Reduced recovery of a Cryptococcus neoformans adherence mutant from a rat model of cryptococcosis.
Stable mutants of Cryptococcus neoformans (strain CSF-1) induced by treatment with ultraviolet light and nitrosoguanidine were isolated that demonstrated reduced adherence to glial cells in culture. Adherence of the mutants, as measured by a radiometric assay, was reduced by 50-70% of that attained for the parent CSF-1 strain. The adherence mutants appeared to be phenotypically similar to the CSF-1 strain. However, all but one mutant (designated as CSF-23) demonstrated slightly slower growth rates than the wild-type strain. The CSF-1 and CSF-23 strains were injected intravenously and intratracheally into normal rats and rats immunosuppressed by cyclophosphamide treatment, and the organ distribution and recovery of viable yeasts determined over 2-96 h. During this relatively short period of observation the majority of the yeasts were localized in the lungs. By either route of injection, the recovery of the CSF-23 adherence mutant was reduced by as much as 90% of that obtained for the wild-type strain. The results indicated that host cell adherence may be important for the persistence of cryptococci in tissue and that further studies with the adherence mutants are warranted.
Merkel
G J
GJ
Department of Microbiology and Immunology, Indiana University School of Medicine, Fort Wayne 46805, USA.
Scofield
B A
BA
Rescorla
F J
FJ
Yang
R
R
Grosfeld
J L
JL
D000818:Animals; D002448:Cell Adhesion; D002460:Cell Line; D003453:Cryptococcosis / Q000235:genetics / Q000382:microbiology*; D003455:Cryptococcus neoformans / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D007165:Immunosuppression Therapy; D008168:Lung / Q000382:microbiology; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000009:adverse effects; D016296:Mutagenesis; D009154:Mutation; D009457:Neuroglia / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014018:Tissue Distribution; D014466:Ultraviolet Rays
D008769:Methylnitronitrosoguanidine