Genome Sequence and Phenotypic Analysis of a Protein Lysis-Negative, Attenuated Anthrax Vaccine Strain.

is a Gram-positive bacterium that causes the zoonotic disease anthrax. Here, we studied the characteristic phenotype and virulence attenuation of the putative No. II vaccine strain, PNO2, which was reportedly introduced from the Pasteur Institute in 1934.

Rapid Identification of Bacillus anthracis and On-Site Using Novel Single-Nucleotide Polymorphisms.

Bacillus anthracis is a spore-forming bacterium that causes life-threatening infections in animals and humans and has been used as a bioterror agent. Rapid and reliable detection and identification of B. anthracis are of primary interest for both medical and biological threat-surveillance purposes.

A CRISPR/Cas12a-based DNAzyme visualization system for rapid, non-electrically dependent detection of .

As next-generation pathogen detection methods, CRISPR-Cas-based detection methods can perform single-nucleotide polymorphism (SNP) level detection with high sensitivity and good specificity. They do not require any particular equipment, which opens up new possibilities for the accurate detection and identification of In this study, we developed a complete detection system for based on Cas12a. We used two chromosomally located SNP targets and two plasmid targets to identify with high accuracy.

Orthogonal modular biosynthesis of nanoscale conjugate vaccines for vaccination against infection.

Unlabelled: Conjugate vaccines represent one of the most effective means for controlling the occurrence of bacterial diseases. Although nanotechnology has been greatly applied in the field of vaccines, it is seldom used for conjugate vaccine research because it is very difficult to connect polysaccharides and nanocarriers. In this work, an orthogonal and modular biosynthesis method was used to produce nanoconjugate vaccines using the SpyTag/SpyCatcher system.

Application of CRISPR/Cas9 System for Plasmid Elimination and Bacterial Killing of Group Strains.

The CRISPR-Cas system has been widely applied in prokaryotic genome editing with its high efficiency and easy operation. We constructed some "scissors plasmids" via using the temperature-sensitive pJOE8999 shuttle plasmid, which carry the different 20nt (N20) guiding the Cas9 nuclease as a scissors to break the target DNA. We successfully used scissors plasmids to eliminate native plasmids from and , and specifically killed .

Obtaining Specific Sequence Tags for and Visually Detecting Them Using the CRISPR-Cas12a System.

Three worldwide historical plague pandemics resulted in millions of deaths. , the etiologic agent of plague, is also a potential bioterrorist weapon. Simple, rapid, and specific detection of is important to prevent and control plague.

Expression of Antigens Fused to Different Vectors and Their Effectiveness as Vaccines.

Pertussis is an acute respiratory tract infection caused by . Even though its current vaccine coverage is relatively broad, they still have some shortcomings such as short protection time and might be incapable of blocking the spread of the disease. In this study, we developed new pertussis vaccine candidates by separately fusing three pertussis antigens ( fimbriae 2 "Fim2", pertussis toxin S1 subunit "PtxS1", and filamentous hemagglutinin "FHA") to each of two immune-boosting carrier proteins (B subunits of AB5 toxin family: cholera toxin B subunit "CTB" and shiga toxin B subunit "StxB").

Safety and immunogenicity of a new glycoengineered vaccine against Acinetobacter baumannii in mice.

Acinetobacter baumannii poses a serious threat to human health, mainly because of its widespread distribution and severe drug resistance. However, no licensed vaccines exist for this pathogen. In this study, we created a conjugate vaccine against A.

[Biosynthesis of polysaccharide conjugate vaccines against Klebsiella pneumoniae serotype O2 strains].

The main purpose of this research is to synthesize and evaluate a new glycoconjugate vaccine against Klebsiella pneumonia (Kp). First, the gene (waaL) responsible for the expression of O antigen ligase was deleted to block the synthesis of bacterial LPS. Then the vector that encodes a glycosyltransferase (PglL) was transferred into the mutant.

Biosynthesis of Self-Assembled Proteinaceous Nanoparticles for Vaccination.

Recent years have seen enormous advances in nanovaccines for both prophylactic and therapeutic applications, but most of these technologies employ chemical or hybrid semi-biosynthetic production methods. Thus, production of nanovaccines has to date failed to exploit biology-only processes like complex sequential post-translational biochemical modifications and scalability, limiting the realization of the initial promise for offering major performance advantages and improved therapeutic outcomes over conventional vaccines. A Nano-B5 platform for in vivo production of fully protein-based, self-assembling, stable nanovaccines bearing diverse antigens including peptides and polysaccharides is presented here.

SpoVG is Necessary for Sporulation in .

The spore constitutes the infectious form of the bacterium, and sporulation is an important process in the organism's life cycle. Herein, we show that disruption of SpoVG resulted in defective sporulation. Confocal microscopy demonstrated that a Δ mutant could not form an asymmetric septum, the first morphological change observed during sporulation.

Application of an -Linked Glycosylation System in Serotype O:9 to Generate a New Candidate Vaccine against .

