scholarly journals Viral and Bacterial Co-Infections in the Lungs: Dangerous Liaisons

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1725
Author(s):  
Justine Oliva ◽  
Olivier Terrier
Keyword(s):  
Respiratory Tract ◽  
Current Knowledge ◽  
Influenza Infection ◽  
Public Health Problem ◽  
Experimental Models ◽  
Influenza Viruses ◽  
Host Cells ◽  
Tract Infections

Respiratory tract infections constitute a significant public health problem, with a therapeutic arsenal that remains relatively limited and that is threatened by the emergence of antiviral and/or antibiotic resistance. Viral–bacterial co-infections are very often associated with the severity of these respiratory infections and have been explored mainly in the context of bacterial superinfections following primary influenza infection. This review summarizes our current knowledge of the mechanisms underlying these co-infections between respiratory viruses (influenza viruses, RSV, and SARS-CoV-2) and bacteria, at both the physiological and immunological levels. This review also explores the importance of the microbiome and the pathological context in the evolution of these respiratory tract co-infections and presents the different in vitro and in vivo experimental models available. A better understanding of the complex functional interactions between viruses/bacteria and host cells will allow the development of new, specific, and more effective diagnostic and therapeutic approaches.

scholarly journals The Triad Hsp60-miRNAs-Extracellular Vesicles in Brain Tumors: Assessing Its Components for Understanding Tumorigenesis and Monitoring Patients

2021 ◽  
Vol 11 (6) ◽  
pp. 2867
Author(s):  
Francesca Graziano ◽  
Domenico Gerardo Iacopino ◽  
Giacomo Cammarata ◽  
Gianluca Scalia ◽  
Claudia Campanella ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Extracellular Vesicles ◽  
Current Knowledge ◽  
Disease Status ◽  
Experimental Models ◽  
Host Cells ◽  
Target Cells ◽  
Original Cell

Brain tumors have a poor prognosis and progress must be made for developing efficacious treatments, but for this to occur their biology and interaction with the host must be elucidated beyond current knowledge. What has been learned from other tumors may be applied to study brain tumors, for example, the role of Hsp60, miRNAs, and extracellular vesicles (EVs) in the mechanisms of cell proliferation and dissemination, and resistance to immune attack and anticancer drugs. It has been established that Hsp60 increases in cancer cells, in which it occurs not only in the mitochondria but also in the cytosol and plasma-cell membrane and it is released in EVs into the extracellular space and in circulation. There is evidence suggesting that these EVs interact with cells near and far from their original cell and that this interaction has an impact on the functions of the target cell. It is assumed that this crosstalk between cancer and host cells favors carcinogenesis in various ways. We, therefore, propose to study the triad Hsp60-related miRNAs-EVs in brain tumors and have standardized methods for the purpose. These revealed that EVs with Hsp60 and related miRNAs increase in patients’ blood in a manner that reflects disease status. The means are now available to monitor brain tumor patients by measuring the triad and to dissect its effects on target cells in vitro, and in experimental models in vivo.

scholarly journals The Evolution of Antimicrobial Resistance in Respiratory Pathogens in Canada: What are the Clinical Consequences?

1998 ◽  
Vol 9 (suppl e) ◽  
pp. 10E-15E
Author(s):  
Donald E Low
Keyword(s):  
Antimicrobial Resistance ◽  
Respiratory Tract ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Antibiotic Use ◽  
Respiratory Pathogens ◽  
Important Public Health Problem ◽  
Tract Infections

The use of antimicrobial agents has led to reductions in illnesses and deaths from a variety of infectious diseases. Antimicrobial resistance has followed the introduction of almost every new antimicrobial agent and is now emerging as an important public health problem, especially in respiratory tract pathogens in the community. During the past decade in Canada, a rapid and relentless increase in antimicrobial resistance inStreptococcus pneumoniaeandHaemophilus inflluenzaehas been witnessed. Adverse implications as a result of the treatment of an infection with an antibiotic to which the offending pathogen is resistant have been recognized in only a few infectious disease syndromes (eg. bacterial meningitis). More often, resistance in vitro does not result in resistance in vivo (eg, respiratory tract infections). Therefore, before recommendations regarding empirical or directed therapy are changed, it is essential that evidence to support those decisions is obtained. More important, the prevention and control of such resistance must be addressed by reducing the burden of antibiotic selective pressure by curtailing inappropriate antibiotic use.

Preliminary Report of In vitro and In vivo Effectiveness of Dornase Alfa on SARS-CoV-2 Infection (Preprint)

2020 ◽  
Author(s):  
Hacer Kuzu Okur ◽  
Koray Yalcin ◽  
Cihan Tastan ◽  
Sevda Demir ◽  
Bulut Yurtsever ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Mononuclear Cells ◽  
Multiple Organ ◽  
Peripheral Blood Mononuclear ◽  
Dornase Alfa ◽  
Tract Infections ◽  
Adult Peripheral Blood

UNSTRUCTURED Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). Coronavirus disease 2019 (COVID-19) pandemic affected more than two million people over the world, resulting in unprecedented health, social and economic crises. The COVID-19, viral pneumonia that progresses to ARDS and even multiple organ failure, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High blood neutrophil levels are an early indicator of SARS-CoV-2 infection and predict severe respiratory diseases. A similar mucus structure is detected in COVID-19 patients due to the accumulation of excessive NET in the lungs. Here, we show our preliminary results with dornase alfa that may have an in-vitro anti-viral effect against SARS-CoV-2 infection in a bovine kidney cell line, MDBK without drug toxicity on healthy adult peripheral blood mononuclear cells. In this preliminary study, we also showed that dornase alfa can promote clearance of NET formation in both an in-vitro and three COVID-19 cases who showed clinical improvement in radiological analysis (2-of-3 cases), oxygen saturation (SpO2), respiratory rate, disappearing of dyspnea and coughing.

scholarly journals Rho-Proteins and Downstream Pathways as Potential Targets in Sepsis and Septic Shock: What Have We Learned from Basic Research

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1844
Author(s):  
Maria Luísa da Silveira Hahmeyer ◽  
José Eduardo da Silva-Santos
Keyword(s):  
Septic Shock ◽  
Actin Polymerization ◽  
Current Knowledge ◽  
Cecal Ligation ◽  
Experimental Models ◽  
Rho Proteins ◽  
Growing Cell ◽  
Sepsis And Septic Shock

Sepsis and septic shock are associated with acute and sustained impairment in the function of the cardiovascular system, kidneys, lungs, liver, and brain, among others. Despite the significant advances in prevention and treatment, sepsis and septic shock sepsis remain global health problems with elevated mortality rates. Rho proteins can interact with a considerable number of targets, directly affecting cellular contractility, actin filament assembly and growing, cell motility and migration, cytoskeleton rearrangement, and actin polymerization, physiological functions that are intensively impaired during inflammatory conditions, such as the one that occurs in sepsis. In the last few decades, Rho proteins and their downstream pathways have been investigated in sepsis-associated experimental models. The most frequently used experimental design included the exposure to bacterial lipopolysaccharide (LPS), in both in vitro and in vivo approaches, but experiments using the cecal ligation and puncture (CLP) model of sepsis have also been performed. The findings described in this review indicate that Rho proteins, mainly RhoA and Rac1, are associated with the development of crucial sepsis-associated dysfunction in different systems and cells, including the endothelium, vessels, and heart. Notably, the data found in the literature suggest that either the inhibition or activation of Rho proteins and associated pathways might be desirable in sepsis and septic shock, accordingly with the cellular system evaluated. This review included the main findings, relevance, and limitations of the current knowledge connecting Rho proteins and sepsis-associated experimental models.

scholarly journals In Vitro and In Vivo Activities of E5700 and ER-119884, Two Novel Orally Active Squalene Synthase Inhibitors, against Trypanosoma cruzi

2004 ◽  
Vol 48 (7) ◽  
pp. 2379-2387 ◽  
Author(s):  
Julio A. Urbina ◽  
Juan Luis Concepcion ◽  
Aura Caldera ◽  
Gilberto Payares ◽  
Cristina Sanoja ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Public Health Problem ◽  
Squalene Synthase ◽  
Host Cells ◽  
In Vivo Studies ◽  
Inorganic Pyrophosphate ◽  
Orally Active

ABSTRACT Chagas' disease is a serious public health problem in Latin America, and no treatment is available for the prevalent chronic stage. Its causative agent, Trypanosoma cruzi, requires specific endogenous sterols for survival, and we have recently demonstrated that squalene synthase (SQS) is a promising target for antiparasitic chemotherapy. E5700 and ER-119884 are quinuclidine-based inhibitors of mammalian SQS that are currently in development as cholesterol- and triglyceride-lowering agents in humans. These compounds were found to be potent noncompetitive or mixed-type inhibitors of T. cruzi SQS with K i values in the low nanomolar to subnanomolar range in the absence or presence of 20 μM inorganic pyrophosphate. The antiproliferative 50% inhibitory concentrations of the compounds against extracellular epimastigotes and intracellular amastigotes were ca. 10 nM and 0.4 to 1.6 nM, respectively, with no effects on host cells. When treated with these compounds at the MIC, all of the parasite's sterols disappeared from the parasite cells. In vivo studies indicated that E5700 was able to provide full protection against death and completely arrested the development of parasitemia when given at a concentration of 50 mg/kg of body weight/day for 30 days, while ER-119884 provided only partial protection. This is the first report of an orally active SQS inhibitor that is capable of providing complete protection against fulminant, acute Chagas' disease.

