl TM. Vancomycin resistance in staphylococci. Clin Microbiol Rev 2002 15 430-438. Answer This patient has line sepsis. The causation of his infection is not clear initially, and his presentation, without any localizing features, gives rise to the possibility of a line infection. The catheter sites frequently do not reveal any evidence of infection, but high-grade bacteremia (3 of 4 bottles) with grampositive cocci strongly suggests an endovascular infection. With a high prevalence of methicillin resistance in staphylococcal infections in hospital and nursing home settings, vancomycin therapy should be initiated along with discontinuation of the line....

Oregano Contains Antimicrobial Substances

Antimicrobial activity of oregano has been found at least against such organisms as Bacillus cereus, Acinetobacter baumanii, Aeromonas veronii, bg sobria, Candida albicans, Candida lipolytica, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp., Enterica typhimurium, Salmonella enteritidis, Serratia marcescens, Staphylococcus aureus, Aspergillus ochraceus, A. flavus, A. paraciticus, Clostridium perfringens, Erwinia carotovora, Listeria monocytogenes, Lactobacillus plantarum, Leuconostoc mesenteroides, Debaryomyces hansenii, Hansenula anomala, Kloeckera apiculata, Lodderomyces elongiporus, Rhodotorula rubra, Saccharomyces cerevisiae, Torulopsis glabrata.

Box 92 Bacterial meningitis causal organisms

Adults Pneumococci Meningococci Staphylococci Listeria monocytogenes Streptococci Staphylococci Staphylococci Staphylococcus epidermidis The epidemiology of meningitis is complex and varies with the age of the patient and geography. About 70 of cases are seen in children. The introduction of childhood vaccination against Haemophilus influenzae type b has led to a dramatic fall in the incidence of this pathogen, which previously was the most common cause of meningitis in children less than five years old. Now, with the exception of the neonatal period and the elderly, Neisseria meningitidis and Streptococcus pneumoniae account for about 70 of all cases of bacterial meningitis. Neonatal meningitis may be caused by any organism but the most frequently encountered pathogens are gram negative bacilli, particularly Escherichia coli, other enteric bacilli, Pseudomonas spp., Listeria monocytogenes, and group B streptococci. Neonatal meningitis is not discussed further here. In the elderly...

Pathophysiology and clinical presentation

Specific features may suggest the aetiology of meningitis. A diffuse maculopapular eruption, which progresses to include petechiae or frank purpura, accompanies 50-60 of cases of meningococcal meningitis. Other bacteria - L. monocytogenes, staphylococci, pneumococci, and H. influenzae - and viruses, particularly echovirus 9, may also cause rashes. Rarely, a rash may be due to a reaction to an antibiotic or other drug but this seldom occurs early in the course of the disease. Focal neurological signs, seizures, and cranial nerve palsies resulting from rhomboencephalitis are seen in some patients with listerial infection.86 Pneumococcal meningitis is associated with otitis media, a history of skull fracture, alcoholism, or sickle cell disease, and up to 50 will have pneumonia. Staphylococci or gram negative bacilli often cause meningitis complicating the implantation of neurosurgical devices such as shunts. In those with immune suppression, including AIDS, simultaneous infection with...

Differential Diagnosis

Acute Cervical Lymphadenitis With or Without Abscess. Typically unilateral seen in any age group but more commonly in children aged 1-4 years. Group A -hemolytic streptococcus and Staphylococcus aureus account for 80 of cases. Probably occurs as a result of bacteria from oropharynx and upper respiratory tract seeding the draining lymph nodes. Viral cervical adenitis is usually self-limited and bilateral. Unilateral, solitary cervical node enlargement may be present in 50-70 of patients with Kawasaki disease.

Patients and Methods

Of the patients who already had other kinds of surgery, 35 had previously had two operations, 14 had had three operations, and five had had four operations. Time from trauma to the epidermofascioosteoplastic treatment was between 5 and 27 months,with an average time of 10 months. In all cases, cultures were positive for Staphylococcus and in 16 cases also for Pseudomonas aeruginosa.

Caenorhabditis elegans Answers from a Worm

C. elegans was extensively tested for its ability to serve as a model host for many different human pathogens 29 . C. elegans adult nematodes die over the course of several days while feeding on lawns of Enterococcus faecalis. The individuals are killed after an active invasion of the pathogen. Interestingly, E.faecium is only able to kill eggs and hatchlings, not the adult animal 30 . It was shown that there is a remarkable overlap between virulence factors required for mouse and nematode pathogenesis 31 . This includes pathogens like Streptococcus pneumoniae, Salmonella typhimurium, P. aeroginosa, Yersinia pestis, and Serratia marcescens 32, 33 . Staphylococcus aureus virulence factors were also identified by using a high-throughput C. elegans-killing model 34 . For streptococcal species hydrogen-peroxide-mediated killing was shown in C. elegans larvae 35 . In a large screen of Pseudomonas mutant strains it was demonstrated that the production and secretion of phenazines were...

