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Communications Biology Jun 2024The Mycoplasma Immunoglobulin Binding/Protease (MIB-MIP) system is a candidate 'virulence factor present in multiple pathogenic species of the Mollicutes, including the...
The Mycoplasma Immunoglobulin Binding/Protease (MIB-MIP) system is a candidate 'virulence factor present in multiple pathogenic species of the Mollicutes, including the fast-growing species Mycoplasma feriruminatoris. The MIB-MIP system cleaves the heavy chain of host immunoglobulins, hence affecting antigen-antibody interactions and potentially facilitating immune evasion. In this work, using -omics technologies and 5'RACE, we show that the four copies of the M. feriruminatoris MIB-MIP system have different expression levels and are transcribed as operons controlled by four different promoters. Individual MIB-MIP gene pairs of M. feriruminatoris and other Mollicutes were introduced in an engineered M. feriruminatoris strain devoid of MIB-MIP genes and were tested for their functionality using newly developed oriC-based plasmids. The two proteins are functionally expressed at the surface of M. feriruminatoris, which confirms the possibility to display large membrane-associated proteins in this bacterium. However, functional expression of heterologous MIB-MIP systems introduced in this engineered strain from phylogenetically distant porcine Mollicutes like Mesomycoplasma hyorhinis or Mesomycoplasma hyopneumoniae could not be achieved. Finally, since M. feriruminatoris is a candidate for biomedical applications such as drug delivery, we confirmed its safety in vivo in domestic goats, which are the closest livestock relatives to its native host the Alpine ibex.
Topics: Bacterial Vaccines; Mycoplasma; Animals; Bacterial Proteins; Immunoglobulins; Gene Expression Regulation, Bacterial; Mycoplasma Infections; Goats
PubMed: 38942984
DOI: 10.1038/s42003-024-06497-8 -
Scientific Reports Jun 2024Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, causes a spectrum of symptoms ranging from mild upper to severe lower...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, causes a spectrum of symptoms ranging from mild upper to severe lower respiratory tract infections. However, the dynamics of nucleocapsid (N) protein antigenemia and RNAemia are not fully understood. We conducted a cohort study involving 117 patients with clinically confirmed COVID-19, focusing on the kinetics of antigenemia and RNAemia and their association with various clinical characteristics. The patients had a median age of 66.0 years (52.0-79.0 years), with a gender distribution of 46.2% male and 53.8% female. Antigenemia reached 100% in fatal cases during the first week after admission. The sensitivity/specificity of antigenemia for diagnosis were 64.7%/73.0% at admission, 69.1%/100% in Week 1, and 66.3%/100% in Week 2. Additionally, the rates of antigenemia in asymptomatic patients were 27.3% upon admission and 22.0% in Week 1, respectively; however, no antigenemia was in samples collected in Week 2. Viral RNAemia was not detected in asymptomatic patients, but RNAemia viral loads were elevated in fatal cases. Kaplan-Meier survival curves demonstrated a higher mortality rate when antigenemia concentrations were elevated in the follow-up samples (P = 0.005). Our study provides a comprehensive analysis of the kinetics of viral N-protein antigenemia and RNAemia according to disease severity and clinical classification. Our findings suggest that highest concentrations of antigenemia in fatal cases occur in the first week after admission, indicating that early elevated antigenemia may serve as a marker of mortality risk.
Topics: Humans; Male; COVID-19; Female; Middle Aged; Aged; SARS-CoV-2; RNA, Viral; Severity of Illness Index; Antigens, Viral; Coronavirus Nucleocapsid Proteins; Cohort Studies; Phosphoproteins
PubMed: 38942808
DOI: 10.1038/s41598-024-65489-0 -
Nature Communications Jun 2024Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this...
Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this setting are not understood. Here we perform bulk and single-cell RNA sequencing of samples from the lower respiratory tract and blood, and assess plasma cytokine profiling to study the effects of dexamethasone on both systemic and pulmonary immune cell compartments. In blood samples, dexamethasone is associated with decreased expression of genes associated with T cell activation, including TNFSFR4 and IL21R. We also identify decreased expression of several immune pathways, including major histocompatibility complex-II signaling, selectin P ligand signaling, and T cell recruitment by intercellular adhesion molecule and integrin activation, suggesting these are potential mechanisms of the therapeutic benefit of steroids in COVID-19. We identify additional compartment- and cell- specific differences in the effect of dexamethasone that are reproducible in publicly available datasets, including steroid-resistant interferon pathway expression in the respiratory tract, which may be additional therapeutic targets. In summary, we demonstrate compartment-specific effects of dexamethasone in critically ill COVID-19 patients, providing mechanistic insights with potential therapeutic relevance. Our results highlight the importance of studying compartmentalized inflammation in critically ill patients.
