【摘要】 目的了解深圳地区2所三级综合医院呼吸重症监护室(RICU)分离的革兰阴性(G~-)菌产AmpC酶和超广谱β-内酰胺酶(ESBLs)情况及其耐药性与基因型特征。方法选择分离自上述2所医院RICU的对第一、二代及1种以上第三代头孢菌素耐药的大肠埃希菌和肺炎克雷伯菌,采用纸片扩散法及E-test进行药敏试验,酶提取物三维试验检测单产AmpC酶,美国临床实验室标准化研究所(CLSI)推荐的表型筛选和确证试验检测产ESBLs菌株,聚合酶链反应(PCR)通用引物扩增AmpC酶和ESBLs基因及其序列测定以确定基因亚型。结果检出单产AmpC酶、单产ESBLs、合产AmpC酶和ESBLs的菌株分别为9株(9.38%)、52株(54.17%)和10株(10.42%)。单产AmpC酶菌株对头孢吡肟和亚胺培南具有较高的敏感性,耐药率分别为33.33%和0.00%;单产ESBLS菌株对亚胺培南、哌拉西林/他唑巴坦及头孢哌酮/舒巴坦的敏感性较高,耐药率分别为0.00%、34.62%和19.23%;合产AmpC酶和ESBLs的菌株仅对亚胺培南敏感,未发现耐药株。检出AmpC酶基因型为DHA-1和ACT-1,分别占76.92%和26.08%;ESBLs基因型为CTX-M系列和SHV-5,分别占96.77%和3.23%。结论该2所综合医院RICU存在产质粒介导DHA-1、ACT-1型AmpC酶和CTX-M、SHV型ESBLs的G~-菌流行株,其对大多数新型广谱β-内酰胺类抗生素耐药,对亚胺培南敏感,值得临床关注。更多还原

【Abstract】 Objective To investigate antimicrobial resistance,genotypies and the prevalence of AmpCβ-lactamas-es -producing and extended-spectrumβ-lactamases(ESBLs)-producing gram-negative strains from specimens of respiratory intensive care units(RICUs) in 2 hospitals of Shenzhen.Methods A total of 96 multidrug-resistant Escherichia coli and Klebsiella pneumoniae strains were detected by three-dimensional test for AmpCβ-lactamases and phenotypic confirmatory test based on Clinical and Laboratory Standard Institute(CLSI) criteria for ESBLs.Antimicrobial susceptibility of AmpCβ-lactamases-and ESBLs-producing strains was detected by Kirby-Bauer and E-test methods.Universal primer PCR for AmpCβ-lactamases and ESBLs gene amplification and DNA sequencing were carried out for genotyping of theseβ-lactamases.Results AmpCβ-lactamases,ESBLs and AmpCβ-lactamases combined with ESBLs-producing strains were found in 9(9.38%),52(54.17%)and 10(10.42%) strains,respectively. AmpCβ-lactamases -producing strains were more susceptible to cefepime and imipenem,the resistant rate being 33.33%and 0.00%respectively.ESBLs-producing strains were more susceptible to imipenem,piperacillin/tazobac-tam and cefoperazone/sulbactam,the resistant rate being 0.00%,34.62%and 19.23%respectively.AmpCβ-lac-amases combined with ESBLs-producing strains were only sensitive to imipenem and no imipenem-resistant one was found.The genotypes of AmpCβ-lactamases were DHA-land ACT-1,the incidence being 76.92%and 26.08%respectively. ESBLs genotypes were CTX-M series and SHV-5,the incidence being 96.77%and 3.23%respectively. Conclusion There are epidemic strains of plasmid-mediated DHA-1,ACT-1 type AmpCβ-lactamases and CTX-M, SHV type ESBLs-producing gram-negative strains in RICUs in two hospitals,they are resistant to most new broad-spectrumβ-lactam antibiotics,but sensitive to imipenem.更多还原