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In the present study, the presence of the Enterobacterales, Staphylococcus spp., Mammaliicoccus spp., and Enterococcus spp. in cloacal samples of nestling ospreys (Pandion haliaetus), a fish-eating specialist, from Mono Lake, California, USA was examined by a multiphasic approach, including antimicrobial and biocide susceptibility testing, genotyping, and whole genome sequencing of selected isolates. The most commonly detected species was Escherichia coli, followed by Mammaliicoccus sciuri, Staphylococcus delphini, Enterococcus faecalis, Enterococcus faecium, Hafnia alvei, Klebsiella pneumoniae, Citrobacter braakii and single isolates of Edwardsiella tarda, Edwardsiella albertii, Klebsiella aerogenes, Plesiomonas shigelloides and Staphylococcus pseudintermedius. Multi-drug resistance (MDR) was observed in two E. coli isolates and in an Enterococcus faecium isolate. The MDR blaCTX-M-55-positive E. coli belonged to the pandemic clone ST58. The results of the present study suggest that nestling ospreys are exposed to MDR bacteria, possibly through the ingestion of contaminated fish. Ospreys may be good biosentinels for the presence of these microorganisms and antibiotic resistance in the local environment and the risk for other wildlife, livestock and humans., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Loncaric et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

We report a case of air sac nematode ( Serratospiculum tendo) infection in an adult male Austral Peregrine Falcon ( Falco peregrinus cassini) admitted to a rehabilitation center in Mendoza Province, Argentina, in September 2017. This case of air sac nematodes reported in an Argentine raptor is only the second report of S. tendo in South America. We recommend examination of all raptors, especially those falcon species that include insects in their diet and inhabit open lands and those in rehabilitation centers or kept for falconry, education, or captive breeding. Fecal analysis and microscopic examination of oral swabs for evidence of parasites are simple noninvasive diagnostic procedures that allow easy detection of these parasites under field and captive circumstances.

We evaluated the prevalence of WNV and SLEV neutralizing antibodies in captive and free-ranging raptors from Argentina by plaque-reduction neutralization test. Eighty plasma samples from 12 species were analyzed. Only one captive adult Crowned Eagle (Harpyhaliaetus coronatus) was WNV seropositive (prevalence: 1.25%; antibody titer of 1:80). Two captive Crowned Eagles were SLEV seropositive (prevalence: 2.50%; antibody titers: 1:80 and 1:40).These findings expand the geographic distribution of WNV and SLEV and confirm their activity in central and northeastern Argentina. West Nile virus activity in Argentina may represent a potential threat to Crowned Eagles and other endangered raptors in this country.

Clinical respiratory illness was compared in five homozygous chicken lines, originating from homozygous B2, B8, B12 and B19, and heterozygous B2/B12 birds after infection with either of two strains of the infectious bronchitis virus (IBV). All chickens used in these studies originated from White Leghorn and Ancona linages. IBV Gray strain infection of MHC homozygous B12 and B19 haplotype chicks resulted in severe respiratory disease compared to chicks with B2/B2 and B5/B5 haplotypes. Demonstrating a dominant B2 phenotype, B2/B12 birds were also more resistant to IBV. Respiratory clinical illness in B8/B8 chicks was severe early after infection, while illness resolved similar to the B5 and B2 homozygous birds. Following M41 strain infection, birds with B2/B2 and B8/B8 haplotypes were again more resistant to clinical illness than B19/B19 birds. Real time RT-PCR indicated that infection was cleared more efficiently in trachea, lungs and kidneys of B2/B2 and B8/B8 birds compared with B19/B19 birds. Furthermore, M41 infected B2/B2 and B8/B8 chicks performed better in terms of body weight gain than B19/B19 chicks. These studies suggest that genetics of B defined haplotypes might be exploited to produce chicks resistant to respiratory pathogens or with more effective immune responses., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Even when different diagnostic modalities are available, mycobacteriosis is difficult to diagnose in a live bird. To investigate the diagnostic value of sampling different tissues and using different diagnostic methods, we evaluated results of mycobacterial culture, Ziehl-Neelsen (ZN) staining, and single-amplification polymerase chain reaction assay (PCR) of 18 ring-neck doves (Streptopelia risoria) with confirmed natural infection with Mycobacterium avium avium. Results of testing liver biopsy, duodenal aspirate, and bone marrow aspirate samples and liver and spleen samples collected at necropsy were compared. Results showed the use of one single technique did not allow identification of all infected birds. In liver biopsy and bone marrow aspirate samples, culture had the highest sensitivity, whereas PCR assay and ZN staining had low sensitivity, and their combination was less sensitive than culture alone. Examination of ZN staining of the intestinal aspirate samples failed to detect infection in most birds. More splenic lesions contained acid-fast organisms than did liver lesions, suggesting that splenic biopsy may have the greatest potential for diagnosis of mycobacterial infection antemortem. Sensitivity was higher for postmortem examination of multiple liver sections than of a single biopsy section; therefore, obtaining multiple liver biopsy sections may increase detection of mycobacteria. Examination of multiple tissues and the use of several different diagnostic techniques significantly increases the probability of diagnosis of mycobacteriosis.

