In addition, C. jejuni infections are associated occasionally APR-246 ic50 with serious neuropathies and other significant sequelae in humans [1]. Historically, this bacterium has been considered fastidious, requiring microaerobic atmosphere and complex

media for optimal growth under laboratory conditions. However, C. jejuni has been isolated from a variety of animals, such as poultry and cattle, as well as other ex vivo niches [2, 3], which highlight the remarkable capability of this bacterium for persistence in different environments as well as its adaptation potential. Despite lacking classical stress response mechanisms [4], C. jejuni has disparate traits that promote its adaptability, including a competency for natural transformation and a highly branched respiratory chain [5, 6]. The latter is composed of individual respiratory proteins (RPs) that impact vital functions in C. jejuni, spanning growth and host colonization [5, 7–11]. The RPs include formate dehydrogenase, hydrogenase, CP673451 research buy fumarate reductase, nitrate and nitrite reductases, and others that facilitate the transfer of

electrons (from donors to acceptors), which drives respiration and, as such, energy metabolism in C. jejuni[5, 11]. Further, whole genome expression studies and other transcriptional analyses showed that genes encoding RPs were differentially expressed in response to shifts in temperature, pH, and oxygen concentration [7, 12–14]. Additionally, many RPs in C. jejuni are transported via the twin-arginine translocation mTOR inhibitor (Tat) system [11], which is specialized in the translocation of pre-folded substrates, including cofactor containing redox proteins, across the cytoplasmic membrane. Of relevant

interest is the impairment of the Tat function in C. jejuni, which leads to pleiotropic phenotypes, including defects in motility, biofilm formation, flagellation, resistance to oxidative Temsirolimus in vitro stress, and chicken colonization [15]. These phenotypes are likely the result of multiple additive effects caused by defects in translocation of the Tat substrates, including RPs. Taken together, these observations further suggest that RPs might impact various adaptation and survival phenotypes in C. jejuni. However, beyond the aforementioned studies and the role of RPs in C. jejuni’s respiration, little is known about the contributions of these proteins to the success of C. jejuni under changing environmental conditions; a property that is critical for understanding the transmission of this pathogen between environments and hosts. Therefore, in this study, we describe the role of five RPs that were predicted to be Tat-dependent [15] in C. jejuni’s motility, resistance to hydrogen peroxide (H2O2) and biofilm formation under different temperature and/or oxygen conditions. We also assessed the contribution of RPs to the bacterium’s in vitro interactions with intestinal epithelial cells of two important hosts (humans and chickens).