TY - JOUR
T1 - H-NS nucleoid protein controls virulence features of Klebsiella pneumoniae by regulating the expression of type 3 pili and the capsule polysaccharide
AU - Ares, Miguel A.
AU - Fernández-Vázquez, José L.
AU - Rosales-Reyes, Roberto
AU - Jarillo-Quijada, Ma Dolores
AU - von Bargen, Kristine
AU - Torres, Javier
AU - González-y-Merchand, Jorge A.
AU - Alcántar-Curiel, María D.
AU - De la Cruz, Miguel A.
N1 - Publisher Copyright:
© 2016 Ares, Fernández-Vázquez, Rosales-Reyes, Jarillo-Quijada, von Bargen, Torres, González-y-Merchand, Alcántar-Curiel and De la Cruz.
PY - 2016
Y1 - 2016
N2 - Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial infections. Main virulence determinants of K. pneumoniae are pili, capsular polysaccharide, lipopolysaccharide, and siderophores. The histone-like nucleoid-structuring protein (H-NS) is a pleiotropic regulator found in several gram-negative pathogens. It has functions both as an architectural component of the nucleoid and as a global regulator of gene expression. We generated a Δhns mutant and evaluated the role of the H-NS nucleoid protein on the virulence features of K. pneumoniae. A Δhns mutant down-regulated the mrkA pilin gene and biofilm formation was affected. In contrast, capsule expression was derepressed in the absence of H-NS conferring a hypermucoviscous phenotype. Moreover, H-NS deficiency affected the K. pneumoniae adherence to epithelial cells such as A549 and HeLa cells. In infection experiments using RAW264.7 and THP-1 differentiated macrophages, the Δhns mutant was less phagocytized than the wild-type strain. This phenotype was likely due to the low adherence to these phagocytic cells. Taken together, our data indicate that H-NS nucleoid protein is a crucial regulator of both T3P and CPS of K. pneumoniae.
AB - Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial infections. Main virulence determinants of K. pneumoniae are pili, capsular polysaccharide, lipopolysaccharide, and siderophores. The histone-like nucleoid-structuring protein (H-NS) is a pleiotropic regulator found in several gram-negative pathogens. It has functions both as an architectural component of the nucleoid and as a global regulator of gene expression. We generated a Δhns mutant and evaluated the role of the H-NS nucleoid protein on the virulence features of K. pneumoniae. A Δhns mutant down-regulated the mrkA pilin gene and biofilm formation was affected. In contrast, capsule expression was derepressed in the absence of H-NS conferring a hypermucoviscous phenotype. Moreover, H-NS deficiency affected the K. pneumoniae adherence to epithelial cells such as A549 and HeLa cells. In infection experiments using RAW264.7 and THP-1 differentiated macrophages, the Δhns mutant was less phagocytized than the wild-type strain. This phenotype was likely due to the low adherence to these phagocytic cells. Taken together, our data indicate that H-NS nucleoid protein is a crucial regulator of both T3P and CPS of K. pneumoniae.
KW - Adherence
KW - Capsule
KW - H-NS
KW - K. pneumoniae
KW - Phagocytosis
KW - T3P
KW - Virulence
UR - http://www.scopus.com/inward/record.url?scp=85006221924&partnerID=8YFLogxK
U2 - 10.3389/fcimb.2016.00013
DO - 10.3389/fcimb.2016.00013
M3 - Artículo
C2 - 26904512
SN - 2235-2988
VL - 6
JO - Frontiers in Cellular and Infection Microbiology
JF - Frontiers in Cellular and Infection Microbiology
IS - FEB
M1 - 13
ER -