title: Molecular epidemiology of Streptococcus zooepidemicus isolated from the respiratory tracts of Thoroughbred racehorses in training.
abstract: The objective of this study was to characterise the molecular epidemiology of Streptococcus zooepidemicus isolated from the respiratory tracts of 198 Thoroughbred racehorses based at three Newmarket training yards over a 10 month period. Typing utilised two separate PCR procedures targeting the M-like protein hypervariable and the 16S-23S RNA gene intergenic spacer regions of the bacterium. S. zooepidemicus, isolated from 23% (224/983) of study samples, comprised 24 different types of varying prevalence. The four most common types, A1HV4, A1HV2, C1HVu and D1HV1, accounted for 45% of all the typed isolates. Overall, the findings were similar to those reported in a study of Welsh Mountain ponies and confirm that in equids, S. zooepidemicus is not a homogeneous, clonal population but instead represents a wide diversity of strain types. This diversity also highlights potential difficulties in using vaccines to control S. zooepidemicus infections in horses as it is likely that the induction of a heterologous, cross-protective immunity will be required.
authors.affiliation: Equine Epidemiology and Disease Surveillance, Centre for Preventive Medicine, Animal Health Trust, Newmarket, Suffolk CB8 7UU, UK.
authors.forename: Nuria
authors.initials: N
authors.lastname: Barquero
authors.forename: Neil
authors.initials: N
authors.lastname: Chanter
authors.forename: Ross
authors.initials: R
authors.lastname: Laxton
authors.forename: James L N
authors.initials: JL
authors.lastname: Wood
authors.forename: J Richard
authors.initials: JR
authors.lastname: Newton
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D006734:Horse Diseases / Q000453:epidemiology* / Q000382:microbiology*; D006736:Horses; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D012621:Seasons; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D018502:Streptococcus equi / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial