MPG and infection: To check the temperature sensitivity of Mpg during the infection of macrophages, we compared the colony forming units (CFUs) of Mpg in the murine macrophage cell line J774A.1 at different temperature (30 °C and 37 °C) with those of M. gordonae, which is the phylogenetically closest species to Mpg, and M. marinum, which is also known to have an optimal temperature of 30 °C as seen in Mpg25.