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antipathogenic activity of probiotics against salmonella typhimurium and clostridium difficile in anaerobic batch culture systems: is it due to synergies in probiotic mixtures or the specificity of single strains?probiotics are currently being investigated for prevention of infections caused by enteric pathogens. the aim of this in vitro study was to evaluate the influence of three single probiotics: lactobacillus casei ncimb 30185 (pxn 37), lactobacillus acidophilus ncimb 30184 (pxn 35), bifidobacterium breve ncimb 30180 (pxn 25) and a probiotic mixture containing the above strains plus twelve other strains belonging to the lactobacillus, bifidobacterium, lactococcus, streptococcus and bacillus genera o ...201324091275
rapid immuno-analytical system physically integrated with lens-free cmos image sensor for food-borne pathogens.to realize an inexpensive, pocket-sized immunosensor system, a rapid test devise based on cross-flow immuno-chromatography was physically combined with a lens-free cmos image sensor (cis), which was then applied to the detection of the food-borne pathogen, salmonella typhimurium (s. typhimurium). two ciss, each retaining 1.3 mega pixel array, were mounted on a printed circuit board to fabricate a disposable sensing module, being connectable with a signal detection system. for the bacterial analy ...201424090753
the gdac1 locus modifies spontaneous and salmonella-induced colitis in mice deficient in either gpx2 or gpx1 gene.we previously identified the gdac1 (gpx-deficiency-associated colitis 1) locus, which influences the severity of spontaneous colitis in gpx1- and gpx2-double-knockout (gpx1/2-dko) mice. congenic gpx1/2-dko mice in the 129s1/svimj (129) background but carrying the gdac1(b6) allele have milder spontaneous colitis than 129 gpx1/2-dko mice carrying the gdac1(129) allele. here, we evaluated the effect of the gdac1(b6) allele on 129 strain non-dko mice that had a wild-type (wt) gpx1 or gpx2 allele and ...201324090658
structure, function, and on-off switching of a core unit contact between chea kinase and chew adaptor protein in the bacterial chemosensory array: a disulfide mapping and mutagenesis study.the ultrasensitive, ultrastable bacterial chemosensory array of escherichia coli and salmonella typhimurium is representative of the large, conserved family of sensory arrays that control the cellular chemotaxis of motile bacteria and archaea. the core framework of the membrane-bound array is a lattice assembled from three components: a transmembrane receptor, a cytoplasmic his kinase (chea), and a cytoplasmic adaptor protein (chew). structural studies in the field have revealed the global archi ...201324090207
the ssec translocon component in salmonella enterica serovar typhimurium is chaperoned by ssca.salmonella enterica is a causative agent of foodborne gastroenteritis and the systemic disease known as typhoid fever. this bacterium uses two type three secretion systems (t3sss) to translocate protein effectors into host cells to manipulate cellular function. salmonella pathogenicity island (spi)-2 encodes a t3ss required for intracellular survival of the pathogen. genes in spi-2 include apparatus components, secreted effectors and chaperones that bind to secreted cargo to coordinate their rel ...201324090070
salmonella prostatitis in a man with spinal cord injury.prostatitis is a very unusual manifestation of salmonella urinary tract infection and has not been reported in men with spinal cord injury (sci).201424090046
role of porin proteins in acquisition of transferrin iron by enteropathogens.acquisition of iron from key innate immune defence proteins such as transferrin (tf) and lactoferrin is an important mechanism by which pathogenic bacteria obtain essential iron for growth within their host. bacterial species that do not produce siderophores often use specific tf-binding proteins, the best characterized being the neisseriaceae-type tf-binding proteins tbpa and tbpb. previous work from our laboratory has shown that siderophore-producing enteric species such as escherichia coli al ...201324089578
antigenotoxic, and anticytotoxic activities of an ethanolic extract of lafoensia pacari (lythraceae) stem bark in bacteria and mice.lafoensia pacari (lythraceae), popularly known in brazil as "pacari", is a small tree native to the cerrado that is used in folk medicine to treat cancer and as an anti-inflammatory and cicatrizing agent. we evaluated the genotoxic, cytotoxic, antigenotoxic, and anticytotoxic activities of an ethanol extract of l. pacari stem bark (eesb) using the ames test and the mouse bone marrow micronucleus test. in the ames test, eesb did not significantly increase the number of his(+) revertants in salmon ...201324085450
growth-inhibiting and morphostructural effects of constituents identified in asarum heterotropoides root on human intestinal bacteria.the growth-inhibiting and morphostructural effects of seven constituents identified in asarum heterotropoides root on 14 intestinal bacteria were compared with those of the fluoroquinolone antibiotic ciprofloxacin.201324083511
understanding the sequential activation of type iii and type vi secretion systems in salmonella typhimurium using boolean modeling.three pathogenicity islands, viz. spi-1 (salmonella pathogenicity island 1), spi-2 (salmonella pathogenicity island 2) and t6ss (type vi secretion system), present in the genome of salmonella typhimurium have been implicated in the virulence of the pathogen. while the regulation of spi-1 and spi-2 (both encoding components of the type iii secretion system - t3ss) are well understood, t6ss regulation is comparatively less studied. interestingly, inter-connections among the regulatory elements of ...201324079299
an eimeria vaccine candidate based on eimeria tenella immune mapped protein 1 and the tlr-5 agonist salmonella typhimurium flic flagellin.immune mapped protein-1 (imp1) is a new protective protein in apicomplexan parasites, and exits in eimeria tenella. but its structure and immunogenicity in e. tenella are still unknown. in this study, impi in e. tenella was predicted to be a membrane protein. to evaluate immunogenicity of impi in e. tenella, a chimeric subunit vaccine consisting of e. tenella imp1 (etimp1) and a molecular adjuvant (a truncated flagellin, flic) was constructed and over-expressed in escherichia coli and its effica ...201324076159
new function of molybdenum trioxide nanoplates: toxicity towards pathogenic bacteria through membrane stress.inorganic nanostructures are highly recognized for their potential use in the development of new functional materials for biomedical applications. in this study, we investigated the antibacterial efficiency of molybdenum trioxide (moo3) nanoplates against four types of pathogenic bacteria. moo3 nanoplates are synthesized by a simple wet chemical approach. x-ray diffraction and ft-ir analysis showed the presence of an orthorhombic phase of moo3 nanoplates. field emission scanning electron microsc ...201324075787
chemical composition and bioactivity of essential oils of hypericum helianthemoides, hypericum perforatum and hypericum scabrum.a number hypericum species are well known for their therapeutic efficacy and use in traditional medicine. the various species of hypericum have been traditionally used for the treatment of wounds, eczema, burns, trauma, rheumatism, neuralgia, gastroenteritis, ulcers, hysteria, bedwetting and depression.201424073965
