Inhibition of Aminoglycoside 6′- N -Acetyltransferase Type Ib-Mediated Amikacin Resistance by Antisense Oligodeoxynucleotides

Abstract

Amikacin has been very useful in the treatment of infections caused by multiresistant bacteria because it is refractory to the actions of most modifying enzymes. However, the spread of AAC(6)-I-type acetyltransferases, enzymes capable of catalyzing inactivation of amikacin, has rendered this antibiotic all but useless in some parts of the world. The aminoglycoside 6-N-acetyltransferase type Ib, which is coded for by the aac(6)-Ib gene, mediates resistance to amikacin and other aminoglycosides. RNase H mapping and computer prediction of the secondary structure led to the identification of five regions accessible for interaction with antisense oligodeoxynucleotides in the aac(6)-Ib mRNA. Oligodeoxynucleotides targeting these regions could bind to native mRNA with different efficiencies and mediated RNase H digestion. Selected oligodeoxynucleotides inhibited AAC(6)-Ib synthesis in cell-free coupled transcription-translation assays. After their introduction into an Escherichia coli strain harboring aac(6)-Ib by electroporation, some of these oligodeoxynucleotides decreased the level of resistance to amikacin. Our results indicate that use of antisense compounds could be a viable strategy to preserve the efficacies of existing antibiotics to which bacteria are becoming increasingly resistant.

Restoration of antibiotic susceptibility in fluoroquinolone-resistant Escherichia coli by targeting acrB with antisense phosphorothioate oligonucleotide encapsulated in novel anion liposome

“…The development of antisense oligonucleotides has shown some promise to reverse antibiotics resistance. [36][37][38] Interrupting expression of resistance genes in this manner could restore susceptibility to key antibiotics, which would be co-administered with the antisense compound. This would extend the lifespan of existing antibiotics, which offer clinically proven therapies, and are often cheaper, more effective or less toxic than the alternatives.…”

Bases moleculares de la infección asociada a implantes ortopédicos

“…Finalmente, una de las estrategias más prometedoras es el uso de vacunas y la terapia génica. El uso de oligonucleótidos antisentido se ha utilizado inicialmente para interferir con la expresión de genes relacionados con la resistencia a antimicrobianos 72,73 .…”

Inhibition of aac(6′)-Ib -mediated amikacin resistance by nuclease-resistant external guide sequences in bacteria

“…M1 RNA, aac(6Ј)-Ib mRNA, and the C5 protein were prepared as described before (13). The aac(6Ј)-Ib mRNA and the oligoribonucleotides and analogs were 5Ј-end-labeled as described before (33). Radioactivity was visualized using a STORM 840 PhosphorImager and quantified using ImageQuant (Molecular Dynamics).…”