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A novel Sarcocystis species has recently been reported in the domestic pigeon (Columba livia f. domestica) as intermediate host, causing severe central nervous signs similar to Paramyxovirus-1 or Salmonella Typhimurium var. cop. infection. Transmission of the parasite via the northern goshawk (Accipiter gentilis) as definitive host has been established. Experimental infection of domestic pigeons with sporocysts excreted by experimentally infected northern goshawks reproduced the natural infection in the pigeon, proving the causative role of the parasite in the disease. Here, we describe in greater detail the course of the fulminant biphasic disease depending on the infectious dose. Pigeons infected with 10(3) or 10(4) sporocysts showed clinical signs of polyuria and apathy around 10-11 days postinfection (dpi) and sudden neurological signs 51-57 dpi as a second phase of disease. Pigeons infected with higher doses died within 7-12 dpi, also showing polyuria and apathy but without nervous signs. At necropsy, livers and spleens had multifocal necroses and infestations with parasitic stages, namely, schizonts. Moreover, lesions and schizonts were also found in the lung, bone marrow, and next to blood vessels in the connective tissue of various organs. Pigeons infected with 102 sporocysts remained symptomless until 58-65 dpi, when sudden central nervous signs occurred. Major histopathologic findings of pigeons with neurological signs were encephalitis and myositis of virtually every skeletal muscle with high infestations of sarcocysts. Only mild myocarditis and very few cysts were found in the heart muscles. Importantly, a sentinel pigeon developed identical lesions when compared to those of low-dose infected pigeons, suggesting a risk of mechanical transmission of sporocysts from freshly infected to uninfected pigeons in a flock. By contrast, chickens failed to develop any clinical signs or pathologic lesions in the same experiment. The findings further characterize the new highly pathogenic disease in domestic pigeons, which clinically mimics paramyxovirosis and salmonellosis in both phases of the disease and exclude chickens as further intermediate host species.

Sarcosporidian cysts in the skeletal muscle of domestic pigeons (Columba livia f. domestica) have previously been attributed to infection with Sarcocystis falcatula, which is shed in the faeces of the opossum (Didelphis virginiana). Here, we describe fatal spontaneous encephalitis and myositis associated with Sarcocystis infections in three flocks of racing pigeons with 47 of 244 animals affected. The clinical course was characterized by depression, mild diarrhoea, torticollis, opisthotonus, paralysis and trembling. Histopathological examination of 13 pigeons revealed generalized severe granulomatous and necrotizing meningoencephalitis and myositis with sarcosporidian cysts. Light and transmission electron microscopy identified cysts in heart and skeletal muscle of 1 to 2 mm in length and 20 to 50 microm in width. These were subdivided into small chambers by fine septae and filled with lancet-shaped cystozoites (7.5 x 1.5 microm) and dividing metrocytes, which is characteristic for Sarcocystis. The cysts had smooth walls and were devoid of protrusions typical of S. falcatula. Polymerase chain reaction amplification and sequencing of the internal transcribed spacer region (ITS-1) and the complete 28S rRNA identified a novel Sarcocystis species with only 51% ITS-1 nucleotide sequence similarity with S. falcatula. A phylogenetic comparison of the 28S rRNA revealed close sequence homologies with Frenkelia microti, Frenkelia glareoli and Sarcocystis neurona. The clinical, histopathological, electron microscopic and genetic data are unlike any previously described protozoan infections in pigeons, suggesting a novel, severe disease due to an as yet undescribed Sarcocystis species.

The lesser kestrel (Falco naumanni) is one of the most endangered bird species in Europe, and a captive breeding and reintroduction project was established. A breeding project is vulnerable to pathogens, e.g., mycoplasmas, reducing the reproductive success and carrying the risk to release pathogens with the birds to the wild. Therefore, 18 infertile eggs and 43 dead in shell embryos of the breeding project, as well as 27 nestlings and 34 adult birds of the captive and three different free-ranging populations were investigated for the occurrence of mycoplasmas by culture and a Mycoplasma genus-specific polymerase chain reaction. All eggs, embryos, and hand-reared nestlings from the captive group were negative. In contrast, all parent-reared nestlings and 88% of the adults were positive. Mycoplasma falconis and unidentifiable mycoplasmas were detected in all groups. Mycoplasma buteonis was found in the captive and only in two of the three free-ranging populations. Sequencing the 16S rRNA gene of six randomly selected unidentified isolates showed that five isolates were similar and most likely had been found previously in a falcon from Germany. The remaining isolate demonstrated a very high homology to unidentified Mycoplasma isolates obtained previously from semen samples of raptors. The results suggest that these isolates might represent two new species. Mycoplasmas seem not to play a major role as pathogens in the breeding project, and there is no evidence that releasing birds poses a risk to the free-ranging population with regard to mycoplasmas. The study seems to be the first to describe the occurrence and role of mycoplasmas in the lesser kestrel.

Certain Mycoplasma spp. are pathogens of poultry, but little is known of the role of mycoplasmas in disease of birds of prey. Species-specific polymerase chain reactions (PCRs) for the detection of the poultry pathogens Mycoplasma gallisepticum, Mycoplasma imitans, Mycoplasma iowae, Mycoplasma meleagridis and Mycoplasma synoviae were therefore evaluated for use in birds of prey. The specificities of the PCR methods were established using avian and other mycoplasmas and also selected walled bacteria. The sensitivities of the different PCR assays varied between 100 fg and 10 pg DNA. Fifty-three tracheal swabs from healthy captive and free-ranging birds of prey were then investigated using these PCRs, and in no case was an amplicon obtained for M. gallisepticum/M. imitans, M. iowae or M. synoviae. Species-specific primers for M. meleagridis amplified a product from eight birds of prey but restriction enzyme analysis as well as sequencing of PCR products demonstrated these results to be false positives. Alignment studies of the sequenced products with the 16S rRNA gene sequence of various Mycoplasma species in GenBank demonstrated an identity of 91% to M. meleagridis but of 98% to Mycoplasma buteonis or Mycoplasma gallopavonis. Isolation and attempted identification of these mycoplasmas suggested it may be a previously unrecognized species.

Mycoplasmas are well-known avian pathogens of poultry and some passerines. Although reported in birds of prey, their role as pathogens is still unclear. Healthy, free-ranging raptor nestlings sampled during a routine ringing (banding) program, and birds of prey from rehabilitation centers, tested positive for Mycoplasma spp. by culture and a genus-specific polymerase chain reaction (PCR). Given the lack of clinical signs and disease, we suggest that mycoplasmas in raptors may be commensal rather than pathogenic. Using immunobinding assay and species-specific PCR tests, Mycoplasma buteonis, M. falconis, and M. gypis were identified; M. falconis was only detected in falcons. Additionally, some isolates could not be identified. This is the first report of Mycoplasma spp. isolations from Western Marsh Harriers (Circus aeroginosus), a Eurasian Hobby (Falco subbuteo), and a Barn Owl (Tyto alba).

Mycoplasmas are well-known pathogens in a variety of animals. In poultry it is known that some species can be transmitted by semen and infect the uterus of females. As the prevalence of mycoplasmas in birds of prey is very high and artificial insemination is a commonly used technique for reproduction, the possibility of transmission Mycoplasma spp. by contaminated semen in birds of prey was investigated. Isolation of mycoplasmas was possible in five out of 32 (15.6%) semen samples of different bird of prey species. Two additional semen samples were positive for mycoplasma DNA using a Mycoplasma-genus-specific polymerase chain reaction. The isolation of mycoplasmas from a testicular sample indicates the testis as the possible source of contamination. Sequencing of large parts (>90%) of the 16S rRNA gene of the isolated mycoplasmas suggests that all isolates belong to the same species. Alignment of the sequenced products with the 16S rRNA gene of Mycoplasma species in GenBank demonstrated a similarity of 97% to Mycoplasma verecundum, but serological testing by immunobinding assay failed to identify it as such. It is recommended that the semen of donor birds of prey is examined for mycoplasmas before its use in artificial insemination.

Between 2002 and 2006, a large number of juvenile northern goshawks (Accipiter gentilis) with central nervous signs were examined. They were aged between 45 and 55 days and had been fed on frozen and thawed day-old chicks. High-performance liquid chromatography showed that the birds had whole blood thiamine levels between 2.2 and 6.0 microg/l; the concentrations of other blood constituents were within their reference ranges. Treatment with thiamine hydrochloride rapidly resolved the clinical signs. Measurements of the concentration of thiamine in 22 free-ranging and captive goshawks showed that they ranged from 45.1 to 200 microg/l.

