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implication of sialidases in salmonella infection: genome release of sialidase knockout strains from salmonella enterica serovar typhimurium lt2.sialidases, which are widely distributed in nature, cleave the α-ketosidic bond of terminal sialic acid residue. these emerging virulence factors degrade the host glycan. we report here the release of seven sialidase and one sialic acid transporter deletion in salmonella enterica serovar typhimurium strain lt2, which are important in cellular invasion during infection.201728495784
characterization of the salmonella enterica serotype isangi isolated from patients for the first time in china.no studies have reported the isolation of serotype salmonella isangi from cases of salmonellosis in mainland china. we investigated an outbreak of foodborne disease with salmonella and collected the samples from the patients and surplus foods. salmonella strains were isolated and the serotype was identified according to the kauffmann-white scheme. the relatedness of the isolates was determined using pulsed-field gel electrophoresis (pfge) and whole genome sequencing (wgs). antimicrobial suscepti ...201728497996
effect of chemical denaturants on the conformational stability of gyrb subunit of dna gyrase from salmonella enterica serovar typhi.dna gyrase, a type ii topoisomerase maintains the topology of dna by introducing negative supercoils using energy generated by atp hydrolysis. it is composed of two subunits, gyra and gyrb (gyra2gyrb2 hetero-tetramer). gyrb comprises two domains, a 43kda amino n-terminus (gbntd) and 47kda carboxyl c- terminus (gbctd). till now no study has been reported in terms of stability of gyrase b and its domains using chemical denaturants related to its function. to understand the role of each domain in g ...201728499947
real-time pcr method for detection of salmonella spp. in environmental samples.the methods currently used for detecting salmonella in environmental samples require 2 days to produce results and have limited sensitivity. here, we describe the development and validation of a real-time pcr salmonella screening method that produces results in 18 to 24 h. primers and probes specific to the gene inva, group d, and salmonella enterica serovar enteritidis organisms were designed and evaluated for inclusivity and exclusivity using a panel of 329 salmonella isolates representing 126 ...201728500041
persistence of salmonella typhimurium lt2 in soil enhanced after growth in lettuce medium.the persistence of salmonella in the environment is influenced by a multitude of biotic and abiotic factors. in addition, its persistence can be influenced by preadaptation before the introduction into the environment. in order to study how preadaptation changes the survival of salmonella in soil and therefore its potential to colonize the phytosphere, we developed a new medium based on lettuce material [lettuce medium (lm)]. salmonella enterica serovar typhimurium strain lt2 was used as a model ...201728503171
multiple clones and low antimicrobial resistance rates for salmonella enterica serovar infantis populations in greece.all the salmonella enterica ser. infantis strains isolated under official control programs in greece during a four year period were studied, 23 of human origin, 16 from food animals and one from food. molecular analyses (pfge) in combination with antimicrobial susceptibility testing were used to study whether the occurrence s. infantis in greece resulted from different biotypes or a successful spread of one clone. low rates of antimicrobial resistance were observed, except for streptomycin among ...201728504096
inactivation of gram (-) bacteria salmonella enterica by chlorophyllin-based photosensitization: mechanism of action and new strategies to enhance the inactivation efficiency.this study is focused on the enhancement of susceptibility of gram (-) bacteria s. enterica to chlorophyllin-based (chl) photosensitization combining it with other antimicrobial tools. in order to find best combinations, the mechanism by which chl-based photosensitization inactivates bacteria must be identified. data confirmed that photosensitization (chl 1.5×10(-5)m, for 1-120min, 405nm, 0-46.1j/cm(2)) reduced s. enterica population, just by 2.05 log (cfu/ml). fluorimetric measurements indicate ...201728505496
development of a gold nanoparticle-based universal oligonucleotide microarray for multiplex and low-cost detection of foodborne pathogens.bacterial foodborne diseases remain major threats to food safety and public health, especially in developing countries. in this study a novel assay, combining gold nanoparticle (gnp)-based multiplex oligonucleotide ligation-pcr and universal oligonucleotide microarray technology, was developed for inexpensive, specific, sensitive, and multiplex detection of eight common foodborne pathogens, including shigella spp., campylobacter jejuni, bacillus cereus, escherichia coli o157:h7, listeria monocyt ...201728505584
tumor necrosis factor receptor-associated factor 6 (traf6) mediates ubiquitination-dependent stat3 activation upon salmonella enterica serovar typhimurium infection.salmonella enterica serovar typhimurium can inject effector proteins into host cells via type iii secretion systems (t3sss). these effector proteins modulate a variety of host transcriptional responses to facilitate bacterial growth and survival. here we show that infection of host cells with s typhimurium specifically induces the ubiquitination of tumor necrosis factor receptor-associated factor 6 (traf6). this traf6 ubiquitination is triggered by the salmonella pathogenicity island 1 (spi-1) t ...201728507064
temporal genomic phylogeny reconstruction indicates a geospatial transmission path of salmonella cerro in the united states and a clade-specific loss of hydrogen sulfide production.salmonella cerro has become one of the most prevalent salmonella serotypes isolated from dairy cattle in several u.s. states, including new york where it represented 36% of all salmonella isolates of bovine origin in 2015. this serotype is commonly isolated from dairy cattle with clinical signs of salmonellosis, including diarrhea and fever, although it has also been identified in herds without evidence of clinical disease or decreased production. to better understand the transmission patterns a ...201728507536
iron- and hepcidin-independent downregulation of the iron exporter ferroportin in macrophages during salmonella infection.retention of iron in tissue macrophages via upregulation of hepcidin (hamp) and downregulation of the iron exporter ferroportin (fpn) is thought to participate in the establishment of anemia of inflammation after infection. however, an upregulation of fpn has been proposed to limit macrophages iron access to intracellular pathogens. therefore, we studied the iron homeostasis and in particular the regulation of fpn after infection with salmonella enterica serovar typhimurium in mice presenting ti ...201728507548
salinity stress does not affect root uptake, dissemination and persistence of salmonella in sweet-basil (ocimum basilicum).crop produce can be contaminated in the field during cultivation by bacterial human pathogens originating from contaminated soil or irrigation water. the bacterial pathogens interact with the plant, can penetrate the plant via the root system and translocate and survive in above-ground tissues. the present study is first to investigate effects of an abiotic stress, salinity, on the interaction of plants with a bacterial human pathogen. the main sources of human bacterial contamination of plants ...201728512466
label-free biosensing of salmonella enterica serovars at single-cell level.the emerging nanotechnologies have greatly facilitated the development of label-free biosensors. the atomic force microscopy (afm) has been used to study the molecular mechanism of the reactions for protein and aptamers. the surface plasmon resonance (spr) have been used in fast detections of various pathogens such as bacteria. this study used both afm and spr to investigate the complex reactions between aptamers and outer membrane proteins (omps) on the surface of s. typhimurium.201728514955
loss of humoral and cellular immunity to invasive nontyphoidal salmonella during current or convalescent plasmodium falciparum infection in malawian children.invasive nontyphoidal salmonella (ints) infections are commonly associated with plasmodium falciparum infections, but the immunologic basis for this linkage is poorly understood. we hypothesized that p. falciparum infection compromises the humoral and cellular immunity of the host to nts, which increases the susceptibility of the host to ints infection. we prospectively recruited children aged between 6 and 60 months at a community health centre in blantyre, malawi, and allocated them to the fol ...201728515136
zinc supplementation, via gpr39, upregulates pkcζ to protect intestinal barrier integrity in caco-2 cells challenged by salmonella enterica serovar typhimurium.background: zinc has been shown to improve intestinal barrier function against salmonella enterica serovar typhimurium (s. typhimurium) infection, but the mechanisms involved in this process remain undefined.objective: we aimed to explore the roles of g protein-coupled receptor (gpr)39 and protein kinase cζ (pkcζ) in the regulation by zinc of intestinal barrier function.methods: a transwell caco-2 monolayer was pretreated with 0, 50, or 100 μm zn and then incubated with s. typhimurium for 0-6 h. ...201728515165
ca(2+) in hybridization solutions for fluorescence in situ hybridization facilitates the detection of enterobacteriaceae.fluorescence in situ hybridization (fish) has been employed to identify microorganisms at the single cell level under a microscope. extensive efforts have been made to improve and extend the fish technique; however, the development of a widely applicable protocol is a continuing challenge. the present study evaluated the effects of divalent cations in the hybridization solution on the fish-based detection of various species of bacteria and archaea with rrna-targeted probes. a flow cytometric ana ...201728515389
salmonella diva vaccine reduces disease, colonization and shedding due to virulent s. typhimurium infection in swine.non-host-adapted salmonella serovars, including the common human food-borne pathogen salmonella enterica serovar typhimurium (s. typhimurium), are opportunistic pathogens that can colonize food-producing animals without causing overt disease. interventions against salmonella are needed to enhance food safety, protect animal health and allow the differentiation of infected from vaccinated animals (diva).201728516860
genomic analysis of salmonella enterica serovar typhimurium dt160 associated with a 14-year outbreak, new zealand, 1998-2012.during 1998-2012, an extended outbreak of salmonella enterica serovar typhimurium definitive type 160 (dt160) affected >3,000 humans and killed wild birds in new zealand. however, the relationship between dt160 within these 2 host groups and the origin of the outbreak are unknown. whole-genome sequencing was used to compare 109 salmonella typhimurium dt160 isolates from sources throughout new zealand. we provide evidence that dt160 was introduced into new zealand around 1997 and rapidly propagat ...201728516864
gut microbiota-mediated protection against diarrheal infections.the mammalian gut microbiota is a highly abundant and diverse microbial community that resides in the gastrointestinal tract. one major benefit that the gut microbiota provides to its host is colonization resistance-the ability to prevent colonization by foreign microbes, including diarrheal pathogens such as clostridium difficile , salmonella enterica serovar typhimurium and diarrheagenic escherichia coli .201728520994
nleb/ssek effectors from citrobacter rodentium, escherichia coli, and salmonella enterica display distinct differences in host substrate specificity.many gram-negative bacterial pathogens use a syringe-like apparatus called a type iii secretion system to inject virulence factors into host cells. some of these effectors are enzymes that modify host proteins to subvert their normal functions. nleb is a glycosyltransferase that modifies host proteins with n-acetyl-d-glucosamine to inhibit antibacterial and inflammatory host responses. nleb is conserved among the attaching/effacing pathogens enterohemorrhagic escherichia coli (ehec), enteropatho ...201728522607
amylases and their importance during glycan degradation: genome sequence release of salmonella amylase knockout strains.amylases catalyze the cleavage of α-d-1,4 and α-d-1,6-glycosidic bonds in starch and related carbohydrates. amylases are widely distributed in nature and are important in carbohydrate metabolism. this is the release of four single and two double deletions in salmonella enterica serovar typhimurium lt2 that are important for glycan degradation during infection.201728522713
proteome remodelling by the stress sigma factor rpos/σ(s) in salmonella: identification of small proteins and evidence for post-transcriptional regulation.the rpos/σ(s) sigma subunit of rna polymerase is the master regulator of the general stress response in many gram-negative bacteria. extensive studies have been conducted on σ(s)-regulated gene expression at the transcriptional level. in contrast, very limited information regarding the impact of σ(s) on global protein production is available. in this study, we used a mass spectrometry-based proteomics approach to explore the wide σ(s)-dependent proteome of the human pathogen salmonella enterica ...201728522802
investigation of optimum ohmic heating conditions for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in apple juice.control of foodborne pathogens is an important issue for the fruit juice industry and ohmic heating treatment has been considered as one of the promising antimicrobial interventions. however, to date, evaluation of the relationship between inactivation of foodborne pathogens and system performance efficiency based on differing soluble solids content of apple juice during ohmic heating treatment has not been well studied. this study aims to investigate effective voltage gradients of an ohmic heat ...201728525985
impact of acanthamoeba cysts on stress resistance of salmonella enterica serovar typhimurium, yersinia enterocolitica 4/o:3, listeria monocytogenes 1/2a, and escherichia coli o:26.the formation of robust resting cysts enables acanthamoeba to resist harsh environmental conditions. this study investigated to what extent these cysts are resistant to physical and chemical stresses as applied in food industry cleaning and disinfection procedures. moreover, it was assessed whether certain intracystic meat-borne bacterial pathogens are more stress resistant than free-living bacterial monocultures and if intracystic passage and subsequent association with trophozoites induces cro ...201728526786
