Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Zoonoses

Cryptococcus has gained medical importance over the last decade, as it represents a potential risk for immunosuppressed and immunocompetent individuals. Previous studies reported cryptococcosis in equines is uncommon, sporadic cases have been reported with rhinitis, sinusitis, pneumonia and meningitis. There are no epidemiological data on the prevalence of this fungus in horses and donkeys.The current study was carried to investigate the possible role of these animals in the epidemiology of such pathogen. A total of 275 samples were collected from different localities in Egypt included 263 nasal swabs (183 from horses, 52 from donkeys and 28 from humans) in addition to 12 soil samples. Bacteriological examination and identification of Cryptococcus were performed. The overall occurrence of Cryptococcus spp. in the investigated samples was 14.8, 11.5, 25 and 10.7% in horse, donkeys, soil and human, respectively.Molecular serotyping of Cryptococcus spp. isolates recovered from the nasal passage of horses and donkeys proved that C. gattii (B) and C. neoformans were identified; in addition, two hybrids between C. neoformans (A) and C. gattii (B) were identified in horse samples. While in case of soil samples, the isolates were identified as C. gattii (B).The human isolates were serotyped as C. gattii in two isolates and C.neoformans in only one isolate. Molecular detection of some virulence genes among the identified isolates showed that LAC1 and CAP59 genes have been the most frequently detected genes. In horse, soil and human samples both LAC1&CAP59 genes were identified in C.gattii and C.neoformans isolates, on the other hand PLB1detected only in C.gattii. While the identified virulence genes in donkeys{u2019} C. gattii and C. neoformans isolates demonstrated higher laccase (LAC1) genes

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