Question

select all that apply
selective media should be used to enrich a patient sample for a suspected pathogen when the ______.

□ pathogen is an anaerobe

□ normal microbiota will grow faster than the pathogen

□ pathogen is likely to exhibit motility

□ pathogen is present in small numbers

□ patient sample has been contaminated

Explanation:

• For "normal microbiota will grow faster than the pathogen": Selective media inhibits normal microbiota, allowing the pathogen (which grows slower) to be enriched.
• For "pathogen is present in small numbers": Selective media helps increase the number of the rare pathogen by suppressing others.
• For "patient sample has been contaminated": Contamination means unwanted microbes; selective media selects for the pathogen and suppresses contaminants.
• "Pathogen is an anaerobe" relates to anaerobic media, not selective (selective targets based on growth factors, not oxygen). "Pathogen motility" relates to motility media, not selective.

Answer:

• normal microbiota will grow faster than the pathogen
• pathogen is present in small numbers
• patient sample has been contaminated