The expression of aminoglycoside resistance genes in integron cassettes is not controlled by riboswitches
Nucleic Acids Research publish this investigation article
August 26th, 2022
Regulation of gene expression is a key factor influencing the success of antimicrobial resistance determinants. A variety of determinants conferring resistance against aminoglycosides (Ag) are commonly found in clinically relevant bacteria, but whether their expression is regulated or not is controversial. The expression of several Ag resistance genes has been reported to be controlled by a riboswitch mechanism encoded in a conserved sequence. Yet this sequence corresponds to the integration site of an integron, a genetic platform that recruits genes of different functions, making the presence of such a riboswitch counterintuitive. We provide, for the first time, experimental evidence against the existence of such Ag-sensing riboswitch. We first tried to reproduce the induction of the well characterized aacA5 gene using its native genetic environment, but were unsuccessful. We then broadened our approach and analyzed the inducibility of all AgR genes encoded in integrons against a variety of antibiotics. We could not observe biologically relevant induction rates for any gene in the presence of several aminoglycosides. Instead, unrelated antibiotics produced mild but consistently higher increases in expression, that were the result of pleiotropic effects. Our findings rule out the riboswitch control of aminoglycoside resistance genes in integrons
Hipolito A., Garcia-Pastor L., Blanco P., Trigo de Roza F., Kieffer N., Vergara E., Jove T., Alvarez J. and Escudero JA..
 | Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
| Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
 | Université de Limoges (UL). |
 | Institut national de la santé et de la recherche médicale (INSERM). |
Related news in other media:
- Desmienten una teoría sobre resistencia a antibióticos nueve años después - ucm.es
- Investigadores españoles desmienten una teoría sobre resistencia a antibióticos - eldebate.com
- Nuevas aportaciones nacionales al estudio de la resistencia a los antibióticos - imfarmacias.es
- Veterinarios españoles desmienten una teoría sobre resistencia a antibióticos 9 años después - animalshealth.es
