Multidrug-resistant Salmonella enterica serovar Virchow encoding blaCTX-M3 located on an IncN plasmid isolated from Turkish food of avian origin

Abstract number: P635

Avsaroglu M.D., Junker E., Schroeter A., Helmuth R., Akcelik M., Bozoglu F., Guerra B.

Objectives: Characterisation of plasmid mediated extended spectrum cephalosporins resistance by a blaCTX-M3 in S. Virchow isolated from Turkish Food of avian origin.

Methods: 76 chicken meat samples were collected from different markets in Ankara, Turkey (2005–2006). All isolates were tested for their susceptibility to 17 antimicrobial agents, and ampicillin resistant isolates were tested for an extra panel of 11 b-lactams. One S. Virchow PT26 (DMC19) isolate showed a resistance phenotype typical for ESBLs. The presence of blaCTX-M3 was detected by PCR/sequencing. The complete resistance repertoire (resistance genes, class 1 integron and mutations in the quinolone resistance determining regions) of this strain was characterised by molecular methods. The strain was typed by XbaI-PFGE and plasmid profile analysis. Location of ESBLs was determined by hybridisation assay. The plasmid was analysed by RFLP. The incompatibility group of the plasmid was investigated according to replicon typing by PCR. Conjugative properties were examined by bacterial matings.

Results: The S. Virchow isolate had a multi-drug resistance pattern of [AMP–EFT–CTX-CRO-CPD-ATM]–STR–SUL–TMP–SXT-NAL. Together with blaCTX-M3, the strain also carried blaTEM-1-strA/B-sul2-dfrA14 genes. A gyrATyr-87 mutation was responsible for the NAL resistance. No qnrA, B or S genes were detected. The strain did not possess any class 1 integron. The strain showed a common PFGE pattern like other S. Virchow isolates. It had only one plasmid of about 45 kb, named pBD2006. The blaCTX-M3 gene was located on this plasmid. After several intents the pBD2006 could not be transferred by conjugation. The plasmid belongs to the IncN incompatibility group.

Conclusions: blaCTX-M3 genes located in very big plasmids (300 kb) are wide spread among humans isolates in Mediterranean Regions. In the present study, the gene, located on a smaller plasmid, could be associated to food products of avian origin.

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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