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Alstedt U, Voigt K, Jäger MC, Knubben-Schweizer G, Zablotski Y, Strube C, Wenzel C. Rumen and Liver Fluke Infections in Sheep and Goats in Northern and Southern Germany. Animals (Basel) 2022; 12:ani12070876. [PMID: 35405863 PMCID: PMC8997043 DOI: 10.3390/ani12070876] [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: 02/17/2022] [Revised: 03/18/2022] [Accepted: 03/29/2022] [Indexed: 01/27/2023] Open
Abstract
Simple Summary Little is known about the distribution of rumen and liver flukes in sheep and goats in Germany or about the occurring rumen fluke species. These fluke infections can be detected by the parasite’s eggs in the host animal’s feces. Therefore, fecal samples from 223 sheep farms and 143 goat farms from northern and southern Germany were examined. The eggs of rumen flukes were detected on 2.2% of the samples, the eggs of common liver flukes on 2.7%, and the eggs of small liver flukes on 21.1% of the examined sheep farms. The rumen flukes were identified as the emerging species Calicophoron daubneyi. No rumen fluke eggs were detected on any of the goat farm samples, but common and small liver fluke eggs were detected in 5.6% and 7.0% of the goat herds, respectively. Differences in the geographical distribution of rumen and liver flukes between and within the two regions were identified. Rumen flukes were more frequently found in the north, while the two liver fluke species were more frequently found in the south of Germany. Sheep sharing the pasture with other ruminants were more likely to be infected with rumen flukes. Abstract Paramphistomidosis has recently been identified as an emerging parasitosis in Europe. This study estimated the prevalence of rumen flukes, Fasciola hepatica and Dicrocoelium dendriticum, in small ruminants in Germany and identified occurring rumen fluke species and potential predictors for fluke infections. Pooled fecal samples from 223 sheep farms and 143 goat farms in northern and southern Germany were examined by the sedimentation technique, and molecular species identification was performed on rumen-fluke-positive samples. In sheep, a flock prevalence of 2.2% was detected for rumen flukes. Calicophoron daubneyi was identified on four of five positive farms, while species identification failed in one flock. No rumen fluke eggs were detected in the examined goat herds. F. hepatica eggs were detected in 2.7% of the sheep flocks, while the herd prevalence was 5.6% in goats. Higher prevalence values of 21.1% (sheep) and 7.0% (goats) were observed for D. dendriticum. Mixed grazing with other ruminants and previously identified infections with rumen flukes and/or F. hepatica were identified as predictors for paramphistomidosis. The distribution of the three trematode species followed a geographical pattern associated with conditions favoring the relevant intermediate hosts. C. daubneyi is an established parasite in German sheep at a currently low prevalence.
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Affiliation(s)
- Uta Alstedt
- Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (U.A.); (K.V.); (G.K.-S.); (Y.Z.)
| | - Katja Voigt
- Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (U.A.); (K.V.); (G.K.-S.); (Y.Z.)
| | | | - Gabriela Knubben-Schweizer
- Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (U.A.); (K.V.); (G.K.-S.); (Y.Z.)
| | - Yury Zablotski
- Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (U.A.); (K.V.); (G.K.-S.); (Y.Z.)
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
| | - Christoph Wenzel
- Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, 85764 Oberschleissheim, Germany; (U.A.); (K.V.); (G.K.-S.); (Y.Z.)
- Correspondence:
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Kahl A, von Samson-Himmelstjerna G, Krücken J, Ganter M. Chronic Wasting Due to Liver and Rumen Flukes in Sheep. Animals (Basel) 2021; 11:549. [PMID: 33669891 PMCID: PMC7923292 DOI: 10.3390/ani11020549] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 12/14/2022] Open
Abstract
Grazing sheep and goats are constantly exposed to helminth infections in many parts of the world, including several trematode species that causes a range of clinical diseases. The clinical picture of flukes is dependent upon the organs in which they develop and the tissues they damage within the respective organs. Accordingly, infections with the common liver fluke Fasciola hepatica, which, as juvenile worm migrates through the liver parenchyma for several weeks, may be associated with hepatic disorders such as impairment of carbohydrate, protein and fat metabolism, followed by chronic wasting. In contrast, the lancet fluke Dicrocoelium dendriticum, which does not exhibit tissue migration and thus does not lead to major tissue damage and bleeding, also does not lead to significant clinical symptoms. Rumen flukes such as Cotylophoron daubneyi cause catarrhal inflammation during their migration through the intestinal and abomasal epithelium during its juvenile stages. Depending on the infection intensity this may result in a range of clinical symptoms including diarrhoea, inappetence or emaciation. In this review, we aim to provide an update on the current knowledge on flukes particularly concerning the clinical relevance of the most important fluke species in sheep.
