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influence of aerobic and anaerobic conditions on survival of escherichia coli o157:h7 and salmonella enterica serovar typhimurium in luria-bertani broth, farm-yard manure and slurry.the influence of aerobic and anaerobic conditions on the survival of the enteropathogens escherichia coli o157:h7 and salmonella serovar typhimurium was investigated in microcosms with broth, cattle manure or slurry. these substrates were inoculated with a green fluorescent protein transformed strain of the enteropathogens at 10(7) cells g(-1) dry weight. survival data was fitted to the weibull model. the survival curves in aerobic conditions generally showed a concave curvature, while the curva ...201021035246
roles of spvb and spvc in s. typhimurium colitis via the alternative pathway.salmonella enterica subspecies i serovar typhimurium (s. typhimurium) is a frequent cause of diarrhea worldwide. it employs 2 type iii secretion systems (ttss) to elicit mucosal inflammation via the ttss-1-dependent 'classical' or the ttss-2-dependent 'alternative' pathway. if ttss-1 is defective (in invg or invc mutants), the pathogen is confined to the alternative pathway; transits the epithelium in a dendritic cell-dependent fashion, relocalizes from cd11c(+) dendritic cells to cd11c(-) cells ...201021036103
inactivation of the rlud pseudouridine synthase has minimal effects on growth and ribosome function in wild-type escherichia coli and salmonella enterica.the escherichia coli rlud gene encodes a pseudouridine synthase responsible for the pseudouridine (ψ) modifications at positions 1911, 1915, and 1917 in helix 69 of 23s rrna. it has been reported that deletion of rlud in k-12 strains of e. coli is associated with extremely slow growth, increased readthrough of stop codons, and defects in 50s ribosomal subunit assembly and 30s-50s subunit association. suppressor mutations in the prfb and prfc genes encoding release factor 2 (rf2) and rf3 that res ...201021037010
ethanolamine utilization contributes to proliferation of salmonella enterica serovar typhimurium in food and in nematodes.only three pathogenic bacterial species, salmonella enterica, clostridium perfringens, and listeria monocytogenes, are able to utilize both ethanolamine and 1,2-propanediol as a sole carbon source. degradation of these substrates, abundant in food and the gut, depends on cobalamin, which is synthesized de novo only under anaerobic conditions. although the eut, pdu, and cob-cbi gene clusters comprise 40 kb, the conditions under which they confer a selection advantage on these food-borne pathogens ...201021037291
leaching of salmonella enterica in clay columns comparing two manure application methods.transfer of zoonotic bacterial pathogens through intact soil columns was monitored in an outdoor lysimeter over 36 d. manure spiked with salmonella enterica serovar senftenberg was applied to either the soil surface or injected 0.08 m into the soil to compare leaching associated with the two manure application methods. the highest concentrations of s. enterica (up to 60,000 s. enterica cfu/ml) were detected on day 1 in the first drainage samples, with measurable but declining concentrations pers ...201021039451
loop-mediated isothermal amplification assay targeting the ompa gene for rapid detection of riemerella anatipestifer.a novel loop-mediated isothermal amplification (lamp) assay was developed and evaluated for the detection of riemerella anatipestifer (ra) infection. the lamp assay exhibited a higher sensitivity than conventional polymerase chain reaction (pcr) and microbial isolation. the specificity of the assay was determined by restriction enzyme digestion of the lamp products and detection of escherichia coli, salmonella enterica and pasteurella multocida. the lamp assay was able to detect ra effectively i ...201021040782
quantitative pcr-based competitive index for high-throughput screening of salmonella virulence factors.salmonella enterica serovar typhimurium is an intracellular pathogen and a main cause of food-borne illness. in this study, a quantitative pcr (qpcr)-based competitive index (ci) method was developed to simultaneously compare the growth of multiple salmonella strains. this method was applied to a mixture of 17 salmonella mutants lacking regulator genes, and their survival ratios were compared based on expression of natural resistance-associated macrophage protein 1 (nramp1). nramp1, as a major h ...201021041489
enteric pathology and salmonella-induced cell death in healthy and siv-infected rhesus macaques.the goal of this study was to morphologically characterize a ligated ileal loop model of salmonella enterica serotype typhimurium infection in rhesus macaques (macaca mulatta) and to verify the occurrence of salmonella-induced cell death in vivo. eight adult healthy male rhesus macaques were used for ligated ileal loop surgery. four macaques had been intravenously inoculated with simian immunodeficiency virus (siv) mac251. ileal ligated loops were inoculated with wild-type (wt) s. typhimurium st ...201021041540
conjugates of bovine serum albumin with chitin oligosaccharides prepared through the maillard reaction.chitin neoglycoconjugates (bsa-co) were obtained by the conjugation of bovine serum albumin (bsa) with chitin oligosaccharides (co) through the maillard reaction (nonenzymatic glycation). co produced by acid hydrolysis of chitin were fractionated using an ultrafiltration membrane system (1-3 kda cutoff). the maillard reaction was carried out by heating a freeze-dried mixture containing bsa and co at 60 °c (under 43% relative humidity for 6 and 12 h). bsa-co were characterized by available amino ...201021043451
micro ecosystems from feed industry surfaces: a survival and biofilm study of salmonella versus host resident flora strains.the presence of salmonella enterica serovars in feed ingredients, products and processing facilities is a well recognized problem worldwide. in norwegian feed factories, strict control measures are implemented to avoid establishment and spreading of salmonella throughout the processing chain. there is limited knowledge on the presence and survival of the resident microflora in feed production plants. information on interactions between salmonella and other bacteria in feed production plants and ...201021044298
the small regulatory rna molecule mica is involved in salmonella enterica serovar typhimurium biofilm formation.luxs is the synthase enzyme of the quorum sensing signal ai-2. in salmonella typhimurium, it was previously shown that a luxs deletion mutant is impaired in biofilm formation. however, this phenotype could not be complemented by extracellular addition of quorum sensing signal molecules.201021044338
the structural characterization of the o-polysaccharide antigen of the lipopolysaccharide of escherichiacoli serotype o118 and its relation to the o-antigens of escherichiacoli o151 and salmonellaenterica o47.mild acid hydrolysis of the lipopolysaccharide produced by escherichiacoli o118:h16 standard strain (nrcc 6613) afforded an o-polysaccharide (o-ps) composed of d-galactose, 2-acetamidoylamino-2,6-dideoxy-l-galactose, 2-acetamido-2-deoxy-d-glucose, ribitol, and phosphate (1:1:1:1:1). from doc-page, sugar and methylation analyses, one- and two-dimensional nmr spectroscopy, capillary electrophoresis-mass spectrometry, hydrolysis, and sequential smith-type periodate oxidation studies, the o-ps was d ...201021044779
