1
|
Xiang C, Li Y, Jing S, Han S, He H. Trichomonas gallinae Kills Host Cells Using Trogocytosis. Pathogens 2023; 12:1008. [PMID: 37623968 PMCID: PMC10459183 DOI: 10.3390/pathogens12081008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/18/2023] [Accepted: 07/18/2023] [Indexed: 08/26/2023] Open
Abstract
Trichomonas gallinae (T. gallinae) is an infectious parasite that is prevalent worldwide in poultry and can cause death in both poultry and wild birds. Although studies have shown that T. gallinae damages host cells through direct contact, the mechanism is still unclear. In this study, we found that T. gallinae can kill host cells by ingesting fragments of the host cells, that is, by trogocytosis. Moreover, we found that the PI3K inhibitor wortmannin and the cysteine protease inhibitor E-64D prevented T. gallinae from destroying host cells. To the best of our knowledge, our study has demonstrated for the first time that T. gallinae uses trogocytosis to kill host cells. Understanding this mechanism is crucial for the prevention and control of avian trichomoniasis and will contribute to the development of vaccines and drugs for the prevention and control of avian trichomoniasis.
Collapse
Affiliation(s)
- Chen Xiang
- National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (C.X.); (S.H.)
- University of Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Li
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, China; (Y.L.); (S.J.)
| | - Shengfan Jing
- College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, China; (Y.L.); (S.J.)
| | - Shuyi Han
- National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (C.X.); (S.H.)
- University of Chinese Academy of Sciences, Beijing 100101, China
| | - Hongxuan He
- National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (C.X.); (S.H.)
| |
Collapse
|
2
|
Sigrist B, Ng TWC, Albini S, Wolfrum N. A new duplex real-time PCR for simultaneous detection and differentiation of Tetratrichomonas gallinarum and Trichomonas gallinae. J Vet Diagn Invest 2022; 34:631-637. [PMID: 35593583 DOI: 10.1177/10406387221098069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Tetratrichomonas gallinarum and Trichomonas gallinae are pathogenic avian parasites that infect a wide range of bird species. The pathologic potential of T. gallinarum is controversial, whereas T. gallinae causes disease in many avian species. Infections are often asymptomatic in doves and pigeons; thus, columbids are presumed to represent the natural hosts for trichomonads. The detection of T. gallinarum and T. gallinae is based on direct microscopic observation or a conventional PCR assay. Microscopy is not very sensitive, and identification of the trichomonads at the genus or species level is not possible. Conventional PCR assays have been developed primarily for phylogenetic studies, which detect a wide range of Trichomonas spp. but do not allow their differentiation. We developed a duplex real-time PCR (rtPCR) assay for the simultaneous detection and differentiation of T. gallinarum and T. gallinae. We found that the rtPCR assay detected 102 plasmid DNA copies of T. gallinarum and as few as 101 plasmid DNA copies of T. gallinae.
Collapse
Affiliation(s)
- Brigitte Sigrist
- Department of Poultry and Rabbit Diseases, Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - T W Cherry Ng
- Department of Poultry and Rabbit Diseases, Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sarah Albini
- Department of Poultry and Rabbit Diseases, Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Nina Wolfrum
- Department of Poultry and Rabbit Diseases, Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| |
Collapse
|
3
|
Trichomonosis in Austrian Songbirds—Geographic Distribution, Pathological Lesions and Genetic Characterization over Nine Years. Animals (Basel) 2022; 12:ani12101306. [PMID: 35625152 PMCID: PMC9137778 DOI: 10.3390/ani12101306] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 12/10/2022] Open
Abstract
In the early summer of 2012, sudden mass mortality among songbirds, particularly in greenfinches (Chloris chloris, syn: Carduelis chloris) was observed in Austria, which was caused by the protozoan parasite Trichomonas gallinae. This pathogen induced fibrinonecrotic ingluvitis and/or esophagitis, leading to impairment of food intake and ultimately death due to starvation. The pathogen was successfully detected within the lesions by polymerase chain reaction (PCR) and chromogenic in situ hybridization. The epizootic resulted in a significant decline in the Austrian greenfinch population. Continuing passive surveillance in the subsequent years (2013–2020) revealed that the condition occurred each year and was present in the entire country. Genetic characterization of the pathogen showed the presence of an identical strain irrespective of geographical location, bird species, and year.
Collapse
|
4
|
Thomas RC, Dunn JC, Orsman CJ, Morris AJ, Hipperson H, Grice PV, Hamer KC, Goodman SJ. Successful storage of Trichomonas gallinae on Whatman FTA cards following culture. CONSERV GENET RESOUR 2022. [DOI: 10.1007/s12686-022-01263-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractLogistical constraints concerning parasite sample storage can hinder progress with the discovery of genetic variation on a global scale. New storage methods are being developed to address this, but require testing in order to understand how widely applicable these methods are. Whatman FTA cards have been tested previously under laboratory conditions for storing low-concentration Trichomonas gallinae isolates with the conclusion that they are not suitable, but have not been tested under field conditions. Here, we conducted a field-test, comparing FTA cards with storage in ethanol for T. gallinae samples collected and cultured from wild Columbiformes in Africa using standard field methods, before transportation to the UK. After 6 months storage, both methods resulted in an overall prevalence of 100% following PCR amplification (n = 59), suggesting that FTA cards are suitable for estimation of T. gallinae prevalence. However, samples stored in ethanol produced more, and longer, sequences than those stored on FTA cards. These data suggest storage in ethanol is preferable for the acquisition of high quality genetic strain data, but that FTA cards can be used successfully to ascertain infection prevalence and identify parasite strains under field conditions.
Collapse
|
5
|
Himmel T, Harl J, Matt J, Weissenböck H. A citizen science-based survey of avian mortality focusing on haemosporidian infections in wild passerine birds. Malar J 2021; 20:417. [PMID: 34688278 PMCID: PMC8542282 DOI: 10.1186/s12936-021-03949-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 10/08/2021] [Indexed: 11/17/2022] Open
Abstract
Background Haemosporidioses are common in birds and their manifestations range from subclinical infections to severe disease, depending on the involved parasite and bird species. Clinical haemosporidioses are often observed in non-adapted zoo or aviary birds, whereas in wild birds, particularly passerines, haemosporidian infections frequently seem to be asymptomatic. However, a recent study from Austria showed pathogenic haemosporidian infections in common blackbirds due to high parasite burdens of Plasmodium matutinum LINN1, a common parasite in this bird species, suggesting that virulent infections also occur in natural hosts. Based on these findings, the present study aimed to explore whether and to what extent other native bird species are possibly affected by pathogenic haemosporidian lineages, contributing to avian morbidity. Methods Carcasses of passerine birds and woodpeckers were collected during a citizen science-based survey for avian mortality in Austria, from June to October 2020. Tissue samples were taken and examined for haemosporidian parasites of the genera Plasmodium, Haemoproteus and Leucocytozoon by nested PCR and sequencing the mitochondrial cytb barcode region, histology, and chromogenic in situ hybridization applying genus-specific probes. Results From over 160 dead bird reportings, 83 carcasses of 25 avian species were submitted for investigation. Overall haemosporidian infection rate was 31%, with finches and tits prevailing species counts and infections. Sequence analyses revealed 17 different haplotypes (4 Plasmodium, 4 Haemoproteus, 9 Leucocytozoon), including 4 novel Leucocytozoon lineages. Most infected birds presented low parasite burdens in the peripheral blood and tissues, ruling out a significant contribution of haemosporidian infections to morbidity or death of the examined birds. However, two great tits showed signs of avian malaria, suggesting pathogenic effects of the detected species Plasmodium relictum SGS1 and Plasmodium elongatum GRW06. Further, exo-erythrocytic tissue stages of several haemosporidian lineages are reported. Conclusions While suggesting generally little contribution of haemosporidian infections to mortality of the investigated bird species, the findings indicate a possible role of certain haemosporidian lineages in overall clinical manifestation, either as main causes or as concurrent disease agents. Further, the study presents new data on exo-erythrocytic stages of previously reported lineages and shows how citizen science can be used in the field of haemosporidian research. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03949-y.
