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baer protein from salmonella enterica serovar paratyphi a induces inflammatory response in murine and human cell lines.baer is the response regulator of the two-component system, baesr, found in escherichia coli (e. coli) and salmonella. several biological functions of baer, related to multidrug efflux and bacterial virulence, have been described. herein, we report a putative function of baer during inflammatory response of the host by using baer protein of salmonella enterica paratyphi a (s. paratyphi a) origin overexpressed in e. coli, and raw 264.7 and thp-1 cells as in vitro models. baer (3 μg/ml) upregulate ...201324055826
design of a core-shell type immuno-magnetic separation system and multiplex pcr for rapid detection of pathogens from food samples.we report an immuno-magnetic separation system developed by the immobilization of pathogen-specific antibodies on the core-shell magnetic beads. the magnetic beads were grafted with glycidylmethacrylate (gma) using surface-initiated atom transfer radical polymerization (si-atrp). for immuno-magnetic separation (ims) of target bacterial cells from others, antibodies for escherichia coli and salmonella enterica serovar typhimurium cells were immobilized on the magnetic beads via glutaraldehyde cou ...201324048640
bacterial tir-containing proteins and host innate immune system evasion.the innate immune system provides the first line of host defence against invading pathogens. key to upregulation of the innate immune response are toll-like receptors (tlrs), which recognize pathogen-associated molecular patterns (pamps) and trigger a signaling pathway culminating in the production of inflammatory mediators. central to this tlr signaling pathway are heterotypic protein-protein interactions mediated through toll/interleukin-1 receptor (tir) domains found in both the cytoplasmic r ...201322772799
unique n-terminal arm of mycobacterium tuberculosis phop protein plays an unusual role in its regulatory function.mycobacterium tuberculosis phop, a master regulator involved in complex lipid biosynthesis and expression of unknown virulence determinants, is composed of an n-terminal receiver domain and a c-terminal effector domain. the two experimentally characterized phop orthologs, from escherichia coli and salmonella enterica, display vastly different regulatory capabilities. here, we demonstrate that the 20-residue-long n-terminal arm unique to m. tuberculosis phop plays an essential role in the expande ...201323963455
a whole-cell biosensor for the detection of gold.geochemical exploration for gold (au) is becoming increasingly important to the mining industry. current processes for au analyses require sampling materials to be taken from often remote localities. samples are then transported to a laboratory equipped with suitable analytical facilities, such as inductively coupled plasma-mass spectrometry (icp-ms) or instrumental neutron activation analysis (inaa). determining the concentration of au in samples may take several weeks, leading to long delays i ...201323950889
optimization of antimicrobial combined effect of organic acids and temperature on foodborne salmonella and escherichia coli in cattle feed by response surface methodology.despite the importance of feedstuffs and feed ingredients in the food chain, few studies have analyzed the effectiveness of usual methods for the microbial decontamination of feeds. this work aimed to study the combined effect of temperature and organic acids (formic or lactic) on the inactivation of 10 isolates of salmonella enterica and escherichia coli obtained from vegetable feed ingredients, including cereals and other processed materials, in cattle feed. a central composite design was used ...201323941518
modulators of antibiotic activity from ipomoea murucoides.reinvestigation of the chcl3-soluble extract from the flowers of ipomoea murucoides, through preparative-scale recycling hplc, yielded three pentasaccharides of 11-hydroxyhexadecanoic acid, murucoidins xvii-xix, in addition to the known murucoidin iii and v, all of which were characterized by nmr spectroscopy and mass spectrometry. these compounds were found to be macrolactones of the known pentasaccharides simonic acid b and operculinic acid a. the acylating groups corresponded to acetic, (2s)- ...201323920226
effects of subtherapeutic concentrations of antimicrobials on gene acquisition events in yersinia, proteus, shigella, and salmonella recipient organisms in isolated ligated intestinal loops of swine.to assess antimicrobial resistance and transfer of virulence genes facilitated by subtherapeutic concentrations of antimicrobials in swine intestines.201323879845
probiotic bacteria reduce salmonella typhimurium intestinal colonization by competing for iron.host inflammation alters the availability of nutrients such as iron to limit microbial growth. however, salmonella enterica serovar typhimurium thrives in the inflamed gut by scavenging for iron with siderophores. by administering escherichia coli strain nissle 1917, which assimilates iron by similar mechanisms, we show that this nonpathogenic bacterium can outcompete and reduce s. typhimurium colonization in mouse models of acute colitis and chronic persistent infection. this probiotic activity ...201323870311
transport and catabolism of the sialic acids n-glycolylneuraminic acid and 3-keto-3-deoxy-d-glycero-d-galactonononic acid by escherichia coli k-12.escherichia coli can transport and catabolize the common sialic acid, n-acetylneuraminic acid (neu5ac), as a sole source of carbon and nitrogen, which is an important mucus-derived carbon source in the mammalian gut. herein we demonstrate that e. coli can also grow efficiently on the related sialic acids, n-glycolylneuraminic acid (neu5gc) and 3-keto-3-deoxy-d-glycero-d-galactonononic acid (kdn), which are transported via the sialic acid transporter nant and catabolized using the sialic acid ald ...201323848303
electrochemical immunoassay for salmonella typhimurium based on magnetically collected ag-enhanced dna biobarcode labels.we describe a sensitive electrochemical immunoassay for salmonella enterica serovar typhimurium, a common foodborne pathogen which can cause infection at extremely small doses. the assay is based on the recognition of dna biobarcode labels by differential pulse anodic stripping voltammetry (dpasv), following ag enhancement. the biobarcodes consist of latex spheres (mean diameter 506 nm ± 22 nm) modified by ferromagnetic fe3o4 particles. each biobarcode is loaded by adsorption with approx. 27 mol ...201323833764
evaluation of the adjuvant effect of salmonella-based escherichia coli heat-labile toxin b subunits on the efficacy of a live salmonella-delivered avian pathogenic escherichia coli vaccine.the present study evaluated the adjuvant effect of live attenuated salmonella organisms expressing the heat-labile toxin of escherichia coli b subunit (ltb) on the efficacy of an avian pathogenic escherichia coli (apec) vaccine. the asd(+) (aspartate semialdehyde dehydrogenase) plasmid pmmp906 containing the ltb gene was introduced into a salmonella enterica typhimurium strain lacking the lon, cpxr and asd genes to generate the adjuvant strain. live recombinant salmonella-delivered apec vaccine ...201323815619
role of antilipopolysaccharide antibodies in serum bactericidal activity against salmonella enterica serovar typhimurium in healthy adults and children in the united states.recent observations from africa have rekindled interest in the role of serum bactericidal antibodies in protecting against systemic infection with salmonella enterica serovar typhimurium. to determine whether the findings are applicable to other populations, we analyzed serum samples collected from healthy individuals in the united states. we found that all but 1 of the 49 adult samples tested had robust bactericidal activity against s. typhimurium in a standard in vitro assay. the activity was ...201323803904
