Phylogenetic groups, extended-spectrum β-lactamases and metallo-β-lactamase in Escherichia coli isolated from fecal samples of patients with diarrhea in Iran.
OBJECTIVE
The aims of this study were to investigate the phenotypic and genotypic of extended-spectrum β-lactamase (ESBL) and metallo-β-lactamases (MBLs) and determine phylogenetic background E. coli isolates from fecal samples of patients with diarrhea in Kerman, southeast of Iran.


BACKGROUND
The emergence of ESBLs and MBLs-producing E. coli caused problems in antibiotic treatments. E. coli strains can be assigned to four main phylog-groups, including: A, B1, B2 and D.


METHODS
E. coli isolates (n=216) were obtained from fecal samples of patients with diarrhea between June and December 2013. ESBLs and MBLs were confirmed by disk-diffusion and broth micro-dilution methods. Using PCR, the ESBL-positive isolates were screened to determine the phylo-groups and the presence of bla CTX-M-15, bla OXA-1, bla PER-1, bla VIM and bla IMP genes.


RESULTS
ESBL-positive isolates (n= 56) were detected. Among ESBL-positive isolates, 51 isolates were positive for bla CTX-M15 and one isolate was positive for both bla CTX-M-15 and bla OXA-1 genes. None of the isolates were positive for bla PER-1, bla VIM and bla IMP genes. PCR assay for phylotyping of isolates indicated that the isolates were belonged to groups A (54.16%), B1 (11.11%), B2 (12.96%) and D (21.75%). The isolates possessed bla CTX-M-15 gene were belonged to A (35 isolates), B1 (5), B2 (3) and D (8) phylo-groups.


CONCLUSIONS
Our results indicate that bla CTX-M-15 gene is widespread among diarrheagenic E. coli isolates. ESBL-producing E. coli isolates were disseminated among a diversity of phylo-groups. Further studies are necessary to identify the ESBL genes in relation to phylogenetic groups.
Department of Microbiology, International Branch, Shahid Beheshti University of Medical science, Tehran, Iran.
Hesam
H
Alizade
Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran.
Fatemeh
F
Fallah
Molecular Microbiology Department, Faculty of Veterinary Medicine, Shahid Bahonar University, Kerman, Iran.
Reza
R
Ghanbarpour
Research Center for Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran.
Mohammad Reza
MR
Aflatoonian
Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran.
Hossein
H
Goudarzi
Department of Food Hygiene and Public Health, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Iran ; Research Center for Modeling in Health, Institute for Futures Studies in Health, Kerman University of Medic al Sciences, Iran.
Hamid
H
Sharifi
Diarrhea; Escherichia coli; Extended-spectrum β-lactamase; Metallo-β-lactamases