title: ICEPmu1, an integrative conjugative element (ICE) of Pasteurella multocida: structure and transfer.
abstract: BACKGROUND
  Integrative and conjugative elements (ICEs) have not been detected in Pasteurella multocida. In this study the multiresistance ICEPmu1 from bovine P. multocida was analysed for its core genes and its ability to conjugatively transfer into strains of the same and different genera.
  
  
  METHODS
  ICEPmu1 was identified during whole genome sequencing. Coding sequences were predicted by bioinformatic tools and manually curated using the annotation software ERGO. Conjugation into P. multocida, Mannheimia haemolytica and Escherichia coli recipients was performed by mating assays. The presence of ICEPmu1 and its circular intermediate in the recipient strains was confirmed by PCR and sequence analysis. Integration sites were sequenced. Susceptibility testing of the ICEPmu1-carrying recipients was conducted by broth microdilution.
  
  
  RESULTS
  The 82 214 bp ICEPmu1 harbours 88 genes. The core genes of ICEPmu1, which are involved in excision/integration and conjugative transfer, resemble those found in a 66 641 bp ICE from Histophilus somni. ICEPmu1 integrates into a tRNA(Leu) and is flanked by 13 bp direct repeats. It is able to conjugatively transfer to P. multocida, M. haemolytica and E. coli, where it also uses a tRNA(Leu) for integration and produces closely related 13 bp direct repeats. PCR assays and susceptibility testing confirmed the presence and the functional activity of the ICEPmu1-associated resistance genes in the recipient strains.
  
  
  CONCLUSIONS
  The observation that the multiresistance ICEPmu1 is present in a bovine P. multocida and can easily spread across strain and genus boundaries underlines the risk of a rapid dissemination of multiple resistance genes, which will distinctly decrease the therapeutic options.
authors: Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Neustadt-Mariensee, Germany.
authors: Geovana Brenner
authors: GB
authors: Michael
authors: Kristina
authors: K
authors: Kadlec
authors: Michael T
authors: MT
authors: Sweeney
authors: Elzbieta
authors: E
authors: Brzuszkiewicz
authors: Heiko
authors: H
authors: Liesegang
authors: Rolf
authors: R
authors: Daniel
authors: Robert W
authors: RW
authors: Murray
authors: Jeffrey L
authors: JL
authors: Watts
authors: Stefan
authors: S
authors: Schwarz
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000235:genetics; D022761:Gene Transfer, Horizontal; D016978:Mannheimia haemolytica / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010326:Pasteurella Infections / Q000382:microbiology / Q000662:veterinary; D016979:Pasteurella multocida / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D012140:Respiratory Tract Diseases / Q000382:microbiology / Q000662:veterinary; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial