Antibiotic Resistance and Genetic Profiles of Isolated from Farmed Pacific White Shrimp () in Ningde Regions.

To better understand the antibiotic resistance, virulence genes, and some related drug-resistance genes of in farmed pacific white shrimp (i) in Ningde regions, Fujian province, we collected and isolated a total of 102 strains of from farmed pacific white shrimp in three different areas of Ningde in 2022. The Kirby-Bauer disk method was used to detect resistance to 22 antibiotics, and resistant genes (such as quinolones (VC136, VC457, A), tetracyclines ( A, M, B), sulfonamides (I, II, III), aminoglycosides (A, B), phenicols (, A, R, cfr), β-lactams (B), and macrolides ()) were detected by using PCR. The findings in this study revealed that was most resistant to sulfamoxazole, rifampicin, and erythromycin, with resistance rates of 56.9%, 36.3%, and 33.3%, respectively. Flufenicol, chloramphenicol, and ofloxacin susceptibility rates were 97.1%, 94.1%, and 92.2%, respectively. In all, 46% of the bacteria tested positive for multi-drug resistance. The virulence gene test revealed that all bacteria lacked the and genes. Furthermore, 91.84% and 52.04% of the isolates were largely mediated by and II, respectively, with less than 5% resistance to aminoglycosides and macrolides. There was a clear mismatch between the antimicrobial resistance phenotypes and genotypes, indicating the complexities of resistance.