Virulence Determinants and Multidrug Resistance of Isolated from Migratory Birds.

Migratory birds are carriers of multidrug resistant pathogenic . However, their roles in the dissemination of these resistant pathogens are still being neglected in Bangladesh. The present study was therefore carried out to detect multidrug resistant . In addition, these isolates were also screened for the presence of avian pathogenic (APEC)-associated virulence genes. A total of 66 fecal matter samples of migratory birds were screened. were isolated and identified by culturing and biochemical tests followed by polymerase chain reaction (PCR). APEC-associated virulence genes were detected by PCR. Disk diffusion assays were employed to investigate antibiogram profiles. Bivariate analysis was performed to assess correlations in resistance patterns between antimicrobials and to assess associations between virulence genes of . Among the 66 samples assessed by PCR, 55 (83.33%) were found positive for Of these 55 isolates, the APEC-associated virulence gene was detected in 67.27% of the isolates, which was significantly higher than in the cases of (29.09%) and (5.45%) genes. In addition, three isolates were found positive for all three virulence genes, while 23 and 12 isolates were positive for one and two virulence genes respectively. In the bivariate analysis, significant associations were detected between and virulence genes. Using the antibiogram, all isolates were found to be multidrug resistant (MDR). The isolates exhibited 100% resistance against ampicillin and erythromycin in addition to varying percentages of resistance against streptomycin, tetracycline, ciprofloxacin, and chloramphenicol. Highly positive correlations between tetracycline and ciprofloxacin, chloramphenicol and ciprofloxacin, chloramphenicol and tetracycline were observed by bivariate analysis. To the best of our knowledge, this is the first study that reports APEC-associated virulence genes of MDR from migratory birds in Bangladesh. Results indicate that migratory birds are reservoirs of MDR isolates carrying APEC-associated virulence genes, which can seriously contribute to the development of human and animal diseases.