The DTR (Difficult to Treat) Pseudomonas aeruginosa

According to the IDSA 2024 Guidance on the Treatment of Antimicrobial-Resistant Gram-Negative Infections, Difficult-to-Treat Resistance (DTR) in P. aeruginosa is defined as an isolate that exhibits non-susceptibility (resistance or intermediate) to all of the following first-line agents: piperacillin-tazobactam, ceftazidime, cefepime, aztreonam, meropenem, imipenem-cilastatin, ciprofloxacin, and levofloxacin. 

Treatment Approach: Preferred treatments for DTR P. aeruginosa (outside of the urinary tract) include newer agents like ceftolozane-tazobactam, ceftazidime-avibactam, or imipenem-cilastatin-relebactam.

Alternatives: Cefiderocol is listed as an option for infections outside the urinary tract, particularly for MBL-producing strains