title: Transmission and persistence of livestock-associated methicillin-resistant Staphylococcus aureus among veterinarians and their household members.
abstract: After the first isolation of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2003, this MRSA variant quickly became the predominant MRSA obtained from humans as part of the Dutch national MRSA surveillance. Previous studies have suggested that human-to-human transmission of LA-MRSA, compared to that of other MRSA lineages, rarely occurs. However, these reports describe the transmission of LA-MRSA based on epidemiology and limited molecular characterization of isolates, making it difficult to assess whether transmission actually occurred. In this study, we used whole-genome maps (WGMs) to identify possible transmission of LA-MRSA between humans. For this, we used LA-MRSA isolates originating from a 2-year prospective longitudinal cohort study in which livestock veterinarians and their household members were repeatedly sampled for the presence of S. aureus. A considerable degree of genotypic variation among LA-MRSA strains was observed. However, there was very limited variability between the maps of the isolates originating from the same veterinarian, indicating that each of the veterinarians persistently carried or had reacquired the same LA-MRSA strain. Comparison of WGMs revealed that LA-MRSA transmission had likely occurred within virtually every veterinarian household. Yet only a single LA-MRSA strain per household appeared to be involved in transmission. The results corroborate our previous finding that LA-MRSA is genetically diverse. Furthermore, this study shows that transmission of LA-MRSA between humans occurs and that carriage of LA-MRSA can be persistent, thus posing a potential risk for spread of this highly resistant pathogen in the community.
authors.affiliation: Laboratory for Infectious Diseases and Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands Thijs.bosch@rivm.nl.
authors.forename: T
authors.initials: T
authors.lastname: Bosch
authors.affiliation: Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, the Netherlands Laboratory for Medical Microbiology and Immunology, St. Elisabeth Hospital, Tilburg, the Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Verkade
authors.affiliation: Laboratory for Infectious Diseases and Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: van Luit
authors.affiliation: Laboratory for Infectious Diseases and Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Landman
authors.affiliation: Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, the Netherlands Laboratory for Medical Microbiology and Immunology, St. Elisabeth Hospital, Tilburg, the Netherlands Department of Medical Microbiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Kluytmans
authors.affiliation: Laboratory for Infectious Diseases and Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
authors.forename: L M
authors.initials: LM
authors.lastname: Schouls
mesh_terms: D000818:Animals; D002353:Carrier State / Q000453:epidemiology; D005191:Family Characteristics; D005192:Family Health; D016680:Genome, Bacterial; D006801:Humans; D058751:Livestock; D008137:Longitudinal Studies; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D017720:Molecular Epidemiology; D058889:Molecular Typing; D009426:Netherlands; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000635:transmission* / Q000662:veterinary*; D018634:Veterinarians; D015047:Zoonoses / Q000453:epidemiology / Q000635:transmission