Editor: Stefan Schwarz
Characterization of antimicrobial resistance in Salmonella enterica food and animal isolates from Colombia: identification of a qnrB19-mediated quinolone resistance marker in two novel serovars
Article first published online: 30 SEP 2010
© 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 313, Issue 1, pages 10–19, December 2010
How to Cite
Karczmarczyk, M., Martins, M., McCusker, M., Mattar, S., Amaral, L., Leonard, N., Aarestrup, F. M. and Fanning, S. (2010), Characterization of antimicrobial resistance in Salmonella enterica food and animal isolates from Colombia: identification of a qnrB19-mediated quinolone resistance marker in two novel serovars. FEMS Microbiology Letters, 313: 10–19. doi: 10.1111/j.1574-6968.2010.02119.x
- Issue published online: 9 NOV 2010
- Article first published online: 30 SEP 2010
- Accepted manuscript online: 20 SEP 2010 12:00AM EST
- Received 28 May 2010; revised 25 August 2010; accepted 25 August 2010.Final version published online 30 September 2010.
- plasmid-mediated quinolone resistance (PMQR);
Ninety-three Salmonella isolates recovered from commercial foods and exotic animals in Colombia were studied. The serotypes, resistance profiles and where applicable the quinolone resistance genes were determined. Salmonella Anatum (n=14), Uganda (19), Braenderup (10) and Newport (10) were the most prevalent serovars, and resistance to tetracycline (18.3%), ampicillin (17.2%) and nalidixic acid (14%) was most common. Nalidixic acid-resistant isolates displayed minimum inhibitory concentrations ranging from 32 to 1024 μg mL−1. A Thr57Ser substitution in ParC was the most frequent (12 of the 13 isolates). Six isolates possessed an Asp87Tyr substitution in GyrA. No alterations in GyrA in a further seven nalidixic acid-resistant isolates were observed. Of these, four serovars including two Uganda, one Infantis and a serovar designated 6,7:d:-, all carried qnrB19 genes associated with 2.7 kb plasmids, two of which were completely sequenced. These exhibited 97% (serovar 6,7:d:- isolate) and 100% (serovar Infantis isolate) nucleotide sequence identity with previously identified ColE-like plasmids. This study demonstrates the occurrence of the qnrB19 gene associated with small ColE plasmids hitherto unrecognized in various Salmonella serovars in Colombia. We also report unusual high-level quinolone resistance in the absence of any DNA gyrase mutations in serovars S. Carrau, Muenchen and Uganda.