Review Question - QID 106942

The 4-year-old is presenting with gastroenteritis caused by Yersinia enterocolitica, which he most likely contracted from other children at the daycare.

Yersinia enterocolitica is a zoonotic, Gram-negative coccobacillus that is motile at 25 C but not at 37 C, and is not a lactose fermenter or a hydrogen sulfide producer. It is typically transmitted in the feces of pets (especially from puppies) and is found in contaminated milk and pork. Infections are commonly seen in daycare centers and in the northern climates. Y. enterocolitica typically causes gastroenteritis in the infected individuals, with the following presentations: infants present with a fever with bloody diarrhea that contains pus, adolescents may present with symptoms that mimic Crohn's disease or appendicitis, and adults present with diarrhea. Treatment is usually supportive, but fluoroquinolones or 3rd-generation cephalosporins can be prescribed.

Bottone reviews Y. enterocolitica, stating that the bacterial group is not homogenous but consists of several strains. The dominant serogroups are O:3, O:5, O:8, O:9, and O:27. Bottone states that this bacteria is epidemically linked to porcine sources. Y. enterocolitica predominantly affects the gastrointestinal tract, but there may also be extraintestinal sequelae such as arthritis and erythema nodosum. Bacteremia may occur but typically presents in patients who are immunocompromised, who have an overload of iron, or who may be currently treated with desferrioxamine.

Grahek-Ogden et al. discuss an outbreak of Y. enterocolitica (O:9) in Norway. Since Y. enterocolitica has a predilection for northern climates, infections by this bacteria are the third-leading cause of acute enteritis in Norway. The authors report that the outbreak involved 11 persons, and the source of the bacteria was a "ready-to-eat pork product" called Brawn, which is a traditional Christmas dish involving layering meat including pork and veal and cooked at a lower temperature not sufficient to kill off bacteria. Their study was the first to confirm a link between the pork product and the Y. entercolitica infection in Norway, as many previous studies only showed an association between eating pork and infectious symptoms.

Incorrect Answers:
Importantly, all of these organisms/agents cause watery diarrhea, not bloody diarrhea.
Answer 2: Enterotoxigenic E. coli is a Gram-negative rod that is a lactose fermenter. It causes traveler's diarrhea.
Answer 3: Vibrio cholerae is a Gram-negative, oxidase positive, comma-shaped bacteria that grows in alkaline media, which causes rice-water diarrhea.
Answer 4: Clostridium perfringens is a Gram-positive, obligate anaerobic bacilli that also causes gas gangrene.
Answer 5: Rotavirus is a dsRNA virus that is a major cause of gastroenteritis in children and is a common cause of acute diarrhea for those who are in day-care and kindergarten.