• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Food microbiology >Milk-originated Bacillus cereus sensu lato strains harbouring Bacillus anthracis-like plasmids are genetically and phenotypically diverse
【24h】

Milk-originated Bacillus cereus sensu lato strains harbouring Bacillus anthracis-like plasmids are genetically and phenotypically diverse

机译：带有炭疽杆菌样质粒的牛奶起源的蜡状芽孢杆菌菌株在遗传和表型上都不同

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Bacillus cereus sensu lato is widely distributed in food products, including raw and processed milk. Plasmids often determine bacterial virulence and toxicity, but their role in the evolution of B. cereus sensu lato is only partly known. Here, we observed that nearly 8% of B. cereus sensu lato isolates were positive for pXO1-like plasmids and 12% for pXO2-like plasmids in raw and ultra-heat-treated (UHT) milk from one dairy plant. However, pXOl-like plasmids were significantly more frequent in raw milk, while pXO2-like plasmids were more frequent in processed milk. Strains from raw and UHT milk were enterotoxigenic, with up to one-fifth of the isolates being psychrotolerant. Phylogenetic assessment using multi-locus sequence typing revealed a polyphyletic structure for these bacilli, with distinct groups of cold-adapted isolates and pathogenic strains (including emetic B. cereus). Populations corresponding to both sampling sites exhibited significant linkage disequilibrium and the presence of purifying selection. The far-from-clonal population structure indicated the presence of sequence types or ecotypes adapted to specific conditions in the dairy industry. A high recombination-to-mutation ratio suggested an important role for horizontal gene transfer among 6. cereus sensu lato isolates in milk.
机译：蜡状芽孢杆菌广泛分布于食品中，包括生乳和加工乳。质粒通常决定细菌的毒性和毒性，但是它们在蜡状芽孢杆菌进化中的作用仅是部分已知的。在这里，我们观察到在一家乳品厂的原始和超高温处理（UHT）牛奶中，蜡状芽孢杆菌近8％的分离株对pXO1样质粒呈阳性，而对pXO2样质粒呈阳性，为12％。然而，在生乳中pXO1样质粒明显更频繁，而在加工乳中pXO2样质粒更频繁。生牛奶和超高温灭菌牛奶中的菌株具有产毒作用，其中多达五分之一的分离物具有抗精神病性。使用多基因座序列分型的系统发育评估揭示了这些杆菌的多系结构，具有不同组的冷适应分离株和致病菌株（包括蜡状芽孢杆菌）。对应于两个采样位点的种群表现出显着的连锁不平衡和纯化选择的存在。远离克隆的种群结构表明存在适合乳业特定条件的序列类型或生态类型。较高的重组突变率表明，乳汁中蜡状蜡状菌分离株之间的水平基因转移具有重要作用。6。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号