Cytochrome-linked respiration in host grown M. leprae isolated from an Armadillo (Dasypus novemcinctus, L.)

The bacilli were isolated from an armadillo (Dasypus novemcinctus, L.) and cytochrome systems as well as oxidation of succinate and NADH by M. leprae were studied. Cell-free extracts of M. leprae contained cytochromes of the a + a3, b, c and o type. Whole cell suspensions catalyzed the oxidation of succinate. The process was unaffected by rotenone but was markedly inhibited by thenoyltrifluoroacetone, antimycin A and cyanide. Cell-free preparations of M. leprae also oxidized NADH with oxygen as the terminal electron acceptor. Although NADH oxidation was completely inhibited by rotenone, the process was inhibited to only 50% by 5 millimols cyanide. The results indicated that complete respiratory system is present in M. leprae isolated from leprous tissues of an armadillo. The effect of inhibitors on succinate and NADH oxidations showed that the respiration in host-grown M. leprae is mediated through the cytochrome system with oxygen as the final electron acceptor.