Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109.
Microbiol Spectr. 2015 Jun;3(3). doi: 10.1128/microbiolspec.MBP-0016-2015.
Among common infections, urinary tract infections (UTI) are the most frequently diagnosed urologic disease. The majority of UTIs are caused by uropathogenic Escherichia coli. The primary niche occupied by E. coli is the lower intestinal tract of mammals, where it resides as a beneficial component of the commensal microbiota. Although it is well-known that E. coli resides in the human intestine as a harmless commensal, specific strains or pathotypes have the potential to cause a wide spectrum of intestinal and diarrheal diseases. In contrast, extraintestinal E. coli pathotypes reside harmlessly in the human intestinal microenvironment but, upon access to sites outside of the intestine, become a major cause of human morbidity and mortality as a consequence of invasive UTI (pyelonephritis, bacteremia, or septicemia). Thus, extraintestinal pathotypes like uropathogenic E. coli (UPEC) possess an enhanced ability to cause infection outside of the intestinal tract and colonize the urinary tract, the bloodstream, or cerebrospinal fluid of human hosts. Due to the requirement for these E. coli to replicate in and colonize both the intestine and extraintestinal environments, we posit that physiology and metabolism of UPEC strains is paramount. Here we discuss that the ability to survive in the urinary tract depends as much on bacterial physiology and metabolism as it does on the well-considered virulence determinants.
在常见感染中，尿路感染（UTI）是最常见的泌尿科疾病。大多数 UTI 是由尿路致病性大肠杆菌引起的。大肠杆菌的主要栖居地是哺乳动物的下消化道，在那里它作为共生微生物群落的有益组成部分存在。尽管众所周知，大肠杆菌作为无害共生体存在于人类肠道中，但特定的菌株或血清型有可能引起广泛的肠道和腹泻疾病。相比之下，肠外大肠杆菌血清型在人类肠道微环境中无害地存在，但一旦进入肠道以外的部位，就会成为人类发病率和死亡率的主要原因，导致侵袭性尿路感染（肾盂肾炎、菌血症或败血症）。因此，像尿路致病性大肠杆菌（UPEC）这样的肠外血清型具有增强的在肠道外引起感染和定植泌尿道、血液或人类宿主的脑脊液的能力。由于这些大肠杆菌需要在肠道和肠外环境中复制和定植，我们假设 UPEC 菌株的生理学和代谢是至关重要的。在这里，我们讨论了在泌尿道中存活的能力在多大程度上取决于细菌的生理学和代谢，以及精心考虑的毒力决定因素。
