AN OXIDATIVE ENVIRONMENT PROMOTES GROWTH OF MYCOBACTERIUM ABSCESSUS

Mycobacterium abscessus (M. abscessus) infections, particularly those causing chronic lung diseases, are becoming more prevalent worldwide. M. abscessus infections are difficult to treat due to antibiotic resistance. Thus, new treatment options are urgently needed. M. abscessus are intracellular pathogens that primarily infect macrophages and fibroblasts. Because this bacterium has only recently been identified as a separate species, very little is known about M. abscessus-host interactions and how M. abscessus growth is regulated. Oxidative stress has long been shown to inhibit growth of bacterial organisms. However, some intracellular bacteria, such as Mycobacterium tuberculosis, grow well in oxidizing environments. In the present study, we show that M. abscessus infection causes the host cell environment to become more oxidizing. Furthermore, we show that a more oxidizing environment leads to enhanced growth of M. abscessus inside macrophages. In the presence of the antioxidants, MnTE-2-PyP (chemical name: Manganese (II) Meso-Tetrakis-(N-Methylpyridinium-2-yl) porphryin) or N-acetyl-L-cysteine (NAC), M. abscessus growth is inhibited. These results lead us to postulate that antioxidants may aid in the treatment for M. abscessus infections