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Höglund J, Daş G, Tarbiat B, Geldhof P, Jansson DS, Gauly M. Ascaridia galli - An old problem that requires new solutions. Int J Parasitol Drugs Drug Resist 2023; 23:1-9. [PMID: 37516026 PMCID: PMC10409999 DOI: 10.1016/j.ijpddr.2023.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 07/31/2023]
Abstract
Reports of Ascaridia galli in laying hens in Europe have increased since the ban on conventional battery cages in 2012. As this parasite is transmitted directly via the faecal-oral route by parasite eggs containing a larva, it is reasonable to assume that the escalating problem is related to the increased exposure now occurring in modern welfare-friendly cage-free housing systems. On many farms, A. galli reappears in subsequent flocks, even though the birds have no access to the outdoors, biosecurity is high and empty houses are cleaned and disinfected during downtime. Since the egg production cycle lasts only ≈80 weeks and recombinant antigen production for helminth vaccines has not yet been solved, the development of a vaccine seems to be an unrealistic option. Therefore, disrupting the life cycle of the parasite by other means, including the strategic use of dewormers, appears to be the key to controlling infection. Of concern is that only one class of anthelmintics is licenced for poultry in Europe and that are usually administered indiscriminately through the birds' drinking water and often too late when the parasite is already established. If current calendar-based parasite control strategies are not changed, there is a risk that resistance to anthelmintics may develop, as has already been demonstrated with nematodes in livestock. We insist that treatments can be more effective and the risk of developing drug resistance can be mitigated if we invest in a better understanding of A. galli responses to more prudent and judicious use of anthelmintics. This review identifies knowledge gaps and highlights aspects of sustainable parasite control that require further research to support commercial egg producers.
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Affiliation(s)
- Johan Höglund
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Gürbüz Daş
- Institute of Nutritional Physiology 'Oskar Kellner', Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
| | - Behdad Tarbiat
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Peter Geldhof
- Laboratory for Parasitology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
| | - Désirée S Jansson
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Matthias Gauly
- Free University of Bolzano, Department of Animal Science, Piazza Università 5, 39100, Bolzano, Italy.
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2
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Bagheri S, Mitra T, Paudel S, Abdelhamid MK, Könnyü S, Wijewardana V, Kangethe RT, Cattoli G, Lyrakis M, Hess C, Hess M, Liebhart D. Aerosol vaccination of chicken pullets with irradiated avian pathogenic Escherichia coli induces a local immunostimulatory effect. Front Immunol 2023; 14:1185232. [PMID: 37261344 PMCID: PMC10227613 DOI: 10.3389/fimmu.2023.1185232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/02/2023] [Indexed: 06/02/2023] Open
Abstract
The present study investigated the expression of cytokines and cellular changes in chickens following vaccination with irradiated avian pathogenic Escherichia coli (APEC) and/or challenge. Four groups of 11-week-old pullets, each consisting of 16 birds were kept separately in isolators before they were sham inoculated (N), challenged only (C), vaccinated (V) or vaccinated and challenged (V+C). Vaccination was performed using irradiated APEC applied via aerosol. For challenge, the homologous strain was administered intratracheally. Birds were sacrificed on 3, 7, 14 and 21 days post challenge (dpc) to examine lesions, organ to body weight ratios and bacterial colonization. Lung and spleen were sampled for investigating gene expression of cytokines mediating inflammation by RT-qPCR and changes in the phenotype of subsets of mononuclear cells by flow cytometry. After re-stimulation of immune cells by co-cultivation with the pathogen, APEC-specific IFN-γ producing cells were determined. Challenged only birds showed more severe pathological and histopathological lesions, a higher probability of bacterial re-isolation and higher organ to body weight ratios compared to vaccinated and challenged birds. In the lung, an upregulation of IL-1β and IL-6 following vaccination and/or challenge at 3 dpc was observed, whereas in the spleen IL-1β was elevated. Changes were observed in macrophages and TCR-γδ+ cells within 7 dpc in spleen and lung of challenged birds. Furthermore, an increase of CD4+ cells in spleen and a rise of Bu-1+ cells in lung were present in vaccinated and challenged birds at 3 dpc. APEC re-stimulated lung and spleen mononuclear cells from only challenged pullets showed a significant increase of IFN-γ+CD8α+ and IFN-γ+TCR-γδ+ cells. Vaccinated and challenged chickens responded with a significant increase of IFN-γ+CD8α+ T cells in the lung and IFN-γ+TCR-γδ+ cells in the spleen. Re-stimulation of lung mononuclear cells from vaccinated birds resulted in a significant increase of both IFN-γ+CD8α+ and IFN-γ+TCR-γδ+ cells. In conclusion, vaccination with irradiated APEC caused enhanced pro-inflammatory response as well as the production of APEC-specific IFN-γ-producing γδ and CD8α T cells, which underlines the immunostimulatory effect of the vaccine in the lung. Hence, our study provides insights into the underlying immune mechanisms that account for the defense against APEC.
