Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
t cell augments the antitumor activity of tumor-targeting salmonella.systemic administration of salmonella to tumor-bearing mice leads to preferential accumulation within tumor sites and retardation of tumor growth. however, the detailed mechanism of salmonella-induced antitumor immune response via host t cell remains uncertain. herein, we used wild-type, cd4(+) t-cell-deficient, and cd8(+) t-cell-deficient mice to study the role of t cell in the antitumor immune responses induced by salmonella enterica serovar choleraesuis (salmonella choleraesuis). when systemi ...201121360146
pathogen detection using a liquid array technology.low concentrations of microbial pathogens in pure and mixed samples were detected using a bead-based, liquid array technology. a 20-bp sequence in the 23s rrna gene, rrl, was amplified in four microorganisms: bacillus cereus, escherichia coli, salmonella enterica and staphylococcus aureus. pcr products were positively identified with the luminex(®) 100™ system. the system could detect very low amounts of dna and the instrument response was proportional to the input concentration. the lower limit ...201121361936
new flagellin gene for salmonella enterica serovar typhi from the east indonesian archipelago.phase variation is a property unique of some salmonella enterica serovar typhi strains from indonesia. salmonella typhi isolates from indonesia have been described that in addition to the phase 1 hd flagellin gene contain a second flagellin gene named z66. s. typhi isolates from indonesia with a mutant hd gene named hj have also been described. here, we have identified another flagellin gene of s. typhi, named ind, showing a closest homology with the flagellin gene of serratia marcescens. the in ...201121363982
2008 outbreak of salmonella saintpaul infections associated with raw produce.raw produce is an increasingly recognized vehicle for salmonellosis. we investigated a nationwide outbreak that occurred in the united states in 2008.201121345092
identification of a salmonellosis outbreak by means of molecular sequencing. 201121345093
salmonella enterica serotype virchow associated with human infections in switzerland: 2004-2009.salmonellosis is one of the most important foodborne diseases and a major threat to public health. salmonella serotype virchow ranks among the top five serovars in europe.201121345197
a comparison of transmission characteristics of salmonella enterica serovar enteritidis between pair-housed and group-housed laying hens.abstract: human cases of bacterial gastro-enteritis are often caused by the consumption of eggs contaminated with salmonella species, mainly salmonella enterica serovar enteriditis (salmonella enteritidis). to reduce human exposure, in several countries worldwide surveillance programmes are implemented to detect colonized layer flocks. the sampling schemes are based on the within-flock prevalence, and, as this changes over time, knowledge of the within-flock dynamics of salmonella enteritidis is ...201121345201
po157_sal, a novel conjugative plasmid detected in outbreak isolates of escherichia coli o157:h7.in addition to the large virulence plasmid po157, a novel 38-kb conjugative plasmid, po157_sal, was identified and sequenced from an escherichia coli o157:h7 outbreak-associated chinese isolate that shares high similarity with a plasmid in salmonella enterica serovar agona. the plasmid was found in 15 of 326 isolates, 12 of which were of the same pulsed-field gel electrophoresis type.201121346051
salmonella enterica serovar typhimurium lacking hfq gene confers protective immunity against murine typhoid.salmonella enterica is an important enteric pathogen and its various serovars are involved in causing both systemic and intestinal diseases in humans and domestic animals. the emergence of multidrug-resistant strains of salmonella leading to increased morbidity and mortality has further complicated its management. live attenuated vaccines have been proven superior over killed or subunit vaccines due to their ability to induce protective immunity. of the various strategies used for the generation ...201121347426
a mutation in the poxa gene of salmonella enterica serovar typhimurium alters protein production, elevates susceptibility to environmental challenges, and decreases swine colonization.control of foodborne salmonella within the farm-retail continuum is a complex issue since over 2500 serovars of salmonella exist, the host range of salmonella spp. varies greatly, and salmonella is environmentally ubiquitous. to identify salmonella enterica serovar typhimurium (salmonella typhimurium) genes important for pathogen survival, our research group previously screened a signature-tagged mutagenesis bank in an ex vivo swine stomach content assay. a mutation in the poxa gene, a member of ...201121348575
cellular aspects of immunity to intracellular salmonella enterica.salmonella enterica is a frequent gastrointestinal pathogen with ability to cause diseases ranging from local gastrointestinal inflammation and diarrhea to life-threatening typhoid fever. salmonella is an invasive, facultative intracellular pathogen that infects various cell types of the host and can survive and proliferate in different populations of immune cells. during pathogenesis, salmonella is confronted with various lines of immune defense. to successfully colonize host organisms, the pat ...201121349094
