Antimicrobial resistance patterns and high prevalence of the mcr-1 gene in pathogenic Escherichia coli from diseased poultry

This study assessed the prevalence of the mcr-1 gene, which provides resistance to colistin (polymyxin E), in Escherichia coli strains isolated from sick poultry in the Peshawar, Mardan, and Charsadda regions of Pakistan. Samples were collected from 246 poultry birds showing symptoms such as diarrhoea, respiratory distress, and other systemic infections. After enrichment in Brain Heart Infusion broth, the samples were cultured on selective media containing colistin. The isolated colonies were further cultured on Eosin Methylene Blue agar and analyzed with PCR to detect the mcr-1 gene. The study found varying levels of mcr-1 gene prevalence across the three regions, with Charsadda exhibiting the highest frequency. Antibiogram analysis showed high resistance to ampicillin, colistin, and sulfamethoxazole, and low resistance to tetracycline, norfloxacin and cefixime. In conclusion, the findings suggest that colistin resistance exists in E. coli from poultry in these regions, with notable resistance trends to commonly used antibiotics such as ampicillin and sulfamethoxazole. Consequently, these antibiotics should be avoided for treating E. coli infections, and alternatives like ceftazidime and cefepime should be considered. This research emphasizes the importance of ongoing monitoring of antibiotic resistance in poultry pathogens and the need for more targeted treatment approaches.