常见奈瑟菌(种)和卡他莫拉菌的生化鉴定及耐药性研究

Biochemical identification and drug resistance of Neisseria catarrhalis and Moraxella catarrhalis

目的建立一套奈瑟菌(种)NC和卡他莫拉菌MC生化鉴定方法,了解NC和MC的耐药状况。方法对可疑菌株进行氧化酶试验、DNA酶试验、分解产酸试验,三汀精水解试验、β内酰胺酶试验,根据实验结果进行区分;采用琼脂平皿二倍稀释法测定最低抑菌浓度(MIC)。结果127株卡他莫拉菌中β内酰胺酶阳性率为94%,84株奈瑟菌中β内酰胺酶阳性率2.3%。卡他莫拉菌DNA酶试验、三汀精水解试验阳性率为100%。84株奈瑟菌中有2株对PIPC/SBT、PIPC/TAZ及CFP/SBT敏感,127株卡他莫拉菌中有120株对PIPC/SBT、PIPC/TAZ及CFP/SBT敏感。结论通过氧化酶试验、DNA酶试验、分解产酸试验、三汀精水解试验、β内酰胺酶试验,可将NC和MC一一区分开来;PIPC/SBT、PIPC/TAZ及CFP/SBT对β内酰胺酶阳性的NC和MC有较好的抗菌活性。

Objective To develop a novel method for identification ofNeisseria catarrhalis （NC） and Moraxella catarrhalis （MC） and to determine their drug resistances.Methods The bacterial isolates were identified by oxidase test, DNase test, tributyrin hydrolysis test, and β - lactamase test. β - lactamase was determined by nitrocefin strip test. The minimum inhibitory concentrations of four antimicrobial agents were per - fonnod by an agar dilution technique with diagnostic sensitivity test agar. Results β - iactamase positive rates were 2.3 % for Neisseria catarrhalis , and 94% for Moraxella catarrhalis . Two of 84 strains of Neisseria catarrhalis and 120 of 127 strains of Moraxella catarrhalis were susceptible to piperacillin （PIPC）/sulbactam （SBT）, PIPC/Tazobaetam （TAZ）, and cefoperazone （CFP）/SBT. Conclusions This method is rapid, accurate and simple for identifying and differentiating NC and MC. PIPC/SBT, PIPC/TAZ, and CFP/SBT showed high antimicrobial activity against β - lactamase positive NC and MC.