Infection and immunity
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Infection and immunity · Mar 1990
Effective vaccination of mice against leprosy bacilli with subunits of Mycobacterium leprae.
Model vaccines against leprosy bacilli have consisted of nonvirulent, live, attenuated Mycobacterium bovis BCG and irradiated, heat-killed, or autoclaved intact M. leprae. We report that immunization with various cell wall fractions of M. leprae, progressively depleted of lipids, carbohydrates, and soluble proteins, as well as a partially purified protein(s) derived from a pellet fraction of sonicated M. leprae, conferred significant protection against subsequent infection with live leprosy bacilli. Moreover, lymphocytes from regional lymph nodes and spleens of mice immunized with these M. leprae-derived subunits responded by proliferation when stimulated with M. leprae in vitro. Our results provide the first evidence that vaccination with M. leprae-derived fractions protects mice against leprosy bacilli.
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Infection and immunity · Mar 1990
Mortality and bacteriology of sepsis following cecal ligation and puncture in aged mice.
Epidemiologic data suggest that elderly adults are more susceptible to invasive bacterial infection by indigenous gut flora than are younger adults. The purpose of this investigation was to characterize a murine model of clinically encountered peritonitis in the aged. We subjected three different age groups (young, 16 weeks; mature, 12 months; senescent, 24 months) of C57BL/6NNia mice to surgically induced peritonitis by the cecal ligation and puncture procedure. ⋯ The shift from mixed infection during sepsis to predominantly gram-negative bacterial infection reflected a similar progressive shift in bacterial types found in the cecum. At death, senescent mice had 100-fold fewer coliform bacteria in the bloodstream than those found in mature mice (2.5 x 10(9) versus 4.6 x 10(11), respectively). The increased sensitivity of aged mice to invasive bacterial infection documented in this series of experiments accords well with human epidemiologic experience and demonstrates the appropriateness of the model for continued investigations of sepsis in the aged.