A5089121517- Escherichia coli research studies
- Bacterial Genetics and Biotechnology
- Viral gastroenteritis research and epidemiology
- Probiotics and Fermented Foods
- Bacteriophages and microbial interactions
- Antibiotic Resistance in Bacteria
- Vibrio bacteria research studies
- Clostridium difficile and Clostridium perfringens research
- Gut microbiota and health
- Salmonella and Campylobacter epidemiology
- Enterobacteriaceae and Cronobacter Research
- Urinary Tract Infections Management
- Infant Nutrition and Health
- Antimicrobial Resistance in Staphylococcus
- RNA and protein synthesis mechanisms
- Bacterial biofilms and quorum sensing
- Barrier Structure and Function Studies
- Nosocomial Infections in ICU
- Biochemical and Structural Characterization
- Genetic factors in colorectal cancer
- Listeria monocytogenes in Food Safety
- Helicobacter pylori-related gastroenterology studies
- Cancer Research and Treatments
- Plant Ecology and Taxonomy Studies
- Diphtheria, Corynebacterium, and Tetanus
Virginia Commonwealth University
2020-2025
Virginia Commonwealth University Medical Center
2024
University of Maryland, Baltimore
2009-2020
University of Maryland Medical Center
2016
University of Baltimore
2012
Office of Infectious Diseases
1998-2012
University of Maryland, College Park
2009
Universidade Federal de São Paulo
2005
Emory University
2005
University of Wisconsin–Madison
2002
We present the complete genome sequence of uropathogenic Escherichia coli , strain CFT073. A three-way comparison CFT073, enterohemorrhagic E. EDL933, and laboratory MG1655 reveals that, amazingly, only 39.2% their combined (nonredundant) set proteins actually are common to all three strains. The pathogen genomes as different from each other is benign strain. difference in disease potential between O157:H7 CFT073 reflected absence genes for type III secretion system or phage- plasmid-encoded...
Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. O157:H7 are intestinal pathogens that profoundly damage the microvilli subapical cytoskeleton of epithelial cells. Here we report finding in EPEC a 35-kbp locus containing several regions implicated formation these lesions. DNA probes throughout this hybridize to other three genera cause similar lesions but do not avirulent members same species. The different virulence uropathogenic insert into chromosome at identical site...
The ability to attach epithelial cells, efface the microvillus surface, and disrupt underlying cytoskeleton is characteristic of enteropathogenic Escherichia coli (EPEC). Recently, eae, a gene necessary for this phenomenon, was described (A. E. Jerse, J. Yu, B. D. Tall, Kaper, Proc. Natl. Acad. Sci. USA 87:7839-7843, 1990). We report use novel suicide vector containing pir-dependent R6K replicon sacB Bacillus subtilis construct an eae deletion mutant EPEC. This system enables positive...
Enteropathogenic Escherichia coli (EPEC) are an important aetiological agent in infant diarrhoea and the prototype for a family of pathogens exhibiting unique virulence mechanism known as attaching effacing (AE) (Nataro Kaper, 1998). All genes necessary AE encoded on 35 kb chromosomal pathogenicity island called locus enterocyte effacement (LEE), which contains encoding type III secretion system, secreted proteins (Esp) adhesin intimin (McDaniel et al., 1995; McDaniel 1997). Study LEE will...
Enteropathogenic Escherichia coli (EPEC) causes a characteristic histopathology in intestinal epithelial cells called the attaching and effacing lesion. Although histopathological lesion is well described bacterial factors responsible for it are poorly characterized. We have identified four EPEC chromosomal genes whose predicted protein sequences similar to components of recently secretory pathway (type III) exporting proteins lacking typical signal sequence. designated sepA, sepB, sepC,...
ABSTRACT We report the complete 43,359-bp sequence of locus enterocyte effacement (LEE) from EDL933, an enterohemorrhagic Escherichia coli O157:H7 serovar originally isolated contaminated hamburger implicated in outbreak hemorrhagic colitis. The was EDL933 chromosome with a homologous-recombination-driven targeting vector. Recent completion LEE enteropathogenic E. (EPEC) E2348/69 afforded opportunity for comparative analysis entire pathogenicity island. have identified total 54 open reading...
ABSTRACT A uropathogenic Escherichia coli strain CFT073-specific DNA microarray that includes each open reading frame was used to analyze the transcriptome of CFT073 bacteria isolated directly from urine infected CBA/J mice. The in vivo expression profiles were compared E. grown statically exponential phase rich medium, revealing strategies this pathogen uses for colonization, growth, and survival urinary tract environment. most highly expressed genes overall encoded translational machinery,...
The eaeA gene of enteropathogenic Escherichia coli (EPEC) is necessary for intimate attachment to epithelial cells in vitro.Enterohemorrhagic E. (EHEC) strains also possess an eac and are capable microvillus effacement vitro animal models.To assess the role EHEC eae attachment, we constructed deletion/insertion mutation wild-type 0157:H7 strain 86-24 by using linear electroporation a recombinant allele.The mutant obtained was deficient inducing f-actin accumulation HEp-2 incapable attaching...
