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characterization of a blandm‑1‑harboring plasmid from a salmonella enterica clinical isolate in china.the plasmid-mediated transmission of antibiotic resistance genes has been reported to be involved in the development of antibiotic resistance in bacteria, and poses a serious threat for the success of bacterial infection treatment and human health worldwide. the present study used a 454 gs‑flx pyrosequencing system to determine the ~140 kb nucleotide sequence of plasmid phs36‑ndm, which was identified in a salmonella stanley isolate from the stool sample of an 11‑month‑old girl at lishui central ...201728627648
coupling killing to neutralization: combined therapy with ceftriaxone/pep19-2.5 counteracts sepsis in rabbits.sepsis, which is induced by severe bacterial infections, is a major cause of death worldwide, and therapies combating the disease are urgently needed. because many drugs have failed in clinical trials despite their efficacy in mouse models, the development of reliable animal models of sepsis is in great demand. several studies have suggested that rabbits reflect sepsis-related symptoms more accurately than mice. in this study, we evaluated a rabbit model of acute sepsis caused by the intravenous ...201728620220
vaccination against salmonella infection: the mucosal way.salmonella enterica subspecies enterica includes several serovars infecting both humans and other animals and leading to typhoid fever or gastroenteritis. the high prevalence of associated morbidity and mortality, together with an increased emergence of multidrug-resistant strains, is a current global health issue that has prompted the development of vaccination strategies that confer protection against most serovars. currently available systemic vaccine approaches have major limitations, includ ...201728615285
rna target profiles direct the discovery of virulence functions for the cold-shock proteins cspc and cspe.the functions of many bacterial rna-binding proteins remain obscure because of a lack of knowledge of their cellular ligands. although well-studied cold-shock protein a (cspa) family members are induced and function at low temperature, others are highly expressed in infection-relevant conditions. here, we have profiled transcripts bound in vivo by the cspa family members of salmonella enterica serovar typhimurium to link the constitutively expressed cspc and cspe proteins with virulence pathways ...201728611217
resistance to the cyclotide cycloviolacin o2 in salmonella enterica caused by different mutations that often confer cross-resistance or collateral sensitivity to other antimicrobial peptides.antimicrobial peptides (amps) are essential components of innate immunity in all living organisms, and these potent broad-spectrum antimicrobials have inspired several antibacterial development programs in the past 2 decades. in this study, the development of resistance to the gram-negative bacterium-specific peptide cycloviolacin o2 (cyo2), a member of the cyclotide family of plant miniproteins, was characterized in salmonella enterica serovar typhimurium lt2. mutants isolated from serial passa ...201728607015
the snake raiser lung: an unusual cause of salmonella enterica subspecies arizonae pneumonia. 201728602385
schmallenberg virus infection confirmed in scotland.schmallenberg virus infection in malformed lambsfood chain issues after lead poisoning incidentsuspected ragwort poisoning in heifersewe abortions due to salmonella enterica serovar urbanacoxiella burnetii detected in aborted lambsthese are among matters discussed in the disease surveillance report for february 2017 from sac consulting: veterinary services (sac c vs).201728600415
non-typhi salmonella enterica urinary tract infections.non-typhi salmonella enterica urinary tract infections (utis) are not frequent and rarely reported in the literature. we aimed to characterize clinical presentations and risk factors for the infection.201728600113
draft genome sequences of salmonella lysozyme gene knockout mutants.lysozyme enzymes hydrolyze the β-1,4-glycosidic bond in oligosaccharides. these enzymes are part of a broad group of glucoside hydrolases that are poorly characterized; however, they are important for growth and are being recognized as emerging virulence factors. this is the release of four lysozyme-encoding-gene-deletion mutants in salmonella enterica serovar typhimurium lt2.201728596411
transcriptomic analysis of the swarm motility phenotype of salmonella enterica serovar typhimurium mutant defective in periplasmic glucan synthesis.movement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. salmonella enterica serovar typhimurium mutants defective in osmoregulated periplasmic glucans (opg) synthesis are unable to exhibit motility on moist surfaces (swarming); however, their mobility in liquid (swim motility) remains unaffected. in order to understand the role of opg in swarm motility, transcriptomic analysis was perform ...201728593349
borrelidins c-e: new antibacterial macrolides from a saltern-derived halophilic nocardiopsis sp.chemical investigation of a halophilic actinomycete strain belonging to the genus nocardiopsis inhabiting a hypersaline saltern led to the discovery of new 18-membered macrolides with nitrile functionality, borrelidins c-e (1-3), along with a previously reported borrelidin (4). the planar structures of borrelidins c-e, which are new members of the rare borrelidin class of antibiotics, were elucidated by nmr, mass, ir, and uv spectroscopic analyses. the configurations of borrelidines c-e were det ...201728587270
evidence for improved encapsulated pathway behavior in a bacterial microcompartment through shell protein engineering.bacterial microcompartments are a class of proteinaceous organelles comprising a characteristic protein shell enclosing a set of enzymes. compartmentalization can prevent escape of volatile or toxic intermediates, prevent off-pathway reactions, and create private cofactor pools. encapsulation in synthetic microcompartment organelles will enhance the function of heterologous pathways, but to do so, it is critical to understand how to control diffusion in and out of the microcompartment organelle. ...201728585808
factors influencing the salmonella internalization into seedpods and whole plants of arachis hypogaea (l.).here we investigated whether salmonella enterica serovar typhimurium atcc 14028 was capable of internalizing in peanut seedpods and plants when exposed to inoculated soil and the edaphic factors that influenced uptake. intact dry virginia (dv) and fresh green virginia (gv) seedpods were exposed to soil containing 6.5 log (cfu/g) salmonella under different soil moisture conditions. internalization of s. typhimurium into peanut plants germinated in inoculated soil was also examined with and withou ...201728576367
signal transduction pathway mediated by the novel regulator loia for low oxygen tension induced salmonella typhimurium invasion.salmonella enterica serovar typhimurium (s. typhimurium) is a major intestinal pathogen of both humans and animals. salmonella pathogenicity island 1 (spi-1)-encoded virulence genes are required for s. typhimurium invasion. while oxygen (o2) limitation is an important signal for spi-1 induction under host conditions, how the signal is received and integrated to the central spi-1 regulatory system in s. typhimurium is not clear. here, we report a signal transduction pathway that activates spi-1 e ...201728575106
