Microbiology (Reading)
March 2025
Novel treatment options are needed for the gastric pathogen due to its increasing antibiotic resistance. The vitamin K analogue menadione has been extensively studied due to interest in its anti-bacterial and anti-cancer properties. Here, we investigated the effects of menadione on growth, viability, antibiotic resistance, motility and gene expression using clinical isolates.
View Article and Find Full Text PDFDespite increasing evidence on antimicrobial resistance (AMR), there is limited literature on antimicrobial access and use in humans and animals in community settings globally. This study assessed knowledge and perceptions of AMR, as well as practices relating to the use of antimicrobials in humans and animals in Wakiso district, Uganda. This was a cross-sectional study among 418 participants that employed quantitative data collection methods.
View Article and Find Full Text PDFBackground: Private pharmacies are the first point of contact for the public regarding acquisition of medicines and other pharmaceuticals in many low- and middle-income countries including Uganda. Most antimicrobial stewardship (AMS) programmes in Uganda have targeted pharmacies in public health facilities, with little known about private pharmacies. This study explored knowledge and practices related to AMS in private pharmacies in Wakiso district, central Uganda.
View Article and Find Full Text PDFis the leading cause of peptic ulcers and gastric cancer. The most common treatment regimens use combinations of two or three antibiotics and a proton pump inhibitor (PPI) to suppress stomach acid. The World Health Organization designated clarithromycin-resistant as a high priority pathogen for drug development, due to increasing antibiotic resistance globally.
View Article and Find Full Text PDFis highly polymorphic, and some strains are much more likely to cause disease than others. Biofilm formation can help bacteria to survive antibiotic treatment, immune attack and other stresses, promoting persistent infection. We hypothesized that isolates from patients with more severe associated disease would be better at forming biofilms than isolates from patients with less severe disease.
View Article and Find Full Text PDFIndividuals infected with harbor unique and diverse populations of quasispecies, but diversity between and within different regions of the human stomach and the process of bacterial adaptation to each location are not yet well understood. We applied whole-genome deep sequencing to characterize the within- and between-stomach region genetic diversity populations from paired antrum and corpus biopsies of 15 patients, along with single biopsies from one region of an additional 3 patients, by scanning allelic diversity. We combined population deep sequencing with more conventional sequencing of multiple single colony isolates from individual biopsies to generate a unique dataset.
View Article and Find Full Text PDFBackground: Inappropriate use of antimicrobials in both humans and animals is a key driver of antimicrobial resistance (AMR). In addition, human behaviours such as poor disposal of antimicrobials in the environment can increase their exposure to microbes which can impact on humans and animals. However, evidence on access, use and disposal of antimicrobials for humans and animals at community level in Uganda is limited.
View Article and Find Full Text PDFAntimicrobial stewardship (AMS), as one of the global strategies to promote responsible use of antimicrobials to prevent antimicrobial resistance (AMR), remains poor in many low-and middle-income countries (LMICs). We implemented a project aimed at strengthening AMS in Wakiso district, Uganda using a One Health approach. A total of 86 health practitioners (HPs), including animal health workers, and 227 community health workers (CHWs) participated in training workshops, and over 300 pupils from primary schools were sensitized on AMR, AMS, and infection prevention and control (IPC).
View Article and Find Full Text PDFThe study of archaeal proteins and the processes to which they contribute poses particular challenges due to the often extreme environments in which they function. DNA recombination, replication and repair proteins of the halophilic euryarchaeon, Haloferax volcanii (Hvo) are of particular interest as they tend to resemble eukaryotic counterparts in both structure and activity, and genetic tools are available to facilitate their analysis. In the present study, we show using bioinformatics approaches that the Hvo RecA-like protein RadA is structurally similar to other recombinases although is distinguished by a unique acidic insertion loop.
View Article and Find Full Text PDFHelicobacter pylori infections are usually established in early childhood and continuously stimulate immunity, including T-helper 1 (Th1), Th17, and regulatory T-cell (Treg) responses, throughout life. Although known to be the major cause of peptic ulcer disease and gastric cancer, disease occurs in a minority of those who are infected. Recently, there has been much interest in beneficial effects arising from infection with this pathogen.
