In Vitro Evaluation of Putative Virulence Attributes of Oral Isolates of Candida spp. Obtained from Elderly Healthy Individuals

Abstract

Identification of Candida isolates obtained from oral cavity of elderly healthy individuals revealed the predominance of non-albicans Candida species (88.9%) compared to Candida albicans (11%). CHROMagar Candida differential medium and PCR revealed the presence of Candida tropicalis (33.3%), Candida glabrata (27.8%), and Candida krusei (16.7%). We investigated the presence of virulence attributes in a total of 18 isolates, including acid protease and phospholipase production, hemolytic activity, and biofilm production. Extracellular protease was found in five isolates (27.8%) whereas extracellular phospholipase was found in three isolates (17%). All isolates showed hemolytic activity. About 56% of the isolates were weakly positive for biofilm formation (score +) whereas a minority (5.6%) of them showed strong biofilm formation (score 4+). Susceptibility in vitro of the isolates to fluconazole was carried out by microdilution method. Fluconazole showed a strong inhibition against most buccal isolates. The resistant isolates were 2 C. tropicalis, 2 C. glabrata, and 1 C. krusei.

Trichosporon asahii causing nosocomial urinary tract infections in intensive care unit patients: genotypes, virulence factors and antifungal susceptibility testing

“…In contrast to the extensive studies regarding virulence of C. albicans, few similar investigations of T. asahii strains have been reported. We attempted to detect several virulence factors as for C. albicans with slight modifications (Dagdeviren et al, 2005;Furlaneto-Maia et al, 2008). All isolates presented haemolytic activity to different degrees after 96 h incubation, longer than for C. albicans (48 h).…”

“…With reference to C. albicans (Furlaneto-Maia et al, 2008;Negri et al, 2010), protease and phospholipase were detected by the formation of a precipitation halo around each colony due to degradation. An aliquot (5 ml) of a 1610 8 c.f.u.…”

“…The plates were incubated at 35 uC in 5 % CO 2 for 96 h. The presence of a translucent halo around the inoculation site, viewed with transmitted light, indicated positive haemolytic activity (H z ). H z expressed the ratio of the colony diameter to the diameter of the translucent zone of haemolysis (mm) (Furlaneto-Maia et al, 2008;Negri et al, 2010). C. albicans ATCC 90028 and ATCC 2201 were used as positive and negative control, respectively.…”

Investigation of Oral Candida Albicans Colonization in Patients Treated with Rapid Maxillary Expansion

“…Different solid culture media have been used in different studies to detect mutants. In our study, we used Sabouraud dextrose agar containing chloramphenicol, which is one of the most commonly used methods for determining the frequency of C. albicans (25).…”

Hemólise produzida por Candida tropicalis isoladas de amostras clínicas

“…Dados relativos à produção de fator hemolítico por C. tropicalis são escassos [19][20][21] . O presente estudo 16 , C. albicans possui a capacidade de utilizar ferro derivado de hemoglobina, por meio da produção de um fator responsável pela lise dos eritrócitos, uma habilidade que pode ser compartilhada por C. tropicalis e representar uma vantagem adaptativa para o estabelecimento de infecções em seus hospedeiros.…”