TagP, a PAAR-domain containing protein, plays roles in the fitness and virulence of .

Background: Type VI secretion system (T6SS) is widely present in Gram-negative bacteria and directly mediates antagonistic prokaryote interactions. PAAR (proline-alanine-alanine-arginine repeats) proteins have been proven essential for T6SS-mediated secretion and target cell killing. Although PAAR proteins are commonly found in , their biological functions are not fully disclosed yet.

Delivery of antigens via outer membrane vesicles offered improved protection against plague.

Outer membrane vesicles (OMVs) from Gram-negative bacteria can be used as a vaccine platform to deliver heterologous antigens. Here, the major protective antigens of F1 and LcrV, were fused either with the leader sequence or the transmembrane domain of the outer membrane protein A (OmpA), resulting in chimeric proteins OmpA-ls-F1V and OmpA-F1V, respectively. We show that OmpA-ls-F1V and OmpA-F1V can be successfully delivered into the lumen and membrane of the OMVs of respectively.

A protein O-GlcNAc glycosyltransferase regulates the antioxidative response in Yersinia pestis.

Post-translational addition of O-linked N-acetylglucosamine (O-GlcNAc) to proteins is commonly associated with a variety of stress responses and cellular processes in eukaryotes, but its potential roles in bacteria are unclear. Here, we show that protein HmwC acts as an O-GlcNAc transferase (OGT) responsible for O-GlcNAcylation of multiple proteins in Yersinia pestis, a flea-borne pathogen responsible for plague. We identify 64 O-GlcNAcylated proteins (comprising 65 sites) with differential abundance under conditions mimicking the mammalian host (Mh) and flea vector (Fv) environments.

Unveiling the dance of evolution: Pla-mediated cleavage of Ymt modulates the virulence dynamics of .

Unlabelled: has recently evolved into a highly lethal flea-borne pathogen through the pseudogenization of extensive genes and the acquisition of exogenous plasmids. Particularly noteworthy are the newly acquired pPCP1 and pMT1 plasmids, which encode the virulence determinants Pla and murine toxin (Ymt), crucial for subcutaneous infection and survival within flea vector of , respectively. This study reveals that Pla can cleave Ymt at K299 both and expressing Ymt displays enhanced biofilm formation and increased blood survival, indicating significant roles of Pla-mediated Ymt cleavage in these phenotypes.

Development and evaluation of a multi-target droplet digital PCR assay for highly sensitive and specific detection of Yersinia pestis.

Background: Plague, caused by the bacterium Yersinia pestis, is a zoonotic disease that poses considerable threats to human health. Nucleic acid tests are crucial for plague surveillance and the rapid detection of Y. pestis.

A novel sORF gene mutant strain of Yersinia pestis vaccine EV76 offers enhanced safety and improved protection against plague.

We recently identified two virulence-associated small open reading frames (sORF) of Yersinia pestis, named yp1 and yp2, and null mutants of each individual genes were highly attenuated in virulence. Plague vaccine strain EV76 is known for strong reactogenicity, making it not suitable for use in humans. To improve the immune safety of EV76, three mutant strains of EV76, Δyp1, Δyp2, and Δyp1&yp2 were constructed and their virulence attenuation, immunogenicity, and protective efficacy in mice were evaluated.

Characterization of an aspartate aminotransferase encoded by YPO0623 with frequent nonsense mutations in .

, the causative agent of plague, is a genetically monomorphic bacterial pathogen that evolved from approximately 7,400 years ago. We observed unusually frequent mutations in YPO0623, mostly resulting in protein translation termination, which implies a strong natural selection. These mutations were found in all phylogenetic lineages of , and there was no apparent pattern in the spatial distribution of the mutant strains.

and Plague: some knowns and unknowns.

Since its first identification in 1894 during the third pandemic in Hong Kong, there has been significant progress of understanding the lifestyle of , the pathogen that is responsible for plague. Although we now have some understanding of the pathogen's physiology, genetics, genomics, evolution, gene regulation, pathogenesis and immunity, there are many unknown aspects of the pathogen and its disease development. Here, we focus on some of the knowns and unknowns relating to and plague.

Comparative Lysine Acetylome Analysis of Y. pestis YfiQ/CobB Mutants Reveals that Acetylation of SlyA Lys73 Significantly Promotes Biofilm Formation of Y. pestis.

Increasing evidence shows that protein lysine acetylation is involved in almost every aspect of cellular physiology in bacteria. Yersinia pestis is a flea-borne pathogen responsible for millions of human deaths in three global pandemics. However, the functional role of lysine acetylation in this pathogen remains unclear.

Interplays of mutations in , , and contribute to phage resistance in .

Plague caused by remains a public health threat worldwide. Because multidrug-resistant strains have been found in both humans and animals, phage therapy has attracted increasing attention as an alternative strategy against plague. However, phage resistance is a potential drawback of phage therapies, and the mechanism of phage resistance in is yet to be investigated.

Development and evaluation of a multiplex droplet digital polymerase chain reaction method for simultaneous detection of five biothreat pathogens.

