Pathogenicity Study of Dematiaceous Fungi Isolated from Chicken Feeds on Immunoincompetent Chickens

Abstract

This study was carried out to investigate the pathogenicity of dematiaceous fungi isolated from chicken feeds sample in immunoincompetent chickens. A total of 40 chicken feed samples were collected from Ihiala market and screened for the presence of dematiaceous fungi using spread plate technique. The isolates obtained were characterized and identified using their microscopic and macroscopic characteristics. They were challenged orally using 0.5 ml of each of the test isolate to investigate the pathogenic potentials of each test isolate on the chickens. Dematiaceous fungi were detected in 13 chicken feed samples out of 40 chicken feed samples analysed. Alternaria alternata, Phialophora verrucosa, Madurella grisea, Madurella mycetomatis, Exophiala jeanselmei were the dematiaceous fungi detected from the feed sample. There was significant (P<0.05) decrease in the body weight of the infected immunoincompetent chickens. The total mean viable plate counts of the challenged isolates from the internal organs (heart, liver, lungs) of immunoincompetent chickens were significantly (P<0.05) higher. No count was recorded on the non-infected chicken. It was observed that the test isolate showed reasonable pathogenic features among immunoincompetent chickens and Alternaria alternata proved to be most pathogenic among the tested isolates.