patterns in antimicrobial susceptibility of salmonellae isolated at a tertiary care hospital in northern india.multidrug-resistant salmonellae have emerged worldwide as also in india. the aim of this study was to study the antimicrobial susceptibility pattern of salmonella enterica serovars isolated at a tertiary care hospital in northern india.201728574025
recovery of salmonella enterica from australian layer and processing environments following outbreaks linked to eggs. 201728570831
a toxin involved in salmonella persistence regulates its activity by acetylating its cognate antitoxin, a modification reversed by cobb sirtuin deacetylase.bacterial toxin-antitoxin systems trigger the onset of a persister state by inhibiting essential cellular processes. the tact toxin of salmonella enterica is known to induce a persister state in macrophages through the acetylation of aminoacyl-trnas. here, we show that the tact toxin and the taca antitoxin work as a complex that modulates tact activity via the acetylation state of taca. tact acetylates taca at residue k44, a modification that is removed by the nad(+)-dependent cobb sirtuin deace ...201728559487
sugar sulfates are not hydrolyzed by the acid-inducible sulfatase asla from salmonella enterica enteritidis nal(r) and kentucky 3795 at ph 5.5.the open reading frames sen0085 and seka_a4361, from salmonella enterica serovar enteritidis nal(r) and serovar kentucky 3795, respectively, corresponding to the acid-inducible sulfatase gene asla from salmonella enterica serovar typhimurium, were previously suggested by microarray analysis to be differentially expressed under acid conditions. however, growth and enzyme activity tests in the present study demonstrated that both wild-type strains exhibited sulfatase activity with 4-nitrophenyl su ...201728558253
structural and functional dissection reveals distinct roles of ca2+-binding sites in the giant adhesin siie of salmonella enterica.the giant non-fimbrial adhesin siie of salmonella enterica mediates the first contact to the apical site of epithelial cells and enables subsequent invasion. siie is a 595 kda protein composed of 53 repetitive bacterial immunoglobulin (big) domains and the only known substrate of the spi4-encoded type 1 secretion system (t1ss). the crystal structure of big50-52 of siie revealed two distinct ca2+-binding sites per big domain formed by conserved aspartate or glutamate residues. in a mutational ana ...201728558023
global gene-expression analysis of the response of salmonella enteritidis to egg white exposure reveals multiple egg white-imposed stress responses.chicken egg white protects the embryo from bacterial invaders by presenting an assortment of antagonistic activities that combine together to both kill and inhibit growth. the key features of the egg white anti-bacterial system are iron restriction, high ph, antibacterial peptides and proteins, and viscosity. salmonella enterica serovar enteritidis is the major pathogen responsible for egg-borne infection in humans, which is partly explained by its exceptional capacity for survival under the har ...201728553268
the in vitro and in vivo protective effects of tannin derivatives against salmonella enterica serovar typhimurium infection.in this study, we investigated the protective effects of tannin-derived components, gallic acid (ga) and tannic acid (ta), in vitro and in vivo against salmonella infection in mice. both ga and ta showed antibacterial effects against salmonella (s.) typhimurium as well as inhibitory effects on the adherence, invasion, and intracellular growth of the pathogens in macrophages. following a lethal dose of salmonella infection in mice, reduced virulence in both ga- and ta-treated groups was observed ...201728552635
evaluation of radio-frequency heating in controlling salmonella enterica in raw shelled almonds.this study was conducted to investigate the efficacy of radio-frequency (rf) heating to reduce salmonella enterica serovars enteritidis, typhimurium, and senftenberg in raw shelled almonds compared to conventional convective heating, and the effect of rf heating on quality by measuring changes in the color and degree of lipid oxidation. agar-grown cells of three pathogens were inoculated onto the surface or inside of raw shelled almonds using surface inoculation or the vacuum perfusion method, r ...201728551280
quantitative proteomic analysis of host epithelial cells infected by salmonella enterica serovar typhimurium.systems-level analyses have the capability to offer new insight into host-pathogen interactions on the molecular level. using salmonella infection of host epithelial cells as a model system, we previously analyzed intracellular bacterial proteome as a window into pathogens' adaptations to their host environment [infect. immun. 2015; j. proteome res. 2017]. herein we extended our efforts to quantitatively examine protein expression of host cells during infection. in total, we identified more than ...201728544771
first detection of a fosfomycin resistance gene, fosa7, in salmonella enterica serovar heidelberg isolated from broiler chickens.we previously described salmonella enterica serovar heidelberg isolates harboring a chromosomal gene cluster similar to the glutathione s-transferase gene, a putative fosa gene conferring resistance to fosfomycin. here, we show that this new gene, named fosa7, confers resistance to fosfomycin. the introduction of fosa7 into the fosfomycin-susceptible salmonella enterica serovar enteritidis resulted in a substantial increase in the fosfomycin mic. this finding increases the awareness of antibioti ...201728533247
genetic basis for loss of immuno-reactive o-chain in salmonella enterica serovar enteritidis veterinary isolates.fifty-two rough salmonella enterica serovar enteritidis (s. enteritidis) isolates from broilers and the environment were characterized for their serological and genotypic properties. under routine diagnostic serotyping methods such isolates lack the immuno-reactivity of the o-chain of the lipopolysaccharide (lps), and are referred to as non-typeable. using a modified slide agglutination method, the isolates could be differentiated into three different serological variants. twenty-six isolates (5 ...201728532797
identification of transcriptional modules and key genes in chickens infected with salmonella enterica serovar pullorum using integrated coexpression analyses.salmonella enterica pullorum is one of the leading causes of mortality in poultry. understanding the molecular response in chickens in response to the infection by s. enterica is important in revealing the mechanisms of pathogenesis and disease progress. there have been studies on identifying genes associated with salmonella infection by differential expression analysis, but the relationships among regulated genes have not been investigated. in this study, we employed weighted gene coexpression ...201728529955