human single-chain urokinase is activated by the omptins pgte of salmonella enterica and pla of yersinia pestis despite mutations of active site residues.fibrinolysis is important in cell migration and tightly regulated by specific inhibitors and activators; of the latter, urokinase (upa) associates with enhancement of cell migration. active upa is formed through cleavage of the single-chain upa (scupa). the salmonella enterica strain 14028r cleaved human scupa at the peptide bond lys158-ile159, the site cleaved also by the physiological activator human plasmin. the cleavage led to activation of scupa, while no cleavage or activation were detecte ...201323763588
proposed model for the high rate of rearrangement and rapid migration observed in some inca/c plasmid lineages.inca/c plasmids are a class of plasmids from the enterobacteriaceae that are relatively large (49 to >180 kbp), that are readily transferred by conjugation, and that carry multiple antimicrobial resistance genes. reconstruction of the phylogeny of these plasmids has been difficult because of the high rate of remodeling by recombination-mediated horizontal gene transfer (hgt). we hypothesized that evaluation of nucleotide polymorphisms relative to the rate of hgt would help to develop a clock to ...201323747695
crystallization and preliminary x-ray analysis of the flagellar motor `brake' molecule ycgr with c-di-gmp from escherichia coli.in escherichia coli and salmonella enterica, bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-gmp), a ubiquitous bacterial second-messenger molecule that participates in many cellular processes, can regulate flagellar motor speed and reduce cell swimming velocity by binding to the pilz-containing protein ycgr. here, the crystallization and preliminary x-ray crystallographic analysis of ycgr with c-di-gmp are reported. the crystals diffracted to 2.3 å resolution and belonged to space grou ...201323722848
genome-wide analysis of the salmonella fis regulon and its regulatory mechanism on pathogenicity islands.fis, one of the most important nucleoid-associated proteins, functions as a global regulator of transcription in bacteria that has been comprehensively studied in escherichia coli k12. fis also influences the virulence of salmonella enterica and pathogenic e. coli by regulating their virulence genes, however, the relevant mechanism is unclear. in this report, using combined rna-seq and chromatin immunoprecipitation (chip)-seq technologies, we first identified 1646 fis-regulated genes and 885 fis ...201323717649
malaria-associated l-arginine deficiency induces mast cell-associated disruption to intestinal barrier defenses against nontyphoidal salmonella bacteremia.coinfection with malaria and nontyphoidal salmonella serotypes (nts) can cause life-threatening bacteremia in humans. coinfection with malaria is a recognized risk factor for invasive nts, suggesting that malaria impairs intestinal barrier function. here, we investigated mechanisms and strategies for prevention of coinfection pathology in a mouse model. our findings reveal that malarial-parasite-infected mice, like humans, develop l-arginine deficiency, which is associated with intestinal mastoc ...201323690397
distribution of extended-spectrum cephalosporin resistance determinants in salmonella enterica and escherichia coli isolated from broilers in southern japan.this study was conducted to investigate the distribution and diversity of extended-spectrum cephalosporin (esc) resistance determinants in salmonella enterica and escherichia coli obtained from the same cecal samples and to provide evidence of transmission of the resistance determinants among these bacteria in broiler farms in southern japan. salmonella enterica and e. coli were characterized by serotyping and multilocus sequence typing, respectively. an antimicrobial susceptibility test, plasmi ...201323687161
the expression of adhesin ef-tu in response to mucin and its role in lactobacillus adhesion and competitive inhibition of enteropathogens to mucin.to analyse the expression of ef-tu in lactobacillus strains with response to mucin exposure and its role in interfering with adhesion of enteropathogens to mucin.201323663754
sensitivity of mycobacterium avium subsp paratuberculosis, escherichia coli and salmonella enterica serotype typhimurium to low ph, high organic acids and ensiling.to evaluate the persistence of mycobacterium avium subsp paratuberculosis (myco. paratuberculosis), salmonella enterica serotype typhimurium (salm.typhimurium) and a commensal escherichia coli (e. coli) isolate under the low ph and high organic acid (oa) conditions of ensiling of forages.201323647636
adjuvant effect of escherichia coli heat labile enterotoxin b subunit against internal egg contamination in domestic fowl immunised with a live salmonella enterica serovar enteritidis vaccine.this study evaluated the effect of salmonella enterica serovar enteritidis (se) secreting escherichia coli heat labile enterotoxin b subunit (ltb) protein as an adjuvant for a live se vaccine (jol919) against virulent se challenge in hens. the eltb gene encoding ltb was inserted into the asd+ β-lactamase signal plasmid pjhl65. this plasmid was transformed into δlonδcpxrδasd se to generate the ltb strain jol1228. one-hundred female domestic fowl were divided into five groups and hens in immunised ...201323642467
characterization of salmonella enterica serovar typhimurium aconitase a.aconitases (acn) are iron-sulfur proteins that catalyse the reversible isomerization of citrate and isocitrate via the intermediate cis-aconitate in the krebs cycle. some acn proteins are bi-functional and under conditions of iron starvation and oxidative stress lose their iron-sulfur clusters and become post-transcriptional regulators by binding specific mrna targets. many bacterial species possess two genetically distinct aconitase proteins, acna and acnb. current understanding of the regulati ...201323637460
macrophage environment turns otherwise mccj25-resistant salmonella into sensitive.microcin j25 (mccj25) is a plasmid-encoded antibiotic peptide produced by escherichia coli (e. coli). mccj25 enters into the sensitive e. coli strains by the outer membrane receptor fhua and the inner membrane proteins tonb, exbb, exbd and sbma. the resistance of salmonella enterica serovar typhimurium (s. typhimurium) to mccj25 is attributed to the inability of its fhua protein to incorporate the antibiotic into the cell.201323634875
[mutagenesis of cysteine residues in dptc from salmonella enteric serovar cerro 87 and its effects on dna phosphorothioate modification].dna phosphorothioate modification (dna sulfur modification, a non-bridging oxygen swapped with a sulfur) exists in diverse bacteria. salmonella enterica serovar cerro 87 is one of the bacteria that harbor the dna sulfur modification. the modification is carried out by the products of a four-membered gene cluster, dptbcde. transformation of escherichia coli dh10b with the dptbcde gene cluster endows the strain with dna sulfur modification capability. deletion of dptc abolished the modification. h ...201323627113