Brucellosis is a major zoonotic public health threat worldwide, causing veterinary morbidity and major economic losses in endemic regions. However, no efficacious brucellosis vaccine is yet available, and live attenuated vaccines commonly used in animals can cause human infection. - and -linked glycosylation systems have been successfully developed and exploited for the production of successful bioconjugate vaccines.

Genotyping and population diversity of Bacillus anthracis in China based on MLVA and canSNP analysis.

In pastoral parts of China, anthrax still presents a major risk to livestock and threatens the health of local human populations. Currently, whole-genome-based molecular markers, such as single-nucleotide polymorphisms (SNPs) and variable number tandem repeats (VNTRs), are the most effective tools for genotyping Bacillus anthracis. In this study, 191 isolates were selected to assess the diversity of B.

Highly Efficient Genome Engineering in and Using the CRISPR/Cas9 System.

Genome editing is an effective tool for the functional examination of bacterial genes and for live attenuated vaccine construction. Here, we report a method to edit the genomic DNA of and using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas)9 system. Using two prophages in as targets, large-fragment deletion mutants were achieved with rates of 100 or 20%.

Disruption of SpoIIID decreases sporulation, increases extracellular proteolytic activity and virulence in Bacillus anthracis.

Endospores are important for maintenance of the B. anthracis lifecycle and necessary for its effective spread between hosts. Our experiments with B.

Genome sequence of Bacillus anthracis typing phage AP631.

AP631, a virulent bacteriophage of Bacillus anthracis, is widely used in China to identify anthrax bacteria. In this study, we report the complete AP631 phage genome sequence as well as comparative genomic analysis with other bacteriophages of B. cereus and related species.

Construction of a high-efficiency cloning system using the Golden Gate method and I-SceI endonuclease for targeted gene replacement in Bacillus anthracis.

To investigate gene function in Bacillus anthracis, a high-efficiency cloning system is required with an increased rate of allelic exchange. Golden Gate cloning is a molecular cloning strategy allowing researchers to simultaneously and directionally assemble multiple DNA fragments to construct target plasmids using type IIs restriction enzymes and T4 DNA ligase in the same reaction system. Here, a B.

An H-NS Family Protein, Sfh, Regulates Acid Resistance by Inhibition of Glutamate Decarboxylase Expression in .

The glutamate-dependent acid-resistance system is the most effective acid tolerance pathway in , allowing survival in extremely acidic environments. However, the regulation of this system in remains elusive. In the current study, we identified significant differences in the levels of glutamate decarboxylase between three strains with different levels of acid resistance using blue native-polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing (IEF)/sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis.

Role of the virulence plasmid in acid resistance of Shigella flexneri.

Virulence plasmid (VP) acquisition was a key step in the evolution of Shigella from a non-pathogenic Escherichia coli ancestor to a pathogenic genus. In addition, the co-evolution and co-ordination of chromosomes and VPs was also a very important step in the evolutionary process. To investigate the cross-talk between VPs and bacterial chromosomes, we analyzed the expression profiles of protein complexes and protein monomers in three wild-type Shigella flexneri strains and their corresponding VP deletion mutants.

Proteomic Analysis of Shigella Virulence Effectors Secreted under Different Conditions.

A series of novel effector molecules secreted by the type three secretion system (T3SS) of spp. have been reported in recent years. In this study, a proteomic approach was applied to study T3SS effectors systematically.

Experimental Validation of Bacillus anthracis A16R Proteogenomics.

Anthrax, caused by the pathogenic bacterium Bacillus anthracis, is a zoonosis that causes serious disease and is of significant concern as a biological warfare agent. Validating annotated genes and reannotating misannotated genes are important to understand its biology and mechanisms of pathogenicity. Proteomics studies are, to date, the best method for verifying and improving current annotations.

Comparative proteomics of Shigella flexneri 2a strain 301 using a rabbit ileal loop model reveals key proteins for bacterial adaptation in host niches.

Objectives: Many studies focusing on changes in the host following Shigella spp invasion have been reported in recent years. However, the key factors required for the adaptation of these pathogens to host niches have usually been neglected.

Methods: In this study, a comparative proteomic analysis was performed to examine changes in the protein expression profile of Shigella flexneri within the host using a rabbit ileal loop model to reveal proteins that are associated with pathogenic adaptation.

Curing Both Virulent Mega-Plasmids from Bacillus anthracis Wild-Type Strain A16 Simultaneously Using Plasmid Incompatibility.

Plasmid-cured derivative strains of Bacillus anthracis are frequently used in laboratory studies. Plasmid incompatibility, which does not increase the risk of chromosomal mutation, is a useful method for plasmid curing. However, in bacteria containing multiple plasmids, it often requires the sequential introduction of multiple, specific incompatibility plasmids.

The function of PlcR in Bacillus anthracis vaccine strain A16R.

Bacillus anthracis, B. thuringiensis and B. cereus are members of the B.

The effect of quorum sensing system for growth competitiveness on Shigella flexneri.

Quorum sensing (QS) regulates the onset of bacterial social responses related to cell density. Comparison between the gene sequences of all components of QS system of Escherichia coli and Shigella strains, shows that the QS system is generally lost or mutated in Shigella. Since AI-2 is produced and processed by the lsr operon, we analyzed the potential function of the lsr operon.