Central indwelling catheters

Organisms usually Staph. epidermidis but can be other Staph spp. and even Gram -ve organisms. May be erythema exudate around entry or exit sites of line, tenderness erythema over subcutaneous tunnel or discomfort over line tract. Blood cultures must be taken from each lumen and peripherally and labelled individually. Add vancomycin 1g bd IV if not in standard protocol. Split dose between all lumens unless cultures known to be +ve in one lumen only. Lock and leave in line for 1h, then flush through. If no response or clinical deterioration, remove line immediately.

Choice of antibiotics

In the immunocompetent patient, empirical treatment should be with a combination of a third generation cephalosporin (for example, cefotaxime) and metronidazole.150 Vancomycin is added to this regimen if staphylococci are suspected. Treatment should be given for no less than six weeks but must be determined for each case by clinical response and improvement of CT scan appearances. In the immunosuppressed the choice of treatment will depend on the immune defect, as outlined above. For neutropenic patients and those post transplantation, empirical therapy should include amphotericin B because of the high frequency of fungal infections that occur. In HIV positive patients with multiple lesions, pyrimethamine and sulfadiazine are used to treat toxoplasmosis. If there is not a rapid clinical and radiological response then other pathologies need to be considered.

G St Johns Wort Hypericum perforatum L

This is a perennial herb native to Europe, Western Asia, North Africa, Madeira, and Azores and introduced to North America and Australia. Aerial parts including fresh buds and flowers have been traditionally used for their sedative, anti-inflammatory, anxiolitic, and astringent qualities to treat burns, insomnia, shock, hysteria, gastritis, hemorrhoids, kidney disorders, etc. Chemical compounds identified include phloro-glucinols (hyperforin and adhyperforin), naphthodianthrones (hypericin, pseudohy-pericin, and isohypericin), flavonoids (kaempferol, luteolin, myricetin, quercetin, hyperoside, and quercetin), essential oils (a- and P-pinene, limonene, myrcene, and caryophyllene), as well as proanthocyanidins, phytosterols, coumarins, xanthones, carotenoids, and phenolic acids. The components of this herb inhibit the reuptake of serotonin, dopamine, and norepinephrine. Hyperforin has antibiotic properties inhibiting Staphylococcus aureus. The flavonoids act as free radical scavengers...

Sputum and tracheal aspirates

Sputum and tracheal aspirates are of only limited diagnostic value because of the frequency of bacterial colonization. Patients with suspected ventilator-associated pneumonia commonly have Gram-negative organisms in their sputum, but not in samples from which pneumonia can be reliably diagnosed (postmortem or pleural aspirates). However, the isolation of Staphylococcus aureus or anaerobic Gram-negative organisms in sputum is mirrored in 80 per cent of cases by similar isolation in diagnostic cultures. The absence of Gram-negative organisms from purulent sputum excludes them as a cause of pneumonia. Similarly, the culture of tracheal aspirates has an almost 100 per cent sensitivity but only a 29 per cent specificity for the diagnosis of pneumonia. When pneumonia is confirmed, the same organism has usually been cultured in tracheal aspirates but, despite the polymicrobial nature of nosocomial pneumonia, there is a higher incidence of polymicrobial cultures from tracheal aspirates...

Acute bacterial meningitis

Meningitic infection may follow CSF drainage operations for hydrocephalus. This may occur in the immediate postoperative period or be delayed for weeks or months. Clinical features of raised intracranial pressure may coexist due to shunt blockage. Bacteraemia is inevitable and blood cultures identify the responsible organism - usually Staphylococcus albus. The infection seldom resolves with antibiotic therapy alone and shunt removal is usually required.

PCR Methods for Microbial Diagnostics

Besides the identification and classification of bacterial pathogens, the detection of specific antibiotic resistance in clinical isolates has always been the second major task of microbiological diagnostics. In recent years the molecular mechanisms of antibiotic resistance have been thoroughly characterized, providing the basis for molecular tool to detect a multitude of antibiotic resistance mechanisms on the level of chromosomal or episomal DNA 34, 38, 39 . The introduction of real-time PCR methods offers a cost-effective, user-friendly format for genetic methods that fuels their use for the detection and characterization of antimicrobial resistance determinants in routine diagnostic microbiology. The implementation of these assays to detect resistance in clinically important slow-growing organisms (e.g., Mycobacterium tuberculosis), to rapidly identify clinically important resistance mechanisms, and to overcome laborious and time-consuming culture techniques in the control and...