effects of resveratrol and essential oils on growth performance, immunity, digestibility and fecal microbial shedding in challenged piglets.a study was conducted to evaluate the effects of resveratrol and essential oils from medicinal plants on the growth performance, immunity, digestibility, and fecal microbial shedding of weaned piglets. a total of 48 weaned piglets (8 kg initial weight, 28-d-old) were randomly allotted to four dietary treatments with 3 replications of 4 piglets each. the dietary treatments were nc (negative control; basal diet), pc (positive control; basal diet+0.002% apramycin), t1 (basal diet+0.2% resveratrol), ...201325049839
survival of enteric pathogens during butterhead lettuce growth: crop stage, leaf age, and irrigation.the survival of salmonella enterica serovar thompson and escherichia coli o157 was investigated on growing butterhead lettuce plants in the plant-growth chamber and greenhouse. all inoculation tests were made under conditions that approximate the greenhouse conditions for butterhead lettuce cultivation in flanders (belgium). the survival and proliferation of the pathogens on the leaves was determined at days 0, 4, and 8 after inoculation using standard plating techniques on selective medium. in ...201323614801
divergent protein motifs direct elongation factor p-mediated translational regulation in salmonella enterica and escherichia coli.elongation factor p (ef-p) is a universally conserved bacterial translation factor homologous to eukaryotic/archaeal initiation factor 5a. in salmonella, deletion of the efp gene results in pleiotropic phenotypes, including increased susceptibility to numerous cellular stressors. only a limited number of proteins are affected by the loss of ef-p, and it has recently been determined that ef-p plays a critical role in rescuing ribosomes stalled at ppp and ppg peptide sequences. here we present an ...201323611909
prognostic value of endotoxemia in patients with gram-negative bacteremia is bacterial species dependent.the prognostic impact of endotoxemia detection in sepsis is unclear. endotoxemia is detectable in <70% of patients with gram-negative (gn) bacteremias. mortality proportion data were available from 27 published studies of patients with gn bacteremia in various settings. among ten studies restricted to specific types of gn bacteremia, endotoxemia was associated with significantly increased mortality risk for neisseria meningitidis (4 studies; 138 bacteremias; or 26.0; 95% ci, 1.6-321) but not for ...201323594418
evolution of pan-genomes of escherichia coli, shigella spp., and salmonella enterica.multiple sequencing of genomes belonging to a bacterial species allows one to analyze and compare statistics and dynamics of the gene complements of species, their pan-genomes. here, we analyzed multiple genomes of escherichia coli, shigella spp., and salmonella enterica. we demonstrate that the distribution of the number of genomes harboring a gene is well approximated by a sum of two power functions, describing frequent genes (present in many strains) and rare genes (present in few strains). t ...201323585535
comparison of quantitative pcr and flow cytometry as cellular viability methods to study bacterial membrane permeabilization following supercritical co2 treatment.foodborne illness due to bacterial pathogens is increasing worldwide as a consequence of the higher consumption of fresh and minimally processed food products, which are more easily cross-contaminated. the efficiency of food pasteurization methods is usually measured by c.f.u. plate counts, a method discriminating viable from dead cells on the basis of the ability of cells to replicate and form colonies on standard growth media, thus ignoring viable but not cultivable cells. supercritical co2 (s ...201323579687
synergistic effect between colistin and bacteriocins in controlling gram-negative pathogens and their potential to reduce antibiotic toxicity in mammalian epithelial cells.pathogens resistant to most conventional antibiotics are a harbinger of the need to discover novel antimicrobials and anti-infective agents and develop innovative strategies to combat them. the aim of this study was to assess the in vitro activity of colistin alone or in combination with two bacteriocins, nisin a and pediocin pa-1/ach, against salmonella choleraesuis atcc 14028, pseudomonas aeruginosa atcc 27853, yersinia enterocolitica atcc 9610, and escherichia coli atcc 35150 (o157:h7). the s ...201323571533
evolution of inchi1 plasmids: two distinct lineages.the inchi1 plasmid psrc27-h from salmonella enterica serovar typhimurium carries a region containing several genes that confer resistance to different antibiotics, and this resistance region is in the same position as related resistance regions in a group of sequenced inchi1 plasmids from various sources that includes phcm1. four further additional segments are found in phcm1 relative to another inchi1 plasmid, r27. using pcr or dna sequencing to detect the presence or absence of each of these a ...201323567475
characterization of bla(shv) genes on plasmids from escherichia coli and salmonella enterica isolates from canadian food animals (2006-2007).bla(shv) genes from escherichia coli and salmonella enterica isolates from chicken (n = 19) and pork (n = 1) were identified as bla(shv-2) (n = 5) or bla(shv-2a) (n = 15). eighteen were on plasmids of the inci1 (n = 15), incp (n = 2), and incfib (n = 1) incompatibility groups. these plasmids were all transferable by conjugation between e. coli and s. enterica.201323563948
active films based on cocoa extract with antioxidant, antimicrobial and biological applications.novel films of ethylene-vinyl alcohol copolymer (evoh) containing flavonoid-rich cocoa were developed. to understand their potential application as active packaging material, antioxidant and antimicrobial properties of the films were determined as well as the antioxidant activity of the release compounds in caco-2 human epithelial colorectal adenocarcinoma cells. exposure of the films to aqueous food simulant showed antioxidant capacity. the release of cocoa extract components was dependent on t ...201323561077
efficient mobilization of a resistance derivative of pslt, the virulence plasmid specific of salmonella enterica serovar typhimurium, by an inci1 plasmid.puo-stvr2 is a derivative of pslt, the virulence plasmid specific of salmonella enterica serovar typhimurium, which confers multidrug resistance. this plasmid is widespread among closely related isolates of s. typhimurium, and often coexists with other plasmids like pstr12. the latter belongs to incompatibility group inci1, was assigned to st48 by pmlst (plasmid multilocus sequence typing), and confers resistance to streptomycin/spectinomycin, chloramphenicol, trimethoprim and sulphonamides, wit ...201323541844
study of probiotic potential of four wild lactobacillus rhamnosus strains.the four wild lactobacillus rhamnosus strains were examined in vitro for resistance to simulated gastro and intestinal juices, adhesion to ht-29 cells, antagonistic activity against enteric pathogens and immunomodulating activity. the strains l. rhamnosus sb5l, j5l and in1l were able to survive in simulated gastro juice while the strain l. rhamnosus sb31l lost viability exposed to simulated gastro juice for 3 h. the four strains had high viability in simulated small intestinal juice with little ...201323528983
outbreaks associated to large open air festivals, including music festivals, 1980 to 2012.in the minds of many, large scale open air festivals have become associated with spring and summer, attracting many people, and in the case of music festivals, thousands of music fans. these festivals share the usual health risks associated with large mass gatherings, including transmission of communicable diseases and risk of outbreaks. large scale open air festivals have however specific characteristics, including outdoor settings, on-site housing and food supply and the generally young age of ...201323517872
