| salmonella enterica causes more severe inflammatory disease in c57/bl6 nramp1g169 mice than sv129s6 mice. | salmonella enterica serovar typhimurium (s. typhimurium) causes systemic inflammatory disease in mice by colonizing cells of the mononuclear leukocyte lineage. mouse strains resistant to s. typhimurium, including sv129s6, have an intact nramp1 (slc11a1) allele and survive acute infection, whereas c57/bl6 mice, homozygous for a mutant nramp1 allele, nramp1(g169d) , develop lethal infections. restoration of nramp1 (c57/bl6 nramp1(g169) ) reestablishes resistance to s. typhimurium; mice survive at ... | 2013 | 23446432 |
| the actin-polymerizing activity of sipa is not essential for salmonella enterica serovar typhimurium-induced mucosal inflammation. | salmonella enterica serovar typhimurium depends on type iii secretion systems to inject effector proteins into host cells to promote bacterial invasion and to induce intestinal inflammation. sipa, a type iii effector, is known to play important roles in both the invasion and the elicitation of intestinal inflammation. the actin-modulating activity of sipa has been shown to promote salmonella entry into epithelial cells. to investigate whether the actin-modulating activity of sipa is required for ... | 2013 | 23439302 |
| no protective effects of high-dosage dietary zinc oxide on weaned pigs infected with salmonella enterica serovar typhimurium dt104. | twenty-eight-day-old weaned pigs were fed diets with a low (lzn), medium (mzn), or high (mzn) zn concentration (50 to 80, 150, or 2,500 mg zn/kg of diet, respectively) provided as zinc oxide (zno)(24 pigs per group). they were infected orally with salmonella enterica serovar typhimurium dt104 on day 32. salmonellae were cultivated from feces (up to 42 days postinfection [dpi]) and organs (2 and 42 dpi). activation of the adaptive systemic and mucosal immune systems was investigated by recording ... | 2013 | 23435881 |
| an essential role for the atg8 ortholog lc3c in antibacterial autophagy. | autophagy defends the mammalian cytosol against bacterial invasion. efficient bacterial engulfment by autophagy requires cargo receptors that bind (a) homolog(s) of the ubiquitin-like protein atg8 on the phagophore membrane. the existence of multiple atg8 orthologs in higher eukaryotes suggests that they may perform distinct functions. however, no specific role has been assigned to any mammalian atg8 ortholog. we recently discovered that the autophagy receptor calcoco2/ndp52, which detects cytos ... | 2013 | 23434839 |
| reconciling a salmonella enterica metabolic model with experimental data confirms that overexpression of the glyoxylate shunt can rescue a lethal ppc deletion mutant. | the in silico reconstruction of metabolic networks has become an effective and useful systems biology approach to predict and explain many different cellular phenotypes. when simulation outputs do not match experimental data, the source of the inconsistency can often be traced to incomplete biological information that is consequently not captured in the model. to address this problem, general approaches continue to be needed that can suggest experimentally testable hypotheses to reconcile incons ... | 2013 | 23432746 |
| regulation of chemokines, ccl3 and ccl4, by interferon γ and nitric oxide synthase 2 in mouse macrophages and during salmonella enterica serovar typhimurium infection. | interferon γ (ifn-γ) increases the expression of multiple genes and responses; however, the mechanisms by which ifn-γ downmodulates cellular responses is not well understood. in this study, the repression of ccl3 and ccl4 by ifn-γ and nitric oxide synthase 2 (nos2) in macrophages and upon salmonella typhimurium infection of mice was investigated. | 2013 | 23431040 |
| stabilization of cooperative virulence by the expression of an avirulent phenotype. | pathogens often infect hosts through collective actions: they secrete growth-promoting compounds or virulence factors, or evoke host reactions that fuel the colonization of the host. such behaviours are vulnerable to the rise of mutants that benefit from the collective action without contributing to it; how these behaviours can be evolutionarily stable is not well understood. we address this question using the intestinal pathogen salmonella enterica serovar typhimurium (hereafter termed s. typhi ... | 2013 | 23426324 |
| inactivation of salmonella enterica serovar typhimurium and quality maintenance of cherry tomatoes treated with gaseous essential oils. | the antimicrobial activity of the essential oils (eos) from cinnamon bark, oregano, mustard, and of their major components cinnamaldehyde, carvacrol, and allyl isothiocyanate (ait) was evaluated as a gaseous treatment to reduce salmonella enterica serovar typhimurium in vitro and on tomatoes. in vitro tests showed that mustard eo and ait had the greatest inhibition of salmonella, followed by cinnamon eo and cinnamaldehyde, while oregano and carvacrol showed the least inhibition. scanning electro ... | 2013 | 23398191 |
| rida proteins prevent metabolic damage inflicted by plp-dependent dehydratases in all domains of life. | pyridoxal 5'-phosphate (plp) is a coenzyme synthesized by all forms of life. relevant to the work reported here is the mechanism of the plp-dependent threonine/serine dehydratases, which generate reactive enamine/imine intermediates that are converted to keto acids by members of the rida family of enzymes. the rida protein of salmonella enterica serovar typhimurium lt2 is the founding member of this broadly conserved family of proteins (formerly known as yjgf/yer057c/uk114). rida proteins were r ... | 2013 | 23386433 |
| rac and rab gtpases dual effector nischarin regulates vesicle maturation to facilitate survival of intracellular bacteria. | the intracellular pathogenic bacterium salmonella enterica serovar typhimurium (salmonella) relies on acidification of the salmonella-containing vacuole (scv) for survival inside host cells. the transport and fusion of membrane-bound compartments in a cell is regulated by small gtpases, including rac and members of the rab gtpase family, and their effector proteins. however, the role of these components in survival of intracellular pathogens is not completely understood. here, we identify nischa ... | 2013 | 23386062 |
| cooperation of the multidrug efflux pump and lipopolysaccharides in the intrinsic antibiotic resistance of salmonella enterica serovar typhimurium. | in gram-negative bacteria, drug susceptibility is associated with multidrug efflux systems and an outer membrane (om) barrier. previous studies revealed that salmonella enterica serovar typhimurium has 10 functional drug efflux pumps. among them, acrb is a major factor to maintain the intrinsic drug resistance in this organism. the lipopolysaccharide (lps) content of om is also important for resistance to lipophilic drugs; however, the interplay between the multidrug efflux pump and lps in the i ... | 2013 | 23378414 |
| colonization and internalization of salmonella enterica in tomato plants. | the consumption of fresh tomatoes has been linked to numerous food-borne outbreaks involving various serovars of salmonella enterica. recent advances in our understanding of plant-microbe interactions have shown that human enteric pathogenic bacteria, including s. enterica, are adapted to survive in the plant environment. in this study, tomato plants (solanum lycopersicum cv. micro-tom) grown in sandy loam soil from virginia's eastern shore (ves) were inoculated with s. enterica serovars to eval ... | 2013 | 23377940 |
