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Proteomics in studies of Staphylococcus aureus virulence

100%

Bonar E., Wójcik I., Wladyka B.

issue 3

367-381

Staphylococcus aureus is a widespread, opportunistic pathogen that causes community and hospital acquired infections. Its high pathogenicity is driven by multifactorial and complex mechanisms determined by the ability of the bacterium to express a wide variety of virulence factors. The proteome secreted into extracellular milieu is a rich reservoir of such factors which include mainly nonenzymatic toxins and enzymes. Simultaneously, membrane proteins, membrane-cell wall interface proteins and cell wall-associated proteins also strongly influence staphylococcal virulence. Proteomics shows a great potential in exploring the role of the extracellular proteome in cell physiology, including the pathogenic potential of particular strains of staphylococci. In turn, understanding the bacterial physiology including the interconnections of particular factors within the extracellular proteomes is a key to the development of the ever needed, novel antibacterial strategies. Here, we briefly overview the latest applications of gel-based and gel-free proteomic techniques in the identification of the virulence factors within S. aureus secretome and surfacome. Such studies are of utmost importance in understanding the host-pathogen interactions, analysis of the role of staphylococcal regulatory systems and also the detection of posttranslational modifications emerging as important modifiers of the infection process.

A novel member of the thermolysin family, cloning and biochemical characterization of metalloprotease from Staphylococcus pseudintermedius

76%

Wladyka B., Bista M., Sabat A. J., Bonar E., Grzeszczuk S., Hryniewicz W., Dubin A.

Acta Biochimica Polonica

2008

vol. 55

issue 3

525-536

Thermolysins constitute a family of secreted bacterial metalloproteases expressed, among others, by several pathogens. Strains of Staphylococcus pseudintermedius isolated from diseased dogs and judged as protease-positive, by skim milk agar plate culture, were investigated for protease content. No proteolytic activity was detected when the bacteria were grown in regular liquid media. Unexpectedly, supplementation of the medium with calcium ions resulted in expression of a metalloprotease and profound changes in the profile of extracellular proteins. On the basis of homology to other staphylococcal metalloproteases, the nucleotide sequence of the gene encoding this protease (Pst) and its flanking regions was determined. The full-length pst codes for a protein with an open reading frame of 505 amino acids. The internal region contains the HEXXH catalytic domain that is conserved in members of the thermolysin family. Regardless of the presence of calcium in the medium, the expression of the protease gene was of the same intensity. This suggests that regulation of the metalloprotease production by calcium ions is at a post-transcriptional level. Isolates of S. pseudintermedius exhibit a proteolytic phenotype due to the metalloprotease expression, however only in presence of calcium ions, which most probably stabilize the structure of the protease.

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2 Acta Biochimica Polonica

1 2015

1 2008

2 Bonar E.

2 Wladyka B.

1 Bista M.

1 Dubin A.

1 Grzeszczuk S.

1 Hryniewicz W.

1 Sabat A. J.

1 Wójcik I.

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Proteomics in studies of Staphylococcus aureus virulence

A novel member of the thermolysin family, cloning and biochemical characterization of metalloprotease from Staphylococcus pseudintermedius