Oral colonization by Candida spp. in liver transplant patients: Molecular identification and antifungal susceptibilityOral colonization by Candida spp. in liver transplant

Candida species are commensal to normal oral microbiota; however, they can cause infections if immune functions are reduced. The aim of this study was to investigate oral colonization, identify species, and test the susceptibility profile to antifungals. A descriptive study included 97 liver transplant patients who attended the transplant center of a referral hospital in southern Brazil. Two oral swab collections were performed, with a 6-month gap between collections. The samples were identified by sequencing the internal transcribed spacer ITS region of the ribosomal DNA. The sensitivity test was performed with fluconazole, amphotericin B, and micafungin using a broth microdilution method recommended by Clinical and Laboratory Standards Institute document M27-A4. Eighty-two patients were investigated and 15 were excluded for presenting clinical infection. The identification of yeasts showed colonization in 66% and 61.9% in collections A and B, respectively. Candida albicans was the most prevalent species in both collections (n = 29/50 and n = 27/49, respectively). In 31 (62%) patients, the yeast species remained the same for 6 months, and in 19 (38%) the colonizing species was substituted. Thirty-two isolates from collection A were sensitive (S) to Fluconazole, 13 sensitive dose-dependent (SDD), and five resistant (R). In collection B, 32 were S, 12 SDD, and 5 R. For amphotericin B and micafungin, all isolates were sensitive. With knowledge of the species and identification of strains resistant to fluconazole, useful information can be alerts about the emergence of antifungal resistance strains. Lay Summary Study of great importance because it is the first investigation that identifies Candida in the oral cavity of liver transplant patients, allowing an understanding of epidemiology and contributing to the knowledge about strains resistant to fluconazole.