Stabilities of Human Strains of Mycoplasma to Various Physical and Chemical Treatments

Abstract

Stability of mycoplasmas against ultraviolet, urea, SDOC, NaCl solution, organic solvent and enzymic treatments was examined. The mycoplasma strains used were M. pneumoniae CL. FH, M. orale N-1, M. salivarium-C Hup 127, M. fermentans-C and M. hominis Type 1-C. M. orale N-1 was kindly supplied by Dr. Hayflick. These mycoplasma suspensions were tested in the resting states.
The results obtained were as follows;
1) Four strains were generally stable to UV-irradiation; but M. orale was slightly less resistant than others. This strain was inactivated by the irradiation for 7 minutes. On the contrary, M. pneumoniae still survived after the irradiation for 10min.
2) The strains of mycoplasma were fairly sensitive to urea. All strains were not destroyed in 0.1M urea, but M. pneumoniae and M. salivarium were inactivated by the treatment of 1.0M urea for 120min. All strains were completely inactivated by the treatment of 3.0M urea for 60min.
3) In the case of SDOC, all strains except M. orale were not inactivated in 0.01% SDOC solution. However, all strains were inactivated in 0.1% SDOC solution.
4) Two strains tested, except M. pneumoniae, survived for 7 days in 1% NaCl solution, but all strains were inactivated in 3% NaCl solution for 24 hours.
5) In stability test of the strains to various organic solvents, it was interesting that M. orale and M. salivarium still survived against petroleum ether treatment for 24 hours at 4°C. Other two strains were completely inactivated by the treatment of organic solvents, such as chloroform, ethyl ether, toluene, n-butanol and benzen, for 24 hours at 4°C.
6) Treatments of various enzymes, such as α-amylase, lipase, pepsin, trypsin and papain, could not inactivate mycoplasmas, but only pronase which was derived from bacteria could effect to the activities of mycoplasma, and especially, M. pneumoniae was destroyed by digestion of this enzyme for 3 hours at 37°C.