| structure of a pathogenic type 3 secretion system in action. | type 3 secretion systems use 3.5-megadalton syringe-like, membrane-embedded 'injectisomes', each containing an ~800-å-long needle complex to connect intracellular compartments of infectious bacteria and hosts. here we identify requirements for substrate association with, transport through and exit from the injectisome of salmonella enterica serovar typhimurium. this guided the design of substrates that become trapped within the secretion path and enabled visualization of injectisomes in action i ... | 2014 | 24317488 |
| evaluation of genotoxic effects of new molecules with possible trypanocidal activity for chagas disease treatment. | chagas disease is responsible for a large number of human infections and many are also at risk of infection. there is no effective drug for chagas disease treatment. the institute of pharmaceutical technology at fiocruz, brazil, has designed three nitro analogs of the nitroimidazole-thiadiazole, megazol: two triazole analogs ptal 05-02 and pamt 09 and a pyrazole analog ptal 04-09. a set of salmonella enterica serovar typhimurium strains were used in the bacterial reverse mutation test (ames test ... | 2013 | 24311974 |
| pyroptosis and adaptive immunity mechanisms are promptly engendered in mesenteric lymph-nodes during pig infections with salmonella enterica serovar typhimurium. | in this study, we explored the transcriptional response and the morphological changes occurring in porcine mesenteric lymph-nodes (mln) along a time course of 1, 2 and 6 days post infection (dpi) with salmonella typhimurium. additionally, we analysed the expression of some salmonella effectors in tissue to complete our view of the processes triggered in these organs upon infection. the results indicate that besides dampening apoptosis, swine take advantage of the flagellin and prgj expression by ... | 2013 | 24308825 |
| salmonella neck abscess as an opportunistic infection in diabetes mellitus. | salmonella neck infections represent an uncommon cause of focal salmonellosis. while the incidence of nontyphoid salmonellosis is estimated at over 2 million cases annually, extraintestinal manifestations account for less than 1% of cases. this paper describes two patients with salmonella neck abscesses as the initial presentation of diabetes mellitus. the first patient was diagnosed as having salmonella enterica serotype enteritidis sternocleidomastoid pyomyositis and the second patient salmone ... | 2013 | 24307959 |
| a link between gut community metabolism and pathogenesis: molecular hydrogen-stimulated glucarate catabolism aids salmonella virulence. | glucarate, an oxidized product of glucose, is a major serum organic acid in humans. still, its role as a carbon source for a pathogen colonizing hosts has not been studied. we detected high-level expression of a potential glucarate permease encoding gene gudt when salmonella enterica serovar typhimurium are exposed to hydrogen gas (h(2)), a gaseous by-product of gut commensal metabolism. a gudt strain of salmonella is deficient in glucarate-dependent growth, however, it can still use other monos ... | 2013 | 24307595 |
| redundancy in the periplasmic adaptor proteins acra and acre provides resilience and an ability to export substrates of multidrug efflux. | the components of the acrab-tolc efflux pump function as a tripartite efflux system conferring resistance to multiple antibiotics and the individual components can also function in conjunction with other efflux pumps. this study aimed to establish whether redundancy exists between the homologous periplasmic adaptor proteins (paps) acra and acre and to measure the impact of this redundancy on antimicrobial resistance and the potential efficacy of inhibitor molecules. | 2014 | 24302652 |
| first report of a salmonella enterica serovar typhimurium isolate with carbapenemase (kpc-2) in colombia. | | 2014 | 24295970 |
| 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. | 2013 | 24274891 |
| 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 ... | 2014 | 24271179 |
| 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 ... | 2014 | 24268431 |
| 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 ... | 2014 | 24256574 |
| 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. ... | 2014 | 24237042 |
| 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 ... | 2013 | 24211643 |
| 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. | 2014 | 24185747 |
| 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 ... | 2014 | 24166960 |
| 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 ... | 2013 | 24148706 |
| 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 ... | 2014 | 24144726 |
| 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 ... | 2013 | 24138507 |
| 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. | 2013 | 24136846 |
| 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. | 2013 | 24129621 |
| 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 ... | 2014 | 24126602 |
| 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 ... | 2013 | 24126127 |
| 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 ... | 2013 | 24116175 |
| 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 ... | 2014 | 24105651 |
| 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 ... | 2013 | 24100307 |
| the gdac1 locus modifies spontaneous and salmonella-induced colitis in mice deficient in either gpx2 or gpx1 gene. | we previously identified the gdac1 (gpx-deficiency-associated colitis 1) locus, which influences the severity of spontaneous colitis in gpx1- and gpx2-double-knockout (gpx1/2-dko) mice. congenic gpx1/2-dko mice in the 129s1/svimj (129) background but carrying the gdac1(b6) allele have milder spontaneous colitis than 129 gpx1/2-dko mice carrying the gdac1(129) allele. here, we evaluated the effect of the gdac1(b6) allele on 129 strain non-dko mice that had a wild-type (wt) gpx1 or gpx2 allele and ... | 2013 | 24090658 |
| the ssec translocon component in salmonella enterica serovar typhimurium is chaperoned by ssca. | salmonella enterica is a causative agent of foodborne gastroenteritis and the systemic disease known as typhoid fever. this bacterium uses two type three secretion systems (t3sss) to translocate protein effectors into host cells to manipulate cellular function. salmonella pathogenicity island (spi)-2 encodes a t3ss required for intracellular survival of the pathogen. genes in spi-2 include apparatus components, secreted effectors and chaperones that bind to secreted cargo to coordinate their rel ... | 2013 | 24090070 |
