Isolation, identification, toxin profile and antibiogram of Escherichia coli isolated from broilers and layers in Mymensingh district of Bangladesh

The study was conducted to isolate and identify E. coli from apparently healthy broilers and layers from different poultry farms adjacent to the Bangladesh Agricultural University, Mymensingh, Bangladesh, during the period of January to May 2006 and characterize their ability to produce enterotoxin and also the antibiogram of the isolates. A total of 110 fecal samples were collected from broiler (n=55) and layer (n=55) chickens. E. coli were isolated and identified by cultural, biochemical, motility test and the heat-stable toxins were determined by Infant Mouse Assay (IMA). In case of broilers, 35 (63.6%) samples were found positive while 31 (56.4%) from layers. The overall prevalence of E. coli was 60%. Among the isolates of E. coli, 22.86% isolates from broiler and 38.71% isolates from layer were found positive for their ability to produce enterotoxin based on mice inoculation test. The antibiotic sensitivity pattern showed that the isolates were highly sensitive to chloramphenicol, ciprofloxacin, kenamycin and cephalexin and an increasing trend of resistance was recorded in both broiler and layer isolates. It may be concluded from the results of this study that the high resistance of E. coli to antibiotics constitutes a threat to poultry industry in Bangladesh.