RevoDx Diarrheagenic Escherichia coli (DEC) Detection Kit

Diarrheagenic Escherichia coli (DEC) refers to a group of E. coli strains that are pathogenic to humans and cause diarrhea. These strains have evolved various virulence factors enabling them to infect the gastrointestinal tract, leading to different forms of diarrhea. Diagnosing Diarrheagenic Escherichia coli (DEC) is fundamental for effective patient management, outbreak control, public health surveillance, and efficient use of healthcare resources. Accurate and timely diagnosis allows for targeted treatment, appropriate public health responses, and the implementation of preventive measures to reduce the burden of diarrheal diseases. Enteroaggregative Escherichia coli (EAEC) adheres to the intestinal mucosa in a stacked-brick formation and produces toxins and other virulence factors that cause prolonged watery diarrhea. EAEC strains typically harbor a large virulence plasmid called pAA, which carries several essential genes that contribute to the virulence of EAEC: aggR encodes the AggR transcriptional activator, a master regulator that controls the expression of multiple virulence genes on the pAA plasmid and the bacterial chromosome. AggR regulates the expression of fimbriae, dispersin, and other factors necessary for the characteristic “stacked-brick” adhesion of EAEC to intestinal epithelial cells. aatA is part of the aat operon, encoding the AatA transporter protein involved in exporting the dispersin protein to the bacterial surface. Dispersin helps EAEC disperse within the mucous layer, preventing clumping and facilitating effective colonization and biofilm formation. Enteropathogenic Escherichia coli (EPEC) adheres to the intestinal epithelium, causing characteristic lesions known as attaching and effacing (A/E) lesions. These disrupt the intestinal surface, leading to malabsorption and diarrhea. Typical and atypical EPEC carry the locus of enterocyte effacement (LEE) which contains eae, the gene that encodes intimin. The eae gene, encoding the Intimin protein, is central to the pathogenic mechanism of Enteropathogenic Escherichia coli (EPEC) and is a crucial target for diagnosis and understanding the biology of this significant diarrheal pathogen. Shiga toxin-producing Escherichia coli (STEC) is a group of pathogenic E. coli* strains that can cause a range of gastrointestinal illnesses, from mild diarrhea to severe, life-threatening conditions like hemorrhagic colitis and hemolytic uremic syndrome (HUS). The key factor in STEC pathogenicity is the production of Shiga toxins, which are responsible for the severe symptoms and complications associated with these infections. Shiga toxin-producing E. Coli (STEC) strains produce one or both of the two major types of Shiga toxins, designated Stx1 and Stx2. Shiga toxin-producing Escherichia coli (STEC) O157:H7 is a pathogenic strain of E. coli that is known for causing severe gastrointestinal illness. It is one of the most well-known and studied serotypes of STEC due to its association with outbreaks of foodborne illness and its potential to cause severe complications. Diagnostic and preventive measures focus on detecting the pathogen in food and stool samples, ensuring food safety, and managing outbreaks effectively. Enteroinvasive Escherichia coli (EIEC) is a type of diarrheagenic E. coli that is closely related to Shigella species, both genetically and functionally. EIEC causes disease by invading and multiplying within the epithelial cells of the colon, leading to an inflammatory response that results in diarrhea, which can be watery or dysenteric (bloody). The ial gene, also known as the “invasion-associated locus” gene, is an important genetic marker used to differentiate Enteroinvasive Escherichia coli (EIEC) from other types of E. coli. The ial gene is located on the large virulence plasmid (pINV), which is essential for the invasive properties of both EIEC and Shigella. The detection of both the ial and stx genes in a clinical sample would indeed prompt a diagnosis of Shigella dysenteriae type 1. This combination of genes is characteristic of this specific pathogen, which is known for its invasive properties and the production of Shiga toxin, leading to severe dysenteric illness. Enterotoxigenic Escherichia coli (ETEC) is a significant cause of diarrhea, particularly in developing countries and among travelers to these regions. ETEC is one of the six recognized pathotypes of diarrheagenic E. coli and is distinguished by its ability to produce enterotoxins that lead to intestinal fluid secretion and diarrhea. Enterotoxigenic Escherichia coli (ETEC) is known for producing two main types of enterotoxins: heat-labile toxin (LT) and heat-stable toxin (ST). These toxins are key virulence factors that lead to the watery diarrhea characteristic of ETEC infections.

Intended Use

RevoDx Diarrheagenic Escherichia coli (DEC) Detection Kit is a real-time PCR test intended for the qualitative detection and identification of nucleic acids of the Diarrheagenic Escherichia coli (DEC) strains from stool and rectal swab specimens from individuals with signs and/or symptoms of gastrointestinal infection.