| enhancement of host immune responses by oral vaccination to salmonella enterica serovar typhimurium harboring both flic and fljb flagella. | flagellin, the structural component of the flagellar filament in various motile bacteria, can contribute to the activation of nf-κb and proinflammatory cytokine expression during the innate immune response in host cells. thus, flagellin proteins represent a particularly attractive target for the development of vaccine candidates. in this study, we investigated the immune response by increasing the flagella number in the iacp mutant strain and the adjuvant activity of the flagellin component fljb ... | 2013 | 24069357 |
| a novel csra titration mechanism regulates fimbrial gene expression in salmonella typhimurium. | a hierarchical control of fimbrial gene expression limits laboratory grown cultures of salmonella enterica serovar typhimurium (s. typhimurium) to the production of type i fimbriae encoded by the fimaicdhf operon. here we show that an unlikely culprit, namely the 5'-untranslated region (5'-utr) of a messenger (m)rna, coordinated the regulation. binding of csra to the 5'-utr of the pefacdef transcript was required for expression of plasmid-encoded fimbriae. the 5'-utr of the fimaicdhf transcript ... | 2013 | 24056837 |
| preadaptation to cold stress in salmonella enterica serovar typhimurium increases survival during subsequent acid stress exposure. | salmonella is an important cause of bacterial food-borne gastroenteritis. salmonella encounters multiple abiotic stresses during pathogen elimination methods used in food processing, and these stresses may influence its subsequent survivability within the host or in the environment. upon ingestion, salmonella is exposed to gastrointestinal acidity, a first line of the host innate defense system. this study tested the hypothesis that abiotic stresses encountered during food processing alter the m ... | 2013 | 24056458 |
| probing the arca regulon under aerobic/ros conditions in salmonella enterica serovar typhimurium. | hydrogen peroxide (h₂o₂) is a reactive oxygen species (ros), which is part of the oxidative burst encountered upon internalization of salmonella enterica serovar typhimurium (s. typhimurium) by phagocytic cells. it has previously been established that, the arcab two-component system plays a critical role in ros resistance, but the genes regulated by the system remained undetermined to date. we therefore investigated the arca regulon in aerobically growing s. typhimurium before and after exposure ... | 2013 | 24044554 |
| inflammatory responses induced by lipopolysaccharide are amplified in primary human monocytes but suppressed in macrophages by complement protein c5a. | monocytes and macrophages are important innate immune cells equipped with danger-sensing receptors, including complement and toll-like receptors. complement protein c5a, acting via c5ar, is shown in this study to differentially modulate lps-induced inflammatory responses in primary human monocytes versus macrophages. whereas c5a enhanced secretion of lps-induced il-6 and tnf from primary human monocytes, c5a inhibited these responses while increasing il-10 secretion in donor-matched human monocy ... | 2013 | 24043889 |
| fimy does not interfere with fimz-fimw interaction during type 1 fimbria production by salmonella enterica serovar typhimurium. | the production of type 1 fimbriae in salmonella enterica serovar typhimurium is controlled, in part, by three proteins, fimz, fimy, and fimw. amino acid sequence analysis indicates that fimz belongs to the family of bacterial response regulators of two-component systems. in these studies, we have demonstrated that introducing a mutation mimicking phosphorylation of fimz is necessary for activation of its target gene, fima. in addition, the interaction of fimz with fimw, a repressor of fima expre ... | 2013 | 24042120 |
| a novel insight on signal transduction mechanism of rcscdb system in salmonella enterica serovar typhimurium. | the rcscdb system of salmonella enterica serovar typhimurium is implicated in the control of capsule and flagella synthesis. the hybrid sensor rcsc, the phosphotransferase rcsd and the rcsb regulator, constitute the main components of the rcscdb system. the proposed rcs signaling cascade involves the autophosphorylation of rcsc and the transfer of the phosphate group to rcsb, mediated by rcsd. we previously reported that the overexpression of rcsb repress the transcription of rcsd by an autoregu ... | 2013 | 24023746 |
| tetracycline accelerates the temporally-regulated invasion response in specific isolates of multidrug-resistant salmonella enterica serovar typhimurium. | multidrug-resistant (mdr) salmonella isolates are associated with increased morbidity compared to antibiotic-sensitive strains and are an important health and safety concern in both humans and animals. salmonella enterica serovar typhimurium is a prevalent cause of foodborne disease, and a considerable number of s. typhimurium isolates from humans and livestock are resistant to three or more antibiotics. the majority of these mdr s. typhimurium isolates are resistant to tetracycline, a commonly ... | 2013 | 24020473 |
| hfq and arca are involved in the stationary phase-dependent activation of salmonella pathogenicity island 1 (spi1) under shaking culture conditions. | in salmonella enterica serovar typhimurium, many genes encoded within salmonella pathogenicity island 1 (spi1) are required to induce intestinal/diarrheal disease. in this study, we compared the expression of four spi1 genes (hila, invf, prgh, and sipc) under shaking and standing culture conditions and found that the expression of these genes was highest during the transition from the exponential to stationary phase under shaking conditions. to identify regulators associated with the stationary ... | 2013 | 24018968 |
| proof-of-concept study for successful inter-laboratory comparison of mlva results. | multiple-locus variable-number of tandem repeats analysis (mlva) is widely used for typing of pathogens. methods such as mlva based on determining dna fragment size by the use of capillary electrophoresis have an inherent problem as a considerable offset between measured and real (sequenced) lengths is commonly observed. this discrepancy arises from variation within the laboratory set-up used for fragment analysis. to obtain comparable results between laboratories using different set-ups, some f ... | 2013 | 24008232 |
