Which Enterobacteriaceae is known for causing traveler's diarrhea?

• A. Salmonella enterica
• B. Escherichia coli O157:H7
• C. Shigella flexneri
• D. Enterotoxigenic Escherichia coli (ETEC)

Answer: (D)

Enterotoxigenic Escherichia coli (ETEC) is the correct answer as it is the primary causative agent of traveler's diarrhea, which commonly occurs in individuals traveling to areas with poor sanitation and hygiene conditions. ETEC typically produces specific enterotoxins, such as heat-labile toxin (LT) and heat-stable toxin (ST), that lead to the watery diarrhea associated with the infection. The important characteristics of ETEC include its ability to adhere to intestinal mucosa and its secretion of toxins that disrupt normal intestinal function, resulting in diarrhea.

While Salmonella enterica, Escherichia coli O157:H7, and Shigella flexneri are also notable pathogens within the Enterobacteriaceae family, they are generally associated with different types of gastrointestinal illness. Salmonella enterica is more commonly linked to foodborne infections, particularly from contaminated poultry or eggs, and causes symptoms like fever and abdominal cramps. Escherichia coli O157:H7 is associated with severe, often bloody diarrhea and can lead to more severe complications like hemolytic-uremic syndrome, typically following the consumption of undercooked ground beef or unpasteurized products. Shigella flexneri causes bacillary dysentery