19 research outputs found

    Mapping the phylogeny and lineage history of geographically distinct BCG vaccine strains

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    The bacillus Calmette-Guérin (BCG) vaccine has been in use for prevention of tuberculosis for over a century. It remains the only widely available tuberculosis vaccine and its protective efficacy has varied across geographical regions. Since it was developed, the BCG vaccine strain has been shared across different laboratories around the world, where use of differing culture methods has resulted in genetically distinct strains over time. Whilst differing BCG vaccine efficacy around the world is well documented, and the reasons for this may be multifactorial, it has been hypothesized that genetic differences in BCG vaccine strains contribute to this variation. Isolates from an historic archive of lyophilized BCG strains were regrown, DNA was extracted and then whole-genome sequenced using Oxford Nanopore Technologies. The resulting whole-genome data were plotted on a phylogenetic tree and analysed to identify the presence or absence of regions of difference (RDs) and single-nucleotide polymorphisms (SNPs) relating to virulence, growth and cell wall structure. Of 50 strains available, 36 were revived in culture and 39 were sequenced. Morphology differed between the strains distributed before and after 1934. There was phylogenetic association amongst certain geographically classified strains, most notably BCG-Russia, BCG-Japan and BCG-Danish. RD2, RD171 and RD713 deletions were associated with late strains (seeded after 1927). When mapped to BCG-Pasteur 1172, the SNPs in sigK, plaA, mmaA3 and eccC5 were associated with early strains. Whilst BCG-Russia, BCG-Japan and BCG-Danish showed strong geographical isolate clustering, the late strains, including BCG-Pasteur, showed more variation. A wide range of SNPs were seen within geographically classified strains, and as much intra-strain variation as between-strain variation was seen. The date of distribution from the original Pasteur laboratory (early pre-1927 or late post-1927) gave the strongest association with genetic differences in regions of difference and virulence-related SNPs, which agrees with the previous literature

    Performance of the ALICE experiment at the CERN LHC

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    ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Development of Escherichia coli and Mycobacterium smegmatis recombinants expressing major Mycobacterium tuberculosis-specific antigenic proteins

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    Objective/background: Mycobacterium tuberculosis is an obligate pathogenic bacterial species in the family Mycobacteriaceae and the causative agent of most tuberculosis (TB) cases. Until today, the only approved TB vaccine is Bacille Calmette Guerin (BCG), which has been used since 1921. While BCG provides fairly effective protection for infants and young children, its efficacy in adults is variable around the world. This could be due to several parameters including strains of the vaccine and exposure of individuals to different environmental bacterial infections. The situation is complicated by the emergence of multidrug resistant strains of M. tuberculosis. This urged the demand to develop new improved vaccines and immunotherapies against TB. Development of nonpathogenic recombinant constructs delivering M. tuberculosis-specific antigenic proteins provides the chance to evaluate candidates to be included in diagnostic tools and preventive vaccines. In our study, we are introducing some of the major M. tuberculosis genes in Escherichia coli and Mycobacterium smegmatis. Methods: DNA corresponding to the genes Rv3891, Rv3020, Rv0287, Rv3875, Rv3874, Rv3872, Rv2346c, and Rv3619 were PCR-amplified from M. tuberculosis genomic DNA and visualized on gel electrophoresis at the expected DNA size. Products were subsequently ligated to the plasmid pGEMTeasy and used to transform TOP10 E. coli. Transformed colonies were selected on appropriate media. At the second stage, genes-DNA were subcultured in expression vectors pDE22 and pGESTH1; the recombinant plasmids were finally used to transform. M. smegmatis and E. coli, respectively. Expression of proteins in E. coli was confirmed by Western blotting and in M. smegmatis by reverse transcriptase polymerase chain reaction (RT-PCR). Results: Amplified genes were successfully cloned and transformed in E. coli and M. smegmatis. Colonies of recombinant bacteria were detected on appropriate media. Western blotting and RT-PCR confirmed the expression of our corresponding proteins in both the bacterial vehicles. Conclusion: Positive results of cloning and expression suggest that the constructed clones are ready tools for further assessment of their immunogenicity and can be included in improved diagnostic tools and vaccines against TB

    Three Rounds of Read Correction Significantly Improve Eukaryotic Protein Detection in ONT Reads

