Unveiling resistance patterns, kmt1 sequence analyses, virulence traits, and antibiotic resistance genes of multidrug-resistant Pasteurella multocida retrieved from poultry and rabbits.

Pasteurella multocida is incriminated in fowl cholera in poultry and snuffles in rabbits, causing significant economic losses in the poultry industry worldwide. This study investigated the prevalence, kmt1 gene sequencing, antibiogram, pathogenicity, and PCR detection of the virulence and resistance genes of P. multocida recovered from chickens, ducks, and rabbits. Approximately 150 samples were collected from diseased chickens, ducks, and rabbits (50 for each) from commercial farms in Ismailia government, Egypt. The collected samples were bacteriologically examined, and the recovered isolates were subsequently subjected to kmt1 gene sequencing, antibiogram, pathogenicity test, and PCR-based detection of virulence and antibiotic resistance genes. The overall prevalence of P. multocida was 20% (30/150). The highest prevalence was recorded in rabbits (24%; 12/50), followed by ducks (20%; 10/50) and chickens (16%; 8/50). The lung was the most predominant infected organ. Moreover, the kmt1 phylogenetic analysis emphasized that the tested P. multocida strains presented remarkable genetic identity with other P. multocida strains from the USA, Denmark, China, India, and Iran. Chloramphenicol and ciprofloxacin exhibited promising results in treating P. multocida. Moreover, the prevalence of oma87, ptfA, luxS, tadG, and nanB virulence genes was 100%, 86.7%, 76.6%, 73.3%, and 56.7% respectively. Herein, 13.3% of the tested strains were multidrug-resistant (MDR) to 5 antibiotic classes and carried bla(ROB-1) and tetH genes. Besides, 10% of the tested P. multocida strains were extensively drug resistant (XDR) to 7 antibiotic classes and harbored the bla(ROB-1), tetH, and ermX genes. Moreover, 10% of the recovered P. multocida strains were MDR to 5 antibiotic classes and had tetH and ermX genes. Pathogenicity test revealed that the mortality rate was 20% at 1 day post-infection, reaching its highest point (100%) at 2 days post-infection. Briefly, this study highlights the occurrence of MDR and XDR P. multocida in domestic birds and rabbits, revealing a public health threat. The oma87, ptfA, luxS, and tadG virulence genes and the bla(ROB-1), tetH, and ermX antibiotic resistance genes are usually associated with emerging MDR P. multocida strains.