In a survey for primary paracoccidioidomycosis (PCM) infection (and not the clinical disease), two groups of blood donors were analyzed. One study group was drawn from donors living in a rural area where PCM is endemic, and the other group from urban residents of a large city, São Paulo. Anti-Paracoccidioides brasiliensis (Pb) specific antibodies (IgG) in sera were analyzed by ELISA, using crude Pb exoantigens (exoAg) and purified specific Pb 43 kDa glycoprotein (gp43). The results showed that 21% of 700 rural samples and 0.9% of 350 urban samples were positive for exoAg and gp43. To avoid cross-reactions, the sera were adsorbed first with Histoplasma capsulatum antigens and secondly with Leishmania amazonensis antigens. In the first adsorption with H. capsulatum, reactivity to gp43 fell to 12.8% in the rural group and to 0% in the urban group. In the succeeding adsorption with L. amazonensis, this reactivity fell to 12.3% in the rural group. There was a statistically greater proportion of persons with gp43-reactive antibodies in rural group than in the urban group, indicating that rural residents had frequently become exposed to Pb and contracted primary, subclinical PCM. The present report is the first epidemiological study using ELISA to detect antibodies against gp43 in blood donors.

The present study analyses human immunoglobulin G (IgG) antibodies directed against the Paracoccidioides brasiliensis exoantigen, gp43, as well as the presence of gp43-IgG immune complexes (ICs) in 31 samples of saliva and serum from 19 patients with paracoccidioidomycosis (PCM) and 12 normal donors. Additional analysis of secretory IgA (sIgA) was performed on the same saliva samples. Consistent with previous findings, a significant increased specific IgG level was observed in PCM patients' saliva and serum (P < 0.05). The analysis of serum gp43 and gp43-IgG IC demonstrated a higher level in patients with PCM (P < 0.05); however, this difference was not statistically significant with regard to gp43 and gp43-IgG in saliva when compared to the healthy donors. A high level of sIgA in saliva of PCM patients compared to that of normal donors was also observed (P < 0.05). Patients exhibiting low levels of serum IgG but with high titres of IC were observed, thus strengthening the idea of the necessity to use more than one marker for diagnosis and treatment monitoring of PCM. This is the first report of sIgA in PCM patients' saliva and may be indicative of a protective role in neutralizing antigens on mucosal surfaces.

The aim of this study was to evaluate the effect of ten pesticides on Paracoccidioides brasiliensis, and thereby to investigate the possible association between these data and the difficulty in isolating P. brasiliensis from agricultural soil. Six fungicides (Alto 100, Benlate, Captan, Dithane, Plantacol, Rovral), two herbicides (Pivot, Roundup) and two insecticides (Azodrin and Curacron) were evaluated. Five P. brasiliensis isolates from the environment (labelled group 'N,' for 'nature') and five isolates from patients (group 'P'), were grown on Sabouraud's dextrose agar, at 35 degrees C, with ten different concentrations of each pesticide. The dose of pesticide that causes 50% growth inhibition (ED50) was calculated for each isolate. All pesticides assayed inhibited P. brasiliensis in a dose-dependent manner, and great variability among ED50 values was observed in isolates from both groups. No statistically significant difference was observed between averages of ED50 from groups N and P, except with Alto 100. The inhibitory effect of pesticides on P. brasiliensis suggests that they can interfere with attempts to isolate P. brasiliensis from soil, where tonnes of pesticides are applied over large areas planted with various crops.

The dimorphic fungus Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, a human granulomatous disease. Recently the first case of natural disease in dogs was reported. The complement system is an important effector component of humoral immunity against infectious agents. Therefore, the aim of this study was to evaluate the activation of the dog alternative complement pathway by P. brasiliensis. Initially, the ability of erythrocytes of guinea pig, rabbit, sheep, chicken and swine to activate the dog alternative pathway was evaluated. The guinea pig erythrocytes showed the greatest capacity to activate dog alternative pathway. The alternative (AH50) hemolytic activity was evaluated in 27 serum samples from healthy dogs and the mean values were 87.2 AH50/ml. No significant differences were observed in relation to sex and age. The alternative pathway activation by P. brasiliensis was higher in serum samples from adult dogs when compared to puppies and aged dogs (p ≤ 0.05). This is the first report of dog alternative complement pathway activation by P. brasiliensis and suggests that it may play a protective role in canine paracoccidioidomycosis.

This study aimed to partially characterize the antigenic fractions of human dentin extract, and to evaluate the anti-dentin antibodies levels in patients undergoing orthodontic treatment. Two dentin extract fractions (FI and FIIa) were used to analyze the saliva samples from three groups of subjects. One group had 13 subjects who presented radiographic signs of mild to moderate root resorption 12 months after starting orthodontic treatment (T12); saliva samples taken prior to treatment served as controls (T0). The other groups had 10 subjects with radiographic signs of mild to severe root resorption up to 48 months after orthodontic therapy (PT); 10 individuals not undergoing orthodontic treatment were selected as controls (ST). Western blot analysis revealed the presence of dentinal fractions of approximately 35 to 70 kDa in (T12) and (PT) but not in the control samples. In immunoenzymatic assays, the anti-FI salivary IgG levels were significantly higher in T12 and PT groups than in the controls (P< 0.05). Our results demonstrate that dentinal fractions may be presented to the immune system and detected by salivary IgG. The levels of anti-dentin antibodies may remain elevated even years after finishing of orthodontic therapy.