Which organism is commonly associated with preceding gastroenteritis in Guillain-Barré syndrome?

• A. Campylobacter jejuni
• B. Escherichia coli
• C. Staphylococcus aureus
• D. Salmonella enterica

Answer: (A)

Guillain-Barré syndrome is an acute immune-mediated attack on the peripheral nerves that often follows an infection. The body’s immune response to certain pathogens can cross-react with nerve components (molecular mimicry), leading to demyelination or axonal damage. Among infections that precede GBS, Campylobacter jejuni is the most classically linked cause of preceding gastroenteritis. This organism is strongly associated with GBS and is notably tied to the axonal variants of the syndrome through antibodies against nerve gangliosides.

Other gastroenteritis-causing organisms, such as certain strains of E. coli or Salmonella, can precede GBS but are not as consistently linked as Campylobacter jejuni. Staphylococcus aureus is not a typical antecedent trigger for GBS.

So, the best fit is Campylobacter jejuni because it is the classic preceding infection associated with Guillain-Barré syndrome.