In vitro and in vivo ketoconazole sensitivity disparity in a cutaneous candidiasis case of Kluyveromyces marxianus: A case report

Introduction: Cutaneous candidiasis is an infection caused by the yeast, Candida albicans or other Candida-related species. Recently, Candida infections of the skin have become more prevalent and could be attributed to an increase in the number of immunocompromised individuals. Kluyveromyces marxianus (formerly Candida kefyr) is a rare yeast and a less common cause of cutaneous infection in humans, although it is usually associated with invasive candidiasis, especially among immunocompromised patients. Case summary: A case of cutaneous candidiasis on a 49-year-old adult male patient was evaluated. Laboratory examinations were conducted, including morphological identification, gram staining and molecular identification using Polymerase Chain Reaction (PCR), and gene sequencing. An antifungal susceptibility test was carried out using conventional drugs. Morphological identification revealed the presence of yeast as the most predominant isolate, while molecular and gene sequencing identified the isolate as Kluveromyces marxianus. Antifungal susceptibility test against ketoconazole, fluconazole and Amphotericin B showed a zone of inhibition with mean (± SD) of 38.5 (±0.5mm), 24.5 (±0.5mm) and 0 (±0.0mm), respectively. The patient was treated with both oral and topical ketoconazole but showed no complete therapeutic clearance of the lesion after four months of therapy. Conclusion: This study revealed an in vitro and in vivo ketoconazole sensitivity disparity in a case of Kluyveromyces marxianus, a cutaneous non- Candida albicans species. Based on this finding, further study of this pathogen is imminent to mitigate the health implications, especially in developing countries like Nigeria, for effective patient management.