Oxacillin promotes membrane vesicle secretion in a SarA-Sle1 regulatory cascade.

Membrane vesicles (MVs) are nanoscale particles secreted by living bacteria and . Bacterial MVs encapsulate various proteins, making them promising candidates for developing vaccines, drug carriers, and cancer immunotherapy agents. However, the mechanisms underlying MV secretion in Gram-positive bacteria remain unclear.

Alkaline shock protein 23 (Asp23)-controlled cell wall imbalance promotes membrane vesicle biogenesis in Staphylococcus aureus.

Membrane vesicles (MVs) are produced by species across all domains of life and have diverse physiological functions as well as promising applications. While the mechanisms for vesiculation in Gram-negative bacteria are well-established, the genetic determinants and regulatory factors responsible for MV biogenesis in Gram-positive bacteria remain largely unknown. Here, we demonstrate that a Q225P substitution in the alternative sigma factor B (SigB) triggers MV production in Staphylococcus aureus strain Newman by hindering the specific binding of SigB to the asp23 promoter, thereby repressing expression of alkaline shock protein 23 (Asp23).

Optimizing a high-sensitivity NanoLuc-based bioluminescence system for in vivo evaluation of antimicrobial treatment.

Focal and systemic infections are serious threats to human health. Preclinical models enable the development of new drugs and therapeutic regimens. In vivo, animal bioluminescence (BL) imaging has been used with bacterial reporter strains to evaluate antimicrobial treatment effects.

Simultaneous multiplex genome loci editing of using an engineered CRISPR-guided base editor.

TD serves as an exceptional chassis for next generation industrial biotechnology to produce various products. However, the simultaneous editing of multiple loci in TD remains a significant challenge. Herein, we report the development of a multiple loci genome editing system, named CRISPR-deaminase-assisted base editor (CRISPR-BE) in TD.

Membrane Vesicles Kill Tumor Cells Through a Caspase-1-Dependent Pyroptosis Pathway.

Introduction: Nanosized outer membrane vesicles (OMVs) from Gram-negative bacteria have attracted increasing interest because of their antitumor activity. However, the antitumor effects of MVs isolated from Gram-positive bacteria have rarely been investigated.

Methods: MVs of s USA300 were prepared and their antitumor efficacy was evaluated using tumor-bearing mouse models.

A TonB dependent transporter YncD of Salmonella enterica Serovar Typhi possesses vaccine potential.

Multiple TonB dependent transporters (TBDTs) contribute to bacterial virulence due to the importance roles that their substrates play in bacterial growth, and possess vaccine potential. A putative TBDT, YncD, had been identified as one of in vivo induced antigens during human infection of typhoid fever, and is required for the pathogenicity of Salmonella enterica Serovar Typhi. The present study was aimed to determine the function and immunogenicity of YncD.

Sub-MIC vancomycin enhances the antibiotic tolerance of vancomycin-intermediate Staphylococcus aureus through downregulation of protein succinylation.

Bacteria develop tolerance after transient exposure to antibiotics, and tolerance is a significant driver of resistance. The purpose of this study is to evaluate the mechanisms underlying tolerance formation in vancomycin-intermediate Staphylococcus aureus (VISA) strains. VISA strains were cultured with sub-minimum inhibitory concentrations (sub-MICs) of vancomycin.

GehB Inactivates Lipoproteins to Delay the Healing of Acute Wounds Infected with Staphylococcus aureus.

Staphylococcus aureus is one of the most prevalent bacteria found in acute wounds. S. aureus produces many virulence factors and extracellular enzymes that contribute to bacterial survival, dissemination, and pathogenicity.

Loaded delta-hemolysin shapes the properties of membrane vesicles.

Background: Membrane vesicles (MVs) are nanoscale vesicular structures produced by bacteria during their growth and . Some bacterial components can be loaded in bacterial MVs, but the roles of the loaded MV molecules are unclear.

Methods: MVs of RN4220 and its derivatives were prepared.

Therapeutic potential of bacteriophage endolysins for infections caused by Gram-positive bacteria.

Gram-positive (G) bacterial infection is a great burden to both healthcare and community medical resources. As a result of the increasing prevalence of multidrug-resistant G bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), novel antimicrobial agents must urgently be developed for the treatment of infections caused by G bacteria. Endolysins are bacteriophage (phage)-encoded enzymes that can specifically hydrolyze the bacterial cell wall and quickly kill bacteria.

Genomic Epidemiology and Phenotypic Characterization of Staphylococcus aureus from a Tertiary Hospital in Tianjin Municipality, Northern China.

Staphylococcus aureus remains a dangerous pathogen and poses a great threat to public health worldwide. The prevalence of the S. aureus clonotype is temporally and geographically variable.

Engineering a mevalonate pathway in for the production of lycopene.

Introduction: Red-colored lycopene has received remarkable attention in medicine because of its antioxidant properties for reducing the risks of many human cancers. However, the extraction of lycopene from natural hosts is limited. Moreover, the chemically synthesized lycopene raises safety concerns due to residual chemical reagents.

Hcp1-loaded staphylococcal membrane vesicle vaccine protects against acute melioidosis.

is the causal agent of melioidosis, a deadly tropical infectious disease that lacks a vaccine. On the basis of the attenuated RN4220-Δ (RN), we engineered the RN4220-Δ/ strain (RN-Hcp1) to generate hemolysin-coregulated protein 1 (Hcp1)-loaded membrane vesicles (MVs). The immunization of BALB/c mice with MVs mixed with adjuvant by a three-dose regimen increased the serum specific IgG production.

Identification of Lysine Succinylome and Acetylome in the Vancomycin-Intermediate Staphylococcus aureus XN108.

Protein posttranslational modifications (PTMs) play important roles in regulating numerous biological functions of prokaryotic and eukaryotic organisms. Lysine succinylation (Ksucc) and acetylation (Kac) are two important PTMs that have been identified in various bacterial species. However, the biological functions of Ksucc and Kac in vancomycin-intermediate S.

CcpA Regulates Biofilm Formation through Direct Repression of Staphylokinase Expression.

represents a notorious opportunistic pathogen causing various infections in biofilm nature, imposing remarkable therapeutic challenges worldwide. The catabolite control protein A (CcpA), a major regulator of carbon catabolite repression (CCR), has been recognized to modulate biofilm formation, while the underlying mechanism remains to be fully elucidated. In this study, the reduced biofilm was firstly determined in the deletion mutant of clinical isolate XN108 using both crystal violet staining and confocal laser scanning microscopy.

A vancomycin resistance-associated WalK(S221P) mutation attenuates the virulence of vancomycin-intermediate Staphylococcus aureus.

Introduction: Vancomycin-intermediate Staphylococcus aureus (VISA) is typically associated with a decline in virulence. We previously reported a WalK(S221P) mutation that plays an important role in mediating vancomycin resistance in VISA XN108. Whether this mutation is implicated in bacterial virulence remains unknown.

Microglia activation in the mPFC mediates anxiety-like behaviors caused by Staphylococcus aureus strain USA300.

Introduction: Staphylococcus aureus (S. aureus) is considered as one of the major causative agents of serious hospital- and community-acquired infections. Recent studies have reported that S.

Staphylococcus aureus small-colony variants: Formation, infection, and treatment.

Staphylococcus aureus (Sau) plays an important role in human infections occurring in both the community and hospital settings. Sau-related chronic and relapsing infections are mainly attributed to small-colony variants (SCVs), a type of subpopulation that has a size one-tenth that of normal colonies and is accompanied by several unique characteristics, including a lack of or reduced pigmentation, decreased hemolytic activity, increased biofilm formation, enhanced resistance to antimicrobials, upregulated genes encoding adhesion molecules, and downregulated genes for virulence factors. This review summarizes the significance of genetic mutations involved in diverse biosynthesis pathways that contribute to Sau-SCV promotion.

Pyocyanin biosynthesis protects Pseudomonas aeruginosa from nonthermal plasma inactivation.

Pseudomonas aeruginosa is an important opportunistic human pathogen, which raises a worldwide concern for its increasing resistance. Nonthermal plasma, which is also called cold atmospheric plasma (CAP), is an alternative therapeutic approach for clinical infectious diseases. However, the bacterial factors that affect CAP treatment remain unclear.

The Q225P Mutation in SigB Promotes Membrane Vesicle Formation in Staphylococcus aureus.

Both Gram-positive and Gram-negative bacteria release nano-sized lipid bilayered particles, known as membrane vesicles (MVs), into external environments. Although MVs play a variety of roles in bacterial physiology and pathogenesis, the mechanisms underlying MV formation in Gram-positive microorganisms such as Staphylococcus aureus remain obscure. Bacterial MV production can be induced in response to stress conditions, and the alternative sigma factor B (SigB) functions as a central regulator of the stress response in Gram-positive bacteria.