Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| rapid oligonucleotide-based recombineering of the chromosome of salmonella enterica. | recombinant engineering using red recombinase-based approaches offers efficient and rapid approaches to deletion and modification of genes. here we describe a novel application of red recombinant engineering that enables direct manipulation of chromosomal loci by electroporation with short synthetic dna molecules. we demonstrate the use of this approach for the generation of scarless in-frame deletions in chromosomal genes of salmonella enterica. furthermore, we describe rapid site-directed muta ... | 2009 | 19151186 |
| evaluation of the bacterial diversity in cecal contents of laying hens fed various molting diets by using bacterial tag-encoded flx amplicon pyrosequencing. | laying hens are typically induced to molt to begin a new egg-laying cycle by withdrawing feed for up to 12 to 14 d. fasted hens are more susceptible to colonization and tissue invasion by salmonella enterica serovar enteritidis. much of this increased incidence in fasted hens is thought to be due to changes in the native intestinal microflora. an alternative to feed withdrawal involves feeding alfalfa meal crumble to hens, which is indigestible by poultry but provides fermentable substrate to th ... | 2009 | 19151343 |
| studying the mechanism of rna separations using rna chromatography and its application in the analysis of ribosomal rna and rna:rna interactions. | dna/rna chromatography presents a versatile platform for the analysis of nucleic acids. although the mechanism of separation of double stranded (ds) dna fragments is largely understood, the mechanism by which rna is separated appears more complicated. to further understand the separation mechanisms of rna using ion pair reverse phase liquid chromatography, we have analysed a number of dsrna and single stranded (ss) rna fragments. the high-resolution separation of dsrna was observed, in a similar ... | 2009 | 19155018 |
| rapid dna amplification using a battery-powered thin-film resistive thermocycler. | a prototype handheld, compact, rapid thermocycler was developed for multiplex analysis of nucleic acids in an inexpensive, portable configuration. instead of the commonly used peltier heating/cooling element, electric thin-film resistive heater and a miniature fan enable rapid heating and cooling of glass capillaries leading to a simple, low-cost thin-film resistive thermocycler (tfrt). computer-based pulse width modulation control yields heating rates of 6-7 k/s and cooling rates of 5 k/s. the ... | 2009 | 19159110 |
| pseudogene accumulation in the evolutionary histories of salmonella enterica serovars paratyphi a and typhi. | of the > 2000 serovars of salmonella enterica subspecies i, most cause self-limiting gastrointestinal disease in a wide range of mammalian hosts. however, s. enterica serovars typhi and paratyphi a are restricted to the human host and cause the similar systemic diseases typhoid and paratyphoid fever. genome sequence similarity between paratyphi a and typhi has been attributed to convergent evolution via relatively recent recombination of a quarter of their genomes. the accumulation of pseudogene ... | 2009 | 19159446 |
| the salmonella pathogenicity island 2-encoded type iii secretion system is essential for the survival of salmonella enterica serovar typhimurium in free-living amoebae. | free-living amoebae represent a potential reservoir and predator of salmonella enterica. through the use of type iii secretion system (t3ss) mutants and analysis of transcription of selected t3ss genes, we demonstrated that the salmonella pathogenicity island 2 is highly induced during s. enterica serovar typhimurium infection of acanthamoeba polyphaga and is essential for survival within amoebae. | 2009 | 19168655 |
| salmonella enterica serovar typhimurium mutants unable to convert malate to pyruvate and oxaloacetate are avirulent and immunogenic in balb/c mice. | previously, we showed that the salmonella enterica serovar typhimurium sr-11 tricarboxylic acid (tca) cycle must operate as a complete cycle for full virulence after oral infection of balb/c mice (m. tchawa yimga, m. p. leatham, j. h. allen, d. c. laux, t. conway, and p. s. cohen, infect. immun. 74:1130-1140, 2006). in the same study, we showed that for full virulence, malate must be converted to both oxaloacetate and pyruvate. moreover, it was recently demonstrated that blocking conversion of s ... | 2009 | 19168732 |
| sequence analysis of the plasmid pgy1 harbored in salmonella enterica serovar paratyphi a. | the cryptic plasmid pgy1, which is harbored by a clinical isolate of salmonella enterica serovar paratyphi a, was identified in a 9-year-old girl with paratyphoid fever in 2005, and its dna sequence was determined. it is 3592 bp in length and had a g+c content of 43.3%. three orfs were predicted that share low similarity with hypothetical proteins in the genbank database. pgy1 shared 36.6% sequence homology with the cryptic plasmid pimvs1 from salmonella typhimurium. its unique sequence makes it ... | 2009 | 19169860 |
| acid stress activation of the sigma(e) stress response in salmonella enterica serovar typhimurium. | the alternative sigma factor sigma(e) is activated by unfolded outer membrane proteins (omps) and plays an essential role in salmonella pathogenesis. the canonical pathway of sigma(e) activation in response to envelope stress involves sequential proteolysis of the anti-sigma factor rsea by the pdz proteases degs and rsep. here we show that sigma(e) in salmonella enterica sv. typhimurium can also be activated by acid stress. a sigma(e)-deficient mutant exhibits increased susceptibility to acid ph ... | 2009 | 19170886 |
| isolation of salmonella enterica serotype isangi from a suspected case of enteric encephalopathy. | nontyphoidal salmonella species are thought to be potentially infectious to humans and many are documented to cause human diseases. we isolated s. isangi from the blood of a 30-year-old man with complaints of diarrhoea, fever, and altered sensorium. the serotype of the isolate was confirmed at national salmonella centre (vet.), division of bacteriology and mycology, indian veterinary research institute, izzatnagar, india. the isolate was not an extended spectrum beta-lactamase (esbl) producer an ... | 2009 | 19172065 |
| aroa and arod mutations influence biofilm formation in salmonella enteritidis. | aro mutants of salmonella enterica are frequently used as live vaccines for the oral vaccination of domestic animals. interestingly, besides their auxotrophy, they appear to be of reduced resistance to the components of innate immune response due to a defect in outer membrane and/or cell wall integrity. because different extracellular structures associated with the cell wall or outer membrane are involved in biofilm formation, we were interested in the ability of aroa and arod mutants of s. ente ... | 2009 | 19054077 |
| the survival of salmonella enterica serovar typhimurium dt104 and total viable counts on beef surfaces at different relative humidities and temperatures. | the aim of this study was to investigate changes in salmonella and total viable count (tvc) survival on beef carcass surfaces stored for 72 h under different combinations of relative humidity (i.e. rh 75% or 96%) and temperature (5 degrees c or 10 degrees c). | 2009 | 19054240 |