View Article and Find Full Text PDFThe bacterial pathogen Helicobacter pylori commonly colonizes the human gastric mucosa during early childhood and persists throughout life. The organism has evolved multiple mechanisms for evading clearance by the immune system and, despite inducing inflammation in the stomach, the majority of infections are asymptomatic. H.
View Article and Find Full Text PDFThe aggregation of α-synuclein (Syn or S) to form insoluble fibrils is important in the pathogenesis of Parkinson's disease, but key risk factors remain ill-defined. We have developed Fluorescence Resonance Energy Transfer (FRET)-based assays for α-synuclein aggregation, using Green Fluorescent Protein variants Cerulean (C) or Venus (V), fused to each other (CV, VC) or to human synuclein (SC, SV etc). Bacterially expressed proteins were purified to homogeneity, and C-terminal fusions SC and SV largely retained their ability to aggregate in vitro.
View Article and Find Full Text PDFThe vacuolating cytotoxin, VacA, is an important virulence factor secreted by the gastric pathogen Helicobacter pylori. Certain vacA genotypes are strongly associated with disease risk, but the association is not absolute. The factors determining vacA gene expression are not fully understood, and the mechanisms of its regulation are elusive.
View Article and Find Full Text PDFCronobacter sakazakii is associated with severe and often fatal cases of infant meningitis and necrotizing enterocolitis. The form of meningitis differs from that due to Neisseria meningitidis and Streptococcus spp., in that it is highly invasive and destructive towards human brain cells.
View Article and Find Full Text PDFCarriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gastric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA or producing more active forms of it, providing the first evidence of a positive role for the minimally active s2/i2 toxin.
View Article and Find Full Text PDFPersistent Helicobacter pylori infection induces chronic inflammation in the human gastric mucosa, which is associated with development of peptic ulceration, gastric atrophy, and gastric adenocarcinoma. It has been postulated that secretion of immunomodulatory molecules by H. pylori facilitates bacterial persistence, and membrane vesicles (MV), which have the potential to cross the gastric epithelial barrier, may mediate delivery of these molecules to host immune cells.
View Article and Find Full Text PDFBackground: Strict regulation of replisome components is essential to ensure the accurate transmission of the genome to the next generation. The sliding clamp processivity factors play a central role in this regulation, interacting with both DNA polymerases and multiple DNA processing and repair proteins. Clamp binding partners share a common peptide binding motif, the nature of which is essentially conserved from phage through to humans.
View Article and Find Full Text PDFCNS Neurol Disord Drug Targets
December 2012
The neural protein α-synuclein aggregates both in vivo and in vitro to form insoluble fibrils that are involved in Parkinson's disease pathogenesis. We have generated α-synuclein/fluorescent-protein fusion constructs overexpressed in muscle cells of the nematode, Caenorhabdtis elegans. Green Fluorescent Protein (GFP) variants, Cerulean (C) or Venus (V), were fused to the C-terminus of human α-synuclein (S); the resultant fusion genes were designated SV and SC, plus a CV fusion as well as S, C and V singly.
View Article and Find Full Text PDFBiochemical and structural analysis of archaeal proteins has enabled us to gain great insight into many eukaryotic processes, simultaneously offering fascinating glimpses into the adaptation and evolution of proteins at the extremes of life. The archaeal PCNAs, central to DNA replication and repair, are no exception. Characterisation of the proteins alone, and in complex with both peptides and protein binding partners, has demonstrated the diversity and subtlety in the regulatory role of these sliding clamps.
View Article and Find Full Text PDFHalophilic archaea maintain intracellular salt concentrations close to saturation to survive in high-salt environments and their cellular processes have adapted to function under these conditions. Little is known regarding halophilic adaptation of the DNA processing machinery, particularly intriguing since protein-DNA interactions are classically salt sensitive. To investigate such adaptation, we characterised the DNA-binding capabilities of recombinant RPA3 from Haloferax volcanii (HvRPA3).
View Article and Find Full Text PDFBackground: The high intracellular salt concentration required to maintain a halophilic lifestyle poses challenges to haloarchaeal proteins that must stay soluble, stable and functional in this extreme environment. Proliferating cell nuclear antigen (PCNA) is a fundamental protein involved in maintaining genome integrity, with roles in both DNA replication and repair. To investigate the halophilic adaptation of such a key protein we have crystallised and solved the structure of Haloferax volcanii PCNA (HvPCNA) to a resolution of 2.
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