Mapping the poultry insectome in and around broiler breeder pullet farms identifies new potential Dipteran vectors of Histomonas meleagridis.

BACKGROUND: Histomonas meleagridis can infect chickens and turkeys. It uses the eggs of the cecal worm Heterakis gallinarum as a vector and reservoir. Litter beetles (Alphitobius diaperinus) and other arthropod species have been implicated as potential vectors, but little information about other arthropod species as potential vectors is known. METHODS: Four broiler breeder pullet farms were sampled every 4 months. On each farm, three types of traps were set inside and outside two houses. Trapped arthropod specimens were morphologically identified at order level and grouped into families/types when possible. Selected specimens from abundant types found both inside and outside barns were screened for H. meleagridis and H. gallinarum by qPCR. RESULTS: A total of 4743 arthropod specimens were trapped. The three most frequently encountered orders were Diptera (38%), Coleoptera (17%), and Hymenoptera (7%). Three hundred seventeen discrete types were differentiated. More arthropods were trapped outside than inside. Alpha diversity was greater outside than inside but not significantly influenced by season. The composition of the arthropod populations, including the insectome, varied significantly between trap location and seasons. Up to 50% of litter beetles tested positive for H. meleagridis DNA 4 months after an observed histomonosis outbreak. Sporadically litter beetles were positive for H. gallinarum DNA. Thirteen further arthropod types were tested, and specimens of four Dipteran families tested positive for either one or both parasites. CONCLUSIONS: This study describes the insectome in and around broiler breeder pullet farms and identifies new potential vectors of H. meleagridis through qPCR. The results show a limited but present potential of arthropods, especially flies, to transmit histomonosis between farms.

Concurrent Infection of Histomonas meleagridis and Pentatrichomonas hominis in a Blackhead Disease Outbreak in Turkeys.

Intestinal health plays a major role in profitable and efficient turkey production. Blackhead disease (histomoniasis) is caused by Histomonas meleagridis, an anaerobic protozoan parasite. Histomonas meleagridis disrupts intestinal integrity and may cause systemic infection. Some field outbreaks of blackhead disease are associated with low morbidity and mortality, while in some instances, it may cause severe morbidity and mortality. In the current study, a presumptive diagnosis of blackhead disease was made based on the characteristic gross lesions in the liver and ceca. The cecal culture, PCR, and sequencing confirmed the presence of H. meleagridis and Pentatrichomonas hominis. Pentatrichomonas hominis has been reported in enteritis cases of several other species, such as dogs, cats, and cattle. The impact of P. hominis on intestinal health of turkeys has not previously been studied, and to the best of our knowledge, this is the first case report of concurrent H. meleagridis and P. hominis infection in turkeys.

Reporte de caso- Infección simultánea de Histomonas meleagridis y Pentatrichomonas hominis en un brote de enfermedad de la cabeza negra en pavos. La salud intestinal juega un papel importante en la producción rentable y eficiente de pavos. La enfermedad de la cabeza negra (histomoniasis) es causada por Histomonas meleagridis, que es un parásito protozoario anaeróbico. Histomonas meleagridis altera la integridad intestinal y puede causar una infección sistémica. Algunos brotes de campo de la enfermedad de la cabeza negra están asociados con una baja morbilidad y mortalidad, mientras que en algunos casos puede causar una morbilidad y mortalidad severas. En el presente estudio, se realizó un diagnóstico presuntivo de la enfermedad de la cabeza negra con base a las lesiones macroscópicas características en el hígado y el ciego. El cultivo cecal, un método de PCR y secuenciación confirmaron la presencia de H. meleagridis y Pentatrichomonas hominis. Se ha reportado la presencia de Pentatrichomonas hominis en casos de enteritis de varias otras especies, como perros, gatos y ganado. El impacto de P. hominis en la salud intestinal de los pavos no se había estudiado previamente y según nuestro conocimiento, este es el primer reporte de un caso de infección simultánea por H. meleagridis y P. hominis en pavos.

A Survey of Coccidia and Nematodes in Pastured Poultry in the State of Georgia.

The aim of this study was to evaluate and quantify the parasitological challenge in pastured poultry production in the state of Georgia. Over the course of 1 yr, fecal samples from six turkey flocks, 10 broiler flocks, and 13 layer flocks were collected on a pastured farm in 2-wk intervals to determine counts of Eimeria oocysts and nematode eggs. Average coccidia counts were 10,198 oocysts per gram of feces (OPG) in broiler flocks, 1470 OPG in layer flocks, and 695 OPG in turkey flocks. The means in broiler and turkey flocks were higher at their first week on pasture. Counts in broilers and layers were significantly higher in spring than in winter and summer. Coccidia counts in broilers were lower than published numbers in conventionally reared poultry, indicating the rotation system of the pastures might effectively reduce the infection pressure. Next-generation sequencing of PCR products showed the presence of most described Eimeria spp. in broilers, layers, and turkeys. In addition, operational taxonomic units (OTUs) x, y, and z were found. The frequency of species was similar for broilers and layers, with the exception that Eimeria praecox and OTU z were more common in layers. In layer flocks, the average count of roundworm eggs per gram of feces (EPG) was 509 EPG with 80% of the samples being positive. The mean counts had no clear pattern related to age. There was an increase of EPG with the increase of temperatures during spring and summer with the peak at midfall. Worm eggs from laying hens were identified as Ascaridia galli. The seasonal differences suggest that higher temperatures might result in an increase of egg survival and sporulation in the environment.

Artículo regular­Muestreo de coccidias y nematodos en aves en pastoreo en el estado de Georgia El objetivo de este estudio fue evaluar y cuantificar el desafío parasitológico en la producción avícola en pastoreo en el estado de Georgia. En el transcurso de un año, se recolectaron muestras fecales de seis parvadas de pavos, 10 parvadas de pollos de engorde y 13 parvadas de gallinas de postura en una granja de pastoreo en intervalos de dos semanas para determinar los conteos de ooquistes de Eimeria y huevos de nematodos. Los recuentos promedio de coccidias fueron 10,198 ooquistes por gramo de heces (OPG) en parvadas de pollos de engorde, 1470 ooquistes por gramo de heces en parvadas ponedoras y 695 ooquistes por gramo de heces en parvadas de pavos. Los promedios en las parvadas de pollos de engorde y pavos fueron más altos en su primera semana en pastoreo. Los conteos en pollos de engorde y ponedoras fueron significativamente más altos en primavera que en invierno y verano. Los recuentos de coccidios en pollos de engorde fueron más bajos que los números publicados en aves criadas de manera convencional, lo que indica que el sistema de rotación de pastizales podría reducir efectivamente la presión de infección. La secuenciación de próxima generación de los productos de PCR mostró la presencia de la mayoría de las especies de Eimeria spp descritas en pollos de engorde, gallinas de postura y pavos. Además, se encontraron unidades taxonómicas operativas (OTU) x, y, z. La frecuencia de especies fue similar para pollos de engorde y gallinas de postura, con la excepción de que Eimeria praecox y las unidades taxonómicas operativas z fueron más comunes en gallinas de postura. En las parvadas de gallinas de postura, el recuento promedio de huevos de helmintos intestinales por gramo de heces (EPG) fue de 509 EPG, con el 80% de las muestras positivas. Los recuentos medios no tenían un patrón claro relacionado con la edad. Hubo un aumento de huevos de helmintos intestinales por gramo de heces con el aumento de las temperaturas durante la primavera y el verano con el pico a la mitad del otoño. Los huevos de helmintos de las gallinas de postura se identificaron como Ascaridia galli. Las diferencias estacionales sugieren que las temperaturas más altas podrían resultar en un aumento de la supervivencia de los huevos y su esporulación en el medio ambiente.

Molecular subtyping and phylogeny of Blastocystis sp. isolated from turkey (Meleagris gallopavo) populations in Penang, Malaysi.

Most poultry farms in Malaysia preferred rearing chickens either for eggs or/and meat than turkeys. This is due to several challenges such as parasitic load and heat stress in rearing turkey. Blastocystis is one of the most common protozoan parasites infecting poultry. As no study was conducted on Blastocystis infection in turkey in Malaysia, this study aims to determine the current status, the morphological characteristics and subtyping of Blastocystis from turkey reared either in closed house or free-range system in Penang, Malaysia. It was found that the prevalence of Blastocystis sp. infection in turkeys were moderately high with 41.6% (25/60) in the closed house and 45.0% (45/100) in free-range system as infection was higher in the female turkeys with no gastrointestinal signs and symptoms. Vacuolar form was the most common form found in the in vitro culture ranged between 5 to 20 µm in diameter with a rough surface coat and undulating cell surface viewed under the scanning electron microscope. Meanwhile, the ultrastructure of the cells from turkey isolates were varies with partially expanded electron-opaque vacuoles to electron-dense in fully distended vacuoles. Interestingly, sequence analysis for 30 positive Blastocystis isolates from turkeys revealed one subtypes with three alleles namely, ST7 allele 99 (73.4%, n=22), ST7 allele 100 (23.3%, n=7) and ST7 allele 101 (3.3%, n=1). Findings from this study added to our understanding on Blastocystis infection in turkey production.

