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molecular and pathogenic characterization of salmonella enterica serovar bovismorbificans strains of animal, environmental, food, and human origin in hungary.in this study, we characterized 110 strains of salmonella enterica serovar bovismorbificans contaminating environment, animals, food of animal origin, and human, to assess their significance along the food chain in hungary. additionally, five strains from germany were tested for comparative purposes. characterization involved antibiotic susceptibility testing, class 1 integron detection by polymerase chain reaction, plasmid profiling, virulotyping (using virulence gene-specific polymerase chain ...201020001326
salicylidene acylhydrazide-mediated inhibition of type iii secretion system-1 in salmonella enterica serovar typhimurium is associated with iron restriction and can be reversed by free iron.salmonella enterica serovar typhimurium is an animal and zoonotic pathogen of worldwide importance. intestinal colonization, induction of enteritis and systemic translocation by this bacterium requires type iii protein secretion. strategies that target this process have the potential to control infection, pathology and transmission. we defined the global transcriptional response of s. typhimurium to inp0403, a member of a family of salicylidene acylhydrazides that inhibit type iii secretion (t3s ...201020002188
microbial alkaloid staurosporine induces formation of nanometer-wide membrane tubular extensions (cytonemes, membrane tethers) in human neutrophils.in the present work, we demonstrate that microbial alkaloid staurosporine (sts) and ro 31-8220, structurally related to sts protein kinase c inhibitor, caused development of membrane tubular extensions in human neutrophils upon adhesion to fibronectin-coated substrata. sts-induced tubular extensions interconnected neutrophils in a network and bound serum-opsonized bacteria salmonella enterica serovar typhimurium. the diameter of sts-induced extensions varied in the range 160-200 nm. the extensio ...201020009568
performing comparative peptidomics analyses of salmonella from different growth conditions.host-pathogen interactions are complex competitions during which both the host and the pathogen adapt rapidly to each other in order for one or the other to survive. salmonella enterica serovar typhimurium is a pathogen with a broad host range that causes a typhoid fever-like disease in mice and severe food poisoning in humans. the murine typhoid fever is a systemic infection in which s. typhimurium evades part of the immune system by replicating inside macrophages and other cells. the transitio ...201020013197
global trends in typhoid and paratyphoid fever.typhoid and paratyphoid fever continue to be important causes of illness and death, particularly among children and adolescents in south-central and southeast asia, where enteric fever is associated with poor sanitation and unsafe food and water. high-quality incidence data from asia are underpinning efforts to expand access to typhoid vaccines. efforts are underway to develop vaccines that are immunogenic in infants after a single dose and that can be produced locally in countries of endemicity ...201020014951
deficiencies in elements involved in tlr4-receptor signalling in rbl-2h3 cells.rbl-2h3 cells express toll-like receptors, including tlr4. this study aims to assess various aspects of the tlr4 pathway.201020016926
thioridazine protects the mouse from a virulent infection by salmonella enterica serovar typhimurium 74.when administered to mice at doses of 100microg/mouse and 200microg/mouse, thioridazine (tdz) significantly protected animals from the lethality produced by a virulent strain of salmonella enterica serovar typhimurium and reduced the number of bacteria retrieved from the spleen, liver and heart blood. the protection conferred by tdz against a virulent salmonella infection is hypothesised to be due to a reduction in the 55kda virulence protein of the outer membrane of the organism, as this protei ...201020005679
a live oral recombinant salmonella enterica serovar typhimurium vaccine expressing clostridium perfringens antigens confers protection against necrotic enteritis in broiler chickens.necrotic enteritis (ne) in broiler chickens is caused by clostridium perfringens, and there is currently no effective vaccine for ne. we previously showed that in broiler chickens protection against ne can be achieved through intramuscular immunization with alpha toxin (at) and hypothetical protein (hp), and we subsequently identified b-cell epitopes in hp. in the present study, we identified b-cell epitopes in at recognized by chickens immune to ne. the gene fragments encoding immunodominant ep ...201020007363
resistance development profiling of piperacillin in combination with the novel {beta}-lactamase inhibitor bli-489.to evaluate development of resistance to the piperacillin/bli-489 combination.201020008048
identification of conserved amino acid residues of the salmonella sigmas chaperone crl involved in crl-sigmas interactions.proteins that bind sigma factors typically attenuate the function of the sigma factor by restricting its access to the rna polymerase (rnap) core enzyme. an exception to this general rule is the crl protein that binds the stationary-phase sigma factor sigma(s) (rpos) and enhances its affinity for the rnap core enzyme, thereby increasing expression of sigma(s)-dependent genes. analyses of sequenced bacterial genomes revealed that crl is less widespread and less conserved at the sequence level tha ...201020008066
application of a short, disordered n-terminal flagellin segment, a fully functional flagellar type iii export signal, to expression of secreted proteins.recently, we have demonstrated that the 26-47 segment of salmonella enterica serovar typhimurium flagellin is capable of mediating flagellar export. in order to reveal whether other parts of the n-terminal region have any significant influence on secretion, a series of plasmids were constructed containing the lac promoter followed by the 26-47, 2-65, or 2-192 portion of salmonella flagellin, to which various heterologous proteins of different size were fused (18 constructs overall). essentially, ...201020008166
regulation of salmonella enterica pathogenicity island 1 by dna adenine methylation.dna adenine methylase (dam(-)) mutants of salmonella enterica are attenuated in the mouse model and present multiple virulence-related defects. impaired interaction of salmonella dam(-) mutants with the intestinal epithelium has been tentatively correlated with reduced secretion of pathogenicity island 1 (spi-1) effectors. in this study, we show that s. enterica dam(-) mutants contain lowered levels of the spi-1 transcriptional regulators hila, hilc, hild, and invf. epistasis analysis indicates ...201020008574
transport and distribution of salmonella enterica serovar typhimurium in loamy and sandy soil monoliths with applied liquid manure.a leaching experiment, where liquid manure spiked with salmonella enterica serovar typhimurium (tet(+)) dsm554 was applied to soil surfaces, was conducted on intact soil monoliths (60 cm in diameter and 100 cm long). a total of 6.5 x 10(10) cfu was applied to each column. we found that salmonella serovar typhimurium could be transported to a 1-m depth in loamy soil at concentrations reaching 1.3 x 10(5) cfu/ml of leachate. the test strain was found in concentrations ranging from 300 to 1.3(5) ce ...201020023094
