Postcopulatory genital grooming in male rats: prevention of sexually transmitted infections.

Prevention of postcopulatory genital grooming in male rats increased the likelihood that they would be genitally infected with a marker microorganism (Staphylococcus aureus) inoculated previously into the vagina of female rats. Male as well as female rat saliva was found to have very minimal bactericidal effects on the marker organism indicating that physical washing during postcopulatory grooming can prevent the transmission of infectious organisms. Saliva of both male and female rats, however, was found to have bactericidal effects on 2 murine pathogens (Pasteurella pneumotropica and Mycoplasma pulmonis) that infect the genitalia of males and females, revealing that the physical washing effect can be enhanced by specific antibacterial properties of saliva for some reputed genital pathogens.