红嘴鸥中分离的非伤寒沙门菌分子特征分析

目的 非伤寒沙门菌是一类肠道病原体,能引起人的腹泻性疾病。特从每年飞抵云南省昆明市的红嘴鸥中分离的非伤寒沙门菌,作分子分型研究,以反映红嘴鸥对于人群健康的潜在影响。方法 从2013年11月-2014年1月间,分3次分别采集500份红嘴鸥粪便样本,进行沙门菌的分离培养。得到菌株之后开展药敏试验和脉冲场凝胶电泳(PFGE)分析。结果 500份粪便样品分离到78株非伤寒沙门菌,其中鼠伤寒沙门菌75株(96.15%),韦尔克斯沙门菌1株,印第安纳沙门菌2株。药敏试验显示,所有非伤寒沙门菌对于利福平的耐药率高达97.44%,其次为萘啶酸(28.21%)和复方新诺明(25.64%);而对庆大霉素和环丙沙星则完全敏感。PFGE结果显示,75株鼠伤寒沙门菌形成了3个带型,并且带型之间的同源性关系均大于95%,66株表现为完全一致的带型特征。与分离自病人的鼠伤寒沙门菌比较后发现,红嘴鸥中分离的鼠伤寒沙门菌与病人分离的菌株的PFGE带型被区分成了两个聚类群。结论 红嘴鸥有很高的非伤寒沙门菌携带率,以鼠伤寒沙门菌为主;PFGE结果表明,红嘴鸥携带的非伤寒沙门菌可能与其生活环境和食物构成等因素密切相关,但尚未发现这些菌株与人群患病的相关性。

Molecular characteristics of non-typhoid Salmonella isolated from Larus ridibundus in Kunming,China

We isolated non-typhoid Salmonella from L.ridibundus in Kunming every year, and performed the molecular typing methods, for refecting the potential influence for human health. Three times of feces collections were performed from Nov 2013 to Feb 2014, and totally 500 feces were acquired from L.ridibundus. We isolated the non-typhoid Salmonella and performed the antibiotics resistant test and pulsed-eld gel electrophoresis (PFGE). Results showed that 78 non-typhoid Salmonella strains were isolated from all the feces, and 75 strains (96.15%) were S.typhimurium, one was S.waycross, and two S.indiana were also found. The antibiotics resistant tests showed that 97.44% of all the strains were resistant to rifampin, 28.21% to nalidixic acid, and 25.64% to sulfamethoxazole/trimethoprim. However, all the strains were sensitive to gentamicin and ciprofloxacin. The PFGE results showed 75 S.typhimurium were divided into three patterns, and the similarity of three patterns was greater than 95%. Of 66 strains showed the same PFGE pattern in the study. Comparing the PFGE patterns with patients in our database, we found that S.typhimurium isolated from L.ridibundus were different from patients, separating into two groups. The carrier rate of non-typhoid Salmonella were very high in L.ridibundus, mainly for S.typhimurium. The PFGE results reflected the strains isolated from L.ridibundus maybe had the relations with their living environment or eating habits. No correlations were found between L.ridibundus and patients in our study.