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Tao Y, Hite JL, Lafferty KD, Earn DJD, Bharti N. Transient disease dynamics across ecological scales. THEOR ECOL-NETH 2021; 14:625-640. [PMID: 34075317 PMCID: PMC8156581 DOI: 10.1007/s12080-021-00514-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 05/04/2021] [Indexed: 11/25/2022]
Abstract
Analyses of transient dynamics are critical to understanding infectious disease transmission and persistence. Identifying and predicting transients across scales, from within-host to community-level patterns, plays an important role in combating ongoing epidemics and mitigating the risk of future outbreaks. Moreover, greater emphases on non-asymptotic processes will enable timely evaluations of wildlife and human diseases and lead to improved surveillance efforts, preventive responses, and intervention strategies. Here, we explore the contributions of transient analyses in recent models spanning the fields of epidemiology, movement ecology, and parasitology. In addition to their roles in predicting epidemic patterns and endemic outbreaks, we explore transients in the contexts of pathogen transmission, resistance, and avoidance at various scales of the ecological hierarchy. Examples illustrate how (i) transient movement dynamics at the individual host level can modify opportunities for transmission events over time; (ii) within-host energetic processes often lead to transient dynamics in immunity, pathogen load, and transmission potential; (iii) transient connectivity between discrete populations in response to environmental factors and outbreak dynamics can affect disease spread across spatial networks; and (iv) increasing species richness in a community can provide transient protection to individuals against infection. Ultimately, we suggest that transient analyses offer deeper insights and raise new, interdisciplinary questions for disease research, consequently broadening the applications of dynamical models for outbreak preparedness and management. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12080-021-00514-w.
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Affiliation(s)
- Yun Tao
- Intelligence Community Postdoctoral Research Fellowship Program, Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106 USA
| | - Jessica L. Hite
- School of Veterinary Medicine, Department of Pathobiological Sciences, University of Wisconsin, Madison, WI 53706 USA
| | - Kevin D. Lafferty
- Western Ecological Research Center at UCSB Marine Science Institute, U.S. Geological Survey, CA 93106 Santa Barbara, USA
| | - David J. D. Earn
- Department of Mathematics and Statistics, McMaster University, Hamilton, ON L8S 4K1 Canada
| | - Nita Bharti
- Department of Biology Center for Infectious Disease Dynamics, Penn State University, University Park, PA 16802 USA
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Hite JL, Cressler CE. Parasite-Mediated Anorexia and Nutrition Modulate Virulence Evolution. Integr Comp Biol 2020; 59:1264-1274. [PMID: 31187120 DOI: 10.1093/icb/icz100] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Temporary but substantial reductions in voluntary food intake routinely accompany parasite infection in hosts ranging from insects to humans. This "parasite-mediated anorexia" drives dynamic nutrient-dependent feedbacks within and among hosts, which should alter the fitness of both hosts and parasites. Yet, few studies have examined the evolutionary and epidemiological consequences of this ubiquitous but overlooked component of infection. Moreover, numerous biomedical, veterinary, and farming practices (e.g., rapid biomass production via high-calorie or high-fat diets, low-level antibiotics to promote growth, nutritional supplementation, nonsteroidal anti-inflammatory drugs like Ibuprofen) directly or indirectly alter the magnitude of host anorexia-while also controlling host diet and therefore the nutrients available to hosts and parasites. Here, we show that anorexia can enhance or diminish disease severity, depending on whether the current dietary context provides nutrients that bolster or inhibit immune function. Feedbacks driven by nutrition-mediated competition between host immune function and parasite production can create a unimodal relationship between anorexia and parasite fitness. Subsequently, depending on the host's diet, medical or husbandry practices that suppress anorexia could backfire, and inadvertently select for more virulent parasites and larger epidemics. These findings carry implications for the development of integrated treatment programs that consider links between host feeding behavior, nutrition, and disease severity.