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Affiliation(s)
- Sina Bagheri
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Taniya Mitra
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Surya Paudel
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Mohamed Kamal Abdelhamid
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Simon Könnyü
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Viskam Wijewardana
- Animal Production and Health Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Richard Thiga Kangethe
- Animal Production and Health Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Manolis Lyrakis
- Platform for Bioinformatics and Biostatistics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Claudia Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Michael Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Dieter Liebhart
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
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3
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Aerosol delivered irradiated Escherichia coli confers serotype-independent protection and prevents colibacillosis in young chickens. Vaccine 2023; 41:1342-1353. [PMID: 36642629 DOI: 10.1016/j.vaccine.2022.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/30/2022] [Accepted: 12/03/2022] [Indexed: 01/14/2023]
Abstract
Escherichia coli causes colibacillosis in chickens, which has severe economic and public health consequences. For the first time, we investigated the efficacy of gamma-irradiated E. coli to prevent colibacillosis in chickens considering different strains and application routes. Electron microscopy, alamarBlue assay and matrix assisted laser desorption/ionization time-of- flight mass spectrometry showed that the cellular structure, metabolic activity and protein profiles of irradiated and non-treated E. coli PA14/17480/5-ovary (serotype O1:K1) were similar. Subsequently, three animal trials were performed using the irradiated E. coli and clinical signs, pathological lesions and bacterial colonization in systemic organs were assessed. In the first animal trial, the irradiated E. coli PA14/17480/5-ovary administered at 7 and 21 days of age via aerosol and oculonasal routes, respectively, prevented the occurrence of lesions and systemic bacterial spread after homologous challenge, as efficient as live infection or formalin-killed cells. In the second trial, a single aerosol application of the same irradiated strain in one-day old chickens was efficacious against challenges with a homologous or a heterologous strain (undefined serotype). The aerosol application elicited better protection as compared to oculonasal route. Finally, in the third trial, efficacy against E. coli PA15/19103-3 (serotype O78:K80) was shown. Additionally, previous results of homologous protection were reconfirmed. The irradiated PA15/19103-3 strain, which also showed lower metabolic activity, was less preferred even for the homologous protection, underlining the importance of the vaccine strain. In all the trials, the irradiated E. coli did not provoke antibody response indicating the importance of innate or cell mediated immunity for protection. In conclusion, this proof-of-concept study showed that the non-adjuvanted single aerosol application of irradiated "killed but metabolically active" E. coli provided promising results to prevent colibacillosis in chickens at an early stage of life. The findings open new avenues for vaccine production with E. coli in chickens using irradiation technology.
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Matos M, Bilic I, Palmieri N, Mitsch P, Sommer F, Tvarogová J, Liebhart D, Hess M. Epidemic of cutaneous fowlpox in a naïve population of chickens and turkeys in Austria: Detailed phylogenetic analysis indicates co-evolution of fowlpox virus with reticuloendotheliosis virus. Transbound Emerg Dis 2022; 69:2913-2923. [PMID: 34974640 PMCID: PMC9787674 DOI: 10.1111/tbed.14446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/20/2021] [Accepted: 12/28/2021] [Indexed: 12/30/2022]
Abstract
Cutaneous fowlpox is a disease of chickens and turkeys caused by the fowlpox virus (FWPV), characterized by the development of proliferative lesions and scabs on unfeathered areas. FWPVs regularly carry an integrated, active copy of the reticuloendotheliosis virus (REV), and it has been hypothesized that such FWPVs are more problematic in the field. Extensive outbreaks are usually observed in tropical and sub-tropical climates, where biting insects are more difficult to control. Here, we report an epidemic of 65 cutaneous fowlpox cases in Austria in layer chickens (91% of the cases) and broiler breeders and turkeys, all of them unvaccinated against the disease, from October 2018 to February 2020. The field data revealed appearance in flocks of different sizes ranging from less than 5000 birds up to more than 20,000 animals, with the majority raised indoors in a barn system. The clinical presentation was characterized by typical epithelial lesions on the head of the affected birds, with an average decrease of 6% in egg production and an average weekly mortality of 1.2% being observed in the flocks. A real-time multiplex polymerase chain reaction (PCR) confirmed the presence of FWPV-REV DNA, not only in the lesions but also in the environmental dust from the poultry houses. The integration of the REV provirus into the FWPV genome was confirmed by PCR, and revealed different FWPV genome populations carrying either the REV long terminal repeats (LTRs) or the full-length REV genome, reiterating the instability of the inserted REV. Two selected samples were fully sequenced by next generation sequencing (NGS), and the whole genome phylogenetic analysis revealed a regional clustering of the FWPV genomes. The extensive nature of these outbreaks in host populations naïve for the virus is a remarkable feature of the present report, highlighting new challenges associated with FWPV infections that need to be considered.