Collapse
Affiliation(s)
- Tanja Himmel
- Institute of Pathology, Department for Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Josef Harl
- Institute of Pathology, Department for Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Julia Matt
- Institute of Pathology, Department for Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Herbert Weissenböck
- Institute of Pathology, Department for Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| |
Collapse
|
6
|
Martínez-Herrero MC, Sansano-Maestre J, Azami-Conesa I, González-González F, Suárez Regalado L, Garijo-Toledo MM, Gómez-Muñoz MT. Sequence subtyping of Trichomonas gallinae from Bonelli's eagle ( Aquila fasciata) during four years (2014-2017) reveals that MLS type is associated with lesions. Avian Pathol 2021; 50:339-349. [PMID: 34126819 DOI: 10.1080/03079457.2021.1940099] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Avian trichomonosis is a parasitic disease that affects wild birds. The objective of this work was to determine the importance of avian trichomonosis in Bonelli's eagles to improve conservation measures in this population. One hundred and eighty-eight birds were studied: 181 chicks, two juveniles, one subadult and four adults. The birds were externally examined and gross lesions at the oropharynx registered. Samples from the oropharyngeal cavity were obtained for Trichomonas spp. detection by culture and PCR, and positive samples were subjected to a multilocus sequence typing approach, including the ITS1/5.8S/ITS2 region (ITS), ribosomal RNA small subunit (18S) and Fe-hydrogenase gene (FeHyd). Global prevalence of T. gallinae infection was 37.8% in total, 45.5% in nestlings. Thirty-three percent of the birds developed lesions that ranged from mild (n = 41) to moderate (n = 14) or severe (n = 7). Multilocus sequence typing analysis showed five different MLS types, ITS-A/18S-VI/FeHyd-A1 and ITS-D/18S-II/Fe-C4 being the most frequent. An association between ITS-A/18S-VI/FeHyd-A1 and moderate or severe lesions was observed, but birds with type ITS-A/18S-VI/FeHyd-A2 also developed lesions. On the contrary, birds with MLS type ITS-D/18S-II/FeHyd-C4 displayed only a low proportion of mild lesions. Chicks raised in nests were at higher risk for T. gallinae infection and development of lesions than chicks raised in captivity. Discordances between samples cultured in TYM and samples subjected to PCR from oropharyngeal swabs were observed, swab-ITS-PCR being more sensitive.RESEARCH HIGHLIGHTS45.5% of Bonelli's eagles in the nest carried T. gallinae and 39.4% showed lesions.PCR from oral swabs showed higher sensitivity than culture in TYM for detection of T. gallinae.MLS types ITS-A/18S-VI/Fe-A1 (and A2) are a risk factor for the development of lesions.
Collapse
Affiliation(s)
- M C Martínez-Herrero
- Parasitology and Parasitic Diseases Research Group (PARAVET). Department of Animal Production and Health, Public Veterinary Health and Food Science and Technology, Faculty of Veterinary Medicine, Universidad Cardenal Herrera-CEU, CEU Universities, Alfara del Patriarca, Valencia, Spain
| | - J Sansano-Maestre
- Faculty of Veterinary Medicine and Experimental Sciences, Universidad Católica de Valencia Valencia, Spain
| | - I Azami-Conesa
- Departament of Animal Health, Faculty of Veterinary Medicine, Madrid, Spain
| | - F González-González
- Group of Rehabilitation of the Autochtonous Fauna and their Habitat (GREFA) Majadahonda, Madrid, Spain
| | - L Suárez Regalado
- Group of Rehabilitation of the Autochtonous Fauna and their Habitat (GREFA) Majadahonda, Madrid, Spain
| | - M M Garijo-Toledo
- Parasitology and Parasitic Diseases Research Group (PARAVET). Department of Animal Production and Health, Public Veterinary Health and Food Science and Technology, Faculty of Veterinary Medicine, Universidad Cardenal Herrera-CEU, CEU Universities, Alfara del Patriarca, Valencia, Spain
| | - M T Gómez-Muñoz
- Departament of Animal Health, Faculty of Veterinary Medicine, Madrid, Spain
| |
Collapse
|
7
|
Chou S, Hadano S, Kojima A, Yorisaki M, Yasuda M, Ike K, Tokiwa T. Genetic characterization of Trichomonas gallinae (Rivolta, 1878) in companion birds in Japan and the genotypical relationship in the Asia region. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2021; 55:527-534. [PMID: 34246556 DOI: 10.1016/j.jmii.2021.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 05/08/2021] [Accepted: 05/28/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND/PURPOSE Avian trichomonosis is a parasitic infection that affects a wide range of avian species, including free-ranging and pet birds worldwide, and Trichomonas gallinae has been considered as the only causative agent for decades. The sequence of the 5.8S ribosomal RNA with internal transcribed spacer (ITS) regions was widely used for identifying genotypes and determining inter-specific and intra-specific diversity. Moreover, the sequence of Fe-hydrogenase (FeHyd) was proposed as the second genetic marker for providing improved resolution of strain subtyping discrimination. Though the correlation between genetic variability and strain virulence is controversial, FeHyd analyses seemed to be useful to investigate the host or geographic origin of isolates. This study aimed to investigate the genetic characteristics of avian Trichomonas spp. METHODS Forty-seven oral swabs and crop lavage fluids were collected from 9 avian genera, which were diagnosed as Trichomonas-positive by microscopy in animal hospitals in Japan, were analyzed. RESULTS Genetic analysis of clonal isolates revealed the prevalence of the single genotype, ITS-OBT-Tg-1, by ITS region analysis, while two different subtypes, A2 and novel A3, were suggested by FeHyd gene analysis among Japanese companion birds. Phylogenetic analyses of available ITS sequences obtained from the Asia region (China, Iran, Iraq, and Saudi Arabia) were also preformed, revealing endemic ITS-OBT-Tg-1, ITS-OBT-Tg-2, ITS-OBT-Ttl-1, genotype III, and Saudi Arabia's unique lineages. Furthermore, ITS-OBT-Tg-2 predominance in these countries indicates different strains origination from Japan. CONCLUSION This is the first report of the genetic characterization of T. gallinae in Japan with discovery of novel subtype A3.
Collapse
Affiliation(s)
- Shyun Chou
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo 180-8602, Japan.
| | - Shinichiro Hadano
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo 180-8602, Japan
| | - Atsushi Kojima
- Little Animal and Bird Clinic LITTLE BIRD, Gotokuji, Setagaya, Tokyo, 154-0021, Japan; Research and Education Center for Prevention of Global Infectious Diseases of Animals, Tokyo University of Agriculture and Technology, Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Mario Yorisaki
- Morishita Bird Clinic, Shin-ohashi, Koto, Tokyo, 135-0007, Japan; Laboratory of Veterinary Pathology, Co-department of Veterinary Medicine, Iwate University, Ueda, Morioka, Iwate, 020-8550, Japan
| | - Masaru Yasuda
- Masa-no-Mori Pet Clinic, Kigoshimachi, Kanazawa, Ishikawa, 920-0203, Japan
| | - Kazunori Ike
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo 180-8602, Japan
| | - Toshihiro Tokiwa
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo 180-8602, Japan
| |
Collapse
|
8
|
Molecular characterization of Trichomonas gypaetinii isolated from the upper alimentary tract of Steller's sea eagles (Haliaeetus pelagicus) and white-tailed sea eagles (Haliaeetus albicilla) in Hokkaido, Japan. Parasitol Res 2021; 120:2189-2198. [PMID: 33855618 DOI: 10.1007/s00436-021-07160-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 04/08/2021] [Indexed: 10/21/2022]
Abstract
Recent phylogenetic and morphologic studies of Trichomonas spp. suggests that there are more than 3 species that infect the upper alimentary tract of wild birds, which include T. gallinae, T. stableri, and T. gypaetinii. In this study, investigations were conducted on the prevalence of trichomonads in the upper alimentary tract of 12 Steller's sea eagles (Haliaeetus pelagicus) and 18 white-tailed sea eagles (H. albicilla). All birds were rescued from the wild and kept at a rehabilitation facility in Hokkaido, Japan, for variable durations and did not show any symptoms of trichomonosis. The ITS1-5.8SrRNA-ITS2 (ITS) genomic region of Trichomonas spp. was detected from 29 samples by PCR, and flagellates were confirmed from 4 samples by culture. Morphologic observations and measurement recordings were conducted under a light microscope on trophozoites obtained from the cultured isolates. Genomic sequences of the ITS, 18S ribosomal RNA (18S rRNA), Fe-hydrogenase, and RNA polymerase II largest subunit (Rpb1) regions were determined by direct sequencing, and phylogenetic analyses were conducted with previously published sequences of Trichomonas spp. All isolates were concluded as T. gypaetinii based on morphologic and molecular characterizations of the ITS and 18S rRNA genes. This is the first study to isolate T. gypaetinii from Haliaeetus eagles and further provide novel sequences of the Fe-hydrogenase and Rpb1 genes of T. gypaetinii. Both genomic regions also confirmed that T. gypaetinii belong to independent clusters from other Trichomonas spp.
Collapse
|
9
|
Molecular characterization of the Fe‑hydrogenase gene marker in Trichomonas gallinae isolated from birds in Riyadh, Saudi Arabia. Parasitol Int 2020; 81:102263. [PMID: 33278606 DOI: 10.1016/j.parint.2020.102263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 11/28/2020] [Accepted: 11/29/2020] [Indexed: 11/22/2022]
Abstract
Trichomonas gallinae causes avian oropharyngeal trichomonosis. This pathogen affects a large number of bird species and may cause substantial economic losses to the poultry industry. Al-Azizia poultry market in Riyadh, Saudi Arabia is among the largest poultry markets in the Arabian Gulf. Birds traded in this market may be exposed to a variety of T. gallinae strains. Genetic diversity of T. gallinae among birds in the market was examined using Fe‑hydrogenase gene sequences. These sequences were amplified by PCR for twenty-nine isolates of T. gallinae from four different avian species, including 21 feral pigeons, one common mynah, three chickens, and four turkeys. Sequence analysis showed ten variant gene sequences. Nine sequences comprise a new subtype, including A(KSAF1), C(KSAF1) and C(KSAF3) with 34.48% (n = 10), 6.90% (n = 2), 6.90% (n = 2) of the isolates, respectively. Analyses also showed an additional five new sequences (KSAF1.1., KSAF2, KSAF13, KSAF14, KSAF15), representing 17.24% of the isolates. Subtype II (KSAF) was found in four feral pigeons (13.80%). To our knowledge, this report is the first to describe genotypes of T. gallinae from pigeons in Saudi Arabia using Fe‑hydrogenase gene sequences for subtyping. Subtype analysis infers the presence of multiple genotypes of T. gallinae in Saudi avian populations.
Collapse
|
10
|
Martínez-Herrero MC, Sansano-Maestre J, Ortega J, González F, López-Márquez I, Gómez-Muñoz MT, Garijo-Toledo MM. Oral trichomonosis: Description and severity of lesions in birds in Spain. Vet Parasitol 2020; 283:109196. [PMID: 32731053 DOI: 10.1016/j.vetpar.2020.109196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
Avian trichomonosis is a parasitic disease caused by the flagellated protozoan Trichomonas gallinae. Columbiformes are the reservoir host of the parasite, with high levels of infection, but also other domestic and wild birds from a variety of orders are susceptible to the infection and development of gross lesions. In this paper we describe the type and severity of lesions in wild birds in four avian orders (Accipitriformes, Falconiformes, Strigiformes and Columbiformes). A total of 94 clinical cases diagnosed of trichomonosis were selected for the categorization of their lesions in the upper digestive tract. The affected birds were classified into three different categories (mild, moderate and severe) based on size (in relation to the tracheal opening), depth and location of the lesions. Mild cases are those with small and superficial lesions far from the oropharyngeal opening; moderate cases possess larger and deeper lesions, and severe cases very large and deep lesions that impede swallowing or affect the skull. Mild lesions were found in 10.6 % of cases; moderate lesions were observed in 18.1 % of the birds and severe lesions in 71.3 %. Treatment outcomes in birds with either mild or moderate lesions were favorable, while severe lesions were related to poor body score, leading to death or euthanasia in most cases. A relationship between severe lesions and avian order was found, with a higher percentage of birds with this type in Falconiformes, Columbiformes and Strigiformes. Multifocal lesions were more frequent in Columbiformes and Falconiformes. In Strigiformes, 93.3 % of birds showed lesions in the upper jaw. This study seeks to further understanding of avian trichomonosis and to provide information that will be useful to veterinarians and related professionals for assessment, prognosis and treatment choice for these birds.
Collapse
Affiliation(s)
- M C Martínez-Herrero
- Department of Animal and Health Production, Public Health and Food Science and Technology, Faculty of Veterinary, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Tirant lo Blanc, 7, 46115, Alfara del Patriarca, Spain.
| | - J Sansano-Maestre
- Department of Animal Production and Public Health, Faculty of Experimental and Veterinary Sciences, Catholic University of Valencia, Calle Guillem de Castro, 94, 46003, Valencia, Spain.
| | - J Ortega
- Department of Animal and Health Production, Public Health and Food Science and Technology, Faculty of Veterinary, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Tirant lo Blanc, 7, 46115, Alfara del Patriarca, Spain.
| | - F González
- GREFA - Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat, Wildlife Veterinary Hospital, Carretera Monte del Pilar, s/n, 28220, Majadahonda, Spain.
| | - I López-Márquez
- GREFA - Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat, Wildlife Veterinary Hospital, Carretera Monte del Pilar, s/n, 28220, Majadahonda, Spain.
| | - M T Gómez-Muñoz
- Department of Animal Health, Faculty of Veterinary Sciences, Complutense University of Madrid, Av. Puerta de Hierro, s/n, 28040, Madrid, Spain.
| | - M M Garijo-Toledo
- Department of Animal and Health Production, Public Health and Food Science and Technology, Faculty of Veterinary, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Tirant lo Blanc, 7, 46115, Alfara del Patriarca, Spain.
