Resumen de Stress Response in Mycoplasmas
Melissa L. Madsen, F. Chris Minion
Because mycoplasmas lack cell walls and have a limited genome capacity, there has been interest in their regulation of gene expression in these unique organisms. Their restriction to the host environment only adds to the intrigue. That environment, however, is not constant, changing with the host adaption to colonization and disease by the mycoplasma. This review focuses on the types of stresses the mycoplasma might encounter in vivo including heat shock, oxidative stress, osmolarity shifts, hormone exposure, and iron deprivation. Biofilm studies are included because of their use by other pathogens as a defense measure to resist killing in the host. The field of mycoplasmology is still in its infancy, particularly in regards to gene regulatory mechanisms. There have even been suggestions that mycoplasmas may not have the capacity to respond to changing environmental conditions. The studies reported here, however, show unequivocally that mycoplasmas do respond to their environment by altering transcription rates. How that is accomplished is still unknown except in one instance, heat shock. In summary, like all bacteria, mycoplasmas respond to their environment. That response may be limited, but it appears essential to their survival.