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Affiliation(s)
- Alexandra Kahl
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin, Germany; (G.v.S.-H.); (J.K.)
| | - Georg von Samson-Himmelstjerna
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin, Germany; (G.v.S.-H.); (J.K.)
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin, Germany; (G.v.S.-H.); (J.K.)
| | - Martin Ganter
- Clinic for Swine and Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173 Hannover, Germany;
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Martinez-Ibeas AM, Munita MP, Lawlor K, Sekiya M, Mulcahy G, Sayers R. Rumen fluke in Irish sheep: prevalence, risk factors and molecular identification of two paramphistome species. BMC Vet Res 2016; 12:143. [PMID: 27430977 PMCID: PMC4950795 DOI: 10.1186/s12917-016-0770-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 07/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rumen flukes are trematode parasites found globally; in tropical and sub-tropical climates, infection can result in paramphistomosis, which can have a deleterious impact on livestock. In Europe, rumen fluke is not regarded as a clinically significant parasite, recently however, the prevalence of rumen fluke has sharply increased and several outbreaks of clinical paramphistomosis have been reported. Gaining a better understanding of rumen fluke transmission and identification of risk factors is crucial to improve the control of this parasitic disease. In this regard, a national prevalence study of rumen fluke infection and an investigation of associated risk factors were conducted in Irish sheep flocks between November 2014 and January 2015. In addition, a molecular identification of the rumen fluke species present in Ireland was carried out using an isolation method of individual eggs from faecal material coupled with a PCR. After the DNA extraction of 54 individual eggs, the nuclear fragment ITS-2 was amplified and sequenced using the same primers. RESULTS An apparent herd prevalence of 77.3 % was determined. Several risk factors were identified including type of pasture grazed, regional variation, and sharing of the paddocks with other livestock species. A novel relationship between the Suffolk breed and higher FEC was reported for the first time. The predominant rumen fluke species found was C. daubneyi. Nevertheless, P. leydeni was unexpectedly identified infecting sheep in Ireland for the first time. CONCLUSIONS An exceptionally high prevalence of rumen fluke among Irish sheep flocks has been highlighted in this study and a more thorough investigation is necessary to analyse its economic impact. The isolation of individual eggs coupled with the PCR technique used here has proven a reliable tool for discrimination of Paramphistomum spp. This technique may facilitate forthcoming studies of the effects of paramphistomosis on livestock production. The most noteworthy finding was the identification of P. leydeni affecting sheep in Ireland, however further studies are required to clarify its implications. Also, a significant relationship between Suffolk breed and a heavier infection was found, which can be used as a starting point for future research on control strategies of rumen fluke infection.