Enteropathogenic Escherichia coli (EPEC) is the prototype organism of a group pathogenic Gram‐negative bacteria that cause attaching and effacing (AE) intestinal lesions. All EPEC genes necessary for AE phenotype are encoded within 35.6 kb pathogenicity island termed locus enterocyte effacement (LEE). The LEE encodes 41 predicted open reading frames (ORFs), including components type III secretion apparatus secreted molecules involved in disruption host cell cytoskeleton. To initiate our...
Enteropathogenic Escherichia coli (EPEC) infections are a leading cause of infant diarrhea in developing countries. Recently eaeA, gene necessary for the characteristic intimate attachment EPEC to epithelial cells tissue culture, was described. We conducted randomized, double-blind study determine role eaeA human infection. 11 adult volunteers ingested 2 x 10(10) colony-forming units O127:H6 strain E2348/69, and an equal number received same dose isogenic deletion mutant constructed from...
The mechanisms by which enteropathogenic Escherichia coli (EPEC), an important cause of diarrhea among infants in developing countries, induce symptoms are not defined. EPEC have a type III secretion system required for characteristic attaching and effacing changes that modify the cytoskeleton apical surface host cells. Infection polarized intestinal epithelial cell monolayers leads to loss transepithelial electrical resistance, also requires system. We demonstrate here EspF, protein is...
Enteropathogenic Escherichia coli (EPEC) is capable of attaching intimately to epithelial cells and effacing their microvilli. A chromosomal locus, eaeA (originally eae), required for the intimate attachment aspect this effect. We report mapping a region EPEC chromosome that located immediately downstream gene also necessary attachment. An isogenic in-frame deletion mutation in one open reading frames identified was engineered. Because resulting mutant, like an deficient ability attach...
Summary Enteropathogenic Escherichia coli (EPEC) form adherent microcolonies on the surface of tissue culture cells in a pattern termed localized adherence. Localized adherence requires presence large EPEC factor (EAF) plasmid. Recently bundle‐forming pilus has been described possessing EAF An analysis 22 non‐invasive Tn phoA mutants revealed that seven have insertions plasmid and are incapable We report here mapping these mutants. The nucleotide sequence gene interrupted TnphoA ( bfpA ) was...
Summary Enteropathogenic Escherichia coli (EPEC) adhere to epithelial cells in microcolonies, a pattern termed localized adherence (LA). LA is dependent upon the presence of 50–70MDa plasmids, EPEC factor (EAF) plasmids. Expression an EAF plasm id‐encoded type IV fimbria, bundle‐forming pilus (BFP), associated with phenotype. Tn phoA insertions bfpA , gene encoding major structural subunit BFP, abolish LA. While bfpA:: mutants cannot be complemented for by plasmids carrying alone trans this...
Summary Enteropathogenic Escherichia coli (EPEC) is a leading cause of infant diarrhoea. EPEC mediates several effects on host epithelial cells, including activation signal‐transduction pathways, cytoskeletal rearrangement along with pedestal and attachingleffacing lesion formation. It has been previously shown that the eaeB ( espB ) gene encodes secreted protein required for signal transduction adherence, while eaeA intimin, an membrane intimate adherence contributes to focusing proteins...
Summary Escherichia coli is the leading cause of urinary tract infections (UTIs). Despite association numerous bacterial factors with uropathogenic E. (UPEC), few such have been proved to be required for UTI in animal models. Previous investigations urovirulence relied on prior identification phenotypic characteristics. We used signature‐tagged mutagenesis (STM) an unbiased effort identify genes that are essential UPEC survival within murine tract. A library 2049 transposon mutants...
Enteropathogenic Escherichia coli (EPEC), an important paediatric diarrhoeal pathogen, employs multiple adhesins to colonize the small bowel and produces characteristic ‘attaching effacing’ (A/E) lesions on intestinal enterocytes. EPEC that have been associated with A/E adhesion colonization include bundle-forming pili (BFP), EspA filaments intimin. BFP are involved in bacteria–bacteria interaction microcolony formation but their role cell remains unclear; components of type III secretion...
We reported previously that mutation of the chromosomal gene eaeA from enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 prevented bacterial attachment in vivo. Attachment was restored when EHEC or enteropathogenic E. (EPEC) introduced into mutant on a plasmid. In this communication we have compared gnotobiotic piglets pathogenicities wild-type strain 86-24 and its UMD619 with those two plasmid-complemented strains expressing IntiminO157 IntiminO127 (EPEC). colonized surface...
The cytoskeletal lesions associated with enteropathogenic Escherichia coli adhering to cultured HeLa epithelial cells were examined by immunofluorescence microscopy. microfilament-associated proteins actin, alpha-actinin, talin, and ezrin localized adherent E. coli, whereas tropomyosin, keratin vimentin (intermediate filaments), tubulin (microtubules), vinculin not localized. These structures differed significantly from those Salmonella typhimurium internalization (invasion).
Enteropathogenic Escherichia coli (EPEC) is a causative agent of infant diarrhoea in developing countries. The EspF protein the product espF gene found on locus enterocyte effacement, key pathogenicity island carried by EPEC and enterohemorrhagic E. coli. injected from adherent into host cells via type III secretion system was previously shown to induce apoptotic cell death be required for disruption intestinal barrier function. In this work, we show immunofluorescence fractionation studies...