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stress salmonella

Franziska A Mandl, Volker C Kirsch, Ilke Ugur, Elena Kunold, Jan Vomacka, Christian Fetzer, Sabine Schneider, Klaus Richter, Thilo M Fuchs, Iris Antes, Stephan A Sieber
Gram-negative bacteria represent a challenging task for antibacterial drug discovery owing to their impermeable cell membrane and restricted uptake of small molecules. We herein describe the synthesis of natural-product-derived epoxycyclohexenones and explore their antibiotic activity against several pathogenic bacteria. A compound with activity against Salmonella Typhimurium was identified, and the target enzymes were unraveled by quantitative chemical proteomics. Importantly, two protein hits were linked to bacterial stress response, and corresponding assays revealed an elevated susceptibility to reactive oxygen species upon compound treatment...
October 26, 2016: Angewandte Chemie
Peng Zhang, Hui Liu, Xiaocheng Li, Suzhen Ma, Shuai Men, Heng Wei, Jingjing Cui, Hongning Wang
The harm of Salmonella typhimurium (S. typhimurium) to public health mainly by the consumption of contaminated agricultural products or water stresses an urgent need for rapid detection methods to help control the spread of S. typhimurium. In this work, an intelligently designed sensor system took creative advantage of triple trigger sequences-regenerated strand displacement amplification and self-protective hairpin template-generated-scaffolded silver nanoclusters (AgNCs) for the first time. In the presence of live S...
September 12, 2016: Biosensors & Bioelectronics
Alexandra Vergnes, Julie P M Viala, Rabah Ouadah-Tsabet, Bérengère Pocachard, Laurent Loiseau, Stéphane Méresse, Frédéric Barras, Laurent Aussel
Iron-sulfur (Fe-S)-containing proteins contribute to various biological processes, including redox reactions or regulation of gene expression. Living organisms have evolved by developing distinct biosynthetic pathways to assemble these clusters, including ISC (Iron Sulfur Cluster) and SUF (Sulfur mobilization). Salmonella enterica serovar Typhimurium is an intracellular pathogen responsible for a wide range of infections, from gastroenteritis to severe systemic diseases. Salmonella possesses all known prokaryotic systems to assemble Fe-S clusters, including ISC and SUF...
October 5, 2016: Cellular Microbiology
Agata Jurczak-Kurek, Tomasz Gąsior, Bożena Nejman-Faleńczyk, Sylwia Bloch, Aleksandra Dydecka, Gracja Topka, Agnieszka Necel, Magdalena Jakubowska-Deredas, Magdalena Narajczyk, Malwina Richert, Agata Mieszkowska, Borys Wróbel, Grzegorz Węgrzyn, Alicja Węgrzyn
A large scale analysis presented in this article focuses on biological and physiological variety of bacteriophages. A collection of 83 bacteriophages, isolated from urban sewage and able to propagate in cells of different bacterial hosts, has been obtained (60 infecting Escherichia coli, 10 infecting Pseudomonas aeruginosa, 4 infecting Salmonella enterica, 3 infecting Staphylococcus sciuri, and 6 infecting Enterococcus faecalis). High biological diversity of the collection is indicated by its characteristics, both morphological (electron microscopic analyses) and biological (host range, plaque size and morphology, growth at various temperatures, thermal inactivation, sensitivity to low and high pH, sensitivity to osmotic stress, survivability upon treatment with organic solvents and detergents), and further supported by hierarchical cluster analysis...
October 4, 2016: Scientific Reports
Chelsey M VanDrisse, Kristy L Hentchel, Jorge C Escalante-Semerena
Acetylation of small molecules is widespread in nature, and in some cases, cells use this process to detoxify harmful chemicals. Streptomyces species utilize a Gcn5 N-acetyltransferase (GNAT), known as Bar, to acetylate and detoxify a self-produced toxin, phosphinothricin (PPT), a glutamate analogue. Bar homologues, such as MddA from Salmonella enterica acetylate methionine analogues such as methionine sulfoximine (MSX) and methionine sulfone (MSO), but not PPT, even though Bar homologues are annotated as PPT acetyltransferases...
September 30, 2016: Applied and Environmental Microbiology
Alejandro Pezza, Lucas B Pontel, Carolina López, Fernando C Soncini
Copper homeostasis is essential for bacterial pathogen fitness and infection, and has been the focus of a number of recent studies. In Salmonella, envelope protection against copper overload and macrophage survival depends on CueP, a major copper-binding protein in the periplasm. This protein is also required to deliver the metal ion to the Cu/Zn superoxide dismutase SodCII. The Salmonella-specific CueP-coding gene was originally identified as part of the Cue regulon under the transcriptional control of the cytoplasmic copper sensor CueR, but its expression differs from the rest of CueR-regulated genes...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jinsong Feng, Guillaume Lamour, Rui Xue, Mehr Negar Mirvakliki, Savvas G Hatzikiriakos, Jie Xu, Hongbin Li, Shuo Wang, Xiaonan Lu
Campylobacter jejuni is a microaerophilic pathogen and leading cause of human gastroenteritis. The presence of C. jejuni encased in biofilms found in meat and poultry processing facilities may be the major strategy for its survival and dissemination in aerobic environment. In this study, Staphylococcus aureus, Salmonella enterica, or Pseudomonas aeruginosa was mixed with C. jejuni F38011 as a culture to form dual-species biofilms. After 4days' exposure to aerobic stress, no viable C. jejuni cells could be detected from mono-species C...
