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Hoyle DV, Wee BA, Macleod K, Chase-Topping ME, Bease AG, Tongue SC, Gally DL, Delannoy S, Fach P, Pearce MC, Gunn GJ, Holmes A, Allison L. Phylogenetic relationship and virulence composition of Escherichia coli O26:H11 cattle and human strain collections in Scotland; 2002-2020. Front Microbiol 2023; 14:1260422. [PMID: 38029122 PMCID: PMC10657854 DOI: 10.3389/fmicb.2023.1260422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/05/2023] [Indexed: 12/01/2023] Open
Abstract
O26 is the commonest non-O157 Shiga toxin (stx)-producing Escherichia coli serogroup reported in human infections worldwide. Ruminants, particularly cattle, are the primary reservoir source for human infection. In this study, we compared the whole genomes and virulence profiles of O26:H11 strains (n = 99) isolated from Scottish cattle with strains from human infections (n = 96) held by the Scottish Escherichia coli O157/STEC Reference Laboratory, isolated between 2002 and 2020. Bovine strains were from two national cross-sectional cattle surveys conducted between 2002-2004 and 2014-2015. A maximum likelihood phylogeny was constructed from a core-genome alignment with the O26:H11 strain 11368 reference genome. Genomes were screened against a panel of 2,710 virulence genes using the Virulence Finder Database. All stx-positive bovine O26:H11 strains belonged to the ST21 lineage and were grouped into three main clades. Bovine and human source strains were interspersed, and the stx subtype was relatively clade-specific. Highly pathogenic stx2a-only ST21 strains were identified in two herds sampled in the second cattle survey and in human clinical infections from 2010 onwards. The closest pairwise distance was 9 single-nucleotide polymorphisms (SNPs) between Scottish bovine and human strains and 69 SNPs between the two cattle surveys. Bovine O26:H11 was compared to public EnteroBase ST29 complex genomes and found to have the greatest commonality with O26:H11 strains from the rest of the UK, followed by France, Italy, and Belgium. Virulence profiles of stx-positive bovine and human strains were similar but more conserved for the stx2a subtype. O26:H11 stx-negative ST29 (n = 17) and ST396 strains (n = 5) were isolated from 19 cattle herds; all were eae-positive, and 10 of these herds yielded strains positive for ehxA, espK, and Z2098, gene markers suggestive of enterohaemorrhagic potential. There was a significant association (p < 0.001) between nucleotide sequence percent identity and stx status for the bacteriophage insertion site genes yecE for stx2 and yehV for stx1. Acquired antimicrobial resistance genes were identified in silico in 12.1% of bovine and 17.7% of human O26:H11 strains, with sul2, tet, aph(3″), and aph(6″) being most common. This study describes the diversity among Scottish bovine O26:H11 strains and investigates their relationship to human STEC infections.
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Affiliation(s)
- Deborah V. Hoyle
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Bryan A. Wee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Kareen Macleod
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Margo E. Chase-Topping
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Andrew G. Bease
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Sue C. Tongue
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College (SRUC), Inverness, United Kingdom
| | - David L. Gally
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Sabine Delannoy
- Unité ColiPath – Plateforme IdentyPath, Laboratoire de Sécurité des Aliments, Agence Nationale De Sécurité Sanitaire de l’alimentation, de l’environnement et du travail (ANSES), Maisons-Alfort, France
| | - Patrick Fach
- Unité ColiPath – Plateforme IdentyPath, Laboratoire de Sécurité des Aliments, Agence Nationale De Sécurité Sanitaire de l’alimentation, de l’environnement et du travail (ANSES), Maisons-Alfort, France
| | - Michael C. Pearce
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College (SRUC), Inverness, United Kingdom
| | - George J. Gunn
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College (SRUC), Inverness, United Kingdom
| | - Anne Holmes
- Scottish E. coli O157/STEC Reference Laboratory (SERL), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Lesley Allison
- Scottish E. coli O157/STEC Reference Laboratory (SERL), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
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2
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Mutch CP, Ross DA, Bularga A, Nicola Rose Cave R, Chase-Topping ME, Anand A, Mills NL, Koch O, Mackintosh CL, Perry MR. Performance status: A key factor in predicting mortality in the first wave of COVID-19 in South-East Scotland. J R Coll Physicians Edinb 2022; 52:204-212. [PMID: 36369813 PMCID: PMC9659484 DOI: 10.1177/14782715221120137] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/25/2023] Open
Abstract
BACKGROUND COVID-19 mortality risk factors have been established in large cohort studies; long-term mortality outcomes are less documented. METHODS We performed multivariable logistic regression to identify factors associated with in-patient mortality and intensive care unit (ICU) admission in symptomatic COVID-19 patients admitted to hospitals in South-East Scotland from 1st March to 30th June 2020. One-year mortality was reviewed. RESULTS Of 726 patients (median age 72; interquartile range: 58-83 years, 55% male), 104 (14%) required ICU admission and 199 (27%) died in hospital. A further 64 died between discharge and 30th June 2021 (36% overall 1-year mortality). Stepwise logistic regression identified age >79 (odds ratio (OR), 4.77 (95% confidence interval (CI), 1.96-12.75)), male sex (OR, 1.83 (95% CI, 1.21-2.80)) and higher European Cooperative Oncology Group/World Health Organization performance status as associated with higher mortality risk. DISCUSSION Poor functional baseline was the predominant independent risk factor for mortality in COVID-19. More than one-third of individuals had died by 1 year following admission.
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Affiliation(s)
- Callum P Mutch
- Clinical Infection Research Group, NHS Lothian Infection Service, Western General Hospital, Edinburgh, EH4 2JP, UK
| | - Daniella A Ross
- Clinical Infection Research Group, NHS Lothian Infection Service, Western General Hospital, Edinburgh, EH4 2JP, UK
| | - Anda Bularga
- BHF Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, UK
| | - Roo Nicola Rose Cave
- Epidemiology Research Group, Usher Institute, University of Edinburgh, Edinburgh, UK
| | - Margo E Chase-Topping
- Epidemiology Research Group, Usher Institute, University of Edinburgh, Edinburgh, UK
| | - Atul Anand
- BHF Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, UK
| | - Nicholas L Mills
- BHF Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, UK
- Epidemiology Research Group, Usher Institute, University of Edinburgh, Edinburgh, UK
| | - Oliver Koch
- Clinical Infection Research Group, NHS Lothian Infection Service, Western General Hospital, Edinburgh, EH4 2JP, UK
| | - Claire L Mackintosh
- Clinical Infection Research Group, NHS Lothian Infection Service, Western General Hospital, Edinburgh, EH4 2JP, UK
| | - Meghan R Perry
- Clinical Infection Research Group, NHS Lothian Infection Service, Western General Hospital, Edinburgh, EH4 2JP, UK
- Epidemiology Research Group, Usher Institute, University of Edinburgh, Edinburgh, UK
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3
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Fernández Rivas C, Porphyre T, Chase-Topping ME, Knapp CW, Williamson H, Barraud O, Tongue SC, Silva N, Currie C, Elsby DT, Hoyle DV. High Prevalence and Factors Associated With the Distribution of the Integron intI1 and intI2 Genes in Scottish Cattle Herds. Front Vet Sci 2021; 8:755833. [PMID: 34778436 PMCID: PMC8585936 DOI: 10.3389/fvets.2021.755833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Integrons are genetic elements that capture and express antimicrobial resistance genes within arrays, facilitating horizontal spread of multiple drug resistance in a range of bacterial species. The aim of this study was to estimate prevalence for class 1, 2, and 3 integrons in Scottish cattle and examine whether spatial, seasonal or herd management factors influenced integron herd status. We used fecal samples collected from 108 Scottish cattle herds in a national, cross-sectional survey between 2014 and 2015, and screened fecal DNA extracts by multiplex PCR for the integrase genes intI1, intI2, and intI3. Herd-level prevalence was estimated [95% confidence interval (CI)] for intI1 as 76.9% (67.8-84.0%) and intI2 as 82.4% (73.9-88.6%). We did not detect intI3 in any of the herd samples tested. A regional effect was observed for intI1, highest in the North East (OR 11.5, 95% CI: 1.0-130.9, P = 0.05) and South East (OR 8.7, 95% CI: 1.1-20.9, P = 0.04), lowest in the Highlands. A generalized linear mixed model was used to test for potential associations between herd status and cattle management, soil type and regional livestock density variables. Within the final multivariable model, factors associated with herd positivity for intI1 included spring season of the year (OR 6.3, 95% CI: 1.1-36.4, P = 0.04) and watering cattle from a natural spring source (OR 4.4, 95% CI: 1.3-14.8, P = 0.017), and cattle being housed at the time of sampling for intI2 (OR 75.0, 95% CI: 10.4-540.5, P < 0.001). This study provides baseline estimates for integron prevalence in Scottish cattle and identifies factors that may be associated with carriage that warrant future investigation.