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Affiliation(s)
- Miguel Matos
- Clinic for Poultry and Fish MedicineDepartment for Farm Animals and Veterinary Public HealthUniversity of Veterinary Medicine ViennaViennaAustria
| | - Ivana Bilic
- Clinic for Poultry and Fish MedicineDepartment for Farm Animals and Veterinary Public HealthUniversity of Veterinary Medicine ViennaViennaAustria
| | - Nicola Palmieri
- Clinic for Poultry and Fish MedicineDepartment for Farm Animals and Veterinary Public HealthUniversity of Veterinary Medicine ViennaViennaAustria
| | | | | | - Jana Tvarogová
- Clinic for Poultry and Fish MedicineDepartment for Farm Animals and Veterinary Public HealthUniversity of Veterinary Medicine ViennaViennaAustria
| | - Dieter Liebhart
- Clinic for Poultry and Fish MedicineDepartment for Farm Animals and Veterinary Public HealthUniversity of Veterinary Medicine ViennaViennaAustria
| | - Michael Hess
- Clinic for Poultry and Fish MedicineDepartment for Farm Animals and Veterinary Public HealthUniversity of Veterinary Medicine ViennaViennaAustria
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Seroprevalence of pullorum disease in chicken across mainland China from 1982 to 2020: A systematic review and meta-analysis. Res Vet Sci 2022; 152:156-166. [PMID: 35973235 DOI: 10.1016/j.rvsc.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 10/15/2022]
Abstract
Pullorum disease (PD), caused by the bacterium Salmonella pullorum, severely threatens the health of chickens worldwide, especially in China, and generating concerns for public health safety. Greater awareness of the seroprevalence may facilitate the prevention and control of this disease. We conducted systematic review and meta-analysis on the seroprevalence of PD in chicken flocks across mainland China. The results show that the overall pooled estimates of PD seroprevalence in chicken flocks was 18.2%. Furthermore, during 38-year period the seroprevalence of PD was markedly high in all seven regions, being at least 14.9% in central China. Our results suggest PD was highly prevalent in autumn, followed by winter. Chickens older than 120 days (22.6%, CI95: 14.5%-31.9%) had a significantly higher positive rate of PD than those <120 days in age (9.4%, CI95: 3.7%-17.4%). Additionally, the rearing mode used is a risk factor associated with the seroprevalence of PD, it being considerably lower for caged chickens (13.7%, CI95: 7.1%-22.0%) than free-range chickens (30.4%, CI95: 17.3-45.4%). Our findings demonstrate that PD still poses a major threat to poultry industries in mainland China, and therefore comprehensive and stringent strategies are needed to prevent and control this disease.
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Feyera T, Shifaw A, Sharpe B, Elliott T, Ruhnke I, Walkden-Brown SW. Worm control practices on free-range egg farms in Australia and anthelmintic efficacy against nematodes in naturally infected layer chickens. Vet Parasitol Reg Stud Reports 2022; 30:100723. [PMID: 35431079 DOI: 10.1016/j.vprsr.2022.100723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/16/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
This study investigated worm control practices by free-range egg farmers and the efficacy of the commercial anthelmintics levamisole (LEV), piperazine (PIP), flubendazole (FLBZ) and fenbendazole (FBZ) against gastrointestinal nematodes on two free-range layer farms in Australia. An online survey comprising 36 questions was designed and implemented using SurveyMonkey. The survey contained questions about participant demographics, farm and flock characteristics, perceived intestinal worm importance, infection monitoring, deworming and other worm control practices. A link for the survey was emailed to free range egg producers from their industry body in December 2019. The anthelmintic efficacy trial was conducted in a total of 229 layers naturally infected with Ascaridia galli, Hetarakis gallinarum, Capillaria spp. and/or tape worms. Chickens received a single oral dose of LEV (28 mg/kg), PIP (100 mg/kg), FBZ (10 mg/kg) or LEV-PIP co-administered at their full individual doses, and FLBZ (Flubenol®), 30 ppm or 60 ppm) in the feed over 7 days. Anthelmintic efficacies were estimated by both worm count reduction (WCR %) and excreta egg count reduction (EECR %) tests 10 days after start of treatment. The survey with a response rate of 16/203, revealed that worm infection was of moderate concern to the producers and the majority (68%) felt that the current anthelmintics work effectively. The level of understanding of worms, monitoring and control practices did not reveal any major deficiencies of concern. The most commonly used anthelmintic was LEV (73%) followed by PIP (45%). Based on a standard cut-off value (≥90%), LEV, LEV-PIP, and FBZ attained the desired efficacy but PIP exhibited reduced efficacy against immature A. galli (61-85%), all stages of H. gallinarum (42-77%) and Capillaria spp. (25-44%). FLBZ was highly effective against all stages of roundworms and tapeworm infections. Even though there was some association between the efficacies estimated by WCR % and EECR % the latter was poorly associated in the natural infection model and hence does not provide a reasonable alternative for assessing anthelmintic efficacy when immature stages of the lifecycle are included. These results show no evidence of loss of susceptibility to the tested anthelmintics on these farms supporting the perception of producers that participated in the survey that current treatments work effectively. The reduced efficacy of PIP against some species and immature stages is related to its spectrum of activity rather than providing evidence of emerging resistance.
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Affiliation(s)
- Teka Feyera
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia; Department of Veterinary Clinical Studies, College of Veterinary Medicine, Jigjiga University, Jigjiga P. O. Box 1020, Ethiopia.
| | - Anwar Shifaw
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | | | - Timothy Elliott
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Isabelle Ruhnke
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Stephen W Walkden-Brown
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
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Escherichia coli Isolated from Organic Laying Hens Reveal a High Level of Antimicrobial Resistance despite No Antimicrobial Treatments. Antibiotics (Basel) 2022; 11:antibiotics11040467. [PMID: 35453218 PMCID: PMC9027956 DOI: 10.3390/antibiotics11040467] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 02/01/2023] Open
Abstract
The present study investigated the resistance characteristics of E. coli isolates originating from 18 organic laying hen flocks. E. coli was isolated from different organs at three different time points, resulting in 209 E. coli isolates. The antibiotic susceptibility was determined by applying a microdilution assay. General, a high resistance rate was found. The antibiotic susceptibility was independent from the presence of pathological lesions, the isolation site, or the affiliation to a pathogenic serogroup. The majority of the isolates proved to be multi-drug-resistant (95.70%), of which 36.84% could be categorized as extensively drug-resistant. All isolates were resistant to oxacillin and tylosin. Resistance rates to amoxicillin (67.94%), cefoxitin (55.98%), ceftazidime (82.30%), colistin (73.68%), nalidixic acid (91.87%), streptomycin (42.58%), tetracycline (53.59%), and sulfamethoxazole (95.22%) were high. None of the isolates revealed pan-drug-resistance. A great heterogeneity of resistance profiles was found between isolates within a flock or from different organs of the same bird, even when isolates originated from the same organ. An increase in antimicrobial resistance was found to be correlated with the age of the birds. The fact, that no antibiotic treatment was applied except in two flocks, indicates that resistant bacteria circulating in the environment pose a threat to organic systems.