the effect of curcumin and cotrimoxazole in salmonella typhimurium infection in vivo.typhoid fever is a disease caused by salmonella typhi and commonly treated by an antimicrobial agent such as cotrimoxazole. on the other hand, herbal usage has risen as an adjunctive therapy to treat many diseases. curcuma (curcuma domestica) is a commonly used herb which consists of curcumin as its major active compound. curcumin has been known for its antimicrobial effect, but there is no proof regarding the usage of curcumin and cotrimoxazole together. this research was conducted by using typ ...201324073354
enhancement of host immune responses by oral vaccination to salmonella enterica serovar typhimurium harboring both flic and fljb flagella.flagellin, the structural component of the flagellar filament in various motile bacteria, can contribute to the activation of nf-κb and proinflammatory cytokine expression during the innate immune response in host cells. thus, flagellin proteins represent a particularly attractive target for the development of vaccine candidates. in this study, we investigated the immune response by increasing the flagella number in the iacp mutant strain and the adjuvant activity of the flagellin component fljb ...201324069357
lymph node colonization dynamics after oral salmonella typhimurium infection in mice.an understanding of how pathogens colonize their hosts is crucial for the rational design of vaccines or therapy. while the molecular factors facilitating the invasion and systemic infection by pathogens are a central focus of research in microbiology, the population biological aspects of colonization are still poorly understood. here, we investigated the early colonization dynamics of salmonella enterica subspecies 1 serovar typhimurium (s. tm) in the streptomycin mouse model for diarrhea. we f ...201324068916
development of a novel hexa-plex pcr method for identification and serotyping of salmonella species.salmonella is one of the most important foodborne pathogens, which causes a huge economic burden worldwide. to detect salmonella rapidly is very meaningful in preventing salmonellosis and decreasing economic losses. currently, isolation of salmonella is confirmed by biochemical and serobased serotyping methods, which are time consuming, labor intensive, and complicated. to solve this problem, a hexa-plex polymerase chain reaction (pcr) method was developed using comparative genomics analysis and ...201424066904
antitumour and anti-inflammatory effects of palladium(ii) complexes on ehrlich tumour.palladium(ii) complexes are an important class of cyclopalladated compounds that play a pivotal role in various pharmaceutical applications. here, we investigated the antitumour, anti-inflammatory, and mutagenic effects of two complexes: [pd(dmba)(cl)tu] (1) and [pd(dmba)(n3)tu] (2) (dmba = n,n-dimethylbenzylamine and tu = thiourea), on ehrlich ascites tumour (eat) cells and peritoneal exudate cells (pecs) from mice bearing solid ehrlich tumour. the cytotoxic effects of the complexes on eat cell ...201324066514
antimicrobial activity and cytotoxicity of some 2-amino-5-alkylidene-thiazol-4-ones.we report a small, focused library of 30 diverse 2-amino-5-alkylidene-thiazol-4-ones that was assayed in a whole-cell antibacterial screen against a panel of several bacterial strains and a yeast. most of the compounds exhibited modest to significant antibacterial activity against pseudomonas aeruginosa, bacillus subtilis and staphylococcus aureus, and no activity against salmonella typhimurium and escherichia coli. the antibacterial activity depends markedly upon substituents on the thiazol-4-o ...201324062019
a novel csra titration mechanism regulates fimbrial gene expression in salmonella typhimurium.a hierarchical control of fimbrial gene expression limits laboratory grown cultures of salmonella enterica serovar typhimurium (s. typhimurium) to the production of type i fimbriae encoded by the fimaicdhf operon. here we show that an unlikely culprit, namely the 5'-untranslated region (5'-utr) of a messenger (m)rna, coordinated the regulation. binding of csra to the 5'-utr of the pefacdef transcript was required for expression of plasmid-encoded fimbriae. the 5'-utr of the fimaicdhf transcript ...201324056837
preadaptation to cold stress in salmonella enterica serovar typhimurium increases survival during subsequent acid stress exposure.salmonella is an important cause of bacterial food-borne gastroenteritis. salmonella encounters multiple abiotic stresses during pathogen elimination methods used in food processing, and these stresses may influence its subsequent survivability within the host or in the environment. upon ingestion, salmonella is exposed to gastrointestinal acidity, a first line of the host innate defense system. this study tested the hypothesis that abiotic stresses encountered during food processing alter the m ...201324056458
real-time and sensitive detection of salmonella typhimurium using an automated quartz crystal microbalance (qcm) instrument with nanoparticles amplification.the accidental contamination of salmonella in raw and processed foods is a major problem for the food industry worldwide. at present many of the currently used methods for salmonella detection are time and labour intensive. therefore, rapid detection is a key to the prevention and identification of problems related to health and safety. this paper describes the application of a new quartz crystal microbalance (qcm) instrument with a microfluidic system for the rapid and real time detection of sa ...201324054660
identification of potent inhibitors for salmonella typhimurium quorum sensing via virtual screening and pharmacophore modeling.the quorum sensing (qs) enhanced transcriptional regulator sdia of s. typhimurium is the best known and potential target and responds to a broad range of ahls and ahl analogs. on the other hand, in many gram-negative bacteria including s. typhimurium, brominated furanones were reported to have inhibitory activity against the qs phenotypes. motivated by both, we designed an in silico group of halogenated ahls by substituting halogen compounds (br, cl, f and i) on the lactone ring of ahls and anal ...201324050691
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
probing the arca regulon under aerobic/ros conditions in salmonella enterica serovar typhimurium.hydrogen peroxide (h₂o₂) is a reactive oxygen species (ros), which is part of the oxidative burst encountered upon internalization of salmonella enterica serovar typhimurium (s. typhimurium) by phagocytic cells. it has previously been established that, the arcab two-component system plays a critical role in ros resistance, but the genes regulated by the system remained undetermined to date. we therefore investigated the arca regulon in aerobically growing s. typhimurium before and after exposure ...201324044554
inflammatory responses induced by lipopolysaccharide are amplified in primary human monocytes but suppressed in macrophages by complement protein c5a.monocytes and macrophages are important innate immune cells equipped with danger-sensing receptors, including complement and toll-like receptors. complement protein c5a, acting via c5ar, is shown in this study to differentially modulate lps-induced inflammatory responses in primary human monocytes versus macrophages. whereas c5a enhanced secretion of lps-induced il-6 and tnf from primary human monocytes, c5a inhibited these responses while increasing il-10 secretion in donor-matched human monocy ...201324043889
