Insertional inactivation of a chromosomal locus that modulates expression of potential virulence determinants in Staphylococcus aureus.

摘要: A single insertion of transposon Tn551 into a unique chromosomal locus Staphylococcus aureus ISP479C has resulted in pleiotropic effect on the expression both extracellular and cell wall proteins. In particular, protein clumping activity with fibrinogen were rendered undetectable mutant 1E3 compared parent. The secretion alpha-hemolysin was modestly increased. Southern blot phenotypic analyses indicated that this is distinct from agr, xpr, sar, three previously described global regulatory loci. Transduction experiments demonstrated genotype associated could be transferred back parental strain ISP479C. transductant 1E3-2 displayed profile similar to original mutant. Northern (RNA) studies showed may involved modulating target genes at mRNA level. rabbit endocarditis model, there significant decrease infectivity rate intravegetation bacterial density parent an inoculum 10(3) CFU. Since fibrinogen-binding protein(s) are major surface proteins mediate adhesion host tissues, important genetic element virulence determinants S. aureus.