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Zloch A, Kuchling S, Hess M, Hess C. In addition to birds' age and outdoor access, the detection method is of high importance to determine the prevalence of gastrointestinal helminths in laying hens kept in alternative husbandry systems. Vet Parasitol 2021; 299:109559. [PMID: 34507201 DOI: 10.1016/j.vetpar.2021.109559] [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: 06/08/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 01/16/2023]
Abstract
The prevalence of gastrointestinal helminths was investigated in sixty-six commercial non-caged layer flocks. Twenty-nine flocks were housed indoors in aviaries or floor systems, nineteen flocks were kept in conventional free-range systems with outdoor access, and eighteen flocks in organic free-range systems. Flocks were investigated at end of rearing (mean age 17 weeks), peak of egg production (mean age 38 weeks) and before slaughter (mean age 74 weeks). Four different methods were applied to determine worm infestation. During necropsies, worm infestations were recorded and mucosal scrapings were evaluated for the presence of worm eggs. Faecal samples from each flock were investigated by simple flotation method and McMaster counting technique. No gastrointestinal helminths were found in pullets. During production, 87.9 % of the layer flocks were infected with at least one nematode species at the peak of production. The prevalence further increased significantly up to 98.5 % at the end of production (p=0.05). This increase could be ascribed mainly to infections with Ascaridia (A.) galli and/or Heterakis (H.) gallinarum which were most prevalent in all husbandry systems. Furthermore, their prevalence increased significantly with the age of birds (p=0.023; p < 0.001). With regard to the husbandry system, the prevalence of Capillaria spp. was significantly higher in flocks from outdoor systems compared to flocks that were kept indoors. Cestodes were only detected at the end of production with a prevalence of 15.2 % and significantly more flocks with access to outdoor run were found positive. Interestingly, H. gallinarum was found with a high prevalence indoor and in outdoor systems. Anthelminthic treatment did not impact the prevalence of nematode infections. Comparing four different methods for the detection of helminths it was revealed that their efficiencies varied depending on the worm species. Overall, the simple flotation method was superior to detect A. galli and Capillaria spp. This method proved also very efficient for the detection of H. gallinarum but the additional evaluation of the worm infestation during necropsy increased the level of prevalence. Cestodes were mainly found during necropsies when the worm infestation was evaluated. The detection of parasite eggs in mucosal scrapings from the intestines was the least effective method for all helminths. These findings lead to the recommendation to combine faecal investigations with an evaluation of the worm infestation during necropsy of at least five birds.
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Affiliation(s)
- Angelika Zloch
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria; Tierarzt GmbH Dr. Mitsch, Haufgasse 24, 1110, Vienna, Austria.
| | - Sabrina Kuchling
- Austrian Agency for Health and Food Safety (AGES), Division for Data, Statistics and Risk Assessment, Zinzendorfgasse 27/1, 8010, Graz, Austria.
| | - Michael Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
| | - Claudia Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
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Daş G, Wachter L, Stehr M, Bilic I, Grafl B, Wernsdorf P, Metges CC, Hess M, Liebhart D. Excretion of Histomonas meleagridis following experimental co-infection of distinct chicken lines with Heterakis gallinarum and Ascaridia galli. Parasit Vectors 2021; 14:323. [PMID: 34120639 PMCID: PMC8201732 DOI: 10.1186/s13071-021-04823-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/03/2021] [Indexed: 11/19/2022] Open
Abstract
Background Histomonosis is a severe re-emerging disease of poultry caused by Histomonas meleagridis, a protozoan parasite which survives in the environment via the cecal worm Heterakis gallinarum. Following infection, the parasites reside in the ceca and are excreted via host feces. In the present work, male birds of conventional broiler (Ross 308, R), layer (Lohmann Brown Plus, LB) and a dual-purpose (Lohmann Dual, LD) chicken line were infected with 250 embryonated eggs of Ascaridia galli and Heterakis gallinarum, respectively, with the latter nematode harboring Histomonas meleagridis, to investigate a co-infection of nematodes with the protozoan parasite in different host lines. Methods In weekly intervals, from 2 to 9 weeks post infection (wpi), individual fecal samples (n = 234) from the chickens were collected to quantify the excretion of H. meleagridis by real-time PCR and to determine the number of nematode eggs per gram (EPG) in order to elucidate excretion dynamics of the flagellate and the nematodes. This was further investigated by indirect detection using plasma samples of the birds to detect antibodies specific for H. meleagridis and worms by ELISA. The infection with H. meleagridis was confirmed by histopathology and immunohistochemistry to detect the flagellate in the cecum of representing birds. Results The excretion of H. meleagridis could already be observed from the 2nd wpi in some birds and increased to 100% in the last week of the experiment in all groups independent of the genetic line. This increase could be confirmed by ELISA, even though the number of excreted H. meleagridis per bird was generally low. Overall, histomonads were detected in 60% to 78% of birds with temporary differences between the different genetic lines, which also showed variations in the EPG and worm burden of both nematodes. Conclusions The infection with H. gallinarum eggs contaminated with H. meleagridis led to a permanent excretion of the flagellate in host feces. Differences in the excretion of H. meleagridis in the feces of genetically different host lines occurred intermittently. The excretion of the protozoan or its vector H. gallinarum was mostly exclusive, showing a negative interaction between the two parasites in the same host. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04823-1.
