Snyder Jennifer A, Haugen Brian J, Buckles Eric L, Lockatell C Virginia, Johnson David E, Donnenberg Michael S, Welch Rodney A, Mobley Harry L T
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, USA.
Infect Immun. 2004 Nov;72(11):6373-81. doi: 10.1128/IAI.72.11.6373-6381.2004.
A uropathogenic Escherichia coli strain CFT073-specific DNA microarray that includes each open reading frame was used to analyze the transcriptome of CFT073 bacteria isolated directly from the urine of infected CBA/J mice. The in vivo expression profiles were compared to that of E. coli CFT073 grown statically to exponential phase in rich medium, revealing the strategies this pathogen uses in vivo for colonization, growth, and survival in the urinary tract environment. The most highly expressed genes overall in vivo encoded translational machinery, indicating that the bacteria were in a rapid growth state despite specific nutrient limitations. Expression of type 1 fimbriae, a virulence factor involved in adherence, was highly upregulated in vivo. Five iron acquisition systems were all highly upregulated during urinary tract infection, as were genes responsible for capsular polysaccharide and lipopolysaccharide synthesis, drug resistance, and microcin secretion. Surprisingly, other fimbrial genes, such as pap and foc/sfa, and genes involved in motility and chemotaxis were downregulated in vivo. E. coli CFT073 grown in human urine resulted in the upregulation of iron acquisition, capsule, and microcin secretion genes, thus partially mimicking growth in vivo. On the basis of gene expression levels, the urinary tract appears to be nitrogen and iron limiting, of high osmolarity, and of moderate oxygenation. This study represents the first assessment of any E. coli pathotype's transcriptome in vivo and provides specific insights into the mechanisms necessary for urinary tract pathogenesis.
使用包含每个开放阅读框的尿路致病性大肠杆菌菌株CFT073特异性DNA微阵列，分析直接从受感染的CBA/J小鼠尿液中分离出的CFT073细菌的转录组。将体内表达谱与在丰富培养基中静态生长至指数期的大肠杆菌CFT073的表达谱进行比较，揭示了这种病原体在体内用于在尿路环境中定殖、生长和存活的策略。体内总体表达最高的基因编码翻译机制，这表明尽管存在特定的营养限制，细菌仍处于快速生长状态。参与黏附的毒力因子1型菌毛的表达在体内高度上调。在尿路感染期间，五种铁获取系统均高度上调，负责荚膜多糖和脂多糖合成、耐药性和微菌素分泌的基因也是如此。令人惊讶的是，其他菌毛基因，如pap和foc/sfa，以及参与运动性和趋化性的基因在体内下调。在人尿中生长的大肠杆菌CFT073导致铁获取、荚膜和微菌素分泌基因上调，从而部分模拟体内生长。根据基因表达水平，尿路似乎存在氮和铁限制、高渗透压和中等氧合。这项研究是对任何大肠杆菌致病型体内转录组的首次评估，并为尿路发病机制所需的机制提供了具体见解。