identification and characterization of the aspartate chemosensory receptor of campylobacter jejuni.campylobacter jejuni is a highly motile bacterium that responds via chemotaxis to environmental stimuli to migrate towards favourable conditions. previous in silico analysis of the c. jejuni strain nctc11168 genome sequence identified 10 open reading frames, tlp1-10, that encode putative chemosensory receptors. we describe the characterization of the role and specificity of the tlp1 chemoreceptor (cj1506c). in vitro and in vivo models were used to determine if tlp1 had a role in host colonizatio ...201020025667
qsec mediates salmonella enterica serovar typhimurium virulence in vitro and in vivo.the autoinducer-3 (ai-3)/epinephrine (epi)/norepinephrine (ne) interkingdom signaling system mediates chemical communication between bacteria and their mammalian hosts. the three signals are sensed by the qsec histidine kinase (hk) sensor. salmonella enterica serovar typhimurium is a pathogen that uses hks to sense its environment and regulate virulence. salmonella serovar typhimurium invades epithelial cells and survives within macrophages. invasion of epithelial cells is mediated by the type i ...201020028809
combined ramr mutation and presence of a tn1721-associated tet(a) variant in a clinical isolate of salmonella enterica serovar hadar resistant to tigecycline.a salmonella enterica serovar hadar strain resistant to tigecycline (mic, 16 microg/ml) was isolated. molecular characterization revealed the presence of a plasmid-borne tet(a) variant associated with tn1721 mediating a rise of the mic for tigecycline when transferred to escherichia coli. additionally, a truncating mutation in ramr was detected. transformation with wild-type ramr but not with the mutated ramr lowered the mic for tigecycline. characterization of this salmonella isolate implicates ...201020028818
mutations in the salmonella enterica serovar choleraesuis camp-receptor protein gene lead to functional defects in the spi-1 type iii secretion system.salmonella enterica serovar choleraesuis (salmonella choleraesuis) causes a lethal systemic infection (salmonellosis) in swine. live attenuated salmonella choleraesuis vaccines are effective in preventing the disease, and isolates of salmonella choleraesuis with mutations in the camp-receptor protein (crp) gene (salmonella choleraesuis deltacrp) are the most widely used, although the basis of the attenuation remains unclear. the objective of this study was to determine if the attenuated phenotyp ...201019775595
seroprevalence of antibodies against salmonella enterica subsp. enterica serovar gallinarum-pullorum in wild doves (zenaida asiatica and zenaida macroura) from the northeast of mexico.a cross-sectional survey was conducted in order to determine the seroprevalence and to identify some factors associated with the presence of antibodies against salmonella enterica subsp. enterica serovar gallinarum-pullorum in white-winged (zenaida asiatica) and mourning doves (zenaida macroura) from hunting areas of northeast mexico. from september to october 2006, 201 serum samples were analyzed with the seroagglutination test. the overall seroprevalence of s. enterica subsp. enterica serovar ...201019800701
emergence of multidrug-resistant salmonella enterica serovar typhi with reduced susceptibility to fluoroquinolones in cambodia.from december 2006 to april 2009, we conducted an etiology study among cambodian patients presenting with acute fever of unknown origin. salmonella enterica serovar typhi was detected in 0.9% (41/4985) blood cultures. antimicrobial susceptibility testing showed decreased susceptibility to ampicillin (56% resistant; mic(90), >256 microg/ml), chloramphenicol (56% resistant; mic(90), >256 microg/ml), trimethoprim/sulfamethoxazole (56% resistant; mic(90), >256 microg/ml), nalidixic acid (81% resista ...201019800753
characterization of extended-spectrum cephalosporin-resistant salmonella enterica serovar heidelberg isolated from humans in the united states.during the past decade, extended-spectrum cephalosporin resistance has increased among human isolates of salmonella enterica serovar heidelberg, the fourth most common serotype in the united states. we therefore characterized 54 heidelberg isolates with decreased susceptibility (minimum inhibitory concentrations >or=2 mg/l) to ceftriaxone or ceftiofur; 49 (90.7%) contained the cmy-type beta-lactamase (bla(cmy)) gene. the 49 bla(cmy)-positive human heidelberg isolates demonstrated a high degree o ...201019785533
characterization of the first extended-spectrum beta-lactamase-producing nontyphoidal salmonella strains isolated in tehran, iran.the infections caused by salmonella remain a significant public health problem throughout the world. beta-lactams and fluoroquinolones are generally used to treat invasive salmonella infections, but emergence and spread of antibiotic-resistant strains are being increasingly notified in many countries. in particular, detection of extended-spectrum beta-lactamases (esbls) in salmonella spp. is a newly emerging threat worldwide. this study was carried out to characterize beta-lactamase-producing sa ...201019785534
antioxidant and antibacterial activities of the leaf essential oils of himalayan lauraceae species.the leaf essential oils from seven himalayan lauraceae species viz. neolitsea pallens, lindera pulcherrima, dodecadenia grandiflora, persea duthiei, persea odoratissima, persea gamblei and phoebe lanceolata exhibited potent antioxidant and antibacterial activities. the in vitro antioxidant activity was assessed by using beta-carotene bleaching assay, reducing power, dpph radical scavenging and inhibition of lipid peroxidation methods. the oils of d. grandiflora and l. pulcherrima showed a potent ...201019766161
ten years experience of salmonella infections in cambridge, uk.review of all salmonella infections diagnosed in the cambridge area over 10 years.201019819256
salmonella enterica serovar typhimurium can detect acyl homoserine lactone production by yersinia enterocolitica in mice.luxr-type transcription factors detect acyl homoserine lactones (ahls) and are typically used by bacteria to determine the population density of their own species. escherichia coli and salmonella enterica serovar typhimurium cannot synthesize ahls but can detect the ahls produced by other bacterial species using the luxr homolog, sdia. previously we determined that s. typhimurium did not detect ahls during transit through the gastrointestinal tract of a guinea pig, a rabbit, a cow, 5 mice, 6 pig ...201019820103
antimicrobial resistance and virulence genes in salmonella enterica isolates from dairy cows.one hundred sixty salmonella enterica isolates from clinically healthy dairy cows were assayed for antibiotic susceptibilities, the presence of class 1 integrons, antimicrobial resistance genes and virulence genes, and conjugal transfer of antimicrobial resistance determinants. one hundred nine (68%) of the salmonella isolates were resistant to at least 1 antibiotic, and 14 isolates (9%) were multiresistant. the most prevalent resistance observed was to streptomycin (64%). class 1 integrons were ...201019821743
