WBR0381
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Microbiology |
| Sub Category | SubCategory::Genitourinary |
| Prompt | [[Prompt::A 45 year old Caucasian female patient presents to the emergency department with fever and flank pain that started on the same day. Upon further questioning, the patient admits to having recent onset dysuria and urinary frequency for which she did not seek medical care. Her temperature is 38.9 degrees C (102 degrees F), her heart rate is 96 beats per minute, and her blood pressure measures 116/88 mmHg. Physical examination reveals positive Murphy’s punch sign (costovertebral angle tenderness). The diagnosis of acute pyelonephritis is made. Urine cultures are taken and appropriate antibiotic therapy is initiated. Eosin Methylene Blue (EMB) agar shows the growth of a specific bacterial strain as seen in the image below. Which of the following virulence factors is implicated in this patient’s condition?]] |
| Answer A | AnswerA:: |
| Answer A Explanation | AnswerAExp:: |
| Answer B | AnswerB:: |
| Answer B Explanation | AnswerBExp:: |
| Answer C | AnswerC:: |
| Answer C Explanation | AnswerCExp:: |
| Answer D | AnswerD:: |
| Answer D Explanation | AnswerDExp:: |
| Answer E | AnswerE:: |
| Answer E Explanation | AnswerEExp:: |
| Right Answer | RightAnswer:: |
| Explanation | [[Explanation::E. coli is the most common causative agent of acute pyelonephritis. It is a lactose-fermenting gram-negative, catalase-positive rod that grows on the selective EMB agar. As depicted in the image above, metallic green sheen is characteristic of E. coli strains on EMB. E. coli contain several virulence factors. Fimbriae are adhesions that are implicated in cystitis and acute pyelonephritis. Fimbriae are present in nearly all strains of E. coli that cause pyelonephritis. Educational Objective: |
| Approved | Approved::No |
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| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |