Isolation of Shiga toxin-producing Escherichia coli from raw milk in Kermanshah, Iran.
OBJECTIVE
Infectious diarrhoeal diseases are great problem throughout the world and are responsible for considerable morbidity and mortality. Shiga toxin-producing Escherichia coli (STEC) is a major cause of gastroenteritis that may be complicated by hemorrhagic colitis (HC) or the hemolytic uremic syndrome (HUS), which is the main cause of acute renal failure in children. Food-borne outbreaks associated with Shiga toxin-producing Escherichia coli have been well documented worldwide. The aim of this study was to investigate the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains in raw milk samples.


METHODS
Raw milk samples collected from various cow farms in Kermanshah, Iran during June - September 2009 were investigated for STEC using PCR targeting stx1 and stx2 and then eaeA.


RESULTS
Of 206 samples, 36 (17.47%) were contaminated with STEC. STEC isolates harbored 56.41% and 43.59% stx 2 and stx 1 gene respectively. In antibiotic resistance test, all strains were sensitive to ceftazidime, cefepime, gentamicin, imipenem and ciprofloxacin. 23.08% of isolates were resistat to tetracycline, and 38.5% of them showed intermediate sensitvity to cephalothin.


CONCLUSIONS
The high presence of STEC in raw milk confirms the important role of raw milk as putative vehicle of infection to human. Moreover, this study suggests that the development of antibiotic resistant STEC must be a major concern in Iran and more studies are needed to identify the prevalence of STEC in other food samples.
Medical biology Research Center, University of Medical Sciences, Kermanshah, Iran.
Pantea
P
Mohammadi
Department of Microbiology, Faculty of Medicine, University of Medical Sciences, Kermanshah, Iran.
Ramin
R
Abiri
Department of Statistics and Epidemiology, Faculty of Health, University of Medical Sciences, Kermanshah, Iran.
Mansour
M
Rezaei
Department of Microbiology, Alzahra University, Tehran, Iran.
Siavosh
S
Salmanzadeh-Ahrabi
Antimicrobial resistance; Iran; STEC; raw milk