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serovars, bacteriophage types and antimicrobial sensitivities associated with salmonellosis in dogs in the uk (1954-2012).serovars and bacteriophage (phage) types were determined for 442 isolates of salmonella enterica from dogs in the uk submitted to the scottish salmonella reference laboratory from 1954 to 2012. the most frequent serovars were salmonella typhimurium (196 isolates; 44.3 per cent), dublin (40 isolates; 9.0 per cent), enteritidis (28 isolates; 6.3 per cent), montevideo (19 isolates; 4.3 per cent), virchow (10 isolates; 2.3 per cent), heidelberg (8 isolates; 1.8 per cent) and derby (8 isolates; 1.8 p ...201424277916
n-acetylation of three aromatic amine hair dye precursor molecules eliminates their genotoxic potential.n-acetylation has been described as a detoxification reaction for aromatic amines; however, there is only limited data available showing that this metabolic conversion step changes their genotoxicity potential. to extend this database, three aromatic amines, all widely used as precursors in oxidative hair dye formulations, were chosen for this study: p-phenylenediamine (ppd), 2,5-diaminotoluene (dat) and 4-amino-2-hydroxytoluene (aht). aiming at a deeper mechanistic understanding of the interpla ...201424275315
effects of quaternary benzo(c)phenanthridine alkaloids on growth performance, shedding of organisms, and gastrointestinal tract integrity in pigs inoculated with multidrug-resistant salmonella spp.to evaluate effects of quaternary benzo(c)phenanthridine alkaloids (qbas) against salmonella spp and determine effects on growth performance, organism shedding, and gastrointestinal tract integrity in pigs inoculated with salmonella enterica serovar typhimurium.201324274891
quantitative assessment of the dose-response of alkylating agents in dna repair proficient and deficient ames tester strains.mutagenic and clastogenic effects of some dna damaging agents such as methyl methanesulfonate (mms) and ethyl methanesulfonate (ems) have been demonstrated to exhibit a nonlinear or even "thresholded" dose-response in vitro and in vivo. dna repair seems to be mainly responsible for these thresholds. to this end, we assessed several mutagenic alkylators in the ames test with four different strains of salmonella typhimurium: the alkyl transferases proficient strain ta1535 (ogt+/ada+), as well as t ...201424273186
flagellin in fusion with human rotavirus structural proteins exerts an adjuvant effect when delivered with replicating but non-disseminating adenovectors through the intrarectal route.human rotavirus (hrv) is the worldwide leading cause of gastroenteritis in young children. two live attenuated hrv vaccines have been approved since 2006. however, these live vaccines still have potential risks including reversion of virulence. adenoviruses are suitable vectors for mucosal administration of subunit vaccines. in addition to the adjuvant effect of certain adenovirus components, the use of an adjuvant like flagellin is also another means to increase the immune response to the immun ...201424271565
core lipopolysaccharide-specific phage ssu5 as an auxiliary component of a phage cocktail for salmonella biocontrol.salmonella spp. are among the major food-borne pathogens that cause mild diarrhea to severe bacteremia. the use of bacteriophages to control various food-borne pathogens, including salmonella, has emerged as a promising alternative to traditional chemotherapy. we isolated the siphoviridae family phage ssu5, which can infect only rough strains of salmonella. the blocking of ssu5 adsorption by periodate treatment of host salmonella cells and spotting and adsorption assays with mutants that contain ...201424271179
proteomic analysis of intestinal mucosa responses to salmonella enterica serovar typhimurium in naturally infected pig.salmonella enterica serovar typhimurium (s. typhimurium) is one of the most frequent salmonella serotypes isolated from european pigs. despite the advances in understanding the mechanisms involved in host-pathogen interactions and host cell responses to s. typhimurium, the global change that occurs in naturally exposed populations has been poorly characterized. here, we present a proteomics study on intestinal mucosa of pigs naturally infected with s. typhimurium, in order to better understand t ...201424268431
neutralization of the antimicrobial effect of glyphosate by humic acid in vitro.in the present study, the neutralization ability of the antimicrobial effect of glyphosate by different humic acids was investigated. the minimal inhibitory concentrations of glyphosate for different bacteria such as bacillus badius, bifidobacterium adolescentis, escherichia coli, e. coli 1917 strain nissle, enterococcus faecalis, enterococcus faecium, salmonella enteritidis and salmonella typhimurium were determined in the presence or absence of different concentrations of humic acid (0.25, 0.5 ...201424268342
combining de novo and reference-guided assembly with scaffold_builder.genome sequencing has become routine, however genome assembly still remains a challenge despite the computational advances in the last decade. in particular, the abundance of repeat elements in genomes makes it difficult to assemble them into a single complete sequence. identical repeats shorter than the average read length can generally be assembled without issue. however, longer repeats such as ribosomal rna operons cannot be accurately assembled using existing tools. the application scaffold_ ...201324267787
novel strategy combining sybr green i with carbon nanotubes for highly sensitive detection of salmonella typhimurium dna.a simple, selective, sensitive and label-free fluorescent method for detecting trps-harboring salmonella typhimurium was developed in this study. this assay used the non-covalent interaction of single-stranded dna (ssdna) probes with swnts, since swnts can quench fluorescence. fluorescence recovery (78% with 1.8 nm target dna) was detected in the presence of target dna as ssdna probes detached from swnts hybridized with target dna, and the resulting double-stranded dna (dsdna) intercalated with ...201424267562
a dual-color flow cytometry protocol for the simultaneous detection of vibrio parahaemolyticus and salmonella typhimurium using aptamer conjugated quantum dots as labels.a sensitive, specific method for the collection and detection of pathogenic bacteria was demonstrated using quantum dots (qds) as a fluorescence marker coupled with aptamers as the molecular recognition element by flow cytometry. the aptamer sequences were selected using a bacterium-based selex strategy in our laboratory for vibrio parahaemolyticus and salmonella typhimurium that, when applied in this method, allows for the specific recognition of the bacteria from complex mixtures including shr ...201324267076
conjugative transfer of an inca/c plasmid-borne blacmy-2 gene through genetic re-arrangements with an incx1 plasmid.our observation that in the mexican salmonella typhimurium population none of the st19 and st213 strains harbored both the salmonella virulence plasmid (pstv) and the prevalent inca/c plasmid (pa/c) led us to hypothesize that restriction to horizontal transfer of these plasmids existed. we designed a conjugation scheme using st213 strain yu39 as donor of the blacmy-2 gene (conferring resistance to ceftriaxone; cro) carried by pa/c, and two e. coli lab strains (dh5α and hb101) and two typhimurium ...201324262067
