[Spider bite or infection caused by Panton Valentine leucocidin-producing Staphylococcusaureus?] / Morsure d'araignée ou infection à Staphylococcusaureus producteur de toxine de Panton Valentine ?

INTRODUCTION: Spiders, especially those of the genus Loxoceles such as L. rufescens, endemic in Mediterranean regions, are frequently reported as causes of venom poisoning in humans in the south of France. The most common signs consist of cutaneous necrosis presenting initially as inflammatory cellulitis and progressing towards the emergence of a necrotic centre. PATIENTS AND METHODS: We report 4 cases, initially considered as spider bites due to their sudden occurrence and pain. Rigorous clinical examination coupled with collection of samples for laboratory analysis ultimately enabled the diagnosis to be corrected to one of suppurative skin infection caused by Staphylococcusaureus producing the cytotoxin Panton Valentine leucocidin. DISCUSSION: These observations highlight the potential for confusion between spider bites and infections with PVL-producing S. aureus.

[Staphylococcal toxic shock syndrome should be considered in the event of diffuse erythema with fever and shock]. / Érythème généralisé fébrile et choc : choc toxinique staphylococcique.

BACKGROUND: Toxic shock syndrome (TSS) was first described by Todd in 1978. The relevant Lancet publication reported 7 cases of children with fever, exanthema, hypotension and diarrhoea associated with multiple organ failure. An association between TSS and use of hyper-absorbent tampons in menstruating women was discovered in the 1980s. Following the market withdrawal of such tampons, TSS virtually disappeared. Herein we report a new case of TSS in a 15-year-old girl. PATIENTS AND METHODS: A 15-year-old patient was admitted to intensive care for severe sepsis and impaired consciousness associated with diffuse abdominal pain. Dermatological examination revealed diffuse macular exanthema. Laboratory tests showed hepatic cytolysis (ASAT 101 U/L, ALAT 167 U/L, total bilirubin 68µmol/L) and an inflammatory syndrome. Lumbar puncture and blood cultures were sterile while thoraco-abdomino-pelvic and brain scans were normal. The patient was menstruating and had been using a tampon over the previous 24hours. Vaginal sampling and tampon culture revealed TSST-1 toxin-producing S. aureus. Management consisted of intensive care measures and treatment with amoxicillin-clavulanic acid and clindamycin for 10 days. CONCLUSION: In case of septic shock associated with diffuse macular exanthema a diagnosis of TSS must be envisaged, particularly in menstruating women.

Clinical manifestations and outcome of skin infections caused by the community-acquired methicillin-resistant Staphylococcus aureus clone ST80-IV.

BACKGROUND: Several Panton-Valentin leukocidin-positive clones of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are spreading worldwide. The European clone ST80-IV is the main CA-MRSA clone in Europe. There is no reported study of the specific clinical manifestations and outcome of skin infections caused by the clone ST80-IV, using strict definitions of skin diseases. METHODS: Single-centre observational prospective cohort of S. aureus skin infections caused by the clone ST80-IV. RESULTS: From November 1999 to October 2009, we diagnosed skin infections due to the clone ST80-IV in 20 patients (median age 28 years, median 27; range 1-66). All the isolates had all the following characteristics: lukPV, etd and edin gene-positive, agr 3 allele, spa-type t044 and ST80. All the isolates were resistant to beta-lactam agents, kanamycin, tetracycline and fusidic acid. During the study period, the 20 patients had the following manifestations: 19 primary abscesses (18 single abscess and one patient with two), eight furuncles, four folliculitis, one case of cellulitis, one wound infection and one felon. Surgical treatment and drainage was required for all the primary abscesses. The infections occurred mainly in the perineal area (50%). No secondary infections occurred in family members. Despite strict hygiene measures, systemic antibiotics and nasal mupirocine, four patients (20%) had recurrent skin infections over a period of a few months to 6 years. CONCLUSIONS: The CA-MRSA clone ST80-IV is responsible for suppurative skin infections such as furuncles and abscesses, which can recur over a period of several years.

[Molecular fingerprint of bacterial communities and 16S rDNA intra-species heterogeneity: a pitfall that should be considered]. / Empreinte moléculaire des communautés bactériennes et hétérogénéité intraspécifique de l'ADNr 16S: est-il raisonnable d'occulter le problème?