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Affiliation(s)
- Cristina Fernández Rivas
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Scotland, United Kingdom
| | - Thibaud Porphyre
- Laboratoire de Biométrie et Biologie Évolutive, UMR5558, CNRS, VetAgro Sup, Université de Lyon, Villeurbanne Cedex, France
| | - Margo E Chase-Topping
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Scotland, United Kingdom
| | - Charles W Knapp
- Centre for Water, Environment, Sustainability and Public Health, Department of Civil & Environmental Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Helen Williamson
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Scotland, United Kingdom
| | - Olivier Barraud
- INSERM, CHU Limoges, UMR1092, Université de Limoges, Limoges, France
| | - Sue C Tongue
- Epidemiology Research Unit, Scotland's Rural College (SRUC), An Lòchran, Inverness Campus, Inverness, United Kingdom
| | - Nuno Silva
- Moredun Research Institute, Edinburgh, United Kingdom
| | - Carol Currie
- Moredun Research Institute, Edinburgh, United Kingdom
| | - Derek T Elsby
- Environmental Research Institute, University of the Highlands and Islands, Thurso, United Kingdom
| | - Deborah V Hoyle
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Scotland, United Kingdom
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4
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Porphyre T, Correia-Gomes C, Chase-Topping ME, Gamado K, Auty HK, Hutchinson I, Reeves A, Gunn GJ, Woolhouse MEJ. Vulnerability of the British swine industry to classical swine fever. Sci Rep 2017; 7:42992. [PMID: 28225040 PMCID: PMC5320472 DOI: 10.1038/srep42992] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 01/18/2017] [Indexed: 12/03/2022] Open
Abstract
Classical swine fever (CSF) is a notifiable, highly contagious viral disease of swine which results in severe welfare and economic consequences in affected countries. To improve preparedness, it is critical to have some understanding of how CSF would spread should it be introduced. Based on the data recorded during the 2000 epidemic of CSF in Great Britain (GB), a spatially explicit, premises-based model was developed to explore the risk of CSF spread in GB. We found that large outbreaks of CSF would be rare and generated from a limited number of areas in GB. Despite the consistently low vulnerability of the British swine industry to large CSF outbreaks, we identified concerns with respect to the role played by the non-commercial sector of the industry. The model further revealed how various epidemiological features may influence the spread of CSF in GB, highlighting the importance of between-farm biosecurity in preventing widespread dissemination of the virus. Knowledge of factors affecting the risk of spread are key components for surveillance planning and resource allocation, and this work provides a valuable stepping stone in guiding policy on CSF surveillance and control in GB.
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Affiliation(s)
- Thibaud Porphyre
- Epidemiology Research Group, Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, Scotland, UK
| | - Carla Correia-Gomes
- Epidemiology Research Unit, Future Farming Systems, Scotland's Rural College, Inverness, Scotland, UK
| | - Margo E Chase-Topping
- Epidemiology Research Group, Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, Scotland, UK
| | - Kokouvi Gamado
- Biomathematics &Statistics Scotland, Edinburgh, Scotland, UK
| | - Harriet K Auty
- Epidemiology Research Unit, Future Farming Systems, Scotland's Rural College, Inverness, Scotland, UK
| | - Ian Hutchinson
- Epidemiology Research Unit, Future Farming Systems, Scotland's Rural College, Inverness, Scotland, UK
| | - Aaron Reeves
- Epidemiology Research Unit, Future Farming Systems, Scotland's Rural College, Inverness, Scotland, UK
| | - George J Gunn
- Epidemiology Research Unit, Future Farming Systems, Scotland's Rural College, Inverness, Scotland, UK
| | - Mark E J Woolhouse
- Epidemiology Research Group, Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, Scotland, UK
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5
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Mainda G, Lupolova N, Sikakwa L, Bessell PR, Muma JB, Hoyle DV, McAteer SP, Gibbs K, Williams NJ, Sheppard SK, La Ragione RM, Cordoni G, Argyle SA, Wagner S, Chase-Topping ME, Dallman TJ, Stevens MP, Bronsvoort BMD, Gally DL. Phylogenomic approaches to determine the zoonotic potential of Shiga toxin-producing Escherichia coli (STEC) isolated from Zambian dairy cattle. Sci Rep 2016; 6:26589. [PMID: 27220895 PMCID: PMC4879551 DOI: 10.1038/srep26589] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/27/2016] [Indexed: 11/17/2022] Open
Abstract
This study assessed the prevalence and zoonotic potential of Shiga toxin-producing Escherichia coli (STEC) sampled from 104 dairy units in the central region of Zambia and compared these with isolates from patients presenting with diarrhoea in the same region. A subset of 297 E. coli strains were sequenced allowing in silico analyses of phylo- and sero-groups. The majority of the bovine strains clustered in the B1 ‘commensal’ phylogroup (67%) and included a diverse array of serogroups. 11% (41/371) of the isolates from Zambian dairy cattle contained Shiga toxin genes (stx) while none (0/73) of the human isolates were positive. While the toxicity of a subset of these isolates was demonstrated, none of the randomly selected STEC belonged to key serogroups associated with human disease and none encoded a type 3 secretion system synonymous with typical enterohaemorrhagic strains. Positive selection for E. coli O157:H7 across the farms identified only one positive isolate again indicating this serotype is rare in these animals. In summary, while Stx-encoding E. coli strains are common in this dairy population, the majority of these strains are unlikely to cause disease in humans. However, the threat remains of the emergence of strains virulent to humans from this reservoir.
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Affiliation(s)
- Geoffrey Mainda
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK.,Ministry Livestock and Fisheries, Kabwe, Zambia
| | - Nadejda Lupolova
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | | | - Paul R Bessell
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | | | - Deborah V Hoyle
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - Sean P McAteer
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | | | | | | | | | | | - Sally A Argyle
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - Sam Wagner
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | | | | | - Mark P Stevens
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | | | - David L Gally
- Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
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6
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Dallman TJ, Ashton PM, Byrne L, Perry NT, Petrovska L, Ellis R, Allison L, Hanson M, Holmes A, Gunn GJ, Chase-Topping ME, Woolhouse MEJ, Grant KA, Gally DL, Wain J, Jenkins C. Applying phylogenomics to understand the emergence of Shiga-toxin-producing Escherichia coli O157:H7 strains causing severe human disease in the UK. Microb Genom 2015; 1:e000029. [PMID: 28348814 PMCID: PMC5320567 DOI: 10.1099/mgen.0.000029] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 07/22/2015] [Indexed: 11/18/2022] Open
Abstract
Shiga-toxin-producing Escherichia coli (STEC) O157:H7 is a recently emerged zoonotic pathogen with considerable morbidity. Since the emergence of this serotype in the 1980s, research has focussed on unravelling the evolutionary events from the E. coli O55:H7 ancestor to the contemporaneous globally dispersed strains observed today. In this study, the genomes of over 1000 isolates from both human clinical cases and cattle, spanning the history of STEC O157:H7 in the UK, were sequenced. Phylogenetic analysis revealed the ancestry, key acquisition events and global context of the strains. Dated phylogenies estimated the time to evolution of the most recent common ancestor of the current circulating global clone to be 175 years ago. This event was followed by rapid diversification. We show the acquisition of specific virulence determinates has occurred relatively recently and coincides with its recent detection in the human population. We used clinical outcome data from 493 cases of STEC O157:H7 to assess the relative risk of severe disease including haemolytic uraemic syndrome from each of the defined clades in the population and show the dramatic effect Shiga toxin repertoire has on virulence. We describe two strain replacement events that have occurred in the cattle population in the UK over the last 30 years, one resulting in a highly virulent strain that has accounted for the majority of clinical cases in the UK over the last decade. There is a need to understand the selection pressures maintaining Shiga-toxin-encoding bacteriophages in the ruminant reservoir and the study affirms the requirement for close surveillance of this pathogen in both ruminant and human populations.
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Affiliation(s)
| | - Philip M Ashton
- Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Lisa Byrne
- Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Neil T Perry
- Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Liljana Petrovska
- Animal Laboratories and Plant Health Agency, Woodham Lane, Surrey KT15 3NB, UK
| | - Richard Ellis
- Animal Laboratories and Plant Health Agency, Woodham Lane, Surrey KT15 3NB, UK
| | - Lesley Allison
- Scottish E. coli O157/VTEC Reference Laboratory, Department of Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - Mary Hanson
- Scottish E. coli O157/VTEC Reference Laboratory, Department of Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - Anne Holmes
- Scottish E. coli O157/VTEC Reference Laboratory, Department of Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - George J Gunn
- Future Farming Systems, R&D Division, SRUC, Drummondhill, Stratherrick Rd., Inverness IV2 4JZ, Scotland, UK
| | - Margo E Chase-Topping
- Centre for Immunity, Infection and Evolution, Kings Buildings, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Mark E J Woolhouse
- Centre for Immunity, Infection and Evolution, Kings Buildings, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Kathie A Grant
- Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - David L Gally
- Division of Infection and Immunity, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin EH25 9RG, UK
| | - John Wain
- University of East Anglia, Norwich NR4 7TJ, UK
| | - Claire Jenkins
- Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
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7
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Hickey GL, Diggle PJ, McNeilly TN, Tongue SC, Chase-Topping ME, Williams DJ. Corrigendum to “The feasibility of testing whether Fasciola hepatica is associated with increased risk of verocytotoxin producing Escherichia coli O157 from an existing study protocol” [Prev. Vet. Med. 119 (2015) 97–104]. Prev Vet Med 2015. [PMCID: PMC4718928 DOI: 10.1016/j.prevetmed.2015.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Mainda G, Bessell PR, Bessell PB, Muma JB, McAteer SP, Chase-Topping ME, Gibbons J, Stevens MP, Gally DL, deC Bronsvoort BM. Prevalence and patterns of antimicrobial resistance among Escherichia coli isolated from Zambian dairy cattle across different production systems. Sci Rep 2015. [PMID: 26211388 PMCID: PMC4515737 DOI: 10.1038/srep12439] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This study focused on the use of antibiotics on small, medium and commercial-sized dairy farms in the central region of Zambia and its relationship to antibiotic resistance in Escherichia coli. A stratified random sample of 104 farms was studied, representing approximately 20% of all dairy farms in the region. On each farm, faecal samples were collected from a random sample of animals and a standardised questionnaire on the usage of antibiotics was completed. An E. coli isolate was obtained from 98.67% (371/376) of the sampled animals and tested for resistance to six classes of antibiotics. The estimated prevalence of resistance across the different farming systems was: tetracycline (10.61; 95%CI: 7.40–13.82), ampicillin (6.02; 95%CI: 3.31–8.73), sulfamethoxazole/ trimethoprim (4.49; 95%CI: 2.42–6.56), cefpodoxime (1.91; 95%CI: 0.46–3.36), gentamicin (0.89; 95%CI: 0.06–1.84) and ciprofloxacin (0%). Univariate analyses indicated certain diseases, exotic breeds, location, farm size and certain management practices as risk factors for detection of resistance, whereas multivariate analyses showed an association with lumpy skin disease and a protective effect for older animals (>25 months). This study has provided novel insights into the drivers of antibiotic use and their association with antibiotic resistance in an under-studied region of Southern Africa.