| altered expression and localization of ion transporters contribute to diarrhea in mice with salmonella-induced enteritis. | salmonella enterica serovar typhimurium is an enteropathogen that causes self-limiting diarrhea in healthy individuals, but poses a significant health threat to vulnerable populations. our understanding of the pathogenesis of salmonella-induced diarrhea has been hampered by the lack of a suitable mouse model. after a dose of oral kanamycin, salmonella-infected congenic balb/c.d2(nrampg169) mice, which carry a wild-type nramp1 gene, develop clear manifestations of diarrhea. we used this model to ... | 2013 | 24001788 |
| identification of the first blacmy-2 gene in salmonella enterica serovar typhimurium isolates obtained from cases of paediatric diarrhoea illness detected in south america. | the objectives of this study were to investigate clinical isolates of salmonella enterica serovar typhimurium resistant to β-lactam antibiotics, to characterise their mechanisms of antibiotic resistance and to evaluate the possible biological cost of expressing resistance genes. two oxyimino-cephalosporin-resistant salmonella isolates obtained from children with diarrhoea were characterised. the occurrence of plasmid-encoded blacmy-2 genes was confirmed by molecular methods and conjugation assay ... | 2013 | 27873624 |
| mechanism of antimicrobial action of sodium metasilicate against salmonella enterica serovar typhimurium. | sodium metasilicate (sms) is an alkaline antimicrobial approved by the u.s. department of agriculture for use in poultry processing and ready-to-eat poultry products. the objectives of this study were to determine the effectiveness of sms against salmonella enterica serovar typhimurium in suspension and to elucidate the antimicrobial mechanism of action of sms. salmonella typhimurium (atcc 14028) was exposed to 0 (positive control), 0.5%, 1%, 2% (wt/vol) sms and 0.1 n naoh (high ph) solutions fo ... | 2013 | 23980709 |
| epithelial entry rather than the ensuing systemic immune response determines the pathogenicity of two salmonella enterica serovar typhimurium strains in a mouse model. | most studies of salmonella enterica serovar typhimurium infection focus only on the pathogenicity of one strain. we investigated whether differences in pathogenicity of two wild-type s. typhimurium strains; dt120 and sl1344, were related to gut invasion or the resulting immune response. oral administration of a ten-fold lower number of sl1344 (10(6) cfu) as compared to dt120 (10(7) cfu) resulted in higher bacterial counts in liver and lymph nodes, and led to massive neutrophil infiltration of th ... | 2013 | 23978790 |
| innate immune detection of flagellin positively and negatively regulates salmonella infection. | salmonella enterica serovar typhimurium is a flagellated bacterium and one of the leading causes of gastroenteritis in humans. bacterial flagellin is required for motility and also a prime target of the innate immune system. innate immune recognition of flagellin is mediated by at least two independent pathways, tlr5 and naip5-naip6/nlrc4/caspase-1. the functional significance of each of the two independent flagellin recognition systems for host defense against wild type salmonella infection is ... | 2013 | 23977202 |
| emergence of pulsed electric fields resistance in salmonella enterica serovar typhimurium sl1344. | in this investigation we selected and isolated a culture derived from salmonella enterica serovar typhimurium sl1344 with stable increased resistance to pulsed electric fields (pef) after repeated rounds of pef treatment and outgrowth of survivors. the resulting culture showed a higher resistance to pef treatments under different treatment conditions. the acquisition of pef resistance was only observed in stationary phase cells. the cytoplasmic membrane of the resistant variant showed a higher r ... | 2013 | 23973831 |
| roles of yehz, a putative osmoprotectant transporter, in tempering growth of salmonella enterica serovar typhimurium. | salmonella, a main cause of foodborne diseases, encounters a variety of environmental stresses and overcomes the stresses by multiple resistance strategies. one of the general responses to hyperosmotic stress is to import or produce compatible solutes so that cells maintain fluid balance and protect proteins and lipids from denaturation. the prop and prou systems are the main transport systems for compatible solutes. the osmu system, recently identified as a third osmoprotectant transport system ... | 2013 | 23966021 |
| signal peptide etiquette during assembly of a complex respiratory enzyme. | salmonella enterica serovar typhimurium is a gram-negative pathogen capable of respiration with a number of terminal electron acceptors. tetrathionate reductase is important for the infection process and is encoded by the ttrbca operon where ttra and ttrb are metallocofactor-containing proteins targeted to the periplasmic side of the membrane by two different tat targeting peptides. in this work, the inter-relationship between these two signal peptides has been explored. molecular genetics and b ... | 2013 | 23961722 |
| diverse secreted effectors are required for salmonella persistence in a mouse infection model. | salmonella enterica serovar typhimurium causes typhoid-like disease in mice and is a model of typhoid fever in humans. one of the hallmarks of typhoid is persistence, the ability of the bacteria to survive in the host weeks after infection. virulence factors called effectors facilitate this process by direct transfer to the cytoplasm of infected cells thereby subverting cellular processes. secretion of effectors to the cell cytoplasm takes place through multiple routes, including two separate ty ... | 2013 | 23950998 |
| the putative thiosulfate sulfurtransferases pspe and glpe contribute to virulence of salmonella typhimurium in the mouse model of systemic disease. | the phage-shock protein pspe and glpe of the glycerol 3-phosphate regulon of salmonella enterica serovar typhimurium are predicted to belong to the class of thiosulfate sulfurtransferases, enzymes that traffic sulfur between molecules. in the present study we demonstrated that the two genes contribute to s. typhimurium virulence, as a glpe and pspe double deletion strain showed significantly decreased virulence in a mouse model of systemic infection. however, challenge of cultured epithelial cel ... | 2013 | 23940650 |