crystallization and preliminary crystallographic analysis of the type iii secretion translocator chaperone sica from salmonella enterica.sica is a member of the class ii chaperones in type iii secretion systems which bind to the pore-forming translocators in the bacterial cytoplasm and prevent them from premature association and degradation. in this study, sica from salmonella enterica serovar typhimurium was overexpressed, purified and crystallized using peg 8000 as the precipitant. x-ray diffraction data were collected using synchrotron radiation and processed at 3.5 å resolution. the crystal belonged to the monoclinic space gr ...201021045315
distribution of pathogenicity islands among colombian isolates of salmonella.salmonella pathogenicity islands (spis) are regions scattered along the bacterial chromosome, with an acknowledged pivotal role during gastrointestinal and systemic infection. the distribution of spis has been investigated in reference strains. however, there is a lack of studies on their presence and/or assortment within the genomes of salmonella enterica (s. enterica) serovars that circulate in different geographical regions. therefore, in this study, we aimed to determine the presence of gene ...201021045367
molecular cloning and characterization of clya genes in various serotypes of salmonella enterica.cytolysin a (clya) is a pore-forming hemolytic protein encoded by the clya gene. it has been identified in salmonella enterica serovars typhi and paratyphi a. to identify and characterize the clya genes in various salmonella enterica strains, 21 different serotypes of strains isolated from clinical specimens were presently examined. full-length clya genes were found in s. enterica serovar brandenburg, indiana, panama, and schwarzengrund strains by polymerase chain reaction amplification. the cly ...201021046345
immune response induced by ppgpp-defective salmonella enterica serovar gallinarum in chickens.to protect chickens from typhoid caused by salmonella enterica serovar gallinarum (s. gallinarum), the attenuated 9r strain has been used in the field as a vaccine. however, safety concerns have been raised because the mutations in 9r are undefined while its efficacy is still a question under debate. a global regulator, ppgpp, synthesized by rela and spot, has been shown to induce various virulence genes in s. gallinarum (jeong et al., 2008). in this study, two mutant strains defective in ppgpp- ...201021046347
salmonella enterica serovar typhi and s. paratyphi a: need to expand the qrdr region? 201021050501
membrane tubules attach salmonella typhimurium to eukaryotic cells and bacteria.using scanning electron microscopy techniques we measured the diameter of adhesive tubular appendages of salmonella enterica serovar s. typhimurium. the appendages interconnected bacteria in biofilms grown on gallstones or coverslips, or attached bacteria to host cells (human neutrophils). the tubular appendage diameter of bacteria of virulent flagellated c53 strain varied between 60 and 70 nm, thus considerably exceeding in size of flagella or pili. nonflagellated bacteria of mutant sjw 880 str ...201021054581
protective effect of lactobacillus casei strain shirota against lethal infection with multi-drug resistant salmonella enterica serovar typhimurium dt104 in mice.the anti-infectious activity of lactobacilli against multi-drug resistant salmonella enterica serovar typhimurium dt104 (dt104) was examined in a murine model of an opportunistic antibiotic-induced infection.201021059159
salmonella enterica response regulator ssrb relieves h-ns silencing by displacing h-ns bound in polymerization mode and directly activates transcription.the response regulator ssrb activates expression of genes encoded within and outside of a pathogenicity island (spi-2), which is required for systemic infection of salmonella. ssrb binds upstream of the sifa, sifb, and ssej effector genes and directly regulates transcription. ssrb also relieves gene silencing by the nucleoid protein h-ns. single molecule experiments with magnetic tweezers demonstrated that ssrb displaces h-ns from dna only when it is bound in a polymerization (stiffening) mode a ...201021059643
recognition of heptameric seed sequence underlies multi-target regulation by rybb small rna in salmonella enterica.prokaryotic regulatory small rnas act by a conserved mechanism and yet display a stunning structural variability. in the present study, we used mutational analysis to dissect the functional anatomy of rybb, a σ(e)-dependent srna that regulates the synthesis of major porins in escherichia coli and salmonella. mutations in the chromosomal rybb locus that altered the expression of an ompc-lac fusion were identified. some of the mutations cluster within a seven-nucleotide segment at the 5' end of th ...201020979336
enteric fever in a 6-year-old traveler caused by salmonella enterica serotypes typhi and paratyphi a: laboratory detection strategies and treatment options.we report the first pediatric case of enteric fever caused by salmonella enterica serotypes typhi and paratyphi a. mixed infections are infrequently reported, potentially because detection of two different salmonella serotypes in blood cultures is technically challenging. we suggest laboratory strategies to aid in the recognition of mixed infections.201020980563
simultaneous analysis of multiple enzymes increases accuracy of pulsed-field gel electrophoresis in assigning genetic relationships among homogeneous salmonella strains.due to a highly homogeneous genetic composition, the subtyping of salmonella enterica serovar enteritidis strains to an epidemiologically relevant level remains intangible for pulsed-field gel electrophoresis (pfge). we reported previously on a highly discriminatory pfge-based subtyping scheme for s. enterica serovar enteritidis that relies on a single combined cluster analysis of multiple restriction enzymes. however, the ability of a subtyping method to correctly infer genetic relatedness amon ...201020980570
structure and gene cluster of the o-antigen of salmonella enterica o44.the o-polysaccharide (o-antigen) of salmonella enterica o44 was studied by sugar analysis along with 1d and 2d (1)h and (13)c nmr spectroscopy. the following structure of the pentasaccharide repeating unit containing only common monosaccharides was established: [formula: see text]. the o-antigen gene cluster of s. enterica o44 was sequenced. the gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the s. enterica ...201020709316
a proteomic analysis reveals differential regulation of the σ(s)-dependent ycigfe(katn) locus by yncc and h-ns in salmonella and escherichia coli k-12.the stationary phase sigma factor σ(s) (rpos) controls a regulon required for general stress resistance of the closely related enterobacteria salmonella and escherichia coli. the σ(s)-dependent yncc gene encodes a putative dna binding regulatory protein. application of the surface-enhanced laser desorption/ionization-time of flight (seldi-tof) proteinchip technology for proteome profiling of wild-type and mutant strains of salmonella enterica serovar typhimurium revealed potential protein target ...201020713450
humanized nonobese diabetic-scid il2rgammanull mice are susceptible to lethal salmonella typhi infection.salmonella enterica serovar typhi, the cause of typhoid fever, is host-adapted to humans and unable to cause disease in mice. here, we show that s. typhi can replicate in vivo in nonobese diabetic (nod)-scid il2rgamma(null) mice engrafted with human hematopoietic stem cells (hu-src-scid mice) to cause a lethal infection with pathological and inflammatory cytokine responses resembling human typhoid. in contrast, s. typhi does not exhibit net replication or cause illness in nonengrafted or immunoc ...201020713716
