Molecular detection of Vibrio cholerae and Vibrio parahaemolyticus from healthy broilers and backyard chickens for the first time in Bangladesh-A preliminary study

Abstract

Many of the Vibrio spp. are major public health concerns globally. Vibrio cholerae and Vibrio parahaemolyticus are the etiology of pandemic and epidemic diarrhea and foodborne illness, respectively. Poultry has the potential to harbor pathogenic Vibrio spp., which can have a detrimental impact on public health if they are transmitted to humans. We, therefore, screened 54 cloacal swab samples from healthy chickens (broiler=27, backyard= 27) to detect V. cholerae and V. parahaemolyticus. Vibrio spp. were isolated and identified by culturing, biochemical tests, PCR, and antibiogram profiles were determined by disk diffusion method. By PCR, 29.63% (16/54; 95% CI: 19.14-42.83%) samples were positive for Vibrio spp., where backyard chickens had a significantly higher (p< 0.05) occurrence (44.44%; 27.59-62.69%) than broilers (14.82%; 95% CI: 5.92-32.48%). V. parahaemolyticus was found in 22.22% (6/27; 95% CI: 10.61-40.76%) of backyard chicken samples, which was significantly dominant (p< 0.05) than in broilers (0/27, 0%, 95% CI: 0.00-12.46%). In addition, V. cholerae was positive in 7.41% (2/27; 95% CI: 1.32-23.37%) of broiler, and 14.82% (4/27; 95% CI: 5.92-32.48%) of backyard chicken samples. The toxR gene was found in all V. cholerae isolates, suggesting the presence of other virulence genes, whereas no isolates of V. parahaemolyticus contained the tdh gene. Isolated Vibrio spp. had high to moderate resistance to tetracycline, azithromycin, erythromycin, and streptomycin. The occurrence of antibiotic-resistant V. cholerae and V. parahaemolyticus in broiler and backyard chickens is of public health concern because of the possibility of food chain contamination.