fimy does not interfere with fimz-fimw interaction during type 1 fimbria production by salmonella enterica serovar typhimurium.the production of type 1 fimbriae in salmonella enterica serovar typhimurium is controlled, in part, by three proteins, fimz, fimy, and fimw. amino acid sequence analysis indicates that fimz belongs to the family of bacterial response regulators of two-component systems. in these studies, we have demonstrated that introducing a mutation mimicking phosphorylation of fimz is necessary for activation of its target gene, fima. in addition, the interaction of fimz with fimw, a repressor of fima expre ...201324042120
new decontamination method based on caprylic acid in combination with citric acid or vanillin for eliminating cronobacter sakazakii and salmonella enterica serovar typhimurium in reconstituted infant formula.the antimicrobial effects of natural compounds (caprylic acid, ca; citric acid, cta; and vanillin, vnl) on the inactivation of cronobacter sakazakii and salmonella enterica serovar typhimurium were examined in reconstituted infant formula. the samples were treated with: 1) ca, cta, or vnl alone (0, 10, 20, 30, 40, 60, and 80 mm); 2) a combination of ca (10 and 20 mm) and cta (15 and 30 mm); and 3) a combination of ca (10 and 20 mm) and vnl (15 and 30 mm), at mild feeding temperatures (40 °c and ...201324042002
commensal akkermansia muciniphila exacerbates gut inflammation in salmonella typhimurium-infected gnotobiotic mice.excessive mucin degradation by intestinal bacteria may contribute to inflammatory bowel diseases because access of luminal antigens to the intestinal immune system is facilitated. this study investigated how the presence of a mucin degrading commensal bacterium affects the severity of an intestinal salmonella enterica typhimurium-induced gut inflammation. using a gnotobiotic c3h mouse model with a background microbiota of eight bacterial species (sihumi) the impact of the mucin-degrading commens ...201324040367
use of quantitative microbial risk assessment when investigating foodborne illness outbreaks: the example of a monophasic salmonella typhimurium 4,5,12:i:- outbreak implicating beef burgers.a major community outbreak of salmonellosis occurred in france in october 2010. classical epidemiological investigations led to the identification of beef burgers as the cause of the outbreak and the presence of the emerging monophasic salmonella typhimurium 4,5,12:i:-. the objective of this study was to understand the events that led to this large outbreak, that is to say, what are the contributing factors associated with consumer exposure to salmonella. to this end, intensive microbiological i ...201324036262
requirement for cobalamin by salmonella enterica serovars typhimurium, pullorum, gallinarum and enteritidis during infection in chickens.salmonella enterica serovar typhimurium synthesizes cobalamin (vitamin b12) only during anaerobiosis. two percent of the s. typhimurium genome is devoted to the synthesis and uptake of vitamin b12 and to b12-dependent reactions. to understand the requirement for cobalamin synthesis better, we constructed mutants of salmonella serovars enteritidis and pullorum that are double-defective in cobalamin biosynthesis (δcobsδcbia). we compared the virulence of these mutants to that of their respective w ...201124031771
an investigation on in vitro and in vivo antimicrobial properties of the antidepressant: amitriptyline hydrochloride.the antidepressant drug amitriptyline hydrochloride was obtained in a dry powder form and was screened against 253 strains of bacteria which included 72 gram positive and 181 gram negative bacteria and against 5 fungal strains. the minimum inhibitory concentration (mic) was determined by inoculating a loopful of an overnight peptone water culture of the organism on nutrient agar plates containing increasing concentrations of amitriptyline hydrochloride (0, 10 μg/ml, 25 μg/ml, 50 μg/ml, 100 μg/ml ...201024031539
the contribution of genes required for anaerobic respiration to the virulence of salmonella enterica serovar gallinarum for chickens.salmonella enterica serovar gallinarum (sg) is an intracellular pathogen of chickens. to survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. the fumarate reductase (frdabcd), dimethyl sulfoxide (dmso)-trimethylamine n-oxide (tmao) reductase (dmsabc), and nitrate reductase (narghij) operons in salmonella typhimurium (stm) encode enzymes involved in anaerobic respiration to the electron acceptors fumara ...200924031452
distinguishable epidemics of multidrug-resistant salmonella typhimurium dt104 in different hosts.the global epidemic of multidrug-resistant salmonella typhimurium dt104 provides an important example, both in terms of the agent and its resistance, of a widely disseminated zoonotic pathogen. here, with an unprecedented national collection of isolates collected contemporaneously from humans and animals and including a sample of internationally derived isolates, we have used whole-genome sequencing to dissect the phylogenetic associations of the bacterium and its antimicrobial resistance genes ...201324030491
entropic origin of cobalt-carbon bond cleavage catalysis in adenosylcobalamin-dependent ethanolamine ammonia-lyase.adenosylcobalamin-dependent enzymes accelerate the cleavage of the cobalt-carbon (co-c) bond of the bound coenzyme by >10(10)-fold. the cleavage-generated 5'-deoxyadenosyl radical initiates the catalytic cycle by abstracting a hydrogen atom from substrate. kinetic coupling of the co-c bond cleavage and hydrogen-atom-transfer steps at ambient temperatures has interfered with past experimental attempts to directly address the factors that govern co-c bond cleavage catalysis. here, we use time-reso ...201324028405
antibacterial effect of light emitting diodes of visible wavelengths on selected foodborne pathogens at different illumination temperatures.the antibacterial effect of light emitting diodes (leds) in the visible region (461, 521 and 642 nm) of the electromagnetic spectrum was investigated on escherichia coli o157:h7, salmonella typhimurium, listeria monocytogenes and staphylococcus aureus. the irradiances of the 461, 521 and 642 nm leds were 22.1, 16 and 25.4 mw/cm², respectively. bacterial cultures suspended in tryptic soy broth were illuminated by 10-watt leds at a distance of 4.5 cm for 7.5h at 20, 15 and 10 °c. regardless of the ...201324026011
plum coatings of lemongrass oil-incorporating carnauba wax-based nanoemulsion.nanoemulsions containing lemongrass oil (lo) were developed for coating plums and the effects of the nanoemulsion coatings on the microbial safety and physicochemical storage qualities of plums during storage at 4 and 25 °c were investigated. the emulsions used for coating were produced by mixing a carnauba wax-based solution (18%, w/w) with lo at various concentrations (0.5% to 4.0%, w/w) using dynamic high pressure processing at 172 mpa. the coatings were evaluated for their ability to inhibit ...201324024904