UNLABELLED: Molecular fingerprinting methods are currently used to study microbial communities by culture independent approaches. They are proposed as identification tool owing to the availability of rapid automated methods. The 16S rRNA gene (16S rDNA) is an efficient marker for bacterial identification and microbial communities analysis. However, the 16S rDNA polymorphism among strains of the same species is an underestimated pitfall of the fingerprinting approaches. AIM OF THE STUDY: We studied the 16S rDNA variability among strains of three bacterial species of medical interest. MATERIAL AND METHODS: Total DNA was extracted from clinical isolates of Pseudomonas aeruginosa (N=20), Clostridium difficile (N=20) and Enterobacter cloacae (N=14). The Polymerase Chain Reaction (PCR) products obtained with consensus primers flanking the 16S rDNA variable regions V3 and V6-V7-V8 were separated by Temporal Temperature Gradient gel Electrophoresis (TTGE). DNA extracted from TTGE bands were sequenced and analysed. RESULTS: All the isolates of P. aeruginosa and of C. difficile displayed one single TTGE band with constant migration distances suggesting that there was no 16S rDNA polymorphism among strains in these two species. Oppositely, the isolates of E. cloacae gave complex TTGE patterns formed by multiple bands with variable migration distances. These patterns corresponded to 16S rRNA genes variable in a single genome as well as among strains of the species. CONCLUSION: Intra-species and/or intragenomic variability of 16S rDNA should be taken into account for pertinent interpretation of molecular fingerprint. For this purpose, a comprehensive description of the polymorphism of this marker is necessary.

Evaluation of a capillary zone electrophoresis system versus a conventional agarose gel system for routine serum protein separation and monoclonal component typing.

Capillary zone electrophoresis of serum proteins is increasingly gaining impact in clinical laboratories. During 2003, we compared the fully automated capillary electrophoresis (CE) system from Beckman (Paragon CZE 2000) with the method agarose gel electrophoresis Sebia (Hydrasis-Hyris, AGE). This new study focused on the evaluation of analytical performance and a comparison including 115 fresh routine samples (group A) and a series of 97 frozen pathologic sera with suspicion of monoclonal protein (group B). Coefficients of variation (CVs %) for the five classical protein fractions have been reported to be consistenly < 9% in within-run and < 10% in between-run imprecision studies with the Paragon 2000 system. The results of the comparison study (group A) demonstrated a good correlation between the CE system and AGE, except for beta-globulin (r = 0.65). Among the 97 pathologic serum samples (group B), there were 90 in which we detected a monoclonal protein by immunofixation (IF) (immunosubtraction (IS) was not used). AGE and Paragon 2000 failed to detect 7 and 12 monoclonal proteins, respectively, leading to a concordance to 92% for AGE and 87% for Paragon 2000 for identifying electrophoretic abnormalities in this group. Beta-globulin abnormalities and M paraprotein were well detected with Paragon 2000. Only 81% (21 vs 26) of the gammopathies were immunotyped with IS by two readers blinded to the IF immunotype. The Paragon 2000 is a reliable alternative to conventional agarose gel electrophoresis combining the advantages of full automation (rapidity, ease of use and cost) with high analytical performance. Qualified interpretation of results requires an adaptation period which could further improve concordance between the methods. Recently, this CE system has been improved by the manufacturer (Beckman) concerning the migration buffer and detection of beta-globulin abnormalities.

Assessment of cetirizine, an antihistamine, to prevent cutaneous reactions to nevirapine therapy: results of the viramune-zyrtec double-blind, placebo-controlled trial.

We conducted a 12-week, multicenter, randomized, double-blind, placebo-controlled trial of cetirizine to assess the ability of antihistamines to prevent nevirapine-associated rash in patients infected with human immunodeficiency virus type 1. Patients initiating treatment with nevirapine were randomized to receive either cetirizine, 10 mg q.d. (104 patients), or placebo (96 patients) during the first 6 weeks of therapy. Rash occurred in 22 (11%) of 200 patients; 10 (9.6%) were in the cetirizine group and 12 (12.5%) were in the placebo group (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.31-1.81; P=.5). Five of 22 rashes were cases of hypersensitivity syndrome. The rate of nevirapine discontinuation due to rash was similar in the 2 groups (7.7% and 6.25% in the cetirizine and placebo groups, respectively; P=.4). Multivariate analysis showed no treatment-group effect but indicated that age >40 years (OR, 3.83; 95% CI, 1.4-10.46; P=.008) was associated with an increased risk of rash. Cetirizine has no preventive effect on nevirapine-associated rash.