| genetic stability of vaccine strain salmonella typhi ty21a over 25 years. | the attenuated live bacterial vaccine strain salmonella enterica serovar typhi ty21a is the main constituent of vivotif, the only licensed oral vaccine against typhoid fever. the strain was developed in the 1970s by chemical mutagenesis. in the course of this mutagenesis, a number of mutations were introduced into the vaccine strain. characterisation of the vaccine strain during development as well as release of master- and working seed lots (msl and wsl) and commercial batches is based on pheno ... | 2009 | 19121604 |
| calprotectin s100a9 calcium-binding loops i and ii are essential for keratinocyte resistance to bacterial invasion. | epithelial cells expressing calprotectin, a heterodimer of s100a8 and s100a9 proteins, are more resistant to bacterial invasion. to determine structural motifs that affect resistance to bacterial invasion, mutations were constructed in s100a9 targeting the calcium-binding loops i and ii (e36q, e78q, e36q,e78q) and the c terminus (s100a9(1-99) and s100a9(1-112)), which contains putative antimicrobial zinc-binding and phosphorylation sites. the s100a8 and mutated s100a9 encoding plasmids were tran ... | 2009 | 19122197 |
| typhoid rhabdomyolysis with acute renal failure and acute pancreatitis: a case report and review of the literature. | we report a case of typhoid rhabdomyolysis with acute renal failure and acute pancreatitis in a 23-year-old vietnamese male who was admitted to the intensive care unit with a 15-day history of fever followed by severe abdominal pain. on examination, the patient was febrile and his abdomen was diffusely tender. serum creatinine was 533 micromol/l, pancreatic amylase 1800 u/l and lipase 900 u/l; the myoglobin blood level was high, which is associated with significant myoglobinuria. blood, urine an ... | 2009 | 19147385 |
| prevalence and risk factors for bacterial food-borne zoonotic hazards in slaughter pigs: a review. | the hygiene package and regulation ec-2160/2003 require information flow from farm to slaughterhouse to enhance european consumers protection in a 'farm to fork' approach. this obligation especially concerns food-borne zoonotic hazards transmitted to humans through pork consumption, such as thermophilic campylobacter spp., listeria monocytogenes, salmonella enterica and yersinia enterocolitica. prevalence estimates of these four hazards are affected by the sampling strategy and diagnostic proced ... | 2009 | 19175574 |
| occurrence of extended-spectrum beta-lactamase-producing salmonella enterica in northern spain with evidence of ctx-m-9 clonal spread among animals and humans. | among the 1233 salmonella enterica isolates obtained in two spanish hospitals, five isolates (0.4%) (serovars: virchow, four; livingstone, one) had the phenotype of an extended-spectrum beta-lactamase (esbl) producer. the genetic characterization of the esbl of s. enterica livingstone revealed a bla(shv-2) gene. the bla(ctx-m-10) gene in a phage-related genetic environment was found in one s. enterica virchow isolate, and the bla(ctx-m-9) gene within the in60 integron was found in the three rema ... | 2009 | 19175621 |
| importance of subunit vaccine antigen of major fli c antigenic site of salmonella enteritidis ii: a challenge trial. | salmonella enterica subsp. enterica serovar enteritidis (se) infection in chickens shows a mild pathogenicity except for young ages, compared with other animals, and laying hens sometimes produce se-contaminated eggs leading to public health concerns. to reduce the problem, se bacterin in poultry farms has been applied. we previously demonstrated that a subunit antigen, g.m. part polypeptide in se-fli c (sep 9), could be a candidate subunit antigen of se vaccine which may show less side effects ... | 2009 | 19186198 |
| the cysteine 354 and 277 residues of salmonella enterica serovar typhi envz are determinants of autophosphorylation and ompr phosphorylation. | an initial biochemical characterization of the salmonella enterica serovar typhi (s. typhi) envz sensor protein and several mutant derivatives was performed. autophosphorylation levels were higher for escherichia coli envz, intermediate for s. enterica serovar typhimurium envz and very low for s. typhi envz, in spite of their high amino acid sequence identity. consequently, ompr phosphorylation was related to envz autophosphorylation. among the mutant derivatives, a c354g mutation in s. typhi en ... | 2009 | 19187206 |
| synergistic role of curli and cellulose in cell adherence and biofilm formation of attaching and effacing escherichia coli and identification of fis as a negative regulator of curli. | curli are adhesive fimbriae of escherichia coli and salmonella enterica. expression of curli (csga) and cellulose (bcsa) is co-activated by the transcriptional activator csgd. in this study, we investigated the contribution of curli and cellulose to the adhesive properties of enterohaemorragic (ehec) o157:h7 and enteropathogenic e. coli (epec) o127:h6. while single mutations in csga, csgd or bcsa in epec and ehec had no dramatic effect on cell adherence, double csgabcsa mutants were significantl ... | 2009 | 19187284 |
| serovar distribution and antimicrobial susceptibility of swine salmonella isolates from clinically ill pigs in diagnostic submissions from indiana in the united states. | to determine serovar distribution and levels of antimicrobial susceptibility of salmonella isolated from clinically ill pigs in diagnostic submissions. | 2009 | 19187513 |
| recombinant attenuated salmonella harboring 4-1bb ligand gene enhances cellular immunity. | to transfect antigen presenting cells (apcs) with 4-1bb ligand dna by attenuated salmonella enterica serovar typhimurium in vivo, and to observe the effects of ectogenous 4-1bbl on the immune functions of infected rats. | 2009 | 19187795 |
| rethinking typhoid fever vaccines: implications for travelers and people living in highly endemic areas. | 2009 | 19192128 | |
| effects of the dicarboxylic acids malate and fumarate on e. coli o157:h7 and salmonella enterica typhimurium populations in pure culture and in mixed ruminal microorganism fermentations. | the dicarboxylic acids malate and fumarate increase ruminal ph, reduce methane production, increase propionate and total volatile fatty acid (vfa) production, and reduce lactic acid accumulation in a manner similar to ionophores. these acids stimulate the ruminal bacterium selenomonas ruminantium to ferment lactate to produce propionate. thus, dicarboxylic acids have been suggested as nonantibiotic modifiers of the ruminal fermentation, but their impact on ruminal microbial ecology remains unkno ... | 2009 | 19194750 |
| the structure and biological aspects of peptide antibiotic microcin j25. | microcin j25 (mccj25) is a plasmid-encoded peptide of 21 l-amino acids (g1-g-a-g-h5-v-p-e-y-f10-v-g-i-g-t15-p-i-s-f-y20-g), excreted to the medium by an escherichia coli strain. mccj25 is active on gram-negative bacteria related to the producer strain, including some pathogenic strains. the four-plasmid genes mcjabcd, are involved in mccj25 production: mcja encodes a 58-residue precursor, mcjb and mcjc codify two processing enzymes required for the in vivo synthesis of the mature peptide and mcj ... | 2009 | 19199920 |
| molecular characterization of antimicrobial resistance in salmonella isolated from animals in japan. | aims: to investigate the prevalence of integrons and antimicrobial resistance genes in salmonella recovered from animals in japan. methods and results: forty-eight out of ninety-four (51.1%) salmonella isolates showed multidrug resistance phenotypes and harboured at least one antimicrobial resistance gene. twenty-two out of forty-seven (46.8%) salmonella enterica serovar typhimurium that were multidrug-resistant were of definitive phage type dt104. class 1 integrons were identified in 34/94 isol ... | 2009 | 19200308 |