| pmdt1, a small cole1-like plasmid mobilizing a new variant of the aac(6')-ib-cr gene in salmonella enterica serovar typhimurium. | to characterize a 5.9 kb aac(6')-ib-cr-harbouring plasmid that was detected in a clinical salmonella typhimurium dt104b strain. | 2013 | 23361643 |
| stochasticity in colonial growth dynamics of individual bacterial cells. | conventional bacterial growth studies rely on large bacterial populations without considering the individual cells. individual cells, however, can exhibit marked behavioral heterogeneity. here, we present experimental observations on the colonial growth of 220 individual cells of salmonella enterica serotype typhimurium using time-lapse microscopy videos. we found a highly heterogeneous behavior. some cells did not grow, showing filamentation or lysis before division. cells that were able to gro ... | 2013 | 23354712 |
| development of ceftriaxone resistance affects the virulence properties of salmonella enterica serotype typhimurium strains. | development of antibiotic resistance may alter the virulence properties of bacterial organisms. in this study, nine clinical ceftriaxone-susceptible salmonella enterica serotype typhimurium strains were subjected to stepwise selection with increasing concentrations of ceftriaxone in culture media. mutations in virulence-associated genes and antibiotic efflux genes were analyzed by polymerase chain reaction (pcr) and dna sequencing. the expression levels of virulence genes inva and stn as well as ... | 2013 | 23320420 |
| salmonella polarises peptide-mhc-ii presentation towards an unconventional type b cd4+ t-cell response. | distinct peptide-mhc-ii complexes, recognised by type a and b cd4(+) t-cell subsets, are generated when antigen is loaded in different intracellular compartments. conventional type a t cells recognize their peptide epitope regardless of the route of processing, whereas unconventional type b t cells only recognise exogenously supplied peptide. type b t cells are implicated in autoimmune conditions and may break tolerance by escaping negative selection. here we show that salmonella differentially ... | 2013 | 23319341 |
| intratumoral injection of attenuated salmonella vaccine can induce tumor microenvironmental shift from immune suppressive to immunogenic. | attenuated salmonella vaccines show therapeutic anti-cancer effects, but the underlying mechanism has not been well investigated. in the current study, intratumoral (i.t.) injection of recombinant attenuated salmonella enterica serovar typhimurium vaccine (rasv) significantly inhibited her-2/neu-expressing tumor growth. although depletion of cd8(+) cells in rasv-treated mice significantly restored tumor growth, the induction of her-2/neu-specific cytotoxic t lymphocytes (ctls) was not well corre ... | 2013 | 23318147 |
| characterization of an acid-inducible sulfatase in salmonella enterica serovar typhimurium. | sulfatases of enteric bacteria can provide access to heavily sulfated mucosal glycans. in this study, we show that asla (stm0084) of salmonella enterica serovar typhimurium lt2 encodes a sulfatase that requires mildly acidic ph for its expression and activity. asla is not regulated by sulfur compounds or tyramine but requires the envz-ompr and phopq regulatory systems, which play an important role in pathogenesis. | 2013 | 23315743 |
| molecular characterization of the inve regulator in the secretion of type iii secretion translocases in salmonella enterica serovar typhimurium. | the type iii secretion systems (t3sss) are exploited by many gram-negative pathogenic bacteria to deliver a set of effector proteins into the host cytosol during cell entry. the t3ss of salmonella enterica serovar typhimurium is composed of more than 20 proteins that constitute the membrane-associated base, the needle and the tip complex at the distal end of the t3ss needle. membrane docking and piercing between the t3ss and host cells is followed by the secretion of effector proteins. therefore ... | 2013 | 23288540 |
| human isolates of salmonella enterica serovar typhimurium from taiwan displayed significantly higher levels of antimicrobial resistance than those from denmark. | salmonella enterica serovar typhimurium is a major zoonotic pathogen with a high prevalence of antimicrobial resistance. this pathogen can disseminate across borders and spread far distances via the food trade and international travel. in this study, we compared the genotypes and antimicrobial resistance of 378 s. typhimurium isolates collected in taiwan and denmark between 2009 and 2010. genotyping revealed that many s. typhimurium strains were concurrently circulating in taiwan, denmark and ot ... | 2013 | 23279815 |
| exploring the immune response of porcine mesenteric lymph nodes to salmonella enterica serovar typhimurium: an analysis of transcriptional changes, morphological alterations and pathogen burden. | infections caused by salmonella enterica serovar typhimurium (s. typhimurium) cause important economic problems in the swine industry and threaten the integrity of a safe and healthy food supply. controlling the prevalence of salmonella in pig production requires a thorough knowledge of the response processes that occurs in the gut associated immune tissues. to explore the in vivo porcine response to s. typhimurium, mln samples from four control pigs and twelve infected animals at 1, 2 and 6 day ... | 2013 | 23274115 |
| salmonella infection in a remote, isolated wild pig population. | although wild pig populations are known to sometimes be infected by salmonella, the situation in australia has received little attention and few population-based, planned studies have been conducted. understanding the distribution of salmonella infections within wild pig populations allows the potential hazard posed to co-grazing livestock to be assessed. we sampled a remote and isolated wild pig population in northwestern australia. faecal and mesenteric lymph node samples were collected from 6 ... | 2013 | 23266110 |
| critical role of type i interferon-induced macrophage necroptosis during infection with salmonella enterica serovar typhimurium. | | 2013 | 23262973 |
| molecular identification in monophasic and nonmotile variants of salmonella enterica serovar typhimurium. | variant strains of salmonella enterica serovar typhimurium, lacking one or both flagellar phases have been widely reported. the monophasic s.1,4,[5],12:i:- variant has emerged worldwide in the past few years and has become one of the most frequently encountered in many countries. in contrast, monophasic s.1,4,[5],12:-:1,2 and nonmotile s.1,4,[5],12:-:- strains are rarely described. this study investigated seven molecular markers to identify and delineate monophasic s.1,4,[5],12:i:- (n = 90), s.1 ... | 2012 | 23233427 |
| exposure of salmonella enterica serovar typhimurium to a protective monoclonal iga triggers exopolysaccharide production via a diguanylate cyclase-dependent pathway. | sal4 is a monoclonal polymeric iga antibody directed against the o antigen (o-ag) of salmonella enterica serovar typhimurium (s. typhimurium), which is sufficient to protect mice against intestinal infections from s. typhimurium. we recently reported that the exposure of s. typhimurium to sal4 results in the immediate loss of flagellum-based motility, in alterations to the outer membrane (om) integrity, and in the concomitant appearance of a mucoid phenotype that is reminiscent of cells in the e ... | 2013 | 23230292 |
