title: Salmonella enterica serotype Enteritidis phage types 4, 7, 6, 8, 13a, 29 and 34: a comparative analysis of genomic fingerprints from geographically distant isolates.
abstract: OBJECTIVE
  To evaluate genetic heterogeneity in the most common phage types of Salmonella enterica serovar Enteritidis.
  
  
  RESULTS
  A total of 233 isolates of Salm. Enteritidis from England, Northern Ireland, Spain, Hong Kong and the USA belonging to phage types (PT) 4 (n=88), PT7 (n=12), PT6 (n=72), PT8 (n=14), PT13a (n=29), PT29 (n=14) and PT34 (n=4) were characterized by PstI-SphI (PS) ribotyping and pulsed-field gel electrophoresis after digestion of DNA with XbaI. PS ribotyping differentiated the isolates into 53 different PS types and PFGE showed 14 different macrorestriction profiles; with the combination of both methods, 73 combined types were identified. Some of these clones appeared to be present within several countries. Movement of foodstuffs, animals or people may have been involved in the spread of these strains. On the other hand, some clones were only found in specific locations.
  
  
  CONCLUSIONS
  Several well defined clonal lines seem to co-exist within the different phage types included in this study, and a combined typing approach may constitute a useful tool for epidemiological investigations. Clustering analysis of ribotypes and PFGE types agree with previous studies and suggest that phage types that share receptor binding properties can be distinguished as two families: the PT4 family including PT7 and PT6, and the PT8 family including PT13a. The other phage types are difficult to place in a family unless the geographical site of isolation is known.
  
  
  CONCLUSIONS
  This paper reports on an extensive assessment of the use of molecular tools for the study of the epidemiology of the enteric pathogen Salm. Enteritidis. It also gives new information regarding relationships among some common phage types.
authors.affiliation: Department of Bacterial Diseases, Veterinary Laboratories Agency-Weybridge, UK. e.liebana@VLA.DEFRA.gsi.gov.uk
authors.forename: Ernesto
authors.initials: E
authors.lastname: Liebana
authors.forename: L
authors.initials: L
authors.lastname: Garcia-Migura
authors.forename: J
authors.initials: J
authors.lastname: Guard-Petter
authors.forename: S W J
authors.initials: SW
authors.lastname: McDowell
authors.forename: S
authors.initials: S
authors.lastname: Rankin
authors.forename: H M
authors.initials: HM
authors.lastname: Opitz
authors.forename: F A
authors.initials: FA
authors.lastname: Clifton-Hadley
authors.forename: R H
authors.initials: RH
authors.lastname: Davies
mesh_terms: D016172:DNA Fingerprinting; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry; D005060:Europe; D018740:Genetic Heterogeneity; D016679:Genome, Viral; D006723:Hong Kong; D009656:North America; D012483:Salmonella Phages / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D019779:Salmonella enterica / Q000821:virology*
chemical_list: C046184:endodeoxyribonuclease PaeI; C025580:endodeoxyribonuclease XBAI; C024388:CTGCAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific