鲍曼不动杆菌耐药性及β内酰胺酶基因型研究

Study on the resistance and genotyping of β-lactamases in Acinetobacter baumannii

目的 明确浙江湖州地区临床分离的鲍曼不动杆菌耐药性及 β内酰胺酶基因型。方法 采用ATB药敏试验条板微量肉汤法测定临床分离的 6 0株鲍曼不动杆菌对 18种抗菌药物的敏感性 ,采用聚合酶链反应 (PCR)及序列分析的方法分析 β内酰胺酶基因型。 结果 鲍曼不动杆菌对亚胺培南、美洛培南的耐药率为 1 7% ,哌拉西林 /他唑巴坦的耐药率为 4 8 3% ,对其他抗菌药物的耐药率均在 5 0 %以上。有 18株菌株扩增到SHV型 β内酰胺酶 ,17株为ESBLsSHV 12 ,另 1株(HZ0 1株 )扩增序列全长含 82 6个核苷酸 ,与SHV 1相比 ,第 35、191、2 38、2 4 0位氨基酸有不同 ,被命名为SHV 4 8(GenBank登录号 :AY2 5 916 4 )。结论 浙江湖州地区临床分离的鲍曼不动杆菌耐药严重 ,至少存在 3种不同类型的 β内酰胺酶 ,基因型分别为SHV 12、SHV 4 8、TEM 1。

Objective To investigate the resistance and genotyping of β-Lactamases in Acinetobacter baumannii isolated from Huzhou, Zhejiang province. Methods Microdilute tests were performed to detect the susceptibility of 18 kinds of antimicrobial agents against 60 strains of A cinetobacter baumannii Genotypes of β-lactamases was analyzed by PCR and verificated by DNA sequencing. Results The resistant rates of 60 strains to Imipenam, Meropenem and Piperacillin/ Tazobactam were 1.7%, 1.7% and 48.3%, respectively. The resistant rates to other antimicrobial agents were more than 50%. SHV type β-lactamases were positive in 18 of 60 isolates tested, 17 of which were SHV-12. The other strain (HZ01) was amplicated the sequence including 826 nucleotides, which has the amino acid mutations in position 35, 191, 238 and 240 compared with SHV-1. It is a new SHV type β-lactamases nominated SHV-48 (GenBank number: AY259164).Conclusion The resistance of Acinetobacter baumannii isolated from Huzhou of Zhejiang province was a serious issue and at least 3 kinds of β-lactamases exsisted including SHV-12, SHV-48 and TEM-1.