A 23-year-old man is seen in the emergency room for an infectedwound on his hand. The wound is swollen, feverish, and red, and amoderate amount of pus has accumulated at the site. On questioning,the patient explains that he was involved in a fist fight at alocal night club 1 week earlier. During the fight, he had hit theother man involved in the mouth and broken several of his teeth, atwhich time he was bitten deeply by his opponent. The wound is aresult of that bite. The physician lances the wound and bacterialculture of the drainage is performed.
After 48 hours incubation in 10% CO2, tiny opaque colonies witha pale yellow pigment are observed on blood agar and chocolate agarplates. The organism Gram stains as a small gram-negative bacilli.Colonies are oxidase positive and catalase negative.
Questions:
– What organism is the most likely pathogen isolated in thisexample? What was the source of the organism?
-What other common colony characteristics would be helpful inpresumptively identifying this organism?
