Análise da suscetibilidade de Cryptococcus neoformans isolados das fezes de Columba livia no município de Caxias Maranhão

Abstract

The Columba livia was introduced in Brazil around the sixteenth century, being considered a domestic species and, because it has synanthropic characteristics, it easily becomes a reservoir of pathogens, and an important source in the chain of transmission of pathogens, as cryptococcosis, which has as its etiological agent the Cryptococcus neoformans or Cryptococcus gattii, however, in a lower frequency. Globally, cryptococcosis recurrences are observed during maintenance therapy, and limited access to drugs facilitates the adaptation of these microorganisms to antifungal agents. In the development of new antifungal drugs, medicinal plants have been highlighted, with research pointing out the fungicidal potential of several species, including some typical of the Brazilian Cerrado region. This research aimed to analyze the susceptibility of environmental isolates of C. neoformans obtained from feces of C. livia, against crude plant extracts and antifungal agents. The study population was composed of feces of Columba livia, collected in urban environments in the city of Caxias, Maranhão. The fungal isolates were identified phenotypically by biochemical tests and microscopy. The tests of sensitivity to plant extracts were carried out using the technique of diffusion in agar Müeller-Hinton, while the tests with antifungal agents were performed using the disc diffusion technique. Of the 36 stool samples collected from C. livia, 69.44% showed growth of colonies of the fungus. The susceptibility tests of C. neoformans strains against raw plant extracts showed variable sensitivity. Extracts A and B were effective in controlling the strains of C. neoformans, and a high number of strains of C. neoformans resistant to amphotericin B and itraconazole was observed. Thus, it was demonstrated that environments in which there are deposits of C. livia excreta, especially in urban areas with human flow are sources for the growth and dissemination of Cryptococcus neoformans. The fungal strains presented a pattern of resistance and susceptibility varied in relation to raw plant extracts and antifungals.