Figure 1 |
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Jedidiah J. a 3-year-old male presents to the emergency with a 2 hr history of vomiting, diarrhea, fever, irritability, and lethargy. The child had gone to sleep on the living room couch at 10 p.m. His grandfather found him on the floor at 2 a.m. covered with feces. He bathed him, and brought him to the emergency room. The patient's history was significant for his being in group daycare.
In the emergency room, he had two episodes of vomiting and one episode
of diarrhea. His temperature was 38.9oC, pulse 160 beats per
min, and respiratory rate 36/min, and he was noted to be dehydrated. His
stool was mucoid and contained bloody streaks. A methylene blue stain of
his feces is shown below in figure 1. Other laboratory
studies included a cerebrospinal fluid examination, done because of his
lethargy, which was within normal limits; a peripheral white blood cell
count of 13,200/microliter with 85% neutrophils; a negative blood culture;
and a negative stool examination for ova and parasites. Figure
2 shows a MacConkey agar plate culture of the organism recovered from
the feces of the patient. Figure 3 shows the biochemical
reactions obtained in a triple sugar iron (TSI) slant, a urea-motility-indole
(UMI) tube (look for motility), and a UMI with added Kovac's reagent (to
detect indole production; red positive; yellow negative).
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Figure 1 |
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Obtain the answers to the following questions and email your answers to nchamberlain@kcom.edu by the deadline (Feb. 2, 2000; 4:00 PM).
1. Why were the white blood cells present in his stool?
2. Based on the laboratory results seen in figures 1, 2, and 3, what organism is likely causing this illness (I only need the genus)?
3. What was the significance of his being in a group daycare?
4. What special characteristics of this organism lead to its spread?
Take Care and Think Microbiologically!
Neal R. Chamberlain, Ph.D.
Infectious Diseases, Course Director.