新生儿重症监护病房多重耐药鲍曼不动杆菌β-内酰胺酶的基因型

β-lactamase genotyping of multi-drug resistant Acinetobacter baumannii in a neonatal intensive care unit

目的 了解新生儿重症监护病房内多重耐药鲍曼不动杆菌耐药性及其β-内酰胺酶基因携带情况，为控制医院感染及合理用药提供依据。方法收集本院新生儿重症监护病房分离出的26株多重耐药鲍曼不动杆菌，采用琼脂稀释法检测其对抗菌药物的最低抑菌浓度，聚合酶链反应技术检测多重耐药鲍曼不动杆菌菌株8内酰胺酶基因携带情况。结果26株多重耐药鲍曼不动杆菌临床分离菌株对头孢他啶、头孢西丁、哌拉西林-他唑巴坦及环丙沙星耐药率100．0％，对其余抗菌药物耐药率为80．8％～96．2％。26株测试菌株中axa-51均为阳性，20株（77％）axa-23阳性，14株（54％）ampC阳性，11株（42％）axa-23和ampC同时阳性。未检出携带axa-24、axa-58、imp1、imp-4和vim2基因的菌株。结论鲍曼不动杆菌的耐药性严重，axa23和ampC是本院新生儿重症监护病房内多重耐药鲍曼不动杆菌携带的主要口内酰胺酶基因。

Objective To investigate the correlation between drug resistance and β lactamase genes of multi drug resistance Acinetobacter baumannii （MDR AB） in neonatal intensive care unit to provide evidence for rational antibiotics administration and nosocomial infection control. Methods Twenty-six MDR-AB strains were separated and collected from clinical specimens. The minimum inhibitory concentrations of 13 antimicrobial agents were determined by agar dilution method. Genotypes of β-lactamase were detected by polymerase chain reaction. Results The resistant rates of the 26 strains to Ceftazidime, Cefoxitin, Piperacillin tazobaetam and Ciprofloxacin were 100.0% About 80.8% to 96.2% of these strains were resistant to the other antimicrobial drugs. Among the 26 MDR-AB strains, 100% （26/26） strains possessed axa 51, 77% （20/26） possessed axa-23 gene, 54% （14/26） carried ampC gene, both oxa 23 and ampC were identified in 42% （11/26） strains, while oxa 24, axa 58, imp-1, imp 4 and vim 2 gene were not identified. Conclusions The drug resistance of Acinetobacter baumannii is serious, axa-23 and ampC are the major β lactamase genes carried by MDR AB in neonatal intensive care unit.