Pyelonephritis. X. Microbial interference in streptococcal infections in the rat kidney.

Abstract

Abstract Interactions of bacteriocin-producing strains of Streptococcus faccalis were studied in vitro and in vivo. In addition, experiments were done to evaluate the effect of physico-chemical parameters unique to the kidney on interactions of selected organisms. This was accomplished by incorporation of sodium or potassium chloride, urea, creatihine, varying pH, and increasing osmolality of the agar (sucrose). Effect of excess glucose as an energy source was evaluated. While results did not follow a predictable pattern, both increase and decrease in inhibition could be demonstrated, depending on combination of organisms used and parameter studied. Studies in vivo were done with experimental hematogenous pyelonephritis in the rat. The bacteriocin-producing strain ( S. faecalis variety (var.) zymogenes ) was able to inhibit but never completely eliminate susceptible S. faecalis G-K whether given one week prior to, simultaneously with, or one week after the G-K strain. When given simultaneously, it also predominated over another susceptible strain, ATCC 9790. However, with the less susceptible strain 3256, the results in vivo did not parallel those noted in vitro as the susceptible strain became more numerous. When S. faecalis var. zymogenes was given simultaneously with strain 2866 which was resistant to it in vitro, the latter at first predominated, but subsequently kidney bacterial populations tended to equalize. These data suggest that bacteriocin production and susceptibility thereto play an important role in determining the result of mixed renal infection. However, effect of physico-chemical characteristics of the kidney environment on bacteriocin activity may determine final outcome.