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Affiliation(s)
- Gürbüz Daş
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany
| | - Lukas Wachter
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Manuel Stehr
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany
| | - Ivana Bilic
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Beatrice Grafl
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Patricia Wernsdorf
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Cornelia C Metges
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany
| | - Michael Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria.,Christian Doppler Laboratory for Innovative Poultry Vaccines (IPOV), Clinic for Poultry and Fish Medicine, Vienna, Austria
| | - Dieter Liebhart
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria.
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Wattrang E, Eriksson H, Albihn A, Dalgaard TS. Quantification of IgY to Erysipelothrix rhusiopathiae in serum from Swedish laying hens. BMC Vet Res 2021; 17:111. [PMID: 33676514 PMCID: PMC7938349 DOI: 10.1186/s12917-021-02813-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/19/2021] [Indexed: 05/09/2023] Open
Abstract
Background Erysipelas, caused by Erysipelothrix rhusiopathiae (ER), is an important emerging disease in free-range and organic egg-production. The aim of the present study was to assess if quantification of ER specific IgY titers may aid the understanding of erysipelas in commercial laying hens. The methodology was validated with sequentially collected sera from experimentally ER infected SPF-chickens and subsequently applied on sera from Swedish commercial laying hens collected during and after outbreaks of erysipelas or collected at slaughter from healthy hens housed in furnished cages, barn production or in organic production (with outdoor access). Results In experimentally infected SPF-chickens, titers to ER were significantly increased approximately one week after infection while IgY to ER in uninfected age-matched controls remained low. Also chickens infected with low doses of ER, not displaying clinical signs of disease and with low recovery of ER in blood samples showed high titers of IgY to ER. For laying hens during and after erysipelas outbreaks the majority of samples were considered positive for antibodies to ER with a large variation in levels of IgY titers to ER between individuals. For healthy laying hens at slaughter all samples were deemed positive for antibodies to ER. An influence of flock on levels of IgY titers to ER was observed for both healthy hens and hens during erysipelas outbreaks. For healthy laying hens at slaughter no influence of the housing systems included in the study, history of erysipelas outbreaks at the farm or vaccination on levels of IgY titers to ER was noticed. Conclusions Taken together, these results show that high numbers of commercial laying hens showed high IgY titers to ER, comparable to those elicited by experimental ER infection, indicating that ER or bacteria that raises antibodies that cross-react with ER are common in this environment.
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Affiliation(s)
- Eva Wattrang
- Department of Microbiology, National Veterinary Institute, Uppsala, Sweden.
| | - Helena Eriksson
- Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, Uppsala, Sweden
| | - Ann Albihn
- Department of Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
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11
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Bethonico Terra MT, Pacheco WJ, Harrison M, McCrea BA, Hauck R. A survey of coccidia and nematodes in pastured poultry in the state of Georgia. Avian Dis 2021; 65:250-256. [PMID: 33647964 DOI: 10.1637/aviandiseases-d-20-00120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 03/01/2021] [Indexed: 11/05/2022]
Abstract
The aim of this study was to evaluate and quantify the parasitological challenge in pastured poultry production in the state of Georgia. Over the course of one year, fecal samples from six turkey flocks, ten broiler flocks and 13 layer flocks were collected on a pastured farm in two-week intervals to determine counts of Eimeria oocysts and nematode eggs. Average coccidia counts were 10,198 oocysts per gram of feces (OPG) in broiler flocks, 1,470 OPG in layer flocks and 695 OPG in turkey flocks. The means in broiler and turkey flocks were higher at their first week on pasture. Counts in broilers and layers were significantly higher in spring than in winter and summer. Coccidia counts in broilers were lower than published numbers in conventionally reared poultry, indicating the rotation system of the pastures might effectively reduce the infection pressure. Next-generation sequencing of PCR products showed the presence of most described Eimeria spp. in broilers, layers, and turkeys. In addition, Operational Taxonomic Units (OTUs) x, y and z were found. The frequency of species was similar for broilers and layers, with the exception that Eimeria praecox and OTU z were more common in layers. In layer flocks, the average count of roundworm eggs per gram of feces (EPG) was 509 EPG with 80% of the samples being positive. The mean counts had no clear pattern related to age. There was an increase of EPG with the increase of temperatures during spring and summer with the peak at mid-fall. Worm eggs from laying hens were identified as A. galli. The seasonal differences suggest that higher temperatures might result in an increase of egg survival and sporulation in the environment.