immunity to salmonellosis.salmonella enterica is a genetically broad species harboring isolates that display considerable antigenic heterogeneity and significant differences in virulence potential. salmonella generally exhibit an invasive potential and they can survive for extended periods within cells of the immune system. they cause acute or chronic infections that can be local (e.g. gastroenteritis) or systemic (e.g. typhoid). in vivo salmonella infections are complex with multiple arms of the immune system being enga ...201121349095
salmonella enterica strains belonging to o serogroup 1,3,19 induce chlorosis and wilting of arabidopsis thaliana leaves.the number of outbreaks and illness linked to the consumption of contaminated salad leaves have increased dramatically in the last decade. escherichia coli and salmonella enterica are the most common food-borne pathogens linked to consumption of fresh produce. different serovars of s. enterica subspecies enterica have been shown to bind the surface of salad leaves, to exhibit tropism towards the stomata and to invade leaves and reach the underlying mesophyll. however the consequences of leaf inv ...201121349136
genetic analysis of the bacterial hook-capping protein flgd responsible for hook assembly.flgd of salmonella enterica is a 232 aa protein that acts as the hook cap to promote assembly of flge into the hook structure. the n-terminal 86 residues (flgd(n)) complement flgd mutants, albeit to a small degree. however, little is known about the role of the c-terminal region of flgd (flgd(c)). here we isolated pseudorevertants from salmonella flge mutants. about half of the extragenic mutations lay within flgd(c) and only one in flgd(n). these suppressor mutations prevented mutant flge subun ...201121349976
function-specific accelerations in rates of sequence evolution suggest predictable epistatic responses to reduced effective population size.changes in effective population size impinge on patterns of molecular evolution. notably, slightly deleterious mutations are more likely to drift to fixation in smaller populations, which should typically also lead to an overall acceleration in the rates of evolution. this prediction has been validated empirically for several endosymbiont and island taxa. here, we first show that rate accelerations are also evident in bacterial pathogens whose recent shifts in virulence make them prime candidate ...201121349981
five commercial dna extraction systems tested and compared on a stool sample collection.in this study, 5 different commercial dna extraction systems were tested on a stool sample collection containing 81 clinical stool specimens that were culture-positive for diarrheagenic escherichia coli, campylobacter jejuni, salmonella enterica, or clostridium difficile. the purified dnas were analyzed by polymerase chain reaction (pcr) directed toward the relevant organisms. the results showed that conventional pcr combined with the extraction systems biorobot ez1 (qiagen, hilden, germany), bu ...201121353945
characterization of the quinolone resistance mechanism in foodborne salmonella isolates with high nalidixic acid resistance.sixteen salmonella strains resistant to nalidixic acid isolated from kimbab, the most popular ready-to-eat (rte) food in korea, and chicken meat were selected for this study. the resistant strains were shown to have high minimal inhibitory concentrations (mics) against nalidixic acid (512~4096 µg/ml). among them, 4 salmonella enterica serovar haardt isolates showed multi-drug resistance (mdr) patterns with reduced susceptibility to fluoroquinolone (0.5 µg/ml of ciprofloxacin mics). the mechanism ...201121354645
salmonella in chicken meat, eggs and humans; adelaide, south australia, 2008.varieties of salmonella enterica are the second most commonly notified causes of gastroenteritis in australia. outbreaks of salmonella infection are commonly linked to food, particularly foods containing chicken meat and eggs. a number of european countries have introduced interventions based on salmonella surveillance systems in the food industry and these have led to subsequent decreases in notification rates in humans. a descriptive case-series of human salmonella infections notified in metro ...201121429610
treatment with ca(oh)2 for inactivation of salmonella typhimurium and enterococcus faecalis in soil contaminated with infected horse manure.to investigate the inactivation of salmonella enterica serovar typhimurium and the faecal indicator enterococcus faecalis in horse manure:soil mixtures by application of hydrated lime (ca(oh)(2)).201121435122
diversity and antimicrobial activity of pseudovibrio spp. from irish marine sponges.to evaluate the diversity and antimicrobial activity present among pseudovibrio spp. isolated from marine sponges.201121435124
o-antigen structure and gene clusters of escherichia coli o51 and salmonellaenterica o57; another instance of identical o-antigens in the two species.the o-polysaccharides were released by mild acid hydrolysis from the lipopolysaccharides of escherichia coli o51 and salmonella enterica o57 and found to possess the same structure, which was established by sugar analysis and 1d and 2d nmr spectroscopy: [formula in text]. the o-antigen gene clusters of e. coli o51 and s. enterica o57 were sequenced and found to contain the same genes with a high-level similarity. all genes expected for the synthesis of the o-antigen were identified based on thei ...201121439556