| distribution and genotypic characterization of salmonella serovars isolated from tropical seafood of cochin, india. | to determine the distribution of salmonella serovars in seafood and to examine the intraserovar genetic variations in salmonella enterica subsp. enterica serovar rissen and salmonella weltevreden by polymerase chain reaction (pcr)-ribotyping and enterobacterial repetitive intergenic consensus (eric)-pcr methods. | 2009 | 19200318 |
| expression of porcine toll-like receptor 2, 4 and 9 gene transcripts in the presence of lipopolysaccharide and salmonella enterica serovars typhimurium and choleraesuis. | salmonella enterica serovar typhimurium (st) and choleraesuis (sc) are among the most frequently isolated salmonellae serovars causing enteric disease in swine. enteric disease in young pigs is of major concern in modern production systems due to the negative implications on animal health, food safety and economic return. epithelial cells express toll-like receptors (tlr) that recognize conserved microbial structures and act as mediators of innate and adaptive immune responses. however, little i ... | 2009 | 19200608 |
| methods to monitor autophagy of salmonella enterica serovar typhimurium. | autophagy is an important component of the mammalian innate immune system and is able to specifically target intracellular bacterial pathogens. salmonella enterica serovar typhimurium is an intracellular pathogen that causes gastroenteritis in humans. autophagy has been shown to target s. typhimurium during in vitro infection of mammalian cultured cells and protects the cytosol of these cells from bacterial colonization. here we discuss autophagic sequestration of s. typhimurium and how it can b ... | 2009 | 19200891 |
| expression profile of toll-like receptors within the gastrointestinal tract of 2-day-old salmonella enteriditis-infected broiler chickens. | salmonella enterica serovar enteriditis (se) causes a majority of foodborne illness in the u.s. a more productive avian innate immune response could reduce bacterial colonization and the incidence of infection in humans. however, quantification and comparison of the toll-like receptors (tlr), a component of the innate immune system that recognize bacterial pathogens, and their response to se colonization across the avian gastrointestinal (gi) tract has not been reported. therefore, we assessed t ... | 2009 | 19201111 |
| distribution of mutation frequencies among salmonella enterica isolates from animal and human sources and genetic characterization of a salmonella heidelberg hypermutator. | hypermutation is an important mechanism used by different salmonella enterica subspecies enterica to regulate genetic stability in adaptation to changing environments, including antimicrobial treatments and industrial processes. strong hypermutator strains generally contain a mutation in genes of the methyl mismatch repair (mmr) system and have mutation frequencies up to 1000-fold higher than wild type strains. the objectives of this study were to determine the distribution of mutation frequenci ... | 2009 | 19201550 |
| a conserved alpha-helix essential for a type vi secretion-like system of francisella tularensis. | francisella tularensis harbors genes with similarity to genes encoding components of a type vi secretion system (t6ss) recently identified in several gram-negative bacteria. these genes include igla and iglb encoding igla and iglb, homologues of which are conserved in most t6sss. we used a yeast two-hybrid system to study the interaction of the igl proteins of f. tularensis lvs. we identified a region of igla, encompassing residues 33 to 132, necessary for efficient binding to iglb, as well as f ... | 2009 | 19201795 |
| innate immunity mediated by myd88 signal is not essential for induction of lipopolysaccharide-specific b cell responses but is indispensable for protection against salmonella enterica serovar typhimurium infection. | salmonella organisms are gram negative and facultative anaerobic bacteria that cause typhoid fever in humans. in this study, we evaluated lps-specific adaptive immunity in innate immune-deficient mice after oral administration of attenuated salmonella enterica serovar typhimurium (s. typhimurium) strains. of interest, identical levels of lps-specific igg and iga abs were elicited in the systemic (i.e., serum and spleen) and mucosal (i.e., fecal extract and small intestine) compartments of wild-t ... | 2009 | 19201885 |
| prevalence and characterization of salmonellae in commercial ground beef in the united states. | commercially produced ground beef samples (n = 4,136) were collected from seven regions of the united states over a 24-month period (july 2005 to june 2007) and analyzed for the presence of salmonella enterica by using methods that concurrently provided total prevalence and enumerable levels. the overall prevalence of salmonella strains was 4.2%. enumeration showed that 94.2% were present at levels below 2 cfu/g. regional monthly prevalences of salmonella strains varied from 1.8% to 6.5% but wer ... | 2009 | 19201965 |
| gfp plasmid-induced defects in salmonella invasion depend on plasmid architecture, not protein expression. | we have investigated the impact of plasmids and gfp expression on invasion of cultured epithelial cells by salmonella enterica typhimurium strain sl1344. the invasiveness of sl1344 carrying plasmids derived from pbr322, encoding promoterless gfp or constitutively expressed rpsm-gfp, was compared under optimal growth conditions with that of sl1344(pbr322), unmodified sl1344 and a strain with chromosome-integrated rpsm-gfp. the strain carrying pbr322 exhibited normal invasion, but the presence of ... | 2009 | 19202094 |
| surface display of the receptor-binding domain of the f17a-g fimbrial adhesin through the autotransporter aida-i leads to permeability of bacterial cells. | surface exposure of antigens on bacterial cells can be critical for eliciting an effective antibody response. therefore, we investigated the cellular localization of the fimbrial f17a-g receptor-binding domain, fused to the translocator domain of the aida-i autotransporter. synthesis of the fusion protein, under the control of the l-arabinose-inducible pbad promoter, was shown to permeabilize escherichia coli k-12 and salmonella enterica serovar typhimurium cells. the presence of permeable cells ... | 2009 | 19202095 |
| a novel phop-regulated locus encoding the cytolysin clya and the secreted invasin taia of salmonella enterica serovar typhi is involved in virulence. | salmonella enterica serovar typhi causes a human-restricted systemic infection called typhoid fever. we have identified a typhi genomic region encoding two orfs, sty1498 and sty1499, that are expressed during infection of human macrophages and organized in an operon. sty1498 corresponds to clya, which encodes a pore-forming cytolysin, and sty1499 encodes a 27 kda protein, without any attributed function, which we have named taia (typhi-associated invasin a). in order to evaluate the roles of the ... | 2009 | 19202096 |
| effects of mesalamine (5-aminosalicylic acid) on bacterial gene expression. | 5-aminosalicylic acid (5-asa) is a well-established treatment for inflammatory bowel disease (ibd) and may reduce the risk of colon cancer in patients with chronic colitis, but the mechanisms underlying these effects have not been fully elucidated. although 5-asa delivery is targeted to the distal gut, little is known about its effects on the luminal bacteria that reside there. intestinal bacteria are believed play a role in causing or perpetuating ibd, and bioremediation has been studied as a t ... | 2009 | 19202572 |
