ABSTRACT
Aim: The purpose of this study was to find the isolation rate of enteropathogenic Escherichia coli [EPEC] from lettuce samples collected in Tehran
Background: During the last decade, the prevalence of infectious diarrheal diseases due to consumption of contaminated food especially raw vegetable has been increasingly reported. Enteropathogenic Escherichia coli strains are an important group of diarrheagenic E. coli that can cause infant diarrhea especially in the developing world
Material and Methods: One hundred lettuce samples collected in Tehran were transported to the laboratory, homogenized by a stomacher in EC broth containing cefixime, and cultured on MacConkey agar plates. Bacterial DNA was extracted by boiling method and PCR was performed using three pairs of primers targeting stx1, stx2 and eaeA genes
Results: Screening of 100 lettuce samples by PCR showed four samples were positive for the presence of EPEC
Conclusion: This study suggests contamination of the lettuce by the EPEC and its possible role as the source of infection in this region
ABSTRACT
We intended to find out the diversity of EPEC isolates among asymptomatic or diarrheal children in Iran using ribotyping. Enteropathogenic Escherichia coli [EPEC] is responsible for gastroenteritis especially in young children. A total of 39 EPEC collected strains were serotyped and the presence of virulence genes as well as EAF plasmid among the strains was studied. Adherence assay was also performed. Clonal diversity of the isolates was investigated using ribotyping. Of 39 studied strains of E. coli, 6 serogroups of EPEC were represented. The presence of the stx gene was ascertained in 7 isolates and the eaeA, eaeB and bfpA genes were harbored by 5, 3 and 1 strains, respectively. Ribotyping yielded 9 different clusters. According to our results there was not a significant correlation between the results of serotyping and those of ribotyping. However, different serotypes of E. coli may belong to the same ribotype clusters and vice versa
ABSTRACT
To identify and classify Iranian isolates of diarrheagenic Escherichia coli E. coli on the basis of presence of virulence genes and to determine antibiotic susceptibility of isolated strains. The current cross-sectional study was conducted in 2005 at the Pasteur Institute, Tehran, Iran. One hundred and ninety-three diarrheagenic E. coli isolated from diarrheal patients in different regions of Iran were included in current study. Virulence factor genes for diarrheagenic E. coli were detected by polymerase chain reaction. Of the 193 diarrheagenic E. coli detected by PCR, 86 44.5% were Shiga toxin-producing E. coli STEC, 74 38.4% enteropathogenic E. coli EPEC, 19 9.8% enteroaggregative E. coli, and 14 7.3% enterotoxigenic E. coli isolates. Susceptibility to 12 clinically important antimicrobial agents was determined for 193 strains of diarrheagenic E. coli. A high incidence of resistance to tetracycline 63%, ampicillin 62%, streptomycin 56%, amoxicillin/clavulanic acid 44.5%, trimethoprim/sulfamethoxazole 39.5%, and cephalothin 37% was observed. The STEC and EPEC strains with high resistance to tetracycline and ampicillin, but highly susceptible to quinolones are among the most important causative agent of diarrhea in Iran. This study suggests that antimicrobial resistance is widespread among E. coli strains colonizing Iranian patients. Guidelines for appropriate use of antibiotics in developing countries require updating