Environmental regulation of the long polar fimbriae 2 of enterohemorrhagic Escherichia coli O157:H7.

ABSTRACT: The molecular mechanisms controlling expression of the long polar fimbriae 2 (Lpf2) of enterohemorrhagic Escherichia coli (EHEC) O157:H7 were evaluated. Primer extension was used to locate the lpfA2 transcriptional start site in EHEC strain EDL933 at 171 bp upstream of the lpfA2 start codon. Semi-quantitative RT-PCR demonstrated that the highest lpfA2 expression occurs between an OD600 of 1.0 and 1.2 in DMEM at pH 6.5 and 37 °C. The level of lpfA2 transcription at OD600 1.2 and pH 6.5 was four times greater than that at pH 7.2. Although lpfA2 expression was decreased under iron-depleted conditions, its expression was increased in a ferric-uptake-regulator (Fur) mutant strain. The lpfA2 transcript was 0.7 and 2 times more abundant in wt EHEC grown in DMEM pH 6.5 plus iron and MacConkey brot

SUBMITTER: Arenas-Hernandez MM 

PROVIDER: S-EPMC4139445 | biostudies-literature | 2014 Aug

REPOSITORIES: biostudies-literature