The Survival of Gonococci and Meningococci in Subcutaneous Diffusion Chambers in Mice

Abstract

THE use of a Millipore diffusion chamber technique for the study of antimicrobial systems in vivo was reported by Roantree and Collis (1960) and by Steward and Roantree (1961 (Logan and Hanson, 1974).The work of Ark0 (1972) on subcutaneous chambers in small laboratory animals provided a new approach to the study of Neisseria gonorrhoeae in experimental animals. Flynn and Waitkins (1973) found that gonococci survived for only 1 day when held in simple open chambers implanted subcutaneously in mice. In subsequent experiments, Waitkins (1975) showed that when gonococci were taken into cells grown in tissue culture and then held in chambers in mice, the survival time of the intracellular bacteria was extended.The present study was undertaken in an attempt to determine the extent to which the longer survival of gonococci within tissue-culture cells may simply have been due to protection of the organisms from the cellular defences of the host. Standardised suspensions of gonococci were placed in Millipore diffusion chambers which were implanted subcutaneously instead of intraperitoneally as in most previous reports. Our diffusion chambers allowed the diffusion of all humoral factors but excluded any cells and are described as '' closed ", whereas Arko's chambers allowed free access of both humoral and cellular elements and are described as " open ".Studies on the survival of gonococci in these Millipore chambers were made in groups of mice and the results obtained in normal mice compared with those in mice pre-immunised with whole gonococci. Similar studies were also carried out with meningococci (N. mezingitidis) in the chambers in place of gonococci. MATERIALS AND METHODSExperimental animals. Swiss albino Webster mice of 18-22 g were used. They were fed a standard diet and water was given ad libitum.