SUSCEPTIBILITY AND RESISTANCE OF INBRED MICE TO PARACOCCIDIOIDES-BRASILIENSIS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 66  (5) , 585-594
Abstract
Nine different inbred strains of mice inoculated intraperitoneally with yeast cells of Paracoccidioides brasiliensis showed significantly varying patterns of susceptibility. The A/SN strain was found to be the most resistant, while BI0D2/nSn, B10.A and B10D2/oSn the most susceptible strains. These susceptibility differences were not dependent on the size of challenge inocula and sex of animals. All strains studied showed a mean survival time proportional to the size of inocula used. Although almost all infected male mice presented a shorter survival time when compared with females, significant mortality differences between sexes were found only in two of the strains studied, namely BALB/c and B10D2/nSn. The H-2 region did not influence the susceptibility pattern since the A/SN and B10.A strains share the same H-2 haplotype and were respectively highly resistant and susceptible to P. brasiliensis. Furthermore, the presence of C5 and unresponsiveness to lipopolysaccharide had no influence on the mortality data observed. Specific antibodies were detected only in a small number of animals and titres were consistently low, appearing later in the resistant (A/SN) than in a susceptible strain (B10.A). Omentum, spleen and liver were the most affected organs in both strains, but the susceptible mice had more granulomatous lesions and earlier dissemination of the fungus.