Characterization of the yehUT Two-Component Regulatory System of Salmonella enterica Serovar Typhi and Typhimurium

Abstract

Proteins exhibiting hyper-variable sequences within a bacterial pathogen may be associated with host adaptation. Several lineages of the monophyletic pathogen Salmonella enterica serovar Typhi (S. Typhi) have accumulated non-synonymous mutations in the putative two-component regulatory system yehUT. Consequently we evaluated the function of yehUT in S. Typhi BRD948 and S. Typhimurium ST4/74. Transcriptome analysis identified the cstA gene, encoding a carbon starvation protein as the predominantly yehUT regulated gene in both these serovars. Deletion of yehUT had no detectable effect on the ability of these mutant Salmonella to invade cultured epithelial cells (S. Typhi and S. Typhimurium) or induce colitis in a murine model (S. Typhimurium only). Growth, metabolic and antimicrobial susceptibility tests identified no obvious influences of yehUT on these phenotypes.

Bacterial peptide transporters: Messengers of nutrition to virulence

“…74 Nutrient starvation also induces the expression of YehU/YehT, the only 2 component system known to regulate cst genes, in E. coli as well as in Salmonella. 72,75 TppB is transcriptionally regulated by leucine and anaerobiosis in Salmonella, 76 whereas in E. coli, the tppB homolog ydgR is regulated by EnvZ/OmpR 2 component system, 77 showing its involvement in stress response. The stationary phase specific sigma factor RpoS, which is known to regulate several virulence factors required in mammalian host, induces the expression of OppA2 in B. burgdorferi.…”

Food Addiction and Its Impact on Weight-Based Stigma and the Treatment of Obese Individuals in the U.S. and Australia

“…The Yale Food Addiction Scale (YFAS) is the primary method of assessing and diagnosing food addiction [ 6 ]. It has been used to study the prevalence of food addiction in various U.S. populations, such as undergraduates [ 6 ] and individuals with binge eating disorder [ 7 ], as well as in other international samples [ 8 , 9 ]. It has recently been paired with actual food stimuli and a dopamine uptake inhibitor to directly measure appetitive processes [ 10 ].…”

“…It has recently been paired with actual food stimuli and a dopamine uptake inhibitor to directly measure appetitive processes [ 10 ]. While Pedram and colleagues [ 9 ] report a positive association between food addiction diagnosis and body mass index (BMI), a brief review conducted by Meule [ 8 ] demonstrates a non-linear relationship, whereby rates of food addiction are higher among under-, as well as over-weight individuals, compared with normal weight counterparts, that increases further with obesity.…”

“…Greater acceptance of the claim that obesity is a form of food addiction may have important implications for the way that obesity is treated. Paradoxically, we found previously that support for the concept of food addiction was associated with the belief that obese individuals are largely responsible for their weight [ 11 ]. Excess weight is also a highly stigmatized condition, whereby responsibility for weight and weight gain is placed on the individual [ 12 ], often at the expense of contributing factors, such as genetics, health conditions and obesogenic environments.…”

Variation at HLA-DRB1 is associated with resistance to enteric fever

“…The genetic variability of the most common agent of enteric fever ( S . Typhi) together with its virulence mechanisms and epidemiology have been investigated in detail 7,8 , whereas little is known about the human host determinants influencing susceptibility to enteric fever. There are a number of very rare genetic diseases, for example, mediated by mutations in the interleukin (IL)-12 or interferon (IFN)-γ pathways, that result in hypersusceptibility to non-typhoidal Salmonella and other intracellular bacteria 9 , but the corresponding mutations have not, as yet, been associated with enteric fever susceptibility.…”