Prevalence of Escherichia coli H7 in Diarrhoeic Cattle from Jaipur Region, Rajasthan, India
Warsha Chaudhary *
Department of Veterinary Medicine, Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
Nirmal Kumar Jeph
Department of Veterinary Medicine, Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
Jyoti Bishnoi
Centre for Diagnosis, Surveillance and Response of Zoonotic Diseases (CDSRZ), Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
Sharda Kilaka
Department of Veterinary Parasitology, Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
Saksham Mandawat
Department of Veterinary Medicine, Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
Priyanka Meena
Department of Veterinary Medicine, Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
Dharm Singh Meena
Department of Veterinary Medicine, Post Graduate Institute of Veterinary Education and Research, Jaipur, India.
*Author to whom correspondence should be addressed.
Abstract
Shiga toxin-producing Escherichia coli (STEC), particularly E. coli O157:H7, is an important food-borne pathogen associated with gastrointestinal disease in humans and animals. This study investigated the occurrence of E. coli O157:H7 among diarrhoeic cattle in and around Jaipur, Rajasthan. A total of 100 diarrhoeic faecal samples were collected and processed for isolation and identification of E. coli using conventional bacteriological techniques. Of these samples, 82 isolates were identified as Escherichia coli based on characteristic growth on MacConkey agar and eosin methylene blue agar. All isolates were screened on Sorbitol MacConkey agar for presumptive detection of E. coli O157:H7. None of the isolates exhibited the sorbitol non-fermenting phenotype associated with O157:H7. Molecular confirmation was performed by PCR targeting the rfbO157 and fliCH7 genes. All 82 isolates were negative for rfbO157, whereas six isolates (7.31%) yielded the expected 625 bp amplicon specific to fliCH7. The findings indicate that E. coli O157 was not detected in the studied cattle population, although a small proportion of isolates possessed the H7 flagellar antigen gene. These results suggest that diarrhoeic cattle in the study area may harbour non-O157 E. coli strains carrying H7-associated genetic markers. The study supports the value of molecular surveillance for accurate characterisation of potentially pathogenic E. coli in cattle.
Keywords: Escherichia coli, Shiga toxin-producing E. coli, STEC, O157:H7, diarrhoeic cattle, Jaipur, Rajasthan, rfbO157, fliCH7, PCR, molecular surveillance