WBR291

Author	PageAuthor::Gerald
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Microbiology
Sub Category	SubCategory::Gastrointestinal
Prompt	[[Prompt::A 25-year-old male presents to the clinic with abdominal cramps, general malaise, fever, and bloody diarrhea 6 hours after consuming undercooked poultry. Two of his family members also have similar symptoms. Laboratory studies reverals the causal agent as microaerophilic Gram-negative curved rods. Which of the following descriptions of the pathogen is correct?]]
Answer A	AnswerA::Negative for glucose fermentation test.
Answer A Explanation	AnswerAExp::A - Correct. Campylobacter jejuni is negative for glucose fermentation test.
Answer B	AnswerB::Negative for catalase test.
Answer B Explanation	AnswerBExp::Campylobacter jejuni is positive for catalase test.
Answer C	AnswerC::Negative for nitrate reduction test.
Answer C Explanation	AnswerCExp::Campylobacter jejuni is positive for nitrate reduction test.
Answer D	AnswerD::Negative for oxidase test.
Answer D Explanation	AnswerDExp::Campylobacter jejuni is positive for oxidase test.
Answer E	AnswerE::Immotile on wet mount.
Answer E Explanation	AnswerEExp::Campylobacter jejuni contains polar flagella and is motile on wet mount.
Right Answer	RightAnswer::A
Explanation	[[Explanation::Campylobacter jejuni is a curved, helical-shaped, non-spore forming, Gram-negative, microaerophilic bacteria. It is one of the most common causes of human gastroenteritis in the world. It has been linked with subsequent development of Guillain-Barré syndrome, which usually develops two to three weeks after the initial illness. C. jejuni is commonly associated with poultry, and it naturally colonizes the digestive tract of many bird species. Campylobacter is grown on specially selective agar plates at 42°C, the normal avian body temperature, rather than at 37°C, the temperature at which most other pathogenic bacteria are grown. Since the colonies are oxidase positive, they will usually only grow in scanty amounts on the plates. Microaerophilic conditions are required for luxurious growth. A selective blood agar medium (Skirrow's medium) can be used. Greater selectivity can be gained with an infusion of a cocktail of antibiotics: vancomycin, polymixin-B, trimethoprim and actidione. Important oxidase-positive pathogens: Campylobacter Helicobacter Legionella Neisseria Pseudomonas Vibrio Educational Objective: References: ]]
Approved	Approved::No
Keyword	WBRKeyword::Campylobacter jejuni
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