title: Studies on the relationship between the pathogenicity of Paracoccidioides brasiliensis in mice and its growth rate under different oxygen atmospheres.
abstract: We performed comparative studies of the pathogenicity of six strains of Paracoccidioides brasiliensis (Bt-9, Bt-4, Pb-9, Pb-18, Bt-7 and B-1183) for young adult male ddY mice and the growth rate of each strain under different oxygen atmospheres (aerobic, micro-aerobic and anaerobic atmospheres) at 37 degrees C. 10(6) units of yeast cells were intravenously injected into each mouse. The pathogenicity of each isolate was determined by a scoring system based on organ culture and histopathological findings. The growth rates under different oxygen atmospheres were determined by a scoring system in which 300 fungal units per strain were counted. The strain Bt-9 showed the greatest pathogenicity, followed by Bt-4, Pb-9 and Pb-18 had on intermediate rank of pathogenicity. Bt-7 and B-1183 were the least pathogenic of the strains tested. Except for strain Bt-7 all strains showed an excellent growth under an aerobic atmosphere. Bt-4 and Bt-9 also showed excellent growth under a micro-aerobic atmosphere, followed by Pb-9, whereas the growth of Pb-18, Bt-7 and B-1183 was limited. There was a correlation between the growth rate under a micro-aerobic atmosphere and the pathogenicity of a strain. The growth rate of P. brasiliensis under a micro-aerobic atmosphere strongly correlated to its pathogenicity.
authors.affiliation: Department of Fungal Infection, Chiba University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Sano
authors.forename: M
authors.initials: M
authors.lastname: Miyaji
authors.forename: K
authors.initials: K
authors.lastname: Nishimura
authors.forename: M F
authors.initials: MF
authors.lastname: de Franco
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000818:Animals; D001921:Brain / Q000382:microbiology / Q000473:pathology; D006321:Heart / Q000382:microbiology; D007668:Kidney / Q000382:microbiology / Q000473:pathology; D008099:Liver / Q000382:microbiology / Q000473:pathology; D008168:Lung / Q000382:microbiology / Q000473:pathology; D008297:Male; D051379:Mice; D009206:Myocardium / Q000473:pathology; D009924:Organ Culture Techniques; D010100:Oxygen / Q000378:metabolism*; D010228:Paracoccidioides / Q000254:growth & development / Q000472:pathogenicity*; D010229:Paracoccidioidomycosis / Q000382:microbiology* / Q000473:pathology; D012044:Regression Analysis; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000382:microbiology / Q000473:pathology; D014774:Virulence
chemical_list: D010100:Oxygen