Aviisotricha hoazini n. gen., n. sp., the Morphology and Molecular Phylogeny of an Anaerobic Ciliate from the Crop of the Hoatzin (Opisthocomus hoazin), the Cow Among the Birds.

The hoatzin is the only known avian species that has evolved a foregut fermentation system similar to that of ruminant animals. Due to the closeness of the bird's fermentation chamber, the crop, to the bird's beak it exudes an unpleasant odour; therefore, the hoatzin is called the "cow among the birds". In addition to Eubacteria and Archaea, responsible for digestion of the vegetation they consume, the bird's crop contains a holotrich ciliate, described here for the first time in detail. Cytological staining of this isotrichid-like ciliate with the Chatton-Lwoff and Protargol staining procedures, as well as SEM and TEM, justified the establishment of the new genus Aviisotricha n. gen. with its new type species Aviisotricha hoazini n. gen., n. sp.. Phylogenetic analyses of a portion of the small subunit rRNA gene supported the taxonomic placement of this new genus and species in the family Isotrichidae. Aviisotricha is compared with Balantidium, Dasytricha and Isotricha with special reference to their dorsal brushes, which show similarity to the paralabial organelle of the Entodiniomorphida. The possible phylogenetic origin of Aviisotricha is discussed and a taxonomic revision of the family Isotrichidae is given.

Trichomonas gallinae: Prevalence and molecular characterization from pigeons in Minoufiya governorate, Egypt.

Trichomonas gallinae infects the upper digestive tract of pigeons. It is transmitted from mother to young squabs by feeding crop milk. Generally, infection resulted in severe mortalities in young birds. In this study, we examined 3315 pigeons of different ages from the Minoufiya governorate for the clinical infection by T. gallinae. The infection was confirmed in infected birds by microscopical examination of oral swabs, histopathological examination, and PCR of the ITS1/5.8S/ITS2 gene. The prevalence was 63 (1.9%). The parasite was found in 35 (2.04%) from Ashmoun, 15 (1.66%) from Minoof, 8 (1.6%) from Quesna, and 5 (2.5%) from El-Shohada birds. The infection was mainly detected in squabs 60 (1.8%). The sequence of T. gallinae ITS1/5.8S/ITS2 gene from Egypt has high nucleotide sequence identity (up to100%) to T. gallinae from pigeon of USA, Austria, Canada, and Spain. The sequence belongs to genotype B of T. gallinae. Histopathological examination presented the parasites in crop, liver, larynx, and trachea as poorly eosinophilic bodies with severe inflammatory cell infiltration. This is the first study to present the prevalence and genotype of T. gallinae from Minoufiya governorate, Egypt.

Effects of different inoculation routes on the parasitic sites of Cryptosporidium baileyi infection in chickens.

Cryptosporidiosis is prevalent in domesticated, caged, and wild birds. Cryptosporidium baileyi, an ascendant species of avian Cryptosporidium, is an important pathogen. It causes respiratory disease in chickens, especially chickens younger than 50 days. In this study, SEM, histological, semi-quantitative PCR, and nested PCR techniques were used to explore the impact of different inoculation routes on sites of C. baileyi infection in chickens. Results showed that inoculation with sporozoites or oocysts via the rectum was an effective means of causing infection. This may provide an important reference for the development of the transfection system of C. baileyi in chickens. Numerous endogenous stages of C. baileyi were observed in the bursas of Fabricius (BF) and cloacas of chickens inoculated with sporozoites or oocysts via the rectum, but no parasite was seen in the tracheas of any of these chickens. In chickens infected with oocysts via the crop, the number of parasites in the BF was approximately 23-fold more than in the trachea. All blood samples collected after inoculation were negative for C. baileyi. These data show that C. baileyi was not transferred by blood circulation between the BF and respiratory tract. Different routes of inoculation were here found to distinctly affect sites of parasitism in chickens. These findings may facilitate further understanding of the biology of C. baileyi and efforts to control avian cryptosporidiosis.

Racing pigeons: a reservoir for nitro-imidazole-resistant Trichomonas gallinae.

