Mycological and molecular identification of mycoses involved in mastitis from Holstein dairy cattle with special reference to Candida albicans

Globally, mastitis is an incredibly devastating, multifactorial disease that affects the dairy industry. However, cases of mycotic mastitis in dairy cows have increased in recent years. This study aimed to investigate the prevalence of mycotic mastitis with special reference to Candida albicans in Holstein-Friesian dairy cows from some farms in Menoufia province, Egypt. For the study, 150 milk samples (n = 150, 20 from healthy cows and 130 from cows with subclinical and clinical mastitis) were collected from 15 smallholder dairy farms located in three localities (Quesina, Elbagour, and Shibin El-Kom) five farms from each. The samples were subjected to mycological culture and subsequently verified using traditional morphological and biochemical tests to confirm fungal characteristics followed by antimycotic susceptibility testing using Vitec 2 system. Finally, molecular identification was carried out via PCR and phylogenetic analysis. 27 samples out of 130 were positive for fungal culture representing (20.77%). Candida species were recorded the highest percentage (62.96%) of the detected fungi (17/27). In addition, C. albicans was the predominant species (3/27), which corresponds to 11.11%. Antifungal susceptibility testing of the fungal isolates showed the highest susceptibility to micafungin, followed by caspofungin (88.88% and 86.19%, respectively). However, the lowest susceptibility was noted against amphotericin B (50.55%). The three isolates of C. albicans were confirmed by PCR by amplifying the ITS region, which was then sequenced for phylogenetic analysis. The sequences have been deposited in GenBank under the following accession numbers: OR97266, OR97267, and OR97268. Our results indicate that Candida spp., especially C. albicans, is one of the major causes of mycotic mastitis in dairy cows in Egypt. Moreover, micafungin might be the efficient medication for treating these cases of mycotic mastitis, followed by caspofungin.