WBR0048

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Author PageAuthor::William J Gibson
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Microbiology
Sub Category SubCategory::Pulmonology, SubCategory::General Principles, SubCategory::Infectious Disease
Prompt [[Prompt::A 7 year old child is brought to his pediatrician by his mother for a 4 day history of increasingly severe cough. On physical exam, the patient is febrile and in between fits of coughing, displays an inspiratory whoop. The child immigrated from rural India with his family 2 years ago. Which of the following media could be used to culture the causal organism?]]
Answer A AnswerA::Eaton’s Agar
Answer A Explanation AnswerAExp::Incorrect - Eaton’s agar is used to culture Mycoplasma Pneumoniae.
Answer B AnswerB::Charcoal Yeast Extract
Answer B Explanation AnswerBExp::Incorrect - Charcoal yeast extract is used to culture Legionella.
Answer C AnswerC::Tellurite Agar
Answer C Explanation AnswerCExp::Incorrect - Tellurite agar is used to culture Corynebacterium diptheria
Answer D AnswerD::Bordet-Genou Agar
Answer D Explanation AnswerDExp::Correct - Bordetella Perusis may be cultured on Bordet-Genou Agar
Answer E AnswerE::Lowenstein-Jensen
Answer E Explanation AnswerEExp::Incorrect - Lowenstein-Jensen agar is used to culture Mycobacterium Tuberculosis.
Right Answer RightAnswer::D
Explanation [[Explanation::The patient in this vignette is suffering from whooping cough, an infection caused by the organism Bordetella Pertusis. The patient’s immigration history suggests that he did not receive routine vaccinations, placing him at higher risk for whooping cough, a very rare infection in the US due to vaccination (part of DTaP vaccine). Whooping cough is characterized by fits of paroxysmal coughing and in 50% of patients an inspiratory “whoop” can be appreciated as the patient attempts to draw air through a partially closed glottis. Bordetella Pertusis is a gram negative, aerobic coccobaccilus which can be cultured on Bordet-Genou Agar.

Educational Objective: Bordetella Pertusis is cultured on Bordet-Genou agar.

References: First Aid 2012 page 148. Tags: #Microbiology #Respiratory
Educational Objective:
References: ]]

Approved Approved::Yes
Keyword WBRKeyword::WJG
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