Molecular detection of multi-drug resistant Enterococcus spp. from poultry in Chattogram, Bangladesh

Abstract

Enterococcus spp. are commensal bacteria found in the gastrointestinal tracts of both humans and animals. This can turn highly infectious when their relationship with the host is disrupted, particularly under stressful conditions. The objective of this study was to detect and characterize multi-drug resistant (MDR) Enterococcus spp, E. faecalis, and E. faecium in poultry cloacal samples from Chattogram, Bangladesh. A total of 60 cloacal samples from poultry (broiler, Sonali, and Deshi) were collected from live bird market (LBM) and commercial farm to detect Enterococcus spp., E. faecalis, and E. faecium. Antibiotic resistance profiles of these bacteria were determined using the disk diffusion method. Of the 60 cloacal samples from poultry, 40 (66.7%, 95% CI: 53.3%-78.3%) tested positive for Enterococcus spp. Among all the samples, only 2 (3.3%; 95%CI: 0.4%-11.5) were identified as Enterococcus faecalis. However, no E. faecium were detected in this study. Antibiotic susceptibility testing revealed that all Enterococcus spp isolates (n=40) frequently exhibited phenotypic resistance to sulfamethoxazole-trimethoprim and ciprofloxacin (80%), vancomycin (62.5%), ampicillin (55%). Moderate to lower resistance of Enterococcus spp. isolates were detected against gentamicin (47.5%), tigecycline (42.5%) and nitrofurantoin (30%). Out of 38 Enterococcus spp. isolates, 30 isolates (78.9%; 95% CI: 62.7%-90.4%) exhibited a phenotypic multidrug-resistant (MDR) profile. The multiple antibiotic resistance (MAR) indices of Enterococcus spp. isolates ranged from 0.14 to 1. Bivariate analysis revealed a high significant positive correlation between resistance profiles of tigecycline and ampicillin, vancomycin and ampicillin, nitrofurantoin and ampicillin, gentamycin and ciprofloxacin, vancomycin and tigecycline, nitrofurantoin and tigecycline, nitrofurantoin and vancomycin. The presence of MDR Enterococcus in poultry is alarming, as it highlights a potential public health threat due to their possibility to enter into the food chain.