| effects of natural mutations in the ramra locus on invasiveness of epidemic fluoroquinolone-resistant salmonella enterica serovar typhimurium isolates. | fluoroquinolone (fq) resistance is increasing worldwide among salmonella species. among the mechanisms involved, increased efflux via the tripartite acrab-tolc efflux system is mainly modulated through control of expression via the ramra regulatory locus gene products. interestingly, in some reference strains these have also been experimentally shown to regulate cell invasion-related genes of the type iii secretion system 1 (t3ss-1). in this study, we investigated whether natural mutations occur ... | 2013 | 23230062 |
| the copper supply pathway to a salmonella cu,zn-superoxide dismutase (sodcii) involves p(1b)-type atpase copper efflux and periplasmic cuep. | periplasmic cu,zn-superoxide dismutases (cu,zn-sods) are implicated in bacterial virulence. it has been proposed that some bacterial p(1b)-type atpases supply copper to periplasmic cupro-proteins and such transporters have also been implicated in virulence. here we show that either of two p(1b)-type atpases, copa or golt, is needed to activate a periplasmic cu,zn-sod (sodcii) in salmonella enterica serovar typhimurium. a δcopa/δgolt mutant accumulates inactive zn-sodcii which can be activated by ... | 2013 | 23171030 |
| an altered immune response, but not individual cationic antimicrobial peptides, is associated with the oral attenuation of ara4n-deficient salmonella enterica serovar typhimurium in mice. | salmonella enterica serovar typhimurium (s. typhimurium) uses two-component regulatory systems (tcrs) to respond to stimuli in the local microenvironment. upon infection, the salmonella tcrss phop-phoq (phopq) and pmra-pmrb (pmrab) are activated by environmental signals in the intestinal lumen and within host cells. tcrs-mediated gene expression results in lipopolysaccharide (lps) modification and cationic antimicrobial peptide resistance. the pmra-regulated pmrhfijklm operon mediates 4-amino-4- ... | 2012 | 23166721 |
| deletion of invh gene in salmonella enterica serovar typhimurium limits the secretion of sip effector proteins. | the type-iii secretion system-i (t3ss-i) of salmonella enterica serovar typhimurium (s. typhimurium) is an essential component to mediate active invasion and subsequent inflammation in genetically susceptible c57bl/6 mice. s. typhimurium translocates its effector proteins through salmonella pathogenicity island-i (spi-i) encoded t3ss-i needle complex. this study focuses on invh gene of s. typhimurium, which plays an active role in spi-i mediated effector protein translocation. the deletion of in ... | 2013 | 23159244 |
| m cell differentiation: distinct lineage or phenotypic transition? salmonella provides answers. | whether m cells arise from a distinct lineage or result from phenotypic transition is a matter of debate. in this issue of cell host & microbe, tahoun et al. (2012) provide evidence that sopb, a virulence factor of salmonella enterica serovar typhimurium, can induce phenotypic transition of lymphoid follicle-associated enterocytes into m cells. | 2012 | 23159049 |
| neutrophil elastase alters the murine gut microbiota resulting in enhanced salmonella colonization. | the intestinal microbiota has been found to play a central role in the colonization of salmonella enterica serovar typhimurium in the gastrointestinal tract. in this study, we present a novel process through which salmonella benefit from inflammatory induced changes in the microbiota in order to facilitate disease. we show that salmonella infection in mice causes recruitment of neutrophils to the gut lumen, resulting in significant changes in the composition of the intestinal microbiota. this oc ... | 2012 | 23155475 |
| systemic flagellin immunization stimulates mucosal cd103+ dendritic cells and drives foxp3+ regulatory t cell and iga responses in the mesenteric lymph node. | mucosal immunity is poorly activated after systemic immunization with protein ags. nevertheless, induction of mucosal immunity in such a manner would be an attractive and simple way to overcome the intrinsic difficulties in delivering ag to such sites. flagellin from salmonella enterica serovar typhimurium (flic) can impact markedly on host immunity, in part via its recognition by tlr5. in this study, we show that systemic immunization with soluble flic (sflic) drives distinct immune responses c ... | 2012 | 23152564 |
| tissue dyslipidemia in salmonella-infected rats treated with amoxillin and pefloxacin. | this study investigated the effects of salmonella infection and its chemotherapy on lipid metabolism in tissues of rats infected orally with salmonella typhimurium and treated intraperitoneally with pefloxacin and amoxillin. | 2012 | 23137290 |
| genetic analysis of non-hydrogen sulfide-producing salmonella enterica serovar typhimurium and s. enterica serovar infantis isolates in japan. | whole-genome sequencing of non-h(2)s-producing salmonella enterica serovar typhimurium and s. enterica serovar infantis isolates from poultry meat revealed a nonsense mutation in the phsa thiosulfate reductase gene and carriage of a cmy-2 β-lactamase. the lack of production of h(2)s might lead to the incorrect identification of s. enterica isolates carrying antimicrobial resistance genes. | 2013 | 23135931 |
| inactivation of salmonella enterica serovar typhimurium on fresh produce by cold atmospheric gas plasma technology. | cold atmospheric gas plasma treatment (cap) is an alternative approach for the decontamination of fresh and minimally processed food. in this study, the effects of growth phase, growth temperature and chemical treatment regime on the inactivation of salmonella enterica serovar typhimurium (s. typhimurium) by nitrogen cap were examined. furthermore, the efficacy of cap treatment for decontaminating lettuce and strawberry surfaces and potato tissue inoculated with s. typhimurium was evaluated. it ... | 2013 | 23122497 |
| draft genome sequence of salmonella enterica serovar typhimurium st1660/06, a multidrug-resistant clinical strain isolated from a diarrheic patient. | salmonella enterica serovar typhimurium is one of the most prevalent serovars of salmonella that causes human gastroenteritis. here, we report the draft genome sequence of the s. typhimurium multidrug-resistant strain st1660/06. comparative genomic analysis unveiled three strain-specific genomic islands that potentially confer the multidrug resistance and virulence of the strain. | 2012 | 23105062 |
| genome expression analysis of nonproliferating intracellular salmonella enterica serovar typhimurium unravels an acid ph-dependent phop-phoq response essential for dormancy. | genome-wide expression analyses have provided clues on how salmonella proliferates inside cultured macrophages and epithelial cells. however, in vivo studies show that salmonella does not replicate massively within host cells, leaving the underlying mechanisms of such growth control largely undefined. in vitro infection models based on fibroblasts or dendritic cells reveal limited proliferation of the pathogen, but it is presently unknown whether these phenomena reflect events occurring in vivo. ... | 2013 | 23090959 |