salmonella enterica serovar israel causing perforating appendicitis. 201019828346
development of an oligonucleotide-based microarray to detect multiple foodborne pathogens.escherichia coli o157:h7, salmonella enterica, listeria monocytogenes and campylobacter jejuni are considered important pathogens causing the most food-related human illnesses worldwide. current methods for pathogen detection have limitations in the effectiveness of identifying multiple foodborne pathogens. in this study, a pathogen detection microarray was developed using various 70-mer oligonucleotides specifically targeting the above pathogens. to reduce the cost of detection, each microarray ...201019833198
myo-inositol transport by salmonella enterica serovar typhimurium.in salmonella enterica serovar typhimurium, the genomic island gei4417/4436 has recently been identified to be responsible for myo-inositol (mi) utilization. here, two of the four island-encoded permeases are identified as the mi transporters of this pathogen. in-frame deletion of iolt1 (stm4418) led to a severe growth defect, and deletion of iolt1 (stm4419) to a slight growth defect in the presence of mi. these phenotypes could be complemented by providing the putative transporter genes in tran ...201019833776
supplement 2003-2007 (no. 47) to the white-kauffmann-le minor scheme.this supplement reports the characterization of 70 new salmonella serovars recognized between 2003 and 2007 by the who collaborating center for reference and research on salmonella: 44 were assigned to salmonella enterica subspecies enterica, 11 to subspecies salamae, 5 to subspecies arizonae, 8 to subspecies diarizonae, one to subspecies houtenae and one to salmonella bongori. one new serovar, mygdal, displayed a new h factor, h:z(91).201019840847
flow cytometric characterization of peyer's patch and cecal tonsil t lymphocytes in laying hens following challenge with salmonella enterica serovar enteritidis.two trials were conducted to determine t cell changes in peyer's patches (pp) and cecal tonsils (ct) of specific-pathogen-free single-comb white leghorn hens challenged with salmonella enterica serovar enteritidis (se). each week, crop lavage samples were obtained from 4 or 3 hens in trials 1 and 2, respectively. these birds were then sacrificed and their intestinal tracts excised. the crop sample and contents of one cecum from each hen were cultured for the presence of se. cells were purified f ...201019732961
diagnostic utility of a single widal test in the diagnosis of typhoid fever at aga khan university hospital (akuh), nairobi, kenya.typhoid fever is a systemic illness caused by salmonella enterica serovar typhi (s. typhi) and is endemic in kenya, where a single widal test done on an acute phase serum is the most commonly used test. using a cut-off value of 1:320 for both o and h agglutinins as being diagnostic of s. typhi, only 18 (26%) of our patients had diagnostic titres; 37 (53.6%) had o and h titres less than 1:40. our study showed that widal testing done on an acute phase serum of a patient suspected to have typhoid f ...201019850607
effect of adjuvants on immune response and protective immunity elicited by recombinant hsp60 (groel) of salmonella typhi against s. typhi infection.heat shock proteins (hsps) have been reported to be dominant antigens for the host immune response to various pathogens and thus, have great potential for use in vaccination. in the present study, we evaluated the immunogenicity and protective efficacy of groel of salmonella enterica serovar typhi against lethal infection by s. typhi ty2 in mice with or without adjuvants. anti groel-igg titers were significantly higher in mice immunized with either groel-alone or in combination with alum/complet ...201019851830
phage-type specific markers identified by diversity arrays technology (dart) analysis of salmonella enterica ssp. enterica serovars enteritidis and typhimurium.diversity arrays technology (dart) was applied to differentiate between s. enterica serovar enteritidis and typhimurium strains, respectively. ten and eleven, mainly phage and plasmid-related markers were identified for serovars enteritidis and typhimurium. in combination, these markers can be used for subtyping among and within phage types.201019852988
evaluation of live-attenuated salmonella vaccines expressing campylobacter antigens for control of c. jejuni in poultry.campylobacter jejuni is a zoonotic bacterial pathogen of worldwide importance. it is estimated that 460,000 human infections occur in the united kingdom per annum and these involve acute enteritis and may be complicated by severe systemic sequelae. such infections are frequently associated with the consumption of contaminated poultry meat and strategies to control c. jejuni in poultry are expected to limit pathogen entry into the food chain and the incidence of human disease. toward this aim, a ...201019853682
phage therapy to reduce preprocessing salmonella infections in market-weight swine.contamination of meat products with food-borne pathogens usually results from the carcass coming in contact with the feces of an infected animal during processing. in the case of salmonella, pigs can become colonized with the organism during transport and lairage from contaminated trailers and holding pens, resulting in increased pathogen shedding just prior to processing. increased shedding, in turn, amplifies the likelihood of carcass contamination by magnifying the amount of bacteria that ent ...201019854929
psgi15, a small cole-like qnrb19 plasmid of a salmonella enterica serovar typhimurium strain carrying salmonella genomic island 1 (sgi1). 201019861336
the use of chromogenic bacteria as coloured substitutes for pathogens: a simple strategy during design and development of a new method for sample pretreatment.in the present study, chromogenic (red) bacteria were used to simulate actual target bacteria during set-up and optimization of an isolation process of bacteria, designed for food samples. isolation of bacteria from food in the context of molecular biological detection of food pathogens is a multistep process. development of such a separation method requires continuous monitoring of the location of the presumable targets in the sample tubes. therefore, red-coloured pigmented bacteria were used a ...201019874486
molecular basis and evolution of multiple drug resistance in the foodborne pathogen salmonella enterica serovar ohio.the molecular basis and evolution of multidrug resistance were established for 54 isolates of salmonella enterica serovar ohio, recorded between 1991 and 2005 in asturias, a northern region of spain. all isolates were closely related, as shown by cluster analysis of xbai-blni combined profiles. of these, 33.3% were resistant to one or more unrelated agent(s). sulphonamides, streptomycin, tetracycline, and trimethoprim, encoded by sul1, aada1, tet(a) or tet(b), and dfra1, respectively, were the m ...201019877766
