Global spread of mouse-adapted Staphylococcus aureus lineages CC1, CC15, and CC88 among mouse breeding facilities

• Published in: International journal of medical microbiology Vol. 308; no. 6; pp. 598 - 606
• Main Authors: Mrochen, Daniel M., Grumann, Dorothee, Schulz, Daniel, Gumz, Janine, Trübe, Patricia, Pritchett-Corning, Kathleen, Johnson, Sarah, Nicklas, Werner, Kirsch, Petra, Martelet, Karine, Brandt, Jens van den, Berg, Sabine, Bröker, Barbara M., Wiles, Siouxsie, Holtfreter, Silva
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01.08.2018
• Subjects: Adaptation, Physiological; Animals; Animals, Laboratory - microbiology; Anti-Bacterial Agents - pharmacology; Breeding; Canada; CC88; China; Colonization; Drug Resistance, Bacterial - genetics; France; Genotype; Germany; Global; Host adaptation; Immune Evasion; Immune evasion cluster; Laboratory mice; Methicillin-Resistant Staphylococcus aureus - genetics; Mice; Multilocus Sequence Typing; New Zealand; Staphylococcal Infections - transmission; Staphylococcus aureus; Staphylococcus aureus - classification; Staphylococcus aureus - drug effects; Staphylococcus aureus - isolation & purification; United States; Virulence Factors - genetics; New Zealand; Canada; France; United States; China; Germany; Host adaptation; Immune evasion cluster; Laboratory mice; Genotype; Staphylococcus aureus; Colonization; Global; CC88
• ISSN: 1438-4221; 1618-0607
• DOI: 10.1016/j.ijmm.2017.11.006

[Display omitted] •We have genotyped 230 S. aureus isolates colonizing laboratory mice from 11 animal facilities around the globe.•The lineages CC1, CC15, and CC88 were common and widespread among laboratory mice.•Murine isolates frequently displayed genetic features that imply adaptation to the murine host. We previously reported that laboratory mice from all global vendors are frequently colonized with Staphylococcus aureus (S. aureus). Genotyping of a snap sample of murine S. aureus isolates from Charles River, US, showed that mice were predominantly colonized with methicillin-sensitive CC88 strains. Here, we expanded our view and investigated whether laboratory mice from other global animal facilities are colonized with similar strains or novel S. aureus lineages, and whether the murine S. aureus isolates show features of host adaptation. In total, we genotyped 230 S. aureus isolates from various vendor facilities of laboratory mice around the globe (Charles River facilities in the USA, Canada, France, and Germany; another US facility) and university- or company-associated breeding facilities in Germany, China and New Zealand. Spa typing was performed to analyse the clonal relationship of the isolates. Moreover, multiplex PCRs were performed for human-specific virulence factors, the immune-evasion cluster (IEC) and superantigen genes (SAg). We found a total of 58 different spa types that clustered into 15 clonal complexes (CCs). Three of these S. aureus lineages had spread globally among laboratory mice and accounted for three quarters of the isolates: CC1 (13.5%), CC15 (14.3%), and CC88 (47.0%). Compared to human colonizing isolates of the same lineages, the murine isolates frequently lacked IEC genes and SAg genes on mobile genetic elements, implying long-term adaptation to the murine host. In conclusion, laboratory mice from various vendors are colonized with host-adapted S. aureus-strains of a few lineages, predominantly the CC88 lineage. S. aureus researchers must be cautioned that S. aureus colonization might be a relevant confounder in infection and vaccination studies and are therefore advised to screen their mice before experimentation.