AUTHOR=Di Pasquale Pamela , Caterino Marianna , Di Somma Angela , Squillace Marta , Rossi Elio , Landini Paolo , Iebba Valerio , Schippa Serena , Papa Rosanna , Selan Laura , Artini Marco , Palamara Anna Teresa , Duilio Angela 

TITLE=Exposure of E. coli to DNA-Methylating Agents Impairs Biofilm Formation and Invasion of Eukaryotic Cells via Down Regulation of the N-Acetylneuraminate Lyase NanA

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00147

DOI=10.3389/fmicb.2016.00147

ISSN=1664-302X

ABSTRACT=<p>DNA methylation damage can be induced by endogenous and exogenous chemical agents, which has led every living organism to develop suitable response strategies. We investigated protein expression profiles of <italic>Escherichia coli</italic> upon exposure to the alkylating agent methyl-methane sulfonate (MMS) by differential proteomics. Quantitative proteomic data showed a massive downregulation of enzymes belonging to the glycolytic pathway and fatty acids degradation, strongly suggesting a decrease of energy production. A strong reduction in the expression of the N-acetylneuraminate lyases (NanA) involved in the sialic acid metabolism was also observed. Using a null NanA mutant and DANA, a substrate analog acting as competitive inhibitor, we demonstrated that down regulation of NanA affects biofilm formation and adhesion properties of <italic>E. coli</italic> MV1161. Exposure to alkylating agents also decreased biofilm formation and bacterial adhesion to Caco-2 eukaryotic cell line by the adherent invasive <italic>E. coli</italic> (AIEC) strain LF82. Our data showed that methylation stress impairs <italic>E. coli</italic> adhesion properties and suggest a possible role of NanA in biofilm formation and bacteria host interactions.</p>