Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 15 de 15
1.
Microb Genom ; 10(2)2024 Feb.
Article En | MEDLINE | ID: mdl-38354031

Mycobacterium bovis the main agent of bovine tuberculosis (bTB), presents as a series of spatially-localised micro-epidemics across landscapes. Classical molecular typing methods applied to these micro-epidemics, based on genotyping a few variable loci, have significantly improved our understanding of potential epidemiological links between outbreaks. However, they have limited utility owing to low resolution. Conversely, whole-genome sequencing (WGS) provides the highest resolution data available for molecular epidemiology, producing richer outbreak tracing, insights into phylogeography and epidemic evolutionary history. We illustrate these advantages by focusing on a common single lineage of M. bovis (1.140) from Northern Ireland. Specifically, we investigate the spatial sub-structure of 20 years of herd-level multi locus VNTR analysis (MLVA) surveillance data and WGS data from a down sampled subset of isolates of this MLVA type over the same time frame. We mapped 2108 isolate locations of MLVA type 1.140 over the years 2000-2022. We also mapped the locations of 148 contemporary WGS isolates from this lineage, over a similar geographic range, stratifying by single nucleotide polymorphism (SNP) relatedness cut-offs of 15 SNPs. We determined a putative core range for the 1.140 MLVA type and SNP-defined sequence clusters using a 50 % kernel density estimate, using cattle movement data to inform on likely sources of WGS isolates found outside of core ranges. Finally, we applied Bayesian phylogenetic methods to investigate past population history and reproductive number of the 1.140 M. bovis lineage. We demonstrate that WGS SNP-defined clusters exhibit smaller core ranges than the established MLVA type - facilitating superior disease tracing. We also demonstrate the superior functionality of WGS data in determining how this lineage was disseminated across the landscape, likely via cattle movement and to infer how its effective population size and reproductive number has been in flux since its emergence. These initial findings highlight the potential of WGS data for routine monitoring of bTB outbreaks.


Mycobacterium bovis , Tuberculosis, Bovine , Animals , Cattle , Mycobacterium bovis/genetics , Bayes Theorem , Phylogeny , Tuberculosis, Bovine/epidemiology , Molecular Epidemiology
2.
Viruses ; 14(7)2022 06 28.
Article En | MEDLINE | ID: mdl-35891403

Polymicrobial pneumonias occur frequently in cattle, swine, and sheep, resulting in major economic losses. Individual pathogens comprising these complex infections may be mild on their own but can instead exhibit synergism or increase host susceptibility. Two examples of such pathogens, Mycoplasma ovipneumoniae (M. ovipneumoniae) and influenza D viruses (IDVs), naturally infect domestic sheep. In sheep, the role of M. ovipneumoniae in chronic nonprogressive pneumonia is well-established, but the pathogenesis of IDV infection has not previously been studied. We utilized a specific-pathogen-free sheep flock to study the clinical response to IDV infection in naïve vs. M. ovipneumoniae-exposed lambs. Lambs were inoculated intranasally with M. ovipneumoniae or mock infection, followed after four weeks by infection with IDV. Pathogen shedding was tracked, and immunological responses were evaluated by measuring acute phase response and IDV-neutralizing antibody titers. While lamb health statuses remained subclinical, M. ovipneumoniae-exposed lambs had significantly elevated body temperatures during IDV infection compared to M. ovipneumoniae-naïve, IDV-infected lambs. Moreover, we found a positive correlation between prior M. ovipneumoniae burden, early-infection IDV shedding, and IDV-neutralizing antibody response. Our findings suggest that IDV infection may not induce clinical symptoms in domestic sheep, but previous M. ovipneumoniae exposure may promote mild IDV-associated inflammation.


