| genomic variability of serial human isolates of salmonella enterica serovar typhimurium associated with prolonged carriage. | salmonella enterica serovar typhimurium is an important foodborne human pathogen that often causes self-limiting but severe gastroenteritis. prolonged excretion of s. typhimurium after the infection can lead to secondary transmissions. however, little is known about within-host genomic variation in bacteria associated with asymptomatic shedding. genomes of 35 longitudinal isolates of s. typhimurium recovered from 11 patients (children and adults) with culture-confirmed gastroenteritis were seque ... | 2015 | 26311853 |
| [structure and function of the bacterial flagellar type iii protein export system in salmonella
]. | the bacterial flagellum is a filamentous organelle that propels the bacterial cell body in liquid media. for construction of the bacterial flagellum beyond the cytoplasmic membrane, flagellar component proteins are transported by its specific protein export apparatus from the cytoplasm to the distal end of the growing flagellar structure. the flagellar export apparatus consists of a transmembrane export gate complex and a cytoplasmic atpase ring complex. flagellar substrate-specific chaperones b ... | 2015 | 26310179 |
| draft genome sequences of 19 salmonella enterica serovar typhimurium [4,5:i:-] strains resistant to nalidixic acid from a long-term outbreak in italy. | here, we present the draft genome sequences of 19 salmonella enterica serovar typhimurium monophasic variant [4,5:i:-] strains involved in a long-term salmonellosis outbreak that occurred in central italy in 2013 to 2014. | 2015 | 26294627 |
| vasculature disruption enhances bacterial targeting of autochthonous tumors. | attenuated salmonella enterica serovar typhimurium (s. typhimurium) has been developed as a vector to deliver therapeutic agents to tumors. the potential of s. typhimurium in cancer therapy is largely due to its reported propensity to accumulate at greater than 1,000-fold higher concentrations in tumors relative to healthy tissues. in this study, we compared bacterial colonization of tumors in a subcutaneous transplantation model with a more clinically relevant autochthonous tumor model. followi ... | 2015 | 26284135 |
| mdsabc-mediated pathway for pathogenicity in salmonella enterica serovar typhimurium. | mdsabc is a salmonella-specific tripartite efflux pump that has been implicated in the virulence of salmonella enterica serovar typhimurium; however, little is known about the virulence factors associated with this pump. we observed mdsabc expression-dependent alterations in the degree of resistance to extracellular oxidative stress and macrophage-mediated killing. thin-layer chromatography and tandem mass spectrometry analyses revealed that overexpression of mdsabc led to increased secretion of ... | 2015 | 26283336 |
| inactivated salmonella enterica serovar typhimurium monophasic variant (s. typhimurium 1,4,[5],12:i-) in sows is effective to control infection in piglets under field condition. | the monophasic variant of salmonella enterica serovar typhimurium, namely salmonella 1,4,[5],12:i-, has been increasingly responsible for foodborne human cases of disease and is most frequently detected in pork, since the variant is widely spread in pig farms. the aim of this study was to assess the efficacy of an autologous vaccine in decreasing the prevalence of salmonella 1,4,[5],12:i-, in pigs. the trial was performed in a multisite pig production system of northern italy. the autogenous vac ... | 2015 | 26260858 |
| biofilm formation ability of salmonella enterica serovar typhimurium acrab mutants. | recent studies offer contradictory findings about the role of multidrug efflux pumps in bacterial biofilm development. thus, the aim of this study was to investigate the involvement of the acrab efflux pump in biofilm formation by investigating the ability of acrb and acrab null mutants of salmonella enterica serovar typhimurium to produce biofilms. three models were used to compare the ability of s. typhimurium wild-type and its mutants to form biofilms: formation of biofilm on polystyrene surf ... | 2015 | 26260191 |
| streptomycin induced stress response in salmonella enterica serovar typhimurium shows distinct colony scatter signature. | we investigated the streptomycin-induced stress response in salmonella enterica serovars with a laser optical sensor, bardot (bacterial rapid detection using optical scattering technology). initially, the top 20 s. enterica serovars were screened for their response to streptomycin at 100 μg/ml. all, but four s. enterica serovars were resistant to streptomycin. the mic of streptomycin-sensitive serovars (enteritidis, muenchen, mississippi, and schwarzengrund) varied from 12.5 to 50 μg/ml, while s ... | 2015 | 26252374 |
| regulation and function of the salmonella mgtc virulence protein. | salmonella enterica serovar typhimurium produces many virulence proteins to cause diseases. the salmonella mgtc protein is one of such virulence proteins specially required for intracellular proliferation inside macrophages and mouse virulence. in this review, we will cover how the mgtc gene is turned on or off and what the signals required for mgtc expression are. later in this review, we will discuss a recent understanding of mgtc function in salmonella pathogenesis by identifying its target p ... | 2015 | 26231375 |
| intestinal inflammation leads to a long-lasting increase in resistance to systemic salmonellosis that requires macrophages but not b or t lymphocytes at the time of pathogen challenge. | intestinal inflammation is associated with systemic translocation of commensal antigens and the consequent activation of b and t lymphocytes. the long-term consequences of such immune activation are not completely understood. | 2015 | 26222341 |
| exposure of salmonella enterica serovar typhimurium to three humectants used in the food industry induces different osmoadaptation systems. | common salt (nacl) is frequently used by the food industry to add flavor and to act as a humectant in order to reduce the water content of a food product. the improved health awareness of consumers is leading to a demand for food products with reduced salt content; thus, manufacturers require alternative water activity-reducing agents which elicit the same general effects as nacl. two examples include kcl and glycerol. these agents lower the water activity of a food matrix and also contribute to ... | 2015 | 26209672 |
| salmonella typhimurium co-opts the host type i ifn system to restrict macrophage innate immune transcriptional responses selectively. | innate immune inflammatory responses are subject to complex layers of negative regulation at intestinal mucosal surfaces. although the type i ifn system is critical for amplifying antiviral immunity, it has been shown to play a homeostatic role in some models of autoimmune inflammation. type i ifn is triggered in the gut by select bacterial pathogens, but whether and how the type i ifn might regulate innate immunity in the intestinal environment have not been investigated in the context of salmo ... | 2015 | 26202980 |
| rescuing chemotaxis of the anticancer agent salmonella enterica serovar typhimurium vnp20009. | the role of chemotaxis and motility in salmonella enterica serovar typhimurium tumor colonization remains unclear. we determined through swim plate assays that the well-established anticancer agent s. typhimurium vnp20009 is deficient in chemotaxis, and that this phenotype is suppressible. through genome sequencing, we revealed that vnp20009 and four selected suppressor mutants had a single nucleotide polymorphism (snp) in chey causing a mutation in the conserved proline residue at position 110. ... | 2015 | 26200833 |