Trimethoprim and trimethoprimsulfamethoxazole cotrimoxazole

Trimethoprim and sulfamethoxazole act at different parts of the same pathway of synthesis of bacterial folate. Their long half-lives allow both to be given at 12-h intervals. Trimethoprim is active against most staphylococci, streptococci (not enterococci), Enterobacteriaceae, and Hemophilus species, but not Ps. aeruginosa or anaerobes. Trimethoprim can be used for urinary tract infection but in hospital-acquired infections susceptibility needs first to be demonstrated. Sulfamethoxazole adds little to trimethoprim for most infections, but trimethoprim-sulfamethoxazole is commonly used to treat Pneumocystis pneumonia in AIDS. Adverse effects are common at the high dose used (120 mg kg day intravenously in four divided doses) and are due mostly to the sulfonamide. Rash, nausea, vomiting, and diarrhea are common, and occasionally Stevens-Johnson syndrome occurs. Administration in pregnancy is contraindicated.

Microbiology and Pathogenesis

The bacteriological profile of brain abscess has changed significantly over the past 50 years. In the older literature, aerobic streptococci, pneu-mococci and Staphylococcus aureus predominated, with relatively few Gram-negative and anerobic infections reported 1,2 . More recent series have shown a significant increase in anerobic abscesses, the most common isolates being Bacteroides spp. and anerobic streptococci. The incidence of Gram-negative infections has also increased, sometimes comprising more than 20 of cases. Although most abscesses are caused by a single organism, mixed infections occur in up to 33 of cases, particularly otogenic abscesses. The incidence of negative cultures remains around 25 however, the use of meticulous microbiological techniques can result in positive cultures in virtually 100 of brain abscesses, even in the face of antibiotic therapy 3 .

Extremely Narrow Spectrum Drugs

Warrant the investment necessary to develop them. Even for the most prevalent pathogens the cost of development would be clearly higher than the potential sales, given the present expectations for the price of antibiotics. A good example of this dilemma is provided by the so called pyrimidinones 87 . This class of antibiotics stems from a natural compound called TAN 1057, which was too toxic to be clinically useful and had a very narrow spectrum of gram-positive activity. Following a total synthesis approach, this class was optimized and resulted in a toxi-cologically safe derivative with outstanding, extremely bactericidal activity against two of the most pressing resistance problems in today's hospitals, MRSA and VRE. However, all attempts to expand its spectrum to include at least all other relevant gram-positive pathogens have failed so far, and the market potential of such a reserve drug was too low to warrant development. Thus, we cannot expect a narrow-spectrum approach to...

History and Development of Antimicrobial Drugs

Alexander Fleming, a British scientist, was working with cultures of Staphylococcus when he noticed that colonies growing near a Ten years after Fleming's discovery, two other scientists in Britain, Ernst Chain and Howard Florey, were successful in their attempts to purify penicillin. In 1941, the drug was tested for the first time on a police officer with a life-threatening Staphylococcus aureus infection. He improved so dramatically that within 24 hours his illness seemed under control. Unfortunately, the supply of purified penicillin ran out, and the man eventually died of the infection. Later, with greater supplies of the drug, the experiment was repeated and two deathly ill patients were successfully cured. World War II spurred a cooperation of British and American scientists to determine the chemical structure of penicillin and to develop the means for its large-scale production so that it could be used to treat infected soldiers and workers. Several different penicillins were...

Normal Flora of the Skin

Microscopic Arachnid Skin Causes Acne

The skin represents a distinct ecological habitat, analogous to a cool desert, compared to the warm, moist tropical conditions that exist in other body systems. Large numbers of microorganisms live on and in the various components of the normal skin. For example, depending on the body location and amount of skin moisture, the number of bacteria on the skin surface may range from only about 1,000 organisms per square centimeter on the back to more than 10 million in the groin and armpit, where moisture is more plentiful. The numbers actually increase after a hot shower because of increased flow from the skin glands where many reside. Most of the microbial skin inhabitants can be categorized in three groups diphtheroids, staphylococci, and yeasts (table 22.1, and see figure 22.1). Although generally harmless, skin organisms are opportunistic pathogens, meaning that they can only cause disease in people with impaired body defenses. Staphylococci Staphylococci The second group of...