| inc a/c plasmids are prevalent in multidrug-resistant salmonella enterica isolates. | bacterial plasmids are fragments of extrachromosomal double-stranded dna that can contain a variety of genes that are beneficial to the host organism, like those responsible for antimicrobial resistance. the objective of this study was to characterize a collection of 437 salmonella enterica isolates from different animal sources for their antimicrobial resistance phenotypes and plasmid replicon types and, in some cases, by pulsed-field gel electrophoresis (pfge) in an effort to learn more about ... | 2009 | 19181840 |
| salmonella enterica serotype typhimurium std fimbriae bind terminal alpha(1,2)fucose residues in the cecal mucosa. | the std operon encodes a fimbrial adhesin of salmonella enterica serotype typhimurium that is required for attachment to intestinal epithelial cells and for cecal colonization in the mouse. to study the mechanism by which this virulence factor contributes to colonization we characterized its binding specificity. std-mediated binding to human colonic epithelial (caco-2) cells could be abrogated by removing n-linked glycans. adherence of std fimbriated s. typhimurium to caco-2 cells could be block ... | 2009 | 19183274 |
| anthrax protective antigen delivered by salmonella enterica serovar typhi ty21a protects mice from a lethal anthrax spore challenge. | bacillus anthracis, the etiological agent of anthrax disease, is a proven weapon of bioterrorism. currently, the only licensed vaccine against anthrax in the united states is ava biothrax, which, although efficacious, suffers from several limitations. this vaccine requires six injectable doses over 18 months to stimulate protective immunity, requires a cold chain for storage, and in many cases has been associated with adverse effects. in this study, we modified the b. anthracis protective antige ... | 2009 | 19179420 |
| control of foodborne pathogens and soft-rot bacteria on bell pepper by three strains of bacterial antagonists. | forty-two representative strains of native bacteria associated with fresh peeled baby carrots were isolated and characterized. two of these strains, identified as pseudomonas fluorescens ag3a (pf ag3a) and bacillus yd1, were evaluated in conjunction with another known antagonist, p. fluorescens 2-79 (pf 2-79), for their potential as biocontrol agents of human pathogens (listeria monocytogenes, yersinia enterocolitica, salmonella enterica, and escherichia coli o157:h7) and soft-rot bacteria (erwi ... | 2009 | 19205468 |
| a method for investigating protein-protein interactions related to salmonella typhimurium pathogenesis. | we successfully modified an existing method to investigate protein-protein interactions in the pathogenic bacterium salmonella enterica serovar typhimurium (salmonella typhimurium). this method includes (i) addition of a histidine-biotin-histidine tag to the bait proteins via recombinant dna techniques, (ii) in vivo cross-linking with formaldehyde, (iii) tandem affinity purification of bait proteins under fully denaturing conditions, and (iv) identification of the proteins cross-linked to the ba ... | 2009 | 19206470 |
| pathogen trafficking pathways and host phosphoinositide metabolism. | phosphoinositide (pi) glycerolipids are key regulators of eukaryotic signal transduction, cytoskeleton architecture and membrane dynamics. the host cell pi metabolism is targeted by intracellular bacterial pathogens, which evolved intricate strategies to modulate uptake processes and vesicle trafficking pathways. upon entering eukaryotic host cells, pathogenic bacteria replicate in distinct vacuoles or in the host cytoplasm. vacuolar pathogens manipulate pi levels to mimic or modify membranes of ... | 2009 | 19208094 |
| hydrophobic peptides: novel regulators within bacterial membrane. | identification of short coding sequences is challenging, both experimentally and in silico, and functional natural peptides (< 50 amino acids) have to a large extent been overlooked in gram-negative bacteria. recent results have converged to highlight the role of hydrophobic peptides that form a novel class of active molecules in escherichia coli and salmonella enterica serovar typhimurium. these peptides can play a regulatory role by interacting with protein partners at the inner membrane and b ... | 2009 | 19210615 |
| sequence analysis of escherichia coli o157:h7 bacteriophage phiv10 and identification of a phage-encoded immunity protein that modifies the o157 antigen. | bacteriophage phiv10 is a temperate phage, which specifically infects escherichia coli o157:h7. the nucleotide sequence of the phiv10 genome is 39 104 bp long and contains 55 predicted genes. phiv10 is closely related to two previously sequenced phages, the salmonella enterica serovar anatum (group e1) phage epsilon15 and a prophage from e. coli apec o1. the attachment site of phiv10, like those of its two closest relatives, overlaps the 3' end of guaa in the host chromosome. phiv10 encodes an o ... | 2009 | 19210675 |
| antimicrobial properties of the equine alpha-defensin defa1 against bacterial horse pathogens. | defensins are small effector molecules of the innate immune system, synthesised by various organisms including plants and animals. the peptides act as endogenous antibiotics with an antimicrobial activity against a broad spectrum of microbes including bacteria, fungi and viruses. alpha-defensins are a subgroup of the defensin family, their synthesis is limited to some tissues and furthermore to some mammalian species including the horse. equine defa1 is an enteric alpha-defensin exclusively prod ... | 2009 | 19211153 |
| re-emerging chloramphenicol sensitivity and emerging low level ciprofloxacin resistance among salmonella enterica serotype typhi isolates in north india. | ciprofloxacin has become the antibiotic of choice for the treatment of typhoid fever with the emergence and worldwide spread of salmonella enterica typhi strains resistant to chloramphenicol. however, the rampant use of ciprofloxacin gradually led to an increase in its minimum inhibitory concentration against s. enterica typhi. this threatened its therapeutic efficacy and resulted in the re-emergence of chloramphenicol-sensitive s. enterica typhi strains. | 2009 | 19211419 |
| effect of a direct-fed microbial (primalac) on structure and ultrastructure of small intestine in turkey poults. | the effects of dietary supplementation of the direct-fed microbial (dfm) primalac in mash or crumbled feed on histological and ultrastructural changes of intestinal mucosa was determined in 2 populations of poults; 1 with and 1 without a salmonella spp. challenge. three hundred thirty-six 1-d-old female large white turkey poults were randomly distributed into 8 treatment groups with 6 replicates of 7 poults in each pen. the poults were placed on 1 of 4 dietary treatments in a 2 x 2 x 2 factorial ... | 2009 | 19211517 |
| effects of allspice, cinnamon, and clove bud essential oils in edible apple films on physical properties and antimicrobial activities. | essential oils (eos) derived from plants are rich sources of volatile terpenoids and phenolic compounds. such compounds have the potential to inactivate pathogenic bacteria on contact and in the vapor phase. edible films made from fruits or vegetables containing eos can be used commercially to protect food against contamination by pathogenic bacteria. eos from cinnamon, allspice, and clove bud plants are compatible with the sensory characteristics of apple-based edible films. these films could e ... | 2009 | 19895483 |