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Affiliation(s)
- Jessica L Hite
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA
| | - Clayton E Cressler
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA
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Hite JL, Pfenning AC, Cressler CE. Starving the Enemy? Feeding Behavior Shapes Host-Parasite Interactions. Trends Ecol Evol 2019; 35:68-80. [PMID: 31604593 DOI: 10.1016/j.tree.2019.08.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 01/09/2023]
Abstract
The loss of appetite that typically accompanies infection or mere exposure to parasites is traditionally considered a negative byproduct of infection, benefitting neither the host nor the parasite. Numerous medical and veterinary practices directly or indirectly subvert this 'illness-mediated anorexia'. However, the ecological factors that influence it, its effects on disease outcomes, and why it evolved remain poorly resolved. We explore how hosts use anorexia to defend against infection and how parasites manipulate anorexia to enhance transmission. Then, we use a coevolutionary model to illustrate how shifts in the magnitude of anorexia (e.g., via drugs) affect disease dynamics and virulence evolution. Anorexia could be exploited to improve disease management; we propose an interdisciplinary approach to minimize unintended consequences.
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Affiliation(s)
- Jessica L Hite
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA.
| | - Alaina C Pfenning
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA
| | - Clayton E Cressler
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA
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Anthelmintic resistance and novel control options in equine gastrointestinal nematodes. Parasitology 2018; 146:425-437. [DOI: 10.1017/s0031182018001786] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractControl of equine nematodes has relied on benzimidazoles (BZs), tetrahydropyrimidines and macrocyclic lactones. The intensive use of anthelmintics has led to the development of anthelmintic resistance (AR) in equine cyathostomins and Parascaris equorum. Field studies indicate that BZ and pyrantel resistance is widespread in cyathostomins and there are also increasing reports of resistance to macrocyclic lactones in cyathostomins and P. equorum. The unavailability of reliable laboratory-based techniques for detecting resistance further augments the problem of nematode control in horses. The only reliable test used in horses is the fecal egg count reduction test; therefore, more focus should be given to develop and validate improved methodologies for diagnosing AR at an early stage, as well as determining the mechanisms involved in resistance development. Therefore, equine industry and researchers should devise and implement new strategies for equine worm control, such as the use of bioactive pastures or novel feed additives, and control should increasingly incorporate alternative and evidence-based parasite control strategies to limit the development of AR. This review describes the history and prevalence of AR in equine nematodes, along with recent advances in developing resistance diagnostic tests and worm control strategies in horses, as well as giving some perspective on recent research into novel control strategies.
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van der Voort M, Van Meensel J, Lauwers L, de Haan M, Evers A, Van Huylenbroeck G, Charlier J. Economic modelling of grazing management against gastrointestinal nematodes in dairy cattle. Vet Parasitol 2017; 236:68-75. [DOI: 10.1016/j.vetpar.2017.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/11/2017] [Accepted: 02/02/2017] [Indexed: 11/17/2022]
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Saqui-Salces M, Tsao AC, Gillilland MG, Merchant JL. Weight gain in mice on a high caloric diet and chronically treated with omeprazole depends on sex and genetic background. Am J Physiol Gastrointest Liver Physiol 2017; 312:G15-G23. [PMID: 27810953 PMCID: PMC5283905 DOI: 10.1152/ajpgi.00211.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/28/2016] [Indexed: 01/31/2023]
Abstract
The impact of omeprazole (OM), a widely used over-the-counter proton pump inhibitor, on weight gain has not been extensively explored. We examined what factors, e.g., diet composition, microbiota, genetic strain, and sex, might affect weight gain in mice fed a high caloric diet while on OM. Inbred C57BL/6J strain, a 50:50 hybrid (B6SJLF1/J) strain, and mice on a highly mixed genetic background were fed four diets: standard chow (STD, 6% fat), STD with 200 ppm OM (STD + O), a high-energy chow (HiE, 11% fat), and HiE chow with OM (HiE + O) for 17 wk. Metabolic analysis, body composition, and fecal microbiota composition were analyzed in C57BL/6J mice. Oral glucose tolerance tests were performed using mice on the mixed background. After 8 wk, female and male C57BL/6J mice on the HiE diets ate less, whereas males on the HiE diets compared with the STD diets gained weight. All diet treatments reduced energy expenditure in females but in males only those on the HiE + O diet. Gut microbiota composition differed in the C57BL/6J females but not the males. Hybrid B6SJLF1/J mice showed similar weight gain on all test diets. In contrast, mixed strain male mice fed a HiE + O diet gained ∼40% more weight than females on the same diet. In addition to increased weight gain, mixed genetic mice on the HiE + O diet cleared glucose normally but secreted more insulin. We concluded that sex and genetic background define weight gain and metabolic responses of mice on high caloric diets and OM.
