烧伤病房鲍曼不动杆菌分离株耐药性及β-内酰胺酶基因型检测

目的 :分析烧伤病房鲍曼不动杆菌分离株的耐药情况及其 β 内酰胺酶 (BLA)耐药基因类型。 方法 :采用微量稀释法测定临床分离的 14 1株鲍曼不动杆菌对 2 4种抗菌药物的敏感性 ,并对其中 11株采用聚合酶链反应 (PCR)及序列分析的方法分析BLA基因型TEM、SHV、CTX -M - 1、CTX -M - 2、CTX -M - 9、OXA、PER及VEB。结果 :所有菌株均对头孢哌酮 /舒巴坦敏感 ,亚胺培南、美洛培南、多粘菌素E和哌拉西林 /他唑巴坦的耐药率分别为 3.5 %、3.8%、5 .4 %和 4 1.1% ,头孢吡肟、头孢曲松、头孢他啶、氨曲南、头孢噻肟和头孢哌酮的耐药率在 5 5 .2 %～ 73.2 %之间 ,其余抗生素的耐药率在 5 1.4 %～ 10 0 .0 %之间。 11株TEM型基因扩增全部阳性 ,任选 6株测序结果均为TEM - 1型。有 2株菌株扩增到SHV型基因 ,经测序均为SHV - 12型ESBLs。结论 :烧伤病房鲍曼不动杆菌分离株多重耐药状况极其严重 ,至少存在 2种不同类型的BLA基因 ,基因型分别为TEM - 1、SHV - 12。对其感染的治疗 ,应以抗生素敏感性试验资料为依据 ,可选用碳青霉烯类、头孢哌酮 /舒巴坦、多粘菌素E及其它敏感的抗生素。

Detection on the Resistance and Genotype of β- Lactamases in Acinetobacter Baumannii Isolated from Burn Units

Objective:To investigate the antimicrobial resistance and the genotype of the plasmid-mediated β-Lactamases -encoding genes of acinetobacter baumannii isolated from burn units in the 98th hospital of PLA.Methodes:Microdilute tests were performed to detect the susceptibility of 24 kinds of antimicrobial agents against 141 strains of acinetobacter baumannii.TEM,SHV,CTX-M-1,CTX-M-2,CTX-M-9,OXA,PER and VEB genotypes of β-Lactamases were analyzed by PCR and verificated by DNA sequencing in 11 of 141 isolates tested. Results:There was no strain resistant to cefoperazone/ sulbactam. The resistant rates to imipeneme, meropeneme , polymyxin E and piperacillin/ tazobactam were 3.5%,3.8%,5.4% and 41.1% respectively. The resistant rates to cefepime,ceftriaxone, ceftazidime, aztreonam, cefotaxime and cefoperazone were between 55.2% and 73.2%. The resistant rates to other antimicrobial agents were more than 50%.TEM type β-Lactamases genes were positive in all of the 11 isolates tested, 6 of which were TEM-1. SHV type β-Lactamases genes were positive in 2 of 11 isolates tested, they were SHV-12. Conclusions:The multiple-drug-resistance of acinetobacter baumannii isolated from burn units in the 98th hospital of PLA is a serious issue and at least 2 kinds of β-Lactamases genes exsisted including TEM-1 and SHV-12. To deal with the infection which strains cause, such antimicrobial as carbapenems,cefoperazone/sulbactam, polymyxin E and others which are sensitive to such strains can be used on the basis of the sensitive test of antimicrobial.