Development of Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Rapid and On-Site Detection of Avian Influenza Virus
In this study, we analyzed 800 matrix gene sequences of newly isolated AIV in the EU and designed a highly efficient LAMP primer set that covers all AIV subtypes. The designed LAMP primer set was optimized in real-time RT-LAMP (rRT-LAMP) assay. The rRT-LAMP assay detected AIV samples belonging to nine various subtypes with the specificity and sensitivity comparable to the official standard rRT-PCR assay. Further, a two-color visual detection RT-LAMP assay protocol was adapted with the aim to develop on-site diagnostic tests. The on-site testing successfully detected spiked AIV in birds oropharyngeal and cloacal swabs sampl...
Source: Frontiers in cellular and infection microbiology - April 19, 2021 Category: Microbiology Source Type: research

CryptoType – Public Datasets for MALDI-TOF-MS Based Differentiation of Cryptococcus neoformans/gattii Complexes
Yeasts of the Cryptococcus neoformans/gattii species complexes are human pathogens mostly in immune compromised individuals, and can cause infections from dermal lesions to fungal meningitis. Differences in virulence and antifungal drug susceptibility of species in these complexes indicate the value of full differentiation to species level in diagnostic procedures. MALDI-TOF MS has been reported to sufficiently discriminate these species. Here, we sought to re-evaluate sample pre-processing procedures and create a set of publicly available references for use with the MALDI Biotyper system. Peak content using four different...
Source: Frontiers in cellular and infection microbiology - April 19, 2021 Category: Microbiology Source Type: research

Beneficial Effect of Alkaloids From Sophora alopecuroides L. on CUMS-Induced Depression Model Mice via Modulating Gut Microbiota
It was recently shown that the gut microbiota of both depression patients and depression model animals is significantly altered, suggesting that gut microbes are closely related to depression. Here, we investigated the effects of Sophora alopecuroides L.-derived alkaloids on the gut microbiota of mice with depression-like behaviors. We first established a mouse model of depression via chronic unpredictable mild stress (CUMS) and detected changes in depression-like behaviors and depression-related indicators. Simultaneously, 16S rRNA sequencing was performed to investigate gut microbiota changes. Sophora alopecuroides L.-de...
Source: Frontiers in cellular and infection microbiology - April 19, 2021 Category: Microbiology Source Type: research

Galleria mellonella Larvae as an Infection Model to Investigate sRNA-Mediated Pathogenesis in Staphylococcus aureus
Small regulatory RNAs (sRNAs) are key players in bacterial regulatory networks. Monitoring their expression inside living colonized or infected organisms is essential for identifying sRNA functions, but few studies have looked at sRNA expression during host infection with bacterial pathogens. Insufficient in vivo studies monitoring sRNA expression attest to the difficulties in collecting such data, we therefore developed a non-mammalian infection model using larval Galleria mellonella to analyze the roles of Staphylococcus aureus sRNAs during larval infection and to quickly determine possible sRNA involvement in staphyloco...
Source: Frontiers in cellular and infection microbiology - April 19, 2021 Category: Microbiology Source Type: research

Nanoparticles as Potential Novel Therapies for Urinary Tract Infections
Urinary tract infection (UTI) is one of the most common reasons for antibiotic treatment. Nevertheless, uropathogens are steadily becoming resistant to currently available therapies. In this context, nanotechnology emerges as an innovative and promising approach among diverse strategies currently under development. In this review we deeply discuss different nanoparticles (NPs) used in UTI treatment, including organic NPs, nanodiamonds, chemical and green synthesized inorganic NPs, and NPs made of composite materials. In addition, we compare the effects of different NPs against uropathogens in vivo and in vitro and discuss ...
Source: Frontiers in cellular and infection microbiology - April 19, 2021 Category: Microbiology Source Type: research