Liver samples of psittacine birds with a histological suspicion of an adenovirus infection, confirmed by electron microscopy examination, were subjected to virus isolation attempts using a heterologous cell culture system and a homologous cell culture system in the form of chicken embryo liver cells and psittacine embryo fibroblasts, respectively. Whereas isolation in chicken embryo liver cells failed, virus was isolated successfully in the psittacine embryo fibroblasts cell culture system. Molecular investigations identified the virus as a specific psittacine adenovirus (PsAdV). Additionally, on the basis of the hexon gene sequence data obtained, a real-time polymerase chain reaction (PCR) for specific detection of PsAdV was developed. To ensure an exclusive hybridization with PsAdV, selected primers were located within the variable L1 region of the hexon gene. Furthermore, the specificity of the real-time PCR was confirmed by investigation of a panel of different avian adenoviruses and unrelated DNA viruses. Using this PCR, the threshold cycle values obtained support the propagation of PsAdV in the homologous cell culture system in comparison with the chicken cell culture system. Moreover, the developed PCR represents a reliable method for specific and sensitive detection of PsAdV in clinical samples.

Mycoplasmas are commensals and pathogens of different avian species, especially poultry and passeriforms. The role of mycoplasmas in raptors has not yet been completely determined, and especially not the possibility of vertical transmission. Therefore 424 raptor eggs were examined for the occurrence of mycoplasmas using culture, and 155 of these eggs with a Mycoplasma genus-specific polymerase chain reaction (PCR) assay. This PCR was tested for its sensitivity and specificity, especially for use in a bird population of unknown mycoplasma status (prevalence and species). The size of the amplified PCR product was large (1013 base pairs) to enable use of the product for species differentiation by sequencing. Culture and PCR yielded only one positive result, in an egg of a Northern Goshawk (Accipiter gentilis). The isolate was identified as Mycoplasma lipofaciens using an immunobinding assay, as well as by sequencing part of its 16S rRNA gene.

Some Mycoplasma species are well-known avian pathogens and are of importance in poultry breeder flocks due to their pathogenic potential for embryos. Mycoplasmas are regularly detected in birds of prey, and a strain of Mycoplasma lipofaciens that was isolated from an egg of a Northern Goshawk (Accipiter gentilis) was examined for its pathogenicity in specific pathogen free chicken embryos since birds of prey eggs were not available for this purpose. The strain was found to be pathogenic, causing a high mortality as well as dwarfing, curled toes and infiltrations of heterophils in the liver, kidney, intestine and chorioallantoic membrane.

A natural outbreak of avipoxvirus occurred in recently purchased stone curlews (Burhinus oedicnemus) at a breeding farm and subsequently spread to other stone curlews residing at the farm. The initial outbreak was characterized by mild vesicular skin lesions on the legs, which then developed crusts and bled. The overall morbidity rate was 100%, but none of the birds died, and all recovered without complication. Four gallinaceous species, also kept on the farm, did not develop lesions. Avipoxvirus was identified from the skin lesions by virus isolation, electron microscopy, and monoclonal antibody testing, as well as by polymerase chain reaction testing. Eight months after this outbreak, 7 male stone curlews developed large, round, crusty lesions on their legs. Although poxvirus virions were identified in the lesions, results of virus isolation were negative. These lesions possibly were the result of a recrudescence of the original infection in male birds that were stressed because they were housed together during the breeding season. This is the first clinical description of an avipoxvirus infection in stone curlews.

A total of 64 Pasteurella multocida strains (46 out of 11 different feral bird species, partly injured by cat bites, and 18 strains originating from clinically healthy cats) were biochemically differentiated. As a result, 67.4% of the strains from feral birds and 61.1% from the cats were classified as the subspecies multocida, whilst 21.7% and 27.8% were identified as the subspecies septica. The percentage of frequency for both the subspecies was of a comparable order of magnitude from the birds injured by cat bites and from cats (58.6% and 61.1%, 24.1% and 27.8% resp.), whereas the frequency from other feral birds differed considerably (82.4% and 17.6%). Maltose-positive strains were only demonstrable in birds with wounds inflicted by cats. To date, maltose-positive strains have only been obtained from one cat and one human being with an injury caused by a cat. The results of this investigation confirm the possibility of the direct transmission of Pasteurella multocida via cat bites. 19 strains from feral birds and 15 strains from cats were tested for their capability to produce toxins. The results of these tests were negative. The present paper also describes the pathologic-anatomical and histopathological lesions caused by the infection in feral birds.

Summary Three isolates of avian pneumovirus (APV) were isolated in Germany during 1987 and 1988 from turkeys with clinical signs of turkey rhinotracheitis and one was isolated during 1990 from a broiler breeder flock with typical signs of swollen head syndrome. The isolates were typed using type-specific reverse transcriptase-polymerase chain reactions. The three isolates from turkeys were identified as type A, while the isolate from the broiler breeders was type B. During the late 1980s no APV live-virus vaccine was used in poultry flocks in Germany, which is indicative of the presence of both types at that time. Previous isolates detected from elsewhere in Europe during the 1980s had been only of type B. [ABSTRACT FROM AUTHOR]