residues at the cytoplasmic end of transmembrane helix 2 determine the signal output of the tarec chemoreceptor.baseline signal output and communication between the periplasmic and cytoplasmic domains of the escherichia coli aspartate chemoreceptor tar(ec) are both strongly influenced by residues at the c-terminus of transmembrane helix 2 (tm2). in particular, the cytoplasmic aromatic anchor, composed of residues trp-209 and tyr-210 in wild-type tar(ec), is important for determining the chea kinase-stimulating activity of the receptor and its ability to respond to chemoeffector-induced stimuli. here, we h ...201323495653
microbial variome database: point mutations, adaptive or not, in bacterial core genomes.analysis of genetic differences (gene presence/absence and nucleotide polymorphisms) among strains of a bacterial species is crucial to understanding molecular mechanisms of bacterial pathogenesis and selecting targets for novel antibacterial therapeutics. however, lack of genome-wide association studies on large and epidemiologically well-defined strain collections from the same species makes it difficult to identify the genes under positive selection and define adaptive polymorphisms in those ...201323493258
recombinant heat shock protein 60 (hsp60/groel) of salmonella enterica serovar typhi elicits cross-protection against multiple bacterial pathogens in mice.heat shock proteins (hsps) or stress proteins are recognized as protective antigens against a wide range of bacterial diseases. conservation of hsps across different life forms also appears to contribute to the antigenicity of these proteins. due to their high sequence homology, there exists an immunological cross-recognition between different bacterial species. in the present study, we evaluated the efficacy of recombinant groel of salmonella enterica serovar typhi as a vaccine candidate agains ...201323474314
bovine whole-blood culture as a tool for the measurement of endotoxin activities in gram-negative bacterial vaccines.in order to analyze bovine immune reactions against the gram-negative bacterial vaccine, bovine whole-blood culture was used to investigate the pro-inflammatory cytokine responses stimulated with lipopolysaccharides (lps) extracted from escherichia coli, salmonella enterica, pseudomonas aeruginosa, and klebsiella pneumoniae. we also examined the interaction between lps and aluminum hydroxide gel for endotoxin activity and pro-inflammatory cytokine responses of whole bovine blood. alteration in t ...201323465356
first national workshop on antibiotic resistance in cambodia: phnom penh, cambodia, 16-18 november 2011.the first national workshop on antibiotic resistance in cambodia was organised by the cambodian ministry of health with support from several national and international partner institutions. it brought together policy-makers, clinicians, pharmacists, laboratory technicians and other professionals dealing with the problems of bacterial infection and antibiotic resistance across the country. antibiotic resistance data from starting up and experienced laboratories were presented, showing high rates ...201327873603
evidence for recent acquisition and successful transmission of bla(ctx-m-15) in salmonella enterica in south korea.we identified two distinct bla(ctx-m)-bearing and five distinct bla(cmy-2)-bearing genetic structures located on plasmids from salmonella enterica and escherichia coli isolates (n = 35) collected from chickens in south korea. all salmonella plasmids shared a common replicon, bla(ctx-m-15) transposon, and core resistance phenotype, while e. coli bla(ctx-m-15) plasmids included four distinct replicons.201323439639
response of restraint stress-selected lines of japanese quail to heat stress and escherichia coli challenge.japanese quail selected for divergent corticosterone response to restraint stress were evaluated for their susceptibility to heat stress and challenge with escherichia coli. these quail lines are designated as high stress (hs), low stress (ls), and the random-bred control (cs) lines. heat stress (35°c, 8 h/d) began at 24 d until the end of the study at 39 d. birds were challenged with an aerosol spray containing 2 × 10(9) cfu of e. coli at 25 and 32 d. at 38 d, the surviving birds were necropsie ...201323436510
antibacterial activity and probiotic potential of lactobacillus plantarum hkn01: a new insight into the morphological changes of antibacterial compound-treated escherichia coli by electron microscopy.among several bacteria examined, an antibacterial-producing lactobacillus strain with probiotic characteristics was selected and identified based on 16s rrna gene sequencing. subsequent purification and mode of action of the antibacterial compounds on target cells including e. coli were investigated. maximum production of the antibacterial compound was recorded at 18 h incubation at 30 degrees c. interestingly, antibacterial activity remained unchanged after heating at 121 degrees c for 45 min, ...201323412066
synthesis and characterization of bactericidal silver nanoparticles using cultural filtrate of simulated microgravity grown klebsiella pneumoniae.silver nanoparticles were synthesized by biological method using cultural filtrate of klebsiella pneumoniae cultured under simulated microgravity and silver nitrate solution as precursor. the nanoparticles exhibited typical plasmon absorption maximum of silver nanoparticles between 405 and 407 nm. spherical silver nanoparticles were found to have size between 15 and 37 nm by tem analysis. xrd pattern corresponding to planes (111), (200), (220) (311) revealed the crystalline nature of the biosynt ...201323410925
insights into the evolution of gene organization and multidrug resistance from klebsiella pneumoniae plasmid pkf3-140.plasmid-mediated transfer of drug-resistance genes among various bacterial species is considered one of the most important mechanisms for the spread of multidrug resistance. to gain insights into the evolution of gene organization and antimicrobial resistance in clinical bacterial samples, a complete plasmid genome of klebsiella pneumoniae pkf3-140 is determined, which has a circular chromosome of 147,416bp in length. among the 203 predicted genes, 142 have function assignment and about 50 appea ...201323402892
novel antibody/gold nanoparticle/magnetic nanoparticle nanocomposites for immunomagnetic separation and rapid colorimetric detection of staphylococcus aureus in milk.we demonstrated the new antibody/gold nanoparticle/magnetic nanoparticle nanocomposites (antibody/aunp/mnps) and their application in the detection of the foodborne pathogen, staphylococcus aureus (s. aureus), in milk. the nanocomposites were synthesized by coating the mnps with bovine serum albumin (bsa) then adsorbing the aunps and anti-s. aureus antibodies on their surface. using the completed immunomagnetic nanostructures, s. aureus inoculated in the milk sample was captured and isolated fro ...201323370174
recombinant salmonella vaccination technology and its application to human bacterial pathogens.salmonella enterica is a gram-negative intracellular bacterial pathogen which causes salmonellosis in humans and animals. during the past several decades, extensive studies have shown that the attenuated salmonella vaccine vector is an optimal vehicle for delivering passenger antigens to mucosal sites to induce humoral, cellular, and mucosal immunity. this immunity leads to protection against challenges with the wild-type pathogens from which the passenger antigens were derived. a myriad of stud ...201323360265