scholarly journals A Conserved PapB Family Member, TosR, Regulates Expression of the Uropathogenic Escherichia coli RTX Nonfimbrial Adhesin TosA while Conserved LuxR Family Members TosE and TosF Suppress Motility

2014 ◽  
Vol 82 (9) ◽  
pp. 3644-3656 ◽  
Author(s):  
Michael D. Engstrom ◽  
Christopher J. Alteri ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Virulence Factors ◽  
Upper Urinary Tract ◽  
Host Cells ◽  
Promoter Regions ◽  
Content Type ◽  
Tract Infections

ABSTRACTA heterogeneous subset of extraintestinal pathogenicEscherichia coli(ExPEC) strains, referred to as uropathogenicE. coli(UPEC), causes most uncomplicated urinary tract infections. However, no core set of virulence factors exists among UPEC strains. Instead, the focus of the analysis of urovirulence has shifted to studying broad classes of virulence factors and the interactions between them. For example, the RTX nonfimbrial adhesin TosA mediates adherence to host cells derived from the upper urinary tract. The associatedtosoperon is well expressedin vivobut poorly expressedin vitroand encodes TosCBD, a predicted type 1 secretion system. TosR and TosEF are PapB and LuxR family transcription factors, respectively; however, no role has been assigned to these potential regulators. Thus, the focus of this study was to determine how TosR and TosEF regulatetosAand affect the reciprocal expression of adhesins and flagella. Among a collection of sequenced UPEC strains, 32% (101/317) were found to encode TosA, and nearly all strains (91% [92/101]) simultaneously carried the putative regulatory genes. Deletion oftosRalleviatestosArepression. Thetospromoter was localized upstream oftosRusing transcriptional fusions of putative promoter regions withlacZ. TosR binds to this region, affecting a gel shift. A 100-bp fragment 220 to 319 bp upstream oftosRinhibits binding, suggesting localization of the TosR binding site. TosEF, on the other hand, downmodulate motility when overexpressed by preventing the expression offliC, encoding flagellin. Deletion oftosEFincreased motility. Thus, we present an additional example of the reciprocal control of adherence and motility.

scholarly journals In Vitro and Murine Efficacy and Toxicity Studies of Nebulized SCC1, a Methylated Caffeine-Silver(I) Complex, for Treatment of Pulmonary Infections

2009 ◽  
Vol 53 (8) ◽  
pp. 3285-3293 ◽  
Author(s):  
Carolyn L. Cannon ◽  
Lisa A. Hogue ◽  
Ravy K. Vajravelu ◽  
George H. Capps ◽  
Aida Ibricevic ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Respiratory Tract Infections ◽  
Airway Epithelial Cells ◽  
Clinical Strain ◽  
Resistant Bacteria ◽  
Infection Model ◽  
Airway Epithelial ◽  
Tract Infections

ABSTRACT The expanding clinical challenge of respiratory tract infections due to resistant bacteria necessitates the development of new forms of therapy. The development of a compound composed of silver coupled to a methylated caffeine carrier (silver carbene complex 1 [SCC1]) that demonstrated in vitro efficacy against bacteria, including drug-resistant organisms, isolated from patients with respiratory tract infections was described previously. The findings of current in vitro studies now suggest that bactericidal concentrations of SCC1 are not toxic to airway epithelial cells in primary culture. Thus, it was hypothesized that SCC1 could be administered by the aerosolized route to concentrate delivery to the lung while minimizing systemic toxicity. In vivo, aerosolized SCC1 delivered to mice resulted in mild aversion behavior, but it was otherwise well tolerated and did not cause lung inflammation following administration over a 5-day period. The therapeutic efficacy of SCC1 compared to that of water was shown in a 3-day prophylaxis protocol, in which mice infected with a clinical strain of Pseudomonas aeruginosa had increased survival, decreased amounts of bacteria in the lung, and a lower prevalence of bacteremia. Similarly, by using an airway infection model in which bacteria were impacted in the airways by agarose beads, the administration of SCC1 was significantly superior to water in decreasing the lung bacterial burden and the levels of bacteremia and markers of airway inflammation. These observations indicate that aerosolized SCC1, a novel antimicrobial agent, warrants further study as a potential therapy for bacterial respiratory tract infections.

