Antibiotic resistance in different ecological niches in Bangladesh

The rapid and wide scale environmental spread of multi-drug resistant bacteria is a seriousissue in recent years. Drug resistant bacteria have already occupied different ecologicalniches in many places, from wilderness to densely populated urban areas. To investigate theecological niches in Bangladesh samples were collected from wild migratory bird speciesOpen Bill Stork (Anastomus oscitans) and from the nearby water sources where these birdsvisited. A total of 76 E. coli isolates from the 170 OBS (Open Bill Stork) fecal samples and8 E. coli isolates from 3 river sources were isolated. Disk diffusion was used for checking thesusceptibility of the isolates against antibiotics that are common in human and veterinarymedicine in Bangladesh. It was found that 28.95%OBS and all water E. coli isolates wereresistant to at least one of the tested antibiotics. Common resistant phenotypes wereAmpicillin, Tetracycline, Aztreonam, Nalidixic Acid and Ciprofloxacin. Multi-drugresistance identified from 2.63%OBS and most of the water isolates. Very fewESBL(Extended Spectrum Beta-Lactamase) producing E. coli were found from OBS,whereas 50% of E. coli water isolates were ESBL producer, with all the ESBL producerspossessing the CTX-M-15 gene. The most concerning aspect of our findings was the presenceof human associated E. coli sequence types in water samples, for example ST156-complex156, ST10-complex10 and ST46. This study concludes the contaminationof environmental niches in Bangladesh by resistant bacteria