proteome remodelling by the stress sigma factor rpos/σ(s) in salmonella: identification of small proteins and evidence for post-transcriptional regulation.the rpos/σ(s) sigma subunit of rna polymerase is the master regulator of the general stress response in many gram-negative bacteria. extensive studies have been conducted on σ(s)-regulated gene expression at the transcriptional level. in contrast, very limited information regarding the impact of σ(s) on global protein production is available. in this study, we used a mass spectrometry-based proteomics approach to explore the wide σ(s)-dependent proteome of the human pathogen salmonella enterica ...201728522802
amylases and their importance during glycan degradation: genome sequence release of salmonella amylase knockout strains.amylases catalyze the cleavage of α-d-1,4 and α-d-1,6-glycosidic bonds in starch and related carbohydrates. amylases are widely distributed in nature and are important in carbohydrate metabolism. this is the release of four single and two double deletions in salmonella enterica serovar typhimurium lt2 that are important for glycan degradation during infection.201728522713
genomic analysis of salmonella enterica serovar typhimurium dt160 associated with a 14-year outbreak, new zealand, 1998-2012.during 1998-2012, an extended outbreak of salmonella enterica serovar typhimurium definitive type 160 (dt160) affected >3,000 humans and killed wild birds in new zealand. however, the relationship between dt160 within these 2 host groups and the origin of the outbreak are unknown. whole-genome sequencing was used to compare 109 salmonella typhimurium dt160 isolates from sources throughout new zealand. we provide evidence that dt160 was introduced into new zealand around 1997 and rapidly propagat ...201728516864
salmonella diva vaccine reduces disease, colonization and shedding due to virulent s. typhimurium infection in swine.non-host-adapted salmonella serovars, including the common human food-borne pathogen salmonella enterica serovar typhimurium (s. typhimurium), are opportunistic pathogens that can colonize food-producing animals without causing overt disease. interventions against salmonella are needed to enhance food safety, protect animal health and allow the differentiation of infected from vaccinated animals (diva).201728516860
zinc supplementation, via gpr39, upregulates pkcζ to protect intestinal barrier integrity in caco-2 cells challenged by salmonella enterica serovar typhimurium.background: zinc has been shown to improve intestinal barrier function against salmonella enterica serovar typhimurium (s. typhimurium) infection, but the mechanisms involved in this process remain undefined.objective: we aimed to explore the roles of g protein-coupled receptor (gpr)39 and protein kinase cζ (pkcζ) in the regulation by zinc of intestinal barrier function.methods: a transwell caco-2 monolayer was pretreated with 0, 50, or 100 μm zn and then incubated with s. typhimurium for 0-6 h. ...201728515165
salinity stress does not affect root uptake, dissemination and persistence of salmonella in sweet-basil (ocimum basilicum).crop produce can be contaminated in the field during cultivation by bacterial human pathogens originating from contaminated soil or irrigation water. the bacterial pathogens interact with the plant, can penetrate the plant via the root system and translocate and survive in above-ground tissues. the present study is first to investigate effects of an abiotic stress, salinity, on the interaction of plants with a bacterial human pathogen. the main sources of human bacterial contamination of plants ...201728512466
iron- and hepcidin-independent downregulation of the iron exporter ferroportin in macrophages during salmonella infection.retention of iron in tissue macrophages via upregulation of hepcidin (hamp) and downregulation of the iron exporter ferroportin (fpn) is thought to participate in the establishment of anemia of inflammation after infection. however, an upregulation of fpn has been proposed to limit macrophages iron access to intracellular pathogens. therefore, we studied the iron homeostasis and in particular the regulation of fpn after infection with salmonella enterica serovar typhimurium in mice presenting ti ...201728507548
tumor necrosis factor receptor-associated factor 6 (traf6) mediates ubiquitination-dependent stat3 activation upon salmonella enterica serovar typhimurium infection.salmonella enterica serovar typhimurium can inject effector proteins into host cells via type iii secretion systems (t3sss). these effector proteins modulate a variety of host transcriptional responses to facilitate bacterial growth and survival. here we show that infection of host cells with s typhimurium specifically induces the ubiquitination of tumor necrosis factor receptor-associated factor 6 (traf6). this traf6 ubiquitination is triggered by the salmonella pathogenicity island 1 (spi-1) t ...201728507064
inactivation of gram (-) bacteria salmonella enterica by chlorophyllin-based photosensitization: mechanism of action and new strategies to enhance the inactivation efficiency.this study is focused on the enhancement of susceptibility of gram (-) bacteria s. enterica to chlorophyllin-based (chl) photosensitization combining it with other antimicrobial tools. in order to find best combinations, the mechanism by which chl-based photosensitization inactivates bacteria must be identified. data confirmed that photosensitization (chl 1.5×10(-5)m, for 1-120min, 405nm, 0-46.1j/cm(2)) reduced s. enterica population, just by 2.05 log (cfu/ml). fluorimetric measurements indicate ...201728505496
multiple clones and low antimicrobial resistance rates for salmonella enterica serovar infantis populations in greece.all the salmonella enterica ser. infantis strains isolated under official control programs in greece during a four year period were studied, 23 of human origin, 16 from food animals and one from food. molecular analyses (pfge) in combination with antimicrobial susceptibility testing were used to study whether the occurrence s. infantis in greece resulted from different biotypes or a successful spread of one clone. low rates of antimicrobial resistance were observed, except for streptomycin among ...201728504096
persistence of salmonella typhimurium lt2 in soil enhanced after growth in lettuce medium.the persistence of salmonella in the environment is influenced by a multitude of biotic and abiotic factors. in addition, its persistence can be influenced by preadaptation before the introduction into the environment. in order to study how preadaptation changes the survival of salmonella in soil and therefore its potential to colonize the phytosphere, we developed a new medium based on lettuce material [lettuce medium (lm)]. salmonella enterica serovar typhimurium strain lt2 was used as a model ...201728503171
real-time pcr method for detection of salmonella spp. in environmental samples.the methods currently used for detecting salmonella in environmental samples require 2 days to produce results and have limited sensitivity. here, we describe the development and validation of a real-time pcr salmonella screening method that produces results in 18 to 24 h. primers and probes specific to the gene inva, group d, and salmonella enterica serovar enteritidis organisms were designed and evaluated for inclusivity and exclusivity using a panel of 329 salmonella isolates representing 126 ...201728500041
