A clinical microbiology laboratory is validating a new multiplex PCR assay for the simultaneous detection of several gastrointestinal pathogens, including Salmonella, Shigella, and Campylobacter. To ensure the accuracy and reliability of the assay, it is crucial to include appropriate controls. Which of the following sets of controls would be MOST comprehensive?

A patient with a history of neutropenia develops a severe sinus infection. Tissue biopsy reveals broad, ribbon- like, non-septate hyphae with right-angle branching. The MOST likely causative organism belongs to the order:

A microbiology laboratory is performing antimicrobial susceptibility testing using the Kirby-Bauer disk diffusion method. A bacterial isolate shows no zone of inhibition around a specific antibiotic disk. This result could be due to:

A patient with a history of solid organ transplantation develops diarrhea and abdominal cramps. Stool studies are negative for bacterial pathogens and C. difficile toxins. Colonoscopy reveals characteristic cytomegalic inclusion bodies in colonic biopsies. The MOST likely causative agent is:

During an investigation of a foodborne outbreak linked to a church supper, 80 people ate the suspected chicken dish, and 32 subsequently developed gastroenteritis. Among 50 people who did not eat the chicken dish, 5 developed similar symptoms. What is the attack rate among those who ate the chicken dish?