1,003 research outputs found
Mycobacterium bovis prevalence affects the performance of a commercial serological assay for bovine tuberculosis in African buffaloes
The endemic presence of bovine tuberculosis (BTB) in African buffaloes in South Africa has severe consequences for BTB control in domestic cattle, buffalo ranching and wildlife conservation, and poses a potential risk to public health. This study determined the BTB prevalence in free-ranging buffaloes in two game reserves and assessed the influence of the prevalence of mycobacterial infections on the performance of a commercial cattle-specific serological assay for BTB (TB ELISA). Buffaloes (n = 997) were tested with the tuberculin skin test and TB ELISA; a subset (n = 119) was tested longitudinally. Culture, PCR and sequencing were used to confirm infection with M. bovis and/or non-tuberculous mycobacteria (NTM). Prevalence of BTB, but not NTM, influenced the TB ELISA performance. Multiple testing did not increase test confidence. The findings strongly illustrate the need for development of novel assays that can supplement existing assays for a more comprehensive testing scheme for BTB in African buffaloes
Bovine tuberculosis in African buffaloes : observations regarding Mycobacterium bovis shedding into water and exposure to environmental mycobacteria
Includes bibliographyBackground: African buffaloes are the maintenance host for Mycobacterium bovis in the endemically infected Kruger National Park (KNP). The infection is primarily spread between buffaloes via the respiratory route, but it is not known whether shedding of M. bovis in nasal and oral excretions may lead to contamination of ground and surface water and facilitate the transmission to other animal species. A study to investigate the possibility of water contamination with M. bovis was conducted in association with a BCG vaccination trial in African buffalo. Groups of vaccinated and nonvaccinated buffaloes were kept together with known infected in-contact buffalo cows to allow natural M. bovis transmission under semi-free ranging conditions. In the absence of horizontal transmission vaccinated and control buffaloes were experimentally challenged with M. bovis. Hence, all study buffaloes in the vaccination trial could be considered potential shedders and provided a suitable setting for investigating questions relating to the tenacity of M. bovis shed in water. Results: Serial water samples were collected from the drinking troughs of the buffaloes once per season over an eleven-month period and cultured for presence of mycobacteria. All water samples were found to be negative for M. bovis, but 16 non-tuberculous Mycobacterium spp. isolates were cultured. The non-tuberculous Mycobacterium species were further characterised using 5'-16S rDNA PCR-sequencing, resulting in the identification of M. terrae, M. vaccae (or vanbaalenii), M. engbaekii, M. thermoresistibile as well as at least two species which have not yet been classified. Conclusion: The absence of detectable levels of Mycobacterium bovis in the trough water suggests that diseased buffalo do not commonly shed the organism in high quantities in nasal and oral discharges. Surface water may therefore not be likely to play an important role in the transmission of bovine tuberculosis from buffalo living in free-ranging ecosystems. The study buffalo were, however, frequently exposed to different species of non-tuberculous, environmental mycobacteria, with an unknown effect on the buffaloes' immune response to mycobacteria.Peer Reviewe
Spinal manipulation and mobilisation among infants, children, and adolescents: an international Delphi survey of expert physiotherapists
Objective: The aim of this study was to establish international consensus regarding the use of spinal manipulation and mobilisation among infants, children, and adolescents among expert international physiotherapists. Methods: Twenty-six international expert physiotherapists in manual therapy and paediatrics voluntarily participated in a 3-Round Delphi survey to reach a consensus via direct electronic mail solicitation using QualtricsÂź. Consensus was defined a-priori as â„75% agreement on all items with the same ranking of agreement or disagreement. Round 1 identified impairments and conditions where spinal mobilisation and manipulation might be utilised. In Rounds 2 and 3, panelists agreed or disagreed using a 4-point Likert scale. Results: Eleven physiotherapists from seven countries representing five continents completed all three Delphi rounds. Consensus regarding spinal mobilisation or manipulation included: Manipulation is not recommended: (1) for infants across all conditions, impairments, and spinal levels; and (2) for children and adolescents across most conditions and spinal levels. Manipulation may be recommended for adolescents to treat spinal region-specific joint hypomobility (thoracic, lumbar), and pain (thoracic). Mobilisation may be recommended for children and adolescents with hypomobility, joint pain, muscle/myofascial pain, or stiffness at all spinal levels.Conclusion: Consensus revealed spinal manipulation should not be performed on infants regardless of condition, impairment, or spinal level. Additionally, the panel agreed that manipulation may be recommended only for adolescents to treat joint pain and joint hypomobility (limited to thoracic and/or lumbar levels). Spinal mobilisation may be recommended for joint hypomobility, joint pain, muscle/myofascial pain, and muscle/myofascial stiffness at all spinal levels among children and adolescents.</p
