海洋渔业2025，Vol.47Issue(3)：384-393,10.
乳酸链球菌素Z与抑菌剂复配对大黄鱼内脏变形假单胞菌的体外抑制作用
An in vitro synergistic interaction of nisin Z and other antimicrobial agents against Pseudomonas plecoglossicida in Larimichthys crocea viscera
摘要
Abstract
Pseudomonas plecoglossicida can induce epidemic of visceral white spot disease in Larimichthys crocea,resulting in massive economic losses.However,long-term use of antibiotics to treat the disease can easily lead to residues in fish body and bacterial resistance.To explore the substitute of antibiotics used in the prevention and treatment of visceral white spot disease and promote the healthy development of aquaculture industry,nisin Z combined with antimicrobial agents(11 kinds of aquatic veterinary antibiotics and 5 kinds of food additives)was used to inhibit in vitro pathogen Pseudomonas plecoglossicida.First,the minimum inhibition concentration(MIC)of nisin Z and other antimicrobial agents were determined by 96-well micro-dilution method.Secondly,96-well micro-dilution method combined with chessboard method was used to determine the MIC and fractional inhibitory concentration(FIC)of nisin Z combined with antimicrobial agents.Finally,24 h bactericidal curve was drawn by plate counting method,and the effects of the combination of nisin Z and antimicrobial agents on Pseudomonas plecoglossicida were further determined by electron microscopy observation.The results showed that nisin Z alone had no inhibitory effect on Pseudomonas plecoglossicida,but its combination with aquatic veterinary antibiotic sulfonamide(SD)or food additive ethylenediaminetetraacetic acid disodium salt(EDTA-2Na),respectively,exhibited synergistic inhibitory effects.The minimum combination concentration of nisin Z was 3 125 mg·L-1,the MIC of SD decreased from 128 mg·L-1 to 32 mg·L-1,the FIC index was 0.25(FIC≤0.5).The MIC value of EDTA-2Na decreased from 400 mg·L-1 to 200 mg·L-1 with a FIC index of 0.5(FIC≤0.5),indicating that combination of antimicrobial agents enhanced the antimicrobial activity of nisin Z.The bactericidal curve and electron microscope observation showed that the combination of nisin Z and EDTA-2Na made the surface of Pseudomonas plecoglossicida rough,the membrane boundary blurred,the cells destroyed completely,and the growth and reproduction of Pseudomonas plecoglossicida were effectively inhibited within 24 h.Moreover,the combination of nisin Z and SD also caused serious damage to the morphology of Pseudomonas plecoglossicida,leaving cell structure seriously damaged,membrane dissolved and intracellular substances leaked.Nisin Z combined with sulfadiazine completely killed Pseudomonas plecoglossicida in 8 h.The results indicate that nisin Z combined with other antimicrobial agents can not only reduce the dosage of antibiotics,but also can replace antibiotics in the treatment of visceral white spot disease in L.crocea.关键词
大黄鱼/内脏白点病/变形假单胞菌/乳酸链球菌素Z/复配/抗生素替代物Key words
Larimichthys crocea/visceral white spot disease/Pseudomonas plecoglossicida/nisin Z/synergistic interaction/antibiotics alternatives分类
农业科技引用本文复制引用
徐春霞,张杰,林国文,陈小强,黄惠珍,张芳芳,迟海..乳酸链球菌素Z与抑菌剂复配对大黄鱼内脏变形假单胞菌的体外抑制作用[J].海洋渔业,2025,47(3):384-393,10.基金项目
福建省属公益类科研院所基本科研专项(2022R1036001) （2022R1036001）
