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1.
J Med Imaging Radiat Sci ; 55(4): 101449, 2024 Jul 13.
Article in English | MEDLINE | ID: mdl-39004006

ABSTRACT

INTRODUCTION: Artificial Intelligence (AI) is revolutionizing medical imaging and radiation therapy. AI-powered applications are being deployed to aid Medical Radiation Technologists (MRTs) in clinical workflows, decision-making, dose optimisation, and a wide range of other tasks. Exploring the levels of AI education provided across the United States is crucial to prepare future graduates to deliver the digital future. This study aims to assess educators' levels of AI knowledge, the current state of AI educational provisions, the perceived challenges around AI education, and important factors for future advancements. METHODS: An online survey was electronically administered to all radiologic technologists in the American Society of Radiologic Technologists (ASRT) database who indicated that they had an educator role in the United States. This was distributed through the membership of the ASRT, from February to April 2023. All quantitative data was analysed using frequency and descriptive statistics. The survey's open-ended questions were analysed using a conceptual content analysis approach. RESULTS: Out of 5,066 educators in the ASRT database, 373 valid responses were received, resulting in a response rate of 7.4%. Despite 84.5% of educators expressing the importance of teaching AI, 23.7% currently included AI in academic curricula. Of the 76.3% that did not include AI in their curricula, lack of AI knowledge among educators was the top reason for not integrating AI in education (59.1%). Similarly, AI-enabled tools were utilised by only 11.1% of the programs to assist teaching. The levels of trust in AI varied among educators. CONCLUSION: The study found that although US educators of MRTs have a good baseline knowledge of general concepts regarding AI, they could improve on the teaching and use of AI in their curricula. AI training and guidance, adequate time to develop educational resources, and funding and support from higher education institutions were key priorities as highlighted by educators.

2.
BMJ Open ; 14(4): e081675, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38626958

ABSTRACT

INTRODUCTION: Gonorrhoea, the sexually transmissible infection caused by Neisseria gonorrhoeae, has a substantial impact on sexual and reproductive health globally with an estimated 82 million new infections each year worldwide. N. gonorrhoeae antimicrobial resistance continues to escalate, and disease control is largely reliant on effective therapy as there is no proven effective gonococcal vaccine available. However, there is increasing evidence from observational cohort studies that the serogroup B meningococcal vaccine four-component meningitis B vaccine (4CMenB) (Bexsero), licensed to prevent invasive disease caused by Neisseria meningitidis, may provide cross-protection against the closely related bacterium N. gonorrhoeae. This study will evaluate the efficacy of 4CMenB against N. gonorrhoeae infection in men (cis and trans), transwomen and non-binary people who have sex with men (hereafter referred to as GBM+). METHODS AND ANALYSIS: This is a double-blind, randomised placebo-controlled trial in GBM+, either HIV-negative on pre-exposure prophylaxis against HIV or living with HIV (CD4 count >350 cells/mm3), who have had a diagnosis of gonorrhoea or infectious syphilis in the last 18 months (a key characteristic associated with a high risk of N. gonorrhoeae infection). Participants are randomised 1:1 to receive two doses of 4CMenB or placebo 3 months apart. Participants have 3-monthly visits over 24 months, which include testing for N. gonorrhoeae and other sexually transmissible infections, collection of demographics, sexual behaviour risks and antibiotic use, and collection of research samples for analysis of N. gonorrhoeae-specific systemic and mucosal immune responses. The primary outcome is the incidence of the first episode of N. gonorrhoeae infection, as determined by nucleic acid amplification tests, post month 4. Additional outcomes consider the incidence of symptomatic or asymptomatic N. gonorrhoeae infection at different anatomical sites (ie, urogenital, anorectum or oropharynx), incidence by N. gonorrhoeae genotype and antimicrobial resistance phenotype, and level and functional activity of N. gonorrhoeae-specific antibodies. ETHICS AND DISSEMINATION: Ethical approval was obtained from the St Vincent's Hospital Human Research Ethics Committee, St Vincent's Hospital Sydney, NSW, Australia (ref: 2020/ETH01084). Results will be disseminated in peer-reviewed journals and via presentation at national and international conferences. TRIAL REGISTRATION NUMBER: NCT04415424.


Subject(s)
Anti-Infective Agents , Gonorrhea , HIV Infections , Meningococcal Infections , Meningococcal Vaccines , Sexual and Gender Minorities , Male , Humans , Gonorrhea/epidemiology , Gonorrhea/prevention & control , Gonorrhea/drug therapy , Meningococcal Vaccines/therapeutic use , Meningococcal Infections/epidemiology , Homosexuality, Male , Neisseria gonorrhoeae/genetics , HIV Infections/drug therapy , Randomized Controlled Trials as Topic , Multicenter Studies as Topic
3.
Cell Rep ; 43(4): 114012, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38573856

ABSTRACT

Plasmodium falciparum is a human-adapted apicomplexan parasite that causes the most dangerous form of malaria. P. falciparum cysteine-rich protective antigen (PfCyRPA) is an invasion complex protein essential for erythrocyte invasion. The precise role of PfCyRPA in this process has not been resolved. Here, we show that PfCyRPA is a lectin targeting glycans terminating with α2-6-linked N-acetylneuraminic acid (Neu5Ac). PfCyRPA has a >50-fold binding preference for human, α2-6-linked Neu5Ac over non-human, α2-6-linked N-glycolylneuraminic acid. PfCyRPA lectin sites were predicted by molecular modeling and validated by mutagenesis studies. Transgenic parasite lines expressing endogenous PfCyRPA with single amino acid exchange mutants indicated that the lectin activity of PfCyRPA has an important role in parasite invasion. Blocking PfCyRPA lectin activity with small molecules or with lectin-site-specific monoclonal antibodies can inhibit blood-stage parasite multiplication. Therefore, targeting PfCyRPA lectin activity with drugs, immunotherapy, or a vaccine-primed immune response is a promising strategy to prevent and treat malaria.


Subject(s)
Erythrocytes , Plasmodium falciparum , Polysaccharides , Protozoan Proteins , Humans , Antigens, Protozoan/metabolism , Antigens, Protozoan/immunology , Antigens, Protozoan/genetics , Erythrocytes/parasitology , Erythrocytes/metabolism , Lectins/metabolism , Lectins/genetics , Malaria, Falciparum/parasitology , Plasmodium falciparum/metabolism , Polysaccharides/metabolism , Protein Binding , Protozoan Proteins/metabolism , Protozoan Proteins/genetics
4.
Microbiol Spectr ; 12(1): e0260123, 2024 Jan 11.
Article in English | MEDLINE | ID: mdl-38054719

ABSTRACT

IMPORTANCE: Haemophilus influenzae biogroup aegyptius is a human-adapted pathogen and the causative agent of Brazilian purpuric fever (BPF), an invasive disease with high mortality, that sporadically manifests in children previously suffering conjunctivitis. Phase variation is a rapid and reversible switching of gene expression found in many bacterial species, and typically associated with outer-membrane proteins. Phase variation of cytoplasmic DNA methyltransferases has been shown to play important roles in bacterial gene regulation and can act as epigenetic switches, regulating the expression of multiple genes as part of systems called phasevarions (phase-variable regulons). This study characterized two alleles of the ModA phasevarion present in H. influenzae biogroup aegyptius, ModA13, found in non-BPF causing strains and ModA16, unique to BPF causing isolates. Phase variation of ModA13 and ModA16 led to genome-wide changes to DNA methylation resulting in altered protein expression. These changes did not affect serum resistance in H. influenzae biogroup aegyptius strains.


