Modulation by staphylococci of the response of mice infected with Neisseria gonorrhoeae.

Most strains of Neisseria gonorrhoeae are rapidly eliminated from the peritoneal cavity of mice following an experimental infection. However, we could modify the rate of clearance of N. gonorrhoeae by preteating (48 h) the mice with sublethal doses of Staphylococcus aureus coagulase-positive strains which provoke the rapid appearance of activated phagocytes; we showed that these have increased activities of their B-galactosidase and their enzymes able to reduce nitroblue tetrazolium (NBT). Presumably, these activated phagocytes participated in the more efficient elimination of N. gonorrhoeae cells from the peritoneal cavity, that is 3 log units instead of 1 for the control, within the first 2 hours after their injection. There was no increase in the clearance of N. gonorrhoeae from the peritoneal cavity of mice when these were pretreated with cyclophosphamide. The use of enzyme-treated staphylococci (protoplasts) showed that some component of the coagulase-positive S. aureus cell wall seems responsible for the stimulation observed. This modulation of the response of mice to N. gonorrhoeae could serve as an improved method to evaluate the virulence of different N. gonorrhoeae strains.