[1] DALHOUSIE UNIV,DEPT MICROBIOL,HALIFAX,NS,CANADA
[2] DALHOUSIE UNIV,DEPT PEDIAT,HALIFAX,NS,CANADA
[3] DALHOUSIE UNIV,DEPT MATH,HALIFAX,NS,CANADA
[4] SUNY DOWNSTATE MED CTR,DEPT MICROBIOL,BROOKLYN,NY 11203
[5] VICTORIA GEN HOSP,RENAL TRANSPLANT CLIN,HALIFAX,NS,CANADA