the prevalence of swine enteropathogens in brazilian grower and finish herds.diarrhoea among growing and finishing pigs is an important problem in many herds. the prevalence of l. intracellularis, b. pilosicoli, b. hyodysenteriae, salmonella spp., enterotoxigenic e. coli, trichuris suis and the occurrence of mixed infection were investigated. fecal samples for forty-six herds with diarrhea or a history of diarrhea were randomly collected in minas gerais state, brazil. the enteric pathogens were detected by culture (e. coli and salmonella sp.), pcr (l. intracellularis and ...201324159297
complete nucleotide sequences of virulence-resistance plasmids carried by emerging multidrug-resistant salmonella enterica serovar typhimurium isolated from cattle in hokkaido, japan.in the present study, we have shown that virulence-resistance plasmids from emerging multidrug-resistant isolates of salmonella enterica serovar typhimurium were derived from a virulence-associated plasmid, essential for systematic invasiveness of s. typhimurium in mice (pslt), through acquisition of a large insert containing a resistance island flanked by is1294 elements. a bla cmy-2-carrying plasmid from a cefotaxime-resistant isolate comprised a segment of escherichia coli plasmid par060302 a ...201324155970
multiple interfaces between a serine recombinase and an enhancer control site-specific dna inversion.serine recombinases are often tightly controlled by elaborate, topologically-defined, nucleoprotein complexes. hin is a member of the dna invertase subclass of serine recombinases that are regulated by a remote recombinational enhancer element containing two binding sites for the protein fis. two hin dimers bound to specific recombination sites associate with the fis-bound enhancer by dna looping where they are remodeled into a synaptic tetramer competent for dna chemistry and exchange. here we ...201324151546
combining de novo and reference-guided assembly with scaffold_builder.genome sequencing has become routine, however genome assembly still remains a challenge despite the computational advances in the last decade. in particular, the abundance of repeat elements in genomes makes it difficult to assemble them into a single complete sequence. identical repeats shorter than the average read length can generally be assembled without issue. however, longer repeats such as ribosomal rna operons cannot be accurately assembled using existing tools. the application scaffold_ ...201324267787
bioprotection of ready-to-eat probiotic artichokes processed with lactobacillus paracasei lmgp22043 against foodborne pathogens.the survival of 3 pathogens listeria monocytogenes atcc19115, salmonella enterica subsp. enterica atcc13311, and escherichia coli atcc8739 was evaluated over time in ready-to-eat (rte) artichoke products processed or not with the probiotic strain lactobacillus paracasei lmgp22043. both probiotic and standard products (final ph about 4.0; aw = 0.98) dressed with oil and packaged in modified atmosphere were inoculated with pathogens at a level of about 3 log cfu/g and stored at 4 ºc for 45 d. path ...201324245894
transmission of an oxygen availability signal at the salmonella enterica serovar typhimurium fis promoter.the nucleoid-associated protein fis is a global regulator of gene expression and chromosome structure in escherichia coli and salmonella enterica. despite the importance of fis for infection and intracellular invasion, very little is known about the regulation of s. enterica fis expression. under standard laboratory growth conditions, fis is highly expressed during rapid growth but is then silenced as growth slows. however, if cells are cultured in non-aerated conditions, fis expression is susta ...201324358360
helicobacter and salmonella persistent infection strategies.some host-adapted bacterial pathogens are capable of causing persistent infections in humans. for example, helicobacter pylori inhabits the human gastric mucosa and persistence can be lifelong. salmonella enterica serovar typhi causes systemic infections that involve colonization of the reticuloendothelial system and some individuals become lifelong carriers. in this review, i compare and contrast the different lifestyles of helicobacter and salmonella within the host and the strategies they hav ...201324296347
compound(s) secreted by lactobacillus casei strain shirota yit9029 irreversibly and reversibly impair the swimming motility of helicobacter pylori and salmonella enterica serovar typhimurium, respectively.we conducted experiments in order to examine whether the probiotic lactobacillus casei strain shirota yit9029 (lcs) in vitro and in vivo antagonism of helicobacter pylori and salmonella, involves inhibition of the swimming motility of these pathogens. we report the irreversible inhibition of the swimming motility of h. pylori strain 1101 and reversible inhibition of salmonella enterica serovar typhimurium (s. typhimurium) strain sl1344 by compound(s) secreted by lcs. in h. pylori 1101, irreversi ...201323873784
antimicrobial peptides from plants: stabilization of the γ core of a tomato defensin by intramolecular disulfide bond.cysteine-containing antimicrobial peptides of diverse phylogeny share a common structural signature, the γ core, characterized by a strong polarization of charges in two antiparallel β sheets. in this work, we analyzed peptides derived from the tomato defensin solyc07g007760 corresponding to the protein γ core and demonstrated that cyclization of the peptides, which results in segregation of positive charges to the turn region, produces peptides very active against gram negative bacteria, such a ...201323420649
modulation of humoral and cell-mediated immunity against avian influenza and newcastle disease vaccines by oral administration of salmonella enterica serovar typhimurium expressing chicken interleukin-18.interleukin-18 (il-18) has been known to induce interferon-γ (ifn-γ) production and promote th1 immunity. although mammalian il-18 has been characterized in great detail, the properties and application of chicken il-18 remain largely uninvestigated as of yet. in this study, we evaluated the immunomodulatory properties of salmonella enterica serovar typhimurium expressing chicken interleukin-18 (chil-18) on immune responses induced by avian influenza (ai) and newcastle disease (nd) vaccines. afte ...201323559899
recombinant salmonella enterica serovar typhimurium as a vaccine vector for hiv-1 gag.the hiv/aids epidemic remains a global health problem, especially in sub-saharan africa. an effective hiv-1 vaccine is therefore badly required to mitigate this ever-expanding problem. since hiv-1 infects its host through the mucosal surface, a vaccine for the virus needs to trigger mucosal as well as systemic immune responses. oral, attenuated recombinant salmonella vaccines offer this potential of delivering hiv-1 antigens to both the mucosal and systemic compartments of the immune system. so ...201323989890
liquid based formulations of bacteriophages for the management of waterborne bacterial pathogens in water microcosms.water resources are contaminated by life-threatening multidrug resistant pathogenic bacteria. unfortunately, these pathogenic bacteria do not respond to the traditional water purification methods. therefore, there is a need of environmentally friendly strategies to overcome the problems associated with the antimicrobial resistant bacterial pathogens. in the present study, highly potent lytic phages against multidrug-resistant salmonella enterica serovar paratyphi b, pseudomonas aeruginosa and kl ...201324416943