| identification of salmonella typhimurium deubiquitinase ssel substrates by immunoaffinity enrichment and quantitative proteomic analysis. | ubiquitination is a key protein post-translational modification that regulates many important cellular pathways and whose levels are regulated by equilibrium between the activities of ubiquitin ligases and deubiquitinases. here, we present a method to identify specific deubiquitinase substrates based on treatment of cell lysates with recombinant enzymes, immunoaffinity purification, and global quantitative proteomic analysis. as a model system to identify substrates, we used a virulence-related ... | 2015 | 26147956 |
| generating a metal-responsive transcriptional regulator to test what confers metal sensing in cells. | frmr from salmonella enterica serovar typhimurium (a csor/rcnr-like transcriptional de-repressor) is shown to repress the frmra operator-promoter, and repression is alleviated by formaldehyde but not manganese, iron, cobalt, nickel, copper, or zn(ii) within cells. in contrast, repression by a mutant frmre64h (which gains an rcnr metal ligand) is alleviated by cobalt and zn(ii). unexpectedly, frmr was found to already bind co(ii), zn(ii), and cu(i), and moreover metals, as well as formaldehyde, t ... | 2015 | 26109070 |
| a mannose family phosphotransferase system permease and associated enzymes are required for utilization of fructoselysine and glucoselysine in salmonella enterica serovar typhimurium. | salmonella enteric serovar typhimurium, a major cause of food-borne illness, is capable of using a variety of carbon and nitrogen sources. fructoselysine and glucoselysine are maillard reaction products formed by the reaction of glucose or fructose, respectively, with the ε-amine group of lysine. we report here that s. typhimurium utilizes fructoselysine and glucoselysine as carbon and nitrogen sources via a mannose family phosphotransferase (pts) encoded by gfrabcd (glucoselysine/fructoselysine ... | 2015 | 26100043 |
| salmonella engages host micrornas to modulate sumoylation: a new arsenal for intracellular survival. | posttranslational modifications (ptms) can alter many fundamental properties of a protein. one or combinations of them have been known to regulate the dynamics of many cellular pathways and consequently regulate all vital processes. understandably, pathogens have evolved sophisticated strategies to subvert these mechanisms to achieve instantaneous control over host functions. here, we present the first report of modulation by intestinal pathogen salmonella enterica serovar typhimurium (s. typhim ... | 2015 | 26100020 |
| fluoroquinolone induction of phage-mediated gene transfer in multidrug-resistant salmonella. | fluoroquinolones are broad-spectrum antibiotics that inhibit bacterial dna gyrase and topoisomerase activity, which can cause dna damage and result in bacterial cell death. in response to dna damage, bacteria induce an sos response to stimulate dna repair. however, the sos response may also induce prophage with production of infectious virions. salmonella strains typically contain multiple prophages, and certain strains including phage types dt120 and dt104 contain prophage that upon induction a ... | 2015 | 26078016 |
| an enterobacterial common antigen mutant of salmonella enterica serovar typhimurium as a vaccine candidate. | due to increasing rates of invasive salmonella enterica serovar typhimurium infection, there is a need for an effective vaccine to prevent this disease. previous studies showed that a mutation in the first gene of the enterobacterial common antigen biosynthetic pathway, weca, resulted in attenuation of s. typhimurium in a murine model of salmonellosis. furthermore, immunization with a weca(-) strain protected against lethal challenge with the parental wild type s. typhimurium strain. herein, we ... | 2015 | 26070977 |
| acetylation regulates survival of salmonella enterica serovar typhimurium under acid stress. | the ability to acetylate lysine residues is conserved across organisms, and acetylation of lysine residues plays important roles in various cellular functions. maintaining intracellular ph homeostasis is crucial for the survival of enteric bacteria in the acidic gastric tract. it has been shown that eukaryotes can stabilize the intracellular ph by histone deacetylation. however, it remains unknown whether bacteria can utilize a reversible protein acetylation system to adapt to an acidic environm ... | 2015 | 26070677 |
| infection with salmonella enterica serovar typhimurium leads to increased proportions of f4/80+ red pulp macrophages and decreased proportions of b and t lymphocytes in the spleen. | infection of mice with salmonella enterica serovar typhimurium (salmonella) causes systemic inflammatory disease and enlargement of the spleen (splenomegaly). splenomegaly has been attributed to a general increase in the numbers of phagocytes, lymphocytes, as well as to the expansion of immature cd71+ter119+ reticulocytes. the spleen is important for recycling senescent red blood cells (rbcs) and for the capture and eradication of blood-borne pathogens. conservation of splenic tissue architectur ... | 2015 | 26068006 |
| diffusion and persistence of multidrug resistant salmonella typhimurium strains phage type dt120 in southern italy. | sixty-two multidrug resistant salmonella enterica serovar typhimurium strains isolated from 255 clinical strains collected in southern italy in 2006-2008 were characterised for antimicrobial resistance genes, pulsotype, and phage type. most strains (83.9%) were resistant to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (acssut) encoded in 88.5% by the salmonella genomic island (sgi1) and in 11.5% by the inh-like integron (bla oxa-30-aada1) and cata1, sul1, and tet ... | 2015 | 26060815 |
| small molecules with big effects: cyclic di-gmp-mediated stimulation of cellulose production by the amino acid ʟ-arginine. | in this issue of science signaling, mills et al. show that the amino acid ʟ-arginine increases the concentration of the second messenger c-di-gmp in salmonella enterica serovar typhimurium through a specific diguanylate cyclase, leading to increased production of the exopolysaccharide cellulose, which is an extracellular matrix component of environmental and host-associated biofilms. | 2015 | 26060328 |
| defining the core genome of salmonella enterica serovar typhimurium for genomic surveillance and epidemiological typing. | salmonella enterica serovar typhimurium is the most common salmonella serovar causing foodborne infections in australia and many other countries. twenty-one s. typhimurium strains from salmonella reference collection a (sara) were analyzed using illumina high-throughput genome sequencing. single nucleotide polymorphisms (snps) in 21 sara strains ranged from 46 to 11,916 snps, with an average of 1,577 snps per strain. together with 47 strains selected from publicly available s. typhimurium genome ... | 2015 | 26019201 |
| hamp domain rotation and tilting movements associated with signal transduction in the phoq sensor kinase. | hamp domains are α-helical coiled coils that often transduce signals from extracytoplasmic sensing domains to cytoplasmic domains. limited structural information has resulted in hypotheses that specific hamp helix movement changes downstream enzymatic activity. these hypotheses were tested by mutagenesis and cysteine cross-linking analysis of the phoq histidine kinase, essential for resistance to antimicrobial peptides in a variety of enteric pathogens. these results support a mechanistic model ... | 2015 | 26015499 |