Prevalence of infection and disease, the degree of organ involvement and the nature of the lesions were investigated in 11 white and 18 non-white ring-neck doves coming from a flock naturally infected with Mycobacterium avium subsp. avium. Lesions were common in the liver, spleen, lung, kidney, intestines, ovary and bone marrow. Overall, 18 out of 29 (62%) birds were considered infected with a sequevar of M. avium subsp. avium that contains serotypes 2, 3, 4 and 9. The prevalence of infection in the white doves (36.4%) was significantly lower than in the non-white morphs (77.7%). White doves had on average fewer organs affected (mean =3.1) than the non-white doves (mean =5.9). A diffuse pattern of inflammation in the liver and spleen was observed mainly in non-white doves. Focal or multifocal granulomatous inflammation of the liver and spleen was predominant in white doves. Genetic mechanisms of immunity to mycobacteriosis may be contributing or determining these differences. There are three basic colour morphs in ring-neck doves--dark or wild type, blond and white--and the alleles coding for colour are sex-linked and located on the sex (Z) chromosome. Female's single sexual chromosomed (ZW) and homozygous males (ZZ) can be white if they carry the white alleles. It is very probable that the gene or genes modulating the immune response to M. avium subsp. avium infection in these doves could be associated to these loci or at least located in the same (Z) chromosome, as the association with white colour suggests.

The white-winged duck (Cairina scutulata) is critically endangered. Breeding collections of this duck are established in the United Kingdom and the USA. Infection with Mycobacterium avium avium serotype 1 is a major cause of mortality in the UK collection. In this study, the aetiopathogenesis of deaths occurring in the US collection was studied. All ducks (n=21) that died over a 21-month period were examined. Mycobacteriosis was diagnosed in 20 ducks, killing 19 of them. Multifocal to diffuse granulomatous lesions, often with abundant intralesional organisms, were seen in all 20 ducks. Unusual manifestations of this disease were the extensive involvement of the respiratory system and the absence of multinucleated giant cells. Sequence analysis showed that the ducks were infected with a sequevar of M. a. avium that contains serotypes 2, 3, 4, and 9. Given that the long-term ingestion of metals affects immune function, we measured an array of such elements in the liver of six ducks. Concentrations were undetectable or low. The disseminated nature of the disease, high concentration of mycobacteria and absence of multinucleated giant cells within lesions suggest that these ducks were unable to effectively kill the mycobacteria and point to a possible defect or inhibition in cell mediated immunity. Taken together with previously reported UK data, these results suggest that captive white-winged ducks are highly susceptible to at least two sequevars of M. a. avium and that mycobacteriosis is a major threat to ex situ breeding. We hypothesize that the minimal heterozygosis previously shown in these ducks could be contributing to an apparently ineffective immune response.

Prevalence of anthrax spores in feces of raptors was determined from samples collected in November-December 2000 and April-May 2001 in an agricultural region of Santa Fé province, Argentina. Feces were tested from 48 birds of six raptor species. One of 14 chimango caracaras (Milvago chimango) and one of eight road-side hawks (Buteo magnirostris) tested positive. The prevalence of Bacillus anthracis spores in feces for the six species was 4% (n=48). The prevalence was 7% (n=14) for chimango caracaras, 13% for road-side hawks (n=8), and 0% for the remaining species (Burrowing owl [Speotyto cunicularia] [n=17], Swainson's hawk [Buteo swainsoni] [n=3], Aplomado falcon [Falco femoralis] [n=2], and American kestrel [Falco sparverius] [n=4]). Grouped by their feeding habits, prevalence for scavenger species was not significantly different than for predators (7% vs. 3%, P>0.999). This study provides evidence that in central Argentina scavenger and non-scavenger raptors may have a role in the epidemiology of anthrax. Long-term studies to determine the extent of this potential involvement in the epidemiology of anthrax in central Argentina are required.