| |
Collapse
|
11
|
Alrefaei AF, Low R, Hall N, Jardim R, Dávila A, Gerhold R, John S, Steinbiss S, Cunningham AA, Lawson B, Bell D, Tyler K. Multilocus Analysis Resolves the European Finch Epidemic Strain of Trichomonas gallinae and Suggests Introgression from Divergent Trichomonads. Genome Biol Evol 2020; 11:2391-2402. [PMID: 31364699 PMCID: PMC6735722 DOI: 10.1093/gbe/evz164] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2019] [Indexed: 12/12/2022] Open
Abstract
In Europe, Trichomonas gallinae recently emerged as a cause of epidemic disease in songbirds. A clonal strain of the parasite, first found in the United Kingdom, has become the predominant strain there and spread to continental Europe. Discriminating this epidemic strain of T. gallinae from other strains necessitated development of multilocus sequence typing (MLST). Development of the MLST was facilitated by the assembly and annotation of a 54.7 Mb draft genome of a cloned stabilate of the A1 European finch epidemic strain (isolated from Greenfinch, Chloris chloris, XT-1081/07 in 2007) containing 21,924 protein coding genes. This enabled construction of a robust 19 locus MLST based on existing typing loci for Trichomonas vaginalis and T. gallinae. Our MLST has the sensitivity to discriminate strains within existing genotypes confidently, and resolves the American finch A1 genotype from the European finch epidemic A1 genotype. Interestingly, one isolate we obtained from a captive black-naped fruit dove Ptilinopsus melanospilus, was not truly T. gallinae but a hybrid of T. gallinae with a distant trichomonad lineage. Phylogenetic analysis of the individual loci in this fruit dove provides evidence of gene flow between distant trichomonad lineages at 2 of the 19 loci examined and may provide precedence for the emergence of other hybrid trichomonad genomes including T. vaginalis.
Collapse
Affiliation(s)
- Abdulwahed Fahad Alrefaei
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk, United Kingdom.,Department of Zoology, King Saud University, College of Science, Riyadh, Saudi Arabia
| | - Ross Low
- Earlham Institute, Norwich Research Park Innovation Centre, Colney Ln, Norwich, United Kingdom
| | - Neil Hall
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk, United Kingdom.,Earlham Institute, Norwich Research Park Innovation Centre, Colney Ln, Norwich, United Kingdom
| | - Rodrigo Jardim
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Alberto Dávila
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Rick Gerhold
- University of Tennessee, Center for Wildlife Health, Knoxville, Tennessee
| | - Shinto John
- Institute of Zoology, Zoological Society of London, Regent's Park, London, United Kingdom
| | - Sascha Steinbiss
- Wellcome Trust Sanger Institute, Parasite Genomics, Hinxton, Cambridge, United Kingdom
| | - Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London, United Kingdom
| | - Becki Lawson
- Institute of Zoology, Zoological Society of London, Regent's Park, London, United Kingdom
| | - Diana Bell
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Kevin Tyler
- University of East Anglia, School of Medicine, Biomedical Research Centre, Norwich, Norfolk, United Kingdom
| |
Collapse
|
12
|
Trimmel NE, Walzer C. Infectious Wildlife Diseases in Austria-A Literature Review From 1980 Until 2017. Front Vet Sci 2020; 7:3. [PMID: 32154271 PMCID: PMC7046627 DOI: 10.3389/fvets.2020.00003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/02/2020] [Indexed: 12/28/2022] Open
Abstract
This literature review examines infectious wildlife disease research in Austria. We analyzed 226 research papers, published between 1980 and 2017. We determined that wildlife disease papers increased significantly from 0.8 ± 0.8 publications per year in the first decade (1980–1989) when compared to 2008–2017 with an average of 12.9 ± 4.1 publications per year. We illustrate information about the most investigated diseases and highlight the lack of research into certain wildlife pathogens. A special emphasis was given to diseases with zoonotic potential. The review showed that research focused on a few select species like the red fox (Vulpes vulpes), red deer (Cervus elaphus), and wild boar (Sus scrofa), all game species. Moreover, diseases affecting livestock and human health were seen more often. The review also found that only a low number of publications actually stated disease prevalence and confidence interval data. The reported diseases identified were classified according to their notifiable status and the distribution at the wildlife–human and wildlife–livestock interface. Furthermore, we try to argue why research into some diseases is prioritized, and why other diseases are underrepresented in current Austrian research. While spatiotemporal indicators could not be assessed due to the variability in methodologies and objectives of various studies, the information provided by this review offers the first comprehensive evaluation of the status of infectious wildlife disease research in Austria. Therefore, this study could assist investigators to identify further areas of priorities for research and conservation efforts and for wildlife management professionals to inform policy and funding strategies. With this review, we want to encourage research in the field of wildlife diseases in Austria to enhance current knowledge in the prevention of further loss in biodiversity and to find new measures to promote “One Health” on a global scale.
Collapse
Affiliation(s)
- Nina Eva Trimmel
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Chris Walzer
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria.,Wildlife Conservation Society, Bronx, NY, United States
| |
Collapse
|
13
|
Rijks JM, Laumen AAG, Slaterus R, Stahl J, Gröne A, Kik ML. Trichomonosis in Greenfinches ( Chloris chloris) in the Netherlands 2009-2017: A Concealed Threat. Front Vet Sci 2019; 6:425. [PMID: 31850382 PMCID: PMC6896826 DOI: 10.3389/fvets.2019.00425] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/11/2019] [Indexed: 11/30/2022] Open
Abstract
Finch trichomonosis in Europe is caused by a Trichomonas gallinae subtype A1 strain, considered to be clonal because lacking genetic heterogeneity in partial genotyping. The disease recently emerged and has been associated with a 66% reduction of the British breeding greenfinch (Chloris chloris) population. In contrast, in the Netherlands, where trichomonosis was detected in 2009, the breeding greenfinch population continued to grow in subsequent years. This study aimed to elucidate whether this discrepancy in population trends is because Trichomonas infection in Dutch greenfinches is associated with less severe disease, i.e., disease being less fatal. Therefore, it characterized and quantified trichomonosis in a convenience sample of greenfinches found dead and examined post-mortem between 2009 and 2017 and compared results to published data from Great Britain. Trichomonads were detected by cytology, histology, or culture in 95/101 greenfinches. The birds with trichomonads all had microscopic lesions in the upper digestive tract consistent with trichomonosis, indicating the trichomonads caused disease. The occurrence of significant lesions due to other causes was low. Some greenfinches with trichomonosis showed no macroscopic lesions. These birds showed significantly less ulceration of the mucosa and less extensive heterophil infiltration, but extent of macrophage infiltration and presence of bacteria was similar to that of birds with macroscopic lesions, and significant lesions due to other causes were equally rare. Therefore, trichomonosis was considered similarly fatal in both groups. The frequency of fatal trichomonosis in the Dutch greenfinches did not differ significantly from that reported from Great Britain. Partial genotyping of the ITS1-5,8S-ITS2 and Fe-hydrogenase regions of T. gallinae was performed to detect genetic heterogeneity, that could indicate the presence of other, possibly less virulent, strains. In 60/63 samples there was full alignment of sequences with the clonal strain of T. gallinae subtype A1. The remaining three samples had the same single synonymous nucleotide difference in the Fe-hydrogenase region; however, pathology is these three was identical to the others. Collectively, the results provide no clear evidence for less severe disease as explanation for the discrepancy in census data trends. We conclude that trichomonosis is a threat concealed in Dutch breeding greenfinch census data.