scholarly journals Hope in the Treatment of Candida Vaginitis: Ibrexafungerp

2021 ◽  
Author(s):  
Ayşe Sultan Karakoyun
Keyword(s):  
Current Knowledge ◽  
Public Health Problem ◽  
Clinical Findings ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Over The Counter ◽  
Synthase Inhibitor ◽  
Increased Activity

Candida vaginitis (CV) is a neglected but growing public health problem. It is estimated that three out of four women have had at least one CV attack. The diagnosis and treatment of CV is often inadequate due to the tendency of women to self-diagnose and use over-the-counter drugs when they have vaginal or vulvar complaints, and clinicians plan treatment only according to clinical findings. There are limitations regarding the safety and efficacy of oral azoles, which are primarily preferred for the treatment of vaginitis, and these drugs have not revealed the desired levels of clinical or mycological cure. Also, there are a few options for current drugs used for treatment are not numerous the development of new antifungal drugs is thus urgently needed. Ibrexafungerp (IBX) is a semisynthetic triterpenoid glucan synthase inhibitor derived from enfumafungin. IBX has been shown to be a promising oral antifungal in the treatment of acute CV, and its use was approved on June 1, 2021. IBX is remarkable by it’s high oral bioavailability, low risk of side effects, few drug-drug interactions, good tissue penetration, increased activity at low pH in the vagina, and efficacy with regard to multi-drug-resistant fungi. In this review, in vitro and in vivo data on IBX were evaluated and compiled in light of current knowledge.

scholarly journals Pathogenesis and Transmission of Genetically Diverse Swine-Origin H3N2 Variant Influenza A Viruses from Multiple Lineages Isolated in the United States, 2011–2016

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Xiangjie Sun ◽  
Joanna A. Pulit-Penaloza ◽  
Jessica A. Belser ◽  
Claudia Pappas ◽  
Melissa B. Pearce ◽  
...  
Keyword(s):  
United States ◽  
Respiratory Tract ◽  
Influenza A ◽  
Seasonal Influenza ◽  
The United States ◽  
Influenza Viruses ◽  
Upper Respiratory Tract ◽  
Pandemic Preparedness

ABSTRACTWhile several swine-origin influenza A H3N2 variant (H3N2v) viruses isolated from humans prior to 2011 have been previously characterized for their virulence and transmissibility in ferrets, the recent genetic and antigenic divergence of H3N2v viruses warrants an updated assessment of their pandemic potential. Here, four contemporary H3N2v viruses isolated during 2011 to 2016 were evaluated for their replicative ability in bothin vitroandin vivoin mammalian models as well as their transmissibility among ferrets. We found that all four H3N2v viruses possessed similar or enhanced replication capacities in a human bronchial epithelium cell line (Calu-3) compared to a human seasonal influenza virus, suggestive of strong fitness in human respiratory tract cells. The majority of H3N2v viruses examined in our study were mildly virulent in mice and capable of replicating in mouse lungs with different degrees of efficiency. In ferrets, all four H3N2v viruses caused moderate morbidity and exhibited comparable titers in the upper respiratory tract, but only 2 of the 4 viruses replicated in the lower respiratory tract in this model. Furthermore, despite efficient transmission among cohoused ferrets, recently isolated H3N2v viruses displayed considerable variance in their ability to transmit by respiratory droplets. The lack of a full understanding of the molecular correlates of virulence and transmission underscores the need for close genotypic and phenotypic monitoring of H3N2v viruses and the importance of continued surveillance to improve pandemic preparedness.IMPORTANCESwine-origin influenza viruses of the H3N2 subtype, with the hemagglutinin (HA) and neuraminidase (NA) derived from historic human seasonal influenza viruses, continue to cross species barriers and cause human infections, posing an indelible threat to public health. To help us better understand the potential risk associated with swine-origin H3N2v viruses that emerged in the United States during the 2011-2016 influenza seasons, we use bothin vitroandin vivomodels to characterize the abilities of these viruses to replicate, cause disease, and transmit in mammalian hosts. The efficient respiratory droplet transmission exhibited by some of the H3N2v viruses in the ferret model combined with the existing evidence of low immunity against such viruses in young children and older adults highlight their pandemic potential. Extensive surveillance and risk assessment of H3N2v viruses should continue to be an essential component of our pandemic preparedness strategy.

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