In Vitro and In Vivo Testing of Microbe Growth on Antimicrobial Nursing Scrubs.

Around 5% to 10% of hospitalized patients develop a hospital-acquired infection (HAI). Scrubs are a potential vector of HAIs. To compare the antimicrobial characteristics of scrubs with and without an antimicrobial fabric coating, as tested in the laboratory (in vitro) and hospital (in vivo) environments.

Stress Responses in Pathogenic Vibrios and Their Role in Host and Environmental Survival.

Vibrio is a genus of bacteria commonly found in estuarine, marine, and freshwater environments. Vibrio species have evolved to occupy diverse niches in the aquatic ecosystem, with some having complex lifestyles. About a dozen of the described Vibrio species have been reported to cause human disease, while many other species cause disease in other organisms.

Characterization of Vibrio cholerae isolates from freshwater sources in northwest Ohio.

Vibrio cholerae is a natural inhabitant of aquatic ecosystems worldwide, typically residing in coastal or brackish water. While more than 200 serogroups have been identified, only serogroups O1 and O139 have been associated with epidemic cholera. However, infections other than cholera can be caused by nonepidemic, non-O1/non-O139 V.

Regulated Proteolysis in Allowing Rapid Adaptation to Stress Conditions.

The lifecycle of the causative agent of the severe secretory diarrheal disease cholera, , is characterized by the transition between two dissimilar habitats, i.e., as a natural inhabitant of aquatic ecosystems and as a pathogen in the human gastrointestinal tract.

Characterization of the Vibrio cholerae Phage Shock Protein Response.

The phage shock protein (Psp) system is a stress response pathway that senses and responds to inner membrane damage. The genetic components of the Psp system are present in several clinically relevant Gram-negative bacteria, including However, most of the current knowledge about the Psp response stems from studies in and In fact, the Psp response in has remained completely uncharacterized. In this study, we demonstrate that does have a functional Psp response system.

A Periplasmic Antimicrobial Peptide-Binding Protein Is Required for Stress Survival in .

must sense and respond appropriately to stresses encountered in the aquatic environment and the human host. One stress encountered in both environments is exposure to antimicrobial peptides (AMPs), produced as a part of the innate immune response by all multicellular organisms. Previous transcriptomic analysis demonstrated that expression of Stress-inducible protein A (SipA) (VCA0732), a hypothetical protein, was highly induced by AMP exposure and was dependent on a specific uncharacterized two-component system.

Genome Sequence of Vibrio cholerae Strain D1, Isolated from the Maumee River in Toledo, Ohio.

Vibrio cholerae is a human bacterial pathogen and an inhabitant of aquatic environments. It is endemic to many regions of the world but is typically found in warm climates in saltwater. Here, we present the sequence of a V.

Vibrio responses to extracytoplasmic stress.

A critical factor for bacterial survival in any environment is the ability to sense and respond appropriately to any stresses encountered. This is especially important for bacteria that inhabit environments that are constantly changing, or for those that inhabit more than one biological niche. Vibrio species are unique in that they are aquatic organisms, and must adapt to ever-changing temperatures, salinity levels and nutrient concentrations.

Infant Mouse Model of Vibrio cholerae Infection and Colonization.

Cholera is an epidemic diarrheal disease caused by Vibrio cholerae that continues to cause significant morbidity and mortality in many parts of the world. Several different animal models have been used by scientists over the years to study the pathogenesis of cholera. However, the most commonly used is the infant (suckling) mouse model, which has been found to replicate important aspects of human intestinal colonization.

Random Transposon Mutagenesis of Vibrio cholerae.

Transposon-based random mutagenesis of bacterial genomes has proven to be a powerful genetic tool for the identification of genes and regulatory elements that contribute to specific phenotypes. One such approach that has been used in Vibrio cholerae for many years is the introduction of mariner transposons to generate random libraries of mutants. These libraries have been successfully used for a wide variety of genetic screens and selections in this important bacterial pathogen.

Preparation of Vibrio cholerae Samples for RNA-seq Analysis.

Massively parallel cDNA sequencing (RNA-seq) is a powerful tool for providing an unbiased approach to assess transcript abundance under a variety of conditions. In comparison to microarrays, this technique provides increased resolution and sensitivity and the ability to identify rare transcripts and sRNAs. Here, we describe the sample preparation (based on Illumina technology) used for transcriptomic analysis of V.

RAIL: A new tool for defining bacterial promoter regions.

In this issue of the , Hustmyer and colleagues describe a new method for rapidly generating reporter libraries (Hustmyer citation). This RAIL technique (apid rbitrary PCR nsertion ibraries) uses arbitrary PCR and isothermal DNA assembly to insert random fragments of promoter regions into reporter plasmids, resulting in libraries that can be screened to identify regions required for gene expression. This technique will likely be useful for a number of different genetic applications.

Sterilization of Biofilm on a Titanium Surface Using a Combination of Nonthermal Plasma and Chlorhexidine Digluconate.

