AUTHOR=De la Cruz Miguel A. , Ares Miguel A. , von Bargen Kristine , Panunzi Leonardo G. , Martínez-Cruz Jessica , Valdez-Salazar Hilda A. , Jiménez-Galicia César , Torres Javier 

TITLE=Gene Expression Profiling of Transcription Factors of Helicobacter pylori under Different Environmental Conditions

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00615

DOI=10.3389/fmicb.2017.00615

ISSN=1664-302X

ABSTRACT=<p><italic>Helicobacter pylori</italic> is a Gram-negative bacterium that colonizes the human gastric mucosa and causes peptic ulcers and gastric carcinoma. <italic>H. pylori</italic> strain 26695 has a small genome (1.67 Mb), which codes for few known transcriptional regulators that control bacterial metabolism and virulence. We analyzed by qRT-PCR the expression of 16 transcriptional regulators in <italic>H. pylori</italic> 26695, including the three sigma factors under different environmental conditions. When bacteria were exposed to acidic pH, urea, nickel, or iron, the sigma factors were differentially expressed with a particularly strong induction of <italic>fliA</italic>. The regulatory genes <italic>hrcA, hup</italic>, and <italic>crdR</italic> were highly induced in the presence of urea, nickel, and iron. In terms of biofilm formation <italic>fliA, flgR, hp1021, fur, nikR</italic>, and <italic>crdR</italic> were induced in sessile bacteria. Transcriptional expression levels of <italic>rpoD, flgR, hspR, hp1043</italic>, and <italic>cheY</italic> were increased in contact with AGS epithelial cells. Kanamycin, chloramphenicol, and tetracycline increased or decreased expression of regulatory genes, showing that these antibiotics affect the transcription of <italic>H. pylori</italic>. Our data indicate that environmental cues which may be present in the human stomach modulate <italic>H. pylori</italic> transcription.</p>