Poster Presentation International Pasteurellaceae Conference 2014

Plasmid-mediated florfenicol resistance in Actinobacillus pleuropneumoniae (#59)

Janine T. Bosse 1 , Yanwen Li 1 , Tom Atherton 1 , Stephanie Walker 1 , Susanna M. Williamson 2 , Jon Rogers 2 , Roy R. Chaudhuri 3 4 , Lucy A. Weinert 3 , Matt T. Holden 5 , Duncan J. Maskell 3 , Alexander W. Tucker 3 , Brendan W. Wren 6 , Andrew N. Rycroft 7 , Paul R. Langford 1 , on behalf of the BRaDP1T Consortium 1 3 6 7
  1. Department of Medicine, Imperial College London, London, UK
  2. Animal Health and Veterinary Laboratories Agency (AHVLA), Bury St Edmunds, UK
  3. Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
  4. Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
  5. The Pathogen Sequencing Unit, The Wellcome Trust Sanger Institute, Cambridge, UK
  6. Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, London, UK
  7. Department of Pathology and Pathogen Biology, The Royal Veterinary College, Hatfield, UK

Since the licensing in Europe in 2000 of florfenicol for treatment of respiratory disease in pigs, low levels of resistance have been reported in Actinobacillus pleuropneumoniae (APP) isolates from Germany, Spain, the Czech republic and Italy. In some cases the floR gene has been identified by PCR, but no plasmid has been previously isolated. As part of a screen to determine antimicrobial resistance profiles of APP clinical isolates in the UK, we have recently identified one (from 2010) that is florfenicol resistant (MIC of 8 mg/L). It harboured a 7.7 kb plasmid carrying the floR gene. Transformation of this plasmid into Escherichia coli Stellar cells by heat shock conferred resistance to chloramphenicol (5 µg/ml). The complete DNA sequence of the APP plasmid showed similarity to ones found in Mannheimia haemolytica (pMH1405, 7.7 kb) isolated in Japan1 and, to a lesser extent, one from Pasteurella multocida (pCCK381, 10.9 kb) isolated in the UK2. In addition to the floR gene, the APP plasmid carries replication and mobilization genes that are highly conserved in all 3 Pasteurellaceae-derived plasmids, suggesting that the plasmids are mobilizable. 

Acknowledgements

This work was supported by a Longer and Larger (LoLa) grant from the Biotechnology and Biological Sciences Research Council (grant numbers BB/G020744/1, BB/G019177/1, BB/G019274/1 and BB/G003203/1), the UK Department for Environment, Food and Rural Affairs and Zoetis awarded to the Bacterial Respiratory Diseases of Pigs-1 Technology (BRaDP1T) consortium.

  1. Katsuda K, Kohmoto M, Mikami O, Tamamura Y, and Uchida I. 2012. Plasmid-mediated florfenicol resistance in Mannheimia haemolytica isolated from cattle. Vet Microbiol. 155:444-447.
  2. Kehrenberg C, and Schwarz S. 2005. Plasmid-borne florfenicol resistance in Pasteurella multocida. J Antimicrob Chemother. 55:773-775.