Physiology, metabolism, antibiotic resistance, and genetic diversity of Harveyi clade bacteria isolated from coastal mariculture system in China in the last two decades

Vibrio bacteria, particularly members of the Harveyi clade, are most important pathogens aquatic organisms that cause significant economic losses in world. It is difficult to provide specific data on taxa clade for biological research and prevention strategies. Therefore, we conducted an extensive phenotypic antibiotic resistance study, as well phylogenetic molecular typing 192 isolates collection from 2000 2020 with a typical interannual difference coastal area China. The had interspecific genetic diversity. Based multilocus sequence analysis (MLSA) housekeeping genes ( gyrB , pyrH recA atpA ), were rapidly accurately classified into 10 species. population these was composed 95 types (STs), which 92 STs newly identified, indicating high degree ST327 ranked first, accounting 11.5% total number (22 out 192), followed by ST215 6.25%, while 63 included single isolates. At metabolic level, physiological biochemical experiments revealed all positive oxidase negative melibiose. showed varied tolerance 11 antibiotics. No resistant neomycin. percentages sulfadimidine-resistant strains (61 sulfadiazine (44 sulfamonomethoxine sulfamethoxazole (33 thiamphenicol (34 ciprofloxacin (52 enrofloxacin (31 192) 31.77%, 22.92%, 17.19%, 17.71%, 27.08%, 16.15%, respectively. A proportion 61.8% presented multiple index (MARI) lower than 0.1, risk transmission low mariculture systems These results substantial support further studies identification diversity