Morphological and molecular diagnosis of invasive aspergillosis in chickens

Abstract

Confirmatory diagnosis of invasive aspergillosis is paramount to ensure proper treatment and effective management of the disease in food and companion animals. Suspected invasive aspergilllosis in chickens was encountered at post-mortem. Morphological and molecular methods were employed to identify Aspergillus from samples collected from dead chickens at post-mortem. Morphologically, two species of Aspergillus were identified, namely Aspergillus fumigatus and Aspergillus flavus. Molecular identification based on polymerase chain reaction (PCR) and sequence analysis of the partial 5.8 S rRNA, complete internal transcribed spacer-2 and partial 28S rRNA sequences bolstered morphological identification to arrive at the confirmatory diagnosis of the disease. Various hotspots that differentiate A. flavus from A. fumigatus and from other Aspergillus species were identified based on multiple sequence analysis. Maximum likelihood phylogenetic tree showed that isolates from the same species were grouped in the same clade. It is important to correctly identify the Aspergillus species in order to efficiently manage the disease.