佛山市中医院耐碳青霉烯类肠杆菌目细菌的产酶型别及耐药性分析

Analysis of enzyme producing genotypes and drug resistance of carbapenem-resistantEnterobacteriaceae in Foshan Hospital of Traditional Chinese Medicine

目的了解佛山市中医院耐碳青霉烯类肠杆菌目细菌(CRE)的产酶类别、对头孢他啶/阿维巴坦(CZA)等常用抗菌药物的耐药性,以及CZA与美罗培南(MEM)、氨曲南(ATM)的联合作用,为临床合理用药提供依据。方法收集佛山市中医院2020年1月1日至2022年3月1日临床分离的CRE 95株,对临床常用抗菌药物的耐药性进行回顾性分析,用改良碳青霉烯灭活试验(mCIM试验)联合乙二胺四乙酸改良碳青霉烯灭活试验(eCIM试验)与胶体金免疫层析技术2种方法检测碳青霉烯酶,采用纸片扩散法检测CZA同MEM、ATM的联合药敏试验。结果95株CRE中,mCIM试验阳性菌株93株(97.9%),不产酶2株(2.1%);eCIM试验阳性菌株49株(51.6%)。93株产酶CRE菌株中产丝氨酸酶44株(47.3%),产金属β-内酰胺酶49株(52.7%)。胶体金免疫层析法检测6个基因型结果除了1株不是KPC基因型外,其他与mCIM和eCIM表型结果一致。44株产丝氨酸酶菌株的敏感率为97.7%,49株产金属β-内酰胺酶菌株的敏感率为0.0%。35株携带KPC基因型肺炎克雷伯菌中有33株CZA和MEM、CZA和ATM有协同作用,23株携带NDM基因型大肠埃希菌中有19株CZA和ATM有协同作用。结论佛山市中医院CRE的碳青霉烯酶型以金属β-内酰胺酶为主,肺炎克雷伯菌以KPC基因型为主,大肠埃希菌以NDM基因型为主,产丝氨酸酶菌株对CZA有较高敏感性;通过检测CZA和ATM是否有协同作用可以给临床抗感染治疗提供有力证据。

Objective To investigate the genotypes of carbapenem-resistant Enterobacteriaceae(CRE)and drug resistance to ceftazidime/avibactam(CZA)in Foshan Hospital of Traditional Chinese Medicine,so as to provide a solid basis for clinical rational medication.Methods 95 strains of CRE isolated from Foshan Hospital of Traditional Chinese Medicine from January 1 st,2020 to March 1 st,2022 were collected.The drug resistance of commonly used antibiotics in clinic was analyzed retrospectively.Carbapenem enzyme was detected by modified carbapenem inactivation method(mCIM)combined with EDTA-carbapenem inactivation method(eCIM)test and colloidal gold immunochromatography.The combined drug sensitivity test of CZA with meropenem(MEM)or with aztreonam(ATM)was detected by K-B method.Results Among 95 CRE strains,93 strains were positive for mCIM test(97.9%),2 strains did not produce enzyme(2.1%),49 strains were positive for eCIM test(51.6%).Among 93 enzyme-producing strains,44 strains produced serine enzyme(47.3%)and 49 strains produced metallo-β-lactamase(52.7%).The results of six genotypes by colloidal gold immunochromatography were consistent with mCIM and eCIM phenotypes except that one strain was not KPC genotype.The sensitivity rate of 44 strains producing serinase were 97.7%and 49 strains producing metallo-β-lactamase were 0.0%.Among 35 strains of Klebsiella pneumoniae producing KPC enzyme gene,33 strains of CZA had synergistic effect with MEM,CZA and ATM,and 19 strains had synergistic effect with CZA and ATM in 23 strains of E.coli producing NDM enzyme gene.Conclusion The dominant carbapenemase type of CRE in Foshan Hospital of Traditional Chinese Medicine is metallo-β-lactamase,KPC genotype is dominant in Klebsiella pneumoniae,NDM genotype is dominant in Escherichia coli,and serine producing strains are highly sensitive to CZA.Detection the synergistic effect of CZA and ATM can provide strong evidence for clinical anti-infection.