2015-2017年聊城市腹泻病例中沙门氏菌分子分型及耐药性研究

目的 对2015-2017年聊城地区主动监测哨点医院腹泻患者中分离到的沙门氏菌进行病原学分析,了解沙门氏菌的感染现状及血清型分布、分子分型特征和耐药情况。方法 对2015-2017年分离自腹泻患者的41株沙门氏菌进行脉冲场凝胶电泳(PFGE)和药物敏感性测试,并用BioNumerics软件分析菌株之间的相似度,用微量肉汤稀释法进行菌株耐药性检测。结果 腹泻患者中沙门氏菌总分离率为7.16%,且不同年龄段分离率存在差异。分离的沙门氏菌共有8个血清型,其中鼠伤寒沙门氏菌和肠炎沙门氏菌分别为18株和7株,为优势血清型;PFGE分析发现41株菌共产生了34种不同的PFGE带型,相同血清型的沙门氏菌的PFGE带型比较相近,不同血清型的PFGE带型具有多态性,未发现菌株成簇存在现象。测试菌株对四环素耐药率最高为73.17%,多重耐药率达68.29%,发现6株携带不同耐药基因类型的产广谱β-内酰胺酶的鼠伤寒沙门氏菌。结论 聊城地区沙门氏菌具有一定的血清型及遗传的多样性,高耐药和多重耐药现象严重,应加强病例及环境联合耐药监测。

Molecular typing and antimicrobial resistance test of Salmonella from diarrheal cases in Liaocheng city,China,from 2015 to 2017

To investigate the serotype distribution, molecular types and drug resistance of Salmonella by analyzing the etiology of Salmonella isolated from diarrhea patients in the active surveillance sentinel hospital in Liaocheng from 2015 to 2017.Total of the 41 strains of Salmonella isolated from diarrhea patients from 2015 to 2017 were analyzed by pulsed-field gel electrophoresis (PFGE) and drug susceptibility test. The similarity in the strains was analyzed by BioNumerics software, and the strain resistance was measured by a micro-broth dilution method.The results showed that the total isolation rate of Salmonella in patients with diarrhea was 7.16%, and the separation rates was different in the different age group. There are 8 serotypes in the isolated Salmonella, including 18 strains of Salmonella typhimurium and 7 strains of Salmonella enteritidis, which are the dominant serotypes. PFGE analysis showed that there were 34 different PFGE bands in 41strains, and the PFGE bands of Salmonella with the same serotype were similar, while the PFGE bands of different serotypes were polymorphic, and no clusters were found. The tested strains had the highest rate of resistance to tetracycline of 73.17% and multi-drug resistance rate of 68.29%. Six strains of Salmonella typhimurium carrying different drug resistance genes and producing broad-spectrum β-lactamase were found.In conclusion,Salmonella in Liaocheng area has a certain degree of serotype and genetic diversity, high drug resistance and serious multi-drug resistance. Therefore, drug resistance surveillance in cases and the environment should be strengthened.