The Ringleaders: Understanding the Apicomplexan Basal Complex Through Comparison to Established Contractile Ring Systems
The actomyosin contractile ring is a key feature of eukaryotic cytokinesis, conserved across many eukaryotic kingdoms. Recent research into the cell biology of the divergent eukaryotic clade Apicomplexa has revealed a contractile ring structure required for asexual division in the medically relevant genera Toxoplasma and Plasmodium; however, the structure of the contractile ring, known as the basal complex in these parasites, remains poorly characterized and in the absence of a myosin II homolog, it is unclear how the force required of a cytokinetic contractile ring is generated. Here, we review the literature on the basal...
Source: Frontiers in cellular and infection microbiology - April 19, 2021 Category: Microbiology Source Type: research

Comparative Analysis of Virulence Mechanisms of Trypanosomatids Pathogenic to Humans
Trypanosoma brucei, Leishmania spp., and T. cruzi are flagellate protozoans of the family Trypanosomatidae and the causative agents of human African trypanosomiasis, leishmaniasis, and Chagas disease, respectively. These diseases affect humans worldwide and exert a significant impact on public health. Over the course of evolution, the parasites associated with these pathologies have developed mechanisms to circumvent the immune response system throughout the infection cycle. In cases of human infection, this function is undertaken by a group of proteins and processes that allow the parasites to propagate and survive during...
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

Deletion of the ATP2 Gene in Candida albicans Blocks Its Escape From Macrophage Clearance
Macrophages provide the first-line defense against invasive fungal infections and, therefore, escape from macrophage becomes the basis for the establishment of Candida albicans invasive infection. Here, we found that deletion of ATP2 (atp2Δ/Δ) in C. albicans resulted in a dramatic decrease from 69.2% (WT) to 1.2% in the escape rate in vitro. The effect of ATP2 on macrophage clearance stands out among the genes currently known to affect clearance. In the normal mice, the atp2Δ/Δ cells were undetectable in major organs 72 h after systemic infection, while WT cells persisted in vivo. However, in t...
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

The Building Blocks of Antimicrobial Resistance in Pseudomonas aeruginosa: Implications for Current Resistance-Breaking Therapies
P. aeruginosa is classified as a priority one pathogen by the World Health Organisation, and new drugs are urgently needed, due to the emergence of multidrug-resistant (MDR) strains. Antimicrobial-resistant nosocomial pathogens such as P. aeruginosa pose unwavering and increasing threats. Antimicrobial stewardship has been a challenge during the COVID-19 pandemic, with a majority of those hospitalized with SARS-CoV2 infection given antibiotics as a safeguard against secondary bacterial infection. This increased usage, along with increased handling of sanitizers and disinfectants globally, may further accelerate the develop...
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

Inhibiting Pyridoxal Kinase of Entamoeba histolytica Is Lethal for This Pathogen
Pyridoxal 5’-phosphate (PLP) functions as a cofactor for hundreds of different enzymes that are crucial to the survival of microorganisms. PLP-dependent enzymes have been extensively characterized and proposed as drug targets in Entamoeba histolytica. This pathogen is unable to synthesize vitamin B6via de-novo pathway and relies on the uptake of vitamin B6 vitamers from the host which are then phosphorylated by the enzyme pyridoxal kinase to produce PLP, the active form of vitamin B6. Previous studies from our lab shows that EhPLK is essential for the survival and growth of this protozoan parasite and its active site...
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

The Type II Secretory System Mediates Phage Infection in Vibrio cholera
In this study, we aimed to identify its receptor on V. cholerae. The outer membrane protein EpsD in the type II secretory system (T2SS) was found to be related to VP2-specific adsorption to V. cholerae, and the T2SS inner membrane protein EpsM had a role in successful VP2 infection, although it was not related to adsorption of VP2. The tail fiber protein gp20 of VP2 directly interacts with EpsD. Therefore, we found that in V. cholerae, in addition to the roles of the T2SS as the transport apparatus of cholera toxin secretion and filamentous phage release, the T2SS is also used as the receptor for phage infection and probab...
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

Editorial: Molecular Basis of Stage Conversion in Apicomplexan Parasites
(Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

