SPECIATION OF CANDIDA ISOLATES AND INVITRO FLUCONAZOLE SUSCEPTIBILITY PROFILE OF OROPHARYNGEAL CANDIDIASIS IN PEOPLE LIVING WITH HIV/AIDS IN UNIVERSITY OF BENIN TEACHING HOSPITAL, BENIN

Abstract

Oropharyngeal candidiasis (OPC) is the most prevalent opportunistic fungal infection in
people living with HIV/AIDS (PLWHA). In recent times, there have been concerns about the
rising incidence of non albicans Candida (NAC) causing this infection. These species also
tend to have reduced susceptibility to fluconazole compared with C.albicans. This study
investigated the distribution of Candida species in the oral cavities of PLWHA as well as
their fluconazole susceptibility profiles.
Three hundred and fifty adults with confirmed HIV infection attending the antiretroviral
treatment clinic at the University of Benin Teaching Hospital were recruited to participate in
the study. Three hundred and fifty HIV-negative voluntary blood donors were recruited as
controls. Their oral cavities were sampled using swab sticks and the presence or absence of
OPC lesions was noted. Socio-demographic and clinical data were obtained using a
structured researcher-administered questionnaire. Isolates of Candida were identified using
germ tube test, CHROMagar Candida (CHROMagar, France) and API Candida yeast
identification system (Biomérieux, France). In vitro fluconazole susceptibility was
determined using the disc diffusion method according to the M44-A2 document of the
Clinical and Laboratory Standards Institute (CLSI). Data were analysed using SPSS version
21 and significance level was set at P ≤ 0.05.
The isolation rates for Candida amongst HIV-infected subjects and HIV-negative controls
were 20.6% and 3.4%, respectively. The prevalence of OPC was 4.9%. In PLWHA, Candida
albicans was the most frequently isolated species (81.3%). Non-albicans Candida isolated
included C.parapsilosis (6.7%), C.glabrata (5.3%), C.tropicalis
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(2.7%), C.krusei (2.7%) and C.famata (1.3%). Ninety four per cent of OPC cases were
caused by C.albicans. CD4+ cell counts< 200cells/µL and absence of HAART were
associated with OPC. 24% of all Candida isolates from PLWHA showed resistance to
fluconazole with NAC demonstrating 50% resistance rate.
Candida albicans is the most frequently isolated species but non albicans species also
colonise the mouths of some HIV-infected adults. The fluconazole resistance rate is quite
high even among C.albicans isolates. It is recommended that identification and susceptibility
testing be routinely carried out for all cases of OPC, especially in PLWHA. Future research
should substantiate the role of non-albicans Candida in OPC and determine susceptibility
profile of Candida species to a variety of alternative antifungal agents.