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Affiliation(s)
| | - Wilmer J Pacheco
- Department of Poultry Science, Auburn University, Auburn, AL 36849
| | | | | | - Ruediger Hauck
- Auburn University Editorial Board Members-Approved Rev. Department of Pathobiology and Department of Poultry Science 260 Lem Morrison Dr. UNITED STATES Auburn Alabama 36849 1 344 844 4152
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12
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Laying hen mortality in different indoor housing systems: a meta-analysis of data from commercial farms in 16 countries. Sci Rep 2021; 11:3052. [PMID: 33542280 PMCID: PMC7862694 DOI: 10.1038/s41598-021-81868-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 01/13/2021] [Indexed: 12/27/2022] Open
Abstract
Societal concern with the welfare of egg laying hens housed in conventional cages is fostering a transition towards cage-free systems in many countries. However, although cage-free facilities enable hens to move freely and express natural behaviours, concerns have also been raised over the possibility that cage-free flocks experience higher mortality, potentially compromising some aspects of their welfare. To investigate this possibility, we conducted a large meta-analysis of laying hen mortality in conventional cages, furnished cages and cage-free aviaries using data from 6040 commercial flocks and 176 million hens from 16 countries. We show that except for conventional cages, mortality gradually drops as experience with each system builds up: since 2000, each year of experience with cage-free aviaries was associated with a 0.35–0.65% average drop in cumulative mortality, with no differences in mortality between caged and cage-free systems in more recent years. As management knowledge evolves and genetics are optimized, new producers transitioning to cage-free housing may experience even faster rates of decline. Our results speak against the notion that mortality is inherently higher in cage-free production and illustrate the importance of considering the degree of maturity of production systems in any investigations of farm animal health, behaviour and welfare.
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13
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García Cuadrado MN, Martínez-Moreno FJ, Zafra Leva R, Acosta García I. Helminth communities in the alimentary tract of free raised chickens on rainfed and irrigated agrosystems from southwest Spain. ITALIAN JOURNAL OF ANIMAL SCIENCE 2021. [DOI: 10.1080/1828051x.2021.1980443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- M. N. García Cuadrado
- Laboratorio de Parasitología. Centro de Ciencias e Investigación Tecnológica de Extremadura, Badajoz, Spain
| | - F. J. Martínez-Moreno
- Departamento de Sanidad Animal (Parasitología y Enfermedades Parasitarias), Facultad de Medicina Veterinaria, University of Córdoba, Sanidad Animal Building, Rabanales Campus, Córdoba, Spain
| | - R. Zafra Leva
- Departamento de Sanidad Animal (Parasitología y Enfermedades Parasitarias), Facultad de Medicina Veterinaria, University of Córdoba, Sanidad Animal Building, Rabanales Campus, Córdoba, Spain
| | - I. Acosta García
- Departamento de Sanidad Animal (Parasitología y Enfermedades Parasitarias), Facultad de Medicina Veterinaria, University of Córdoba, Sanidad Animal Building, Rabanales Campus, Córdoba, Spain
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14
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Nassik S, Tallouzt S, Karbach N, Touzani C, Bidoudan Y, Aamarine N, Hess C. First Report of Isolation of Gallibacterium anatis from Layer Chickens in Morocco with Decrease in Laying Performance. Avian Dis 2020; 63:727-730. [PMID: 31865689 DOI: 10.1637/aviandiseases-d-19-00119] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/12/2019] [Indexed: 11/05/2022]
Abstract
Gallibacterium is a genus of the family of Pasteurellaceae. It is well known as a commensal inhabitant of the respiratory and reproductive tract of healthy chickens. But in the last years, Gallibacterium anatis is increasingly reported in field cases with a decrease in laying performance due to infections of the reproductive tract. The aim of the present study was to investigate the implication of G. anatis infection in layer flocks facing a decrease in laying performance in Morocco. Birds were received from five different laying hen farms in two regions in Morocco showing a drop of egg production. Necropsy revealed 46.1 % (24/52) of sampled birds showed variable lesions in ovaries, salpinx, and trachea. In fact, 24 birds were affected by salpingitis, 18 by oophoritis, and 11 birds by atrophy of ovaries. Furthermore, tracheitis was observed in 24 birds. Bacteriological investigation was done from different organs, and G. anatis was found in ovaries (n = 20), trachea (n = 17), and cloaca (n = 3). Identification was based on growth morphology, Gram staining, and biochemical properties. Additionally, polymerase chain reaction test using specific primers for the genus identification was carried out. All isolates showed bands of 925 bp specific for G. anatis expressing the virulent toxin GtxA. Antibiotic resistance testing was performed and revealed that isolates were sensitive to enrofloxacin, florfenicol, and gentamycin but resistant to ampicillin, erythromycin, oxytetracycline, and sulfamethoxazole-trimethoprim. The present study is the first report of G. anatis in Morocco, demonstrating the need for further epidemiologic investigations as well as in regard to antibiotic resistance development.
