The performance of a real-time PCR-based assay was retrospectively analyzed (according to Europea... more The performance of a real-time PCR-based assay was retrospectively analyzed (according to European Organization for Research and Treatment of Cancer/Mycosis Study Group criteria) in the samples of patients with invasive aspergillosis. A total of 711 serial samples (356 whole-blood and 355 serum samples) from 38 adult patients were analyzed. The Aspergillus fumigatus PCR assay results were positive for 89 of 356 (25%) whole-blood samples and 90 of 355 (25.35%) serum samples. Positive PCR results were seen in 29 of 31 (93.5%) patients for which serum was analyzed and in 31 of 33 (93.9%) cases with whole-blood specimens. Both blood and serum samples were available in 26 cases, and significant differences were not observed in this subgroup of cases. The average number of threshold cycles (C(T)) for positive blood samples was 37.6, and the average C(T) for serum was 37.4. The DNA concentration ranged between 2 and 50 fg per μl of sample, with average DNA concentrations of 10.2 and 11.7 fg in positive blood and serum samples, respectively (P > 0.01). The performance of this PCR-based quantitative assay was similar for both serum and blood samples. We recommend serum samples as the most convenient hematological sample to use for Aspergillus DNA quantification when serial determinations are done.
The incidence of fungal infections due to C. parapsilosis and closely related cryptic species (-p... more The incidence of fungal infections due to C. parapsilosis and closely related cryptic species (-psilosis complex) has increased in the last few years, but differences in virulence among these species have not been widely studied. Fifteen clinical isolates of C. parapsilosis, C. orthopsilosis, and C. metapsilosis, including the type strains, were used to evaluate their virulence in Galleria mellonella larvae. Fluctuations in the hemocyte density and in the phagocytic activity were also tested. Differences in the median survival for these species were demonstrated at 37 °C (2.6 ± 1.02, 2.3 ± 0.92, and 4.53 ± 1.65 d for C. parapsilosis, C. orthopsilosis, and C. metapsilosis, respectively). Galleria mellonella hemocytes phagocytosed C. metapsilosis strains more effectively than did for C. orthopsilosis and C. parapsilosis (P<0.05). The phagocytosis rate was lower for C. parapsilosis than for C. orthopsilosis (P<0.05). The hemocyte density was increased in larvae infected with C. metapsilosis compared with those infected with C. parapsilosis or C. orthopsilosis (P<0.05). Moreover, in vitro studies of virulence factors such as pseudohyphae production and hydrolytic enzyme secretion showed that the capability of C. metapsilosis strains to produce those virulence factors was reduced. Infections due to -psilosis complex species produced tissue damage in G. mellonella and pseudohyphae could be also observed during infection with C. parapsilosis.
The performance of a real-time PCR-based assay was retrospectively analyzed (according to Europea... more The performance of a real-time PCR-based assay was retrospectively analyzed (according to European Organization for Research and Treatment of Cancer/Mycosis Study Group criteria) in the samples of patients with invasive aspergillosis. A total of 711 serial samples (356 whole-blood and 355 serum samples) from 38 adult patients were analyzed. The Aspergillus fumigatus PCR assay results were positive for 89 of 356 (25%) whole-blood samples and 90 of 355 (25.35%) serum samples. Positive PCR results were seen in 29 of 31 (93.5%) patients for which serum was analyzed and in 31 of 33 (93.9%) cases with whole-blood specimens. Both blood and serum samples were available in 26 cases, and significant differences were not observed in this subgroup of cases. The average number of threshold cycles (C(T)) for positive blood samples was 37.6, and the average C(T) for serum was 37.4. The DNA concentration ranged between 2 and 50 fg per μl of sample, with average DNA concentrations of 10.2 and 11.7 fg in positive blood and serum samples, respectively (P > 0.01). The performance of this PCR-based quantitative assay was similar for both serum and blood samples. We recommend serum samples as the most convenient hematological sample to use for Aspergillus DNA quantification when serial determinations are done.
The incidence of fungal infections due to C. parapsilosis and closely related cryptic species (-p... more The incidence of fungal infections due to C. parapsilosis and closely related cryptic species (-psilosis complex) has increased in the last few years, but differences in virulence among these species have not been widely studied. Fifteen clinical isolates of C. parapsilosis, C. orthopsilosis, and C. metapsilosis, including the type strains, were used to evaluate their virulence in Galleria mellonella larvae. Fluctuations in the hemocyte density and in the phagocytic activity were also tested. Differences in the median survival for these species were demonstrated at 37 °C (2.6 ± 1.02, 2.3 ± 0.92, and 4.53 ± 1.65 d for C. parapsilosis, C. orthopsilosis, and C. metapsilosis, respectively). Galleria mellonella hemocytes phagocytosed C. metapsilosis strains more effectively than did for C. orthopsilosis and C. parapsilosis (P<0.05). The phagocytosis rate was lower for C. parapsilosis than for C. orthopsilosis (P<0.05). The hemocyte density was increased in larvae infected with C. metapsilosis compared with those infected with C. parapsilosis or C. orthopsilosis (P<0.05). Moreover, in vitro studies of virulence factors such as pseudohyphae production and hydrolytic enzyme secretion showed that the capability of C. metapsilosis strains to produce those virulence factors was reduced. Infections due to -psilosis complex species produced tissue damage in G. mellonella and pseudohyphae could be also observed during infection with C. parapsilosis.
Uploads
Papers by Sara Gago