Extensive dissemination of CTX-M-1- and CMY-2-producing Escherichia coli in poultry farms in Tunisia.

We characterized 67 Escherichia coli isolates with reduced susceptibility to cefotaxime obtained from 136 samples of healthy broilers housed in 36 Tunisian farms. All these isolates harboured blaCTX-M-1 and/or blaCMY-2 genes located mostly on self-conjugative IncI1 plasmids. qnrS1, qnrA6 and aac(6')-Ib-cr were detected in six isolates. Considerable genetic diversity was detected among isolates from different farms. To our knowledge, this is the first detailed documentation of a high occurrence of blaCTX-M-1 and blaCMY-2 in E. coli at the poultry farm level in Tunisia as well as the first description of plasmid-mediated quinolone resistance in food animals in Tunisia which may contribute to the dissemination of these genes throughout Tunisia.

Nosocomial outbreak of Myroides odoratimimus urinary tract infection in a Tunisian hospital.

We report a nosocomial outbreak of urinary tract infection caused by Myroides odoratimimus, previously called Flavobacterium odoratum, in the urology unit of a Tunisian hospital. From May to November 2010, seven isolates of M. odoratimimus were recovered from urine. Pulsed-field gel electrophoresis clearly differentiated these isolates into two possibly related clones from two different periods. All patients but one had urinary calculi and underwent endourological surgery. All Myroides isolates were resistant to all antibiotics tested. Three patients were successfully treated with ciprofloxacin and rifampicin. Clinicians should be aware that M. odoratimimus may induce serious and prolonged nosocomial outbreaks of urinary tract infections.

[Resistance to third generation cephalosporins in Sfax hospitals, Tunisia (1999-2005)]. / Etude de la résistance des entérobactéries aux céphalosporines de troisième génération dans les hôpitaux de Sfax, Tunisie (1999-2005).

OBJECTIVES: The authors wanted to assess the prevalence and to monitor the trends of resistance to broad-spectrum cephalosporins among various species of enterobacteria in the region of Sfax (Tunisia). METHODS: A retrospective study was carried out in the microbiology laboratory at the Habib-Bourguiba Teaching Hospital in Sfax. Data concerning a seven-year period (1999-2005) were analyzed with the Whonet 5.4 software. All clinical isolates of enterobacteria were identified with the API 20 E system. Antimicrobial susceptibilities were determined by disk diffusion on Mueller Hinton agar according to CA-SFM recommendations. RESULTS: During the study period, 24,702 non-duplicate clinical strains of enterobacteria were identified. Fifteen percent (3,826) clinical isolates showed acquired resistance to third generation cephalosporins (3rdGC). The overall frequency of resistance increased from 10% in 1999 to 18% in 2005. This increase was statistically significant. High prevalence rates of 3rdGC resistance have been observed in intensive care units (48%), hematology and oncology wards (27%) and pediatric wards (25%). Klebsiella pneumoniae, Indole positive Proteus and Enterobacter showed high prevalence rates of broad-spectrum cephalosporin resistance. CONCLUSION: This study revealed a high rate of 3rdGC resistance enterobacteria in our region, particularly in intensive care units. The frequency of acquired resistance to broad-spectrum cephalosporins seemed to be increasing. Implementation of infection control measures and identification of the mechanism responsible for third generation cephalosporins resistance are necessary to limit the spreading of these resistant enterobacteria in hospitals and community settings.

[Use of molecular subtyping methods to investigate two nosocomial outbreaks due to Salmonella Livingstone in Sfax hospital, Tunisia]. / Application de marqueurs génotypiques dans l'investigation de deux épidémies d'infections nosocomiales à Salmonella Livingstone dans le CHU de Sfax, Tunisie.

OBJECTIVE: The aim of the study was to investigate two nosocomial outbreaks due to Salmonella Livingstone in a pediatric ward in Sfax hospital using molecular typing techniques. MATERIALS AND METHODS: We included 84 strains of S. Livingstone isolated from patients hospitalized in a pediatric ward between November 1999 through August 2002 in addition to one environmental sample. Three epidemiological unrelated strains of S. Livingstone were also tested. The molecular typing techniques were: plasmid analysis, enterobacterial repetitive intergenic consensus (ERIC-PCR), random amplification of polymorphic DNA (RAPD-PCR) and pulsed field gel electrophoresis (PFGE). RESULTS: The plasmid analysis and the ERIC-PCR generated a similar profile for outbreak isolates including the environmental sample while the epidemiologically unrelated strains demonstrated distinct patterns. The RAPD-PCR applied on 20 strains showed three patterns but one profile was predominating. All the strains isolate of S. Livingstone, except the veterinary strain, could not be typed by PFGE. CONCLUSION: Using the molecular typing techniques, we showed that these two outbreaks in the pediatric ward were due to the clonal spread of a single strain of S. Livingstone. The identification of the source of contamination and the improvement of hygiene conditions are required.