Publication Date:
2004-11-01
Description:
Staphylococcus aureus, a leading cause of bacterial infections in humans, is endowed with a wealth of virulence factors that contribute to the disease process. Several extracellular proteolytic enzymes, including cysteine proteinases referred to as the staphopains (staphopain A, encoded by thescpAgene, and staphopain B, encoded bysspB), have proposed roles for staphylococcal virulence. Here we present data regarding the distribution, copy number and genetic variability of the genes encoding the staphopains in a large number ofS. aureusstrains. The polymorphism of thescpAandsspBgenes in three laboratory strains and 126 clinical isolates was analyzed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Both genes were detected in all isolates by PCR amplification and, based on the PCR-RFLP patterns, classified as four types forscpAand six types forsspB. Those with the most divergent patterns were subjected to DNA sequencing and compared with genomic sequence data for the seven available strains ofS. aureus. Southern blot analysis of thescpAandsspBsequences indicates that they are strongly conserved as single-copy genes in the genome of eachS. aureusstrain investigated. Taken together, these data suggest that the staphopains have important housekeeping and/or virulence functions, and therefore may constitute an interesting target for the development of therapeutic inhibitors for the treatment of staphylococcal diseases.
Print ISSN:
1431-6730
Electronic ISSN:
1437-4315
Topics:
Biology
,
Chemistry and Pharmacology
Permalink