Na-V-ATPase inhibitor curbs VRE growth and unveils Na pathway structure.

Vancomycin-resistant Enterococcus faecium (VRE) is a major cause of nosocomial infections, particularly endocarditis and sepsis. With the diminishing effectiveness of antibiotics against VRE, new antimicrobial agents are urgently needed. Our previous research demonstrated the crucial role of Na-transporting V-ATPase in Enterococcus hirae for growth under alkaline conditions.

[Mechanism of high-frequent horizontal gene transfer in Gram positive bacterial pathogens].

Horizontal gene transfer through transconjugation and natural transformation plays a major role in the spread of antimicrobial resistance. Although the phenomenon of genetic element transmission has long been known, the rapid increase in the number of antimicrobial resistant bacteria in recent years and the accompanying accumulation of genomic information have revealed that horizontal gene transfer contributes to genome plasticity in various ways. The author reported the molecular mechanism of the antimicrobial activity of the accessory factor bacteriocin encoded by the junctional transfer plasmid of Enterococcus faecalis, a representative Gram-positive opportunistic pathogen that is concerned as highly antimicrobial resistant, and found diversity in the selfimmune system based on epidemiological studies.

Enterococcal Linear Plasmids Adapt to Enterococcus faecium and Spread within Multidrug-Resistant Clades.

Antimicrobial resistance (AMR) of bacterial pathogens, including enterococci, is a global concern, and plasmids are crucial for spreading and maintaining AMR genes. Plasmids with linear topology were identified recently in clinical multidrug-resistant enterococci. The enterococcal linear-form plasmids, such as pELF1, confer resistance to clinically important antimicrobials, including vancomycin; however, little information exists about their epidemiological and physiological effects.

Advances of genetic engineering in streptococci and enterococci.

In the post-genome era, reverse genetic engineering is an indispensable methodology for experimental molecular biology to provide a deeper understanding of the principal relationship between genomic features and biological phenotypes. Technically, genetic engineering is carried out through allele replacement of a target genomic locus with a designed nucleotide sequence, so called site-directed mutagenesis. To artificially manipulate allele replacement through homologous recombination, researchers have improved various methodologies that are optimized to the bacterial species of interest.

Elucidation of host diversity of the VanD-carrying genomic islands in enterococci and anaerobes.

Background: VanD is a rare type of vancomycin resistance worldwide. However, the host diversity of the gene cluster and the structural similarity of their genomic islands are not well understood.

Methods: Three VanD-type strains (AA620, AA622 and AA624) isolated from a Japanese patient who underwent vancomycin treatment in 2017 were analysed.

Inactivation of GalU Leads to a Cell Wall-Associated Polysaccharide Defect That Reduces the Susceptibility of Enterococcus faecalis to Bacteriolytic Agents.

Enterococcal plasmid-encoded bacteriolysin Bac41 is a selective antimicrobial system that is considered to provide a competitive advantage to cells that carry the Bac41-coding plasmid. The Bac41 effector consists of the secreted proteins BacL and BacA, which attack the cell wall of the target cell to induce bacteriolysis. Here, we demonstrated that , which encodes UTP-glucose-1-phosphate uridylyltransferase, is involved in susceptibility to the Bac41 system in Spontaneous mutants that developed resistance to the antimicrobial effects of BacL and BacA were revealed to carry a truncation deletion of the C-terminal amino acid (aa) region 288 to 298 of the translated GalU protein.

Progress Overview of Bacterial Two-Component Regulatory Systems as Potential Targets for Antimicrobial Chemotherapy.

Bacteria adapt to changes in their environment using a mechanism known as the two-component regulatory system (TCS) (also called "two-component signal transduction system" or "two-component system"). It comprises a pair of at least two proteins, namely the sensor kinase and the response regulator. The former senses external stimuli while the latter alters the expression profile of bacterial genes for survival and adaptation.

Roles of the Tol-Pal system in the Type III secretion system and flagella-mediated virulence in enterohemorrhagic Escherichia coli.

The Tol-Pal system is a protein complex that is highly conserved in many gram-negative bacteria. We show here that the Tol-Pal system is associated with the enteric pathogenesis of enterohemorrhagic E. coli (EHEC).

Unbiased homeologous recombination during pneumococcal transformation allows for multiple chromosomal integration events.

The spread of antimicrobial resistance and vaccine escape in the human pathogen can be largely attributed to competence-induced transformation. Here, we studied this process at the single-cell level. We show that within isogenic populations, all cells become naturally competent and bind exogenous DNA.

Three New Integration Vectors and Fluorescent Proteins for Use in the Opportunistic Human Pathogen .

Here, we describe the creation of three integration vectors, pPEPX, pPEPY and pPEPZ, for use with the opportunistic human pathogen . The constructed vectors, named PEP for Pneumococcal Engineering Platform (PEP), employ an IPTG-inducible promoter and BglBrick and BglFusion compatible multiple cloning sites allowing for fast and interchangeable cloning. PEP plasmids replicate in and harbor integration sites that have homology in a large set of pneumococcal strains, including recent clinical isolates.

Dissemination and genetic analysis of the stealthy vanB gene clusters of Enterococcus faecium clinical isolates in Japan.

Background: VanB-type vancomycin (VAN) resistance gene clusters confer VAN resistances on Enterococcus spp. over a wide range of MIC levels (MIC = 4-1000 mg/L). However, the epidemiology and the molecular characteristics of the VAN susceptible VanB-type Enterococcus still remain unclear.

New colony multiplex PCR assays for the detection and discrimination of vancomycin-resistant enterococcal species.

New colony multiplex PCR assays for detection of seven types of vancomycin-resistance determinants and eight types of Enterococcus species were developed. For 135 enterococcal isolates examined in this study, these assays showed high sensitivity and specificity, and could provide the rapid and accurate detection of vancomycin-resistant determinants and Enterococcus spp.

Partial Diversity Generates Effector Immunity Specificity of the Bac41-Like Bacteriocins of Enterococcus faecalis Clinical Strains.

Unlabelled: Bacteriocin 41 (Bac41) is the plasmid-encoded bacteriocin produced by the opportunistic pathogen Enterococcus faecalis Its genetic determinant consists of bacL1 (effector), bacL2 (regulator), bacA (effector), and bacI (immunity). The secreted effectors BacL1 and BacA coordinate to induce the lytic cell death of E. faecalis Meanwhile, the immunity factor BacI provides self-resistance to the Bac41 producer, E.

The Bordetella Secreted Regulator BspR Is Translocated into the Nucleus of Host Cells via Its N-Terminal Moiety: Evaluation of Bacterial Effector Translocation by the Escherichia coli Type III Secretion System.

Bordetella bronchiseptica is genetically related to B. pertussis and B. parapertussis, which cause respiratory tract infections in humans.

Bacteriocin protein BacL1 of Enterococcus faecalis targets cell division loci and specifically recognizes L-Ala2-cross-bridged peptidoglycan.

Bacteriocin 41 (Bac41) is produced from clinical isolates of Enterococcus faecalis and consists of two extracellular proteins, BacL1 and BacA. We previously reported that BacL1 protein (595 amino acids, 64.5 kDa) is a bacteriolytic peptidoglycan D-isoglutamyl-L-lysine endopeptidase that induces cell lysis of E.

Bacteriocin protein BacL1 of Enterococcus faecalis is a peptidoglycan D-isoglutamyl-L-lysine endopeptidase.

Enterococcus faecalis strains are commensal bacteria in humans and other animals, and they are also the causative agent of opportunistic infectious diseases. Bacteriocin 41 (Bac41) is produced by certain E. faecalis clinical isolates, and it is active against other E.

The type III secreted protein BspR regulates the virulence genes in Bordetella bronchiseptica.

Bordetella bronchiseptica is closely related with B. pertussis and B. parapertussis, the causative agents of whooping cough.

Btc22 chaperone is required for secretion and stability of the type III secreted protein Bsp22 in Bordetella bronchiseptica.

The type III secretion system (T3SS) is a sophisticated protein secretion machinery that delivers bacterial virulence proteins into host cells. A needle-tip protein, Bsp22 , is one of the secreted substrates of the T3SS and plays an essential role in the full function of the T3SS in Bordetella bronchiseptica. In this study, we found that BB1618 functions as a chaperone for Bsp22 .

Iron starvation regulates the type III secretion system in Bordetella bronchiseptica.

The type III secretion system (T3SS) plays a key role in the exertion of full virulence by Bordetella bronchiseptica. However, little is known about the environmental stimuli that induce expression of T3SS genes. Here, it is reported that iron starvation is a signal for T3SS gene expression in B.

EspJ effector in enterohemorrhagic E. coli translocates into host mitochondria via an atypical mitochondrial targeting signal.

EHEC is a bacterial pathogen causing diarrhea and hemorrhagic colitis in humans. To exert virulence, EHEC exploits a subset of effectors that are translocated into host cells via the type III secretion system. EspJ, which was recently identified as a type III secreted effector, is conserved in related pathogens such as EPEC and Citrobacter rodentium.