| detection of cell surface hydrophobicity, biofilm and fimbirae genes in salmonella isolated from tunisian clinical and poultry meat. | the aim of this study was to evaluate the ability of 15 serotypes of salmonella to form biofilm on polystyrene, polyvinyl chloride (pvc) and glass surfaces. . | 2014 | 26005652 |
| salmonella infection inhibits intestinal biotin transport: cellular and molecular mechanisms. | infection with the nontyphoidal salmonella is a common cause of food-borne disease that leads to acute gastroenteritis/diarrhea. severe/prolonged cases of salmonella infection could also impact host nutritional status, but little is known about its effect on intestinal absorption of vitamins, including biotin. we examined the effect of salmonella enterica serovar typhimurium (s. typhimurium) infection on intestinal biotin uptake using in vivo (streptomycin-pretreated mice) and in vitro [mouse (y ... | 2015 | 25999427 |
| mathematical model of flagella gene expression dynamics in salmonella enterica serovar typhimurium. | flagellar assembly in salmonella is controlled by an intricate genetic and biochemical network. this network comprises of a number of inter-connected feedback loops, which control the assembly process dynamically. critical among these are the flia-flgm feedback, fliz-mediated positive feedback, and flit-mediated negative feedback. in this work, we develop a mathematical model to track the dynamics of flagellar gene expression in salmonella. analysis of our model demonstrates that the network is ... | 2015 | 25972986 |
| interaction of salmonella enterica serovar typhimurium with intestinal organoids derived from human induced pluripotent stem cells. | the intestinal mucosa forms the first line of defense against infections mediated by enteric pathogens such as salmonellae. here we exploited intestinal "organoids" (ihos) generated from human induced pluripotent stem cells (hipscs) to explore the interaction of salmonella enterica serovar typhimurium with ihos. imaging and rna sequencing were used to analyze these interactions, and clear changes in transcriptional signatures were detected, including altered patterns of cytokine expression after ... | 2015 | 25964470 |
| outbreak of salmonella enterica serovar typhimurium phage type dt41 in danish poultry production. | salmonella enterica subspecies enterica serovar typhimurium (s. typhimurium) is one of the most prevalent serovars in europe - where both poultry and poultry related products are common sources of human salmonellosis. due to efficient control programs, the prevalence of s. typhimurium in danish poultry production is very low. despite this, during the past decades there has been a reoccurring problem with infections with s. typhimurium phage type dt41 in the danish poultry production without iden ... | 2015 | 25962983 |
| parallel evolutionary pathways to antibiotic resistance selected by biocide exposure. | biocides are widely used to prevent infection. we aimed to determine whether exposure of salmonella to various biocides could act as a driver of antibiotic resistance. | 2015 | 25953808 |
| improvement of bacterial clearance and relief of clinical signs of salmonella enterica serovar typhimurium infection in pigs through upregulation of th 1-specific responses by administration of a combination of two silicate minerals, biotite and bentonite. | biotite and bentonite are phyllosilicate minerals that were originally used in industrial applications. several beneficial activities of them have recently been reported, especially regulation of the immune system and antimicrobial effects. therefore, we investigated the immune-enhancing and bacterial clearance effects of a biotite and bentonite mixture (bbm) on experimental infection of salmonella enterica serovar typhimurium (s. typhimurium) to determine whether the bbm could be used as an alt ... | 2015 | 25947887 |
| proteomic analyses of intracellular salmonella enterica serovar typhimurium reveal extensive bacterial adaptations to infected host epithelial cells. | salmonella species can gain access into nonphagocytic cells, where the bacterium proliferates in a unique membrane-bounded compartment. in order to reveal bacterial adaptations to their intracellular niche, here we conducted the first comprehensive proteomic survey of salmonella isolated from infected epithelial cells. among ∼ 3,300 identified bacterial proteins, we found that about 100 proteins were significantly altered at the onset of salmonella intracellular replication. in addition to subst ... | 2015 | 25939512 |
| h-ns silencing of the salmonella pathogenicity island 6-encoded type vi secretion system limits salmonella enterica serovar typhimurium interbacterial killing. | the secretion of bacterial toxin proteins is achieved by dedicated machineries called secretion systems. the type vi secretion system (t6ss) is a widespread versatile machine used for the delivery of protein toxins to both prokaryotic and eukaryotic cells. in salmonella enterica serovar typhimurium, the expression of the t6ss genes is activated during macrophage or mouse infection. here, we show that the t6ss gene cluster is silenced by the histone-like nucleoid structuring h-ns protein using a ... | 2015 | 25916986 |
| replication of salmonella enterica serovar typhimurium in human monocyte-derived macrophages. | salmonella enterica serovar typhimurium is a common cause of food-borne gastrointestinal illness, but additionally it causes potentially fatal bacteremia in some immunocompromised patients. in mice, systemic spread and replication of the bacteria depend upon infection of and replication within macrophages, but replication in human macrophages is not widely reported or well studied. in order to assess the ability of salmonella typhimurium to replicate in human macrophages, we infected primary mon ... | 2015 | 25895967 |
| novel pegylated silver coated carbon nanotubes kill salmonella but they are non-toxic to eukaryotic cells. | resistance of food borne pathogens such as salmonella to existing antibiotics is of grave concern. silver coated single walled carbon nanotubes (swcnts-ag) have broad-spectrum antibacterial activity and may be a good treatment alternative. however, toxicity to human cells due to their physico-chemical properties is a serious public health concern. although pegylation is commonly used to reduce metal nanoparticle toxicity, swcnts-ag have not been pegylated as yet, and the effect of pegylation of ... | 2015 | 25888864 |
| use of ensure® nutrition shakes as an alternative formulation method for live recombinant attenuated salmonella typhi vaccines. | to be effective, orally administered live salmonella vaccines must first survive their encounter with the low ph environment of the stomach. to enhance survival, an antacid is often given to neutralize the acidic environment of the stomach just prior to or concomitant with administration of the vaccine. one drawback of this approach, from the perspective of the clinical trial volunteer, is that the taste of a bicarbonate-based acid neutralization system can be unpleasant. thus, we explored an al ... | 2015 | 25879849 |
| efficiency of conditionally attenuated salmonella enterica serovar typhimurium in bacterium-mediated tumor therapy. | increasing numbers of cancer cases generate a great urge for new treatment options. applying bacteria like salmonella enterica serovar typhimurium for cancer therapy represents an intensively explored option. these bacteria have been shown not only to colonize solid tumors but also to exhibit an intrinsic antitumor effect. in addition, they could serve as tumor-targeting vectors for therapeutic molecules. however, the pathogenic s. typhimurium strains used for tumor therapy need to be attenuated ... | 2015 | 25873375 |
