Exploration of inflammasomes as targets for therapy of Pseudomonas aeruginosa infection

Pseudomonas aeruginosa is a common Gram-negative opportunistic bacterial pathogen capable of infecting humans with compromised natural defenses and causing severe pulmonary disease. It is the major cause of severe chronic pulmonary disease in cystic fibrosis (CF) patients subsequently resulting in progressive deterioration of lung function. Interaction between P. aeruginosa and host induces a number of marked inflammatory responses and is associated with complex therapeutic problems. NOD-like receptors (NLRs) can recognize a variety of endogenous and exogenous ligands and its activation initiate inflammasome formation that induces maturation of the proinflammatory cytokine interleukin (IL)-1β through activation of caspase-1. Through a literature search, no prior research on mutant strains as well as clinical isolates of P. aeruginosa from CF patients at different stages of infection has been conducted to explore NLR-mediated innate immune responses to this bacterial infection. All the work presented in this thesis focuses on the exploration of inflammasomes as targets for therapy of P. aeruginosa infection. We hypothesized that genetic alterations of P. aeruginosa affect the innate immune response of human monocytes. THP-1 human monocytic cells were infected with clinical P. aeruginosa isolates from CF patients, or with P. aeruginosa mutant strains lacking flagella, pili, lipopolysaccharide, or pyocyanin. The overall involvement of NLRs in innate immune recognition of P. aeruginosa was addressed through demonstrating of NLR-mediated caspase-1 activation or P. aeruginosa-induced IL-1β secretion. Our findings suggest that P. aeruginosa, which lost certain virulence factors during pulmonary infection, may fail to induce caspase-1 activation and secretion of IL-1β in the process of host-pathogen interactions. This may reveal novel mechanism of the pathogen adaptation to avoid detection by NLR(s). As P. aeruginosa infections are characterized by strong inflammation of infected tissues anti-inflammatory therapies in combination with antibiotics have been considered for the treatment of associated diseases. Spleen tyrosine kinase (SYK), a non-receptor tyrosine kinase, is an important regulator of inflammatory responses. Several studies have highlighted SYK as a key player in the pathogenesis of a multitude of diseases. Inhibition of SYK activity was explored as a therapeutic option in several inflammatory conditions; however, this has not been studied in bacterial infections. We used a model of an in vitro infection of human monocytic cell line THP-1 and lung epithelial cell line H292 with both wild type and flagella-deficient mutant of P. aeruginosa strain K, as well as with clinical isolates from CF patients, to study the effect of a small molecule SYK inhibitor R406 on inflammatory responses induced by this pathogen. The role of SYK in regulation of inflammasome activation was also determined by evaluating the effect of SYK inhibitor on innate immune responses in P. aeruginosa infected cells. The results suggest that SYK is involved in the regulation of inflammatory responses to P. aeruginosa, and R406 may potentially be useful in dampening the damage caused by severe inflammation associated with this infection

Sustainable green approach to synthesize Fe 3 O 4 /α-Fe 2 O 3 nanocomposite using waste pulp of Syzygium cumini and its application in functional stability of microbial cellulases

Synthesis of nanomaterials following green routes have drawn much attention in recent years due to the low cost, easy and eco-friendly approaches involved therein. Therefore, the current study is focused towards the synthesis of Fe(3)O(4)/α-Fe(2)O(3) nanocomposite using waste pulp of Jamun (Syzygium cumini) and iron nitrate as the precursor of iron in an eco-friendly way. The synthesized Fe(3)O(4)/α-Fe(2)O(3) nanocomposite has been extensively characterized through numerous techniques to explore the physicochemical properties, including X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, Ultraviolet-Vis spectroscopy, field emission scanning electron microscope, high resolution transmission electron microscope and vibrating sample magnetometer. Further, efficiency of the Fe(3)O(4)/α-Fe(2)O(3) nanocomposite has been evaluated to improve the incubation temperature, thermal/pH stability of the crude cellulase enzymes obtained from the lab isolate fungal strain Cladosporium cladosporioides NS2 via solid state fermentation. It is found that the presence of 0.5% Fe(3)O(4)/α-Fe(2)O(3) nanocomposite showed optimum incubation temperature and thermal stability in the long temperature range of 50–60 °C for 15 h along with improved pH stability in the range of pH 3.5–6.0. The presented study may have potential application in bioconversion of waste biomass at high temperature and broad pH range

