Avian mycobacteriosis in free-living raptors in Majorca Island, Spain

Abstract

Avian mycobacteriosis is a chronic, infectious disease caused by different species of mycobacteria, usually belonging to the Mycobacterium avium complex. From 2004 to 2007, 589 raptors brought dead or sick to a wildlife rehabilitation centre in Majorca (Balearic Islands, Spain) were necropsied. The birds belonged to 12 different species, chiefly common kestrel (Falco tinnunculus) (n0297), scops owl (Otus scops) (n 0109), barn owl (Tyto alba) (n 075), long-eared owl (Asio otus) (n 058), peregrine falcon (Falco peregrinus) (n 027), and booted eagle (Hieraaetus pennatus) (n013). Gross lesions compatible with mycobacteriosis were observed in 14 birds (2.4%) found in several locations in Majorca. They were 12 kestrels (prevalence in this species, 4.0%), one long-eared owl (1.7%) and one scops owl (0.9%), all the birds presenting whiteÁyellowish nodules from pinpoint size to 1 cm in diameter in diverse organs, mainly in the liver, spleen and intestine. Affected organs were subjected to bacteriology and molecular identification by polymerase chain reaction and, in all cases, infection with M. avium subspecies avium was confirmed. The observed prevalences are similar to those previously observed in Holland, although the actual prevalence detected in this study is likely to be higher than reported because only birds with gross lesions were subjected to culture. Further molecular characterization with a set of six mycobacterial interspersed repetitive unitÁvariable number tandem repeat loci was used to sub-type the isolates in order to show the existence of possible epidemiological links. Six different genotypes were found, which points to infection from multiple foci. No temporal or geographical aggregation of the cases was observed to be associated with the presence of positive birds or with the different variable number tandem repeat allelic profiles. The most feasible origin might be water or food sources, although the reservoir of mycobacteria remains unknown.

Tuberculosis in Birds: Insights into theMycobacterium aviumInfections

“…Avian tuberculosis in domestic birds is primarily an intestinal and hepatic disease with dissemination to other organs including the lungs, air sacs, spleen, bone marrow, and skin [2, 6, 11, 23]. Similarly, avian tuberculosis reported in free living birds including raptors were presented with the disseminated form involving the digestive tract, liver and spleen [8, 28, 29]. The disease has a long incubation period and a protracted course and if appreciable, the symptoms can prolong for weeks or months.…”

Avian tuberculosis in a captured Ruppell's griffon vulture (Gyps ruppellii): a case report

“…A number of reports describe the clinical dis- ease and pathological lesions caused by M. avium (Lumeij et al, 1981;Schroder, 1981;Smit et al, 1987;Hoop et al, 1996;Hoenerhoff et al, 2004;Tell et al, 2004;Heatley et al, 2007;Millan et al, 2010). Interestingly, there is no previous report of avian tuberculosis in a vulture, despite records on morbidity and mortality of many different species of raptorial birds (Kaliner and Cooper, 1973;Lairmore et al, 1985;Morishita et al, 1998;Hoenerhoff et al, 2004;Tell et al, 2004;Heatley et al, 2007;Millan et al, 2010). The features of lesions caused by mycobacterial infections may vary according to the infected avian species.…”

“…The disease may be present in a variety of clinical forms with most organ systems being affected. According to various authors, avian tuberculosis has been reported as the cause of death in 1 to 30% of raptor cases examined post mortem (Greenwood, 1977;Lumeij et al, 1981;Smit et al, 1987;Hoop et al, 1996;Morishita et al, 1998;Tell et al, 2004;Millan et al, 2010). The highest numbers of cases are diagnosed in captured birds from zoological gardens (Lumeij et al, 1981;Schroder, 1981;Tell et al, 2001;Jones, 2006).…”

Molecular analysis and MIRU-VNTR typing of Mycobacterium avium subsp. paratuberculosis strains from various sources

“…() and Millán et al . (). PCR products were visualized after electrophoresis on 2 % agarose gel with GR Safe II nucleic acid strain (Lab Supply Mall, Innovita, Inc) under UV transilluminator.…”