Phosphoenolpyruvate phosphotransferase system components positively regulate Klebsiella biofilm formation.

Klebsiella pneumoniae is one of the leading causes of device-related infections (DRIs), which are associated with attachment of bacteria to these devices to form a biofilm. The latter is composed of not only bacteria but also extracellular polymeric substances (EPSes) consisting of extracellular DNAs, polysaccharides, and other macromolecules. The phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) regulates diverse processes of bacterial physiology. In the genome of K. pneumoniae MGH 78578, we found an uncharacterized enzyme II complex homolog of PTS: KPN00353 (EIIA homolog), KPN00352 (EIIB homolog), and KPN00351 (EIIC homolog). The aim of this study was to characterize the potential physiological role of KPN00353, KPN00352, and KPN00351 in biofilm formation by K. pneumoniae. We constructed the PTS mutants and recombinant strains carrying the gene(s) of PTS. The recombinant K. pneumoniae strain overexpressing KPN00353-KPN00352-KPN00351 produced more extracellular matrix than did the vector control according to transmission and scanning electron microscopy. Judging by quantification of biofilm formation, of extracellular DNA (eDNA), and of capsular polysaccharide, the recombinant strain overexpressing KPN00353-KPN00352-KPN00351 produced more biofilm and capsular polysaccharide after overnight culture and more eDNA in the log phase as compared to the vector control. The genes, KPN00353-KPN00352-KPN00351, encode a putative enzyme II complex in PTS and positively regulate biofilm formation by enhancing production of eDNA and capsular polysaccharide in K. pneumoniae. Five proteins related to chaperones, to the citric acid cycle, and to quorum sensing are upregulated by the KPN00353-KPN00352-KPN00351 system.

Horng YT ，Wang CJ ，Chung WT ，Chao HJ ，Chen YY ，Soo PC ... -  《-》

The Fructose-Specific Phosphotransferase System of Klebsiella pneumoniae Is Regulated by Global Regulator CRP and Linked to Virulence and Growth.

Klebsiella pneumoniae is an opportunistic pathogen, and its hypervirulent variants cause serious invasive community-acquired infections. A genomic view of K. pneumoniae NTUH-2044 for the carbohydrate phosphotransferase system (PTS) found a putative fructose PTS, namely, the Frw PTS gene cluster. The deletion mutant and the complemented mutant of frwC (KP1_1992), which encodes the putative fructose-specific enzyme IIC, were constructed, and the phenotypes were characterized. This transmembrane PTS protein is responsible for fructose utilization. frwC deletion can enhance biofilm formation and capsular polysaccharide (CPS) biosynthesis but decreases the growth rate and lethality in mice. frwC expression was repressed in the cyclic AMP receptor protein (CRP) mutant. Electrophoretic mobility shift assay showed that CRP can directly bind to the promoter of frwC These results indicated that frwC expression is controlled by CRP directly and that such regulation contributes to bacterial growth, CPS synthesis, and the virulence of the Δcrp strain. The findings help elucidate fructose metabolism and the CRP regulatory mechanism in K. pneumoniae.

Lin D ，Fan J ，Wang J ，Liu L ，Xu L ，Li F ，Yang J ，Li B ... -  《-》

Cellobiose-specific phosphotransferase system of Klebsiella pneumoniae and its importance in biofilm formation and virulence.

Wu MC ，Chen YC ，Lin TL ，Hsieh PF ，Wang JT ... -  《-》

The phosphoenolpyruvate phosphotransferase system regulates Vibrio cholerae biofilm formation through multiple independent pathways.

Houot L ，Chang S ，Pickering BS ，Absalon C ，Watnick PI ... -  《-》

Signature-tagged mutagenesis of Klebsiella pneumoniae to identify genes that influence biofilm formation on extracellular matrix material.

Boddicker JD ，Anderson RA ，Jagnow J ，Clegg S ... -  《-》