effect of microbial loading on the efficiency of cold atmospheric gas plasma inactivation of salmonella enterica serovar typhimurium.in recent years the application of cold atmospheric gas plasma (cap) aimed at the removal of microbial contamination from fresh and minimally processed food has received increased attention. for cap to be successfully adopted by the food production industry, factors which affect its potential for microbial inactivation must be evaluated. in this study, we examined the effects of initial microbial concentration, present on filter discs, on the inactivation of salmonella enterica serovar typhimuri ...201121439667
salmonella in raccoons (procyon lotor) in southern ontario, canada.numerous serotypes of salmonella have been detected in a variety of wild animals, including raccoons (procyon lotor). raccoons are common, mid-size omnivores that live in close association with people in urban and rural areas in ontario. although raccoons are known to shed salmonella, little is known about their potential long-term role in maintaining salmonella infections. we sampled feces from raccoons in three areas of ontario: one primarily urban site around niagara, one primarily rural site ...201121441187
synergistic suppression of prostatic cancer cells by coexpression of both murine double minute 2 small interfering rna and wild-type p53 gene in vitro and in vivo.our objective was to evaluate cell growth and death effects by inhibiting murine double minute 2 (mdm2) expression in human prostate cancer cells overexpressing the wild-type (wt) p53 gene. prostate pc-3 tumor cells were transfected with a plasmid containing either mdm2 small interfering (si-mdm2) or the wt p53 gene (pp53) alone, or both (pmp53), using lipofectamine in vitro and attenuated salmonella enterica serovar typhi vaccine strain ty21a (salmonella typhi ty21a) in vivo. cell growth, apopt ...201121444629
evaluation of a newly developed elisa against widal, tubex-tf and typhidot for typhoid fever surveillance.typhoid fever is endemic in many parts of the world and represents a major cause of acute febrile illness (afi). rapid and accurate laboratory methods for diagnosis of this disease are needed for both patient care and surveillance situations.201121444985
re-emergence of susceptibility to conventionally used drugs among strains of salmonella typhi in central west india.typhoid fever (enteric fever) is a global health problem causing high morbidity and mortality, especially in endemic areas such as india. the problem is exacerbated as the causative agent, salmonella enterica subspecies enterica serovar typhi (s. typhi), rapidly develops resistance to drugs used in treatment. however, non-responsiveness of s. typhi to quinolones has been reported simultaneously with the re-emergence of susceptibility to chloramphenicol. the present study investigates the re-emer ...201121444993
salmonella phage st64b encodes a member of the ssek/nleb effector family.salmonella enterica is a species of bacteria that is a major cause of enteritis across the globe, while certain serovars cause typhoid, a more serious disease associated with a significant mortality rate. type iii secreted effectors are major contributors to the pathogenesis of salmonella infections. genes encoding effectors are acquired via horizontal gene transfer, and a subset are encoded within active phage lysogens. because the acquisition of effectors is in flux, the complement of effector ...201121445262
a study of bactericidal effect and optimization of pathogenic bacteria using tio2 photocatalyst.the photocatalytic degradation of salmonella choleraesuis subsp. and vibrio parahaemolyticus in water by tio2 catalysts was investigated in a batch reactor. after 30 min of irradiation with uv light in the presence of 1 mg/ml of tio2, death ratio of s. choleraesuis subsp. and v. parahaemolyticus was 60% and 83%, respectively. and complete killing of the cells was achieved after 3 h of illumination in the presence of tio2. we established the response surface methodology to investigate the effect ...201121456234
analysis of antimicrobial resistance genes detected in multidrug-resistant salmonella enterica serovar typhimurium isolated from food animals.multidrug-resistant (mdr) salmonella enterica serovar typhimurium is the most prevalent penta-resistant serovar isolated from animals by the u.s. national antimicrobial resistance monitoring system. penta-resistant isolates are often resistant to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. to investigate mdr in salmonella typhimurium (including variant 5-), one isolate each from cattle, poultry, and swine with at least the ampicillin, chloramphenicol, streptomy ...201121457076
sula-induced filamentation in salmonella enterica serovar typhimurium: effects on spi-1 expression and epithelial infection.salmonella enterica serovar typhimurium is capable of adopting a filamentous phenotype in response to damage. how this adaptive response affects bacterial virulence is unclear. we have examined the hypothesis that filamentation affects the ability of salmonella to infect host cells.201121457414
[invasive gastroenteritis, anything new?].invasive gastroenteritis is characterized by fever and inflammatory diarrhea and can be caused by nontyphoideal salmonella serotypes and shigella spp.-enteroinvasive escherichia coli (eiec), among other pathogens. this review describes emerging monophasic variants of salmonella enterica serotype 1,4,[5],12:i:- and provides an evolutionary consideration of shigella spp.-eiec as a single pathotype. in 1997, a monophasic variant of s. enterica serotype 1,4,[5],12:i:-, phage-type u302, multidrug res ...201121458713
