Nicole Bouziges

CTX-M β-Lactamase-Producing Escherichia coli in French Hospitals: Prevalence, Molecular Epidemiology, and Risk Factors

ABSTRACT In 2004, 65 CTX-M-producing Escherichia coli isolates were collected from infected patients in four French hospitals. The blaCTX-M-15 genes were predominant. Pulsed-field gel electrophoresis highlighted a clonal propagation of CTX-M-15-producing strains belonging to phylogenetic group B2, notably in the community. The main risk factors for acquiring these isolates were urinary tract infections or the presence of a urinary catheter in diabetic or renal failure patients.

qnrA in CTX-M-Producing Escherichia coli Isolates from France

ABSTRACT By PCR, we screened for qnr genes 112 clinical isolates of extended-spectrum β-lactamase-producing Escherichia coli collected from hospitals in France during 2004. For the first time, 7.7% of CTX-M-producing E. coli isolates presented a plasmid-mediated resistance to quinolones. All strains harbored a qnrA gene located on a sul1-type class 1 integron with similar structure to the In36 integron.

Molecular Epidemiology of Enterobacteriaceae Isolates Producing Extended-Spectrum β-Lactamases in a French Hospital

ABSTRACT In 2002, 80 isolates of Enterobacteriaceae producing extended-spectrum β-lactamases (ESBLs) were collected from infected patients in our hospital. Enterobacter aerogenes was the most common bacterium isolated from all specimens (36.5%). The ESBLs were predominantly (90%) TEM derivatives (TEM-24, TEM-3). Pulsed-field gel electrophoresis highlighted that E. aerogenes, Klebsiella pneumoniae, and Citrobacter koseri had a clonal propagation.

Miniaturized Oligonucleotide Arrays A new tool for discriminating colonization from infection due to Staphylococcus aureus in diabetic foot ulcers

OBJECTIVE—We sought to evaluate the use of oligonucleotide arrays to discriminate colonization from infection due to Staphylococcus aureus in diabetic foot ulcers. RESEARCH DESIGN AND METHODS—We included diabetic patients hospitalized in a diabetic foot department for an episode of foot ulcer. Only patients who had no antibiotic treatment during the previous 6 months were included. At admission, ulcers were classified on clinical examination, according to the Infectious Diseases Society of America system. Seventy-two patients with a culture positive only for S. aureus as the sole pathogen were included. In individuals with a grade 1 ulcer, a second wound bacterial specimen was obtained 1 month later. Using oligonucleotide arrays, S. aureus resistance and virulence genes were compared between grade 1 and grades 2–4 ulcers. RESULTS—S. aureus was initially isolated from 22 grade 1 and 50 grade 2–4 ulcers: 35 were methicillin resistant and 37 methicillin sensitive. In 20 grade 1 ulcers (92%), no virulence genes were identified, whereas these genes were present in all but 1 grade 2–4 ulcers. During follow-up, the two grade 1 ulcers that were infected with strains carrying virulence genes rapidly deteriored; the array technology showed unchanged genotype profiles. On the contrary, two grade 1 ulcers healed: the genotype profiles were different from those at inclusion but without appearance of virulence genes. CONCLUSIONS—The DNA array appears as a promising technique and is easy to perform. Our observational study suggests that it might help distinguish colonized grade 1 from infected grade 2 wounds, predict ulcer outcome, and contribute to a more adequate use of antibiotics.

Beneficial effects of implementing guidelines on microbiology and costs of infected diabetic foot ulcers

Aims/hypothesisIn 2003, guidelines for management of diabetic foot infection (DFI) were written by the authors’ team according to the guidelines of the International Working Group on the Diabetic Foot. The effects of implementing these guidelines on the microbiology and costs of infected diabetic foot ulcers were assessed.MethodsFrom 2003 to 2007, potential beneficial effects of implementing these guidelines were assessed by comparison over time of bacteriological data (number of bacterial samples, number of microorganisms isolated in cultures, prevalence of multidrug-resistant organisms [MDRO] and colonising flora), and costs related to use of antimicrobial agents and microbiology laboratory workload.ResultsThe study included 405 consecutive diabetic patients referred to the Diabetic Foot Unit for a suspected DFI. From 2003 to 2007, a significant decrease was observed in the median number of bacteria species per sample (from 4.1 to 1.6), prevalence of MDRO (35.2% vs 16.3%) and methicillin-resistant Staphylococcus aureus (52.2% vs 18.9%) (pu2009<u20090.001). Moreover, prevalence of pathogens considered as colonisers dramatically fell from 23.1% to 5.8% of all isolates (pu2009<u20090.001). In parallel, implementation of guidelines was associated with a saving of €14,914 (US

