Oral yeast carriage in HIV‐infected and non‐infected populations in Rosario, Argentina

Abstract

Summary The objectives of the present study were: (i) to assess the frequency of oral colonisation by Candida species in HIV‐positive patients and to compare it with a population of HIV‐negative individuals, (ii) to determine the prevalence of C. dubliniensis in both populations and (iii) to determine the susceptibility of C. dubliniensis and other Candida species isolated from HIV‐positive patients to the most commonly used antifungal agents. Oral samples were obtained from 101 HIV‐positive and 108 HIV‐negative subjects. For yeast identification, we used morphology in cornmeal agar, the API 20C Aux, growth at 45 °C, d‐xylose assimilation, morphology in sunflower seed agar and PCR. The frequency of isolation of Candida in HIV‐positive patients was: C. albicans, 60.7%; C. dubliniensis, 20.2%; C. glabrata, 5.6%; C. krusei, 5.6%; C. tropicalis, 4.5%; others, <5%. The frequency of isolation of Candida in HIV‐negative patients was: C. albicans, 73.9%; C. tropicalis, 15.5%; C. dubliniensis, 2.1%; C. glabrata, 2.1%; C. parapsilosis, 2.1%; others, <5%. The oral colonisation by yeast in the HIV‐positive patients was higher than that in the HIV‐negative subjects. The susceptibilities of 42 Candida isolates to three antifungal agents were determined. All isolates of C. dubliniensis were susceptible to fluconazole, although several individuals had been previously treated with this drug. Out of the 42 Candida isolates, 10 presented resistance to fluconazole and 10 to itraconazole. The presence of Candida species, resistant to commonly used antifungal agents, represents a potential risk in immunocompromised patients.

Oral colonization by yeasts in HIV-positive patients in Brazil

“…In this study, we found no difference in the CD4+ T-lymphocyte counts between patients positive or negative for oral carriage of yeast. Other studies have also found no correlation between CD4+ T-lymphocyte counts and yeast colonization 2,7,19,20 . On the other hand, BACK-BRITO et al 2 and YANG et al 40 observed significantly lower yeast counts in patients with a lower viral load (< 400 copies/mL), suggesting that viral load might be a higher risk factor for the occurrence of candidiasis as compared to the CD4+ T-lymphocyte count.…”

“…LUQUE et al 20 also observed that 59% of Argentinian HIV-positive patients carried two or three different species of yeast in their oral cavity. C. albicans and C. glabrata were the most frequently identified combination of yeast infections in our study.…”

“…In this study, C. dubliniensis was identified in 6.25% of isolates. Previous findings indicated that the rate of C. dubliniensis oral isolates recovered from HIV-postive patients was 0.3% in Tanzania 13 , 17% in United States of America 39 , and 20% in Argentina 20 .…”

Oral Candida colonization in HIV-infected patients in Londrina-PR, Brazil: antifungal susceptibility and virulence factors

“…While a slight decrease [34] or no effect [5,10] on oropharyngeal yeast colonization in patients receiving ART has been reported, other authors also observed a protective effect of ART treatment regimens [7,11]. On the other hand, higher oropharyngeal Candida carriage has been detected in ART-treated HIVinfected individuals [2].…”

“…Candida species are harmless colonizers of the gastrointestinal and reproductive tracts in 50% to 60% of healthy people with no symptoms of candidiasis [1,2]. In individuals infected with human immunodeficiency virus (HIV), the prevalence of asymptomatic colonization of oral mucous is higher, approaching 80% [3][4][5][6][7][8][9][10][11].…”