antimicrobial resistance, virulence-associated genes, and pulsed-field gel electrophoresis profiles of salmonella enterica subsp. enterica serovar typhimurium isolated from piglets with diarrhea in korea.salmonella enterica subsp. enterica serovar typhimurium was isolated from diarrheic piglets in 2 periods, 2000-2001 (n = 25) and 2005-2006 (n = 17). to compare the characteristics of the isolates collected during the 2 periods, all isolates were tested for antimicrobial resistance, the presence of virulence genes, and pulsed-field gel electrophoresis (pfge) patterns. all 42 isolates were resistant to at least 1 of the 20 antimicrobials tested, and 39 (93%) were resistant to 2 or more antimicrobi ...201121461195
rapid identification of salmonella enterica serovars, typhimurium, choleraesuis, infantis, hadar, enteritidis, dublin and gallinarum, by multiplex pcr.salmonella enterica subsp. enterica poses a threat to both human and animal health, with more than 2500 serovars having been reported to date. salmonella serovars are identified by slide and tube agglutination tests using o and h antigen-specific anti-sera, although this procedure is both labor intensive and time consuming. establishment of a method for rapid screening of the major salmonella serovars is therefore required. we have established multiplex polymerase chain reaction (m-pcr) assays f ...201121329737
salmonella typhi sense host neuroendocrine stress hormones and release the toxin haemolysin e.salmonella enterica serovar typhi (s. typhi) causes typhoid fever. we show that exposure of s. typhi to neuroendocrine stress hormones results in haemolysis, which is associated with the release of haemolysin e in membrane vesicles. this effect is attributed to increased expression of the small rna mica and rna chaperone hfq, with concomitant downregulation of outer membrane protein a. deletion of mica or the two-component signal-transduction system, cpxar, abolishes the phenotype. the hormone r ...201121331094
evaluation of commonly-used farm disinfectants in wet and dry models of salmonella farm contamination.two experimental models of salmonella contamination were used in an attempt to mimic the conditions of disinfectant use on farms. a wet model, for conditions such as boot dips, used disinfectant application to a slurry of poultry faeces inoculated with salmonella enteritidis or salmonella typhimurium. a dry model, for disinfectant application to surfaces and equipment with adherent or residual organic material, used salmonella-inoculated poultry faeces that were air-dried onto wooden dowels, imm ...201121331946
growth of salmonella enterica and staphylococcus aureus in no-knead bread dough during prolonged yeast fermentation.a convenient bread making method involving prolonged fermentation of no-knead (nonkneaded) dough has become popular in recent years. in the present study, the microbial safety of no-knead dough made with a 375:325:5:1 weight ratio of flour, water, salt, and bread yeast was investigated. three brands of dehydrated yeast were used for this study. the growth of inoculated salmonella enterica and staphylococcus aureus in no-knead dough during fermentation was significant (p<0.05), regardless of yeas ...201121333150
[left-sided endocarditis due to gram-negative bacilli: epidemiology and clinical characteristics].the aim of this study is to describe the epidemiological, clinical characteristics, and outcome of patients with left-side endocarditis caused by gram-negative bacteria.201121334783
effectiveness of chitosan against mature biofilms formed by food related bacteria.chitosan has proven antimicrobial properties against planktonic cell growth. little is known, however, about its effects on already established biofilms. oriented for application in food industry disinfection, the effectiveness of both medium molecular weight (mmw) chitosan and its enzymatically hydrolyzed product was tested against mature biofilms of four pathogenic strains, listeria monocytogenes, bacillus cereus, staphylococcus aureus and salmonella enterica, and a food spoilage species, pseu ...201121340015
human igg isotypes and activating fc? receptors in the interaction of salmonella enterica serovar typhimurium with phagocytic cells.several classes and multiple subclasses of immunoglobulins are produced towards protein and polysaccharide antigens in response to salmonella infection and play a key role in protection against systemic disease. the targeting of salmonella to fc receptors (fcr) on phagocytes is a key step in the antibody-mediated antibacterial functions of host cells. we wished to compare the relative efficiency of different human igg subclasses, which targeted the salmonella enterica ompa surface protein in mod ...201121323662
a flagellin-producing lactococcus strain: interactions with mucin and enteropathogens.bacillus cereus ch is a probiotic strain used in human nutrition whose adhesion to mucin is dependent on its surface-associated flagellin. flagellins from the surface of several probiotic bacillus strains were efficiently extracted with 5 m licl and identified by peptide fingerprinting. based on the proteomic analysis, cloning of the gene coding for the flagellin of b. cereus ch was performed in the lactococcal vector pnz8110 under the control of a nisin-inducible promoter. the resulting strain, ...201121323981
efficacy of european starling control to reduce salmonella enterica contamination in a concentrated animal feeding operation in the texas panhandle.european starlings (sturnus vulgaris) are an invasive bird species known to cause damage to plant and animal agriculture. new evidence suggests starlings may also contribute to the maintenance and spread of diseases within livestock facilities. identifying and mitigating the risk pathways that contribute to disease in livestock is necessary to reduce production losses and contamination of human food products. to better understand the impact starlings have on disease transmission to cattle we ass ...201121324202
