title: Naturally attenuated, orally administered Mycobacterium microti as a tuberculosis vaccine is better than subcutaneous Mycobacterium bovis BCG.
abstract: Mycobacterium microti is phylogenetically closely related to Mycobacterium tuberculosis and is a member of that complex of organisms. It is a curved, acid-fast bacillus that is naturally attenuated with a narrow host range for Microtus species only. In this study, we confirm the unique susceptibility of voles to infection with M. microti and the relative resistance of mice with a significantly lower organism burden after 8 weeks of infection. In addition, histopathologic examination of lungs reveals a lack of cellular, granulomatous aggregates characteristically seen in murine M. tuberculosis infection. In the past, M. microti has been used successfully in humans as a vaccine against tuberculosis but was associated with cutaneous reactions. In an attempt to circumvent this adverse effect, we report the efficacy of aerosol and oral vaccination with M. microti. High-dose orogastric vaccination with M. microti resulted in a statistically significant improvement in protection against aerosol challenge with virulent M. tuberculosis in the murine model compared with subcutaneous M. bovis BCG Pasteur vaccination.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. ymanabe@jhmi.edu
authors.forename: Yukari C
authors.initials: YC
authors.lastname: Manabe
authors.forename: Cherise P
authors.initials: CP
authors.lastname: Scott
authors.forename: William R
authors.initials: WR
authors.lastname: Bishai
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003411:Arvicolinae; D001500:BCG Vaccine / Q000008:administration & dosage / Q000627:therapeutic use*; D004333:Drug Administration Routes; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009161:Mycobacterium / Q000276:immunology*; D009163:Mycobacterium bovis / Q000276:immunology*; D013045:Species Specificity; D014397:Tuberculosis, Pulmonary / Q000517:prevention & control*; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D001500:BCG Vaccine; D014613:Vaccines, Attenuated