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Affiliation(s)
- Geoffrey Mainda
- 1] Divisions of Immunity and Infection, Veterinary Clinical Sciences [2] District Veterinary Office, Ministry of Agriculture and Livestock, P.O. Box 80285, Kabwe, Zambia
| | - Paul R Bessell
- Genetics and Genomics, The Roslin Institute and The Royal (Dick) School of Veterinary Sciences, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, United Kingdom
| | | | - John B Muma
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Zambia
| | - Sean P McAteer
- Divisions of Immunity and Infection, Veterinary Clinical Sciences
| | - Margo E Chase-Topping
- Centre for Immunity, Infection and Evolution, Kings Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, EH9 3FL, United Kingdom
| | - James Gibbons
- School of Veterinary Medicine, Veterinary Science Centre, Belfield, Dublin 4, Eire
| | - Mark P Stevens
- Divisions of Immunity and Infection, Veterinary Clinical Sciences
| | - David L Gally
- Divisions of Immunity and Infection, Veterinary Clinical Sciences
| | - Barend M deC Bronsvoort
- 1] Divisions of Immunity and Infection, Veterinary Clinical Sciences [2] Genetics and Genomics, The Roslin Institute and The Royal (Dick) School of Veterinary Sciences, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, United Kingdom
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9
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Hickey GL, Diggle PJ, McNeilly TN, Tongue SC, Chase-Topping ME, Williams DJL. The feasibility of testing whether Fasciola hepatica is associated with increased risk of verocytotoxin producing Escherichia coli O157 from an existing study protocol. Prev Vet Med 2015; 119:97-104. [PMID: 25779556 PMCID: PMC4401447 DOI: 10.1016/j.prevetmed.2015.02.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/19/2015] [Accepted: 02/22/2015] [Indexed: 02/04/2023]
Abstract
Interaction between Fasciola hepatica and VTEC O157 in cattle. Simulations that calculate statistical power for association between two pathogens. Simulation parameters for a study constrained by a pre-determined design. Augmenting a prospective study on VTEC O157 prevalence with a co-infection study. Results show an 87% power to detect an odds ratio of 2.
The parasite Fasciola hepatica is a major cause of economic loss to the agricultural community worldwide as a result of morbidity and mortality in livestock, including cattle. Cattle are the principle reservoir of verocytotoxigenic Escherichia coli O157 (VTEC O157), an important cause of disease in humans. To date there has been little empirical research on the interaction between F. hepatica and VTEC O157. It is hypothesised that F. hepatica, which is known to suppress type 1 immune responses and induce an anti-inflammatory or regulatory immune environment in the host, may promote colonisation of the bovine intestine with VTEC O157. Here we assess whether it is statistically feasible to augment a prospective study to quantify the prevalence of VTEC O157 in cattle in Great Britain with a pilot study to test this hypothesis. We simulate data under the framework of a mixed-effects logistic regression model in order to calculate the power to detect an association effect size (odds ratio) of 2. In order to reduce the resources required for such a study, we exploit the fact that the test results for VTEC O157 will be known in advance of testing for F. hepatica by restricting analysis to farms with a VTEC O157 sample prevalence of >0% and <100%. From a total of 270 farms (mean 27 cows per farm) that will be tested for VTEC O157, power of 87% can be achieved, whereby testing of F. hepatica would only be necessary for an expected 50 farms, thus considerably reducing costs. Pre-study sample size calculations are an important part of any study design. The framework developed here is applicable to the study of other co-infections.
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Affiliation(s)
- Graeme L Hickey
- Department of Epidemiology and Population Health, Institute of Infection and Global Heath, University of Liverpool, The Farr Institute@HeRC, Waterhouse Building, 1-5 Brownlow Street, Liverpool L69 3GL, UK.
| | - Peter J Diggle
- Department of Epidemiology and Population Health, Institute of Infection and Global Heath, University of Liverpool, The Farr Institute@HeRC, Waterhouse Building, 1-5 Brownlow Street, Liverpool L69 3GL, UK
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands, Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Sue C Tongue
- SRUC (Scotland's Rural College), West Mains Road, Edinburgh, Scotland EH9 3JG, UK
| | - Margo E Chase-Topping
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK
| | - Diana J L Williams
- Department of Infection Biology, Institute of Infection and Global Heath, University of Liverpool, Liverpool L69 7ZJ, UK; School of Veterinary Science, University of Liverpool, Leahurst Campus, Chester High Road, Neston CH64 7TE, UK
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10
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Schnettler E, Tykalová H, Watson M, Sharma M, Sterken MG, Obbard DJ, Lewis SH, McFarlane M, Bell-Sakyi L, Barry G, Weisheit S, Best SM, Kuhn RJ, Pijlman GP, Chase-Topping ME, Gould EA, Grubhoffer L, Fazakerley JK, Kohl A. Induction and suppression of tick cell antiviral RNAi responses by tick-borne flaviviruses. Nucleic Acids Res 2014; 42:9436-46. [PMID: 25053841 PMCID: PMC4132761 DOI: 10.1093/nar/gku657] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Arboviruses are transmitted by distantly related arthropod vectors such as mosquitoes (class Insecta) and ticks (class Arachnida). RNA interference (RNAi) is the major antiviral mechanism in arthropods against arboviruses. Unlike in mosquitoes, tick antiviral RNAi is not understood, although this information is important to compare arbovirus/host interactions in different classes of arbovirus vectos. Using an Ixodes scapularis-derived cell line, key Argonaute proteins involved in RNAi and the response against tick-borne Langat virus (Flaviviridae) replication were identified and phylogenetic relationships characterized. Analysis of small RNAs in infected cells showed the production of virus-derived small interfering RNAs (viRNAs), which are key molecules of the antiviral RNAi response. Importantly, viRNAs were longer (22 nucleotides) than those from other arbovirus vectors and mapped at highest frequency to the termini of the viral genome, as opposed to mosquito-borne flaviviruses. Moreover, tick-borne flaviviruses expressed subgenomic flavivirus RNAs that interfere with tick RNAi. Our results characterize the antiviral RNAi response in tick cells including phylogenetic analysis of genes encoding antiviral proteins, and viral interference with this pathway. This shows important differences in antiviral RNAi between the two major classes of arbovirus vectors, and our data broadens our understanding of arthropod antiviral RNAi.