Environmental Adaptation and Stress Response

Present in the E.faecalis V583 genome are a number of proteins involved in heat shock response, including homologues of heat shock proteins DnaK (EF1308) and GroEL (EF2633), gsp66 and gsp67, respectively 39 . The genome also contains a homologue of CtsR (EF3283) from B.subtilis which has been shown to control molecular chaperone gene expression 40 . Unlike Staphylococcus aureus, S. pneumoniae, S. pyogenes, and L. lactis, the groR operon does not show the presence of CtsR binding sites, and this suggests that in E.faecalis the groE and dnaK operons are primarily controlled by HrcA 39 . CtsR recognition sites have been noted upstream from the clpB (EF2355), clpP (EF0771), and clpE (EF0706) genes 40 . The Clp ATP-dependent proteases have been shown in B. subtilis to play essential roles in stress survival 41 . Recent data from L. monocytogenes suggests that in that organism, clpB is required for virulence and has a role in ther-motolerance, but is not involved in other stress responses...

Molecular Strain Typing Methods for Epidemiological Studies

Most molecular epidemiological tests are performed using pulsed field gel electrophoresis (PFGE), which can identify organisms with larger genomes or multiple chromosomes. For PFGE analysis, the DNA is digested with restriction enzymes that cut infrequently within the genomic sequences. The resulting large (hundreds of thousands of base pairs) fragments are resolved by PFGE (see Chapter 5 for a more detailed description of this system). Patterns of organisms will differ depending on the chromosomal DNA sequence of the organisms (Fig. 12-5). Tenover and colleagues devised a system to interpret the patterns of a test organism in comparison with the strain of organism known to be involved in the outbreak.95 The interpretation of PFGE results is fairly straightforward and follows the rule of three (Table 12.9). This method has been used for typing numerous species, including strains of Pseudomonas aeruginosa, Mycobacterium avium, Escherichia coli, N. gonorrhoeae, VRE, and MRSA....

Active Packaging Antimicrobial Films 19321 Synthetic Polymer Films

The development of antimicrobial films has been significantly restricted by the legal status of antimicrobial compounds available for food contact use or as food preservatives or additives currently only a limited number of such approved compounds exist, and approval varies among countries. Silver-substituted zeolites, a broad-spectrum high-activity antimicrobial with low human toxicity, has been extensively used commercially in Japan as a thin laminant on packaging film surfaces its use on food contact surfaces in the European Union and the U.S., however, is unclear 23 . Some U.S. Food and Drug Administration (FDA) generally regarded as safe (GRAS) materials that have been considered for use as antimicrobials in synthetic polymer films include organic acids (benzoic, lactic, propionic, malic, succinic, tartaric, sorbic), enzymes (lactoperoxidase, lactoferrin, lysozyme, chitinase, glucose oxidase, ethanol oxidase), isothiocyanates (allylisothiocyanate), bacteriocinsc (nisin, pediocin,...

Cranial Epidural Abscess EDA

The bacteriology of cranial EDA correlates with the underlying cause of infection. Cases associated with para-nasal sinusitis, otitis and mastoiditis reflect the organisms of the underlying infection, most often hemolytic or microaerophilic streptococci and anerobes. Post-traumatic and or post-operative cases are most often caused by staphylococci.

Bacterial Diseases of the Blood Vascular System

Endocarditis is the term used for infections of the heart valves or the inner, blood-bathed surfaces of the heart, and it can be acute or subacute. Acute bacterial endocarditis starts abruptly with fever, and usually an infection such as pneumonia is present somewhere else in the body or there is evidence of injected-drug abuse. Virulent species such as Staphylococcus aureus and Streptococcus pneumoniae are usually the cause, and they infect both normal and abnormal heart valves. They can often produce a rapidly progressive disease, often with valve destruction and formation of abscesses in the heart muscle, leading to heart failure. By contrast, subacute bacterial endocarditis is usually caused by organisms with little virulence, and it has a much more protracted course. Streptococcus pneumoniae, p. 576

Reservoirs of Infectious Agents in Hospitals

Outbreaks of nosocomial infections are sometimes traced to infected health care personnel. Clearly, those who report to work with even a mild case of influenza can expose patients to an infectious agent that has serious or fatal consequences to those with impaired health. A more troublesome source of infection is a health care worker who is a carrier of a pathogen such as Staphylococcus aureus or Streptococcus pyogenes. These personnel often do not recognize they pose a risk to patients until they have been implicated in an outbreak. Carriers who are members of a surgical team pose a particular threat to patients, because inoculation of a pathogen directly into a surgical site can result in a systemic infection. Many hospital-acquired infections originate from the patient's own flora. Nearly any invasive procedure can transmit microorganisms that are part of the normal flora to otherwise sterile body sites. When intravenous fluids are administered, for example, Staphylococcus...