residues of a proposed gate region in type i atp-binding cassette import systems are crucial for function as revealed by mutational analysis.the type i atp-binding cassette (abc) importer for positively charged amino acids of the thermophilic bacterium geobacillus stearothermophilus consists of the extracellular solute binding protein, artj, and a homodimer each of the transmembrane subunit, artm, and the nucleotide-binding and -hydrolyzing subunit, artp. we have investigated the functional consequences of mutations affecting conserved residues from two peptide regions in artm, recently proposed to form a 'gate' by which access of a ...201323747295
evaluation of silver-infused polylactide films for inactivation of salmonella and feline calicivirus in vitro and on fresh-cut vegetables.there is a growing trend to develop packaging materials with an active role in guarantying that the quality and safety characteristics of packaged products will remain or improve from preparation throughout shelf-life. in the present study, 0.001-1.0 wt.% silver ions were satisfactorily incorporated into polylactide (pla) films by a solvent casting technique. silver migration from the films was measured by voltamperometry and then correlated with its antimicrobial efficacy against salmonella ent ...201323376782
identification of an iron acquisition machinery in flavobacterium columnare.flavobacterium columnare, a fastidious gram-negative pathogen and the causative agent of columnaris disease, is one of the most harmful pathogens in the freshwater fish-farming industry. nevertheless the virulence mechanisms of f. columnare are not well understood. bacterial iron uptake from the host during infection is an important mechanism of virulence. here we identified and analyzed part of the iron uptake machinery of f. columnare. under iron-limited conditions during in vitro growth, synt ...201324113246
persistence and leaching potential of microorganisms and mineral n in animal manure applied to intact soil columns.pathogens may reach agricultural soils through application of animal manure and thereby pose a risk of contaminating crops as well as surface and groundwater. treatment and handling of manure for improved nutrient and odor management may also influence the amount and fate of manure-borne pathogens in the soil. a study was conducted to investigate the leaching potentials of a phage (salmonella enterica serovar typhimurium bacteriophage 28b) and two bacteria, escherichia coli and enterococcus spec ...201323124240
manipulation of innate immunity by a bacterial secreted peptide: lantibiotic nisin z is selectively immunomodulatory.innate immunity is triggered by a variety of bacterial molecules, resulting in both protective and potentially harmful pro-inflammatory responses. further, innate immunity also provides a mechanism for the maintenance of homeostasis between the host immune system and symbiotic or non-pathogenic microorganisms. however, the bacterial factors that mediate these protective effects have been incompletely defined. here, it was demonstrated that the lantiobiotic nisin z is able to modulate host immune ...201323109507
[antimicrobial resistance of bacteria causing diarrhea in children from corrientes, argentina].in corrientes (argentina), from january 2004 to april 2005, fecal samples from under 5 years-old children with acute diarrhea were collected; the stool samples were cultured onto selective media, and those colonies suspected to be salmonella, vibrio, aeromonas, shigella, or escherichia coli o157 were identified. the antimicrobial susceptibility was assessed by the disk diffusion method. among 590 samples, the 7.7% were positive (salmonella spp 32.6% and shigella spp 67.4%). of 31 shigella isolat ...201323427459
prevalence, antimicrobial resistance and relation to indicator and pathogenic microorganisms of salmonella enterica isolated from surface waters within an agricultural landscape.during a 12 month period (june 2007-may 2008), the prevalence and susceptibility of salmonella serovars and their relation to specific pathogenic and indicator bacteria in river and coastal waters was investigated. a total of 240 water samples were collected from selected sites in acheron and kalamas rivers and the ionian sea coast in north western greece. the samples were analyzed for salmonella spp., listeria spp., campylobacter spp., escherichia coli o157, staphylococci, pseudomonas spp., tot ...201322901425
screening for efflux pump systems of bacteria by the new acridine orange agar method.development of a non-toxic, fluorescent-based, agar system for the screening of overexpressed bacterial efflux pump systems with common, inexpensive uv accessories.201322351659
[current situation and problems associated with inactivation of microorganisms in water using copper].the current situation and problems associated with inactivation of microorganisms in water using copper were elucidated.201324125817
in vitro evaluation of anti-infective activity of a lactobacillus plantarum strain against salmonella enterica serovar enteritidis.salmonella enterica serovar enteritidis infections are known to exhibit worldwide prevalence with increased morbidity and mortality. the conventional strategies like antibiotic therapy and vaccination have not only proved to be of sub-optimal efficacy but also led to the development of multidrug resistant strains of salmonella. antimicrobial activities of probiotics against various enteropathogens and other health promoting effects have assumed greater significance in recent years. the present s ...201323668384
biotechnological production of phenyllactic acid and biosurfactants from trimming vine shoot hydrolyzates by microbial coculture fermentation.coculture fermentations show advantages for producing food additives from agroindustrial wastes, considering that different specified microbial strains are combined to improve the consumption of mixed sugars obtained by hydrolysis. this technology dovetails with both the growing interest of consumers towards the use of natural food additives and with stricter legislations and concern in developed countries towards the management of wastes. the use of this technology allows valorization of both c ...201323417349
intravaginal live attenuated salmonella increase local antitumor vaccine-specific cd8(+) t cells.we have recently reported that the intravaginal instillation of synthetic toll-like receptor 3 (tlr3) or tlr9 agonists after a subcutaneous vaccination against human papillomavirus e7 highly increases (~5-fold) the number of vaccine-specific cd8(+) t cells in the genital mucosa of mice, without affecting e7-specific systemic responses. here, we show that the instillation of live attenuated salmonella enterica serovar typhimurium similarly, though more efficiently (~15- fold), increases both e7-s ...201323483225
antagonistic activity of lactobacillus acidophilus la10 against salmonella enterica serovar enteritidis se86 in mice.salmonella enterica serovar enteritidis is one of the main pathogens responsible for foodborne illness in brazil. probiotic bacteria can play a role in defense and recovery from enteropathogenic infections. in this study, the ability of lactobacillus acidophilus la10 to colonise and exert antagonistic effects in the gastrointestinal tract was tested before and during experimental infection in conventional mice contaminated with s. enteritidis (se86). a dose of 0.1 ml containing 10(8) viable cell ...201324159284