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Affiliation(s)
- Esther Schnettler
- MRC - University of Glasgow Centre for Virus Research, Glasgow G11 5JR, UK The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Hana Tykalová
- Faculty of Science, University of South Bohemia and Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice (Budweis), Czech Republic
| | - Mick Watson
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Mayuri Sharma
- Markey Centre for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette IN 47907, USA
| | - Mark G Sterken
- Laboratory of Virology, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Darren J Obbard
- Institute of Evolutionary Biology and Centre for Infection Immunity and Evolution, University of Edinburgh, EH9 3JT, UK
| | - Samuel H Lewis
- Institute of Evolutionary Biology and Centre for Infection Immunity and Evolution, University of Edinburgh, EH9 3JT, UK
| | - Melanie McFarlane
- MRC - University of Glasgow Centre for Virus Research, Glasgow G11 5JR, UK
| | - Lesley Bell-Sakyi
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Gerald Barry
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Sabine Weisheit
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Sonja M Best
- Innate Immunity and Pathogenesis Unit, Laboratory of Virology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
| | - Richard J Kuhn
- Markey Centre for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette IN 47907, USA
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University, 6708 PB Wageningen, The Netherlands
| | | | - Ernest A Gould
- Unité des Virus Emergents, Faculté de Médicine Timone, 13385 Marseille Cedex 05, France Centre for Hydrology and Ecology, Maclean Building, Oxon OX10 8BB, UK
| | - Libor Grubhoffer
- Faculty of Science, University of South Bohemia and Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice (Budweis), Czech Republic
| | - John K Fazakerley
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Alain Kohl
- MRC - University of Glasgow Centre for Virus Research, Glasgow G11 5JR, UK The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
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11
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Herbert LJ, Vali L, Hoyle DV, Innocent G, McKendrick IJ, Pearce MC, Mellor D, Porphyre T, Locking M, Allison L, Hanson M, Matthews L, Gunn GJ, Woolhouse ME, Chase-Topping ME. E. coli O157 on Scottish cattle farms: evidence of local spread and persistence using repeat cross-sectional data. BMC Vet Res 2014; 10:95. [PMID: 24766709 PMCID: PMC4022360 DOI: 10.1186/1746-6148-10-95] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 03/26/2014] [Indexed: 11/30/2022] Open
Abstract
Background Escherichia coli (E. coli) O157 is a virulent zoonotic strain of enterohaemorrhagic E. coli. In Scotland (1998-2008) the annual reported rate of human infection is 4.4 per 100,000 population which is consistently higher than other regions of the UK and abroad. Cattle are the primary reservoir. Thus understanding infection dynamics in cattle is paramount to reducing human infections. A large database was created for farms sampled in two cross-sectional surveys carried out in Scotland (1998 - 2004). A statistical model was generated to identify risk factors for the presence of E. coli O157 on farms. Specific hypotheses were tested regarding the presence of E. coli O157 on local farms and the farms previous status. Pulsed-field gel electrophoresis (PFGE) profiles were further examined to ascertain whether local spread or persistence of strains could be inferred. Results The presence of an E. coli O157 positive local farm (average distance: 5.96km) in the Highlands, North East and South West, farm size and the number of cattle moved onto the farm 8 weeks prior to sampling were significant risk factors for the presence of E. coli O157 on farms. Previous status of a farm was not a significant predictor of current status (p = 0.398). Farms within the same sampling cluster were significantly more likely to be the same PFGE type (p < 0.001), implicating spread of strains between local farms. Isolates with identical PFGE types were observed to persist across the two surveys, including 3 that were identified on the same farm, suggesting an environmental reservoir. PFGE types that were persistent were more likely to have been observed in human clinical infections in Scotland (p < 0.001) from the same time frame. Conclusions The results of this study demonstrate the spread of E. coli O157 between local farms and highlight the potential link between persistent cattle strains and human clinical infections in Scotland. This novel insight into the epidemiology of Scottish E. coli O157 paves the way for future research into the mechanisms of transmission which should help with the design of control measures to reduce E. coli O157 from livestock-related sources.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Margo E Chase-Topping
- Centre for Immunity, Infection and Evolution, University of Edinburgh, King's Buildings, Edinburgh, UK.
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12
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Chase-Topping ME, Handel I, Bankowski BM, Juleff ND, Gibson D, Cox SJ, Windsor MA, Reid E, Doel C, Howey R, Barnett PV, Woolhouse MEJ, Charleston B. Understanding foot-and-mouth disease virus transmission biology: identification of the indicators of infectiousness. Vet Res 2013; 44:46. [PMID: 23822567 PMCID: PMC3716626 DOI: 10.1186/1297-9716-44-46] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 06/05/2013] [Indexed: 11/28/2022] Open
Abstract
The control of foot-and-mouth disease virus (FMDV) outbreaks in non-endemic countries relies on the rapid detection and removal of infected animals. In this paper we use the observed relationship between the onset of clinical signs and direct contact transmission of FMDV to identify predictors for the onset of clinical signs and identify possible approaches to preclinical screening in the field. Threshold levels for various virological and immunological variables were determined using Receiver Operating Characteristic (ROC) curve analysis and then tested using generalized linear mixed models to determine their ability to predict the onset of clinical signs. In addition, concordance statistics between qualitative real time PCR test results and virus isolation results were evaluated. For the majority of animals (71%), the onset of clinical signs occurred 3-4 days post infection. The onset of clinical signs was associated with high levels of virus in the blood, oropharyngeal fluid and nasal fluid. Virus is first detectable in the oropharyngeal fluid, but detection of virus in the blood and nasal fluid may also be good candidates for preclinical indicators. Detection of virus in the air was also significantly associated with transmission. This study is the first to identify statistically significant indicators of infectiousness for FMDV at defined time periods during disease progression in a natural host species. Identifying factors associated with infectiousness will advance our understanding of transmission mechanisms and refine intra-herd and inter-herd disease transmission models.
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Affiliation(s)
- Margo E Chase-Topping
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - Ian Handel
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom
| | | | | | - Debi Gibson
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom
| | - Sarah J Cox
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom
| | | | - Elizabeth Reid
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom
| | - Claudia Doel
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom
| | - Richard Howey
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Paul V Barnett
- The Pirbright Institute, Surrey GU24 0NF, United Kingdom
| | - Mark EJ Woolhouse
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
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13
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Rodriguez-Andres J, Rani S, Varjak M, Chase-Topping ME, Beck MH, Ferguson MC, Schnettler E, Fragkoudis R, Barry G, Merits A, Fazakerley JK, Strand MR, Kohl A. Phenoloxidase activity acts as a mosquito innate immune response against infection with Semliki Forest virus. PLoS Pathog 2012; 8:e1002977. [PMID: 23144608 PMCID: PMC3493465 DOI: 10.1371/journal.ppat.1002977] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 09/05/2012] [Indexed: 02/05/2023] Open
Abstract
Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest virus (SFV) (Togaviridae; Alphavirus). Production of recombinant SFV expressing the PO cascade inhibitor Egf1.0 blocked PO activity in U4.4 cell- conditioned medium, which resulted in enhanced spread of SFV. Infection of adult female Aedes aegypti by feeding mosquitoes a bloodmeal containing Egf1.0-expressing SFV increased virus replication and mosquito mortality. Collectively, these results suggest the PO cascade of mosquitoes plays an important role in immune defence against arboviruses. Arboviruses are transmitted to vertebrates by arthropod vectors such as mosquitoes. Infection of mosquitoes with arboviruses activates immune defence responses including the RNA interference pathway. Another component of the insect immune system is the phenoloxidase (PO) cascade, which produces melanin that accumulates at wound sites and around invading microorganisms. Some pathogen-associated pattern recognition molecules are known to activate the PO cascade, which results in the proteolytic processing of inactive prophenoloxidase (PPO) to PO. PO then catalyses the formation of compounds that ultimately form melanin. Some of these products are also known to have anti-microbial properties but whether activation of the PO cascade provides any defence against arboviruses is unclear. Using the arbovirus, Semliki Forest virus, we show that this virus activates the PO cascade. By using recombinant Semliki Forest virus expressing an inhibitor of the PO cascade, we also demonstrate that this pathway inhibits virus spread in cell culture. Moreover, inhibition of this pathway leads to higher virus genome levels and higher mortality of infected mosquitoes. In conclusion, Semliki Forest virus activates the PO cascade which exhibits antiviral activity and can be added to the list of mosquito anti-viral defence mechanisms.
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Affiliation(s)
- Julio Rodriguez-Andres
- The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
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14
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Ciccolini M, Dahl J, Chase-Topping ME, Woolhouse MEJ. Disease transmission on fragmented contact networks: livestock-associated Methicillin-resistant Staphylococcus aureus in the Danish pig-industry. Epidemics 2012; 4:171-8. [PMID: 23351369 DOI: 10.1016/j.epidem.2012.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 08/17/2012] [Accepted: 09/07/2012] [Indexed: 11/28/2022] Open
Abstract
Animal trade in industrialised livestock-production systems creates a complex, heterogeneous, contact network that shapes between-herd transmission of infectious diseases. We report the results of a simple mathematical model that explores patterns of spread and persistence of livestock-associated Methicillin-resistant Staphylococcus aureus (LA-MRSA) in the Danish pig-industry associated with this trade network. Simulations show that LA-MRSA can become endemic sustained by animal movements alone. Despite the extremely low predicted endemic prevalence, eradication may be difficult, and decreasing within-farm prevalence, or the time it takes a LA-MRSA positive farm to recover a negative status, fails to break long-term persistence. Our results suggest that a low level of non-movement induced transmission strongly affects MRSA dynamics, increasing endemic prevalence and probability of persistence. We also compare the model-predicted risk of 291 individual farms becoming MRSA positive, with results from a recent Europe-wide survey of LA-MRSA in holdings with breeding pigs, and find a significant correlation between contact-network connectivity properties and the model-estimated risk measure.
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Affiliation(s)
- M Ciccolini
- Centre for Immunity, Infection and Evolution, University of Edinburgh, King's Buildings, UK.
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15
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Chase-Topping ME, Rosser T, Allison LJ, Courcier E, Evans J, McKendrick IJ, Pearce MC, Handel I, Caprioli A, Karch H, Hanson MF, Pollock KGJ, Locking ME, Woolhouse MEJ, Matthews L, Low JC, Gally DL. Pathogenic potential to humans of bovine Escherichia coli O26, Scotland. Emerg Infect Dis 2012; 18:439-48. [PMID: 22377426 PMCID: PMC3309639 DOI: 10.3201/eid1803.111236] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin-producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx(2) in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26-associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx(2) phage acquisition.