Communicable Diseases , Mycoplasma ovipneumoniae , Orthomyxoviridae Infections , Orthomyxoviridae , Pneumonia , Sheep Diseases , Thogotovirus , Animals , Antibodies, Neutralizing , Cattle , Orthomyxoviridae Infections/veterinary , Sheep , Swine
3.
Vet Rec ; 191(10): e1974, 2022 11.
Article En | MEDLINE | ID: mdl-35841612

BACKGROUND: Colostrum-derived antibodies are crucial for the protection of newborn lambs from infectious diseases. Several colostrum replacer products that contain bovine antibodies are on the market. We investigated the absorption and persistence of bovine antibodies from a powdered colostrum replacer in newborn lambs. METHODS: We tested a lamb colostrum replacer containing bovine serum in lambs that were separated from their dams at birth. Immunoglobulin G (IgG) uptake was analysed by ELISA, and the persistence of antigen-specific antibodies was analysed by parainfluenza 3 virus (PI-3) neutralisation assay. RESULTS: Serum antibody ELISA performed on days 1 and 14 revealed IgG levels of 17.9 ± 2.8 and 27.5 ± 2.5 mg/ml, respectively. PI-3 antibodies derived from the colostrum replacer were present for 86.3 ± 10.6 days. CONCLUSIONS: Antibodies derived from bovine serum protein delivered to lambs via a commercial colostrum replacer are readily absorbed and persist for months, suggesting that these products may offer adequate protection.


Colostrum , Immunoglobulins , Pregnancy , Female , Sheep , Animals , Animals, Newborn , Immunoglobulins/metabolism , Immunoglobulin G , Sheep, Domestic , Parturition
4.
Vet Microbiol ; 265: 109334, 2022 Feb.
Article En | MEDLINE | ID: mdl-35033769

Mycoplasma ovipneumoniae (M. ovipneumoniae) is a respiratory pathogen associated with mild to moderate respiratory disease in domestic lambs and severe pneumonia outbreaks in wild ruminants such as bighorn sheep. However, whether M. ovipneumoniae by itself causes clinical respiratory disease in domestic sheep in the absence of secondary bacterial pathogens is still unclear. The goal of our study was to better understand the role of M. ovipneumoniae as a respiratory pathogen in domestic sheep and to explore potential antibiotic treatment approaches. Therefore, we inoculated four 4-month-old, specific-pathogen-free lambs with fresh nasal wash fluids from M. ovipneumoniae-infected sheep. The lambs were monitored for M. ovipneumoniae colonization, M. ovipneumoniae-specific antibodies, clinical signs, and cellular and molecular correlates of lung inflammation for eight weeks. All lambs then were treated with gamithromycin and observed for an additional four weeks. M. ovipneumoniae inoculation resulted in stable colonization of the upper respiratory tract in all M. ovipneumoniae-inoculated, but in none of the four mock-infected control lambs. All M. ovipneumoniae-infected lambs developed a robust antibody response to M. ovipneumoniae within 2 weeks. However, we did not observe significant signs of respiratory disease, evidence of lung damage or inflammation in any of the infected lambs. Interestingly, treatment with gamithromycin, which blocked growth of the M. ovipneumoniae in vitro, failed to reduce M. ovipneumoniae colonization. These observations indicate that, in the absence of co-infections, M. ovipneumoniae caused asymptomatic colonization of the upper respiratory tract that was resistant to clearance by the host immune response and by gamithromycin treatment.


Mycoplasma ovipneumoniae , Sheep Diseases , Sheep, Bighorn , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Asymptomatic Infections , Sheep , Sheep Diseases/epidemiology
5.
Psychol Rep ; 124(5): 1998-2017, 2021 Oct.
Article En | MEDLINE | ID: mdl-32718228

Self-harm is a complex and idiosyncratic behaviour. This article focuses on how those who self-harm manage their own risk. Utilising opportunity sampling, ten members of a self-harm support group were interviewed about how they risk manage their self-harm and the data analysed using interpretative phenomenological analysis. The analysis showed that all participants were actively involved in risk management of their self-harm. Through a process of managing consequences, exercising control in the process, and an awareness of the social context. It is posited that people who self-harm should be viewed as actively engaging with the risks of self-harm whilst it is a coping mechanism, as opposed to passive or ignoring. This understanding can be integrated into current risk management plans within services and invites a more dynamic conversation of self-harm between services users and services. Effective risk management involves good relationships between individuals who self-harm and clinicians, services which promote positive risk taking as opposed to defensive practice, and true collaboration between services and service users.


