Urinary tract infection is the most frequently diagnosed kidney and urologic disease, and Escherichia coli is by far the most common etiologic agent. Defined blocks of DNA termed pathogenicity islands have been found in uropathogenic strains to carry genes not generally found in fecal strains. We have identified one of these regions of DNA within the chromosome of the highly virulent E. coli CF...

Vibrio cholerae, a Gram-negative facultative pathogen, is the etiologic agent for the diarrheal disease cholera. We previously characterized a clinical isolate, AM-19226, that translocates a type III secretion system (T3SS) effector protein with actin-nucleating activity, VopF, into the host cells. From comparative genomic studies, we identified a divergent T3SS island in additional isolates wh...

Edwardsiella ictaluri is the leading cause of mortality in channel catfish culture, but little is known about its pathogenesis. The use of signature-tagged mutagenesis in a waterborne infection model resulted in the identification of 50 mutants that were unable to infect/survive in catfish. Nineteen had minitransposon insertions in miscellaneous genes in the chromosome, 10 were in genes that ma...

Upon entry into the host, Salmonella enterica strains are presumed to encounter an iron-restricted environment. Consequently, these bacteria have evolved a variety of often-redundant high-affinity acquisition systems to obtain iron in this restricted environment. We have identified an iron transport system that is encoded within the centisome 63 pathogenicity island of Salmonella typhimurium. T...

A gene encoding a putative AraC-type transcriptional regulator was identified on the 153-kb pathogenicity island (PAI) found among virulent Enterococcus faecalis strains. In an effort to understand the function of this regulator, designated PerA (for pathogenicity island-encoded regulator), we first examined the expression of the perA gene in the original PAI strain MMH594 and in an unrelated c...

Francisella tularensis is one of the most infectious bacteria known and is the etiologic agent of tularemia. Francisella virulence arises from a 33 kilobase (Kb) pathogenicity island (FPI) that is regulated by the macrophage locus protein A (MglA) and the stringent starvation protein A (SspA). These proteins interact with both RNA polymerase (RNAP) and the pathogenicity island gene regulator (P...

1 Junior Investigator, MSc Candidate, Faculty of Science, Microbiology Department, Universidad Javeriana 2 Professor of Microbiology, Medical Microbiology Specialization Director, PhD Candidate, Universidad Javeriana, Faculty of Science, Department of Microbiology 3 Internist, Gastroenterologist, Epidemiologist, Professor of Medicine, Gastroenterology Unit, National University of Colombia. .......

The locus of enterocyte effacement (LEE) is a 35.6 kb pathogenicity island inserted in the genome of some bacteria such as enteropathogenic Escherichia coli, enterohemorrhagic E.coli, Citrobacter rodentium, and Escherichia albertii. LEE comprises the genes responsible for causing attaching and effacing lesions, a characteristic lesion that involves intimate adherence of bacteria to enterocytes,...

The neuraminidase gene, nanH, is present in the O1, non-toxigenic Vibrio cholerae Amazonia strain. Its location has been assigned to a 150 kb NotI DNA fragment, with the use of pulsed-field gel electrophoresis and DNA hybridization. This NotI fragment is positioned inside 630 kb SfiI and 1900 kb I-CeuI fragments of chromosome 1. Association of the pathogenicity island VPI-2, carrying nanH and o...

Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent s...