The secretion of aspartyl proteinase, a virulence enzyme, by isolates of Candida albicans from the oral cavity of HIV-infected subjects (original) (raw)
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Biotypes of Candida albicans isolates from the oral mucosa of HIV seropositive and control subjects
Purpose: This study evaluated the Candida albicans biotypes from oral mucosa according to some host variables, such as HIV infection; medication use – protease inhibitors (PI), non protease inhibitors (NPI) or no medication (NM); dental prosthesis wearing (PW) or not (NPW); and yeast variables (activity levels of protease and phospholipase). Methods: Samples from the oral mucosa of 193 HIV + subjects and 205 HIV – subjects were collected by means of sterile swabs and seeded onto Sabouraud dextrose agar. The isolates were identified by microculture on slide, germ tube formation, auxanogram, and zimogram. Ninety-two isolates were obtained from HIV + individuals: 49 from patients under PI, 31 from patients under NPI and 12 from patients with no medication. The control group comprised 63 isolates from HIV – patients.
Virulence of Candida albicans isolated from HIV infected and non infected individuals
SpringerPlus, 2015
Background HIV/AIDS is now a major global health problem. In 2012, there were 1.6 million AIDS related deaths and at least 32 million adults and children were living with HIV globally. The situation is still far from the global vision of zero new HIV infections, zero discrimination and zero AIDS-related deaths (UNAIDS 2013). Fungal infections remain a clinical challenge in HIV patients with severe immune suppression conditions. The Candida species contributes up to 33.1 % of fungal infections among HIV diagnosed individuals.
Biotypes of Cândida albicans isolates from aids patients
Revista de Patologia Tropical, 2007
The phenotypic features of C. albicans oral isolates recovered from AIDS patients were determined by serotyping, morphotyping and biotyping in nine media with different biochemical charaeterístics. The patients were divided into: Group l, comprising subjects with detectable lesions of lhe oral mucosa and Group 2, corresponding to carrier patients. Despite observing a greater frequency of serotype B isolates among subjects with symptomatic oral candidosis as compared to lhe other group of patients, these results were not statistically significam. When correlating lhe presence of serotypes A and B with T lymphocyte counts, we verified thal occurrence of serotype B was more prevalent (p<0.05) than serotype A in individuais with CD4"" T < 200 cells/mm3. The occurrence of fringes greater than 3 mm in length was a typical feature of the oral isolates from our AIDS patients, though no differences in this respect were detected between the two groups of subjects. A lack of ability to assimilate urea and sorbose and variation in sensibility to 5-fluorocytosine were also features expressed by the majority of the isolates, with a predominance of the biotype 347 in 51.9% of ali the oral isolates studied.
Characterization of Candida albicans isolates from the oral cavity of HIV-positive patients
PubMed, 1998
Characterization of Candida albicans isolates from the oral cavity of Ethiopian Human Immunodeficiency Virus (HIV)-positive patients and HIV-negative individuals was undertaken. After identification of isolates using conventional methods and determination of carbohydrate assimilation profiles, serotyping was performed by slide agglutination with the Iatron IF6 serotyping system. Sensitivity of the isolates to 5-Fluorocytosine (5-FC) was assessed using the broth macrodilution method. There was no difference in phenotype, by any of the three methods used, between the HIV-positive and HIV-negative individuals. Serotype A was found to be dominant in strains isolated from both HIV-positive (34/40 = 85%) and HIV-negative (17/20 = 85%) study subjects. These data suggest that the C. albicans strains causing oral candidiasis in patients with HIV infection are identical to the commensal ones found in healthy individuals.
Archives of Oral Biology, 2016
The colonization by Candida species is one of the most important factors related to the development of oral candidiasis in HIV-infected individuals. The aim of the study was to evaluate and discuss the phospholipase, proteinase, DNAse and haemolytic activities of Candida albicans isolated from the oral cavity of HIV individuals with high efficiency antiretroviral therapy. Seventy-five isolates of C. albicans obtained from saliva samples of patients with HIV and 41 isolates from HIV-negative individuals were studied. Haemolytic activity was determined in Sabouraud dextrose agar plates containing 3% glucose and 7% sheep red cells. Culture medium containing DNA base-agar, egg yolk, and bovine albumin were used to determine DNase, phospholipase and proteinase activities, respectively. All isolates from the HIV patients group had haemolytic activity, 98% showed phospholipase activity, 92% were positive for proteinase and 32% DNAse activity. Regarding the group of indivídios HIV negative, all 41 isolates presented hemolytic activity, 90.2% showed phospholipase and proteinase activity and 12.2% were positive for DNAse. The phospholipase activity was more intense for the group of HIV positive individuals. DNase production was more frequently observed in the group of HIV-positive individuals. The percentage of isolates having DNAse activity was also significantly different between the groups of patients not using any antiretroviral therapy, those using transcriptase inhibitors and those using transcriptase inhibitor and protease inhibitor in combination.