delineation of b-cell epitopes of salmonella enterica serovar typhi hemolysin e: potential antibody therapeutic target.hemolysin e (hlye) is an immunogenic novel pore-forming toxin involved in the pathogenesis of typhoid fever. thus, mapping of b-cell epitopes of salmonella enterica serovar typhi (s. typhi) is critical to identify key immunogenic regions of hlye. a random 20-mer peptide library was used for biopanning with enriched anti-hlye polyclonal antibodies from typhoid patient sera. bioinformatic tools were used to refine, analyze and map the enriched peptide sequences against the protein to identify the ...201728526816
identification of transcriptional modules and key genes in chickens infected with salmonella enterica serovar pullorum using integrated coexpression analyses.salmonella enterica pullorum is one of the leading causes of mortality in poultry. understanding the molecular response in chickens in response to the infection by s. enterica is important in revealing the mechanisms of pathogenesis and disease progress. there have been studies on identifying genes associated with salmonella infection by differential expression analysis, but the relationships among regulated genes have not been investigated. in this study, we employed weighted gene coexpression ...201728529955
getting "inside" type i ifns: type i ifns in intracellular bacterial infections.type i interferons represent a unique and complex group of cytokines, serving many purposes during innate and adaptive immunity. discovered in the context of viral infections, type i ifns are now known to have myriad effects in infectious and autoimmune disease settings. type i ifn signaling during bacterial infections is dependent on many factors including whether the infecting bacterium is intracellular or extracellular, as different signaling pathways are activated. as such, the repercussions ...201728529959
genetic basis for loss of immuno-reactive o-chain in salmonella enterica serovar enteritidis veterinary isolates.fifty-two rough salmonella enterica serovar enteritidis (s. enteritidis) isolates from broilers and the environment were characterized for their serological and genotypic properties. under routine diagnostic serotyping methods such isolates lack the immuno-reactivity of the o-chain of the lipopolysaccharide (lps), and are referred to as non-typeable. using a modified slide agglutination method, the isolates could be differentiated into three different serological variants. twenty-six isolates (5 ...201728532797
first detection of a fosfomycin resistance gene, fosa7, in salmonella enterica serovar heidelberg isolated from broiler chickens.we previously described salmonella enterica serovar heidelberg isolates harboring a chromosomal gene cluster similar to the glutathione s-transferase gene, a putative fosa gene conferring resistance to fosfomycin. here, we show that this new gene, named fosa7, confers resistance to fosfomycin. the introduction of fosa7 into the fosfomycin-susceptible salmonella enterica serovar enteritidis resulted in a substantial increase in the fosfomycin mic. this finding increases the awareness of antibioti ...201728533247
vacuolation activity and intracellular trafficking of artb, the binding subunit of an ab5 toxin produced by salmonella enterica serovar typhi.various salmonella enterica serovars, including s. enterica serovar typhi, encode an ab5 toxin (artab), the a subunit of which is an adp-ribosyltransferase related to the s1 subunit of pertussis toxin. however, although the a subunit is able to catalyze adp-ribosylation of host g proteins, a cytotoxic phenotype has yet to be identified for the holotoxin. here we show that its b subunit pentamer (artb) binds to receptors on the surface of vero (african green monkey kidney) cell, cho (chinese hams ...201728533468
in vitro assessment of pediococcus acidilactici kp10 for its potential use in the food industry.selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. a bacteriocin-producing lactic acid bacterium (lab), pediococcus acidilactici kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. the inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol ...201728535747
salmonella typhi genomics: envisaging the future of typhoid eradication.next-generation whole-genome sequencing has revolutionised the study of infectious diseases in recent years. the availability of genome sequences and its understanding have transformed the field of molecular microbiology, epidemiology, infection treatments and vaccine developments. we review the key findings of the publicly accessible genomes of salmonella enterica serovar typhi since the first complete genome to the most recent release of thousands of salmonella typhi genomes, which remarkably ...201728544285
quantitative proteomic analysis of host epithelial cells infected by salmonella enterica serovar typhimurium.systems-level analyses have the capability to offer new insight into host-pathogen interactions on the molecular level. using salmonella infection of host epithelial cells as a model system, we previously analyzed intracellular bacterial proteome as a window into pathogens' adaptations to their host environment [infect. immun. 2015; j. proteome res. 2017]. herein we extended our efforts to quantitatively examine protein expression of host cells during infection. in total, we identified more than ...201728544771
flagellin fljb as an adjuvant to the recombinant adenovirus rabies glycoprotein vaccine increases immune responses against rabies in mice.rabies virus (rabv) causes an acute progressive viral encephalitis. although currently licensed vaccines have an excellent safety and efficacy record, the development of a safer and more cost-effective vaccine is still being sought. an e1-deleted, replication-defective human adenovirus type 5 (had5) vector expressing rabv glycoprotein (had5-g) is thought to be a promising candidate vaccine for immune prophylaxis against rabies. salmonella enterica serovar typhimurium (s. typhimurium) flagellin i ...201728550434
evaluation of radio-frequency heating in controlling salmonella enterica in raw shelled almonds.this study was conducted to investigate the efficacy of radio-frequency (rf) heating to reduce salmonella enterica serovars enteritidis, typhimurium, and senftenberg in raw shelled almonds compared to conventional convective heating, and the effect of rf heating on quality by measuring changes in the color and degree of lipid oxidation. agar-grown cells of three pathogens were inoculated onto the surface or inside of raw shelled almonds using surface inoculation or the vacuum perfusion method, r ...201728551280
the in vitro and in vivo protective effects of tannin derivatives against salmonella enterica serovar typhimurium infection.in this study, we investigated the protective effects of tannin-derived components, gallic acid (ga) and tannic acid (ta), in vitro and in vivo against salmonella infection in mice. both ga and ta showed antibacterial effects against salmonella (s.) typhimurium as well as inhibitory effects on the adherence, invasion, and intracellular growth of the pathogens in macrophages. following a lethal dose of salmonella infection in mice, reduced virulence in both ga- and ta-treated groups was observed ...201728552635