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Affiliation(s)
| | - Amy C. Tsao
- 2Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
| | | | - Juanita L. Merchant
- 2Internal Medicine, University of Michigan, Ann Arbor, Michigan; and ,3Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
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Verschave SH, Vercruysse J, Claerebout E, Rose H, Morgan ER, Charlier J. The parasitic phase of Ostertagia ostertagi: quantification of the main life history traits through systematic review and meta-analysis. Int J Parasitol 2014; 44:1091-104. [PMID: 25229178 DOI: 10.1016/j.ijpara.2014.08.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
Abstract
Predictive models of parasite life cycles increase our understanding of how parasite epidemiology is influenced by global changes and can be used to support decisions for more targeted worm control. Estimates of parasite population dynamics are needed to parameterize such models. The aim of this study was to quantify the main life history traits of Ostertagia ostertagi, economically the most important nematode of cattle in temperate regions. The main parameters determining parasite density during the parasitic phase of O. ostertagi are (i) the larval establishment rate, (ii) hypobiosis rate, (iii) adult mortality and (iv) female fecundity (number of eggs laid per day per female). A systematic review was performed covering studies from 1962 to 2007, in which helminth-naïve calves were artificially infected with O. ostertagi. The database was further extended with results of unpublished trials conducted at the Laboratory for Parasitology of Ghent University, Belgium. Overall inverse variance weighted estimates were computed for each of the traits through random effects models. An average establishment rate (±S.E.) of 0.269±0.022 was calculated based on data of 27 studies (46 experiments). The establishment rate declined when infection dose increased and was lower in younger animals. An average proportion of larvae entering hypobiosis (±S.E.) of 0.041 (±0.009) was calculated based on 27 studies (54 experiments). The proportion of ingested larvae that went into hypobiosis was higher in animals that received concomitant infections with nematode species other than O. ostertagi (mixed infections). An average daily adult mortality (±S.E.) of 0.028 (±0.002) was computed based on data from 28 studies (70 experiments). Adult mortality was positively correlated with infection dose. A daily fecundity (±S.E.) of 284 (±45) eggs per female was found based on nine studies (10 experiments). The average female sex ratio of O. ostertagi based on individual animal data (n=75) from six different studies was estimated to be 0.55. We believe that this systematic review is the first to summarise the available data on the main life history traits of the parasitic phase of O. ostertagi. In conclusion, this meta-analysis provides novel estimates for the parameterization of life cycle-based transmission models, explicitly reports measures of variance around these estimates, gives evidence for density dependence of larval establishment and adult mortality, shows that host age affects larval establishment and, to our knowledge, provides the first evidence for O. ostertagi of a female-biased sex ratio.
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Affiliation(s)
- S H Verschave
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
| | - J Vercruysse
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - E Claerebout
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - H Rose
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, United Kingdom; Cabot Institute, University of Bristol, Cantocks Close, Bristol BS8 1TS, United Kingdom
| | - E R Morgan
- Cabot Institute, University of Bristol, Cantocks Close, Bristol BS8 1TS, United Kingdom; School of Veterinary Sciences, University of Bristol, Langford House, Langford, Bristol BS40 5DU, United Kingdom
| | - J Charlier
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Fox NJ, Marion G, Davidson RS, White PCL, Hutchings MR. Modelling parasite transmission in a grazing system: the importance of host behaviour and immunity. PLoS One 2013; 8:e77996. [PMID: 24223133 PMCID: PMC3819330 DOI: 10.1371/journal.pone.0077996] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 09/14/2013] [Indexed: 11/18/2022] Open
Abstract
Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts' immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites' free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance) can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes is required to fully understand transmission dynamics. Understanding of both physiological and behavioural defence strategies will aid the development of novel approaches for control.