a pdms/paper/glass hybrid microfluidic biochip integrated with aptamer-functionalized graphene oxide nano-biosensors for one-step multiplexed pathogen detection.infectious pathogens often cause serious public health concerns throughout the world. there is an increasing demand for simple, rapid and sensitive approaches for multiplexed pathogen detection. in this paper we have developed a polydimethylsiloxane (pdms)/paper/glass hybrid microfluidic system integrated with aptamer-functionalized graphene oxide (go) nano-biosensors for simple, one-step, multiplexed pathogen detection. the paper substrate used in this hybrid microfluidic system facilitated the ...201323929394
comparative study of the protective capacity against salmonella infection between probiotic and nonprobiotic lactobacilli.to investigate the immunoprotective ability of three lactobacilli strains against salmonella enterica serovar typhimurium in a mouse model. to identify the probiotic properties involved in the protection against infection caused by this pathogen.201323163296
the ubiquitin ligase parkin mediates resistance to intracellular pathogens.ubiquitin-mediated targeting of intracellular bacteria to the autophagy pathway is a key innate defence mechanism against invading microbes, including the important human pathogen mycobacterium tuberculosis. however, the ubiquitin ligases responsible for catalysing ubiquitin chains that surround intracellular bacteria are poorly understood. the parkin protein is a ubiquitin ligase with a well-established role in mitophagy, and mutations in the parkin gene (park2) lead to increased susceptibility ...201324005326
immune-responsive gene 1 protein links metabolism to immunity by catalyzing itaconic acid production.immunoresponsive gene 1 (irg1) is highly expressed in mammalian macrophages during inflammation, but its biological function has not yet been elucidated. here, we identify irg1 as the gene coding for an enzyme producing itaconic acid (also known as methylenesuccinic acid) through the decarboxylation of cis-aconitate, a tricarboxylic acid cycle intermediate. using a gain-and-loss-of-function approach in both mouse and human immune cells, we found irg1 expression levels correlating with the amount ...201323610393
antigenicity and immunogenicity of plasmodium vivax merozoite surface protein-3.a recent clinical trial in african children demonstrated the potential utility of merozoite surface protein (msp)-3 as a vaccine against plasmodium falciparum malaria. the present study evaluated the use of plasmodium vivax msp-3 (pvmsp-3) as a target antigen in vaccine formulations against malaria caused by p. vivax. recombinant proteins representing msp-3α and msp-3β of p. vivax were expressed as soluble histidine-tagged bacterial fusions. antigenicity during natural infection was evaluated by ...201323457498
porcine circovirus type 2 (pcv2) vaccination reduces pcv2 in a pcv2 and salmonella enterica serovar choleraesuis coinfection model.we previously reported that prior porcine circovirus type 2 (pcv2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of salmonella enterica serovar choleraesuis in infected pigs. here, we evaluated whether pcv2 vaccination is effective in reducing fecal shedding and tissue dissemination of s. choleraesuis and improving clinical signs associated with pcv2 and s. choleraesuis infection in 15 cesarean-derived, colostrum-deprived pigs ran ...201323107657
resident bacteria on leaves enhance survival of immigrant cells of salmonella enterica.although salmonella enterica apparently has comparatively low epiphytic fitness on plants, external factors that would influence its ability to survive on plants after contamination would be of significance in the epidemiology of human diseases caused by this human pathogen. viable population sizes of s. enterica applied to plants preinoculated with pseudomonas syringae or either of two erwinia herbicola strains was ≥10-fold higher than that on control plants that were not precolonized by such i ...201323506362
from pasteur to probiotics: a historical overview of cheese and microbes.cheese is a food which has been produced for centuries. while cheese was originally developed as a product which extended the shelf life of milk, over time distinct cheese varieties arose, being shaped by geographic, climate, cultural, and economic factors. global demand for artisan cheeses is creating new economic opportunities. consumers seeking distinctive products with regional flavor, or terroir, are becoming connoisseurs of hand-crafted cheeses with distinctive tastes and character. these ...201326184821
survival of foodborne pathogens on inshell walnuts.the survival of salmonella enterica enteritidis pt 30 or five-strain cocktails of s. enterica, escherichia coli o157:h7, and listeria monocytogenes was evaluated on inshell walnuts during storage. inshell walnuts were separately inoculated with an aqueous preparation of the pathogens at levels of 10 to 4 log cfu/nut, dried for 24 h, and then stored at either 4 °c or ambient conditions (23-25 °c, 25-35% relative humidity) for 3 weeks to more than 1 year. during the initial 24-h drying period, bac ...201324026009
use of marination for controlling salmonella enterica and listeria monocytogenes in raw beef.the effect of marination on the survival and growth of the pathogens salmonella enterica and listeria monocytogenes on beef pieces was investigated. five marinades were used: soy sauce base marinade without (sb) or with lactic acid (sbla), red wine base marinade without (wb) or with 0.5% v/v oregano essential oil (wbo), and sterile saline used as control (c). inoculated fresh beef pieces were marinated for 18 h at 5 °c, removed from the marinade and subjected to storage trials at 5 °c and 15 °c. ...201324010604
effect of electropermeabilization by ohmic heating for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in buffered peptone water and apple juice.the effect of electric field-induced ohmic heating for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in buffered peptone water (bpw) (ph 7.2) and apple juice (ph 3.5; 11.8 °brix) was investigated in this study. bpw and apple juice were treated at different temperatures (55°c, 58°c, and 60°c) and for different times (0, 10, 20, 25, and 30 s) by ohmic heating compared with conventional heating. the electric field strength was fixed at ...201323995939
attachment of bacterial pathogens to a bacterial cellulose-derived plant cell wall model: a proof of concept.this study aimed to establish, as a proof of concept, whether bacterial cellulose (bc)-derived plant cell wall models could be used to investigate foodborne bacterial pathogen attachment. attachment of two strains each of salmonella enterica and listeria monocytogenes to four bc-derived plant cell wall models (namely, bc, bc-pectin [bcp], bc-xyloglucan [bcx], and bc-pectin-xyloglucan [bcpx]) was investigated. chemical analysis indicated that the bcpx composite (31% cellulose, 45.6% pectin, 23.4% ...201323941519
determination of 5-log reduction times for escherichia coli o157:h7, salmonella enterica, or listeria monocytogenes in acidified foods with ph 3.5 or 3.8 3.a critical factor in ensuring the safety of acidified foods is the establishment of a thermal process that assures the destruction of acid-resistant vegetative pathogenic and spoilage bacteria. for acidified foods such as dressings and mayonnaises with ph values of 3.5 or higher, the high water phase acidity (acetic acid of 1.5 to 2.5% or higher) can contribute to lethality, but there is a lack of data showing how the use of common ingredients such as acetic acid and preservatives, alone or in c ...201323834800
