Abstract

Avian gastric yeast (Macrorhabdus ornithogaster) is an anamorphic ascomycetous yeast which colonises the junction between proventriculus and ventriculus in many species of birds. Although a normal flora, sometimes it causes a subclinical infection and at times lead to gastric infections. The present study confirmed the presence of Macrorhabdus ornithogaster from faecal samples of budgerigar with symptoms like regurgitation and chronic wasting. Gram’s staining of the direct smear demonstrates large number of pleomorphic Gram positive organisms. The organism could be cultured on blood agar, Sabouraud’s dextrose agar and De Man Rogosa and Sharpe agar but not on MacConkey agar. The organisms were found to be negative for catalase and oxidase and did not reduce nitrate. It produced acid from maltose, sucrose, glucose, galactose and trehalose and not from raffinose and lactose. The cultural and biochemical characters of the isolate along with clinical symptoms confirmed the case as avian gastric yeast infection.

Keywords : Macrorhabdus ornithogaster, Avian Gastric Yeast, Budgerigars, De Man Rogosa and Sharpe agar