Topics: Dexamethasone; Humans; COVID-19 Drug Treatment; COVID-19; SARS-CoV-2; Lung; Cytokines; Critical Illness; Male; Single-Cell Analysis; Female; Middle Aged; T-Lymphocytes; Aged; Lymphocyte Activation
PubMed: 38942804
DOI: 10.1038/s41467-024-49756-2 -
Scientific Reports Jun 2024Methicillin-resistant Staphylococcus (MRS) has been associated with neonatal infections, with colonization of the anovaginal tract being the main source of vertical...
Methicillin-resistant Staphylococcus (MRS) has been associated with neonatal infections, with colonization of the anovaginal tract being the main source of vertical transmission. The COVID-19 pandemic has altered the frequency of antibiotic usage, potentially contributing to changes in the dynamics of bacterial agents colonizing humans. Here we determined MRS colonization rates among pregnant individuals attending a single maternity in Rio de Janeiro, Brazil before (January 2019-March 2020) and during (May 2020-March 2021) the COVID-19 pandemic. Anovaginal samples (n = 806 [521 samples before and 285 during the pandemic]) were streaked onto chromogenic media. Colonies were identified by MALDI-TOF MS. Detection of mecA gene and SCCmec typing were assessed by PCR and antimicrobial susceptibility testing was done according to CLSI guidelines. After the onset of the pandemic, MRS colonization rates increased significantly (p < 0.05) from 8.6% (45) to 54.7% (156). Overall, 215 (26.6%) MRS isolates were detected, of which S. haemolyticus was the most prevalent species (MRSH, 84.2%; 181 isolates). SCCmec type V was the most frequent among MRS (63.3%; 136), and 31.6% (68) of MRS strains had a non-typeable SCCmec, due to new combinations of ccr and mecA complexes. Among MRS strains, 41.9% (90) were resistant to at least 3 different classes of antimicrobial agents, and 60% (54) of them were S. haemolyticus harboring SCCmec V. MRS colonization rates and the emergence of multidrug-resistant variants detected in this study indicate the need for continuing surveillance of this important pathogen within maternal and child populations.
Topics: Humans; Female; Pregnancy; COVID-19; Staphylococcal Infections; Methicillin-Resistant Staphylococcus aureus; Adult; Brazil; Pregnancy Complications, Infectious; Anti-Bacterial Agents; SARS-CoV-2; Microbial Sensitivity Tests; Pandemics; Vagina
PubMed: 38942787
DOI: 10.1038/s41598-024-64422-9 -
Nature Communications Jun 2024In a pivotal trial (EPIC-HR), a 5-day course of oral ritonavir-boosted nirmatrelvir, given early during symptomatic SARS-CoV-2 infection (within three days of symptoms...
In a pivotal trial (EPIC-HR), a 5-day course of oral ritonavir-boosted nirmatrelvir, given early during symptomatic SARS-CoV-2 infection (within three days of symptoms onset), decreased hospitalization and death by 89.1% and nasal viral load by 0.87 log relative to placebo in high-risk individuals. Yet, nirmatrelvir/ritonavir failed as post-exposure prophylaxis in a trial, and frequent viral rebound has been observed in subsequent cohorts. We develop a mathematical model capturing viral-immune dynamics and nirmatrelvir pharmacokinetics that recapitulates viral loads from this and another clinical trial (PLATCOV). Our results suggest that nirmatrelvir's in vivo potency is significantly lower than in vitro assays predict. According to our model, a maximally potent agent would reduce the viral load by approximately 3.5 logs relative to placebo at 5 days. The model identifies that earlier initiation and shorter treatment duration are key predictors of post-treatment rebound. Extension of treatment to 10 days for Omicron variant infection in vaccinated individuals, rather than increasing dose or dosing frequency, is predicted to lower the incidence of viral rebound significantly.
Topics: Humans; SARS-CoV-2; Ritonavir; COVID-19 Drug Treatment; COVID-19; Viral Load; Antiviral Agents; Indazoles; Models, Theoretical; Post-Exposure Prophylaxis; Lactams; Leucine; Nitriles; Proline
PubMed: 38942778
DOI: 10.1038/s41467-024-49458-9 -
The International Journal on Drug Policy Jun 2024There is limited empirical work assessing the effectiveness of treatment as prevention (TasP) in reducing HCV prevalence among people who inject drugs (PWID). Here, we...
BACKGROUND
There is limited empirical work assessing the effectiveness of treatment as prevention (TasP) in reducing HCV prevalence among people who inject drugs (PWID). Here, we used survey data from the UK during 2010-2020, to evaluate the impact of direct-acting antiviral agent (DAA) treatment scale-up, which started in 2015, on HCV prevalence among PWID.
