鲍曼不动杆菌PER型超广谱β 内酰胺酶耐药基因研究

目的探讨某院产PER型超广谱β 内酰胺酶（ESBLs）鲍曼不动杆菌分子流行病学特点及耐药机制。方法选取该院2009年1-5月临床分离的非重复鲍曼不动杆菌129株，采用K B纸片扩散法进行药敏试验，聚合酶链反应（PCR）扩增PER基因并测序，肠杆菌科基因间重复一致序列（ERIC） PCR进行同源性分析。结果78株鲍曼不动杆菌携带PER 1型基因，阳性率60.47%（78/129）。PER 1阳性鲍曼不动杆菌对亚胺培南、美罗培南、氨苄西林/舒巴坦、米诺环素和头孢哌酮/舒巴坦的耐药率分别为46.15%、44.87%、38.46%、10.26%和8.97%，对其余10种抗菌药物的耐药率均＞60%；PER 1阳性菌株对头孢他啶、头孢噻肟、头孢吡肟、环丙沙星和左氧氟沙星的耐药率明显高于PER 1阴性菌株（均P＜0.05）。78株PER 1阳性菌株包括7型，分别为A型（1株）、B型（1株）、C型（55株）、D型（18株）、E型（1株）、F型（1株）、G型（1株），C和D型为主要克隆型。结论C和D型PER 1阳性鲍曼不动杆菌为该院最主要的流行株。产PER 1型ESBLs鲍曼不动杆菌呈多重耐药，米诺环素、头孢哌酮/舒巴坦可作为该院鲍曼不动杆菌感染治疗的最佳选药。

Study on drug resistance genes of PER type extended spectrum β lactamases in Acinetobacter baumannii

ObjectiveTo investigate molecular epidemiological characteristics and antimicrobial resistance mechanism of PER type extended spectrum β lactamases (ESBLs) producing Acinetobacter baumannii(A. baumannii). Methods129 A.baumannii clinical strains isolated from a hospital between January and May 2009 were performed antimicrobial susceptibility testing by Kirby Bauer disk diffusion method, PER gene was amplified by polymerase chain reaction (PCR),PCR amplified products of PER gene were sequenced, genotypes were identified by enterobacterial repetitive intergenic consensus PCR (ERIC PCR).ResultsPER 1 gene was detected in 78 of 129 clinical isolates, positive rate was 60.47%（78/129）. The resistance rates of PER 1 positive strains to imipenem, meropenem, ampicillin/sulbactam, minocycline and cefoperazone/sulbactam was 46.15%, 44.87%, 38.46%, 10.26% and 8.97% respectively,the resistance rates to the other 10 kinds of antimicrobial agents were all >60%; The resistance rates of PER 1 positive strains to ceftazidime, cefotaxime, cefepime, ciprofloxacin, and levofloxacin were significantly higher than PER 1 negative strains (all P<0.05). 78 PER 1 positive strains were divided into 7 types, including type A(1), B(1), C(55), D(18), E(1), F(1), and G(1), of which the main clones were type C and D.ConclusionType C and D PER 1 positive A.baumannii are the main epidemic strains in this hospital. PER 1 type ESBL producing A.baumannii strains are multi drug resistant, minocycline and cefoperazone/sulbactam are optimal antimicrobial agents for treating A. baumannii infection in this hospital.