WBR0301

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Microbiology
Sub Category	SubCategory::Infectious Disease
Prompt	[[Prompt::A lab technician is conducting a test to speciate a gram positive organism he obtained from an operating room wound swab. After isolating the organism, he inoculates it perpendicularly to streaks of a beta-hemolytic staphylococcus on sheep blood agar plates and incubates them at 37 C for 2 days. While examining the plates, he notices the pattern seen below. Which of the following is the most likely isolated organism? ]]
Answer A	AnswerA::Streptococcus agalactiae
Answer A Explanation	AnswerAExp::
Answer B	AnswerB::Streptococcus viridans
Answer B Explanation	AnswerBExp::
Answer C	AnswerC::Streptococcus pyogenes
Answer C Explanation	AnswerCExp::
Answer D	AnswerD::Staphylococcus epidermidis
Answer D Explanation	AnswerDExp::
Answer E	AnswerE::Listeria monocytogenes
Answer E Explanation	AnswerEExp::
Right Answer	RightAnswer::A
Explanation	[[Explanation::Reference: Darling CL. Standardization and evaluation of the CAMP reaction for the prompt, presumptive identification of Streptococcus agalactiae (Lancefield group B) in clinical material. J Clin Microbiol. 1975;1(2):171-4. Educational Objective: References: ]]
Approved	Approved::No
Keyword	WBRKeyword::Streptococcus agalactiae, WBRKeyword::Group B streptococcus, WBRKeyword::CAMP test, WBRKeyword::Beta-Hemolysis
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::