| complete genome sequence of salmonella enterica serovar typhimurium myophage mushroom. | salmonella enterica serovar typhimurium (s. typhimurium) is a leading cause of foodborne illness worldwide. over the past two decades, strains resistant to antibiotics have begun to emerge, highlighting the need for alternative treatment strategies such as bacteriophage therapy. here, we present the complete genome of mushroom, an s. typhimurium myophage. | 2015 | 25858827 |
| salmonella promotes virulence by repressing cellulose production. | cellulose is the most abundant organic polymer on earth. in bacteria, cellulose confers protection against environmental insults and is a constituent of biofilms typically formed on abiotic surfaces. we report that, surprisingly, salmonella enterica serovar typhimurium makes cellulose when inside macrophages. we determine that preventing cellulose synthesis increases virulence, whereas stimulation of cellulose synthesis inside macrophages decreases virulence. an attenuated mutant lacking the mgt ... | 2015 | 25848006 |
| bistable expression of csgd in salmonella enterica serovar typhimurium connects virulence to persistence. | pathogenic bacteria often need to survive in the host and the environment, and it is not well understood how cells transition between these equally challenging situations. for the human and animal pathogen salmonella enterica serovar typhimurium, biofilm formation is correlated with persistence outside a host, but the connection to virulence is unknown. in this study, we analyzed multicellular-aggregate and planktonic-cell subpopulations that coexist when s. typhimurium is grown under biofilm-in ... | 2015 | 25824832 |
| increased ferroportin-1 expression and rapid splenic iron loss occur with anemia caused by salmonella enterica serovar typhimurium infection in mice. | the gram-negative intracellular bacterium salmonella enterica serovar typhimurium causes persistent systemic inflammatory disease in immunocompetent mice. following oral inoculation with s. typhimurium, mice develop a hematopathological syndrome akin to typhoid fever with splenomegaly, microcytic anemia, extramedullary erythropoiesis, and increased hemophagocytic macrophages in the bone marrow, liver, and spleen. additionally, there is marked loss of iron from the spleen, an unanticipated result ... | 2015 | 25824831 |
| characterization of a large novel phage-like plasmid in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium is a food-borne pathogen and a leading cause of gastroenteritis in humans. recently, we sequenced a phage-type dt108 strain (l945) and found reads with high similarity to both salmonella typhi strain ct18 plasmid phcm2 and bacteriophage ssu5. in this study, we completely sequenced the novel phage-like plasmid which was designated as pstm_φ. the presence of this phage-like plasmid was examined in a collection of 284 salmonella typhimurium isolates using pcr ... | 2015 | 25795590 |
| ceftriaxone-resistant salmonella enterica serotype typhimurium sequence type 313 from kenyan patients is associated with the blactx-m-15 gene on a novel inchi2 plasmid. | multidrug-resistant bacteria pose a major challenge to the clinical management of infections in resource-poor settings. although nontyphoidal salmonella (nts) bacteria cause predominantly enteric self-limiting illness in developed countries, nts is responsible for a huge burden of life-threatening bloodstream infections in sub-saharan africa. here, we characterized nine s. typhimurium isolates from an outbreak involving patients who initially failed to respond to ceftriaxone treatment at a refer ... | 2015 | 25779570 |
| extensive genetic variability linked to is26 insertions in the fljb promoter region of atypical monophasic variants of salmonella enterica serovar typhimurium. | fifty-nine monophasic salmonella enterica serovar typhimurium isolates, collected in belgium during the period from 2008 to 2011, have been serotyped as 4,[5]:i:- and shown to harbor an fljb coding sequence. the genetic differences between these strains and phenotypically biphasic salmonella typhimurium were analyzed through pcr and dna sequencing. genetic alterations in the fljb promoter region affecting expression of the phase 2 flagellin were observed in 53 isolates. other genetic events in t ... | 2015 | 25724958 |
| complete genome sequence of salmonella enterica serovar typhimurium siphophage shivani. | here, we describe the complete genome sequence of siphophage shivani, a t5-like constituent phage in the therapeutic phage cocktail intestiphage developed for bacterial gastroenteritis. shivani was isolated against a foodborne pathogen, salmonella enterica, which is one of the leading causes of gastroenteritis. | 2015 | 25720685 |
| whole genome sequencing for the retrospective investigation of an outbreak of salmonella typhimurium dt 8. | salmonella enterica serovar typhimurium dt8 is uncommon within the european union. an increase in this phage type was reported in the summer of 2013 in the states of jersey. | 2015 | 25713745 |
| extensive amplification of gi-vii-6, a multidrug resistance genomic island of salmonella enterica serovar typhimurium, increases resistance to extended-spectrum cephalosporins. | gi-vii-6 is a chromosomally integrated multidrug resistance genomic island harbored by a specific clone of salmonella enterica serovar typhimurium (s.typhimurium). it contains a gene encoding cmy-2 β-lactamase (bla cmy-2), and therefore contributes to extended-spectrum cephalosporin resistance. to elucidate the significance of gi-vii-6 on adaptive evolution, spontaneous mutants of s. typhimurium strain l-3553 were selected on plates containing cefotaxime (ctx). the concentrations of ctx were hig ... | 2015 | 25713569 |
| analysis of the salmonella regulatory network suggests involvement of ssrb and h-ns in σ(e)-regulated spi-2 gene expression. | the extracytoplasmic functioning sigma factor σ(e) is known to play an essential role for salmonella enterica serovar typhimurium to survive and proliferate in macrophages and mice. however, its regulatory network is not well-characterized, especially during infection. here we used microarray to identify genes regulated by σ(e) in salmonella grown in three conditions: a nutrient-rich condition and two others that mimic early and late intracellular infection. we found that in each condition σ(e) ... | 2015 | 25713562 |
| stress enhances the sensitivity of salmonella enterica serovar typhimurium to bacteriocins. | the aim of this study was to evaluate the potential application of bacteriocins against gram-negative bacteria when associated with others food preservation methods. | 2015 | 25693498 |
| diguanylate cyclase null mutant reveals that c-di-gmp pathway regulates the motility and adherence of the extremophile bacterium acidithiobacillus caldus. | an understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. for this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. in many bacteria, the intracellular levels of c-di-gmp molecules regulate the transition from the motile planktonic state to ses ... | 2015 | 25689133 |
| chloramphenicol and tetracycline decrease motility and increase invasion and attachment gene expression in specific isolates of multidrug-resistant salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium is one of the most common serovars isolated from humans and livestock, and over 35% of these isolates are resistant to three or more antibiotics. multidrug-resistant (mdr) salmonella is a public health concern as it is associated with increased morbidity in patients compared to antibiotic sensitive strains, though it is unknown how the antibiotic resistant isolates lead to a more severe infection. cellular invasion is temporally regulated in salmonella and ... | 2014 | 25688233 |