Collapse
Affiliation(s)
- Jolianne M Rijks
- Dutch Wildlife Health Centre (DWHC), Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Andrea A G Laumen
- Dutch Wildlife Health Centre (DWHC), Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Roy Slaterus
- Dutch Centre for Field Ornithology (Sovon), Nijmegen, Netherlands
| | - Julia Stahl
- Dutch Centre for Field Ornithology (Sovon), Nijmegen, Netherlands
| | - Andrea Gröne
- Dutch Wildlife Health Centre (DWHC), Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Pathology Division, Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Marja L Kik
- Dutch Wildlife Health Centre (DWHC), Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Pathology Division, Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
14
|
Membrane associated proteins of two Trichomonas gallinae clones vary with the virulence. PLoS One 2019; 14:e0224032. [PMID: 31647841 PMCID: PMC6812828 DOI: 10.1371/journal.pone.0224032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 10/03/2019] [Indexed: 11/19/2022] Open
Abstract
Oropharyngeal avian trichomonosis is mainly caused by Trichomonas gallinae, a protozoan parasite that affects the upper digestive tract of birds. Lesions of the disease are characterized by severe inflammation which may result in fatality by starvation. Two genotypes of T. gallinae were found to be widely distributed in different bird species all over the world. Differences in the host distribution and association with lesions of both genotypes have been reported. However, so far no distinct virulence factors of this parasite have been described and studies might suffer from possible co-infections of different genotypes. Therefore, in this paper, we analyzed the virulence capacity of seven clones of the parasite, established by micromanipulation, representing the two most frequent genotypes. Clones of both genotypes caused the maximum score of virulence at day 3 post-inoculation in LMH cells, although significant higher cytopathogenic score was found in ITS-OBT-Tg-1 genotype clones at days 1 and 2, as compared to clones with ITS-OBT-Tg-2. By using one representative clone of each genotype, a comparative proteomic analysis of the membrane proteins enriched fraction has been carried out by a label free approach (Data available via ProteomeXchange: PXD013115). The analysis resulted in 302 proteins of varying abundance. In the clone with the highest initial virulence, proteins related to cell adhesion, such as an immuno-dominant variable surface antigen, a GP63-like protein, an armadillo/beta-catenin-like repeat protein were found more abundant. Additionally, Ras superfamily proteins and calmodulins were more abundant, which might be related to an increased activity in the cytoskeleton re-organization. On the contrary, in the clone with the lowest initial virulence, larger numbers of the identified proteins were related to the carbohydrate metabolism. The results of the present work deliver substantial differences between both clones that could be related to feeding processes and morphological changes, similarly to the closely related pathogen Trichomonas vaginalis.
Collapse
|
15
|
Santos N, Jambas J, Monteiro A, Amaral J, Martins N, Garcia J, Fernández AM, Tyler KM, Almeida T, Abrantes J, Esteves PJ. Trichomonas Infection in a Community of Free-Ranging Domestic and Wild Columbiformes and Bonelli's Eagle ( Aquila fasciata). Front Vet Sci 2019; 6:148. [PMID: 31192234 PMCID: PMC6549518 DOI: 10.3389/fvets.2019.00148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/29/2019] [Indexed: 11/13/2022] Open
Abstract
Trichomonas gallinae is a pathogen of conservation relevance, whose main maintenance hosts are Columbiformes, but spillover to avian predators has been described. The goal of this study was to characterize the epidemiology of Trichomonas spp. in a community of free-ranging domestic and wild Columbiformes and an endangered predator, Bonelli's eagle Aquila fasciata. We surveyed 253 live-captured Rock doves, 16 nestling Bonelli's eagles and 41 hunted Columbiformes. Oro-esophageal swabs were incubated in culture media and Trichomonas spp. isolated from Bonelli's eagle (6.3%, CI95 1.1-28.3), Turtle dove Streptopelia turtur (56.3%, CI95 39.3-71.8), Wood pigeon Columba palumbus (83.3%, CI95 43.7-97.0) and Rock dove Columba livia (68.4%, CI95 62.4-73.8). Infected Rock doves showed significantly poorer body condition than uninfected ones (p = 0.022). From a subset of 32 isolates, 18S and ITS1/5.8S/ITS2 rRNA genes were sequenced and Maximum-Likelihood trees inferred. Four ribotypes of Trichomonas spp. were identified. In this study area Trichomonas spp. seem to persist in a multi-host system involving several species of Columbiformes. Conservation actions aimed at increasing the availability of trophic resources for Bonelli's eagles through Rock dove restocking should consider the risk of pathogen transmission and of introduction of alien strains.
Collapse
Affiliation(s)
- Nuno Santos
- CIBIO/InBio-Research Center in Biodiversity and Genetic Resources, Universidade do Porto, Vairão, Portugal
| | - José Jambas
- Oriolus Ambiente Ecoturismo Lda, Atenor, Portugal
| | - António Monteiro
- Parque Natural do Douro Internacional, Instituto de Conservação da Natureza e Florestas I.P., Mogadouro, Portugal
| | - Jorge Amaral
- Parque Natural do Douro Internacional, Instituto de Conservação da Natureza e Florestas I.P., Mogadouro, Portugal
| | - Nuno Martins
- Palombar-Associação para a Conservação da Natureza e do Património Rural, Uva, Portugal
| | - Javier Garcia
- Department of Biodiversity and Environmental Management, University of León, León, Spain
| | | | - Kevin Morris Tyler
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Tereza Almeida
- CIBIO/InBio-Research Center in Biodiversity and Genetic Resources, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Joana Abrantes
- CIBIO/InBio-Research Center in Biodiversity and Genetic Resources, Universidade do Porto, Vairão, Portugal
| | - Pedro J Esteves
- CIBIO/InBio-Research Center in Biodiversity and Genetic Resources, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| |
Collapse
|
16
|
Chavatte JM, Giraud P, Esperet D, Place G, Cavalier F, Landau I. An outbreak of trichomonosis in European greenfinches Chloris chloris and European goldfinches Carduelis carduelis wintering in Northern France. ACTA ACUST UNITED AC 2019; 26:21. [PMID: 30957740 PMCID: PMC6452646 DOI: 10.1051/parasite/2019022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/26/2019] [Indexed: 11/21/2022]
Abstract
Avian trichomonosis is a common and widespread disease, traditionally affecting columbids and raptors, and recently emerging among finch populations mainly in Europe. Across Europe, finch trichomonosis is caused by a single clonal strain of Trichomonas gallinae and negatively impacts finch populations. Here, we report an outbreak of finch trichomonosis in the wintering populations of Chloris chloris (European greenfinch) and Carduelis carduelis (European goldfinch) from the Boulonnais, in northern France. The outbreak was detected and monitored by bird ringers during their wintering bird ringing protocols. A total of 105 records from 12 sites were collected during the first quarter of 2017, with 46 and 59 concerning dead and diseased birds, respectively. Fourteen carcasses from two locations were necropsied and screened for multiple pathogens; the only causative agent identified was T. gallinae. Genetic characterization was performed by four markers (small subunit ribosomal RNA, hydrogenosomal iron-hydrogenase, and RNA polymerase II subunit 1 genes, and the internal transcribed spacers (ITS) region) and confirmed the T. gallinae strain to be A1, which affects the finch populations of Europe. This was also confirmed by an ITS-based phylogenetic analysis which further illustrated the diversity of the Trichomonas infecting birds. Preliminary data on the survival and dispersion of infected birds were obtained from ring-returns of diseased individuals. The anthropogenic spread of diseases through bird feeding practices is highlighted and some suggestions to prevent pathogen transmission via backyard supplementary feeders for garden birds are given.