| a low-ph medium in vitro or the environment within a macrophage decreases the transcriptional levels of fima, fimz and lrp in salmonella enterica serovar typhimurium. | many salmonella typhimurium isolates produce type 1 fimbriae and exhibit fimbrial phase variation in vitro. static broth culture favours the production of fimbriae, while solid agar medium inhibits the generation of these appendages. little information is available regarding whether s. typhimurium continues to produce type 1 fimbriae during in vivo growth. we used a type 1 fimbrial phase-variable strain s. typhimurium lb5010 and its derivatives to infect raw 264.7 macrophages. following entry in ... | 2013 | 23938383 |
| pathoadaptive mutations in salmonella enterica isolated after serial passage in mice. | how pathogenic bacteria adapt and evolve in the complex and variable environment of the host remains a largely unresolved question. here we have used whole genome sequencing of salmonella enterica serovar typhimurium lt2 populations serially passaged in mice to identify mutations that adapt bacteria to systemic growth in mice. we found unique pathoadaptive mutations in two global regulators, phoq and stpa, which increase the competitive indexes of the bacteria 3- to 5-fold. also, all mouse-adapt ... | 2013 | 23936152 |
| 15-deoxy-δ12,14-prostaglandin j2 inhibits macrophage colonization by salmonella enterica serovar typhimurium. | 15-deoxy-δ(12,14)-prostaglandin j2 (15d-pgj2) is an anti-inflammatory downstream product of the cyclooxygenase enzymes. it has been implicated to play a protective role in a variety of inflammatory mediated diseases, including rheumatoid arthritis, neural damage, and myocardial infarctions. here we show that 15d-pgj2 also plays a role in salmonella infection. salmonella enterica typhimurium is a gram-negative facultative intracellular pathogen that is able to survive and replicate inside phagocy ... | 2013 | 23922794 |
| salmonella enterica serovar typhimurium baesr two-component system positively regulates soda in response to ciprofloxacin. | in response to antibiotics, bacteria activate regulatory systems that control the expression of genes that participate in detoxifying these compounds, like multidrug efflux systems. we previously demonstrated that the baesr two-component system from salmonella enterica serovar typhimurium (s. typhimurium) participates in the detection of ciprofloxacin, a bactericidal antibiotic, and in the positive regulation of mdta, an efflux pump implicated in antibiotic resistance. in the present work, we pr ... | 2013 | 23918818 |
| in vitro and in vivo investigation on genomic stability of salmonella enterica typhimurium dt41 obtained from broiler breeders in denmark. | salmonella enterica serovar typhimurium phage type dt41 has previously been identified from salmonella-positive broiler breeder flocks in denmark and isolates obtained from different flocks have demonstrated major diversity by multiple-locus variable-number tandem-repeats analysis (mlva) typing. to elucidate whether the high diversity observed by mlva was related to multiple independent introductions at farm level or genetic instability of markers, we investigated the genomic stability of differ ... | 2013 | 23915994 |
| prevalence and characterization of apramycin-resistant salmonella enterica serotype typhimurium isolated from healthy and diseased pigs in korea during 1998 through 2009. | apramycin resistance was observed in 22.8% (81 of 355) of salmonella typhimurium isolates collected from pigs from 1998 through 2009 in korea. all apramycin-resistant salmonella typhimurium isolates also were cross-resistant to gentamicin and tobramycin. among the seven types of aminoglycoside resistance genes tested, only four types were detected in the apramycin-resistant salmonella typhimurium isolates: aac (3)-iv, aac (3)-ii, aac (3)-iii, and ant (2'')-i. although the aac (3)-iv gene was fou ... | 2013 | 23905803 |
| combined stimulation of toll-like receptor 5 and nod1 strongly potentiates activity of nf-κb, resulting in enhanced innate immune reactions and resistance to salmonella enterica serovar typhimurium infection. | pathogen recognition receptors (prrs) are essential components of host innate immune systems that detect specific conserved pathogen-associated molecular patterns (pamps) presented by microorganisms. members of two families of prrs, transmembrane toll-like receptors (tlrs 1, 2, 4, 5, and 6) and cytosolic nod receptors (nod1 and nod2), are stimulated upon recognition of various bacterial pamps. such stimulation leads to induction of a number of immune defense reactions, mainly triggered via activ ... | 2013 | 23897616 |
| complete genome sequence of salmonella enterica serovar typhimurium u288. | salmonella enterica serovar typhimurium u288 has firmly established itself within the united kingdom pig production industry. the prevalence of this highly pathogenic multidrug-resistant serovar at such a critical point in the food chain is therefore of great concern. to enhance our understanding of this microorganism, whole-genome and plasmid sequencing was performed. | 2013 | 23887910 |
| antimicrobial resistance of human salmonella enterica serovar typhimurium u302 strains: prevalence of r-type assut in slovakia, 2006-2011. | salmonella enterica serovar typhimurium is a common cause of non-typhoid salmonellosis in humans. since 2006, an increase in the human infections caused by u302 phage type in slovakia has been documented and, from 2006 to 2011, a total of 291 u302 human strains were isolated. antimicrobial susceptibility testing demonstrated that these strains had a high overall antimicrobial resistance and 244 (83.8%) of the tested strains were multidrug-resistant (mdr). the most prevalent resistance was to amp ... | 2013 | 23883849 |
| emergence of a multidrug-resistant (assuttm) strain of salmonella enterica serovar typhimurium dt120 in england in 2011 and the use of multiple-locus variable-number tandem-repeat analysis in supporting outbreak investigations. | in summer 2011, two outbreaks of a unique, multidrug-resistant strain of salmonella enterica serovar typhimurium phage type 120 (dt120) occurred mainly in the midlands, england. the first outbreak occurred among guests attending a wedding in july 2011 ('wedding outbreak'), followed by a more geographically dispersed outbreak in august and september 2011 ('midlands outbreak'). fifty-one cases were confirmed. detailed epidemiological and environmental health investigations suggested that pork was ... | 2013 | 23869962 |