Molecular Biology and Cytogenetics of Chronic Lymphocytic Leukemia

Cytogenetics Translocation

Early cytogenetic studies in chronic lymphocytic leukemia (CLL), performed in the 1960s and 1970s, failed to detect clonal cytogenetic abnormalities. This inauspicious start to the investigation of genetic abnormalities in CLL was the consequence of the low spontaneous mitotic rate in CLL and the use of the T-cell mitogen phytohemaglutinin to obtain analyzable metaphases. With the discovery of polyclonal B-cell mitogens, the first cytogenetic abnormality in CLL, trisomy 12, was discovered in 1980.1,116 Subsequent studies have shown clonal cytogenetic abnormalities in approximately 50 percent of cases of CLL.2 The most frequent abnormalities are structural abnormalities of chromosome 13q14 and trisomy of chromosome 12, occurring in 10 to 20 percent of cases. Abnormalities of chromosomes 6q, 11q, 14q, and 17p are each found in less than 5 percent of cases. In patients with a cytogenetic abnormality, 50 percent have a single abnormality, 25 percent have two abnormalities, and the...

Pneumonia Antibiotics and Mechanical Ventilation

Pulmonary complications are common and are a major cause of morbidity and mortality for patients requiring neurointensive care. In one study on patients with SAH, half the deaths attributable to medical causes were pulmonary in origin. Risk of pneumonia appears to peak within the first 3 days (early-onset pneumonia or EOP) and has been found to be associated with trauma and, in non-trauma patients, with a Glasgow Coma Scale (GCS) of less than 9. In this cohort of patients, the organisms responsible for EOP were Staphylococcus aureus (33 ), Haemophilus (23 ), other gram-positive cocci (22 ) and other gram-negative bacilli (19 ). A second peak occurred on days 5 and 6 in this group, gram-negative bacilli other than Haemo-philus spp. accounted for 45.4 of organisms isolated. EOP appears to be related to aspiration of gastric contents occurring at the time of, or soon after, injury or ictus. Late-onset pneumonia is more likely to be ventilator-associated pneumonia, and caused by organisms...

Common Bacterial Wound Infections

The following sections present some aspects ofwound infections caused by staphylococci, streptococci, and Pseudomonas sp. Staphylococcal Wound Infections Staphylococci lead the causes of wound infections, both surgical (figure 27.3) and accidental. Staphylococci are commonly present in the nostrils or on the skin. Of the 30 or more recognized species of staphylococci, only two account for most human wound infections. Staphylococci are pyogenic, meaning that they characteristically cause the production of a purulent discharge, otherwise known as pus. They usually cause an inflammatory reaction, with swelling,

Hemolysin Structure and Biology

A-Hemolysin is a 33.2 kDa protein toxin secreted by Staphylococcus aureus. It forms a multisubunit ring (four to eight identical subunits) on the surface of a cell or artificial bilayer and then inserts a beta-barrel channel across the target membrane.45,46 The x-ray crystal structure of the pore-forming heptamer was described in 1996 by Song and colleagues47 (Figure 11.3). The heptamer is about 10 nm long, and

Alpf Medical Research - Mushroom

Martin, S.T. and Beelman, R.B., Growth and enterotoxin production of Staphylococcus aureus in fresh packaged mushrooms (Agaricus bisporus), J. FoodProt., 59, 819-826, 1996. 69. Anderson, J.E., Beelman, R.B., and Doores, S., Persistence of serological and biological activities of Staphylococcus enterotoxin A in canned mushrooms, J. FoodProt., 59, 1292-1299, 1996.

Specific Therapy for Pneumonia

-Ceftriaxone (Rocephin) 2 gm IV q12h OR -Cefotaxime (Claforan) 2 gm IV q6h OR -Erythromycin 500 mg IV q6h OR -Vancomycin 1 gm IV q12h if drug resistance. Staphylococcus aureus Pneumonia -Nafcillin 2 gm IV q4h OR -Oxacillin 2 gm IV q4h. of D5W over 60 min IV q24h AND Ceftizoxime (Cefizox) 1-2 gm IV q8h OR Cefotaxime (Claforan) 1-2 gm IV q6h. Methicillin-resistant staphylococcus aureus

Fermented Meat Products

Traditionally, fermented meat products, such as salami, pepper-oni, and summer sausage, were produced by enabling the small numbers of lactic acid bacteria naturally present to multiply to the point of dominance. Relying on the natural fermentation of meat is inherently risky, however, because the incubation conditions used to initiate fermentation can potentially support the growth and toxin production of pathogens such as Staphylococcus aureus and Clostridium botulinum. The development and use of reliable starter cultures assures rapid production of lactic acid, inhibiting the growth of pathogens and enhancing flavor development. Starter cultures used by U.S. sausage-makers typically contain species of Lactobacillus and or Pediococcus, depending on the type of sausage.