development of a live oral attaching and effacing escherichia coli vaccine candidate using vibrio cholerae cvd 103-hgr as antigen vector.attaching and effacing escherichia coli (aeec) share the ability to induce pedestal formation and intimate adherence of the bacteria to the intestinal epithelial cell and effacement of microvilli of epithelial tissue. the locus of enterocyte effacement (lee) pathogenicity island encodes the ability to induce attaching and effacing (a/e) lesions and contains the gene eae, which encodes intimin, an outer membrane protein that is an adhesin for a/e lesion formation. here we show the utility of usin ...201019878715
functional analysis of the nicotinate mononucleotide:5,6-dimethylbenzimidazole phosphoribosyltransferase (cobt) enzyme, involved in the late steps of coenzyme b12 biosynthesis in salmonella enterica.in salmonella enterica, the cobt enzyme activates the lower ligand base during the assembly of the nucleotide loop of adenosylcobalamin (adocbl) and other cobamides. previously, mutational analysis identified a class of alleles (class m) that failed to restore adocbl biosynthesis during intragenic complementation studies. to learn why class m cobt mutations were deleterious, we determined the nature of three class m cobt alleles and performed in vivo and in vitro functional analyses guided by av ...201019880598
sdia bridges chemical signaling between salmonella enterica serovar typhimurium and yersinia enterocolitica in mice. 201019880607
multilocus variable-number tandem-repeat analysis and plasmid profiling to study the occurrence of blacmy-2 within a pulsed-field gel electrophoresis-defined clade of salmonella enterica serovar typhimurium.salmonella enterica serovar typhimurium circulating in food animal populations and carrying resistance to antimicrobial agents represents a human health risk. recently, a new clade of s. typhimurium, wa-typ035/187, was reported in cattle and humans in the pacific northwest, united states of america. the objective of this study was to describe a possible mechanism of acquisition of expanded-spectrum cephalosporin resistance in this clade. ceftazidime resistance increased steadily among wa-typ035/ ...201019880639
salmonella enterica serovar typhimurium trxa mutants are protective against virulent challenge and induce less inflammation than the live-attenuated vaccine strain sl3261.in salmonella enterica serovar typhimurium, trxa encodes thioredoxin 1, a small, soluble protein with disulfide reductase activity, which catalyzes thiol disulfide redox reactions in a variety of substrate proteins. thioredoxins are involved as antioxidants in defense against oxidative stresses, such as exposure to hydrogen peroxide and hydroxyl radicals. we have made a defined, complete deletion of trxa in the mouse-virulent s. typhimurium strain sl1344 (sl1344 trxa), replacing the gene with a ...201019884329
norepinephrine augments salmonella enterica-induced enteritis in a manner associated with increased net replication but independent of the putative adrenergic sensor kinases qsec and qsee.stress has long been correlated with susceptibility to microbial infection. one explanation for this phenomenon is the ability of pathogens to sense and respond to host stress-related catecholamines, such as norepinephrine (ne). in gram-negative enteric pathogens, it has been proposed that ne may facilitate growth by mediating iron supply, or it may alter gene expression by activating adrenergic sensor kinases. the aim of this work was to investigate the relative importance of these processes in ...201019884332
a new generation of stable, nonantibiotic, low-copy-number plasmids improves immune responses to foreign antigens in salmonella enterica serovar typhi live vectors.we hypothesized that adequately engineered attenuated salmonella enterica serovar typhi strains can serve as multivalent mucosal live vector vaccines to immunize against unrelated human pathogens. toward this ultimate goal, we have developed a novel genetic stabilization system for antigen-expressing plasmids, engineered to encode the single-stranded binding protein (ssb), an essential protein involved in dna metabolism which was deleted from the live vector chromosome. we utilized full-length p ...201019884333
unusual class 1 integron configuration found in salmonella genomic island 2 from salmonella enterica serovar emek.salmonella genomic island 2 (sgi2) is an independently derived genomic island related to sgi1 with the integron in a different position. the integron in sgi2 was found to include an additional 2.1 kb derived from the tni module of tn5058, tn502, or tn512 that was not detected previously. independent evolution of the backbone was confirmed with 21 single base differences found in over 11.5 kb, representing 40% of the 27.4-kb sgi2 backbone.201019884375
first report of extended-spectrum-beta-lactamase-producing salmonella enterica serovar kentucky isolated from poultry in ireland.therapy of invasive human salmonellosis is complicated by increasing antimicrobial resistance. food animals are the principal source of infection with nontyphoid salmonella. we report the emergence of broad-spectrum-cephalosporin resistance in salmonella enterica serovar kentucky in poultry in ireland.201019884382
inhibition of fungi and gram-negative bacteria by bacteriocin bactn635 produced by lactobacillus plantarum sp. tn635.the aim of this study was to evaluate 54 lactic acid bacteria (lab) strains isolated from meat, fermented vegetables and dairy products for their capacity to produce antimicrobial activities against several bacteria and fungi. the strain designed tn635 has been selected for advanced studies. the supernatant culture of this strain inhibits the growth of all tested pathogenic including the four gram-negative bacteria (salmonella enterica atcc43972, pseudomonas aeruginosa atcc 49189, hafnia sp. and ...201019888697
detection of mutations in the gyra gene in fluoroquinolone resistance salmonella enterica serotypes typhi and paratyphi a isolated from the infectious diseases hospital, kuwait.enteric fever due to salmonella enterica is a major health problem, and fluoroquinolones such as ciprofloxacin are mostly the antibiotic of choice for treatment. resistance to ciprofloxacin has been noticed to increase due to the emergence of new mutations in the bacterial dna.201019889623
physical and chemical characterization and immunologic properties of salmonella enterica serovar typhi capsular polysaccharide-diphtheria toxoid conjugates.typhoid fever remains a serious public health problem in developing countries, especially among young children. recent studies showed more than 50% of typhoid cases are in children under 5 years old. licensed vaccines, such as salmonella enterica serovar typhi capsular vi, did not confer protection against typhoid fever for this age group. vi conjugate, prepared by binding vi to pseudomonas aeruginosa recombinant exoprotein a (repa), induces protective levels of antibody at as young as 2 years o ...201019889941
listeria monocytogenes does not survive ingestion by acanthamoeba polyphaga.listeria monocytogenes is a ubiquitous bacterium capable of infecting humans, particularly pregnant women and immunocompromised individuals. although the intracellular invasion and pathogenesis of listeriosis in mammalian tissues has been well studied, little is known about the ecology of l. monocytogenes , and in particular the environmental reservoir for this bacterium has not been identified. this study used short-term co-culture at 15, 22 and 37 degrees c to examine the interaction of l. mon ...201019892759
