Phenotypic characteristics and population genetics ofEnterococcus faecaliscultured 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.

High-level Gentamicin Resistance and Detection of aac (6’)Ie-aph (2”)Ia Gene in Enterococci Isolated from Pediatric Hospital in Northwest of Iran

“…In the past 4 decades in Iran, aminoglycosides, particularly gentamicin, have been used broadly in the treatment of infections, which can be one of the causes of high prevalence of HLGR isolates in Iran's hospitals (25). In our study, high-level resistance to gentamicin was observed in 31 % of isolated enterococci.…”

The Antibacterial Effect of Aqueous Extract of Garlic against Resistant Enterococci

“…In this study, a total of 120 Enterococcal isolates were investigated. Various studies in Iran suggests that this bacterium is endemic in hospitals and has an important role in hospital infections (11,12). In a study in Babol, the frequency of isolation for E. faecalis and E. faecium were reported as 63% and 33%, respectively (13 (13).…”

Genetic characterization of high-level gentamicin-resistant strains of Enterococcus faecalis in Iran

“…No information is available on HLGR strains of E. faecalis in Iran or on the role of plasmids encoding this resistance. We previously used multilocus enzyme electrophoresis (MEE) to study the population genetics of E. faecalis in Iran and showed that the Iranian population of this species is not clonal (Feizabadi et al 2003). We also identified a considerable number of isolates that were highly resistant to aminoglycosides, which suggested the possible existence of successful HLGR strains.…”

“…E. faecalis ATCC 29212 and a Danish isolate with an HLGR phenotype (kindly provided by Frank Aarestrup) were used as controls, and E. faecalis JH2-2 was used as the recipient in conjugation experiments. All isolates were identified to species level using standard bacteriological methods (Manero and Blanch 1999), and the results were confirmed by PCR (Feizabadi et al 2003). Isolates with HLGR phenotype were recognized using disks containing 120 µg gentamicin (Antalek et al 1995) and were confirmed by the macro-broth dilution method (Barisic and Punda-Polic 2000).…”

“…Twenty Iranian HLGR isolates containing plasmids were then used as donors in conjugation experiments with the susceptible JH2-2 strain in a donor:recipient ratio of 1:10 (Ma et al 1998). Isolates selected for conjugation belonged to genetically distinct groups based on the results of MEE analysis (Feizabadi et al 2003) or different date of isolation.…”