102 research outputs found

    Design, Concept, and Visualization of urban multi-level growing table systems in Hyper Urban Areas

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    As of a 2019 study conducted by the National Urban Gardening Program (National Urban Gardening Program), urban farming accounts for approximately 19% of the total national farming output and is expected to triple to almost 45% by 2025. There is intensive research being conducted on aspects of reduced recidivism, communal health benefits, natural carbon capture systems, improved urban ecology and the necessity for reducing the carbon footprint of food, (informally dubbed “food miles”) there is little substantive research on optimisation, and maximation of crop productivity in hyper-urban areas. The purpose of this report is to understand the functionalities of urban growing table, being mindful of its possible limitations, and to fully design an integrated modular growing table. There should be emphasis on making the growing table as modular as possible, while still ensuring the mobility, relative costs, and equitable access to water source, heating source, nutrient sources, and other factors. Aspects like ergonomics, workability, ventilation, air circulation also need to be taken into account for the design considered

    New Horizons in the Diagnosis of Tuberculosis of the Spine: The Role of Whole Genome Sequencing

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    Study Design Prospective study. Purpose To evaluate the utility of whole genome sequencing (WGS) in drug resistance testing, lineage of the organisms, and organism-related factors responsible for bacilli settling in the spine. Overview of Literature The workstream for the diagnosis of tuberculosis (TB) involves isolation and culture of the organism and drug resistance testing using phenotypic methods. Xpert MTB/RIF Ultra is a genetic-based method that detects for Mycobacterium tuberculosis DNA in the rpoB gene. Meanwhile, WGS is a newer genetic-based method that assesses the whole genome of the bacterium. Very few studies have reported the use of WGS for extrapulmonary TB. Herein, we used WGS to diagnose spinal TB. Methods Tissues from 61 patients undergoing surgery for spinal TB underwent histologic examination, Xpert MTB/RIF Ultra, and culture and sensitivity testing. DNA from the cultured bacteria was sent for WGS. The test bacterial genome was compared to a reference strain of pulmonary TB. Results Acid-fast bacilli were observed in 9/58 specimens. Meanwhile, histology confirmed TB in all the patients. Bacilli were cultured in 28 patients (48.3%), and the average time to culture was 18.7 days. Xpert MTB/RIF Ultra was positive in 47 patients (85%). WGS was performed in 23 specimens. Overall, 45% of the strains belonged to lineage 2 (East Asian). There was one case of multidrug-resistant TB and two cases of non-tuberculous mycobacteria on WGS. We could not confirm any genomic difference between pulmonary and spinal TB strains. Conclusions Xpert MTB/RIF Ultra of tissues or pus is the investigation of choice when diagnosing spinal TB. Meanwhile, WGS can diagnose multidrug-resistant TB and non-tuberculous mycobacteria more accurately. No mutations were identified in spinal and pulmonary TB bacteria

    Cost-Effectiveness of Automated Digital Microscopy for Diagnosis of Active Tuberculosis.

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    BACKGROUND: Automated digital microscopy has the potential to improve the diagnosis of tuberculosis (TB), particularly in settings where molecular testing is too expensive to perform routinely. The cost-effectiveness of TB diagnostic algorithms using automated digital microscopy remains uncertain. METHODS: Using data from a demonstration study of an automated digital microscopy system (TBDx, Applied Visual Systems, Inc.), we performed an economic evaluation of TB diagnosis in South Africa from the health system perspective. The primary outcome was the incremental cost per new TB diagnosis made. We considered costs and effectiveness of different algorithms for automated digital microscopy, including as a stand-alone test and with confirmation of positive results with Xpert MTB/RIF ('Xpert', Cepheid, Inc.). Results were compared against both manual microscopy and universal Xpert testing. RESULTS: In settings willing to pay 2000perincrementalTBdiagnosis,universalXpertwasthepreferredstrategy.However,whereresourceswerenotsufficienttosupportuniversalXpert,andatestingvolumeofatleast30specimensperdaycouldbeensured,automateddigitalmicroscopywithXpertconfirmationoflowpositiveresultscouldfacilitatethediagnosisof79842000 per incremental TB diagnosis, universal Xpert was the preferred strategy. However, where resources were not sufficient to support universal Xpert, and a testing volume of at least 30 specimens per day could be ensured, automated digital microscopy with Xpert confirmation of low-positive results could facilitate the diagnosis of 79-84% of all Xpert-positive TB cases, at 50-60% of the total cost. The cost-effectiveness of this strategy was 1280 per incremental TB diagnosis (95% uncertainty range, UR: 340340-3440) in the base case, but improved under conditions likely reflective of many settings in sub-Saharan Africa: 677perdiagnosis(95677 per diagnosis (95% UR: 450-935)whensensitivityofmanualsmearmicroscopywasloweredto0.5,and935) when sensitivity of manual smear microscopy was lowered to 0.5, and 956 per diagnosis (95% UR: 4040-2910) when the prevalence of multidrug-resistant TB was lowered to 1%. CONCLUSIONS: Although universal Xpert testing is the preferred algorithm for TB diagnosis when resources are sufficient, automated digital microscopy can identify the majority of cases and halve the cost of diagnosis and treatment when resources are more scarce and multidrug-resistant TB is not common

