A clinical microbiology laboratory is investigating an outbreak of vancomycin-resistantEnterococcus faecium (VRE) in a hospital. Whole-genome sequencing of isolates from different patients reveals the presence of the vanA operon on a mobile genetic element that is highly conserved across all isolates. This finding MOST strongly suggests:

A microbiology laboratory receives a blood culture from a patient with suspected bacterial endocarditis. After
24 hours of incubation, Gram-positive cocci in clusters are observed on the Gram stain. Catalase test is positive, and coagulase test is negative. Further testing reveals susceptibility to novobiocin. The MOST likely organism is:

For epidemiological tracking and outbreak investigations of Clostridioides difficile infection (CDI), which molecular typing method based on PCR amplification targeting repetitive elements within the pathogenicity locus (PaLoc) has historically been widely used and designated by specific nomenclature (e.g., NAP1/BI
/027)?

A patient presents with perianal itching, particularly at night. Microscopic examination of cellophane tape preparation from the perianal area reveals oval-shaped eggs with one flattened side. The MOST likely causative organism is:

A patient with HIV infection and a CD4+ T-cell count of 30 cells/µL develops progressive multifocal leukoencephalopathy (PML). The causative agent of PML is: