A5016550228- Escherichia coli research studies
- Burkholderia infections and melioidosis
- Viral gastroenteritis research and epidemiology
- Bacterial Genetics and Biotechnology
- Antibiotic Resistance in Bacteria
- Bacteriophages and microbial interactions
- Probiotics and Fermented Foods
- Clostridium difficile and Clostridium perfringens research
- Chemical Looping and Thermochemical Processes
- Vibrio bacteria research studies
- Odor and Emission Control Technologies
- Gut microbiota and health
- Salmonella and Campylobacter epidemiology
- Quantum Computing Algorithms and Architecture
- Enterobacteriaceae and Cronobacter Research
- Quantum Information and Cryptography
- Brucella: diagnosis, epidemiology, treatment
- Insect symbiosis and bacterial influences
- Effects of Environmental Stressors on Livestock
- Bacterial biofilms and quorum sensing
- Advancements in Semiconductor Devices and Circuit Design
- Agriculture Sustainability and Environmental Impact
- Vehicle emissions and performance
- Meat and Animal Product Quality
- Subcritical and Supercritical Water Processes
The University of Texas Medical Branch at Galveston
2015-2024
Google (United States)
2023-2024
Galveston College
2012-2024
John Sealy Hospital
2007-2023
University of Tolima
2022
GTx (United States)
2016
Bipar
2006-2015
Ipsos (Brazil)
2014
Hospital Alemán
2013
Universitat Politècnica de València
1970-2011
The interbacterial communication system known as quorum sensing (QS) utilizes hormone-like compounds referred to autoinducers regulate bacterial gene expression. Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is the agent responsible for outbreaks of bloody diarrhea in several countries. We previously proposed that EHEC uses a QS regulatory “sense” it within intestine and activate genes essential intestinal colonization. used by LuxS/autoinducer 2 (AI-2) extensively involved...
Summary Quorum sensing is a cell‐to‐cell signalling mechanism in which bacteria secrete hormone‐like compounds called autoinducers. When these auto‐inducers reach certain threshold concentration, they interact with bacterial transcriptional regulators, thereby regulating gene expression. Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 as well E. K‐12 produces the autoinducer‐2 (AI‐2), synthesized by product of luxS gene, and previous work from our laboratory has shown that genes encoding...
ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is responsible for outbreaks of bloody diarrhea and hemolytic-uremic syndrome in many countries. EHEC virulence mechanisms include the production Shiga toxins (Stx) formation attaching effacing (AE) lesions on intestinal epithelial cells. We recently reported that genes involved AE lesion were regulated by quorum sensing through autoinducer-2, which synthesized product luxS gene. In this study we hybridized an E. gene array with cDNA...
Summary Enteropathogenic Escherichia coli (EPEC) utilizes a type III protein secretion system to target effector molecules into the host cell leading effacement of intestinal mucosa. This apparatus shares many structural features flagellar export involved in flagella assembly and motility. We report here that fliC insertional mutants constructed two wild‐type EPEC strains were markedly impaired adherence microcolony formation on cultured cells. An E. K‐12 strain harbouring H6 gene plasmid...
ABSTRACT The uropathogenic Escherichia coli strain CFT073 has multiple iron acquisition systems, including heme and siderophore transporters. A tonB mutant derivative of failed to use as an source or utilize the siderophores enterobactin aerobactin, indicating that transport these compounds in is TonB dependent. − showed reduced virulence a mouse model urinary tract infection. Virulence was restored when gene introduced on plasmid. To determine importance individual TonB-dependent systems...
In this study, we identified the iron-transport systems of Escherichia coli O157:H7 strain EDL933. This synthesized and transported enterobactin had a ferric citrate transport system but lacked ability to produce or use aerobactin. It used haem haemoglobin, not transferrin lactoferrin, as iron sources. We cloned gene encoding an iron-regulated haem-transport protein showed that E. haem-utilization (chuA) encoded 69 kDa outer membrane was in response limitation. Expression laboratory...
The mechanisms underlying the adherence of Escherichia coli O157:H7 and other enterohemorrhagic E. (EHEC) strains to intestinal epithelial cells are poorly understood. We have identified a chromosomal region (designated lpfABCC'DE) in EHEC containing six putative open reading frames that was found be closely related long polar (LP) fimbria operon (lpf) Salmonella enterica serovar Typhimurium, both gene order conservation deduced amino acid sequences. show lpfABCC'DE is organized as an its...
Abstract Background Adherent and invasive Escherichia coli (AIEC) are commonly found in ileal lesions of Crohn's Disease (CD) patients, where they adhere to intestinal epithelial cells invade into survive macrophages, thereby gaining access a typically restricted host niche. Colonization leads strong inflammatory responses the gut suggesting that AIEC could play role CD immunopathology. Despite extensive investigation, genetic determinants accounting for phenotype remain poorly defined. To...
Bacterial pathogens sense host cues to activate expression of virulence genes. Most these signals are sensed through histidine kinases (HKs), which comprise the main sensory mechanism in bacteria. The stress hormones epinephrine (Epi) and norepinephrine QseC HK, initiates a complex signaling cascade regulate gene enterohemorrhagic Escherichia coli (EHEC). Epi activates genes encoding QseEF 2-component system. QseE is an QseF response regulator. Here, we show that second bacterial adrenergic...
Riboflavin, the precursor for cofactors flavin mononucleotide (FMN) and adenine dinucleotide, is an essential metabolite in all organisms. While functions de novo riboflavin biosynthesis import may coexist bacteria, extent of this co-occurrence undetermined. The RibM, RibN, RfuABCD energy-coupling factor-RibU bacterial transporters have been experimentally characterized. In addition, ImpX, RfnT RibXY are proposed as based on positional clustering with biosynthetic pathway (RBP) genes or...
We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device matched to 50 Ω environment with Klopfenstein-taper impedance transformer and achieves bandwidth 250–300 MHz input saturation powers up −95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used benchmark these devices, providing calibration for readout power, estimation added noise, platform comparison against standard...
ABSTRACT Adherence of enterohemorrhagic Escherichia coli (EHEC) to the intestinal epithelium is essential for initiation infection. Intimin only factor demonstrated play a role in colonization by EHEC O157:H7. Other attempts identify additional adhesion factors vitro have been unsuccessful, suggesting that expression these under tight regulation. We sought genes involved control adherence O157:H7 cultured epithelial cells. A total 5,000 independent transposon insertion mutants were screened...
Summary Escherichia coli O157:H7 causes diarrhoea, haemorrhagic colitis, and the haemolytic uraemic syndrome. We have identified a protein of previously unknown function encoded on pO157 virulence plasmid E. O157:H7, which is first described protease that specifically cleaves C1 esterase inhibitor (C1‐INH), member serine family. The protein, named StcE for s ecreted pro t ease C 1 from E HEC (formerly Tagn), C1‐INH to produce (unique) ≈ 60–65 kDa fragments. does not digest other inhibitors,...
Genes encoding the synthesis and transport of aerobactin, a hydroxamate siderophore associated with increased virulence enteric bacteria, were mapped within pathogenicity island in Shigella flexneri . The island, designated SHI‐2 for 2, was located downstream selC , site insertion islands several other pathogens. DNA sequence analysis revealed presence multiple sequences upstream aerobactin genes an integrase gene that nearly identical to int found Escherichia coli O157:H7. adjacent similar...
ABSTRACT The type III secretion system (TTSS) of enteropathogenic Escherichia coli (EPEC) has been associated with the ability these bacteria to induce proinflammatory cytokines, including interleukin-8 (IL-8), in cultured epithelial cells. However, identity effector molecule directly involved this event is unknown. In study, we determined that native flagellar filament and its flagellin monomer are activators IL-8 release T84 Supernatants wild-type EPEC strain E2348/69 isogenic mutants...
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is responsible for worldwide outbreaks of bloody diarrhea, hemorrhagic colitis, and life-threatening hemolytic uremic syndrome. After colonizing the large intestine, EHEC forms attaching effacing (AE) lesions on intestinal epithelial cells. These cause destruction microvilli elicit actin rearrangement to form pedestals that cup each bacterium individually. responds a signal produced by microbial flora, autoinducer-3 (AI-3), host hormones...