dietary supplementation with white button mushrooms augments the protective immune response to salmonella vaccine in mice.we previously showed that dietary white button mushrooms (wbms) enhanced natural killer cell activity and that in vitro wbm supplementation promotes maturation and function of dendritic cells (dcs). the current study investigated whether wbm consumption would enhance pathogen-specific immune response using a salmonella vaccination and infection animal model. c57bl/6 mice were fed diets containing 0%, 2%, or 5% wbm for 4 wk before oral vaccination with live attenuated salmonella typhimurium sl147 ...201424259557
a simple method for the extraction of mutagens from airborne particles.organic materials were extracted with acetone from filters of airborne particles by soaking, shaking, soxhletion, and sonication. these extracts were tested with and without s9 for mutagenicity using ames assay and arabinose-resistant assay of salmonella typhimurium. among the extraction methods, soaking extract had the highest mutagenic activity followed by sonication, shaking, and soxhletion in both the assays. with the samples studied, it was concluded that soaking with acetone for 1/2 hr is ...198524258105
a l-lysine transporter of high stereoselectivity of the amino acid-polyamine-organocation (apc) superfamily: production, functional characterization, and structure modeling.membrane proteins of the amino acid-polyamine-organocation (apc) superfamily transport amino acids and amines across membranes and play an important role in the regulation of cellular processes. we report the heterologous production of the lysp-related transporter stm2200 from salmonella typhimurium in escherichia coli, its purification, and functional characterization. stm2200 is assumed to be a proton-dependent apc transporter of l-lysine. the functional interaction between basic amino acids a ...201424257746
signal-specific temporal response by the salmonella phop/phoq regulatory system.the two-component system phop/phoq controls a large number of genes responsible for a variety of physiological and virulence functions in salmonella enterica serovar typhimurium. here we describe a mechanism whereby the transcriptional activator phop elicits expression of dissimilar gene sets when its cognate sensor phoq is activated by different signals in the periplasm. we determine that full transcription of over half of the genes directly activated by phop requires the mg(2+) transporter mgt ...201424256574
genotoxicity assessment of multispecies probiotics using reverse mutation, mammalian chromosomal aberration, and rodent micronucleus tests.genotoxicity assessment is carried out on freeze dried powder of cultured probiotics containing lactobacillus rhamnosus lcr177, bifidobacterium adolescentis ba286, and pediococcus acidilactici pa318. ames tests, in vitro mammalian chromosome aberration assay, and micronucleus tests in mouse peripheral blood are performed. for 5 strains of salmonella typhimurium, the ames tests show no increased reverse mutation upon exposure to the test substance. in cho cells, the frequency of chromosome aberra ...201324250262
evidence of microevolution of salmonella typhimurium during a series of egg-associated outbreaks linked to a single chicken farm.the bacterium salmonella enterica serovar typhimurium (s. typhimurium) is one of the most frequent causes of foodborne outbreaks of gastroenteritis. between 2005-2008 a series of s. typhimurium outbreaks occurred in tasmania, australia, that were all traced to eggs originating from a single chicken farm. we sequenced the genomes of 12 isolates linked to these outbreaks, in order to investigate the microevolution of a pathogenic s. typhimurium clone in a natural, spatiotemporally restricted popul ...201324245509
role of salmonella typhimurium small rnas ryhb-1 and ryhb-2 in the oxidative stress response.as part of the response to specific stress conditions, bacteria express small molecules of non-coding rna which maintain cellular homeostasis by regulating gene expression, commonly at the post-transcriptional level. among these, in salmonella enterica sv. typhimurium, the paralog small non-coding rnas ryhb-1 and ryhb-2 play an important role in iron homeostasis. in addition, in the present work, we show that ryhb-1 and ryhb-2 also participate in the response to hydrogen peroxide (h2o2). deletio ...201424239962
comparative phenotypic and genotypic characterization of temporally related nontyphoidal salmonella isolated from human clinical cases, pigs, and the environment in north carolina.nontyphoidal salmonella infections caused by antimicrobial-resistant (amr) strains are of great public health concern. we compared the phenotypic and genotypic relationships among temporally and spatially related amr salmonella isolates (n=1058) representing several predominant serovars, including salmonella typhimurium, salmonella typhimurium var. 5-, salmonella derby, salmonella heidelberg, salmonella muenchen, salmonella schwarzengrund, and salmonella rissen of human clinical cases (n=572), p ...201424237109
effect of chitosan on salmonella typhimurium in broiler chickens.public concern with the incidence of antibiotic-resistant bacteria, particularly among foodborne pathogens such as salmonella, has been challenging the poultry industry to find alternative means of control. the purposes of the present study were to evaluate in vitro and in vivo effects of chitosan on salmonella enterica serovar typhimurium (st) infection in broiler chicks. for in vitro crop assay experiments, tubes containing feed, water, and st were treated with either saline as a control or 0. ...201424237042
genotoxicity and antileishmanial activity evaluation of physalis angulata concentrated ethanolic extract.antileishmanial in vitro tests, as well as ames and micronucleus assays were performed with a concentrated ethanolic extract of physalis angulata (eepa) results: eepa did not present mutagenic effect in salmonella typhimurium strains at concentration reaching 3000 μg/plate and did not induce mutagenic effects after two oral administrations with a 24h interval at a dose level of 2000 mg/kg. eepa presented antileishmanial activity and presented an ic₅₀ value of 5.35 ± 2.50 μg/ml and 4.50 ± 1.17 μg ...201324231691
functional insight from the tetratricopeptide repeat-like motifs of the type iii secretion chaperone sica in salmonella enterica serovar typhimurium.sica functions both as a class ii chaperone for sipb and sipc of the type iii secretion system (t3ss)-1 and as a transcriptional cofactor for the arac-type transcription factor invf in salmonella enterica subsp. enterica serovar typhimurium. bioinformatic analysis has predicted that sica possesses three tetratricopeptide repeat (tpr)-like motifs, which are important for protein-protein interactions and serve as multiprotein complex mediators. to investigate whether the tpr-like motifs in sica ar ...201424224875
impact of phytopathogen infection and extreme weather stress on internalization of salmonella typhimurium in lettuce.internalization of human pathogens, common in many types of fresh produce, is a threat to human health since the internalized pathogens cannot be fully inactivated/removed by washing with water or sanitizers. given that pathogen internalization can be affected by many environmental factors, this study was conducted to investigate the influence of two types of plant stress on the internalization of salmonella typhimurium in iceberg lettuce during pre-harvest. the stresses were: abiotic (water str ...201424220663
