Absolute Free ABMM Exam Practice for Comprehensive Preparation 

A microbiology laboratory is investigating an outbreak of bloodstream infections in a neonatal intensive care unit. Isolates of Staphylococcus epidermidis from multiple infants show indistinguishable banding patterns by pulsed-field gel electrophoresis (PFGE). This finding MOST strongly suggests:

Which biosafety level (BSL) is required for clinical laboratory work involving the propagation (culture) of Coccidioides immitis/posadasii? 

A Gram-positive rod is isolated from the blood culture of a neonate with sepsis. The organism exhibits weak beta-hemolysis on sheep blood agar, is catalase-positive, hydrolyzes esculin in the presence of bile, and demonstrates characteristic "tumbling" motility in a wet mount prepared from a broth culture incubated at 25° C. Which organism is most likely? 

A patient develops a vesicular rash on their hands and feet, accompanied by fever and oral ulcers. The MOST likely causative agent is:

A clinical isolate of Klebsiella pneumoniae from a patient with a refractory urinary tract infection exhibits resistance to carbapenems (imipenem, meropenem, ertapenem). PCR analysis reveals the presence of the blaKPC gene. Which of the following enzymatic mechanisms is responsible for this resistance?