E. coli (Escherichia coli) Common gut bacterium; most strains harmless, but certain pathotypes cause diarrheal or systemic illness.
stx2 gene Encodes Shiga toxin type 2, one of the two major Shiga toxin variants (stx1 and stx2). Stx2 is more commonly associated with severe human disease.
Mechanism:
Stx2 inhibits protein synthesis in host cells cell death vascular damage, hemorrhagic colitis, and potentially hemolytic uremic syndrome (HUS).
Pathogens carrying stx2:
- STEC (Shiga toxin-producing E. coli) Includes O157:H7 and non-O157 serotypes.
- EHEC (Enterohemorrhagic E. coli) Subset of STEC that also carries eae (intimin gene).
Detection significance:
Presence of stx2 indicates potential for severe disease and is a key target for surveillance in food, clinical, and environmental samples.
