Chen Yi, Luo Yan, Pettengill James, Timme Ruth, Melka David, Doyle Matthew, Jackson Alikeh, Parish Mickey, Hammack Thomas S, Allard Marc W, Brown Eric W, Strain Errol A
Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, USA
Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland, USA.
J Clin Microbiol. 2017 Mar;55(3):931-941. doi: 10.1128/JCM.02140-16. Epub 2017 Jan 4.
Three multistate outbreaks between 2014 and 2016, involving case patients in and outside the United States, were linked to stone fruit, caramel apples, and packaged leafy green salad contaminated with singleton sequence type 382 (ST382), a serotype IVb-v1 clone with limited genomic divergence. Isolates from these outbreaks and other ST382 isolates not associated with these outbreaks were analyzed by whole-genome sequencing (WGS) analysis. The primary differences among ST382 strains were single nucleotide polymorphisms (SNPs). WGS analysis differentiated ST382 from a clonal complex 1 outbreak strain co-contaminating the caramel apples. WGS clustered food, environmental, and clinical isolates within each outbreak, and also differentiated among the three outbreak strains and epidemiologically unrelated ST382 isolates, which were indistinguishable by pulsed-field gel electrophoresis. ST382 appeared to be an emerging clone that began to diverge from its ancestor approximately 32 years before 2016. We estimated that there was 1.29 nucleotide substitution per genome (2.94 Mbp) per year for this clone.
2014年至2016年间发生了三起多州疫情，涉及美国境内外的病例患者，这些疫情与被单一序列型382（ST382）污染的核果、焦糖苹果和包装叶类绿色沙拉有关，ST382是一种基因组差异有限的IVb-v1血清型克隆。通过全基因组测序（WGS）分析对这些疫情中的分离株以及与这些疫情无关的其他ST382分离株进行了分析。ST382菌株之间的主要差异是单核苷酸多态性（SNP）。WGS分析将ST382与共同污染焦糖苹果的克隆复合体1疫情菌株区分开来。WGS在每次疫情中对食品、环境和临床分离株进行了聚类，还区分了三起疫情的菌株以及在流行病学上无关的ST382分离株，这些分离株通过脉冲场凝胶电泳无法区分。ST382似乎是一个新兴克隆，在2016年之前约32年开始与其祖先分化。我们估计该克隆每个基因组（2.94 Mbp）每年有1.29个核苷酸替换。