Potential Applications of Ozone in the Food Industry

Ozone is a strong antimicrobial agent in both gaseous and aqueous phases. It is well known that ozone is an effective disinfectant in water and waste-water treatments 55 . Ozone is 1.5 times more effective as an antimicrobial agent than chlorine. Additionally, ozone is much more effective for a wider spectrum of microorganisms than chlorine and other disinfectants 56 . It reacts up to 3000 times faster than chlorine with organic materials and produces no harmful decomposition products 57 . Numerous studies have focused on the inactivation of pathogens and spores by aqueous ozone, including Cryptosporidium parvum 58,59 , Giardia spp. 60 , bacillus and clostridium spores 61, 62 , Salmonella Typhimurium, E. coli, Yersinia enterocolitica, Pseudomonas aeruginosa, Staphylococcus aureus, and L. monocytogenes 63 .

Congenital Dermal Sinus

Infants are frequently referred to the pediatric neurosurgeon with a midline spinal dimple, occasionally with discharge from the tract. This may be the initial presentation of many congenital dermal sinuses but a significant number present with meningitis due to skin or gut organisms. Multiple episodes of meningitis may even occur before the diagnosis is made, since the cutaneous opening of the tract may be minute. Nevertheless, meningitis due to organisms such as Staphylococcus aureus or Escherichia coli in an infant rather than a neonate should arouse suspicion and, particularly after recurrent episodes, a concerted effort to identify a sinus tract should be made. The opening may be anywhere along the midline of the spine and may even occur in the occiput. Fig. 27.5. Sagittal T1-weighted MR image of a 14-year-old boy with a congenital dermal sinus entering the theca at the L4 level. He had had two episodes of staphylococcal meningitis prior to referral. Fig. 27.5. Sagittal...

Us World Market And Testing Trends 19992008

There is no question that many microbiological tests are being conducted nationally and internationally on food, pharmaceutical products, environmental samples, and water. The most popular tests are total viable cell count, coliform E. coli count, and yeast and mold counts. A large number of tests are also performed on pathogens such as salmonella, listeria and Listeria mono-cytogenes, E. coli O157 H7, Staphylococcus aureus, campylobacter, and other organisms. In 1998 the number of worldwide industrial microbiological tests was estimated to be 755 million with a total market value of US 1.1 billion, assuming the average price per test to be US 1.47. They also estimated that 56 of the tests were for food 30 for pharmaceuticals 10 for beverages and 4 for environmental water tests 25 . Of these tests, 420 million were done in food laboratories with 360 million for routine tests'' (total viable cell counts, coliform counts, and yeast and mold counts) and 60 million for specific pathogen...

Invasion Breaching the Anatomical Barriers

Skin is the most difficult anatomical barrier for a microbe to penetrate. Bacterial pathogens that invade via this route rely on trauma of some sort that destroys the integrity of the skin. Staphylococcus aureus, for example, a common cause of wound infections, accesses tissues via the lesion. Yersinia pestis, the causative agent of plague, exploits fleas, relying on them to

Biological activities of Turkish Oregano

The essential oils of O. onites and O. vulgare subsp. hirtum were found to be effective against all the molds and bacteria tested except for P. aeruginosa. The other microorganisms tested were Bacillus subtilis, Staphylococcus aureus, E. coli, A. niger, Aspergillus candidus, P. chrysogenum, Fusarium sp. (Dortunc and Cevikbas, 1992).

Bacterial Skin Diseases

Folliculitis, furuncles, and carbuncles represent different outcomes of hair follicle infections. In folliculitis, a small red bump, or pimple, develops at the site of the involved hair follicle. Often, the hair can be pulled from its follicle, accompanied by a small amount of pus, and then the infection goes away without further treatment. If, however, the infection extends from the follicle to adjacent tissues, causing localized redness, swelling, severe tenderness, and pain, the lesion is called a furuncle or boil. Pus may drain from the boil along with a plug of inflammatory cells and dead tissue. A carbuncle is a large area of redness, swelling, and pain punctuated by several sites of draining pus. Carbuncles usually develop in areas of the body where the skin is thick, such as the back of the neck. Fever is often present, along with other signs of a serious infection. Most furuncles and carbuncles, as well as many cases of folliculitis, are caused by Staphylococcus aureus, a...