a novel role for antibiotic resistance plasmids in facilitating salmonella adaptation to non-host environments.it is believed that the main role of plasmids that encode multiple antibiotic resistance is to confer their hosts the ability to survive in the presence of antimicrobial compounds. in the pathogenic bacterium salmonella, plasmids of the incompatibility group hi1 account for a significant proportion of antibiotic resistance phenotypes. in this work, we show that plasmid r27 has a strong impact on the global transcriptome of salmonella typhimurium strain sl1344 when cells grow at low temperature a ...201424024872
insights into the cross-immunity mechanism within effector families of bacteria type vi secretion system from the structure of sttae4-ectai4 complex.the gram-negative bacteria type vi secretion system (t6ss) has been found to play an important role in interbacterial competition, biofilm formation and many other virulence-related processes. the bacteria harboring t6ss inject the effectors into their recipient's cytoplasm or periplasm to kill them and meanwhile, to avoid inhibiting itself, the cognate immunity proteins were produced to acts as the effector inhibitor. tae4 (type vi amidase effector 4) and tai4 (type vi amidase immunity 4) are n ...201324023903
a novel insight on signal transduction mechanism of rcscdb system in salmonella enterica serovar typhimurium.the rcscdb system of salmonella enterica serovar typhimurium is implicated in the control of capsule and flagella synthesis. the hybrid sensor rcsc, the phosphotransferase rcsd and the rcsb regulator, constitute the main components of the rcscdb system. the proposed rcs signaling cascade involves the autophosphorylation of rcsc and the transfer of the phosphate group to rcsb, mediated by rcsd. we previously reported that the overexpression of rcsb repress the transcription of rcsd by an autoregu ...201324023746
antimutagenic potential and modulation of carcinogen-metabolizing enzymes by ginger essential oil.essential oil extracted from ginger (geo) was evaluated for its mutagenicity to salmonella typhimurium ta 98, ta 100, ta 102, and ta 1535 strains with and without microsomal activation. geo was found to be non-mutagenic up to a concentration of 3 mg/plate. it was also assessed for antimutagenic potential against direct acting mutagens such as sodium azide, 4-nitro-o-phenylenediamine, n-methyl-n'-nitro-n-nitrosoguanidine, tobacco extract, and 2-acetamidoflourene, which needs microsomal activation ...201424023002
fate of e. coli o157:h7, salmonella spp. and potential surrogate bacteria on apricot fruit, following exposure to uv-c light.some soft fruit, such as tree-ripened apricots, cannot be washed with aqueous sanitizers, due to their innate softness and delicate surfaces. in this study, ultraviolet-c (uv-c) light was investigated for its efficacy in inactivating 4-5 individual strains of escherichia coli o157:h7 and salmonella spp. on apricots, in addition to a four-strain composite of shiga toxin-negative e. coli o157:h7 and a cocktail of three attenuated strains of salmonella typhimurium and salmonella typhimurium lt2. al ...201324021820
effect of various conditions on inactivation of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes in fresh-cut lettuce using ultraviolet radiation.the effect of various conditions on inactivation of foodborne pathogens and quality of fresh-cut lettuce during ultraviolet (254 nm, uvc) radiation was investigated. lettuce was inoculated with a cocktail of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes and treated at different temperatures (4 and 25 °c), distances between sample and lamp (10 and 50 cm), type of exposure (illuminated from one or two sides), uv intensities (1.36 to 6.80 mw/cm²), and exposure times ( ...201324021819
is there any association between imidapril hydrochloride stability profile under dry air conditions and cancer initiation?stability study for imidapril hydrochloride (imd) was performed under stress conditions of increased temperature (t=373 k) and decreased relative air humidity (rh=0%) in order to obtain and identify its degradation product. the degradation sample stored for 15 days under the above environmental conditions was analyzed by lc-ms technique and it was found that the only degradation impurity formed in the course of the investigated drug degradation was imd diketopiperazine derivative (dkp) which was ...201324021249
conformational changes of the bacterial type i atp-binding cassette importer hisqmp2 at distinct steps of the catalytic cycle.prokaryotic solute binding protein-dependent atp-binding cassette import systems are divided into type i and type ii and mechanistic differences in the transport process going along with this classification are under intensive investigation. little is known about the conformational dynamics during the catalytic cycle especially concerning the transmembrane domains. the type i transporter for positively charged amino acids from salmonella enterica serovar typhimurium (lao-hisqmp2) was studied by ...201424021237
probiotic characterization of potential hydrolases producing lactococcus lactis subsp. lactis isolated from pickled yam.the aim of this study was to characterize potential probiotic strain co-producing α-amylase and β-galactosidase. sixty-three strains, isolated from pickle samples were screened for their hydrolase producing capacity by utilizing different starches as carbon source. one out of 63 strains, isolated from traditionally fermented pickled yam showing maximum hydrolase activity (α-amylase (36.9 u/ml) and β-galactosidase (42.6 u/ml)) within a period of 48 hours was identified as lactococcus lactis subsp ...201424020495
tetracycline accelerates the temporally-regulated invasion response in specific isolates of multidrug-resistant salmonella enterica serovar typhimurium.multidrug-resistant (mdr) salmonella isolates are associated with increased morbidity compared to antibiotic-sensitive strains and are an important health and safety concern in both humans and animals. salmonella enterica serovar typhimurium is a prevalent cause of foodborne disease, and a considerable number of s. typhimurium isolates from humans and livestock are resistant to three or more antibiotics. the majority of these mdr s. typhimurium isolates are resistant to tetracycline, a commonly ...201324020473
novel determinants of intestinal colonization of salmonella enterica serotype typhimurium identified in bovine enteric infection.cattle are naturally infected with salmonella enterica serotype typhimurium and exhibit pathological features of enteric salmonellosis that closely resemble those in humans. cattle are the most relevant model of gastrointestinal disease resulting from nontyphoidal salmonella infection in an animal with an intact microbiota. we utilized this model to screen a library of targeted single-gene deletion mutants to identify novel genes of salmonella typhimurium required for survival during enteric inf ...201324019407
hfq and arca are involved in the stationary phase-dependent activation of salmonella pathogenicity island 1 (spi1) under shaking culture conditions.in salmonella enterica serovar typhimurium, many genes encoded within salmonella pathogenicity island 1 (spi1) are required to induce intestinal/diarrheal disease. in this study, we compared the expression of four spi1 genes (hila, invf, prgh, and sipc) under shaking and standing culture conditions and found that the expression of these genes was highest during the transition from the exponential to stationary phase under shaking conditions. to identify regulators associated with the stationary ...201324018968