comparison of enrichment broths for the recovery of healthy and heat-injured salmonella typhimurium on raw duck wings.this study was performed to optimiz esalmonella typhimurium recovery from raw duck wings with five nonselective broths (buffered peptone water, tryptic soy broth, lactose broth, universal preenrichment broth, nutrient broth) and four selective broths (selenite broth, bax system mp media [mp], salmonella ad media [ad], one broth-salmonella [ob]). healthy or heat-injured (50 and 85% injury) cells were inoculated at a level of 10(2), 10(1), or 10(0) cfu/25 g on raw duck wings. growth was modeled us ...201324215702
customizable pcr-microplate array for differential identification of multiple pathogens.customizable pcr-microplate arrays were developed for the rapid identification of salmonella typhimurium, salmonella saintpaul, salmonella typhi, shigella dysenteriae, escherichia coli o157:h7, francisella tularensis subsp. tularensis, francisella tularensis subsp. novicida, vibrio cholerae, vibrio parahaemolyticus, yersinia pestis, and yersinia pseudotuberculosis. previously, we identified highly specific primers targeting each of these pathogens. here, we report the development of customizable ...201324215700
hr-mas nmr reveals a ph-dependent lps alteration by de-o-acetylation at abequose in the o-antigen of salmonella enterica serovar typhimurium.nmr spectroscopy can detect biomolecules like lipopolysaccharide directly on the surface of the cell, thus avoiding isolation and purification, and providing a more realistic description than the one derived from in vitro studies. here we present a high-resolution magic-angle spinning nmr study of the o-antigen of salmonella enterica serovar typhimurium (s. typhimurium) performed directly on the cells showing the alteration of its acetylation state over time. the o-antigen region of s. typhimuri ...201324211643
a novel antisense rna from the salmonella virulence plasmid pslt expressed by non-growing bacteria inside eukaryotic cells.bacterial small rnas (srnas) are regulatory molecules playing relevant roles in response to environmental changes, stressful conditions and pathogenesis. the intracellular bacterial pathogen salmonella enterica serovar typhimurium (s. typhimurium) is known to regulate expression of some srnas during colonization of fibroblasts. here, we characterize a previously unknown srna encoded in the s. typhimurium pslt virulence plasmid that is specifically up-regulated by non-growing dormant bacteria per ...201324205037
the antioxidant and antigenotoxic potential of methanol extract of cladonia foliacea (huds.) willd.in this article, the genotoxic and antigenotoxic effects of methanol extract of of cladonia foliacea (huds.) willd. (cme) were studied using wp2, ames (ta1535 and ta1537), and sister chromatid exchange (sce) test systems. the results of our studies showed that 5 µm concentration of aflatoxin b1(afb1) changed the frequencies of sce and malondialdehyde (mda) levels, superoxide dismutase (sod), glutathione (gsh), and glutathione peroxidase (gpx) activities. when 5 and 10 µg/ml concentrations of cme ...201624193055
evaluation of the genotoxicity of clomiphene citrate.clomiphene citrate (cc) is a selective estrogen-receptor modulator that is primarily used to enhance follicular development in women receiving in vitro fertilization (ivf) treatment. although some studies suggested large increases in ovarian cancer risk related to fertility medications, this association has not been confirmed in other studies. whether there could be a residual, small risk is still an open question. it is known that genomic instability and multiple genetic changes may be required ...201424189048
photochemical reaction of 7,12-dimethylbenz[a]anthracene (dmba) and formation of dna covalent adducts.dmba, 7,12-dimethylbenz[a]anthracene, is a widely studied polycyclic aromatic hydrocarbon that has long been recognized as a probable human carcinogen. it has been found that dmba is phototoxic in bacteria as well as in animal or human cells and photomutagenic in salmonella typhimurium strain ta102. this article tempts to explain the photochemistry and photomutagenicity mechanism. light irradiation converts dmba into several photoproducts including benz[a]anthracene-7,12-dione, 7-hydroxy-12-keto ...200524187532
in silico identification and experimental characterization of regulatory elements controlling the expression of the salmonella csrb and csrc genes.the small rnas csrb and csrc of salmonella indirectly control the expression of numerous genes encoding widespread cellular functions, including virulence. the expression of csrb and csrc genes, which are located in different chromosomal regions, is coordinated by positive transcriptional control mediated by the two-component regulatory system bara/sira. here, we identified by computational analysis an 18-bp inverted repeat (ir) sequence located far upstream from the promoter of salmonella enter ...201424187088
genomic investigation of lysogen formation and host lysis systems of the salmonella temperate bacteriophage spn9cc.to understand phage infection and host cell lysis mechanisms in pathogenic salmonella, a novel salmonella enterica serovar typhimurium-targeting bacteriophage, spn9cc, belonging to the podoviridae family was isolated and characterized. the phage infects s. typhimurium via the o antigen of lipopolysaccharide (lps) and forms clear plaques with cloudy centers due to lysogen formation. phylogenetic analysis of phage major capsid proteins revealed that this phage is a member of the lysogen-forming p2 ...201424185850
a thin-layer chromatography autographic method for the detection of inhibitors of the salmonella phop-phoq regulatory system.the phop-phoq system from salmonella enterica serovar typhimurium controls the expression of factors that are critical for the bacterial entry into host cells and the bacterial intramacrophage survival. therefore it constitutes an interesting target to search for compounds that would control salmonella virulence. localisation of such compounds in complex matrixes could be facilitated by thin-layer chromatography (tlc) bioautography.201424185747
antimicrobial susceptibility assays in paper-based portable culture devices.to detect antibiotic-resistant bacteria in areas remote from microbiology laboratories, we designed portable culture devices performing an analogue of the kirby-bauer disk diffusion test inside patterned papers embedded in tape. we quantified the antibiotic susceptibility of several strains of escherichia coli and salmonella typhimurium by measuring blue-colored zones of inhibited growth.201424185315
ammonia sanitisation of sewage sludge using urea.the aim of the study was to develop a simple, low-cost treatment for sewage sludge using urea as a sanitising agent. sewage sludge was spiked with enterococcus faecalis and salmonella typhimurium, treated with 0.5, 1, 1.5 and 2% w/w urea at laboratory scale, and the viability was monitored during 4 months of storage at 4, 10 and 22 °c (only 0.5%). a linear relationship was identified between salmonella spp. inactivation rate and ammonia (nh3) concentration. temperature had a positive impact on s ...201324185072
nanosilica coating for bonding improvements to zirconia.resin bonding to zirconia cannot be established from standard methods that are currently utilized in conventional silica-based dental ceramics. the solution-gelatin (sol-gel) process is a well developed silica-coating technique used to modify the surface of nonsilica-based ceramics. here, we use this technique to improve resin bonding to zirconia, which we compared to zirconia surfaces treated with alumina sandblasting and tribochemical silica coating. we used the shear bond strength test to exa ...201324179333