Identification of parasitic arthropods collected from domestic and wild animals in Yucatan, Mexico.

The morphological characterization of ectoparasites from domestic and wild animals is crucial to distinguish those that may be involved in the transmission of zoonotic pathogens. The objectives of this work were to identify parasitic arthropods collected from several hosts in Yucatan State, Mexico and to determine the prevalence of the parasite Trypanosoma cruzi in sylvatic specimens of Triatoma dimidiata. Morphological traits and scanning electron microscopy were used to confirm some parasitic identities. In total, 834 parasitic arthropods of various taxa were identified. Amblyomma americanum, Amblyomma maculatum, Amblyomma parvum, Dermacentor variabilis, and Rhipicephalus sanguineus were identified from dogs, horses, sheep, and deer. The flea Ctenocephalides felis was identified from dogs and the human flea, Pulex irritans was found on horses and sheep. The Neotropical deer ked Lipoptena mazamae was identified from brown brocket deer Mazama pandora. The chewing lice Chelopistes meleagridis, Menacanthus stramineus, Menopon gallinae, Myrsidea sp. and Lipeurus caponis were identified from poultry (Meleagris gallopavo and Gallus gallus). Other chewing lice, Tyranniphilopterus sp., Columbicola columbae, and Physconelloides eurysema were identified from wild birds Pachyramphus aglaiae, Patagioenas flavirostris and Zenaida asiatica, respectively. Trypanosoma cruzi was present in 52.5% of sylvatic adult T. dimidiata. Several of these findings represent new records of ectoparasites for Yucatan and new distribution areas in Mexico. The implications for human and animal health are discussed.

Epidemiologic significance of Toxoplasma gondii infections in turkeys, ducks, ratites and other wild birds: 2009-2020.

Toxoplasma gondii infections are common in humans and animals worldwide. Wild and domestic avian species are important in the epidemiology of T. gondii infections because felids prey on them and excrete millions of oocysts in the environment, disseminating the infection. Herbivorous birds are also excellent sentinels of environmental contamination with T. gondii oocysts because they feed on the ground. Toxoplasma gondii infections in birds of prey reflect infections in intermediate hosts. Humans can become infected by consuming undercooked avian tissues. Here, the authors reviewed prevalence, persistence of infection, clinical disease, epidemiology and genetic diversity of T. gondii strains isolated from turkeys, geese, ducks, ratites and avian species (excluding chickens) worldwide 2009-2020. Genetic diversity of 102 T. gondii DNA samples isolated worldwide is discussed. The role of migratory birds in dissemination of T. gondii infection is discussed.

Comparative investigation of IFN-γ-producing T cells in chickens and turkeys following vaccination and infection with the extracellular parasite Histomonas meleagridis.

The re-emerging disease histomonosis is caused by the protozoan parasite Histomonas meleagridis that affects chickens and turkeys. Previously, protection by vaccination with in vitro attenuated H. meleagridis has been demonstrated and an involvement of T cells, potentially by IFN-γ production, was hypothesized. However, comparative studies between chickens and turkeys on H. meleagridis-specific T cells were not conducted yet. This work investigated IFN-γ production within CD4+, CD8α+ and TCRγδ+ (chicken) or CD3ε+CD4-CD8α- (turkey) T cells of spleen and liver from vaccinated and/or infected birds using clonal cultures of a monoxenic H. meleagridis strain. In infected chickens, re-stimulated splenocytes showed a significant increase of IFN-γ+CD4+ T cells. Contrariwise, significant increments of IFN-γ-producing cells within all major T-cell subsets of the spleen and liver were found for vaccinated/infected turkeys. This indicates that the vaccine in turkeys causes more intense systemic immune responses whereas in chickens protection might be mainly driven by local immunity.

Pathology caused by three species of Eimeria that infect the turkey with a description of a scoring system for intestinal lesions.

Three-week-old turkey poults were infected with pure lines of three species of Eimeria (E. adenoeides, E. gallopavonis, and E. meleagrimitis) recently isolated from commercial turkey farms. The lines had been propagated from a single oocyst and identified by species-specific PCR amplification of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Five to six days after infection their intestines were removed and examined for the presence of intestinal lesions. A description and review of the pathology caused by these parasites is provided, and a scoring system developed by which the severity of the lesions can be evaluated. The system is similar to that described by Johnson, J. and Reid, W. M. [1970. Anticoccidial drugs: lesion scoring techniques in battery and floor-pen experiments with chickens. Experimental Parasitology, 28, 30-36] for chickens in which a score of zero to four is assigned to lesions of increasing severity. The intestinal lesions observed here, and their assigned scores, are supported by representative illustrations. It is hoped that they may prove a useful tool for evaluating the pathology caused by E. adenoeides, E. gallopavonis, and E. meleagrimitis in the turkey.RESEARCH HIGHLIGHTSA scoring system has been developed for intestinal lesions caused by three species of Eimeria that infect the turkey.The lesions attributable to these species are illustrated.