characterization of the salmonella enterica serotype isangi isolated from patients for the first time in china.no studies have reported the isolation of serotype salmonella isangi from cases of salmonellosis in mainland china. we investigated an outbreak of foodborne disease with salmonella and collected the samples from the patients and surplus foods. salmonella strains were isolated and the serotype was identified according to the kauffmann-white scheme. the relatedness of the isolates was determined using pulsed-field gel electrophoresis (pfge) and whole genome sequencing (wgs). antimicrobial suscepti ...201728497996
implication of sialidases in salmonella infection: genome release of sialidase knockout strains from salmonella enterica serovar typhimurium lt2.sialidases, which are widely distributed in nature, cleave the α-ketosidic bond of terminal sialic acid residue. these emerging virulence factors degrade the host glycan. we report here the release of seven sialidase and one sialic acid transporter deletion in salmonella enterica serovar typhimurium strain lt2, which are important in cellular invasion during infection.201728495784
complete genome sequence of bacteriophage sen8, a temperate phage isolated from salmonella enterica subsp. salamae.a temperate phage, sen8, having a broad activity against pathogenic salmonella serovars, was isolated from salmonella enterica subsp. salamae strain sen8. the complete genome sequence of phage sen8 was determined (35,203 bp) and showed relatedness to p2-like phages (salmonella phages fels-2 and re-2010).201728495765
salmonella enterica serovar panama meningitis in exclusive breastfeeding infants: report of 4 cases, clinical features and therapeutic challenges.the pathway of nontyphoid salmonella meningitis, especially in exclusive breastfeeding infants, has not been well characterized.201728489741
evaluating the trends of bloodstream infections among pediatric and adult patients at a teaching hospital of kathmandu, nepal: role of drug resistant pathogens.bloodstream infections (bsis) are among the significant causes of morbidity and mortality for patients of all age groups. however, very little is known about the trends of bacterial bloodstream infections and antimicrobial susceptibilities among pediatric and adult population from nepal. in this study, we have investigated the different etiological agents responsible for bloodstream infections among pediatric and adult patients and the role of drug resistant organisms in these infections at a te ...201728484498
antimicrobial resistance of salmonella enterica serovars typhi and paratyphi isolates from a general hospital in karawaci, tangerang, indonesia: a five-year review.typhoid and paratyphoid fever known as enteric fever pose important global public health problem, with 21.6 million cases and approximately 250,000 deaths annually. it is a prevalent disease in indonesia, but data on the antimicrobial resistance pattern is limited. this study aim was to provide data on the antimicrobial resistance pattern of s. typhi and s. paratyphi bloodstream isolates in a general hospital in karawaci, tangerang, banten, indonesia, during the period of january 2011 to decembe ...201728484494
comparative analysis of extended-spectrum-β-lactamase ctx-m-65-producing salmonella enterica serovar infantis isolates from humans, food animals, and retail chickens in the united states.we sequenced the genomes of 10 salmonella enterica serovar infantis isolates containing blactx-m-65 obtained from chicken, cattle, and human sources collected between 2012 and 2015 in the united states through routine national antimicrobial resistance monitoring system (narms) surveillance and product sampling programs. we also completely assembled the plasmids from four of the isolates. all isolates had a d87y mutation in the gyra gene and harbored between 7 and 10 resistance genes [aph(4)-ia, ...201728483962
genotypic and phenotypic characterization of multidrug resistant salmonella typhimurium and salmonella kentucky strains recovered from chicken carcasses.salmonella typhimurium is the leading cause of human non-typhoidal gastroenteritis in the us. s. kentucky is one the most commonly recovered serovars from commercially processed poultry carcasses. this study compared the genotypic and phenotypic properties of two salmonella enterica strains typhimurium (st221_31b) and kentucky (sk222_32b) recovered from commercially processed chicken carcasses using whole genome sequencing, phenotype characterizations and an intracellular killing assay. illumina ...201728481935
a systems-level model reveals that 1,2-propanediol utilization microcompartments enhance pathway flux through intermediate sequestration.the spatial organization of metabolism is common to all domains of life. enteric and other bacteria use subcellular organelles known as bacterial microcompartments to spatially organize the metabolism of pathogenicity-relevant carbon sources, such as 1,2-propanediol. the organelles are thought to sequester a private cofactor pool, minimize the effects of toxic intermediates, and enhance flux through the encapsulated metabolic pathways. we develop a mathematical model of the function of the 1,2-p ...201728475631
contribution of the csga and bcsa genes to salmonella enterica serovar pullorum biofilm formation and virulence.salmonella biofilm formation is important to environmental stress resistance and virulence. however, the roles of the csga and bcsa genes, which affect curli protein and cellulose production, respectively, in salmonella enterica serovar pullorum, are unknown. here we constructed deletions in the csga and bcsa genes in s. enterica serovar pullorum strain s6702 and evaluated several aspects of biofilm formation and virulence. δcsga showed decreased production of curli fimbriae, while δbcsa had red ...201728470089
urine disinfection and in situ pathogen killing using a microbial fuel cell cascade system.microbial fuel cells (mfcs) are emerging as an effective means of treating different types of waste including urine and wastewater. however, the fate of pathogens in an mfc-based system remains unknown, and in this study we investigated the effect of introducing the enteric pathogen salmonella enterica serovar enteritidis in an mfc cascade system. the mfcs continuously fed with urine showed high disinfecting potential. as part of two independent trials, during which the bioluminescent s. enterit ...201728463976
fatal systemic salmonellosis in a florida manatee ( trichechus manatus latirostris).a subadult male florida manatee ( trichechus manatus latirostris) stranded dead on florida's atlantic coast in january 2015. necropsy and histopathologic findings confirmed chronic systemic bacterial infection caused by salmonella enterica serotype iv 50:z4,z23,:- involving renal, respiratory, lymphatic, and skeletal systems. this was a unique case of systemic salmonellosis in a florida manatee.201728463629
interaction of ethidium and tetraphenylphosphonium cations with salmonella enterica cells.one of the main causes of bacterial resistance to antimicrobials is multidrug resistance induced by the increased efficiency of the efflux pumps. in this study we analyzed how the conditions of assay affect the efflux of indicator substrates ethidium (et(+)) and tetraphenylphosphonium (tpp(+)) in salmonella enterica ser. typhimurium cells. impact of the outer membrane permeability barrier, composition and temperature of the medium on accumulation of the indicator compounds also was analyzed.201728462872