Self-Injurious Behavior , Adaptation, Psychological , Humans , Qualitative Research
6.
Infect Genet Evol ; 81: 104235, 2020 07.
Article En | MEDLINE | ID: mdl-32035245

BACKGROUND: In the recent past (1997-2012), Northern Ireland in the United Kingdom suffered an outbreak of Brucella abortus, which at its height affected over 200 cattle herds. Initially, isolates were characterized using multi-locus variable number tandem repeats analysis (MLVA). While informative in this setting, hyper-variability in some loci limited the resolution necessary to infer fine-scale disease transmission networks. Consequently, we applied whole-genome sequencing to isolates from this outbreak to evaluate higher resolution markers for disease epizootiology. RESULTS: Phylogenetic analysis revealed that the B. abortus outbreak in Northern Ireland was caused by two distinct pathogen lineages. One contained isolates consistent with the 1997-2012 outbreak being linked to a previous endemic infection thought eradicated. The dominant second lineage exhibited little genetic diversity throughout the recrudescent outbreak, with limited population sub-structure evident. This finding was inconsistent with prior MLVA molecular characterizations that suggested the presence of seven clonal complexes. Spatio-temporal modeling revealed a significant association of pairwise SNP differences between isolates and geographic distances. However, effect sizes were very small due to reduced pathogen diversity. CONCLUSIONS: Genome sequence data suggested that hyper-variability in some MLVA loci contributed to an overestimate of pathogen diversity in the most recent outbreak. The low diversity observed in our genomic dataset made it inappropriate to apply phylodynamic methods to these data. We conclude that maintaining data repositories of genome sequence data will be invaluable for source attribution/epizootiological inference should recrudescence ever re-occur. However genomic epizootiological methods may have limited utility in some settings, such as when applied to recrudescent/re-emergent infections of slowly-evolving bacterial pathogens.


Brucella abortus/genetics , Brucellosis, Bovine/epidemiology , Brucellosis, Bovine/microbiology , Animals , Cattle , Disease Outbreaks , Genetic Variation/genetics , Genomics/methods , Genotype , Livestock/genetics , Livestock/microbiology , Minisatellite Repeats/genetics , Molecular Epidemiology/methods , Multilocus Sequence Typing/methods , Northern Ireland/epidemiology , Phylogeny , Polymorphism, Single Nucleotide/genetics , Whole Genome Sequencing/methods
7.
Pulm Ther ; 5(2): 97-102, 2019 Dec.
Article En | MEDLINE | ID: mdl-32026405

This article is co-authored by the mother of a patient living with asthma, and two consultants in respiratory medicine from Birmingham Women's and Children's Hospital. The commentary article describes the mother's experience of the diagnosis and treatment process of her son's asthma. The consultants then discuss paediatric asthma diagnosis and management in the context of the patient's experiences.

8.
PLoS One ; 10(9): e0136721, 2015.
Article En | MEDLINE | ID: mdl-26325586

BACKGROUND: Brucellosis is the most common bacterial zoonoses worldwide. Bovine brucellosis caused by Brucella abortus has far reaching animal health and economic impacts at both the local and national levels. Alongside traditional veterinary epidemiology, the use of molecular typing has recently been applied to inform on bacterial population structure and identify epidemiologically-linked cases of infection. Multi-locus variable number tandem repeat VNTR analysis (MLVA) was used to investigate the molecular epidemiology of a well-characterised Brucella abortus epidemic in Northern Ireland involving 387 herds between 1991 and 2012. RESULTS: MLVA identified 98 unique B. abortus genotypes from disclosing isolates in the 387 herds involved in the epidemic. Clustering algorithms revealed the relatedness of many of these genotypes. Combined with epidemiological information on chronology of infection and geographic location, these genotype data helped to identify 7 clonal complexes which underpinned the outbreak over the defined period. Hyper-variability of some VNTR loci both within herds and individual animals led to detection of multiple genotypes associated with single outbreaks. However with dense sampling, these genotypes could still be associated with specific clonal complexes thereby permitting inference of epidemiological links. MLVA- based epidemiological monitoring data were congruent with an independent classical veterinary epidemiology study carried out in the same territory. CONCLUSIONS: MLVA is a useful tool in ongoing disease surveillance of B. abortus outbreaks, especially when combined with accurate epidemiological information on disease tracings, geographical clustering of cases and chronology of infection.


