Characterization of beta tubulin DNA sequences within the Candida parapsilosis complex

Background and Candida parapsilosis is a common cause of candidemia in children and onco-hematologic patients as well as in patients with septic arthritis, peritonitis, vaginitis, and nail and skin infections. Here, we evaluated intra- and inter-species beta tubulin DNA sequence variation within the C. parapsilosis complex with a view to establishing its utility in the identification and phylogenetic analysis of the species.
The novel primers successfully amplified the target for all 23 strains included in the study.
Results and Multiple alignment of 623–629 bp-long nucleotide (nt) sequences reflecting the beta tubulin gene indicated an inter-species divergence ranging from 0 to 68 nt in C. parapsilosis, C. orthopsilosis and C. metapsilosis with a mean similarity of 84.7% among the species. Meanwhile, intra-species differences of 0–20 and 0–6 nt were found within the strains of C. parapsilosis and C. orthopsilosis, respectively. The phylogenetic tree topology was characterized by a clade made up by C. parapsilosis and C. orthopsilosis, while C. metapsilosis formed a related but separate lineage. Our data provide the basis for further discoveries of the relationship between the species belonging to the C. parapsilosis complex and the value of beta tubulin DNA sequence data in the identification and taxonomy of C. parapsilosis and other pathogenic yeasts.