| a phosphotransferase system permease is a novel component of cadc signaling in salmonella enterica. | in salmonella enterica serovar typhimurium, proteolytic cleavage of the membrane-bound transcriptional regulator cadc acts as a switch to activate genes of the lysine decarboxylase system in response to low ph and lysine signals. to identify the genetic factors required for the proteolytic activation of cadc, we performed genome-wide random mutagenesis. we show that a phosphotransferase system (pts) permease stm4538 acts as a positive modulator of cadc function. the transposon insertion in stm45 ... | 2013 | 23066934 |
| flagella overexpression attenuates salmonella pathogenesis. | flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. previous work showing appendage overexpression, referred to as attenuating gene expression (age), was found to enfeeble wild-type salmonella. thus, this approach was adapted to di ... | 2012 | 23056473 |
| genetic manipulation of pathogenicity loci in non-typhimurium salmonella. | the traditional genetic tools used in salmonella enterica serovar typhimurium rely heavily on a high-transducing mutant of bacteriophage p22. p22 recognizes its hosts by the structure of their o-antigens, which vary among serovars of salmonella; therefore, it cannot be used in most non-typhimurium salmonella, including the majority of those causing food-borne illnesses in both humans and livestock. bacteriophage p1 infects a variety of enteric bacteria, including gale mutants of serovar typhimur ... | 2012 | 23041268 |
| on-cell mas nmr: physiological clues from living cells. | while structural information on biomolecules is mainly obtained from purified in vitro samples, nmr can also be applied in the context of entire cells or organisms. the present study describes maturation processes in living salmonella enterica serovar typhimurium, a prevalent cause for human gastroenteritis. in our physiological study, we follow the composition of the o-antigen on the outer bacterial membrane with high-resolution mas nmr spectroscopy. we detect and characterize an evolution of t ... | 2012 | 23030432 |
| very long o-antigen chains enhance fitness during salmonella-induced colitis by increasing bile resistance. | intestinal inflammation changes the luminal habitat for microbes through mechanisms that have not been fully resolved. we noticed that the fepe regulator of very long o-antigen chain assembly in the enteric pathogen salmonella enterica serotype typhimurium (s. typhimurium) conferred a luminal fitness advantage in the mouse colitis model. however, a fepe mutant was not defective for survival in tissue, resistance to complement or resistance to polymyxin b. we performed metabolite profiling to ide ... | 2012 | 23028318 |
| microbial amyloids induce interleukin 17a (il-17a) and il-22 responses via toll-like receptor 2 activation in the intestinal mucosa. | the toll-like receptor 2 (tlr2)/tlr1 receptor complex responds to amyloid fibrils, a common component of biofilm material produced by members of the phyla firmicutes, bacteroidetes, and proteobacteria. to determine whether this tlr2/tlr1 ligand stimulates inflammatory responses when bacteria enter intestinal tissue, we investigated whether expression of curli amyloid fibrils by the invasive enteric pathogen salmonella enterica serotype typhimurium contributes to t helper 1 and t helper 17 respon ... | 2012 | 23027540 |
| the pmrab system-inducing conditions control both lipid a remodeling and o-antigen length distribution, influencing the salmonella typhimurium-host interactions. | the salmonella enterica serovar typhimurium lipopolysaccharide consisting of covalently linked lipid a, non-repeating core oligosaccharide, and the o-antigen polysaccharide is the most exposed component of the cell envelope. previous studies demonstrated that all of these regions act against the host immunity barrier. the aim of this study was to define the role and interaction of pmrab-dependent gene products required for the lipopolysaccharide component synthesis or modification mainly during ... | 2012 | 23019341 |
| expression of stm4467-encoded arginine deiminase controlled by the stm4463 regulator contributes to salmonella enterica serovar typhimurium virulence. | arginine deiminase (adi), carbamate kinase (ck), and ornithine transcarbamoylase (otc) constitute the adi system. in addition to metabolic functions, the adi system has been implicated in the virulence of certain pathogens. the pathogenic intracellular bacterium salmonella enterica serovar typhimurium possesses the stm4467, stm4466, and stm4465 genes, which are predicted to encode adi, ck, and otc, respectively. here we report that the stm4467 gene encodes an adi and that adi activity plays a ro ... | 2012 | 23006851 |
| targeting essential genes in salmonella enterica serovar typhimurium with antisense peptide nucleic acid. | we investigated the capability of antisense peptide nucleic acids (pnas) conjugated to the (kff)(3)k cell-penetrating peptide to target possible essential genes (liga, rpoa, rpod, enga, tsf, and kdta) in salmonella enterica serovar typhimurium and inhibit bacterial growth in vitro and in cell culture. all targeted pna-based gene inhibition has shown great potency in gene expression inhibition in a sequence-specific and dose-dependent manner at micromolar concentrations. among tested pnas, the an ... | 2012 | 23006748 |
| prevalence of salmonella enterica serovar 4,[5],12:i:- in england and wales, 2010. | difficulties in accurately identifying serovar 4,[5],12:i:- as monophasic variants of salmonella enterica serovar typhimurium mean there is confusion in the reporting of serovars typhimurium and 4,[5],12:i:-. to gain insight into the prevalence and diversity of these monophasic variants in england and wales, screening for fljb, hin and the serovar 4,[5],12:i:- dt193-associated genomic island was conducted on 609 s. enterica isolates designated as definitive phage type (dt) 193, and 142 isolates ... | 2012 | 22995432 |
| persistence of salmonella enterica during dehydration and subsequent cold storage. | despite the fact that salmonella enterica serotype typhimurium sl 1344 has served as a model pathogen in many studies, information regarding its desiccation response is still scarce. in this study, we investigated environmental conditions that affect salmonella survival following dehydration and subsequent cold storage, using a 96-well polystyrene plate model. the sl 1344 strain exhibited high survival compared with other typhimurium isolates and s. enterica serotypes. further characterization o ... | 2012 | 22986208 |
| membrane topology of salmonella invasion protein sipb confers osmotolerance. | salmonella enterica serovar typhimurium is a major cause of human gastrointestinal illness worldwide. this pathogen can persist in a wide range of environments, making it of great concern to public health. here, we report that the salmonella pathogenicity island (spi)-1 effector protein sipb exhibits a membrane topology that confers bacterial osmotolerance. disruption of the sipb gene or the invg gene (spi-1 component) significantly reduced the osmotolerance of s. typhimurium lt2. biochemical as ... | 2012 | 22975346 |
| phenotypic analysis of salmonella enterica serovar typhimurium rpoe mutants encoding rna polymerase extracytoplasmic stress response sigma factors σ(e) with altered promoter specificity. | we previously identified mutants in the rpoe gene of salmonella enterica serovar typhimurium (s. typhimurium) encoding rna polymerase extracytoplasmic stress response sigma factors σ(e) with altered promoter specificity. the replacement of the conserved r171 residue in the conserved region 4.2 of σ(e) by different amino acid residues exhibited different phenotypes. while r171a almost completely abolished sigma factor activity, r171g and r171c mutant changes imparted a relaxed recognition phenoty ... | 2013 | 22972381 |
