Epidemiological study of paracoccidioidomycosis and histoplasmosis in a suburb of San Félix city, Bolívar state, Venezuela

Epidemiologic studies of deep mycosis have been scarce in Bolivar state, where paracoccidioidomycosis and histoplasmosis are considered as endemic diseases. The aim of this study was to determine paracoccidioidomycosis and histoplasmosis prevalences in people from a suburb of San Féix, Bolívar state, Venezuela. Three-hundred volunteers agreed to participate in this study and they were inoculated with paracoccidioidine and histoplasmine. Identification and epidemiologic data were registered. Reading of skin tests after 24 hours was performed in 275 persons. Paracoccidioidine test was positive in 10.2% (n=28). A higher percentage of positive reactions in the age group of 40-50 years old (n=10; 35.7%) was observed. Bricklayers, farmers and miners were positive in 27.3% (3 out of 11), a higher percentage than in people with other occupations. Histoplasmine test was positive in 7.6% of cases (n=21). The higher percentage of reactivity was observed in the age group of 40-50 years old (n=9; 42.9%). There was a direct proportional relationship between staying time in the locality and H. capsulatum infection mainly in persons staying in the area for more than 30 years (p < 0.05). These results showed low prevalences of P. brasiliensis and H. capsulatum infection in this area.

Antimicrobial and safety aspects, and biotechnological potential of bacteriocinogenic enterococci isolated from mallard ducks (Anas platyrhynchos)

Samples from the intestinal content and carcasses of mallard ducks (Anas platyrhynchos) were evaluated for enterococci with antimicrobial activity, presence of genes coding bacteriocins and their expression, and potential virulence factors. Enterococcus faecalis comprised the largest enterococcal species with antagonistic activity followed by E. faecium, E. hirae, Enterococcus spp., and the non-enterococci. Although all E. faecalis isolates manifested a potent direct antimicrobial activity, no activity was detected in supernatants of most producer cultures. However, all E. faecium isolates showed antimicrobial activity in their supernatants and encoded bacteriocins, although the occurrence in the isolates of several enterocin genes did not always correlate with a higher antagonistic activity in supernatants. The efaAfm determinant was the only virulence gene detected in E. faecium, while E. faecalis showed a larger number of virulence determinants, and E. hirae did not carry any of the virulence genes examined. The rapid identification of genes coding described bacteriocins permits recognition of isolates that are potentially producers of novel bacteriocins. Purification of the antimicrobial activity of E. hirae DCH5 and Lactococcus garvieae DCC43 revealed unique chromatographic fragments after MALDI-TOF mass spectrometry analysis, suggesting the antagonistic peptides were purified to homogeneity. Bacteriocinogenic E. faecium and E. hirae isolates may be considered hygienic for production of bacteriocins, and potentially safe due to their low incidence of potential virulence genes and susceptibility to most clinically relevant antibiotics. However, the presence among the enterococci of E. faecalis strains with a potent antagonistic activity and multiple virulence factors, raises concerns regarding their potential pathogenicity to consumers.