global gene-expression analysis of the response of salmonella enteritidis to egg white exposure reveals multiple egg white-imposed stress responses.chicken egg white protects the embryo from bacterial invaders by presenting an assortment of antagonistic activities that combine together to both kill and inhibit growth. the key features of the egg white anti-bacterial system are iron restriction, high ph, antibacterial peptides and proteins, and viscosity. salmonella enterica serovar enteritidis is the major pathogen responsible for egg-borne infection in humans, which is partly explained by its exceptional capacity for survival under the har ...201728553268
inhibitor-assisted high-pressure inactivation of bacteria in skim milk.the combined inactivation effects of high hydrostatic pressure (hhp) and antimicrobial compounds (potassium sorbate and ε-polylysine [ε-pl]) on 4 different bacterial strains present in skim milk and the effect of these treatments on milk quality were investigated in this study. hhp treatment at 500 mpa for 5 min reduced the populations of escherichia coli, salmonella enterica typhimurium, listeria monocytogenes, and staphylococcus aureus from 6.5 log colony-forming units (cfus) or higher to less ...201728556370
phage applications for improving food safety and infection control in egypt.the study investigated the use of bacteriophages to control bacterial contamination of chicken skin, eggs, tomatoes and meat.201728557189
structural and functional dissection reveals distinct roles of ca2+-binding sites in the giant adhesin siie of salmonella enterica.the giant non-fimbrial adhesin siie of salmonella enterica mediates the first contact to the apical site of epithelial cells and enables subsequent invasion. siie is a 595 kda protein composed of 53 repetitive bacterial immunoglobulin (big) domains and the only known substrate of the spi4-encoded type 1 secretion system (t1ss). the crystal structure of big50-52 of siie revealed two distinct ca2+-binding sites per big domain formed by conserved aspartate or glutamate residues. in a mutational ana ...201728558023
sugar sulfates are not hydrolyzed by the acid-inducible sulfatase asla from salmonella enterica enteritidis nal(r) and kentucky 3795 at ph 5.5.the open reading frames sen0085 and seka_a4361, from salmonella enterica serovar enteritidis nal(r) and serovar kentucky 3795, respectively, corresponding to the acid-inducible sulfatase gene asla from salmonella enterica serovar typhimurium, were previously suggested by microarray analysis to be differentially expressed under acid conditions. however, growth and enzyme activity tests in the present study demonstrated that both wild-type strains exhibited sulfatase activity with 4-nitrophenyl su ...201728558253
the ubik protein is an accessory factor necessary for bacterial ubiquinone (uq) biosynthesis and forms a complex with the uq biogenesis factor ubij.ubiquinone (uq), also referred to as coenzyme q, is a widespread lipophilic molecule in both prokaryotes and eukaryotes in which it primarily acts as an electron carrier. eleven proteins are known to participate in uq biosynthesis in escherichia coli, and we recently demonstrated that uq biosynthesis requires additional, nonenzymatic factors, some of which are still unknown. here, we report on the identification of a bacterial gene, yqic, which is required for efficient uq biosynthesis, and whic ...201728559279
a toxin involved in salmonella persistence regulates its activity by acetylating its cognate antitoxin, a modification reversed by cobb sirtuin deacetylase.bacterial toxin-antitoxin systems trigger the onset of a persister state by inhibiting essential cellular processes. the tact toxin of salmonella enterica is known to induce a persister state in macrophages through the acetylation of aminoacyl-trnas. here, we show that the tact toxin and the taca antitoxin work as a complex that modulates tact activity via the acetylation state of taca. tact acetylates taca at residue k44, a modification that is removed by the nad(+)-dependent cobb sirtuin deace ...201728559487
three new lactobacillus plantarum strains in the probiotic toolbox against gut pathogen salmonella enterica serotype typhimurium.the benefits of probiotic bacteria have been widely explored. however, fermented foods and digestive system of humans and animals are an inexhaustible source of new potentially probiotic microorganisms. in this study we present three new lactobacillus plantarum strains isolated from different dairy products: cow's cheese, sheep's cheese and whey. in order to determine the antibacterial activity of yet unexplored l. plantarum strains against salmonella enterica serotype typhimurium, in vitro comp ...201728559733
mitigation of salmonella on pet food kibbles by using liquid and powdered 3-hydroxy-3-methylbutyric acid.in recent years, several pet food recalls have been attributed to salmonella contamination. in addition to the negative impacts on animal health, salmonella-contaminated pet foods have been linked to infection in humans. with that in mind, the u.s. food and drug administration has set forth a zero-tolerance policy for salmonella in pet foods. typically, pet foods are extruded or processed at high temperatures that are sufficient to reduce pathogenic bacteria. however, the possibility for postext ...201728561638
susceptibility of salmonella biofilm and planktonic bacteria to common disinfectant agents used in poultry processing.poultry contaminated with salmonella enterica subsp. enterica are a major cause of zoonotic foodborne gastroenteritis. salmonella heidelberg is a common serotype of salmonella that has been implicated as a foodborne pathogen associated with the consumption of improperly prepared chicken. to better understand the effectiveness of common antimicrobial disinfectants (i.e., peroxyacetic acid [paa], acidified hypochlorite [ach], and cetylpyridinium chloride [cpc]), environmental isolates of nontyphoi ...201728561639
recovery of salmonella enterica from australian layer and processing environments following outbreaks linked to eggs. 201728570831
complete genome sequences of three salmonella enterica subsp. enterica serovar saintpaul isolates associated with a 2013 multistate outbreak in the united states.in 2013, a multistate outbreak of salmonella enterica subsp. enterica serovar saintpaul from cucumber caused 84 cases of salmonellosis in the united states. in this announcement, we report the complete genome sequences of three clinical salmonella saintpaul isolates associated with the 2013 outbreak.201728572327
evaluation of different solvents to extract antibacterial compounds from jalapeño peppers.chili peppers (capsicum spp.) may possess antibacterial properties and have potential to be used in foods as antimicrobial. the complete chili pepper extract should be evaluated to determine which compounds are responsible for the antimicrobial activity. extraction of compounds from the pepper is completed using a solvent. the type of solvent used for extraction influences which compounds are isolated, therefore the best extraction method needs to be determined. the purpose of this study was to ...201728572934
