武汉地区住院患者克罗诺杆菌感染及其临床分离株分子特征与耐药性研究

Cronobacter infections and the molecular properties and drug resistance of the clinical isolates in hospitalized patients in Wuhan area

目的:研究武汉地区住院患者克罗诺杆菌感染及其临床分离株分子特征与耐药性。方法:选取2021年6月~2022年5月在武汉市第一医院就诊的克罗诺杆菌感染住院患者137例为研究对象,对患者克罗诺杆菌分离株行血清型分型鉴定、脉冲场凝胶电泳(PFGE)分子分型分析、克隆群结构特征分析与耐药性检验。结果:483例患者检出克罗诺杆菌感染137例,总检出率28.36%。男、女检出率差异无统计学意义(P>0.05),年龄分布以低龄(0~6岁)检出率最高,科室分布以儿科检出率最高,感染后易发疾病类型为脑膜炎(P<0.05);血清型分型鉴定以O 1为主要血清型分型,占比36.50%(50/137),ST型分布以ST4、ST1为主,分别占比40.15%(55/137)和31.38%(43/137),CC结构特征以CC4、CC7为主,分别占比32.85%(45/137)和40.15%(55/137);经内切酶Xba I和Spe I酶切后,分成14个PFGE图谱类型,其中BQ9、BQ11和BQ12相似系数较高(98.0%);耐药性检验结果提示,氨苄西林的耐药性较强(67.15%),对测定的其他抗生素全部敏感,未发现多重耐药菌株。结论:武汉地区住院患者克罗诺杆菌感染血清型分型以O 1型为主,PFGE分子分型具有多样性,其中氨苄西林的耐药性较强。

Objective:To investigate the Cronobacter infections and its molecular properties and drug resistance of the clinical isolates in hospitalized patients in Wuhan area.Methods:One hundred and thirty-seven hospitalized patients with Cronobacter infection who were treated in the applicant′s department in Wuhan First Hospital from June 2021 to May 2022 were selected as the study objects.The isolated Cronobacter strains from the patients were subjected to serotyping,molecular typing analysis by pulsed field gel electrophoresis(PFGE),clonal group structural characteristics analysis and drug resistance tests.Results:Cronobacter infection was confirmed in 137 of the 483 patients,with a total positive rate of 28.36%.There was no statistically significant difference in positive rate between males and females(P>0.05).The highest positive rate was seen in younger patient group(0-6 years old)and in the pediatrics department.Meningitis was more secondary to the infection(all P<0.05).Serotype identification indicated O 1 as the main serotype(36.50%;50/137).ST types primarily consisted of ST4 and ST1(40.15%,55/137;31.38%,43/137,respectively),while structural characteristics of CC mainly encompassed CC4 and CC7(32.85%,45/137;40.15%,55/137,respectively).After digestion with Xba I and Spe I,the samples were divided into 14 PFGE pattern types,among which BQ9,BQ11 and BQ12 exhibited a high similarity coefficient(98.0%).The drug resistance test results indicated that there was a strong resistance to ampicillin(67.15%),while all other tested antibiotics were found to be sensitive.No multidrug-resistant strains were detected.Conclusion:O 1 type is the major serotype of Cronobacter infection in hospitalized patients in Wuhan area,and the molecular type of PFGE is rich and diverse.This bacteria can be strongly resistant to ampicillin.