seasonal variation, chemical composition, and analgesic and antimicrobial activities of the essential oil from leaves of tetradenia riparia (hochst.) codd in southern brazil.the seasonal variation of the chemical composition of the essential oil from fresh leaves of tetradenia riparia (hochst.) codd grown in southern brazil was analyzed by gc-ms, and the analgesic and antimicrobial activities of this oil were assayed. the yield of essential oil ranged from 0.17% to 0.26%, with the maximum amount in winter and the minimum in spring. the results obtained from principal components analysis (pca) revealed the existence of high chemical variability in the different seaso ...201020714310
growth and virulence properties of biofilm-forming salmonella enterica serovar typhimurium under different acidic conditions.this study was designed to characterize the viability and potential virulence of bofilm-forming salmonella enterica serovar typhimurium under different ph levels, ranging from 5 to 7. the plate count method and real-time reverse transcription-pcr (rt-pcr) were used to evaluate the survival of s. typhimurium grown in trypticase soy broth (tsb) adjusted to ph 5, 6, and 7 (tsb-5, tsb-6, and tsb-7, respectively) at 37°c for 10 days. in tsb-5 and tsb-6, the numbers of viable cells estimated by using ...201020971873
salmonella virchow and salmonella weltevreden in a random survey of the asian house gecko, hemidactylus frenatus, in houses in northern australia.abstract background: salmonella enterica serotype virchow is the most common cause of invasive nontyphoid salmonellosis in north queensland, particularly in infants, but the zoonotic source is unknown. this study aimed at determining (i) the prevalence of the introduced asian house gecko, hemidactylus frenatus, in houses in north queensland and (ii) whether they were a potential source of salmonella virchow. methods: asian house geckos were collected in a random survey of houses in townsville, n ...201020973656
occurrence and distribution of various genetic structures of class 1 and class 2 integrons in salmonella enterica isolates from foodborne disease patients in korea for 16 years.we have investigated the distribution of integrons among 752 multidrug-resistant salmonella isolates from human febrile and/or diarrheal patients during 1992-2007 and analyzed their genetic characteristics. here, we report extensive integron analysis results within human isolates during the last 16 years. the gene or gene cassette(s) in the class 1 integrons found in the isolates were dfra7, dfra12-orff-aada2, aada2, bla(pse1), dfra1-aada1, dfra17-aada5, bla(oxa1)-aada1, aadb-aada1, aada22, aada ...201020973732
salmonella enterica serovar typhimurium binds to hela cells via fim-mediated reversible adhesion and irreversible type three secretion system 1-mediated docking.the food-borne pathogen salmonella enterica serovar typhimurium invades mammalian epithelial cells. this multistep process comprises bacterial binding to the host cell, activation of the salmonella type three secretion system 1 (t1), injection of effector proteins, triggering of host cell actin rearrangements, and s. typhimurium entry. while the latter steps are well understood, much less is known about the initial binding step. earlier work had implicated adhesins (but not t1) or t1 (but not ot ...201020974826
discovery of novel secreted virulence factors from salmonella enterica serovar typhimurium by proteomic analysis of culture supernatants.salmonella enterica serovar typhimurium is a leading cause of acute gastroenteritis throughout the world. this pathogen has two type iii secretion systems (ttss) encoded in salmonella pathogenicity islands 1 and 2 (spi-1 and spi-2) that deliver virulence factors (effectors) to the host cell cytoplasm and are required for virulence. while many effectors have been identified and at least partially characterized, the full repertoire of effectors has not been catalogued. in this proteomic study, we ...201020974834
chromosomal rearrangements formed by rrn recombination do not improve replichore balance in host-specific salmonella enterica serovars.most of the ∼2,600 serovars of salmonella enterica have a broad host range as well as a conserved gene order. in contrast, some salmonella serovars are host-specific and frequently exhibit large chromosomal rearrangements from recombination between rrn operons. one hypothesis explaining these rearrangements suggests that replichore imbalance introduced from horizontal transfer of pathogenicity islands and prophages drives chromosomal rearrangements in an attempt to improve balance.201020976060
exploitation of the ubiquitin system by invading bacteria.a variety of bacterial intracellular pathogens target the host cell ubiquitin system during invasion, a process that involves transient but fundamental changes in the actin cytoskeleton and plasma membrane. these changes are induced by bacterial proteins, which can be surface associated, secreted or injected directly into the host cell. here, the invasion strategies of two extensively studied intracellular bacteria, salmonella enterica serovar typhimurium and listeria monocytogenes, are used to ...201020977569
the friedreich's ataxia protein frataxin modulates dna base excision repair in prokaryotes and mammals.dna-repair mechanisms enable cells to maintain their genetic information by protecting it from mutations that may cause malignant growth. recent evidence suggests that specific dna-repair enzymes contain iscs (iron-sulfur clusters). the nuclearencoded protein frataxin is essential for the mitochondrial biosynthesis of iscs. frataxin deficiency causes a neurodegenerative disorder named friedreich's ataxia in humans. various types of cancer occurring at young age are associated with this disease, ...201020819074
multiple-locus variable-number tandem-repeat analysis for discriminating within salmonella enterica serovar typhimurium definitive types and investigation of outbreaks.summarythe discriminatory power of multiple-locus variable-number tandem-repeat analysis (mlva) needs to be evaluated for all salmonella enterica subspecies enterica serovar typhimurium (s. typhimurium) phage types so that the power of this methodology is understood and results can be interpreted correctly during outbreak investigations. we evaluated the ability of mlva to characterize four definitive phage types (dt) problematic in new zealand. mlva discriminated between dt104 isolates although ...201020822575
molecular and virulence characteristics of multi-drug resistant salmonella enteritidis strains isolated from poultry.forty-six salmonella enterica subspecies enterica serovar enteritidis (s. enteritidis) strains were isolated from chicken meat, faeces, and eggshells collected from hatcheries throughout korea. the strains were examined for the presence of antimicrobial resistance and virulence genes. all 46 isolates were resistant to at least one of 21 antibiotics used in this study, 30 (65.2%) were resistant to three or more antimicrobials, and a single remarkable isolate was resistant to 15 antimicrobials. th ...201020822940
