WBR0048
| 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 pneumophila |
| 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 causes whopping cough and is cultured on Bordet-Genou agar. References: First Aid 2014 page 122 First Aid 2012 page 148 |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::MIcrobiology, WBRKeyword::Respiratory, WBRKeyword::Cough, WBRKeyword::Bacteria, WBRKeyword::Laboratory |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |