[Extended-spectrum betalactamases producing Escherichia coli: a new health-care associated infection threat?]. / Escherichia coli producteurs de bêtalactamases à spectre étendu: de nouvelles menaces nosocomiales ?

OBJECTIVES: Study the health-care associated infection risk due to Extended-Spectrum Betalactamases Producing Escherichia coli (ESBL Esc) isolated from diagnostic samples. METHODS: Descriptive, longitudinal and prospective study of 104 diagnostic isolates of ESBL Esc, one per patient, identified in Amiens university hospital between February 1999 and December 2005. Patients (sex, age, contamination risk factor, antecedent hospitalization) and microbiological data were progressively collected, entered into EPI INFO 6.04dFr software (ENSP, France) database, and compared using the chi-square test and Wilcoxon rank sum test, as appropriate. A p value of less than 0.05 was considered significant. RESULTS: Diagnostic ESBL Esc isolates raised, per 1000 isolates of Esc, from 1.2 in 1999 to 6 in 2005. Global and acquired isolates number of ESBL Esc varied from 7 and 3 in 2002 to 25 and 19 in 2003 (P=0.22). ESBL Esc global and acquired incidence per 10(5) patient-days were, 0.8 and 0.6 in 1999 and 4.99 and 3.4 in 2005 (P<10(-6)), but rose from 0.6 acquired isolate in 2002 to 3.9 in 2003 (P=0.002). ESBL Esc, isolated from urines, stools, pulmonary, blood and surgical site samples of patients of>/=65 years aged (68.3%), were imipenem and latamoxef sensitive. Their acquisition risk factors found were hospitalization during the last 6 month period (40/104) and transfer from other institutions (20/104). CONCLUSION: ESBL Esc isolates, among ESBL-producing Enterobacteriaceae, constitute an escalating health-care associated risk in our institution. The research at admission time of ESBL-producing Enterobacteriaceae, mainly in acute geriatric wards, strict isolation precaution and hand hygiene observance, rational antibiotic usage, are the key actions to control their cross transmission. Nonetheless, other studies are needed to determine whether we are in front of an ESBL Esc new clone emergence.

Molecular diversity of Proteus mirabilis isolates producing extended-spectrum beta-lactamases in a French university hospital.

Between February 1997 and December 2002, 3340 hospitalised patients yielded samples positive for Proteus mirabilis, of whom 45 (1.3%) were colonised/infected by P. mirabilis producing extended-spectrum beta-lactamases (ESBLs). The gross incidence of patients colonised/infected by ESBL-producing P. mirabilis was 1.61/10(5) days of hospitalisation, with 20% of isolates being collected from patients in urology wards, most frequently (53.3%) from urine samples. Seventeen (37.7%) of the 43 isolates were obtained from samples collected within 48 h of hospitalisation, indicating that they were community-acquired. Isoelectric focusing assays and sequencing identified the TEM-24, TEM-92 and TEM-52 ESBLs. Pulsed-field gel electrophoresis revealed eight pulsotypes (I-VIII), with the two most common pulsotypes, IV and VI, comprising ten (23.3%) and 12 (26.6%) isolates, respectively. These pulsotypes were considered to represent epidemic strains and spread in various wards of the hospital.

Regional dissemination of Salmonella enterica serovar Enteritidis is season dependent.

OBJECTIVE: To carry out epidemiological typing of clinical isolates of Salmonella enterica serovar Enteritidis by pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD) and analysis of their antibiotic resistance. METHODS: Over a 12-month period, 44 Salmonella Enteritidis isolates, recovered from 40 patients admitted to the University Hospital Center of Amiens, France and from three outpatients, were characterized by the analysis of phenotypic and genotypic traits and clinical data from medical reports. RESULTS: Forty nontyphoidal salmonellosis episodes were diagnosed in hospitalized patients (34 episodes of gastroenteritis, two episodes of bacteremia not affecting other organs, one episodes of bacteremia plus urinary infection, one episodes of bacteremia plus gastroenteritis, one episodes of chronic colitis plus gastroenteritis and one episode of peritonitis), and three carriers were observed in outpatients. By means of PFGE, RAPD and antibiotic susceptibility patterns 44 isolates were subdivided into 16 clonally related groups. Two of them were predominantly implicated in the course of these infections, being responsible for two successive waves of infection, while the others were encountered sporadically.