systematic analysis of the ssrab virulon of salmonella enterica.intracellular salmonella enterica serovar typhimurium deploys the salmonella pathogenicity island 2 (spi2)-encoded type iii secretion system (t3ss) to modify host cell functions and accomplish intracellular replication. this virulence function is controlled by the two-component system ssrab that regulates the expression of several operons in spi2 and, in addition, a large number of genes for non-spi2-encoded effector proteins. here, we analyzed the relative expression levels of members of the ss ...201019858298
division of the salmonella-containing vacuole and depletion of acidic lysosomes in salmonella-infected host cells are novel strategies of salmonella enterica to avoid lysosomes.salmonella has evolved several strategies to counteract intracellular microbicidal agents like reactive oxygen and nitrogen species. however, it is not yet clear how salmonella escapes lysosomal degradation. some studies have demonstrated that salmonella can inhibit phagolysosomal fusion, whereas other reports have shown that the salmonella-containing vacuole (scv) fuses/interacts with lysosomes. here, we have addressed this issue from a different perspective by investigating if the infected hos ...201019858305
antimicrobial substances produced by coliform strains active against foodborne pathogens.in the present study, 31 coliform strains were isolated from salad, cheese, and meat products sold in commercial establishments in rio de janeiro city, and were tested for antibiotic resistance and antimicrobial substance production. thirteen strains (41.9%) were resistant to at least one antibiotic tested, among which one presented resistance to nine different antibiotics. two strains (6.4%) exhibited inhibitory activity against the indicator strains, escherichia coli lmifrj and salmonella ente ...201019895262
immunisation of the equine uterus against streptococcus equi subspecies zooepidemicus using an intranasal attenuated salmonella vector.attenuated salmonella enterica serovar typhimurium mgn707, expressing the szp protective protein of the mb9 serovar of streptococcus equi subspecies zooepidemicus (szp-mb9) was tested for its safety and efficacy as a nebulised intranasal vaccine against streptococcal uterine infections in mares. in a preliminary study, vaccinated mares (n=5) displayed serum, nasal and uterine responses (p<0.05) to s. typhimurium lipopolysaccharide (st-lps). subsequently, vaccinated mares (expressor group, n=7), ...201019482493
higher hospital costs and lengths of stay associated with quinolone-resistant salmonella enterica infections in hong kong.the study sought to determine the differences in lengths of stay and medical costs between patients admitted to hospital with non-typhoidal salmonellosis that were either quinolone resistant (qr) or quinolone susceptible (qs).201019528063
mobility and survival of salmonella typhimurium and human adenovirus from spiked sewage sludge applied to soil columns.this study investigated the survival and transport of sewage sludge-borne pathogenic organisms in soils.201019583795
antimicrobial mortar surfaces for the improvement of hygienic conditions.to evaluate the effectiveness of various antimicrobial mortar formulations in inhibiting the growth of a selection of pathogens of environmental and hygienic concern.201019583799
effect of chlorate, molybdate, and shikimic acid on salmonella enterica serovar typhimurium in aerobic and anaerobic cultures.experiments were conducted to determine factors that affect sensitivity of salmonella enterica serovar typhimurium to sodium chlorate (5mm). in our first experiment, cultures grown without chlorate grew more rapidly than those with chlorate. an extended lag before logarithmic growth was observed in anaerobic but not aerobic cultures containing chlorate. chlorate inhibition of growth during aerobic culture began later than that observed in anaerobic cultures but persisted once inhibition was appa ...201019524056
molecular leakage at implant-abutment connection--in vitro investigation of tightness of internal conical implant-abutment connections against endotoxin penetration.microleakage has been discussed as a major contributing factor for inflammatory reactions at the implant-abutment connection. in previous studies, the tightness against corpuscular bodies (viable bacteria) has been successfully investigated under static and dynamic conditions. the aim of this study was to investigate the tightness against endotoxins of two implant systems (astratech and ankylos) with conical internal connections under static conditions. the inner parts of eight implants of each ...201019629543
salmonella enterica serotypes and antibiotic susceptibility in new zealand, 2002-2007.we analysed the serotypes and antibiotic susceptibility of 1560 human and 1505 non-human salmonella isolated in new zealand (nz) between 2002 and 2007. the most common serotypes in humans were salmonella enterica serovar typhimurium, s. enteritidis, s. brandenburg and s. infantis. over the 6-year period human cases due to s. agona and s. enteritidis increased and cases due to s. typhimurium decreased. the most common serotypes from non-human sources were s. typhimurium, s. brandenberg, s. hindma ...201019653924
cyclic di-gmp signalling controls virulence properties of salmonella enterica serovar typhimurium at the mucosal lining.cyclic di-gmp (c-di-gmp), a novel secondary signalling molecule present in most bacteria, controls transition between motility and sessility. in salmonella enterica serovar typhimurium (s. typhimurium) high c-di-gmp concentrations favour the expression of a biofilm state through expression of the master regulator csgd. in this work, we investigate the effect of c-di-gmp signalling on virulence phenotypes of s. typhimurium. after saturation of the cell with c-di-gmp by overexpression of a di-guan ...201019691499
salmonella enterica serovar typhi in japan, 2001-2006: emergence of high-level fluoroquinolone-resistant strains.the phage types and antimicrobial susceptibilities of 226 isolates of salmonella enterica serovar typhi from imported cases in japan between 2001 and 2006 were investigated. most (93.8%) had travelled to asian countries, particularly south east asia. twenty-one phage types were identified with e1 (30.5%), uvs (15.9%) and b1 (9.3%) being the most common. the frequency of multidrug-resistant strains reached 37.0% in 2006 with phage types e1 and e9 predominating. almost half (48.2%) of the isolates ...201019631017
an enteric pathogen salmonella enterica serovar typhimurium suppresses tumor growth by downregulating cd44high and cd4t regulatory (treg) cell expression in mice: the critical role of lipopolysaccharide and braun lipoprotein in modulating tumor growth.an antitumor activity associated with several bacterial pathogens, including salmonella enterica serovar typhimurium, has been reported; however, the underlying immunological mechanism(s) that lead to an antitumor effect are currently unclear. furthermore, such pathogens cannot be used to suppress tumor growth because of their potential for causing sepsis. recently, we reported the characterization of s. typhimurium isogenic mutants from which braun lipoprotein genes (lppa and b) and the multico ...201019713997
