CASE HISTORY
In October 2013,Kelsey was a 28-year-old computer programmer who worked for a prominent technology firm in Silicon Valley.In the middle of the night,Kelsey awoke with abdominal cramps and diarrhea.Her temperature spiked as high as 40°C (104°F).She had a bad headache and could not retain sufficient fluids.After three days,her fever subsided,but the diarrhea continued (about 20 times a day)and began showing blood.Kelsey was admitted to the hospital,where she was given intravenous fluids to control her dehydration.The physician asked her about her dietary history preceding the onset of symptoms.Kelsey recalled that the night before onset,she had eaten rotisserie chicken cooked at the supermarket.An antibody test confirmed the diagnosis of Salmonella enterica serovar heidelberg.Because of the severity of her symptoms,Kelsey was treated with antibiotics,although sometimes antibiotics may prolong the persistence of Salmonella.When amoxicillin failed to control the infection because of bacterial resistance,ciprofloxacin was used.Ultimately,Kelsey's illness was one of more than 400 cases in 23 states traced to contaminated chicken from one California farm.Kelsey recovered,but three months later,S.heidelberg could still be detected in her feces.
Kelsey's diarrhea could be caused by which of the following:

Question

Quizplus · Accepted Answer

The Salmonella infection created a hypertonic environment in the lumen of Kelsey's gut, leading water to leave her epithelial cells. Salmonella bacteria cause infection by releasing enterotoxins that trigger fluid secretion by gut epithelial cells. The enterotoxins can also cause inflammation and cell damage, which can lead to blood in the stool. The hypertonic environment in the lumen of the gut pulls water out of the epithelial cells, leading to diarrhea. This can cause dehydration and electrolyte imbalances, which may require intravenous fluid therapy. Antibiotics may be used to treat Salmonella infections, but care must be taken to avoid increasing antibiotic resistance, and the duration of antibiotic use should be appropriate to the severity of the infection.

CASE HISTORY In October 2013,Kelsey Was a 28-Year-Old Computer Programmer Who Worked