Granulomatous encephalomyelitis and intestinal ganglionitis in a spectacled Amazon parrot (Amazona albifrons) infected with Mycobacterium genavense.

An approximately 30-year-old male spectacled Amazon parrot (Amazona albifrons) was presented with a 2-week history of ataxia, head shaking, weight loss and seizures. Gross findings on necropsy examination included atrophy of the musculature, ruffled feathers and minimal epicardial and abdominal fat. Microscopically, there were perivascular cuffs of macrophages with fewer lymphocytes in the grey and white matter of the brain and spinal cord. These lesions were accompanied by gliosis and mild vacuolation of the white matter. In the small intestine, up to 70% of the intestinal ganglia were effaced by infiltrates of macrophages and fewer lymphocytes. The intestinal lamina propria contained multiple inflammatory aggregates of a similar nature. Ziehl-Neelsen staining revealed the presence of numerous bacilli within the cytoplasm of macrophages in the central nervous system (CNS) and enteric ganglia. Amplification of the DNAJ gene confirmed a mycobacterial infection and subsequent polymerase chain reaction (PCR) using a species-specific primer confirmed the aetiology as Mycobacterium genavense. Infection of the CNS with Mycobacterium spp. is uncommon and has not been previously reported in a parrot. This case is unusual in that the organism exhibited tropism for neural tissue.

Humoral response to Mycobacterium avium subsp. avium in naturally infected ring-neck doves (Streptopelia risoria).

Creation of a reliable and easy to use serologic test would greatly improve ante mortem diagnosis of Mycobacterium avium subsp. avium and aid in the control of avian mycobacteriosis, particularly in captive birds. In order to determine whether serodiagnostics could be of value in testing ring-neck doves (Streptopelia risoria) for M. a. avium infection, Western blot analysis was used to assess the humoral response of ring-neck doves exposed to M. a. avium, and to evaluate whether an association could be made between the humoral response and necropsy findings, histopathology, culture, and PCR testing. Western blot results were examined for reactivity patterns associating humoral response with infection status, severity and type of lesions (diffuse vs. multifocal granulomatous inflammation) and phenotype (white vs. non-white). A sensitivity of 88.24% and a specificity of 100% were achieved utilizing Western blot analysis to detect M. a. avium infection in ring-neck doves, offering a negative predictive value of 93% and a positive predictive value of 100%. While Western blot analysis results did not reflect lesion severity, lesion type did partially correspond with the humoral response. The findings of the present study indicate that serologic testing can be used as a valuable ante mortem screening tool for identifying ring-neck doves infected with M. a. avium.