In vitro susceptibility of fungi to killing by neutrophil granulocytes discriminates between primary pathogenicity and opportunism.
Pathogenic fungi, according to their propensity to cause infection of apparently normal individuals, can be grouped into either primary pathogens (e.g., Coccidioides, Histoplasma, Paracoccidioides, Blastomyces, and Sporothrix) or opportunists (e.g., Candida, Mucoraceae, Aspergillus spp., Petriellidium, and Trichosporon). There is, however, no unifying concept explaining the difference between the virulence of the two fungal categories. Previously we have speculated that neutrophils are the common denominator of the high natural resistance to opportunistic fungi. Accordingly, we then compared the susceptibility to killing by neutrophil granulocytes of Histoplasma, Blastomyces, Paracoccidioides, and Sporothrix with that of 14 opportunistic fungi. We found the four virulent dimorphic yeasts, in contrast to opportunistic fungi, to be resistant to killing by neutrophils. Virulent dimorphic yeasts were ingested by neutrophils, and triggered a respiratory burst comparably to opportunists but were less susceptible to hydrogen peroxide, suggesting that differences in the susceptibility to microbicidal products of leukocytes may explain the difference in virulence.
ACESSO AO ARTIGOhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=423588
- Mechanisms of fungal pathogenicity: correlation of virulence in vivo, susceptibility to killing by polymorphonuclear neutrophils in vitro, and neutrophil superoxide anion induction among Blastomyces dermatitidis isolates.
- Susceptibility of Propionibacterium acnes to killing and degradation by human neutrophils and monocytes in vitro.
- In vitro killing of Actinobacillus actinomycetemcomitans and Capnocytophaga spp. by human neutrophil cathepsin G and elastase.
- Eosinophils versus Neutrophils in Host Defense: KILLING OF NEWBORN LARVAE OF TRICHINELLA SPIRALIS BY HUMAN GRANULOCYTES IN VITRO
- Coexistence of Trust and Opportunism in Cooperative Projects between Startups