A5055764058- Tuberculosis Research and Epidemiology
- Insect symbiosis and bacterial influences
- Insect and Pesticide Research
- Insect Resistance and Genetics
- Mycobacterium research and diagnosis
- Legume Nitrogen Fixing Symbiosis
- HIV/AIDS Research and Interventions
- Pneumonia and Respiratory Infections
- Insect-Plant Interactions and Control
- Entomopathogenic Microorganisms in Pest Control
- Biochemical and Structural Characterization
- Toxin Mechanisms and Immunotoxins
- Antimicrobial Peptides and Activities
- HIV Research and Treatment
- SARS-CoV-2 and COVID-19 Research
- Dengue and Mosquito Control Research
- Agricultural pest management studies
- HIV/AIDS drug development and treatment
- Fungal Infections and Studies
- Respiratory viral infections research
- Pneumocystis jirovecii pneumonia detection and treatment
- SARS-CoV-2 detection and testing
- Invertebrate Immune Response Mechanisms
- Lipid Membrane Structure and Behavior
- Nail Diseases and Treatments
National Health Laboratory Service
2017-2025
University of the Witwatersrand
2017-2025
Biologie Fonctionnelle Insectes et Interactions
2011-2024
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2020-2024
Institut National des Sciences Appliquées de Lyon
2019-2024
Africa Health Research Institute
2024
UCLouvain
2024
Université Claude Bernard Lyon 1
2011-2023
Universidade Federal do Piauí
2020
Centre de Biophysique Moléculaire
2001-2006
Long-term intracellular symbiosis (or endosymbiosis) is widely distributed across invertebrates and recognized as a major driving force in evolution. However, the maintenance of immune homeostasis organisms chronically infected with mutualistic bacteria challenging task, little known about molecular processes that limit endosymbiont immunogenicity host inflammation. Here, we investigated peptidoglycan recognition protein (PGRP)-encoding genes cereal weevil Sitophilus zeamais ’s association...
The solution structure of termicin from hemocytes the termite Pseudacanthotermes spiniger was determined by proton two-dimensional nuclear magnetic resonance spectroscopy and molecular modeling techniques. Termicin is a cysteine-rich antifungal peptide also exhibiting weak antibacterial activity. global fold consists an alpha-helical segment (Phe4-Gln14) two-stranded (Phe19-Asp25 Gln28-Phe33) antiparallel beta-sheet forming "cysteine stabilized alphabeta motif" (CSalphabeta) found in...
The vacuolar ATPase (V-ATPase) is a 1MDa transmembrane proton pump that operates via rotary mechanism fuelled by ATP. Essential for eukaryotic cell homeostasis, it plays central roles in bone remodeling and tumor invasiveness, making key therapeutic target. Its importance arthropod physiology also makes promising pesticide major challenge designing lead compounds against the V-ATPase its ubiquitous nature, such any must be capable of targeting particular isoforms. Here, we have characterized...
Nutritional symbioses between insects and intracellular bacteria (endosymbionts) are a major force of adaptation, allowing animals to colonize nutrient-poor ecological niches. Many beetles feeding on tyrosine-poor substrates rely surplus aromatic amino acids produced by bacterial endosymbionts. This is crucial for the biosynthesis thick exoskeleton, cuticle, which made matrix chitin with proteins pigments built from tyrosine-derived molecules, providing an important defensive barrier against...
Background/Objectives: Both tuberculosis (TB) and SARS-CoV-2 share similar symptoms transmission routes. In early 2021, USAID Stop TB Partnership recommended an integrated approach for simultaneous COVID-19 testing in high burden countries, using a nasopharyngeal swab sputum individuals with respiratory symptoms. We extended this clinical evaluation, single both Mycobacterium complex (MTBC) at two healthcare facilities South Africa. Methods: A total of 2274 were screened enrolment....
Background/Objectives: Tuberculosis (TB) and SARS-CoV-2 share similar symptoms transmission routes. In early 2021, USAID Stop TB Partnership recommended an integrated approach for simultaneous COVID-19 testing in high burden countries individuals with respiratory symptoms. this evaluation, we tested a single sputum both Mycobacterium tuberculosis complex (MTBC) from participants at two healthcare facilities South Africa. The diagnostic accuracy of the Xpert Xpress (Xpress) assay using swab...
Background: Reflexed cryptococcal antigenaemia (CrAg) testing has been offered on remnant CD4 specimens with a count 100 cells/µL from 2017 in South Africa. The Western Cape is the only province to introduce CrAg for counts of 200 cells/µL.Objectives: objective this study was assess reflexed detection rate Cape.Method: retrospective analysis laboratory data conducted between September 2022 and May 2024. reported following categories at provincial, district, sub-district levels: (1) cells/µL,...
The hydrophobic cavity of Lipid Transfer Protein 1 from Nicotiana tabacum is investigated in detail by NMR using xenon as a spy. analysis the 129Xe chemical shifts and self-relaxation times gives evidence protein−xenon interaction. Thermodynamics binding characterized through study aliphatic 1H 13C shift variation function pressure. constant evaluated to 75.5 ± 1.0 M-1 at 293 K. location inside deduced SPINOE experiments. noble gas appears occupy four sites, experiments indicate that it...