interactions of the transmembrane polymeric rings of the salmonella enterica serovar typhimurium type iii secretion system.the type iii secretion system (t3ss) is an interspecies protein transport machine that plays a major role in interactions of gram-negative bacteria with animals and plants by delivering bacterial effector proteins into host cells. t3sss span both membranes of gram-negative bacteria by forming a structure of connected oligomeric rings termed the needle complex (nc). here, the localization of subunits in the salmonella enterica serovar typhimurium t3ss nc were probed via mass spectrometry-assisted ...201020824104
specific responses of salmonella enterica to tomato varieties and fruit ripeness identified by in vivo expression technology.recent outbreaks of vegetable-associated gastroenteritis suggest that enteric pathogens colonize, multiply and persist in plants for extended periods of time, eventually infecting people. genetic and physiological pathways, by which enterics colonize plants, are still poorly understood.201020824208
genetic diversity among offspring from archived salmonella enterica ssp. enterica serovar typhimurium (demerec collection): in search of survival strategies.extensive phenotypic and genomic diversity was detected among offspring of salmonella enterica ssp. enterica serovar typhimurium lt2 (nonmutator) and lt7 (mutator, mutl) strains after decades of storage in sealed nutrient agar stabs. in addition to numerous losses in carbon and nitrogen metabolism, the acquired new metabolites indicated that alternate pathways were established. particularly striking was the array of phage types when this phenotype was expected to be a stable feature. evidence is ...201020825350
bacteraemia with pleural effusions complicating typhoid fever caused by high-level ciprofloxacin-resistant salmonella enterica serotype typhi.an unusual case of bacteraemia with bilateral pleural effusion caused by salmonella enterica serotype typhi in a 10-year-old previously healthy girl is reported. the organism was isolated from pleural fluid aspirate and from blood, and exhibited high-level ciprofloxacin resistance (mic 16 μg/ml) associated with triple mutations in the qrdrs of the gyra and parc genes leading to the amino-acid changes ser83→phe and asp87→asn in gyra and ser80→ile in parc. the patient was successfully treated with ...201020828458
effect of temperature and time of storage on protein stability and anti-salmonella activity of egg white.hen egg white contains numerous molecules of interest for human health, including antimicrobial proteins. little information is available concerning changes in the antimicrobial activity of egg white during storage; therefore, we analyzed the potential of egg white to inhibit growth of salmonella enterica serovar enteritidis following storage at 4, 20, or 37°c for 30 days prior to inoculation. egg white displayed higher anti-salmonella activity after a few days of storage at 20 and 37°c. the rat ...201020828465
occurrence and antimicrobial resistance profiles of salmonella species in retail meat products.in the present study, a total of 225 retail meat products (poultry meat, ground beef, and beef samples) were tested for the prevalence of salmonella. of these, 50 (22.2%) were positive for salmonella. overall, the pathogen was detected in 22 (29.3%) samples of poultry meat (n = 75), 16 (21.3%) samples of ground beef (n = 75), and 12 (16%) samples of beef (n = 75). the most common isolate was salmonella enterica serovar typhimurium (9.8%), followed by s. bongori species (8.9%) and s. enterica sub ...201020828466
use of high-concentration-short-time chlorine dioxide gas treatments for the inactivation of salmonella enterica spp. inoculated onto roma tomatoes.salmonella outbreaks have been recently linked to the consumption of fresh tomatoes. thus, there is a need to develop systems that reduce the risk of microbial contamination to increase product shelf-life and keep fresh fruit attributes. the objectives of this study were to evaluate high-concentration-short-time chlorine dioxide gas treatments effects on salmonella-inoculated roma tomatoes and determine the optimal treatment conditions for microbial inactivation and shelf-life extension. effects ...201020832678
the effects of x-ray radiation on escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri inoculated on whole roma tomatoes.in the last two decades several foodborne disease outbreaks associated with produce were reported. tomatoes, in particular, have been associated with several multi-state salmonella outbreaks. inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole roma tomato surfaces by x-ray at 0.1, 0.5, 0.75, 1.0, and 1.5 kgy was studied. the main purpose of this study was to achieve a 5 log reduction in consistent with the recommendation ...201020832685
latency of the lipid a deacylase pagl is involved in producing a robust permeation barrier in the outer membrane of salmonella enterica.lipid a deacylase pagl, which detoxifies endotoxin, is latent in salmonella enterica. this study determined the biological significance of this latency. pagl latency was beneficial for bacteria in producing a robust permeation barrier through lipid a modifications under host-mimetic conditions that induced the modification enzymes, including pagl.201020833808
role of cross talk in regulating the dynamic expression of the flagellar salmonella pathogenicity island 1 and type 1 fimbrial genes.salmonella enterica, a common food-borne pathogen, differentially regulates the expression of multiple genes during the infection cycle. these genes encode systems related to motility, adhesion, invasion, and intestinal persistence. key among them is a type three secretion system (t3ss) encoded within salmonella pathogenicity island 1 (spi1). in addition to the spi1 t3ss, other systems, including flagella and type 1 fimbriae, have been implicated in salmonella pathogenesis. in this study, we inv ...201020833811
suitable disk antimicrobial susceptibility breakpoints defining salmonella enterica serovar typhi isolates with reduced susceptibility to fluoroquinolones.infections with salmonella enterica serovar typhi isolates that have reduced susceptibility to ofloxacin (mic ≥ 0.25 μg/ml) or ciprofloxacin (mic ≥ 0.125 μg/ml) have been associated with a delayed response or clinical failure following treatment with these antimicrobials. these isolates are not detected as resistant using current disk susceptibility breakpoints. we examined 816 isolates of s. typhi from seven asian countries. screening for nalidixic acid resistance (mic ≥ 16 μg/ml) identified is ...201020837759
stimulation of human dendritic cells by wild-type and m protein mutant vesicular stomatitis viruses engineered to express bacterial flagellin.vesicular stomatitis viruses (vsvs) containing wild-type (wt) or mutant matrix (m) proteins are being developed as candidate vaccine vectors due to their ability to induce innate and adaptive immunity. viruses with wt m protein, such as recombinant wild-type (rwt) virus, stimulate maturation of dendritic cells (dc) through toll-like receptor 7 (tlr7) and its adaptor molecule myd88. however, m protein mutant viruses, such as rm51r-m virus, stimulate both tlr7-positive and tlr7-negative dc subsets ...201020844045
oral delivery of a dna vaccine against tuberculosis using operator-repressor titration in a salmonella enterica vector.attenuated salmonella enterica offers a vaccine delivery route that has the benefits of enhanced immunogenicity and oral delivery. the majority of immunization studies have been conducted to deliver recombinant proteins, expressed from a gene that is either chromosomally integrated or carried on a low- or medium-copy number plasmid. there are, however, an increasing number of reports demonstrating the delivery of dna vaccines, but the high-copy number plasmids that are preferentially used for th ...201020851079