Integrated taxonomic approaches to seven species of capillariid nematodes (Nematoda: Trichocephalida: Trichinelloidea) in poultry from Japan and Indonesia, with special reference to their 18S rDNA phylogenetic relationships.

Morphological and genetic analyses were performed on seven species of the family Capillariidae (Nematoda: Trichocephalida: Trichinelloidea), viz. Eucoleus perforans, Eucoleus contortus, Aonchotheca bursata, Baruscapillaria obsignata, Capillaria anatis, Capillaria phasianina, and Capillaria spinulosa, detected in poultry from Japan and Indonesia. Two Eucoleus spp., perforating the esophageal mucosa of the Japanese green pheasant farmed in Japan (E. perforans) and domestic goose in Indonesia (E. contortus), were morphologically characterized. Furthermore, we observed substantial nucleotide differences between their 18S ribosomal RNA gene (rDNA), revealing maximum identity (97.27%) over the 1797-bp length. Similarly, B. obsignata in the small intestine of Japanese green pheasants in Japan, a chicken, geese, domestic pigeons, and a turkey in Indonesia, and C. anatis in the ceca of chickens in Indonesia were morphologically and molecular-genetically compared with previously reported isolates of these species in Japan. Aonchotheca bursata collected from the small intestine of the Japanese green pheasant was also molecular-genetically characterized for the first time; however, sequencing of the 18S rDNA of C. phasianina from the cecum of the same bird was unsuccessful. Capillaria worms in the ceca of a domestic duck and geese in Indonesia were identified as C. spinulosa, which had only previously been recorded in wild birds of the Anseriformes in the Palaearctic region. Morphologically, this species was closest to Capillaria pudendotecta recorded from the ceca of wild and captive swans, except for the lack of vaginal appendages in female worms and shorter esophagi relative to the body length in both male and female worms. Phylogenetically, these two species were closely related, although substantial nucleotide changes were noted. The 18S rDNA nucleotide sequences of the species isolated here were consistent with the recent taxonomic system established for Capillariidae based primarily on the morphology of male caudal ends.

Development of an in vivo model for Toxoplasma gondii infections in chickens and turkeys simulating natural routes of infection.

Turkeys and chickens were orally infected with tissue cysts (one mouse brain) or oocysts (103, 105 or 106 oocysts) of three T. gondii strains of the clonal types II and III (ME49, CZ-Tiger, NED) to investigate the influence of the applied T. gondii strain and infective doses on the distribution of T. gondii in several organs and tissues and the serologic response of chickens and turkeys. Organ samples from 16 different tissues, including heart, brain, muscles and gizzard were analyzed by PCR. Brain and heart were found most frequently positive for T. gondii DNA in both species, followed by gizzard. Serological analysis with kinetic ELISA for turkey samples and IFAT for chicken samples were performed once a week. In both species a dose-depending serological response was found. Turkeys seroconverted one week after infection with CZ-Tiger strain and medium and high doses of ME49 oocysts. In chickens, infection with medium and high doses of CZ-Tiger led to seroconversion one week p.i. Frequency of T. gondii positive organs showed a trend of a dose-effect in both species after infection with the type II strains. The NED strain showed low virulence in chickens and turkeys, demonstrated by clearly less T. gondii positive organs. Infection with tissue cysts of all three strains revealed T. gondii stages in tissues of turkeys and chickens. In conclusion, our data show a risk for human infection with T. gondii due to consumption of chicken and turkey meat.

Isolation and Genetic Characterization of Toxoplasma gondii from Tissues of Wild Turkeys (Meleagris gallopavo) in Pennsylvania.