salmonella enterica serovar choleraesuis derivatives harbouring deletions in rpos and phop regulatory genes as vehicles for dna vaccines.we investigated the use of two previously described attenuated strains of salmonella enterica subspecies enterica serovar choleraesuis (s. choleraesuis), deltaphop and deltarpos, compared with the commercial attenuated sc-54 strain, as bactofection vehicles, to deliver an epitope model (3xflag) to the intestinal immune system. the gene encoding the epitope 3xflag was subcloned into the pcmvbetam2a mammalian expression vector (creating pcmv3xflagm2a) and introduced into s. choleraesuis strains. t ...201019720478
bacterial nitric oxide detoxification prevents host cell s-nitrosothiol formation: a novel mechanism of bacterial pathogenesis.s-nitrosylation is an important mediator of multiple nitric oxide-dependent biological processes, including eukaryotic cellular events such as macrophage apoptosis and proinflammatory signaling. many pathogenic bacteria possess no detoxification mechanisms, such as the nitric oxide reductase (norb) of neisseria meningitidis and the flavohemoglobins (hmp) of salmonella enterica and escherichia coli, which serve to protect the microorganism from nitrosative stress within the intracellular environm ...201019720623
sporadic salmonella enterica serotype javiana infections in georgia and tennessee: a hypothesis-generating study.from 1996 to 2004, the incidence of salmonella javiana infections increased in foodnet, the u.s. national active foodborne disease surveillance programme. contact with amphibians and consumption of tomatoes have been associated with outbreaks of s. javiana infection. to generate and test hypotheses about risk factors associated with sporadic s. javiana infections, we interviewed patients with laboratory-confirmed s. javiana infection identified in georgia and tennessee during august-october 2004 ...201019723360
feeding the bt cationic peptides to chickens at hatch reduces cecal colonization by salmonella enterica serovar enteritidis and primes innate immune cell functional activity.the bt/tamus 2032 (bt) cationic peptides are a group of related cationic peptides produced by a gram-positive soil bacterium, brevibacillus texasporus. cationic amphiphilic peptides produced by host cells have been found to stimulate or prime the innate immune responses in mammals, but little information is available on the effects of bacterial-produced peptides on host immunity. we have previously shown that bt, provided as a feed additive for 4 days after hatch, significantly induced protectio ...201019735207
a synthetic furanone potentiates the effect of disinfectants on salmonella in biofilm.to study a possible effect of a synthetic brominated furanone on biofilm formation and biofilm resistance to disinfectants in salmonella enterica.201019735326
minimal penetration of lipopolysaccharide across the murine blood-brain barrier.lps given peripherally or into the brain induces a neuroinflammatory response. how peripheral lps induces its effects on brain is not clear, but one mechanism is that lps crosses the blood-brain barrier (bbb). alternatively, lps acts outside the bbb by stimulating afferent nerves, acting at circumventricular organs, and altering bbb permeabilities and functions. here, we labeled lps with radioactive iodine (i-lps) and coinjected it with radioactively labeled albumin (i-alb) which acted as a vasc ...201019735725
[investigation of potential risk factors for salmonella enterica subsp enterica serotype napoli: a nested case-control study in lombardia region].enter-net surveillance system has detected the re-emergence of salmonella enterica subsp enterica serotype napoli (s. napoli) since 2002. preliminary data show that food vehicle could not be the only one implicated in the transmission of this serotype. a nested case-control study has been conducted using data form a prospective cohort: for each salmonellosis notification in lombardia from may 2004 to december 2005 an ad hoc epidemiological investigation has been performed. cases have been define ...201021425643
the damx protein of escherichia coli and salmonella enterica.we recently showed that disruption of damx causes bile sensitivity in salmonella enterica. the damx gene is part of an operon that contains genes with heterogeneous functions: dna adenine methylation, biosynthesis of aromatic compounds, carbohydrate metabolism, and trna charging. the damx gene encodes a protein with a predicted size of 46 kda. in salmonella, damx is found in the inner membrane of both dividing and non-dividing cells. the damx protein contains a peptidoglycan-binding spor domain, ...201021327035
salmonella's iron armor for battling the host and its microbiota.most salmonella enterica serotypes are associated with acute intestinal inflammation and diarrhea in humans. while the mechanisms triggering intestinal inflammation are well studied, relatively little is known about how the pathogen benefits from causing disease. recent work has provided first insights into the genetic design that enables s. enterica to benefit from the host response by outgrowing the microbiota in the gut. the pathogen gained an edge over its competitors by acquiring genes conf ...201021327120
serotypes and antimicrobial resistance of salmonella enterica ssp in central thailand, 2001-2006.this study was carried out to elucidate the epidemiological trends and antimicrobial susceptibilities against salmonella serovars among thai patients and asymptomatic carriers during 2001-2006 in central thailand. a total of 1,401 human and 260 non-human isolates from various sources were included. the isolates were characterized using serotyping and antimicrobial susceptibility testing. the most common serovars in patients submitting stool samples were s. weltevreden, s. stanley, s. anatum, and ...201021329317
emergence and properties of fluoroquinolone resistant salmonella enterica serovar typhi strains isolated from nepal in 2002 and 2003.a total of 171 salmonella enterica serovar typhi strains isolated from nepal, mostly from patients with typhoid fever in 2002-2003, were tested for antimicrobial susceptibility by disk diffusion assay. selected s. enterica serovar typhi isolates were tested for mics by e-test for ceftriaxone, ciprofloxacin and ofloxacin. mutations of dna gyrase gyra and gyrb and topoisomerase iv parc and pare were identified by sequencing of pcr amplicons. by disk diffusion assay, 75/171 s. enterica serovar typh ...201021329318
a murine model to study the antibacterial effect of copper on infectivity of salmonella enterica serovar typhimurium.this study investigated the effect of copper as an antibacterial agent on the infectivity of salmonella enterica serovar typhimurium. mice were infected orally with a standardized dose of unstressed salmonella typhimurium and copper-stressed cells of salmonella typhimurium. bacterial counts in ileum, blood, liver and spleen were observed up to 168 h under normal aerobic conditions. serum sensitivity, phagocytosis, malondialdehyde levels and histopathology were studied for both set of animals. a ...201021318012