Collapse
Affiliation(s)
- Jean-Marc Chavatte
- UMR 7245 MCAM MNHN CNRS, Muséum National d'Histoire Naturelle, 61 rue Buffon, CP52, 75231 Paris Cedex 05, France - Cap-Ornis Baguage, 10 Rue de la Maladrerie, 59181 Steenwerck, France
| | - Philippe Giraud
- Laboratoire Départemental d'Analyse du Pas-de-Calais (LDA 62), 2 Rue du Genévrier, SP18, 62022 Arras Cedex, France
| | - Delphine Esperet
- Laboratoire Labéo Manche, 1352 Avenue de Paris, CS 33608, 50008 Saint-Lô Cedex, France
| | - Grégory Place
- Cap-Ornis Baguage, 10 Rue de la Maladrerie, 59181 Steenwerck, France
| | - François Cavalier
- Cap-Ornis Baguage, 10 Rue de la Maladrerie, 59181 Steenwerck, France
| | - Irène Landau
- UMR 7245 MCAM MNHN CNRS, Muséum National d'Histoire Naturelle, 61 rue Buffon, CP52, 75231 Paris Cedex 05, France
| |
Collapse
|
17
|
Purple K, Amacker T, Williams C, Gerhold R. Artificially decreased dissolved oxygen increases the persistence of Trichomonas gallinae in water. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 9:100-103. [PMID: 31011532 PMCID: PMC6463543 DOI: 10.1016/j.ijppaw.2019.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 11/30/2022]
Abstract
Water containing organic material has been shown to increase the persistence of the avian pathogenic protozoa, Trichomonas gallinae. We hypothesized that the decrease in dissolved oxygen due to microbes in the organic material could increase persistence of the microaerophilic trichomonads. Using simulated birdbaths, we determined 1) the levels of dissolved oxygen in distilled water with various amounts of organic material, 2) the concentration of the oxygen-scavenging enzyme Oxyrase® needed to achieve the dissolved oxygen levels obtained in organic material contaminated water, and finally, 3) the persistence of two T. gallinae isolates in Oxyrase®-supplemented water. An average of 9.6% dissolved oxygen was obtained with the addition of 15 g organic material to 500 ml of distilled water, whereas organic material-free water had 86.2% dissolved oxygen. The addition of 0.5% and 1.0% (vol/vol) Oxyrase® to organic material-free water yielded dissolved oxygen of 18.6% and 6.9%, respectively. Using 0.5% and 1.0% concentrations of Oxyrase®, we evaluated the persistence of two trichomonad isolates by inoculating ∼1 million trichomonads into 500 ml distilled water in triplicate. At various time-points, 0.5 ml aliquots of trichomonad-inoculated water were obtained and placed into Hollander Fluid media, incubated at 37 °C, and read by light microscopy every other day for 5 days. In our 1% Oxyrase® treatments, the longest recorded persistence of broad-winged hawk 1 increased from the previously reported 4hrs to 30hrs and Cooper's hawk 4 from 16hrs to 30hrs. These results indicate that the mechanism for organic material-mediated trichomonad persistence is associated with decreased dissolved oxygen, further demonstrating the importance of keeping birdbaths free of organic debris to discourage trichomonad persistence. Low (9.6%) dissolved oxygen (DO) levels were achieved in waterers with addition of organic material (OM). Addition of 1% Oxyrase resulted in similar DO findings (6.9%) with a pH of 7.24 Lower DO is likely mechanism of increased Trichomonas gallinae persistence in waterers with OM. Results underscore the need to keep bird waterers clean to minimize T. gallinae transmission.
Collapse
Affiliation(s)
- Kathryn Purple
- Comparative and Experimental Medicine, University of Tennessee College of Veterinary Medicine, 2407 River Drive, Knoxville, TN, 37996, USA.,Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, 2407 River Drive, Knoxville, TN, 37996, USA
| | - Todd Amacker
- Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, 274 Ellington Plant Sciences Building, Knoxville, TN, 37996, USA
| | - Chauntelle Williams
- Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, 274 Ellington Plant Sciences Building, Knoxville, TN, 37996, USA
| | - Richard Gerhold
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, 2407 River Drive, Knoxville, TN, 37996, USA.,Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, 274 Ellington Plant Sciences Building, Knoxville, TN, 37996, USA
| |
Collapse
|
18
|
Lawson B, Robinson RA, Toms MP, Risely K, MacDonald S, Cunningham AA. Health hazards to wild birds and risk factors associated with anthropogenic food provisioning. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531146 PMCID: PMC5882997 DOI: 10.1098/rstb.2017.0091] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Provision of supplementary food for wild birds at garden feeding stations is a common, large-scale and year-round practice in multiple countries including Great Britain (GB). While these additional dietary resources can benefit wildlife, there is a concomitant risk of disease transmission, particularly when birds repeatedly congregate in the same place at high densities and through interactions of species that would not normally associate in close proximity. Citizen science schemes recording garden birds are popular and can integrate disease surveillance with population monitoring, offering a unique opportunity to explore inter-relationships between supplementary feeding, disease epidemiology and population dynamics. Here, we present findings from a national surveillance programme in GB and note the dynamism of endemic and emerging diseases over a 25-year period, focusing on protozoal (finch trichomonosis), viral (Paridae pox) and bacterial (passerine salmonellosis) diseases with contrasting modes of transmission. We also examine the occurrence of mycotoxin contamination of food residues in bird feeders, which present both a direct and indirect (though immunosuppression) risk to wild bird health. Our results inform evidence-based mitigation strategies to minimize anthropogenically mediated health hazards, while maintaining the benefits of providing supplementary food for wild birds.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
Collapse
Affiliation(s)
- Becki Lawson
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Robert A Robinson
- British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK
| | - Mike P Toms
- British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK
| | - Kate Risely
- British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK
| | - Susan MacDonald
- Fera Science Ltd, National Agri-Food Innovation Campus, Sand Hutton, York YO41 1LZ, UK
| | - Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| |
Collapse
|
19
|
Oropharyngeal Trichomonosis Due to Trichomonas gypaetinii in a Cinereous Vulture (Aegypius monachus) Fledgling in Spain. J Wildl Dis 2019; 55:153-157. [DOI: 10.7589/2017-11-274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
20
|
Endemic infection of the common mynah Acridotheres tristis with Trichomonas gallinae the agent of avian trichomonosis. Parasitology 2018; 145:1548-1552. [DOI: 10.1017/s0031182018000513] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
AbstractAvian trichomonosis is an architypal disease of wild columbids and those birds that predate them. Increasingly though, it has been reported in passerines; a recent and ongoing epidemic in the chaffinches and greenfinches of Europe and outbreaks amongst house finches, American goldfinches and purple finches in North America. The parasite, Trichomonas gallinae, causes lesions in the upper respiratory tract which can cause mortality associated with dehydration and emaciation. This paper reports for the first time, the widespread, endemic and often asymptomatic infection of common mynah (Acridotheres tristis) around the Faisalabad District, Pakistan. Parasite typing was used to investigate the potential for transmission among the frequently sympatric species. Type C parasites were found in mynah, and while this is analagous to the pandemic finch strain which is Type A, it is the first known example of passerine infections of this parasite genotype. Subtype analysis showed the strain to be C4 a subtype which has a widespread distribution in columbids.
