Inflammatory response of the urinary bladder wall to streptococcal infection

Group A streptococci have been implicated as the etiological factor in certain disease processes and suggested in numerous others. One of the latter is a severe inflammation of the bladder, known as interstitial cystitis. The experiments reported in this thesis investigated the response of the bladder to an induced streptococcal infection. The investigation was carried out by injecting Group A, Type 12 Beta Hemolytic Streptococcus pyogenes directly into the bladder wall of rabbits. Both single and multiple injections were used. In addition, lyophilized streptococci were given subcutaneously. Bladder sections were studied quantitively and qualitatively. Serum antibody determinations were carried out to demonstrate the possible presence of anti-DNA antibodies, and fluorescent studies utilizing acridine orange were used to demonstrate DNA within the tissue. Immunofluorescence was used to identify streptococcal antigen within the tissue. The examination of histological sections showed a chronic inflammation which was characterized by acute intermittent exacerbations sixty days after a single injection of 8 x 10[4] bacteria into the bladder wall. The bladder sections of the subcutaneously injected animals also show pathological changes. Serum anti-DNA antibodies, plus other unidentified antibodies, were found in all tested rabbits injected with streptococci, Fluorescent studies demonstrated a decrease in DNA fluorescence in 50% of the streptococcus-treated animals tested. The immunofluorescent technique demonstrated the presence of streptococcal antigen in single bladder injected animals for a minimum of sixty days, and a minimum of one hundred and eighty day in multiple injected animals. The streptococcal antigen also was demonstrated in the bladder of subcutaneously injected rabbits. These results indicate that Group A streptococci are capable of producing a progressive chronic inflammation of the bladder. The fact that the viable causative bacteria are no longer present, but streptococcal antigen remains in the bladder suggests that some induced immunological responsible for the chronic inflammation. The significance of anti-DNA antibodies and a decrease of DNA fluorescence in bladder tissue are not known, but it is likely that they are related to tissue injury. The finding that streptococci given subcutaneously can localize in the bladder has far-reading implications. It is suggested that streptococcus in the initial etiological factor in interstitial cystitis.