| the arf gtpase-activating protein family is exploited by salmonella enterica serovar typhimurium to invade nonphagocytic host cells. | to establish intracellular infections, salmonella bacteria trigger host cell membrane ruffling and invasion by subverting cellular arf guanine nucleotide exchange factors (gefs) that activate arf1 and arf6 gtpases by promoting gtp binding. a family of cellular arf gtpase-activating proteins (gaps) can downregulate arf signaling by stimulating gtp hydrolysis, but whether they do this during infection is unknown. here, we uncovered a remarkable role for distinct arf gap family members in salmonell ... | 2015 | 25670778 |
| toll-like receptor 2 (tlr2) and tlr9 play opposing roles in host innate immunity against salmonella enterica serovar typhimurium infection. | toll-like receptors (tlrs) are evolutionarily conserved host proteins that are essential for effective host defense against pathogens. however, recent studies suggest that some tlrs can negatively regulate immune responses. we observed here that tlr2 and tlr9 played opposite roles in regulating innate immunity against oral infection of salmonella enterica serovar typhimurium in mice. while tlr9-/- mice exhibited shortened survival, an increased cytokine storm, and more severe salmonella hepatiti ... | 2015 | 25667264 |
| complete genome of salmonella enterica serovar typhimurium t5-like siphophage stitch. | salmonellosis, caused by salmonella, is a leading cause of food poisoning worldwide. with the continuing rise of bacterial antibiotic resistance, efforts are focused on seeking new approaches for treatment of bacterial infections, namely, bacteriophage therapy. here, we report the complete genome of s. typhimurium siphophage stitch. | 2015 | 25657270 |
| gas chromatography-mass spectrometry-based metabolite profiling of salmonella enterica serovar typhimurium differentiates between biofilm and planktonic phenotypes. | the aim of this study was to utilize gas chromatography coupled with mass spectrometry (gc-ms) to compare and identify patterns of biochemical change between salmonella cells grown in planktonic and biofilm phases and salmonella biofilms of different ages. our results showed a clear separation between planktonic and biofilm modes of growth. the majority of metabolites contributing to variance between planktonic and biofilm supernatants were identified as amino acids, including alanine, glutamic ... | 2015 | 25636852 |
| flagella-independent surface motility in salmonella enterica serovar typhimurium. | flagella are multiprotein complexes necessary for swimming and swarming motility. in salmonella enterica serovar typhimurium, flagella-mediated motility is repressed by the phop/phoq regulatory system. we now report that salmonella can move on 0.3% agarose media in a flagella-independent manner when experiencing the phop/phoq-inducing signal low mg(2+). this motility requires the phop-activated mgta, mgtc, and pagm genes, which specify a mg(2+) transporter, an inhibitor of salmonella's own f1fo ... | 2015 | 25624475 |
| delineating community outbreaks of salmonella enterica serovar typhimurium by use of whole-genome sequencing: insights into genomic variability within an outbreak. | whole-genome next-generation sequencing (ngs) was used to retrospectively examine 57 isolates from five epidemiologically confirmed community outbreaks (numbered 1 to 5) caused by salmonella enterica serovar typhimurium phage type dt170. most of the human and environmental isolates confirmed epidemiologically to be involved in the outbreaks were either genomically identical or differed by one or two single nucleotide polymorphisms (snps), with the exception of those in outbreak 1. the isolates f ... | 2015 | 25609719 |
| hydrogen peroxide and hypochlorous acid influx through the major s. typhimurium porin ompd is affected by substitution of key residues of the channel. | ompd is the major salmonella enterica serovar typhimurium (s. typhimurium) porin and mediates hydrogen peroxide (h2o2) influx. the results described herein extend this finding to hypochlorous acid (hocl), another reactive oxygen species that is also part of the oxidative burst generated by the phagosome. s. typhimurium cells lacking ompd show decreased hocl influx, and ompd-reconstituted proteoliposomes show an increase in the uptake of the toxic compound. to understand this physiologically rele ... | 2015 | 25600570 |
| plane of nutrition influences the performance, innate leukocyte responses, and resistance to an oral salmonella enterica serotype typhimurium challenge in jersey calves. | two experiments investigated how plane of nutrition influences performance, leukocyte responses, and resistance to an oral salmonella enterica serotype typhimurium challenge. in experiment 1, 46 (2±1 d of age) calves were randomly assigned to 2 diets: a low (lpn; n=23) and high plane of nutrition (hpn; n=23). the lpn calves were fed 409 g/d of dry matter (dm) of a 20% crude protein and 20% fat milk replacer, whereas hpn calves were fed 610 and 735 g/d of dm of a 28% crude protein and 25% fat mil ... | 2015 | 25597967 |
| mouse models for assessing the cross-protective efficacy of oral non-typhoidal salmonella vaccine candidates harbouring in-frame deletions of the atp-dependent protease lon and other genes. | in balb/c mouse models of salmonella enterica serovar typhimurium infection, a single oral immunization with a mutant strain with an insertion of the chloramphenicol resistance gene into the atp-dependent protease clpp or lon gene decreased the number of salmonellae in each tissue sample 5 days after oral challenge with virulent s. typhimurium at weeks 26 and 54 post-immunization. these data suggested that an oral immunization with the clpp- or lon-disrupted s. typhimurium strain could provide l ... | 2015 | 25589672 |
| repressor activity of the rpos/σs-dependent rna polymerase requires dna binding. | the rpos/σ(s) sigma subunit of rna polymerase (rnap) activates transcription of stationary phase genes in many gram-negative bacteria and controls adaptive functions, including stress resistance, biofilm formation and virulence. in this study, we address an important but poorly understood aspect of σ(s)-dependent control, that of a repressor. negative regulation by σ(s) has been proposed to result largely from competition between σ(s) and other σ factors for binding to a limited amount of core r ... | 2015 | 25578965 |
| two-component regulators control hila expression by controlling fimz and hile expression within salmonella enterica serovar typhimurium. | salmonellae initiate disease through the invasion of host cells within the intestine. this ability to invade requires the coordinated action of numerous genes, many of which are found within salmonella pathogenicity island 1 (spi-1). the key to this process is the ability of the bacteria to respond to the environment, thereby upregulating the necessary genes under optimal conditions. central to the control of spi-1 is the transcriptional activator hila. work has identified at least 10 different ... | 2015 | 25547794 |
| the frequency and duration of salmonella-macrophage adhesion events determines infection efficiency. | salmonella enterica causes a range of important diseases in humans and a in a variety of animal species. the ability of bacteria to adhere to, invade and survive within host cells plays an important role in the pathogenesis of salmonella infections. in systemic salmonellosis, macrophages constitute a niche for the proliferation of bacteria within the host organism. salmonella enterica serovar typhimurium is flagellated and the frequency with which this bacterium collides with a cell is important ... | 2015 | 25533091 |
