Prevalence, antimicrobial susceptibility, and genotyping of Streptococcus agalactiae in Tilapia fish (Oreochromis niloticus) in Egypt

Objectives: (fibrinogen-binding protein FbsA), cfb (CAMP factor), and pbp1A/ponA (penicillin-binding protein 1A). Materials and Methods: gene. All S. agalactiae isolates were examined for the susceptibility to ten antimicrobial agents by the disc diffusion method. The virulence-associated genes (fbsA, cfb, and pbp1A/ponA) were characterized using multiplex-PCR. Results: = 21/300) samples. The isolates showed high resistance against ampicillin and erythromycin (20/21; 95%) for each. The most predominant antibiotypes through isolates were P, CN, SXT, CRO, TE, CTX, E, AMP, at 10.5% for each antibiotype. A total of 19 (90.5%) of S. agalactiae isolates showed multi-drug resistance (MDR), and those were recovered from market Tilapia fish. The virulence-associated genes (fbsA, cfb, and pbp1A/ponA) were identified in the S. agalactiae as 100%, 76%, and 52%, respectively. Conclusions: The MDR S. agalactiae detected in raw Tilapia fish pose a significant health hazard to consumers due to their zoonotic characteristics.