sequence analysis of a group of low molecular-weight plasmids carrying multiple is903 elements flanking a kanamycin resistance aph gene in salmonella enterica serovars.a group of low molecular-weight cole1-like plasmids carrying the aph sequence type aph(ii) from three different salmonella serovars were sequenced. these plasmids carry two or more copies of is903 elements, with up to 21bp sequence differences to one another, two of which flank the aph gene. this group of plasmids did not appear to carry any known mobilization genes and instead carry three open reading frames encoding hypothetical proteins of unknown function possibly organized in an operon. the ...201121324339
effect of lactic acid bacteria probiotic culture for the treatment of salmonella enterica serovar heidelberg in neonatal broiler chickens and turkey poults.in the present study, a series of experiments was conducted to evaluate the ability of a commercial probiotic culture (floramax, ivs-wynco llc, springdale, ar) to reduce salmonella enterica serovar heidelberg (sh) in chicks and turkey poults. in experiments 1 and 2, chicks were randomly assigned to treatment groups and then challenged via oral gavage with sh. chicks were treated 1 h following sh challenge with the probiotic culture via oral gavage. at 24 and 72 h posttreatment, cecal tonsils and ...201121325226
specific detection of salmonella enterica and escherichia coli strains by using elisa with bacteriophages as recognition agents.the use of bacteriophages, instead of antibodies, in the elisa-based detection of bacterial strains was tested. this procedure appeared to be efficient, and specific strains of salmonella enterica and escherichia coli could be detected. the sensitivity of the assay was about 10(5) bacterial cells/well (10(6)/ml), which is comparable with or outperforms other elisa tests detecting intact bacterial cells without an enrichment step. the specificity of the assay depends on the kind of bacteriophage ...201121318732
biological and virulence characteristics of salmonella enterica serovar typhimurium following deletion of glucose-inhibited division (gida) gene.salmonella enterica serovar typhimurium is a frequent cause of enteric disease due to the consumption of contaminated food. identification and characterization of bacterial factors involved in salmonella pathogenesis would help develop effective strategies for controlling salmonellosis. to investigate the role of glucose-inhibited division gene (gida) in salmonella virulence, we constructed a salmonella mutant strain in which gida was deleted. deletion of gida rendered salmonella deficient in th ...201121320585
detection of low numbers of healthy and sub-lethally injured salmonella enterica in chocolate.the capacity to detect low levels of healthy and sub-lethally injured salmonella enterica cells in chocolate by two alternative rapid detection methods iq-check(tm)salmonella ii real-time pcr (bio-rad) and vidas® easy slm (biomérieux) was assessed and compared with iso 6579:2005. chocolate, a low moisture food known to support the survival of salmonella, was challenged as food matrix. buffered peptone water (bpw) did not support the recovery of low levels of sub-lethally injured s. enterica inde ...201121320732
the genetics and structure of the o-specific polysaccharide of yersinia pseudotuberculosis serotype o:10 and its relationship with escherichia coli o111 and salmonella enterica o35.the o-specific polysaccharide (ops) is a variable constituent of the lipopolysaccharide of gram-negative bacteria. the polymorphic nature of opss within a species is usually first defined serologically, and the current serotyping scheme for yersinia pseudotuberculosis consists of 21 o serotypes of which 15 have been characterized genetically and structurally. here, we present the structure and dna sequence of y. pseudotuberculosis o:10 ops. the o unit consists of one residue each of d-galactopyr ...201121321053
impact of salmonella infection on host hormone metabolism revealed by metabolomics.the interplay between pathogens and their hosts has been studied for decades using targeted approaches, such as the analysis of mutants and host immunological responses. although much has been learned from such studies, they focus on individual pathways and fail to reveal the global effects of infection on the host. to alleviate this issue, high-throughput methods, such as transcriptomics and proteomics, have been used to study host-pathogen interactions. recently, metabolomics was established a ...201121321075
lingonberry (vaccinium vitis-idaea) and european cranberry (vaccinium microcarpon) proanthocyanidins: isolation, identification, and bioactivities.european, small-fruited cranberries (vaccinium microcarpon) and lingonberries (vaccinium vitis-idaea) were characterized for their phenolic compounds and tested for antioxidant, antimicrobial, antiadhesive, and antiinflammatory effects. the main phenolic compounds in both lingonberries and cranberries were proanthocyanidins comprising 63-71% of the total phenolic content, but anthocyanins, hydroxycinnamic acids, hydroxybenzoic acids, and flavonols were also found. proanthocyanidins are polymeric ...201121370878