Trichomonas gallinae , the cause of avian trichomonosis, is most commonly found in the order Columbiformes. Racing pigeons are often treated preventively with nitro-imidazoles, which could result in the emergence of resistant isolates, and these isolates can be a threat to wildlife when exchanges occur. The sequence type of 16 T. gallinae isolates obtained from racing pigeons and 15 isolates from wild pigeons was determined based on the ITS1/5.8S rRNA/ITS2 region sequence. In addition, the resistance profiles of these isolates against 5 different nitro-imidazoles (metronidazole, dimetridazole, ronidazole, tinidazole, and carnidazole) were determined. Two different Trichomonas sequence types were isolated. Sequence type A isolates were recovered from racing and wild pigeons, in contrast to sequence type B, which was only isolated from wild pigeons. Isolates with sequence type B were all susceptible to the tested nitro-imidazoles, except for tinidazole resistance in 3 isolates. Resistance to the nitro-imidazoles was observed more frequently in isolates obtained from racing pigeons than from wild pigeons, with most isolates belonging to sequence type A. A higher percentage of the sequence type A isolated from racing pigeons, in comparison with those isolated from the wild pigeons, were resistant to the nitro-imidazoles and displayed higher mean lethal concentration (MLC) values. Two isolates belonging to sequence type A, 1 recovered from a racing pigeon and 1 from a wild pigeon, displayed a similar resistance pattern, suggesting a potential exchange of resistant isolates between racing pigeons and wild pigeons.

Survey on helminthofauna in pheasants from Eastern Europe.

In order to assess the parasitological status in imported pheasants, 51 birds (Phasianus colchicus) coming from Poland and Rumania and used in Italy in repopulation interventions for hunting purposes were examined. From each animal the trachea, oesophagus, crop and intestine were collected and examined for the presence of nematodes. The examination of the oesophagi and crops of 5 birds revealed the presence of parasites pertaining to the family Capillariidae: Eucoleus contortus was found in all of the 5 animals, E. annulatus was present along with the previous parasite in one animal coming from Poland. The examination of the tracheae revealed the presence of Syngamus trachea in 5 animals (9.80%). Adult or larval stages of Heterakis gallinarum (37.25% of birds) and Capillariidae (35.29%) were found in the intestinal tracts. Aonchotheca caudinflata was detected only in one bird coming from Poland; the capillarids found in all of the remaining pheasants exhibited morphological characteristics referable to Capillaria phasianina, a species never reported in Italy. The release of game from foreign countries, therefore, may always constitute a risk for the autochthonous one due to the spread of new parasitic infections.

Correlates of helminth community in the red-legged partridge (Alectoris rufa L.) in Spain.

Between 1992 and 1996, 587 wild red-legged partridges (Alectoris rufa) from 16 Spanish provinces were examined to study the variations of helminth communities in this game species across a broad geographical area. The survey revealed 13 species of helminth parasites. Dicrocoelium sp.. Rhabdometra nigropunctata, and Cheilospirura gruweli were the most common species, whereas Raillietina bolivari, Choanotaenia infundibulum, Tetrameres sp., and Capillaria anatis were the most rare. Subulura suctoria, Heterakis gallinarum, Heterakis tenuicaudata, Capillaria contorta, Trichostrongylus tenuis, and Raillietina tetragona occurred with intermediate frequencies. The abundance of C. gruweli, S. suctoria, H. tenuicaudata, T. tenuis, and R. tetragona was inversely correlated to latitude and directly correlated to yearly mean temperature, whereas the abundance of Dicrocoelium sp. was directly correlated to latitude and inversely correlated to yearly mean temperature. The abundance of R. tetragona was inversely correlated to latitude and yearly mean humidity. The number of helminths per partridge and the number of helminth species per partridge were lower in young birds than in adults. Partridge body condition was inversely correlated to abundance of C. contorta. Richer infracommunities were linked to richer component communities. At the infracommunity level, total number of helminths per partridge and number of helminth species per partridge were inversely correlated to latitude and directly correlated to yearly mean temperature. At the component community level, both species richness and diversity (Simpson's index) were inversely correlated to latitude and directly correlated to mean temperature. Across the broad geographical range of the study area, the helminth parasite communities of red-legged partridges had marked geographical variation in their structure. Our results suggest that this variation is determined by the distribution of both intermediate and definitive hosts. We discuss the implications of this variation for the hypothesis that supplementary releases of captive-bred partridges for sport hunting can affect the helminth fauna of wild red-legged partridges.

