Archive
Research Article
- Research Article | Molecular Biology and PhysiologyProtein Interactomes of Streptococcus mutans YidC1 and YidC2 Membrane Protein Insertases Suggest SRP Pathway-Independent- and -Dependent Functions, Respectively
Streptococcus mutans is a prevalent oral pathogen and major causative agent of tooth decay. Many proteins that enable this bacterium to thrive in its environmental niche and cause disease are embedded in its cytoplasmic membrane.
- Research Article | Ecological and Evolutionary ScienceComparative Genomics Reveals Prophylactic and Catabolic Capabilities of Actinobacteria within the Fungus-Farming Termite Symbiosis
Actinobacteria have repeatedly been isolated in fungus-farming termites, and our genome analyses provide insights into the potential roles they may serve in defense and for plant biomass breakdown. These insights, combined with their relatively higher abundances in fungus combs than in termite gut, suggest that they are more likely to play roles in fungus combs than in termite guts.
- Editor's Pick Research ArticleEvaluating the Antimicrobial Properties of Commercial Hand Sanitizers
In response to the coronavirus disease 2019 (COVID-19) pandemic, hand hygiene has taken on a prominent role in efforts to mitigate SARS-CoV-2 transmission and infection, which has led to a radical increase in the number and types of hand sanitizers manufactured to meet public demand. To our knowledge, no studies have evaluated or compared the antimicrobial performance of hand sanitizers that are being produced under COVID-19 emergency...
- Research ArticleSerum Antibody Responses against Carbapenem-Resistant Klebsiella pneumoniae in Infected Patients
Carbapenem-resistant Klebsiella pneumoniae is a rapidly emerging public health threat that can cause fatal infections in up to 50% of affected patients. Due to its resistance to nearly all antimicrobials, development of alternate therapies like antibodies and vaccines is urgently needed.
- Research ArticleGenomic Epidemiology of CC30 Methicillin-Resistant Staphylococcus aureus Strains from Argentina Reveals Four Major Clades with Distinctive Genetic Features
The rise in prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is of public health concern. In Argentina, several studies documented a shift in the epidemiology of CA-MRSA since 2009, with clonal complex 30 (CC30) and, in particular, sequence type 30 MRSA SCCmec type IV(ST30-MRSA-IV) replacing other clones both in...
- Research ArticleA Spontaneous rapZ Mutant Impairs Infectivity of Lytic Bacteriophage vB_EcoM_JS09 against Enterotoxigenic Escherichia coli
The development of phage-resistant bacteria is a challenging problem for phage therapy. However, our knowledge of phage resistance mechanisms is still limited.
- Research ArticleWhole-Genome Enrichment and Sequencing of Chlamydia trachomatis Directly from Patient Clinical Vaginal and Rectal Swabs
Chlamydia trachomatis is an obligate intracellular bacterium that is not easily cultured, which limits our understanding of urogenital and rectal C. trachomatis transmission and impact on morbidity. To provide a publicly available workflow for whole-genome target enrichment and sequencing of...
- Research ArticleHigh-Throughput Screen for Inhibitors of the Type IV Pilus Assembly ATPase PilB
Many bacterial pathogens use their type IV pili (T4P) to facilitate and maintain infection of a human host. Small chemical compounds that inhibit the production or assembly of T4P have promise in the treatment and prevention of infections, especially in the era of increasing threats from antibiotic-resistant bacteria.
- Research ArticleComparative Study of the Susceptibility to Oxidative Stress between Two Types of Mycobacterium bovis BCG Tokyo 172
This study revealed the difference of in vivo and in vitro antioxidative stress properties of BCG Tokyo 172 types I and II as one of the bacteriological characteristics. In particular, the bacilli exhibited differences in catalase/peroxidase activity, which could explain their different protective effects against infection.
- Editor's Pick Research ArticlePathogenesis Study of Enterovirus 71 Using a Novel Human SCARB2 Knock-In Mouse Model
Enterovirus 71 (EV71) is associated with severe hand-foot-mouth disease. Recently, outbreaks of EV71 infection with high mortality have been reported in the Asia-Pacific region, posing a great challenge for global public health.