changes in ultrastructure and fourier transform infrared spectrum of salmonella enterica serovar typhimurium cells after exposure to stress conditions.the effect of exposure to acid (ph 2.5), alkaline (ph 11.0), heat (55°c), and oxidative (40 mm h₂o₂) lethal conditions on the ultrastructure and global chemical composition of salmonella enterica serovar typhimurium cect 443 cells was studied using transmission electron microscopy and fourier transform infrared spectroscopy (ft-ir) combined with multivariate statistical methods (hierarchical cluster analysis and factor analysis). infrared spectra exhibited marked differences in the five spectral ...201020851964
salmonella enterica in commercial swine feed and subsequent isolation of phenotypically and genotypically related strains from fecal samples.the purpose of this study was to determine the occurrence and genotypic relatedness of salmonella enterica isolates recovered from feed and fecal samples in commercial swine production units. of 275 feed samples, salmonella was detected in 10 feed samples that originated from 8 of 36 (22.2%) barns, with a prevalence of 3.6% (10/275 samples). in fecal samples, a prevalence of 17.2% was found at the early finishing stage (1,180/6,880 samples), with a significant reduction in prevalence (7.4%) when ...201020851969
occurrence of purulent arthritis broilers vertically infected with salmonella enterica serovar enteritidis in korea.salmonella enterica serovar enteritidis (salmonella enteritidis) has been associated with morbidity and mortality in broiler chickens worldwide. the present study described purulent arthritis of broilers infected with salmonella enteritidis and investigated antibiograms and genetic characteristics of salmonella enteritidis isolates from epidemiologically related properties such as a hatchery and breeder farm in an attempt to elucidate the source of contamination. clinical disease and mortality w ...201020852102
potent antilisterial cell-free supernatants produced by complex red-smear cheese microbial consortia.the microbial surface ripening consortia of 49 soft cheeses were investigated with respect to their inhibition of listeria monocytogenes. when l. monocytogenes egde (serovar 1/2a) was cultivated in cell-free supernatants obtained from consortia grown for 8 h in liquid medium, a strong bactericidal activity was observed in several cases. the cell-free supernatants of 2 of these consortia (i and ii) reduced an initial l. monocytogenes inoculum of 5 × 10(7) cfu/ml to zero after 24 h of incubation. ...201020854983
macrorestriction analysis and antimicrobial susceptibility profiling of salmonella enterica at a university teaching hospital, kuala lumpur.the genetic diversity and antimicrobial resistance rates of clinical salmonella isolates (2007-2008) at the university of malaya medical centre, kuala lumpur, were investigated and the genetic diversity of the isolates was determined by pulsed-field gel electrophoresis (pfge) and repetitive extragenic palindromic (rep)-pcr. xbai-pfge analysis generated 57 profiles (dice coefficient, f=0.08-1.00), whereas rep-pcr using the rep primer generated only 35 (f=0.34-1.00). pfge was therefore the more di ...201020858996
optical genetic mapping defines regions of chromosomal variation in serovars of s. enterica subsp. enterica of concern for human and animal health.summaryinfections involving salmonella enterica subsp. enterica serovars have serious animal and human health implications; causing gastroenteritis in humans and clinical symptoms, such as diarrhoea and abortion, in livestock. in this study an optical genetic mapping technique was used to screen 20 field isolate strains from four serovars implicated in disease outbreaks. the technique was able to distinguish between the serovars and the available sequenced strains and group them in agreement wit ...201020860874
improved detection of five major gastrointestinal pathogens by use of a molecular screening approach.the detection of bacterial and parasitic gastrointestinal pathogens through culture and microscopy is laborious and time-consuming. we evaluated a molecular screening approach (msa) for the detection of five major enteric pathogens: salmonella enterica, campylobacter jejuni, giardia lamblia, shiga toxin-producing escherichia coli (stec), and shigella spp./enteroinvasive e. coli (eiec), for use in the daily practice of a clinical microbiology laboratory. the msa consists of prescreening of stool ...201020861334
analysis and construction of pathogenicity island regulatory pathways in salmonella enterica serovar typhi.signal transduction through protein-protein interactions and protein modifications are the main mechanisms controlling many biological processes. here we described the implementation of medscan information extraction technology and pathway studio software (ariadne genomics inc.) to create a salmonella specific molecular interaction database. using the database, we have constructed several signal transduction pathways in salmonella enterica serovar typhi which causes typhoid fever, a major health ...201020861532
carbohydrate binding of salmonella phage p22 tailspike protein and its role during host cell infection.tsps (tailspike proteins) are essential infection organelles of bacteriophage p22. upon infection, p22tsp binds to and cleaves the o-antigen moiety of the lps (lipopolysaccharide) of its salmonella host. to elucidate the role of tsp during infection, we have studied binding to oligosaccharides and polysaccharides of salmonella enterica typhimurium and enteritidis in vitro. p22tsp is a trimeric β-helical protein with a carbohydrate-binding site on each subunit. octasaccharide o-antigen fragments ...201020863318
gut inflammation provides a respiratory electron acceptor for salmonella.salmonella enterica serotype typhimurium (s. typhimurium) causes acute gut inflammation by using its virulence factors to invade the intestinal epithelium and survive in mucosal macrophages. the inflammatory response enhances the transmission success of s. typhimurium by promoting its outgrowth in the gut lumen through unknown mechanisms. here we show that reactive oxygen species generated during inflammation react with endogenous, luminal sulphur compounds (thiosulphate) to form a new respirato ...201020864996
compact disk (cd)-shaped device for single cell isolation and pcr of a specific gene in the isolated cell.for immediate discrimination among isolated cells we propose a novel device and technique for isolation of cells and sequential detection of specific gene(s) within them by polymerase chain reaction (pcr). in this study, we isolated salmonella enterica cells and detected the salmonella-specific inva gene from isolated cells by pcr on a compact disk (cd)-shaped device. this device enabled liquid flow by centrifugal force without a micro pump, and was fabricated from silicon wafer and glass to avo ...201020865405
tetrabutylammonium phosphate-assisted separation of multiplex polymerase chain reaction products in non-gel sieving capillary electrophoresis.a method based on non-gel sieving capillary electrophoresis (ngs-ce) with ultraviolet (uv) detection has been developed for the separation of multiplex polymerase chain reaction (pcr) products of three pathogenic bacteria in which hydroxypropylmethylcellulose was used as the sieving medium and dynamic capillary coating. in the method, an ion pair reagent, tetrabutylammonium phosphate (tbap), was first used in ngs-ce to improve the detection sensitivities and resolutions of dna fragments. the int ...201020868644
