Passive serum therapy with polyclonal antibodies against Mycobacterium tuberculosis protects against post-chemotherapy relapse of tuberculosis infection in SCID mice.

We investigated the protective role of immune-sera against reactivation of Mycobacterium tuberculosis infection in SCID mice and found that passive immunization with sera obtained from mice treated with detoxified M. tuberculosis extracts (delivered in liposomes in a composition known as RUTI) exerted significant protection. Our SCID mouse model consisted of aerosol infection by M.

Immunotherapy with fragmented Mycobacterium tuberculosis cells increases the effectiveness of chemotherapy against a chronical infection in a murine model of tuberculosis.

Reduction of colony forming units by rifampicin-isoniazid therapy given 9-17 weeks post-infection was made more pronounced by immunotherapy with a vaccine made of fragmented Mycobacterium tuberculosis cells detoxified and liposomed (RUTI), given on weeks 17, 19 and 21 post-infection, in the murine model of tuberculosis in C57BL/6 and DBA/2 inbred strains. RUTI triggered a Th1/Th2 response, as demonstrated by the production of IgG1, IgG2a and IgG3 antibodies against a wide range of peptides. The histological analysis did not show neither eosinophilia nor necrosis, and granulomatous infiltration was only slightly increased in C57BL/6 mice when RUTI was administered intranasally.

Catalase-peroxidase activity has no influence on virulence in a murine model of tuberculosis.

The capacity to generate a chronic and persistent infection in the experimental murine model of tuberculosis induced aerogenically by a low-dose inoculum was determined in eight isoniazid-resistant clinical strains of Mycobacterium tuberculosis showing different catalase-peroxidase (C-P) activities. Determination of bacillary concentration in lung and spleen and the percentage of pulmonary parenchyma occupied by granulomas were monitored. Data showed no relation between the lack of C-P activity and the ability to develop a persistent infection, highlighting the potential of C-P negative strains to spread through the community.

Widespread bronchogenic dissemination makes DBA/2 mice more susceptible than C57BL/6 mice to experimental aerosol infection with Mycobacterium tuberculosis.

We have used the murine model of aerosol-induced experimental tuberculosis to assess the effects of four clinical isolates and a reference strain of Mycobacterium tuberculosis on resistant C57BL/6 mice and susceptible DBA/2 mice. Histological studies and detection of 25 cytokines potentially involved in the infection were carried out. DBA/2 mice showed higher concentrations of bacilli in bronchoalveolar lavage fluid and lung tissue.