Collapse
|
21
|
Martínez-Herrero M, Garijo-Toledo M, Liebhart D, Ganas P, Martínez-Díaz R, Ponce-Gordo F, Carrero-Ruiz A, Hess M, Gómez-Muñoz M. Novel avian oropharyngeal trichomonads isolated from European turtle doves ( Streptopelia turtur ) and racing pigeons ( Columba livia ): genetic and morphometric characterisation of clonal cultures. INFECTION GENETICS AND EVOLUTION 2017; 55:93-103. [DOI: 10.1016/j.meegid.2017.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 07/09/2017] [Accepted: 08/28/2017] [Indexed: 11/16/2022]
|
22
|
Marx M, Reiner G, Willems H, Rocha G, Hillerich K, Masello JF, Mayr SL, Moussa S, Dunn JC, Thomas RC, Goodman SJ, Hamer KC, Metzger B, Cecere JG, Spina F, Koschkar S, Calderón L, Romeike T, Quillfeldt P. High prevalence of Trichomonas gallinae in wild columbids across western and southern Europe. Parasit Vectors 2017; 10:242. [PMID: 28521843 PMCID: PMC5437606 DOI: 10.1186/s13071-017-2170-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 05/03/2017] [Indexed: 11/04/2022] Open
Abstract
Background Avian trichomonosis is known as a widespread disease in columbids and passerines, and recent findings have highlighted the pathogenic character of some lineages found in wild birds. Trichomonosis can affect wild bird populations including endangered species, as has been shown for Mauritian pink pigeons Nesoenas mayeri in Mauritius and suggested for European turtle doves Streptopelia turtur in the UK. However, the disease trichomonosis is caused only by pathogenic lineages of the parasite Trichomonas gallinae. Therefore, understanding the prevalence and distribution of both potentially pathogenic and non-pathogenic T. gallinae lineages in turtle doves and other columbids across Europe is relevant to estimate the potential impact of the disease on a continental scale. Results We examined 281 samples from four wild columbid species for Trichomonas infection and determined the genetic lineages. The overall prevalence was 74%. There were significant differences between the species (P = 0.007). The highest prevalence was found in stock doves Columba oenas (86%, n = 79) followed by wood pigeons Columba palumbus (70%, n = 61) and turtle doves (67%, n = 65), while three of five collared doves Streptopelia decaocto (60%) were infected. We found seven different lineages, including four lineages present in columbids in the UK, one lineage already described from Spain and three new lineages, one of those found in a single turtle dove migrating through Italy and another one found in a breeding stock dove. Stock doves from Germany and collared doves from Malta were infected with a potentially pathogenic lineage (lineage A/B), which is known to cause lesions and mortality in columbids, raptors and finches. Conclusions Generally, turtle doves showed high prevalence of Trichomonas infection. Furthermore, the potentially pathogenic lineage A/B (or genotype B according to previous literature) was found in a recovering stock dove population. Both findings are worrying for these columbid species due to the occasional epidemic character of trichomonosis, which can have severe negative effects on populations. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2170-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Melanie Marx
- Department of Animal Ecology & Systematics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany.
| | - Gerald Reiner
- Department of Clinical Veterinary Sciences, Justus-Liebig-University, Frankfurter Strasse 112, 35392, Giessen, Germany
| | - Hermann Willems
- Department of Clinical Veterinary Sciences, Justus-Liebig-University, Frankfurter Strasse 112, 35392, Giessen, Germany
| | - Gregorio Rocha
- Department of Agro-forestry Engineering, University of Extremadura, Avda. Virgen del Puerto 2, 10600, Plasencia, Cáceres, Spain
| | | | - Juan F Masello
- Department of Animal Ecology & Systematics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Sylvia L Mayr
- Department of Clinical Veterinary Sciences, Justus-Liebig-University, Frankfurter Strasse 112, 35392, Giessen, Germany
| | - Sarah Moussa
- Department of Animal Ecology & Systematics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Jenny C Dunn
- School of Life Sciences, University of Lincoln, Joseph Banks Laboraties, Lincoln, LN6 7TS, UK
| | - Rebecca C Thomas
- School of Biology, Irene Manton Building, University of Leeds, Leeds, LS2 9JT, UK
| | - Simon J Goodman
- School of Biology, Irene Manton Building, University of Leeds, Leeds, LS2 9JT, UK
| | - Keith C Hamer
- School of Biology, Irene Manton Building, University of Leeds, Leeds, LS2 9JT, UK
| | - Benjamin Metzger
- BirdLife Malta, Xemxija Waterfront Apartments, Flat 1/2, Triq Is-Simar, Xemxija, St Paul's Bay, SPB 9025, Malta
| | - Jacopo G Cecere
- ISPRA, Institute for Environmental Protection and Research, Via Ca' Fornacetta 9, 40064, Ozzano Dell'Emilia, BO, Italy
| | - Fernando Spina
- ISPRA, Institute for Environmental Protection and Research, Via Ca' Fornacetta 9, 40064, Ozzano Dell'Emilia, BO, Italy
| | | | - Luciano Calderón
- Department of Animal Ecology & Systematics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Tanja Romeike
- Department of Animal Ecology & Systematics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Petra Quillfeldt
- Department of Animal Ecology & Systematics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| |
Collapse
|
23
|
Zadravec M, Slavec B, Krapež U, Gombač M, Švara T, Poljšak-Prijatelj M, Gruntar I, Račnik J. Trichomonosis outbreak in a flock of canaries (Serinus canaria f. domestica) caused by a finch epidemic strain of Trichomonas gallinae. Vet Parasitol 2017; 239:90-93. [PMID: 28413077 DOI: 10.1016/j.vetpar.2017.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 03/20/2017] [Accepted: 04/01/2017] [Indexed: 11/19/2022]
Abstract
In the present paper, an outbreak of trichomonosis in a flock of 15 breeding pairs of canaries is described. Trichomonosis was diagnosed on characteristic clinical signs, microscopic examination of crop/esophageal swabs, gross pathology and histopathology. Trichomonads were successfully grown in culture media and were characterized by multi-locus sequence typing. The three genomic loci ITS1-5.8S-ITS2, 18S rRNA and Fe-hydrogenase were analyzed. Molecular characterization confirmed the finch trichomonosis strain, identical to the strain that caused emerging disease in free-living passerine birds in Europe. Flock treatment with metronidazole (200mg/L) in drinking water for 5days was partially effective. After individual treatment with oral application of metronidazole (20mg/kg SID) for 5days no further clinical signs were observed in the flock over next 30 months.
Collapse
Affiliation(s)
- Marko Zadravec
- Veterinary Faculty, Institute of Poultry, Birds, Small Mammals and Reptiles, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| | - Brigita Slavec
- Veterinary Faculty, Institute of Poultry, Birds, Small Mammals and Reptiles, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| | - Uroš Krapež
- Veterinary Faculty, Institute of Poultry, Birds, Small Mammals and Reptiles, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| | - Mitja Gombač
- Veterinary Faculty, Institute of Pathology, Wildlife, Fish and Bees, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| | - Tanja Švara
- Veterinary Faculty, Institute of Pathology, Wildlife, Fish and Bees, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| | - Mateja Poljšak-Prijatelj
- Faculty of Medicine, Institute of Microbiology and Immunology, Zaloška 4, 1000 Ljubljana, Slovenia.
| | - Igor Gruntar
- Veterinary Faculty, Institute of Microbiology and Parasitology, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| | - Joško Račnik
- Veterinary Faculty, Institute of Poultry, Birds, Small Mammals and Reptiles, Gerbičeva 60, 1000 Ljubljana, Slovenia.