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Affiliation(s)
- Naomi J. Fox
- Disease Systems Team, SRUC, Edinburgh, United Kingdom
- Environment Department, University of York, York, United Kingdom
- Biomathematics and Statistics Scotland, Edinburgh, United Kingdom
| | - Glenn Marion
- Biomathematics and Statistics Scotland, Edinburgh, United Kingdom
- * E-mail:
| | - Ross S. Davidson
- Disease Systems Team, SRUC, Edinburgh, United Kingdom
- Biomathematics and Statistics Scotland, Edinburgh, United Kingdom
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Szyszka O, Kyriazakis I. What is the relationship between level of infection and ‘sickness behaviour’ in cattle? Appl Anim Behav Sci 2013. [DOI: 10.1016/j.applanim.2013.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Do the changes in the behaviours of cattle during parasitism with Ostertagia ostertagi have a potential diagnostic value? Vet Parasitol 2013; 193:214-22. [DOI: 10.1016/j.vetpar.2012.10.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/24/2012] [Accepted: 10/26/2012] [Indexed: 11/21/2022]
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Dobrowolski P, Tomaszewska E, Radzki RP, Bienko M, Wydrych J, Zdybel A, Pierzynowski SG. Can 2-oxoglutarate prevent changes in bone evoked by omeprazole? Nutrition 2012; 29:556-61. [PMID: 23218481 DOI: 10.1016/j.nut.2012.07.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/04/2012] [Accepted: 07/17/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Proton-pump inhibitors, such as omeprazole, are widely used in the prevention and treatment of gastroesophageal diseases. However, an association between proton-pump inhibitors and the increased risk of bone fractures has been observed, especially in patients treated for extended periods. Conversely, 2-oxoglutarate, a precursor of hydroxyproline, the most abundant amino acid in bone collagen, counteracts the bone loss. The aim of the present study was to elucidate the influence of omeprazole on bone and investigate whether dietary 2-oxoglutarate supplementation could prevent the effects of omeprazole. METHODS Eighteen male Sprague-Dawley rats were used. Rats received omeprazole in the diet and 2-oxoglutarate in the drinking water. Body and organ weights and serum concentrations of cholecystokinin and gastrin were measured. The femurs, tibias, and calvarias were collected. Histomorphometric analysis of bone and cartilage tissues was conducted. Bone densitometric and peripheral quantitative computed tomographic analyses of the femur and tibia were performed. RESULTS Omeprazole decreased the femur and tibia weights, the mechanical properties of the femur, the volumetric bone density and content, the trabecular and cortical bone mineral content, the total, trabecular, and cortical bone areas, the mean cortical thickness, and the periosteal circumference of the femur. Omeprazole had a minor effect on the examined bone morphology and exerted negligible effects on the cartilage. 2-Oxoglutarate lowered the gastrin concentration. CONCLUSIONS Omeprazole treatment exerts its effects mostly on bone mineralization and cancellous bone, adversely affecting bone properties. This adverse effect of omeprazole was not markedly abolished by 2-oxoglutaric acid, which acted as an anti-hypergastrinemic agent.
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Affiliation(s)
- Piotr Dobrowolski
- Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Lublin, Poland.
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Szyszka O, Tolkamp BJ, Edwards SA, Kyriazakis I. The effects of acute versus chronic health challenges on the behavior of beef cattle1. J Anim Sci 2012; 90:4308-18. [DOI: 10.2527/jas.2011-4765] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Schutz JS, Carroll JA, Gasbarre LC, Shelton TA, Nordstrom ST, Hutcheson JP, Van Campen H, Engle TE. Effects of gastrointestinal parasites on parasite burden, rectal temperature, and antibody titer responses to vaccination and infectious bovine rhinotracheitis virus challenge1. J Anim Sci 2012; 90:1948-54. [DOI: 10.2527/jas.2011-4059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J. S. Schutz
- Department of Animal Science, Colorado State University, Fort Collins 80523-1171
| | - J. A. Carroll
- USDA-ARS-Livestock Issues Research Unit, Lubbock, TX 79403
| | - L. C. Gasbarre
- Immunology and Disease Resistance Laboratory, USDA-ARS, Beltsville, MD 20705
| | - T. A. Shelton
- Intervet-Schering Plough Animal Health, De Soto, KS 66018
| | | | | | - H. Van Campen
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins 80523-1619
| | - T. E. Engle
- Department of Animal Science, Colorado State University, Fort Collins 80523-1171
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Luque A, Walker LR, Pedley JC, Pedley KC, Hillrichs K, Simpson HV, Simcock DC. Teladorsagia circumcincta: survival of adults in vitro is enhanced by the presence of a mammalian cell line. Exp Parasitol 2009; 124:247-51. [PMID: 19852958 DOI: 10.1016/j.exppara.2009.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 09/21/2009] [Accepted: 10/15/2009] [Indexed: 11/25/2022]
Abstract
Adult Teladorsagia circumcincta survival and motility in vitro was examined in a range of different cell culture media, supplements and gas mixes. Under optimum conditions, worms survived for 14 days, exhibiting high motility for 9 days and egg production for 72 h. Optimum conditions involved co-culture of worms with a HeLa cell line in a supplemented cell medium (CEM) and an atmosphere containing 10% CO(2), 5% O(2) 85% N(2), 65% humidity at 37 degrees C. The incubation medium consisted of Minimum Essential Medium with 10% fetal calf serum, 1% non-essential amino acids, 1% glutamax and 1% penicillin-neomycin-streptomycin cocktail mix. Compared with optimum conditions, incubation in CEM alone, cell conditioned CEM, RPMI alone, Medium 199 alone, reduced CO(2) or O(2), or when cells were replaced with Escherichia coli, both survival and motility were reduced. Optimum conditions for adult T. circumcincta maintenance for culture, anthelmintic testing or generation of excretory/secretory products are described.