| plekhm1 regulates salmonella-containing vacuole biogenesis and infection. | the host endolysosomal compartment is often manipulated by intracellular bacterial pathogens. salmonella (salmonella enterica serovar typhimurium) secrete numerous effector proteins, including sifa, through a specialized type iii secretion system to hijack the host endosomal system and generate the salmonella-containing vacuole (scv). to form this replicative niche, salmonella targets the rab7 gtpase to recruit host membranes through largely unknown mechanisms. we show that pleckstrin homology d ... | 2015 | 25500191 |
| pathogen detection in complex samples by quartz crystal microbalance sensor coupled to aptamer functionalized core-shell type magnetic separation. | a quartz crystal microbalance sensor (qcm) was developed for sensitive and specific detection of salmonella enterica serovar typhimurium cells in food samples by integrating a magnetic bead purification system. although many sensor formats based on bioaffinity agents have been developed for sensitive and specific detection of bacterial cells, the development of robust sensor applications for food samples remained a challenging issue. a viable strategy would be to integrate qcm to a pre-purificat ... | 2015 | 25467500 |
| effect of zinc on growth performance, gut morphometry, and cecal microbial community in broilers challenged with salmonella enterica serovar typhimurium. | to evaluate the effects of supplemental zinc on growth performance, gut morphometry, and the cecal microbial community in broilers challenged with salmonella typhimurium, 180, 1-day-old male cobb 500 broiler chicks were randomly assigned to 3 treatments with ten replicates for a 42 day experiment. the 3 treatments were: unchallenged, s. typhimurium-challenged, and s. typhimurium-challenged with 120 mg/kg of zinc supplementation in the diet. salmonella infection caused a reduction in body-weight ... | 2014 | 25467118 |
| development of a computational framework for the analysis of protein correlation profiling and spatial proteomics experiments. | standard approaches to studying an interactome do not easily allow conditional experiments but in recent years numerous groups have demonstrated the potential for co-fractionation/co-migration based approaches to assess an interactome at a similar sensitivity and specificity yet significantly lower cost and higher speed than traditional approaches. unfortunately, there is as yet no implementation of the bioinformatics tools required to robustly analyze co-fractionation data in a way that can als ... | 2015 | 25464368 |
| two-ball structure of the flagellar hook-length control protein flik as revealed by high-speed atomic force microscopy. | the bacterial flagellar hook is a short and uniquely curved tube that connects the basal body to the filament. hook length is controlled at 55 nm on average by a soluble protein flik in salmonella enterica serovar typhimurium. the n-terminal segment of flik responsible for measuring the hook length is considered to be intrinsically disordered. here, we show by high-speed atomic force microscopy that a flik molecule in solution takes on a shape of two balls linked by a flexible string; the larger ... | 2015 | 25463436 |
| natural surface coating to inactivate salmonella enterica serovar typhimurium and maintain quality of cherry tomatoes. | the objective of the present study was to investigate the effectiveness of zein-based coatings in reducing populations of salmonella enterica serovar typhimurium and preserving quality of cherry tomatoes. tomatoes were inoculated with a cocktail of s. typhimurium lt2 plus three attenuated strains on the smooth skin surface and stem scar area. the zein-based coatings with and without cinnamon (up to 20%) and mustard essential oil or a commercial wax formulation were applied onto tomatoes and the ... | 2015 | 25462924 |
| transposition and homologous recombination drive evolution of puo-stvr2, a multidrug resistance derivative of pslt, the virulence plasmid specific of salmonella enterica serovar typhimurium. | five variants of a resistant derivative of pslt (termed puo-stvr2) were detected in clinical isolates of salmonella enterica serovar typhimurium recovered in spain. the structure of these variants revealed the involvement of is1, is26 and tn21-like transposition, as well as homologous recombination in the generation of deletions, inversions and insertions which, depending on the variant, affected an orf of unknown function, genes encoding a possible iron acquisition system, and/or resistance pro ... | 2015 | 25461846 |
| salmonella enterica: living a double life in epithelial cells. | intracellular bacterial pathogens can occupy a membrane-bound vacuole or live freely within the cytosol of mammalian cells. many studies have shown that the enteric bacterium, salmonella enterica serovar typhimurium (s. typhimurium), is a vacuolar pathogen. recent data, however, have revealed that within epithelial cells there are subpopulations of vacuolar and cytosolic salmonella. release from the salmonella-containing vacuole leads to transcriptional reprogramming of bacteria and their robust ... | 2015 | 25461569 |
| genotyping of salmonella enterica serovar typhimurium isolates by multilocus variable number of tandem repeat high-resolution melting analysis (mlv-hrma). | salmonella enterica serovar typhimurium (salmonella typhimurium) is one of the most important virulent foodborne pathogens in industrialized countries. the ability to type bacterial strains is essential for surveillance, investigation of outbreaks, and epidemiological studies. multilocus variable number tandem repeat combined with high-resolution melting analysis (mlv-hrma) is a fast, cost-efficient, and easy sample genotyping method. in this study, mlv-hrma and multilocus variable number tandem ... | 2015 | 25457374 |
| cxcl8-l1 and cxcl8-l2 are required in the zebrafish defense against salmonella typhimurium. | in recent years zebrafish has emerged as an excellent model for studying the cxcl8 signaling pathway in inflammation elicited upon tissue damage or infection. zebrafish has two true homologs of mammalian cxcl8, named cxcl8-l1 and cxcl8-l2. previously, we have shown that in wound-associated inflammation, these chemokines are up-regulated and are relevant for neutrophil recruitment. in infections, no such knowledge is available as most studies performed on this subject in zebrafish have mainly foc ... | 2015 | 25445910 |
| regulation of biofilm formation in salmonella enterica serovar typhimurium. | in animals, plants and the environment, salmonella enterica serovar typhimurium forms the red dry and rough (rdar) biofilm characterized by extracellular matrix components curli and cellulose. with complex expression control by at least ten transcription factors, the bistably expressed orphan response regulator csgd directs rdar morphotype development. csgd expression is an integral part of the hfq regulon and the complex cyclic diguanosine monophosphate signaling network partially controlled by ... | 2014 | 25437188 |
| salmonella enterica serovar typhimurium δmsbb triggers exacerbated inflammation in nod2 deficient mice. | the intracellular pathogen salmonella enterica serovar typhimurium causes intestinal inflammation characterized by edema, neutrophil influx and increased pro-inflammatory cytokine expression. a major bacterial factor inducing pro-inflammatory host responses is lipopolysaccharide (lps). s. typhimurium δmsbb possesses a modified lipid a, has reduced virulence in mice, and is being considered as a potential anti-cancer vaccine strain. the lack of a late myristoyl transferase, encoded by msbb leads ... | 2014 | 25423082 |
