WBR0076

Author	PageAuthor::William J Gibson
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Microbiology, MainCategory::Pathology
Sub Category	SubCategory::Dermatology
Prompt	Prompt::A patient who works in a wool factory presents to the Emergency Room with a boil-like black ulcer which developed on her forearm over the past 3 days. Which component of the organism causing this disease induces the production of TNF and IL-1?
Answer A	AnswerA::Peptidoglycan
Answer A Explanation	AnswerAExp::Peptidoglycan is composed of a sugar backbone with cross-linking by peptide side chains. It provides support for bacterial cells and protects against osmotic forces but does not directly induce IL-1 and TNF.
Answer B	AnswerB::Lipoteichoic acid
Answer B Explanation	AnswerBExp::See explanation
Answer C	AnswerC::Lipid A
Answer C Explanation	AnswerCExp::Lipid A is a molecule found on the outer membrane of Gram Negative bacteria. It does induce the production of TNF and IL-1, but the bacteria suspected by this clinical presentation is Bacillus Anthracis, a gram-positive organism.
Answer D	AnswerD::D-Glutamate Capsule
Answer D Explanation	AnswerDExp::Bacillus Anthracis is the only organism with a D-Glutamate Capsule. However, it does not induce the production of IL-1 and TNF.
Answer E	AnswerE::Glycocalyx
Answer E Explanation	AnswerEExp::The glycocalyx mediates bacterial adhesion to structures such as catheters, biological membranes and other surfaces. It does not directly induce IL-1 and TNF.
Right Answer	RightAnswer::B
Explanation	[[Explanation:: Educational Objective: References: ]]
Approved	Approved::No
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