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Affiliation(s)
- Margo E Chase-Topping
- Centre for Immunity, Infection, and Evolution, University of Edinburgh, Kings Buildings, Edinburgh EH9 3J5, UK.
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16
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Zhang XS, Chase-Topping ME, McKendrick IJ, Savill NJ, Woolhouse ME. Spread of E. coli O157 infection among Scottish cattle farms: stochastic models and model selection. Epidemics 2011; 2:11-20. [PMID: 20640032 PMCID: PMC2890141 DOI: 10.1016/j.epidem.2010.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 01/29/2010] [Accepted: 02/02/2010] [Indexed: 12/14/2022] Open
Abstract
Identifying risk factors for the presence of Escherichia coli O157 infection on cattle farms is important for understanding the epidemiology of this zoonotic infection in its main reservoir and for informing the design of interventions to reduce the public health risk. Here, we use data from a large-scale field study carried out in Scotland to fit both "SIS"-type dynamical models and statistical risk factor models. By comparing the fit (assessed using maximum likelihood) of different dynamical models we are able to identify the most parsimonious model (using the AIC statistic) and compare it with the model suggested by risk factor analysis. Both approaches identify 2 key risk factors: the movement of cattle onto the farm and the number of cattle on the farm. There was no evidence for a role of other livestock species or seasonality, or of significant risk of local spread. However, the most parsimonious dynamical model does predict that farms can infect other farms through routes other than cattle movement, and that there is a nonlinear relationship between the force of infection and the number of infected farms. An important prediction from the most parsimonious model is that although only approximately 20% farms may harbour E. coli O157 infection at any given time approximately 80% may harbour infection at some point during the course of a year.
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Affiliation(s)
- Xu-Sheng Zhang
- Centre for Infectious Diseases, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
- Corresponding author. Present address: Statistics, Modelling and Bioinformatics Department, Health Protection Agency, Centre for Infections, London, NW9 5EQ, UK.
| | - Margo E. Chase-Topping
- Centre for Infectious Diseases, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - Iain J. McKendrick
- Biomathematics and Statistics Scotland (BioSS), James Clerk Maxwell Building, Kings Buildings, Edinburgh, EH9 3JZ, UK
| | - Nicholas J. Savill
- Centre for Infectious Diseases, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
| | - Mark E.J. Woolhouse
- Centre for Infectious Diseases, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK
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17
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McLeish NJ, Simmonds P, Robertson C, Handel I, McGilchrist M, Singh BK, Kerr S, Chase-Topping ME, Sinka K, Bronsvoort M, Porteous DJ, Carman W, McMenamin J, Leigh-Brown A, Woolhouse MEJ. Sero-prevalence and incidence of A/H1N1 2009 influenza infection in Scotland in winter 2009-2010. PLoS One 2011; 6:e20358. [PMID: 21687661 PMCID: PMC3110753 DOI: 10.1371/journal.pone.0020358] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 04/20/2011] [Indexed: 11/18/2022] Open
Abstract
Background Sero-prevalence is a valuable indicator of prevalence and incidence of A/H1N1 2009 infection. However, raw sero-prevalence data must be corrected for background levels of cross-reactivity (i.e. imperfect test specificity) and the effects of immunisation programmes. Methods and Findings We obtained serum samples from a representative sample of 1563 adults resident in Scotland between late October 2009 and April 2010. Based on a microneutralisation assay, we estimate that 44% (95% confidence intervals (CIs): 40–47%) of the adult population of Scotland were sero-positive for A/H1N1 2009 influenza by 1 March 2010. Correcting for background cross-reactivity and for recorded vaccination rates by time and age group, we estimated that 34% (27–42%) were naturally infected with A/H1N1 2009 by 1 March 2010. The central estimate increases to >40% if we allow for imperfect test sensitivity. Over half of these infections are estimated to have occurred during the study period and the incidence of infection in late October 2009 was estimated at 4.3 new infections per 1000 people per day (1.2 to 7.2), falling close to zero by April 2010. The central estimate increases to over 5.0 per 1000 if we allow for imperfect test specificity. The rate of infection was higher for younger adults than older adults. Raw sero-prevalences were significantly higher in more deprived areas (likelihood ratio trend statistic = 4.92,1 df, P = 0.03) but there was no evidence of any difference in vaccination rates. Conclusions We estimate that almost half the adult population of Scotland were sero-positive for A/H1N1 2009 influenza by early 2010 and that the majority of these individuals (except in the oldest age classes) sero-converted as a result of natural infection with A/H1N1 2009. Public health planning should consider the possibility of higher rates of infection with A/H1N1 2009 influenza in more deprived areas.
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Affiliation(s)
- Nigel J. McLeish
- Centre for Infectious Diseases, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Peter Simmonds
- Centre for Infectious Diseases, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Chris Robertson
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, United Kingdom
- Health Protection Scotland, Glasgow, United Kingdom
| | - Ian Handel
- Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark McGilchrist
- Health Informatics Centre, University of Dundee, Dundee, United Kingdom
| | - Brajendra K. Singh
- Centre for Infectious Diseases, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Shona Kerr
- Molecular Medicine Centre, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Margo E. Chase-Topping
- Centres for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Katy Sinka
- Health Protection Scotland, Glasgow, United Kingdom
| | - Mark Bronsvoort
- Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - David J. Porteous
- Molecular Medicine Centre, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - William Carman
- West of Scotland Specialist Virology Centre, Gartnavel General Hospital, Glasgow, United Kingdom
| | | | - Andrew Leigh-Brown
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark E. J. Woolhouse
- Centre for Infectious Diseases, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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18
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Charleston B, Bankowski BM, Gubbins S, Chase-Topping ME, Schley D, Howey R, Barnett PV, Gibson D, Juleff ND, Woolhouse MEJ. Relationship between clinical signs and transmission of an infectious disease and the implications for control. Science 2011; 332:726-9. [PMID: 21551063 PMCID: PMC5844461 DOI: 10.1126/science.1199884] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Control of many infectious diseases relies on the detection of clinical cases and the isolation, removal, or treatment of cases and their contacts. The success of such "reactive" strategies is influenced by the fraction of transmission occurring before signs appear. We performed experimental studies of foot-and-mouth disease transmission in cattle and estimated this fraction at less than half the value expected from detecting virus in body fluids, the standard proxy measure of infectiousness. This is because the infectious period is shorter (mean 1.7 days) than currently realized, and animals are not infectious until, on average, 0.5 days after clinical signs appear. These results imply that controversial preemptive control measures may be unnecessary; instead, efforts should be directed at early detection of infection and rapid intervention.
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Affiliation(s)
- Bryan Charleston
- Institute for Animal Health, Pirbright Laboratory, Ash Road, Woking, Surrey GU24 0NF, UK.
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Abstract
REASON FOR PERFORMING STUDY The recovery quality scoring systems (RQSSs) in current use have not been critically reviewed for reliability. OBJECTIVE To examine reliability (reproducibility) of 4 RQSSs when applied to a ranked series. METHODS A DVD incorporating the recordings of 9 horses recovering from general anaesthesia was evaluated by final year students over 5 days. On Day 1, each evaluator ranked recoveries from 1-9 (1 = best). Over the following 4 days, each evaluator scored the same recoveries using 4 different RQSSs (3 of them in common usage and previously published) applied in random order. The scores from each RQSS were ranked and plotted against the Day 1 ranking of each evaluator to establish the extent of agreement using generalisability theory. The same 9 recoveries were also ranked by 12 experienced equine anaesthetists and the Spearman Rank Correlation coefficient calculated to determine the agreement between experienced and inexperienced evaluators. RESULTS The recoveries were evaluated by 117 students. All 4 RQSSs were equally reliable with low (<4%) interobserver variability. The main (80%) source of total variation arose from differences between horses. The overall ranking within each RQSS was strongly correlated with Day 1 ranking. There was strong correlation (r = 0.983) between the students' ranking and that established by experienced anaesthetists. Interobserver reliability was similar with all 4 RQSSs. CONCLUSION All 4 RQSSs studied were similarly reliable. POTENTIAL RELEVANCE The selection of a universally acceptable RQSS from amongst the 4 examined can be based on criteria other than reliability, e.g. ease of use. This will facilitate wider scale multi-centre studies in recovery quality after anaesthesia in horses.
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Affiliation(s)
- E Vettorato
- Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush Veterinary Centre, Midlothian.
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20
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Viñuela-Fernández I, Jones E, Chase-Topping ME, Price J. Comparison of subjective scoring systems used to evaluate equine laminitis. Vet J 2010; 188:171-7. [PMID: 20541956 DOI: 10.1016/j.tvjl.2010.05.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Revised: 05/06/2010] [Accepted: 05/07/2010] [Indexed: 11/30/2022]
Abstract
This study compared three subjective scoring systems used to assess lameness associated with equine laminitis: (1) visual analogue scale, (2) Obel score and (3) clinical grading system (CGS). Two groups of 12 observers, consisting of equine veterinarians and final-year veterinary students, scored lameness severity after watching video footage of 14 horses on two occasions. Generalizability theory was used to investigate the reliability of the three systems and the effects of observer experience. Overall reliability across all times and observers was high. Intra-observer reliability was higher than inter-observer reliability for all scoring systems, with student reliability being consistently lower than veterinarians, especially for Obel and CGS. All three methods were reasonably reliable tools for assessing lameness, but they were more limited in the hands of inexperienced observers.