Toxoplasmosis in wild turkeys (Meleagris gallopavo) is of epidemiological interest because turkeys feed from the ground, and detection of infection in turkeys indicates contamination by oocysts in the environment. During the 2018 spring hunting season in Pennsylvania, fresh (unfixed, not frozen) samples were obtained from 20 harvested wild turkeys and tested for Toxoplasma gondii infection. Hearts from all wild turkeys and skeletal muscle from 1 were bioassayed for T. gondii by inoculation in outbred Swiss Webster (SW) and interferon-gamma gene knockout (KO) mice. Antibodies to T. gondii were detected in 1:5 dilution of neat serum from 5 of 15 wild turkeys and in fluid from the heart of 1 of 4 wild turkeys with the modified agglutination test (MAT); neat serum was not available from 4 wild turkeys. Viable T. gondii was isolated from hearts of 5 wild turkeys, 1 with MAT of 1:10, 1 with MAT of 1:5, and 3 seronegative (MAT < 1:5). Toxoplasma gondii was isolated from both heart and skeletal muscle in the 1 wild turkey that had skeletal muscle submitted. The KO mice inoculated with tissue from all 5 infected wild turkeys died or were euthanatized when ill, 7-21 days post-inoculation (PI). Tachyzoites were detected in lungs of all KO mice, and the T. gondii strains were successfully propagated in cell culture. The SW mice inoculated with tissues of wild turkeys remained asymptomatic, and tissue cysts were seen in the brains of infected mice when euthanatized in good health at 46 days PI; 1 of the 2 SW mice inoculated with the heart of 1 turkey died on day 26, and tachyzoites were detected in its lung. Genetic typing on DNA extracted from culture-derived tachyzoites using the PCR restriction fragment length polymorphism with 10 genetic markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) revealed that 4 isolates belonged to ToxoDB PCR-RFLP genotype #5 and 1 was genotype #216.

PCR and serology confirm the infection of turkey hens and their resilience to histomonosis in mixed flocks following high mortalities in toms.

BACKGROUND: Histomonosis, caused by the protozoan parasite Histomonas meleagridis, is a severe disease especially in turkeys where it can cause high mortalities. Recently, outbreaks were described in which turkey hens showed no clinical signs despite high mortalities in toms, from which they were separated only by a wire fence. The present study investigated three similar outbreaks of histomonosis whereby in two of them only a few hens were being affected and none in the third. Hens from all flocks were kept until end of production and slaughtered as scheduled. However, in all three cases, the disease progressed in toms reaching nearly 100% within two weeks. METHODS: Following diagnosis of the disease, tissue samples were obtained from toms and hens at necropsy. Environmental dust, cloacal swabs and blood were taken on three successive farm visits within compartments of hens and toms and tested by real-time PCR or ELISA. The DNA from a total of 18 samples positive for H. meleagridis was further subjected to conventional PCR utilizing the 18S rRNA primers and sequenced for phylogenetic analysis. RESULTS: All tissue samples and some cloacal swabs were tested positive. Dust samples confirmed the presence of H. meleagridis DNA that spread within entire houses up to 6 weeks after the first clinical signs of histomonosis. Sequence analysis of the 18S rRNA locus demonstrated the presence of the same strain in birds of both sexes within each of the turkey houses. Investigation of serum samples two weeks post-initial diagnosis and prior to euthanasia resulted in antibody detection in 73% of toms and 70% of hens. Until the end of the investigation the number of positive hens per farm increased up to 100% with mean OD-values approaching those noticed in toms prior to euthanasia. CONCLUSIONS: For the first time it could be demonstrated that turkey hens kept in the same house as toms became infected during fatal outbreaks in toms. This highlights the value of different diagnostics methods in order to trace the parasite in connection with the host response. The strange phenomenon that only single hens succumb to the diseases despite being infected requires further investigations.

Detection of Histomonas meleagridis DNA in dust samples obtained from apparently healthy meat turkey flocks without effect on performance.

Environmental dust samples obtained from 65 turkey flocks in France, of which six suffered from histomonosis whereas the rest remained apparent healthy until the end of production, were tested for the presence of Histomonas meleagridis DNA by recently developed real-time PCR based on the 18S rRNA locus. In order to determine the genotype of detected histomonads, positive samples were further subjected to conventional 18S PCR and sequencing. Additionally, production data of all tested flocks, such as average daily gain, feed conversion ratio and production index, were statistically evaluated and compared to see the effect of positive dust samples in apparently healthy flocks. Histomonad DNA was detected in the dust obtained from all six clinically affected and, surprisingly, in nine apparent healthy flocks. Sequencing of the 18S rRNA gene resulted in only one DNA sample homologous to H. meleagridis whereas 11 others revealed the presence of several other flagellates. Average daily gain and production index were negatively affected in flocks with clinical histomonosis, resulting in significant difference in comparison with the data obtained from clinically healthy flocks independent of the presence of histomonad DNA in the dust. Overall, there was no significant difference following statistical analysis of production parameters between the two last mentioned groups of tested flocks. Altogether, this is the first investigation demonstrating the presence of H. meleagridis DNA in environmental dust samples obtained from clinically unaffected turkey flocks. However, this finding could not be correlated with impact on production based on analysis and comparison of selected production data. RESEARCH HIGHLIGHTS Environmental dust obtained from clinically healthy turkey flocks, in addition to dust from flocks affected by histomonosis, was found positive for the presence of Histomonas meleagridis DNA. Histomonas-positive dust samples in clinically unaffected flocks did not have a negative effect on production parameters. The results demonstrate a wider spread of H. meleagridis DNA in flocks of commercial meat turkeys than previously thought.