- Research ArticleGraXRS-Dependent Resistance of Staphylococcus aureus to Human Osteoarthritic Synovial Fluid
Osteoarthritis, a degenerative disease that results in the breakdown of joint cartilage and underlying bone, is the most prevalent joint disease in the United States. Surgical intervention, including total joint replacement, is a clinically effective procedure that can help to restore the patient’s quality of life.
- Research ArticleThe ABC-Type Efflux Pump MacAB Is Involved in Protection of Serratia marcescens against Aminoglycoside Antibiotics, Polymyxins, and Oxidative Stress
The opportunistic pathogen Serratia marcescens can cause urinary tract infections, respiratory infections, meningitis, and sepsis in immunocompromised individuals. These infections are challenging to treat due to the intrinsic resistance of S. marcescens to an extensive array of antibiotics.
... - Research ArticleBroadly Reactive H2 Hemagglutinin Vaccines Elicit Cross-Reactive Antibodies in Ferrets Preimmune to Seasonal Influenza A Viruses
H1N1 and H3N2 influenza viruses have cocirculated in the human population since 1977. Nearly every human alive today has antibodies and memory B and T cells against these two subtypes of influenza viruses.
- Research ArticleMachine Learning Prediction and Experimental Validation of Antigenic Drift in H3 Influenza A Viruses in Swine
Influenza A viruses (IAV) in swine constitute a major economic burden to an important global agricultural sector, impact food security, and are a public health threat. Despite significant improvement in surveillance for IAV in swine over the past 10 years, sequence data have not been integrated into a systematic vaccine strain selection process for predicting antigenic phenotype and identifying determinants of antigenic drift.
... - Research ArticleMicrobial Diversity and Mercury Methylation Activity in Periphytic Biofilms at a Run-of-River Hydroelectric Dam and Constructed Wetlands
Monomethylmercury (MMHg) is a biomagnifiable neurotoxin of global concern with risks to human health mostly associated with fish consumption. Hydroelectric reservoirs are known to be sources of MMHg many years after their impoundment.
- Research ArticleStreptococcus suis MsmK: Novel Cell Division Protein Interacting with FtsZ and Maintaining Cell Shape
Bacterial cell division is a highly ordered process regulated in time and space and is a potential target for the development of antimicrobial drugs. Bacteria of distinct shapes depend on different cell division mechanisms, but the mechanisms used by ovococci remain largely unknown.
- Research ArticleStage-Specific De Novo Synthesis of Very-Long-Chain Dihydroceramides Confers Dormancy to Entamoeba Parasites
Entamoeba is a protozoan parasite that thrives in its niche by alternating its two forms between a proliferative trophozoite and dormant cyst. Cysts are the only form able to transmit to a new host and are differentiated from trophozoites in a process termed “encystation.” During Entamoeba encystation, cell metabolites, components, and morphology drastically change, which occur sequentially in an orchestrated manner....
- Research ArticleStaphylococcus aureus Responds to Physiologically Relevant Temperature Changes by Altering Its Global Transcript and Protein Profile
Enteric bacterial pathogens, like Escherichia coli, are known to experience large temperature differences as they are transmitted through the fecal oral route. This change in temperature has been demonstrated to influence bacterial gene expression and facilitate infection. Staphylococcus aureus is a...
- Research ArticlePhotochromic Fluorophores Enable Imaging of Lowly Expressed Proteins in the Autofluorescent Fungus Candida albicans
Understanding the spatial and temporal organization of proteins of interest is key to unraveling cellular processes and identifying novel possible antifungal targets. Only a few therapeutic targets have been discovered in Candida albicans, and resistance mechanisms against these therapeutic agents are rapidly acquired.
- Research ArticleBovine Immune Response to Vaccination and Infection with Leptospira borgpetersenii Serovar Hardjo
Leptospirosis is an underdiagnosed, underreported zoonotic disease of which domestic livestock can be carriers. As a reservoir host for Leptospira borgpetersenii serovar Hardjo, cattle may present with reproductive issues, including abortion, birth of weak or infected calves, or failure to breed.
