Materials and Methods

1. Candida species isolated from the oral mucosa of a South African population of HIV-positive women Dos Santos Abrantes PM, Africa CWJ. Department of Medical Biosciences, University of the Western Cape, Modderdam Rd. Bellville E-mail: Prof. C Africa (cafrica@uwc.ac.za) Abstract Results In total, 92 Candida strains were isolated from the oral mucosa of 90 (63%) HIV-positive females. Of these, 75 strains were identified as C. albicans, 10 as C. glabrata and 7 as C. dubliniensis. Two women were colonized by both C. albicans and C. glabrata. Figures 1 and 2 demonstrate inhibition of fungal growth in the presence of fluconazole impregnated felt disks and fluconazole resistance, respectively, when cultures were incubated at 37˚C for 24 hours. A significant association was seen between drug susceptibility patterns and species prevalence (p=0.001) and between susceptibility patterns in the different species isolated and overall health status (p=0.029). Table one shows the overall results per Candida species in the different categories. Candida infections are known contributors to the higher morbidity and mortality rates seen in HIV-positive patients, especially in underdeveloped countries. Females are more predisposed to Candida infections than their male counterparts. In this study, the prevalence and fluconazole susceptibility of Candida species in HIV-positive women was investigated. A significant association between Candida species colonization and health status was found, as well as between Candida species and drug susceptibility results. C. albicans was the only species isolated from pregnant/recently pregnant women. Because an association between pregnancy outcomes and Candida has previously been reported, this deserves further investigation. One of the most common HIV-associated opportunistic infections is candidiasis, caused by the pseudohyphae-forming yeasts of the Candida genus. These can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Candida is known to bind to the oral epithelial cells in women due to hormonal shifts during the menstrual cycle and the contraceptive pill [1]. Seropositive women have been shown to have a higher oral colonization of Candida species, which increases with higher HIV viral loads [2]. The oral colonization of Candida species in women has been reported to shift from C. albicans to non-albicans species over time and after antifungal therapy. The introduction of highly active anti-retroviral therapy (HAART) did not greatly reduce the number of Candida infections over time, possibly due to antifungal prophylaxis over the years and consequent increase in non-albicans resistant species [3]. Fluconazole, a triazole antifungal drug, is routinely given as treatment for candidiasis in healthcare facilities in South Africa. However, studies have shown that the widespread and repeated use of this drug may have resulted in increased Candida drug resistance levels. The colonization and resistance patterns of Candida species in HIV-positive women and their association with factors such as HAART, pregnancy and health status have not been previously described. This deserves further investigation, as the presence of drug-resistant Candida species could seriously affect the wellbeing of these patients. The objective of this study was to investigate the prevalence of Candida species in HIV-infected South African females and to compare their colonization and susceptibility patterns with other parameters that may be distinguishing in women. Introduction Fig. 1: Fluconazole susceptibility. Fig. 2: Fluconazole resistance. Table 1: Prevalence of Candida in HIV-positive women. Examining the number of isolates per species, 69 (92%) of C. albicans, 7 (100%) of C. dubliniensis and 4 (40%) of C. glabrata showed susceptibility to fluconazole. Overall, 13% of clinical strains demonstrated resistance to fluconazole. Candida prevalence was the highest in the 21-40year old age groups. C. albicans was the only species isolated from the oral mucosa of patients who were either pregnant or had recently given birth. Women enrolled in this study who were in anti-retroviral medication for a longer period of time seemed to have a lower carriage of C. albicans. The lower fluconazole resistance levels seen in severely immunocompromised (AIDS+) patients who harbored C. glabrata in their oral mucosa is an encouraging result that has not been previously documented and deserves further investigation. The increase in Candida colonization in women in the 21-50 year old bracket could be due to the reproductive cycle hormonal shifts but a larger sample size is needed to confirm this theory. This study emphasizes the need for ARV compliance and monitoring of these patients, as the numbers of invasive Candida species seemed to decrease after continuous anti-retroviral treatment. The fact that Candida albicans was the only species isolated from the oral mucosa of patients who were either pregnant or had recently given birth also deserves further investigation. A comparative culture from a vaginal swab from pregnant or recently pregnant mothers would be an interesting extension of this study, as this could be an useful tool in confirming pregnancy outcomes [4]. Objectives Discussion Materials and Methods Samples were collected from 146 HIV-positive women presenting with white pseudomembranous plaque in the tongue or visible oral candidiasis at community hospitals in the Western Cape, South Africa, by scraping the patient’s oral mucosa and tongue using a sterile mouth swab. Ethical clearance for this project was granted by the Ethics Committee of the University of the Western Cape. Participants were required to answer a questionnaire and data from their respective hospital files was collected, where appropriate. This included their age, race, gender of sexual partner, date of HIV diagnosis, duration of ARV therapy, the specific ARV drugs the patient was taking, pregnancy status and the presence of other concurrent infections. The samples were transported to the Medical Microbiology laboratories at UWC for inoculation onto selective media, species differentiation using growth in chromogenic and differential media and drug susceptibility testing using incubation in Yeast Nitrogen Base Agar (YNBG) in the presence of 25g fluconazole impregnated felt disks. Type strains of C. albicans (ATCC 90028 and NCPF 3281), C. krusei (ATCC 2159), C. glabrata (ATCC 26512), C. tropicalis (ATCC 950) and C. dubliniensis (NCPF 3949a) served as positive controls. Bibliography [1] Brusca MI, Rosa A, Albaina O, Moraques MD, Verdugo F, Pontón J. The impact of oral contraceptives on women's periodontal health and the subgingival occurrence of aggressive periodontopathogens and Candida species. J Periodontol. 2010 Jul; 81(7):1010-8. [2] Ohmit SE, Sobel JD, Schuman P, Duerr A, Mayer K, Rompalo A, Klein RS. Longitudinal study of mucosal Candida species colonization and candidiasis among human immunodeficiency virus (HIV)-seropositive and at risk HIV-seronegative women. J Infect Dis. 2003 Jul; 188(1):118-27. [3] Traeder C, Kowoll S, Arastéh K. Candida Infection in HIV-positive Patients. Mycoses. 2008 Sep; 51 Suppl 2:58-61. [4] Hay P, Czeizel AE. Asymptomatic Trichomonas and Candida colonization and pregnancy outcome. Best Pract Res ClinObstetGynaecol. 2007 Jun; 21(3):403-9. Acknowledgements The authors would like to thank Mr. Norman Coldrey, Mr. Ernest Maboza and Mr. Claude Bayingana for their assistance during the course of this study and the National Research Foundation for funding this project.