产超ESBL菌的耐药表型及四种检出方法比较

Resistant phenotype of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumonia and comparison of four detecting methods

目的 :探讨产超广谱 β 内酰胺酶 (ESBL)大肠埃希菌和肺炎克雷伯菌耐药表型流行情况 ,比较 4种ESBL检出方法。方法 :首先筛选出可疑产ESBL菌 ,再用确证试验、双纸片协同试验、GNS NT卡和EtestESBL试条进行实验比较。根据GNS NT卡的药敏结果统计耐药情况。结果 :316株菌中 118株可疑产ESBL ;确证试验证实 96株产ESBL ,协同试验证实 90株有协同现象 ;其中确证产ESBL的 2 8株菌经GNS NT卡和EtestESBL试条测试 ,2 4株阳性。β 内酰胺类的氨曲南 (ATN )、头孢噻肟 (CTX)、头孢泊肟 (CPO)、头孢三嗪 (CRO)、头孢他啶 (CTD)耐药率均较高 ,亚安培南 (IMP)均敏感 ;非 β 内酰胺类药物的耐药率也较高。结论 :确证试验与双纸片协同试验的阳性符合率较低 ,GNS NT卡和EtestESBL试条的灵敏度不及前二者。ATN、CTX、CRO和CPO为检测ESBL较适底物 ,产ESBL菌对硝基呋喃类、喹诺酮类。

Objective:To investigate the prevalence of drug resistant phenotype of extended spectrum beta lactamases (ESBLs) producing E. coli and K. pneumonia and to compare the four of detecting methods for ESBLs . Methods:After the suspected E. coli and K. pneumonia were isolated from ESBLs, the disc diffusion confirmatory test, double disc synergy test, GNS NT sensitive card and Etest ESBLs test were used for experimental comparison. According to the GNS NT sensitive card, drug resistance condition was counted. Results:Among 316 strains, 118 were suspected producing ESBLs and 96 of them were confirmed by the disc diffusion confirmatory test, and the synergy phenomenon in 90 strains was confirmed by the synergy test. Twenty eight strains were confirmed producing ESBLs, 24 strains showed positive respectively by GNS NT card and Etest tests. The resistance rate of beta lactams such as aztreonam (ATN), cefotaxime (CTX), ceftriaxone (CRO), ceftazidime (CTD) and cefpodoxime (CPO) are higher, but imipenem (IMP) is sensitive. The resistance rate of non beta lactam agents is also high. Conclusion:The positive accordance rate of the confirmatory test and double disc synergy test is lower. The sensitivity of GNS NT card and Etest ESBLs is lower than the above two tests. ANT, CTX, CRO and CPO are the suitable substances for the determination of the substrates of ESBLs. The sensitivity of nitrofurans, quinlones, aminoglycosides and sulfonamides for producing ESBLs strains is poorer.