detection of novel gyra mutations in nalidixic acid-resistant isolates of salmonella enterica from patients with diarrhoea.the aim of the current study was to detect mutations in the gyra gene of quinolone-resistant salmonella spp. isolates recovered in tehran, iran. between april 2008 and september 2009, 174 salmonella spp. were collected and assayed for quinolone resistance and detection of gyra mutations. isolates identified as salmonella enterica were tested for susceptibility by the disk diffusion method. polymerase chain reaction (pcr) amplification and sequencing of the gyra gene segment encoding the quinolon ...201121371866
structural and functional studies of a 50 kda antigenic protein from salmonella enterica serovar typhi.the high typhoid incidence rate in developing and under-developed countries emphasizes the need for a rapid, affordable and accessible diagnostic test for effective therapy and disease management. typhidot®, a rapid dot enzyme immunoassay test for typhoid, was developed from the discovery of a ~50 kda protein specific for salmonella enterica serovar typhi. however, the structure of this antigen remains unknown till today. studies on the structure of this antigen are important to elucidate its fu ...201121371926
national outbreak of salmonella serotype saintpaul infections: importance of texas restaurant investigations in implicating jalapeño peppers.in may 2008, pulsenet detected a multistate outbreak of salmonella enterica serotype saintpaul infections. initial investigations identified an epidemiologic association between illness and consumption of raw tomatoes, yet cases continued. in mid-june, we investigated two clusters of outbreak strain infections in texas among patrons of restaurant a and two establishments of restaurant chain b to determine the outbreak's source.201121373185
immunoassay based on carbon nanotubes-enhanced elisa for salmonella enterica serovar typhimurium.among the methods used to detect pathogenic bacteria, enzyme linked immunosorbent assay (elisa) is one of the most widely used techniques in routine sample analysis. for salmonella enterica serovar typhimurium detection, a typical elisa yields a sensitivity of 10(6)-10(7)cfu/ml. to enhance the detection sensitivity, single-walled carbon nanotubes (swcnts) was employed in this study as a labelling platform for antibody and horseradish peroxidase (hrp) co-immobilizing. with high proteins recovery ...201121376561
substructure within salmonella enterica subsp. enterica isolates from australian wildlife.multilocus sequence typing of 56 salmonella enterica subsp. enterica strains isolated from australian wildlife hosts was performed. the results of population assignment algorithms revealed that the 56 strains could be subdivided into two distinct clades. strains belonging to the two clades were further distinguished phenotypically, genotypically, and with respect to host distribution.201121378038
real-time monitoring of salmonella enterica in free-range geese.free-range geese were sampled longitudinally and salmonella isolates characterized to reveal highly diverging colonization dynamics. one flock was intermittently colonized with one strain of salmonella enterica serovar enteritidis from 2 weeks of age, while in another, s. enterica serovar mbandaka appeared after 9 weeks, without dissemination but with multiple serovars appearing at later stages.201121378040
isolation of lactobacillus salivarius 1077 (nrrl b-50053) and characterization of its bacteriocin, including the antimicrobial activity spectrum.lactobacillus salivarius 1077 (nrrl b-50053) was isolated from poultry intestinal materials, and in vitro anti-campylobacter jejuni activity was demonstrated. the isolate was then used for bacteriocin production and its enrichment. the protein content of the cell-free supernatant from the spent medium was precipitated by ammonium sulfate and dialyzed to produce the crude antimicrobial preparation. a typical bacteriocin-like response of sensitivity to proteolytic enzymes and resistance to lysozym ...201121378051
prevalence, distribution, and diversity of salmonella enterica in a major produce region of california.a survey was initiated to determine the prevalence of salmonella enterica in the environment in and around monterey county, ca, a major agriculture region of the united states. trypticase soy broth enrichment cultures of samples of soil/sediment (n = 617), water (n = 252), wildlife (n = 476), cattle feces (n = 795), and preharvest lettuce and spinach (n = 261) tested originally for the presence of pathogenic escherichia coli were kept in frozen storage and later used to test for the presence of ...201121378057
absence of pmrab-mediated phosphoethanolamine modifications of citrobacter rodentium lipopolysaccharide affects outer membrane integrity.the pmrab two-component system of enterobacteria regulates a number of genes whose protein products modify lipopolysaccharide (lps). the lps is modified during transport to the bacterial outer membrane (om). a subset of pmrab-mediated lps modifications consists of the addition of phosphoethanolamine (petn) to lipid a by pmrc and to the core by cpta. in salmonella enterica, petn modifications have been associated with resistance to polymyxin b and to excess iron. to investigate putative functions ...201121378194
optimization of rapid salmonella enterica detection in liquid whole eggs by sybr green i-based real-time reverse transcriptase-polymerase chain reaction.eggs and egg products have a high risk of salmonella enterica serovar enteritidis contamination leading to gastroenteritis outbreaks in humans. thus, a rapid screening tool for viable salmonella enteritidis cells in the egg industry is needed. our objective was to rapidly and sensitively detect viable salmonella enteritidis from spiked liquid whole eggs (lwes) within 24 h using sybr green i-based real-time reverse transcriptase-polymerase chain reaction (pcr) targeting the salmonella specific in ...201121381900
