Further Studies on the Effects of Spleen Extract on Bacteria

Abstract

In a previous paper (Nutini and Kreke, 1942) we have shown that extracts prepared from both human and beef spleens are capable of completely inhibiting the in vitro growth of Streptococcus pyogenes in concentrations as low as 1: 2,000. Since the ultimate effect of any germicidal substance on an organism is usually preceded by changes in the metabolism, the present investigations were undertaken in an effort to determine whether such is the case with hemolytic streptococci subjected to the influence of spleen extract, and thus indirectly to determine the mode of action of the extract. For this purpose studies were conducted on the organism from both bacteriologic and chemical viewpoints, including morphology, staining reaction, fermentation, and biochemistry.In addition, investigation of the effect of spleen extract on other organisms, reported in this same article (Nutini and Kreke, 1942) as preliminary work, has been greatly extended. The latter work was instituted with a view to determining whether or not the germicidal activity of the splenic extract was specific for hemolytic streptococci, since the preliminary tests seemed to indicate this. The experiments, performed in much the same manner as those with streptococci, were confined principally to staphylococci and organisms of the colon-typhoiddysentery group, although the pneumococcus and tubercle bacillus were also included. EXPERIMENTAL of the extract, and this concentration was used throughout the following experiments.The effect of the spleen extract on the staining reaction was the first of the bacteriologic reactions investigated. Control tubes containing brain heart in-177 on July 16, 2020 by guest

Further Studies on Effects of Tissue Extracts on Staphylococcus Aureus

“…with all of the extracts were typical of those in previous experiments (5). In a series of three experiments the various tissue extracts were added in concentrations of 0.5 and 1.0 per cent to the solid nutrient media.…”

Effect of Staphylococcus aureus Extracts on Various Bacteria

“…For some time past, reports dealing with the effect of protein-free alcoholic extracts of various animal tissues on the growth of certain bacteria in vitro and in vivo have come from these laboratories (Nutini and Kreke, 1942;Nutini, Kreke, and Schroeder, 1945; Nutini and Lynch, 1945). The effectiveness of such extracts suggested further research using extracts of specific bacteria instead of the animal tissues.…”