Molecular characterization of fungi causing colonization and infection in organ transplant recipients: A one-year prospective study

Background and Purpose: Organ transplant recipients are vulnerable to fungal infections. The aim of this study was to determine the prevalence of fungal colonization and infections among patients who underwent various transplantations and molecularly characterize the etiological agents. Materials and Methods: This study was conducted on candidates for transplantation in Imam Khomeini Hospital, Tehran, Iran, from April ۲۰۱۷ to April ۲۰۱۸. All patients were monitored for fungal colonization or infections before and after transplantation. Isolated fungi were identified using molecular methods. Results: A total of ۱۲۵ patients, including ۸۶ males and ۳۹ females, with the mean age of ۵۲.۲ years participated in the study (age range: ۱۵-۷۵ years). Out of ۱۲۵ patients, ۸۴ (۶۷.۲%) cases had fungal colonization that appeared pre- and post-transplantation in ۲۱ and ۶۳ cases, respectively (alone or concurrent with another infection in ۵۵ and ۲۹ cases, respectively). In addition, a total of ۳۹ episodes of fungal infections were diagnosed in ۳۶ (۲۸.۸%) recipients (alone or concurrent with colonization in ۷ and ۲۹ cases, respectively). Out of the ۳۹ fungal infections, ۹ cases appeared pre-transplantation, while the other ۳۰ cases occurred post-transplantation. However, no fungal colonization or infection was observed in ۳۴ (۲۷.۲%) patients. Oral candidiasis (n=۲۰) was the most common type of infection, followed by funguria (n=۷), onychomycosis (n=۵), candidemia (n=۳), rhinocerebral mucormycosis (n=۱), cutaneous mucormycosis (n=۱), cutaneous aspergillosis (n=۱), and peritonitis (n=۱). Six yeast species were recovered from colonization cases with the dominance of Candida albicans both before and after transplantation. The observed fungal infections were caused by ۱۱ distinct species, including the members of Candida (i.e., C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei), Aspergillus (i.e., A. oryzae and A. candidus), Rhizopus (i.e., R. oryzae and R. microsporus), Trichosporon asahii, and Trichophyton interdigitale. The results also indicated that the development of a fungal infection post-transplantation was associated with fungal colonization (r=۰.۰۱۸۴; P=۰.۰۴۳). Conclusion: Based on the results, fungal colonization was a common finding in transplant recipients at Imam Khomeini Hospital. However, the incidence of fungal infections was comparable with those of other centers. As the oral cavity was the most common site of colonization and infection, it might be beneficial to take further care about the oral health of patients using effective mouthwash.

کلیدواژه ها:

Aspergillosis ، Candidiasis ، Invasive fungal infections ، Mucormycosis ، organ transplantation