Genetic support of extended-spectrum beta-lactamases

Area of Science:

• Microbiology
• Genetics
• Molecular Biology

Background:

• Extended-spectrum beta-lactamases (ESBLs) are enzymes conferring resistance to beta-lactam antibiotics.
• ESBL genes are prevalent in Gram-negative bacteria, particularly Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii.
• Common ESBL types include TEM, SHV, and CTX-M derivatives, with VEB, GES, and PER being less frequent.

Purpose of the Study:

• To investigate the genetic mechanisms underlying the acquisition and spread of ESBL genes in Gram-negative bacteria.
• To highlight the diversity of genetic elements involved in ESBL gene mobilization.

Main Methods:

• Review of scientific literature on ESBL gene dissemination.
• Analysis of genetic vehicles associated with ESBL acquisition.

Main Results:

• ESBL genes are acquired through various mechanisms, frequently involving mobile genetic elements.
• Key genetic vehicles include insertion sequences (ISs), transposons, and class 1 integrons.
• The presence of ISCR1 elements within sul1-type integrons also facilitates ESBL spread.

Conclusions:

• The diverse array of genetic vehicles significantly contributes to the widespread dissemination of ESBLs.
• Understanding these mobilization mechanisms is crucial for developing strategies to control antimicrobial resistance.