patterns in antimicrobial susceptibility of salmonellae isolated at a tertiary care hospital in northern india.multidrug-resistant salmonellae have emerged worldwide as also in india. the aim of this study was to study the antimicrobial susceptibility pattern of salmonella enterica serovars isolated at a tertiary care hospital in northern india.201728574025
quantitative risk assessment of antimicrobial-resistant foodborne infections in humans due to recombinant bovine somatotropin usage in dairy cows.recombinant bovine somatotropin (rbst) is a production-enhancing technology that allows the dairy industry to produce milk more efficiently. concern has been raised that cows supplemented with rbst are at an increased risk of developing clinical mastitis, which would potentially increase the use of antimicrobial agents and increase human illnesses associated with antimicrobial-resistant bacterial pathogens delivered through the dairy beef supply. the purpose of this study was to conduct a quanti ...201728574304
signal transduction pathway mediated by the novel regulator loia for low oxygen tension induced salmonella typhimurium invasion.salmonella enterica serovar typhimurium (s. typhimurium) is a major intestinal pathogen of both humans and animals. salmonella pathogenicity island 1 (spi-1)-encoded virulence genes are required for s. typhimurium invasion. while oxygen (o2) limitation is an important signal for spi-1 induction under host conditions, how the signal is received and integrated to the central spi-1 regulatory system in s. typhimurium is not clear. here, we report a signal transduction pathway that activates spi-1 e ...201728575106
factors influencing the salmonella internalization into seedpods and whole plants of arachis hypogaea (l.).here we investigated whether salmonella enterica serovar typhimurium atcc 14028 was capable of internalizing in peanut seedpods and plants when exposed to inoculated soil and the edaphic factors that influenced uptake. intact dry virginia (dv) and fresh green virginia (gv) seedpods were exposed to soil containing 6.5 log (cfu/g) salmonella under different soil moisture conditions. internalization of s. typhimurium into peanut plants germinated in inoculated soil was also examined with and withou ...201728576367
next generation sequencing-based multigene panel for high throughput detection of food-borne pathogens.contamination of food by chemicals or pathogenic bacteria may cause particular illnesses that are linked to food consumption, commonly referred to as foodborne diseases. bacteria are present in/on various foods products, such as fruits, vegetables and ready-to-eat products. bacteria that cause foodborne diseases are known as foodborne pathogens (fbps). accurate detection methods that are able to reveal the presence of fbps in food matrices are in constant demand, in order to ensure safe foods wi ...201728578266
exploiting a host-commensal interaction to promote intestinal barrier function and enteric pathogen tolerance.commensal intestinal bacteria can prevent pathogenic infection; however, limited knowledge of the mechanisms by which individual bacterial species contribute to pathogen resistance has restricted their potential for therapeutic application. here, we examined how colonization of mice with a human commensal enterococcus faecium protects against enteric infections. we show that e. faecium improves host intestinal epithelial defense programs to limit salmonella enterica serotype typhimurium pathogen ...201628580440
insights into pg-binding, conformational change, and dimerization of the ompa c-terminal domains from salmonella enterica serovar typhimurium and borrelia burgdorferi.salmonella enterica serovar typhimurium can induce both humoral and cell-mediated responses when establishing itself in the host. these responses are primarily stimulated against the lipopolysaccharide and major outer membrane (om) proteins. ompa is one of these major om proteins. it comprises a n-terminal eight-stranded β-barrel transmembrane domain and a c-terminal domain (ompa(ctd) ). the ompa(ctd) and its homologs are believed to bind to peptidoglycan (pg) within the periplasm, maintaining b ...201728580643
evidence for improved encapsulated pathway behavior in a bacterial microcompartment through shell protein engineering.bacterial microcompartments are a class of proteinaceous organelles comprising a characteristic protein shell enclosing a set of enzymes. compartmentalization can prevent escape of volatile or toxic intermediates, prevent off-pathway reactions, and create private cofactor pools. encapsulation in synthetic microcompartment organelles will enhance the function of heterologous pathways, but to do so, it is critical to understand how to control diffusion in and out of the microcompartment organelle. ...201728585808
borrelidins c-e: new antibacterial macrolides from a saltern-derived halophilic nocardiopsis sp.chemical investigation of a halophilic actinomycete strain belonging to the genus nocardiopsis inhabiting a hypersaline saltern led to the discovery of new 18-membered macrolides with nitrile functionality, borrelidins c-e (1-3), along with a previously reported borrelidin (4). the planar structures of borrelidins c-e, which are new members of the rare borrelidin class of antibiotics, were elucidated by nmr, mass, ir, and uv spectroscopic analyses. the configurations of borrelidines c-e were det ...201728587270
two novel roles of buffalo milk lactoperoxidase, antibiofilm agent and immunomodulator against multidrug resistant salmonella enterica serovar typhi and listeria monocytogenes.the increasing occurrence of multidrug resistant bacteria causing bacteremia infection, constitutes a major health problem, difficult-to-treat bacteremia due to its ability to form biofilm. buffalo milk lactoperoxidase (bmlpo) is effective and safe to use as bacteriostatic agent. the mic of bmlpo and amikacin were used to evaluate the antibiofilm activity against resistant l. monocytogenes and s. typhi. prophylactic effects of bmlpo against l. monocytogenes and s. typhi bacteremia in vivo have b ...201728587762
the rcs-regulated colanic acid capsule maintains membrane potential in salmonella enterica serovar typhimurium.the rcs phosphorelay and psp (phage shock protein) systems are envelope stress responses that are highly conserved in gammaproteobacteria. the rcs regulon was found to be strongly induced during metal deprivation of salmonella enterica serovar typhimurium lacking the psp response. nineteen genes activated by the rcsa-rcsb response regulator make up an operon responsible for the production of colanic acid capsular polysaccharide, which promotes biofilm development. despite more than half a centur ...201728588134
evaluation of phenolic profile and antibacterial bioactivities of nigella sativa l. seed extracts.black cumin (nigella sativa l. [n. sativa]) seed extracts demonstrated numerous beneficial biological effects including, among others, antidiabetic, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, antihypertensive, and antioxidant activity. to better understand the phytochemical composition of n. sativa seeds, methanol seed extracts were analyzed for phenolic acid and flavonoid content. furthermore, we tested n. sativa methanol, n-hexane, and aqueous seed extracts for their inhib ...201728590231
