Abstract

PESSOA, Cláudia Cristina Brito; SILVA, Silvia Helena Marques da  and  GOMES, Fabíola Silveira. Production of virulence factors in vitro by isolates of Cryptococcus neoformans and Cryptococcus gattii of clinical origin in Belém, Pará State, Brazil. Rev Pan-Amaz Saude [online]. 2012, vol.3, n.2, pp.59-65. ISSN 2176-6215.  http://dx.doi.org/10.5123/S2176-62232012000200008.

Cryptococcus neoformans and Cryptococcus gattii cause cryptococcal meningitis and are implicated in the infection of immunocompromised and immunocompetent patients, respectively. Their adhesion, colonization and infection attributes depend on some virulence factors, which enable their survival in the host's organism. This study investigated the activity of exoenzymes (phospholipase and proteinase), biofilm formation and production of a hemolytic factor by isolates of C. neoformans (n = 9) and C. gattii (n = 7) from Belém, Pará State, Brazil. Exoenzyme activity was observed in all isolates tested. Phospholipase was also observed in all isolates analyzed, and the C. neoformans isolates were slightly higher (22%) than C. gattii (14%). Proteinase data showed that isolates of C. neoformans presented greater intensity of exoenzyme activity (33%) than the results produced by C. gattii (14%). No production of hemolytic factors by any of the isolates studied was observed. Regarding the formation of biofilm, isolates of C. gattii showed a predominant formation on polysterene surface at 37^o C when compared with the isolates of C. neoformans. This is the first report of in vitro exoenzyme activity and biofilm formation by isolates of Cryptococcus in Pará State. The production of virulence factors and the ability to form biofilms highlights the importance of a more accurate analysis of the circulating isolates in the state, especially when it comes to determining their susceptibility profile to antifungals.

Keywords : Cryptococcus neoformans; Cryptococcus gattii; Exoenzyme; Biofilms; Virulence.

        · abstract in Portuguese | Spanish     · text in Portuguese     · Portuguese ( pdf )