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Affiliation(s)
- I Viñuela-Fernández
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, UK.
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Pearce MC, Chase-Topping ME, McKendrick IJ, Mellor DJ, Locking ME, Allison L, Ternent HE, Matthews L, Knight HI, Smith AW, Synge BA, Reilly W, Low JC, Reid SWJ, Gunn GJ, Woolhouse MEJ. Temporal and spatial patterns of bovine Escherichia coli O157 prevalence and comparison of temporal changes in the patterns of phage types associated with bovine shedding and human E. coli O157 cases in Scotland between 1998-2000 and 2002-2004. BMC Microbiol 2009; 9:276. [PMID: 20040112 PMCID: PMC2808314 DOI: 10.1186/1471-2180-9-276] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 12/29/2009] [Indexed: 11/10/2022] Open
Abstract
Background Escherichia coli O157 is an important cause of acute diarrhoea, haemorrhagic colitis and, especially in children, haemolytic uraemic syndrome (HUS). Incidence rates for human E. coli O157 infection in Scotland are higher than most other United Kingdom, European and North American countries. Cattle are considered the main reservoir for E. coli O157. Significant associations between livestock related exposures and human infection have been identified in a number of studies. Results Animal Studies: There were no statistically significant differences (P = 0.831) in the mean farm-level prevalence between the two studies (SEERAD: 0.218 (95%CI: 0.141-0.32); IPRAVE: 0.205 (95%CI: 0.135-0.296)). However, the mean pat-level prevalence decreased from 0.089 (95%CI: 0.075-0.105) to 0.040 (95%CI: 0.028-0.053) between the SEERAD and IPRAVE studies respectively (P < 0.001). Highly significant (P < 0.001) reductions in mean pat-level prevalence were also observed in the spring, in the North East and Central Scotland, and in the shedding of phage type (PT) 21/28. Human Cases: Contrasting the same time periods, there was a decline in the overall comparative annual reported incidence of human cases as well as in all the major PT groups except 'Other' PTs. For both cattle and humans, the predominant phage type between 1998 and 2004 was PT21/28 comprising over 50% of the positive cattle isolates and reported human cases respectively. The proportion of PT32, however, was represented by few (<5%) of reported human cases despite comprising over 10% of cattle isolates. Across the two studies there were differences in the proportion of PTs 21/28, 32 and 'Other' PTs in both cattle isolates and reported human cases; however, only differences in the cattle isolates were statistically significant (P = 0.002). Conclusion There was no significant decrease in the mean farm-level prevalence of E. coli O157 between 1998 and 2004 in Scotland, despite significant declines in mean pat-level prevalence. Although there were declines in the number of human cases between the two study periods, there is no statistically significant evidence that the overall rate (per 100,000 population) of human E. coli O157 infections in Scotland over the last 10 years has altered. Comparable patterns in the distribution of PTs 21/28 and 32 between cattle and humans support a hypothesized link between the bovine reservoir and human infections. This emphasizes the need to apply and improve methods to reduce bovine shedding of E. coli O157 in Scotland where rates appear higher in both cattle and human populations, than in other countries.
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Abstract
OBJECTIVE To investigate the effects of peri-operative morphine on the quality and duration of recovery from halothane anaesthesia in horses. STUDY DESIGN Prospective randomized study. ANIMALS Twenty-two client owned horses, ASA category I or II. METHODS Horses undergoing elective surgical procedures were divided into two groups and paired according to procedure, body position during surgery, body mass and breed. Group M+ received morphine by intravenous injection (0.15 mg kg(-1)) before induction of anaesthesia and then by infusion (0.1 mg kg(-1) hour(-1)) during anaesthesia. Group M- received the same anaesthetic agents except that morphine was excluded. At the end of surgery, the horses were placed in a recovery box and allowed to recover without assistance. Recoveries were recorded on videotape, beginning when the anaesthetist left the recovery box, and ending when the horse stood up. Recoveries were assessed from digital video recordings by three observers, unaware of treatment. The time to first movement, attempting and attaining sternal recumbency and standing were recorded. The quality of various aspects of the recovery was assessed to produce a total recovery score; high numerical values indicate poor recoveries. The duration of anaesthesia and the total dose of morphine administered were recorded. RESULTS The mean morphine dose (95% CI) was 147 (135-160) mg [equivalent to 0.27 (0.25-0.29) mg kg(-1)]. The recovery scores (median, 95% CI) for the M- and M+ groups were 25, 19-41 and 20, 14-26, respectively. Total score increased as duration of anaesthesia increased, independent of treatment. Untreated (M-) horses made more attempts to achieve sternal recumbency: mean number of attempts (95% CI) for M- was 4.5 (2.7-6.2) compared with 2.0 (1.4-2.6) (M+). Untreated horses made more attempts to stand (2.1, 1.6-2.6) compared with the morphine recipients (1.3, 1.1-1.5). Time to standing (in minutes) was significantly (p = 0.0146) longer for the untreated (31.3, 24.3-38.3) compared with treated animals (26.6, 20.9-32.3). The interval between the first movement in recovery to the time at standing was significantly (p < 0.001) longer for M- (14.5, 12.1-16.9 minutes) compared with M+ animals (7.4, 5.0-9.8 minutes). CONCLUSIONS AND CLINICAL RELEVANCE Recoveries from anaesthesia in the morphine recipients were characterized by fewer attempts to attain sternal recumbency and standing, and a shorter time from the first recovery movement to the time of standing.
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Affiliation(s)
- Louise Clark
- Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Roslin, Midlothian, UK.
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Chase-Topping ME, McKendrick IJ, Pearce MC, MacDonald P, Matthews L, Halliday J, Allison L, Fenlon D, Low JC, Gunn G, Woolhouse MEJ. Risk factors for the presence of high-level shedders of Escherichia coli O157 on Scottish farms. J Clin Microbiol 2007; 45:1594-603. [PMID: 17360845 PMCID: PMC1865900 DOI: 10.1128/jcm.01690-06] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli O157 infections are the cause of sporadic or epidemic cases of often bloody diarrhea that can progress to hemolytic uremic syndrome (HUS), a systematic microvascular syndrome with predominantly renal and neurological complications. HUS is responsible for most deaths associated with E. coli O157 infection. From March 2002 to February 2004, approximately 13,000 fecal pat samples from 481 farms with finishing/store cattle throughout Scotland were examined for the presence of E. coli O157. A total of 441 fecal pats from 91 farms tested positive for E. coli O157. From the positive samples, a point estimate for high-level shedders was identified using mixture distribution analysis on counts of E. coli O157. Models were developed based on the confidence interval surrounding this point estimate (high-level shedder, greater than 10(3) or greater than 10(4) CFU g(-1) feces). The mean prevalence on high-level-shedding farms was higher than that on low-level-shedding farms. The presence of a high-level shedder on a farm was found to be associated with a high proportion of low-level shedding, consistent with the possibility of a higher level of transmission. Analysis of risk factors associated with the presence of a high-level shedder on a farm suggested the importance of the pathogen and individual host rather than the farm environment. The proportion of high-level shedders of phage 21/28 was higher than expected by chance. Management-related risk factors that were identified included the type of cattle (female breeding cattle) and cattle stress (movement and weaning), as opposed to environmental factors, such as water supply and feed.
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Halliday JEB, Chase-Topping ME, Pearce MC, McKendrick IJ, Allison L, Fenlon D, Low C, Mellor DJ, Gunn GJ, Woolhouse MEJ. Herd-level risk factors associated with the presence of Phage type 21/28 E. coli O157 on Scottish cattle farms. BMC Microbiol 2006; 6:99. [PMID: 17140453 PMCID: PMC1713242 DOI: 10.1186/1471-2180-6-99] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Accepted: 12/02/2006] [Indexed: 11/10/2022] Open
Abstract
Background E. coli O157 is a bacterial pathogen that is shed by cattle and can cause severe disease in humans. Phage type (PT) 21/28 is a subtype of E. coli O157 that is found across Scotland and is associated with particularly severe human morbidity. Methods A cross-sectional survey of Scottish cattle farms was conducted in the period Feb 2002-Feb 2004 to determine the prevalence of E. coli O157 in cattle herds. Data from 88 farms on which E. coli O157 was present were analysed using generalised linear mixed models to identify risk factors for the presence of PT 21/28 specifically. Results The analysis identified private water supply, and northerly farm location as risk factors for PT 21/28 presence. There was a significant association between the presence of PT 21/28 and an increased number of E. coli O157 positive pat samples from a farm, and PT 21/28 was significantly associated with larger E. coli O157 counts than non-PT 21/28 E. coli O157. Conclusion PT 21/28 has significant risk factors that distinguish it from other phage types of E. coli O157. This finding has implications for the control of E. coli O157 as a whole and suggests that control could be tailored to target the locally dominant PT.