| impact of maternally-derived antibodies against salmonella enterica serovar typhimurium on the bacterial load in suckling piglets. | the significance of maternal immunity against non-typhoid salmonella spp. acquired by piglets via colostrum and milk was evaluated in a salmonella enterica serovar typhimurium challenge experiment. piglets from sows vaccinated with an experimental inactivated vaccine exhibited high levels of serum immunoglobulins g and a against s. typhimurium 4 days after birth, just prior to experimental oral challenge. the s. typhimurium load in the ileal and caecal wall of piglets 3 days after experimental i ... | 2013 | 22967925 |
| complete genome sequence of bacteriophage ssu5 specific for salmonella enterica serovar typhimurium rough strains. | salmonella enterica serovar typhimurium rough strain-specific phage ssu5 was isolated, and its whole genome was sequenced. the 103,229-bp-long double-stranded dna genome of ssu5 encodes 130 open reading frames with one trna for asparagine. genomic analysis revealed that ssu5 might be the phylogenetic origin of cryptic plasmid phcm2 harbored by salmonella typhi ct18. | 2012 | 22966187 |
| regulation of rama by ramr in salmonella enterica serovar typhimurium: isolation of a ramr superrepressor. | rama is a transcription factor involved in regulating multidrug resistance in salmonella enterica serovar typhimurium sl1344. green fluorescent protein (gfp) reporter fusions were exploited to investigate the regulation of rama expression by ramr. we show that ramr represses the rama promoter by binding to a palindromic sequence and describe a superrepressor ramr mutant that binds to the rama promoter sequence more efficiently, thus exhibiting a rama inactivated phenotype. | 2012 | 22948865 |
| global transcriptional analysis of dehydrated salmonella enterica serovar typhimurium. | despite the scientific and industrial importance of desiccation tolerance in salmonella, knowledge regarding its genetic basis is still scarce. in the present study, we performed a transcriptomic analysis of dehydrated and water-suspended salmonella enterica serovar typhimurium using microarrays. dehydration induced expression of 90 genes and downregulated that of 7 genes. ribosomal structural genes represented the most abundant functional group with a relatively higher transcription during dehy ... | 2012 | 22941081 |
| [model of chronic salmonellosis: parameters of infection and immune response in inbred mice genetically variable in susceptibility to salmonellosis]. | study parameters of chronic infection and immune response in i/st and a/sn line mice in the model of per oral infection of mice with salmonella enterica serovar typhimurium. | 2013 | 22937698 |
| characterization and differential gene expression between two phenotypic phase variants in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium strain 798 has previously been shown to undergo phenotypic phase variation. one of the phenotypes expresses virulence traits such as adhesion, while the other phenotype does not. phenotypic phase variation appears to correlate with the ability of this strain to cause persistent, asymptomatic infections of swine. a new method to detect cells in either phenotypic phase was developed using evans blue-uranine agar plates. using this new assay, rates of phenoty ... | 2012 | 22937065 |
| spontaneous and transient defence against bacteriophage by phase-variable glucosylation of o-antigen in salmonella enterica serovar typhimurium. | as natural killers of bacteria, bacteriophages have forced bacteria to develop a variety of defence mechanisms. the alteration of host receptors is one of the most common bacterial defence strategies against phage infection, which completely blocks phage attachment but comes at a potential fitness cost to the bacteria. here, we report the cost-free, transient emergence of phage resistance in salmonella enterica subspecies enterica serovar typhimurium through a phase-variable modification of the ... | 2012 | 22928771 |
| receptor diversity and host interaction of bacteriophages infecting salmonella enterica serovar typhimurium. | salmonella enterica subspecies enterica serovar typhimurium is a gram-negative pathogen causing salmonellosis. salmonella typhimurium-targeting bacteriophages have been proposed as an alternative biocontrol agent to antibiotics. to further understand infection and interaction mechanisms between the host strains and the bacteriophages, the receptor diversity of these phages needs to be elucidated. | 2012 | 22927964 |
| type i interferon induces necroptosis in macrophages during infection with salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium (s. typhimurium) is a virulent pathogen that induces rapid host death. here we observed that host survival after infection with s. typhimurium was enhanced in the absence of type i interferon signaling, with improved survival of mice deficient in the receptor for type i interferons (ifnar1(-/-) mice) that was attributed to macrophages. although there was no impairment in cytokine expression or inflammasome activation in ifnar1(-/-) macrophages, they were h ... | 2012 | 22922364 |
| cationic antimicrobial peptides serve as activation signals for the salmonella typhimurium phopq and pmrab regulons in vitro and in vivo. | salmonella enterica serovar typhimurium uses two-component regulatory systems (tcrss) to respond to environmental stimuli. upon infection, the tcrss phop-phoq (phopq) and pmra-pmrb (pmrab) are activated by environmental signals detected in the lumen of the intestine and within host cells. tcrs-mediated gene expression leads to upregulation of genes involved in lipopolysaccharide (lps) modification and cationic antimicrobial peptide (camp) resistance. this research expands on previous studies whi ... | 2012 | 22919691 |
| caspase-11 increases susceptibility to salmonella infection in the absence of caspase-1. | inflammasomes are cytosolic multiprotein complexes assembled by intracellular nucleotide-binding oligomerization domain (nod)-like receptors (nlrs) and they initiate innate immune responses to invading pathogens and danger signals by activating caspase-1 (ref. 1). caspase-1 activation leads to the maturation and release of the pro-inflammatory cytokines interleukin (il)-1β and il-18, as well as lytic inflammatory cell death known as pyroptosis. recently, a new non-canonical inflammasome was desc ... | 2012 | 22895188 |
| biofilm formation, cell surface hydrophobicity, and fatty acids analysis of starved salmonella enterica serovar typhimurium in seawater. | salmonella is an international foodborne pathogen widely disseminated in seawater that regularly causes large outbreaks of food poisoning. in this study, we have investigated the effect of starvation on the ability of salmonella enterica serovar typhimurium cells to adhere to polystyrene microplate and hep2 cells in seawater microcosms after incubation for 3 years. cell surface hydrophobicity was evaluated. effect of stress on fatty acids composition was also established. our results showed that ... | 2012 | 22891961 |