inhibition of multidrug efflux as a strategy to prevent biofilm formation.we have recently shown that inactivation of any of the multidrug efflux systems of salmonella results in loss of the ability to form a competent biofilm. the aim of this study was to determine the mechanism linking multidrug efflux and biofilm formation, and to determine whether inhibition of efflux is a viable antibiofilm strategy.201424176982
development of new active packaging film made from a soluble soybean polysaccharide incorporated zataria multiflora boiss and mentha pulegium essential oils.an active edible film from soluble soybean polysaccharide (ssps) incorporated with different concentrations of zataria multiflora boiss (zeo) and mentha pulegium (meo) essential oils was developed, and the film's optical, wettability, thermal, total phenol and antioxidant characteristics were investigated, along with their antimicrobial effectiveness against staphylococcus aureus, bacillus cereus, escherichia coli o157:h7, pseudomonas aeruginosa and salmonella typhimurium. the film's colour beca ...201424176389
the sensitive balance between the fully folded and locally unfolded conformations of a model peroxiredoxin.to reduce peroxides, peroxiredoxins (prxs) require a key "peroxidatic" cys that, in a substrate-ready fully folded (ff) conformation, is oxidized to sulfenic acid and then, after a local unfolding (lu) of the active site, forms a disulfide bond with a second "resolving" cys. for salmonella typhimurium alkyl hydroperoxide reductase c (stahpc) and some other prxs, the ff structure is only known for a peroxidatic cys→ser variant, which may not accurately represent the wild-type enzyme. here, we obt ...201324175952
a cellular genome-wide association study reveals human variation in microtubule stability and a role in inflammatory cell death.pyroptosis is proinflammatory cell death that occurs in response to certain microbes. activation of the protease caspase-1 by molecular platforms called inflammasomes is required for pyroptosis. we performed a cellular genome-wide association study (gwas) using salmonella typhimurium infection of human lymphoblastoid cell lines as a means of dissecting the genetic architecture of susceptibility to pyroptosis and identifying unknown regulatory mechanisms. cellular gwas revealed that a common huma ...201424173717
salmonella typhimurium infections associated with a community college microbiology laboratory--maine, 2013.on may 2, 2013, a case of salmonellosis was reported to the maine center for disease control and prevention. the patient reported symptoms of diarrhea, fever, abdominal pain, and nausea, after attending a community college microbiology laboratory class. a second case was reported on may 8. epidemiologic interviews conducted with both patients indicated common exposure at a community college, including one patient specifically naming the other patient.201324172882
mutagenicity of edible palm oil on the ghanaian market before and after repeated heating.red palm oil produced in ghana largely by village folks has never been tested for its mutagenic potential. the study aimed at determining the mutagenicity of high-energy heated red palm oil (rrpo) and refined, bleached imported palm oil (po) on the ghanaian market. samples of rrpo and po were 1× and 5× heated for 10 min at 180 °c with a cooling period of 5 h in-between. unheated, together with heated samples, were tested for mutagenicity using salmonella typhimurium ta 98 and ta 100 tester stain ...201324171816
rama, which controls expression of the mdr efflux pump acrab-tolc, is regulated by the lon protease.rama regulates the acrab-tolc multidrug efflux system. using salmonella typhimurium, we investigated the stability of rama and its impact on antibiotic resistance.201424169580
the abc-type efflux pump macab protects salmonella enterica serovar typhimurium from oxidative stress.multidrug efflux pumps are integral membrane proteins known to actively excrete antibiotics. the macrolide-specific pump macab, the only abc-type drug efflux pump in salmonella, has previously been linked to virulence in mice. the molecular mechanism of this link between macab and infection is unclear. we demonstrate that macab plays a role in the detoxification of reactive oxygen species (ros), compounds that salmonellae are exposed to at various stages of infection. macab is induced upon expos ...201324169575
isozyme-specific ligands for o-acetylserine sulfhydrylase, a novel antibiotic target.the last step of cysteine biosynthesis in bacteria and plants is catalyzed by o-acetylserine sulfhydrylase. in bacteria, two isozymes, o-acetylserine sulfhydrylase-a and o-acetylserine sulfhydrylase-b, have been identified that share similar binding sites, although the respective specific functions are still debated. o-acetylserine sulfhydrylase plays a key role in the adaptation of bacteria to the host environment, in the defense mechanisms to oxidative stress and in antibiotic resistance. beca ...201324167577
ferric uptake regulator-dependent antinitrosative defenses in salmonella enterica serovar typhimurium pathogenesis.herein we report an important role for the ferric uptake regulator (fur) in the resistance of salmonella enterica serovar typhimurium to the reactive nitrogen species produced by inducible nitric oxide (no) synthase in an nramp1(r) murine model of acute systemic infection. the expression of fur protected salmonella grown under normoxic and hypoxic conditions against the bacteriostatic activity of no. the hypersusceptibility of fur-deficient salmonella to the cytotoxic actions of no coincides wit ...201424166960
an antibiotic-altered microbiota provides fuel for the enteric foe.antibiotic therapies disrupt the intestinal microbiota and render the host susceptible to enteric infections. a recent report by ng et al. explores the ability of two intestinal pathogens (salmonella enterica serovar typhimurium and clostridium difficile) to use this disruption to their advantage and consume host carbohydrates that would otherwise be unavailable in the presence of a normal gut microbiota.201424165893
cellular internalization and cytotoxicity of the antimicrobial proline-rich peptide bac7(1-35) in monocytes/macrophages, and its activity against phagocytosed salmonella typhimurium.bac7(1-35) is an active fragment of the bovine cathelicidin antimicrobial peptide bac7, which selectively inactivates gram-negative bacteria both in vitro and in mice infected with salmonella typhimurium. it has a non-lytic mechanism of action, is rapidly internalized by susceptible bacteria and mammalian cells and likely acts by binding to internal targets. in this study we show that bac7(1-35) accumulates selectively within primed macrophages with respect to resting monocytes. confocal microsc ...201424164261
nod1 and nod2 enhance tlr-mediated invariant nkt cell activation during bacterial infection.invariant nkt (inkt) cells act at the crossroad between innate and adaptive immunity and are important players in the defense against microbial pathogens. inkt cells can detect pathogens that trigger innate receptors (e.g., tlrs, rig-i, dectin-1) within apcs, with the consequential induction of cd1d-mediated ag presentation and release of proinflammatory cytokines. we show that the cytosolic peptidoglycan-sensing receptors nod1 and nod2 are necessary for optimal ifn-γ production by inkt cells, a ...201324163408