The complete mitochondrial genome of Eimeria anseris from the wintering greater white-fronted goose in Shengjin Lake, China, and phylogenetic relationships among Eimeria species.

Coccidiosis is recognized as one of the most widespread and pathogenic parasitic infections in migratory waterfowl throughout the world. It can be caused by several species of Eimeria. We sequenced the complete mitochondrial genome (mtDNA) of Eimeria anseris from wintering greater white-fronted geese (Anser albifrons) in China. The complete E. anseris mtDNA is 6179 bp in size and contains three protein-coding genes (CYT B, COI, and COIII), 12 gene fragments for large subunit ribosomal RNA (rRNA), and seven gene fragments for small subunit rRNA, but no transfer RNA genes. Available complete Eimeria mtDNA sequences are highly conserved in sequence: the sequences are all similar in length; with the same three protein-coding genes and fragmented rRNA genes; ATG is generally the start codon, and TAA and TAG are the most frequently used stop codons. Our molecular phylogenetic analyses show some species clustering into host-specific clades, but many species do not follow clear coevolutionary host segregating patterns. The results suggest that Eimeria spp. from turkeys and chickens are paraphyletic groups, while Eimeria species isolated from rabbits are a monophyletic group. E. anseris, which infects A. albifrons, and another group of Eimeria isolated from chickens form a closely related monophyletic clade.

Distribution and abundance of Eimeria species in commercial turkey flocks across Canada.

Diversity and regional abundance of Eimeria species infecting Canadian commercial turkey flocks are largely unknown. To address this paucity of data regarding coccidiosis and its distribution in Canada, fecal samples from turkey flocks (N = 39) representing 27 commercial farms [ON (n = 20), SK (n = 2), BC (n = 3), AB (n = 1), NS (n = 1)] were screened for coccidia. Identification of all Eimeria species present in each sample was accomplished using a nested-polymerase chain reaction (PCR) assay targeting the mitochondrial cytochrome C oxidase subunit I gene. Most samples (33/39) were Eimeria-positive with 6 Eimeria species identified by the nested-PCR assay (1 to 6 species/sample, average 3.2); 4 samples (4/39, > 10% of samples) contained all 6 species. Eimeria species were common and distributed widely in Canadian commercial turkey flocks. Turkeys reared using in-feed medication or live vaccination for coccidiosis control had similar Eimeria species diversity within individual flocks. These preliminary observations highlight that coccidiosis remains a concern for Canadian turkey producers.

Distribution et abondance d'espèces d' Eimeria infectant des troupeaux de dindes commerciaux à travers le Canada. La diversité et l'abondance régionale d'espèces d'Eimeria infectants des troupeaux de dindes commerciaux canadiens sont pour la plupart inconnues. Pour adresser cette pénurie de données concernant les coccidies et leurs distributions au Canada, des échantillons fécaux provenant de 39 troupeaux de dindes, représentants 27 fermes commerciales [ON (n = 20), SK (n = 2), BC (n = 3), AB (n = 1), NS (n = 1)] étaient cribler pour la coccidie. L'identification de toutes les espèces d'Eimeria trouvées dans chaque échantillon était accomplie en utilisant une PCR nichée pour cibler la sous-unité I mitochondriale du cytochrome C oxydase. La plupart des échantillons (33/39) était positif pour l'Eimeria avec six espèces d'Eimeria identifiées par la PCR nichée (1 à 6 espèces/échantillon, moyenne 3,2); quatre échantillons (4/39, > 10 % d'échantillons) contenaient toutes les six espèces. Les espèces d'Eimeria sont communes et sont largement distribuées dans les troupeaux de dindes commerciaux canadiens. Les dindes élevées en utilisant des anticoccidiens en additifs alimentaire ou vaccinées avec des vaccins vivants pour la coccidie avaient une diversité d'espèces d'Eimeria similaire entre les troupeaux individuels. Ces observations préliminaires indiquent que la coccidie demeure toujours une préocculation pour les éleveurs de dindons.(Traduit par Alex Léveillé et Lisa Gordon).

Cecal coccidiosis in turkeys: Comparative biology of Eimeria species in the lower intestinal tract of turkeys using genetically typed, single oocyst-derived lines.