surface activation of graphene oxide nanosheets by ultraviolet irradiation for highly efficient anti-bacterials.a comprehensive investigation of anti-bacterial properties of graphene oxide (go) and ultraviolet (uv) irradiated go nanosheets was carried out. microscopic characterization revealed that the go nanosheet-like structures had wavy features and wrinkles or thin grooves. fundamental surface chemical states of go nanosheets (before and after uv irradiation) were investigated using x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. minimum inhibitory concentration (mic) resu ...201324013671
cytotoxic, pro-apoptotic, pro-oxidant, and non-genotoxic activities of a novel copper(ii) complex against human cervical cancer.cisplatin remains one of the most effective current chemotherapeutic agents; however, metal complexes synthesis has increased in order to produce new anti-neoplastic drugs with dna binding and apoptotic activities in tumor cells and less toxicity for patients. in this study, we evaluated the cytotoxic activity of a novel copper(ii) complex (lqm402) against cervical cancer cell lines and found that lqm402 exhibited selective cytotoxicity against hela and ca ski cells. fitc-annexin assay and dna f ...201324012731
effect of cell immobilization on heat-induced sublethal injury of escherichia coli, salmonella typhimurium and listeria innocua.the occurrence of sublethally injured cells in foods poses major public health concerns and is an essential aspect when assessing the microbial response to food preservation strategies, yet there is limited research dealing with its specific implications for mild heating. all available studies so far have been performed in broths colonized by planktonic cells, although their susceptibility to lethal agents has often been reported to be markedly different to the stress tolerance of cell colonies ...201324010617
lactic acid resistance of shiga toxin-producing escherichia coli and multidrug-resistant and susceptible salmonella typhimurium and salmonella newport in meat homogenate.this study compared lactic acid resistance of individual strains of wild-type and rifampicin-resistant non-o157 shiga toxin-producing escherichia coli (stec) and of susceptible and multidrug-resistant (mdr) and/or mdr with acquired ampc gene (mdr-ampc) salmonella against e. coli o157:h7. after inoculation of sterile 10% beef homogenate, lactic acid was added to a target concentration of 5%. before acid addition (control), after acid addition (within 2 s, i.e. time-0), and 2, 4, 6 and 8 min after ...201324010606
proof-of-concept study for successful inter-laboratory comparison of mlva results.multiple-locus variable-number of tandem repeats analysis (mlva) is widely used for typing of pathogens. methods such as mlva based on determining dna fragment size by the use of capillary electrophoresis have an inherent problem as a considerable offset between measured and real (sequenced) lengths is commonly observed. this discrepancy arises from variation within the laboratory set-up used for fragment analysis. to obtain comparable results between laboratories using different set-ups, some f ...201324008232
use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the σ⁵⁴ (rpon) regulon of salmonella typhimurium lt2.sigma54, or rpon, is an alternative σ factor found widely in eubacteria. a significant complication in analysis of the global σ⁵⁴ regulon in a bacterium is that the σ⁵⁴ rna polymerase holoenzyme requires interaction with an active bacterial enhancer-binding protein (bebp) to initiate transcription at a σ⁵⁴-dependent promoter. many bacteria possess multiple bebps, which are activated by diverse environmental stimuli. in this work, we assess the ability of a promiscuous, constitutively-active bebp ...201324007446
altered expression and localization of ion transporters contribute to diarrhea in mice with salmonella-induced enteritis.salmonella enterica serovar typhimurium is an enteropathogen that causes self-limiting diarrhea in healthy individuals, but poses a significant health threat to vulnerable populations. our understanding of the pathogenesis of salmonella-induced diarrhea has been hampered by the lack of a suitable mouse model. after a dose of oral kanamycin, salmonella-infected congenic balb/c.d2(nrampg169) mice, which carry a wild-type nramp1 gene, develop clear manifestations of diarrhea. we used this model to ...201324001788
detection of salmonella typhimurium in retail chicken meat and chicken giblets.to detect salmonella typhimurium (s. typhimurium), one of the most frequently isolated serovars from food borne outbreaks throughout the world, in retail raw chicken meat and giblets.201323998006
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
microbiota-liberated host sugars facilitate post-antibiotic expansion of enteric pathogens.the human intestine, colonized by a dense community of resident microbes, is a frequent target of bacterial pathogens. undisturbed, this intestinal microbiota provides protection from bacterial infections. conversely, disruption of the microbiota with oral antibiotics often precedes the emergence of several enteric pathogens. how pathogens capitalize upon the failure of microbiota-afforded protection is largely unknown. here we show that two antibiotic-associated pathogens, salmonella enterica s ...201323995682
redistribution and persistence of microorganisms and steroid hormones after soil-injection of swine slurry.the redistribution and fate of contaminants in pig slurry after direct injection were investigated at two field sites, silstrup (sandy clay loam) and estrup (sandy loam), in denmark. intact soil samples were collected for up to seven weeks after slurry injection and concentrations of salmonella typhimurium bacteriophage 28b (phage 28b), escherichia coli, steroid hormones and other slurry components (water, volatile solids, chloride and mineral n) determined in and around the injection slit. the ...201423994734
mixed biofilm formation by shiga toxin-producing escherichia coli and salmonella enterica serovar typhimurium enhanced bacterial resistance to sanitization due to extracellular polymeric substances.shiga toxin-producing escherichia coli o157:h7 and salmonella enterica serovar typhimurium are important foodborne pathogens capable of forming single-species biofilms or coexisting in multispecies biofilm communities. bacterial biofilm cells are usually more resistant to sanitization than their planktonic counterparts, so these foodborne pathogens in biofilms pose a serious food safety concern. we investigated how the coexistence of e. coli o157:h7 and salmonella typhimurium strains would affec ...201323992495
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
resistant mechanism study of benzalkonium chloride selected salmonella typhimurium mutants.benzalkonium chloride is one of the invaluable biocides that is extensively used in healthcare settings as well as in the food processing industry. after exposing wild-type salmonella typhimurium 14028s or its acrab inactivation mutant to gradually increasing levels of benzalkonium chloride, resistance mutants s-41, s-150, s-ab-23, s-ab-38, and s-ab-73 were selected and these mutants also showed a 2-64-fold stable minimum inhibitory concentration (mic) increase to chloramphenicol, ciprofloxacin, ...201423987991
