PFGE patterns likely share a common source

PFGE patterns likely share a common source

• A. Distinguishable
• B. Indistinguishable
• C. Related to outbreak severity
• D. Randomly related

Answer: (B)

PFGE provides a DNA fingerprint of bacterial isolates. When two or more isolates show indistinguishable PFGE patterns, they are considered to be the same clone, which strongly suggests they come from a common source. In outbreak investigations, this kind of pattern similarity supports linking cases to a single source or contamination event. If patterns are distinguishable, it points toward different strains or sources, making a common source less likely. PFGE pattern similarity does not reflect outbreak severity, and randomly related patterns would not fit a linked outbreak scenario. Therefore, indistinguishable PFGE patterns are the best indication that cases share a common source.

PFGE provides a DNA fingerprint of bacterial isolates. When two or more isolates show indistinguishable PFGE patterns, they are considered to be the same clone, which strongly suggests they come from a common source. In outbreak investigations, this kind of pattern similarity supports linking cases to a single source or contamination event. If patterns are distinguishable, it points toward different strains or sources, making a common source less likely. PFGE pattern similarity does not reflect outbreak severity, and randomly related patterns would not fit a linked outbreak scenario. Therefore, indistinguishable PFGE patterns are the best indication that cases share a common source.