| identification of novel factors involved in modulating motility of salmonella enterica serotype typhimurium. | salmonella enterica serotype typhimurium can move through liquid using swimming motility, and across a surface by swarming motility. we generated a library of targeted deletion mutants in salmonella typhimurium strain atcc14028, primarily in genes specific to salmonella, that we have previously described. in the work presented here, we screened each individual mutant from this library for the ability to move away from the site of inoculation on swimming and swarming motility agar. mutants in gen ... | 2014 | 25369209 |
| host hydrogen rather than that produced by the pathogen is important for salmonella enterica serovar typhimurium virulence. | salmonella enterica serovar typhimurium utilizes molecular hydrogen as a substrate in various respiratory pathways, via h2-uptake enzymes termed hya, hyb, and hyd. a different hydrogenase, the hydrogen-evolving hyc enzyme, removes excess reductant during fermentative growth. virulence phenotypes conferred by mutations in hyc genes, either alone or in combination with mutations in the h2-uptake enzyme genes, are addressed. anaerobically grown δhycb or δhycc single-deletion strains were more sensi ... | 2015 | 25368112 |
| transcriptional profiling of a cross-protective salmonella enterica serovar typhimurium uk-1 dam mutant identifies a set of genes more transcriptionally active compared to wild-type, and stably transcribed across biologically relevant microenvironments. | vaccination with salmonella enterica serovar typhimurium lacking dna adenine methyltransferase confers cross-protective immunity against multiple salmonella serotypes. the mechanistic basis is thought to be associated with the de-repression of genes that are tightly regulated when transiting from one microenvironment to another. this de-repression provides a potential means for the production of a more highly expressed and stable antigenic repertoire capable of inducing cross-protective immune r ... | 2014 | 25364573 |
| pathogenicity of salmonella strains isolated from egg shells and the layer farm environment in australia. | in australia, the egg industry is periodically implicated during outbreaks of salmonella food poisoning. salmonella enterica serovar typhimurium and other nontyphoidal salmonella spp., in particular, are a major concern for australian public health. several definitive types of salmonella typhimurium strains, but primarily salmonella typhimurium definitive type 9 (dt9), have been frequently reported during egg-related food poisoning outbreaks in australia. the aim of the present study was to gene ... | 2015 | 25362057 |
| temporal and anatomical host resistance to chronic salmonella infection is quantitatively dictated by nramp1 and influenced by host genetic background. | the lysosomal membrane transporter, nramp1, plays a key role in innate immunity and resistance to infection with intracellular pathogens such as non-typhoidal salmonella (nts). nts-susceptible c57bl/6 (b6) mice, which express the mutant nramp1d169 allele, are unable to control acute infection with salmonella enterica serovar typhimurium following intraperitoneal or oral inoculation. introducing functional nramp1g169 into the b6 host background, either by constructing a congenic strain carrying n ... | 2014 | 25350459 |
| proteomes of host cell membranes modified by intracellular activities of salmonella enterica. | intracellular pathogens need to establish a growth-stimulating host niche for survival and replication. a unique feature of the gastrointestinal pathogen salmonella enterica serovar typhimurium is the creation of extensive membrane networks within its host. an understanding of the origin and function of these membranes is crucial for the development of new treatment strategies. however, the characterization of this compartment is very challenging, and only fragmentary knowledge of its compositio ... | 2015 | 25348832 |
| evolutionary expansion of a regulatory network by counter-silencing. | horizontal gene transfer plays a major role in bacterial evolution. successful acquisition of new genes requires their incorporation into existing regulatory networks. this study compares the regulation of conserved genes in the phopq regulon of salmonella enterica serovar typhimurium with that of phopq-regulated horizontally acquired genes, which are silenced by the histone-like protein h-ns. we demonstrate that phop upregulates conserved and horizontally acquired genes by distinct mechanisms. ... | 2014 | 25348042 |
| comparative analysis of gene expression: uncovering expression conservation and divergence between salmonella enterica serovar typhimurium strains lt2 and 14028s. | different strains of the same organism can share a large amount of their genetic material, the so called core pangenome. nevertheless, these species can display different lifestyles and it is still not well known to what extent the core pangenome plays a role in the divergence of lifestyles between the two organisms. here, we present a procedure for uncovering the conservation and divergence of gene expression by using large expression compendia. we will use data from two salmonella enterica ser ... | 2015 | 25343862 |
| evaluation of the live vaccine efficacy of virulence plasmid-cured, and phop- or aroa-deficient salmonella enterica serovar typhimurium in mice. | we evaluated the protective efficacy of 94-kb virulence plasmid-cured, and phop- or aroa-deficient strains of salmonella enterica serovar typhimurium (δphop or δaroa s. typhimurium) as oral vaccine candidates in balb/c mice. two weeks after the completion of 3 oral immunizations with 1 × 10(8) colony-forming units (cfu) of virulence plasmid-cured, and δphop or δaroa s. typhimurium at 10-day intervals, s. typhimurium lipopolysaccharide (lps)-specific mucosal secretory immunoglobulin a (s-iga) ant ... | 2015 | 25341392 |
| the mutagenicity analysis of imidapril hydrochloride and its degradant, diketopiperazine derivative, nitrosation mixtures by in vitro ames test with two strains of salmonella typhimurium. | the evaluation of mutagenic properties of imidapril hydrochloride (imd) and its degradation impurity, diketopiperazine derivative (dkp), nitrosation mixtures was conducted in order to analyze the carcinogenic risk of imd long-term treatment in patients. in this study an in vitro ames test with salmonella enterica serovar typhimurium ta 98 and ta 100 strains was used. | 2014 | 25337415 |
| antimicrobial profile of essential oils extracted from wild versus cultivated origanum ehrenberjii against enteric bacteria. | the role of origanum ehrenberjii against bacteria that cause enteric diseases is well known. salmonella and enterococcus cause high rates of enteric infections around the world. the aim of this study was to extract essential oils from cultivated and naturally growing o. ehrenberjii, compare the chemical profiles of the extracts and estimate their antimicrobial efficacy against enteric pathogens. | 2014 | 25313614 |
| pathogenicity and phenotypic analysis of sopb, sopd and pipd virulence factors in salmonella enterica serovar typhimurium and salmonella enterica serovar agona. | salmonella is an important food-borne pathogen causing disease in humans and animals worldwide. salmonellosis may be caused by any one of over 2,500 serovars of salmonella. nonetheless, salmonella enterica serovar typhimurium and salmonella enterica serovar agona are the second most prevalent serovars isolated from humans and livestock products respectively. limited knowledge is available about the virulence mechanisms responsible for diarrheal disease caused by them. to investigate the contribu ... | 2015 | 25312847 |
