Diarrheagenic E. coli can be separated into six distinct pathotypes, with enteroaggregative (EAEC) and diffusely-adherent E. coli (DAEC) among the least characterized. To gain additional insights into these two pathotypes we performed whole genome sequencing of ten DAEC, nine EAEC strains, isolated from Mexican children with diarrhea, and one EAEC plus one commensal E. coli strains isolated from an adult with diarrhea and a healthy child, respectively. These genome sequences were compared to 85 E. coli genomes available in public databases. The EAEC and DAEC strains segregated into multiple different clades; however, six clades were heavily or exclusively comprised of EAEC and DAEC strains, suggesting a phylogenetic relationship between these two pathotypes. EAEC strains harbored the typical virulence factors under control of the activator AggR, but also several toxins, bacteriocins, and other virulence factors. DAEC strains harbored several iron-scavenging systems, toxins, adhesins, and complement resistance or Immune system evasion factors that suggest a pathogenic paradigm for this poorly understood pathotype. Several virulence factors for both EAEC and DAEC were associated with clinical presentations, not only suggesting the importance of these factors, but also potentially indicating opportunities for intervention. Our studies provide new insights into two distinct but related diarrheagenic organisms.

引起腹泻 大肠杆菌 可以分为六种不同的病理类型，具有肠聚集性（EAEC）和弥散性 大肠杆菌（DAEC）最具特色。为了进一步了解这两种病态，我们对十个DAEC，九个EAEC菌株进行了全基因组测序，这些菌株是从墨西哥腹泻儿童中分离出来的，其中一个是EAEC加一个推荐大肠杆菌分别从一个有腹泻的成年人和一个健康的孩子身上分离出的菌株。将这些基因组序列与85大肠杆菌公共数据库中可用的基因组。EAEC和DAEC菌株分为多个不同的进化枝。然而，六个进化枝主要或仅由EAEC和DAEC菌株组成，这表明这两种病态型之间存在系统发育关系。EAEC菌株不仅在激活剂AggR的控制下具有典型的毒力因子，而且还具有多种毒素，细菌素和其他毒力因子。DAEC菌株具有多种除铁系统，毒素，黏附素和补体抗性或免疫系统逃避因子，提示该病原体尚未明确的病原体范例。EAEC和DAEC的几种毒力因子都与临床表现有关，不仅表明这些因子的重要性，而且还潜在地表明了干预的机会。