Subject(s)
Conjunctivitis, Bacterial , Haemophilus Infections , Child , Humans , Haemophilus influenzae/genetics , Phase Variation , Membrane Proteins/genetics , Haemophilus Infections/microbiology , Conjunctivitis, Bacterial/microbiology
5.
Gynecol Oncol ; 179: 85-90, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37944330

ABSTRACT

OBJECTIVE: Aberrant ß-catenin distribution has been theorized as a predictive biomarker for recurrence in early stage, low grade endometrioid endometrial cancer. METHODS: This retrospective single-institution cohort study reviewed 410 patients with endometrial cancer from May 2018 to May 2022. Only endometrioid histology was included. Demographic and clinicopathological data were collected from the medical records. Univariate and multivariate logistic regressions, and sensitivity analyses for early stage, low grade and no specific molecular profile (NSMP) tumors were performed. RESULTS: 297 patients were included for analysis. Most patients were over 60 years old, White, and with a BMI >30 and early stage low grade disease. Aberrant ß-catenin distribution was found in 135 patients (45.5%) and wild type membranous ß-catenin distribution in 162 (54.5%). While TP53 mutation correlated with endometrial cancer recurrence in this cohort (OR = 4.78), aberrant ß-catenin distribution did not correlate in the overall population (OR = 0.75), the early stage low grade cancers (OR = 0.84), or the NSMP group (OR = 1.41) on univariate or multivariate analysis. No correlation between ß-catenin distribution and local (OR = 0.61) or distant recurrences (OR = 0.90) was detected. CONCLUSIONS: Aberrant ß-catenin distribution did not significantly correlate with recurrence in endometrioid endometrial cancer, nor in the early stage, low grade and NSMP sub-cohorts.


Subject(s)
Carcinoma, Endometrioid , Endometrial Neoplasms , Female , Humans , Middle Aged , beta Catenin/genetics , Catenins , Retrospective Studies , Cohort Studies , Neoplasm Recurrence, Local/pathology , Carcinoma, Endometrioid/genetics , Carcinoma, Endometrioid/pathology , Endometrial Neoplasms/genetics , Endometrial Neoplasms/pathology
6.
Microbiol Resour Announc ; 12(12): e0078523, 2023 Dec 14.
Article in English | MEDLINE | ID: mdl-37991358

ABSTRACT

Non-typeable Haemophilus influenzae (NTHi) is a major bacterial pathogen of the human airway. We report high-depth coverage RNA-Seq data from prototype NTHi strains 723 and R2866, encoding two of the most common phase-variable ModA alleles found in NTHi strains, ModA2 and ModA10, respectively.

8.
ACS Infect Dis ; 9(8): 1451-1457, 2023 08 11.
Article in English | MEDLINE | ID: mdl-37467082

ABSTRACT

In the meningitis belt of sub-Saharan Africa, there are cyclic meningococcal epidemics that coincide with clonal waves of Neisseria meningitidis carriage and invasive disease. In the framework of longitudinal colonization and disease studies in Ghana and Burkina Faso, meningococcal isolates belonging to the closely related hypervirulent A:ST-5, A:ST-7, and A:ST-2859 clones have been collected from 1998 to 2011 during meningococcal outbreaks. A comparative whole-genome sequencing study with 100 of these isolates identified the pilin glycosylation (pgl) locus as one hot spot of recombination. Frequent exchange of pgl genes in N. meningitidis by lateral gene transfer results in differences in the glycosylation patterns of pilin and other cell surface glycoproteins. In this study, we looked at both recombination and phase variation of the pgl genes of these clinical isolates and analyzed the glycan structures resulting from different pgl alleles and their variable expression. Our results indicate that the basal O-linked sugar of the glycans expressed by these isolates is masked by various additional mono- or disaccharide structures whose expression is highly variable due to the phase-variable expression of pgl genes. We also observed a distinct glycoform in two isolates with pgl loci that were modified by recombination. These data suggest that variation in N. meningitidis protein glycosylation could be crucial for bacterial adaptation to evade herd immunity in semi-immune populations. Investigating pilin glycosylation in N. meningitidis can shed light on the mechanisms by which this pathogen evades the host immune response, and may help identify potential targets for novel therapies and vaccines.