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Affiliation(s)
- Saâdia Nassik
- Avian Pathology Unit, Institut Agronomique et Vétérinaire Hassan II, BP: 1010, Rabat, 6202 Morocco, .,Contributed equally to this work
| | - Siham Tallouzt
- Avian Pathology Unit, Institut Agronomique et Vétérinaire Hassan II, BP: 1010, Rabat, 6202 Morocco.,Contributed equally to this work
| | - Nsrine Karbach
- Industrial Layer Farm Integration of Rhamna 43402, Morocco
| | - Charifa Touzani
- Avian Pathology Unit, Institut Agronomique et Vétérinaire Hassan II, BP: 1010, Rabat, 6202 Morocco
| | - Yassmina Bidoudan
- Avian Pathology Unit, Institut Agronomique et Vétérinaire Hassan II, BP: 1010, Rabat, 6202 Morocco
| | - Nadim Aamarine
- MENA, Boehringer Ingelheim, Ingelheim am Rhein 55216, Germany
| | - Claudia Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna 1210, Austria
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15
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Rayner AC, Higham LE, Gill R, Michalski JP, Deakin A. A survey of free-range egg farmers in the United Kingdom: Knowledge, attitudes and practices surrounding antimicrobial use and resistance. Vet Anim Sci 2019; 8:100072. [PMID: 32734089 PMCID: PMC7386762 DOI: 10.1016/j.vas.2019.100072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/21/2019] [Accepted: 09/25/2019] [Indexed: 12/30/2022] Open
Abstract
Antimicrobial resistance (AMR) is a significant global challenge affecting human health and attention has been drawn to practices of all stakeholders involved in antimicrobial prescription and administration, including in the livestock sector. This survey of free-range egg farmers (n = 117) was conducted to investigate knowledge, attitudes and practices surrounding antimicrobial use, and identify farmer-led solutions towards responsible antimicrobial use. Most participants proved knowledgeable of AMR and selected treatments based on principles of responsible medicine use. 'Worms' and 'infectious diseases' were the most common reasons for medicine use. Farms with a higher number of poultry houses, younger flock ages at depopulation and farms visited by a vet less than once a year or 3-4 times a year (compared to annually or twice a year) were more likely to select 'ANTIBIOTICS ONLY', as opposed to 'BOTH ANTIBIOTICS AND ANTIPARASITICS' or 'ANTIPARASITICS ONLY' as their most frequently used medicines. Participants from farms with a younger flock age at depopulation, from company-owned farms, and participants purchasing medicines from agricultural merchants instead of veterinary practices were less likely to be taking measures to reduce or replace antimicrobial use. Participants from larger farms and those that had less contact with their vet were less likely to think that they could reduce or replace the amount of antibiotics used. Survey results provided evidence for the important role of veterinarians in guiding antimicrobial stewardship through engagement, collaboration and education. Discussion groups in which farmers share best practices could assist the free-range egg industry in further promoting responsible antimicrobial use.
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Affiliation(s)
- Ann Catherine Rayner
- FAI Farms Ltd., Northfield Farm, Wytham, Oxford OX2 8QJ, UK
- Corresponding author.
| | | | - Roger Gill
- The Lakes Free Range Company Ltd, Meg Bank, Stainton, Penrith, UK
| | | | - Amanda Deakin
- FAI Farms Ltd., Northfield Farm, Wytham, Oxford OX2 8QJ, UK
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16
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Hess C, Grafl B, Bagheri S, Kaesbohrer A, Zloch A, Hess M. Antimicrobial Resistance Profiling of Gallibacterium anatis from Layers Reveals High Number of Multiresistant Strains and Substantial Variability Even Between Isolates from the Same Organ. Microb Drug Resist 2019; 26:169-177. [PMID: 31526229 DOI: 10.1089/mdr.2019.0056] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In this investigation, data on antimicrobial resistance (AMR) profiles of 213 Gallibacterium anatis isolates were determined from 93 laying hens originating from 39 flocks. Each flock was sampled three times during its life time for the presence of G. anatis. The broth microdilution method was applied comprising 21 antimicrobial substances. Multidrug resistance was found in 96.2% of the G. anatis isolates. Most of the isolates were resistant to tetracycline (89.2%), tylosin (94.8%), enrofloxacin (58.2%), nalidixic acid (77.4%), and sulfamethoxazole (77.0%). Resistance against antimicrobial substances increased significantly with the age of birds. A total of 99 different AMR profiles were detected. On flock level, different AMR profiles were found in 71.8% of the flocks independent of the sampling time point. On bird level, identical AMR profiles were mostly found in isolates originating from the same organ of a single bird, but 22 such paired isolates differed in their AMR profile. Variations of AMR profiles were found within isolates from a single bird, but from different organs. Isolates from systemic organs were significantly more resistant to different antimicrobial substances compared to isolates from the reproductive tract. No influence could be found in regard to an increase of resistance and applied antibiotic treatment.