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Affiliation(s)
- A Luque
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North 5301, New Zealand
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Forbes AB, Warren M, Upjohn M, Jackson B, Jones J, Charlier J, Fox MT. Associations between blood gastrin, ghrelin, leptin, pepsinogen and Ostertagia ostertagi antibody concentrations and voluntary feed intake in calves exposed to a trickle infection with O. ostertagi. Vet Parasitol 2009; 162:295-305. [PMID: 19342178 DOI: 10.1016/j.vetpar.2009.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 02/17/2009] [Accepted: 03/02/2009] [Indexed: 12/01/2022]
Abstract
Twenty-five, castrated male Holstein-cross calves, between 4 and 5 months of age, weighing 156.5+/-12.2 kg and reared under conditions designed to minimise the risk of parasitic infection, were allocated to one of the five treatment groups on the basis of initial bodyweight. The groups were (1) ad libitum (ad lib) fed controls (ALC); (2) ad lib fed infected (INF) and treated with topical eprinomectin on Day 56; (3) controls pair-fed with the INF group (PFC); (4) ad lib fed controls treated with eprinomectin on Days 0 and 56 (E-ALC) and (5) ad lib fed, infected and treated with eprinomectin on Days 0 and 56 (E-INF). Infection comprised a trickle infection with the equivalent of 10,000 larvae of Ostertagia ostertagi per day from Day 0 to Day 56 and the study concluded on Day 77. Parameters measured throughout the study included: liveweight, feed intake, faecal egg counts; plasma pepsinogen, gastrin, ghrelin and leptin; plasma antibodies to adult O. ostertagi. No significant differences in feed intake or liveweight gain were observed between any of the different groups, a finding thought to result from the high quality of feed offered. Significant differences between the INF and control groups however were observed in faecal egg counts, plasma pepsinogen, gastrin and O. ostertagi antibodies, which were all elevated, and leptin, which was reduced. Values of these parameters for the E-INF group were intermediate between the INF and ALC groups. Plasma ghrelin showed no association with either feed intake or parasitism. Further studies are needed to fully elucidate the roles of various biochemical and neuroendocrine mediators for inappetence in ruminants with parasitic gastroenteritis.
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Reinhardt CD, Hutcheson JP, Nichols WT. A fenbendazole oral drench in addition to an ivermectin pour-on reduces parasite burden and improves feedlot and carcass performance of finishing heifers compared with endectocides alone1. J Anim Sci 2006; 84:2243-50. [PMID: 16864886 DOI: 10.2527/jas.2005-598] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two studies utilizing 1,862 yearling heifers were conducted to determine the effects of a fenbendazole oral drench in addition to an ivermectin pour-on (SG+IVPO), compared with an ivermectin pour-on (IVPO) or a doramectin injectable (DMX) alone, on parasite burden, feedlot performance, and carcass merit of feedlot cattle. In the first study, heifers receiving the SG+IVPO had fewer (P = 0.02) cattle retreated for disease and 73% fewer (P = 0.06) worm eggs per fecal sample 98 d after treatment than heifers treated with IVPO. Heifers treated with SG+IVPO consumed more DM, had greater ADG, were heavier at slaughter, and had heavier carcasses than IVPO-treated heifers (P < 0.05). Heifers treated with SG+IVPO also had more (P = 0.07) carcasses grading USDA Prime or Choice than IVPO-treated heifers. In the second study, heifers treated with SG+IVPO had fewer (P < 0.01) worm eggs per fecal sample 35 d after treatment and had fewer numbers of adult and larval Cooperia and Trichostrongylus spp. in the small intestine at slaughter (P < 0.10) compared with heifers treated with DMX. Heifers treated with SG+IVPO consumed more DM, were heavier at slaughter, and had heavier carcasses than DMX-treated heifers (P < 0.01). The SG+IVPO-treated heifers also had greater ADG (P < 0.10). The broad-spectrum effectiveness of a combination of a fenbendazole oral drench and an ivermectin pour-on reduced parasite burden and increased feed intake, ADG, and carcass weight in feedlot heifers compared with treatment with an endectocide alone.
