A5003105310- Bacterial Genetics and Biotechnology
- Bacteriophages and microbial interactions
- Toxin Mechanisms and Immunotoxins
- RNA and protein synthesis mechanisms
- Gut microbiota and health
- Streptococcal Infections and Treatments
- Antimicrobial Resistance in Staphylococcus
- Gene Regulatory Network Analysis
- Blood disorders and treatments
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Evolution and Genetic Dynamics
- Escherichia coli research studies
- CRISPR and Genetic Engineering
- Sepsis Diagnosis and Treatment
- Protist diversity and phylogeny
- Microbial Metabolic Engineering and Bioproduction
- Vibrio bacteria research studies
- RNA modifications and cancer
- Pancreatitis Pathology and Treatment
- Metabolism and Genetic Disorders
- Enzyme Structure and Function
- Clostridium difficile and Clostridium perfringens research
- Inflammatory Bowel Disease
- Oral and gingival health research
- Retinal and Optic Conditions
California University of Pennsylvania
2025
University of Pennsylvania
2012-2024
University of the Sciences
2023-2024
University Medical Center
2003
University of Minnesota Medical Center
1994-2000
University of Minnesota
1994-1998
University of Idaho
1998
University of Minnesota System
1998
Twin Cities Orthopedics
1998
Bacterial urease activity of the gut microbiota alters nitrogen flux, leading to dysbiosis and worsening colitis in mice.
The bacterial SOS response is a DNA damage repair network that strongly implicated in both survival and acquired drug resistance under antimicrobial stress. two regulators, LexA RecA, have therefore emerged as potential targets for adjuvant therapies aimed at combating resistance, although many open questions remain. For example, it not well understood whether hyperactivation viable therapeutic approach or RecA better target. Furthermore, important to determine which antimicrobials could...
ComA is a response regulator protein of Bacillus subtilis which required for the transcription several genes are involved in late-growth expression and responses to environmental stress. Among these degQ, gsiA, srfA. The last an operon needed development genetic competence, surfactin production, normal sporulation. We show here that partially purified protein, isolated from overproducing Escherichia coli strain, phosphorylated vitro by incubation with acetyl phosphate could bind specifically...
It has long been hypothesized that subcellular positioning of chromosomal loci in bacteria may be influenced by gene function and expression state. Here we provide direct evidence membrane protein affects the position Escherichia coli. For two different proteins, observed a dramatic shift their genetic toward upon induction. In related systems which cytoplasmic was produced, or translation eliminated mutating start codon, not observed. Antibiotics block transcription similarly prevented...
Abstract Antimicrobial peptides are an important component of the molecular arsenal employed by hosts against bacteria. Many bacteria in turn possess pathways that provide protection these compounds. In Escherichia coli and related bacteria, PhoQ/PhoP signalling system is a key regulator this antimicrobial peptide defence. Here we show treating E. with sublethal concentrations causes cells to filament, division block controlled system. The filamentation results from increased expression...
SignificanceIn a polymicrobial battlefield where different species compete for nutrients and colonization niches, antimicrobial compounds are the sword shield of commensal microbes in competition with invading pathogens each other. The identification an
Altered plasma acylcarnitine levels are well-known biomarkers for a variety of mitochondrial fatty acid oxidation disorders and can be used as an alternative energy source the intestinal epithelium when short-chain acids low. These membrane-permeable intermediates excreted into gut lumen via bile increased in feces patients with inflammatory bowel disease (IBD).
ABSTRACT Staphylococcus aureus and Streptococcus pyogenes express pyrogenic toxin superantigens (PTSAgs) that are associated with toxic shock syndrome (TSS) staphylococcal food poisoning (SFP). Most PTSAgs cause TSS in deep-tissue infections, whereas only 1 (TSST-1) is menstrual, vaginal TSS. In contrast, SFP has been linked enterotoxins (SEs). Because of the differential abilities to systemic or localized symptoms a site-dependent manner, present study was undertaken assess toxins' cross...
We show that the major role for Spo0A in development of genetic competence is to downregulate expression abrB. AbrB both a negative regulator and positive competence. The effects are exerted at multiple points regulation. A regulatory mechanism independent mecA abrB operates on comK expression.
