BLOOD PARASITE INFECTIONS IN STRIGIFORMES AND PSITTACIFORMES SPECIES IN CAPTIVITY WITH A NEW RECORD OF POTENTIAL FATAL BLOOD PARASITE TRANSMISSION TO PARROTS.

Although parrot species are infrequently infected by hemoparasites in the wild, some fatal infections have been reported in captive individuals. Conversely birds of prey are frequently infected by hemoparasites. In this study, 193 captive birds from Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) centers in Madrid, Spain, belonging to orders Psittaciformes, Accipitriformes, Strigiformes, and Falconiformes, were blood-sampled in search of parasite infections. Molecular and microscopic analyses were conducted to detect parasites of the following genera: Haemoproteus, Plasmodium, Leucocytozoon, Trypanosoma, Babesia, and Lankesterella. Infections by microfilariae and Coccidia were also searched in blood samples. Surprisingly, infections by Haemoproteus syrnii, a common parasite from owls, were detected in the cadavers of two species of parrots, Trichoglossus haematodus and Psittacula cyanocephala. The same haplotype was also detected in the cadavers of two owl species, Tyto alba and Strix rufipes. All these birds were housed and died in the same center. Infections by species of Plasmodium, Leucocytozoon, and Trypanosoma were also found in different species of raptors. Nocturnal raptors (Strigiformes) show significantly higher prevalence of infection by blood parasites than diurnal raptors (Falconiformes and Accipitriformes). In conclusion, a potential fatal transmission of Haemoproteus syrnii, from Strigiformes to Psittaciformes species, is reported and several infections by different blood parasites were detected in birds of prey. These results emphasize the importance of increasing prevention measures to avoid or reduce the transmission of blood parasites among birds from different species housed in these types of centers.

Parasitological and molecular survey of scattered parasitism by trichomonads in some avian species in Iran.

Outbreaks of avian trichomonosis are being reported worldwide; meanwhile, the genetic and virulence variations are under investigation. In this study, the occurrence and genetic variability of oral or faecal trichomonads among various avian species were investigated. Samples obtained from either the oropharyngeal cavity, crop/oesophagus, droppings/cloaca, or conjunctival swabs of avian species were inspected for flagellates. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples was performed to investigate the genetic diversity of the isolates. Investigation of 737 birds revealed an infection rate of 15.7% in the upper gastrointestinal tract, 7.3% in the faecal samples, and 0.7% involvement of the conjunctiva. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples, identified genotypes A and B of Trichomonas gallinae and genogroups A-C and E of Tetratrichomonas gallinarum. A novel ITS genotype of intestinal trichomonads was also detected in hooded crow (Corvus cornix) and common mynah (Acridotheres tristis). In the present study, in addition to Columbiformes and Falconiformes, trichomonads were detected in Passeriformes and Galliformes with the involvement of organs other than the gastrointestinal tract. Genotype A T. gallinae was detected in domestic pigeons (Columba livia domestica), a laughing dove (Spilopelia senegalensis), a common kestrel (Falco tinnunculus), a budgerigar (Melopsittacus undulates), and a canary (Serinus canaria). Distinct genotype B was detected in a common mynah and a budgerigar. Genogroups A-C of T. gallinarum were also demonstrated in Galliformes and Anseriformes. Furthermore, two novel trichomonad ITS genotypes were detected in hooded crows and a common mynah warranting detailed multi-locus molecular analysis.RESEARCH HIGHLIGHTSITS diversity of trichomonads was shown in various avian species.Diversity of the parasites' target organ and clinical manifestations was demonstrated.Two novel ITS genotype trichomonads from common mynah and hooded crow were identified.

Cryptosporidium proventriculi sp. n. (Apicomplexa: Cryptosporidiidae) in Psittaciformes birds.