influence of salmonella status on the long-term outcome of horses after colic surgery.to compare long-term outcome of salmonella-positive versus salmonella-negative horses discharged from hospital after colic surgery.201728462509
effect of water activity on the thermal tolerance and survival of salmonella enterica serovars tennessee and senftenberg in goat's milk caramel.the low thermal tolerance of salmonella enterica in foods with intermediate moisture levels, such as caramel sauces, ensures that mild heat treatment is sufficient to achieve 5-log reductions of this pathogen. this treatment mitigates the risk posed by salmonellae in raw materials; however, recontamination might occur because of survival of the pathogen in products that are not heated before consumption. this study was conducted to evaluate the effect of water activity (aw) on the thermal tolera ...201728459616
isolation and characterization of salmonella enteritidis and salmonella typhimurium from chicken meat in egypt.salmonella enterica serovars enteritidis and typhimurium represent the major serovars associated with human salmonellosis. contamination of meat products with these serovars is considered the main source of infection.201728459222
subtyping of canadian isolates of salmonella enteritidis using multiple locus variable number tandem repeat analysis (mlva) alone and in combination with pulsed-field gel electrophoresis (pfge) and phage typing.salmonella enterica subspecies enterica serovar enteritidis (se) is one of the most common causes of human salmonellosis and in canada currently accounts for over 40% of human cases. reliable subtyping of isolates is required for outbreak detection and source attribution. however, pulsed-field gel electrophoresis (pfge), the current standard subtyping method for salmonella spp., is compromised by the high genetic homogeneity of se. multiple locus variable number tandem repeat analysis (mlva) was ...201728456552
dual host specificity of phage sp6 is facilitated by tailspike rotation.bacteriophage sp6 exhibits dual-host adsorption specificity. the sp6 tailspikes are recognized as important in host range determination but the mechanisms underlying dual host specificity are unknown. cryo-electron tomography and sub-tomogram classification were used to analyze the sp6 virion with a particular focus on the interaction of tailspikes with host membranes. the sp6 tail is surrounded by six v-shaped structures that interconnect in forming a hand-over-hand hexameric garland. each v-sh ...201728456019
metalloriboswitches: rna-based inorganic ion sensors that regulate genes.divalent ions fulfill essential cellular roles and are required for virulence by certain bacteria. free intracellular mg(2+) can approach 5 mm, but at this level mn(2+), ni(2+), or co(2+) can be growth-inhibitory, and magnesium fluoride is toxic. to maintain ion homeostasis, many bacteria have evolved ion sensors embedded in the 5'-leader sequences of mrnas encoding ion uptake or efflux channels. here, we review current insights into these "metalloriboswitches," emphasizing ion-specific binding ...201728455443
effect of dietary bacteriophage supplementation on internal organs, fecal excretion, and ileal immune response in laying hens challenged by salmonella enteritidis.with the current researches on replacing antibiotics with different dietary interventions, bacteriophages (bp) are potential antimicrobial intervention because of their ability to affect specific bacteria. a study was conducted to evaluate the role of bp against salmonella enterica serovar enteritidis (se) on se internal organs colonization and ileum immune response in laying hens. hens were challenged both orally and intracloacally with 108 cfu/ml cells of nalidixic acid resistant salmonella en ...201728453774
salmonella enterica serovar enteritidis liver abscess after blunt abdominal trauma.salmonella enterica serovar enteritidis is among the most reported serotypes of salmonella species worldwide, but rarely reported as the causative agent of a liver abscess.201728443586
genetic and dietary iron overload differentially affect the course of salmonella typhimurium infection.genetic and dietary forms of iron overload have distinctive clinical and pathophysiological features. hfe-associated hereditary hemochromatosis is characterized by overwhelming intestinal iron absorption, parenchymal iron deposition, and macrophage iron depletion. in contrast, excessive dietary iron intake results in iron deposition in macrophages. however, the functional consequences of genetic and dietary iron overload for the control of microbes are incompletely understood. using hfe(+/+) and ...201728443246
invs coordinates expression of prgh and fimz and is required for invasion of epithelial cells by salmonella enterica serovar typhimurium.deep sequencing has revolutionized our understanding of the bacterial rna world and has facilitated the identification of 280 small rnas (srnas) in salmonella despite the suspicions that srnas may play important roles in salmonella pathogenesis, the functions of most srnas remain unknown. to advance our understanding of rna biology in salmonella virulence, we searched for srnas required for bacterial invasion into nonphagocytic cells. after screening 75 srnas, we discovered that the ablation of ...201728439039
antimicrobial activity of free and liposome-encapsulated thymol and carvacrol against salmonella and staphylococcus aureus adhered to stainless steel.antimicrobial activity of thymol, carvacrol and thymol/carvacrol liposomes (tcl) was evaluated against two bacterial pools, each one consisting of four strains of staphylococcus aureus or salmonella enterica. tcl were prepared using thin-film hydration, showing 270.20nm average diameter (polydispersity index of 0.33) and zeta potential of +39.99mv. minimum inhibitory concentration (mic) of thymol, carvacrol and tcl against s. aureus pool was 0.662mg/ml, while mic for salmonella pool was 0.331mg/ ...201728436830
genetic diversity and virulence genes of salmonella enterica subspecies enterica serotype enteritidis isolated from meats and eggs.salmonella enterica subspecies enterica serotype enteritidis (s. enteritidis) is one of the leading causes of food-borne gastroenteritis associated with the consumption of contaminated food products of animal origin. little is known about the genetic diversity and virulence content of s. enteritidis isolated from poultry meats and eggs in iran. a total of 34 s. enteritidis strains were collected from different food sources of animal origin in tehran from may 2015 to july 2016. all of the s. ente ...201728433796
optimizing the restored chemotactic behavior of anticancer agent salmonella enterica serovar typhimurium vnp20009.bacteria, including strains of salmonella, have been researched and applied as therapeutic cancer agents for centuries. salmonella are particularly of interest due to their facultative anaerobic nature, facilitating colonization of differentially oxygenated tumor regions. additionally, salmonella can be manipulated with relative ease, resulting in the ability to attenuate the pathogen or engineer vectors for drug delivery. it was recently discovered that the anti-cancer salmonella enterica serov ...201728433721