METHODS
We fitted a logistic regression to time/location specific data on prevalence from the Needle Exchange Surveillance Initiative in Scotland and Unlinked Anonymous Monitoring programme in England. For each post-intervention year and location, we quantified the effect of TasP as the difference between estimated prevalence and its counterfactual (prevalence in the absence of scale-up). Progress to elimination was assessed by comparing most recent prevalence against one in 2015.
RESULTS
In 2015, prevalence ranged from 0.44 to 0.71 across the 23 locations (3 Scottish, 20 English). Compared to counterfactuals, there was an absolute reduction of 46% (95% credible interval [32%,59%]) in Tayside in 2020, 35% ([24%,44%]) in Glasgow in 2019, and 25% ([10%,39%]) in the Rest of Scotland in 2020. The English sites with highest estimated absolute reductions in 2021 were South Yorkshire (45%, [29%,58%]), Thames Valley (49%, [34%,59%]) and West London (41%, [14%,59%]). Compared to 2015, there was 80% probability that prevalence had fallen by 65% in Tayside, 53% in Glasgow and 36% in the Rest of Scotland. The English sites with highest % prevalence decrease compared to 2015, achieved with probability 80%, were Chesire & Merseyside (70%), South Yorkshire (65%) and Thames Valley (71%). Higher treatment intensity was associated with higher reductions in prevalence.
CONCLUSION
Conclusion. Real-world evidence showing substantial reductions in chronic HCV associated with increase of HCV treatment scale-up in the community thus supporting the effectiveness of HCV treatmen as prevention in people who inject drugs.
PubMed: 38942687
DOI: 10.1016/j.drugpo.2024.104429 -
The Lancet. Public Health Jul 2024Alcohol health-warning labels are a policy option that can contribute to the reduction of alcohol-related harms, but their effects and public perception depend on their...
Effect of alcohol health warning labels on knowledge related to the ill effects of alcohol on cancer risk and their public perceptions in 14 European countries: an online survey experiment.
BACKGROUND
Alcohol health-warning labels are a policy option that can contribute to the reduction of alcohol-related harms, but their effects and public perception depend on their content and format. Our study aimed to investigate the effect of health warnings on knowledge that alcohol causes cancer, the perceptions of three different message topics (responsible drinking, general health harm of alcohol, and alcohol causing cancer), and the role of images included with the cancer message.
METHODS
In this online survey experiment, distributed in 14 European countries and targeting adults of the legal alcohol-purchase age who consumed alcohol, participants were randomly allocated to one of six label conditions using a pseudorandom number generator stratified by survey language before completing a questionnaire with items measuring knowledge and label perceptions. Effect on knowledge was assessed as a primary outcome by comparing participants who had increased knowledge after exposure to labels with the rest of the sample, for the six label conditions. Label perceptions were compared between label conditions as secondary outcomes.
FINDINGS
19 110 participants completed the survey and were eligible for analysis. Our results showed that a third of the participants exposed to the cancer message increased their knowledge of alcohol causing cancer (increase for 1131 [32·5%, 95% CI 29·8 to 35·2] of 3409 participants [weighted percentage] for text-only message; increase for 1096 [33·3%, 30·4 to 36·2] of 3198 [weighted percentage] for message inlcuding pictogram; and increase for 1030 [32·5%, 29·6 to 35·4] of 3242 [weighted percentage] for message including graphic image), compared with an increase for 76 (2·4%, -1·2 to 6·0) of 3018 participants who viewed the control message. Logistic regression showed that cancer messages increased knowledge compared with the control label (odds ratio [OR] 20·20, 95% CI 15·88 to 26·12; OR 21·16, 16·62 to 27·38; OR 20·61, 16·19 to 26·68). Cancer messages had the highest perceived impact and relevance, followed by general health harm and responsibility messages. Text-only and pictogram cancer messages were seen as clear, comprehensive, and acceptable, whereas those including an image of a patient with cancer had lower acceptability and the highest avoidance rating of all the labels. The only identified interaction between perceptions and experimental conditions (with gender) indicated higher comprehensibility and acceptability ratings of cancer labels than responsibility messages and control labels by women, with the results reversed in men.
INTERPRETATION
Health warnings are an effective policy option to increase knowledge of alcohol causing cancer, with a generalisable effect across several countries. Europeans consider alcohol health-warning labels to be comprehensible and acceptable, with cancer-specific health warnings having the highest perceived impact and relevance.
FUNDING
EU4Health.
