Three-year survey of community-acquired methicillin-resistant Staphylococcus aureus producing Panton-Valentine leukocidin in a French university hospital.

A retrospective survey was conducted at Bicêtre Hospital, France from January 2001 to September 2003 to screen for S. aureus isolates with a typical phenotype previously involved in necrotizing pneumonia in France. They were resistant to oxacillin and kanamycin, of intermediate susceptibility to fusidic acid, and susceptible to tobramycin and fluoroquinolones. Seventeen isolates were found and 16 were viable. The Panton-Valentine leukocidin (PVL) genes, various toxin genes and SCCmec IV and agr3 alleles were detected in all isolates. The clonal origin of these isolates was demonstrated by pulsed-field gel electrophoresis. Fourteen isolates were community-acquired methicillin-resistant Staphylococcus (CA-MRSA) isolated from previously healthy patients with skin or soft tissue infections. Three infections were of nosocomial origin, underlining that these PVL-producing CA-MRSA strains may also be hospital acquired. Five CA-MRSA isolates with an identical resistance phenotype collected in a neighbouring teaching hospital (Hôpital Pitié-Salpétrière, Paris, France) were also PVL positive. Three isolates were clonally related to those of the Bicêtre Hospital whereas two were not. This retrospective study identified PVL-producing CA-MRSA in two Parisian hospitals. The incidence at Bicêtre Hospital was 0.8% of all S. aureus and 2% of all MRSA isolated. Our data indicate that these MRSA isolates might become hospital acquired.

[Epidemiology and antimicrobial resistance of Streptococcus pneumoniae strains isolated in Ile de France area during 2001]. / Epidémiologie et résistance aux antibiotiques de Streptococcus pneumoniae en Ile de France en 2001.

OBJECTIVE: The authors wanted to assess the level of Streptococcus pneumoniae antibiotic resistance in Ile de France. METHOD: In 2001, 637 clinical strains of S. pneumoniae were prospectively collected from 32 microbiology laboratories. RESULTS: Fifty one percent of strains were isolated from children under 15 years of age and 49% from adults. In children, 76% of strains came from otitis media, 20% from blood culture, in adults most strains (92%) came from blood culture. The overall prevalence of non-susceptible penicillin pneumococci was 61% higher in children (73%) than in adults (50%). Among the non-susceptible penicillin pneumococci 21.8% were resistant (CMI > 1 mg/l). Strains with decreased susceptibility to amoxicillin and cefotaxime were 38% and 17% respectively. Resistant strains to these two drugs (CMI > 2 mg/l) were rare 2.6% and 0.4% respectively. Among other antimicrobial agents, rate of resistance was 63% to erythromycin, 47% to cotrimoxazole, 40% to tetracycline, and 23% to chloramphenicol. The most frequent serogroups were serogroups 19 and 14, respectively 23% and 18%. Serotypes included in heptavalent vaccine covered 90% of children strains under 2 years of age. CONCLUSIONS: The prevalence of resistance to penicillin was high in children particularly in otitis media pus (76%).

[Development of resistance to beta-lactams and other antibiotics of pneumococci isolated from acute otitis media in France: statement of the National Reference Center 1995-1996]. / Evolution de la résistance aux bêtalactamines et aux autres antibiotiques des pneumocoques isolés d'otites moyennes aiguës en France: bilan du Centre national de référence 1995-1996.

POPULATION AND METHODS: During 1995 and 1996, 393 and 566 strains of Streptococcus pneumoniae, isolated from acute otitis media, were respectively sent to the National Reference Center for Pneumococci by its corresponding centers. RESULTS: The resistance rates for 1995 and 1996 were respectively: for penicillin: 65.4 and 70.3% (18.6 and 24.9% of intermediately resistant strains, 46.8 and 45.4% of fully resistant strains), for erythromycin: 57.5 and 68.5%, for tetracycline: 43.2 and 42.6%, for trimethoprim-sulfamethoxazole: 47.5 and 50.9%. Minimal inhibitory concentrations (MICs) of various betalactams were determined against a representative sample of strains (n = 99). CONCLUSION: Amoxicillin, cefpodoxime and cefuroxime MICs remained low against numerous penicillin resistant strains, indicating that these three oral antibiotics (in combination with clavulanate for amoxicillin) have a useful potential for the treatment of acute otitis media when risk factors for pneumococcal penicillin-resistant infections are detected.

[Streptococcus pneumoniae: serotypes, invasive and antibiotic resistant strains. Current situation in France]. / Streptococcus pneumoniae: sérotypes, souches invasives et résistantes aux antibiotiques. Situation actuelle en France.

OBJECTIVES: Anti-pneumococcal antibiotic therapy has reduced morbidity and mortality of pneumococcal infections, but this success has retarded wide application of vaccination. The emergence and worldwide diffusion of antibiotic-resistant strains raises an important public health problem. The current situation requires determining the respective roles of antibiotic therapy and vaccine immunoprophylaxy. The aim of this work was to examine the data collected by the French National Pneumococci Registry. METHODS: The Nation Surveillance Network for Pneumococcal Infections was initiated in France in 1984. With this registry, it has been possible to follow regularly the evolution of serotypes and their sensitivity to antibiotics in 34,130 strains received from 1984 to 1996 and to compare these results with the clinical data. RESULTS: Serotyping the invasive strains has shown that the relative frequency of these serotypes has been stable: the 23-valence pneumococca vaccine provided good serotype coverage from 1984 to 1996 (87.2% of the invasive strains isolated in 1996 belonged to the vaccine types). Penicillin-resistant pneumococci comprised 3.8% of the strains, isolated in 1987 and 42.8% of those isolated in 1996. Two-thirds of these penicillin-resistant pneumococci had high-level resistance and an equivalent percentage were multiresistant. The consequences of resistant strains on antibiotic therapy for pneumonia, acute otitis and meningitis is discussed. CONCLUSION: Bacterio-clinical surveillance networks provide regular epidemiological data aimed at better use of antibiotics and the promotion of vaccination campaigns. In the future, the vaccination of children under 2 years of age with new conjugated polysaccharide vaccines should be an essential step in the global strategy against pneumococcal infections. The vaccinal formula of such a pediatric vaccine would contain 10 valences, defined according to the serotype results we have obtained: 1, 3, 4, 6, 7, 9, 14, 18, 19, 13. This vaccine would cover 86.1% of the invasive strains and 90.7% of the strains isolated from children with acute otitismedia.

[Presumptive tests and molecular hybridization for the identification of untypable strains of Streptococcus pneumoniae]. / Tests présomptifs et hybridation moléculaire pour l'identification des souches de Streptococcus pneumoniae non typable.

Five different methods for identification of pneumococci (optochine susceptibility, bile solubility, Slidex Pneumo-kit, Phadebact Pneumococcus test, AccuProbe DNA test) were evaluated with a total of 280 Streptococcus pneumoniae non typable strains. 189 strains were identified as pneumococci according to the AccuProbe test results. Among these, 180 strains (95.2%) were optochine sensitive (d > or = 12 mm). Bile solubility was seen in 125 (66.1%) of the pneumococci. Immunological identifications were respectively positive for 67 and 56 among 140 strains. By comparison with the DNA/RNA reassociation method, the poor sensitivities and specificities of the presumptive identification tests are actually demonstrated for pneumococcal non typable strains. Thus, the AccuProbe DNA test is seen as the only adequate method for identification of such strains.