high burden of antimicrobial resistance in asia.antimicrobial resistance is associated with high mortality rates and high medical costs. marked variations in the resistance profiles of bacterial and fungal pathogens as well as the quality of public hygiene have had a considerable impact on the effectiveness of antimicrobial agents in asian countries. in asia, one of the epicentres of antimicrobial drug resistance, there is an alarming number of antibiotic-resistant species, including penicillin- and erythromycin-resistant streptococcus pneumo ...201121382699
related antimicrobial resistance genes detected in different bacterial species co-isolated from swine fecal samples.a potential factor leading to the spread of antimicrobial resistance (ar) in bacteria is the horizontal transfer of resistance genes between bacteria in animals or their environment. to investigate this, swine fecal samples were collected on-farm and cultured for escherichia coli, salmonella enterica, campylobacter spp., and enterococcus spp. which are all commonly found in swine. forty-nine of the samples from which all four bacteria were recovered were selected yielding a total of 196 isolates ...201121385089
occurrence, abundance, and diversity of tetracycline resistance genes in 15 sewage treatment plants across china and other global locations.activated sludge was sampled from 15 sewage treatment plants (stps) across china and other global locations to investigate the occurrence, abundance and diversity of tetracycline resistance genes (tet) in the stps. occurrence and abundance of 14 tet genes were determined using polymerase chain reaction (pcr) and quantitative real time pcr. six genes (tet(a), tet(c), tet(g), tet(m), tet(s), and tet(x)) were detected in all the stps, while no sludge sample contained tet(q). total concentration of ...201121388174
an outbreak of foodborne salmonellosis in rural kwazulu-natal, south africa.salmonella enterica serotype enteritidis is a universally recognized cause of foodborne disease. in south africa, outbreaks of foodborne disease are generally under reported. we investigated the etiology of acute gastroenteritis in 216 patients who presented to a rural hospital in kwazulu-natal, south africa, after consuming a meal at a school function.201121388293
listeria monocytogenes and salmonella enterica enteritidis biofilms susceptibility to different disinfectants and stress-response and virulence gene expression of surviving cells.disinfection of food contact surfaces is a challenging task, aggravated by bacteria's capacity to survive and/or resist antimicrobials by means of mechanisms not yet completely understood. this work evaluated the susceptibility of listeria monocytogenes and salmonella enterica biofilms to four disinfectants, and analyzed how those chemical agents influenced stress-response and virulence genes expression by surviving cells. three strains of each bacterial species mentioned were used, and their bi ...201121388333
porcine toll-like receptors: recognition of salmonella enterica serovar choleraesuis and influence of polymorphisms.salmonella enterica serovar choleraesuis (sc) is a highly invasive pathogen that causes enteric and septicemic diseases in pigs. although there have been some reports on gene expression profiles in the course of infection with sc in pigs, little is known about the genes involved in the infection. by measuring activation, as represented by nuclear factor-+¦b activity, after stimulation by the pathogen, we showed the involvement of toll-like receptor (tlr) 5 and the tlr2-tlr1 heterodimer in the re ...201121388684
the challenge of relating gene expression to the virulence of salmonella enterica serovar typhimurium.the first decade of transcriptomic studies of salmonella enterica serovar typhimurium focused upon gene expression in vitro, and during the infection of mammalian cells. the published regulons and stimulons show that the three type three secretion systems of s. typhimurium respond to a diverse range of environmental conditions, and are controlled by a hierarchy of regulatory proteins. the integration of in vitro generated transcriptomic data with global gene expression of s. typhimurium during i ...201121388802
microarray analysis of virulence gene profiles in salmonella serovars from food/food animal environment.rapid, accurate and inexpensive analysis of the disease-causing potential of foodborne pathogens is an important consideration in food safety and biodefense, particularly in developing countries. the objective of this study is to demonstrate the use of a robust and inexpensive microarray platform to assay the virulence gene profiles in salmonella from food and/or the food animal environment, and then use arraytrackôäó for data analysis.201121389588
a candidate approach implicates the secreted salmonella effector protein spvb in p-body disassembly.p-bodies are dynamic aggregates of rna and proteins involved in several post-transcriptional regulation processes. p-bodies have been shown to play important roles in regulating viral infection, whereas their interplay with bacterial pathogens, specifically intracellular bacteria that extensively manipulate host cell pathways, remains unknown. here, we report that salmonella infection induces p-body disassembly in a cell type-specific manner, and independently of previously characterized pathway ...201121390246