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Affiliation(s)
- Jo EB Halliday
- Centre for Infectious Diseases, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
| | - Margo E Chase-Topping
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh, EH9 3JF, UK
| | - Michael C Pearce
- Scottish Agricultural College, Animal Health Group, Research Division, King's Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Iain J McKendrick
- Biomathematics & Statistics Scotland, King's Buildings, West Mains Road, Edinburgh, EH9 3JZ, UK
| | - Lesley Allison
- Scottish E. coli O157 Reference Laboratory, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK
| | - Dave Fenlon
- Scottish Agricultural College, Animal Health Group, Research Division, King's Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Chris Low
- Scottish Agricultural College, Animal Health Group, Research Division, King's Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Dominic J Mellor
- Comparative Epidemiology & Informatics, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow, G61 1QH, UK
| | - George J Gunn
- Scottish Agricultural College, Animal Health Group, Research Division, King's Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Mark EJ Woolhouse
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh, EH9 3JF, UK
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Chase-Topping ME, Gunn G, Strachan WD, Edwards SA, Smith WJ, Hillman K, Stefopoulou SN, Thomson JR. Epidemiology of porcine non-specific colitis on Scottish farms. Vet J 2006; 173:353-60. [PMID: 16459113 DOI: 10.1016/j.tvjl.2005.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2005] [Indexed: 11/16/2022]
Abstract
The objective of this study was to investigate epidemiological risk factors for porcine non-specific colitis (NSC). Forty-seven Scottish pig farms, with and without a clinical history of diarrhoea during the growing period (15-40 kg), were selected. The study included farm visits, clinical inspection of pigs, completion of farm management questionnaires, pathological tests into the cause of the diarrhoea and analysis of the non-starch polysaccharide (NSP) content of feeds. The results from 17 farms designated as NSC and 10 control farms suggest dietary associations with NSC. Farms with NSC fed diets with significantly higher levels of NSPs, especially containing the sugars glucose, arabinose and xylose. Few management factors were identified, although the high prevalence of infectious colitis reduced the power of the study.
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Affiliation(s)
- M E Chase-Topping
- Centre for Tropical Veterinary Medicine, University of Edinburgh, Edinburgh, Scotland EH25 9RG, UK
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26
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St Rose SG, Hunter N, Matthews L, Foster JD, Chase-Topping ME, Kruuk LEB, Shaw DJ, Rhind SM, Will RG, Woolhouse MEJ. Comparative evidence for a link between Peyer's patch development and susceptibility to transmissible spongiform encephalopathies. BMC Infect Dis 2006; 6:5. [PMID: 16405727 PMCID: PMC1361786 DOI: 10.1186/1471-2334-6-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 01/11/2006] [Indexed: 11/13/2022] Open
Abstract
Background Epidemiological analyses indicate that the age distribution of natural cases of transmissible spongiform encephalopathies (TSEs) reflect age-related risk of infection, however, the underlying mechanisms remain poorly understood. Using a comparative approach, we tested the hypothesis that, there is a significant correlation between risk of infection for scrapie, bovine spongiform encephalopathy (BSE) and variant CJD (vCJD), and the development of lymphoid tissue in the gut. Methods Using anatomical data and estimates of risk of infection in mathematical models (which included results from previously published studies) for sheep, cattle and humans, we calculated the Spearman's rank correlation coefficient, rs, between available measures of Peyer's patch (PP) development and the estimated risk of infection for an individual of the corresponding age. Results There was a significant correlation between the measures of PP development and the estimated risk of TSE infection; the two age-related distributions peaked in the same age groups. This result was obtained for each of the three host species: for sheep, surface area of ileal PP tissue vs risk of infection, rs = 0.913 (n = 19, P < 0.001), and lymphoid follicle density vs risk of infection, rs = 0.933 (n = 19, P < 0.001); for cattle, weight of PP tissue vs risk of infection, rs = 0.693 (n = 94, P < 0.001); and for humans, number of PPs vs risk of infection, rs = 0.384 (n = 46, P = 0.008). In addition, when changes in exposure associated with BSE-contaminated meat were accounted for, the two age-related patterns for humans remained concordant: rs = 0.360 (n = 46, P = 0.014). Conclusion Our findings suggest that, for sheep, cattle and humans alike there is an association between PP development (or a correlate of PP development) and susceptibility to natural TSE infection. This association may explain changes in susceptibility with host age, and differences in the age-susceptibility relationship between host species.
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Affiliation(s)
- Suzanne G St Rose
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh EH9 3JF, UK
| | - Nora Hunter
- Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, UK
| | - Louise Matthews
- Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - James D Foster
- Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, UK
| | - Margo E Chase-Topping
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh EH9 3JF, UK
| | - Loeske EB Kruuk
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Darren J Shaw
- Division of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK
| | - Susan M Rhind
- Division of Animal Health and Welfare, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - Robert G Will
- The National Creutzfeldt-Jakob disease Surveillance Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Mark EJ Woolhouse
- Centre for Infectious Diseases, University of Edinburgh, Ashworth Laboratories, King's Buildings, West Mains Road, Edinburgh EH9 3JF, UK
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Touzeau S, Chase-Topping ME, Matthews L, Lajous D, Eychenne F, Hunter N, Foster JD, Simm G, Elsen JM, Woolhouse MEJ. Modelling the spread of scrapie in a sheep flock: evidence for increased transmission during lambing seasons. Arch Virol 2005; 151:735-51. [PMID: 16307175 DOI: 10.1007/s00705-005-0666-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Accepted: 09/05/2005] [Indexed: 11/26/2022]
Abstract
Presence of scrapie infectivity in the placenta suggests the possibility of increased transmission of scrapie during the lambing season. This hypothesis was explored here using a mathematical model of scrapie transmission dynamics which has previously been successfully used to study several scrapie outbreaks in Scottish sheep flocks. It was applied here to the Langlade experimental sheep flock (INRA Toulouse, France), in which a natural scrapie epidemic started in 1993. Extensive data were available, including pedigree, scrapie histopathological diagnoses and PrP genotypes. Detailed simulations of the scrapie outbreak reveal that the observed patterns of seasonality in incidence can not be accounted for by seasonality in demography alone and provide strong support for the hypothesis of increased transmission during lambing. Observations from several other scrapie outbreaks also showing seasonal incidence patterns support these conclusions.
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Affiliation(s)
- S Touzeau
- INRA, Unité de Mathématiques et Informatique Appliquées, Jouy-en-Josas, France.
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Hoyle DV, Yates CM, Chase-Topping ME, Turner EJ, Davies SE, Low JC, Gunn GJ, Woolhouse MEJ, Amyes SGB. Molecular epidemiology of antimicrobial-resistant commensal Escherichia coli strains in a cohort of newborn calves. Appl Environ Microbiol 2005; 71:6680-8. [PMID: 16269697 PMCID: PMC1287745 DOI: 10.1128/aem.71.11.6680-6688.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Accepted: 06/23/2005] [Indexed: 11/20/2022] Open
Abstract
Pulsed-field gel electrophoresis (PFGE) was used to investigate the dissemination and diversity of ampicillin-resistant (Amp(r)) and nalidixic acid-resistant (Nal(r)) commensal Escherichia coli strains in a cohort of 48 newborn calves. Calves were sampled weekly from birth for up to 21 weeks and a single resistant isolate selected from positive samples for genotyping and further phenotypic characterization. The Amp(r) population showed the greatest diversity, with a total of 56 different genotype patterns identified, of which 5 predominated, while the Nal(r) population appeared to be largely clonal, with over 97% of isolates belonging to just two different PFGE patterns. Distinct temporal trends were identified in the distribution of several Amp(r) genotypes across the cohort, with certain patterns predominating at different points in the study. Cumulative recognition of new Amp(r) genotypes within the cohort was biphasic, with a turning point coinciding with the housing of the cohort midway through the study, suggesting that colonizing strains were from an environmental source on the farm. Multiply resistant isolates dominated the collection, with >95% of isolates showing resistance to at least two additional antimicrobials. Carriage of resistance to streptomycin, sulfamethoxazole, and tetracycline was the most common combination, found across several different genotypes, suggesting the possible spread of a common resistance element across multiple strains. The proportion of Amp(r) isolates carrying sulfamethoxazole resistance increased significantly over the study period (P < 0.05), coinciding with a decline in the most common genotype pattern. These data indicate that calves were colonized by a succession of multiply resistant strains, with a probable environmental source, that disseminated through the cohort over time.
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Affiliation(s)
- Deborah V Hoyle
- Centre for Tropical Veterinary Medicine, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian, Scotland EH25 9RG, United Kingdom
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29
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Chase-Topping ME, Kruuk LEB, Lajous D, Touzeau S, Matthews L, Simm G, Foster JD, Rupp R, Eychenne F, Hunter N, Elsen JM, Woolhouse MEJ. Genotype-level variation in lifetime breeding success, litter size and survival of sheep in scrapie-affected flocks. J Gen Virol 2005; 86:1229-1238. [PMID: 15784917 DOI: 10.1099/vir.0.80277-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Five different sheep flocks with natural outbreaks of scrapie were examined to determine associations between individual performance (lifetime breeding success, litter size and survival) and scrapie infection or PrP genotype. Despite different breed composition and forces of infection, consistent patterns were found among the flocks. Regardless of the flock, scrapie-infected sheep produced on average 34 % fewer offspring than non-scrapie-infected sheep. The effect of scrapie on lifetime breeding success appears to be a function of lifespan as opposed to fecundity. Analysis of litter size revealed no overall or genotype differences among the five sheep flocks. Survival, however, depends on the individual's scrapie status (infected or not) and its PrP genotype. Susceptible genotypes appear to perform less well in lifetime breeding success and life expectancy even if they are never affected with clinical scrapie. One possible explanation for these results is the effect of pre-clinical scrapie. Additional evidence supporting this hypothesis is discussed.