remodelling of the vibrio cholerae membrane by incorporation of exogenous fatty acids from host and aquatic environments.the gram-negative bacteria vibrio cholerae poses significant public health concerns by causing an acute intestinal infection afflicting millions of people each year. v. cholerae motility, as well as virulence factor expression and outer membrane protein production, has been shown to be affected by bile. the current study examines the effects of bile on v. cholerae phospholipids. bile exposure caused significant alterations to the phospholipid profile of v. cholerae but not of other enteric patho ...201021255114
effects of dam and/or seqa mutations on the fatty acid and phospholipid membrane composition of salmonella enterica serovar typhimurium.we examined the phospholipids (phls) and the membrane fatty acid (fa) composition in salmonella enterica serovar typhimurium dam and/or seqa mutants. phosphatidylglycerol, phosphatidylethanolamine (pe), and cardiolipin (cl) are the major phls present in all the strains and accounted for greater than 95% of the total lipid phosphorus. phosphatidic acid and phosphatidylserine are the minor ones. the seqa mutant showed a decrease in pe and an increase in cl and phosphatidylglycerol proportion compa ...201020132031
[srna (srab) regulate the resistant ability of salmonella enterica serovar enteritidis to egg albumen].salmonella species are important food-borne pathogens of human and animal. s. enterica serovar enteritidis is the only serovar that routinely causes human infection through intact egg, the molecular basis of its ability to survive in egg is poorly understood. the importance of post-transcriptional regulation by small non-coding rnas (srna) has recently been recognized. the srnas play diverse physiological roles in stress responses, regulation of metabolism, control of bacterial envelope composit ...201021268901
[cloning and identification of ipaj gene in salmonella pullorum].cloning of ipaj gene from salmonella pullorum c79-13, and identification of expressed ipaj protein as an immunogen of the pathogen.201021268902
change in attachment of salmonella typhimurium, yersinia enterocolitica, and listeria monocytogenes to pork skin and muscle after hot water and lactic acid decontamination.the attachment of salmonella enterica subsp. enterica serovar typhimurium, yersinia enterocolitica, and listeria monocytogenes to pig skin and muscle tissue decontaminated with 80 °c water or 55 °c, 1% lactic acid for 5 and 15s was investigated. attachment properties differed between skin and muscle surfaces. a significantly higher number of firmly attached bacteria was found on the decontaminated skin surface compared to the non-treated skin surface, both on hot water (p<0.0001) and on lactic a ...201021269717
reduction of salmonella enterica on grape tomatoes using microwave heating.grape tomatoes were surface inoculated with salmonella enterica serovars typhimurium, senftenburg, kentucky and enteritidis and heated for 10, 20, 30, 40 and 50 s using a household microwave oven at two different power levels (medium and high). following heating, viable counts, temperature measurements and quality measurements were performed on the tomatoes. at high power level, more than 2 log reduction of salmonella enterica was detected on grape tomatoes after 50 s but the texture were damage ...201021227524
presence of arsenic resistance in salmonella enterica serovar kentucky and other serovars isolated from poultry.a collection of 125 salmonella enterica poultry isolates (71 serovar kentucky isolates, and the remainder belonging to serovars alachua, enteritidis, hadar, heidelberg, montevideo, mbandaka, senftenberg, typhimurium, and worthington) were tested for the ability to grow on tryptic soy agar containing sodium arsenite [as(iii)] or arsenate [as(v)]. all serovar kentucky isolates and 18 of the non-kentucky isolates were able to grow in the presence of 0.1 mm as(iii), and 69 grew in the presence of 1 ...201021313837
salmonella enterica serovars typhi and paratyphi a are avirulent in newborn and infant mice even when expressing virulence plasmid genes of salmonella typhimurium.salmonella enterica serovars typhi and paratyphi a are human host-restricted pathogens. therefore, there is no small susceptible animal host that can be used to assess the virulence and safety of vaccine strains derived from these salmonella serovars.  however, infant mice have been used to evaluate virulence and colonization by another human host-restricted pathogen, vibrio cholerae.201021252450
antimicrobial resistance in salmonella enterica serovar enteritidis in morocco.salmonella enterica is recognised worldwide as one of the major agents of human gastrointestinal infections. the aim of the present work is to ascertain the antimicrobial susceptibilities of 150 salmonella enterica serovar enteritidis isolates from humans in morocco during the period from 2000 to 2008.201021252460
application of phage typing and pulsed-field gel electrophoresis to analyse salmonella enterica isolates from a suspected outbreak in lagos, nigeria.inadequate potable water supply and poor sanitation predispose to food- and water-borne diseases associated with salmonella enterica serovars in developing countries. in this study the possible source of an unprecedented upsurge of salmonella-associated community gastroenteritis was traced using both phage-typing and pulsed-field gel electrophoresis (pfge).201021252464
label-free identification of bacterial microcolonies via elastic scattering.label-free microcolony identification via elastic light scattering was investigated for three different genera: salmonella enterica serovar montevideo, listeria monocytogenes f4244, and escherichia coli dh5α. microcolonies were defined as bacterial colonies in their late-lag phase to early-exponential phase with the diameter range of 100-200 µm. to link biophysical characteristics with corresponding scattering patterns, a phase contrast microscope and a confocal displacement meter were used to m ...201021246511
analysis of tomato and jalapeño and serrano pepper imports into the united states from mexico before and during a national outbreak of salmonella serotype saintpaul infections in 2008.case-control studies conducted during a multistate outbreak of salmonella enterica serotype saintpaul infections in 2008 revealed associations between illness and the consumption of jalapeño peppers, serrano peppers, and tomatoes. traceback investigations of implicated jalapeño and serrano peppers led to farms in tamaulipas and nuevo león, mexico. we conducted a novel analysis of a u.s. food and drug administration database of tomatoes and jalapeño and serrano peppers imported from mexico during ...201021219707
reduction of salmonella enterica contamination on grape tomatoes by washing with thyme oil, thymol, and carvacrol as compared with chlorine treatment.in recent years, multistate outbreaks of salmonella enterica serovars were traced to tomatoes and resulted in serious economic loss for the tomato industry and decreased consumer confidence in the safety of tomato produce. purified compounds derived from essential oils such as thymol and carvacrol had wide inhibitory effects against foodborne pathogens including salmonella. the objective of this study was to determine the antimicrobial activities of thymol, carvacrol, and thyme oil against salmo ...201021219747
