A Quantitative Enzyme-Linked Immunosorbent Assay for Shiga Toxin 2a Requiring Only Commercially Available Reagents.
Shiga toxin (Stx)-producing Escherichia coli (STEC) cause gastrointestinal diseases such as
Hemorrhagic colitis (HC), and in some cases this develops into the life-threatening hemolytic uremic syndrome (HUS). Foodborne pathogen, E. coli O157:H7, is a genetically heterogeneous serotype of STEC. Consumption of as low as ten cells of O157:H7 derived from contaminated bovine origin foods such as beef and cheese, people may develop symptoms ranging from asymptomatic carriage, bloody diarrhea, to fatal HUS. It has been estimated to cause 73,000 illnesses and 60 deaths annually in United States (US), with an estimated economic loss of about 400 million dollars. This pathogen continues to cause most of known outbreaks across the globe.
Therefore, the US Department of Agriculture (USDA) has enforced a “zero tolerance policy” to regulate the prevalence of O157:H7 in foods. Genetic methods, most commonly the lineage specific
polymorphism assay (LSPA) and clade typing, have been used to separate O157:H7 strains by virulence potential and ecology.
For example, human isolates are more commonly classified as
lineage I and I/II than lineage II, and it has been argued that isolates from clades 6 and 8 are more virulent than isolates from other clades. However, we could accomplish this using the Premier EHEC kit sold by Meridian Biosciences, Cincinnati, OH, USA. We also found that our assay was one tenth less sensitive than the commercial kit for mouse feces.
Adv Food Technol Nutr Sci Open J. 2017; 3(1): 6-14. doi: 10.17140/AFTNSOJ-3-139