Author: Professor Dr. Patrice Nordmann

Keywords: AMR; β-lactams; combined resistance; multidrug resistance

Session 4: Conventional and Novel Approaches in the Discovery of New Antimicrobial Agents

Title: Emerging Antibiotic Resistances Worldwide

Abstract:

Clinically significant multidrug resistance is increasingly reported, particularly among enterobacterial species (e.g., Escherichia coli, Klebsiella pneumoniae, Enterobacter spp.), as well as Pseudomonas aeruginosa and Acinetobacter baumannii.

The antibiotic resistance traits that are already widespread in these Gram-negative bacteria are mainly due to extended-spectrum β-lactamase (ESBL) and carbapenemase production. ESBLs confer resistance to all β-lactams, with the exception of cephamycins and carbapenems, whereas carbapenemases confer resistance to virtually all β-lactams, including carbapenems.

Although novel β-lactams have recently been introduced, such as cefiderocol, ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, and aztreonam-avibactam, emerging resistance to these agents has already been observed.

In addition, combined resistance to other antibiotic classes, potentially leading to pandrug resistance, may be associated with virulence traits. This recent development may further complicate the future management of infections associated with multidrug-resistant bacteria.