high-throughput universal probe salmonella serotyping (upss) by nanopcr.salmonella enterica subsp. enterica serovar identification is of great importance with respect to outbreak monitoring and case verification. therefore rapid, sensitive and cost efficient detection of salmonella spp. is indispensable within microbiology labs. to amalgamate single tube isolate identification with salmonella typing, we developed the high-throughput universal probe salmonella serotyping (upss) technique based on nano liter pcr. in comparison to the classical approach, where o- and h ...201020869995
structural insight into the mechanisms of transport across the salmonella enterica pdu microcompartment shell.bacterial microcompartments are a functionally diverse group of proteinaceous organelles that confine specific reaction pathways in the cell within a thin protein-based shell. the propanediol utilizing (pdu) microcompartment contains the reactions for metabolizing 1,2-propanediol in certain enteric bacteria, including salmonella. the pdu shell is assembled from a few thousand protein subunits of several different types. here we report the crystal structures of two key shell proteins, pdua and pd ...201020870711
fitness effects of replichore imbalance in salmonella enterica.a fitness cost due to imbalanced replichores has been proposed to provoke chromosome rearrangements in salmonella enterica serovars. to determine the impact of replichore imbalance on fitness, the relative fitness of isogenic salmonella strains containing transposon-held duplications of various sizes and at various chromosomal locations was determined. although duplication of certain genes influenced fitness, a replichore imbalance of up to 16° did not affect fitness.201020870772
analogies and homologies in lipopolysaccharide and glycoprotein biosynthesis in bacteria.bacteria generate and attach countless glycan structures to diverse macromolecules. despite this diversity, the mechanisms of glycoconjugate biosynthesis are often surprisingly similar. the focus of this review is on the commonalities between lipopolysaccharide (lps) and glycoprotein assembly pathways and their evolutionary relationship. three steps that are essential for both pathways are completed by membrane proteins. these include the initiation of glycan assembly through the attachment of a ...201020871101
mutant prevention concentration (mpc) of ciprofloxacin against salmonella enterica of epidemic and poultry origin.salmonella isolates resistant or with reduced susceptibility to quinolones increased in recent years. the mutant prevention concentration (mpc) is a new alternative that can prevent the selection and multiplication of resistant salmonella spp. strains. the mpc of ciprofloxacin (cipmpc) was evaluated for 312 salmonella enterica strains of epidemic and poultry origin susceptible and resistant to nalidixic acid (nal). the cipmpc for nal-susceptible strains were in the range from 0.002 to 4 μg/ml an ...201020872005
molecular epidemiological investigation of a typhoid fever outbreak in south africa, 2005: the relationship to a previous epidemic in 1993.summaryin 2005, over 600 clinically diagnosed typhoid fever cases occurred in south africa, where an outbreak had been previously described in 1993. case-control and molecular investigations, including salmonella enterica serovar typhi (s. typhi) isolates from that area from 1993, 2005 and later, were undertaken. controls were significantly older than cases (p=0·003), possibly due to immunity from previous infection, and a significantly larger proportion had attended a gathering (p=0·035). expos ...201020875199
influence of rpos mutations on the response of salmonella enterica serovar typhimurium to solar radiation.salmonella enterica serovar typhimurium is an important pathogen, and exhibits considerable resistance to the lethal effects of solar radiation. to evaluate the involvement of the rpos transcription factor in the defense mechanisms of this organism, the sunlight response of a wild type strain (atcc14028) was compared with that of an rpos mutant, which exhibited increased sensitivity. kinetics of cell death was complex in both strains, probably due to the presence of a variety of targets for the ...201020875749
dissemination of invasive salmonella via bacterial-induced extrusion of mucosal epithelia.salmonella enterica is an intracellular bacterial pathogen that resides and proliferates within a membrane-bound vacuole in epithelial cells of the gut and gallbladder. although essential to disease, how salmonella escapes from its intracellular niche and spreads to secondary cells within the same host, or to a new host, is not known. here, we demonstrate that a subpopulation of salmonella hyperreplicating in the cytosol of epithelial cells serves as a reservoir for dissemination. these bacteria ...201020876119
a multi-pronged search for a common structural motif in the secretion signal of salmonella enterica serovar typhimurium type iii effector proteins.many pathogenic gram-negative bacteria use a type iii secretion system (t3ss) to deliver effector proteins into the host cell where they reprogram host defenses and facilitate pathogenesis. the first 20-30 n-terminal residues usually contain the 'secretion signal' that targets effector proteins for translocation, however, a consensus sequence motif has never been discerned. recent machine-learning approaches, such as support vector machine (svm)-based identification and evaluation of virulence e ...201020877914
the protective effect of bdellovibrio-and-like organisms (balo) on tilapia fish fillets against salmonella enterica ssp. enterica serovar typhimurium.to characterize freshwater bdellovibrio-and-like organisms (balo) isolated in china and examine their potential in controlling growth of salmonella enterica ssp. enterica serovar typhimurium on tilapia fillets.201020880363
[salmonella enterica serovar typhimurium infection presenting as a retrocecal mass in an 8-year-old child].minor salmonellosis is due to gram-negative bacilli, which usually cause enterocolitis with potentially severe complications. we report on a case of a clinically uncommon presentation of salmonella enterica serovar typhimurium infection in an 8-year-old child who presented with acute abdominal pain. we discuss clinically uncommon presentations of salmonella disease in children, as well as its pathology and radiology.201020880679
characterization of antimicrobial resistance in salmonella enterica food and animal isolates from colombia: identification of a qnrb19-mediated quinolone resistance marker in two novel serovars.ninety-three salmonella isolates recovered from commercial foods and exotic animals in colombia were studied. the serotypes, resistance profiles and where applicable the quinolone resistance genes were determined. salmonella anatum (n=14), uganda (19), braenderup (10) and newport (10) were the most prevalent serovars, and resistance to tetracycline (18.3%), ampicillin (17.2%) and nalidixic acid (14%) was most common. nalidixic acid-resistant isolates displayed minimum inhibitory concentrations r ...201020883500