Trichomoniasis in birds of prey (order Falconiformes) in Bahrain.

Of 5360 falcons examined at the Sulman Falcon Hospital in Bahrain between 1987 and 1993, 1675 (31.2 per cent) had lesions of trichomoniasis. These lesions were commonly found in the oral and nasal cavities, the infraorbital sinuses, the crop and oesophagus and, more rarely, in the coelomic cavity, attached to the wall of the abdominal air sacs, and in the trachea, partially obstructing its lumen. Several therapeutic methods and the results obtained are described.

A new method for the diagnosis of Trichomonas gallinae infection by culture.

Diagnosis of Trichomonas gallinae infection can reliably be made by the demonstration of organisms in material taken from a bird's mouth and crop. This can be examined directly or incubated in a growth medium until organisms are numerous enough to be easily found in aliquots examined with the microscope. We compared two methods of culture diagnosis of Trichomonas gallinae infection in pigeons. A commercially available kit, In-Pouch TF, proved as sensitive for this purpose as in vitro Diamond's medium, but had practical advantages over the usual in vitro system.

[Naturally-acquired microsporidia (Encephalitozoon cuniculi) infections in hens]. / Natürliche Mikrosporidien-(Encephalitozoon-cuniculi-)Infektionen bei Hühnern.

During a short period of time, four approximately ten months old chickens from an egg production (group A) unit developed symptoms of apathy, lameness, mild diarrhoea and loss of weight. The layers were killed and submitted for necropsy. For the first time, microsporidia infection, probably Encephalitozoon cuniculi (E.c.) was diagnosed in chickens. The diagnosis was mainly based on immunohistochemical methods. E.c. was found particularly in the cells of the cutaneous mucous membrane of the crop and in epithelial cells, the cells of the propria mucosae and the smooth muscle cells of the small intestine. E.c. also frequently occurred in the fibres of the skeletal muscle. Intracellularly, E.c. and its development stages were located primarily in the cytoplasm and less frequently in the nucleus of cells. Retrospective investigations on tissue samples from a domestic cock and 9 hens by immunohistochemical methods also revealed occurrence of this microsporidian. The results showed that in chickens E.c. infections can cause multi-symptomatic illness but may also be clinically inapparent.

Avian toxoplasmosis: experimental infection of chicken and pigeon.

Two groups of 13 new-laying hens each were infected by crop-route with 5000 and 50,000 infective oocysts of T. gondii. Four groups of 5 pigeons each were inoculated by crop-route with 50, 500, 1000 and 5000 infective oocysts. To each group of infected birds suitable controls were added. Hens from the experiment with 5000 infective oocysts were apparently resistant to the infection and they had no clinical signs in the succeeding 40 days p.i. Hens from the experiment with 50,000 infective oocysts showed an egg-drop and mortality in embryonated eggs, especially during the first 2 weeks p.i. Isolation of the parasite was unsuccessfully attempted from 720 embryonated eggs, produced by infected groups, and tested on various days p.i. and at different stages of infection. The parasite was isolated from the brain, heart, liver, spleen and lung of infected birds 7 and 15 days p.i.; 40 days p.i. it was evident only in brain and heart. IgG onset and mean course were monitored by ELISA and high titers were reached by both groups. Pigeons from groups 500, 1000 and 5000 developed rapidly progressive clinical signs as diarrhea, trembling, incoordination, torticollis and death. They had enlargement of liver and spleen and focal necrosis, nodular features in the crop. Pigeons from expt 50 had no clinical signs in spite of the presence of the parasite in their organs for over 45 days p.i. Parasite was isolated from brain, heart, liver, spleen, lung, kidney, crop and muscles from all infected groups. Histopathological and ultrastructural features revealed the presence of multiplying tachizoites even within cells of the crop. Seroconversion, as monitored by ELISA, was recorded in all infected groups although high ELISA-titres were never reached. One of the negative controls from expt 5000 developed specific antibodies but the parasite was not isolated from its organs.