Oral thrush caused by Candida species is usually an opportunistic infection. It is usually caused by Candida albicans, however, over the last decade reports of "non-albicans Candida" causing this condition are increasing. The present study was undertaken to assess the role of C. albicans vis á vis "non-albicans Candida" in the causation of oral thrush. Eighty patients with oral thrush were included in this study. Fifty patients were Human Immunodeficiency Virus (HIV) serop- ositive and 30 patients were HIV seronegative. Oral swabs collected from the lesions in both groups were subjected to a battery of standard mycological tests that yielded Candida species in 78.75% patients. Isolation of C.albicans was 66% from the HIV seropositive group and 60% from the HIV serone- gative group. The "non-albicans Candida" formed 24% of the Candida isolates from the HIV seropositive group while no "non-albicans Candida" was isolated from the HIV seronegative...
Indian Journal of Medical Microbiology, 2007
Purpose: The purpose of the present study was to determine the degree of expression of virulence factors such as adherence, cell surface hydrophobicity (CSH) and production of proteinase by different morphological forms of Candida albicans causing oral candidiasis in human immunodeÞ ciency virus (HIV)-infected individuals. Methods: C. albicans 3153A and two strains isolated from oral thrush in HIV infected individuals were induced to undergo phenotypic switching by exposure to UV light and the degree of expression of virulence factors by the different morphological forms was studied. Results: Three different morphological forms of C. albicans were obtained namely, star (S), wrinkled (W) and ring (R) types from the original smooth (O) variety. It was found that proteinase production was greatest with the W type followed by the R type and O type. The S type produced the least proteinase. Expression of cell surface hydrophobicity and adherence was greatest in the O type followed by the R and then the W type and Þ nally the S type. Conclusions: The differential expression of virulence factors occurs with different phenotypic forms of C. albicans and this may provide a particular morphological type with a distinct advantage over other types in causing candidiasis.
Journal of Medical Microbiology, 2011
Oral candidiasis caused by Candida albicans is recognized as one of the most frequent opportunistic infections in human immunodeficiency virus (HIV)-infected individuals. The overall severity and chronicity of oral candidiasis has been attributed exclusively to the HIV-induced immune deficiency of the affected individuals but not to the virulence factors of the pathogen, i.e. C. albicans. However, genotypic and phenotypic studies have suggested that HIV infection might be associated with preferential selection of C. albicans strains with altered virulence determinants, leading to colonization with Candida populations that are better able to cause disease in these immunologically compromised hosts. If this process of selection is indeed related to pathogenicity, it may be possible to measure alterations in different virulence factors produced by C. albicans in HIV-infected patients. To evaluate this hypothesis, the present work was undertaken to determine simultaneously the expression of five virulence factors in oral C. albicans isolates colonizing and infecting HIV-positive and-negative individuals. The significance of genotypes in the pathogenesis of oral candidiasis was also elucidated. Oral swabs were collected from 335 consecutive individuals (210 HIV-positive and 125 HIV-negative). Virulence factors and genotypes were determined for all the C. albicans strains isolated. The results showed significantly increased expression of proteinase, phospholipase and haemolytic activities, as well as a greater ability to adhere, in isolates from HIV-positive compared with HIV-negative individuals (P,0.05). However, no significant differences in virulence factor expression in isolates colonizing or infecting HIV-positive individuals were seen. Genotype A was the predominant type (71.3 %); however, a relationship could not be established between the genotypes and the virulence factors, or with clinical infection. These data support the concept of preferential C. albicans strain selection with altered virulence determinants in HIV-infected individuals and emphasize the need for further molecular genetic linkage studies that could be helpful in dissecting the molecular causes of preferential strain selection, which may lead to new approaches for therapeutic intervention.
Mycopathologia, 2000
A cross-sectional study was performed to evaluate the prevalence and the aetiology of forms of mucosal fungal infections of HIV-negative and HIV-positive women. Candida albicans was the predominate specie isolated from both groups of patients, with remarkable proportion of isolation from symptomatic women. All 239 C. albicans isolates, regardless of their source, showed activity of proteinase and phospholipase. It was verified that isolates with particularly higher levels of exoenzymes production were significantly more common in HIV-positive patients. However, isolates obtained from the HIV-positive patients in use of HAART, with protease inhibitor, presented lower levels of these exoenzymes, similar to the levels observed in the isolates from HIV-negative patients.