Unveiling multi-drug resistant (MDR) gram negative pathogenic bacteria from poultry chickens in the Noakhali region of Bangladesh

Abstract

Rapidly increasing antibiotic-resistant bacterial strains in Bangladesh’s food and farm animals stem from the excessive and inappropriate use of antibiotics. To assess the prevalence of multi drug resistant (MDR) gram-negative bacteria in poultry chicks, we sought to isolate and identify strains carrying antimicrobial resistance genes. Isolation and identification involved biochemical tests,16SrRNA sequencing, and PCR screening of species-specific genes. MDR patterns were evaluated using CLSI guidelines with seventeen antibiotics across twelve classes. Targeted gene sequences were amplified for detection of ESBL, carbapenem, tetracycline, sulfonamide, and colistin resistance genes. Common isolates, such asEscherichia coli,Klebsiella pneumoniae, Proteus penneri,andEnterobacter hormaechei, exhibited average Multiple Antimicrobial Resistance (MAR) indices of 0.66, 0.76, 0.8, 0.84, and 0.81, 0.76, 0.84, 0.41 for broiler and layer chicken, respectively.Providencia stuartiiandSalmonella enterica, exclusive to broiler samples, had MAR indices of 0.82 and 0.84, respectively. Additional isolatesMorganella morganii,Aeromonasspp., andWohlfahrtiimonas chitiniclasticawere found in layers (Average MAR indices: 0.73, 0.71, and 0.91). Notably,M. morganii, E. hormaechei and W. chitiniclasticawere identified for the first time in Bangladeshi poultry chicken, although their evolution is yet to understand. In this study, Pan-drug resistance was observed in oneP. stuartii(broiler) and oneAeromonasspp. (layer) with a MAR index 1, while all isolates exhibited MAR indices >0.2, indicating MDR. Antimicrobial resistance (AMR) gene screening identifiedblaTEM,blaSHV,tetA, andsul1in a majority of the MDR strains. Interestingly,E. coli(lactose positive and negative) andE. hormaecheiwere exclusively found to possess thetetBgene. In addition,E. coli(lactose negative),Klebsiella pneumoniae,Enterobacter hormaechei,M. morganii, andP. stuartiiwere observed to carry the colistin-resistantmcr1gene, whereassul2was detected inE. coli(lactose positive and negative),E. hormaechei,P. stuartii, andP. penneri. These findings emphasize the health risk of our consumers of both broiler and layer chickens as they have turned to a potent reservoir of various AMR gene carrying MDR and Pan-drug resistant bacteria.