Newly Emerging MDR in as the First Report Commonly Harbor K, and Virulence Genes and 1, 2, A, and A Resistance Genes.

BACKGROUND

is a common food poisoning pathogen in humans. This study aimed to investigate the prevalence, molecular typing, antibiogram profile, pathogenicity, dissemination of virulence and antibiotic resistance genes associated with natural infection among .

METHODS

Consequently, 120 (40 healthy and 80 diseased) were obtained from private fish farms in Port-said Governorate, Egypt. Afterward, samples were processed for clinical, post-mortem, and bacteriological examinations. The recovered isolates were tested for antimicrobial susceptibility, phenotypic assessment of virulence factors, pathogeneicity, and PCR-based detection of virulence and antibiotic resistance genes.

RESULTS

was isolated from 30 (25%) examined fish; the highest prevalence was noticed in the liver (50%). The phylogenetic and sequence analyses of the B gene revealed that the tested isolate displayed a high genetic similarity with other strains from different origins. All the recovered isolates (n =60, 100%) exhibited β-hemolytic and lecithinase activities, while 90% (54/60) of the tested isolates were biofilm producers. Using PCR, the tested isolates harbor K, , and virulence genes with prevalence rates of 91.6%, 86.6%, 83.4%, 50%, and 33.4%, respectively. Moreover, 40% (24/60) of the tested isolates were multidrug-resistant (MDR) to six antimicrobial classes and carried the 1, 2, A, and A genes. The experimentally infected fish with showed variable mortality in direct proportion to the inoculated doses.

CONCLUSION

As far as we know, this is the first report that emphasized the existence of MDR in that reflects a threat to the public health and the aquaculture sector. Newly emerging MDR in commonly carried virulence genes K, and , as well as resistance genes 1, 2, A, and A.