Species distribution and in vitro antifungal susceptibility of oral yeast isolates from Tanzanian HIV-infected patients with primary and recurrent oropharyngeal candidiasis

Omar Jm Hamza,Mainen J Moshi,Elison Nm Simon,Frans Hm Mikx,Paul E Verweij,Antonius Jmm Rijs,André Jam Van Der Ven,Mecky In Matee,Ferdinand Mugusi,Wim Helderman

doi:10.1186/1471-2180-8-135

Abstract

BackgroundIn Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis.MethodsA total of 296 clinical oral yeasts were isolated from 292 HIV-infected patients with oropharyngeal candidiasis at the Muhimbili National Hospital, Dar es Salaam, Tanzania. Identification of the yeasts was performed using standard phenotypic methods. Antifungal susceptibility to fluconazole, itraconazole, miconazole, clotrimazole, amphotericin B and nystatin was assessed using a broth microdilution format according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI; M27-A2).ResultsCandida albicans was the most frequently isolated species from 250 (84.5%) patients followed by C. glabrata from 20 (6.8%) patients, and C. krusei from 10 (3.4%) patients. There was no observed significant difference in species distribution between patients with primary and recurrent oropharyngeal candidiasis, but isolates cultured from patients previously treated were significantly less susceptible to the azole compounds compared to those cultured from antifungal naïve patients.ConclusionC. albicans was the most frequently isolated species from patients with oropharyngeal candidiasis. Oral yeast isolates from Tanzania had high level susceptibility to the antifungal agents tested. Recurrent oropharyngeal candidiasis and previous antifungal therapy significantly correlated with reduced susceptibility to azoles antifungal agents.

Highlights

In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from human immunodeficiency virus (HIV)-infected patients with primary and recurrent oropharyngeal candidiasis
The majority of the patients with recurrent Oropharyngeal candidiasis (OPC) had a history of one previous episode of OPC (n = 92, 71.8%) and the range of recurrences was 1 to 4 episodes
The present study demonstrates that in Tanzania primary and recurrent OPC is predominantly caused by C. albicans

Summary

Introduction

In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis. Oropharyngeal candidiasis (OPC) is the most frequent opportunistic infection encountered in human immunodeficiency virus (HIV)-infected individuals [1,2,3,4]. The occurrence of OPC is associated with CD4 T-lymphocyte below 200 cells/mm, high viral loads and disease progression [2,5,6]. The prolonged course of HIV infection predisposes these patients to recurrent episodes of OPC that can increase in frequency and severity with progressive HIV disease [7]. The incidence and prevalence of opportunistic infections have been reduced worldwide due to use of HAART [9,10,11,12], OPC remains the most frequent HIV-associated oral lesion in most developing countries, including Tanzania [6]

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