舟山市副溶血性弧菌分子流行病学特征研究

Study on Molecular Epidemiological Characteristics of Vibrio Parahaemolyticus Isolated in Zhoushan

目的研究舟山市副溶血性弧菌分子流行病学特征,分析两种不同来源菌株的相关性,了解舟山市副溶血性弧菌的流行规律。方法对50株贝类样品分离株以及18株本市散发性腹泻患者和食物中毒的临床分离株进行血清分型,应用PCR技术对tdh、trh、orf8和toxRS/new毒力基因进行检测,并进行PFGE分子分型分析。结果贝源分离株tdh、toxRS/new和orf8检测结果均为阴性,只有冬季检出的2株trh阳性。临床分离株中有14株tdh、toxRS/new和orf8 3种毒力基因为阳性,1株trh阳性,其余3株4种毒力基因均为阴性,说明这18株中有14株(77.78%)属于流行株,其中13株(92.86%)为O3∶K6型,1株为O1∶KUT型;而PFGE分型结果显示:53株菌株分属9种不同血清群的副溶血性弧菌,但经NotI酶酶切可分成多种不同PFGE酶切图谱,仅少部分相同血清型/不同血清型有相同酶切图谱(按相似度100%分),多数菌株PFGE酶切图谱差异明显。结论舟山市副溶血性弧菌贝类分离株与临床分离株在血清型分型、致病因子和分子特征等方面存在一定差异;初步建立了舟山市副溶血性弧菌基因指纹图谱库。

Objective To understand the molecular epidemiological characteristics of Vibrio Parahaemolyticus isolated in Zhoushan. Methods The serotype test was carried out both on 50 isolates from shellfish and 18 isolates from sporadic cases of diarrhea or food poisoning. The virulent genes, including tdh, trh, off8 and toxRS/new genes, were examined by PCR. Molecular typing was also carried out using pulsed field gel electrophoresis （PFGE）. Results Among the isolates fi＇om Shellfish, results of tdh, toxRS / new and orf8 test were all negative, while only two isolates detected in winter were positive in trh gene test. 14 isolates from clinical cases were tdh, toxRS / new and orf8 positive, and 1 Was trh positive. These results suggest that 14 （ accounting for 77.78% ） of the 18 clinical isolates were pandemic strain, of which 13 （accounting for 92. 86% ） were O3：K6 type, and the other one was O1： KMT type. PFGE typing showed that the tested 53 isolates of Vibrio Parahaemolytieus could be divided into 9different serotypes. However, after divided into many different PFGE restriction map by NotI digestion, only a small part of these Vibrio Parahaemolyticus showed the same restriction map （similarity of 100% points）, and the differences of PFGE restriction map were significant among most isolates. Conclusion There were some differences between Vibrio Parahaemolyticus from shellfish and those from clinical cases in the serotype classification, pathogenic factors and molecular characteristics. The genetic fingerprint database of Vibrio Parahaemolyticus in Zhoushan was set up for the first time.