what were the risk factors and trends in antimicrobial resistance for enteric fever in london 2005-2012?a study was undertaken to determine the risk factors and trends in antimicrobial resistance for enteric fever.201728590238
transcriptomic analysis of the swarm motility phenotype of salmonella enterica serovar typhimurium mutant defective in periplasmic glucan synthesis.movement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. salmonella enterica serovar typhimurium mutants defective in osmoregulated periplasmic glucans (opg) synthesis are unable to exhibit motility on moist surfaces (swarming); however, their mobility in liquid (swim motility) remains unaffected. in order to understand the role of opg in swarm motility, transcriptomic analysis was perform ...201728593349
a versatile toolbox for the control of protein levels using n(ε)-acetyl-l-lysine dependent amber suppression.the analysis of the function of essential genes in vivo depends on the ability to experimentally modulate levels of their protein products. current methods to address this are based on transcriptional or post-transcriptional regulation of mrnas, but approaches based on the exploitation of translation regulation have so far been neglected. here we describe a toolbox, based on amber suppression in the presence of n(ε)-acetyl-l-lysine (ack), for translational tuning of protein output. we chose the ...201728594177
draft genome sequences of salmonella lysozyme gene knockout mutants.lysozyme enzymes hydrolyze the β-1,4-glycosidic bond in oligosaccharides. these enzymes are part of a broad group of glucoside hydrolases that are poorly characterized; however, they are important for growth and are being recognized as emerging virulence factors. this is the release of four lysozyme-encoding-gene-deletion mutants in salmonella enterica serovar typhimurium lt2.201728596411
a functional metagenomic analysis of tetracycline resistance in cheese bacteria.metagenomic techniques have been successfully used to monitor antibiotic resistance genes in environmental, animal and human ecosystems. however, despite the claim that the food chain plays a key role in the spread of antibiotic resistance, metagenomic analysis has scarcely been used to investigate food systems. the present work reports a functional metagenomic analysis of the prevalence and evolution of tetracycline resistance determinants in a raw-milk, blue-veined cheese during manufacturing ...201728596758
application of long amplicon propidium monoazide-pcr to assess the effects of temperature and background microbiota on pathogens in river water.the decay rates of enteric waterborne pathogens were evaluated following the introduction of yersinia enterocolitica, salmonella enterica, campylobacter jejuni and arcobacter butzleri into river water at different temperatures (5, 15 and 25°c) for a period of 28 days. to improve the accuracy of the results a molecular viability assay, long amplicon propidium monoazide-polymerase chain reaction (pma-pcr), was used to quantify the viable cell concentration and results from pcr with and without pma ...201728598346
histopathology case definition of naturally acquired salmonella enterica serovar dublin infection in young holstein cattle in the northeastern united states.salmonella enterica subsp. enterica serovar dublin ( salmonella dublin) is a host-adapted bacterium that causes high morbidity and mortality in dairy cattle worldwide. a retrospective search of archives at the new york animal health diagnostic center revealed 57 culture-confirmed salmonella dublin cases from new york and pennsylvania in which detailed histology of multiple tissues was available. tissues routinely submitted by referring veterinarians for histologic evaluation included sections of ...201728599615
non-typhi salmonella enterica urinary tract infections.non-typhi salmonella enterica urinary tract infections (utis) are not frequent and rarely reported in the literature. we aimed to characterize clinical presentations and risk factors for the infection.201728600113
schmallenberg virus infection confirmed in scotland.schmallenberg virus infection in malformed lambsfood chain issues after lead poisoning incidentsuspected ragwort poisoning in heifersewe abortions due to salmonella enterica serovar urbanacoxiella burnetii detected in aborted lambsthese are among matters discussed in the disease surveillance report for february 2017 from sac consulting: veterinary services (sac c vs).201728600415
molecular subtyping of salmonella typhimurium with multiplex oligonucleotide ligation-pcr (mol-pcr).a multiplex oligonucleotide ligation-pcr (mol-pcr) assay is a valuable high-throughput technique for the detection of bacteria and viruses, for characterization of pathogens and for diagnosis of genetic diseases, as it allows one to combine different types of molecular markers in a high-throughput multiplex assay. a mol-pcr assay starts with a multiplex oligonucleotide ligation reaction for detection of the molecular marker, followed by a singleplex pcr for signal amplification and analysis of t ...201728600761
the snake raiser lung: an unusual cause of salmonella enterica subspecies arizonae pneumonia. 201728602385
a role for the tetraspanin proteins in salmonella infection of human macrophages.infected macrophages play a role in the dissemination of salmonella and may serve as a reservoir of infection in asymptomatic carriers. however, relatively little is known about the early molecular interactions of the bacteria with these cells. we have recently shown that members of the tetraspanin family of membrane proteins are involved in the initial adhesion of a range of bacteria to host cells. this study investigated the role of tetraspanins in salmonella enterica subsp. enterica serovar t ...201728602860
bdm-mediated regulation of flagellar biogenesis in escherichia coli and salmonella enterica serovar typhimurium.synthesis of the flagellar apparatus in escherichia coli is mediated via complex regulatory pathways. a previous study indicated that the protein encoded by the biofilm-dependent modulation (bdm) gene is linked closely with a regulatory pathway for flagellar assembly. however, the specific role of bdm in flagellar biogenesis remains unknown. herein, we showed that bdm interacts with flgm and inhibits its function as an anti-σ28 factor, which induces the transcription of flagellar late-class gene ...201728603807
oxidation of phosphorothioate dna modifications leads to lethal genomic instability.genomic modification by sulfur in the form of phosphorothioate (pt) is widespread among prokaryotes, including human pathogens. apart from its physiological functions, pt sulfur has redox and nucleophilic properties that suggest effects on bacterial fitness in stressful environments. here we show that pts are dynamic and labile dna modifications that cause genomic instability during oxidative stress. in experiments involving isotopic labeling coupled with mass spectrometry, we observed sulfur re ...201728604692
comparison of methods for detection of plasmid-mediated and chromosomally encoded colistin resistance in enterobacteriaceae.because of the emergence of plasmid-mediated (mcr-1 and mcr-2 genes) and chromosomally encoded colistin resistance, reliable methods for detecting colistin resistance/susceptibility in routine laboratories are required. we evaluated the respective performances of the bd phoenix automated system, the newly developed rapid polymyxin np test and the broth microdilution (bmd) reference method to detect colistin resistance in enterobacteriaceae, and particularly those producing mcr-1 and mcr-2.201728606644
