The Staphylococcus aureus Alternative Sigma Factor ςB Controls the Environmental Stress Response but Not Starvation Survival or Pathogenicity in a Mouse …

PF Chan, SJ Foster, E Ingham… - Journal of …, 1998 - Am Soc Microbiol
PF Chan, SJ Foster, E Ingham, MO Clements
Journal of bacteriology, 1998Am Soc Microbiol
The role of ςB, an alternative sigma factor of Staphylococcus aureus, has been
characterized in response to environmental stress, starvation-survival and recovery, and
pathogenicity. ςB was mainly expressed during the stationary phase of growth and was
repressed by 1 M sodium chloride. A sigB insertionally inactivated mutant was created. In
stress resistance studies, ςB was shown to be involved in recovery from heat shock at 54° C
and in acid and hydrogen peroxide resistance but not in resistance to ethanol or osmotic …
Abstract
The role of ςB, an alternative sigma factor ofStaphylococcus aureus, has been characterized in response to environmental stress, starvation-survival and recovery, and pathogenicity. ςB was mainly expressed during the stationary phase of growth and was repressed by 1 M sodium chloride. AsigB insertionally inactivated mutant was created. In stress resistance studies, ςB was shown to be involved in recovery from heat shock at 54°C and in acid and hydrogen peroxide resistance but not in resistance to ethanol or osmotic shock. Interestingly, S. aureus acquired increased acid resistance when preincubated at a sublethal pH 4 prior to exposure to a lethal pH 2. This acid-adaptive response resulting in tolerance was mediated viasigB. However, ςB was not vital for the starvation-survival or recovery mechanisms. ςB does not have a major role in the expression of the global regulator of virulence determinant biosynthesis, staphylococcal accessory regulator (sarA), the production of a number of representative virulence factors, and pathogenicity in a mouse subcutaneous abscess model. However, SarA upregulates sigB expression in a growth-phase-dependent manner. Thus, ςB expression is linked to the processes controlling virulence determinant production. The role of ςB as a major regulator of the stress response, but not of starvation-survival, is discussed.
American Society for Microbiology