About the Authors

Erika J. Crosby

Affiliation Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America

Michael H. Goldschmidt

Affiliation Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America

E. John Wherry

Affiliation Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America

Phillip Scott

pscott@vet.upenn.edu

Affiliation Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: EJC EJW PS. Performed the experiments: EJC. Analyzed the data: EJC MHG. Contributed reagents/materials/analysis tools: EJW PS. Wrote the paper: EJC PS.