The development of competence in Bacillus subtilis is normally dependent on the growth medium. Expression late genes occurs glucose-minimal salts-based media but not complex media. also inhibited when glutamine added to medium and glycerol substituted for glucose. Mutations have been identified two regulatory loci, mecA mecB, which render independent these variables. Although mec mutants expression genes, as well itself, occurred all tested, this was still stage regulated. Thus at least some...
Temperate bacteriophages are viruses that can incorporate their genomes into bacterial hosts, existing there as prophages refrain from killing the host cell until induced. Prophages largely quiescent, but they alter phenotype through factors encoded in (often virulence factors) or by disrupting genes a result of integration. Here we describe another mechanism which prophage modulate phenotype. We show temperate phage integrates Escherichia coli reprograms regulation an anaerobic respiratory...
ABSTRACT Streptococcal pyrogenic exotoxins (SPEs) are superantigens that have been implicated in causing streptococcal toxic shock syndrome (STSS). Most notably, SPE serotype A is made by nearly all M-protein 1 and 3 streptococci, the M types most associated with illness (these strains contain one or more other SPEs, those proteins likely also to contribute disease). We prepared double-, triple-, hexa-amino-acid mutants of PCR mutagenesis procedures. The sites chosen for mutation were...
Although competence normally develops only in glucose-minimal salts media, mecA and mecB mutations permit the expression of late genes complex media as well (D. Dubnau M. Roggiani, J. Bacteriol. 172:4048-4055, 1990). The is dependent on products regulatory comA, comB, comP, sin, abrB, spo0H, spo0A. We show here that this list must be extended to include degU, csh-293, spo0K. -B bypass most these requirements, making itself independent all genes, with exceptions spo0A spo0K (in case mecB)....
Dissemination of organisms from the gut microbiota is a major contributor to sepsis and critical illness. Patients with cirrhosis are prone systemic infections commonly prescribed carbohydrate lactulose manage hepatic encephalopathy (HE). Commensal metabolism believed reduce pathobiont colonization through short-chain fatty acid production, but its direct effects on pathobionts remain unexplored. Here, we show that consumption unexpectedly selects for mutations in Escherichia coli lactose...
Escherichia coli senses and responds to trimethylamine-N-oxide (TMAO) in the environment through TorT-TorS-TorR signal transduction system. The periplasmic protein TorT binds TMAO stimulates hybrid kinase TorS phosphorylate response regulator TorR a phosphorelay. Phosphorylated TorR, turn, activates transcription of torCAD operon, which encodes proteins required for anaerobic respiration via reduction trimethylamine. Interestingly, E. respires both presence absence oxygen, behavior that is...
Bacteria have a remarkable ability to survive, persist, and ultimately adapt environmental challenges. A ubiquitous hazard is DNA damage, most bacteria evolved network of genes combat genotoxic stress.
Streptococcal pyrogenic exotoxin A (SPE A) is secreted by some strains of Streptococcus pyogenes and strongly associated with streptococcal toxic shock syndrome (STSS), a severe often fatal illness. SPE possesses number biological properties, which are shared group exotoxins staphylococcal origins, the toxin superantigens (PTSAgs). A's most extensively studied property superantigenicity. Superantigenic activation T cells monocytes stimulates release cytokines such as tumor necrosis factors...
Previous studies have shown that exponentially growing Escherichia coli can detect mild acidity (~pH 5.5) and, in response, synthesize enzymes protect against severe acid shock. This adaptation is controlled by the EvgS/EvgA phosphorelay, a signal transduction system present virtually every E. isolate whose genome has been sequenced. Here we show that, despite this high level of conservation, displays surprising natural variation pH-sensing capacity, with some strains entirely non-responsive...
Abstract The streptococcal pyrogenic toxins A, B, and C (SPEA, SPEB, SPEC) are responsible for the fever, rash, other toxicities associated with scarlet fever toxic shock syndrome. This role, together ubiquity of diseases caused by Streptococcus pyogenes , have prompted structural analyses SPEA several groups. Papageorgiou et al. (1999) recently reported structure crystallized in absence zinc. Zinc has been shown to be important ability some staphylococcal stimulate proliferation CD4 +...
Colicins are specific and potent toxins produced by Enterobacteriaceae that result in the rapid elimination of sensitive cells. Colicin production is commonly found throughout microbial populations, suggesting its potential importance for bacterial survival complex environments. Nonetheless, as colicin biology has been predominately studied using synthetic models, it remains unclear how contributes to fitness a colicin-producing commensal strain natural environment. To address this gap, we...