Perceived factors and barriers affecting physiotherapistsâ decision to use spinal manipulation and mobilisation among infants, children, and adolescents: an international survey
Objective: To identify factors and barriers, which affect the utilisation of spinal manipulation and mobilisation among infants, children, and adolescents. Methods: Twenty-six international expert physiotherapists in manual therapy and paediatrics were invited to participate in a Delphi investigation using Qualtricsâ. In Round-1 physiotherapists selected from a list of factors and barriers affecting their decision to use spinal manipulation and mobilisation in the paediatric population and had opportunity to add to the list. Round-2 asked respondents to select as many factors and barriers that they agreed with, resulting in a frequency count. The subset of responses to questions around barriers and facilitators are the focus of this study. Results: Twelve physiotherapists completed both rounds of the survey. Medical diagnosis, mechanism of injury, patient presentation, tolerance to handling, and therapistâs knowledge of techniques were the dominant deciding factors to use spinal manipulation and mobilisation among infants, children, and adolescents across spinal levels. More than 90% of the respondents selected manipulation as inappropriate among infants as their top barrier. Additional dominant barriers to using spinal manipulation among infants and children identified by â„ 75% of the respondents included fear of injuring the patient, fear of litigation, lack of communication, lack of evidence, lack of guardian consent, and precision of the examination to inform clinical reasoning. Conclusion: This international survey provides much needed insight regarding the factors and barriers physiotherapists should consider when contemplating the utilisation of spinal mobilisation and manipulation in the paediatric population.</p
âWhat if There's Something Wrong with Her?ââHow Biomedical Technologies Contribute to Epistemic Injustice in Healthcare
While there is a steadily growing literature on epistemic injustice in healthcare, there are few discussions of the role that biomedical technologies play in harming patients in their capacity as knowers. Through an analysis of newborn and pediatric genetic and genomic sequencing technologies (GSTs), I argue that biomedical technologies can lead to epistemic injustice through two primary pathways: epistemic capture and value partitioning. I close by discussing the larger ethical and political context of critical analyses of GSTs and their broader implications for just and equitable healthcare delivery
Genetic diversity of Mycobacterium tuberculosis isolated from tuberculosis patients in the Serengeti ecosystem in Tanzania
SummaryThis study was part of a larger cross-sectional survey that was evaluating tuberculosis (TB) infection in humans, livestock and wildlife in the Serengeti ecosystem in Tanzania. The study aimed at evaluating the genetic diversity of Mycobacterium tuberculosis isolates from TB patients attending health facilities in the Serengeti ecosystem. DNA was extracted from 214 sputum cultures obtained from consecutively enrolled newly diagnosed untreated TB patients aged â„18 years. Spacer oligonucleotide typing (spoligotyping) and Mycobacterium Interspersed Repetitive Units and Variable Number Tandem Repeat (MIRU-VNTR) were used to genotype M. tuberculosis to establish the circulating lineages. Of the214 M. tuberculosis isolates genotyped, 55 (25.7%) belonged to the Central Asian (CAS) family, 52 (24.3%) were T family (an ill-defined family), 38 (17.8%) belonged to the Latin American Mediterranean (LAM) family, 25 (11.7%) to the East-African Indian (EAI) family, 25 (11.7%) comprised of different unassigned (âSerengetiâ) strain families, while 8 (3.7%) belonged to the Beijing family. A minority group that included Haarlem, X, U and S altogether accounted for 11 (5.2%) of all genotypes. MIRU-VNTR typing produced diverse patterns within and between families indicative of unlinked transmission chains. We conclude that, in the Serengeti ecosystem only a few successful families predominate namely CAS, T, LAM and EAI families. Other types found in lower prevalence are Beijing, Haarlem, X, S and MANU. The Haarlem, EAI_Somalia, LAM3 and S/convergent and X2 subfamilies found in this study were not reported in previous studies in Tanzania
Quantifying the UK's carbon dioxide flux: An atmospheric inverse modelling approach using a regional measurement network