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Affiliation(s)
- Margo E Chase-Topping
- Centre for Tropical Veterinary Medicine (CTVM), Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - Loeske E B Kruuk
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
- Centre for Tropical Veterinary Medicine (CTVM), Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - Daniel Lajous
- Institut National de la Recherche Agronomique, Station d'Amélioration Génétique des Animaux, BP 27, 31326 Castanet-Tolosan Cedex, France
| | - Suzanne Touzeau
- Institut National de la Recherche Agronomique, Unité de Mathématiques et Informatique Appliquées, 78352 Jouy-en-Josas Cedex, France
| | - Louise Matthews
- Centre for Tropical Veterinary Medicine (CTVM), Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - Geoff Simm
- Sustainable Livestock Systems Group, Scottish Agricultural College, Bush Estate, Penicuik, Midlothan EH26 0PH, UK
| | - James D Foster
- Institute for Animal Health, Neuropathogenesis Unit, Ogston Building, West Mains Road, Edinburgh EH9 3JF, UK
| | - Rachel Rupp
- Institut National de la Recherche Agronomique, Station d'Amélioration Génétique des Animaux, BP 27, 31326 Castanet-Tolosan Cedex, France
| | - Francis Eychenne
- Institut National de la Recherche Agronomique, Station d'Amélioration Génétique des Animaux, BP 27, 31326 Castanet-Tolosan Cedex, France
| | - Nora Hunter
- Institute for Animal Health, Neuropathogenesis Unit, Ogston Building, West Mains Road, Edinburgh EH9 3JF, UK
| | - Jean-Michel Elsen
- Institut National de la Recherche Agronomique, Station d'Amélioration Génétique des Animaux, BP 27, 31326 Castanet-Tolosan Cedex, France
| | - Mark E J Woolhouse
- Centre for Tropical Veterinary Medicine (CTVM), Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
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Abstract
OBJECTIVE To study the effects of morphine on haemodynamic variables, blood gas values and the requirement for additional anaesthetic drugs in horses undergoing surgery. STUDY DESIGN Prospective randomized study. METHODS Thirty-eight client-owned horses, ASA(American Society of Anesthesiologists) category I or II, undergoing elective surgical procedures, were studied. Horses were divided between two groups, and were paired according to operation, anaesthetist, body position during surgery, mass and breed. Group M+ received morphine by intravenous (IV) injection (0.15 mg kg(-1)) before induction of anaesthesia and then by infusion (0.1 mg kg(-1) hour(-1)) throughout anaesthesia. Group M- received the same anaesthetic technique (pre-anaesthetic medication with romifidine (100 microg kg(-1)) IV; induction with ketamine (2.2 mg kg(-1)) and diazepam (50 microg kg(-1)) IV; maintenance with halothane), except that morphine was excluded. Both groups received flunixin IV (1.1 mg kg(-1)) before surgery. Both groups also received 50% nitrous oxide for the first 10 minutes of anaesthesia. During anaesthesia, end-tidal halothane was maintained at 0.9% (+/-0.1%) in both groups. Heart rate (HR) and respiratory rate (fr), systolic, mean and diastolic arterial pressures were recorded every 5 minutes. Arterial blood samples were analysed every 20 minutes. Additional anaesthetics (ketamine and midazolam) were administered whenever the horse moved. Dobutamine was infused to maintain mean arterial pressure (MAP) > 58 mm Hg, but was discontinued when MAP reached 68 mm Hg. Mechanical ventilation was imposed when PaCO(2) exceeded 9.3 kPa (70 mm Hg). RESULTS Haemodynamic data (HR and MAP) and blood gas measurements were analysed using repeated measure analysis using a mixed covariance pattern model (SAS version 8.2). A Student's t-test was used to investigate differences between groups in the doses of additional anaesthetics required. There were no significant differences between M+ or M- groups in MAP (p = 0.65), HR (p = 0.74), PaO2 (p = 0.40) or PaCO2 (p = 0.20). Fewer horses in the M+ group received additional anaesthetics (15.8% compared to 21.1% in M- group), and the mean dose of ketamine required was higher in the M- group (mean +/- SD: M-, 0.93 +/- 0.70; M+, 0.45 +/- 0.17). These differences were not statistically significant (p = 0.28). CONCLUSIONS Pre-anaesthetic and peri-operative morphine administration is not associated with significant haemodynamic or ventilatory changes. Horses receiving morphine tended to receive fewer and lower doses of additional anaesthetic drugs, although this was not statistically significant.
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Affiliation(s)
- Louise Clark
- Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Easter Bush, Roslin, Midlothian EH25 9RG, UK.
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Matthews L, Haydon DT, Shaw DJ, Chase-Topping ME, Keeling MJ, Woolhouse MEJ. Neighbourhood control policies and the spread of infectious diseases. Proc Biol Sci 2003; 270:1659-66. [PMID: 12964992 PMCID: PMC1691422 DOI: 10.1098/rspb.2003.2429] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We present a model of a control programme for a disease outbreak in a population of livestock holdings. Control is achieved by culling infectious holdings when they are discovered and by the pre-emptive culling of livestock on holdings deemed to be at enhanced risk of infection. Because the pre-emptive control programme cannot directly identify exposed holdings, its implementation will result in the removal of both infected and uninfected holdings. This leads to a fundamental trade-off: increased levels of control produce a greater reduction in transmission by removing more exposed holdings, but increase the number of uninfected holdings culled. We derive an expression for the total number of holdings culled during the course of an outbreak and demonstrate that there is an optimal control policy, which minimizes this loss. Using a metapopulation model to incorporate local clustering of infection, we examine a neighbourhood control programme in a locally spreading outbreak. We find that there is an optimal level of control, which increases with increasing basic reproduction ratio, R(0); moreover, implementation of control may be optimal even when R(0) < 1. The total loss to the population is relatively insensitive to the level of control as it increases beyond the optimal level, suggesting that over-control is a safer policy than under-control.
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Affiliation(s)
- L Matthews
- Centre for Tropical Veterinary Medicine, University of Edinburgh, Easter Bush, Roslin EH25 9RG, UK.
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Synge BA, Chase-Topping ME, Hopkins GF, McKendrick IJ, Thomson-Carter F, Gray D, Rusbridge SM, Munro FI, Foster G, Gunn GJ. Factors influencing the shedding of verocytotoxin-producing Escherichia coli O157 by beef suckler cows. Epidemiol Infect 2003; 130:301-12. [PMID: 12729199 PMCID: PMC2869966 DOI: 10.1017/s0950268802008208] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A study was designed to investigate management factors that might influence the shedding of verocytotoxin-producing Escherichia coli (VTEC) O157 by beef cows in Scotland, where there is a particularly high rate of human infection. Thirty-two herds were visited at least monthly over approximately 1 year for collection of fresh faecal pat samples and information on management factors. The faecal pat samples were tested for VTEC O157 by established culture and immunomagnetic separation methods. Questionnaires were completed at the monthly visits to record management factors. Data were analysed using both univariate and multi-factor (GLMM) analysis. Changes in the number of cows in a group, dogs, wild geese, housing, and the feeding of draff (distillers' grains) were statistically significant as risk factors. The event of calving appeared to reduce the likelihood of shedding. Any effects of weaning or turnout were not statistically significant. It appears that the rate of shedding of VTEC O157 is influenced by several factors but possibly the most important of these are the circumstances of animals being housed, or, when outside, the presence of wild geese.
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Affiliation(s)
- B A Synge
- SAC Veterinary Science Division, Drummondhill, Stratherrick Road, Inverness IV2 4JZ
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Redman CA, Coen PG, Matthews L, Lewis RM, Dingwall WS, Foster JD, Chase-Topping ME, Hunter N, Woolhouse MEJ. Comparative epidemiology of scrapie outbreaks in individual sheep flocks. Epidemiol Infect 2002; 128:513-21. [PMID: 12113497 PMCID: PMC2869849 DOI: 10.1017/s0950268802007008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Data recording the course of scrapie outbreaks in 4 sheep flocks (2 in Cheviot sheep and 2 in Suffolks) are compared. For each outbreak the data on scrapie incidence and sheep demography and pedigrees cover periods of years or decades. A key finding is that the incidence of clinical cases peaks in sheep 2-3 years old, despite very different forces-of-infection. This is consistent with age-specific susceptibility of sheep to scrapie, as has been reported for cattle to bovine spongiform encephalopathy and for humans to variant Creutzfeldt-Jakob disease. Scrapie incidence was higher in ewes than rams and at certain times of years, though these effects were not consistent between flocks. There was no evidence for high levels of vertical transmission.
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Affiliation(s)
- C A Redman
- Centre for Tropical Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, UK
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