Population variability of the FimH type 1 fimbrial adhesin in Klebsiella pneumoniae.
Population variability of the FimH type 1 fimbrial adhesin in Klebsiella pneumoniae.
复制标题
肺炎克雷伯菌中 FimH 1 型菌毛粘附素的群体变异性。
DOI：
10.1128/jb.00601-08
复制
发表时间：
2009
影响因子：
3.2
通讯作者：
Sokurenko,EvgeniV
中科院分区：
文献类型：
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作者：
Stahlhut,SteenG;Chattopadhyay,Sujay;Struve,Carsten;Weissman,ScottJ;Aprikian,Pavel;Libby,StephenJ;Fang,FerricC;Krogfelt,KarenAngeliki;Sokurenko,EvgeniV
FimH 是由不同肠杆菌属表达的 1 型菌毛的粘附亚基。肠道细菌肺炎克雷伯菌是一种环境微生物，也是败血症、尿路感染 (UTI) 和肝脓肿的常见原因。 1 型菌毛已被证明对于 K 的能力至关重要。肺炎球菌在小鼠模型中引起尿路感染。我们在这里展示了 K.肺炎链球菌 fimH 基因存在于 90% 的各种环境和临床来源的菌株中。 FimHalleles 表现出相对较低的核苷酸和结构多样性，但易于在不同细菌克隆之间发生频繁的水平转移事件。在多基因座序列分型中添加 thefimHlocus 显着提高了致病菌株克隆结构的分辨率，包括 K1 封装的肝脏分离株。此外，K.肺炎FimH蛋白是适应性点突变的靶标，尽管其程度与来自同一K的尿路致病性大肠杆菌TonB的FimH不同。肺炎菌株。这种适应性突变包括信号肽中的单个氨基酸缺失，这可能通过影响 FimH 易位到周质中来影响菌毛杆的长度。另一种 FimH 突变 (S62A) 发生在院内尿路致病性克雷伯氏菌克隆的地方性循环过程中。这种突变与在高毒力尿路致病性大肠杆菌菌株中发现的突变相同。大肠杆菌，表明 FimH 突变本质上是病理适应性的。考虑到肠杆菌科中 1 型菌毛的丰富性，我们目前发现 fimH 基因受到适应性微进化的影响，证实了 1 型菌毛介导的粘附在 K 中的重要性。肺炎杆菌。
FimH is an adhesive subunit of type 1 fimbriae expressed by different enterobacterial species. The enteric bacteriumKlebsiella pneumoniaeis an environmental organism that is also a frequent cause of sepsis, urinary tract infection (UTI), and liver abscess. Type 1 fimbriae have been shown to be critical for the ability ofK. pneumoniaeto cause UTI in a murine model. We show here that theK. pneumoniae fimHgene is found in 90% of strains from various environmental and clinical sources. ThefimHalleles exhibit relatively low nucleotide and structural diversity but are prone to frequent horizontal-transfer events between different bacterial clones. Addition of thefimHlocus to multiple-locus sequence typing significantly improved the resolution of the clonal structure of pathogenic strains, including the K1 encapsulated liver isolates. In addition, theK. pneumoniaeFimH protein is targeted by adaptive point mutations, though not to the same extent as FimH from uropathogenicEscherichia colior TonB from the sameK. pneumoniaestrains. Such adaptive mutations include a single amino acid deletion from the signal peptide that might affect the length of the fimbrial rod by affecting FimH translocation into the periplasm. Another FimH mutation (S62A) occurred in the course of endemic circulation of a nosocomial uropathogenic clone ofK. pneumoniae.This mutation is identical to one found in a highly virulent uropathogenic strain ofE. coli, suggesting that the FimH mutations are pathoadaptive in nature. Considering the abundance of type 1 fimbriae inEnterobacteriaceae, our present finding thatfimHgenes are subject to adaptive microevolution substantiates the importance of type 1 fimbria-mediated adhesion inK. pneumoniae.