Molecular detection and antibiotyping of multi-drug resistant Enterococcus faecium from healthy broiler chickens in Bangladesh.

BACKGROUND: Enterococcus faecium is a ubiquitously distributed member of the intestinal microbiota of both humans and animals. Antibiotic resistant E. faecium are a major public health concern. OBJECTIVES: This study aimed to detect multi-drug resistant (MDR) E. faecium and their antibiotic resistance genes from broiler chickens in Bangladesh. METHODS: A total of 100 faecal samples of healthy broilers were screened by conventional methods and polymerase chain reaction (PCR) to detect E. faecium and their resistance genes. Disk diffusion test was employed to determine antibiotic profiles. RESULTS: By PCR, among 100 samples, 45% [95% confidence interval (CI): 35.62%-54.76%] were positive for E. faecium. Based on antibiogram, all the E. faecium isolates were found resistant to ampicillin, and frequently (93.33%-55.56%) resistant to ceftriaxone, cefotaxime, streptomycin, erythromycin, and imipenem; moderate to lower (26.67%-4.44%) resistance to tetracycline, ciprofloxacin, norfloxacin, chloramphenicol, gentamicin, and vancomycin. Interestingly, 80% (95% CI: 66.18%-89.10%) E. faecium isolates were MDR in nature. In addition, the indices of multiple antibiotic resistance (MAR) ranged from 0.08 to 0.83. By bivariate analysis, high positive significant correlations were observed between resistance profiles of erythromycin and imipenem, ciprofloxacin and norfloxacin, erythromycin and streptomycin, ceftriaxone and cefotaxime, tetracycline and chloramphenicol, and streptomycin and imipenem. Furthermore, the prevalence of resistance genes of E. faecium was 58.33% (tetA), 33.33% (tetB), 35.56% (blaTEM ), 60% (CITM), 13.33% (aadA1), and 12% (SHV). CONCLUSIONS: To the best of our knowledge, this is the first study in Bangladesh to detect MDR and MAR E. faecium and their associated resistance genes. The detection of MDR and MAR E. faecium and their corresponding resistance genes from healthy broilers is of public health concern because of their potential to enter into the food chain.

Migratory birds travelling to Bangladesh are potential carriers of multi-drug resistant Enterococcus spp., Salmonella spp., and Vibrio spp.

Antimicrobial resistance (AMR) is a major health crisis globally. Migratory birds could be a potential source for antibiotic resistant (ABR) bacteria. Not much is known about their role in the transmission of ABR in Bangladesh. In this study, a total of 66 freshly dropped fecal materials of migratory birds were analyzed. Bacterial isolation and identification were based on cultural properties, biochemical tests, and polymerase chain reaction (PCR). The disk diffusion method was employed to evaluate antibiogram profiles. By PCR, out of 66 samples, the detection rate of Enterococcus spp. (60.61%; 95% confidence interval: 48.55-71.50%) was found significantly higher than Salmonella spp. (21.21%; 95% CI: 13.08-32.51%) and Vibrio spp. (39.40%; 95% CI: 28.50-51.45%). Enterococcus isolates were frequently found resistant (100-40%) to ampicillin, streptomycin, meropenem, erythromycin, and gentamicin; Salmonella isolates were frequently resistant (72-43%) to chloramphenicol, tetracycline, ampicillin, streptomycin, and erythromycin; and Vibrio spp. isolates were frequently resistant (77-31%) to vancomycin, ampicillin, erythromycin, tetracycline, and streptomycin. In addition, 60% (95% CI: 44.60-73.65%) Enterococcus spp., 85.71% (95% CI: 60.06-97.46%) Salmonella spp., and 76.92% (95% CI: 57.95-88.97%) Vibrio spp. isolates were multi-drug resistant (MDR) in nature. Three isolates (one from each bacterium) were found resistant against six classes of antibiotics. The bivariate analysis revealed strong associations (both positive and negative) between several antibiotic pairs which were resistant to isolated organisms. To the best of our knowledge, this is the first study in detecting MDR Enterococcus spp., Salmonella spp., and Vibrio spp. from migratory birds travelling to Bangladesh. Frequent detection of MDR bacteria from migratory birds travelling to Bangladesh suggests that these birds have the potential to carry and spread ABR bacteria and could implicate potential risks to public health. We recommend that these birds should be kept under an AMR surveillance program to minimize the potential risk of contamination of the environment with ABR as well as to reduce their hazardous impacts on health.

Molecular Detection of Avian Pathogenic Escherichia coli (APEC) for the First Time in Layer Farms in Bangladesh and Their Antibiotic Resistance Patterns.

Avian pathogenic Escherichia coli (APEC) causes significant economic losses in poultry industries. Here, we determined for the first time in Bangladesh, the prevalence of APEC-associated virulence genes in E. coli isolated from layer farms and their antibiotic resistance patterns. A total of 99 samples comprising internal organs, feces, and air were collected from 32 layer farms. Isolation was performed by culturing samples on eosin-methylene blue agar plates, while the molecular detection of APEC was performed by PCR, and antibiograms were performed by disk diffusion. Among the samples, 36 were positive for the APEC-associated virulence genes fimC, iucD, and papC. Out of 36 isolates, 7, 18, and 11 were positive, respectively, for three virulence genes (papC, fimC, and iucD), two virulence genes, and a single virulence gene. Although the detection of virulence genes was significantly higher in the internal organs, the air and feces were also positive. The antibiograms revealed that all the isolates (100%) were resistant to ampicillin and tetracycline; 97.2%, to chloramphenicol and erythromycin; 55.5%, to enrofloxacin; 50.0%, to norfloxacin and ciprofloxacin; 19.4%, to streptomycin; 11.1%, to colistin; and 8.33%, to gentamicin. Interestingly, all the isolates were multidrug-resistant (MDR). Spearman's rank correlation coefficient analysis revealed the strongest significant correlation between norfloxacin and ciprofloxacin resistance. This is the first study in Bangladesh describing the molecular detection of APEC in layer farms. Isolated APEC can now be used for detailed genetic characterization and assessing the impact on public health.