Various optimum conditions for streptolysin O production in Todd Hewitt broth

Abstract

At the beginning, the reagents, especially streptolysin o (SLO) used for antistreptolysin o (ASO) determination, have to be imported, making the cost of this test high. The Department of Microbiology, Chulalongkorn Hospital, has prepared this antigen for routine use. At the present time, there is some problem about the inconstancy of the potency of SLO produced in the Department of Microbiology. The purpose of this study is to solve that problem by determining various optimum conditions for SLO production in Todd Hewitt broth. It was found from the study that 15 % of fresh medium of about 10 – 12 hour – preculture were the suitable size and age of starter for SLO production by the strain C 203 S of Streptococcus pyogenes (group A) in Todd Hewitt broth. The optimal incubation period, temperature and initial ph in the step of SLO preparation were 4 hours, 37℃ and about 7.8, respectively. Neither special carbondioxide tension nor agitation was required for cultivation. The improvement of the method for SLO production, by Streptococcus pyogenes (group A) C 203 S in Todd Hewitt broth, according to various optimum conditions found from this study is satisfactory. It not only increases the level of SLO obtained but also saves time, is economical and is still quite easy to carry out at any average laboratory.