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Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis (S1, PS2, and PS3) and by the new species, P. lutzii. Considering that genetic differences in the Paracoccidioides genus could elicit distinct immune responses by the host, current research investigated serum IgG levels to antigens from P. brasiliensis B339 (S1), P. brasiliensis LDR3 (PS2), and atypical strain LDR2 ( P. lutzii), in patients with chronic PCM from the northern and west regions of Paraná, Brazil ( n = 35). Cell-free antigen (CFA) and high molecular mass fraction (hMM) were produced from each strain. Samples were analyzed by ELISA and immunodiffusion (ID). ELISA positivity using CFA: B339-100 %, LDR3-83 %, and LDR2-74 %. Response to CFA from B339 was more intense ( p < 0.05), while there was no difference between LDR3-LDR2. IgG anti-hMM was higher for antigens from B339 or LDR3, when compared with LDR2 ( p < 0.05). There was a positive correlation for each strain between CFA-hMM and for hMM between B339-LDR3 and LDR3-LDR2. ID positivity with CFA: B339-63 %, LDR3-66 %, and LDR2-60 %. We conclude that the intensity of reaction of the patients’ sera varies with the strain used; hMM influences tests that use CFA, independently of strain; using ID, positive rates were very similar, but there was a large number of false negative results; ELISA tests using antigens from P. brasiliensis S1 were able to detect a larger number of patients than PS2 and P. lutzii (which had a considerable number of false negative results), and therefore, its use may be more appropriate in this region of Brazil. [ABSTRACT FROM AUTHOR]

In this study, Swiss mice were experimentally infected with Paracoccidoides brasiliensis (Pb18) and we investigated the levels of gp43 in urine and plasma, anti-gp43 and IgG-gp43 immune complexes in plasma. These levels were correlated with the histopathological findings. Blood and urine samples were collected from mice at 7, 28, 56 and 84 days after intravenous inoculation of 10 5 yeast cells, and analysed by ELISA. The results showed increased levels of soluble gp43 in the plasma in all periods, and anti-gp43 IgG and immune complexes after day 28. High gp43 levels were detected in the urine, except for day 28, coincident with the presence of compact granulomas in lungs. All the infected mice showed fungal cells in the lungs, with initial granulomatous lesions at day 7, dissemination of lesions to other organs at day 56, and granulomas lacking the surrounding mononuclear cells infiltration, especially at days 56 and 84. Our results suggest that gp43 diffuses passively into the urine, and the determination of gp43 levels in urine samples may be a non-invasive alternative method for diagnosis and follow up of PCM. Further studies are needed to determine if the cellular immune response correlate with decreased urine gp43 levels. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the immune response of young dogs experimentally infected with Paracoccidioides brasiliensis. Six dogs were infected intravenously with P. brasiliensis and one control dog was inoculated with sterile saline. The infected animals were sacrificed in groups of two at 1. 6 and 12 months after infection. During the experimental period, the immune responses of the dogs to the fungus were followed by ELISA (IgM and IgG), by the immunodiffusion test and by the skin test with gp43. After killing the dogs, samples from several organs were submitted to histopathological analysis (H&E and Grocott stains) but the fungus was not observed in any tissue. Attempts to isolate the fungus from these tissue samples were also unsuccessful. All infected dogs, except one, reacted positively to the immunodiffusion and skin tests. All infected dogs showed a humoral immune response to the gp43 antigen detected by ELISA. The IgM and IgG response peaked by the first and second month, respectively. We conclude that young dogs appear to be resistant to the development of paracoccidioidomycosis. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the susceptibility of dogs to develop paracoccidioidomycosis by experimental infection. Puppies were inoculated with Paracoccidioides brasiliensis by an intravenous route and two out of four died 1 week postinoculation, showing, at histopathological analysis, granulomas in the lungs, spleen and liver. P . brasiliensis was isolated from these organs. The animals that survived the infection showed a strong reaction when skin was tested with gp43, a specific antigen of P . brasiliensis . These animals were killed at 1 and 5 months after infection, and no lesions, macroscopic or microscopic, were observed in the lungs, spleen or liver; furthermore no P . brasiliensis culture was obtained from these organs. These results suggest that dogs can develop paracoccidioidomycosis and reinforces the importance of this animal as a sensitive indicator of P . brasiliensis in the environment. [ABSTRACT FROM AUTHOR]

The effect of storage on mycoflora profile was monitored bimonthly in 36 corn (Zea mays L.) samples, dividing the same sample into groups dried to 11 and 14% moisture content (1008 analysis). These groups were further subdivided based on the initial total count (moulds and yeasts) up to 10[sup 4] CFU g[sup –1] (12 samples, range 1.6 × 10[sup 4] to 9.0 × 10[sup 4], mean 3.8 × 10[sup 4] CFU g[sup –1]) and up to 10[sup 5] CFU g[sup –1] (24 samples, range 1.0 × 10[sup 5] to 5.0 × 10[sup 5], mean 2.7 × 10[sup 5] CFU g[sup –1]). In the corn group dried to 11%, the fumonisin content was analysed at the initial stage (freshly harvested) and at the end of 12-month storage. Fusarium spp. and Penicillium spp. prevailed at the freshly harvested stage (100%), maintaining this profile throughout 12 months, in corn dried to both 11 and 14%. Cladosporium spp., Aspergillus spp. and Phoma spp. were also detected at lower frequencies during the storage. Fusarium spp. and the total fungal colony count during 12-month storage carried out with samples dried to 11 or 14% moisture content were statistically evaluated using ANOVA for randomized complete block design. The correlation between storage time and Fusarium spp. and total fungal colony count data was analysed by Pearson's correlation test. There was no difference in Fusarium spp. and total counts in the 10[sup 4] CFU g[sup –1] initial total count group throughout the storage time (p < 0.05). There was a negative correlation between fungal population and storage time (p < 0.05) in the 10[sup 5] CFU g[sup –1] initial total count group. Fumonisins were detected in all freshly harvested corn, at a mean concentration of 9.9 ± 6.0 µg g[sup –1] (range 0.74–22.6 µg g[sup –]1). These values did not change in the 12-month stored corn (mean of 9.9 ± 5.8 µg g[sup –1], range 0.81–23.7 µg g[sup –1]). These post harvest data indicated the importance of moisture content at the crop harvesting/predrying stage to control fungal growth and further fumonisin production. [ABSTRACT FROM AUTHOR]