    New horizons in the diagnosis of tuberculosis of the spine : the role of whole genome sequencing

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    STUDY DESIGN : Prospective study. PURPOSE : To evaluate the utility of whole genome sequencing (WGS) in drug resistance testing, lineage of the organisms, and organism-related factors responsible for bacilli settling in the spine. OVERVIEW OF LITERATURE : The workstream for the diagnosis of tuberculosis (TB) involves isolation and culture of the organism and drug resistance testing using phenotypic methods. Xpert MTB/RIF Ultra is a genetic-based method that detects for Mycobacterium tuberculosis DNA in the rpoB gene. Meanwhile, WGS is a newer genetic-based method that assesses the whole genome of the bacterium. Very few studies have reported the use of WGS for extrapulmonary TB. Herein, we used WGS to diagnose spinal TB. METHODS : Tissues from 61 patients undergoing surgery for spinal TB underwent histologic examination, Xpert MTB/RIF Ultra, and culture and sensitivity testing. DNA from the cultured bacteria was sent for WGS. The test bacterial genome was compared to a reference strain of pulmonary TB. RESULTS : Acid-fast bacilli were observed in 9/58 specimens. Meanwhile, histology confirmed TB in all the patients. Bacilli were cultured in 28 patients (48.3%), and the average time to culture was 18.7 days. Xpert MTB/RIF Ultra was positive in 47 patients (85%). WGS was performed in 23 specimens. Overall, 45% of the strains belonged to lineage 2 (East Asian). There was one case of multidrug-resistant TB and two cases of non-tuberculous mycobacteria on WGS. We could not confirm any genomic difference between pulmonary and spinal TB strains. CONCLUSIONS : Xpert MTB/RIF Ultra of tissues or pus is the investigation of choice when diagnosing spinal TB. Meanwhile, WGS can diagnose multidrug-resistant TB and non-tuberculous mycobacteria more accurately. No mutations were identified in spinal and pulmonary TB bacteria.https://asianspinejournal.orgOrthopaedic Surger

    Comparison of three commercial molecular assays for detection of rifampin and isoniazid resistance among Mycobacterium tuberculosis isolates in a high-HIV-prevalence setting

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    In a head to head comparison of the MTBDRplus Version 2.0 (Hain Lifescience), Xpert® MTB/RIF (Cepheid) and the Anyplex™ MTB/NTM (Seegene) assays we demonstrate equal sensitivity (59/61; 96.7%) and specificity (53/54; 98.1%) for detecting rifampicin resistance with further analysis of discordances. The Xpert does not detect Isoniazid resistance while Anyplex showed high false positivity.National Health Laboratory Serviceshttp://jcm.asm.org2016-03-31hb201

    Drug resistant tuberculosis in Africa: Current status, gaps and opportunities

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    Background: The World Health Organization End TB Strategy targets for 2035 are ambitious and drug resistant tuberculosis is an important barrier, particularly in Africa, home to over a billion people. Objective: We sought to review the current status of drug resistant tuberculosis in Africa and highlight key areas requiring improvement. Methods: Available data from 2016 World Health Organization global tuberculosis database were extracted and analysed using descriptive statistics. Results: The true burden of drug resistant tuberculosis on the continent is poorly described with only 51% of countries having a formal survey completed. In the absence of this data, modelled estimates were used and reported 92 629 drug resistant tuberculosis cases with 42% of these occurring in just two countries: Nigeria and South Africa. Of the cases estimated, the majority of patients (70%) were not notified, representing ‘missed cases’. Mortality among patients with multi-drug resistant tuberculosis was 21%, and was 43% among those with extensively drug resistant tuberculosis. Policies on the adoption of new diagnostic tools was poor and implementation was lacking. A rifampicin result was available for less than 10% of tuberculosis cases in 23 of 47 countries. Second-line drug resistance testing was available in only 60% of countries. The introduction of the short multi-drug resistant tuberculosis regimen was a welcome development, with 40% of countries having implemented it in 2016. Bedaquiline has also been introduced in several countries. Conclusion: Drug resistant tuberculosis is largely missed in Africa and this threatens prospects to achieve the 2035 targets. Urgent efforts are required to confirm the true burden of drug resistant tuberculosis in Africa. Adoption of new tools and drugs is essential if the 2035 targets are to be met

