Metallo-beta-lactamases: the quiet before the storm?

Area of Science:

• Microbiology
• Molecular Biology
• Infectious Diseases

Background:

• Metallo-beta-lactamases (MBLs) are enzymes conferring resistance to beta-lactam antibiotics.
• Their prevalence is increasing, particularly in Gram-negative bacteria like Pseudomonas aeruginosa.
• MBLs hydrolyze all beta-lactams and currently lack clinical inhibitors.

Purpose of the Study:

• To highlight the clinical significance and rapid dissemination of MBLs.
• To emphasize the need for surveillance and inhibitor development.
• To discuss the genetic mechanisms facilitating MBL spread.

Main Methods:

• Literature review and synthesis of existing data on MBL prevalence and characteristics.
• Analysis of genetic elements (integrons, transposons) associated with MBL gene acquisition.
• Review of reported MBL types (IMP, VIM, SPM, GIM) and geographical distribution.

Main Results:

• Nearly 30% of imipenem-resistant Pseudomonas aeruginosa strains harbor MBLs.
• MBLs confer broad-spectrum beta-lactam resistance, though resistance levels vary in Acinetobacter spp. and Enterobacteriaceae.
• MBL genes are often located on mobile genetic elements, facilitating rapid spread, sometimes alongside aminoglycoside resistance genes.

Conclusions:

• The rise of MBLs poses a significant threat to current antibiotic therapies.
• Effective surveillance and the development of MBL inhibitors are crucial for combating antimicrobial resistance.
• The genetic mobility of MBLs necessitates global monitoring and strategic interventions.