Prevalence and antibiotic resistance of Escherichia coli O157:H7 in raw sheep milk in different regions of Khuzestan province in 2022
Subject Areas : Food Hygiene
Shokoufe Maleknezhad Ahrami
1
,
Ali Fazlara
2
,
Mehdi Zarei
3
1 - M.Sc. Graduate of Food Hygiene and Quality Control, Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
2 - Professor, Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
3 - Professor, Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Keywords: Escherichia coli O157:H7, Polymerase chain reaction, Antibiotic resistance, Raw sheep milk,
Abstract :
Escherichia coli O157:H7 is a significant foodborne pathogen responsible for gastroenteritis, with low infectious doses, and as an enterohemorrhagic strain, it can cause hemorrhagic dysentery. Raw milk, including sheep milk, is a known source of contamination with this pathogen, posing a potential risk for severe human infections. This study aimed to evaluate the potential of raw sheep milk as a vector for the transmission of E. coli O157:H7 and its associated health risks. A total of 114 raw sheep milk samples were collected in Khuzestan province over four months (April–July 2022). After biochemical assays, the isolates were identified by using specific primers targeting the O157 (rfb), H7 (flic), stx1, and stx2 genes for identification. The study confirmed the isolation of E. coli O157:H7 from 3 samples (2.63%). Antibiogram was then conducted on the confirmed isolates. The results revealed that all isolates were 100% susceptible to imipenem, ceftazidime, and ceftazidime-clavulanic acid. Sixty-six percent of the isolates were susceptible to ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole, while 33% showed susceptibility to nalidixic acid and nitrofurantoin. None of the isolates were susceptible to ampicillin or clindamycin, indicating significant resistance to these antibiotics. The contamination of raw sheep milk with E. coli O157:H7 in the Khuzestan region suggests that consuming raw sheep milk may be associated with an increased risk of infections caused by this pathogen.