resistance to the cyclotide cycloviolacin o2 in salmonella enterica caused by different mutations that often confer cross-resistance or collateral sensitivity to other antimicrobial peptides.antimicrobial peptides (amps) are essential components of innate immunity in all living organisms, and these potent broad-spectrum antimicrobials have inspired several antibacterial development programs in the past 2 decades. in this study, the development of resistance to the gram-negative bacterium-specific peptide cycloviolacin o2 (cyo2), a member of the cyclotide family of plant miniproteins, was characterized in salmonella enterica serovar typhimurium lt2. mutants isolated from serial passa ...201728607015
anaerobic cysteine degradation and potential metabolic coordination in salmonella enterica and escherichia coli.salmonella enterica has two cyur-activated enzymes that degrade cysteine, i.e., the aerobic cdsh and an unidentified anaerobic enzyme; escherichia coli has only the latter. to identify the anaerobic enzyme, transcript profiling was performed for e. coli without cyur and with overexpressed cyur thirty-seven genes showed at least 5-fold changes in expression, and the cyupa (formerly yhaom) operon showed the greatest difference. homology suggested that cyup and cyua represent a cysteine transporter ...201728607157
rna target profiles direct the discovery of virulence functions for the cold-shock proteins cspc and cspe.the functions of many bacterial rna-binding proteins remain obscure because of a lack of knowledge of their cellular ligands. although well-studied cold-shock protein a (cspa) family members are induced and function at low temperature, others are highly expressed in infection-relevant conditions. here, we have profiled transcripts bound in vivo by the cspa family members of salmonella enterica serovar typhimurium to link the constitutively expressed cspc and cspe proteins with virulence pathways ...201728611217
in vitro characterization of lactobacillus plantarum strains with inhibitory activity on enteropathogens for use as potential animal probiotics.the present study evaluates the probiotic properties of three lactobacillus plantarum strains mjm60319, mjm60298, and mjm60399 possessing antimicrobial activity against animal enteric pathogens. the three strains did not show bioamine production, mucinolytic and hemolytic activity and were susceptible to common antibiotics. the l. plantarum strains survived well in the simulated orogastrointestinal transit condition and showed adherence to caco-2 cells in vitro. the l. plantarum strains showed s ...201728611498
the potential of a brown microalga cultivated in high salt medium for the production of high-value compounds.amphora sp. was isolated from the sfax solar saltern and cultivated under hypersaline conditions. it contains moderate rates of proteins, lipids, sugars, and minerals and a prominent content of bioactive compounds: polyphenols, chlorophyll a, carotenoids, and fatty acids. the analysis of fatty acids with gc/ms showed that the c16 series accounted for about 75% of amphora sp. lipids. saturated fatty acids whose palmitic acid was the most important (27.41%) represented 41.31%. amphora sp. was foun ...201728612024
in vitro and in vivo generation of heterophil extracellular traps after salmonella exposure.the release of extracellular traps (ets) by granulocytes is a unique strategy to stop the dissemination of microbial pathogens. this study was undertaken to elucidate the potential of avian granulocytes (heterophils) to form ets that can arrest and kill salmonella organisms. after in vitro exposure of isolated heterophils and in vivo infection of day-old chicks with salmonella enterica subsp. enterica serovars infantis (si) or enteritidis (se), the generation of ets as well as the trapping and s ...201728615122
vaccination against salmonella infection: the mucosal way.salmonella enterica subspecies enterica includes several serovars infecting both humans and other animals and leading to typhoid fever or gastroenteritis. the high prevalence of associated morbidity and mortality, together with an increased emergence of multidrug-resistant strains, is a current global health issue that has prompted the development of vaccination strategies that confer protection against most serovars. currently available systemic vaccine approaches have major limitations, includ ...201728615285
development of biopolymer composite films using a microfluidization technique for carboxymethylcellulose and apple skin particles.biopolymer films based on apple skin powder (asp) and carboxymethylcellulose (cmc) were developed with the addition of apple skin extract (ase) and tartaric acid (ta). asp/cmc composite films were prepared by mixing cmc with asp solution using a microfluidization technique to reduce particle size. then, various concentrations of ase and ta were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. fourier transform infrared (ftir), optical, mechanical, w ...201728617325
genetic analysis of salmonella enterica serovar gallinarum biovar pullorum based on characterization and evolution of crispr sequence.salmonella enterica serovar gallinarum biovar pullorum (s. pullorum) is the cause of pullorum disease, characterized by white diarrhea, which leads to high mortality in poultry. in this study, we aimed to assess the genetic diversity of 655 s. pullorum strains from 1962 to 2015 in china, europe, and south america. a sequence typing scheme based on clustered regularly interspaced short palindromic repeats (crispr) was used to reveal the genetic relationships among these strains in this study. ove ...201728619172
coupling killing to neutralization: combined therapy with ceftriaxone/pep19-2.5 counteracts sepsis in rabbits.sepsis, which is induced by severe bacterial infections, is a major cause of death worldwide, and therapies combating the disease are urgently needed. because many drugs have failed in clinical trials despite their efficacy in mouse models, the development of reliable animal models of sepsis is in great demand. several studies have suggested that rabbits reflect sepsis-related symptoms more accurately than mice. in this study, we evaluated a rabbit model of acute sepsis caused by the intravenous ...201728620220
inactivation of nonpathogenic escherichia coli, escherichia coli o157:h7, salmonella enterica typhimurium, and listeria monocytogenes in ice using a uvc light-emitting diode.ice, widely used in the food industry, is a potential cause of food poisoning resulting from microbial contamination. direct microbial inactivation of ice is necessary because microorganisms may have been present in the source water used to make it and/or may have been introduced due to poor hygiene during production or handling of the ice. nonthermal and nondestructive microbial inactivation technologies are needed to control microorganisms in ice. we evaluated the applicability of a uvc light- ...201728621585
indigenous probiotic lactobacillus isolates presenting antibiotic like activity against human pathogenic bacteria.indigenous lactic acid bacteria are well known probiotics having antibacterial activity against potentially pathogenic bacteria. this study aims to characterize the curd lactobacilli for their probiotic potentiality and antagonistic activity against clinical bacteria.201728621711
