To determine whether Fur regulation of tcf was specific to S. Typhi , the tcfA was transformed into S. Typhimurium .
To determine whether Fur regulation of tcf was specific to S. Typhi , the tcfA was transformed into their isogenic fur mutants .
To determine whether Fur regulation of tcf was specific to S. Typhi , the tcfA was transformed into E. coli K-12 .