[1] Univ Wisconsin, Wisconsin State Lab Hyg, Madison, WI 53706 USA
[2] Univ Wisconsin, Dept Bacteriol, Madison, WI 53706 USA
[3] Univ Wisconsin, Dept Med Microbiol & Immunol, Madison, WI 53706 USA
[4] Univ Wisconsin, Dept Pathol & Lab Med, Madison, WI 53706 USA
[5] Meriter Hosp, Dept Pathol, Madison, WI 53715 USA
[6] Gundersen Lutheran Med Ctr, Microbiol Res Lab, La Crosse, WI 54601 USA
[7] Gundersen Lutheran Med Ctr, Dept Infect Dis, La Crosse, WI 54601 USA