Differentiating the Eimeria species causing cecal coccidiosis in turkeys is challenging. To obtain benchmark biological data for Eimeria gallopavonis Hawkins 1952 and Eimeria meleagridis Tyzzer 1929 and to support the stability of the species concept for each, genetically typed, single oocyst-derived lines of E. gallopavonis Weybridge strain and E. meleagridis USAR97-01 were used to redescribe the biological, pathological, and morphological features of these parasites. Oocysts of E. meleagridis and E. gallopavonis overlap in dimensions, but oocysts of the former have a single polar granule compared with multiple in the latter. Mature first-generation meronts of E. gallopavonis were observed histologically as early as 48 h post-inoculation alongside the villi in jejunum (before and after Meckel's diverticulum), ileum, cecal neck and rectum, but not cecal pouches. Three asexual cycles were observed suggesting that early workers apparently overlooked one asexual cycle. Examination of endogenous development of a culture labeled "Eimeria adenoeides Weybridge strain" suggested that this strain (found in a number of publications as a large oocyst strain of "Eimeria adenoeides") matched the species description of E. gallopavonis and so has been renamed herein. Macroscopic lesions induced by E. gallopavonis consisted of caseous material distally from posterior of the yolk stalk through the remaining intestinal tract, excluding the cecal pouches. For E. meleagridis, only the first asexual generation was observed outside of the cecal pouches within the jejunum around the yolk stalk. Second- and 3rd-generation asexual stages developed almost exclusively in the cecal pouches (but not cecal necks). Macroscopic lesions described for E. meleagridis were similar to those of E. adenoeides. Marked corrugation of the cecal serosal surface was observed. Cecal pouches contained creamy colored, caseous material varying from loose material to granular. Distinguishing features of the Eimeria species infecting the lower part of the small intestine are summarized in the present study, and new type specimens were designated for E. gallopavonis and E. meleagridis to provide a stable reference for future work with these parasites.

Genotypic Characterization of Cryptosporidium Species in Humans and Peri-Domestic Animals in Ekiti and Oyo States, Nigeria.

Cryptosporidiosis is one of the leading causes of diarrhea in humans and several other vertebrate species. Because surveys of Cryptosporidium genotypes from animals and humans living in the same region are rare, our understanding of the importance of zoonotic transmission in the epidemiology of cryptosporidiosis remains superficial. PCR was used to amplify a portion of the Cryptosporidium 18S small subunit ribosomal RNA gene from fecal DNA from humans and livestock living in Ekiti and Oyo states, Nigeria. PCR-positive samples were further analyzed using PCR targeting the heat-shock protein HSP-70, the actin, and the sporozoite glycoprotein gene gp60. A questionnaire was used to collect demographic information. Sixteen of 187 samples collected were Cryptosporidium 18S PCR positive. Of these, 5 samples originating from HIV-positive patients, 5 from otherwise healthy children, 2 from chickens, 3 from goats, and 1 from a dog were positive for at least 1 marker. Sequencing of the 18S rRNA amplicons revealed the presence of Cryptosporidium parvum in 2 HIV positive patients and in a child; the actin sequence confirmed the presence of this species. Two samples of HIV-positive patients amplified Cryptosporidium hominis 18S rRNA, one of them confirmed by the HSP-70, actin, and gp60 sequences. Cryptosporidium meleagridis was found in another HIV patient, while C. hominis was detected in 3 children (of which 2 were confirmed by gp60). Cryptosporidium muris was found in 1 child. In birds, we found C. meleagridis and, significantly, C. parvum, whereas we detected C. parvum and C. muris in 1 goat each. The only dog sampled was positive for Cryptosporidium canis. We conclude that, in the environment we surveyed, humans and animals are a potential part of the same transmission cycle. Measures to prevent zoonotic transmission should therefore be considered to reduce the prevalence of cryptosporidiosis.

Analysis of Toxoplasma gondii clonal type-specific antibody reactions in experimentally infected turkeys and chickens.

