Bacteriology and Mycobacteriology Cases

Results from testing performed in the clinical microbiology laboratory can be used to confirm a diagnosis of bacterial infection as well as aid in the choice of appropriate antimicrobial therapy for individual patients. The challenge for the clinical microbiology laboratory is to provide accurate, clinically relevant information in a timely manner. This is often done with traditional methods such as culture, but more recently with more technologically sophisticated methods such as direct detection of pathogen nucleic acids or assessment of surrogate markers of infection such as specific proteins or other molecules. This chapter reviews the conventional and advanced methods used in the clinical microbiology laboratory and provides a number of detailed patient cases in which the laboratory was critical in determining the etiology of infection. Each case includes the clinical presentation, differential diagnosis, relevant laboratory findings, and a discussion pertinent to the pathogen identified and a brief review of other potential etiologies for the clinical syndrome described.