| a multi-omic view of host-pathogen-commensal interplay in salmonella-mediated intestinal infection. | the potential for commensal microorganisms indigenous to a host (the 'microbiome' or 'microbiota') to alter infection outcome by influencing host-pathogen interplay is largely unknown. we used a multi-omics "systems" approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen salmonella enterica serovar typhimurium (s. typhimurium), and commensal gut microorganisms during intestinal infection with s. typh ... | 2013 | 23840608 |
| antimicrobial activity of plant compounds against salmonella typhimurium dt104 in ground pork and the influence of heat and storage on the antimicrobial activity. | salmonella enterica is a predominant foodborne pathogen that causes diarrheal illness worldwide. a potential method of inhibiting pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. the objectives of this study were to investigate the influence of heat (70°c for 5 min) and subsequent cold storage (4°c up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against salmonella enterica serovar typh ... | 2013 | 23834804 |
| postharvest handling conditions affect internalization of salmonella in baby spinach during washing. | internalization of foodborne pathogens in fruits and vegetables is an increasing safety concern. the aim of this research was to assess the potential for internalization of an enteric pathogen (salmonella enterica serotype typhimurium) in a leafy vegetable (baby spinach) during washing as influenced by three postharvest handling conditions: (i) illumination, (ii) negative temperature differential, and (iii) relative humidity (rh). to compare these potential postharvest handling conditions, leave ... | 2013 | 23834788 |
| salmonella enterica serovar typhimurium virulence-resistance plasmids derived from the pslt carrying nonconventional class 1 integrons with dfra12 gene in their variable region and sul3 in the 3' conserved segment. | drug-resistant derivatives of serovar-specific virulence plasmids, such as pslt, in clinically-relevant salmonella enterica serovar typhimurium strains, represent a threat for human health. we have analysed 14 s. typhimurium isolates recovered in italy and the united kingdom from swine and from cases of human infection for the presence of virulence-resistance (vr) plasmids. they were negative for the multidrug resistance (mdr) region of the salmonella genomic island 1 (sgi1), but expressed resis ... | 2013 | 23808958 |
| expansion of salmonella enterica serovar typhimurium st34 clone carrying multiple resistance determinants in china. | | 2013 | 23796940 |
| draft genome sequences for ten salmonella enterica serovar typhimurium phage type 135 variants. | salmonella enterica serovar typhimurium (s. typhimurium) is a common cause of gastroenteritis in humans. here, we report the draft genome sequences of 10 isolates of an s. typhimurium phage type 135 variant that is linked to egg-associated outbreaks in tasmania, australia. | 2013 | 23792739 |
| longitudinal study of distributions of similar antimicrobial-resistant salmonella serovars in pigs and their environment in two distinct swine production systems. | the aim of this longitudinal study was to determine and compare the prevalences and genotypic profiles of antimicrobial-resistant (ar) salmonella isolates from pigs reared in antimicrobial-free (abf) and conventional production systems at farm, at slaughter, and in their environment. we collected 2,889 pig fecal and 2,122 environmental (feed, water, soil, lagoon, truck, and floor swabs) samples from 10 conventional and eight abf longitudinal cohorts at different stages of production (farrowing, ... | 2013 | 23793629 |
| unsaturated long chain free fatty acids are input signals of the salmonella enterica phop/phoq regulatory system. | the salmonella enterica serovar typhimurium phop/phoq system has largely been studied as a paradigmatic two-component regulatory system not only to dissect structural and functional aspects of signal transduction in bacteria but also to gain knowledge about the versatile devices that have evolved allowing a pathogenic bacterium to adjust to or counteract environmental stressful conditions along its life cycle. mg(2+) limitation, acidic ph, and the presence of cationic antimicrobial peptides have ... | 2013 | 23782700 |
| β-1,3/1,6-glucan alleviated intestinal mucosal barrier impairment of broiler chickens challenged with salmonella enterica serovar typhimurium. | this study investigated the protective effect of β-1,3/1,6-glucan on gut morphology, intestinal epithelial tight junctions, and bacterial translocation of broiler chickens challenged with salmonella enterica serovar typhimurium. ninety salmonella-free arbor acre male broiler chickens were randomly divided into 3 groups: negative control group (nc), salmonella typhimurium-infected positive group (pc), and the salmonella typhimurium-infected group with dietary 100 mg/kg of β-1,3/1,6-glucan supplem ... | 2013 | 23776263 |
| evidence of metabolic switching and implications for food safety from the phenome(s) of salmonella enterica serovar typhimurium dt104 cultured at selected points across the pork production food chain. | salmonella enterica serovar typhimurium dt104 is a recognized food-borne pathogen that displays a multidrug-resistant phenotype and that is associated with systemic infections. at one extreme of the food chain, this bacterium can infect humans, limiting the treatment options available and thereby contributing to increased morbidity and mortality. although the antibiotic resistance profile is well defined, little is known about other phenotypes that may be expressed by this pathogen at key points ... | 2013 | 23770904 |
| attenuated salmonella enterica serovar typhimurium lacking the znuabc transporter: an efficacious orally-administered mucosal vaccine against salmonellosis in pigs. | we have recently demonstrated that an attenuated strain of salmonella enterica serovar typhimurium unable to synthesize the zinc transporter znuabc (s. typhimurium δznuabc), is able to protect mice against systemic and enteric salmonellosis and is safe in pigs. here, we have tested the protective effects of s. typhimurium δznuabc in pigs. resistance to challenge with the fully virulent strain s. typhimurium atcc 14028 was assessed in animals vaccinated with s. typhimurium δznuabc (two dosages te ... | 2013 | 23770333 |
