Which infectious diarrhea pathogen is most commonly acquired from eating undercooked beef?

Escherichia coli, particularly certain strains such as Enterohemorrhagic E. coli (EHEC) or O157:H7, is commonly associated with outbreaks of infectious diarrhea linked to undercooked beef. This pathogenic strain can lead to severe gastrointestinal symptoms, including bloody diarrhea and abdominal cramps. The bacteria can be present in the intestines of cattle and contaminate beef products during processing if proper cooking temperatures are not achieved.

When considering the other options, while Yersinia can cause gastroenteritis and is sometimes associated with undercooked pork or beef, it is less prevalent as a foodborne pathogen in comparison to E. coli. Giardia lamblia is primarily linked to contaminated water sources rather than meat. Salmonella is another well-known pathogen often found in poultry and eggs, although it can be associated with beef as well; however, it does not have the same specific association with undercooked beef as E. coli does. Therefore, the correlation between E. coli and undercooked beef stands out as particularly significant, leading to its identification as the correct answer.