Subject(s)
Meningitis , Neisseria meningitidis , Humans , Neisseria meningitidis/genetics , Fimbriae Proteins/genetics , Glycosylation , Serogroup , Disease Outbreaks , Polysaccharides
9.
Microbiol Spectr ; 11(4): e0158323, 2023 08 17.
Article in English | MEDLINE | ID: mdl-37436144

ABSTRACT

Many bacterial surface proteins and carbohydrates are modified with phosphorylcholine (ChoP), which contributes to host mimicry and can also promote colonization and survival in the host. However, the ChoP biosynthetic pathways that are used in bacterial species that express ChoP have not been systematically studied. For example, the well-studied Lic-1 pathway is absent in some ChoP-expressing bacteria, such as Neisseria meningitidis and Neisseria gonorrhoeae. This raises a question as to the origin of the ChoP used for macromolecule biosynthesis in these species. In the current study, we used in silico analyses to identify the potential pathways involved in ChoP biosynthesis in genomes of the 26 bacterial species reported to express a ChoP-modified biomolecule. We used the four known ChoP biosynthetic pathways and a ChoP transferase as search terms to probe for their presence in these genomes. We found that the Lic-1 pathway is primarily associated with organisms producing ChoP-modified carbohydrates, such as lipooligosaccharide. Pilin phosphorylcholine transferase A (PptA) homologs were detected in all bacteria that express ChoP-modified proteins. Additionally, ChoP biosynthesis pathways, such as phospholipid N-methyltransferase (PmtA), phosphatidylcholine synthase (Pcs), or the acylation-dependent phosphatidylcholine biosynthesis pathway, which generate phosphatidylcholine, were also identified in species that produce ChoP-modified proteins. Thus, a major finding of this study is the association of a particular ChoP biosynthetic pathway with a cognate, target ChoP-modified surface factor; i.e., protein versus carbohydrate. This survey failed to identify a known biosynthetic pathway for some species that express ChoP, indicating that a novel ChoP biosynthetic pathway(s) may remain to be identified. IMPORTANCE The modification of bacterial surface virulence factors with phosphorylcholine (ChoP) plays an important role in bacterial virulence and pathogenesis. However, the ChoP biosynthetic pathways in bacteria have not been fully understood. In this study, we used in silico analysis to identify potential ChoP biosynthetic pathways in bacteria that express ChoP-modified biomolecules and found the association between a specific ChoP biosynthesis pathway and the cognate target ChoP-modified surface factor.


Subject(s)
Biosynthetic Pathways , Phosphorylcholine , Phosphorylcholine/metabolism , Biosynthetic Pathways/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Fimbriae Proteins/metabolism , Transferases/metabolism
11.
Front Pharmacol ; 14: 1163442, 2023.
Article in English | MEDLINE | ID: mdl-37063296

ABSTRACT

This review summarizes the current understanding of the role of plasma membrane transporters in regulating intracellular inorganic phosphate ([Pi]In) in mammals. Pi influx is mediated by SLC34 and SLC20 Na+-Pi cotransporters. In non-epithelial cells other than erythrocytes, Pi influx via SLC20 transporters PiT1 and/or PiT2 is balanced by efflux through XPR1 (xenotropic and polytropic retrovirus receptor 1). Two new pathways for mammalian Pi transport regulation have been described recently: 1) in the presence of adequate Pi, cells continuously internalize and degrade PiT1. Pi starvation causes recycling of PiT1 from early endosomes to the plasma membrane and thereby increases the capacity for Pi influx; and 2) binding of inositol pyrophosphate InsP8 to the SPX domain of XPR1 increases Pi efflux. InsP8 is degraded by a phosphatase that is strongly inhibited by Pi. Therefore, an increase in [Pi]In decreases InsP8 degradation, increases InsP8 binding to SPX, and increases Pi efflux, completing a feedback loop for [Pi]In homeostasis. Published data on [Pi]In by magnetic resonance spectroscopy indicate that the steady state [Pi]In of skeletal muscle, heart, and brain is normally in the range of 1-5 mM, but it is not yet known whether PiT1 recycling or XPR1 activation by InsP8 contributes to Pi homeostasis in these organs. Data on [Pi]In in cultured cells are variable and suggest that some cells can regulate [Pi] better than others, following a change in [Pi]Ex. More measurements of [Pi]In, influx, and efflux are needed to determine how closely, and how rapidly, mammalian [Pi]In is regulated during either hyper- or hypophosphatemia.