genome and transcriptome adaptation accompanying emergence of the definitive type 2 host-restricted salmonella enterica serovar typhimurium pathovar.salmonella enterica serovar typhimurium definitive type 2 (dt2) is host restricted to columba livia (rock or feral pigeon) but is also closely related to s. typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. dt2 isolates formed a distinct phylogenetic cluster within s. typhimurium based on whole-genome-sequence polymorphisms. comparative genome analysis of dt2 94-213 and s. typhimurium sl1344, dt104, and d23580 identified few differe ...201323982073
decay of salmonella enterica, escherichia coli and bacteriophage ms2 on the phyllosphere and stored grains of wheat (triticum aestivum).cereal crops grown in the biosolids-amended soil can potentially become contaminated with pathogenic micro-organisms during growth and at the time of harvesting. there is small but unquantified potential risk of transfer of enteric pathogens to humans and animals from contaminated plants and grains. this study examined decay of escherichia coli, salmonella enterica serovar typhimurium and bacteriophage ms2 on the wheat phyllosphere and on stored grains. this was done to assess the health implica ...201423980794
mechanism of antimicrobial action of sodium metasilicate against salmonella enterica serovar typhimurium.sodium metasilicate (sms) is an alkaline antimicrobial approved by the u.s. department of agriculture for use in poultry processing and ready-to-eat poultry products. the objectives of this study were to determine the effectiveness of sms against salmonella enterica serovar typhimurium in suspension and to elucidate the antimicrobial mechanism of action of sms. salmonella typhimurium (atcc 14028) was exposed to 0 (positive control), 0.5%, 1%, 2% (wt/vol) sms and 0.1 n naoh (high ph) solutions fo ...201323980709
epithelial entry rather than the ensuing systemic immune response determines the pathogenicity of two salmonella enterica serovar typhimurium strains in a mouse model.most studies of salmonella enterica serovar typhimurium infection focus only on the pathogenicity of one strain. we investigated whether differences in pathogenicity of two wild-type s. typhimurium strains; dt120 and sl1344, were related to gut invasion or the resulting immune response. oral administration of a ten-fold lower number of sl1344 (10(6) cfu) as compared to dt120 (10(7) cfu) resulted in higher bacterial counts in liver and lymph nodes, and led to massive neutrophil infiltration of th ...201323978790
identification of salmonella typhimurium-specific dna aptamers developed using whole-cell selex and facs analysis.conventional methods for detection of infective organisms, such as salmonella, are complicated and require multiple steps, and the need for rapid detection has increased. biosensors show great potential for rapid detection of pathogens. in turn, aptamers have great potential for biosensor assay development, given their small size, ease of synthesis and labeling, lack of immunogenicity, a lower cost of production than antibodies, and high target specificity. in this study, ssdna aptamers specific ...201323978634
innate immune detection of flagellin positively and negatively regulates salmonella infection.salmonella enterica serovar typhimurium is a flagellated bacterium and one of the leading causes of gastroenteritis in humans. bacterial flagellin is required for motility and also a prime target of the innate immune system. innate immune recognition of flagellin is mediated by at least two independent pathways, tlr5 and naip5-naip6/nlrc4/caspase-1. the functional significance of each of the two independent flagellin recognition systems for host defense against wild type salmonella infection is ...201323977202
gim3e: condition-specific models of cellular metabolism developed from metabolomics and expression data.genome-scale metabolic models have been used extensively to investigate alterations in cellular metabolism. the accuracy of these models to represent cellular metabolism in specific conditions has been improved by constraining the model with omics data sources. however, few practical methods for integrating metabolomics data with other omics data sources into genome-scale models of metabolism have been developed.201323975765
epidemic increase in salmonella bloodstream infection in children, bwamanda, the democratic republic of congo.salmonella enterica is the leading cause of bloodstream infection in children in sub-saharan africa, but few data are available from central-africa. we documented during the period november 2011 to may 2012 an epidemic increase in invasive salmonella bloodstream infections in hgr bwamanda, a referral hospital in equateur province, dr congo. salmonella spp. represented 90.4 % (103 out of 114) of clinically significant blood culture isolates and comprised salmonella typhimurium (54.4 %, 56 out of ...201423975545
atg16l1 is required for autophagy in intestinal epithelial cells and protection of mice from salmonella infection.intestinal epithelial cells aid in mucosal defense by providing a physical barrier against entry of pathogenic bacteria and secreting antimicrobial peptides (amps). autophagy is an important component of immune homeostasis. however, little is known about its role in specific cell types during bacterial infection in vivo. we investigated the role of autophagy in the response of intestinal epithelial and antigen-presenting cells to salmonella infection in mice.201323973919
emergence of pulsed electric fields resistance in salmonella enterica serovar typhimurium sl1344.in this investigation we selected and isolated a culture derived from salmonella enterica serovar typhimurium sl1344 with stable increased resistance to pulsed electric fields (pef) after repeated rounds of pef treatment and outgrowth of survivors. the resulting culture showed a higher resistance to pef treatments under different treatment conditions. the acquisition of pef resistance was only observed in stationary phase cells. the cytoplasmic membrane of the resistant variant showed a higher r ...201323973831
impact of cyadox on human colonic microflora in chemostat models.the aim of this study was to evaluate the microbiological safety of cyadox, a new member of quinoxaline-1,4-dioxides (qdnos), on human intestinal flora. four chemostats containing human fecal flora were exposed to 0, 16, 32, and 128 μg/ml of cyadox, respectively. bacterial populations, resistance rates of two predominant bacteria and short-chain fatty acids (scfa) were monitored daily prior to and during drug moa laboratory of risk assessment for quality and safety of livestock and poultry produ ...201323973379
comparison of efficacy of salmonella typhimurium a1-r and chemotherapy on stem-like and non-stem human pancreatic cancer cells.the xpa1 human pancreatic cancer cell line is dimorphic, with spindle stem-like cells and round non-stem cells. we report here the in vitro ic 50 values of stem-like and non-stem xpa1 human pancreatic cells cells for: (1) 5-fluorouracil (5-fu), (2) cisplatinum (cddp), (3) gemcitabine (gem), and (4) tumor-targeting salmonella typhimurium a1-r (a1-r). ic 50 values of stem-like xpa1 cells were significantly higher than those of non-stem xpa1 cells for 5-fu (p = 0.007) and cddp (p = 0.012). in contr ...201323966167
