title: A longitudinal study of Staphylococcus aureus colonization in pigs in Ireland.
abstract: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in livestock has refocused attention on S. aureus colonization and transmission in pigs. This study investigated the effect of the S. aureus colonization status of a sow on the colonization status of her piglets, and whether pigs carry the same strain of S. aureus throughout production. Nasal swabs were collected from the piglets of six healthy sows two days after birth and two days before and two days after they were moved into each production stage. The average prevalence of S. aureus colonization varied between 26% and 73%. The odds of being S. aureus positive were almost 12 times higher for piglets born to nasal-positive sows than for those born to nasal-negative sows, and three times higher again for piglets born to sows that were both nasal- and vaginal-positive. Isolates recovered from piglets immediately after birth were indistinguishable from those of the dam as determined by phenotypic and molecular typing, including microarray analysis and optical mapping. All isolates belonged to clonal complex 9 and the majority exhibited a novel spa type, t10449. The findings show that the S. aureus colonization status of the sow influences the colonization status of her piglets in the early production stages but strains carried by pigs change over time. Multiresistant S. aureus was detected, in particular post-weaning. Results suggest that sow status and management practices, including mixing of pigs and antimicrobial usage at weaning, should be considered when implementing control measures for S. aureus on a farm.
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: Burns
authors.affiliation: Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Ireland; Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, St. James's Hospital, Dublin 8, Ireland.
authors.forename: A C
authors.initials: AC
authors.lastname: Shore
authors.affiliation: Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, St. James's Hospital, Dublin 8, Ireland.
authors.forename: G I
authors.initials: GI
authors.lastname: Brennan
authors.affiliation: Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Ireland.
authors.forename: D C
authors.initials: DC
authors.lastname: Coleman
authors.affiliation: National Reference Laboratory for Antimicrobial Resistance (Food, Feed and Animal Health), Department of Agriculture, Food and the Marine, Backweston Laboratories, Celbridge, Co. Kildare, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Egan
authors.affiliation: School of Public Health, Physiotherapy and Population Science, Science Centre, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Fanning
authors.affiliation: School of Mathematical Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: M C
authors.initials: MC
authors.lastname: Galligan
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: J F
authors.initials: JF
authors.lastname: Gibbons
authors.affiliation: National Reference Laboratory for Antimicrobial Resistance (Food, Feed and Animal Health), Department of Agriculture, Food and the Marine, Backweston Laboratories, Celbridge, Co. Kildare, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Gutierrez
authors.affiliation: Laboratory of Medical Microbiology, Vaccine & Infectious Diseases Institute, University of Antwerp, Antwerp, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Malhotra-Kumar
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: B K
authors.initials: BK
authors.lastname: Markey
authors.affiliation: Laboratory of Medical Microbiology, Vaccine & Infectious Diseases Institute, University of Antwerp, Antwerp, Belgium.
authors.forename: J S
authors.initials: JS
authors.lastname: Sabirova
authors.affiliation: School of Public Health, Physiotherapy and Population Science, Science Centre, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland. Electronic address: nola.leonard@ucd.ie.
authors.forename: F C
authors.initials: FC
authors.lastname: Leonard
mesh_terms: D000818:Animals; D005260:Female; D007494:Ireland / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000502:physiology*; D058889:Molecular Typing; D009666:Nose / Q000382:microbiology; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000502:physiology*; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology; D014621:Vagina / Q000382:microbiology; D014886:Weaning
keywords: Colonization; Longitudinal study; Pigs; Staphylococcus aureus; Typing