The captive native adult psittacines at human care, Amazona aestiva (blue-fronted parrot) and Ara chloropterus (red-and-green macaw), clinically affected with reduced activity/appetite and poor feathering, one found dead Anodorhynchus hyacinthinus (hyacinth macaw) and two exotic dead-in-nest Psittacula krameri (rose-ringed parakeet) were examined for signs and for ante- and post-mortem lesions, and for the presence of avian polyomavirus (APyV; Gammapolyomavirus avis) T/t genes. All individuals were tested-positive for APyV in skin and/or in other tissues such as blood, brain, liver, skin and spleen, and all were tested-negative for psittacine circovirus (BFDV). However, no association was found between the detection of APyV and the presence of macro or microscopic lesions. The APyV sequences detected in the A. aestiva and P. krameri were grouped together with high identity, which may suggest common origins. However, the sequence detected in A. hyacinthinus was dissimilar and grouped separate. The sequences detected had high identity with T/t gene sequences of strains previously described in distinct continents. The evaluation of avian species for APyV may not be available nor demanded in the international avian trade and may represent an avian health hazard. The biosecurity of the commercial avian pet flocks and the captive avifauna in rehabilitation is considered essential.
29 August 2026 in Veterinary Research Communications
The objective of this study was to perform genomic, phylogenomic, and phenotypic characterization of bacterial isolates from a captive Cacatua alba to investigate their antimicrobial resistance profiles, virulence-associated genes, and genomic relationships with publicly available strains. Bacterial isolates obtained from the lungs and encephalon were identified as Escherichia coli (AV037), Enterobacter hormaechei (AV038), and Cupriavidus gilardii (AV039). Comparative genomic analyses, phylogenomic reconstruction, and antimicrobial susceptibility testing (AST) were performed. Genomic analysis identified multiple antimicrobial resistance-associated genes in AV037, AV038, and AV039, with genes associated with efflux pumps, particularly those in the resistance-nodulation-cell division (RND) family, as the predominant resistance-associated mechanism identified. Most identified genes are intrinsic to the respective bacterial species and do not necessarily confer phenotypic antimicrobial resistance when present alone. Phenotypic testing confirmed multidrug-resistant (MDR) profiles, with resistance to β-lactams and aminoglycosides. Susceptibility to carbapenems was preserved in AV037 and AV038, whereas AV039 exhibited resistance to meropenem. Phylogenomic analysis demonstrated that AV037 and AV038 clustered with strains recovered from diverse hosts and geographic regions. In contrast, AV039 clustered predominantly with environmental and human-associated isolates, including strains harboring the mcr-5 gene. These findings are consistent with previous reports describing the recovery of C. gilardii from both environmental and clinical sources. Overall, this study documents the occurrence of MDR bacteria carrying resistance and virulence-associated determinants in a captive C. alba , highlighting the value of genomic surveillance to improve our understanding of the distribution of clinically relevant bacterial isolates across different ecological settings.