title: Molecular characterization of Rhodococcus equi isolates from horses in Poland: pVapA characteristics and plasmid new variant, 85-kb type V.
abstract: BACKGROUND
  Rhodococcus equi is one of the most significant bacterial pathogens affecting foals up to 6 months of age worldwide. Rhodococcosis is present in Poland however information about molecular characterization of R. equi isolates is scarce. This study describes molecular characterization of Rhodococcus equi infection on 13 horse breeding farms in Poland between 2001 and 2012. Samples were collected by tracheobronchial aspiration from pneumonic foals or during necropsy. The R. equi isolates were genotyped by plasmid profiling and pulsed-field gel electrophoresis.
  
  
  RESULTS
  Totally, 58 R. equi isolates were investigated. One isolate lost its plasmid. Among the 57 VapA-positive isolates, 48 contained 85-kb type I plasmid (82.8%), 8 contained 87-kb type I plasmid (13.8%). One isolate (1.7%) had a unique restriction cleavage pattern and the 2nd fragment of EcoRI digests of this plasmid DNA was about 2600 bases smaller than that of the 85 kb type I. This new plasmid variant was designated as the "85-kb type V". Among the 58 isolates typeable with VspI-PFGE, ten PFGE clusters were detected. The majority of foals were infected mostly with isolates of low genetic diversity.
  
  
  CONCLUSIONS
  Most of clinical isolates of R. equi from foals in Poland contain pVapA 85-kb type I and 87-kb type I similarly to the other European countries and the United States. However, the new variant of pVapA 85-kb type V was identified. The chromosomal variability was detected among some of the investigated isolates and the presence of farm-specific isolates might be possible.
authors.affiliation: Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776, Warsaw, Poland. lucjan_witkowski@sggw.pl.
authors.forename: Lucjan
authors.identifier: http://orcid.org/0000-0003-1069-3384
authors.initials: L
authors.lastname: Witkowski
authors.affiliation: Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786, Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rzewuska
authors.affiliation: Department of Animal Hygiene, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Takai
authors.affiliation: Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786, Warsaw, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Chrobak-Chmiel
authors.affiliation: Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786, Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kizerwetter-Świda
authors.affiliation: Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786, Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Feret
authors.affiliation: Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786, Warsaw, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Gawryś
authors.affiliation: University Center of Veterinary Medicine UJ-UR, Mickiewicza 24/28, 30-059, Cracow, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Witkowski
authors.affiliation: Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776, Warsaw, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kita
mesh_terms: D000193:Actinomycetales Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D014644:Genetic Variation; D006734:Horse Diseases / Q000453:epidemiology / Q000382:microbiology*; D006736:Horses; D011044:Poland; D016929:Rhodococcus equi / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C541879:VapA protein, Rhodococcus equi
keywords: Epidemiology; Horse; PFGE; Plasmid profile; Rhodococcosis