Zoonotic pathogen Escherichia albertii has been identified as the cause of several human disease outbreaks; however, factors such as the general symptoms and incubation period of E. albertii infection have yet to be defined. Therefore, we aimed to determine the unique aspects of E. albertii outbreaks in Japan and to examine the genetic characteristics of the causative pathogen. We studied all known E. albertii outbreaks that occurred in Japan up until 2015, which consisted of five confirmed outbreaks and one putative outbreak (Outbreaks 1-6). Outbreaks were re-examined based on personal communications between researchers in prefectural and municipal public health institutes, and through examination of any published study conducted at the time. Draft genome sequences of outbreak-associated E. albertii isolates were also generated. The most common symptom displayed by patients across the six episodes was watery diarrhea (>80%), followed by abdominal pain (50-84%) and fever (37.0-39.5°C) (26-44%). The estimated average incubation period of E. albertii infection was 12-24 h. We assumed that most of the outbreaks were foodborne or waterborne, with restaurant foods, restaurant water, and boxed lunches being the suspected transmission vehicles. Three of the six outbreak-associated E. albertii isolates possessed intact ETT2 regions, while the remaining isolates contained disrupted ETT2-encoding genes. Virulence gene screening revealed that more than half (44/70) of the tested genes were present in all 5 strains examined, and that each of the strains contained more than 1 gene from 14 out of the 21 groups of virulence genes examined in this study. The five E. albertii strains were classified into four of the five known phylogroups. Therefore, we determined that multiple E. albertii genotypes in Japan have the potential to cause outbreaks of diarrhea, abdominal pain, and/or fever following infection of a human host.

中文翻译：

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在日本的艾伯氏大肠埃希菌暴发的流行病学方面和致病性病原体的遗传特征。

人畜共患病病原体大肠埃希氏菌已被确定为导致数次人类疾病暴发的原因。然而，诸如艾伯氏大肠杆菌感染的一般症状和潜伏期等因素尚未确定。因此，我们旨在确定日本的艾伯塔氏病暴发的独特方面，并检查致病性病原体的遗传特征。我们研究了直到2015年在日本发生的所有已知的艾伯塔氏菌暴发，其中包括五次确诊暴发和一次推定暴发（暴发1-6）。根据县和市公共卫生机构的研究人员之间的个人交流，并通过检查当时进行的任何已发表研究，对暴发进行了重新检查。还产生了与暴发相关的艾伯球菌分离株的基因组草图序列。患者在六次发作中表现出的最常见症状是水样腹泻（> 80％），其次是腹痛（50-84％）和发烧（37.0-39.5°C）（26-44％）。估计的艾伯氏大肠杆菌感染的平均潜伏期为12-24小时。我们认为，大多数暴发是食源性或水传播的，餐厅食物，餐厅水和盒装午餐是可疑的传播工具。六个与疫情相关的艾伯氏大肠杆菌分离株中的三个具有完整的ETT2区域，而其余的分离株则包含被破坏的ETT2编码基因。毒力基因筛选显示，在所有接受检测的5种菌株中，超过一半（44/70）的受测基因存在，并且在本研究的21种毒力基因组中，每种菌株均含有超过14种基因。五E. albertii菌株被分类为五个已知系统群中的四个。因此，我们确定日本的多种艾伯氏大肠杆菌基因型有可能在感染人宿主后引起腹泻，腹痛和/或发烧。