First description of a plasmid-mediated quinolone resistance determinant qnrS2 in an Aeromonas veronii biovar sobria clinical isolate

Abstract number: P1534

Sanchez-Cespedes J., Blasco M.D., Marti S., Alba V., Alcaide E., Esteve C., Vila J.

Objective: The main objective of this study was to investigate the prevalence of the qnrA, qnrB and qnrS genes in a collection of environmental and clinical Aeromonas sp.

Methods: Fifty seven Aeromonas sp. isolates (resistant and susceptible to nalidixic acid) were identified by biochemical tests. Thirty two were collected from the environment and the other twenty five were clinical isolates. Screening of the qnrA, qnrB and qnrS genes was performed by multiplex PCR using specific primers and controls for each gene. The sequence obtained was compared with those published in the GenBank. Antimicrobial susceptibilities were performed by E-test and gyrA analyses was carried out by PCR of the QRDR in the qnr+-PCR isolates. Plasmid extraction was carried out in the qnr-carrying strain.

Results: Among all the analysed isolates only one of them was PCR+. The positive strain corresponded to an Aeromonas veronii biovar sobria clinical isolate. It presented two mutations, one in the gyrA gene (Ser83-Ile) and the other in the parC gene (Ser80-Ile). The qnr determinant was sequenced and presented 100% homology when compared with the qnrS2 gene in the GeneBank. The positive isolate had a clinical origin and it showed resistance to nalidixic acid (>256 mg/ml), ciprofloxacin (8 mg/ml) and norfloxacin (12 mg/ml). A 8 Kb plasmid was isolated from the strain carrying the qnr-like determinant. The plasmid was cut off from the agarose gel and the PCR of the qnrS2 gene repeated, showing the same amplification fragment.

Conclusions: This is the first time that a plasmid-mediated quinolone resistance qnr-like determinant has been found outside Enterobacteriaceae and in an Aeromonas veronii biovar sobria clinical isolate.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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