Human Cytomegalovirus Genome Diversity in Longitudinally Collected Breast Milk Samples
Reactivation and shedding of human cytomegalovirus (HCMV) in breast milk during lactation is highly frequent in HCMV-seropositive mothers. This represents a key transmission route for postnatal HCMV infection and can lead to severe disease in preterm neonates. Little is known about HCMV strain composition or longitudinal intrahost viral population dynamics in breast milk from immunocompetent women. We performed HCMV-specific target enrichment and high-throughput sequencing of 38 breast milk samples obtained in Germany between days 10 and 60 postpartum from 15 mothers with HCMV DNA lactia, and assembled HCMV conse...
Source: Frontiers in cellular and infection microbiology - April 16, 2021 Category: Microbiology Source Type: research

The Association Between Intestinal Bacteria and Allergic Diseases —Cause or Consequence?
The incidence of allergic disorders has been increasing over the past few decades, especially in industrialized countries. Allergies can affect people of any age. The pathogenesis of allergic diseases is complex and involves genetic, epigenetic, and environmental factors, and the response to medication is very variable. For some patients, avoidance is the sole effective therapy, and only when the triggers are identifiable. In recent years, the intestinal microbiota has emerged as a significant contributor to the development of allergic diseases. However, the precise mechanisms related to the effects of the microbiome on th...
Source: Frontiers in cellular and infection microbiology - April 15, 2021 Category: Microbiology Source Type: research

Gut Microbiota and Diarrhea: An Updated Review
Diarrhea is a common problem to the whole world and the occurrence of diarrhea is highly associated with gut microbiota, such as bacteria, fungi, and viruses. Generally, diarrheal patients or animals are characterized by gut microbiota dysbiosis and pathogen infections may lead to diarrheal phenotypes. Of relevance, reprograming gut microbiota communities by dietary probiotics or fecal bacteria transplantation are widely introduced to treat or prevent diarrhea. In this review, we discussed the influence of the gut microbiota in the infection of diarrhea pathogens, and updated the research of reshaping the gut microbiota to...
Source: Frontiers in cellular and infection microbiology - April 15, 2021 Category: Microbiology Source Type: research

Phage Endolysin LysP108 Showed Promising Antibacterial Potential Against Methicillin-resistant Staphylococcus aureus
As a potential antibacterial agent, endolysin can directly lyse Gram-positive bacteria from the outside and does not lead to drug resistance. Considering that XN108 is the first reported methicillin-resistant Staphylococcus aureus (MRSA) strain in mainland China with a vancomycin MIC that exceeds 8 µg mL-1, we conducted a systematic study on its phage-encoded endolysin LysP108. Standard plate counting method revealed that LysP108 could lyse S. aureus and Pseudomonas aeruginosa with damaged outer membrane, resulting in a significant reduction in the number of live bacteria. Scanning electron microscopy results showed ...
Source: Frontiers in cellular and infection microbiology - April 15, 2021 Category: Microbiology Source Type: research

Immune Profile in Patients With COVID-19: Lymphocytes Exhaustion Markers in Relationship to Clinical Outcome
We examined various immune parameters including the markers of immune cells exhaustion and activation in 21 patients with COVID-19 disease hospitalised in our hospital during the first wave of the COVID-19 pandemic in Slovakia. The results showed significant progressive lymphopenia and depletion of lymphocyte subsets (CD3+, CD4+, CD8+ and CD19+) in correlation to the disease severity. Clinical recovery was associated with significant increase in CD3+ and CD3+CD4+ T-cells. Most of our patients had eosinopenia on admission, although no significant differences were seen among groups with different disease severity. Non-surviv...
Source: Frontiers in cellular and infection microbiology - April 15, 2021 Category: Microbiology Source Type: research

Protein Serine/Threonine Phosphatase Type 2C of Leishmania mexicana
Protein phosphorylation and dephosphorylation are increasingly recognized as important processes for regulating multiple physiological mechanisms. Phosphorylation is carried out by protein kinases and dephosphorylation by protein phosphatases. Phosphoprotein phosphatases (PPPs), one of three families of protein serine/threonine phosphatases, have great structural diversity and are involved in regulating many cell functions. PP2C, a type of PPP, is found in Leishmania, a dimorphic protozoan parasite and the causal agent of leishmaniasis. The aim of this study was to clone, purify, biochemically characterize and quantify the...
Source: Frontiers in cellular and infection microbiology - April 15, 2021 Category: Microbiology Source Type: research

