A hospital investigates a nosocomial outbreak of Pseudomonas aeruginosa in the ICU. Isolates from multiple patients share identical antibiogram patterns. The most discriminatory molecular epidemiological typing method is:

• A Antibiogram (antibiotic susceptibility pattern)
• B Pulsed-field gel electrophoresis (PFGE) or whole-genome sequencing (WGS) ✓
• C Phage typing
• D Biochemical profiling (API panel)

Explanation

PFGE (restriction endonuclease digestion of genomic DNA followed by gel electrophoresis) has been the gold standard for outbreak typing; WGS now provides even higher discriminatory power at the single-nucleotide level and is replacing PFGE in reference laboratories. Antibiograms and biochemical profiles have low discriminatory power and cannot distinguish clonal from coincidental clusters. Phage typing is used for Salmonella typing and has lower discriminatory power for Pseudomonas.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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