- Research ArticleAn Assessment of Siderophore Production, Mucoviscosity, and Mouse Infection Models for Defining the Virulence Spectrum of Hypervirulent Klebsiella pneumoniae
The pathogenic potential of hvKp strains is primarily mediated by a large virulence plasmid. The minimal set of genes required for the full expression of the hypervirulent phenotype is undefined.
- Research ArticleDissecting Individual Interactions between Pathogenic and Commensal Bacteria within a Multispecies Gut Microbial Community
Studying interactions between bacterial species that reside in the human gut is crucial for gaining a better insight into how they provide protection from pathogen colonization. In vitro models of multispecies bacterial communities wherein behaviors of single species can be accurately tracked are key to such studies. Here, we have developed a synthetic, trackable, gut microbiota community which reduces growth of the human gut...
- Research ArticleLuxR Solos from Environmental Fluorescent Pseudomonads
Cell-cell communication in bacteria is being extensively studied in simple settings and uses chemical signals and cognate regulators/receptors. Many Gram-negative proteobacteria use acyl-homoserine lactones (AHLs) synthesized by LuxI family proteins and cognate LuxR-type receptors to regulate their quorum sensing (QS) target loci.
- Research ArticleStability of SARS-CoV-2 Spike G614 Variant Surpasses That of the D614 Variant after Cold Storage
It has been observed that variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more stable and infectious after storage at −20°C than at 4°C. A SARS-CoV-2 S-D614G variant is currently the most dominant variant in circulation and is associated with enhanced infectivity.
- Research ArticleAdditional Feeding Reveals Differences in Immune Recognition and Growth of Plasmodium Parasites in the Mosquito Host
Mosquitoes must blood feed multiple times to acquire and transmit malaria. However, the impact of an additional mosquito blood meal following malaria parasite infection has not been closely examined.
- Research ArticleExpanding the Known Repertoire of C-Type Lectin Receptors Binding to Toxoplasma gondii Oocysts Using a Modified High-Resolution Immunofluorescence Assay
Knowledge of oocyst biology of Toxoplasma gondii is limited, not the least due to its limited availability. We describe a method that allowed us to process minute amounts of oocysts for immunofluorescence microscopy without compromising their structural properties.
- Research ArticleEscherichia coli Nissle 1917 Enhances Innate and Adaptive Immune Responses in a Ciprofloxacin-Treated Defined-Microbiota Piglet Model of Human Rotavirus Infection
Rotavirus (RV) is a primary cause of malabsorptive diarrhea in children and is associated with significant morbidity and mortality, especially in developing countries. The use of antibiotics exacerbates intestinal microbial imbalance and results in the persistence of RV-induced diarrhea.
- Research ArticleGenome-Based Targeted Sequencing as a Reproducible Microbial Community Profiling Assay
New methods for profiling the microbial communities can create new approaches to understanding the composition and function of those communities. In this study, we combined bacterial genome-specific probe design with a highly multiplexed single primer extension reaction as a new method to profile microbial communities, using stool from various mouse strains as a test case.
- Research ArticleClustering and Erratic Movement Patterns of Syringe-Injected versus Mosquito-Inoculated Malaria Sporozoites Underlie Decreased Infectivity
Malaria still causes a major burden on global health and the economy. The efficacy of live, attenuated malaria sporozoites as vaccine candidates critically depends on their ability to migrate to and infect the host liver.
- Research ArticleComplete Genetic Analysis of Plasmids Carrying mcr-1 and Other Resistance Genes in Avian Pathogenic Escherichia coli Isolates from Diseased Chickens in Anhui Province in China
In this study, three plasmids carrying mcr-1 were isolated and characterized from APEC isolates from Anhui Province in China. The mcr-1 genes were located on IncI2 plasmids, and these plasmids were transferrable.
- Research ArticleTerm Human Placental Trophoblasts Express SARS-CoV-2 Entry Factors ACE2, TMPRSS2, and Furin
Pregnant women worldwide have been affected by COVID-19. As the virus is commonly spread to various organs via the bloodstream and because human placental trophoblasts are directly bathed in maternal blood, feto-placental infection by SARS-CoV-2 seems likely.
- Research ArticleLife Cycle Dominates the Volatilome Character of Dimorphic Fungus Coccidioides spp.