smartphone quantifies salmonella from paper microfluidics.smartphone-based optical detection is a potentially easy-to-use, handheld, true point-of-care diagnostic tool for the early and rapid detection of pathogens. paper microfluidics is a low-cost, field-deployable, and easy-to-use alternative to conventional microfluidic devices. most paper-based microfluidic assays typically utilize dyes or enzyme-substrate binding, while bacterial detection on paper microfluidics is rare. we demonstrate a novel application of smartphone-based detection of salmonel ...201324162816
investigating river pollution flowing into dianchi lake using a combination of gc-ms analysis and toxicological tests.due to the presence of various harmful compounds in polluted water, toxicological tests should be combined to evaluate whether a body of water is polluted. the water quality of four rivers flowing into dianchi lake, which is well known for its heavy and lasting pollution, was investigated in this study using a combination of gc-ms analysis and cytotoxicity and mutagenicity tests. gc-ms analysis showed that the rivers investigated contained a variety of chemicals and suggested that severe water p ...201424162646
the prevalence of swine enteropathogens in brazilian grower and finish herds.diarrhoea among growing and finishing pigs is an important problem in many herds. the prevalence of l. intracellularis, b. pilosicoli, b. hyodysenteriae, salmonella spp., enterotoxigenic e. coli, trichuris suis and the occurrence of mixed infection were investigated. fecal samples for forty-six herds with diarrhea or a history of diarrhea were randomly collected in minas gerais state, brazil. the enteric pathogens were detected by culture (e. coli and salmonella sp.), pcr (l. intracellularis and ...201324159297
detection of salmonella spp, salmonella enteritidis and typhimurium in naturally infected broiler chickens by a multiplex pcr-based assay.the presence of salmonella in the intestinal tract, on the chickens skin and among their feathers, may cause carcasses contamination during slaughtering and processing and possibly it is responsible by the introduction of this microorganism in the slaughterhouses. a rapid method to identify and monitor salmonella and their sorovars in farm is becoming necessary. a pre-enriched multiplex polymerase chain reaction (m-pcr) assay employing specific primers was developed and used to detect salmonella ...201324159281
green synthesis of silver nanoparticles, their characterization, application and antibacterial activity.our research focused on the production, characterization and application of silver nanoparticles (agnps), which can be utilized in biomedical research and environmental cleaning applications. we used an environmentally friendly extracellular biosynthetic technique for the production of the agnps. the reducing agents used to produce the nanoparticles were from aqueous extracts made from the leaves of various plants. synthesis of colloidal agnps was monitored by uv-visible spectroscopy. the uv-vis ...201324157517
complete nucleotide sequences of virulence-resistance plasmids carried by emerging multidrug-resistant salmonella enterica serovar typhimurium isolated from cattle in hokkaido, japan.in the present study, we have shown that virulence-resistance plasmids from emerging multidrug-resistant isolates of salmonella enterica serovar typhimurium were derived from a virulence-associated plasmid, essential for systematic invasiveness of s. typhimurium in mice (pslt), through acquisition of a large insert containing a resistance island flanked by is1294 elements. a bla cmy-2-carrying plasmid from a cefotaxime-resistant isolate comprised a segment of escherichia coli plasmid par060302 a ...201324155970
salmonella typhimurium mediated delivery of apoptin in human laryngeal cancer.an effective cancer therapeutic should target tumours specifically with limited systemic toxicity. here, we transformed an attenuated salmonella typhimurium (s. typhimurium) with an apoptin expressing plasmid into a human laryngeal carcinoma cell line. the expression of the inserted gene was measured using fluorescence and immunoblotting assays. the attenuated s. typhimurium-mediated apoptin significantly decreased cytotoxicity and strongly increased cell apoptosis through the activation of casp ...201324155656
biofilm formation and antibiotic resistance in salmonella typhimurium are affected by different ribonucleases.biofilm formation and antibiotic resistance are important determinants for bacterial pathogenicity. ribonucleases control rna degradation and there is increasing evidence that they have an important role in virulence mechanisms. in this report, we show that ribonucleases affect susceptibility against ribosome-targeting antibiotics and biofilm formation in salmonella.201424150497
salmonella typhimurium ttss-2 deficient mig-14 mutant shows attenuation in immunocompromised mice and offers protection against wild-type salmonella typhimurium infection.development of salmonella enterica serovar typhimurium (s. typhimurium) live attenuated vaccine carrier strain to prevent enteric infections has been a subject of intensive study. several mutants of s. typhimurium have been proposed as an effective live attenuated vaccine strain. unfortunately, many such mutant strains failed to successfully complete the clinical trials as they were suboptimal in delivering effective safety and immunogenicity. however, it remained unclear, whether the existing l ...201324148706
quantitative evaluation of e. coli f4 and salmonella typhimurium binding capacity of yeast derivatives.the target of the present study was to quantify the capacity of different commercially available yeast derivatives to bind e. coli f4 and salmonella typhimurium. in addition, a correlation analysis was performed for the obtained binding numbers and the mannan-, glucan- and protein contents of the products, respectively. in a subsequent experiment, different yeast strains were fermented and treated by autolysis or french press to obtain a concentrated yeast cell wall. the capacity of yeast cell w ...201324148308
engineered salmonella typhimurium expressing e7 fusion protein, derived from human papillomavirus, inhibits tumor growth in cervical tumor-bearing mice.the tumor-suppressing effects of sipb160/hpv16 e7 fusion protein, derived from human papillomavirus, and expressed in salmonella enterica serovar typhimurium, were evaluated in a cervical cancer model. the expressed e7 protein resulted in efficacious cytotoxicity and tumor growth retardation in tc-1 cervical cancer cells. in addition, in mice bearing tc-1 tumors, live cells of salmonella expressing hpv16 e7 were administered orally and induced immune responses through interferon-gamma and tumor ...201424146199
dormant intracellular salmonella enterica serovar typhimurium discriminates among salmonella pathogenicity island 2 effectors to persist inside fibroblasts.salmonella enterica uses effector proteins delivered by type iii secretion systems (ttss) to colonize eukaryotic cells. recent in vivo studies have shown that intracellular bacteria activate the ttss encoded by salmonella pathogenicity island-2 (spi-2) to restrain growth inside phagocytes. growth attenuation is also observed in vivo in bacteria colonizing nonphagocytic stromal cells of the intestinal lamina propria and in cultured fibroblasts. spi-2 is required for survival of nongrowing bacteri ...201424144726
bovine salmonellosis in northeast of iran: frequency, genetic fingerprinting and antimicrobial resistance patterns of salmonella spp.to evaluate serovar and antimicrobial resistance patterns of salmonella spp isolated from healthy, diseased and necropsied cows and calves in this observational study.201424144122
nadph oxidase deficient mice develop colitis and bacteremia upon infection with normally avirulent, ttss-1- and ttss-2-deficient salmonella typhimurium.infections, microbe sampling and occasional leakage of commensal microbiota and their products across the intestinal epithelial cell layer represent a permanent challenge to the intestinal immune system. the production of reactive oxygen species by nadph oxidase is thought to be a key element of defense. patients suffering from chronic granulomatous disease are deficient in one of the subunits of nadph oxidase. they display a high incidence of crohn's disease-like intestinal inflammation and are ...201324143212
ubij, a new gene required for aerobic growth and proliferation in macrophage, is involved in coenzyme q biosynthesis in escherichia coli and salmonella enterica serovar typhimurium.ubiquinone (coenzyme q or q8) is a redox active lipid which functions in the respiratory electron transport chain and plays a crucial role in energy-generating processes. in both escherichia coli and salmonella enterica serovar typhimurium, the yigp gene is located between ubie and ubib, all three being likely to constitute an operon. in this work, we showed that the uncharacterized yigp gene was involved in q8 biosynthesis in both strains, and we have renamed it ubij. under aerobic conditions, ...201424142253
identification of crucial amino acids of bacterial peptide deformylases affecting enzymatic activity in response to oxidative stress.peptide deformylase (pdf) is an essential bacterial metalloprotease involved in deformylation of n-formyl group from nascent polypeptide chains during protein synthesis. iron-containing variants of this enzyme from salmonella enterica serovar typhimurium (spdf) and mycobacterium tuberculosis (mpdf), although inhibited by oxidizing agents like h2o2, exhibited strikingly different 50% inhibitory concentrations (ic50s) that ranged from nanomolar (spdf) to millimolar (mpdf) levels. furthermore, the ...201424142250
genotoxic evaluation of aspirin eugenol ester using the ames test and the mouse bone marrow micronucleus assay.aspirin eugenol ester (aee) is a promising drug candidate for treatment of inflammation, pain and fever and prevention of cardiovascular diseases with less side effects and it is important to characterize its genotoxicity. in this study, the genotoxicity of aee was assessed with two standard genotoxicity assays of the salmonella typhimurium mutagenicity assay (ames test) and the mouse bone marrow micronucleus assay. in the ames test, salmonella strains ta97, ta98, ta100, ta102 and ta1535 were tr ...201324140966
lack of correlation between in vitro antibiosis and in vivo protection against enteropathogenic bacteria by probiotic lactobacilli.increased resistance to infection is one of the beneficial effects attributed to probiotic microorganisms. this effect may be due to several mechanisms: production of inhibitory substances, blocking of adhesion sites on the intestinal surface, competition for nutrients and stimulation of mucosal and systemic immunity. the present study aimed to investigate the correlation between in vitro and in vivo antimicrobial activity of probiotic lactobacilli. the agar spot test was used to show that twent ...201424140789
binding of mgtr, a salmonella transmembrane regulatory peptide, to mgtc, a mycobacterium tuberculosis virulence factor: a structural study.mgtr, a highly hydrophobic peptide expressed in salmonella enterica serovar typhimurium, inhibits growth in macrophages through binding to the membrane protein mgtc that has been identified as essential for replication in macrophages. while the mycobacterium tuberculosis mgtc is highly homologous to its s. typhi analogue, there does not appear to be an mtb homologue for mgtr, raising significant pharmacological interest in this system. here, solid-state nmr and epr spectroscopy in lipid bilayer ...201424140750
genomic diversity and adaptation of salmonella enterica serovar typhimurium from analysis of six genomes of different phage types.salmonella enterica serovar typhimurium (or simply typhimurium) is the most common serovar in both human infections and farm animals in australia and many other countries. typhimurium is a broad host range serovar but has also evolved into host-adapted variants (i.e. isolated from a particular host such as pigeons). six typhimurium strains of different phage types (defined by patterns of susceptibility to lysis by a set of bacteriophages) were analysed using illumina high-throughput genome seque ...201324138507
managing salmonella typhimurium and escherichia coli o157:h7 in soil with hydrated lime - an outdoor study in lysimeters and field plots.an outbreak of salmonella typhimurium or e. coli o157:h7 among domestic animals can have great financial consequences for an animal enterprise but also be a threat for public health as there is a risk for transmission of the infection through the environment. in order to minimize disease transmission, it is important to treat not only the affected animals but also the areas on which they have been kept. in the present study, the effect of hydrated lime as a treatment for salmonella typhimurium o ...201424138468
antimutagenic activity and preventive effect of black tea on buccal mucosa cancer.a black tea product was evaluated for anti-mutagenic and in vivo anticancer effects. at concentrations of 1.25 and 2.5 mg/plate, black tea exhibited anti-mutagenicity with n-methyl-n'-nitro-n-nitrosoguanidine (mnng) in the salmonella typhimurium ta100 strain. a kunming (km) mouse buccal mucosa cancer model was established by injecting mice with u14 squamous cell carcinoma cells. following injection, the wound at the injection site was smeared with black tea. it was observed that the tumor volume ...201324137377
cd90(+) stromal cells are non-professional innate immune effectors of the human colonic mucosa.immune responses at the intestinal mucosa must allow for host protection whilst simultaneously avoiding inappropriate inflammation. although much work has focused on the innate immune functionality of hematopoietic immune cells, non-hematopoietic cell populations - including epithelial and stromal cells - are now recognized as playing a key role in innate defense at this site. in this study we examined the innate immune capacity of primary human intestinal stromal cells (iscs). cd90(+) iscs isol ...201324137162
genome sequences of salmonella enterica serotype typhimurium blood clinical isolate st4848/06 and stool isolate st1489/06.salmonella enterica serotype typhimurium human blood strains isolated from outside africa are rarely sequenced. here, we report the draft genome sequences of two s. typhimurium clinical strains isolated in the same year, one from blood and another from stool, in order to gain insights into the genetic basis leading to invasive diseases.201324136846
causes of morbidity and mortality in free-living birds in an urban environment in germany.free-living birds are often presented to veterinarians at rehabilitation centers as well as in private practice. information about disease processes and causes of death of indigenous free-living birds can aid the clinician in establishing proper treatment and in the assessment of potential zoonotic risks. for the present study, pathogens as causes of morbidity and mortality were determined by performing a complete necropsy on free-living birds presented to the clinic for birds and reptiles of th ...201324136384
