ENRICHMENT OF MULTILOCUS SEQUENCE TYPING CLADE 1 WITH ORAL CANDIDA ALBICANS ISOLATES IN PATIENTS WITH UNTREATED PERIODONTITIS

Abstract

This study investigated the prevalence and cell density of Candida species in periodontal pockets, healthy subgingival sites and in oral rinses of patients with untreated periodontitis. Twenty-one periodontitis patients underwent sampling at two periodontitis sites and for 19/21 patients one periodontally healthy site. Both paper-point and curette sampling techniques were employed. The periodontitis patients and 50 healthy subjects were also sampled by oral rinse. Candida isolates were recovered on CHROMagar Candida medium and representative isolates identified. Candida was recovered from 10/21 (46.7%) periodontitis patients and from 16/50 (32%) healthy subjects. C. albicans predominated in both groups and was recovered from all Candida-positive subjects. Candida-positive periodontitis patients yielded Candida from periodontal pockets with average densities from curette and paper-point samples of 3,528 and 3,910 CFU/sample, respectively, and 1,536 CFU/ml from oral rinses. The majority (18/19) of periodontitis patients’ healthy sites sampled were Candida-negative. The 16 Candida-positive healthy subjects yielded an average of 279 CFU/ml from oral rinses. C. albicans isolates were investigated by multilocus sequence typing (MLST) to determine if specific clonal groups were associated with periodontitis. MLST analysis of 31 C. albicans isolates from periodontitis patients yielded 19 sequence types (STs), 13 of which were novel. Eleven STs belonged to MLST clade 1. In contrast, 16 C. albicans isolates from separate healthy subjects belonged to 16 STs, with four from clade 1. The distribution of STs between both groups was significantly different (p=0.04) and indicates an enrichment of C. albicans isolates in periodontal pockets that warrants a larger study.