The Staphylococcus aureus non-coding RNA IsrR regulates TCA cycle activity and virulence.

Staphylococcus aureus has evolved mechanisms to cope with low iron (Fe) availability in host tissues. Staphylococcus aureus uses the ferric uptake transcriptional regulator (Fur) to sense titers of cytosolic Fe. Upon Fe depletion, apo-Fur relieves transcriptional repression of genes utilized for Fe uptake.

The small non-coding RNA IsrR regulates TCA cycle activity and virulence.

has evolved mechanisms to cope with low iron (Fe) availability in host tissues. uses the ferric uptake transcriptional regulator (Fur) to sense titers of cytosolic Fe. Upon Fe depletion, apo-Fur relieves transcriptional repression of genes utilized for Fe uptake.

RNA Extraction from Gram-Positive Bacteria Membrane Vesicles Using a Polymer-Based Precipitation Method.

Investigations into the biological role and composition of bacterial extracellular vesicles have grown in popularity in recent years. Vesicles perform a variety of functions during interactions with eukaryotic host cells, ranging from antibiotic resistance to immune modulation. It is necessary to isolate vesicles in order to understand their biological functions.

Altered quorum sensing and physiology of Staphylococcus aureus during spaceflight detected by multi-omics data analysis.

Staphylococcus aureus colonizes the nares of approximately 30% of humans, a risk factor for opportunistic infections. To gain insight into S. aureus virulence potential in the spaceflight environment, we analyzed RNA-Seq, cellular proteomics, and metabolomics data from the "Biological Research in Canisters-23" (BRIC-23) GeneLab spaceflight experiment, a mission designed to measure the response of S.

The Small Protein ScrA Influences Staphylococcus aureus Virulence-Related Processes via the SaeRS System.

Staphylococcus aureus is a Gram-positive commensal and opportunistic pathogen able to cause diseases ranging from mild skin infections to life-threatening endocarditis and toxic shock syndrome. The ability to cause such an array of diseases is due to the complex S. aureus regulatory network controlling an assortment of virulence factors, including adhesins, hemolysins, proteases, and lipases.

The Small RNA Teg41 Is a Pleiotropic Regulator of Virulence in Staphylococcus aureus.

Previously, our group demonstrated a role for the small RNA (sRNA) Teg41 in regulating production of the alpha phenol-soluble modulin toxins (αPSMs) in Staphylococcus aureus. Overexpressing Teg41 increased αPSM production while deleting the 3' end of Teg41 (Teg41Δ3' strain) resulted in a decrease in αPSM production, reduced hemolytic activity of S. aureus culture supernatants, and attenuated virulence in a murine abscess model of infection.

RNase III CLASH in MRSA uncovers sRNA regulatory networks coupling metabolism to toxin expression.

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen responsible for significant human morbidity and mortality. Post-transcriptional regulation by small RNAs (sRNAs) has emerged as an important mechanism for controlling virulence. However, the functionality of the majority of sRNAs during infection is unknown.

Excess Growth Hormone Alters the Male Mouse Gut Microbiome in an Age-dependent Manner.

The gut microbiome has an important role in host development, metabolism, growth, and aging. Recent research points toward potential crosstalk between the gut microbiota and the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis. Our laboratory previously showed that GH excess and deficiency are associated with an altered gut microbial composition in adult mice.

The novel protein ScrA acts through the SaeRS two-component system to regulate virulence gene expression in Staphylococcus aureus.

Staphylococcus aureus is a Gram-positive commensal that can also cause a variety of infections in humans. S. aureus virulence factor gene expression is under tight control by a complex regulatory network, which includes, sigma factors, sRNAs, and two-component systems (TCS).

Global Annotation, Expression Analysis, and Stability of Candidate sRNAs in Group B Streptococcus.

Small, noncoding RNAs (sRNAs) are being increasingly identified as important regulatory molecules in prokaryotes. Due to the prevalence of next-generation sequencing-based techniques, such as RNA sequencing (RNA-seq), there is potential for increased discovery of sRNAs within bacterial genomes; however, these elements are rarely included in annotation files. Consequently, expression values for sRNAs are omitted from most transcriptomic analyses, and mechanistic studies have lagged behind those of protein regulators in numerous bacteria.

Detection and Quantification of Secreted Nuclease Activity in Staphylococcus aureus Culture Supernatants.

Staphylococcal secreted nuclease contributes to S. aureus virulence by degrading neutrophil extracellular traps (NETs), which allows the bacterium to evade the host immune system and has also been shown to promote biofilm dispersal. In this chapter, two methods for detecting nuclease activity are described, both of which have increased sensitivity compared to the traditional nuclease agar method.

Rapid electrochemical detection of using nickel oxidation reaction on a rotating disk electrode.

A standalone electrochemical method for detecting the bacterium in water was developed using a nickel electrode and no biorecognition element. Electric current responses from different concentrations were recorded based on their interaction with a locally formed electrocatalyst. A rotating disk electrode was used to minimize the mass transport limitations at the interface.

