碳青霉烯类抗生素耐药鲍曼不动杆菌碳青霉烯酶基因型研究

Carbapenemase genotyping of carbapenem-resistant Acinetobacter baumannii

目的了解临床分离的耐碳青霉烯类抗生素鲍曼不动杆菌的耐药情况以及碳青霉烯酶的基因型。方法收集21株耐碳青霉烯类抗生素鲍曼不动杆菌,采用纸片扩散法(K-B法)进行药敏试验,PCR方法检测碳青霉烯酶基因型。结果 21株碳青霉烯类抗生素耐药鲍曼不动杆菌对阿米卡星、左氧氟沙星和氨曲南的耐药率分别为35.7%、42.9%和78.6%,对其余抗菌药物耐药率均高达92.9%～100%。21株中检出OXA-23基因阳性17株(80.9%),OXA-51基因阳性15株(71.4%),OXA-58基因阳性2株(9.5%)。12株(57.1%)含OXA-23+OXA-51基因,1株(4.8%)含OXA-23+OXA-51+OXA-58基因。上述菌株中均未检出OXA-24、IMP和VIM耐药基因。结论碳青霉烯类抗生素耐药鲍曼不动杆菌多重耐药情况严重,碳青霉烯酶基因型OXA-23和OXA-51携带率高,且以OXA-23+OXA-512种基因型同时存在为主。

Objective To investigate antibiotic resistant profile and carbapenemase genotyping in clinical isolates of carbapenemresistant A. baumannii. Methods A total of 21 strains of earbapenem-resistant A. baumannii were collected. Antibiotic resistance was tested by Kirby-Bauer disk method. Carbapenemase genotyping was analyzed by PCR. Results The resistant rates of the 21 strains to amikacin, levofloxacin and aztreonam were 35.7%, 42.9% and 78.6%, respectively. About 92.9%-100% of these strains were resistant to the other antimicrobial drugs tested. The prevalence of OXA-23, OXA-51 and OXA-58 were 80.9 %, 71. 4 %and 9.5 %, respectively. Both OXA-23 and OXA-51 were identified in 57.1 % of the strains, while OXA-24, IMP or VIM gene was not identified. Conclusions The resistance of carbapenem-resistant A. baurnannii is a serious issue. The prevalence of OXA-23 and OXA-51 type carbapenemase genes is high, and mainly in the form of OXA-23 ＋ OXA-51 coexistence.