Aim: Development a method of treatment of Streptococcus pyogenes bacteria that does not disrupt the integrity of surface structure of cell and provides optimal reproducibility of enzyme preparation activity test results.
Materials and methods: Museum cultures of S. pyogenes M29 and S. pyogenes T1 were used, as well as standard strain S.pyogenes T5 (ATCC) and 3 phage-associated lysine PlyC preparations (enzybiotics): 2 isolated from phage C1, third--recombinant enzyme obtained by cloning phage C1 DNA. 3 methods of S. pyogenes cells treatment were used: inactivation by chloroform, antibiotics and heating.
Results: Treatment of S. pyogenes cells by rifampicin and gentamicin allows simultaneous turbidimetric determination of enzyme preparations activity and streptococci lysis effectiveness with a good reproducibility of test results. Comparison of kinetic curves of streptococci lysis killed by heating with curves of live culture lysis showed that heat treatment of cells results in a decrease oflysis depth and a reduction of enzyme activity. Pattern and effectiveness of lysis of cells incubated with chloroform approached curve of live streptococci lysis, however this method did not exclude lysis of part of cells and required presence of equipment for work with chemical substances. CONCLUSION. S. pyogenes test culture inactivation method by 2-step treatment of culture with antibiotics that does not disrupt the integrity of surface structure of cells and provides optimal reproducibility of enzyme preparation activity test results was developed.