Coccidioidomycosis, or valley fever, causes up to 30% of community-acquired pneumonias in highly populated areas of the U.S. desert southwest where the disease is endemic. The infection is difficult to diagnose by standard serological and histopathological methods, which delays appropriate treatment.
- Research ArticleOligomerization and Cell Egress Controlled by Two Microdomains of Canine Distemper Virus Matrix Protein
Despite the availability of efficient vaccines, morbilliviruses (e.g., canine distemper virus [CDV] and measles virus [MeV]) still cause major health impairments. Although antivirals may support vaccination campaigns, approved inhibitors are to date still lacking.
- Editor's Pick Research ArticleB Cell Receptor-Responsive miR-141 Enhances Epstein-Barr Virus Lytic Cycle via FOXO3 Inhibition
EBV is a human pathogen associated with several malignancies. A key aspect of lifelong virus persistence is the ability to switch between latent and lytic replication modes.
Observation
- ObservationA Point Mutation in the Transcriptional Repressor PerR Results in a Constitutive Oxidative Stress Response in Clostridioides difficile 630Δerm
The intestinal pathogen Clostridioides difficile is one of the major challenges in medical facilities nowadays. In order to better combat the bacterium, detailed knowledge of its physiology is mandatory. C. difficile strain 630Δerm was generated in a laboratory from the patient-isolated...
- ObservationCryptococcus neoformans Coinfection Dampens the TNF-α Response in HIV-1-Infected Human THP-1 Macrophages
Fungal infections are one of the leading causes of death for people who live with HIV/AIDS. Even though these pathogens are independently well studied, it is still enigmatic how coinfection with HIV-1 and C. neoformans alters gene expression and cellular processes, especially in clinically relevant cell types.
Opinion/Hypothesis
- Opinion/HypothesisOriginal Antigenic Sin: the Downside of Immunological Memory and Implications for COVID-19
The concept of original antigenic sin (OAS) was put forth many years ago to explain how humoral memory responses generated against one set of antigens can affect the nature of antibody responses elicited to challenge infections or vaccinations containing a similar but not identical array of antigens. Here, we highlight the link between OAS and the germinal center reaction (GCR), a process unique to activated B cells undergoing somatic...
- Opinion/HypothesisEvenness-Richness Scatter Plots: a Visual and Insightful Representation of Shannon Entropy Measurements for Ecological Community Analysis
Shannon’s entropy is a popular alpha diversity metric because it estimates both richness and evenness in a single equation. However, since its value is dependent on both those parameters, there is theoretically an infinite number of richness/evenness value combinations translating into the same index score.
Resource Report
- Resource ReportMapping Gene-by-Gene Single-Nucleotide Variation in 8,535 Mycobacterium tuberculosis Genomes: a Resource To Support Potential Vaccine and Drug Development
Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis. In the first half of the 20th century, the discovery of the Mycobacterium bovis BCG vaccine and antituberculous drugs heralded a new era in the control of TB.
Commentary
Anat Florentin works in the field of molecular parasitology, studying the cell biology of malaria parasites. In this mSphere of Influence article, she reflects how the book Brave Genius: a Scientist, a Philosopher, and Their Daring Adventures from the French Resistance to the Nobel Prize by Sean B. Carroll (2013) made a powerful impact on her by telling scientific stories in the context of dramatic life events.
Chelsie Armbruster studies catheter-associated urinary tract infection and the contribution of microbe-microbe interactions to infection progression and severity. In this mSphere of Influence article, she reflects on how two papers, A.
Chelsey C. Spriggs works in the field of DNA viral entry with a specific interest in virus-host interactions.
Vanessa L. Hale studies the role of the microbiome in disease susceptibility in animal and human health.
Clare Harding works on the metal biology of the parasite Toxoplasma gondii. In this mSphere of Influence article, she reflects on how two papers from the laboratory of Maria Mota, “Host-mediated regulation of superinfection in malaria” by Portugal et al. (S).
Sumanta K. Naik works in the tuberculosis field, with a specific interest in the host immune response to Mycobacterium tuberculosis infection. In this mSphere of Influence article, he reflects on how the paper “IRGM1 links mitochondrial quality control to autoimmunity” by Prashant Rai et al. (Nat Immunol, 22:312–321, 2021,...