December 5, 2016: International Journal of Food Microbiology
Derek M Foster, Keith P Poulsen, Hannah J Sylvester, Megan E Jacob, Kaitlyn E Casulli, Brian E Farkas
This study aimed to determine the effects of high-pressure processing on the immunoglobulin concentration, microbial load, viscosity, and transfer of passive immunity to calves when applied to bovine colostrum as an alternative to thermal pasteurization. A pilot study using Staphylococcus aureus was conducted to determine which pressure-time treatments are most appropriate for use with bovine colostrum, with the goals of maximizing bacterial inactivation while minimizing IgG content and viscosity changes. Following the pilot study, an inoculation study was conducted in which first-milking colostrum samples from Holstein-Friesian cows were inoculated with known concentrations of various bacteria or viruses and pressure processed at either 300 MPa for up to 60 min or at 400 MPa for up to 30 min...
September 13, 2016: Journal of Dairy Science
Omran A Abu Aboud, John M Adaska, Deniece R Williams, Paul V Rossitto, John D Champagne, Terry W Lehenbauer, Robert Atwill, Xunde Li, Sharif S Aly
BACKGROUND: The primary objective of this cross-sectional study was to estimate the crude, seasonal and cull-reason stratified prevalence of Salmonella fecal shedding in cull dairy cattle on seven California dairies. A secondary objective was to estimate and compare the relative sensitivity (Se) and specificity (Sp) for pools of 5 and 10 enriched broth cultures of fecal samples for Salmonella sp. detection. METHODS: Seven dairy farms located in the San Joaquin Valley of California were identified and enrolled in the study as a convenience sample...
2016: PeerJ
Stoimir Kolarević, Mustafa Aborgiba, Margareta Kračun-Kolarević, Jovana Kostić, Predrag Simonović, Vladica Simić, Aleksandra Milošković, Georg Reischer, Andreas Farnleitner, Zoran Gačić, Radmila Milačič, Tea Zuliani, Janja Vidmar, Marija Pergal, Marina Piria, Momir Paunović, Branka Vuković-Gačić
In this study we have performed a comprehensive genotoxicological survey along the 900 rkm of the Sava River. In total, 12 sites were chosen in compliance with the goals of GLOBAQUA project dealing with the effects of multiple stressors on biodiversity and functioning of aquatic ecosystems. The genotoxic potential was assessed using a complex battery of bioassays performed in prokaryotes and aquatic eukaryotes (freshwater fish). Battery comprised evaluation of mutagenicity by SOS/umuC test in Salmonella typhimurium TA1535/pSK1002...
2016: PloS One
Emilia Galdiero, Antonietta Siciliano, Valeria Maselli, Renato Gesuele, Marco Guida, Domenico Fulgione, Stefania Galdiero, Lucia Lombardi, Annarita Falanga
This study attempts to evaluate the antimicrobial activity and the ecotoxicity of quantum dots (QDs) alone and coated with indolicidin. To meet this objective, we tested the level of antimicrobial activity on Gram-positive and Gram-negative bacteria, and we designed an ecotoxicological battery of test systems and indicators able to detect different effects using a variety of end points. The antibacterial activity was analyzed against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 1025), Escherichia coli (ATCC 11229), and Klebsiella pneumoniae (ATCC 10031), and the results showed an improved germicidal action of QDs-Ind...
2016: International Journal of Nanomedicine
Shawn M D Bearson, Bradley L Bearson, Crystal L Loving, Heather K Allen, InSoo Lee, Darin Madson, Marcus E Kehrli
Salmonella colonization of food animals is a concern for animal health and public health as a food safety risk. Various obstacles impede the effort to reduce asymptomatic Salmonella carriage in food animals, including the existence of numerous serovars and the ubiquitous nature of Salmonella. To develop an intervention strategy that is non-specific yet effective against diverse Salmonella serovars, we explored the prophylactic use of a cytokine to decrease Salmonella in swine by boosting the host's innate immune system...
