Browsing by Author "Fielding, Burtram Clinton"

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    Alkaloids: Therapeutic Potential against Human Coronaviruses
    (MPDI, 2020) Fielding, Burtram Clinton; da Silva Maia Bezerra Filho, Carlos; Ismail, Nasser S.M.
    Alkaloids are a class of natural products known to have wide pharmacological activity and have great potential for the development of new drugs to treat a wide array of pathologies. Some alkaloids have antiviral activity and/or have been used as prototypes in the development of synthetic antiviral drugs. In this study, eleven anti-coronavirus alkaloids were identified from the scientific literature and their potential therapeutic value against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is discussed. In this study, in silico studies showed an affinity of the alkaloids for binding to the receptor-binding domain of the SARS-CoV-2 spike protein, putatively preventing it from binding to the host cell. Lastly, several mechanisms for the known anti-coronavirus activity of alkaloids were discussed, showing that the alkaloids are interesting compounds with potential use as bioactive agents against SARS-CoV-2.
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    Colistin, Carbapenem and Cephalosporin-resistant Klebsiella pneumoniae reported from Misrata, Libya
    (Medpharm Publications, 2017) Shallouf, Mohamed; Abrantes, Pedro Miguel dos Santos; Fielding, Burtram Clinton; Africa, Charlene Wilma Joyce
    Background: National surveillance of antimicrobial resistance has become a mandatory approach to control the spread of antimicrobial resistance and for the establishment of antibiotic treatment guidelines. In this study, clinical isolates of K. pneumoniae were phenotypically investigated for the presences of Colistin and beta-lactams resistance. Methods: Clinical samples were obtained from hospitalized (n=140) and non-hospitalized patients (n=60) in Misrata, Libya. Identification of the isolated species was achieved using the VITEK 2 compact system. Screening for Carbapenem and Cephalosporin-resistance was performed using the disk diffusion method with Carbapenem (10µg) and Cephalosporin (30µg) disks and Minimum Inhibitory Concentration (MIC) determined by VITEK 2. Colistin resistance was determined using both Sensititre Gram-negative Xtra plate format (GNX2F) and VITEK 2. Carbapenemase activity was detected using the RAPIDEC CARBA NP, Modified Hodge test, Carbapenem inactivation method, MAST Combi Carba plus kit (D73C) and Meropenem combined disk test. ESBL and AmpC production was confirmed using Sensititre ESBL confirmatory plates (ESB1F), modified double disk synergy test MDDST, MAST ESBL detection kit D67C, AmpC & ESBL detection kit D68C along with AmpC detection kit D69C. Results and conclusion: Of the 200 clinical isolates, 85 (42.5%) were K. pneumoniae of which 54 (63.52%) demonstrated resistance to at least one of the Carbapenems, 16 (18.82%) were ESBL or AmpC producers and 2 (2.35%) were Carbapenem and Colistin resistant. 13 (21.25%) isolates were susceptible to all antibiotics tested except Ampicillin and Augmentin.
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    Is there a link between the pathogenic human Coronavirus envelope protein and immunopathology? A review of the literature
    (Frontiers Media S.A., 2020) Fielding, Burtram Clinton; Schoeman, Dewald
    Since the severe acute respiratory syndrome (SARS) outbreak in 2003, human coronaviruses (hCoVs) have been identified as causative agents of severe acute respiratory tract infections. Two more hCoV outbreaks have since occurred, the most recent being SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19). The clinical presentation of SARS and MERS is remarkably similar to COVID-19, with hyperinflammation causing a severe form of the disease in some patients. Previous studies show that the expression of the SARS-CoV E protein is associated with the hyperinflammatory response that could culminate in acute respiratory distress syndrome (ARDS), a potentially fatal complication. This immunemediated damage is largely caused by a cytokine storm, which is induced by significantly elevated levels of inflammatory cytokines interleukin (IL)-1β and IL-6, which are partly mediated by the expression of the SARS-CoV E protein.
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    The molecular characterisation of a baculovirus isolated from trichoplusia ni
    (University of the Western Cape, 2001) Fielding, Burtram Clinton; Davison, S.
    In South Africa there are more than 106 insects pests which attack a wide variety of crops. The top ten or twenty of these can seriously limit successful production on the farm. Costs involved in controlling these pests are considerable, often higher than the value of the crop itself. Trichoplusia ri (common name: cabbage looper) is a pest that can cause considerable damage to a wide variety of economically important crops. Although Trichoplusia ni has successfully been controlled with synthetic chemical pesticides, awareness about the negative impact of these control measures on the environment has necessitated the development of safer alternatives. Additionally, cabbage looper resistance to the commonly used pesticides has been reported. Since a Trichoplusia ni multiple nuclear polyhedrosis virus has previously been used in the effective control of the pest, the potential of characterizing a South African baculovirus isolate showed great potential. A latent baculovirus infecting a field population of Trichoplusia ni was isolated and characterised. Initial DNA and protein characterization identified it as a novel baculovirus. The aim of this research was to characterise the baculovirus at a molecular level. This could lead to future improvement of the viral insecticidal properties The family Baculoviridae include more than 600 viruses with only nineteen receiving species status (Murphy et ol., 1995). The genome sequencing and mapping of NPVs could prove important in determining the relationships between these viruses. Additionally, it could be useful in understanding the importance of gene arrangement and the essential domains of genes' This could provide insight into the crs- and trans-regulation among genes (Jin et al., 1997). The determination of gene order and arrangement of the novel baculovirus isolated from a field population of Trichoplusia ni was presented in Chapter 2. Data were used to construct a partial functional map of the TniSNPV genome. Subsequently, the order and homology of genes identified were used as a phylogenetic marker, identi$,ing TniSNpv as a putative member of the Group II NpVs.
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    Staying ahead of the bugs
    (FINWEEK, 2020) Fielding, Burtram Clinton
    In a recent interview on his The DnilySlww, Jon Stewart asked astrophysicist Neil dcGrassc Tyson why the universe is trying to kill us, this in reference to the near-miss meteor event a few months ago. The universe - meaning meteors - has always kind of been trying to kill us, responded the always game Tyson; we just haven't noticed it so much before.