Stool Banking for Fecal Microbiota Transplantation: Methods and Operations at a Large Stool Bank
ConclusionsFurther knowledge sharing should help inform refinements of stool banking guidelines and best practices. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 15, 2021 Category: Microbiology Source Type: research

Plasmodium yoelii Erythrocyte Binding Like Protein Interacts With Basigin, an Erythrocyte Surface Protein
We report that PyEBL specifically interacts with basigin, an erythrocyte surface protein. We further confirmed that the N-terminal cysteine-rich Duffy binding-like region (EBL region 2), is responsible for the interaction, and that the binding is not affected by the C351Y mutation, which was previously shown to modulate virulence of P. yoelii. The identification of basigin as the putative PyEBL receptor offers new insights into the role of this molecule and provides an important base for in-depth studies towards developing novel interventions against malaria. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 14, 2021 Category: Microbiology Source Type: research

Transcriptome Signatures Predict Phenotypic Variations of Candida auris
Health care facilities are facing serious threats by the recently emerging human fungal pathogen Candida auris owing to its pronounced antifungal multidrug resistance and poor diagnostic tools. Distinct C. auris clades evolved seemingly simultaneously at independent geographical locations and display both genetic and phenotypic diversity. Although comparative genomics and phenotypic profiling studies are increasing, we still lack mechanistic knowledge about the C. auris species diversification and clinical heterogeneity. Since gene expression variability impacts phenotypic plasticity, we aimed to characterize transcriptomi...
Source: Frontiers in cellular and infection microbiology - April 14, 2021 Category: Microbiology Source Type: research

Characterization of Three Pleiotropic Drug Resistance Transporter Genes and Their Participation in the Azole Resistance of Mucor circinelloides
In this study, transcription of the eight pdr genes has been analyzed after azole treatment. Only the pdr1 showed increased transcript level in response to all tested azoles. Deletion of this gene caused increased susceptibility to posaconazole, ravuconazole and isavuconazole and altered growth ability of the mutant. In the pdr1 deletion mutant, transcript level of pdr2 and pdr6 significantly increased. Deletion of pdr2 and pdr6 was also done to create single and double knock out mutants for the three genes. After deletion of pdr2 and pdr6, growth ability of the mutant strains decreased, while deletion of pdr2 resulted in ...
Source: Frontiers in cellular and infection microbiology - April 14, 2021 Category: Microbiology Source Type: research

iTIME.219: An Immortalized KSHV Infected Endothelial Cell Line Inducible by a KSHV-Specific Stimulus to Transition From Latency to Lytic Replication and Infectious Virus Release
Kaposi’s sarcoma-associated herpesvirus (KSHV/HHV-8) is the causative agent of Kaposi’s sarcoma and two B cell lymphoproliferative disorders: primary effusion lymphoma and KSHV-associated multicentric Castleman’s disease. These distinct pathologies involve different infected cell types. In Kaposi’s sarcoma, the virus is harbored in spindle-like tumor cells of endothelial origin, in contrast with the two pathologies of B cells. These distinctions highlight the importance of elucidating potential differences in the mechanisms of infection for these alternate target cell types and in the properties of ...
Source: Frontiers in cellular and infection microbiology - April 14, 2021 Category: Microbiology Source Type: research

Mycobacterium PPE31 Contributes to Host Cell Death
Genome scale mutagenesis identifies many genes required for mycobacterial infectivity and survival, but their contributions and mechanisms of action within the host are poorly understood. Using CRISPR interference, we created a knockdown of ppe31Mm gene in Mycobacterium marinum (M. marinum), which reduced the resistance to acid medium. To further explore the function of PPE31, the ppe31 mutant strain was generated in M. marinum and Mycobacterium tuberculosis (M. tuberculosis), respectively. Macrophages infected with the ppe31Mm mutant strain caused a reduced inflammatory mediator expressions. In addition, macrophages ...
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

Chicken Egg Yolk Antibody (IgY) Protects Mice Against Enterotoxigenic Escherichia coli Infection Through Improving Intestinal Health and Immune Response
This study investigated effects of IgY on growth, adhesion inhibitory and morphology of enterotoxigenic Escherichia coli (ETEC) K88 in vitro, and evaluated the protective effects of IgY on intestinal health and immune response of mice infected with ETEC in vivo. Sixty pathogen-free C57BL/6J (4-6 weeks of age) mice were divided into six treatments: control (neither IgY nor ETEC infection), ETEC infection, ETEC-infected mice treated with 250 μL of high-dose (32 mg/mL), medium-dose (16 mg/mL) or low-dose (8 mg/mL) anti-ETEC IgY, or ETEC-infected mice treated with 250 μL of non-specific IgY (16 mg/mL). Anti-ETEC IgY inhi...
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

By Regulating the NLRP3 Inflammasome Can Reduce the Release of Inflammatory Factors in the Co-Culture Model of Tuberculosis H37Ra Strain and Rat Microglia
ConclusionOur results indicate that the NLRP3 inflammasome pathway is an important part of the inflammatory response of microglia caused by tuberculosis infection. By intervening the NLRP3 inflammasome pathway, it can significantly reduce the inflammatory response and mortality of microglia during the tuberculosis H37Ra strain infection. This research can help us further understand the inflammatory response mechanism of the central nervous system during tuberculosis infection and improve its treatment. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

Rapid Detection of Aspergillus fumigatus Using Multiple Cross Displacement Amplification Combined With Nanoparticles-Based Lateral Flow
Aspergillus fumigatus is an opportunistic, ubiquitous, saprophytic mold which can cause infection in the lungs, nose, eyes, brain, and bones in humans, especially in immunocompromised patients. However, it is difficult to diagnose A. fumigatus infection quickly. Here, we introduce a new detection method, namely multiple cross displacement amplification (MCDA) combined with nanoparticle-based lateral flow biosensor (LFB) (MCDA-LFB), which was proved to be fast, reliable, and simple for detecting A. fumigatus. We designed a set of 10 primers targeting the gene annexin ANXC4 of A. fumigatus. The best MCDA condition is 66 °...
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

Regulatory T Cells as an Escape Mechanism to the Immune Response in Taenia crassiceps Infection
This study is aimed to investigate the role of Tregs in T. crassiceps establishment in susceptible and non-susceptible mouse strains. Treg and effector cells were quantified in lymphoid organs before infection and 5, 30, 90, and 130 days post-infection. The proliferative response post-infection was characterized in vitro. The expression of regulatory and inflammatory molecules was assessed on days 5 and 30 post-infection. Depletion assays were performed to assess Treg functionality. Significantly higher Treg percentages were observed in BALB/cAnN mice, while increased percentages of activated CD127+ cells were found in C57...
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

Comparative Phosphoproteomics of Classical Bordetellae Elucidates the Potential Role of Serine, Threonine and Tyrosine Phosphorylation in Bordetella Biology and Virulence
This study provides the first insight into the phosphoproteome of classical Bordetella species and the role that Ser/Thr/Tyr phosphorylation may play in Bordetella biology and virulence. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

Modulation of Immune Response to Chlamydia muridarum by Host miR-135a
We report here chlamydial infection results in decreased miR-135a expression in mouse genital tissue and a fibroblast cell line. Several chemokine and chemokine receptor genes (including CXCL10, CCR5) associated with chlamydial pathogenesis were identified in silico to contain putative miR-135a binding sequence(s) in the 3’ untranslated region. The role of miR-135a in the host immune response was investigated using exogenous miR-135a mimic to restore the immune phenotype associated with decreased miR-135a following Chlamydia muridarum (Cm) infection. We observed miR-135a regulation of Cm-primed bone marrow derived de...
Source: Frontiers in cellular and infection microbiology - April 13, 2021 Category: Microbiology Source Type: research

The Modular Circuitry of Apicomplexan Cell Division Plasticity
The close-knit group of apicomplexan parasites displays a wide variety of cell division modes, which differ between parasites as well as between different life stages within a single parasite species. The beginning and endpoint of the asexual replication cycles is a ‘zoite’ harboring the defining apical organelles required for host cell invasion. However, the number of zoites produced per division round varies dramatically and can unfold in several different ways. This plasticity of the cell division cycle originates from a combination of hard-wired developmental programs modulated by environmental triggers. Al...
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

The Direct Semi-Quantitative Detection of 18 Pathogens and Simultaneous Screening for Nine Resistance Genes in Clinical Urine Samples by a High-Throughput Multiplex Genetic Detection System
In this study, a new urinary tract infection high-throughput multiplex genetic detection system (UTI-HMGS) was developed for the semi-quantitative detection of 18 pathogens and the simultaneously screening of nine resistance genes directly from the clinical urine sample within 4 hours.MethodsWe designed and optimized a multiplex polymerase chain reaction (PCR) involving fluorescent dye-labeled specific primers to detect 18 pathogens and nine resistance genes. The specificity of the UTI-HMGS was tested using standard strains or plasmids for each gene target. The sensitivity of the UTI-HMGS assay was tested by the detection ...
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

Adjunctive S100A8/A9 Immunomodulation Hinders Ciprofloxacin Resistance in Pseudomonas aeruginosa in a Murine Biofilm Wound Model
ConclusionThis study supports the ciprofloxacin augmenting effect and indicates a protective effect in terms of hindered ciprofloxacin resistance of adjuvant S100A8/A9 in P.aeruginosa biofilm infected chronic wounds. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

HIV-1 Impact on Malaria Transmission: A Complex and Relevant Global Health Concern
Malaria/HIV-1 co-infection has become a significant public health problem in the tropics where there is geographical overlap of the two diseases. It is well described that co-infection impacts clinical progression of both diseases; however, less is known about the impact of co-infection on disease transmission. Malaria transmission is dependent upon multiple critical factors, one of which is the presence and viability of the sexual-stage gametocyte. In this review, we summarize evidence surrounding gametocyte production in Plasmodium falciparum and the development factors and the consequential impact that HIV-1 has on mala...
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

Two Acinetobacter baumannii Isolates Obtained From a Fatal Necrotizing Fasciitis Infection Display Distinct Genomic and Phenotypic Characteristics in Comparison to Type Strains
Acinetobacter baumannii has been recognized as a critical pathogen that causes severe infections worldwide not only because of the emergence of extensively drug-resistant (XDR) derivatives, but also because of its ability to persist in medical environments and colonize compromised patients. While there are numerous reports describing the mechanisms by which this pathogen acquires resistance genes, little is known regarding A. baumannii’s virulence functions associated with rare manifestations of infection such as necrotizing fasciitis, making the determination and implementation of alternative therapeutic targets pro...
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

No Evidence for Human Monocyte-Derived Macrophage Infection and Antibody-Mediated Enhancement of SARS-CoV-2 Infection
Vaccines are essential to control the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and to protect the vulnerable population. However, one safety concern of vaccination is the possible development of antibody-dependent enhancement (ADE) of SARS-CoV-2 infection. The potential infection of Fc receptor bearing cells such as macrophages, would support continued virus replication and inflammatory responses, and thereby potentially worsen the clinical outcome of COVID-19. Here we demonstrate that SARS-CoV-2 and SARS-CoV neither infect human monocyte-derived macrophages (hMDM) nor induce inflammatory cyto...
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

Differences in the Genital Microbiota in Women Who Naturally Clear Chlamydia trachomatis Infection Compared to Women Who Do Not Clear; A Pilot Study
In vitro studies indicate IFNγ is central to Chlamydia trachomatis (Ct) eradication, but its function may be compromised by anaerobes typically associated with bacterial vaginosis (BV), a frequent co-morbidity in women with Ct. Here we investigated the associations between natural clearance of cervical Ct infection, the vaginal microbiome, and the requirements for IFNγ by evaluating the vaginal microbial and cytokine composition of Ct treatment visit samples from women who cleared Ct infection in the interim between their Ct screening and Ct treatment visit. The pilot cohort was young, predominantly African Ame...
Source: Frontiers in cellular and infection microbiology - April 12, 2021 Category: Microbiology Source Type: research

