RT Journal Article
T1 The two-component system RstAB regulates production of a polysaccharide capsule with a role in virulence in the marine pathogen Photobacterium damselae subsp. damselae
A1 Matanza Fente, Xosé Manuel
A1 López-Suárez, Laura
A1 Vale, Ana do
A1 Rodríguez Osorio, Carlos
AB The marine bacterium Photobacterium damselae subsp. damselae (Pdd) causes disease in marine animals and humans. Previous studies demonstrated that mutation of the two-component system RstAB strongly impacts virulence of this pathogen, but the RstAB regulon has not been thoroughly elucidated. We here compared the transcriptomes of Pdd RM-71 and ΔrstA and ΔrstB derivatives using RNA-seq. In accordance with previous studies, RstAB positively regulated cytotoxins Dly, PhlyP and PhlyC. This analysis also demonstrated a positive regulation of outer membrane proteins, resistance against antimicrobials and potential virulence factors by this system. Remarkably, RstAB positively regulated two hitherto uncharacterised gene clusters involved in the synthesis of a polysaccharide capsule. Presence of a capsular layer in wild-type cells was confirmed by transmission electron microscopy, whereas rstA and rstB mutants were non-capsulated. Mutants for capsule synthesis genes, wza and wzc exhibited acapsular phenotypes, were impaired in resistance against the bactericidal action of fish serum and mucus, and were strongly impaired in virulence for fish, indicating a major role of capsule in virulence. Collectively, this study demonstrates that RstAB is a major positive regulator of key virulence factors including a polysaccharide capsule essential for full virulence in a pathogenic Photobacterium
PB Wiley
YR 2021
FD 2021
LK http://hdl.handle.net/10347/29116
UL http://hdl.handle.net/10347/29116
LA eng
NO Environmental Microbiology (2021) 23(9), 4859–4880. https://doi.org/10.1111/1462-2920.15731
NO This work was supported by the Agencia Estatal de Investigación (AEI) of Spain co-funded by the FEDER Programme from the European Union (Grant Nos. AGL2016-79738-R and PID2019-110558RB-I00) to Carlos R. Osorio, and by Xunta de Galicia (Spain) [Grant No. ED431C 2018/18]. Xosé M. Matanza is supported by Xunta de Galicia (Spain). The authors acknowledge the support of the i3S Scientific Platform HEMS, member of the national infrastructure PPBI – Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122) and the assistance of Rui Fernandes and Ana Rita Malheiro with electron microscopy. Ana do Vale was supported by Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., within the scope of Norma Transitória – DL57/2016/CP1355/CT0010. We are grateful to the Instituto Galego de Formación en Acuicultura (IGaFA) (Illa de Arousa, Galicia, Spain), and to Insuiña S.L (Oia, Galicia, Spain) for their valuable support in providing fish for the experiments
DS Minerva
RD 25 abr 2026