Antibiotics in development for multiresistant gram-negative bacilli

The rapid increase in antibiotic (ATB) resistance among Gram-negative bacilli(BGN), especially in strains of Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter bau-mannii, with high resistance patterns (XDR), poses a huge threat to health systems worldwide. In the last decade, different ATBs have been developed against XDR, some of which com-bine a lactam 13 along with a 13-lactamase inhibitor, while others use non-13-lactam inhibitors. Most of them have adequate "in vitro" activity on several 13-lactamases of class A, C and D of Ambler. However, combinations such as Ceftazidime/avibactam, Ceftolozane/Tazobactam and Meropenem/vaborbactam have no activity against metallo-13-lactamases(MpL). New combina-tions such as Aztreonan/AVI, Cefepime/Zidebactam, or new cephalosporins such as Cefiderocol, have efficacy against M beta L enzymes. Although some of these combinations are already approved and in the commercialization phase, many of them have yet to define their place within the treatment of microorganisms with high resistance through clinical studies.(c) 2022 Elsevier Espana, S.L.U. y SEMICYUC. All rights reserved.