Genetic relatedness between human and animal Candida albicans isolates recovered from Southeastern Nigeria using random amplification of polymorphic DNA-PCR

Abstract

Candida species is currently recognized as the major cause of a variety of human and animal fungal infections globally. Since the world has become a global village, the knowledge of local epidemiology of Candida albicans and the evaluation of its diversity is important and will help in understanding and controlling their transmission globally. The present study was conducted to evaluate the genetic relatedness between human and animal Candida albicans isolates in Nigeria. The C. albicans isolates (n=15) were typed by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) using three primers (P4, OPA-03 and OPE-18) after identification, antifungal susceptibility and virulence profile screening using standardized methods. A high degree of separation of human and animal C. albicans isolates into distinct genotypes was clearly evident. Some degree of genotypic relatedness was seen but at varying distance of separation. The highest level of genetic similarities (84%) was observed between C. albicans recovered from cow faeces and that recovered from human high vaginal swab, suggesting that they were related but not completely identical. Moreover, no clonal relationship was found. Though this is a preliminary study, we observed different banding patterns suggesting a high degree of discriminatory power for the three primers used. It further confirms the usefulness of RAPD-PCR in molecular typing of Candida isolates. Although no clonal relationship was seen and considering the sample size in this study, the possibility of transfer cannot be ruled out when humans are exposed to animals that harbor virulent and resistant strains or when such animals are eaten.