Acinetobacter: a potential reservoir and dispenser for β-lactamases

Area of Science:

• Microbiology
• Genetics
• Infectious Diseases

Background:

• Acinetobacter species are clinically significant due to inherent and acquired antimicrobial resistance.
• Numerous beta-lactamase enzymes, primarily in Acinetobacter baumannii, contribute to this resistance.

Purpose of the Study:

• To provide an updated taxonomy of the Acinetobacter genus.
• To summarize beta-lactamases found in Acinetobacter species, with a focus on ADCs and CHDLs.
• To explore the role of mobile genetic elements in resistance dissemination.

Main Methods:

• Literature review of Acinetobacter taxonomy and beta-lactamase characterization.
• Analysis of published data on resistance mechanisms in Acinetobacter.
• Focus on Acinetobacter-derived cephalosporinases (ADCs) and carbapenem-hydrolysing class D beta-lactamases (CHDLs).

Main Results:

• Over 210 beta-lactamases from 16 families have been identified in Acinetobacter.
• Acinetobacter-derived cephalosporinases (ADCs) and carbapenem-hydrolysing class D beta-lactamases (CHDLs) are key resistance determinants.
• Integrons and insertion sequence (IS) elements facilitate the spread of resistance genes.

Conclusions:

• Acinetobacter's resistance is driven by a diverse array of beta-lactamases.
• Understanding these enzymes and their genetic context is crucial for combating Acinetobacter infections.
• Updated taxonomic information aids in tracking and managing resistance.