Molecular Characterization of Diarrhoegenic Escherichia coli Isolated from Neonatal Goat-Kids

Faecal samples (n=300) from diarrhoeic neonatal goat-kids of different livestock sheds of ICAR-CIRG, Makhdoom, and field goat-kids of Mathura, UP were aseptically collected, and used for E. coli isolation. On the basis of cultural, morphological, biochemical and molecular characteristics, a total of 193 E. coli isolates were identified from 300 fecal samples. Out of 140 E. coli isolates, only 90 isolates could be serotyped at National Salmonella and Escherichia Centre, Central Research Institute, Kasauli, and the most common serogroups responsible for neonatal diarrhoea were found as O88 (n=11), O22 (n=10), O11 (n=8) and O83 (n=7). Congo red dye agar test was done to determine invasiveness of the isolates, and 77.20% (149/193)E. coli isolates showed Congo red binding activity. Identification of shiga toxin producing E. coli (STEC) was done by PCR amplification of its stx-1 gene, and 5.69% (11/193) isolates were identified as STEC. Pathotype specific primers were used to amplify bundle forming pilus (bfpA) gene of enteropathogenic E. coli (EPEC), and 35.23% (68/193) isolates were identified as EPEC. A multiplex PCR was performed to detect labile toxin producing enterotoxigenic E. coli (ETEC-lt), stable toxin producing enterotoxigenic E. coli (ETEC-st) and enteroinvasive E. coli (EIEC), and 24.35% (47/193), 2.59% (5/193) and 2.07% (4/193) isolates were determined as ETEC-st, ETEC-lt and EIEC, respectively. EPEC and ETEC-st were found as the most prevalent pathotypes associated with neonatal diarrhoea in goat-kids whereas; O88 and O22 were observed as the most common serogroups in causing diarrhoea in the neonatal goat-kids.