effect of salmonella enterica serovar typhimurium vnp20009 and vnp20009 with restored chemotaxis on 4t1 mouse mammary carcinoma progression.a variety of bacterial strains have been evaluated as bio-therapeutic and immunomodulatory agents to treat cancer. one such strain, salmonella enterica serovar typhimurium vnp20009, which is attenuated by a purine auxotrophic mutation and modified lipid a, is characterized in previous models as a safely administered, tumor colonizing agent. however, earlier work tended to use less aggressive cancer cell lines and immunocompromised animal models. here, we investigated the safety and efficacy of v ...201728431394
survival and transfer efficacy of mixed strain salmonella enterica ser. typhimurium from beef burgers to abiotic surfaces and determination of individual strain contribution.the aim of the study was to evaluate the survival and transfer efficacy of 3 salmonella typhimurium strains from beef burgers to abiotic surfaces and determine the individual strain distribution. s. typhimurium population on beef burgers during incubation remained constant at initial levels of contamination approximately 3 and 5 log cfu/g. additionally, the survival of pathogens on soiled hdpe surfaces was significant during incubation at both initial inocula, while ca 1.5 log cfu/cm(2) reductio ...201728431296
an unmodified wobble uridine in trnas specific for glutamine, lysine, and glutamic acid from salmonella enterica serovar typhimurium results in nonviability-due to increased missense errors?in the wobble position of trnas specific for gln, lys, and glu a universally conserved 5-methylene-2-thiouridine derivative (xm5s2u34, x denotes any of several chemical substituents and 34 denotes the wobble position) is present, which is 5-(carboxy)methylaminomethyl-2-thiouridine ((c)mnm5s2u34) in bacteria and 5-methylcarboxymethyl-2-thiouridine (mcm5s2u34) in eukarya. here we show that mutants of the bacterium salmonella enterica serovar typhimurium lt2 lacking either the s2- or the (c)mnm5-gr ...201728430781
occurrence of a novel class 1 integron harboring qnrvc4 in salmonella rissen.we described qnrvc4 in s. rissen 166anss50, a swine isolate, which was detected in the study on quinolone resistance mechanisms of nontyphoidal salmonella in thailand. the isolate was found to harbor a ̴17-kb non-conjugative plasmid carrying qnrvc4 within 8.91kb of a novel in4-like class 1 integron (in805). it contained the multi-drug resistance gene cassettes of qnrvc4-qach4-aaca4-cmla7-blaoxa-10-aada1-dfra14 and unusual 3'-cs of mobc-is6100. this 1014-bp qnrvc4 cassette included with promoter ...201728427794
a second wave of salmonella t3ss1 activity prolongs the lifespan of infected epithelial cells.type iii secretion system 1 (t3ss1) is used by the enteropathogen salmonella enterica serovar typhimurium to establish infection in the gut. effector proteins translocated by this system across the plasma membrane facilitate invasion of intestinal epithelial cells. one such effector, the inositol phosphatase sopb, contributes to invasion and mediates activation of the pro-survival kinase akt. following internalization, some bacteria escape from the salmonella-containing vacuole into the cytosol ...201728426838
gre factors-mediated control of hild transcription is essential for the invasion of epithelial cells by salmonella enterica serovar typhimurium.the invasion of epithelial cells by salmonella enterica serovar typhimurium is a very tightly regulated process. signaling cascades triggered by different environmental and physiological signals converge to control hild, an arac regulator that coordinates the expression of several virulence factors. the expression of hild is modulated at several steps of the expression process. here, we report that the invasion of epithelial cells by s. typhimurium strains lacking the gre factors, grea and greb, ...201728426789
immunometabolic phenotype alterations associated with the induction of disease tolerance and persistent asymptomatic infection of salmonella in the chicken intestine.the adaptation of salmonella enterica to the eukaryotic host is a key process that enables the bacterium to survive in a hostile environment. salmonella have evolved an intimate relationship with its host that extends to their cellular and molecular levels. colonization, invasion, and replication of the bacteria in an appropriate host suggest that modification of host functions is central to pathogenesis. intuitively, this subversion of the cell must be a complex process, since hosts are not inh ...201728421074
regional transmission of salmonella paratyphi a, china, 1998-2012.to explore transmission patterns and genetic relationships of salmonella enterica serovar paratyphi a in china, we conducted a genome-wide single-nucleotide polymorphism analysis on the strains in the 4 provinces in which incidence was highest during 1998-2012. markedly phylogeographic clustering suggested regional virus circulation after introduction from areas in southeastern china.201728418315
dissemination of mcr-1-carrying plasmids among colistin-resistant salmonella strains from humans and food-producing animals in taiwan.we detected the colistin resistance gene mcr-1 in four salmonella serovars isolated from humans and animals with diarrhea. the resistance gene was carried on different plasmids. one mcr-1-carrying conjugative plasmid, a variant of phnshp45, was disseminated among salmonella isolates recovered from humans, pigs, and chickens.201728416545
reversible synthesis of colanic acid and o-antigen polysaccharides in salmonella typhimurium enhances induction of cross-immune responses and provides protection against heterologous salmonella challenge.colanic acid (ca) and lipopolysaccharide (lps) are two major mannose-containing extracellular polysaccharides of salmonella. their presence on the bacterial surface can mask conserved protective outer membrane proteins (omps) from the host immune system. the mannose moiety in these molecules is derived from gdp-mannose, which is synthesized in several steps. the first two steps require the action of phosphomannose isomerase, encoded by pmi (mana), followed by phosphomannomutase, encoded by manb. ...201728412074
modified bacteriophage s16 long tail fiber proteins for rapid and specific immobilization and detection of salmonella cells.bacteriophage-based assays and biosensors rival traditional antibody-based immunoassays for detection of low-level salmonella contaminations. in this study, we harnessed the binding specificity of the long tail fiber (ltf) from bacteriophage s16 as an affinity molecule for the immobilization, enrichment, and detection of salmonella we demonstrate that paramagnetic beads (mbs) coated with recombinant gp37-gp38 ltf complexes (ltf-mbs) are highly effective tools for rapid affinity magnetic separati ...201728411223
salmonella typhimurium diarrhea reveals basic principles of enteropathogen infection and disease-promoted dna exchange.despite decades of research, efficient therapies for most enteropathogenic bacteria are still lacking. in this review, we focus on salmonella enterica typhimurium (s. typhimurium), a frequent cause of acute, self-limiting food-borne diarrhea and a model that has revealed key principles of enteropathogen infection. we review the steps of gut infection and the mucosal innate-immune defenses limiting pathogen burdens, and we discuss how inflammation boosts gut luminal s. typhimurium growth. we also ...201728407482