We present a method to derive atmosphericobservation-based estimates of carbon dioxide (CO 2 ) fluxes at the national scale, demonstrated using data from a network of surface tall-tower sites across the UK and Ireland over the period 2013-2014. The inversion is carried out using simulations from a Lagrangian chemical transport model and an innovative hierarchical Bayesian Markov chain Monte Carlo (MCMC) framework, which addresses some of the traditional problems faced by inverse modelling studies, such as subjectivity in the specification of model and prior uncertainties. Biospheric fluxes related to gross primary productivity and terrestrial ecosystem respiration are solved separately in the inversion and then combined a posteriori to determine net ecosystem exchange of CO 2 . Two different models, Data Assimilation Linked Ecosystem Carbon (DALEC) and Joint UK Land Environment Simulator (JULES), provide prior estimates for these fluxes. We carry out separate inversions to assess the impact of these different priors on the posterior flux estimates and evaluate the differences between the prior and posterior estimates in terms of missing model components. The Numerical Atmospheric dispersion Modelling Environment (NAME) is used to relate fluxes to the measurements taken across the regional network. Posterior CO2 estimates from the two inversions agree within estimated uncertainties, despite large differences in the prior fluxes from the different models. With our method, averaging results from 2013 and 2014, we find a total annual net biospheric flux for the UK of 8±79 TgCO 2 yr -1 (DALEC prior) and 64±85 TgCO 2 yr -1 (JULES prior), where negative values represent an uptake of CO 2 . These biospheric CO 2 estimates show that annual UK biospheric sources and sinks are roughly in balance. These annual mean estimates consistently indicate a greater net release of CO 2 than the prior estimates, which show much more pronounced uptake in summer months
Novel Mycobacterium tuberculosis Complex Pathogen, M. mungi
Seven outbreaks involving increasing numbers of banded mongoose troops and high death rates have been documented. We identified a Mycobacterium tuberculosis complex pathogen, M. mungi sp. nov., as the causative agent among banded mongooses that live near humans in Chobe District, Botswana. Host spectrum and transmission dynamics remain unknown
Experimental Mycobacterium bovis infection in three white rhinoceroses (Ceratotherium simum):Susceptibility, clinical and anatomical pathology
Tuberculosis caused by Mycobacterium bovis is endemic in the African buffalo (Syncerus caffer) population in the Kruger National Park and other conservation areas in South Africa. The disease has been diagnosed in a total of 21 free ranging or semi-free ranging wildlife species in the country with highly variable presentations in terms of clinical signs as well as severity and distribution of tuberculous lesions. Most species are spillover or dead-end hosts without significant role in the epidemiology of the disease. White rhinoceroses (Ceratotherium simum) are translocated from the Kruger National Park in substantial numbers every year and a clear understanding of their risk to manifest overt tuberculosis disease and to serve as source of infection to other species is required. We report the findings of experimental infection of three white rhinoceroses with a moderately low dose of a virulent field isolate of Mycobacterium bovis. None of the animals developed clinical signs or disseminated disease. The susceptibility of the white rhinoceros to bovine tuberculosis was confirmed by successful experimental infection based on the ante mortem isolation of M. bovis from the respiratory tract of one rhinoceros, the presence of acid-fast organisms and necrotizing granulomatous lesions in the tracheobronchial lymph nodes and the detection of M. bovis genetic material by PCR in the lungs of two animals
DNA replication stress restricts ribosomal DNA copy number
Ribosomal RNAs (rRNAs) in budding yeast are encoded by ~100â200 repeats of a 9.1kb sequence arranged in tandem on chromosome XII, the ribosomal DNA (rDNA) locus. Copy number of rDNA repeat units in eukaryotic cells is maintained far in excess of the requirement for ribosome biogenesis. Despite the importance of the repeats for both ribosomal and non-ribosomal functions, it is currently not known how ânormalâ copy number is determined or maintained. To identify essential genes involved in the maintenance of rDNA copy number, we developed a droplet digital PCR based assay to measure rDNA copy number in yeast and used it to screen a yeast conditional temperature-sensitive mutant collection of essential genes. Our screen revealed that low rDNA copy number is associated with compromised DNA replication. Further, subculturing yeast under two separate conditions of DNA replication stress selected for a contraction of the rDNA array independent of the replication fork blocking protein, Fob1. Interestingly, cells with a contracted array grew better than their counterparts with normal copy number under conditions of DNA replication stress. Our data indicate that DNA replication stresses select for a smaller rDNA array. We speculate that this liberates scarce replication factors for use by the rest of the genome, which in turn helps cells complete DNA replication and continue to propagate. Interestingly, tumors from mini chromosome maintenance 2 (MCM2)-deficient mice also show a loss of rDNA repeats. Our data suggest that a reduction in rDNA copy number may indicate a history of DNA replication stress, and that rDNA array size could serve as a diagnostic marker for replication stress. Taken together, these data begin to suggest the selective pressures that combine to yield a ânormalâ rDNA copy number
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