Gastrointestinal tract Candida spp colonization shows mostly a monoclonal pattern: an intra-patient pilot study

Gastrointestinal tract Candida genotypes may associate with isolates later causing infections. We genotyped Candida spp isolates (n = 200 individual colonies) from rectal swabs to assess whether gastrointestinal gut colonization is caused by a single genotype (monoclonal pattern) or a combination of them (polyclonal pattern). C. glabrata showed a sheer monoclonal pattern. C. parapsilosis and C. tropicalis showed a monoclonal pattern involving the presence of either exclusively identical genotypes or a combination of clonally-related genotypes; in the latter case, a dominant genotype was always found. C. albicans showed mostly a polyclonal pattern involving a combination of dominant clonally-related genotypes and unrelated genotypes. Lay Summary We genotyped C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata isolates prospectively from rectal swabs to study the gastrointestinal colonization pattern in the patients. Gastrointestinal tract colonization is mostly monoclonal and commonly dominated by one genotype.