presence of salmonella pathogenicity island 2 genes in seafood-associated salmonella serovars and the role of the ssec gene in survival of salmonella enterica serovar weltevreden in epithelial cells.the type iii secretion system encoded by the salmonella pathogenicity island 2 (spi-2) has a central role in the pathogenesis of systemic infections by salmonella. sixteen genes (ssau, ssab, ssar, ssaq, ssao, ssas, ssap, ssat, sscb, ssef, sseg, ssee, ssed, ssec, ssad and ssca) of spi-2 were targeted for pcr amplification in 57 seafood-associated serovars of salmonella. the ssec gene of spi-2 was found to be absent in two isolates of salmonella enterica serovar weltevreden, sw13 and sw39. absence ...201020884689
evaluation of salmonella enterica serovar enteritidis pathogenicity island-1 proteins as vaccine candidates against s. enteritidis challenge in chickens.salmonella enterica serovar enteritidis (s. enteritidis) is a major cause of gastrointestinal disease in humans worldwide, which mainly results from the consumption of contaminated poultry meat and eggs. vaccination of chickens is an important strategy to lower the prevalence of salmonella in poultry flocks. the s. enteritidis type 3 secretion system (t3ss) encoded on salmonella pathogenicity island-1 (spi-1) is an important virulence factor that plays a role in invasion and systemic spread in c ...201020888713
fliz regulates expression of the salmonella pathogenicity island 1 invasion locus by controlling hild protein activity in salmonella enterica serovar typhimurium.a prerequisite for salmonella enterica to cause both intestinal and systemic disease is the direct injection of effector proteins into host intestinal epithelial cells via a type three secretion system (t3ss); the t3ss genes are carried on salmonella pathogenicity island 1 (spi1). these effector proteins induce inflammatory diarrhea and bacterial invasion. expression of the spi1 t3ss is tightly regulated in response to environmental signals through a variety of global regulatory systems. we have ...201020889744
biologically active isoforms of cobb sirtuin deacetylase in salmonella enterica and erwinia amylovora.sirtuins are nad(+)-dependent protein deacylases that are conserved in all domains of life and are involved in diverse cellular processes, including control of gene expression and central metabolism. eukaryotic sirtuins have n-terminal extensions that have been linked to protein multimerization and cellular localization. here the first evidence of sirtuin isoforms in bacteria is reported. the enterobacterium salmonella enterica synthesizes two isoforms of cobb sirtuin, a shorter 236-amino-acid i ...201020889757
effect of salmonella vaccination of breeder chickens on contamination of broiler chicken carcasses in integrated poultry operations.while measures to control carcass contamination with salmonella at the processing plant have been implemented with some success, on-farm interventions that reduce salmonella prevalence in meat birds entering the processing plant have not translated well on a commercial scale. we determined the impact of salmonella vaccination on commercial poultry operations by monitoring four vaccinated and four nonvaccinated breeder (parental) chicken flocks and comparing salmonella prevalences in these flocks ...201020889797
control by fur of the nitrate respiration regulators narp and narl in salmonella enterica.anaerobic metabolism is controlled by several transcriptional regulators, including arca, fnr, narp, and narl, with the fnr and arca proteins sensitive to the cell's redox status. specifically, the two-component arcab system is activated in response to the oxidation state of membrane-bound quinones, which are the central electron carriers of respiration. fnr, by contrast, directly senses cellular oxidation status through the [4fe-4s] cluster present in its own structure. in this study, a third a ...201020890837
inactivation and recovery of listeria monocytogenes, salmonella enterica and staphylococcus aureus after high hydrostatic pressure treatments up to 900 mpa.high hydrostatic pressure (hp) processing is used in the food industry to enhance the safety and extend the shelf-life of food. although a drastic decrease in microbial viability is achieved immediately after the application of hp treatments, under favorable conditions the injured bacteria can recover. the present study evaluated the inactivation and recovery of five strains of listeria monocytogenes, salmonella enterica and staphylococcus aureus subjected to pressures of 400, 600, and 900 mpa u ...201020890844
evaluation of the pathogenicity and virulence of three strains of salmonella organisms in calves and pigs.to assess in pigs the pathogenicity and virulence of 3 strains of salmonella spp capable of causing atypical salmonellosis in cattle.201020919903
proteomic analysis of salmonella enterica serovar enteritidis following propionate adaptation.salmonella enteritidis is a highly prevalent and persistent foodborne pathogen and is therefore a leading cause of nontyphoidal gastrointestinal disease worldwide. a variety of stresses are endured throughout its infection cycle, including high concentrations of propionate (pa) within food processing systems and within the gut of infected hosts. prolonged pa exposure experienced in such milieus may have a drastic effect on the proteome of salmonella enteritidis subjected to this stress.201020920181
selective testing of ß-galactosidase activity in the laboratory identification of salmonella and shigella species.salmonella and shigella species are pathogens of great medical and public health importance. however, laboratory identification of these organisms is time consuming. using current standard laboratory algorithms, the vast majority of organisms submitted for serological typing with salmonella-specific and shigella-specific antisera are not clinically significant.201020924038
viable but nonculturable state of foodborne pathogens in grapefruit juice: a study of laboratory.several foodborne human pathogens, when exposed to harsh conditions, enter viable but nonculturable (vbnc) state; however, still open is the question whether vbnc pathogens could be a risk for public health, because, potentially, they can resuscitate. moreover, cultural methods for food safety control were not able to detect vbnc forms of foodborne bacteria. particularly, it has not been established whether food chemophysical characteristics can induce vbnc state in contaminating pathogen bacter ...201020932087
effect of chlorine dioxide gas on salmonella enterica inoculated on navel orange surfaces and its impact on the quality attributes of treated oranges.microorganisms, including pathogens of public health significance, have been shown to contaminate orange juice during the mechanical extraction of juice. the problem gets exacerbated when washed oranges have high initial microbial load, due to an insufficient postharvest treatment. the objective of this study was to investigate the reduction of salmonella enterica on orange surfaces using clo₂ gas treatments to achieve a 5 log reduction, consistent with the recommendations of the u.s. department ...201020932090
evolution and population structure of salmonella enterica serovar newport.salmonellosis caused by salmonella enterica serovar newport is a major global public health concern, particularly because s. newport isolates that are resistant to multiple drugs (mdr), including third-generation cephalosporins (mdr-ampc phenotype), have been commonly isolated from food animals. we analyzed 384 s. newport isolates from various sources by a multilocus sequence typing (mlst) scheme to study the evolution and population structure of the serovar. these were compared to the populatio ...201020935094