Intraocular Pharmacokinetics Using Microdialysis

Breaching Endothelial Cells

Passed into the sclerotomy site in each eye and glued by a drop of cyanoa-crylate glue, followed by a drop of rapid setting epoxy adhesive. The catheters were connected in parallel to a double barrel Harvard pump and perfused at a rate of 3.5 mL min (Fig. 4). Gentamicin was administered at a site away from the sampling site. The experiments were carried in two groups of cats normal and bacterial endophthalmitis (Staphylococcus

The Endothelial Cell Surface and C1q Receptors

Various receptor systems have been described on vascular cells that participate in the recognition, activation, and clearance of components involved in humoral defense. Among these molecules are receptors for the complement protein, C1q. Four C1q binding proteins or receptors have been described to date cC1q-R CR or collectin receptor, a 60-kDa calreticulin (CR) homolog, which binds to the collagen-like tail of C1q gC1q-R p33, a 33kDa homotrimeric protein with high affinity for the globular heads of C1q C1q-Rp (CD93), a 129 kDa O-sialoglycopro-tein involved in phagocytosis and CR1 (CD35), the receptor for C3b. In addition to C1q, the collectin receptor (cC1q-R CR) is also able to bind members of the collectin family of proteins including surfactant proteins A and D (SP-A and SP-D) and mannan binding lectin (MBL). Similarly, the gC1q-R p33 molecule can bind plasma proteins other than C1q, including high-molecular-weight kininogen (HK) and FXII, which may play a significant role in the...

Strategies for Reducing Virulence andor Influencing Pathogenesis

9 Enright, M.C., The evolution of a resistant pathogen - the case of MRSA. Curr Opin Pharmacol, 2003. 3 1-6. staphylococci. 44th Interscience Conference on Antimicrobial Agents and Chemotherapy, Washington, DC, 2004, 2004 234. 26 Ishida, H., Fujikawa, K., Chiba, M., Tanaka, M., Otani, T., Sao, K., Abstract F1935 DX-619, a novel Des-F(6)-Quino-lone-resistant MRSA. 44th Interscience Conference on Antimicrobial Agents and Chemotherapy, Washington, DC, 2004, 2004. 35 Choudhry, A.E., et al., Inhibitors of pantothenate kinase novel antibiotics for staphylococcal infections. Antimicrob Agents Chemother, 2003. 47(6) 2051-2055. 39 Butler, M.M., et al., Low Frequencies of Resistance among Staphylococcus and Enterococcus Species to the Bactericidal DNA Polymerase Inhibitor N(3-Hydroxy-butyl 6-(3'-Ethyl-4'-Methylanilino) Uracil. Antimicrob Agents Chemother, 2002. 46(12) 3770-3775. 50 Bae, T., et al., Staphylococcus aureus virulence genes identified by bursa aurealis mutagenesis and nematode...

Neonatal Conjunctivitis

Etiology (Table 4.3) The most frequent pathogens are Chlamydia, followed by gonococci. Neonatal conjunctivitis is less frequently attributable to other bacteria such as Pseudomonas aeruginosa, Haemophilus, Staphylococcus aureus and Streptococcus pneumoniae, or to herpes simplex. The infection occurs at birth. Chlamydia infections are particularly important because they are among the most common undetected maternal genital diseases in Europe, affecting 5 of all pregnant women. Neonatal conjunctivitis sometimes occurs as a result of Crede's method of prophylaxis with silver nitrate, required by law in Europe to prevent bacterial infection. Staphylococcus

Bacteria that Inhabit the Skin

The skin is typically dry and salty, providing an environment inhospitable to many microorganisms. Members of the genus Staphylococcus, however, thrive under these conditions. The pro-pionic acid bacteria, which were discussed earlier, inhabit anaerobic microenvironments of the skin. The Genus Staphylococcus Staphylococcus species are Gram-positive cocci that are facultative anaerobes. Most, such as S. epidermidis, reside harmlessly as a component of the normal flora of the skin. Like most bacteria that aerobically respire, Staphylococcus species are catalase positive. This distinguishes them from Streptococcus, Enterococcus, and Lactococcus species, which are also Gram-positive cocci but are obligate fermenters that lack the enzyme catalase. Several species of Staphylococcus are notable for their medical significance. Staphylococcus aureus causes a variety of diseases, including skin and wound infections, as well as food poisoning. Staphylococcus saprophyticus causes urinary tract...

Tests for Absence of Specific Indicator Microorganisms

The pharmacopoeias specify methods applying to Staphylococcus aureus, Pseudomonas aeruginosa, E. coli and Salmonella spp., with a method for each microorganism. Within each method there are options around choice of media and, in some cases, incubation temperatures. PhEur includes a broader category for enterobacteria and certain other Gram-negative microorganisms and recommends its application to Category 2 products (topical and respiratory preparations and transdermal patches).

