RESUMO
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.