某院耐碳青霉烯类肠杆菌科细菌的临床分布特点及药物敏感性分析

目的分析该院耐碳青霉烯类肠杆菌科细菌(CRE)的临床分布特点及药物敏感性,为临床合理有效治疗CRE菌株提供理论依据。方法收集医院2019年全年临床标本中分离的肠杆菌科细菌(共计2435株),采用VITEK 2 Compact全自动微生物分析系统进行细菌鉴定、药敏试验,对筛选出的CRE菌株采用K-B药敏纸片扩散法对亚胺培南进行复核,并采用改良碳青霉烯灭活(mCIM)试验和EDTA改良碳青霉烯灭活(eCIM)试验进行碳青霉烯酶表型分析。所有实验数据采用WHONET5.6和SPSS17.0软件进行统计分析处理。结果共分离出213株CRE菌株,以肺炎克雷伯菌为主(161株);标本来源以呼吸道痰液标本为主(41.3%);54.5%的标本分离自重症监护室(ICU),CRE菌株在ICU的分离率明显高于普通病房(χ^2=81.00,P<0.01)。药敏结果显示,CRE菌株除对替加环素比较敏感(耐药率为2.8%),对阿米卡星(51.6%)和四环素(52.0%)的耐药率低一些外,对其余大多数抗菌药物的耐药率均在80%以上。与碳青霉烯类敏感肠杆菌科细菌(CSE)的耐药率相比,CRE菌株对除四环素以外的其他抗菌药物的耐药率均明显高于CSE菌株(P<0.01)。mCIM和eCIM试验结果显示,213株CRE菌株中,170株为丝氨酸酶阳性,43株为金属酶阳性,且43株产金属酶的CRE菌株中,22株都来源于ICU,占比超过50%。不同细菌种类的CRE菌株中,耐碳青霉烯类阴沟肠杆菌和耐碳青霉烯类大肠埃希菌产金属酶的比例均≥50%。结论CRE菌株对多种抗菌药物高度耐药,其临床分离率逐年增高,给临床治疗带来困难。因此应加强抗菌药物的管理,合理选择和使用抗菌药物,注重医院感染的预防和监测,防止医院内感染的传播和流行。

Analysis on clinical distribution characteristics and drug susceptibility of carbapenem-resistant Enterobacteriaceae bacteria in a hospital

Objective To analyze the clinical distribution characteristics and drug susceptibility of carbapenem-resistant Enterobacteriaceae(CRE)bacteria in a hospital in order to provide a theoretical basis for rational and effective treatment of CRE strain infection.Methods The enterobacteriaceae strains(a total of 2435 strains)were collected from the clinical samples in a hospital during 2019.The bacterial identification and drug susceptibility test were carried out with the VITEK 2 Compact full-automatic microbiological analysis system.The Kirby-Bauer disk diffusion method was used to conduct the re-examination on imipenem for the selected CRE strains,and the phenotype analysis was performed by adopting the modified carbapenem inactivation method(mCIM)and EDTA-modified carbapenem inactivation method(eCIM).All testing data were analyzed and processed by adopting the WHONET5.6 and SPSS17.0 software.Results A total of 213 strains of CRE bacteria were isolated,which were mainly Klebsiella pneumonia(161 strains).The samples sources were mainly derived from the respiratory tract sputum samples(41.3%),54.5%of samples were isolated from ICU.The isolating rate of CRE strains in ICU was significantly higher than that in the general wards(χ^2=81.00,P<0.01).The drug susceptibility test results showed that except CRE bacterial strains were more sensitive to tigecycline(resistance rate 2.8%)and had lower resistance rate to amikacin(51.6%)and tetracycline(52.0%),the resistance rates to most other antibacterial drugs were>80%.Compared with the resistance rate of carbapenem-sensitive Enterobacteriaceae(CSE),the resistance rate of CRE strains to other antibacterial drugs except tetracycline was significantly higher than that of CSE strains(P<0.01).The mCIM and eCIM test results showed that among 213 strains of CRE,170 strains were serine carbapenemase positive,and 43 strains were metalloenzyme positive,moreover in 43 strains of metalloenzyme producing CRE strains,22 strains were derived from ICU,their proportion exceeded 50%.Among different bacterial kinds of CRE strains,the proportions of metallo-β-lactamase produced by carbapenem-resistant Enterobacter cloacae and carbapenem-resistant Escherichia coli were both greater than 50%.Conclusion CRE bacterial strains have higher resistance to multiple antibacterial drugs,their clinical isolation rates are increased year by year,which brings the difficulty for clinical treatment.Therefore the management of antibacterial drugs should be strengthened and the antibacterial drugs should be selected and used rationally.Meanwhile more attention should be paid to the prevention and monitoring of nosocomial infection for preventing the spread and prevalence of nosocomial infection.