| antibacterial effects of allspice, garlic, and oregano essential oils in tomato films determined by overlay and vapor-phase methods. | physical properties as well as antimicrobial activities against escherichia coli o157:h7, salmonella enterica, and listeria monocytogenes of allspice, garlic, and oregano essential oils (eos) in tomato puree film-forming solutions (tpffs) formulated into edible films at 0.5% to 3% (w/w) concentrations were investigated in this study. antimicrobial activities were determined by 2 independent methods: overlay of the film on top of the bacteria and vapor-phase diffusion of the antimicrobial from th ... | 2009 | 19895486 |
| ceftazidime-resistant salmonella enterica, morocco. | 2009 | 19861080 | |
| case report of pediatric gastroenteritis due to ctx-m-15 extended-spectrum beta-lactamase-producing salmonella enterica serotype enteritidis. | a clinical isolate of salmonella enterica serotype enteritidis in korea was found to produce the extended-spectrum beta-lactamase ctx-m-15. the isolate was recovered in 2008 from the stool of a 3-yr-old boy with gastroenteritis. this isolate was found to be resistant to multiple drugs, including ampicillin, piperacillin, cefotaxime, ceftazidime, cefepime, and aztreonam. the resistance to cefotaxime was transferred by conjugation to recipient escherichia coli j53. the patient was eventually succe ... | 2009 | 19893356 |
| multi-immunogenic outer membrane vesicles derived from an msbb-deficient salmonella enterica serovar typhimurium mutant. | to develop low endotoxic and multi-immunogenic outer membrane vesicles (omvs), a deletion mutant of the msbb gene in salmonella enterica serovar typhimurium (s. typhimurium) was used as a source of low endotoxic omv, and an expression vector of the canine parvovirus (cpv) vp2 epitope fused to the bacterial ompa protein was constructed and transformed into the salmonella deltaamsbb mutant. in a lethality test, balb/c mice injected intraperitoneally with the salmonella deltaamsbb mutant survived f ... | 2009 | 19884791 |
| antimicrobial resistance genes in salmonella enterica isolates from poultry and swine in thailand. | a total of 184 resistant salmonella enterica isolated from poultry and swine were investigated for the distribution of and associations between various antimicrobial resistance genes. all the isolates were screened for the presence of class 2 and 3 integrase genes and 18 resistance genes corresponding to their resistance phenotypes. none of the isolates carried class 2 and 3 integrons. the investigated resistance genes were responsible for resistance in 78% of the isolates. all the strains harbo ... | 2009 | 19887742 |
| genotyping, plasmid analysis, and antimicrobial susceptibility of salmonella enterica serotype enteritidis isolates from humans and chickens in central taiwan. | salmonella enterica serotype enteritidis (se) is the most frequent etiological agent of human salmonellosis. the molecular epidemiology and antimicrobial susceptibility of human and chicken isolates of se were examined. | 2009 | 19864196 |
| infected abdominal aortic aneurysm caused by nontyphoid salmonella in an immunocompromised patient with rheumatoid arthritis. | nontyphoid salmonella strains are important pathogens commonly found worldwide, typically causing gastrointestinal illness. here, we report a case of a 66-yearold man with an abdominal aortic infected (or so-called mycotic) aneurysm caused by salmonella enterica subsp. enterica serovar enteritidis (s. enteritidis). he had multiple risk factors for atherosclerosis: age over 60, a long history of smoking, an 8-year history of diabetes mellitus, and a 10-year history of rheumatoid arthritis treated ... | 2009 | 19856069 |
| molecular epidemiology and genetic environment of acquired bla acc-1 in salmonella enterica serotype livingstone causing a large nosocomial outbreak in tunisia. | eighty-four isolates of salmonella enterica serovar livingstone were collected from patients hospitalized in a pediatric ward in sfax hospital (south tunisia). these isolates were responsible for two nosocomial outbreaks in 2000 and 2002. twenty-eight clinical isolates of s. enterica serovar livingstone were also obtained in two other tunisian hospitals in monastir (central tunisia) and tunis (north tunisia), respectively, in 2002 and 2003. pulsed-field gel electrophoresis yielded that these iso ... | 2009 | 19857134 |
| ctx-m-2-producing salmonella typhimurium isolated from pediatric patients and poultry in brazil. | ten salmonella enterica serovar typhimurium isolates producing ctx-m-2 extended-spectrum beta-lactamase were identified from clinical and poultry sources in two distant cities in brazil between 2003 and 2004. they included two isolates from pediatric patients and eight isolates from poultry or its environment. all isolates exhibited coresistance to non-beta-lactam antimicrobials including tetracycline and trimethoprim/sulfamethoxazole. the ctx-m-2 gene was located on transferable plasmids with s ... | 2009 | 19857139 |
| beta-lactam resistance in salmonella strains isolated from retail meats in the united states by the national antimicrobial resistance monitoring system between 2002 and 2006. | ampicillin-resistant (amp(r)) salmonella enterica isolates (n = 344) representing 32 serotypes isolated from retail meats from 2002 to 2006 were tested for susceptibility to 21 other antimicrobial agents and screened for the presence of five beta-lactamase gene families (bla(cmy), bla(tem), bla(shv), bla(oxa), and bla(ctx-m)) and class 1 integrons. among the amp(r) isolates, 66.9% were resistant to five or more antimicrobials and 4.9% were resistant to 10 or more antimicrobials. coresistance to ... | 2009 | 19854922 |
| identification and characterization of a novel antibacterial peptide, avian beta-defensin 2 from ducks. | in this study, a novel avian beta-defensin (avbd) was isolated from duck pancreas. the complete nucleotide sequence of the gene contained an 195 bp open reading frame encoding 64 amino acids. homology, characterization and comparison of the gene with avbd from other avian species confirmed that it was duck avbd2. the mrna expression of the gene was analyzed in 17 tissues from 21-day-old ducks. avbd2 was highly expressed in the trachea, crop, heart, bone marrow, and pancreas; moderately expressed ... | 2009 | 19851734 |
| intracellular concentrations of enrofloxacin in quinolone-resistant salmonella enterica subspecies enterica serovar choleraesuis. | the emergence of fluoroquinolone-resistant strains of salmonella enterica subspecies enterica serovar choleraesuis is an important concern in several countries, including japan. we examined the intracellular concentration of enrofloxacin in s. choleraesuis to determine the existence of a relationship with the emergence of quinolone resistance. the intracellular concentration of enrofloxacin was significantly lower in nalidixic acid-resistant isolates compared with nalidixic acid-susceptible isol ... | 2009 | 19733466 |
| multistate outbreak of salmonella infections associated with small turtle exposure, 2007-2008. | turtle-associated salmonellosis was increasingly recognized in the united states during the 1960s, leading to a federal ban in 1975 on the sale of turtles <4 inches in carapace length (small turtles). although sporadic reports of turtle-associated salmonella are frequent, outbreaks are rare. in september 2007, several patients with salmonella enterica serotype paratyphi b var java infections reported recent turtle exposure. we conducted an investigation to determine the source and extent of the ... | 2009 | 19841114 |
