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

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 contaminatio

Antimicrobial Resistance, Biofilm Formation, and Virulence Determinants in <i>Enterococcus faecalis</i> Isolated from Cultured and Wild Fish

Fish has always been an integral part of Bengali cuisine and economy. Fish could also be a potential reservoir of pathogens. This study aimed to inquisite the distribution of virulence, biofilm formation, and antimicrobial resistance of Enterococcus faecalis isolated from wild and cultivated fish in Bangladesh. A total of 132 koi fish (Anabas scandens) and catfish (Heteropneustes fossilis) were collected from different markets in the Mymensingh district and analyzed to detect E. faecalis. E. faecalis was detected by conventional culture and polymerase chain reaction (PCR), followed by the detection of virulence genes by PCR. Antibiotic susceptibility was determined using the disk diffusion method, and biofilm-forming ability was investigated by crystal violet microtiter plate (CVMP) methods. A total of 47 wild and 40 cultured fish samples were confirmed positive for E. faecalis by PCR. The CVMP method revealed four per cent of isolates from cultured fish as strong biofilm formers, but no strong producers were found from the wild fish. In the PCR test, 45% of the isolates from the wild and cultivated fish samples were found to be positive for at least one biofilm-producing virulence gene, where agg, ace, gelE, pil, and fsrC genes were detected in 80, 95, 100, 93, and 100% of the isolates, respectively. Many of the isolates from both types of samples were multidrug resistant (MDR) (73% in local fish and 100% in cultured fish), with 100% resistance to erythromycin, linezolid, penicillin, and rifampicin in E. faecalis from cultured fish and 73.08, 69.23, 69.23, and 76.92%, respectively, in E. faecalis from wild fish. This study shows that E. faecalis from wild fish have a higher frequency of virulence genes and biofilm-forming genes than cultivated fish. However, compared to wild fish, cultured fish were found to carry E. faecalis that was more highly multidrug resistant. Present findings suggest that both wild and cultured fish could be potential sources for MDR E. faecalis, having potential public health implications

Molecular Detection and Multidrug Resistance of Shigella spp. Isolated from Wild Waterfowl and Migratory Birds in Bangladesh

Birds, especially wild waterfowl and migratory birds have the potential to carry antibiotic-resistant bacteria, but their role in the dissemination of these resistant pathogens is still neglected in Bangladesh. To the best of our knowledge, this study was carried out for the first time in Bangladesh to isolate and determine the occurrence of multidrug-resistant (MDR) Shigella spp. from fecal materials of wild waterfowl and migratory birds. A total of 80 fecal materials from wild waterfowl (n = 50) and migratory birds (n = 30) were screened to detect MDR Shigella isolates. Shigella spp. were isolated and identified by culturing, staining, and biochemical tests followed by polymerase chain reaction (PCR). A disk diffusion assay was employed to investigate antibiotic phenotypes, while the resistance genes were detected by PCR. Among the 80 samples, 15 (18.75%) were found positive for Shigella spp. by PCR, among which the occurrence rate of Shigella spp. was higher in migratory birds (20%, 6/30) than in wild waterfowl (18%, 9/50). By the disk diffusion test, 86.67% (13/15) of Shigella spp. isolates were found to be MDR in nature, including 93.33% of isolates resistant to imipenem. Moreover, frequent and moderate resistance was also observed against tetracycline (86.67%), azithromycin (80%), ampicillin (66.67%), ciprofloxacin and cotrimoxazole (40%), meropenem (26.67%), and streptomycin (13.33%). The bivariate analysis revealed a positive correlation between the resistance profiles of ciprofloxacin and cotrimoxazole, imipenem and tetracycline, tetracycline and ampicillin, and imipenem and azithromycin. Furthermore, the isolates had a multiple antibiotic resistance index of up to 0.47. Antibiotic resistance genes tetA and SHV were found in 69.23% and 50% of relevant antibiotic-resistant Shigella spp. isolates, respectively. The present study suggests that wild waterfowl and migratory birds are reservoirs of MDR Shigella spp., which may have detrimental impacts on One Health components. We suggest keeping these birds under an AMR monitoring program to avoid the possibility of AMR contamination of the environment and its consequences in all health settings

Phenotypic and Genotypic Detection of Biofilm-Forming Staphylococcus aureus from Different Food Sources in Bangladesh

Staphylococcus aureus is a major foodborne pathogen. The ability of S. aureus to produce biofilm is a significant virulence factor, triggering its persistence in hostile environments. In this study, we screened a total of 420 different food samples and human hand swabs to detect S. aureus and to determine their biofilm formation ability. Samples analyzed were meat, milk, eggs, fish, fast foods, and hand swabs. S. aureus were detected by culturing, staining, biochemical, and PCR. Biofilm formation ability was determined by Congo Red Agar (CRA) plate and Crystal Violet Microtiter Plate (CVMP) tests. The icaA, icaB, icaC, icaD, and bap genes involved in the synthesis of biofilm-forming intracellular adhesion compounds were detected by PCR. About 23.81% (100/420; 95% CI: 14.17&ndash;29.98%) of the samples harbored S. aureus, as revealed by detection of the nuc gene. The CRA plate test revealed 20% of S. aureus isolates as strong biofilm producers and 69% and 11% as intermediate and non-biofilm producers, respectively. By the CVMP staining method, 20%, 77%, and 3% of the isolates were found to be strong, intermediate, and non-biofilm producers. Furthermore, 21% of S. aureus isolates carried at least one biofilm-forming gene, where icaA, icaB, icaC, icaD, and bap genes were detected in 15%, 20%, 7%, 20%, and 10% of the S. aureus isolates, respectively. Bivariate analysis showed highly significant correlations (p &lt; 0.001) between any of the two adhesion genes of S. aureus isolates. To the best of our knowledge, this is the first study in Bangladesh describing the detection of biofilm-forming S. aureus from foods and hand swabs using molecular-based evidence. Our findings suggest that food samples should be deemed a potential reservoir of biofilm-forming S. aureus, which indicates a potential public health significance