First description of Klebsiella pneumoniae clinical isolates carrying both qnrA and qnrB genes in Portugal.

In the present study, 21 multidrug-resistant Klebsiella pneumoniae isolates were recovered from patients hospitalised in the Intensive Care Unit of Hospital Infante D. Pedro in Aveiro, Portugal. Fifteen isolates carried qnr genes. Four strains harboured the quinolone resistance genes qnrA and qnrB, both located on a large plasmid in two strains (KP4 and KP10) and on different plasmids in two strains (KP5 and KP6). These findings indicate an extremely high prevalence of qnr genes associated with various mobile elements such as ISCR1 and class 1 integrons.