Brucella abortus/genetics , Brucellosis, Bovine/epidemiology , Animals , Brucellosis, Bovine/microbiology , Cattle , Female , Genotype , Minisatellite Repeats/genetics , Molecular Epidemiology , Northern Ireland/epidemiology , Spatio-Temporal Analysis
9.
Innate Immun ; 21(6): 598-608, 2015 Aug.
Article En | MEDLINE | ID: mdl-25608515

Amphotericin B (AmB) is a commonly used antifungal drug, with well-documented effects on cellular immune responses. We determined that AmB-stimulated γδ T-cell activation and proliferation in vitro at very low concentrations. AmB also enhanced IFN-γ production by NK cells in combination with IL-18. AmB had a greater effect on IFN-γ production in cells isolated from very young animals. Although innate immunostimulatory aspects of AmB have been defined, AmB has not been extensively applied in non-fungal infection settings. Given that γδ T cells are increased and activated in Salmonella infection in cattle, we assessed the effects of AmB in protection from Salmonella enterocolitis in calves. One injection of AmB, at approximately one-tenth of the concentration used in human patients to counter fungal infection, or saline control, was delivered intravenously to calves prior to infection with Salmonella. This single injection caused no adverse effects, reduced disease symptoms from Salmonella enterocolitis and significantly reduced Salmonella bacteria shed in feces of infected animals. Our findings suggest that AmB may be an inexpensive and readily available prophylactic approach for the prevention of bacterial infection in calves.


Amphotericin B/administration & dosage , Anti-Bacterial Agents/administration & dosage , Killer Cells, Natural/immunology , Salmonella Infections, Animal/prevention & control , Salmonella/drug effects , T-Lymphocytes/immunology , Age Factors , Amphotericin B/adverse effects , Animals , Anti-Bacterial Agents/adverse effects , Cattle , Humans , Interferon-gamma/metabolism , Killer Cells, Natural/drug effects , Lymphocyte Activation/drug effects , Mice , Mice, Knockout , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Salmonella/immunology , T-Lymphocytes/drug effects
14.
Org Lett ; 10(5): 797-800, 2008 Mar 06.
Article En | MEDLINE | ID: mdl-18220403

An efficient method for the copper-catalyzed N-arylation of hydroxylamines with aryl iodides is described. A variety of N- and O-functionalized hydroxylamines were transformed in good to excellent yield with a broad range of aryl coupling partners. Methods for the selective deprotection of either the N- or O-substituents for further functionalization are also described.


Copper/chemistry , Hydrocarbons, Iodinated/chemistry , Hydroxylamines/chemistry , Catalysis , Combinatorial Chemistry Techniques , Molecular Structure
15.
Org Lett ; 7(25): 5729-32, 2005 Dec 08.
Article En | MEDLINE | ID: mdl-16321033

[chemical reaction: see text]. A simple, one-pot method for the alpha-acyloxylation of carbonyl compounds that proceeds at room temperature in the presence of both moisture and air has been developed. Treatment of a variety of aldehydes and both cyclic and acyclic ketones with N-methyl-O-benzoylhydroxylamine hydrochloride provides the alpha-functionalized product in 69-92% isolated yield. The transformation is tolerant of a wide range of functional groups and, significantly, is regiospecific in the discrimination of secondary over primary centers in the case of nonsymmetrical substrates.

...