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Phenotypic characteristics associated with virulence of clinical isolates from the Sporothrix complex.

Almeida-Paes R, de Oliveira LC, Oliveira MM, Gutierrez-Galhardo MC, Nosanchuk JD, Zancopé-Oliveira RM - Biomed Res Int (2015)

Bottom Line: Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce.The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii.Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil 4365, 21045-900 Manguinhos, RJ, Brazil.

ABSTRACT
The Sporothrix complex members cause sporotrichosis, a subcutaneous mycosis with a wide spectrum of clinical manifestations. Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce. Melanization, thermotolerance, and production of proteases, catalase, and urease were investigated in 61 S. brasiliensis, one S. globosa, and 10 S. schenckii strains. The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii. These two species, however, presented similar thermotolerances. Our S. globosa strain had low expression of all studied virulence factors. The relationship between these phenotypes and clinical aspects of sporotrichosis was also evaluated. Strains isolated from patients with spontaneous regression of infection were heavily melanized and produced high urease levels. Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection. A murine sporotrichosis model showed that a S. brasiliensis strain with high expression of virulence factors was able to disseminate and yield a high fungal burden in comparison with a control S. schenckii strain. Our results show that virulence-related phenotypes are variably expressed within the Sporothrix complex species and might be involved in clinical aspects of sporotrichosis.

No MeSH data available.


Related in: MedlinePlus

Box-plot diagrams showing similar thermotolerances between S. brasiliensis and S. schenckii sensu stricto observed at 21 days of growth in Sabouraud Dextrose Agar.
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fig3: Box-plot diagrams showing similar thermotolerances between S. brasiliensis and S. schenckii sensu stricto observed at 21 days of growth in Sabouraud Dextrose Agar.

Mentions: As expected, the S. globosa IPEC 27135 strain was highly inhibited when cultured at 37°C, with a %GI of 86.7% and 82.4% at 15 and 21 days, respectively. The %GI of S. brasiliensis strains ranged from 32.3 to 71% at 15 days and from 35.1 to 72.9% at 21 days, with mean values of 52.5 ± 10.2% and 54.8 ± 8.5%, respectively. For S. schenckii isolates, ranges were 41.4–65.9% and 43.9–64.5% and the mean values were 52.7 ± 8.7% and 55 ± 6.9% at 15 and 21 days of growth at 37°C, respectively. There was no difference between S. brasiliensis and S. schenckii %GI at 15 or 21 days of incubation (Figure 3), with a P value of 0.90 for both times. Additionally, as presented in Figure 4(a), no correlation was seen between the %GI and the degree of melanization of the Sporothrix strains (P = 0.51 at 15 days and P = 0.35 at 21 days). When we tested the thermotolerance of representative strains in presence of tricyclazole, the %GI values increased in five strains and decreased in only one (Figure 4(b)). However, when the strains were cultured in presence of L-DOPA or L-tyrosine, conditions where the fungus can produce eumelanin or pyomelanin in addition to DHN-melanin, we observed that five strains have decreased %GI values, though the decrease was slight in two strains with L-DOPA and one with L-tyrosine. The decrease of %GI values in presence of L-DOPA (Figure 4(c)) was lower than in presence of L-tyrosine (Figure 4(d)).


Phenotypic characteristics associated with virulence of clinical isolates from the Sporothrix complex.

Almeida-Paes R, de Oliveira LC, Oliveira MM, Gutierrez-Galhardo MC, Nosanchuk JD, Zancopé-Oliveira RM - Biomed Res Int (2015)

Box-plot diagrams showing similar thermotolerances between S. brasiliensis and S. schenckii sensu stricto observed at 21 days of growth in Sabouraud Dextrose Agar.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4417584&req=5

fig3: Box-plot diagrams showing similar thermotolerances between S. brasiliensis and S. schenckii sensu stricto observed at 21 days of growth in Sabouraud Dextrose Agar.
Mentions: As expected, the S. globosa IPEC 27135 strain was highly inhibited when cultured at 37°C, with a %GI of 86.7% and 82.4% at 15 and 21 days, respectively. The %GI of S. brasiliensis strains ranged from 32.3 to 71% at 15 days and from 35.1 to 72.9% at 21 days, with mean values of 52.5 ± 10.2% and 54.8 ± 8.5%, respectively. For S. schenckii isolates, ranges were 41.4–65.9% and 43.9–64.5% and the mean values were 52.7 ± 8.7% and 55 ± 6.9% at 15 and 21 days of growth at 37°C, respectively. There was no difference between S. brasiliensis and S. schenckii %GI at 15 or 21 days of incubation (Figure 3), with a P value of 0.90 for both times. Additionally, as presented in Figure 4(a), no correlation was seen between the %GI and the degree of melanization of the Sporothrix strains (P = 0.51 at 15 days and P = 0.35 at 21 days). When we tested the thermotolerance of representative strains in presence of tricyclazole, the %GI values increased in five strains and decreased in only one (Figure 4(b)). However, when the strains were cultured in presence of L-DOPA or L-tyrosine, conditions where the fungus can produce eumelanin or pyomelanin in addition to DHN-melanin, we observed that five strains have decreased %GI values, though the decrease was slight in two strains with L-DOPA and one with L-tyrosine. The decrease of %GI values in presence of L-DOPA (Figure 4(c)) was lower than in presence of L-tyrosine (Figure 4(d)).

Bottom Line: Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce.The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii.Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil 4365, 21045-900 Manguinhos, RJ, Brazil.

ABSTRACT
The Sporothrix complex members cause sporotrichosis, a subcutaneous mycosis with a wide spectrum of clinical manifestations. Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce. Melanization, thermotolerance, and production of proteases, catalase, and urease were investigated in 61 S. brasiliensis, one S. globosa, and 10 S. schenckii strains. The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii. These two species, however, presented similar thermotolerances. Our S. globosa strain had low expression of all studied virulence factors. The relationship between these phenotypes and clinical aspects of sporotrichosis was also evaluated. Strains isolated from patients with spontaneous regression of infection were heavily melanized and produced high urease levels. Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection. A murine sporotrichosis model showed that a S. brasiliensis strain with high expression of virulence factors was able to disseminate and yield a high fungal burden in comparison with a control S. schenckii strain. Our results show that virulence-related phenotypes are variably expressed within the Sporothrix complex species and might be involved in clinical aspects of sporotrichosis.

No MeSH data available.


Related in: MedlinePlus