| bacterial nucleoid-associated protein uncouples transcription levels from transcription timing. | the histone-like nucleoid-structuring (h-ns) protein binds to horizontally acquired genes in the bacterium salmonella enterica serovar typhimurium, silencing their expression. we now report that overcoming the silencing effects of h-ns imposes a delay in the expression of genes activated by the transcriptional regulator phop. we determine that phop-activated genes ancestral to salmonella are expressed before those acquired horizontally. this expression timing reflects the in vivo occupancy of th ... | 2014 | 25293763 |
| use of a live attenuated salmonella enterica serovar typhimurium vaccine on farrow-to-finish pig farms. | salmonella enterica infection in pigs is economically important and poses a zoonotic risk. in this study, the efficacy of an attenuated s. enterica serovar typhimurium strain was evaluated in three farrow-to-finish pig herds. in each herd, 120 piglets were vaccinated orally at 3 and 24 days of age, while 120 piglets served as unvaccinated controls. faeces, ileocaecal lymph nodes and caecal contents were examined for s. typhimurium by isolation and serum was analysed for antibodies against s. typ ... | 2014 | 25278382 |
| a community outbreak of salmonella enterica serotype typhimurium associated with an asymptomatic food handler in two local restaurants. | between january and april 2012, the city of long beach department of health and human services investigated an outbreak involving 19 case patients who had tested positive for salmonella enterica serotype typhimurium with indistinguishable pulsed-field gel electrophoresis patterns. all cases were residents of or traveled to the city of long beach, california, during their incubation period, and the majority of patients reported eating at one of two restaurants in long beach. this article describe ... | 2014 | 25226780 |
| cellular requirements for systemic control of salmonella enterica serovar typhimurium infections in mice. | the rational design of vaccines requires an understanding of the contributions of individual immune cell subsets to immunity. with this understanding, targeted vaccine delivery approaches and adjuvants can be developed to maximize vaccine efficiency and to minimize side effects (s. h. e. kaufmann et al., immunity 33:555-577, 2010; t. ben-yedidia and r. arnon, hum. vaccines 1:95-101, 2005). we have addressed the contributions of different immune cell subsets and their ability to contribute to the ... | 2014 | 25225248 |
| complete proteome of a quinolone-resistant salmonella typhimurium phage type dt104b clinical strain. | salmonellosis is one of the most common and widely distributed foodborne diseases. the emergence of salmonella strains that are resistant to a variety of antimicrobials is a serious global public health concern. salmonella enterica serovar typhimurium definitive phage type 104 (dt104) is one of these emerging epidemic multidrug resistant strains. here we collate information from the diverse and comprehensive range of experiments on salmonella proteomes that have been published. we then present a ... | 2014 | 25196519 |
| genetic mechanisms underlying the pathogenicity of cold-stressed salmonella enterica serovar typhimurium in cultured intestinal epithelial cells. | salmonella encounters various stresses in the environment and in the host during infection. the effects of cold (5°c, 48 h), peroxide (5 mm h2o2, 5 h) and acid stress (ph 4.0, 90 min) were tested on pathogenicity of salmonella. prior exposure of salmonella to cold stress significantly (p < 0.05) increased adhesion and invasion of cultured intestinal epithelial (caco-2) cells. this increased salmonella-host cell association was also correlated with significant induction of several virulence-assoc ... | 2014 | 25192993 |
| the complete plasmid sequences of salmonella enterica serovar typhimurium u288. | salmonella enterica serovar typhimurium u288 is an emerging pathogen of pigs. the strain contains three plasmids of diverse origin that encode traits that are of concern for food security and safety, these include antibiotic resistant determinants, an array of functions that can modify cell physiology and permit genetic mobility. at 148,711 bp, pstu288-1 appears to be a hybrid plasmid containing a conglomerate of genes found in pslt of s. typhimurium lt2, coupled with a mosaic of horizontally-ac ... | 2014 | 25175817 |
| a nutrient-tunable bistable switch controls motility in salmonella enterica serovar typhimurium. | many bacteria are motile only when nutrients are scarce. in contrast, salmonella enterica serovar typhimurium is motile only when nutrients are plentiful, suggesting that this bacterium uses motility for purposes other than foraging, most likely for host colonization. in this study, we investigated how nutrients affect motility in s. enterica and found that they tune the fraction of motile cells. in particular, we observed coexisting populations of motile and nonmotile cells, with the distributi ... | 2014 | 25161191 |
| electroporation-based delivery of cell-penetrating peptide conjugates of peptide nucleic acids for antisense inhibition of intracellular bacteria. | cell penetrating peptides (cpps) have been used for a myriad of cellular delivery applications and were recently explored for delivery of antisense agents such as peptide nucleic acids (pnas) for bacterial inhibition. although these molecular systems (i.e. cpp-pnas) have shown ability to inhibit growth of bacterial cultures in vitro, they show limited effectiveness in killing encapsulated intracellular bacteria in mammalian cells such as macrophages, presumably due to difficulty involved in the ... | 2014 | 25160797 |
| antimutagenicity of methanolic extracts from anemopsis californica in relation to their antioxidant activity. | anemopsis californica has been used empirically to treat infectious diseases. however, there are no antimutagenic evaluation reports on this plant. the present study evaluated the antioxidant activity in relation to the mutagenic and antimutagenic activity properties of leaf (lme) and stem (sme) methanolic extracts of a. californica collected in the central mexican state of querétaro. antioxidant properties and total phenols of extracts were evaluated using dpph (1,1-diphenyl-2-picrylhydrazyl) a ... | 2014 | 25152760 |
| high-throughput assay to phenotype salmonella enterica typhimurium association, invasion, and replication in macrophages. | salmonella species are zoonotic pathogens and leading causes of food borne illnesses in humans and livestock. understanding the mechanisms underlying salmonella-host interactions are important to elucidate the molecular pathogenesis of salmonella infection. the gentamicin protection assay to phenotype salmonella association, invasion and replication in phagocytic cells was adapted to allow high-throughput screening to define the roles of deletion mutants of salmonella enterica serotype typhimuri ... | 2014 | 25146526 |
| genome sequence of salmonella phage 9na. | the virulent double-stranded dna (dsdna) bacteriophage 9na infects salmonella enterica serovar typhimurium and has a long noncontractile tail. we report its complete 52,869-bp genome sequence. phage 9na and two closely related s. enterica serovar newport phages represent a tailed phage type whose molecular lifestyle has not yet been studied in detail. | 2014 | 25146133 |