Molecular detection and genetic analysis of Candida species isolated from bovine clinical mastitis in India.

Bovine clinical mastitis is an economically important disease in dairy industry worldwide resulting in reduction of milk yield and quality. Among mycotic mastitis, Candida spp. are commonly occurring opportunistic mycosis in immunocompromised animals. The micro-organism's causing mastitis has high zoonotic potential and has been linked with rapid growth and introduction of antimicrobial resistance between animals and humans. The present study was conducted to isolate and identify the common pathogenic Candida spp. from bovine mastitis cases in India. The isolates were phenotypically characterized by culturing on Sabouraud's dextrose agar, Hichrome Candida differential agar and germ tube production test. Antibiogram was also performed to determine their antifungal activities. The phenotypically positive isolates were confirmed by polymerase chain reaction (PCR) and genetically analyzed by targeting 18S-ITS1-5.8S-ITS2-28S region specific for Candida spp. and identified the yeast at the species level. The antibiogram showed the isolates were highly sensitive with ketoconazole, clotrimazole and miconazole. The PCR assay identified C. lusitaniae and C. tropicalis based on the two distinctive amplicon sizes (592bp and 737bp) respectively. Also, the sequence analysis and phylogeny confirmed C. lusitaniae in six sequences and C. tropicalis in one sequence. It is worth noting that in this study, the species identification was consistent among PCR and genetic analysis. Therefore, the PCR based identification system of the fungal species performed in this study could be an efficient and time saving tool for early diagnosis of clinical mastitis in milch animal, which allows prompt control and application of speedy effective treatment.