[1] Univ Oxford, Dept Zool, Wellcome Trust Ctr Epidemiol & Infect Dis, Oxford OX1 3FY, England
[2] Erasmus Univ, Med Ctr Rotterdam, Dept Med Microbiol & Infect Dis, Rotterdam, Netherlands
[3] Natl Microbiol Lab, Natl Lab Enter Pathogens, Winnipeg, MB R3E 3R2, Canada