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。
Objective To investigate antimicrobial resistance, genotypies and the prevalence of AmpC β-laetamas- es-producing and extended-spectrum β-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 AmpC β-lactamases and phenotypic confirmatory test based on Clinical and Laboratory Standard Institute （CLSI） criteria for ESBLs. Antimi- crobial susceptibility of AmpC β-lactamases- and ESBLs-produeing strains was detected by Kirby-Bauer and E-test methods. Universal primer PCR for AmpC ~lactamases and ESBLs gene amplification and DNA sequencing were carried out for genotyping of these β-lactamases. Results AmpC β-lactamases, ESBLs and AmpC β-lactarnases combined with ESBLs-producing strains were found in 9（9. 38%）, 52（54. 17%）and 10 （10. 42%） strains, respectively. AmpC β-laetamases -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, piperaeillin/tazobaetam and eefoperazone/sulbaetam , the resistant rate being 0. 00%, 34. 62% and 19. 23% respectively. AmpC β-laetamases combined with ESBLs-producing strains were only sensitive to imipenem and no imipenem-resistant one was found. The genotypes of AmpC β-lactamases were DHA- 1and 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 AmpC β-lactamases and CTX-M, SHV type ESBLs-produeing gram-negative strains in RICUs in two hospitals, they are resistant to most new broad- spectrum β-lactam antibiotics, but sensitive to imipenem.
出处
《中国感染控制杂志》
CAS
2011年第2期92-96,共5页
Chinese Journal of Infection Control
基金
广东省自然科学基金项目(5009113)
2008年深圳市福田区公益性科研项目(FTWS048)
关键词
重症监护室
医院感染
大肠埃希菌
肺炎克雷伯菌
AMPC酶
超广谱Β-内酰胺酶
耐药基因
抗药性
微生物
intensive care unit lnosocomial infection
Escherichia coli
Klebsiella pneumoniae
ArnpC β-lactamases
extended-spectrum β-actamases
drug resistant gene
drug resistance, microbial