fliz induces a kinetic switch in flagellar gene expression.fliz is an activator of class 2 flagellar gene expression in salmonella enterica. to understand its role in flagellar assembly, we investigated how fliz affects gene expression dynamics. we demonstrate that fliz participates in a positive-feedback loop that induces a kinetic switch in class 2 gene expression.201020935096
crl binds to domain 2 of σ(s) and confers a competitive advantage on a natural rpos mutant of salmonella enterica serovar typhi.the rpos sigma factor (σ(s)) is the master regulator of the bacterial response to a variety of stresses. mutants in rpos arise in bacterial populations in the absence of stress, probably as a consequence of a subtle balance between self-preservation and nutritional competence. we characterized here one natural rpos mutant of salmonella enterica serovar typhi (ty19). we show that the rpos allele of ty19 (rpos(ty19)) led to the synthesis of a σ(s)(ty19) protein carrying a single glycine-to-valine ...201020935100
trans-silac: sorting out the non-cell-autonomous proteome.non-cell-autonomous proteins are incorporated into cells that form tight contacts or are invaded by bacteria, but identifying the full repertoire of transferred proteins has been a challenge. here we introduce a quantitative proteomics approach to sort out non-cell-autonomous proteins synthesized by other cells or intracellular pathogens. our approach combines stable-isotope labeling of amino acids in cell culture (silac), high-purity cell sorting and bioinformatics analysis to identify the repe ...201020935649
investigation of the mechanisms by which listeria monocytogenes grows in porcine gallbladder bile.the food-borne pathogen listeria monocytogenes is known to colonize the lumen of the gallbladder in infected mice and to grow rapidly in this environment (j. hardy et al., science 303:851-853, 2004). however, relatively little is known about the mechanisms utilized by the pathogen to survive and grow in this location. we utilized gallbladder bile (gb bile) isolated directly from porcine gallbladders as an ex vivo model of gallbladder growth. we demonstrate that gb bile is generally nontoxic for ...201020937762
molecular and phenotypic characteristics of salmonella enterica serovar 4,5,12:i:- isolated from cattle and humans in iwate prefecture, japan.a total of 15 isolates of salmonella enterica serovar 4,5,12:i:- obtained from diseased cows and patients in iwate prefecture, japan, were characterized to clarify the genetic basis of this serovar. s. typhimurium- specific is200 was detected from all the isolates. a 94-kb plasmid and the spvb gene were detected from all but one of the 15 isolates. the results of pcr mapping of the fljab operon and its flanking regions indicate that there are deletions or mutations in this chromosomal region. th ...201020938106
comparative susceptibility of salmonella typhimurium biofilms of different ages to disinfectants.there is a general consensus that with increasing age a biofilm shows increased resistance to antimicrobials. in this study the susceptibility of 3-, 5- and 7-day-old salmonella enterica serovar typhimurium biofilms to disinfectants was evaluated. it was hypothesized that 7-day-old biofilms would be more resistant to disinfectants compared to 3- and 5-day-old biofilms. biofilms were formed using the mbec™ system and treated with six chemical disinfectants for 1 and 5 min. four disinfectants at t ...201020938850
an outbreak of multidrug-resistant salmonella enterica serotype oranienburg in michigan dairy calves.the objectives of this study were to report an outbreak of highly drug-resistant salmonella enterica serotype oranienburg in dairy calves, and conduct an epidemiological investigation of oranienburg identified on a dairy herd during a study to determine whether discontinuing feeding medicated milk replacer to preweaned dairy calves resulted in increased antimicrobial susceptibility in enteric bacteria. calf fecal samples and swabs of calf and maternity pens were collected monthly over 18 months. ...201020939741
flio regulation of flip in the formation of the salmonella enterica flagellum.the type iii secretion system of the salmonella flagellum consists of 6 integral membrane proteins: flha, flhb, flio, flip, fliq, and flir. however, in some other type iii secretion systems, a homologue of flio is apparently absent, suggesting it has a specialized role. deleting the flio gene from the chromosome of a motile strain of salmonella resulted in a drastic decrease of motility. incubation of the δflio mutant strain in motility agar, gave rise to pseudorevertants containing extragenic b ...201020941389
genetic evolution of the spanish multidrug-resistant salmonella enterica 4,5,12:i:- monophasic variant.we analyzed a collection of 60 salmonella enterica 4,5,12:i:- phage type u302 multidrug-resistant monophasic variant strains, isolated in spain between 2000 and 2007. most strains showed resistance to ampicillin (a), chloramphenicol (c), sulfamethoxazole (su), gentamicin (g), streptomycin (s), tetracycline (t), and co-trimoxazole (sxt) (an acsugstsxt resistance pattern). only one pulsed-field gel electrophoresis (pfge) type was detected, with 19 subtypes (simpson's index of diversity [sid]=0.89) ...201020943866
first report of salmonella enterica serotype paratyphi a azithromycin resistance leading to treatment failure.the prevalence of salmonella enterica serotype paratyphi a infection is increasing, and multidrug resistance is a well-recognized problem. resistance to fluoroquinolones is common and leads to more frequent use of newer agents like azithromycin. we report the first case of azithromycin resistance and treatment failure in a patient with s. paratyphi a infection.201020943875
chemical composition, antioxidant and antibacterial properties of the essential oils of etlingera elatior and cinnamomum pubescens kochummen.plant essential oils are widely used as fragrances and flavours. therefore, the essential oils from the leaves of cinnamomum pubescens kochummen (cp) and the whole plant of etlingera elatior (ee) were investigated for their antioxidant, antibacterial and phytochemical properties.201020945508
krüppel-like factor 4, a novel transcription factor regulates microglial activation and subsequent neuroinflammation.activation of microglia, the resident macrophages of the central nervous system (cns), is the hallmark of neuroinflammation in neurodegenerative diseases and other pathological conditions associated with cns infection. the activation of microglia is often associated with bystander neuronal death. nuclear factor-κb (nf-κb) is one of the important transcription factors known to be associated with microglial activation which upregulates the expression of inducible nitric oxide synthase (inos), cycl ...201020946687
purification of mbp-envz fusion proteins using an automated system.bacteria use two-component signal transduction systems to detect and respond to environmental changes. these systems have been studied systematically in escherichia coli as a model organism. most of the signal transduction systems present in e. coli are conserved in related pathogenic bacteria; however, differences in regulation by these systems have been reported from one bacterial species to another [oropeza, r., and calva, e. (2009). the cysteine 354 and 277 residues of salmonella enterica se ...201020946843
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