| ndp52: the missing link between ubiquitinated bacteria and autophagy. | mammalian cells ubiquitinate bacteria that erroneously enter the cytosol and target these intruding microbes for destruction by autophagy. new work shows that the protein ndp52 directly binds to ubiquitinated bacteria and facilitates the assembly of an autophagic membrane that surrounds these invaders. | 2009 | 19841643 |
| the synergistic activity of triclosan and ciprofloxacin on biofilms of salmonella typhimurium. | triclosan is a biocide whose wide use has raised a debate about the potential benefits vs. hazards of the incorporation of antimicrobials in consumer products. the purpose of the present study was to determine whether exposure of biofilms of salmonella enterica serovar typhimurium to triclosan influences the tolerance of the bacteria towards antibiotics such as ciprofloxacin and vice versa. a synergistic antibiofilm activity was observed when the biofilms were treated with triclosan before or to ... | 2009 | 19843306 |
| identification of salmonella enterica subspecies i, salmonella enterica serovars typhimurium, enteritidis and typhi using multiplex pcr. | this study was designed to develop a multiplex pcr method with five specific primer pairs for the detection of salmonella spp., salmonella subspecies i, salmonella enterica serovars typhimurium, typhi and enteritidis. a multiplex pcr was constructed with five primer pairs for the detection of salmonella and pathogenic salmonella serovars, including a specific primer pair for salmonella typhi, based on the sequence comparison between genomic dna sequences of 12 salmonella strains. each primer pai ... | 2009 | 19843307 |
| induction of cxc chemokine messenger-rna expression in chicken oviduct epithelial cells by salmonella enterica serovar enteritidis via the type three secretion system-1. | the messenger-rna (mrna) expression of selected cytokines and chemokines in primary chicken oviduct epithelial cells (coec) was determined following in vitro infections with wild-type or type three secretion system (t3ss)-mutant salmonella enterica serovar enteritidis (se) strains. all se strains examined in this study elicited the expression of proinflammatory immune mediators including inducible nitric oxide synthase (inos), cxcli1 (k60), cxcli2 (il-8), ccli3 (k203), and ccli4 (mip-1beta). se ... | 2009 | 19848079 |
| effect of x-ray treatments on inoculated escherichia coli o157: h7, salmonella enterica, shigella flexneri and vibrio parahaemolyticus in ready-to-eat shrimp. | this study was conducted to evaluate the inactivation effect of x-ray treatments on escherichia coli o157: h7, salmonella enteric (s. enterica), shigella flexneri (s. flexneri) and vibrio parahaemolyticus (v. parahaemolyticus) artificially inoculated in ready-to-eat (rte) shrimp. a mixed culture of three strains of each tested pathogen was used to inoculate rte shrimp. the shrimp samples were inoculated individually with selected pathogenic bacteria then aseptically placed in sterile plastic cup ... | 2009 | 19835772 |
| comparative analysis of acid resistance in listeria monocytogenes and salmonella enterica strains before and after exposure to poultry decontaminants. role of the glutamate decarboxylase (gad) system. | data on the ability of chemical poultry decontaminants to induce an acid stress response in pathogenic bacteria are lacking. this study was undertaken in order to compare the survival rates in acid broths of listeria monocytogenes and salmonella enterica strains, both exposed to and not exposed to decontaminants. the contribution of the glutamate decarboxylase (gad) acid resistance system to the survival of bacteria in acid media was also examined. four strains (l. monocytogenes serovar 1/2, l. ... | 2009 | 19835779 |
| rpos- and crp-dependent transcriptional control of salmonella typhi taia and hlye genes: role of environmental conditions. | a novel pathogenicity island, spi-18, carries the taia-hlye operon, encoding virulence factors in salmonella typhi. to determine the effects of certain environmental conditions on the expression of these genes, beta-galactosidase assays, rt-pcr reactions, western blot analyses and measurement of hemolytic activity were performed. the conditions studied are those likely found by s. typhi during infection in the human host. we found rpos-dependent transcriptional upregulation in low ph and high os ... | 2009 | 19835951 |
| [serovars of salmonella enterica subspecies enterica and its antimicrobial resistance in slaughterhouse pigs]. | a study was carried out in order to determine the prevalence of salmonella and its serovars among porcine slaughterhouses, to evaluate the antimicrobial resistance profiles and to know the presence of class 1 integrons as possible reservoir of resistance. from a total of 386 samples from four porcine slaughterhouses of buenos aires and santa fe provinces (argentina), 93 (24.1%) salmonella enterica subspecies enterica strains were identified, 52 (55.9%) from cecal contents and 41 (44.1%) from ile ... | 2009 | 19831314 |
| simultaneous enrichment of shiga toxin-producing escherichia coli o157 and o26 and salmonella in food samples using universal preenrichment broth. | universal preenrichment broth (upb) was compared with modified escherichia coli broth with novobiocin (mec+n) for enrichment of shiga toxin-producing e. coli o157 and o26, and with buffered peptone water (bpw) for preenrichment of salmonella enterica. ten strains each of the three pathogens were inoculated into beef and radish sprouts following thermal, freezing, or no treatment. with regard to o157 and o26, upb incubated at 42 degrees c recovered significantly more cells from inoculated beef th ... | 2009 | 19833028 |
| isolation of salmonella enterica in laying-hen flocks and assessment of eggshell contamination in france. | the present investigation was conducted in conjunction with the european union baseline study for the estimation of salmonella prevalence in laying-hen flocks. it aimed at evaluating eggshell contamination in farms positive for salmonella, characterizing the genetic patterns of salmonella strains and identifying the factors associated with salmonella contamination of eggshells. for this purpose, a total of 4,200 eggs were collected from 28 positive flocks and analyzed according to draft annex d ... | 2009 | 19833029 |
| a rapid screen of broth enrichments for salmonella enterica serovars enteritidis, hadar, heidelberg, and typhimurium by using an allelotyping multiplex pcr that targets o- and h-antigen alleles. | salmonella continues to cause significant foodborne outbreaks, best illustrated with recent outbreaks associated with peanut butter, raw tomatoes, and serrano peppers. to ascertain the likely source of the outbreak, bacterial typing is essential to this process. while pcr has become an important detection tool for pathogens in foods, pcr can also identify strain differences by targeting gene(s) or sequences exhibiting polymorphisms or variability in its distribution within the bacterial populati ... | 2009 | 19833046 |
| changes of physiological and biochemical properties of salmonella enterica serovar typhimurium by deletion of cpxr and lon genes using allelic exchange method. | to construct a novel salmonella attenuated live vaccine, the cpxr and lon genes were deleted from a wild-type salmonella enterica serovar typhimurium (s. typhimurium) using allelic exchange method, resulting in s. typhimurium ck31 (deltacpxr), ck38 (deltalon), and ck111 (deltacpxr/lon). these mutated strains were grown normally, as was the wild-type strain. the biochemical properties of the mutants remained highly similar to those of the wild-type. in comparison with the wild-type, 1.5 to 3.3-fo ... | 2009 | 19833153 |
