*1,2Adewole, O. E., 1Jonathan, S. G., 3Olorunmola, F. O., 4Owotade, F. J., 5Gbolagade-Jonathan, P. T., 6Odetoyin, B. W., and 6Olaniran, O.
1Mycology and Applied Microbiology Research Group, Department of Botany, Faculty of Science, University of Ibadan, Nigeria
2Department of Microbiology, Faculty of Sciences, University of Ilesa, Ilesa, Nigeria
3Department of Drugs Research and Production Unit, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
4Department of Oral Medicine and Oral Pathology, Faculty of Dentistry, Obafemi Awolowo University, Ile-Ife, Nigeria
5Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan. Ibadan, Nigeria
6Department of Medical Microbiology and Parasitology, Faculty of Basic Medical Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria
*Correspondence to: oeadewole@yahoo.com, +2347063352347, ORCiD: 0000000177125037
Abstract:
Background: Candida species inhabit humans as commensals but become opportunistic pathogens in immunocompromised individuals. This yeast has developed resistance to anti-fungal medications and infection caused by it is associated with increased morbidity and mortality. Information on the yeast colonization profile and the antifungal sensitivity pattern in the Nigerian population is sparse. This study determined the prevalence and antifungal susceptibility patterns of oral Candida species among cancer patients attending two tertiary care hospitals in Osun State, southwest Nigeria.
Methodology: This was a case-control study of 165 cancer patients attending the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC) Ile-Ife and Osun State University Teaching Hospital (OSUTH) Osogbo, and 165 age and sex matched apparently healthy controls recruited from Ife and Modakeke communities in Osun State, southwest Nigeria. Socio-demographic and clinical information were collected from each participant to determine potential risk factors for Candida colonization and resistance. Oral rinse samples were collected from each cancer patient and the healthy control. Candida species were isolated on Hicrome chromogenic agar and identified by characteristic yeast-like colonies and Gram-staining reaction. Antifungal susceptibility of the Candida species against six selected antifungal agents was determined by the disc diffusion method. Data were analyzed using Chi-square and Fisher Exact tests, with p<0.05 considered as statistical significance.
Results: Candida species were significantly more prevalent in oral cavity of the cancer patients (38.8%, n=64) than the controls (26.7%, n=44) (p=0.0258). The prevalence was highest among elderly cancer patients above 70 years of age (58.3%, n=7), higher in females (42.3%, n=44) than males (32.8%, n=20) and higher among cancer patients on anti-cancer therapy (40.7%, n=50) than those who had not received therapy (33.3%, n=13). Candida species identified include Candida albicans (55.1%, n=70), Candida krusei/Pichia kudriavzevii (27.6%, n=35), Candida parapsilosis (11.8%, n=13), Candida tropicalis (3.1%, n=4), Candida/Diutina rugosa (1.6%, n=2) and Candida/Nakaseomyces glabrata (0.8%, n=1). The highest and lowest susceptibilities of the Candida species were to nystatin (95.2%, n=118) and fluconazole (42.7%, n=53) respectively. The frequency of multi-drug resistance (MDR) was significantly higher (p<0.01) among non-albicans Candida species (43.6%, n=24) than C. albicans (31.9%, n=22).
Conclusion: It was generally observed that Candida species were more prevalent in cancer patients than apparently healthy persons. The observed high resistance rates to commonly used azoles underscore the concerns about current empirical treatment options. Nystatin was the most effective drug against Candida species in the study population. Regular surveillance of anti-fungal susceptibility and anti-fungal stewardship aew urgently needed to mitigate resistance and improve patients outcomes.
Keywords: Oral colonization, Candida, anti-fungal, resistance, immunocompromised, cancer
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