摘要
抗生素对反硝化过程有不同程度的影响,为快速了解喹诺酮类抗生素对水土环境中反硝化可能产生的影响,选取5种典型的喹诺酮类药物:左氧氟沙星(OFL)、盐酸洛美沙星(LOM)、环丙沙星(CIP)、恩诺沙星(ENR)、诺氟沙星(NOR)对反硝化细菌进行单一及联合药敏试验,探究抗生素单独使用和联用时对反硝化细菌的作用效果.本文首先通过高通量测序确定选用的菌种与水土环境中反硝化菌的优势菌群具有一致性,进而从定性和定量的角度出发,分别采用纸片扩散法和微量肉汤稀释法进行实验.采用微量肉汤稀释法得到了OFL、LOM、CIP、ENR、NOR的最小抑菌浓度(Minimum Inhibitory Concentration,MIC)分别为0.25、0.5、0.125、0.0625、1μg·mL^(-1),反硝化菌对5种抗生素的敏感性大小为:ENR>CIP>OFL>LOM>NOR.根据MIC计算抑菌浓度指数(Fractional Inhibitory Concentration Index,FIC)得到的联合抑菌效应显示:OFL与NOR表现为无关作用,与CIP、LOM、ENR均表现为拮抗作用;NOR与CIP、LOM表现为累加作用,与ENR表现为无关作用;CIP与LOM表现为无关作用,与ENR表现为拮抗作用;LOM与ENR表现为无关作用.从喹诺酮类抗生素的抑菌机理推测:联用时产生的不同作用效果可能是对反硝化菌作用点或作用环节差异引起的.水土环境中复合抗生素污染对反硝化作用的影响将因复合抗生素的种类差异变得更为复杂,简便有效的联合药敏试验得出的结果可为水土环境中复合抗生素污染对反硝化影响的快速判定提供一定的参考依据.
Antibiotics have different effects on the denitrification process.To obtain the effects of quinolones on denitrification in soil and water environment quickly,ofloxacin(OFL),lomefloxacin(LOM),ciprofloxacin(CIP),enrofloxacin(ENR)and norfloxacin(NOR)were selected to test the single and combined susceptibility for denitrifying bacteria.Firstly,high-throughput sequencing was used to determine the consistency between the selected strains and the dominant denitrifying bacteria in soil and water environment.Then,the diffusion method and the micro⁃broth dilution method were used for qualitative and quantitative analyses.The results of micro⁃broth dilution method showed that the minimum inhibitory concentrations(MICs)were 0.25,0.5,0.125,0.0625 and 1μg·mL^(-1) for OFL,LOM,CIP,ENR and NOR,respectively;and susceptibility of denitrifying bacteria by each antibiotic followed a sequence of ENR>CIP>OFL>LOM>NOR.The combined effects of antibiotics were revealed the fractional inhibitory concentration indexes(FICs)which were calculated from MICs.The combination of OFL with NOR showed an irrelevant effect,but with CIP,LOM or ENR showed an antagonism effect on denitrifying bacteria.The combination of NOR with CIP or LOM manifested an additive antibacterial effect,but with ENR produced an irrelevant effect.The combination of CIP with LOM showed an irrelevant effect,while with ENR produced an antagonism effect.The combination of LOM with ENR revealed an irrelevant effect.Based on the antibacterial mechanisms of quinolone antibiotics,it can be inferred that the different effects of quinolone combinations might be caused by the differences in action point or action link of denitrifying bacteria.The effects of combined antibiotic contamination on denitrification in the soil and water environment can be more complicated by the variety of coexisting antibiotics.The susceptibility testing is a straightforward and effective approach to judge the effects of combined antibiotic pollution on denitrification in water and soil.
作者
张玉叶
何江涛
张金刚
黄斯艺
ZHANG Yuye;HE Jiangtao;ZHANG Jingang;HUANG Siyi(Beijing Key Laboratory of Water Resources and Environmental Engineering,School of Water Resources and Environment,China University of Geosciences(Beijing),Beijing 100083)
出处
《环境科学学报》
CAS
CSCD
北大核心
2021年第2期670-679,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金重点项目(No.41731282)
国家水体污染控制与治理科技重大专项(No.2018ZX07109⁃004)。