mucosal iga and ifn-γ(+) cd8 t cell immunity are important in the efficacy of live salmonella enteria serovar choleraesuis vaccines.salmonellosis, a disease caused by non-typhoidal salmonella strains which can be transmitted from swine to humans, is one of the leading public health problems around the world. paratyphoid of swine is controlled by vaccinating swine with salmonella enterica serovar choleraesuis (s. choleraesuis) live vaccine strain c500 in china. although the vaccine has good prophylactic efficacy, the mechanism of immunogenicity is unclear. using a c500-derived paratyphoid thermo-stable live vaccine (ptsl vacc ...201728406162
high-avidity iga protects the intestine by enchaining growing bacteria.vaccine-induced high-avidity iga can protect against bacterial enteropathogens by directly neutralizing virulence factors or by poorly defined mechanisms that physically impede bacterial interactions with the gut tissues ('immune exclusion'). iga-mediated cross-linking clumps bacteria in the gut lumen and is critical for protection against infection by non-typhoidal salmonella enterica subspecies enterica serovar typhimurium (s. typhimurium). however, classical agglutination, which was thought t ...201728405025
antimicrobial resistance of salmonella enterica serovar typhimurium in shanghai, china.we aimed to analyze the antimicrobial resistance phenotypes and to elucidate the molecular mechanisms underlying resistance to cephalosporins, ciprofloxacin, and azithromycin in salmonella enterica serovar typhimurium isolates identified from patients with diarrhea in shanghai. the isolates showed high rates of resistance to traditional antimicrobials, and 20.6, 12.7, and 5.5% of them exhibited decreased susceptibility to cephalosporins, ciprofloxacin, and azithromycin, respectively. notably, 47 ...201728400764
molecular characterization and antimicrobial resistance of salmonella enterica from swine slaughtered in two different types of philippine abattoir.salmonella enterica is a well-known pathogen commonly acquired from the consumption of contaminated food. it has been estimated to affect millions of humans and cause hundreds of thousands of deaths per year globally. pork, one of the most commonly consumed meats worldwide, has been identified as one of the main sources of human salmonellosis. in this study, we aimed to detect and characterize s. enterica from slaughtered swine and generate antimicrobial resistance profiles of select isolates. t ...201728400019
oregano essential oil-based natural antimicrobial packaging film to inactivate salmonella enterica and yeasts/molds in the atmosphere surrounding cherry tomatoes.this study investigated the effectiveness of a polyvinyl alcohol (pva) film containing the natural antimicrobial oregano essential oil (oeo) as an active packaging application for decreasing the microbial growth. the film exerted an antimicrobial effect via the atmosphere surrounding the food rather than direct contact, thereby preserving the quality of cherry tomatoes. a packaging film containing microencapsulated oeo was developed. the loading content increased gradually (104.29-234.29 μg oeo/ ...201728399993
purification and characterization of the bacterial flagellar basal body from salmonella enterica.the bacterial flagellum is a motility organelle. the flagellum is composed of three main structures: the basal body as a rotary engine embedded in the cellular membranes and cell wall, the long external filament that acts as a propeller, and the hook acting as a universal joint that connects them. i describe protocols for the purification of the filament and hook-basal body from salmonella enterica serovar typhimurium.201728389946
fluorescent microscopy techniques to study hook length control and flagella formation.the bacterial flagellum is a sophisticated motility device made of about 30 different proteins and consists of three main structural parts: (1) a membrane-embedded basal body, (2) a flexible linking structure (the hook) that connects the basal body to, (3) the rigid filament that extends up to 10 μm from the cell surface. in salmonella enterica serovar typhimurium, the hook structure is controlled to a length of 55 nm by a molecular ruler protein, flik. only upon hook completion, flik induces a ...201728389943
fuel of the bacterial flagellar type iii protein export apparatus.the flagellar type iii export apparatus utilizes atp and proton motive force (pmf) across the cytoplasmic membrane as the energy sources and transports flagellar component proteins from the cytoplasm to the distal growing end of the growing structure to construct the bacterial flagellum beyond the cellular membranes. the flagellar type iii export apparatus coordinates flagellar protein export with assembly by ordered export of substrates to parallel with their order of the assembly. the export a ...201728389941
supplemental invasion of salmonella from the perspective of salmonella enterica serovars kentucky and typhimurium.critical to the development of salmonellosis in humans is the interaction of the bacterium with the epithelial lining of the gastrointestinal tract. traditional scientific reasoning held type iii secretion system (t3ss) as the virulence factor responsible for bacterial invasion. in this study, field-isolated salmonella enterica serovar kentucky and a known human pathogen salmonella enterica serovar typhimurium were mutated and evaluated for the invasion of human colorectal adenocarcinoma epithel ...201728381209
rna-seq-based analysis of drug-resistant salmonella enterica serovar typhimurium selected in vivo and in vitro.the aim of this study was to characterize the mechanism of fluoroquinolone (fq) resistance in salmonella typhimurium. we established the caenorhabditis elegans-salmonella typhimurium model to select for ciprofloxacin resistance in salmonella typhimurium colonizing c. elegans, generating the resistant strains tn4. gradient doses of ciprofloxacin were used to generate the resistant strain tw4 in vitro. rna sequencing was used to establish the whole-transcriptome profile of three strains of salmone ...201728380031
novel dna binding and regulatory activities for σ(54) (rpon) in salmonella enterica serovar typhimurium 14028s.the variable sigma (σ) subunit of the bacterial rna polymerase (rnap) holoenzyme, which is responsible for promoter specificity and open complex formation, plays a strategic role in the response to environmental changes. salmonella enterica serovar typhimurium utilizes the housekeeping σ(70) and five alternative sigma factors, including σ(54) the σ(54)-rnap differs from other σ-rnap holoenzymes in that it forms a stable closed complex with the promoter and requires atp hydrolysis by an activated ...201728373272
chemical composition and biological activities of helicteres vegae and heliopsis sinaloensis.helicteres vegae cristóbal (sterculiaceae) (hv) and heliopsis sinaloensis b.l. turner (asteraceae) (hs) are endangered and poorly studied plant species; related plants have been used against chronic-degenerative and infectious diseases. therefore, hv and hs could be sources of bioactive compounds against these illnesses.201728347185
