耐碳青霉烯类鲍曼不动杆菌的主要耐药机制研究

Study on the main drug resistance mechanism of carbapenems-resistant acinetobacter baumannii

目的研究感染性鲍曼不动杆菌碳青霉烯酶基因分布与耐药相关性。方法回顾性分析鲍曼不动杆菌在2010年1月~2015年12月期间的药物敏感性变迁,留取200株耐碳青霉烯类鲍曼不动杆菌,检测青霉烯酶与外排泵表型,并统计比较200株耐碳青霉烯类鲍曼不动杆菌与200株碳青霉烯类敏感组的差异。结果 2010年1月~2015年12月期间鲍曼不动杆菌耐药严峻,碳青霉烯类鲍曼不动杆菌检出率在35.8%~78.9%。其中在200株耐碳青霉烯类鲍曼不动杆菌菌株中,检出携带OXA-51基因108株,携带OXA-23基因46株,同时携带OXA-51和OXA-23 26株,其余碳青霉烯酶基因均未检测到;外排泵表型在碳青霉烯类耐药菌阳性株为175株,碳青霉烯类敏感株阳性株为115株,χ~2检验碳青霉烯类敏感组的与耐药组比较,差异有统计学意义(χ~2=45.141,P=0.000)。结论近六年鲍曼不动杆菌耐药机制以OXA-51,OXA-23起主要作用,外排泵机制可能在碳青霉烯类耐药机制起作用。

Objective To study the relationship between the distribution of carbapenemase gene and the drug resistance of infectious acinetobacter baumannii. Methods The drug sensitivity changes of acinetobacter baumannii from January 2010 to December 2015 were retrospectively analyzed. 200 strains of carbapenems-resistant acinetobacter baumannii were collected. Phenotype of carbapenemase and efflux pump was detected, and the differences of 200 carbapenemsresistant acinetobacter baumannii and 200 carbapenems-sensitive strains were compared. Results During the period from January 2010 to December 2015, acinetobacter baumannii was highly drug resistant. The detection rate of carbapenems-resistant acinetobacter baumannii was 35.8%-78.9%. Among the 200 strains of carbapenems-resistant acinetobacter baumannii, 108 strains carrying OXA-51 gene were detected, 46 strains carrying OXA-23 gene were detected, while 26 strains carrying both OXA-51 and OXA-23 were detected. Other carbapenemase genes were not detected; there was 175 strains of positive carbapenems-resistant strains with the efflux pump phenotype, and 115 strains of positive carbapenems-sensitive strains. Chi-square test showed that there was statistically significant difference between carbapenems-sensitive group and carbapenems-resistant group（χ~2=45.141, P =0.000）. Conclusion The of drug resistance mechanism of acinetobacter baumannii in the past six years has played a major role in OXA-51 and OXA-23, and the efflux pump mechanism may play a role in the carbapenems drug resistance mechanism.