Due to their ground-feeding behaviour, free-ranging chickens and turkeys are exposed to oocysts and are good indicators of the presence of Toxoplasma gondii in the environment. In addition, poultry may become infected by ingestion of tissues of infected intermediate hosts such as small rodents. Free-ranging poultry are considered an important source of T. gondii infection in humans, especially in developing countries. Knowledge on T. gondii genotypes in infected animals and humans is important for understanding the epidemiology of T. gondii infections. The aim of the present study was to analyse the ability of experimentally infected turkeys and chickens to develop a T. gondii clonal type-specific antibody response (IgY) after i.v. inoculation with tachyzoites of three T. gondii clonal lineages, types I, II and III. A peptide microarray displaying a panel of 101 different synthetic peptides was used for serotyping. Peptide sequences were derived from polymorphic regions of 16 T. gondii proteins (GRA1, GRA3-7, SAG1, SAG2A, SAG3, SAG4, SRS1, SRS2, ROP1, NTPase I and NTPase III and BSR4). The array was probed with 120 sera from experimentally infected chickens and turkeys inoculated with different doses of T. gondii tachyzoites (104, 103 and 102) collected from isolates representative for T. gondii clonal types I (RH), II (ME49) or III (NED) and uninfected controls. After screening of the peptides with reference sera from chickens and turkeys, and evaluation of data by Receiver Operating Characteristics analysis, 41 and 40 peptides were identified that appeared suitable to detect type-specific reactions with sera collected at 2, 5, 7 and 9 weeks p.i. Selected peptides allowed the identification of T. gondii clonal types, until 9 week p.i., which the chickens or turkeys had been inoculated with. At 9 weeks p.i., a high proportion of the experimentally infected chickens (67% (12/18)) and turkeys (61% (11/18)) no longer reacted with the selected peptides. Serotyping of the infection in individual chickens or turkeys was only possible when the whole peptide panel was applied. Clonal type-specific antibody responses were dynamic in both poultry species and depended on the individual animal and the time after infection.

Allocation of Interferon Gamma mRNA Positive Cells in Caecum Hallmarks a Protective Trait Against Histomonosis.

Histomonosis is a parasitic disease of gallinaceous birds characterized by necrotic lesions in cacum and liver that usually turns fatal in turkeys while it is less severe in chickens. Vaccination using in vitro attenuated Histomonas meleagridis has been experimentally shown to confer protection against histomonosis. The protective mechanisms that underpin the vaccine-induced immune response are not resolved so far. Therefore, the actual study aimed to evaluate the location and quantitative distribution patterns of signature cytokines of type 1 [interferon gamma (IFN-γ)] or type 2 [interleukin (IL)-13] immune responses in vaccinated or infected hosts. An intergroup and interspecies difference in the spatial and temporal distribution patterns of cytokine mRNA positive cells was evident. Quantification of cells showed a significantly decreased percentage of IFN-γ mRNA positive cells at 4 days post-inoculation (DPI) in caeca of turkeys inoculated exclusively with the attenuated or the virulent inocula, compared to control birds. The decrement was followed by a surge of cells expressing mRNA for IFN-γ or IL-13, reaching a peak of increment at 10 DPI. By contrast, turkeys challenged following vaccination showed a slight increment of cecal IFN-γ mRNA positive cells at 4 DPI after which positive cell counts became comparable to control birds. The increase in infected birds was accompanied by an extensive distribution of positively stained cells up to the muscularis layer of cecal tissue whereas the vaccine group maintained an intact mucosal structure. In chickens, the level of changes of positive cells was generally lower compared to turkeys. However, control chickens were found with a higher percentage of IFN-γ mRNA positive cells in cecum compared to their turkey counterparts indicating a higher resistance to histomonosis, similar to the observation in immunized turkeys. In chickens, it could be shown that the changes of cytokine-positive cells were related to variations of mononuclear cells quantified by immunofluorescence. Furthermore, gene expression measured by reverse transcription quantitative real time PCR confirmed variations in organs between the different groups of both bird species. Overall, it can be concluded that a proportionally increased, yet controlled, allocation of IFN-γ mRNA positive cells in caeca hallmarks a protective trait against histomonosis.

Distribution and host associations of ixodid ticks collected from wildlife in Florida, USA.

A tick survey was conducted to document tick-host associations with Florida (USA) wildlife, and to determine the relative abundance and distribution of ixodid ticks throughout the state. The survey was conducted using collection kits distributed to licensed Florida hunters as well as the examination of archived specimens from ongoing state wildlife research programs. Collected tick samples were obtained from 66% of Florida counties and were collected from nine wildlife hosts, including black bear, bobcat, coyote, deer, gray fox, Florida panther, raccoon, swine, and wild turkey. In total, 4176 ticks were identified, of which 75% were Amblyomma americanum, 14% Ixodes scapularis, 8% A. maculatum, 3% Dermacentor variabilis, and < 1% were I. affinis and I. texanus. americanum, D. variabilis, and I. scapularis had the broadest host range, while A. maculatum, D. variabilis, and I. scapularis had the widest geographic distribution. While the survey data contribute to an understanding of tick-host associations in Florida, they also provide insight into the seasonal and geographic distribution of several important vector species in the southeastern USA.