epigallocatechin-3-gallate inhibits bacterial virulence and invasion of host cells.increasing antibiotic resistance and beneficial effects of host microbiota has motivated the search for anti-infective agents that attenuate bacterial virulence rather than growth. for example, we discovered that specific flavonoids such as baicalein and quercetin from traditional medicinal plant extracts could attenuate salmonella enterica serovar typhimurium type iii protein secretion and invasion of host cells. here, we show epigallocatechin-3-gallate from green tea extracts also inhibits the ...201728325635
silver nanoparticles against salmonella enterica serotype typhimurium: role of inner membrane dysfunction.the evolution of antibiotics-resistant bacteria is considered a major concern. to explore promising antibacterial materials and clarify their unknown mechanisms, the mode of action of silver nanoparticles (agnps) against salmonella enterica serotype typhimurium was investigated. we investigated the effect of agnps on the bacterial membrane. the n-phenyl-1-naphthylamine assay showed that the permeability of the outer membrane was not changed by treatment with agnps. the o-nitrophenyl-β-d-galactop ...201728321528
a novel hybrid plasmid carrying multiple antimicrobial resistance and virulence genes in salmonella enterica serovar dublin.virulence plasmids and antibiotic resistance plasmids are usually maintained separately in salmonella spp.; however, we report an instance of a hybrid plasmid (pn13-01125) in salmonella enterica serovar dublin. review of the complete sequence of the 172,265-bp plasmid suggests that pn13-01125 is comprised of the previously described psdvr and psh696_135 plasmids and that the mechanism of hybridization likely involves is6 (is26) insertion sequence elements. the plasmid has a low conjugation frequ ...201728320711
a potential role of salmonella infection in the onset of inflammatory bowel diseases.inflammatory bowel disease (ibd) includes a set of pathologies that result from a deregulated immune response that may affect any portion of the gastrointestinal tract. the most prevalent and defined forms of ibd are crohn's disease and ulcerative colitis. although the etiology of ibd is not well defined, it has been suggested that environmental and genetic factors contribute to disease development and that the interaction between these two factors can trigger the pathology. diet, medication use ...201728293241
foodborne salmonellosis in italy: characterization of salmonella enterica serovar typhimurium and monophasic variant 4,[5],12:i- isolated from salami and human patients.salmonella enterica serovar typhimurium (stm) and its monophasic variant 4,[5],12:i:- (vmstm) have been responsible for an increased number of foodborne infections in humans in europe in recent years. the aim of this study was to investigate the origin of three foodborne salmonellosis outbreaks that occurred in pavia province (lombardy region, northern italy) in 2010. phenotypic and genetic characteristics of the stm and vmstm isolates from patients and from food that were recovered in the frame ...201728291384
high binding affinity of repressor iolr avoids costs of untimely induction of myo-inositol utilization by salmonella typhimurium.growth of salmonella enterica serovar typhimurium strain 14028 with myo-inositol (mi) is characterized by a bistable phenotype that manifests with an extraordinarily long (34 h) and variable lag phase. when cells were pre-grown in minimal medium with mi, however, the lag phase shortened drastically to eight hours, and to six hours in the absence of the regulator iolr. to unravel the molecular mechanism behind this phenomenon, we investigated this repressor in more detail. flow cytometry analysis ...201728290506
gene expression values of pattern-recognition receptors in porcine leukocytes and their response to salmonella enterica serovar typhimurium infection.pattern-recognition receptors (prrs) recognize pathogen-associated molecular patterns and play an important role in triggering innate immune responses. prrs distribution and function is well documented in mice and humans, but studies in pigs are scarce. salmonella enterica serovar typhimurium is common pathogen found in pigs and was used as a model for interaction with prrs. this study investigated expression of prrs in porcine leukocyte subpopulations at the mrna level. eight subpopulations of ...201728285125
fermented rapeseed meal is effective in controlling salmonella enterica serovar typhimurium infection and improving growth performance in broiler chicks.the aim of present experiment was to assess the effects of fermented rapeseed meal (frsm) on salmonella enterica serovar typhimurium (s. typhimurium) colonization and growth performance in broiler chicks. two hundred forty day-old male cobb 500 broiler chicks were divided into six experimental treatments with four replicates and 10 birds per each. the treatments were including two positive and negative controls which birds received a basal corn-soybean diet as well as four others which birds rec ...201728284629
genomic heterogeneity of salmonella enterica serovar typhimurium bacteriuria from chronic infection.we sequenced the genomes of 14 sequential salmonella enterica serovar typhimurium isolates obtained over a five year period from a patient with persistent salmonella bacteriuria. the isolates formed five distinct lineages; two of which co-existed over four years. we inferred that the observed within-patient variation resulted from mutation events.201728279807
an association between decreasing incidence of invasive non-typhoidal salmonellosis and increased use of antiretroviral therapy, gauteng province, south africa, 2003-2013.hiv-infected persons are at increased risk of opportunistic infections, including invasive nontyphoidal salmonella (ints) infections; antiretroviral therapy (art) reduces this risk. we explored changing ints incidence associated with increasing art availability in south africa.201728264046
bacterial flagella grow through an injection-diffusion mechanism.the bacterial flagellum is a self-assembling nanomachine. the external flagellar filament, several times longer than a bacterial cell body, is made of a few tens of thousands subunits of a single protein: flagellin. a fundamental problem concerns the molecular mechanism of how the flagellum grows outside the cell, where no discernible energy source is available. here, we monitored the dynamic assembly of individual flagella using in situ labelling and real-time immunostaining of elongating flage ...201728262091
efflux pump overexpression contributes to tigecycline heteroresistance in salmonella enterica serovar typhimurium.bacterial heteroresistance has been identified in several combinations of bacteria and antibiotics, and it complicated the therapeutic strategies. tigecycline is being used as one of the optimal options for the treatment of infections caused by multidrug-resistant salmonella. this study investigated whether heterorresistance to tigecycline exists in a salmonella enterica serovar typhimurium strain harboring the oqxab-bearing inchi2 plasmid phxy0908. mic and population analyses were performed to ...201728261566
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