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Affiliation(s)
- Ana Maria Martinez-Ibeas
- Animal and Biosciences Department, Animal & Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
| | - Maria Pia Munita
- Animal and Biosciences Department, Animal & Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland
| | - Kim Lawlor
- School of Veterinary Medicine UCD, Belfield, Dublin, Ireland
| | - Mary Sekiya
- School of Veterinary Medicine UCD, Belfield, Dublin, Ireland
| | - Grace Mulcahy
- School of Veterinary Medicine UCD, Belfield, Dublin, Ireland
| | - Riona Sayers
- Animal and Biosciences Department, Animal & Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland
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Evaluation of antibody response to various developmental stage specific somatic antigens of Paramphistomum epiclitum in goats. BIOMED RESEARCH INTERNATIONAL 2014; 2014:505484. [PMID: 24995303 PMCID: PMC4065726 DOI: 10.1155/2014/505484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 11/18/2022]
Abstract
Electrophoretic analysis of various developmental stage specific somatic antigens of Paramphistomum epiclitum (Digenea: Paramphistomidae), namely, metacercariae (McAg), immature intestinal flukes (ImIAg), immature ruminal flukes (ImRAg), and adult flukes (AAg), was done by native polyacrylamide gel electrophoresis. Result revealed presence of 3 (range 15.2-40.3 kDa), 13 (9.3-121.2 kDa), 14 (9.3-169.3 kDa), and 15 (8.0-169.3 kDa) polypeptides in McAg, ImIAg, ImRAg, and AAg, respectively. With an aim to identify a suitable immunodiagnostic antigen for early diagnosis of amphistomosis, the IgG antibody response to various developmental stage antigens in goats experimentally infected with metacercariae of P. epiclitum was evaluated by ELISA. The highest OD values were recorded with ImIAg which ranged between 0.23 and 0.55 with a significant increase from the 2nd week till 8th week of infection with a peak at 6th week. The analysis of statistical significance using a one-way analysis of variance with multiple pair wise comparisons revealed that IgG response was significantly higher with all antigens (P < 0.01) except McAg (P > 0.05) with a maximum mean difference of 0.1838 in comparison to control with ImIAg, thus, indicating that ImIAg which could be further exploited for its potential is a candidate for immunodiagnostic antigen for early diagnosis of amphistomosis.
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Ferreras MC, González-Lanza C, Pérez V, Fuertes M, Benavides J, Mezo M, González-Warleta M, Giráldez J, Martínez-Ibeas AM, Delgado L, Fernández M, Manga-González MY. Calicophoron daubneyi (Paramphistomidae) in slaughtered cattle in Castilla y León (Spain). Vet Parasitol 2014; 199:268-71. [DOI: 10.1016/j.vetpar.2013.10.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/23/2013] [Accepted: 10/27/2013] [Indexed: 11/26/2022]
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Sanabria R, Titi A, Mekroud A, Vignoles P, Dreyfuss G, Rondelaud D, Romero J. Paramphistomum daubneyi: characteristics of infection in three lymnaeid species. Parasite 2012. [PMID: 23193532 PMCID: PMC3671451 DOI: 10.1051/parasite/2012194445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Experimental infections of two South American lymnaeids (Lymnaea neotropica and L. viatrix var. ventricosa) with Paramphistomum daubneyi were carried out to determine if these snail species could sustain larval development of this digenean and, if so, to specify their potential for cercarial production. A French population of Galba truncatula infected and raised according to the same protocol served as controls. In both experiments, prevalence of P. daubneyi infections in snails did not significantly differ from each other. In snail groups evaluated for cercarial shedding (first experiment), a significantly lower number of shed cercariae was noted for L. neotropica, while those from G. truncatula and L. v. ventricosa did not differ significantly from each other. Dissection of infected snails at day 65 post-exposure at 20 °C (second experiment) found significantly lower burdens of P. daubneyi rediae and cercariae in the bodies of L. neotropica than in those of G. truncatula and L. v. ventricosa. Compared to total cercarial production observed in dissected snails, the percentage of cercariae which exited from snails was 75.6% for G. truncatula, 21.6% for L. neotropica, and 91.4% for L. v. ventricosa. This last species seems to be a good candidate for metacercarial production of P. daubneyi.
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Affiliation(s)
- R Sanabria
- CEDIVE, Universidad Nacional de La Plata, Chascomús, Buenos Aires, Argentina
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Paraud C, Fournier E, Robergeot V, Kulo A, Pors I, Baudry C, Chartier C. Calicophoron daubneyi infection in grazing goats: Results from a cross-sectional coprological survey in France. Small Rumin Res 2009. [DOI: 10.1016/j.smallrumres.2009.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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8
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Paraud C, Gaudin C, Pors I, Chartier C. Efficacy of oxyclozanide against the rumen fluke Calicophoron daubneyi in experimentally infected goats. Vet J 2008; 180:265-7. [PMID: 18314360 DOI: 10.1016/j.tvjl.2008.01.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 01/04/2008] [Accepted: 01/04/2008] [Indexed: 11/25/2022]
Abstract
Paramphistome infections are very common in ruminants and may induce clinical signs, but little is known about effective treatments. In this study, the efficacy of oxyclozanide against Calicophoron daubneyi was studied in goats and its activity tested against immature stages (10 days post-infection) at a dose of 22.5mg/kg bodyweight (BW) and against adult stages using two doses (15 and 22.5mg/kg BW). There was a reduction (82%) in the number of immature worms (compared to controls) but the result was not statistically significant. When tested against adult stages, however, oxyclozanide reduced the worm burdens by 95.6% and 95.9% at doses of 15 and 22.5mg/kg BW, respectively, with no significant difference between the two doses. The experiment demonstrated that oxyclozanide is highly effective in reducing the number of adult paramphistomes in goats.
