Case Files: Microbiology App - Download Free Sample! Description: 50+ clinical cases with open-ended questions which weave basic science concepts into the clinical scenario. Each case includes an extended discussion, key points, and 3-5 USMLE-style comprehension questions. Tags: microbiology study guide, microbiology book, microbiology books, medicine shelf, medical shelf, med student books, usmle world, usmleworld, usmle world qbank, qbank