12.
Microbiol Spectr ; 11(3): e0500522, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37098897

ABSTRACT

Escherichia coli signal peptidase I (LepB) has been shown to inefficiently cleave secreted proteins with aromatic amino acids at the second position after the signal peptidase cleavage site (P2'). The Bacillus subtilis exported protein TasA contains a phenylalanine at P2', which in B. subtilis is cleaved by a dedicated archaeal-organism-like signal peptidase, SipW. We have previously shown that when the TasA signal peptide is fused to maltose binding protein (MBP) up to the P2' position, the TasA-MBP fusion protein is cleaved very inefficiently by LepB. However, the precise reason why the TasA signal peptide hinders cleavage by LepB is not known. In this study, a set of 11 peptides were designed to mimic the inefficiently cleaved secreted proteins, wild-type TasA and TasA-MBP fusions, to determine whether the peptides interact with and inhibit the function of LepB. The binding affinity and inhibitory potential of the peptides against LepB were assessed by surface plasmon resonance (SPR) and a LepB enzyme activity assay. Molecular modeling of the interaction between TasA signal peptide and LepB indicated that the tryptophan residue at P2 (two amino acids before the cleavage site) inhibited the active site serine-90 residue on LepB from accessing the cleavage site. Replacing the P2 tryptophan with alanine (W26A) allowed for more efficient processing of the signal peptide when the TasA-MBP fusion was expressed in E. coli. The importance of this residue to inhibit signal peptide cleavage and the potential to design LepB inhibitors based on the TasA signal peptide are discussed. IMPORTANCE Signal peptidase I is an important drug target, and understanding its substrate is critically important to develop new bacterium-specific drugs. To that end, we have a unique signal peptide that we have shown is refractory to processing by LepB, the essential signal peptidase I in E. coli, but previously has been shown to be processed by a more human-like signal peptidase found in some bacteria. In this study, we demonstrate how the signal peptide can bind but is unable to be processed by LepB, using a variety of methods. This can inform the field on how to better design drugs that can target LepB and understand the differences between bacterial and human-like signal peptidases.


Subject(s)
Escherichia coli Proteins , Escherichia coli , Humans , Escherichia coli/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Substrate Specificity , Tryptophan/metabolism , Amino Acid Sequence , Protein Sorting Signals
13.
Trends Microbiol ; 31(7): 692-706, 2023 07.
Article in English | MEDLINE | ID: mdl-36863982

ABSTRACT

Phosphorylcholine (ChoP) can be found in all life forms. Although this molecule was first thought to be uncommon in bacteria, it is now appreciated that many bacteria express ChoP on their surface. ChoP is usually attached to a glycan structure, but in some cases, it is added as a post-translational modification to proteins. Recent findings have demonstrated the role of ChoP modification and phase variation (ON/OFF switching) in bacterial pathogenesis. However, the mechanisms of ChoP synthesis are still unclear in some bacteria. Here, we review the literature and examine the recent developments in ChoP-modified proteins and glycolipids and of ChoP biosynthetic pathways. We discuss how the well-studied Lic1 pathway exclusively mediates ChoP attachment to glycans but not to proteins. Finally, we provide a review of the role of ChoP in bacterial pathobiology and the role of ChoP in modulating the immune response.


