The barrier function of the outer membrane of Vibrio alginolyticus in resisting natural antibacterial agents

LIU Xuefei; CHENG Qiufeng; LU Hao; ZHANG Defu; LI Jianrong; SHEN Ronghu

doi:10.3969/j.issn.1673-0569.2025.01.003

Abstract：Vibrio alginolyticus is a co-pathogen of human and aquatic animals,with the number ranking first among the three dominant vibrios in the sea.The incorrect use of antibiotics leads to the emergence of multi-drug resistant bacteria,which poses a serious threat to aquaculture and food safety.In this paper,baicalin,polydatin and phloridzin were used as bacteriostatic agents to study the effects of outer membrane layer and peptidoglycan layer on the viability,drug sensitivity,heavy metal resistance,intracellular protein concentration and AKP activity of Vibrio alginolyticus,and to explore the specific site of the cell wall that play a role in resisting natural bacteriostatic agents.The results showed that the absence of outer membrane layer could change the MIC and MBC of Vibrio alginolyticus to three bacteriostatic agents,decrease the viability,and increase the drug sensitivity of the bacteria to ampicillin,penicillin,streptomycin and ofloxacin.When the concentration of Fe2+in the environment was greater than or equal to 2 500 mg/L,the absence of outer membrane layer affected the resistance of Vibrio alginolyticus to Fe2+.The measurement results of intracellular protein concentration and AKP content in culture medium showed that the absence of outer membrane affected the intracellular protein concentration and the AKP leakage of Vibrio alginolyticus.Conclusion:The outer membrane is the main structure of anti-drug action in the cell wall structure of Vibrio alginolyticus,and can be used as a new target for the study of anti-drug in Gram-negative bacteria.