The Impact of Natural Transformation on the Acquisition of Antibiotic Resistance Determinants

Abstract

Carbapenem and multidrug-resistant (MDR) Acinetobacter baumannii leads the World Health Organization’s list of priority pathogens and represents an unmet medical need. Understanding the mechanisms underpinning the acquisition of antibiotic resistance in this pathogen is fundamental to the development of novel therapeutics as well as to infection prevention and antibiotic stewardship strategies designed to limit its spread.

comCDE (Competence) Operon Is Regulated by CcpA in Streptococcus pneumoniae D39

“…Natural transformation was first found in S. pneumoniae in 1928, and at least 83 bacterial species have been found capable of natural transformation ( 67 ). Although similar mechanisms are employed to acquire and recombine genetic material into their genomes, only a few bacteria have the ability to transform naturally throughout their growth period, such as Neisseria gonorrhoeae ( 68 ) and Acinetobacter baumannii ( 69 ). The remainders are capable of natural transformation only at particular growth stages, and S. pneumoniae undergoes natural transformation during early exponential growth ( 27 ).…”

One Earth: The Equilibrium between the Human and the Bacterial Worlds

“…In some bacterial species, like A. baumanii (a most relevant member of the ESKAPE group), natural transformation seems to be the most relevant mechanism of HGT, posing the question of whether conjugative transfer is the main HGT process in bacteria [63]. In the case of polymyxins (a family of antibiotics that target the cell membrane), it has been speculated that treatment with these antibiotics could lead to the release of free DNA as well as potentiate the onset of the competent state [64]. The onset of competence is triggered by a specific sigma factor that turns on a set of operons (generically termed com genes) involved in the active incorporation of free DNA from the environment.…”