The metabolite transporter PEG344 is required for the full virulence of the hypervirulent Klebsiella pneumoniae strain hvKP1 after pulmonary, but not subcutaneous challenge.

5 years ago

The metabolite transporter PEG344 is required for the full virulence of the hypervirulent Klebsiella pneumoniae strain hvKP1 after pulmonary, but not subcutaneous challenge.

Russo TA, Beanan J, MacDonald U, Olson R, Bulger J

Hypervirulent Klebsiella pneumoniae (hvKP) is an emerging pathotype that is capable of causing tissue-invasive, organ and life threatening infections in healthy individuals from the community. Knowledge on the virulence factors specific to hvKP is limited. In this report we describe a new factor (PEG344) that increases the virulence of the hvKP strain hvKP1. peg344 is present on the hvKP1 virulence plasmid, is broadly prevalent among hvKP strains, and has increased RNA abundance when grown in human ascites. An isogenic derivative of hvKP1 (hvKP1Δpeg344) was constructed and compared with its wild-type parent in in vitro, ex vivo, and infection model studies. Both survival and competition experiments with outbred CD1 mice demonstrated that PEG344 was required for full virulence after pulmonary challenge, but interestingly, not after subcutaneous challenge. In silico analysis suggested that PEG344 serves as an inner membrane transporter. Compared to hvKP1, a small, but significantly significant decrease in growth/survival of hvKP1Δpeg344 was observed in human ascites, but resistance to the bactericidal activity of complement was similar. These data suggested that PEG344 may transport an unidentified growth factor present in ascites. The data presented are important since it expands our limited knowledge base on virulence factors unique to hvKP, which is needed to lay the groundwork for translational approaches to prevent or treat these devastating infections.

Publisher URL: https://www.ncbi.nlm.nih.gov/pubmed/28717029

DOI: PubMed:28717029