bacterial infections

IDSA: New Guidance for Treating the Most Common Drug-Resistant Pathogens

The Infectious Diseases Society of America has published new guidance for treating 3 of the most common drug-resistant pathogens: Extended-spectrum β-lactamase producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales (CRE), and difficult-to-treat resistance (DTR)-Pseudomonas aeruginosa.

“The overarching goal of this guidance document is to assist clinicians—including those with and without infectious diseases expertise—in selecting antibiotic therapy for infections caused by ESBL-E, CRE, and DTR-P aeruginosa,” the guideline writing panel wrote. “Future iterations of this document will address other resistant pathogens.”

After reviewing the published literature and incorporating their clinical and research experience, a panel of 6 infectious diseases specialists answered 7 common questions about ESBL-E, 7 common questions about CRE, and 4 common questions about DTR- P aeruginosa.

The questions addressed the preferred antibiotics for treating uncomplicated cystitis caused by each pathogen, pyelonephritis and complicated urinary tract infections caused by each pathogen, and infections outside of the urinary tract caused by each pathogen.

For CRE infections, the panel also addressed ertapenem and meropenem resistance, carbapenemase testing and presence, and the roles of polymyxins and combination antibiotic therapy.

 For ESBL-E infections, the panel addressed the roles of piperacillin-tazobactam and cefepime in the treatment regimen and the preferred antibiotics for infections caused by Escherichia coliKlebsiella pneumoniaeKlebsiella oxytoca, or Proteus mirabilis that are not susceptible to ceftriaxone, as well as those in which a blaCTX-M gene is not detected.

For DTR-P aeruginosa infections, the panel also addressed the role of combination therapy.

“The field of AMR is dynamic and rapidly evolving, and the treatment of antimicrobial resistant infections will continue to challenge clinicians,” the panel concluded. “As newer antibiotics against resistant pathogens are incorporated into clinical practice, we are learning more about their effectiveness, and propensity to resistance.”


—Amanda Balbi


Tamma PD, Aitken SL, Bonomo RA, Mathers AJ, van Duin D, Clancy CJ. Infectious Diseases Society of America guidance on the treatment of antimicrobial resistant gram-negative infections. IDSA. Published online September 8, 2020.