In vitro killing of mycobacteria by low temperature atmospheric pressure plasma and dielectric barrier discharge plasma for treatment of tuberculosis

Abstract

BackgroundTo prove the efficacy of cold atmospheric plasma (CAP) to inactivate mycobacteria in vitro, we tested the susceptibility of important mycobacterial species to evaluate potential alternative treatment options. MethodsWe tested 8 different mycobacterial species M. tuberculosis22MTB: Mycobacterium tuberculosis. (MTB) (resistant against isoniazid (INH)), M. marinum, M. ulcerans, M. abscessus, M. chelonae, M. africanum, M. terrae and M. avium against two typical CAP devices, a low temperature atmospheric pressure plasma jet (APPJ) and a dielectric barrier discharge plasma (DBD). The tests followed a modified standard procedure by comparing obtained inhibition zones after irradiation of 3, 15, 30 and 60s on selective (Löwenstein-Jensen) medium. ResultsIrradiation by both sources proved high antimycobacterial killing effectiveness against all species including the INH-resistant strain of M. tuberculosis and a set of most important mycobacterial pathogens causing mycobacteriosis. Plasma irradiation <t=60s resulted in significant microbiocidal reduction of mycobacteria of the MTBC-complex and important nontuberculous mycobacteria (NTM) in vitro. DBD and APPJ plasma killed all isolates on Löwenstein-Jensen medium. ConclusionPlasma treatment (both sources) may serve as a future option for treatment of skin tuberculosis evolved from M. tuberculosis (lupus vulgaris), NTM and leprosy and also for surface decontamination after suspected contact with acid fast microbes.