Hyperglycemia-induced oxidative stress and epigenetic regulation of ET-1 gene in endothelial cells

Introduction: Hyperglycemia-induced endothelial dysfunction and the subsequent increase of oxidative stress could lead to aberrant regulation of various genes which are responsible for a range of functions. This study aims to find out how hyperglycemia affect oxidative stress and then the expression and methylation of endothelin 1 (ET-1) gene in in human umbilical vein endothelial cells (HUVEC).Methods: Cells were cultured in growth medium and exposed to low and high glucose concentrations to mimic normal and diabetic condition respectively. Computational analysis were performed using UCSC genome browser and eukaryotic promoter database (EPD). The expression of ET-1 gene was investigated by real time PCR. Cytotoxicity and oxidative stress were determined by MTT and DCFH-DA assays respectively. Promoter methylation was assessed by the bisulfite sequencing method.Results: DCFH-DA assay showed that hyperglycemia can significantly increase the regulation of reactive oxygen species synthesis. The relative expression of ET-1 gene was increased due to exposure to high glucose concentration. MTT assay revealed reduced viability of cells due to the glucose induced damage. Methylation analysis revealed hypomethylation of the promoter of ET-1 however the difference was not significant. Out of 175 CpGs at 25 CpG sites, only 36 CpGs were methylated (20.5% methylation) in cell treated with normal glucose. Upon exposure to high glucose only 30 CpGs were methylated in 175 CpGs at 25 CpG sites (17.1% methylation).Discussion: Our study concludes a significantly high expression of ET-1 gene in response to high glucose exposure in HUVECs. It also reports that hyperglycemic condition leads to elevated oxidative stress. No significant change was found in methylation when cells were treated with high and low glucose concentrations

Identification of potential therapeutic targets for COVID-19 through a structural-based similarity approach between SARS-CoV-2 and its human host proteins

Background: The COVID-19 pandemic caused by SARS-CoV-2 has led to millions of deaths worldwide, and vaccination efficacy has been decreasing with each lineage, necessitating the need for alternative antiviral therapies. Predicting host–virus protein–protein interactions (HV-PPIs) is essential for identifying potential host-targeting drug targets against SARS-CoV-2 infection.Objective: This study aims to identify therapeutic target proteins in humans that could act as virus–host-targeting drug targets against SARS-CoV-2 and study their interaction against antiviral inhibitors.Methods: A structure-based similarity approach was used to predict human proteins similar to SARS-CoV-2 (“hCoV-2”), followed by identifying PPIs between hCoV-2 and its target human proteins. Overlapping genes were identified between the protein-coding genes of the target and COVID-19-infected patient’s mRNA expression data. Pathway and Gene Ontology (GO) term analyses, the construction of PPI networks, and the detection of hub gene modules were performed. Structure-based virtual screening with antiviral compounds was performed to identify potential hits against target gene-encoded protein.Results: This study predicted 19,051 unique target human proteins that interact with hCoV-2, and compared to the microarray dataset, 1,120 target and infected group differentially expressed genes (TIG-DEGs) were identified. The significant pathway and GO enrichment analyses revealed the involvement of these genes in several biological processes and molecular functions. PPI network analysis identified a significant hub gene with maximum neighboring partners. Virtual screening analysis identified three potential antiviral compounds against the target gene-encoded protein.Conclusion: This study provides potential targets for host-targeting drug development against SARS-CoV-2 infection, and further experimental validation of the target protein is required for pharmaceutical intervention

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

The Impact of Health Literacy and Diabetes Knowledge Level on Health Outcomes Among Admitted Diabetic Pilgrims-HAJJ 2016

This cross-sectional study assessed the influence of health literacy and diabetes knowledge on the Hajj pilgrims’ diabetic health outcomes. One hundred and three diabetic pilgrims were recruited from the general internal medicine and surgical departments at Alnoor Specialists Hospital and the general internal medicine department at King Abdullah Medical City in Mecca. Participants were identified from the hospitals’ medical records databases. We assessed Patients\u27 health literacy and diabetes knowledge by using the validated assessment tools REALM-SF and DKT. HbA1c values and other diabetic outcomes were extracted from the medical record. Spearman’s correlation, multiple linear and multivariable logistic regression were used to assess the relationship between health literacy, diabetes knowledge, and glycemic control. The majority of the sample were aged between 55 and 64 years (46.6%), male (57.3%), had diabetes for ≥ 20 years (52.4 %) and were illiterate (28.2 %). Spearman’s correlation showed a non-significant negative correlation between the participants’ HbA1c and the health literacy scores, but showed a significantly negative correlation between HbA1c results and the diabetes knowledge scores. In adjusted models that examined the associations between health literacy, diabetes knowledge, and HbA1c recent results, the regression results indicate that diabetes knowledge can be used as a predictor of glycemic control (β=-2.537, P= .000; 95% CI -3.282, -1.792). Whereas the coefficient for health literacy level was not significantly associated with HbA1c level (β=-.446, P= .296\u3e 0.05; 95% CI -1.288, .397). Diabetes knowledge is the most significant predictor associated with blood glucose control in admitted diabetic pilgrims. Health literacy appears to exert its impact through diabetes knowledge and is not directly correlated with glycemic control. Presentation: 24:4

Syk inhibitor R406 down-regulates inflammation in an in vitro model of Pseudomonas aeruginosa infection

As Pseudomonas aeruginosa infections are characterized by strong inflammation of infected tissues anti-inflammatory therapies in combination with antibiotics have been considered for the treatment of associated diseases. Syk tyrosine kinase is an important regulator of inflammatory responses, and its specific inhibition was explored as a therapeutic option in several inflammatory conditions; however, this has not been studied in bacterial infections. We used a model of in vitro infection of human monocytic cell line THP-1 and lung epithelial cell line H292 with both wild type and flagella-deficient mutant of P. aeruginosa strain K, as well as with clinical isolates from cystic fibrosis patients, to study the effect of a small molecule Syk inhibitor R406 on inflammatory responses induced by this pathogen. One-hour long pretreatment of THP-1 cells with 10 μM R406 resulted in a significant down-regulation of the expression of the adhesion molecule ICAM-1, pro-inflammatory cytokines TNFα and IL-1β, and phosphorylated signaling proteins ERK2, JNK, p-38, and IκBα, as well as significantly decreased TNF-α release by infected H292 cells. The results suggest that Syk is involved in the regulation of inflammatory responses to P. aeruginosa, and R406 may potentially be useful in dampening the damage caused by severe inflammation associated with this infection.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

The effects of social media (Snapchat) interventions on the knowledge of oral health during pregnancy among pregnant women in Saudi Arabia.

BackgroundThere is growing interest in using social media to improve pregnant women's well-being. This study aimed to evaluate the effects of social media (Snapchat) dissemination of health-promoting interventions on knowledge of oral health during pregnancy among pregnant women in Saudi Arabia.Materials and methodsUsing a single-blinded parallel group randomized controlled trial design, 68 volunteers were assigned to either a study group (SG) or a control group (CG). The SG received information about oral health during pregnancy via Snapchat, while the CG received the same information using WhatsApp. The participants were assessed three times: T1 prior to the intervention, T2 immediately following the intervention, and T3 as a follow-up 1 month later.ResultsA total of 63 participants completed the study in the SG or CG. According to paired t-test, total knowledge scores in the SG and CG increased significantly from T1 to T2 (p ConclusionsUsing social media (e.g., Snapchat and WhatsApp) as a health-promoting intervention is a promising method for improving women's knowledge about oral health during pregnancy for short term. However, further studies are needed to compare social media with conventional standard lecturing methods. also, to assess the longevity of the impact (short or long term)