[关键词]
[摘要]
本研究将初始菌株副溶血弧菌F7经过环丙沙星连续体外诱导得到的实验室诱导株H128、H256、H512作为研究对象,研究了菌株F7、H128、H256、H512的药敏性、泳动能力、生长曲线、生物膜形成能力等生物学特性,分析了多药外排泵基因vmeB、vmeD、vpoC、vmrA的相对表达量。结果表明,诱导菌株不仅对诱导抗生素环丙沙星的耐药性明显提高,还对多种非诱导抗生素呈现交叉耐药。与初始菌株F7相比,诱导菌株H128、H256、H512泳动能力下降,泳动圈直径分别为4.83 mm、4.57 mm、5.13 mm,生物膜形成能力增强,吸光值分别为4.35 nm、4.35 nm、4.29 nm。诱导菌株H128、H256、H512均检测到外排泵基因vmeD的相对表达量均高于F7,分别上调了1.20、3.55、2.02倍,仅在H256中检测到vmeB、vpoC、vmrA基因表达量上调,分别上调了1.47、2.90、1.71倍,说明RND型外排系统VmeCD-VpoC是与副溶血弧菌对环丙沙星的耐药性以及交叉耐药相关的主要外排系统。本研究为耐药性副溶血弧菌的风险评估提供参考依据,为解决副溶血弧菌耐药问题提供新的思路。
[Key word]
[Abstract]
In this study, the laboratory-induced strains H128, H256 and H512 obtained from the initial strains of Vibrio parahaemolyticus F7 after continuous in vitro induction with ciprofloxacin were used as the research objects. The biological characteristics of F7, H128, H256, H512 strains, including drug sensitivity, mobility, growth curve and biofilm-forming ability were examined. The relative expressions levels of multidrug efflux efflux pump genes, vmeB, vmeD, vpoC and vmrA were analyzed. The results showed that all the laboratory-induced strains had an increased drug resistance to ciprofloxacin, with their cross-resistance to a variety of non-induced antibiotics also detected. Compared with the original strain F7, the mobility of all the laboratory-induced strains H128, H256 and H512 decreased, with the diameter of moving circle as 4.83 mm, 4.57 mm and 5.13 mm respectively. The biofilm-forming abilities of all laboratory-induced strains were enhanced, with the absorbance reaching 4.35 nm, 4.35 nm and 4.29 nm respectively. The expression level of the efflux pump gene vmeD for all laboratory-induced strains was higher than that of F7 (increase by 1.20, 3.55, and 2.02 times respectively), and the expression levels of the vmeB, vpoC and vmrA genes in H256were higher than that of F7 (increase by 1.47, 2.90, and 1.71 times respectively). These results indicated that the RND efflux system VmeCD-VpoC played important role in the resistance to ciprofloxacin and the main cross-resistance-related efflux systems of Vibrio parahaemolyticus. This study provided a reference for the risk assessment of drug-resistant Vibrio parahaemolyticus, and a new idea for solving the problem of drug resistance of Vibrio parahaemolyticus.
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[基金项目]
“十三五”重点研发计划项目(2017YFC1600100)