2016: Frontiers in Veterinary Science
Yogesh D Walawalkar, Yatindra Vaidya, Vijayashree Nayak
Salmonella Typhi can chronically persist within the gallbladder of patients suffering from gallbladder diseases. This study, intended to improve our understanding of bacterial mechanisms underlying bile adaptation, revealed that bile, which is a bactericidal agent, led to the generation of reactive oxygen species in S Typhi. Salmonella Typhi in response showed a significant increase in the production of anti-oxidative enzymes, namely superoxide dismutase and catalase. The work reports that the quorum-sensing (QS) system of S Typhi regulates the level of these enzymes during oxidative stress...
November 2016: Pathogens and Disease
Gili Aviv, Galia Rahav, Ohad Gal-Mor
UNLABELLED: Salmonella enterica serovar Infantis is one of the prevalent salmonellae worldwide. Recently, we showed that the emergence of S Infantis in Israel was facilitated by the acquisition of a unique megaplasmid (pESI) conferring multidrug resistance and increased virulence phenotypes. Here we elucidate the ecology, transmission properties, and regulation of pESI. We show that despite its large size (~280 kb), pESI does not impose a significant metabolic burden in vitro and that it has been recently fixed in the domestic S Infantis population...
2016: MBio
Jen-Jie Lee, Ying-Chen Wu, Chih-Jung Kuo, Shih-Ling Hsuan, Ter-Hsin Chen
The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions...
September 25, 2016: Veterinary Microbiology
Julie Joseph, Emmanuelle S Ametepe, Naveen Haribabu, Gerard Agbayani, Lakshmi Krishnan, Alexandre Blais, Subash Sad
Virulent intracellular pathogens, such as the Salmonella species, engage numerous virulence factors to subvert host defence mechanisms to induce a chronic infection that leads to typhoid or exacerbation of other chronic inflammatory conditions. Here we show the role of the forkhead transcription factor FoxO3a during infection of mice with Salmonella typhimurium (ST). Although FoxO3a signalling does not affect the development of CD8(+) T cell responses to ST, FoxO3a has an important protective role, particularly during the chronic stage of infection, by limiting the persistence of oxidative stress...
2016: Nature Communications
Christine E Hartman, David J Samuels, Anna C Karls
Transcription sigma factors direct the selective binding of RNA polymerase holoenzyme (Eσ) to specific promoters. Two families of sigma factors determine promoter specificity, the σ(70) (RpoD) family and the σ(54) (RpoN) family. In transcription controlled by σ(54), the Eσ(54)-promoter closed complex requires ATP hydrolysis by an associated bacterial enhancer-binding protein (bEBP) for the transition to open complex and transcription initiation. Given the wide host range of Salmonella enterica serovar Typhimurium, it is an excellent model system for investigating the roles of RpoN and its bEBPs in modulating the lifestyle of bacteria...
2016: Frontiers in Molecular Biosciences
Courtney Reichhardt, Oscar A McCrate, Xiaoxue Zhou, Jessica Lee, Wiriya Thongsomboon, Lynette Cegelski
Microbial biofilms are communities of cells characterized by a hallmark extracellular matrix (ECM) that confers functional attributes to the community, including enhanced cohesion, adherence to surfaces, and resistance to external stresses. Understanding the composition and properties of the biofilm ECM is crucial to understanding how it functions and protects cells. New methods to isolate and characterize ECM are emerging for different biofilm systems. Solid-state nuclear magnetic resonance was used to quantitatively track the isolation of the insoluble ECM from the uropathogenic Escherichia coli strain UTI89 and understand the role of Congo red in purification protocols...
November 2016: Analytical and Bioanalytical Chemistry
Sara A Burt, Simone J M Adolfse, Dina S A Ahad, Monique H G Tersteeg-Zijderveld, Betty G M Jongerius-Gortemaker, Jan A Post, Holger Brüggemann, Regiane R Santos
Essential oils and organic acids are used as feed additives to improve health status and reduce colonization with pathogens. Although bactericidal in vitro, concentrations achieved in the animal gut are probably not lethal to pathogens. The aim of this study was to investigate the effects of cinnamaldehyde, carvacrol and cinnamic, lactic and propionic acids on the ability of Salmonella typhimurium ATCC 14028 (ST) to invade intestinal epithelial cells (IPEC-J2) and on the expression levels of immune related genes in the cells...
August 25, 2016: Phytotherapy Research: PTR
Gayeung Kwon, Jiyun Lee, Young-Hee Lim
Dairy Propionibacterium freudenreichii is a candidate non-lactic acid probiotic. However, little information is available on the effect of P. freudenreichii on lifespan extension in humans. The aim of this study was to evaluate the effects of P. freudenreichii on lifespan extension and to elucidate the mechanism of P. freudenreichii-dependent lifespan extension in Caenorhabditis elegans. The results showed that P. freudenreichii significantly (p < 0.05) extended the lifespan of C. elegans compared with Escherichia coli OP50, a standard food for the worm...
2016: Scientific Reports
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