Subject(s)
Bacteria , Phosphorylcholine , Phosphorylcholine/metabolism , Bacteria/metabolism , Polysaccharides
14.
Nucleic Acids Res ; 51(7): 3240-3260, 2023 04 24.
Article in English | MEDLINE | ID: mdl-36840716

ABSTRACT

Actinobacillus pleuropneumoniae is the cause of porcine pleuropneumonia, a severe respiratory tract infection that is responsible for major economic losses to the swine industry. Many host-adapted bacterial pathogens encode systems known as phasevarions (phase-variable regulons). Phasevarions result from variable expression of cytoplasmic DNA methyltransferases. Variable expression results in genome-wide methylation differences within a bacterial population, leading to altered expression of multiple genes via epigenetic mechanisms. Our examination of a diverse population of A. pleuropneumoniae strains determined that Type I and Type III DNA methyltransferases with the hallmarks of phase variation were present in this species. We demonstrate that phase variation is occurring in these methyltransferases, and show associations between particular Type III methyltransferase alleles and serovar. Using Pacific BioSciences Single-Molecule, Real-Time (SMRT) sequencing and Oxford Nanopore sequencing, we demonstrate the presence of the first ever characterised phase-variable, cytosine-specific Type III DNA methyltransferase. Phase variation of distinct Type III DNA methyltransferase in A. pleuropneumoniae results in the regulation of distinct phasevarions, and in multiple phenotypic differences relevant to pathobiology. Our characterisation of these newly described phasevarions in A. pleuropneumoniae will aid in the selection of stably expressed antigens, and direct and inform development of a rationally designed subunit vaccine against this major veterinary pathogen.


Subject(s)
Actinobacillus pleuropneumoniae , Phase Variation , Animals , Swine , Actinobacillus pleuropneumoniae/genetics , Actinobacillus pleuropneumoniae/metabolism , DNA Modification Methylases/genetics , DNA Modification Methylases/metabolism , DNA Methylation , Methyltransferases/genetics , Methyltransferases/metabolism , Bacteria/genetics , DNA/metabolism
15.
Transl Oncol ; 31: 101643, 2023 May.
Article in English | MEDLINE | ID: mdl-36805917

ABSTRACT

One of the forms of aberrant glycosylation in human tumors is the expression of N-glycolylneuraminic acid (Neu5Gc). The only known enzyme to biosynthesize Neu5Gc in mammals, cytidine-5'-monophosphate-N-acetylneuraminic acid (CMAH), appears to be genetically inactivated in humans. Regardless, low levels of Neu5Gc have been detected in healthy humans. Therefore, it is proposed that the presence of Neu5Gc in humans is from dietary acquisition, such as red meat. Notably, detection of elevated Neu5Gc levels has been repeatedly found in cancer tissues, cells and serum samples, thereby Neu5Gc-containing antigens may be exploited as a class of cancer biomarkers. Here we review the findings to date on using Neu5Gc-containing tumor glycoconjugates as a class of cancer biomarkers for cancer detection, surveillance, prognosis and therapeutic targets. We review the evidence that supports an emerging hypothesis of de novo Neu5Gc biosynthesis in human cancer cells as a source of Neu5Gc in human tumors, generated under certain metabolic conditions.

16.
Antimicrob Agents Chemother ; 67(1): e0096822, 2023 01 24.
Article in English | MEDLINE | ID: mdl-36602335

ABSTRACT

Neisseria gonorrhoeae has developed resistance to all previous antibiotics used for treatment. This highlights a crucial need for novel antimicrobials to treat gonococcal infections. We previously showed that carbamazepine (Cz), one of the most commonly prescribed antiepileptic drugs, can block the interaction between gonococcal pili and the I-domain region of human complement receptor 3 (CR3)-an interaction that is vital for infection of the female cervix. We also show that Cz can completely clear an established N. gonorrhoeae infection of primary human cervical cells. In this study, we quantified Cz in serum, saliva, and vaginal fluid collected from 16 women who were, or were not, regularly taking Cz. We detected Cz in lower reproductive tract mucosal secretions in the test group (women taking Cz) at potentially therapeutic levels using a competitive ELISA. Furthermore, we found that Cz concentrations present in vaginal fluid from women taking this drug were sufficient to result in a greater than 99% reduction (within 24 h) in the number of viable gonococci recovered from ex vivo, human, primary cervical cell infections. These data provide strong support for the further development of Cz as a novel, host-targeted therapy to treat gonococcal cervicitis.


Subject(s)
Epilepsy , Gonorrhea , Humans , Female , Drug Repositioning , Gonorrhea/drug therapy , Neisseria gonorrhoeae , Carbamazepine/therapeutic use , Carbamazepine/pharmacology
17.
Microbiol Spectr ; 11(1): e0409322, 2023 02 14.
Article in English | MEDLINE | ID: mdl-36511712

ABSTRACT

Adherence of nontypeable Haemophilus influenzae (NTHi) to the host airway is an essential initial step for asymptomatic colonization of the nasopharynx, as well as development of disease. NTHi relies on strict regulation of multiple adhesins for adherence to host substrates encountered in the airway. NTHi encode a phase-variable cytoplasmic DNA methyltransferase, ModA, that regulates expression of multiple genes; a phasevarion (phase-variable regulon). Multiple modA alleles are present in NTHi, in which different alleles methylate a different DNA target, and each controls a different set of genes. However, the role of ModA phasevarions in regulating adherence of NTHi to the host airway is not well understood. This study therefore sought to investigate the role of four of the most prevalent ModA phasevarions in the regulation of adherence of NTHi to multiple substrates of the airway. Four clinical isolates of NTHi with unique modA alleles were tested in this study. The adherence of NTHi to mucus, middle ear epithelial cells, and vitronectin was regulated in a substrate-specific manner that was dependent on the ModA allele encoded. The adhesins Protein E and P4 were found to contribute to the ModA-regulated adherence of NTHi to distinct substrates. A better understanding of substrate-specific regulation of NTHi adherence by ModA phasevarions will allow identification of NTHi populations present at the site of disease within the airway and facilitate more directed development of vaccines and therapeutics. IMPORTANCE Nontypeable Haemophilus influenzae (NTHi) is a predominant pathogen of the human airway that causes respiratory infections such as otitis media (OM) and exacerbations in the lungs of patients suffering from chronic obstructive pulmonary disease (COPD). Due to the lack of a licensed vaccine against NTHi and the emergence of antibiotic-resistant strains, it is extremely challenging to target NTHi for treatment. NTHi adhesins are considered potential candidates for vaccines or other therapeutic approaches. The ModA phasevarions of NTHi play a role in the rapid adaptation of the pathogen to different environmental stress conditions. This study addressed the role of ModA phasevarions in the regulation of adherence of NTHi to specific host substrates found within the respiratory tract. The findings of this study improve our understanding of regulation of adherence of NTHi to the airway, which may further be used to enhance the potential of adhesins as vaccine antigens and therapeutic targets against NTHi.


Subject(s)
Haemophilus influenzae , Phase Variation , Humans , Haemophilus influenzae/genetics , Adhesins, Bacterial/genetics , Nasopharynx , Lung
18.
Biochem Biophys Res Commun ; 642: 162-166, 2023 01 29.
Article in English | MEDLINE | ID: mdl-36580827

ABSTRACT

Cutaneous melanoma is one of the most aggressive and deadly types of skin cancer and rates of disease are continuing to increase worldwide. Currently, no serum biomarkers exist for the early detection of cutaneous melanoma. Normal human cells cannot make the sialic acid sugar, Neu5Gc, yet human tumor cells express Neu5Gc and Neu5Gc-containing glycoconjugates have been proposed as tumor biomarkers. We engineered a Neu5Gc-specific lectin based on the pentameric B-subunit of the Shiga toxigenic Escherichia coli subtilase cytotoxin, termed SubB2M. We have detected elevated Neu5Gc-containing biomarkers in the sera of ovarian and breast cancer patients in a highly sensitive surface plasmon resonance (SPR)-based assay using our SubB2M lectin. Here, we used the SubB2M-SPR assay to investigate Neu5Gc-containing glycoconjugates in the serum of cutaneous melanoma patients. We found elevated total serum Neu5Gc levels in primary (n = 24) and metastatic (n = 38) patients compared to cancer-free controls (n = 34). Serum Neu5Gc levels detected with SubB2M can distinguish cutaneous melanoma patients from cancer-free controls with high sensitivity and specificity as determined by ROC curve analysis. These data indicate that serum Neu5Gc-containing glycoconjugates are a novel class of biomarkers for cutaneous melanoma, particularly for primary melanoma, and have the potential to contribute to the early diagnosis of this disease.


Subject(s)
Melanoma , Skin Neoplasms , Humans , Melanoma/diagnosis , Skin Neoplasms/diagnosis , Neuraminic Acids , Lectins , Biomarkers, Tumor , Glycoconjugates , Melanoma, Cutaneous Malignant
19.
Clin Nutr ESPEN ; 51: 377-384, 2022 10.
Article in English | MEDLINE | ID: mdl-36184231

ABSTRACT

BACKGROUND AND AIMS: Although obesity have been generally shown to be an independent risk factor for poor outcomes in COVID-19 infection, some studies demonstrate a paradoxical protective effect ("obesity paradox"). This study examines the influence of obesity categories on clinical outcomes of severe COVID-19 patients admitted to an intensive care unit with acute hypoxic respiratory failure requiring either non-invasive or invasive mechanical ventilation. METHODS: This is a single centre, retrospective study of consecutive COVID-19 patients admitted to the intensive care unit between 03/2020 to 03/2021. Patients were grouped according to the NICE Body Mass Index (BMI) category. Admission variables including age, sex, comorbidities, and ICU severity indices (APACHE-II, SOFA and PaO2/FiO2) were collected. Data were compared between BMI groups for outcomes such as need for invasive mechanical ventilation (IMV), renal replacement therapy (RRT) and 28-day and overall hospital mortality. RESULTS: 340 patients were identified and of those 333 patients had their BMI documented. Just over half of patients (53%) had obesity. Those with extreme obesity (obesity groups II and III) were younger with fewer comorbidities, but were more hypoxaemic at presentation, than the healthy BMI group. Although non-significant, obesity groups II and III paradoxically showed a lower in-hospital mortality than the healthy weight group. However, adjusted (age, sex, APACHE-II and CCI) competing risk regression analysis showed three-times higher mortality in obese category I (sub-distribution hazard ratio = 3.32 (95% CI 1.30-8.46), p = 0.01) and a trend to higher mortality across all obesity groups compared to the healthy weight group. CONCLUSIONS: In this cohort, those with obesity were at higher risk of mortality after adjustment for confounders. We did not identify an "obesity paradox" in this cohort. The obesity paradox may be explained by confounding factors such as younger age, fewer comorbidities, and less severe organ failures. The impact of obesity on indicators of morbidity including likelihood of requirement for organ support measures was not conclusively demonstrated and requires further scrutiny.


Subject(s)
COVID-19 , Respiratory Distress Syndrome , Respiratory Insufficiency , Body Mass Index , COVID-19/therapy , Humans , Obesity/complications , Respiratory Insufficiency/therapy , Retrospective Studies
20.
Antimicrob Agents Chemother ; 66(9): e0231821, 2022 09 20.
Article in English | MEDLINE | ID: mdl-35980187

ABSTRACT

Multidrug-resistant (MDR) N. gonorrhoeae is a current public health threat. New therapies are urgently needed. PBT2 is an ionophore that disrupts metal homeostasis. PBT2 administered with zinc is shown to reverse resistance to antibiotics in several bacterial pathogens. Here we show that both N. meningitidis and MDR N. gonorrhoeae are sensitive to killing by PBT2 alone. PBT2 is, thus, a candidate therapeutic for MDR N. gonorrhoeae infections.


Subject(s)
Gonorrhea , Neisseria meningitidis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Gonorrhea/drug therapy , Gonorrhea/microbiology , Humans , Ionophores/pharmacology , Ionophores/therapeutic use , Microbial Sensitivity Tests , Neisseria gonorrhoeae , Zinc
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