卡他莫拉菌对新型四环素药物Eravacylcine的敏感性分析

Drug susceptibility of new Tetracycline drug eravacylcine in Moraxella catarrhalis

目的探索卡他莫拉菌对新型四环素类抗菌药物Eravacylcine的敏感性,并对卡他莫拉菌四环素类抗菌药物耐药机制进行初步研究。方法收集深圳市南山区人民医院2012—2017年临床分离出的卡他莫拉菌菌株,所有的菌株均通过BD细菌自动鉴定仪鉴定,同时采用质谱仪鉴定细菌种属。采用琼脂平板稀释法检测多西环素、米诺环素、Eracycline的药物MIC值(最小抑菌浓度)。提取卡他莫拉菌菌株基因组DNA,同时采用PCR方法检测了四环素耐药相关基因tetB、tetM、tetW、tetQ、tetO和tetT。结果本研究共收集了207株卡他莫拉菌,在痰液和咽拭子中检出率最高,各占77.8%、20.8%;科室分布以儿科为主,占78.7%,其次为呼吸科,占8.9%。207株卡他莫拉菌对四环素类抗菌药物表现出较高的敏感性,以EUCAST判定标准,米诺环素敏感率为98%,多西环素敏感率为97%,新型四环素类抗菌药物Eravacycline的MIC值基本在0.5 mg/L以下。207株细菌中共检测出tetB阳性菌株136株。结论卡他莫拉菌对四环素类抗菌药物尤其是新型四环素类抗菌药物Eravacycline具有较好的敏感性,但关于卡他莫拉菌四环素类抗菌药物耐药机制仍需进一步研究。

Objective To study the susceptibility of new tetracycline drug eravacylcine and to conduct a preliminary study on the mechanism of tetracycline resistance in M.catarrhalis from our hospital.Methods We collected the M.catarrhalis clinical strains that identified by BD automatic analyzer in hospital from 2012 to 2017,all the strains were classified for specie by mass spectrometry.The MICs(Minimum inhibitory concentration)value of doxycycline,minocycline,eracycline were tested by agar plate dilution method.Then we extracted the genomic DNA of M.catarrhalis strain,and detected the drugresistant genes(tetB,tetM,tetW,tetQ,tetO,tetT)by PCR(polymerase chain reaction).Results A total of 207 strains of M.catarrhalis were collected in our study,with the highest detection rates in sputum and throat swabs,accounting for 77.8%and 20.8%,respectively;the detection rate of Department of Pediatrics and Department of Respiratory were 78.7%and 8.9%.According to the European Committee on Antimicrobial Susceptibility Testing(EUCAST)criteria of M.catarrhalis,the sensitivity rates of M.catarrhalis on minocycline and doxycycline were 98%and 97%.The MIC values of M.catarrhalis on new tetracycline antibiotic eravacycline were almost below 0.5 mg/L.And 136 strains of tetB positive strains were detected in our study.Conclusion The tetracycline antibiotics have good sensitivity on M.catarrhalis,especially the new tetracycline drug eravacycline.However,the mechanism of tetracycline resistance in Moraxella catarrhalis still needs further study.