Staphylococcus aureus Responds to Physiologically Relevant Temperature Changes by Altering Its Global Transcript and Protein Profile.

is an opportunistic pathogen that colonizes the anterior nares of 30 to 50% of the population. Colonization is most often asymptomatic; however, self-inoculation can give rise to potentially fatal infections of the deeper tissues and blood. Like all bacteria, can sense and respond to environmental cues and modify gene expression to adapt to specific environmental conditions.

Staphylococcus aureus Trigger Factor Is Involved in Biofilm Formation and Cooperates with the Chaperone PpiB.

Peptidyl-prolyl isomerases (PPIases) are enzymes that assist in protein folding around proline-peptide bonds, and they often possess chaperone activity. encodes three PPIases, i.e.

Bacterial-like nitric oxide synthase in the haloalkaliphilic archaeon Natronomonas pharaonis.

Bacterial nitric oxide (NO) synthases (bNOS) play diverse and important roles in microbial physiology, stress resistance, and virulence. Although bacterial and mammalian NOS enzymes have been well-characterized, comparatively little is known about the prevalence and function of NOS enzymes in Archaea. Analysis of archaeal genomes revealed that highly conserved bNOS homologs were restricted to members of the Halobacteria.

Extracellular Vesicle Biogenesis and Functions in Gram-Positive Bacteria.

Extracellular vesicles (EVs) are membrane-derived lipid bilayers secreted by bacteria and eukaryotic cells. Bacterial membrane vesicles were discovered over 60 years ago and have been extensively studied in Gram-negative bacteria. During their production, EVs are loaded with proteins, nucleic acids, and various compounds that are subsequently released into the environment.

Reading between the Lines: Utilizing RNA-Seq Data for Global Analysis of sRNAs in Staphylococcus aureus.

Regulatory small RNAs (sRNAs) are known to play important roles in the Gram-positive bacterial pathogen ; however, their existence is often overlooked, primarily because sRNA genes are absent from genome annotation files. Consequently, transcriptome sequencing (RNA-Seq)-based experimental approaches, performed using standard genome annotation files as a reference, have likely overlooked data for sRNAs. Previously, we created an updated genome annotation file, which included annotations for 303 known sRNAs in USA300.

Crosstalk between the growth hormone/insulin-like growth factor-1 axis and the gut microbiome: A new frontier for microbial endocrinology.

Both the GH/IGF-1 axis and the gut microbiota independently play an important role in host growth, metabolism, and intestinal homeostasis. Inversely, abnormalities in GH action and microbial dysbiosis (or a lack of diversity) in the gut have been implicated in restricted growth, metabolic disorders (such as chronic undernutrition, anorexia nervosa, obesity, and diabetes), and intestinal dysfunction (such as pediatric Crohn's disease, colonic polyps, and colon cancer). Over the last decade, studies have demonstrated that the microbial impact on growth may be mediated through the GH/IGF-1 axis, pointing toward a potential relationship between GH and the gut microbiota.

Growth Hormone Deficiency and Excess Alter the Gut Microbiome in Adult Male Mice.

The gut microbiome has been implicated in host metabolism, endocrinology, and pathophysiology. Furthermore, several studies have shown that gut bacteria impact host growth, partially mediated through the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis. Yet, no study to date has examined the specific role of GH on the gut microbiome.

Heterogeneity spacers in 16S rDNA primers improve analysis of mouse gut microbiomes via greater nucleotide diversity.

Illumina-based amplicon sequencing suffers from the deleterious effects of highly homogenous nucleotide composition, limiting the number of high-quality reads generated per run. We attempted to alleviate this limitation by comparing the results obtained from 16S ribosomal DNA (16S rDNA) sequencing of mouse gut microbiomes using Illumina V3-V4 primers (Run 1) and custom primers that incorporate a heterogeneity spacer (0-7 nucleotides) upstream of the 16S priming region (Run 2). Overall, Run 2 had higher quality sequences, a more diverse microbial profile, and higher precision within, and variation between, experimental groups than Run 1.

Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl Isomerase Enzymes in .

Peptidyl-prolyl isomerases (PPIases) are enzymes that catalyze the -to- isomerization around proline bonds, allowing proteins to fold into their correct confirmation. Previously, we identified two PPIase enzymes in (PpiB and PrsA) that are involved in the regulation of virulence determinants and have shown that PpiB contributes to virulence in a murine abscess model of infection. Here, we further examine the role of these PPIases in virulence and, in particular, their regulation of hemolytic toxins.

An unconventional RNA-based thermosensor within the 5' UTR of Staphylococcus aureus cidA.

Staphylococcus aureus is a Gram-positive bacterial pathogen of global concern and a leading cause of bacterial infections worldwide. Asymptomatic carriage of S. aureus on the skin and in the anterior nares is common and recognized as a predisposing factor to invasive infection.