    Whole genome sequencing for drug resistance determination in Mycobacterium tuberculosis

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    South Africa remains challenged with a high tuberculosis burden accompanied by an increase in drug resistant cases. We assessed the use of the Illumina MiSeq, a next-generation sequencing platform for whole genome sequencing, followed by bioinformatic analysis using a commercial software package to determine resistance to selected drugs used for Mycobacterium tuberculosis treatment in our setting. Whole genome sequencing shows potential as a diagnostic platform for the detection of drug resistance in Mycobacterium tuberculosis with the provision of information for several drugs simultaneously

    Whole genome sequencing for drug resistance determination in Mycobacterium tuberculosis

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    South Africa remains challenged with a high tuberculosis burden accompanied by an increase in drug resistant cases. We assessed the use of the Illumina MiSeq, a next-generation sequencing platform for whole genome sequencing, followed by bioinformatic analysis using a commercial software package to determine resistance to selected drugs used for Mycobacterium tuberculosis treatment in our setting. Whole genome sequencing shows potential as a diagnostic platform for the detection of drug resistance in Mycobacterium tuberculosis with the provision of information for several drugs simultaneously.Funding was provided by the National Institute for Communicable Diseases, a division of the National Health Laboratory Service, South Africa.The National Institute for Communicable Diseases, a division of the National Health Laboratory Service, South Africahttp://www.ajlmonline.orgam2020Medical Microbiolog

    Laboratory evaluation of a specimen transport medium for downstream molecular processing of sputum samples to detect Mycobacterium tuberculosis

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    BACKGROUND : Modern molecular-based approaches for the detection of Mycobacterium tuberculosis in sputum samples promise quicker and more accurate detection of cases. However, processing sputum samples at central diagnostic facilities provides a diagnostic approach, but requires a safe and efficient system that is not affected by transport delays and ambient temperature to be feasible. We evaluated the technical properties of PrimeStore®-Molecular Transport Medium(PS-MTM) for its ability to inactivate mycobacteria, ensuring stability of DNA over time at ambient temperatures and to assess the compatibility of the transport medium with DNA extraction systems. METHODS : Assessment of the transport medium for application of sputum samples processed for the detection of M. tuberculosis included the inactivation of M. tuberculosis in spiked sputum samples, compatibility of the medium with three commercial nucleic extraction systems and stability of DNA in the medium at ambient temperature over 28 days. We further performed a clinical laboratory evaluation on 256 sputum specimens sent for tuberculosis investigation. RESULTS : Complete inactivation ofM. tuberculosis occurredwithin 30 min of exposure at a ratio of 1:3 for sputumto PS-MTM. Sputum specimen in PS-MTMshowed very good compatibility with automated bead-based extraction systems, producing high DNA output (estimated lower limits of detection: ~170 CFU/ml). Furthermore, PS-MTM samples remained stable over 28 days at ambient temperature displaying no significant change over time in Ctvalues (b5% on a mean starting value of 22.47). Of the 256 clinical sputumspecimens, 10.2%were culture positive and 11.0% were positive by real-time PCR of PS-MTM samples. CONCLUSIONS : Collecting and transporting sputum from TB suspects in PS-MTM offer safe transport at ambient temperature, DNA stability for extended periods without cooling and specimens directly suitable for molecular testing. This novel approach may support introduction and further scale-up of molecular diagnostics for TB in resource-limited settings.http://www.elsevier.com/locate/jmicmeth2016-10-31hb201

    A subset of circulating blood mycobacteria-specific CD4 T cells can predict the time to Mycobacterium tuberculosis sputum culture conversion

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    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR + Ki67 + on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67 + HLA-DR + Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67 + HLA-DR + T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ + IL2 + TNFα + CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67 + HLA-DR + ) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment
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