occurrence of extended-spectrum β-lactamases among isolates of salmonella enterica subsp. enterica from food-producing animals and food products, in portugal.a total of 1120 salmonella spp. isolates, recovered from poultry, swine and food products of animal origin (bovine, swine and poultry) over the period of 2009-2011, were investigated in order to determine their serotype, susceptibility to a panel of eleven antimicrobials (a, ampicillin; ct, cefotaxime; cp, ciprofloxacin; tm, trimethoprim; su, sulfamethoxazole; c, chloramphenicol; s, streptomycin; g, gentamicin; t, tetracycline; na, nalidixic acid; fl, florfenicol), and the presence of resistance ...201324135677
estrogenic and mutagenic activities of crotalaria pallida measured by recombinant yeast assay and ames test.crotalaria pallida ailton is a plant belonging to the fabaceae family, popularly known as "rattle or rattlesnake" and used in traditional medicine to treat swelling of the joints and as a vermifuge. previous pharmacological studies have also reported anti-inflammatory, antimicrobial and antifungal activities. nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. thus, the purpose of the present st ...201324134316
di- and polynuclear silver(i) saccharinate complexes of tertiary diphosphane ligands: synthesis, structures, in vitro dna binding, and antibacterial and anticancer properties.a series of new silver(i) saccharinate (sac) complexes, [ag2(sac)2(μ-dppm)h2o]·h2o (1), {[ag2(μ-sac)2(μ-dppe)]·3h2o·ch2cl2} n (2), [ag2(μ-sac)2(μ-dppp)] n (3), and [ag(sac)(μ-dppb)] n (4) [dppm is 1,1-bis(diphenylphosphino)methane, dppe is 1,2-bis(diphenylphosphino)ethane, dppp is 1,3-bis(diphenylphosphino)propane, and dppb is 1,4-bis(diphenylphosphino)butane], have been synthesized and characterized by c, h, n elemental analysis, ir spectroscopy, (1)h nmr, (13)c nmr, and (31)p nmr spectroscopy, ...201424132752
invasive non-typhoidal salmonella typhimurium st313 are not host-restricted and have an invasive phenotype in experimentally infected chickens.salmonella enterica serovar typhimurium sequence type (st) 313 is a major cause of invasive non-typhoidal salmonellosis in sub-saharan africa. no animal reservoir has been identified, and it has been suggested that st313 is adapted to humans and transmission may occur via person-to-person spread. here, we show that st313 cause severe invasive infection in chickens as well as humans. oral infection of chickens with st313 isolates d23580 and q456 resulted in rapid infection of spleen and liver wit ...201324130915
genomics of an emerging clone of salmonella serovar typhimurium st313 from nigeria and the democratic republic of congo.salmonella enterica serovar typhimurium st313 is an invasive and phylogenetically distinct lineage present in sub-saharan africa. we report the presence of s. typhimurium st313 from patients in the democratic republic of congo and nigeria.201324129621
the eal-like protein stm1697 regulates virulence phenotypes, motility and biofilm formation in salmonella typhimurium.the ubiquitous second messenger c-di-gmp regulates the switching of bacterial lifestyles from motility to sessility and acute to chronic virulence to adjust bacterial fitness to altered environmental conditions. conventionally, eal proteins being c-di-gmp phosphodiesterases promote motility and acute virulence phenotypes such as invasion into epithelial cells and inhibit biofilm formation. we report here that in contradiction, the eal-like protein stm1697 of salmonella typhimurium suppresses mot ...201324127899
extracellular dna inhibits salmonella enterica serovar typhimurium and s. enterica serovar typhi biofilm development on abiotic surfaces.extracellular dna (edna) was identified and characterized in a 2-day-old biofilms developed by salmonella enterica ser. typhimurium sr-11 and s. enterica ser. typhi st6 using confocal laser scanning microscopy (clsm) and enzymatic extraction methods. results of microtitre plate assay and clsm analysis showed both salmonella strains formed significantly more biofilms in the presence of dnase i; furthermore, a remarkable decrease of biofilm formation was observed when edna was added in the inocula ...201424126602
yersinia enterocolitica inhibits salmonella enterica serovar typhimurium and listeria monocytogenes cellular uptake.yersinia enterocolitica biovar 1b employs two type three secretion systems (t3ss), ysa and ysc, which inject effector proteins into macrophages to prevent phagocytosis. conversely, salmonella enterica serovar typhimurium uses a t3ss encoded by salmonella pathogenicity island 1 (spi1) to actively invade cells that are normally nonphagocytic and a second t3ss encoded by spi2 to survive within macrophages. given the distinctly different outcomes that occur with regard to host cell uptake of s. typh ...201424126528
bacillus cereus var. toyoi modulates the immune reaction and reduces the occurrence of diarrhea in piglets challenged with salmonella typhimurium dt104.a feeding trial with sows and their piglets was performed with the probiotic feed additive bacillus cereus var. toyoi in two consecutive experimental periods. sows (n = 8) were allocated into treatment (bc) and control (co) groups. sows of bc group (n = 4) were fed 3.14 × 10(5) cfu/g bacillus cereus var. toyoi with the diet from d 87 of pregnancy on. their piglets received bacillus cereus var. toyoi supplemented feed (8.7 × 10(5) cfu/g) starting on d 14 of life and further on after weaning (6.5 ...201324126275
polynucleotide phosphorylase (pnpase) is required for salmonella enterica serovar typhimurium colonization in swine.the pnp gene encodes polynucleotide phosphorylase, an exoribonuclease involved in rna processing and degradation. a mutation in the pnp gene was previously identified by our group in a signature-tagged mutagenesis screen designed to search for salmonella enterica serovar typhimurium genes required for survival in an ex vivo swine stomach content assay. in the current study, attenuation and colonization potential of a s. typhimurium pnp mutant in the porcine host was evaluated. following intranas ...201324126127
identification of virulence properties in salmonella typhimurium dt104 using caenorhabditis elegans.salmonella enterica serover typhimurium definitive phage type dt104, resistant to multiple antibiotics, is one of the most widespread salmonella species in human infection worldwide. although several cohort studies indicate that dt104 carrying the multidrug resistance (mdr) locus on salmonella genomic island 1 is a possible hyper-virulent strain compared to dt104 strains without mdr, or other salmonella enterica serotypes, existing experimental evidence regarding virulence properties associated ...201324124587
salmonella infection induces recruitment of caspase-8 to the inflammasome to modulate il-1β production.nucleotide-binding oligomerization domain-like receptors (nlrs) detect pathogens and danger-associated signals within the cell. salmonella enterica serovar typhimurium, an intracellular pathogen, activates caspase-1 required for the processing of the proinflammatory cytokines, pro-il-1β and pro-il-18, and pyroptosis. in this study, we show that salmonella infection induces the formation of an apoptosis-associated specklike protein containing a card (asc)-caspase-8-caspase-1 inflammasome in macro ...201324123685
a new plant-derived antibacterial is an inhibitor of efflux pumps in staphylococcus aureus.an in-depth evaluation was undertaken of a new antibacterial natural product (1) recently isolated and characterised from the plant hypericum olympicum l. cf. uniflorum. minimum inhibitory concentrations (mics) were determined for a panel of bacteria, including: meticillin-resistant and -susceptible strains of staphylococcus aureus, staphylococcus epidermidis and staphylococcus haemolyticus; vancomycin-resistant and -susceptible enterococcus faecalis and enterococcus faecium; penicillin-resistan ...201324119569