| evidence for il-6 promoter nuclear activation in u937 cells stimulated with salmonella enterica serovar typhimurium porins. | interleukin-6 (il-6) is a pleiotropic cytokine and plays an active role in inflammatory and immune responses, contributing to a multitude of physiological and pathophysiological processes. in this study, we address the molecular mechanism of il-6 transcriptional induction and propose a correlation between activated nf-kappab localization and il-6 expression. in particular, we detected, by chip assay, that occupation of the il-6 gene promoter site is dependent on activated nf-kappab. in fact, aft ... | 2009 | 19825524 |
| simultaneous assay of every salmonella typhi gene using one million transposon mutants. | very high-throughput sequencing technologies need to be matched by high-throughput functional studies if we are to make full use of the current explosion in genome sequences. we have generated a very large bacterial mutant pool, consisting of an estimated 1.1 million transposon mutants and we have used genomic dna from this mutant pool, and illumina nucleotide sequencing to prime from the transposon and sequence into the adjacent target dna. with this method, which we have called tradis (transpo ... | 2009 | 19826075 |
| a novel inhibitor of chlamydophila pneumoniae protein kinase d (pknd) inhibits phosphorylation of cdsd and suppresses bacterial replication. | we have shown previously that chlamydophila pneumoniae contains a dual-specific ser/thr protein kinase that phosphorylates cdsd, a structural component of the type iii secretion apparatus. to further study the role of pknd in growth and development we sought to identify a pknd inhibitor to determine whether pknd activity is required for replication. | 2009 | 19828035 |
| characteristics and dynamics of salmonella contamination along the coast of agadir, morocco. | the occurrence of salmonella enterica in the environment of tropical and desert regions has remained largely uninvestigated in many areas of the world, including africa. in the present study, we investigated the presence of salmonella spp. along 122 km of the coastline of agadir (southern morocco) in relation to environmental parameters. a total of 801 samples of seawater (243), marine sediment (279), and mussels (279) were collected from six sites between july 2004 and may 2008. the overall pre ... | 2009 | 19820155 |
| the tbk1 adaptor and autophagy receptor ndp52 restricts the proliferation of ubiquitin-coated bacteria. | cell-autonomous innate immune responses against bacteria attempting to colonize the cytosol of mammalian cells are incompletely understood. polyubiquitylated proteins can accumulate on the surface of such bacteria, and bacterial growth is restricted by tank-binding kinase (tbk1). here we show that ndp52, not previously known to contribute to innate immunity, recognizes ubiquitin-coated salmonella enterica in human cells and, by binding the adaptor proteins nap1 and sintbad, recruits tbk1. knockd ... | 2009 | 19820708 |
| thioredoxin 1 participates in the activity of the salmonella enterica serovar typhimurium pathogenicity island 2 type iii secretion system. | the facultative intracellular pathogen salmonella enterica serovar typhimurium relies on its salmonella pathogenicity island 2 (spi2) type iii secretion system (t3ss) for intracellular replication and virulence. we report that the oxidoreductase thioredoxin 1 (trxa) and spi2 are coinduced for expression under in vitro conditions that mimic an intravacuolar environment, that trxa is needed for proper spi2 activity under these conditions, and that trxa is indispensable for spi2 activity in both ph ... | 2009 | 19767428 |
| a protein important for antimicrobial peptide resistance, ydei/omda, is in the periplasm and interacts with ompd/nmpc. | antimicrobial peptides (amps) kill or prevent the growth of microbes. amps are made by virtually all single and multicellular organisms and are encountered by bacteria in diverse environments, including within a host. bacteria use sensor-kinase systems to respond to amps or damage caused by amps. salmonella enterica deploys at least three different sensor-kinase systems to modify gene expression in the presence of amps: phop-phoq, pmra-pmrb, and rcsb-rcsc-rcsd. the ydei gene is regulated by the ... | 2009 | 19767429 |
| functional characterization of ssae, a novel chaperone protein of the type iii secretion system encoded by salmonella pathogenicity island 2. | the type iii secretion system (t3ss) encoded by salmonella pathogenicity island 2 (spi-2) is involved in systemic infection and intracellular replication of salmonella enterica serovar typhimurium. in this study, we investigated the function of ssae, a small cytoplasmic protein encoded within the spi-2 locus, which shows structural similarity to the t3ss class v chaperones. an s. enterica serovar typhimurium ssae mutant failed to secrete spi-2 translocator sseb and spi-2-dependent effector pipb ... | 2009 | 19767440 |
| salmonella--the ultimate insider. salmonella virulence factors that modulate intracellular survival. | salmonella enterica serovar typhimurium is a common facultative intracellular pathogen that causes food-borne gastroenteritis in millions of people worldwide. intracellular survival and replication are important virulence determinants and the bacteria can be found in a variety of phagocytic and non-phagocytic cells in vivo. invasion of host cells and intracellular survival are dependent on two type iii secretion systems, t3ss1 and t3ss2, each of which translocates a distinct set of effector prot ... | 2009 | 19775254 |
| the plague of athens: epidemiology and paleopathology. | in 430 bc, a plague struck the city of athens, which was then under siege by sparta during the peloponnesian war (431-404 bc). in the next 3 years, most of the population was infected, and perhaps as many as 75,000 to 100,000 people, 25% of the city's population, died. the athenian general and historian thucydides left an eye-witness account of this plague and a detailed description to allow future generations to identify the disease should it break out again. because of the importance of thucyd ... | 2009 | 19787658 |
| salmonella enterica serovar typhi with ctx-m beta-lactamase, germany. | 2009 | 19788837 | |
| diagnosis of endotoxemia with gram-negative bacteremia is bacterial species dependent: a meta-analysis of clinical studies. | endotoxemia is undetectable for up to 60% of cases of bacteremia caused by gram-negative (gn) species, a discordance attributed to the limitations of the limulus assay for endotoxemia. the lipid a structure of the endotoxin molecule is critical for the sensing of gn bacteria by the host immune system although not so for sensing by the limulus assay. the lipid a structure of commensal enterobacteriaceae is hexa-acyl, whereas non-enterobacteriaceae have a broader range of structures. by using a pr ... | 2009 | 19794055 |
| bacterial growth rate and host factors as determinants of intracellular bacterial distributions in systemic salmonella enterica infections. | bacteria of the species salmonella enterica cause a range of life-threatening diseases in humans and animals worldwide. the within-host quantitative, spatial, and temporal dynamics of s. enterica interactions are key to understanding how immunity acts on these infections and how bacteria evade immune surveillance. in this study, we test hypotheses generated from mathematical models of in vivo dynamics of salmonella infections with experimental observation of bacteria at the single-cell level in ... | 2009 | 19797065 |
