Comparison of Susceptibilities of M. tuberculosis H37Ra and M. chelonei subsp. Abscessus to Disinfectants

Objective To determine the susceptibilities of M. tuberculosis H37Ra and M. chelonei subsp, absecessus to several frequently-used disinfectants and to evaluate the practicability of surrogating M. tuberculosis by the latter. Methods A suspension quantitative bactericidal test was set up in accordance with Chinese Technique Standard for Disinfection to evaluate the susceptibility of each mycobacteria strain to each selected disinfectant. Killing log value was used as criterion in comparing the susceptibility to disinfectants between the two strains. Results M. chelonei subsp, abscessus was more resistant to chlorine disinfectant than M. tuberculosis while the two strains were similarly resistant to iodophor disinfectant, peracetic acid, alcohol and glutaraldehyde disinfectant. Conclusion M. chelonei subsp, abscessus has the potential to surrogate M. tuberculosis in evaluating mycobactericidal efficacies of disinfectants.