Fecha de publicación: -- Fuente: PubMed "swarm" Int J Food Microbiol. 2026 Oct 20;463:112129. doi: 10.1016/j.ijfoodmicro.2026.112129. Online ahead of print.ABSTRACTThis study characterizes genomic and phenotypic diversity among Vibrio parahaemolyticus isolates from shrimp aquaculture by integrating phenotypic profiling with pangenomic analysis. Growth was quantified under temperature, salinity, pH, nutrient, and ethanol stresses, together with motility, hemolysis, and antibiotic susceptibility. Core-genome SNP phylogeny identified genetic differentiation among representative isolates, with relationships not consistently associated with sampling location, sample type, or collection period. Comparative genomics showed variation in accessory-gene composition and isolate-specific distributions of blaCARB variants, whereas tet(34), tet(35), and several motility and chemotaxis genes were widely detected. Phenotypic assays showed isolate- and condition-dependent variation in stress responses, antimicrobial susceptibility, hemolysis, and motility. Neither tdh nor trh was detected by PCR or WGS-based screening. No clear hemolytic zones were observed on Columbia blood agar, whereas Ref, 1P1, 2P2, 3P2, 4 M2, and 4 N2 showed hemolytic activity on Wagatsuma agar, indicating a discrepancy between the Wagatsuma phenotype and molecular detection of these hemolysin genes. Isolate 1 M1 exhibited greater swimming without increased swarming activity. Accessory-genome principal coordinate analysis (PCoA) and phenotypic principal component analysis (PCA) showed partial correspondence between genomic and phenotypic relationships. The close accessory-genome relationship between 2P2 and 3P2 was not reflected phenotypically, whereas 2Q2 and 3P2 showed phenotypic similarity despite greater accessory-genome separation. These contrasting relationships indicate that accessory-gene presence and absence alone did not reproduce the measured multivariate phenotypic patterns. These findings indicate that genomic and phenotypic variation represent related but non-equivalent dimensions of strain-level diversity and support integrated genomic and phenotypic characterization for surveillance in aquaculture environments.PMID:42901059 | DOI:10.1016/j.ijfoodmicro.2026.112129