Cryptosporidiosis is a common parasitic infection in birds that is caused by more than 25 Cryptosporidium species and genotypes. Many of the genotypes that cause avian cryptosporidiosis are poorly characterized. The genetic and biological characteristics of avian genotype III are described here and these data support the establishment of a new species, Cryptosporidium proventriculi. Faecal samples from the orders Passeriformes and Psittaciformes were screened for the presence of Cryptosporidium by microscopy and sequencing, and infections were detected in 10 of 98 Passeriformes and in 27 of 402 Psittaciformes. Cryptosporidium baileyi was detected in both orders. Cryptosporidium galli and avian genotype I were found in Passeriformes, and C. avium and C. proventriculi were found in Psittaciformes. Cryptosporidium proventriculi was infectious for cockatiels under experimental conditions, with a prepatent period of six days post-infection (DPI), but not for budgerigars, chickens or SCID mice. Experimentally infected cockatiels shed oocysts more than 30 DPI, with an infection intensity ranging from 4,000 to 60,000 oocysts per gram (OPG). Naturally infected cockatiels shed oocysts with an infection intensity ranging from 2,000 to 30,000 OPG. Cryptosporidium proventriculi infects the proventriculus and ventriculus, and oocysts measure 7.4 × 5.8 µm. None of the birds infected C. proventriculi developed clinical signs.

Detection and molecular characterization of Giardia spp. in captive Psittaciformes in Brazil.

This study aimed to perform the detection and molecular characterization of Giardia spp. in Psittaciformes from the Southern and Southeastern regions of Brazil. Fecal samples were obtained from 359 adult exotic captive Psittaciformes belonging to 13 genera, randomly selected from 33 aviaries located in the Southern and Southeastern regions of Brazil during a bird exhibition at the 2015 Ornithological Championship of the Ornithological Federation of Brazil (FOB). Nested polymerase chain reaction targeting the small subunit rRNA gene identified Giardia spp. in 93/359 (25.9%) fecal samples and 25/33 (75.8%) aviaries. Genetic sequencing identified G. psittaci in 12 birds from six genera. Zoonotic Giardia species was not detected in fecal samples from Psittaciformes.

Molecularly Confirmed Acute, Fatal Sarcocystis falcatula Infection in the Rainbow Lorikeets ( Trichoglossus moluccanus) at the Philadelphia Zoo.

The protozoan parasite Sarcocystis falcatula is an important cause of clinical disease in several avian intermediate hosts. The host range of S. falcatula is wide, and numerous outbreaks of acute sarcocystosis have been reported in passerine and psittacine birds in captivity in the Americas. Previous diagnosis was performed by serologic methods, light, and/or electron microscopic examinations with limited molecular confirmation. Here, we report histological and molecular diagnosis of acute, fatal S. falcatula infections in rainbow lorikeets ( Trichoglossus moluccanus) at the Philadelphia Zoo. Pulmonary sarcocystosis was suspected antemortem in 3 lorikeets (3-5 yr old); these birds died despite antiprotozoal therapy. The predominant lesion was pneumonia associated with S. falcatula-like schizonts in pulmonary vascular endothelium. The multilocus PCR-DNA sequencing ( 18S rDNA, 28S rDNA, ITS-1, and cox1) of frozen lung tissue confirmed S. falcatula infections in all 3 birds. Our results and previous studies suggest that acute pulmonary form of sarcocystosis is a major contributor of death to Old World psittacine birds.

Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

BACKGROUND: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. RESULTS: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. CONCLUSIONS: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates.

Morphological and molecular characterization of Eimeria haematodi, coccidian parasite (Apicomplexa: Eimeriidae) in a rainbow lorikeet (Trichoglossus haematodus).

Eimeria haematodi was first described in 1977 from the rainbow lorikeet (Trichoglossus haematodus) in Papua New Guinea. In the present study, we re-describe this coccidian species morphologically and molecularly from a rainbow lorikeet bird in Western Australia (WA). The oocysts were ovoid to slightly piriform and measured 28.5-37.8 by 25.8-33.0 µm (33.3 by 28.1 µm). Oocyst wall was approximately 1.5 µm thick and bilayered. Micropyle (5-7 µm) and oocyst residuum (8.0-10.0 µm) present; polar granule was absent. Sporocysts ellipsoidal, 11.8-13.6 by 8.0-9.6 µm (12.2 by 8.3 µm), with thin convex Stieda body and granular sporocyst residuum (4.0-5.0 µm). Molecular characterization of E. haematodi was conducted at 18S ribosomal RNA and the mitochondrial cytochrome oxidase gene (COI) loci. At the 18S ribosomal RNA locus, E. haematodi shared 98.1% genetic similarity to E. alabamensis from cattle in New South Wales, Australia. At COI locus, E. haematodi was closest (92.3% similarity) to E. praecox from domestic chickens (Gallus gallus domesticus) from Canada and China.