| evaluation of the efficiency of synthesized efflux pump inhibitors on salmonella enterica ser. typhimurium cells. | multidrug efflux pump inhibitors have a great potential as pharmacological agents that increase the drug susceptibility of bacterial pathogens. our study was focused on the synthesis and evaluation of the efficiency of resistance-nodulation-division (rnd) family efflux pump inhibitors. the efficiency of these inhibitors was investigated on salmonella enterica ser. typhimurium cells using tetraphenylphosphonium (tpp(+) ) and ethidium cations as the efflux pump substrates. results of our study ind ... | 2013 | 23763959 |
| the systemic immune state of super-shedder mice is characterized by a unique neutrophil-dependent blunting of th1 responses. | host-to-host transmission of a pathogen ensures its successful propagation and maintenance within a host population. a striking feature of disease transmission is the heterogeneity in host infectiousness. it has been proposed that within a host population, 20% of the infected hosts, termed super-shedders, are responsible for 80% of disease transmission. however, very little is known about the immune state of these super-shedders. in this study, we used the model organism salmonella enterica sero ... | 2013 | 23754944 |
| role of murine intestinal interleukin-1 receptor 1-expressing lymphoid tissue inducer-like cells in salmonella infection. | interleukin (il)-1 signaling plays a critical role in intestinal immunology. here, we report that the major population of intestinal lamina propria lymphocytes expressing il-1 receptor 1 (il-1r1) is the lymphoid tissue inducer (lti)-like cell, a type of innate lymphoid cell. these cells are significant producers of il-22, and this il-22 production depends on il-1r1 signaling. lti-like cells are required for defense against salmonella enterica serovar typhimurium. moreover, colonic lti-like cell ... | 2013 | 23750260 |
| oxidoreductases that act as conditional virulence suppressors in salmonella enterica serovar typhimurium. | in salmonella enterica serovar typhimurium, oxidoreductases of the thioredoxin superfamily contribute to bacterial invasiveness, intracellular replication and to the virulence in balb/c mice as well as in the soil nematode caenorhabditis elegans. the scsabcd gene cluster, present in many but not all enteric bacteria, codes for four putative oxidoreductases of the thioredoxin superfamily. here we have analyzed the potential role of the scs genes in oxidative stress tolerance and virulence in s. t ... | 2013 | 23750221 |
| length control of the flagellar hook in a temperature-sensitive flge mutant of salmonella enterica serovar typhimurium. | the flagellar hook is a short, curved, extracellular structure located between the basal body and the filament. the hook is composed of the flge protein. in this study, we analyzed flagellum assembly in a temperature-sensitive flge mutant of salmonella enterica serovar typhimurium. when the mutant cells were grown at 30°c, they produced flagella of a normal length (71% of the population) and short hooks without filaments (26%). at 37°c, 70% of the basal bodies lacked hooks, and intact flagella m ... | 2013 | 23749974 |
| identification and characterization of a novel flagellum-dependent salmonella-infecting bacteriophage, ieps5. | a novel flagellatropic phage of salmonella enterica serovar typhimurium, called ieps5, was isolated and characterized. ieps5 has an icosahedral head and a long noncontractile tail with a tail fiber. genome sequencing revealed a double-stranded dna of 59,254 bp having 73 open reading frames (orfs). to identify the receptor for ieps5, tn5 transposon insertion mutants of s. typhimurium sl1344 that were resistant to the phage were isolated. all of the phage-resistant mutants were found to have mutat ... | 2013 | 23747700 |
| spread of oqxab in salmonella enterica serotype typhimurium predominantly by inchi2 plasmids. | to investigate the prevalence and genetic environment of the multiresistance gene oqxab in salmonella enterica serotype typhimurium isolated from food-producing animals. | 2013 | 23737490 |
| potential therapeutic anti-tumor effect of a salmonella-based vaccine. | one of the major obstacles to achieving complete eradication of tumors, even in the presence of circulating tumor-specific immunity, is the tumor-induced immunosuppressive environment, which includes myeloid-derived suppressor cells and regulatory t cells. attenuated microorganisms have emerged as candidates for a novel anti-cancer approach in which they enhance anti-cancer immunity by boosting the innate immune system. herein, we will discuss current innate-immunity activating strategies for an ... | 2013 | 23733040 |
| survival of acid adapted and non-acid adapted salmonella typhimurium in pasteurized orange juice and yogurt under different storage temperatures. | the survival capacity of salmonella enterica serovar typhimurium acid adapted and non-acid adapted cells was monitored in pasteurized yogurt (ph 4.1) and orange juice (ph 3.6) during storage at different temperatures (4, 10, 25 and 37 ). acid adapted and non-acid adapted cells were obtained by means of their growth for 36 h in brain heart infusion broth acidified at ph 4.8 with citric acid and buffered (ph 7.0) brain heart infusion broth, respectively. s. typhimurium showed a great ability to su ... | 2013 | 23729421 |
| crystal structure of the periplasmic disulfide-bond isomerase dsbc from salmonella enterica serovar typhimurium and the mechanistic implications. | the disulfide-bond isomerase dsbc plays a crucial role in the folding of bacterial proteins in the periplasmic space. dsbc has a v-shaped dimeric structure with two domains, and cys98 in the c-terminal domain attacks inappropriate disulfide bonds in substrate proteins due to its high nucleophilic activity. in this article, we present the crystal structure of dsbc from salmonella enterica serovar typhimurium. we evaluated the conserved residues asp95 and arg125, which are located close to cys98. ... | 2013 | 23726983 |
| circadian clock regulates the host response to salmonella. | organisms adapt to day-night cycles through highly specialized circadian machinery, whose molecular components anticipate and drive changes in organism behavior and metabolism. although many effectors of the immune system are known to follow daily oscillations, the role of the circadian clock in the immune response to acute infections is not understood. here we show that the circadian clock modulates the inflammatory response during acute infection with the pathogen salmonella enterica serovar t ... | 2013 | 23716692 |
| choice of bacterial growth medium alters the transcriptome and phenotype of salmonella enterica serovar typhimurium. | the type of bacterial culture medium is an important consideration during design of any experimental protocol. the aim of this study was to understand the impact of medium choice on bacterial gene expression and physiology by comparing the transcriptome of salmonella enterica sl1344 after growth in the widely used lb broth or the rationally designed mops minimal medium. transcriptomics showed that after growth in mops minimal media, compared to lb, there was increased expression of 42 genes invo ... | 2013 | 23704954 |
| molecular characterization of salmonella enterica serovar typhimurium isolated from human, food, and animal sources in malaysia. | salmonella typhimurium is an important nontyphoidal salmonella serovar associated with foodborne diseases in many parts of the world. this organism is the major causative agent of nontyphoidal salmonellosis in malaysia. we aimed to investigate the genetic profiles of the strains isolated from clinical, zoonotic, and dietary sources in malaysia using multilocus variable number tandem repeat analysis (mlva) and pulsed-field gel electrophoresis (pfge). by focusing on the 5 common variable number ta ... | 2013 | 23698477 |
| genomic analysis of salmonella enterica serovar typhimurium definitive phage type 104. | | 2013 | 23697578 |
| expression, purification, crystallization and preliminary x-ray diffraction analysis of a core fragment of flgg, a bacterial flagellar rod protein. | flgg is a bacterial flagellar rod protein and constructs the distal rod connecting to the hook. flgg of salmonella enterica serovar typhimurium is a 260-amino-acid protein composed of a folded core region and n- and c-terminal regions that are unfolded in solution. a core fragment of flgg (flgg47-227) was expressed, purified and crystallized. crystals of native and semet-labelled flgg47-227 were obtained by the sitting-drop vapour-diffusion technique with peg mme 2000 as precipitant. the native ... | 2013 | 23695574 |
| the lipopolysaccharide modification regulator pmra limits salmonella virulence by repressing the type three-secretion system spi/ssa. | the regulatory protein pmra controls expression of lipopolysaccharide (lps) modification genes in salmonella enterica serovar typhimurium, the etiologic agent of human gastroenteritis and murine typhoid fever. pmra-dependent lps modifications confer resistance to serum, fe(3+), and several antimicrobial peptides, suggesting that the pmra gene is required for salmonella virulence. we now report that, surprisingly, a pmra null mutant is actually hypervirulent when inoculated i.p. into c3h/hen mice ... | 2013 | 23690578 |
| the use of factorial design, image analysis, and an efficiency calculation for multiplex pcr optimization. | the quality of multiplex polymerase chain reaction (pcr) assays depends on several factors. therefore, it is important to establish the optimal conditions to achieve efficient amplification. the objective of this study was to implement a 5 × 4 factorial design combined with image analysis using agarose gels and an efficiency calculation to optimize a multiplex pcr assays for the detection of salmonella enterica serovar typhimurium. | 2013 | 23686781 |
| clpp deletion causes attenuation of salmonella typhimurium virulence through mis-regulation of rpos and indirect control of csra and the spi genes. | salmonella enterica serovar typhimurium requires the type iii secretion system encoded by salmonella pathogenicity island 1 (spi1) and controlled by the master regulator, hila, to penetrate the intestinal epithelium. numerous regulators affect virulence through influence on this system, including the proteolytic component clpp, the stationary phase regulator rpos and the carbon-storage regulator csra. however, the mechanism behind the clpp regulation is not fully understood. to elucidate this we ... | 2013 | 23676436 |
| prop is required for the survival of desiccated salmonella enterica serovar typhimurium cells on a stainless steel surface. | consumers trust commercial food production to be safe, and it is important to strive to improve food safety at every level. several outbreaks of food-borne disease have been caused by salmonella strains associated with dried food. currently we do not know the mechanisms used by salmonella enterica serovar typhimurium to survive in desiccated environments. the aim of this study was to discover the responses of s. typhimurium st4/74 at the transcriptional level to desiccation on a stainless steel ... | 2013 | 23666329 |
| raon, a small rna encoded within salmonella pathogenicity island-11, confers resistance to macrophage-induced stress. | bacterial small non-coding rnas act as important regulators that control numerous cellular processes. here we identified raon, a novel small rna encoded in the csph-enve intergenic region on salmonella pathogenicity island-11 (spi-11). raon contributes to survival under conditions of acid and oxidative stress combined with nutrient limitation, which partially mimic the intramacrophage environment. indeed, inactivation of raon reduces the intramacrophage replication of salmonella enterica serovar ... | 2013 | 23657681 |
| biotin sulfoxide reductase contributes to oxidative stress tolerance and virulence in salmonella enterica serovar typhimurium. | oxidative stress converts sulfur residues of molecules like biotin and methionine into their oxidized forms. here we show that the biotin sulfoxide reductase bisc of salmonella enterica serovar typhimurium (s. typhimurium) repairs both oxidized biotin and oxidized methionine. exposure to h2o2 in vitro reduced survival of a s. typhimurium δbisc mutant. furthermore, replication of the δbisc mutant inside ifn-γ activated macrophages was reduced. in vitro tolerance of the mutant to h2o2 was restored ... | 2013 | 23657680 |
| conflicting roles for a cell surface modification in salmonella. | chemical modifications of components of the bacterial cell envelope can enhance resistance to antimicrobial agents. why then are such modifications produced only under specific conditions? here, we address this question by examining the role of regulated variations in o-antigen length in the lipopolysaccharide (lps), a glycolipid that forms most of the outer leaflet of the outer membrane in gram-negative bacteria. we determined that activation of the pmra/pmrb two-component system, which is the ... | 2013 | 23646936 |
