Detection and Zoonotic Implications of Shiga Toxin-Producing Escherichia coli in Black Bengal Goats in Bangladesh.

چکیده اصلی

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) is an important zoonotic pathogen and a global public health concern due to its association with foodborne disease. OBJECTIVES: This study aimed to determine the prevalence of STEC and general E. coli carriage in Black Bengal goats in Bangladesh and assess associated risk factors for zoonotic transmission. METHODS: A total of 300 goats (200 diarrheic and 100 healthy) were sampled from the Shahedul Alam Quadary Teaching Veterinary Hospital and its surrounding areas between July 2023 and June 2024. Recto-anal junction swabs were cultured on MacConkey agar, Eosin Methylene Blue agar, and cefixime-tellurite-supplemented Sorbitol MacConkey agar. Sorbitol non-fermenting colonies were screened for uniplex PCR for stx1, stx2, hlyA and multiplex PCR for eae, ehxA, saa, and subA genes using multiplex PCR. RESULTS: Overall, 4.3% of isolates were sorbitol non-fermenters. Molecular characterization revealed that one isolate (0.3%) from a diarrheic goat carried the stx2 and ehxA genes, while another isolate (0.3%) from a healthy goat was positive for saa and subA. No isolates carried stx1, hlyA, or eae. The isolation rate of E. coli (non-STEC) was significantly higher in diarrheic goats than in healthy ones (p = 0.001). Risk factor analysis revealed significant associations between general E. coli carriage and several factors, including frequent child-animal contact (OR = 2.45, p = 0.031), shared living spaces (OR = 2.36, p = 0.045), and farms near waterlogged areas (OR = 3.72, p = 0.008). Mixed livestock rearing and seasonal humidity also contributed to increased E. coli carriage. CONCLUSIONS: These findings, although representing a low overall prevalence, demonstrate the presence of diverse virulence profiles in Black Bengal goats, including markers associated with severe human disease in LEE-negative strains. The detection of saa and subA suggests that these goats may serve as a reservoir for atypical STEC strains with zoonotic potential, necessitating broader surveillance strategies.

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