Mild Staphylococcus aureus skin infection improves the course of subsequent endogenous S. aureus bacteremia in mice

Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P) or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG) levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect

Staphylococcal enterotoxin sensitization in a community-based population : a potential role in adult-onset asthma

Background: Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult-onset asthma in community-based populations. Objective: We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community-based adult populations. Methods: The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age=60.2years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin-specific IgE using ImmunoCAP. Results: Staphylococcal enterotoxin sensitization (0.35kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (61years), and inhalant allergen sensitization. Current asthma was mostly adult onset (18years old) and showed independent associations with high enterotoxin-specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin-specific IgE level was identified as the major determinant factor for total IgE level. Conclusions and Clinical Relevance: Staphylococcal enterotoxin sensitization was independently associated with adult-onset asthma in adult community populations. Strong correlations between the enterotoxin-specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis

Staphylococcal scalded skin syndrome caused by methicillin-resistant Staphylococcus aureus with superadded fungal infection in a neonate

Staphylococcal scalded skin syndrome (SSSS) or acute staphylococcal epidermolysis is an exfoliative skin disease and a toxin mediated staphylococcal infection affecting mostly neonates and adolescents. We describe here a case of 10-day old full term, vaginally delivered baby weighing 1530gms presenting with erythematous lesions first developing on the face and later spreading to the entire body for the last 6 days. The mucosal areas were spared. Blood culture of the patient revealed growth of Methicllin Resistant Staphylococcus aureus (MRSA). Culture from the skin lesions also revealed growth of MRSA with similar antibiotic sensitivity pattern. Fungal culture from the skin lesions revealed growth of Candida tropicalis. The diagnosis of SSSS was based on clinical criteria and microbiological findings.

Increasing Skin Infections and Staphylococcus aureus Complications in Children, England, 1997-2006

During 1997-2006, general practitioner consultations for skin conditions for children <18 years of age in England increased 19%, from 128.5 to 152.9/1,000 child-years, and antistaphylococcal drug prescription rates increased 64%, from 17.8 to 29.1/1,000 child-years. During the same time period, hospital admissions for Staphylococcus aureus infections rose 49% from 53.4 to 79.3/100,000 child-years.link_to_subscribed_fulltex

A five year outbreak of methicillin-susceptible Staphylococcus aureus phage type 53,85 in a regional neonatal unit

We identified a 5-year outbreak of a methicillin-susceptible Staphylococcus aureus (MSSA) strain, affecting 202 babies on a neonatal unit, by routine weekly phage typing all S. aureus isolates. Multiple staged control measures including strict emphasis on hand hygiene, environmental and staff surveillance sampling, and application of topical hexachlorophane powder failed to end the outbreak. S. aureus PT 53,85 (SA5385) was found on opened packs of Stomahesive®, used as a neonatal skin protectant. Only following the implementation of aseptic handling of Stomahesive®, and the use of topical mupirocin for staff nasal carriers of SA5385, and for babies colonized or infected with S. aureus, did the isolation rate of SA5385 decline. DNA fingerprinting indicated that [gt-or-equal, slanted]95% of SA5385 isolates were clonal. In vitro death rates of SA5385 on Stomahesive® with human serum were significantly lower than on Stomahesive® alone (P = 0·04), and on cotton sheet with serum (P = 0·04), highlighting the potential of this material as a survival niche. Phage typing remains a valuable, inexpensive and simple method for monitoring nosocomial MSSA infection

An in vitro evaluation of the efficacy of tedizolid: implications for the treatment of skin and soft tissue infections

Skin and soft tissue infections (SSTI) are among the most commonly occurring infections and evidence suggests that these are increasing world-wide. The aetiology is diverse, but Staphylococcus aureus predominate and these are often resistant to antimicrobials that were previously effective. Tedizolid is a new oxazolidinone-class antibacterial indicated for the treatment of adults with SSTI caused by Gram-positive pathogens, including S. aureus. The aim of this study was to evaluate the in vitro efficacy of tedizolid in comparison to other clinically used antibacterials against antibiotic sensitive- and resistant-staphylococci, grown in planktonic cultures and as biofilms reflecting the growth of the microorganism during episodes of SSTI. Against a panel of 66 clinical staphylococci, sensitivity testing revealed that a lower concentration of tedizolid was required to inhibit the growth of staphylococci compared to linezolid, vancomycin and daptomycin; with the tedizolid MIC being 8-fold (S. aureus) or 4-fold (S. epidermidis) below that obtained for linezolid. In addition, cfr+ linezolid-resistant strains remained fully susceptible to tedizolid. Against S. aureus biofilms, 10×MIC tedizolid was superior or comparable with 10×MIC comparator agents in activity, and superior to 10×MIC linezolid against those formed by S. epidermidis (65 vs. 33% reduction, respectively). Under flow-conditions both oxazolidinones at 10×MIC statistically out-performed vancomycin in their ability to reduce the viable cell count within a S. aureus biofilm with fewer the 12% of cells surviving compared to 63% of cells. In conclusion, tedizolid offers a realistic lower-dose alternative agent to treat staphylococcal SSTI, including infections caused by multi-drug resistant strains

Superbugs and Superdrugs: A history of MRSA

Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.First published by the Wellcome Trust Centre for the History of Medicine at UCL, 2008.©The Trustee of the Wellcome Trust, London, 2008.All volumes are freely available online at: www.history.qmul.ac.uk/research/modbiomed/wellcome_witnesses/Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.Annotated and edited transcript of a Witness Seminar held on 11 July 2006. Introduction by Professor David Greenwood, University of Nottingham.Because of its unique adaptability and resistance to many antibacterial drugs and antiseptics, methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial menace of the present day. It has invaded medical and surgical wards in hospitals, infecting patients already ill or recovering, and endangering clean surgical operations, encouraged by overcrowding and limited air circulation. It has now spread from hospitals to families and communities. Infection control microbiologists and the Public Health Laboratory Service developed assays, ‘phage typing and other tests to identify strains, with better understanding of their behaviour aided by the discovery of the mecA gene. This Seminar addressed the biological reasons for this behaviour; the difference between resistant and non-resistant strains; the development, evolution and elucidation of drug resistance in hospital infection and its geographical distribution. Suggested by Professor Gordon Stewart and chaired by Dr Robert Bud, surgeons, microbiologists, infection control experts and representatives of the pharmaceutical industry and of the public included: Professor Graham Ayliffe, Professor Mark Casewell, Dr Bilwanath Chattopadhyay, Dr Stephanie Dancer, Dr Bernard Dixon, Dr Georgia Duckworth, Professor Brian Duerden, Professor Michael Emmerson, Professor Gary French, Professor Curtis Gemmell, Professor Alan Glynn, Dr Ian Gould, Professor David Greenwood, Professor Jeremy Hamilton-Miller, Dr Angela Kearns, Dr Bill Newsom, Professor Ian Phillips, Dr Tyrone Pitt, Dr Elizabeth Price, Professor Sir Mark Richmond, Dr Geoffrey Scott, Dr Joe Selkon, Dr David Shanson, Dr Norman Simmons, Professor Dale Smith, Professor Brian Spratt, Dr Robert Sutherland, Professor John West. Reynolds L A, Tansey E M. (eds) (2008) Superbugs and superdrugs: A history of MRSA, Wellcome Witnesses to Twentieth Century Medicine, vol. 32. London: The Wellcome Trust Centre for the History of Medicine at UCL.The Wellcome Trust Centre for the History of Medicine at UCL is funded by the Wellcome Trust, which is a registered charity, no. 210183