roles of yehz, a putative osmoprotectant transporter, in tempering growth of salmonella enterica serovar typhimurium.salmonella, a main cause of foodborne diseases, encounters a variety of environmental stresses and overcomes the stresses by multiple resistance strategies. one of the general responses to hyperosmotic stress is to import or produce compatible solutes so that cells maintain fluid balance and protect proteins and lipids from denaturation. the prop and prou systems are the main transport systems for compatible solutes. the osmu system, recently identified as a third osmoprotectant transport system ...201323966021
iron oxide/gold core/shell nanomagnetic probes and cds biolabels for amplified electrochemical immunosensing of salmonella typhimurium.there is an imminent need for rapid methods to detect and determine pathogenic bacteria in food products as alternatives to the laborious and time-consuming culture procedures. in this work, an electrochemical immunoassay using iron/gold core/shell nanoparticles (fe@au) conjugated with anti-salmonella antibodies was developed. the chemical synthesis and functionalization of magnetic and gold-coated magnetic nanoparticles is reported. fe@au nanoparticles were functionalized with different self-as ...201423962706
signal peptide etiquette during assembly of a complex respiratory enzyme.salmonella enterica serovar typhimurium is a gram-negative pathogen capable of respiration with a number of terminal electron acceptors. tetrathionate reductase is important for the infection process and is encoded by the ttrbca operon where ttra and ttrb are metallocofactor-containing proteins targeted to the periplasmic side of the membrane by two different tat targeting peptides. in this work, the inter-relationship between these two signal peptides has been explored. molecular genetics and b ...201323961722
synthesis, sar and antibacterial activity of hybrid chloro, dichloro-phenylthiazolyl-s-triazines.a series of hybrid novel chloro (1a-9a) and dichloro (10b-18b) phenylthiazolyl-s-triazine were synthesized and subsequently subjected to their antibacterial activity against three gram positive viz. lactobacillus casei (ncim-2651); bacillus cereus (ncim-2458); staphylococcus aureus (ncim-2120) and three gram negative viz salmonella typhimurium (ncim-2501); escherichia coli (ncim-2065); klebsiella aerogenes (ncim-2098). the sar studies around the lead compound revealed that introduction of electr ...201223960775
the ferric enterobactin transporter fep is required for persistent salmonella enterica serovar typhimurium infection.most bacterial pathogens require iron to grow and colonize host tissues. the gram-negative bacterium salmonella enterica serovar typhimurium causes a natural systemic infection of mice that models acute and chronic human typhoid fever. s. typhimurium resides in tissues within cells of the monocyte lineage, which limit pathogen access to iron, a mechanism of nutritional immunity. the primary ferric iron import system encoded by salmonella is the siderophore abc transporter fepbdgc. the fep system ...201323959718
enlarging head size as the only presentation of salmonella typhimurium brain abscess in an infant: a short report.the authors describe a 5-month-old male harbouring a giant salmonella typhimurium cerebral abscess who presented with progressively enlarging head size, without any features of septicemia. the report details the radiological findings, differential diagnoses and management problems regarding the index case.201423957776
simultaneous near-infrared radiant heating and uv radiation for inactivating escherichia coli o157:h7 and salmonella enterica serovar typhimurium in powdered red pepper (capsicum annuum l.).this study was conducted to investigate the efficacy of the simultaneous application of near-infrared (nir) heating and uv irradiation for reducing populations of food-borne pathogens, including salmonella enterica serovar typhimurium and escherichia coli o157:h7 in red pepper powder and to clarify the mechanisms of the lethal effect of the nir-uv combined treatment. also, the effect of the combination treatment on quality was determined by measuring changes in color and pungency constituents. s ...201323956394
lps structure and phoq activity are important for salmonella typhimurium virulence in the galleria mellonella infection model [corrected].the larvae of the wax moth, galleria mellonella, have been used experimentally to host a range of bacterial and fungal pathogens. in this study we evaluated the suitability of g. mellonella as an alternative animal model of salmonella infection. using a range of inoculum doses we established that the ld₅₀ of salmonellatyphimurium strain nctc 12023 was 3.6 × 10³ bacteria per larva. further, a set of isogenic mutant strains depleted of known virulence factors was tested to identify determinants es ...201323951347
diverse secreted effectors are required for salmonella persistence in a mouse infection model.salmonella enterica serovar typhimurium causes typhoid-like disease in mice and is a model of typhoid fever in humans. one of the hallmarks of typhoid is persistence, the ability of the bacteria to survive in the host weeks after infection. virulence factors called effectors facilitate this process by direct transfer to the cytoplasm of infected cells thereby subverting cellular processes. secretion of effectors to the cell cytoplasm takes place through multiple routes, including two separate ty ...201323950998
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
sigirr, a negative regulator of tlr/il-1r signalling promotes microbiota dependent resistance to colonization by enteric bacterial pathogens.enteric bacterial pathogens such as enterohemorrhagic e. coli (ehec) and salmonella typhimurium target the intestinal epithelial cells (iec) lining the mammalian gastrointestinal tract. despite expressing innate toll-like receptors (tlrs), iec are innately hypo-responsive to most bacterial products. this is thought to prevent maladaptive inflammatory responses against commensal bacteria, but it also limits antimicrobial responses by iec to invading bacterial pathogens, potentially increasing hos ...201323950714
human milk hyaluronan enhances innate defense of the intestinal epithelium.breast-feeding is associated with enhanced protection from gastrointestinal disease in infants, mediated in part by an array of bioactive glycan components in milk that act through molecular mechanisms to inhibit enteric pathogen infection. human milk contains hyaluronan (ha), a glycosaminoglycan polymer found in virtually all mammalian tissues. we have shown that synthetic ha of a specific size range promotes expression of antimicrobial peptides in intestinal epithelium. we hypothesize that hya ...201323950179
high density microarrays on blu-ray discs for massive screening.the potential and the capabilities of blu-ray technology (discs and drives) for massive screening applications are presented. high density microarrays are fabricated onto a blu-ray disc and applied for the determination of microcystin residues and pathogenic microorganisms. specific probes were physisorbed onto the bd surface and the biorecognition event was displayed using labeled secondary antibody solution and subsequent signal amplification. the attenuation of the reflected light caused by t ...201423948241