| non-genetic diversity shapes infectious capacity and host resistance. | the spontaneous generation of distinct phenotypes within a clonal population of cells allows for both bet-hedging at the population level and the division of labor among subpopulations. this is emerging as an important theme in bacterial pathogenesis, because bacterial pathogens exhibit phenotypic heterogeneity with respect to characteristics that impact virulence. the phenomenon of persister cells and models of salmonella enterica serovar typhimurium (s. typhimurium) pathogenesis illustrate the ... | 2012 | 22889945 |
| low-shear modeled microgravity enhances salmonella enterica resistance to hydrogen peroxide through a mechanism involving katg and katn. | studies carried out in recent years have established that growth under conditions of reduced gravity enhances salmonella enterica serovar typhimurium virulence. to analyze the possibility that this microgravity-induced increase in pathogenicity could involve alterations in the ability of salmonella to withstand oxidative stress, we have compared the resistance to hydrogen peroxide of various salmonella enterica strains grown under conditions of low shear modeled microgravity (lsmmg) or normal gr ... | 2012 | 22888375 |
| evolution of a multiple antibiotic resistance region in inchi1 plasmids: reshaping resistance regions in situ. | to determine the structure of the resistance region in an inchi1 plasmid conferring resistance to multiple antibiotics, including gentamicin, recovered from a salmonella enterica serovar typhimurium isolate from a horse. | 2012 | 22888274 |
| bacterial infection of macrophages induces decrease in refractive index. | infection of cells by pathogens leads to both biochemical and structural modifications of the host cell. to study the structural modifications in a label-free manner, we use digital holographic microscopy, dhm, to obtain the integral refractive index distribution of cells. primary murine bone marrow derived macrophages (bmdm) infected with salmonella enterica serovar typhimurium, undergo highly significant reduction in refractive index, ri, compared to uninfected cells. infected bmdm cells from ... | 2013 | 22887897 |
| phosphorylation of nlrc4 is critical for inflammasome activation. | nlrc4 is a cytosolic member of the nod-like receptor family that is expressed in innate immune cells. it senses indirectly bacterial flagellin and type iii secretion systems, and responds by assembling an inflammasome complex that promotes caspase-1 activation and pyroptosis. here we use knock-in mice expressing nlrc4 with a carboxy-terminal 3×flag tag to identify phosphorylation of nlrc4 on a single, evolutionarily conserved residue, ser 533, following infection of macrophages with salmonella e ... | 2012 | 22885697 |
| grapefruit juice and its constituents augment the effect of low ph on inhibition of survival and adherence to intestinal epithelial cells of salmonella enterica serovar typhimurium pt193. | the present study examined the survival of salmonella typhimurium and its adherence to intestinal epithelial cells following inoculation into grapefruit juice and apple cider. both liquids significantly inactivated s. typhimurium (0.8-2.2 log reduction compared to the control); surviving salmonella in grapefruit juice was 1.0-1.4 log lower than in apple cider at 24h incubation. grapefruit juice contains the antimicrobial substances naringin (nar) and naringenin (nge); however, the effect of grap ... | 2012 | 22867848 |
| tandem attenuators control expression of the salmonella mgtcbr virulence operon. | the mgtcbr operon from salmonella enterica serovar typhimurium specifies the virulence protein mgtc, the mg(2+) transporter mgtb and the regulatory peptide mgtr. the mgtcbr transcript includes a long leader region harbouring two short open reading frames (orfs). translation of these orfs is anticipated to impact the formation of particular stem-loop structures and control transcription of the coding region by an attenuation-like mechanism. we previously reported that orf mgtm enables salmonella ... | 2012 | 22857388 |
| promoter strength driving tetr determines the regulatory properties of tet-controlled expression systems. | bacteria frequently rely on transcription repressors and activators to alter gene expression patterns in response to changes in the surrounding environment. tet repressor (tetr) is a paradigm transcription factor that senses the environmental state by binding small molecule effectors, the tetracyclines. however, recently isolated peptides that act as inducers of tetr after having been fused to the c-terminus of a carrier protein, suggest that tetr can also regulate gene expression in a signal-tr ... | 2012 | 22848546 |
| zinc prevents salmonella enterica serovar typhimurium-induced loss of intestinal mucosal barrier function in broiler chickens. | the study was carried out to evaluate the beneficial effects of supplemental zinc (zn) on the intestinal mucosal barrier function in salmonella enterica serovar typhimurium-challenged broiler chickens in a 42-day experiment. a total of 336 1-day-old male arbor acres broiler chicks were assigned to eight treatment groups. a 4×2 factorial arrangement of treatments was used in a completely randomized experimental design to study the effects of levels of supplemental zn (0, 40, 80 and 120 mg/kg diet ... | 2012 | 22834550 |
| spi-1 encoded genes of salmonella typhimurium influence differential polarization of porcine alveolar macrophages in vitro. | within the last decade, macrophages have been shown to be capable of differentiating toward a classically activated phenotype (m1) with a high antimicrobial potential or an alternatively activated phenotype (m2). some pathogens are capable of interfering with differentiation in order to down-regulate the anti-microbial activity and enhance their survival in the host. | 2012 | 22817641 |
| comparative genome analysis of the high pathogenicity salmonella typhimurium strain uk-1. | salmonella enterica serovar typhimurium, a gram-negative facultative rod-shaped bacterium causing salmonellosis and foodborne disease, is one of the most common isolated salmonella serovars in both developed and developing nations. several s. typhimurium genomes have been completed and many more genome-sequencing projects are underway. comparative genome analysis of the multiple strains leads to a better understanding of the evolution of s. typhimurium and its pathogenesis. s. typhimurium strain ... | 2012 | 22792393 |
| diarrhea and colitis in mice require the salmonella pathogenicity island 2-encoded secretion function but not sifa or spv effectors. | we investigated the roles of salmonella pathogenicity island 2 (spi-2) and two spi-2 effectors in salmonella colitis and diarrhea in genetically resistant balb/c.d2(slc11a1) congenic mice with the wild-type nramp1 locus. wild-type salmonella enterica serovar typhimurium 14028s caused a pan-colitis, and the infected mice developed frank diarrhea with a doubling of the fecal water content. an ssav mutant caused only a 26% increase in fecal water content, without producing the pathological changes ... | 2012 | 22778101 |
| a whole-cell phenotypic screening platform for identifying methylerythritol phosphate pathway-selective inhibitors as novel antibacterial agents. | isoprenoid biosynthesis is essential for survival of all living organisms. more than 50,000 unique isoprenoids occur naturally, with each constructed from two simple five-carbon precursors: isopentenyl diphosphate (ipp) and dimethylallyl diphosphate (dmapp). two pathways for the biosynthesis of ipp and dmapp are found in nature. humans exclusively use the mevalonate (mva) pathway, while most bacteria, including all gram-negative and many gram-positive species, use the unrelated methylerythritol ... | 2012 | 22777049 |
| a salmonella typhimurium-translocated glycerophospholipid:cholesterol acyltransferase promotes virulence by binding to the rhoa protein switch regions. | salmonella enterica serovar typhimurium translocates a glycerophospholipid:cholesterol acyltransferase (ssej) into the host cytosol after its entry into mammalian cells. ssej is recruited to the cytoplasmic face of the host cell phagosome membrane where it is activated upon binding the small gtpase, rhoa. ssej is regulated similarly to cognate eukaryotic effectors, as only the gtp-bound form of rhoa family members stimulates enzymatic activity. using nmr and biochemistry, this work demonstrates ... | 2012 | 22740689 |
| loss of or inhibition of all multidrug resistance efflux pumps of salmonella enterica serovar typhimurium results in impaired ability to form a biofilm. | to investigate the contribution of multidrug efflux pump systems of salmonella enterica serovar typhimurium to the formation of a competent biofilm. | 2012 | 22733653 |
| the bimodal lifestyle of intracellular salmonella in epithelial cells: replication in the cytosol obscures defects in vacuolar replication. | salmonella enterica serovar typhimurium invades and proliferates within epithelial cells. intracellular bacteria replicate within a membrane bound vacuole known as the salmonella containing vacuole. however, this bacterium can also replicate efficiently in the cytosol of epithelial cells and net intracellular growth is a product of both vacuolar and cytosolic replication. here we have used semi-quantitative single-cell analyses to investigate the contribution of each of these replicative niches ... | 2012 | 22719929 |
| human milk mucin 1 and mucin 4 inhibit salmonella enterica serovar typhimurium invasion of human intestinal epithelial cells in vitro. | many human milk glycans inhibit pathogen binding to host receptors and their consumption by infants is associated with reduced risk of disease. salmonella infection is more frequent among infants than among the general population, but the incidence is lower in breast-fed babies, suggesting that human milk could contain components that inhibit salmonella. this study aimed to test whether human milk per se inhibits salmonella invasion of human intestinal epithelial cells in vitro and, if so, to id ... | 2012 | 22718031 |
| a previously uncharacterized gene stm0551 plays a repressive role in the regulation of type 1 fimbriae in salmonella enterica serotype typhimurium. | salmonella enterica serotype typhimurium produces surface-associated fimbriae that facilitate adherence of the bacteria to a variety of cells and tissues. type 1 fimbriae with binding specificity to mannose residues are the most commonly found fimbrial type. in vitro, static-broth culture favors the growth of s. typhimurium with type 1 fimbriae, whereas non-type 1 fimbriate bacteria are obtained by culture on solid-agar media. previous studies demonstrated that the phenotypic expression of type ... | 2012 | 22716649 |
| the importance of motility and chemotaxis for extra-animal survival of salmonella enterica serovar typhimurium and dublin. | this study investigated the importance of flagella and motility of salmonella enterica serovar typhimurium and dublin in models of extra-animal survival. | 2012 | 22716502 |
| analyzing cellular internalization of nanoparticles and bacteria by multi-spectral imaging flow cytometry. | nanoparticulate systems have emerged as valuable tools in vaccine delivery through their ability to efficiently deliver cargo, including proteins, to antigen presenting cells. internalization of nanoparticles (np) by antigen presenting cells is a critical step in generating an effective immune response to the encapsulated antigen. to determine how changes in nanoparticle formulation impact function, we sought to develop a high throughput, quantitative experimental protocol that was compatible wi ... | 2012 | 22710268 |
| expression and delivery of tetanus toxin fragment c fused to the n-terminal domain of sipb enhances specific immune responses in mice. | live attenuated bacteria can be used as a carrier for the delivery of foreign antigens to a host's immune system. the n-terminal domain of sipb, a translocon protein of the type iii secretion system of salmonella enterica serovar typhimurium, is required for secretion and outer membrane localization. in the present study, vaccine plasmids for antigen delivery in which the non-toxic tetanus toxin fragment c (ttfc), which contains a t cell epitope, is fused to the n-terminal 160 amino acids of sip ... | 2012 | 22708880 |
| slc11a1 (nramp1) impairs growth of salmonella enterica serovar typhimurium in macrophages via stimulation of lipocalin-2 expression. | the expression of the cation transporter nramp1 (slc11a1) in late phagolysosomes confers resistance to infection with several intracellular pathogens, such as salmonella enterica, in mice. the antimicrobial actions of nramp1 are attributable, in part, to modulation of macrophage immune function and cellular iron metabolism--the latter affecting the availability of the essential nutrient iron for intraphagosomal bacteria. here, we provide novel evidence that nramp1 functionality increases the exp ... | 2012 | 22706314 |
| mechanisms used by virulent salmonella to impair dendritic cell function and evade adaptive immunity. | innate and adaptive immunity are inter-related by dendritic cells (dcs), which directly recognize bacteria through the binding of pathogen-associated molecular patterns (pamps) to specialized receptors on their surface. after capturing and degrading bacteria, dcs present their antigens as small peptides bound to mhc molecules and prime naive bacteria-specific t cells. in response to pamp recognition dcs undergo maturation, which is a phenotypic change that increases their immunogenicity and prom ... | 2012 | 22703384 |
| effect of iacp mutation on flagellar phase variation in salmonella enterica serovar typhimurium strain uk-1. | flagella are surface appendages that are important for bacterial motility and invasion of host cells. two flagellin subunits in salmonella enterica serovar typhimurium, flic and fljb, are alternatively expressed by a site-specific dna inversion mechanism called flagellar phase variation. although this inversion mechanism is understood at the molecular level, the key factor controlling the expression of the two flagellin subunits has not been determined. in this study, we found that a putative ac ... | 2012 | 22685287 |
| cysteine catabolism and cysteine desulfhydrase (cdsh/stm0458) in salmonella enterica serovar typhimurium. | cysteine is potentially toxic and can affect diverse functions such as oxidative stress, antibiotic resistance, and swarming motility. the contribution of cysteine catabolism in modulating responses to cysteine has not been examined, in part because the genes have not been identified and mutants lacking these genes have not been isolated or characterized. we identified the gene for a previously described cysteine desulfhydrase, which we designated cdsh (formerly stm0458). we also identified a di ... | 2012 | 22685283 |