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Affiliation(s)
- C D Reinhardt
- Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506, USA.
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Fox MT, Reynolds GW, Scott I, Simcock DC, Simpson HV. Vagal and splanchnic afferent nerves are not essential for anorexia associated with abomasal parasitism in sheep. Vet Parasitol 2006; 135:287-95. [PMID: 16309842 DOI: 10.1016/j.vetpar.2005.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Accepted: 10/11/2005] [Indexed: 11/25/2022]
Abstract
Heavy burdens of the abomasal nematode, Ostertagia (Telodorsagia) circumcincta, in growing lambs result in a reduction in liveweight gain due largely to a drop in voluntary feed intake. The present study investigated: (1) the role of subdiaphragmatic vagal and non-vagal visceral afferent nerves in mediating a reduction in voluntary feed intake, using subdiaphragmatic vagal deafferentation (vagotomy) either alone or in combination with coeliac-superior mesenteric ganglionectomy (vagotomy and sympathectomy); and (2) the association between appetite, abomasal pH, selected blood values (amidated gastrin (G-17-amide), glycine-extended gastrin (G-17-Gly), pepsinogen and leptin) and worm burden, in sheep experimentally infected with 100,000 O. circumcincta infective larvae per os. Neither vagotomy alone nor vagotomy and sympathectomy in combination adversely affected the establishment or course of development of the parasite burden, when compared with a control group subject to sham surgery. Furthermore, neither surgical procedure prevented the drop in appetite seen 5-10 days post-infection, although combined vagotomy and sympathectomy did reduce voluntary feed intake prior to the start of the study. Ostertagia infection resulted in a significant increase in abomasal pH in all three groups, which was accompanied by an increase in blood G-17-amide and in G-17-Gly, the latter reported for the first time in parasitized ruminants. There were no significant differences in blood leptin, also reported for the first time in parasitized sheep, either between groups or in comparison with pre-infection levels, though weak negative correlations were established between blood leptin and appetite from day 5 to the end of the study in all three groups and a positive correlation with blood G-17-amide in the control group over the same period. These data suggest that neither intact subdiaphragmatic vagal afferent nerves or coeliac-superior mesenteric ganglion fibres, nor changes in circulating gastrin and leptin concentrations play a major role in mediating the hypophagic effects of O. circumcincta in parasitized sheep.
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Affiliation(s)
- M T Fox
- Department of Veterinary Pathology and Infectious Diseases, The Royal Veterinary College, Royal College Street, London NW1 OUT, UK.
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Ahmed AF, Constable PD, Misk NA. Effect of orally administered omeprazole on abomasal luminal pH in dairy calves fed milk replacer. ACTA ACUST UNITED AC 2005; 52:238-43. [PMID: 15943608 DOI: 10.1111/j.1439-0442.2005.00715.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The objective of this study was to determine whether oral administration of omeprazole, a proton-pump inhibitor, increased abomasal luminal pH in calves fed milk replacer. Four male dairy calves with cannulae in the abomasal body suckled milk replacer (60 ml/kg body weight every 12 h) and were administered a non-enteric-coated omeprazole (4 mg/kg body weight every 24 h) in a paste formulation for five successive days. Abomasal luminal pH was continuously measured using miniature glass pH electrodes. On the first day of omeprazole administration, there was a significant (P<0.05) increase in mean 24-h pH from 2.89 to 4.17. The mean 24-h pH on days 2, 3, 4 and 5 of omeprazole administration were 3.85, 4.02, 3.97 and 3.39 respectively. We conclude that oral administration of non-enteric-coated omeprazole increased abomasal luminal pH in calves fed milk replacer, but that the effect may decrease over time.
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Affiliation(s)
- A F Ahmed
- Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
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