| |
Collapse
|
24
|
RAPD analysis and sequencing of ITS1/5.8S rRNA/ITS2 and Fe-hydrogenase as tools for genetic classification of potentially pathogenic isolates of Trichomonas gallinae. Res Vet Sci 2016; 107:182-189. [DOI: 10.1016/j.rvsc.2016.05.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/14/2016] [Accepted: 05/30/2016] [Indexed: 11/20/2022]
|
25
|
Detection of the European epidemic strain of Trichomonas gallinae in finches, but not other non-columbiformes, in the absence of macroscopic disease. Parasitology 2016; 143:1294-300. [PMID: 27180976 DOI: 10.1017/s0031182016000780] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Finch trichomonosis is an emerging infectious disease affecting European passerines caused by a clonal strain of Trichomonas gallinae. Migrating chaffinches (Fringilla coelebs) were proposed as the likely vector of parasite spread from Great Britain to Fennoscandia. To test for such parasite carriage, we screened samples of oesophagus/crop from 275 Apodiform, Passeriform and Piciform birds (40 species) which had no macroscopic evidence of trichomonosis (i.e. necrotic ingluvitis). These birds were found dead following the emergence of trichomonosis in Great Britain, 2009-2012, and were examined post-mortem. Polymerase chain reactions were used to detect (ITS1/5·8S rRNA/ITS2 region and single subunit rRNA gene) and to subtype (Fe-hydrogenase gene) T. gallinae. Trichomonas gallinae was detected in six finches [three chaffinches, two greenfinches (Chloris chloris) and a bullfinch (Pyrrhula pyrrhula)]. Sequence data had 100% identity to the European finch epidemic A1 strain for each species. While these results are consistent with finches being vectors of T. gallinae, alternative explanations include the presence of incubating or resolved T. gallinae infections. The inclusion of histopathological examination would help elucidate the significance of T. gallinae infection in the absence of macroscopic lesions.
Collapse
|
26
|
Zadravec M, Trilar T, Slavec B, Gruntar I, Račnik J. No evidence of Trichomonas gallinae in free-living non-fringilid passerine birds in Slovenia. EUR J WILDLIFE RES 2016. [DOI: 10.1007/s10344-016-0998-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
27
|
Kunca T, Smejkalova P, Cepicka I. Trichomonosis in Eurasian sparrowhawks in the Czech Republic. Folia Parasitol (Praha) 2015. [PMID: 26198549 DOI: 10.14411/fp.2015.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Tomas Kunca
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Pavla Smejkalova
- Faculty of Science, Department of Zoology, Charles University in Prague, Prague, Czech Republic
| | - Ivan Cepicka
- Faculty of Science, Department of Zoology, Charles University in Prague, Prague, Czech Republic
| |
Collapse
|
28
|
Liebhart D, Neale S, Garcia-Rueda C, Wood AM, Bilic I, Wernsdorf P, Jaskulska B, Hess M. A single strain of Tetratrichomonas gallinarum causes fatal typhlohepatitis in red-legged partridges (Alectoris rufa) to be distinguished from histomonosis. Avian Pathol 2015; 43:473-80. [PMID: 25175532 DOI: 10.1080/03079457.2014.959435] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Typhlohepatitis was observed in a flock of 2500 red-legged partridges in Great Britain, characterized by the sudden deaths of 15 birds within 2 days. Necropsy of five dead birds revealed severe lesions in the caeca with thickened caecal walls, a reddened lining and bloody contents. The livers contained multiple miliary lesions and similar pathological changes were found in the spleens of some birds. Microscopic examination of intestinal contents showed the occurrence of coccidial oocysts in two partridges. Different methods for the detection of bacteria from liver and intestine samples were conducted without positive results. Histopathological examination revealed the presence of protozoan parasites in the caecum, liver and spleen of the affected birds. In situ hybridization (ISH) for the detection of trichomonads resulted in positive findings and polymerase chain reaction (PCR) confirmed the presence of Tetratrichomonas gallinarum in the lesions. Additionally, archived tissues of red-legged partridges from different flocks suffering from severe typhlohepatitis in Great Britain in 2008 and 2009 were re-investigated by ISH and PCR. Beside the sporadic occurrence of histomonosis, in most of the cases trichomonads were detected by ISH in the caecum and liver of affected birds. Furthermore, dissemination of the flagellate into the lung and bursa of Fabricius could be demonstrated. Analyses of T. gallinarum DNA obtained from the different cases resulted in homologous nucleotide sequences. Altogether, the results demonstrate the circulation of a virulent strain of T. gallinarum in reared red-legged partridges.
Collapse
Affiliation(s)
- D Liebhart
- a Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health , University of Veterinary Medicine , Vienna , Austria
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Molecular characterization of Trichomonas gallinae isolates recovered from the Canadian Maritime provinces’ wild avifauna reveals the presence of the genotype responsible for the European finch trichomonosis epidemic and additional strains. Parasitology 2015; 142:1053-62. [DOI: 10.1017/s0031182015000281] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SUMMARYFinch trichomonosis, caused by Trichomonas gallinae, emerged in the Canadian Maritime provinces in 2007 and has since caused ongoing mortality in regional purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) populations. Trichomonas gallinae was isolated from (1) finches and rock pigeons (Columbia livia) submitted for post-mortem or live-captured at bird feeding sites experiencing trichomonosis mortality; (2) bird seed at these same sites; and (3) rock pigeons live-captured at known roosts or humanely killed. Isolates were characterized using internal transcribed spacer (ITS) region and iron hydrogenase (Fe-hyd) gene sequences. Two distinct ITS types were found. Type A was identical to the UK finch epidemic strain and was isolated from finches and a rock pigeon with trichomonosis; apparently healthy rock pigeons and finches; and bird seed at an outbreak site. Type B was obtained from apparently healthy rock pigeons. Fe-hyd sequencing revealed six distinct subtypes. The predominant subtype in both finches and the rock pigeon with trichomonosis was identical to the UK finch epidemic strain A1. Single nucleotide polymorphisms in Fe-hyd sequences suggest there is fine-scale variation amongst isolates and that finch trichomonosis emergence in this region may not have been caused by a single spill-over event.
Collapse
|
30
|
Martínez-Herrero MC, Sansano-Maestre J, López Márquez I, Obón E, Ponce C, González J, Garijo-Toledo MM, Gómez-Muñoz MT. Genetic characterization of oropharyngeal trichomonad isolates from wild birds indicates that genotype is associated with host species, diet and presence of pathognomonic lesions. Avian Pathol 2014; 43:535-46. [DOI: 10.1080/03079457.2014.967660] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
31
|
Trichomonas gypaetinii n. sp., a new trichomonad from the upper gastrointestinal tract of scavenging birds of prey. Parasitol Res 2014; 114:101-12. [DOI: 10.1007/s00436-014-4165-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 09/23/2014] [Indexed: 10/24/2022]
|
32
|
The protozoan parasite Trichomonas gallinae causes adult and nestling mortality in a declining population of European Turtle Doves, Streptopelia turtur. Parasitology 2014; 142:490-8. [DOI: 10.1017/s0031182014001474] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SUMMARYStudies incorporating the ecology of clinical and sub-clinical disease in wild populations of conservation concern are rare. Here we examine sub-clinical infection by Trichomonas gallinae in a declining population of free-living European Turtle Doves and suggest caseous lesions cause mortality in adults and nestlings through subsequent starvation and/or suffocation. We found a 100% infection rate by T. gallinae in adult and nestling Turtle Doves (n = 25) and observed clinical signs in three adults and four nestlings (28%). Adults with clinical signs displayed no differences in any skeletal measures of size but had a mean 3·7% reduction in wing length, with no overlap compared to those without clinical signs. We also identified T. gallinae as the suggested cause of mortality in one Red-legged Partridge although disease presentation was different. A minimum of four strains of T. gallinae, characterized at the ITS/5·8S/ITS2 ribosomal region, were isolated from Turtle Doves. However, all birds with clinical signs (Turtle Doves and the Red-legged Partridge) carried a single strain of T. gallinae, suggesting that parasite spill over between Columbidae and Galliformes is a possibility that should be further investigated. Overall, we highlight the importance of monitoring populations for sub-clinical infection rather than just clinical disease.
Collapse
|