Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isol...Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isolates of B. coagulans from 22 provinces or autonomous regions in China. B. coagulans isolates were highly diverse and a total of 33(sequence typings) STs were found. These isolates had a weak clonal population structure and strong indications of intraspecies recombination. The evolution direction of B. coagulans was not correlated with geography or isolation source. Fifteen strains were selected for further analysis based on proximity relationships from the phylogenetic tree. Five isolates(B. coagulans-1, B. coagulans-10, B. coagulans-39, B. coagulans-70 and B. coagulans-71) with good spore-forming ability relative to the rest of the isolates were evaluated for constipation relief. B. coagulans-39 significantly relieved constipation symptoms in mice by regulating intestinal flora, increasing the production of short-chain fatty acids and restoring the level of gastrointestinal regulatory peptides. Comparative genomic analysis showed the beneficial effects of B. coagulans-39 might be associated with specific functional genes that are involved in the utilization of various carbohydrates as primary substrates and short-chain fatty acid production.展开更多
目的研究2019年北京市食源性单增李斯特菌的分子特征和耐药性。方法采用多重PCR进行血清群分型,分离的56株菌株经脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)、多位点序列分析(multilocus sequence typing,MLST)鉴定,使用...目的研究2019年北京市食源性单增李斯特菌的分子特征和耐药性。方法采用多重PCR进行血清群分型,分离的56株菌株经脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)、多位点序列分析(multilocus sequence typing,MLST)鉴定,使用微量肉汤法检测菌株的耐药性。结果56株单增李斯特菌中有28株分离自冷锅串串和中式凉拌菜,1/2a,3a是主要的血清群。56株菌共分为29个PFGE带型、14个ST型,ST9、ST5、ST8、ST121是优势ST型。2株菌对环丙沙星耐药,1株菌对四环素耐药。结论冷锅串串和中式凉拌菜是单增李斯特菌污染的高危食品。北京市食品来源单增李斯特菌的ST型别与国内其他地方食品来源菌株一致,与北京市临床分离株一致。展开更多
基金supported by the National Natural Science Foundation of China Program[No.31871773 and No.31820103010]Projects of Innovation and Development Pillar Program for Key Industries in Southern Xinjiang of Xinjiang Production and Construction Corps[2018DB002]+2 种基金National First-Class Discipline Program of Food Science and Technology[JUFSTR20180102]the BBSRC Newton Fund Joint Centre AwardCollaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province。
文摘Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isolates of B. coagulans from 22 provinces or autonomous regions in China. B. coagulans isolates were highly diverse and a total of 33(sequence typings) STs were found. These isolates had a weak clonal population structure and strong indications of intraspecies recombination. The evolution direction of B. coagulans was not correlated with geography or isolation source. Fifteen strains were selected for further analysis based on proximity relationships from the phylogenetic tree. Five isolates(B. coagulans-1, B. coagulans-10, B. coagulans-39, B. coagulans-70 and B. coagulans-71) with good spore-forming ability relative to the rest of the isolates were evaluated for constipation relief. B. coagulans-39 significantly relieved constipation symptoms in mice by regulating intestinal flora, increasing the production of short-chain fatty acids and restoring the level of gastrointestinal regulatory peptides. Comparative genomic analysis showed the beneficial effects of B. coagulans-39 might be associated with specific functional genes that are involved in the utilization of various carbohydrates as primary substrates and short-chain fatty acid production.
文摘目的研究2019年北京市食源性单增李斯特菌的分子特征和耐药性。方法采用多重PCR进行血清群分型,分离的56株菌株经脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)、多位点序列分析(multilocus sequence typing,MLST)鉴定,使用微量肉汤法检测菌株的耐药性。结果56株单增李斯特菌中有28株分离自冷锅串串和中式凉拌菜,1/2a,3a是主要的血清群。56株菌共分为29个PFGE带型、14个ST型,ST9、ST5、ST8、ST121是优势ST型。2株菌对环丙沙星耐药,1株菌对四环素耐药。结论冷锅串串和中式凉拌菜是单增李斯特菌污染的高危食品。北京市食品来源单增李斯特菌的ST型别与国内其他地方食品来源菌株一致,与北京市临床分离株一致。
文摘对出入境动物源性食品中分离的单增李斯特菌进行多位点序列分型（mutilocus sequence typing,MLST）分析,了解其序列型分布特点及不同菌株之间的亲缘关系。提取单增李斯特菌基因组DNA,选择其7个管家基因进行聚合酶链式反应扩增并测序。将测序结果截成标准序列的长度后上传到MLST数据库进行比对分析,获得7个管家基因的等位基因谱和序列分型编码,并将结果采用不加权算术平均组对（unweighted pair group method using arithmetic averages,UPGMA）法进行聚类分析。89株单增李斯特菌共获得51个STs,其中26个为新获得的STs（STnew1-STnew26）;数量最多的5个STs为ST8（9.0%）,ST121（9.0%）、ST7（5.6%）、ST87（5.6%）及新发现的STnew3（7.8%）;其中ST456、ST34、ST343、ST19、ST517、ST201、ST98、ST330和ST73为在国内首次获得。采用UPGMA算法得到的进化树可将89株菌株分为3大类群,分类的结果与单增李斯特菌血清学家系分类结果一致。MLST结果对了解出入境动物源性食品中分离的单增李斯特菌的亲缘关系及流行病学溯源有重要意义。
