Phenotypic characteristics and population genetics of Enterococcus faecalis cultured from patients in Tehran during 2000-2001.
ABSTRACT Conventional bacteriology techniques were used to identify enterococci isolates cultured from patients at different hospitals in Tehran during 2000-2001. The identification was confirmed using species-specific PCR targeting the D-alanyl-D-alanine ligase gene. A total of 59 isolates of Enterococcus faecalis were identified. The rates of resistance to different antibiotics were in the following order: penicillin 84%, ciprofloxacin 42%, high-level gentamicin 30%, nitrofurantoin 14%, imipenem 4%, and chloramphenicol 2%. Resistance to ampicillin was found to be rare among the Iranian isolates of E. faecalis. Multi-locus enzyme electrophoresis was then used to analyze the strains. Forty-five electrophoretic types were obtained when 10 enzyme loci were screened. Although the collection of bacterial isolates was limited in time and location, considerable heterogeneity was found. Analysis of strains for linkage disequilibrium demonstrated that the studied population is not clonal, since the index of association was not significantly different from zero (Ia = 0.0296). Enterococcus faecalis isolates recovered from patients in Tehran were genetically diverse and seemed to possess a high potential for genetic recombinations, though none were resistant to vancomycin.
Article: High Level Resistance of Enterococcus faecium and E. faecalis Isolates from Municipal Sewage Treatment Plants to Gentamicin[show abstract] [hide abstract]
ABSTRACT: Background: Enterococci are members of the normal gut flora and released into the environment via sewage outlets, where they can survive for long times. Infections with high-level gentamicin resistant (HLGR) enterococci are emerging worldwide. HLGR enterococci have developed a resistance to most antibiotics commonly used for enterococcal infections therefore; treatment of infections caused by HLGR enterococci is difficult. The present study investigated the distribution and antibiotic resistance of HLGR Enterococcus faecium and E. faecalis isolates from raw wastewater samples in Tehran. Methods: Raw wastewater samples were collected during the period from November 2006 to May 2007 at 3 sewage treatment plants located in different parts of Tehran. All 90 HLGR enterococcal isolates were identified to the species level by biochemical and PCR assays and subjected to antibiotic susceptibility testing. Results: Sixty four percent (58 of 90) of isolates were E. faecium and 29%(26 of 90) of them were E. faecalis. The highest level of antibiotic resistance was observed with erythromycin (63%), co-trimoxazole (69%) and tetracycline (92%) for E.faecalis and with erythromycin (97%), ciprofloxacin (47%), co-trimoxazole (45.5%) and tetracycline (47%) for E. faecium. Multiresistance against 3 to 4 antimicrobial was present in 27.5% and 15.5% of the isolates, respectively. Conclusion: HLGR E. faecium were more commonly found than E. faecalis. Species identification of HLGR entero-cocci enables us to assess species-specific antibiotic susceptibility patterns in our area. The present study reviled that HLGR E. faecalis remained more susceptible than E. faecium against the usual first-line and alternative treatments.Iranian J Publ Health. 01/2008; 37:103-107.