value addition in the efficacy of conventional antibiotics by nisin against salmonella.frequent and indiscriminate use of existing battery of antibiotics has led to the development of multi drug resistant (mdr) strains of pathogens. as decreasing the concentration of the antibiotic required to treat salmonellosis might help in combating the development of resistant strains, the present study was designed to assess the synergistic effects, if any, of nisin, in combination with conventional anti-salmonella antibiotics against salmonella enterica serovar typhimurium. minimum inhibito ...201324116175
identification of an iron acquisition machinery in flavobacterium columnare.flavobacterium columnare, a fastidious gram-negative pathogen and the causative agent of columnaris disease, is one of the most harmful pathogens in the freshwater fish-farming industry. nevertheless the virulence mechanisms of f. columnare are not well understood. bacterial iron uptake from the host during infection is an important mechanism of virulence. here we identified and analyzed part of the iron uptake machinery of f. columnare. under iron-limited conditions during in vitro growth, synt ...201324113246
microrna-146 function in the innate immune transcriptome response of zebrafish embryos to salmonella typhimurium infection.micrornas (mirnas) have recently been shown to play important roles in development of the immune system and in fine-tuning of immune responses. human mir-146 family members are known as inflammation-inducible mirnas involved in negative feedback regulation of toll-like receptor (tlr) signalling. dysregulation of the mir-146 family has often been linked to inflammatory diseases and malignancies. this study reports on mir-146a and mir-146b as infection-inducible mirnas in zebrafish, which has emer ...201324112639
detecting salmonella serovars in shell eggs by loop-mediated isothermal amplification.shell eggs contaminated with salmonella enteritidis pose serious food safety and public health concerns. more vigilant product testing calls for rapid, accurate, and reliable detection methods for salmonella. two loop-mediated isothermal amplification (lamp) assays targeting different regions of the salmonella invasion protein (encoded by inva) have been reported. in this study, performance of the two lamp assays was compared with that of pcr in detecting salmonella enteritidis and salmonella ty ...201324112582
biofilm formation of salmonella serotypes in simulated meat processing environments and its relationship to cell characteristics.salmonella attached to meat contact surfaces encountered in meat processing facilities may serve as a source of cross-contamination. in this study, the influence of serotypes and media on biofilm formation of salmonella was investigated in a simulated meat processing environment, and the relationships between biofilm formation and cell characteristics were also determined. all six serotypes (salmonella enterica serotype heidelberg, salmonella derby, salmonella agona, salmonella indiana, salmonel ...201324112581
mait recognition of a stimulatory bacterial antigen bound to mr1.mr1-restricted mucosal-associated invariant t (mait) cells represent a subpopulation of αβ t cells with innate-like properties and limited tcr diversity. mait cells are of interest because of their reactivity against bacterial and yeast species, suggesting that they play a role in defense against pathogenic microbes. despite the advances in understanding mait cell biology, the molecular and structural basis behind their ability to detect mr1-ag complexes is unclear. in this study, we present our ...201324108697
c-jun nh2 -terminal kinase is a critical node in the death of cd4+ cd8+ thymocytes during salmonella enterica serovar typhimurium infection.thymic atrophy, due to the depletion of cd4(+) cd8(+) thymocytes, is observed during infections with numerous pathogens. several mechanisms, such as glucocorticoids and inflammatory cytokines, are known to be involved in this process; however, the roles of intracellular signaling molecules have not been investigated. in this study, the functional role of c-jun nh2 -terminal kinase (jnk) during infection-induced thymic atrophy was addressed. the levels of phosphorylated jnk in immature cd4(+) cd8 ...201424105651
caffeine and other methylxanthines as interceptors of food-borne aromatic mutagens: inhibition of trp-p-1 and trp-p-2 mutagenic activity.caffeine is one of the most important biologically active food components. in this article, we demonstrate that caffeine and other methylxanthines significantly reduce the mutagenic activity of two food-derived heterocyclic aromatic amines, trp-p-1 and trp-p-2 in the salmonella typhimurium ta98 strain. moreover, protection against trp-p-1-induced mutagenicity was independent of liver s9 enzymatic fraction, suggesting that mechanisms other than modulation of mutagen bioactivation can contribute t ...201324102551
structure of the periplasmic copper-binding protein cuep from salmonella enterica serovar typhimurium.cuep was initially identified as a copper-resistance gene in salmonella enterica serovar typhimurium, which has evolved to survive in the phagosomes of macrophages. recently, cuep was determined to be a periplasmic copper-binding protein and has been implicated in the transfer of copper ions to sodcii in the periplasm. in this study, the crystal structure of cuep has been determined, revealing a v-shaped dimeric structure. the conserved cysteine and histidine residues are clustered on the surfac ...201324100307
safety and tolerability of a live oral salmonella typhimurium vaccine candidate in siv-infected nonhuman primates.nontyphoidal salmonella (nts) serovars are a common cause of acute food-borne gastroenteritis worldwide and can cause invasive systemic disease in young infants, the elderly, and immunocompromised hosts, accompanied by high case fatality. vaccination against invasive nts disease is warranted where the disease incidence and mortality are high and multidrug resistance is prevalent, as in sub-saharan africa. live-attenuated vaccines that mimic natural infection constitute one strategy to elicit pro ...201324099872
salmonella modulation of host cell gene expression promotes its intracellular growth.salmonella typhimurium has evolved a complex functional interface with its host cell largely determined by two type iii secretion systems (t3ss), which through the delivery of bacterial effector proteins modulate a variety of cellular processes. we show here that salmonella typhimurium infection of epithelial cells results in a profound transcriptional reprogramming that changes over time. this response is triggered by salmonella t3ss effector proteins, which stimulate unique signal transduction ...201324098123
the natural killer cell interferon-gamma response to bacteria is diminished in untreated hiv-1 infection and defects persist despite viral suppression.natural killer (nk) cells are important in innate immune responses to bacterial and viral pathogens. hiv-1 infection is associated with opportunistic bacterial infections and with microbial translocation, but the nature of the nk cell response to bacteria during hiv-1 infection has not been studied extensively. the objective of this study was to compare nk cell responses to bacteria in hiv-1-infected versus that in uninfected individuals.201424091697
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