New species of the feather mite genus Protolichus Trouessart, 1884 (Astigmata, Pterolichidae) from lories and lorikeets (Aves: Psittaciformes).

Five new species of the feather mite genus Protolichus Trouessart, 1884 (Astigmata, Pterolichidae) are described from parrots of the subfamily Loriinae (Psittaciformes: Psittacidae): Protolichus ornatus sp. n. from Trichoglossus ornatus (Linnaeus, 1758), P. lorinus sp. n. from Lorius lory (Linnaeus, 1758), P. placentis sp. n. from Charmosyna placentis (Temminck, 1835), P. pulchellae sp. n. from C. pulchella (Gray GR, 1859), and P. rubiginosus sp. n. from T. rubiginosus (Bonaparte, 1850). Protolichus ornatus belongs to the brachiatus species group; the other new species belong to the crassior species group.

Parasites of Psittaciformes and Accipitriformes in Paraíba state, northeastern Brazil.

In this study, we investigated the presence of gastrointestinal helminths in 97 captive birds (Psittaciformes and Accipitriformes) necropsied between June and December 2011 in the state of Paraiba, Brazil. Forty-three birds were infected. Psittaciformes were infected by nematode Ascaridia hermaphrodita (97.6%) and cestode Raillietina sp. (2.4%). A. hermaphrodita was found in all species of parrots and Raillietina sp. was found only in Amazona aestiva. A. hermaphrodita was the cause of death, by intestinal obstruction, in 14 of the 40 birds investigated. Accipitriformes were infected by nematode Synhimantus (Synhimantus) rectus (100%) and acantocephalan Centrorhynchus tumidulus (50%). In Brazil, Diopsittaca nobilis and A. aestiva are reported for the first time as hosts of A. hermaphrodita and Raillietina sp., respectively. We concluded that Psittaciformes and Accipitriformes in captivity are affected by nematodes, cestodes and acanthocephalans and that implementation of control measures is essential.

Parasites of Psittaciformes and Accipitriformes in Paraíba state, northeastern Brazil / Parasitas de Psittaciformes e Accipitriformes no estado da Paraiba, Brasil

In this study, we investigated the presence of gastrointestinal helminths in 97 captive birds (Psittaciformes and Accipitriformes) necropsied between June and December 2011 in the state of Paraiba, Brazil. Forty-three birds were infected. Psittaciformes were infected by nematode Ascaridia hermaphrodita (97.6%) and cestode Raillietina sp. (2.4%). A. hermaphrodita was found in all species of parrots and Raillietina sp. was found only in Amazona aestiva. A. hermaphrodita was the cause of death, by intestinal obstruction, in 14 of the 40 birds investigated. Accipitriformes were infected by nematode Synhimantus (Synhimantus) rectus (100%) and acantocephalan Centrorhynchus tumidulus (50%). In Brazil, Diopsittaca nobilis and A. aestiva are reported for the first time as hosts of A. hermaphrodita and Raillietina sp., respectively. We concluded that Psittaciformes and Accipitriformes in captivity are affected by nematodes, cestodes and acanthocephalans and that implementation of control measures is essential.

