This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Traveller’s diarrhoea is most commonly caused by 
Select and explain. 
A. ETEC, B. S. dysenteriae, C. EPEC, D. Salmonella
A: ETEC
Answer: A: ETEC 
Explanation: Five types of E.coli include:
1. ETEC (enterotoxogenic E.coli)
2. EIEC (enteroinvasive E.coli)
3. EPEC (enteropathogenic E.coli)
4. EHEC (enterohemorrhagic E.coli)
5. EAEC (enteroaggregative E.coli) 
Traveller's diarrhoea is most commonly caused by enterotoxogenic E.coli and then the other common organism responsible is S. dysenteriae. Intestinal Pathogenic E. Coli.