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Significant contribution of the pgdA gene to the virulence of Streptococcus suis
Author(s) -
Fittipaldi Nahuel,
Sekizaki Tsutomu,
Takamatsu Daisuke,
De La Cruz DomínguezPunaro María,
Harel Josée,
Bui Nhat Khai,
Vollmer Waldemar,
Gottschalk Marcelo
Publication year - 2008
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2008.06463.x
Subject(s) - streptococcus suis , biology , virulence , microbiology and biotechnology , mutant , lysozyme , pathogen , virulence factor , gene , in vitro , peptidoglycan , bacteria , genetics
Summary Streptococcus suis is a major swine pathogen and emerging zoonotic agent. In this study we have determined the muropeptide composition of S. suis peptidoglycan (PG) and found, among other modifications, N‐deacetylated compounds. Comparison with an isogenic mutant showed that the product of the pgdA gene is responsible for this specific modification which occurred in very low amounts. Low level of PG N‐deacetylation correlated with absence of significant lysozyme resistance when wild‐type S. suis was grown in vitro . On the other hand, expression of the pgdA gene was increased upon interaction of the bacterium with neutrophils in vitro as well as in vivo in experimentally inoculated mice, suggesting that S. suis may enhance PG N‐deacetylation under these conditions. Evaluation of the Δ pgdA mutant in both the CD1 murine and the porcine models of infection revealed a significant contribution of the pgdA gene to the virulence traits of S. suis . Reflecting a severe impairment in its ability to persist in blood and decreased ability to escape immune clearance mechanisms mediated by neutrophils, the Δ pgdA mutant was highly attenuated in both models. The results of this study suggest that modification of PG by N‐deacetylation is an important factor in S. suis virulence.