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Affiliation(s)
- C Paraud
- French Food Safety Agency (AFSSA), Laboratoire d'Etudes et de Recherches Caprines, 60 rue de Pied de Fond, 79012 NIORT Cedex, France.
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9
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Seasonal pattern of bovine amphistomosis in traditionally reared cattle in the Kafue and Zambezi catchment areas of Zambia. Trop Anim Health Prod 2007; 39:97-102. [DOI: 10.1007/s11250-007-4406-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Díaz P, Lomba C, Pedreira J, Arias M, Sánchez-Andrade R, Suárez JL, Díez-Baños P, Morrondo P, Paz-Silva A. Analysis of the IgG antibody response against Paramphistomidae trematoda in naturally infected cattle. Application to serological surveys. Vet Parasitol 2006; 140:281-8. [PMID: 16672179 DOI: 10.1016/j.vetpar.2006.04.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 03/22/2006] [Accepted: 04/03/2006] [Indexed: 10/24/2022]
Abstract
The IgG antibody response to Calicophoron daubneyi (Digenea: Paramphistomidae) excretory/secretory antigens was evaluated in naturally infected cattle from Lugo (Galicia, NW Spain) by using an ELISA procedure. Two studies were conducted, first a survey in 524 cattle separated into three groups according to age, G-1 (0-2 years old), G-2 (3-5 years old) and G-3 (> 6 years old). In the second study, three groups of cattle were employed: G-I, naturally infected; G-T, naturally infected and treated with oxyclozanide plus levamisole (Nilzan Plus); G-C, cattle maintained in a farm where C. daubneyi has never diagnosed. Variations on egg-output and haematic parameters (erythrocytes, haematocrite, leukocytes and lymphocytes) were also analyzed. The ELISA procedure showed that 61.2% of the cattle in the first study had been exposed to the trematode, but only 10.1% passed eggs in the feces. Age-association with egg-output was shown but not with the IgG values. In the second experiment, the administration of the anthelmintic reduced significantly the IgG kinetic levels and the C. daubneyi-egg-output was suppressed during 12 weeks in the G-T group. The values of red cells, haematocrite, leukocytes and lymphocytes increased significantly in the treated cattle 5 weeks after chemotherapy; however, new reduction after week 5 was recorded, as results of the challenge of these cattle. This is the first investigation in which evaluation of the IgG humoral response against C. daubneyi in cattle has been carried out. We proved that a notable IgG response in naturally infected cattle is induced, and can be detected by using an ELISA procedure. The IgG antibodies did not increase after challenge infection. Our results proved an important percentage of cattle were exposed to this trematode in the area of study and suitable measures for preventing this relationship must be considered.
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Affiliation(s)
- P Díaz
- Animal Pathology Department, Parasitology and Parasitic diseases, Epidemiology and Zoonoses, Veterinary Faculty, Santiago de Compostela University, 27002 Lugo, Spain
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Rinaldi L, Perugini AG, Capuano F, Fenizia D, Musella V, Veneziano V, Cringoli G. Characterization of the second internal transcribed spacer of ribosomal DNA of Calicophoron daubneyi from various hosts and locations in southern Italy. Vet Parasitol 2005; 131:247-53. [PMID: 15961232 DOI: 10.1016/j.vetpar.2005.04.035] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 04/06/2005] [Accepted: 04/22/2005] [Indexed: 11/21/2022]
Abstract
Isolates of the rumen fluke Calicophoron daubneyi (Digenea: Paramphistomidae) from various hosts and three locations in southern Italy were characterized genetically. The second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA) plus flanking 5.8S and 28S sequence (ITS-2+) was amplified from individual rumen flukes by PCR. PCR-linked restriction fragment length polymorphism (PCR-RFLP) analysis was performed using four different restriction endonucleases, and PCR products were sequenced. The PCR analyses from all the C. daubneyi specimens produced identical fragments, and the PCR-RFLP analyses did not show, with respect to any of the four restriction endonucleases, any differences between the C. daubneyi specimens. The sequence analyses of the ITS-2+ from each of the C. daubneyi specimens showed them all to be 428 bp, and composed of the entire ITS-2 sequence (282 bp) plus the two partial flanking conserved sequences, 5.8S (99 bp) and 28S (47 bp). No intra-specific variation was observed in the nucleotide composition of the ITS-2+ (homology=100%). There was, however, an observable inter-specific variation between the ITS-2+ of C. daubneyi and the ITS-2+ of both Calicophoron calicophorum (homology=97.2 %) and Calicophoronmicrobothrioides (homology=97.4 %), both previously deposited in the GenBank. The finding of the present study shows that, as has already demonstrated for other parasitic helminths, ITS-2 can serve as an effective genetic marker for the molecular identification of paramphistomes, and as a useful tool for developing molecular epidemiological techniques for the study of C. daubneyi transmission patterns and prevalence in definitive and intermediate hosts.
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MESH Headings
- Animals
- Base Sequence
- Buffaloes/parasitology
- Cattle
- Cattle Diseases/parasitology
- DNA, Helminth/chemistry
- DNA, Helminth/genetics
- DNA, Ribosomal Spacer/chemistry
- DNA, Ribosomal Spacer/genetics
- Intestinal Diseases, Parasitic/parasitology
- Intestinal Diseases, Parasitic/veterinary
- Italy
- Molecular Sequence Data
- Paramphistomatidae/genetics
- Polymerase Chain Reaction/veterinary
- RNA, Ribosomal, 28S/chemistry
- RNA, Ribosomal, 28S/genetics
- RNA, Ribosomal, 5.8S/chemistry
- RNA, Ribosomal, 5.8S/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sheep
- Sheep Diseases/parasitology
- Trematode Infections/parasitology
- Trematode Infections/veterinary
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Affiliation(s)
- L Rinaldi
- Dipartimento di Patologia e Sanità Animale, Università degli Studi di Napoli "Federico II" - CREMOPAR Regione Campania, Napoli, Italy
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Silvestre A, Chartier C, Sauvé C, Cabaret J. Relationship between helminth species diversity, intensity of infection and breeding management in dairy goats. Vet Parasitol 2000; 94:91-105. [PMID: 11078947 DOI: 10.1016/s0304-4017(00)00367-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Helminth infection, species diversity (proportion of each species in the community), species number, intensity of infection and anthelmintic resistance were investigated in 16 dairy-goat farms of south-western France. The aim of the study was to estimate which breeding management factors may affect diversity and intensity of infection. Anthelmintic resistance was investigated because this factor may modify composition of nematode communities. Farm history and breeding management were recorded by means of a questionnaire. Natural and experimental infections were compared to determine which strategy was the best to estimate diversity index and number of species from nematode community of a whole herd. A total of 17 species of helminths, among which 14 nematodes, one cestode (Moniezia spp.) and two trematodes (Paramphistomum daubneyi and Dicrocoelium lanceolatum) were recovered in the 26 necropsied culled goats. One culled goat worm burden represented conveniently species number but not species diversity (Shannon index) of parasite community harboured in the whole herd. Experimental sheep infection with larvae from pooled faeces of 15 goats was the best strategy to estimate species diversity in farms. Diversity could be predicted from the number of farms from which goats originated at constitution of the herd, the duration of goat winter withdrawal from pastures, and intensity of infection. Anthelmintic resistance was correlated with the number of farms of origin, area of permanent pastures and intensity of infection. The strategy adopted for the herd constitution was a critical step as species diversity and risk of anthelmintic resistance increased with the number of farms of origin. Intensity of infection was negatively correlated with species diversity. This suggested that more diverse communities were better controlled by the host, in agreement with the widespread statement that diversity would beget stability.
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Affiliation(s)
- A Silvestre
- INRA, Station de Pathologie Aviaire et de Parasitologie, 37380, Nouzilly, France.
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