Department of Clinical Sciences, USA.
Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
Vet Microbiol. 2019 Apr;231:197-206. doi: 10.1016/j.vetmic.2019.03.020. Epub 2019 Mar 18.
Typical enteropathogenic E. coli (tEPEC) carries the highest hazard of death in children with diarrhea and atypical EPEC (aEPEC) was recently identified as significantly associated with diarrheal mortality in kittens. In both children and kittens there is a significant association between aEPEC burden and diarrheal disease, however the infection can be found in individuals with and without diarrhea. It remains unclear to what extent, under what conditions, or by what mechanisms aEPEC serves as a primary pathogen in individuals with diarrhea. It seems likely that a combination of host and bacterial factors enable aEPEC to cause disease in some individuals and not in others. The purpose of this study was to determine the impact of aEPEC on intestinal function and diarrhea in kittens following experimentally-induced carriage and the influence of a disrupted intestinal microbiota on disease susceptibility. Results of this study identify aEPEC as a potential pathogen in kittens. In the absence of disruption to the intestinal microbiota, kittens are resistant to clinical signs of aEPEC carriage but demonstrate significant occult changes in intestinal absorption and permeability. Antibiotic-induced disruption of the intestinal microbiota prior to infection increases subsequent intestinal water loss as determined by % fecal wet weight. Enrichment of the intestinal microbiota with a commensal member of the feline mucosa-associated microbiota, Enterococcus hirae, ameliorated the effects of aEPEC experimental infection on intestinal function and water loss. These observations begin to unravel the mechanisms by which aEPEC infection may be able to exploit susceptible hosts.
典型肠致病性大肠杆菌（tEPEC）对腹泻患儿的死亡风险最高，而非典型肠致病性大肠杆菌（aEPEC）最近被确定与幼猫腹泻性死亡显著相关。在儿童和幼猫中，aEPEC 负荷与腹泻病之间存在显著关联，但感染可在有腹泻和无腹泻的个体中发现。在何种程度、何种条件下或通过何种机制，aEPEC 作为腹泻个体的主要病原体，尚不清楚。似乎很可能是宿主和细菌因素的结合使 aEPEC 能够在某些个体中引起疾病，而在其他个体中则不会。本研究旨在确定实验性携带后 aEPEC 对幼猫肠道功能和腹泻的影响，以及肠道微生物群失调对疾病易感性的影响。本研究的结果表明 aEPEC 是幼猫的一种潜在病原体。在肠道微生物群未失调的情况下，幼猫对 aEPEC 携带的临床症状具有抗性，但表现出肠道吸收和通透性的明显隐匿性变化。感染前用抗生素破坏肠道微生物群会增加随后的肠道水分流失，这可以通过粪便湿重的百分比来确定。用猫黏膜相关微生物群的共生成员屎肠球菌使肠道微生物群富集，可改善 aEPEC 实验感染对肠道功能和水分流失的影响。这些观察结果开始揭示 aEPEC 感染可能利用易感宿主的机制。