Inhibition of Host Gene Expression by KSHV: Sabotaging mRNA Stability and Nuclear Export
Viruses are known for their ability to alter host gene expression. Kaposi sarcoma-associated herpesvirus has two proteins that obstruct host gene expression. KSHV SOX, encoded by the open reading frame 37 (ORF37), induces a widespread cytoplasmic mRNA degradation and a block on mRNA nuclear export. The other KSHV protein, encoded by the open reading frame 10 (ORF10), was recently identified to inhibit host gene expression through its direct function on the cellular mRNA export pathway. In this review, we summarize the studies on both SOX and ORF10 in efforts to elucidate their mechanisms. We also discuss how the findings b...
Source: Frontiers in cellular and infection microbiology - April 9, 2021 Category: Microbiology Source Type: research

Plasmodium Reproduction, Cell Size, and Transcription: How to Cope With Increasing DNA Content?
Plasmodium, the unicellular parasite that causes malaria, evolved a highly unusual mode of reproduction. During its complex life cycle, invasive or transmissive stages alternate with proliferating stages, where a single parasite can produce tens of thousands of progeny. In the clinically relevant blood stage of infection, the parasite replicates its genome up to thirty times and forms a multinucleated cell before daughter cells are assembled. Thus, within a single cell cycle, Plasmodium develops from a haploid to a polypoid cell, harboring multiple copies of its genome. Polyploidy creates several biological challenges, suc...
Source: Frontiers in cellular and infection microbiology - April 9, 2021 Category: Microbiology Source Type: research

High Anti-Leishmania IgG Antibody Levels Are Associated With Severity of Mucosal Leishmaniasis
ConclusionsOur data demonstrate an association between IgG antibody titers and the severity of mucosal disease. The observed reduction in antibody production after successful treatment in most patients preliminarily indicates that these tests can be used to aid in the assessment of therapeutic response. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 9, 2021 Category: Microbiology Source Type: research

Transcription Factors Interplay Orchestrates the Immune-Metabolic Response of Leishmania Infected Macrophages
Leishmaniasis is a group of heterogenous diseases considered as an important public health problem in several countries. This neglected disease is caused by over 20 parasite species of the protozoa belonging to the Leishmania genus and is spread by the bite of a female phlebotomine sandfly. Depending on the parasite specie and the immune status of the patient, leishmaniasis can present a wide spectrum of clinical manifestations. As an obligate intracellular parasite, Leishmania colonize phagocytic cells, mainly the macrophages that orchestrate the host immune response and determine the fate of the infection. Once inside ma...
Source: Frontiers in cellular and infection microbiology - April 7, 2021 Category: Microbiology Source Type: research

A Small-Scale shRNA Screen in Primary Mouse Macrophages Identifies a Role for the Rab GTPase Rab1b in Controlling Salmonella Typhi Growth
Salmonella Typhi is a human-restricted bacterial pathogen that causes typhoid fever, a life-threatening systemic infection. A fundamental aspect of S. Typhi pathogenesis is its ability to survive in human macrophages but not in macrophages from other animals (i.e. mice). Despite the importance of macrophages in establishing systemic S. Typhi infection, the mechanisms that macrophages use to control the growth of S. Typhi and the role of these mechanisms in the bacterium’s adaptation to the human host are mostly unknown. To facilitate unbiased identification of genes involved in controlling the growth of S. Typhi...
Source: Frontiers in cellular and infection microbiology - April 7, 2021 Category: Microbiology Source Type: research

The Female Vaginal Microbiome in Health and Bacterial Vaginosis
The vaginal microbiome is an intricate and dynamic microecosystem that constantly undergoes fluctuations during the female menstrual cycle and the woman’s entire life. A healthy vaginal microbiome is dominated by Lactobacillus which produce various antimicrobial compounds. Bacterial vaginosis (BV) is characterized by the loss or sharp decline in the total number of Lactobacillus and a corresponding marked increase in the concentration of anaerobic microbes. BV is a highly prevalent disorder of the vaginal microbiota among women of reproductive age globally. BV is confirmed to be associated with adverse gynecologic an...
Source: Frontiers in cellular and infection microbiology - April 7, 2021 Category: Microbiology Source Type: research