Clinical and molecular epidemiology of multidrug-resistant Citrobacter spp. infections in a French university hospital

20,046) related to a reduced microbiology laboratory workload and €109,305 (US

Spondylodiscitis Due to Clostridium ramosum Infection in an Immunocompetent Elderly Patient

147,536) due to reduced prescription of extended-spectrum antibiotic agents.Conclusions/interpretationImplementation of guidelines for obtaining specimens for culture from patients with DFI is cost-saving and provides interesting quality indicators in the global management of DFI.

Virulence potential of Escherichia coli strains causing asymptomatic bacteriuria during pregnancy.

Citrobacter spp. are aerobic, gram-negative bacilli that are frequently found in water, soil, food, and the intestines of animals and humans [1]. Even though their level of virulence is low and they rarely cause infections in humans, these pathogens have been associated with a wide spectrum of infections involving the central nervous system and the gastrointestinal, urinary, or respiratory tracts [1]. The fact that Citrobacter spp. are rather uncommon in clinical specimens explains why few studies of them appear in the medical literature [2, 3]. However, these organisms may be responsible for serious infections, especially in immunocompromised hosts. To evaluate the epidemiology of Citrobacter spp. in our 1,700-bed university hospital in southern France, we conducted a prospective study from 1 October 2003 to 30 April 2004. Hospitalized patients were screened for the presence of Citrobacter spp. and nonrepetitive clinical strains isolated consecutively from infection sites were included in the study. Antibiotic susceptibility testing was performed using the Vitek 2 GNS-F7 card (bioMerieux, Marcy l’Etoile, France) and an agar disk-diffusion assay on Mueller-Hinton agar. Strains were classified as susceptible, intermediately resistant or resistant to the other antibiotics tested according to the recommendations of the Antibiotic Susceptibility Testing Committee of the French Society for Microbiology [4]. The strains that were found to be resistant to extended-spectrum cephalosporins were additionally screened for extended-spectrum β-lactamase (ESBL) production using the double-disk synergy test. Isoelectric focusing was performed using polyacrylamide gels as described previously [5]. Macrorestriction analysis of chromosomal DNAwas performed using pulsed-field gel electrophoresis according to previously published procedures and analyzed with Gel compar computer software (Applied Math, Belgium) as described previously [5]. The qnrA, qnrB and qnrS genes were screened using PCR as described previously [5]. During the study period, information concerning patient age, sex and immune status (MacCabe score [6]), hospital ward, source of infection, mortality, comorbid diseases, antecedent of hospitalization (notably prior stay in an intensive care unit), prior antibiotic therapy, date of bacterial isolation, length of hospitalization, and the source of infection were collected to determine the risk factors for infections caused by extended-spectrum, cephalosporinresistant Citrobacter spp. Duplicate isolates from the same patient were excluded. Of the 1,531 Enterobacteriaceae we isolated, 45 strains were Citrobacter spp., i.e., 2.94% isolated from 45 patients. The characteristics of these 45 patients are presented in Table 1. The infections were of nosocomial origin in 62% of cases. Citrobacter koseri was the species isolated most frequently (57.7%), but this finding differs from previous Eur J Clin Microbiol Infect Dis (2007) 26:439–441 DOI 10.1007/s10096-007-0315-3

Endocarditis Due to a New Rod-Shaped Neisseria sp.

ABSTRACT The first ever case of spondylodiscitis caused by Clostridium ramosum in an elderly immunocompetent patient has been reported. C. ramosum is usually an intestinal bacterium but may occasionally be isolated in clinical specimens as an opportunistic pathogen. This report shows that this anaerobic organism can cause bone tropism without there having been any contamination due to spinal surgery. The infection cleared after empirical therapy using intravenous amoxicillin and oral metronidazole.

Faecal carriage of oxyiminocephalosporin-resistant Enterobacteriaceae among paediatric units in different hospitals in the south of France

ABSTRACT We compared the virulence properties of a collection of asymptomatic bacteriuria (ABU) Escherichia coli strains to urinary tract infection (UTI) strains isolated from pregnant women in a university hospital over 1 year. The in vitro and in vivo studies suggest that ABU strains presented a virulence behavior similar to that of strains isolated from cases of cystitis.