RESUMO
Broiler chickens aged 41-day-old from a flock of a broiler complex, presenting depression, reduced food intake, facial edema, dyspnea, gasping, sneezing, and 5% mortality were studied. At necropsy, opaque thoracic and abdominal air sacs and mucous tracheal content were observed. Histopathology of tracheas showed multifocal hyperplasia of mucosa with a large number of small, round and ovoid basophilic organisms on their surface, which were identified as Cryptosporidium spp. In addition, there was an inflammatory response due to infiltration of mononuclear cells and heterophils in the submucosa. Small pin-point colonies without hemolytic activity were isolated from tracheal samples and identified as Ornithobacterium rhinotracheale by conventional and real time polymerase chain reaction (PCR). Results of tracheal histopathology, bacteriology, and PCR identification provided the diagnosis of tracheal cryptosporidiosis associated with non-hemolytic O. rhinotracheale secondary infection. This report describes the unusual dual infection with Cryptosporidium spp. and non-hemolytic O. rhinotracheale causing tracheitis in broiler chickens.
RESUMO
Broiler chickens aged 40 and 46-days-old from two neighboring flocks belonging to a commercial broiler complex, presenting facial edema, severe respiratory signs and 10% mortality were analyzed. Pneumonic lesions and opaque thoracic and abdominal air sacs with foamy exudate were seen at postmortem examination. Histopathology of lungs showed fibrinoheterophilic pneumonia in both cases. Small pin point colonies with extensive -hemolytic activity were isolated from tracheal and lung tissue samples and identified as Ornithobacterium rhinotracheale by polymerase chain reaction (PCR). Results of lung histopathology, bacteriological isolation and PCR identification confirmed the diagnosis of pneumonia caused by -hemolytic O. rhinotracheale infection in both broiler chicken flocks. This paper appears to be the first report of -hemolytic O. rhinotracheale field isolates obtained from broiler chickens associated with severe respiratory signs and pneumonia.