Which pathogen is primarily associated with hemolytic uremic syndrome (HUS)?

Hemolytic uremic syndrome (HUS) is most commonly associated with infection from Escherichia coli O157:H7, a specific strain of E. coli. This pathogenic strain produces Shiga toxin, which can lead to severe gastrointestinal illness and, subsequently, to HUS, particularly in children and immunocompromised individuals. The toxin damages the endothelial cells of blood vessels, triggering a cascade of events that results in the hemolytic anemia, acute kidney injury, and thrombocytopenia characteristic of HUS.

Understanding the context of HUS helps clarify the association with E. coli O157:H7, as this strain is often linked to outbreaks from contaminated food, particularly undercooked ground beef or unpasteurized products. In contrast, other pathogens listed, such as Staphylococcus aureus, Salmonella enterica, and Clostridium difficile, are associated with different types of infections and complications but do not typically lead to the development of HUS. Each of these other bacteria possesses distinct pathogenic mechanisms and clinical presentations that do not overlap with the mechanisms that cause HUS. Therefore, E. coli O157:H7’s unique role and toxic profile make it the primary pathogen associated with this condition.