| intestinal invasion of salmonella enterica serovar typhimurium in the avian host is dose dependent and does not depend on motility and chemotaxis. | salmonella enterica serotype typhimurium (s. typhimurium) can invade in the intestine of the avian host, and knowledge on the mechanisms that govern this is potentially important for prevention of disease. this study investigated the invasion of s. typhimurium in the avian host and to which extent it depended on motility and chemotaxis. wild type and previously well-characterized transposon mutants in flagella genes flic and fljb and in chemotaxis genes chea, cheb and cher were used as challenge ... | 2013 | 23642416 |
| a simple technique based on a single optical trap for the determination of bacterial swimming pattern. | bacterial motility is associated to a wide range of biological processes and it plays a key role in the virulence of many pathogens. here we describe a method to distinguish the dynamic properties of bacteria by analyzing the statistical functions derived from the trajectories of a bacterium trapped by a single optical beam. the approach is based on the model of the rotation of a solid optically trapped sphere. the technique is easily implemented in a biological laboratory, since with only a sma ... | 2013 | 23637869 |
| nontyphoid salmonella infection: microbiology, clinical features, and antimicrobial therapy. | nontyphoid salmonella is the most common bacterial pathogen causing gastrointestinal infection worldwide. most nontyphoid salmonella infection is limited to uncomplicated gastroenteritis that seldom requires antimicrobial treatment. nevertheless, invasive infections, such as bacteremia, osteomyelitis, and meningitis, may occur and require antimicrobial therapy. continuous genetic and genomic evolution in salmonella leading to increased virulence and resistance to multiple drugs are of significan ... | 2013 | 23597525 |
| new sub-family of lysozyme-like proteins shows no catalytic activity: crystallographic and biochemical study of stm3605 protein from salmonella typhimurium. | phage viruses that infect prokaryotes integrate their genome into the host chromosome; thus, microbial genomes typically contain genetic remnants of both recent and ancient phage infections. often phage genes occur in clusters of atypical g+c content that reflect integration of the foreign dna. however, some phage genes occur in isolation without other phage gene neighbors, probably resulting from horizontal gene transfer. in these cases, the phage gene product is unlikely to function as a compo ... | 2013 | 23572252 |
| salmonella modulates metabolism during growth under conditions that induce expression of virulence genes. | salmonella enterica serovar typhimurium (s. typhimurium) is a facultative pathogen that uses complex mechanisms to invade and proliferate within mammalian host cells. to investigate possible contributions of metabolic processes to virulence in s. typhimurium grown under conditions known to induce expression of virulence genes, we used a metabolomics-driven systems biology approach coupled with genome-scale modeling. first, we identified distinct metabolite profiles associated with bacteria grown ... | 2013 | 23559334 |
| salmonella enterica serovar typhimurium skills to succeed in the host: virulence and regulation. | salmonella enterica serovar typhimurium is a primary enteric pathogen infecting both humans and animals. infection begins with the ingestion of contaminated food or water so that salmonellae reach the intestinal epithelium and trigger gastrointestinal disease. in some patients the infection spreads upon invasion of the intestinal epithelium, internalization within phagocytes, and subsequent dissemination. in that case, antimicrobial therapy, based on fluoroquinolones and expanded-spectrum cephal ... | 2013 | 23554419 |
| profiling the gastrointestinal microbiota in response to salmonella: low versus high salmonella shedding in the natural porcine host. | controlling salmonella in the food chain is complicated by the ability of salmonella to colonize livestock without causing clinical symptoms/disease. salmonella-carrier animals are a significant reservoir for contamination of naïve animals, the environment, and our food supply. salmonella carriage and shedding in pigs varies greatly both experimentally and on-farm. to investigate the dynamics between the porcine intestinal microbiota and salmonella shedding, we temporally profiled the microbiota ... | 2013 | 23535116 |
| identification of an outer membrane protein of salmonella enterica serovar typhimurium as a potential vaccine candidate for salmonellosis in mice. | we report our investigation of the functions of pagn in salmonella pathogenesis and its potential as a vaccine candidate. further investigation conducted in this study indicates that the outer membrane protein pagn is important for salmonella adhesion/invasion of epithelial cells as well as bacterial virulence. when pagn was deleted from salmonella enterica serovar typhimurium (s. typhimurium), the adhesion and invasion of ht-29 epithelial cells was significantly decreased compared with the wild ... | 2013 | 23485513 |
| wild birds carry similar salmonella enterica serovar typhimurium strains to those found in domestic animals and livestock. | the objective of this study was to investigate the hypothesis that some sporadic salmonella infections in domesticated animals may be associated with salmonella infections originating from garden birds. phage type and antimicrobial resistance details of isolates of s. typhimurium obtained from wild birds were comparable with those from s. typhimurium infections from domesticated animals or livestock between 2002 and 2010. a small panel of s. typhimurium isolates (n=37) were characterised by mult ... | 2013 | 23481141 |
| delivery of the co-expression plasmid pendo-si-stat3 by attenuated salmonella serovar typhimurium for prostate cancer treatment. | to investigate the therapeutic utility of an attenuated bacterium carrying a plasmid that co-expresses endostatin, an inhibitor of tumor neovasculogenesis, and a shrna that targets stat3 to suppress prostate cancer growth. | 2013 | 23463096 |