Isolation, virulence gene profiling with molecular cloning of ibeA gene and antibiogram of Escherichia coli from respiratory tract infections of broiler chicken in Kashmir, India

Abstract

he present study has determined prevalence, serological diversity, virulence gene profileand in vitro antibiogram of Escherichia coli (E. coli) isolates from respiratory tract of broiler chicken in Kashmir valley along with molecular cloning of ibeA gene, an important zoonotic among invasion-associated genes responsible for neonatal meningitis in humans. A total of 224 broilerchickens with a history of respiratory tract infections, in a flock size of 2692 birds from organised and unorganised poultry farms of Kashmir valley, were screened for E. coli isolation. The prevalence of E. coli in birds with respiratory tract infection was found to be 6.38 per cent. Serogrouping revealed that the E. coli isolates were typeable into 10 serogroups with prevalence rate of 8.8% for serogroup O2, along with few isolates rough or untypeable. The screening of E. coli isolates for virulence gene profile revealed the presence of iss in (89.53%), iucDin (85.46 %), tsh in (51.74 %), cva/cvi in (33.14 %), irp2in (55.23 %), papCin (33.72 %), vat in (31.39 %), astAin (38.95 %), fimCin (93.60 %) and ibeAin (1.16 %) isolates. The antibiogram screening of E. coli isolates revealed majority of isolates to be resistant to tetracycline (94.71%), ampicillin (92.67%) and cephalaxin (79.67%).However, most of the isolates were sensitive to amikacin (74.41%) followed by amoxacillin-sulbactam (68.60%) and gentamicin (67.44%). The study thus, suggests that the E. coli isolates from respiratory tract infection of poultry harbour differential virulence genes along with the genes of zoonotic interest and variable antimicrobial resistance, thus, opening the areas for devising dynamic, emergent and effective treatment line.