Journal of Animal Health and Production

Review Article
J. Anim. Health Prod. 9(s1): 17-26
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Mohammed Taha1, Yasmine Hasanine Tartor1*, Sara Zaki Ibrahim2, Rana Mohamed Abd El-Aziz3

1Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, 44511-Zagazig, Sharkia, Egypt; 2Veterinarian, Faculty of Veterinary Medicine, Zagazig University; 3Cairo International Airport Veterinary Quarantine, General Organization for Veterinary Services, Ministry of Agriculture, Cairo, Egypt

Abstract | Cryptococcosis is a sub-acute or chronic fungal infection of human and animals that is induced by opportunistic capsulated basidiomycetous yeasts of genus Cryptococcus, primarily C. neoformans and C. gattii with a worldwide distribution. The genetic variability of C. neoformans/C. gattii species complex has been investigated by several molecular techniques mainly hybridization and nested and multiplex PCR assays. Other PCR-based methods were employed for identification as PCR fingerprinting, PCR Restriction fragment length polymorphism (PCR-RFLP), Amplified fragment length polymorphism (AFLP), and multi-locus sequence typing (MLST). Moreover, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been recently introduced for Cryptococcus identification and subtyping. Cryptococcus neoformans/C. gattii species complex is recently divided into seven species: C. neoformans, C, deneoformans, C. gattii, C. deuterogattii, C. bacillisporus, C. tetragattii, and C. decagattii in addition to four interspecies hybrids with differences in pathogenicity, epidemiology, and antifungal susceptibility. Long-term usage of antifungal drugs led to the emergence of resistance in C. neoformans and C. gattii species. Thus, antifungal susceptibility is of great importance in the epidemiological investigation for tracking the susceptibility profiles and drug resistance. Moreover, efficient antifungal therapies selection for cryptococcosis treatment is based on minimum inhibitory concentration (MIC) values of the gold standard drugs for cryptococcosis therapy: amphotericin B, fluconazole, 5-flucytosine, voriconazole, ketoconazole, and itraconazole. This review article highlights the main molecular methods used for identification and genotyping of C. neoformans and C. gattii and presents the global prevalence and antifungal susceptibility profiles of these environmental isolates against the commonly used antifungals.

Keywords | Cryptococcus neoformans, Cryptococcus gattii, PCR, Molecular types, MALDI-TOF MS, antifungal susceptibility