salmonella typhimurium intercepts escherichia coli signaling to enhance antibiotic tolerance.bacterial communication plays an important role in many population-based phenotypes and interspecies interactions, including those in host environments. these interspecies interactions may prove critical to some infectious diseases, and it follows that communication between pathogenic bacteria and commensal bacteria is a subject of growing interest. recent studies have shown that escherichia coli uses the signaling molecule indole to increase antibiotic tolerance throughout its population. here, ...201323946425
cytosolic flagellin-induced lysosomal pathway regulates inflammasome-dependent and -independent macrophage responses.naip5/nlrc4 (neuronal apoptosis inhibitory protein 5/nucleotide oligomerization domain-like receptor family, caspase activation recruitment domain domain-containing 4) inflammasome activation by cytosolic flagellin results in caspase-1-mediated processing and secretion of il-1β/il-18 and pyroptosis, an inflammatory cell death pathway. here, we found that although nlrc4, asc, and caspase-1 are required for il-1β secretion in response to cytosolic flagellin, cell death, nevertheless, occurs in the ...201323942123
the potential for self-sanitisation of faecal sludge by intrinsic ammonia.faecal sludge has the potential to be used as a sustainable fertiliser in agriculture, but the sludge must be sanitised due to its content of pathogenic microorganisms. the intrinsic ammonia from the urine may be sufficient for sanitisation of the sludge if it is not too diluted by flush water or lost by ventilation. to evaluate the potential for this sanitisation method, inactivation of enterococcus faecalis, salmonella typhimurium and ascaris suum eggs during treatment were assessed. the inact ...201323941983
the putative thiosulfate sulfurtransferases pspe and glpe contribute to virulence of salmonella typhimurium in the mouse model of systemic disease.the phage-shock protein pspe and glpe of the glycerol 3-phosphate regulon of salmonella enterica serovar typhimurium are predicted to belong to the class of thiosulfate sulfurtransferases, enzymes that traffic sulfur between molecules. in the present study we demonstrated that the two genes contribute to s. typhimurium virulence, as a glpe and pspe double deletion strain showed significantly decreased virulence in a mouse model of systemic infection. however, challenge of cultured epithelial cel ...201323940650
human naip and mouse naip1 recognize bacterial type iii secretion needle protein for inflammasome activation.inflammasome mediated by central nucleotide-binding and oligomerization domain (nod)-like receptor (nlr) protein is critical for defense against bacterial infection. here we show that type iii secretion system (t3ss) needle proteins from several bacterial pathogens, including salmonella typhimurium, enterohemorrhagic escherichia coli, shigella flexneri, and burkholderia spp., can induce robust inflammasome activation in both human monocyte-derived and mouse bone marrow macrophages. needle protei ...201323940371
a low-ph medium in vitro or the environment within a macrophage decreases the transcriptional levels of fima, fimz and lrp in salmonella enterica serovar typhimurium.many salmonella typhimurium isolates produce type 1 fimbriae and exhibit fimbrial phase variation in vitro. static broth culture favours the production of fimbriae, while solid agar medium inhibits the generation of these appendages. little information is available regarding whether s. typhimurium continues to produce type 1 fimbriae during in vivo growth. we used a type 1 fimbrial phase-variable strain s. typhimurium lb5010 and its derivatives to infect raw 264.7 macrophages. following entry in ...201323938383
recombinant flagellin and its cross-talk with lipopolysaccharide--effect on pooled chicken peripheral blood mononuclear cells.toll-like receptors (tlrs) are one of the types of pattern recognition receptors (prrs) that recognize conserved pathogen molecules. tlrs link innate and adaptive arms of immune system and are implicated in the development of defense against invading pathogens. lipopolysaccharide (lps) and flagellin are recognized by tlr4 and tlr5, respectively. in this study, the effect of flagellin and lipopolysaccharide alone and in combination on chicken peripheral blood mononuclear cells (pbmcs) was investi ...201323937992
effect of nacl on heat resistance, antibiotic susceptibility, and caco-2 cell invasion of salmonella.this study evaluated the effects of nacl on heat resistance, antibiotic susceptibility, and caco-2 cell invasion of salmonella. salmonella typhimurium nccp10812 and salmonella enteritidis nccp12243 were exposed to 0, 2, and 4% nacl and to sequential increase of nacl concentrations from 0 to 4% nacl for 24 h at 35°c. the strains were then investigated for heat resistance (60°c), antibiotic susceptibility to eight antibiotics, and caco-2 cell invasion efficiency. s. typhimurium nccp10812 showed in ...201323936782
pathoadaptive mutations in salmonella enterica isolated after serial passage in mice.how pathogenic bacteria adapt and evolve in the complex and variable environment of the host remains a largely unresolved question. here we have used whole genome sequencing of salmonella enterica serovar typhimurium lt2 populations serially passaged in mice to identify mutations that adapt bacteria to systemic growth in mice. we found unique pathoadaptive mutations in two global regulators, phoq and stpa, which increase the competitive indexes of the bacteria 3- to 5-fold. also, all mouse-adapt ...201323936152
genomic comparison of salmonella typhimurium dt104 with non-dt104 strains.dt104 emerged as a new branch of salmonella typhimurium with resistance to multiple antimicrobials. to reveal some general genomic features of dt104 for clues of evolutionary events possibly associated with the emergence of this relatively new type of this pathogen, we mapped 11 independent dt104 strains and compared them with non-dt104 s. typhimurium strains. we found that all 11 dt104 strains contained three insertions absent in non-dt104 strains, i.e., the previously reported st104, st104b an ...201323933962
assessment of the mutagenic potential of cyanobacterial extracts and pure cyanotoxins.the aim of the study was to assess the mutagenic potential of extracts obtained from the cyanobacterial bloom-forming cells harvested from the water body located in lubelszczyzna region of southeastern poland. three cyanotoxins, microcystin-lr, cylindrospermopsin and anatoxin-a were detected in some of the studied samples in different concentrations. all extracts were assessed for their potential mutagenic effects with the use of a short-term bacterial assay, the ames test. mutagenic activity wa ...201323933197
genetic boundaries to delineate the typhoid agent and other salmonella serotypes into distinct natural lineages.the deadly human typhoid agent was initially classified as a species called salmonella typhi but later reclassified as a serovar of salmonella enterica together with other pathogenically diverse serovars. the dynamic changes of salmonella taxonomy reflect the need to clarify the phylogenetic status of the salmonella serovars: are they discrete lineages or variants of a genetic lineage? to answer this question, we compared s. typhi and other salmonella serotypes. we found that the s. typhi and sa ...201323933189
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