Because of the increasingly concern consumers and public policy about problems for environment health due to chemical pesticides, search molecules more safe is currently great importance. Particularly, plants are able fight pathogens as insects, bacteria or fungi; so that could represent a valuable source new molecules.It was observed Medicago truncatula seed flour displayed strong toxic activity towards adults rice weevil Sitophilus oryzae (Coleoptera), major pest stored cereals. The...
ABSTRACT South Africa is a country with high incidence of tuberculosis (TB), complicated by coinfection human immunodeficiency virus (HIV). The Xpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) used in as the test for initial diagnosis TB, and other molecular platforms such m 2000 (Abbott Molecular, Des Plaines, IL, are widely monitoring HIV load. latter platform now also equipped RealTi e (RT) MTB RIF/INH assays TB first-line drug resistance screening but has not been evaluated settings...
The Xpert® Xpress SARS-CoV-2 and SARS-CoV-2/Flu/RSV tests were rapidly developed widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In response to emerging genetic variability, a new target (RNA-dependent RNA-polymerase) has been added both tests: CoV-2 plus CoV-2/Flu/RSV test. A rapid evaluation of was performed in South Africa, using residual specimens. Residual specimens (n = 125) evaluate test included 50 genotyped assessed 45 specimens, 10...
Plant lipid transfer proteins are small soluble extracellular that able to bind and a variety of lipids in vitro. Recently, it has been proposed may play key role plant defence mechanisms, especially during the induction systemic acquired resistance. However, very little is known about expressed developing plants tissues, since almost all biophysical structural data available date on originate from present storage tissues monocot cereal seeds. In this paper, we report functional...
PA1b (pea albumin 1, subunit b) is a small and compact 37-amino acid protein, isolated from pea seeds (Pisum sativum), that adopts cystine knot fold. It acts as potent insecticidal agent against major pests in stored crops vegetables, making it promising bioinsecticide. Here, we investigate the influence of individual residues on structure bioactivity PA1b. A collection 13 mutants was successfully chemically synthesized which involved definition amphiphilic electrostatic characteristics were...
Mycobacterium tuberculosis (Mtb) contributes to the pathogenesis of childhood acute community-acquired pneumonia in settings with a high burden. The incremental value repeated induced sputum (IS) sample, compared single IS or gastric aspirate (GA) is not well known. Two samples were obtained for Mtb culture from children enrolled as cases Pneumonia Etiology Research Child Health (PERCH) study South Africa. Nonstudy attending physicians requested GA if pulmonary was clinically suspected. We...
Four moderate-complexity automated nucleic acid amplification tests for the diagnosis of tuberculosis are reported as having laboratory analytical and clinical performance similar to that Cepheid Xpert MTB/RIF assay. These assays Abbott RealTime MTB RIF/INH Resistance, Becton Dickinson MAX MDR-TB, Hain Lifescience/Bruker FluoroType MTBDR, Roche cobas assays. The study compared feasibility, ease use, operational characteristics these assays/platforms. Manufacturer input was obtained technical...
This study seeks to describe the rollout and current state of South Africa’s GeneXpert molecular diagnostic program for tuberculosis (TB). Xpert MTB/RIF was introduced in 2011 with a subsequent expansion include extra-pulmonary paediatric testing, followed by Ultra 2017. Through centralised laboratory information system use standardised platform more than decade, over 23 million tests were analysed, describing numbers tested, Mycobacterium complex detection, rifampin resistance, unsuccessful...
The PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin extract from Legume seeds with lethal activity on several insect pests, such as mosquitoes, some aphids and cereal weevils. This 37 amino-acid cysteine-rich has been, until now, obtained by biochemical purification or chemical synthesis. In this paper, we present our results for the transient production of in Nicotiana benthamiana agro-infiltration, a yield about 35 µg/g fresh leaves maximum 8 days after infiltration. part PA1...
Peptidoglycan recognition proteins (PGRPs) are ubiquitous among animals and play pivotal functions in insect immunity. Non-catalytic PGRPs involved the activation of immune pathways by binding to peptidoglycan (PGN), whereas amidase capable cleaving PGN into non-immunogenic compounds. Drosophila PGRP-LB belongs downregulates deficiency (IMD) pathway meso-2,6-diaminopimelic (meso-DAP or DAP)-type PGN. While process is well analyzed for non-catalytic PGRPs, little known about enzymatic...
Symbiotic bacteria interact with their host through symbiotic cues. Here, we took advantage of the mutualism between Drosophila and Lactiplantibacillus plantarum (Lp) to investigate a novel mechanism host-symbiont interaction. Using chemically defined diets, found that association Lp improves growth larvae-fed amino acid-imbalanced even though cannot produce limiting acid. We show in this context supports its host's molecular dialogue requires functional operons encoding ribosomal transfer...
HIV viral load (VL) testing plays a key role in the clinical management of as marker adherence and antiretroviral efficacy. To date, national international treatment recommendations have evolved to endorse routine VL testing. South Africa (SA) has recommended since 2004. Progressively, centralised program managed by its National Health Laboratory Service (NHLS) undergone expansive growth. Retrospective de-identified data from 2013 2022 were evaluated review performance. Test volumes...
Abstract PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin, extracted from Legume seeds, with a lethal activity towards several insect pests, such as mosquitoes, some aphids and cereal weevils. This toxin acts by binding to the subunits c e of plasma membrane H + -ATPase (V-ATPase) in midgut. In this study, two weevils, sensitive Sitophilus oryzae strain WAA42, resistance ISOR3 insensitive red flour beetle Tribolium castaneum , were used biochemical histological experiments...