Piperacillin-Tazobactam Resistant Pseudomonas aeruginosa

Piperacillin-Tazobactam Resistant Pseudomonas aeruginosa

While showing excellent activity, resistance to this drug increased slightly in late 2000s

Background

Pseudomonas aeruginosa is a widespread pathogen in the hospital environment that frequently forms “biofilm,” a permanent plaque on medical equipment, and colonizes tissues of long-stay patients. It is considered an opportunistic pathogen, meaning it exclusively strikes affected organ systems of the immunocompromised and seriously ill. Pneumonia, bloodstream, and urinary tract infections are associated with mortality rates that can exceed 50% and high treatment failure because of its intrinsic resistance against many antibiotics.

Piperacillin-tazobactam is a combination antibiotic with powerful antipseudomonal action that is sometimes combined with fluoroquinolones or aminoglycosides to treat critically ill patients. The observed stability of piperacillin resistance rates over time could imply that strains are not acquiring new resistance mechanisms, unlike other Gram-negative pathogens. However, measures to contain the spread of resistant strains are still essential: although in vitro levels remain stable at the national level, individual sites report that multidrug resistance to several agents at once is becoming more common as various resistance mechanisms act in tandem.