Topics: Humans; Europe; Male; Female; Health Knowledge, Attitudes, Practice; Adult; Neoplasms; Middle Aged; Product Labeling; Surveys and Questionnaires; Young Adult; Alcohol Drinking; Adolescent; Public Opinion; Alcoholic Beverages; Aged
PubMed: 38942558
DOI: 10.1016/S2468-2667(24)00102-6 -
RNA (New York, N.Y.) Jun 2024SARS-CoV-2, the causative virus of the COVID-19 pandemic, follows SARS and MERS as recent zoonotic coronaviruses causing severe respiratory illness and death in humans....
SARS-CoV-2, the causative virus of the COVID-19 pandemic, follows SARS and MERS as recent zoonotic coronaviruses causing severe respiratory illness and death in humans. The recurrent impact of zoonotic coronaviruses demands a better understanding of their fundamental molecular biochemistry. Nucleoside modifications, which modulate many steps of the RNA lifecycle, have been found in SARS-CoV-2 RNA, although whether they confer a pro- or anti-viral effect is unknown. Regardless, the viral RNA-dependent RNA polymerase will encounter these modifications as it transcribes through the viral genomic RNA. We investigated the functional consequences of nucleoside modification on the pre-steady state kinetics of SARS-CoV-2 RNA-dependent RNA transcription using an in vitro reconstituted transcription system with modified RNA templates. Our findings show that N6-methyladenosine and 2'O-methyladenosine modifications slow the rate of viral transcription at magnitudes specific to each modification, which has the potential to impact SARS-CoV-2 genome maintenance.
PubMed: 38942480
DOI: 10.1261/rna.079991.124 -
Life Sciences Jun 2024The study evaluated the antiviral effect of Verapamil against respiratory syncytial virus (RSV) and investigated its underlying mechanism.
AIMS
The study evaluated the antiviral effect of Verapamil against respiratory syncytial virus (RSV) and investigated its underlying mechanism.
MATERIALS AND METHODS
RSV-infected BALB/c mice were treated with Verapamil. Body weight, survival rates, viral load, lung damage, inflammatory factors, and the expression of RSV fusion (F) protein were analyzed. In cellular studies, intracellular Ca and viral titers were measured in the presence of Verapamil, Calcium Chloride, and EGTA. A time-of-addition assay assessed the antiviral effect of Verapamil.
KEY FINDINGS
Mice infected with RSV and treated with Verapamil exhibited a significant decrease in weight loss, an increase in survival rates, and reductions in viral titers, RSV F protein expression, inflammatory responses, and lung tissue injury. Verapamil reduced intracellular calcium levels, which correlated with reduced viral titers. The addition of calcium chloride reversed the anti-viral effects mediated by Verapamil, while EGTA potentiated them. The antiviral activity of Verapamil was observed during the early phase of RSV infection, likely by blocking Ca channels and inhibiting virus replication.
SIGNIFICANCE
Verapamil effectively inhibits RSV infection by blocking calcium channels and reducing intracellular calcium levels, thereby impeding viral replication. Thus, Verapamil shows promise as a treatment for RSV.
PubMed: 38942358
DOI: 10.1016/j.lfs.2024.122877 -
The Science of the Total Environment Jun 2024Virus spillovers from managed honey bees, Apis mellifera, are thought to contribute to the decline of wild pollinators, including bumble bees. However, data on the...
Virus spillovers from managed honey bees, Apis mellifera, are thought to contribute to the decline of wild pollinators, including bumble bees. However, data on the impact of such viruses on wild pollinators remain scarce, and the influence of landscape structure on virus dynamics is poorly understood. In this study, we deployed bumble bee colonies in an agricultural landscape and studied changes in the bumble bee virome during field placement under varying habitat composition and configuration using a multiscale analytical framework. We estimated prevalence of viruses and viral loads (i.e. number of viral genomic equivalent copies) in bumble bees before and after placing them in the field using next generation sequencing and quantitative PCR. The results show that viral loads and number of different viruses present increased during placement in the field and that the virus composition of the colonies shifted from an initial dominance of honey bee associated viruses to a higher number (in both viral loads and number of viruses present) of bumble bee associated viruses. Especially DWV-B, typical for honey bees, drastically decreased after the time in the field. Viral loads prior to placing colonies in the field showed no effect on colony development, suggesting low impacts of these viruses in field settings. Notably, we further demonstrate that increased habitat diversity results in a lower number of different viruses present in Bombus colonies, while colonies in areas with well-connected farmland patches decreased in their total viral load after field placement. Our results emphasize the importance of landscape heterogeneity and connectivity for wild pollinator health and that these influences predominate at fine spatial scales.
PubMed: 38942311
DOI: 10.1016/j.scitotenv.2024.174280