metabolic fingerprinting of bacteria by fluorescence lifetime imaging microscopy.bacterial populations exhibit a range of metabolic states influenced by their environment, intra- and interspecies interactions. the identification of bacterial metabolic states and transitions between them in their native environment promises to elucidate community behavior and stochastic processes, such as antibiotic resistance acquisition. in this work, we employ two-photon fluorescence lifetime imaging microscopy (flim) to create a metabolic fingerprint of individual bacteria and populations ...201728623341
characterization of a blandm‑1‑harboring plasmid from a salmonella enterica clinical isolate in china.the plasmid-mediated transmission of antibiotic resistance genes has been reported to be involved in the development of antibiotic resistance in bacteria, and poses a serious threat for the success of bacterial infection treatment and human health worldwide. the present study used a 454 gs‑flx pyrosequencing system to determine the ~140 kb nucleotide sequence of plasmid phs36‑ndm, which was identified in a salmonella stanley isolate from the stool sample of an 11‑month‑old girl at lishui central ...201728627648
elimination of persistent vaccine bacteria of salmonella enterica serovar typhimurium in the guts of immunized mice by inducible expression of truncated ynce.orally administered vaccine bacteria usually persist for a period of time in the intestinal tracts of immunized individuals, and are excreted in feces to the environment resulting in a potential biosafety issue. the releasing risk can be minimized by immediate elimination of the persistent vaccine bacteria once adequate protective immune responses have been elicited by the vaccine bacteria. in a previous study, inducible expression of truncated ynce gene (ynce*) was found lethal to host bacteria ...201728628661
antibacterial activity of crude extracts of some south african medicinal plants against multidrug resistant etiological agents of diarrhoea.this study evaluated the antibacterial activity of some plants used in folklore medicine to treat diarrhoea in the eastern cape province, south africa.201728629407
atp-synthesis capacity of pulsed light-exposed bacteria.the ability of four different bacteria to synthesize new atp upon exposure to different doses of pulsed-light (pl) irradiation was investigated. the bacterial cells were pl treated on a gel surface, resuspended in phosphate buffered saline (pbs) and subsequently incubated in tryptic soy broth (tsb) at 37°c. cellular atp levels were monitored during a 2h incubation period and compared to the respective colony count data. although pl affected atp production in a dose dependent manner, the results ...201728629639
sipa activation of caspase-3 is a decisive mediator of host cell survival at early stages of salmonella enterica serovar typhimurium infection.salmonella invasion protein a (sipa) is a dual-function effector protein that plays roles in both actin polymerization and caspase-3 activation in intestinal epithelial cells. to date its function in other cell types has remained largely unknown despite its expression in multiple cell types and its extracellular secretion during infection. here we show that in macrophages sipa induces increased caspase-3 activation early in infection. this activation required a threshold level of sipa linked to ...201728630067
new insights into the roles of lpf and stg fimbriae in salmonella interactions with enterocytes and m cells.salmonella enterica serovar typhi causes the systemic disease typhoid fever. after ingestion, it adheres to and invades the host epithelium while evading the host innate immune response, causing little if any inflammation. conversely, s typhimurium causes gastroenteritis in humans and thrives in the inflamed gut. upon entering the host, s typhimurium preferentially colonizes peyer's patches, a lymphoid organ in which microfold cells (m cells) overlay an arrangement of b cells, t cells, and antig ...201728630073
control of virulence gene transcription by indirect readout in vibrio cholerae and salmonella enterica serovar typhimurium.indirect readout mechanisms of transcription control rely on the recognition of dna shape by transcription factors (tfs). tfs may also employ a direct readout mechanism that involves the reading of the base sequence in the dna major groove at the binding site. tfs with winged helix-turn-helix (whth) motifs use an alpha helix to read the base sequence in the major groove while inserting a beta sheet 'wing' into the adjacent minor groove. such whth proteins are important regulators of virulence ge ...201728631437
taking control: hijacking of rab gtpases by intracellular bacterial pathogens.intracellular bacterial pathogens survive and replicate within specialized eukaryotic cell organelles. to establish their intracellular niches these pathogens have adopted sophisticated strategies to control intracellular membrane trafficking. since rab-family gtpases are critical regulators of endocytic and secretory membrane trafficking events, many intracellular pathogens have evolved specific mechanisms to modulate or hijack rab gtpases dynamics and trafficking functions. one such strategy i ...201728632996
optimization of inactivated h5n9 highly pathogenic avian influenza vaccine and inactivated salmonella enterica serovar typhimurium vaccine with antigen dose and prime-boost regimen in domestic ducks.owing to the increase in the number of diseases affecting ducks and the demand for food safety by consumers, vaccination has become one of the factors that influence duck meat productivity. the highly pathogenic avian influenza (hpai) virus is one of the most prevalent and causes one of the most lethal diseases in domestic ducks, and salmonella enterica serovar typhimurium is a food-borne pathogen persistent in the domestic duck population. to better understand the optimal usage of hpai and s. e ...201728633491
molecular characterization of salmonella from human and animal origins in uganda.sporadic salmonella outbreaks with varying clinical presentations have been on the rise in various parts of uganda. the sources of outbreaks and factors underlying the different clinical manifestation are curtailed by paucity of information on salmonella genotypes and the associated virulence genes. this study reports molecular diversity of salmonella enterica and their genetic virulence profiles among human and animal isolates. characterization was done using kauffman-white classification schem ...201728634597
regulation of escherichia coli pathogenesis by alternative sigma factor n.σ(n) (also σ(54)) is an alternative sigma factor subunit of the rna polymerase complex that regulates the expression of genes from many different ontological groups. it is broadly conserved in the eubacteria with major roles in nitrogen metabolism, membrane biogenesis, and motility. σ(n) is encoded as the first gene of a five-gene operon including rpon (σ(n)), ptsn, hpf, rapz, and npr that has been genetically retained among species of escherichia, shigella, and salmonella. in an increasing numb ...201728635589
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