骨科患者术后创面感染鲍曼不动杆菌对喹诺酮类抗菌药物的耐药性分析

目的了解医院骨科患者手术后创面感染的鲍曼不动杆菌的耐药情况,以指导医生合理用药,有效控制鲍曼不动杆菌耐药性的进一步发展,预防和减少医院感染的发生。方法从骨科患者手术后创面感染标本分离鲍曼不动杆菌28株,作gyrA基因测序,并进行BLASTn比对;通过测定最小抑菌浓度(minimum inhibitory concentration,MIC)进行药敏试验,测定鲍曼不动杆菌的耐药性;选取经纯培养的鲍曼不动杆菌菌落置入含蛋白酶K溶液的离心管内,分别进行水浴,再离心,留取上清液,以此为模板PCR扩增与喹诺酮类抗菌药物耐药性相关的gyrA、qepA、qnrS、qnrA、qnrB和aac(6)-Ib基因,使用Chromas分析软件进行测序。结果鲍曼不动杆菌对诺氟沙星、氧氟沙星、培氟沙星、依诺沙星、环丙沙星、司帕沙星、左氧氟沙星、加替沙星、莫西沙星的耐药率分别为:96.43%、96.43%、96.43%、89.29%、85.71%、85.71%、82.14%、78.57%和78.57%。PCR检测28株鲍曼不动杆菌gyrA基因100%阳性,即都发生了gyrA基因突变,而其他相关基因检测均阴性。基因测序看出,其83位发生突变,即由TCA转变为TTA。结论本组分离骨科患者手术创面感染的鲍曼不动杆菌对喹诺酮类抗菌药物的耐药情况严重,其中对诺氟沙星、氧氟沙星、培氟沙星等的耐药率均在90%以上。临床抗感染治疗应根据耐药结果进行用药,并控制喹诺酮类抗菌药物的使用。

Analysis of the resistance of Acinetobacter baumannii to quinolone antibacterials

Objective To ascertain the drug resistance of Acinetobacter baumannii infecting the postoperative wounds of Orthopedics patients to guide doctors in the rational use of drugs in order to effectively control the further development of A. baumannii drug resistance and reduce and prevent nosocomial infections. Methods Twenty-eight strains of A. baumannii were isolated from samples from postoperative wounds of Orthopedics patients. The GyrA gene was sequenced and compared using BLASTn. Susceptibility testing was performed hy determining the MIC to measure the drug resistance of A. baurnannii. After pure culturing of A. baurnannii, colonies were selected and placed into a centrifuge tube containing a solution of proteinase K. The tube was then placed in a water bath, centrifuged again, and the supernatant was collected to provide a template for PCR amplification. The gyrA, qepA, qnrS, qnrA, qnrB, and aac （6）-Ib genes that are related to drug resistance to quinolone antibacterials were amplified using PCR and sequenced using the analytical software Chromas. Results A. baumannii resistance to norfloxaein was 96.43 %, resistance to ofloxacin was 96.43 %, resistance to pefloxacin was 96.43%, resistance to enoxacin was 89.29%, resistance to ciprofloxacin was 85.71%, resistance to sparfloxacin was 85.71 %, resistance to levofloxacin was 82.14 %, resistance to gatifloxacin was 78.57 %, and resistance to moxifloxacin was 78.57 %. Twenty-eight strains of A. baumannii all tested positive for the gyrA gene ac cording to PCR testing, i.e. they all had a mutated gyrA gene. The strains tested negative for the other related genes. Gene sequencing revealed a mutation from TCA to TTA at codon 83. Conclusion A. baumannii infecting postoperative wounds of Orthopedics patients was highly resistant to quinolones. Its resistance to norfloxacin, ofloxacin, pefloxacin was above 90%. Clinical treatment of infections should be based on the results of drug susceptibility testing and the use of quinolones should be controlled.