Calcium inhibits bap-dependent multicellular behavior in Staphylococcus aureus

Arrizubieta, M.J., Toledo-Arana, A., Amorena, B., Penades, J.R. and Lasa, I. (2004) Calcium inhibits bap-dependent multicellular behavior in Staphylococcus aureus. Journal of Bacteriology, 186(22), pp. 7490-7498. (doi:10.1128/JB.186.22.7490-7498.2004)

Full text not currently available from Enlighten.

Abstract

Bap (biofilm-associated protein) is a 254-kDa staphylococcal surface protein implicated in formation of biofilms by staphylococci isolated from chronic mastitis infections. The presence of potential EF-hand motifs in the amino acid sequence of Bap prompted us to investigate the effect of calcium on the multicellular behavior of Bap-expressing staphylococci. We found that addition of millimolar amounts of calcium to the growth media inhibited intercellular adhesion of and biofilm formation by Bap-positive strain V329. Addition of manganese, but not addition of magnesium, also inhibited biofilm formation, whereas bacterial aggregation in liquid media was greatly enhanced by metal-chelating agents. In contrast, calcium or chelating agents had virtually no effect on the aggregation of Bap-deficient strain M556. The biofilm elicited by insertion of bap into the chromosome of a biofilm-negative strain exhibited a similar dependence on the calcium concentration, indicating that the observed calcium inhibition was an inherent property of the Bap-mediated biofilms. Site-directed mutagenesis of two of the putative EF-hand domains resulted in a mutant strain that was capable of forming a biofilm but whose biofilm was not inhibited by calcium. Our results indicate that Bap binds Ca2+ with low affinity and that Ca2+ binding renders the protein noncompetent for biofilm formation and for intercellular adhesion. The fact that calcium inhibition of Bap-mediated multicellular behavior takes place in vitro at concentrations similar to those found in milk serum supports the possibility that this inhibition is relevant to the pathogenesis and/or epidemiology of the bacteria in the mastitis process.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Penades, Professor Jose R
Authors: Arrizubieta, M.J., Toledo-Arana, A., Amorena, B., Penades, J.R., and Lasa, I.
College/School:College of Medical Veterinary and Life Sciences > Institute of Infection Immunity and Inflammation
Journal Name:Journal of Bacteriology
ISSN:0021-9193
ISSN (Online):1098-5530

University Staff: Request a correction | Enlighten Editors: Update this record