Identification and Characterization of Zika Virus NS5 Methyltransferase Inhibitors
The recurring outbreak of Zika virus (ZIKV) worldwide makes an emergent demand for novel, safe and efficacious anti-ZIKV agents. ZIKV non-structural protein 5 (NS5) methyltransferase (MTase), which is essential for viral replication, is regarded as a potential drug target. In our study, a luminescence-based methyltransferase assay was used to establish the ZIKV NS5 MTase inhibitor screening model. Through screening a natural product library, we found theaflavin, a polyphenol derived from tea, could inhibit ZIKV NS5 MTase activity with a 50% inhibitory concentration (IC50) of 10.10 μM. Molecular docking and site-directed...
Source: Frontiers in cellular and infection microbiology - April 7, 2021 Category: Microbiology Source Type: research

Molecular Epidemiology of Hypervirulent Carbapenemase-Producing Klebsiella pneumoniae
ConclusionsPositive rates of virulence genes vary remarkably in K. pneumoniae. Genes iucA, p-rmpA2 and p-rmpA were primary ones inducing Hv-blaKPC(+)-KP. IncHI1B plasmids carrying virulence genes and IncFII ones with blaKPC constitute the primary combination responsible for Hv-blaKPC(+)-KP. The making of Hv-blaKPC(+)-KP is mostly via blaKPC(+)-KP acquiring another plasmid harboring virulence genes. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 7, 2021 Category: Microbiology Source Type: research

Comorbidities and Age Are Associated With Persistent COVID-19 PCR Positivity
ConclusionAge, and the presence of co-morbidities should be taken into consideration when interpreting a positive COVID PCR test. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 6, 2021 Category: Microbiology Source Type: research

IgA Antibodies and IgA Deficiency in SARS-CoV-2 Infection
A large repertoire of IgA is produced by B lymphocytes with T-independent and T-dependent mechanisms useful in defense against pathogenic microorganisms and to reduce immune activation. IgA is active against several pathogens, including rotavirus, poliovirus, influenza virus, and SARS-CoV-2. It protects the epithelial barriers from pathogens and modulates excessive immune responses in inflammatory diseases. An early SARS-CoV-2 specific humoral response is dominated by IgA antibodies responses greatly contributing to virus neutralization. The lack of anti-SARS-Cov-2 IgA and secretory IgA (sIgA) might represent a possible ca...
Source: Frontiers in cellular and infection microbiology - April 6, 2021 Category: Microbiology Source Type: research

Impact of the Gut Microbiome on the Progression of Hepatitis B Virus Related Acute-on-Chronic Liver Failure
In this study alterations in the fecal microbiome of 91 patients with HBV-ACLF (109 stool samples), including a cohort of nine patients at different stages of HBV-ACLF, were determined by high-throughput 16S rDNA sequencing. The operational taxonomic units and Shannon indexes indicated that the diversity and abundance of the gut microbiome significantly decreased with the progression of HBV-ACLF (p
Source: Frontiers in cellular and infection microbiology - April 6, 2021 Category: Microbiology Source Type: research

Potential Roles of Oral Microbiota in the Pathogenesis of Immunoglobin A Nephropathy
In conclusion, disturbance in oral microbiota was observed to be associated with IgAN and its sub-phenotypes, which may shed novel insights into disease pathogenesis from a microbiome perspective. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - April 2, 2021 Category: Microbiology Source Type: research

The Role of Gut Microbiota in Duodenal-Jejunal Bypass Surgery-Induced Improvement of Hepatic Steatosis in HFD-Fed Rats
Bariatric surgery including duodenal-jejunal bypass surgery (DJB) improves insulin sensitivity and reduces obesity-associated inflammation. However, the underlying mechanism for such an improvement is still incompletely understood. Our objective was to investigate the role of the gut microbiota in DJB-associated improvement of hepatic steatosis in high fat diet (HFD)-fed rats. To study this, hepatic steatosis was induced in male adult Sprague-Dawley rats by feeding them with a 60% HFD. At 8 weeks after HFD feeding, the rats were subjected to either DJB or sham operation. HFD was resumed 1 week after the surgery for 3 more ...
Source: Frontiers in cellular and infection microbiology - April 2, 2021 Category: Microbiology Source Type: research