| ifnγ expression by an attenuated strain of salmonella enterica serovar typhimurium improves vaccine efficacy in susceptible tlr4-defective c3h/hej mice. | c3h/hej mice carry a mutated allele of tlr4 gene (tlr4 ( d )) and thus are hyporesponsive to the lethal effects of lipopolysaccharide (lps). characteristically, however, the mice are also hypersusceptible to infections, particularly by gram-negative bacteria such as salmonella enterica serovar typhimurium (s. typhimurium) and are known to be difficult to vaccinate against virulent exposure. this is observed despite the expression of wild-type allele of nramp1 gene, another important determinant ... | 2013 | 22684724 |
| myd88 signaling promotes both mucosal homeostatic and fibrotic responses during salmonella-induced colitis. | salmonella enterica serovar typhimurium is a clinically important gram-negative, enteric bacterial pathogen that activates several toll-like receptors (tlrs). while tlr signaling through the adaptor protein myd88 has been shown to promote inflammation and host defense against the systemic spread of s. typhimurium, curiously, its role in the host response against s. typhimurium within the mammalian gastrointestinal (gi) tract is less clear. we therefore used the recently described salmonella-indu ... | 2012 | 22679002 |
| selective purification of recombinant neuroactive peptides using the flagellar type iii secretion system. | the structure, assembly, and function of the bacterial flagellum involves about 60 different proteins, many of which are selectively secreted via a specific type iii secretion system (t3ss) (j. frye et al., j. bacteriol. 188:2233-2243, 2006). the t3ss is reported to secrete proteins at rates of up to 10,000 amino acid residues per second. in this work, we showed that the flagellar t3ss of salmonella enterica serovar typhimurium could be manipulated to export recombinant nonflagellar proteins thr ... | 2012 | 22647788 |
| effect of salmonella enteric serovar typhimurium in pregnant mice: a biochemical and histopathological study. | food borne infections caused by salmonella enterica species are increasing globally and pregnancy poses a significant threat in developing countries, where sanitation facilities are inadequate. thus, the present study was designed to delineate the effect of salmonella infection during pregnancy. | 2012 | 27785189 |
| role of mouse peptidoglycan recognition protein pglyrp2 in the innate immune response to salmonella enterica serovar typhimurium infection in vivo. | peptidoglycan recognition proteins (pgrps) are a family of innate pattern recognition molecules that bind bacterial peptidoglycan. while the role of pgrps in drosophila innate immunity has been extensively studied, how the four mammalian pgrp proteins (pglyrp1 to pglyrp4) contribute to host defense against bacterial pathogens in vivo remains poorly understood. pglyrp1, pglyrp3, and pglyrp4 are directly bactericidal in vitro, whereas pglyrp2 is an n-acetylmuramyl-l-alanine amidase that cleaves pe ... | 2012 | 22615249 |
| the evaluation of a pcr-based method for identification of salmonella enterica serotypes from environmental samples and various food matrices. | the most commonly used method for serotyping salmonella spp. is based on the kaufmann-white scheme, and is composed of serological reactions using antibodies to lps agglutinins. the multiplex pcr used in this investigation was established by kim et al. to serotype the 30 most common clinical salmonella serotypes, as determined by cdc. the pcr assay consists of two five-plex reactions and a single two-plex pcr reaction, based on six genetic loci from salmonella enterica serotype typhimurium and f ... | 2012 | 22608224 |
| stm2209-stm2208 (opvab): a phase variation locus of salmonella enterica involved in control of o-antigen chain length. | stm2209 and stm2208 are contiguous loci annotated as putative protein-coding genes in the chromosome of salmonella enterica. lack of homologs in related enterobacteria and low g+c content suggest that s. enterica may have acquired stm2209-stm2208 by horizontal transfer. stm2209 and stm2208 are co-transcribed from a promoter upstream stm2209, and their products are inner (cytoplasmic) membrane proteins. analysis with the bacterial adenylate cyclase two-hybrid system suggests that stm2209 and stm2 ... | 2012 | 22606300 |
| dietary rice bran promotes resistance to salmonella enterica serovar typhimurium colonization in mice. | dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as salmonella. the ability of rice bran to reduce the susceptibility of mice to a salmonella infection has not been previously investigated. therefore, we hypothesized that the incorporation of rice bra ... | 2012 | 22583915 |
| salmonella biofilm development depends on the phosphorylation status of rcsb. | the rcs phosphorelay pathway is a complex signaling pathway involved in the regulation of many cell surface structures in enteric bacteria. in response to environmental stimuli, the sensor histidine kinase (rcsc) autophosphorylates and then transfers the phosphate through intermediary steps to the response regulator (rcsb), which, once phosphorylated, regulates gene expression. here, we show that salmonella biofilm development depends on the phosphorylation status of rcsb. thus, unphosphorylated ... | 2012 | 22582278 |
| comparative proteomic analysis of salmonella tolerance to the biocide active agent triclosan. | concern has been expressed about the overuse of biocides in farm animal production and food industries. biocide application can create selective pressures that lead to increased tolerance to one or more of these compounds and are concomitant with the emergence of cross-resistance to antibiotics. a triclosan sensitive salmonella enterica serovar typhimurium and the isogenic triclosan tolerant mutant were studied at the proteomic level in order to elucidate cellular mechanisms that facilitate bioc ... | 2012 | 22579747 |
| effect of farm type on within-herd salmonella prevalence, serovar distribution, and antimicrobial resistance. | salmonella represents a major challenge to the pig industry, as pork presents a risk for human salmonellosis. in this study, we have examined the effect of farm type on the prevalence of fattening pigs shedding salmonella on 12 farms at risk for harboring salmonella. on six open (grow-to-finish) and six closed (farrow-to-finish) farms, the prevalence of pigs shedding salmonella was determined on two occasions approximately 2 months apart. the serovar, phage type, and antimicrobial resistance of ... | 2012 | 22564934 |
| targeted therapy via oral administration of attenuated salmonella expression plasmid-vectored stat3-shrna cures orthotopically transplanted mouse hcc. | the development of rna interference-based cancer gene therapies has been delayed due to the lack of effective tumor-targeting delivery systems. attenuated salmonella enterica serovar typhimurium (s. typhimurium) has a natural tropism for solid tumors. we report here the use of attenuated s. typhimurium as a vector to deliver shrna directly into tumor cells. constitutively activated signal transducer and activator of transcription 3 (stat3) is a key transcription factor involved in both hepatocel ... | 2012 | 22555509 |
| srnas and the virulence of salmonella enterica serovar typhimurium. | the combination of genomics and high-throughput cdna sequencing technologies has facilitated the identification of many small rnas (srnas) that play a central role in the post-transcriptional gene regulation of salmonella enterica serovar typhimurium. to date, most of the functionally characterized srnas have been involved in the regulation of processes which are not directly linked to virulence. just five srnas have been found to affect the ability of salmonella to replicate within mammalian ce ... | 2012 | 22546935 |