| effect of the o-antigen length of lipopolysaccharide on the functions of type iii secretion systems in salmonella enterica. | the virulence of salmonella enterica critically depends on the functions of two type iii secretion systems (t3ss), with the salmonella pathogenicity island 1 (spi1)-encoded t3ss required for host cell invasion and the spi2-t3ss enabling salmonella to proliferate within host cells. a further t3ss is required for the assembly of the flagella. most serovars of salmonella also possess a lipopolysaccharide with a complex o-antigen (oag) structure. the number of oag units attached to the core polysacc ... | 2009 | 19797066 |
| superior protective immunity against murine listeriosis by combined vaccination with cpg dna and recombinant salmonella enterica serovar typhimurium. | preexisting antivector immunity can severely compromise the ability of salmonella enterica serovar typhimurium live vaccines to induce protective cd8 t-cell frequencies after type iii secretion system-mediated heterologous protein translocation in orally immunized mice. to circumvent this problem, we injected cpg dna admixed to the immunodominant p60(217-225) peptide from listeria monocytogenes subcutaneously into balb/c mice and coadministered a p60-translocating salmonella strain by the orogas ... | 2009 | 19797070 |
| dsbl and dsbi contribute to periplasmic disulfide bond formation in salmonella enterica serovar typhimurium. | disulfide bond formation in periplasmic proteins is catalysed by the dsba/dsbb system in most gram-negative bacteria. salmonella enterica serovar typhimurium also encodes a paralogous pair of proteins to dsba and dsbb, dsbl and dsbi, respectively, downstream of a periplasmic arylsulfate sulfotransferase (asst). we show that dsbl and dsbi function as a redox pair contributing to periplasmic disulfide bond formation and, as such, affect transcription of the salmonella pathogenicity island 1 (spi1) ... | 2009 | 19797361 |
| edible apple film wraps containing plant antimicrobials inactivate foodborne pathogens on meat and poultry products. | apple-based edible films containing plant antimicrobials were evaluated for their activity against pathogenic bacteria on meat and poultry products. salmonella enterica or e. coli o157:h7 (10(7) cfu/g) cultures were surface inoculated on chicken breasts and listeria monocytogenes (10(6) cfu/g) on ham. the inoculated products were then wrapped with edible films containing 3 concentrations (0.5%, 1.5%, and 3%) of cinnamaldehyde or carvacrol. following incubation at either 23 or 4 degrees c for 72 ... | 2009 | 19799671 |
| activated by different signals, the phop/phoq two-component system differentially regulates metal uptake. | the phop/phoq two-component system controls several physiological and virulence functions in salmonella enterica. this system is activated by low mg(2+), acidic ph, and antimicrobial peptides, but the biological consequences resulting from sensing multiple signals are presently unclear. here, we report that the phop/phoq system regulates different salmonella genes depending on whether the inducing signal is acidic ph or low mg(2+). when salmonella experiences acidic ph, the phop/phoq system prom ... | 2009 | 19801407 |
| analysis of the variability in the number of viable bacteria after mild heat treatment of food. | variability in the numbers of bacteria remaining in saline solution and whole milk following mild heat treatment has been studied with listeria innocua, enterococcus faecalis, salmonella enterica serovar enteritidis, and pseudomonas fluorescens. as expected, the most heat-resistant bacterium was e. faecalis, while p. fluorescens was the least heat resistant, and all bacteria showed greater thermal resistance in whole milk than in saline solution. despite the differences in the inactivation kinet ... | 2009 | 19801476 |
| neonatal sepsis due to salmonella typhi and paratyphi a. | sepsis due to salmonella enterica serovar typhi and paratyphi a is rare in neonates. though described as a mild and unrecognized illness in infants, life-threatening complications and even deaths have been reported. we present five cases of neonatal septicaemia due to s. typhi and s. paratyphi a. the cases were presented because of their interesting clinical presentations and possible modes of transmission. salmonella infections should be considered in the differential diagnosis of sepsis neonat ... | 2009 | 19801808 |
| autophagy in immunity against intracellular bacteria. | autophagy is an innate immune defense mechanism against various intracellular bacterial pathogens, such as salmonella enterica serovar typhimurium (s. typhimurium), listeria monocytogenes and shigella flexneri. s. typhimurium uses type three secretion systems (t3sss) to invade mammalian cells and replicate in salmonella-containing vacuoles (scvs). a small population of intracellular s. typhimurium is targeted by autophagy shortly after infection. evidence suggests that these bacteria are present ... | 2009 | 19802566 |
| a coiled-coil motif that sequesters ions to the hydrophobic core. | most core residues of coiled coils are hydrophobic. occasional polar residues are thought to lower stability, but impart structural specificity. the coiled coils of trimeric autotransporter adhesins (taas) are conspicuous for their large number of polar residues in position d of the core, which often leads to their prediction as natively unstructured regions. the most frequent residue, asparagine (n@d), can occur in runs of up to 19 consecutive heptads, frequently in the motif [i/v]xxntxx. in th ... | 2009 | 19805097 |
| increased expression of mg(2+) transport proteins enhances the survival of salmonella enterica at high temperature. | mg(2+) homeostasis is important for salmonella pathogenesis. in salmonella enterica, the transcription of the mgta gene, which encodes a mg(2+) transporter, is regulated by a mg(2+)-sensing riboswitch [cromie mj, shi y, latifi t, groisman ea (2006) cell 125:71-84]. in a genetic analysis of the determinants of thermotolerance in s. enterica serovar typhimurium, we isolated the chr-1 mutation that increased the resistance of exponential phase cells to killing by high temperature. this mutation is ... | 2009 | 19805196 |
| the long-lived nature of clostridium perfringens iota toxin in mammalian cells induces delayed apoptosis. | mono-adp ribosylation of actin by bacterial toxins, such as clostridium perfringens iota or clostridium botulinum c2 toxins, results in rapid depolymerization of actin filaments and cell rounding. here we report that treatment of african green monkey kidney (vero) cells with iota toxin resulted in delayed caspase-dependent death. unmodified actin did not reappear in toxin-treated cells, and enzyme-active toxin was detectable in the cytosol for at least 24 h. c2 toxin showed comparable, long-live ... | 2009 | 19805536 |
| regulated delayed expression of rfah in an attenuated salmonella enterica serovar typhimurium vaccine enhances immunogenicity of outer membrane proteins and a heterologous antigen. | rfah is a transcriptional antiterminator that reduces the polarity of long operons encoding secreted and surface-associated cell components of salmonella enterica serovar typhimurium, including o antigen and lipopolysaccharide core sugars. a deltarfah mutant strain is attenuated in mice (50% lethal dose [ld(50)], >10(8) cfu). to examine the potential for using rfah in conjunction with other attenuating mutations, we designed a series of strains in which we replaced the native rfah promoter with ... | 2009 | 19805538 |