OTKA K 108481 | Factors influencing the expression of plasmid-mediated quinolone determinants (PMQRs)

Fluoroquinolones are drugs of prime importance, however the number of resistant bacteria is increasing worldwide. Plasmid-mediated resistance determinants confer low level resistance, which can lead to therapy failure. Better understanding the mechanism of PMQR may help to prevent resistance against fluoroquinolones.

Period of the research activity: 


Project leader: 

Szabó, Dóra (Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary)

Financial support: 

OTKA K 108481

Fluoroquinolones are antibiotics used worldwide to treat infections caused by Gram-negative bacteria. As the resistance against fluoroquinolones is primarily determined by chromosomal mutations, the novel mechanism of plasmid-mediated quinolone resistance (PMQR) is still far from being completely understood. PMQR determinants, including Qnr proteins, aminoglycoside acetyltransferase (6’)–Ib-cr variant enzyme, efflux pumps OqxAB and QepA confer low level fluoroquinolone resistance which is difficult to detect and can lead to therapy failure.
The main objective of this project is to reveal the influence of different antibiotics (fluoroquinolones, beta-lactams and aminoglycosides) on the expression of PMQR determinants and of regulatory proteins, as well as on the mutations in the promoter region of PMQR genes.
The analysis of factors influencing the gene expression in vitro and in vivo, may help to decrease resistance during therapy, leading to a more effective antibiotic administration in the future.
The schematic view of the research.

The schematic view of the research.

Researcher(s) of IVMR on the Project: 
Further participants and collaborators on the Project: 
Kocsis, Béla senior lecturer, vice director of institute (Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary)
Kristóf, Katalin head of department (Semmelweis University, Department of Laboratory Medicine, Budapest, Hungary)