Este estudo objetivou-se investigar a presença de parasitos gastrointestinais em aves de cativeiro da Ordem Psittaciformes e Accipitriformes no estado da Paraíba-Brasil. Foram necropsiadas 97 aves durante o período de junho a dezembro de 2011. Em 43 (44.3%) aves, foi detectada a presença de nematóides, cestóides e/ou acantocéfalos. A prevalência de parasitos gastrointestinais em Psittaciformes foi de 45.6% (41/88) e os helmintos identificados foram Ascaridia hermaphrodita (Ascaridoidea, Ascarididae) (40/41, 97.6%) e Raillietina sp. (Cyclophyllidea, Davaineidae) (1/41, 2.4%). A. hermaphrodita foi encontrada em todas as espécies de papagaios e Raillietina sp. foi encontrada apenas na Amazona aestiva. Em aves Accipitriformes, a prevalência foi de 22.2% (2/9) e os helmintos identificados foram Synhimantus (Synhimantus) rectus (Spirurida, Acuariidae) (2/2, 100%) e Centrorhynchus tumidulus (Acanthocephala, Centrorhynchidae) (1/2, 50 %). Todos os parasitos encontrados neste estudo são relatados pela primeira vez em aves Psittaciformes e Accipitriformes no estado da Paraíba. No Brasil, Diopsittaca nobilis e A. aestiva são apresentados pela primeira vez como hospedeiros da A. hermaphrodita e Raillietina sp., respectivamente. Concluiu-se que aves Psittaciformes e Accipitriformes de cativeiro são afetadas por nematóides, cestóides e acantocéfalos, e que a implementação de medidas de controle é imprescindível.

Clinical presentation and pathology of sarcocystosis in psittaciform birds: 11 cases.

Sarcocystosis in psittaciform birds occurs in several different presentations, making ante-mortem diagnosis challenging without specific laboratory tests. This study followed the course of 11 birds diagnosed with sarcocystosis by serologic analysis and/or post-mortem examinations during a 10-month period in 2006-07. The disease presented in three different clinical forms: an acute pulmonary disease (three birds), muscular disease (five), and neurological disease (three). Early diagnosis of sarcocystosis was possible through the combined used of plasma protein electrophoresis and indirect fluorescent antibody serology in birds presented with the neurological and muscular forms of the disease. In three of these birds the plasma electrophoretic patterns revealed marked hypergammaglobulinemia. All of the birds that presented with the acute pulmonary form developed similar gross and microscopic lesions. Definitive diagnosis was ultimately made by microscopic observation of intravascular pulmonary schizonts containing merozoites. Schizonts were identified in the cerebellum and brainstem in two birds with the neurological form of disease. Those birds that initially presented with severe lethargy and weakness were considered to suffer from the muscular form of disease if they had extreme elevations of muscle enzyme activities (creatine phosphokinase, aspartate aminotransferase) and beta and gamma globulins concentrations, and were seropositive for antibodies to Sarcocystis falcatula. In this group the progression of the disease varied. Two birds recovered completely, and secondary aspergillosis was diagnosed in three birds. The histopathological lesions observed are discussed and interpreted in light of earlier findings from experimental infections in budgerigars, which provide insights into the natural course of sarcocystosis in psittaciform birds.

An outbreak of sarcocystosis in psittacines and a pigeon in a zoological collection in Brazil.

This report describes an outbreak of acute pulmonary sarcocystosis in different species of captive psittacines and in a Luzon bleeding-heart pigeon (Gallicolumba luzonica) in a zoological collection in Brazil. A majority of the birds were found dead and had exhibited no previous clinical signs. Grossly, pulmonary congestion and edema were the most-common findings. Enlarged and congested livers and spleens were also frequently observed. Microscopically, there was edema, fibrin exudation, congestion, and perivascular and interstitial lymphoplasmacytic infiltration associated with numerous sinuous schizonts of Sarcocystis sp. in the lungs. Mild to moderate myocarditis, hepatitis, splenitis, and interstitial nephritis were also observed in the birds. Immunohistochemistry confirmed Sarcocystis sp. in the capillaries of lungs, hearts, livers, and spleens of most of the birds, but also in the pancreas, kidney, intestine, proventriculus, and brain of a few birds. The probable source of Sarcocystis sp. in these birds was the wild opossum (Didelphis albiventris), a common inhabitant of a local forest that surrounds the Belo Horizonte Zoo (Fundação Zoo-Botânica). This is the first documentation of Sarcocystis infection in psittacines and a pigeon from Brazil.

[Intestinal parasites of parrots]. / Pasozyty jelitowe papug.

