[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] GUNDERSON MED FDN, MICROBIOL RES LAB, LA CROSSE, WI 54601 USA