Nosocomial infections caused by opportunistic bacteria pose major healthcare problem worldwide. Out of the many microorganisms responsible for such infections, is a ubiquitous bacterium that accounts for 10-20% of hospital-acquired infections. These infections have mortality rates ranging from 18 to 60% and the cost of treatment ranges from $20,000 to $80,000 per infection.

Assay development and high-throughput screening for small molecule inhibitors of a stress response pathway.

Antibiotics are important adjuncts to oral rehydration therapy in cholera disease management. However, due to the rapid emergence of resistance to the antibiotics used to treat cholera, therapeutic options are becoming limited. Therefore, there is a critical need to develop additional therapeutics to aid in the treatment of cholera.

A putative Vibrio cholerae two-component system controls a conserved periplasmic protein in response to the antimicrobial peptide polymyxin B.

The epidemic pathogen Vibrio cholerae senses and responds to different external stresses it encounters in the aquatic environment and in the human host. One stress that V. cholerae encounters in the host is exposure to antimicrobial peptides on mucosal surfaces.

Evolution of a global regulator: Lrp in four orders of γ-Proteobacteria.

Background: Bacterial global regulators each regulate the expression of several hundred genes. In Escherichia coli, the top seven global regulators together control over half of all genes. Leucine-responsive regulatory protein (Lrp) is one of these top seven global regulators.

Regulated intramembrane proteolysis of the virulence activator TcpP in Vibrio cholerae is initiated by the tail-specific protease (Tsp).

Vibrio cholerae uses a multiprotein transcriptional regulatory cascade to control expression of virulence factors cholera toxin and toxin-co-regulated pilus. Two proteins in this cascade are ToxR and TcpP - unusual membrane-localized transcription factors with relatively undefined periplasmic domains and transcription activator cytoplasmic domains. TcpP and ToxR function with each other and two other membrane-localized proteins, TcpH and ToxS, to activate transcription of toxT, encoding the direct activator of toxin and pilus genes.

Single-molecule tracking in live Vibrio cholerae reveals that ToxR recruits the membrane-bound virulence regulator TcpP to the toxT promoter.

Vibrio cholerae causes the human disease cholera by producing a potent toxin. The V. cholerae virulence pathway involves an unusual transcription step: the bitopic inner-membrane proteins TcpP and ToxR activate toxT transcription.

Genome Sequence of Klebsiella pneumoniae Respiratory Isolate IA565.

Klebsiella pneumoniae is a clinically significant opportunistic bacterial pathogen as well as a normal member of the human microbiota. K. pneumoniae strain IA565 was isolated from a tracheal aspirate at the University of Iowa Hospitals and Clinics.

Imaging live cells at the nanometer-scale with single-molecule microscopy: obstacles and achievements in experiment optimization for microbiology.

Single-molecule fluorescence microscopy enables biological investigations inside living cells to achieve millisecond- and nanometer-scale resolution. Although single-molecule-based methods are becoming increasingly accessible to non-experts, optimizing new single-molecule experiments can be challenging, in particular when super-resolution imaging and tracking are applied to live cells. In this review, we summarize common obstacles to live-cell single-molecule microscopy and describe the methods we have developed and applied to overcome these challenges in live bacteria.

Genome Sequence of Klebsiella pneumoniae Urinary Tract Isolate Top52.

Klebsiella pneumoniae is a significant cause of nosocomial infections, including ventilator-associated pneumonias and catheter-associated urinary tract infections. K. pneumoniae strain TOP52 #1721 (Top52) was isolated from a woman presenting with acute cystitis and subsequently characterized using various murine models of infection.

Polymyxin B resistance in El Tor Vibrio cholerae requires lipid acylation catalyzed by MsbB.

Antimicrobial peptides are critical for innate antibacterial defense. Both Gram-negative and Gram-positive microbes have mechanisms to alter their surfaces and resist killing by antimicrobial peptides. In Vibrio cholerae, two natural epidemic biotypes, classical and El Tor, exhibit distinct phenotypes with respect to sensitivity to the peptide antibiotic polymyxin B: classical strains are sensitive and El Tor strains are relatively resistant.

LcrG secretion is not required for blocking of Yops secretion in Yersinia pestis.

Background: LcrG, a negative regulator of the Yersinia type III secretion apparatus has been shown to be primarily a cytoplasmic protein, but is secreted at least in Y. pestis. LcrG secretion has not been functionally analyzed and the relevance of LcrG secretion on LcrG function is unknown.

Degradation of the membrane-localized virulence activator TcpP by the YaeL protease in Vibrio cholerae.

A common mechanism inhibiting the activity of transcription factors is their sequestration to the membrane until they are needed, at which point they are released from the membrane by proteolysis. Acting in contrast to this inhibition mechanism are virulence regulators of Vibrio cholerae, the ToxR and TcpP proteins, which are localized to the inner membrane of the cell, where they bind promoter DNA and activate gene expression. TcpP is rapidly degraded in the absence of another protein, TcpH.