Identificação microbiológica e sensibilidade in vitro de Candida isoladas da cavidade oral de indivíduos HIV positivos

Abstract

A candidíase orofaríngea é a infecção fúngica mais comum entre os pacientes infectados pelo vírus da imunodeficiência humana e seu tratamento é realizado com antifúngicos tópicos ou sistêmicos, que são indicados empiricamente com base em dados clínicos. O objetivo deste estudo foi determinar a freqüência de leveduras em lavados bucais de indivíduos HIV positivos, comparando os resultados entre pacientes com diferentes condições de imunodeficiência e verificar o perfil de susceptibilidade das espécies isoladas frente aos antifúngicos visando avaliar se as opções de tratamento utilizadas na prática clínica atingem a maioria das espécies identificadas. Leveduras foram isoladas em 58% das amostras de lavado bucal coletadas e Candida albicans foi a espécie mais (93%) freqüente. Resistência ou susceptibilidade dose dependente, frente aos antifúngicos testados foi registrada em aproximadamente 17% das amostras. A importante variabilidade de resposta sugere limitações quanto à eficácia das terapias instituídas empiricamente.

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

“…This result is in accordance with results published by Rautemaa et al, 25 who reported that most isolates of C. albicans were sensitive to amphotericin B. Further, Wingeter et al 13 reported that despite over 50 years of use of polyene antifungal drugs, resistance to amphotericin B is rare. However, in their study 2 of 57 isolates showed MIC > 2 µg/ml for amphotericin B, indicating resistance.…”

“…However, its use in dentistry is predominately restricted to local administration, as systemic treatment can be highly toxic to the patient. 23 Similar values for azoles have been reported, as in the study of Wingeter et al 13 They reported that from oral isolates, 72% were sensitive to ketoconazole (MIC < 1 µg/ml), and 86% of the isolates were susceptible to fluconazole (MIC < 8 µg/ml).…”

“…28 In this study, the range of MICs for nystatin was similar to those reported by Hamza et al; 29 they reported intervals between 2 -16 for C. albicans and 2 -4 for C. glabrata and C. tropicalis. Wingeter et al 13 adopted the following end points: ≤ 4, susceptible; 8 -32, susceptible dosedependent; and ≥ 64, resistant. In our study, only one isolate from the HIV-infected group had a MIC value of 8 µg/ml; all other isolates were susceptible to nystatin.…”

“…This result is in accordance with a previous study that reported that 95% of isolates were susceptible. 13 …”

“…For this purpose, the Clinical and Laboratory Standards Institute (CLSI) proposed a reference method for yeast antifungal susceptibility testing using serial dilutions and obtained values of minimal inhibitory concentration. 12,13,14 Fluconazole is considered to be the drug of choice for the treatment of most common HIVassociated opportunistic yeast infections. 14,15 It has been the most widely used drug because of its good absorption, low toxicity and ability to be administered through both oral and intravenous routes.…”