Biothreat agents pose a huge threat to human and public health, necessitating the development of rapid and highly sensitive detection approaches. This study establishes a multiplex droplet digital polymerase chain reaction (ddPCR) method for simultaneously detecting five high-risk bacterial biothreats: , , spp., , and .

Single-cell transcriptomics of immune cells in lymph nodes reveals their composition and alterations in functional dynamics during the early stages of bubonic plague.

Bubonic plague caused by Yersinia pestis is highly infectious and often fatal. Characterization of the host immune response and its subsequent suppression by Y. pestis is critical to understanding the pathogenesis of Y.

Subversion of GBP-mediated host defense by E3 ligases acquired during Yersinia pestis evolution.

Plague has caused three worldwide pandemics in history, including the Black Death in medieval ages. Yersinia pestis, the etiological agent of plague, has evolved a powerful arsenal to disrupt host immune defenses during evolution from enteropathogenic Y. pseudotuberculosis.

-Induced Mitophagy That Balances Mitochondrial Homeostasis and mROS-Mediated Bactericidal Activity.

Manipulating mitochondrial homeostasis is essential for host defense against infection and pathogen survival in cells. This study reports for the first time that Y. pestis infection caused mitochondria damage that subsequently leads to the activation of Pink1/Parkin-independent mitophagy in macrophage, and the effector YopH from the type III secretion system was required for these effects.

Attenuation of Mutants Caused by Iron Uptake Inhibition and Decreased Survivability in Macrophages.

is the etiological agent of plague, a deadly infectious disease that has caused millions of deaths throughout history. Obtaining iron from the host is very important for bacterial pathogenicity possesses many iron uptake systems. Yersiniabactin (Ybt) plays a major role in iron uptake and , and in virulence toward mice as well.

Fpr2/CXCL1/2 Controls Rapid Neutrophil Infiltration to Inhibit Infection.

, also known as group B streptococcus (GBS), can cause pneumonia, meningitis, and bacteremia, making it a pathogen that can increase the risk of death in newborns and immunodeficient individuals. Neutrophils are the first barrier to a host's innate immune defense against these infections. Fpr2(Formyl peptide receptor 2) is an important chemotactic receptor of neutrophils, though its activation would cause pro- and anti-inflammatory effects.

Proteogenomic discovery of sORF-encoded peptides associated with bacterial virulence in Yersinia pestis.

Plague caused by Yersinia pestis is one of the deadliest diseases. However, many molecular mechanisms of bacterial virulence remain unclear. This study engaged in the discovery of small open reading frame (sORF)-encoded peptides (SEPs) in Y.

Secretome and Comparative Proteomics of Yersinia pestis Identify Two Novel E3 Ubiquitin Ligases That Contribute to Plague Virulence.

Plague is a zoonotic disease that primarily infects rodents via fleabite. Transmission from flea to host niches requires rapid adaption of Yersinia pestis to the outer environments to establish infection. Here, quantitative proteome and secretome analyses of Y.

Construction of a Live-Attenuated Vaccine Strain of EV76-B-SHUΔ and Evaluation of Its Protection Efficacy in a Mouse Model by Aerosolized Intratracheal Inoculation.

Plague, which is caused by , is one of the most dangerous infectious diseases. No FDA-approved vaccine against plague is available for human use at present. To improve the immune safety of EV76 based live attenuated vaccine and to explore the feasibility of aerosolized intratracheal inoculation (i.

Corrigendum: Do Specific Pedagogies and Problem-Based Teaching Improve Student Employability? A Cross-Sectional Survey of College Students.

[This corrects the article DOI: 10.3389/fpsyg.2020.

The Effect of Relational Embeddedness, Absorptive Capacity, and Learning Orientation on SMEs' Competitive Advantage.

The combination of external new knowledge and organizational capability has become a cornerstone in the internationalized enterprises. Sources of knowledge acquisition are among the most valuable resources that an internationalized firm can achieve competitive advantage. This study aims to explore this phenomenon between knowledge sources and competitive advantage in the context of internationalized small and medium enterprises (SMEs) mainly by a quantitative approach.

Do Specific Pedagogies and Problem-Based Teaching Improve Student Employability? A Cross-Sectional Survey of College Students.

Higher education policy and manpower training have failed to meet the requirement of rapidly changing society and employers' expectation in Taiwan, resulting in a significant gap between university education and employment. Student employability should also be a focus of all higher education institutions, although whether a high degree of student learning outcomes can represent a high degree of student employability is still unclear. This study explores the relationships among pedagogy for employability, the problem-based teaching mode, absorptive capacity, and student employability in higher education institutions (HEIs).

Potent Neutralizing Antibodies against SARS-CoV-2 Identified by High-Throughput Single-Cell Sequencing of Convalescent Patients' B Cells.

The COVID-19 pandemic urgently needs therapeutic and prophylactic interventions. Here, we report the rapid identification of SARS-CoV-2-neutralizing antibodies by high-throughput single-cell RNA and VDJ sequencing of antigen-enriched B cells from 60 convalescent patients. From 8,558 antigen-binding IgG1 clonotypes, 14 potent neutralizing antibodies were identified, with the most potent one, BD-368-2, exhibiting an IC of 1.