Prevalence, molecular typing, and antimicrobial resistance of bacterial pathogens isolated from ducks

Aim: This study aimed to investigate the prevalence of different bacterial species affecting ducks as well as demonstrating the antimicrobial susceptibility and molecular typing of the isolated strains. Materials and Methods: A total of 500 samples were randomly collected from different duck farms at Ismailia Governorate, Egypt. The collected samples were subjected to the bacteriological examination. Polymerase chain reaction (PCR) was applied for amplification of Kmt1 gene of Pasteurella multocida and X region of protein-A (spA) gene of the isolated Staphylococcus aureus strains to ensure their virulence. The antibiotic sensitivity test was carried out. Results: The most common pathogens isolated from apparently healthy and diseased ducks were P. multocida (10.4% and 25.2%), Escherichia coli (3.6% and 22.8%), Staphylococcus epidermidis (10% and 8.8%), Pseudomonas aeruginosa (2% and 10%), and Proteus vulgaris (0.8% and 10%), respectively. In addition, S. aureus and Salmonella spp. were isolated only from the diseased ducks with prevalence (12.2%) and (2.8%), respectively. Serotyping of the isolated E. coli strains revealed that 25 E. coli strains were belonged to five different serovars O1, O18, O111, O78, and O26, whereas three strains were untypable. Salmonella serotyping showed that all the isolated strains were Salmonella Typhimurium. PCR revealed that four tested P. multocida strains were positive for Kmt1 gene with specific amplicon size 460 bp, while three strains were negative. In addition, all the tested S. aureus strains were positive for spA gene with specific amplicon size 226 bp. The antibiotic sensitivity test revealed that most of the isolated strains were sensitive to enrofloxacin, norfloxacin, and ciprofloxacin. Conclusion: P. multocida is the most predominant microorganism isolated from apparently healthy and diseased ducks followed by E. coli and Staphylococci. The combination of both phenotypic and genotypic characterization is more reliable an epidemiological tool for identification of bacterial pathogens affecting ducks.