evaluation of aerated steam treatment of alfalfa and mung bean seeds to eliminate high levels of escherichia coli o157:h7 and o178:h12, salmonella enterica, and listeria monocytogenes.sprouts contaminated with human pathogens are able to cause food-borne diseases due to the favorable growth conditions for bacteria during germination and because of minimal processing steps prior to consumption. we have investigated the potential of hot humid air, i.e., aerated steam, to treat alfalfa and mung bean seeds which have been artificially contaminated with escherichia coli o157:h7, salmonella enterica subsp. enterica serovar weltevreden, and listeria monocytogenes scott a. in additio ...201323709507
ovalbumin-related protein x is a heparin-binding ov-serpin exhibiting antimicrobial activities.ovalbumin family contains three proteins with high sequence similarity: ovalbumin, ovalbumin-related protein y (ovay), and ovalbumin-related protein x (ovax). ovalbumin is the major egg white protein with still undefined function, whereas the biological activity of ovax and ovay has not yet been explored. similar to ovalbumin and ovay, ovax belongs to the ovalbumin serine protease inhibitor family (ov-serpin). we show that ovax is specifically expressed by the magnum tissue, which is responsible ...201323615912
ligands affecting silver antimicrobial efficacy on listeria monocytogenes and salmonella enterica.although silver is being extensively used in food or other applications as the key component to control microbial proliferation, many factors affecting its real potential are still unknown. in the present work, the presence of specific ligands or the contents in organic matter was correlated with silver speciation and its antibacterial performance. silver was found to be only active in form of free silver ions (fsi). the presence of chloride ions produced an equilibrium of stable silver chloride ...201323561107
the application of high-concentration short-time chlorine dioxide treatment for selected specialty crops including roma tomatoes (lycopersicon esculentum), cantaloupes (cucumis melo ssp. melo var. cantaloupensis) and strawberries (fragaria×ananassa).the effects of high-concentration short-time chlorine dioxide (clo2) gas treatment on food-borne pathogens inoculated onto the surface of tomatoes, cantaloupes, and strawberries were studied. produce were spot-inoculated with a mixture of salmonella enterica (serotypes montevideo, javiana and baildon), escherichia coli o157:h7 (serotypes 204 p, edl 933 and c792) or listeria monocytogenes (serotypes scott a, f 5069 and lcdc 81-861), and treated with clo2 gas at 10 mg/l for 180 s. after clo2 gas t ...201323541196
antimicrobial efficacy of poly (dl-lactide-co-glycolide) (plga) nanoparticles with entrapped cinnamon bark extract against listeria monocytogenes and salmonella typhimurium.nanoencapsulation of active compounds using poly-(d,l-lactide-co-glycolide) (plga) is commonly used in the pharmaceutical industry for drug delivery and may have important applications in the food industry. control of growth of foodborne bacteria with the goals of reducing the number of foodborne illness outbreaks, assuring consumers a safer food supply remains a priority in the food industry. natural antimicrobials are an excellent way to eliminate pathogens without introducing chemical preserv ...201323464835
survival of food-borne pathogens on natural black table olives after post-processing contamination.the aim of this study was to evaluate the survival of salmonella, escherichia coli o157:h7, listeria monocytogenes, and staphylococcus aureus on natural black olives during aerobic storage without brine and to conclude about the safety of this fermented food. fermented black olives (ph 3.95; nacl 6.02%) were artificially inoculated with 4 strains of salmonella enterica ser. enteritidis, 4 strains of s. enterica ser. typhimurium, 3 strains of e. coli o157:h7, 3 strains of l. monocytogenes, and 3 ...201323334099
bactericidal activities of health-promoting, food-derived powders against the foodborne pathogens escherichia coli, listeria monocytogenes, salmonella enterica, and staphylococcus aureus.we evaluated the relative bactericidal activities (ba(50) ) of 10 presumed health-promoting food-based powders (nutraceuticals) and, for comparison, selected known components against the following foodborne pathogens: escherichia coli o157:h7, salmonella enterica, listeria monocytogenes, and staphylococcus aureus. the relative activities were evaluated using quantitative bactericidal activity [(ba(50) value, defined as the percentage of the sample in the assay mixture that resulted in a 50% decr ...201323317422
influence of sterilized human fecal extract on the sensitivity of salmonella enterica atcc 13076 and listeria monocytogenes atcc 15313 to enrofloxacin.there is much debate on whether continuous exposure of commensal bacteria and potential pathogens residing in the human intestinal tract to low levels of antimicrobial agents from treated food animals pose a public health concern. to investigate antimicrobial effects on bacteria under colonic conditions, we studied resistance development in salmonella enterica and listeria monocytogenes exposed to enrofloxacin in the presence of fecal extract. the bacteria were incubated at 37 °c in mueller-hint ...201327029316
multiplex fiber optic biosensor for detection of listeria monocytogenes, escherichia coli o157:h7 and salmonella enterica from ready-to-eat meat samples.listeria monocytogenes, escherichia coli o157:h7 and salmonella enterica are the most common foodborne bacterial pathogens and are responsible for many outbreaks. therefore, multiplex detection of these three using a single assay platform is highly desirable. the objective was to develop and optimize a fiber optic sensor for simultaneous detection of these three from food. the streptavidin coated optical waveguides were immobilized with biotinylated polyclonal antibodies and exposed to the bacte ...201323200648
pickled egg production: inactivation rate of salmonella, escherichia coli o157:h7, listeria monocytogenes, and staphylococcus aureus during acidification step.based on current u.s. food and drug administration acidified foods guidelines, regulatory approval of commercial pickled egg production without a final heat treatment requires challenge studies. we conducted challenge studies to verify common pickled egg processing parameters. hard-boiled eggs were acidified in ambient temperature brine at a 60:40 egg/brine ratio. four acidification treatments were studied in triplicate: 5% acetic acid (aa) or 2.5% aa brine with and without 0.05% sodium benzoate ...201324215686
strain variability of the behavior of foodborne bacterial pathogens: a review.differences in phenotypic responses among strains of the same microbial species constitute an important source of variability in microbiological studies, and as such they need to be assessed, characterized and taken into account. this review provides a compilation of available research data on the strain variability of four basic behavioral aspects of foodborne bacterial pathogens including: (i) virulence; (ii) growth; (iii) inactivation; and (iv) biofilm formation. a particular emphasis is plac ...201324184609
nod1 and nod2 enhance tlr-mediated invariant nkt cell activation during bacterial infection.invariant nkt (inkt) cells act at the crossroad between innate and adaptive immunity and are important players in the defense against microbial pathogens. inkt cells can detect pathogens that trigger innate receptors (e.g., tlrs, rig-i, dectin-1) within apcs, with the consequential induction of cd1d-mediated ag presentation and release of proinflammatory cytokines. we show that the cytosolic peptidoglycan-sensing receptors nod1 and nod2 are necessary for optimal ifn-γ production by inkt cells, a ...201324163408
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