BACKGROUND: The aim of this study was to determine a parasitic species composition, prevalence and intensity of infection in selected parrots. MATERIAL AND METHODS: The studies were carried out on faecal samples of budgerigars Melopsittacus undulatus (n = 36), cockatiels Nymphicus hollandicus (n = 21), grey parrots Psittacus erithacus (n = 18), eastern rosella Platycercus eximius (n = 10) and senegal parrots Poicephalus senegalus (n = 10) using the Willis-Schlaff and McMaster's methods. RESULTS: Protozoans (Isosporidae and Eimeriidae) and nematodes (Ascarididae, Capillaridae and Heterakidae) were detected in the tested samples. Coccidian oocysts were detected in all examined parrots. Isospora and Eimeria oocysts were found in 52.9% Melopsittacus undulatus, 60% Poicephalus senegalus and 66.7% Psittacus erithacus. Mean number of oocysts per gram of feces (OPG) was high: from about 270 to 1500 depending on both parasite and host species. Three species of parrots were infected with the nematodes (Nymphicus hollandicus and Poicephalus senegalus were free from this infection), but only Ascaridia platycerci was present in these hosts, with the highest prevalence (20%) and highest mean number of eggs per gram of feces (EPG = 1242) in Platycercus eximinus. Heterakis gallinarum was observed only in Psittacus erithacus; 16.6% individuals were infected, and EPG was 212. The highest intensity of infection with nematodes of Ascarididae and Capillaridae was in Platycercus eximius. EPG in this species of parrots was 1242 and 2480, respectively. The obtained results show that introduction of parasitological prophylaxis programs is necessary, especially in the larger birds' farmings and zoological shops.

Granulomatous nephritis in psittacines associated with parasitism by the trematode Paratanaisia spp.

Trematodes belonging to the family Eucotylidae are parasites of the kidney and ureter, and affect several bird species. However, psittacines have not been identified as hosts of these parasites. Three birds, an adult female blue and gold macaw (Ara ararauna), an adult female blue-winged macaw (Propyrrhura maracana) and an adult male white-eared parakeet (Pyrrhura leucotis) were admitted at the Veterinary Hospital of the Fundação Zoo-Botânica de Belo Horizonte, Brazil (FZB/BH). All three birds had severe dehydration and cachexia. The blue and gold macaw presented with dyspnea, apathy, and incoordination. Blood cell counts indicated discrete anemia and leucopenia. Blood biochemistry revealed significant increase in levels of uric acid (61 mg/dl) and blood urea nitrogen (22 mg/dl). The bird died within 24 h after admission. The other two birds were admitted with similar clinical signs, but died prior to a complete clinical examination. At the necropsy, in all the three birds, the kidneys were enlarged with brown-yellowish discoloration and irregular cortical surface. On the cut surface, there was a brown-yellowish material with few visible parasites flowing out of the parenchyma. When fragments of the kidneys were placed in 10% formalin, a large number of trematodes came out of the renal parenchyma. The parasites were identified as Paratanaisia robusta infecting all three birds, and P. bragai infecting the blue-winged macaw and the white-eared parakeet. Histologically, there was an interstitial, multifocal to coalescent, lymphoplasmacytic infiltrate with some epithelioid macrophages, and a few heterophils, characterizing a granulomatous nephritis. Adult worms and eggs were observed within dilated tubules and in the renal pelvis. In the blue and gold macaw, some parasite eggs were located interstitially associated with an intense adjacent granulomatous reaction.

A new species of Pterothominx Freitas, 1959 (Nematoda: Capillariidae) parasitising psittacine birds (Psittaciformes).

A new species, Pterothominx (Pterothominx) moraveci n. sp. (Trichinelloidea: Capillariidae) is described from an Australian parrot, Barnardius zonarius Shaw (Psittacidae: Psittaciformes), imported from Germany and kept in captivity in the Czech Republic. Males of the new taxon differ from all other species of the subgenus Pterothominx Freitas, 1959, which mainly parasitise galliform birds, in having a shorter spicule (0.925-1.338; mean 1.050 mm), a shorter body length and a different form of armed spicular sheath and bursa. Females differ in having the smallest eggs (40-50 x 20-25; mean 48 x 23 microm) and in other morphometrical characters. From the species P. (P.) totani (Linstow, 1875), which parasitises charadriiform birds, the new species differs in its smaller number of stichocytes (females 42-46, mean 44; versus 50-54), different form of the bursa and praebursal alae, and other characters. This is the only species of Pterothominx that parasitises psittacine birds.