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Affiliation(s)
- Claudia Hess
- Department for Farm Animals and Veterinary Public Health, Clinic for Poultry and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Beatrice Grafl
- Department for Farm Animals and Veterinary Public Health, Clinic for Poultry and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Sina Bagheri
- Department for Farm Animals and Veterinary Public Health, Clinic for Poultry and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Annemarie Kaesbohrer
- Department for Farm Animals and Veterinary Public Health, Institute of Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | - Angelika Zloch
- Department for Farm Animals and Veterinary Public Health, Clinic for Poultry and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Michael Hess
- Department for Farm Animals and Veterinary Public Health, Clinic for Poultry and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
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17
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Ybañez RHD, Resuelo KJG, Kintanar APM, Ybañez AP. Detection of gastrointestinal parasites in small-scale poultry layer farms in Leyte, Philippines. Vet World 2018; 11:1587-1591. [PMID: 30587893 PMCID: PMC6303491 DOI: 10.14202/vetworld.2018.1587-1591] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 10/09/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Gastrointestinal (GIT) parasites can affect poultry productivity by compromising its health. It is well studied in other countries, but the documented reports in the Philippines have been limited. AIM The aim of the present study was to evaluate the presence of GIT parasites in selected small-scale poultry layer farms in Leyte, Philippines. MATERIALS AND METHODS A total of 243 stool samples from eight small-scale poultry layer farms in Leyte, Philippines, were examined for GIT parasites using floatation and sedimentation technique. Profile parameters were also obtained. Fecal samples were collected and analyzed using floatation and sedimentation techniques. Statistical significance between GIT parasite positivity and profile parameters was determined using Chi-square test. RESULTS GIT parasites were detected in 92.2% of the samples (24.7% with single infection, 42.0% with 2-3 parasites, and 25.5% with three or more parasites). The common parasites detected were Ascaridia spp. (41.2%), Heterakis spp. (59.3%), Capillaria spp. (10.7%), Eimeria spp. (43.2%), and Strongyloides spp. (74.1%). Some profile parameters, including farm location, years in business, number of workers, nearby water system, the practice of fecal cleaning, and presence of other animals, were found to be significantly associated with GIT positivity. CONCLUSION GIT parasites were detected in the poultry of small-scale layer farms in selected areas in Leyte, Philippines. This finding calls for the importance of routine GIT parasite monitoring and the implied need for regular deworming or dewormer rotation in the area.
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Affiliation(s)
- Rochelle Haidee D. Ybañez
- Department of Biology and Environmental Science, College of Science, University of the Philippines Cebu, Gorordo Avenue, Lahug, Cebu City, Philippines
- Unit for Host Defense, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro City, Hokkaido, Japan
| | - Kurt Jimwell G. Resuelo
- Department of Biology and Environmental Science, College of Science, University of the Philippines Cebu, Gorordo Avenue, Lahug, Cebu City, Philippines
| | - Ara Patrice M. Kintanar
- Department of Biology and Environmental Science, College of Science, University of the Philippines Cebu, Gorordo Avenue, Lahug, Cebu City, Philippines
| | - Adrian P. Ybañez
- Department of Biology and Environmental Science, College of Science, University of the Philippines Cebu, Gorordo Avenue, Lahug, Cebu City, Philippines
- Department of Clinical Veterinary Science, College of Veterinary Medicine at Barili Campus, Cebu Technological University, Barili, Cebu, Philippines
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18
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Thapa S, Thamsborg SM, Wang R, Meyling NV, Dalgaard TS, Petersen HH, Mejer H. Effect of the nematophagous fungus Pochonia chlamydosporia on soil content of ascarid eggs and infection levels in exposed hens. Parasit Vectors 2018; 11:319. [PMID: 29843784 PMCID: PMC5975387 DOI: 10.1186/s13071-018-2898-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/14/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND The nematophagous fungus Pochonia chlamydosporia can degrade ascarid (e.g. Ascaridia galli) eggs in agar and soil in vitro. However, it has not been investigated how this translates to reduced infection levels in naturally exposed chickens. We thus tested the infectivity of soil artificially contaminated with A. galli (and a few Heterakis gallinarum) eggs and treated with P. chlamydosporia. Sterilised and non-sterilised soils were used to examine any influence of natural soil biota. METHODS Unembryonated eggs were mixed with sterilised (S)/non-sterilised (N) soil, either treated with the fungus (F) or left as untreated controls (C) and incubated (22 °C, 35 days) to allow eggs to embryonate and fungus to grow. Egg number in soil was estimated on days 0 and 35 post-incubation. Hens were exposed to the soil (SC/SF/NC/NF) four times over 12 days by mixing soil into the feed. On day 42 post-first-exposure (p.f.e.), the hens were euthanized and parasites were recovered. Serum A. galli IgY level and ascarid eggs per gram of faeces (EPG) were examined on days -1 and 36 (IgY) or 40 p.f.e. (EPG). RESULTS Egg recovery in SF soil was substantially lower than in SC soil, but recovery was not significantly different between NF and NC soils. SF hens had a mean worm count of 76 whereas the other groups had means of 355-453. Early mature/mature A. galli were recovered from SF hens whereas hens in the other groups harboured mainly immature A. galli. Heterakis gallinarum counts were low overall, especially in SF. The SF post-exposure IgY response was significantly lower while EPG was significantly higher compared to the other groups. CONCLUSIONS Pochonia chlamydosporia was very effective in reducing ascarid egg numbers in sterilised soil and thus worm burdens in the exposed hens. However, reduced exposure of hens shifted A. galli populations toward a higher proportion of mature worms and resulted in a higher faecal egg excretion within the study period. This highlights a fundamental problem in ascarid control: if not all eggs in the farm environment are inactivated, the resulting low level infections may result in higher contamination levels with associated negative long-term consequences.
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Affiliation(s)
- Sundar Thapa
- Section for Parasitology and Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
| | - Stig M. Thamsborg
- Section for Parasitology and Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
| | - Rui Wang
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010018 People’s Republic of China
| | - Nicolai V. Meyling
- Section for Organismal Biology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Tina S. Dalgaard
- Section for Immunology and Microbiology, Department of Animal Science, Aarhus University, Blichers Allé 20, Building P25, 3334, 8830 Tjele, Denmark
| | - Heidi H. Petersen
- Section for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Helena Mejer
- Section for Parasitology and Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
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Affiliation(s)
- Désirée S Jansson
- Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, Uppsala, Sweden
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