Molecular characterization and antibiotic susceptibility pattern of caprine Shiga toxin producing-Escherichia coli [STEC] isolates from India

The present study was conducted to detect the occurrence, serotype, genotype, phylogenetic relationship and antimicrobial resistance pattern of STEC from healthy goats of West Bengal, India. From the 125 faecal samples collected from healthy goats, 245 isolates were identified as Escherichia coli. The E. coli harbouring any gene for Shiga toxins [stx[1]/stx[2]] was detected in 36 [14.7%] of the 245 E. coli isolates. These STEC strains belonged to 22 different serogroups [O2, O5, O20, O21, O22, O25, O41, O44, O45, O60, O71, O76, O84, O85, O87, O91, O103, O112, O113, O120, O156, and O158] and three were untypeable. The stx[1] and stx[2] was detected in 26 [72.2%] and 21 [58.3%] of Shiga toxin producing-E. coli [STEC] isolates, respectively. Further, E. coli harbouring eaeA only [Enteropathogenic E. coli] and ehxA was detected in 22 [61.1%] and 28 [77.7%] isolates, respectively. Whereas the saa was present in 8 [22.2%] E. coli isolates. The subtyping of the 26 E. coli strains possessing stx[1] showed that 73.% [19/26] of these isolates were positive for stx[1C] subtype. Of the 21 isolates with the stx[2] gene, 42.8% [9/21] were positive for stx[2C], and 38.1% [8/21] were positive for stx[2d] gene. The phylogenetic analysis of STEC strains after RAPD reveals eight major clusters. However, no serogroup specific cluster was observed. Resistance was observed most frequently to erythromycin [80.5%], amikacin [52.7%], cephalothin [50%], kanamycin [41.6%], neomycin [36.1%] and gentamycin [36.1%] and less frequently to norfloxacin [2.7%], enrofloxacin [2.7%], and ciprofloxacin [2.7%]. Multidrug resistance was observed in eleven STEC isolates

Comparative possession of Shiga toxin, intimin, enterohaemolysin and major extended spectrum beta lactamase [ESBL] genes in Escherichia coli isolated from backyard and farmed poultry

The present work was conducted to compare the occurrence of Escherichia coli possessing virulence and ESBL genes in backyard and farmed poultry. Three hundred and sixty samples from the poultry kept in backyard system and 120 samples from the farmed birds were collected from West Bengal, India. Among the E. coli isolates of backyard poultry [O2, O10, O25, O55, O60, O106, UT], none of them possessed any of the Shiga toxin genes and eight E. coli isolates [8/272; 2.9%] harboured eaeA gene alone. Whereas among the E. coli isolated from the farmed poultry [O17, O20, O22, O102, O114, O119, rough, UT], four isolates [4/78, 5.1%] harboured stx[1]/stx[2] gene and 11 isolates [11/78, 14.1%] possessed eaeA gene. None of the E. coli isolates from the backyard poultry harboured any studied ESBL gene. Whereas 29.4% of E. coli isolates from the farmed poultry were found to possess the ESBL genes