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    Background: Eukaryotes’ whole-genome sequencing is crucial for species identification, gene detection, and protein annotation. Oxford Nanopore Technology (ONT) is an affordable and rapid platform for sequencing eukaryotes; however, the relatively higher error rates require computational and bioinformatic efforts to produce more accurate genome assemblies. Here, we evaluated the effect of read correction tools on eukaryote genome completeness, gene detection and protein annotation. Methods: Reads generated by ONT of four eukaryotes, C. albicans, C. gattii, S. cerevisiae, and P. falciparum, were assembled using minimap2 and underwent three rounds of read correction using flye, medaka and racon. The generates consensus FASTA files were compared for total length (bp), genome completeness, gene detection, and protein-annotation by QUAST, BUSCO, BRAKER1 and InterProScan, respectively. Results: Genome completeness was dependent on the assembly method rather than on the read correction tool; however, medaka performed better than flye and racon. Racon significantly performed better than flye and medaka in gene detection, while both racon and medaka significantly performed better than flye in protein-annotation. Conclusion: We show that three rounds of read correction significantly affect gene detection and protein annotation, which are dependent on assembly quality in preference to assembly completeness

    The effect of adjuvants and delivery systems on Th1, Th2, Th17 and Treg cytokine responses in mice immunized with Mycobacterium tuberculosis-specific proteins.

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    Tuberculosis (TB) is a major health problem of global concern. The control of this disease requires appropriate preventive measures, including vaccines. In TB, T helper (Th)1 cytokines provide protection whereas Th2 and T regulatory (Treg) cytokines contribute to the pathogenesis and Th17 cytokines play a role in both protection and pathogenesis. Previous studies with Mycobacterium tuberculosis-specific proteins have identified seven low molecular weight proteins, PE35, ESXA, ESXB, Rv2346c, Rv2347c, Rv3619c, and Rv3620c, as immunodominant antigens inducing Th1-cell responses in humans following natural infection with M. tuberculosis. The aim of this study was to characterize the cytokine responses induced in mice immunized with these proteins, using various adjuvants and delivery systems, i.e. chemical adjuvants (Alum and IFA), non-pathogenic mycobacteria (M. smegmatis and M. vaccae) and a DNA vaccine plasmid (pUMVC6). The immune responses were monitored by quantifying the marker cytokines secreted by Th1 (IFN-ɣ), Th2 (IL-5), Treg (IL-10), and Th17 (IL-17A) cells. DNA corresponding to pe35, esxa, esxb, rv2346c, rv2347c, rv3619c, and rv3620c genes were cloned into the expression vectors pGES-TH-1, pDE22 and pUMVC6 for expression in Escherichia coli, mycobacteria and eukaryotic cells, respectively. Mice were immunized with the recombinants using different adjuvants and delivery systems, and spleen cells were stimulated in vitro with peptides of immunizing proteins to investigate antigen-specific secretion of Th1 (IFN-ɣ), Th2 (IL-5), Treg (IL-10), and Th17 (IL-17A) cytokines. The results showed that spleen cells, from mice immunized with all antigens, secreted the protective Th1 cytokine IFN-ɣ, except ESXB, with one or more adjuvants and delivery systems. However, only Rv3619c consistently induced Th1-biased responses, without the secretion of significant concentrations of Th2, Th17 and Treg cytokines, with all adjuvants and delivery systems. Rv3619c also induced antigen-specific IgG antibodies in immunized mice

    Strain Variation Based on Spike Glycoprotein Gene of SARS-CoV-2 in Kuwait from 2020 to 2021

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    Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which was first identified in Wuhan, China, in December 2019. With the global transmission of the virus, many SARS-CoV-2 variants have emerged due to the alterations of the spike glycoprotein. Therefore, the S glycoprotein encoding gene has widely been used for the molecular analysis of SARS-Co-2 due to its features affecting antigenicity and immunogenicity. We analyzed the S gene sequences of 35 SARS-CoV-2 isolates in Kuwait from March 2020 to February 2021 using the Sanger method and MinION nanopore technology to confirm novel nucleotide alterations. Our results show that the Kuwaiti strains from clade 19A and B were the dominant variants early in the pandemic, while clade 20I (Alpha, V1) was the dominant variant from February 2021 onward. Besides the known mutations, 21 nucleotide deletions in the S glycoprotein in one Kuwaiti strain were detected, which might reveal a recombinant SARS-CoV-2 with the defective viral genome (DVG). This study emphasizes the importance of closely perceiving the emerging clades with these mutations during this continuous pandemic as some may influence the specificity of diagnostic tests, such as RT-PCR and even vaccine design directing these positions
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