structures of the sep22 dodecamer, a dps-like protein from salmonella enterica subsp. enterica serovar enteritidis.the crystal structure of sep22, a dna-binding protein from starved cells from salmonella enterica subsp. enterica serovar enteritidis, has been determined in two forms: the native state at 1.25 å resolution and an iron-soaked form at 1.30 å resolution. the sep22 protomers form a dodecameric shell with 23 symmetry and a single iron ion per protomer was found at the ferroxidase centre in the iron-soaked form. along the threefold axes of the 23 symmetry, hydrophilic asp channels that consist of asp ...201021206015
analysis of interactions of salmonella type three secretion mutants with 3-d intestinal epithelial cells.the prevailing paradigm of salmonella enteropathogenesis based on monolayers asserts that salmonella pathogenicity island-1 type three secretion system (spi-1 t3ss) is required for bacterial invasion into intestinal epithelium. however, little is known about the role of spi-1 in mediating gastrointestinal disease in humans. recently, spi-1 deficient nontyphoidal salmonella strains were isolated from infected humans and animals, indicating that spi-1 is not required to cause enteropathogenesis an ...201021206750
multilocus variable-number of tandem-repeats analysis of salmonella enterica serotype gallinarum and comparison with pulsed-field gel electrophoresis genotyping.salmonella enterica serovar gallinarum is the causative agent of fowl typhoid, a severe disease of poultry, responsible for heavy economic losses. epidemiologic investigation of fowl typhoid significantly benefits from molecular typing tools, rapd and pfge have been proposed for this purpose. pfge, a well established technique, is still the gold standard among typing methods for most bacteria, including salmonella. nevertheless, it has some limitations regarding execution and reproducibility, in ...201021208755
humanized mice are susceptible to salmonella typhi infection.salmonella enterica serovar typhi is a pathogen that only infects humans. currently, there is no animal model for studying this pathogen. recently, alymphoid rag-2(-/-)/γ(c)(-/-) mice engrafted with human leukocytes, known as humanized mice, have been successfully utilized to develop experimental models for several human-specific viral infections, including hiv, human-like dengue fever and hepatitis c virus. little is known about the usefulness and feasibility of the humanized mouse model for th ...201021200387
horizontal gene transfer of a colv plasmid has resulted in a dominant avian clonal type of salmonella enterica serovar kentucky.salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. a wide variety of salmonella serovars have been isolated from production birds and from retail poultry meat. recently, though, s. enterica subsp. enterica serovar kentucky has emerged as one of the prominent salmonella serovars isolated from broiler chickens. recent work suggests that its emergence apparently coincides with its acquisition of a colv virulence plasmid. in the present study, we ...201021203520
inhibition of the early stage of salmonella enterica serovar enteritidis biofilm development on stainless steel by cell-free supernatant of a hafnia alvei culture.compounds present in hafnia alvei cell-free culture supernatant cumulatively negatively influence the early stage of biofilm development by salmonella enterica serovar enteritidis on stainless steel while they also reduce the overall metabolic activity of s. enteritidis planktonic cells. although acylhomoserine lactones (ahls) were detected among these compounds, the use of several synthetic ahls was not able to affect the initial stage of biofilm formation by this pathogen.201020097823
the zur-regulated zint protein is an auxiliary component of the high-affinity znuabc zinc transporter that facilitates metal recruitment during severe zinc shortage.the pathways ensuring the efficient uptake of zinc are crucial for the ability of bacteria to multiply in the infected host. to better understand bacterial responses to zinc deficiency, we have investigated the role of the periplasmic protein zint in salmonella enterica serovar typhimurium. we have found that zint expression is regulated by zur and parallels that of znua, the periplasmic component of the zinc transporter znuabc. despite the fact that zint contributes to salmonella growth in medi ...201020097857
lag phase of salmonella enterica under osmotic stress conditions.salmonella enterica serovar typhimurium was grown at salt concentrations ranging from 0.5 to 7.5% in minimal medium with and without added osmoprotectant and in a rich medium. in minimal medium, the cells showed an initial decline period, and consequently the definition of the lag time of the resultant log count curve was revised. the model of baranyi and roberts (int. j. food microbiol. 23:277-294, 1994) was modified to take into account the initial decline period, based on the assumption that ...201021193660
medicinal plant extracts with efflux inhibitory activity against gram-negative bacteria.it was hypothesised that extracts from plants that are used as herbal medicinal products contain inhibitors of efflux in gram-negative bacteria. extracts from 21 plants were screened by bioassay for synergy with ciprofloxacin against salmonella enterica serotype typhimurium, including mutants in which acrb and tolc had been inactivated. the most active extracts, fractions and purified compounds were further examined by minimum inhibitory concentration testing with five antibiotics for activity a ...201021194895
assessment of 2 salmonella enterica serovar typhimurium-based vaccines against necrotic enteritis in reducing colonization of chickens by salmonella serovars of different serogroups.this study assessed the protective efficacy of oral vaccination with 2 experimental attenuated salmonella typhimurium-vectored vaccines for necrotic enteritis in protecting chickens against intestinal colonization by common serovars of salmonella belonging to the 4 major serogroups affecting chickens. birds were vaccinated orally with 1 × 10⁸ colony-forming units (cfu) of 1 of the vaccine strains χ9241 and χ9352, which express a plasmid-encoded partial recombinant hypothetical protein gene (thp) ...201021197226
characterisation of proteins extracted from the surface of salmonella typhimurium grown under spi-2-inducing conditions by lc-esi/ms/ms sequencing.salmonella enterica has two pathogenicity islands encoding separate type three secretion systems (t3ss). proteins secreted through these systems facilitate invasion and survival. after entry, salmonella reside within a membrane bound vacuole, the salmonella containing vacuole (scv), where translocation of a second set of effectors by the salmonella pathogenicity island 2 (spi-2) t3ss is initiated. spi-2 secretion in vitro can be induced by conditions that mimic the salmonella containing vacuole. ...201021197671
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