Nitrofurans Nitrofurantoin

Nitrofurantoin (Furadantin, Macrodantin) is primarily active against gram-negative bacteria (E. coli, P. mirabilis is variable) and some susceptible gram-positive organisms, such as S. aureus and Enterococcus faecalis. In vitro activity is demonstrated against Staphylococcus saprophyticus and Staphylococcus epidermidis, but it may not be helpful in predicting patient response the same applies for certain species of Klebsiella and Citrobacter. Most Proteus (indole positive), Serratia, and Pseudomonas spp. are resistant. Development of resistant strains is virtually unknown, and cross-resistance with other antimicrobials has not been reported.

Pasteurella multocida Bite Wound Infections

No vaccines are available for use in humans. Immediate cleansing of bite wounds and prompt medical attention usually prevent the development of serious infection and possible permanent impairment of function. Unlike many Gram-negative pathogens, P. multocida is susceptible to penicillin. Usually, before the cultural diagnosis is known, amoxicillin plus a -lactamase inhibitor are administered, available in a single tablet under the trade name Augmentin. This combination is used because amoxicillin is active against P. multocida, and with the addition of the -lactamase inhibitor, the antibiotic is also active against many strains of -lactamase-producing Staphylococcus aureus, another common cause of bite wound infections. This and other antibacterial medications are effective if given early in the infection.

Targeting the Resistance Mechanism

Instead of searching for a novel antibiotic free of cross-resistance, an alternative strategy would be to combine an existing drug with a compound that overcomes or at least reduces the resistance against that particular antibiotic. This approach is especially appealing because it would restore the power of a previously valuable class, and because it has already been clinically validated by the very successful combination of b-lactams with b-lactamase inhibitors capable of protecting the active b-lactam from its destruction by the enzyme 80 . To pursue this approach, the mode of action and, especially, the molecular nature of the resistance mecha-nism(s) have to be carefully considered. There are examples where a combination is not even needed, but structural modification of the antibiotic itself is sufficient to protect it from certain resistance mechanisms (e.g., penicillinase-resistant b-lac-tams such as methicillin, or overcoming inducible MLSB resistance by ketolides, etc.). A...

Pharmacokinetic Properties

(Sulfamylon Cream), the most widely used compound, is effective against P. aeruginosa, an organism that frequently colonizes burns. It is less effective against staphylococci, which also colonize burns. Local absorption of the acetate preparation, which is acidic, can result in respiratory alkalosis. Silver sulfadiazine in a 1 cream can be used as an alternative to mafenide and has good activity against gram-negative bacteria.

Box 93 Bacterial meningitis empirical treatment

Third generation cephalosporins and meropenem have been shown to be more effective than aminoglycosides for the treatment of gram negative bacillary meningitis and should now be used.107,108 Group B streptococcal infection should be treated with penicillin or ampicillin. Listerial infection responds to ampicillin and for those with penicillin allergy, co-trimoxazole is effective. Flucloxacillin or oxacillin in high doses is recommended for Staphylococcus aureus meningitis, with vancomycin for those who cannot have penicillin or if the organism is methicillin resistant (MRSA). Shunt infections are commonly caused by coagulase negative staphylococci, and vancomycin, perhaps with added rifampicin, is effective. In most cases it is necessary to remove the device to eradicate the infection completely.109 The combination of penicillin with metronidazole is recommended for anaerobic infections.

Basal Cisterns Cisternogram

Brain mass lesion with 99mTc-sestamibi uptake. This 39 year old HIV positive man was admitted to hospital with dyspnea and fever in association with Staphylococcus aureus bacteremia and then developed new-onset seizures. A CT scan (left) showed an enhancing mass lesion in the periventricular white matter of the left parietal-occipital lobe (arrow) measuring approximately 3 cm in diameter with peritumoral edema. The radiologic fetatures were most consistent with CNS lymphoma, with toxoplasmosis considered a less likely alternative. SPECT sestamibi brain scanning (right) confirmed increased uptake in the lesion (arrow) further supporting a diagnosis of lymphoma which is almost uniformly sestamibi-avid while toxoplasmosis is usually negative. (Case provided by Dr. W.D. Leslie.) Figure 14. Brain death. This young woman sustained anoxic brain injury while recovering from emeregency surgical replacement of a mitral valve prosthesis infected with Staphylococcus aureus....

Epidemiology of acute bacterial meningitis

The microbial epidemiology of meningitis is changing in older children and adults, in whom nosocomial meningitis accounts for an increasing proportion of infections. Many of these are associated with recent neurosurgical intervention or trauma. In such cases, Pseudomonas aeruginosa, enterococci, Staphylococcus aureus, and the coagulase-negative staphylococci are the most common causative organisms. Table lists the common causes of bacterial meningitis associated with different underlying conditions.