High-Resolution Taxonomy of Fish Streptococcosis: Genomic Typing, Virulence, Antimicrobial Resistance and Control Strategies (A Systematic Review)

HistoryStreptococcosis is a major problem affecting the aquaculture sector, causing significant economic losses and posing a potential zoonotic risk to humans.This review aims to integrate the latest advances in genomic approaches, including whole-genome sequencing (WGS), multilocus sequence typing (MLST), and capsular serotyping, and examine their implications for epidemiology, virulence, and antimicrobial resistance (AMR).The available evidence indicates that Streptococcus agalactiae is the dominant pathogen with the hypervirulent ST283 clone associated with fish-to-human transmission.Comparative genomic studies highlight clonal diversity, host-switching events, and mobile genetic elements that contribute to AMR and virulence determinants.In addition, recent studies emphasize the role of improved diagnostic frameworks, relevant vaccine antigens, and environmental factors such as elevated temperature and high stocking density in exacerbating disease outbreaks.This review provides comprehensive insights into the importance of integrating genomic surveillance, standardized diagnostics, and adaptive vaccine strategies within a One Health framework.Furthermore, key knowledge gaps are identified, including the need for standardized environmental metadata, evaluation of vaccine cross-protection, and continuous genomic monitoring along the aquaculture production chain.