New feather mite taxa of the Rhytidelasma Gaud, 1966 generic group (Astigmata: Pterolichidae) from the red-flanked lorikeet Charmosyna placentis placentis (Psittacidae).

Two new genera and species related to Rhytidelasma Gaud, 1966 and Lorilichus Atyeo & Gaud, 1991 are described from the plumage of the red-flanked Lorikeet Charmosyna placentis placentis (Temminck) (Psittacidae). These are Ceratolichus mirabilis n. g., n. sp. and Charmosylichus anamphiestos n. g., n. sp. In addition, an improved diagnosis of Lorilichus is proposed and two new species of this genus are described from the red-flanked lorikeet, L. longiphallos n. sp. and L. paralobiger n. sp.

Isolation and characterization of an avian isolate of Encephalitozoon hellem.

Members of the phylum Microspora are a group of unusual, obligate intracellular eukaryotic parasites that infect a wide range of hosts. However, there are a limited number of microsporidial infections reported in avian hosts, and no parasite species has been defined as an avian pathogen. A microsporidian organism was recovered from the droppings of a clinically normal peach-faced lovebird (Agapornis roseicollis) and established in in vitro culture. Intermittent parasite spore shedding was documented over a 2-month period using calcofluor M2R staining of cloacal swabs. The organism was identified as Encephalitozoon hellem based on protein and antigenic profiles and molecular sequencing of the small subunit and internal transcribed spacer regions of the ribosomal RNA gene.

Immune and pathophysiological responses to different strains of Giardia duodenalis in neonatal mice.

Numerous studies have demonstrated various strain differences between Giardia isolates, but little is known about the immunology and pathogenesis of infections. This study aimed to compare host responses to strains of Giardi duodenalis differing in levels of virulence and pathogenicity and, by doing so, elucidate the mechanisms via which pathogenic strains establish infections. Marked differences were found in the infection dynamics, histopathological responses and serum antibody responses of neonatal mice infected with either G. duodenalis strain BRIS/83/HEPU/106 (isolated from a human) or BRIS/95/HEPU/2041 (isolated from a sulphur-crested cockatoo, Cacatua galerita). Infections with the bird strain were more intense (6.7-times greater) and persisted longer (by 14days) than infections with the human strain. The bird strain was more pathogenic and caused greater pathophysiological alteration to the gut mucosa, including increased villous atrophy, hyperplasia of goblet cells and vacuolated epithelial cells. Mice infected with the bird strain produced less serum anti-Giardia IgA and IgM, but more total (non-specific) serum IgA than those infected with the human strain of Giardia. This suggests that avian G. duodenalis strains are infective for mammalian hosts and may contribute to zoonotic infections. Furthermore, infection of mice with BRIS/95/HEPU/2041 serves as a good experimental model to provide further insight into the mechanisms via which G. duodenalis causes disease.

Lethal Giardia from a wild-caught sulphur-crested cockatoo (Cacatua galerita) established in vitro chronically infects mice.

An axenic culture of Giardia was established from a sample of infected intestine obtained following autopsy of a sulphur-crested cockatoo (Cacatua galerita). The cockatoo recently captured in the wild and with good muscle tone died along with several other cage mates, apparently of an overwhelming, acute infection of Giardia. Trophozoites which established in the traditional, axenic Giardia medium (TYI-S-33 with supplementary bile) were morphologically identical to G. duodenalis. When outbred Quackenbush Swiss neonatal mice were infected with trophozoites a chronic infection was established and parasites were still present at 38 days post-inoculation. Weight gain by infected mice was reduced by 20%, thus mimicking failure-to-thrive syndrome in children, and maximum parasite load was more than 3-fold higher in comparison with other G. duodenalis strains. Analysis of the electrophoretic karyotype, rDNA and hybridization studies together with Giemsa- and trichrome-stained samples, and scanning electron microscopy indicated that the bird-derived Giardia belonged to the duodenalis group. This is the first report of infection of mammals with Giardia isolated from a bird. These data may have potentially serious implications for contamination of watersheds and establishment of zoonotic infections.