high prevalence of extended-spectrum beta lactamases among salmonella enterica typhimurium isolates from pediatric patients with diarrhea in china.we investigated the extended-spectrum beta lactamases among 62 salmonella enterica typhimurium isolates recovered from children with diarrhea in a chinese pediatric hospital. a large proportion of s. enterica typhimurium isolates were resistant to multiple antimicrobial agents, including ampicillin (90.3%), tetracycline (80.6%), trimethoprim/sulfamethoxazole (74.2%), chloramphenicol (66.1%), cefotaxime (27.4%). forty-nine (79.0%) of s. enterica typhimurium isolates were positive for bla(tem-1b) ...201121390297
sequence diversity in the lasso peptide framework: discovery of functional microcin j25 variants with multiple amino acid substitutions.microcin j25 (mccj25) is a ribosomally synthesized antimicrobial peptide that has an unusual threaded lasso structure in which the c-terminal "tail" of the peptide is fed through a macrocyclic "ring" formed by the n-terminal residues. production of mccj25 in escherichia coli is dependent upon a four-gene cluster encoding the structural gene mcja, two maturation enzymes mcjb and mcjc, and an immunity factor, mcjd, in the form of an mccj25 export pump. here we have developed a system for orthogona ...201121391585
new water resistant biomaterial biocide film based on guar gum.this work was aimed to develop water resistant biocide film from renewable resources for applications in food and water technology. guar gum, a polymeric galactomannan, was intrinsically modified to a new guar gum benzamide. benzoylation was carried out by benzoyl chloride reaction in water medium and a propyl amine spacer was used to impart a high degree of hydrophobicity. the new guar gum benzamide was resistant to water and soluble in non aqueous solvent like dimethyl sulfoxide. cast films of ...201121392974
international collaborative study on the occurrence of plasmid-mediated quinolone resistance in salmonella enterica and escherichia coli isolated from animals, humans, food and the environment in 13 european countries.this study was initiated to collect retrospective information on the occurrence of plasmid-mediated quinolone resistance (pmqr) in salmonella enterica and escherichia coli isolates in europe and to identify the responsible genes.201121393198
extended-spectrum beta-lactamase blactx-m-1 gene carried on an inci1 plasmid in multidrug-resistant salmonella enterica serovar typhimurium dt104 in cattle in france. 201121393226
identifying antimicrobial resistance genes of human clinical relevance within salmonella isolated from food animals in great britain.to investigate the occurrence of antimicrobial resistance genes of human clinical relevance in salmonella isolated from livestock in great britain.201121393227
characterization of the mica gene encoding a small regulatory ¤âe-dependent rna in salmonella enterica serovar typhimurium.the role of mica (repressing small regulatory non-coding rnas of two salmonella porins) was determined in virulence of salmonella enterica serovar typhimurium. transcriptional analysis revealed that the expression of the mica gene is driven by a single ¤â(e)-dependent promoter, micap. its activity increased towards stationary phase; in exponential phase, the activity was induced by several stresses by a degs-dependent mechanism. although phenotypic analysis revealed no significant differences be ...201121394477
trends in phage types of salmonella enterica serovars enteritidis and typhimurium isolated in slovakia from 1995 to 2009.the phage typing of 3900 isolates of salmonella enteritidis and 1741 isolates of salmonella typhimurium has been carried out in the period 1995-2009. among salmonella enteritidis in individual years, the most prevalent phage type (pt) was 8. the most predominant pts of salmonella typhimurium were dt104 and u302.201121396545
plasmid typing and resistance profiling of escherichia fergusonii and other enterobacteriaceae isolates from south korean farm animals.in this study, we focused on determining the distribution and prevalence of major plasmid replicons in +¦-lactam-resistant escherichia fergusonii and enterobacteriaceae of animal and human origin. a high degree of plasmid variability and multiple plasmid replicons were observed among the isolates. the incf and inci1 replicons were the most prevalent in e. fergusonii and salmonella enterica serovar indiana isolated from swine and poultry in south korea, respectively. the presence of broad-host-ra ...201121398479
the crispr/cas immune system is an operon regulated by leuo, h-ns, and leucine-responsive regulatory protein in salmonella enterica serovar typhi.prokaryotes have developed multiple strategies to survive phage attack and invasive dna. recently, a novel genetic program denominated the crispr/cas system was demonstrated to have a role in these biological processes providing genetic immunity. this defense mechanism is widespread in the archaea and bacteria, suggesting an ancient origin. in the last few years, progress has been made regarding the functionality of the crispr/cas system; however, many basic aspects of the system remain unknown. ...201121398529
characterization of the salmonella enterica serovar typhimurium ydci gene, which encodes a conserved dna binding protein required for full acid stress resistance.salmonella enterica serovar typhimurium possesses a stimulon of genes that are differentially regulated in response to conditions of low fluid shear force that increase bacterial virulence and alter other phenotypes. in this study, we show that a previously uncharacterized member of this stimulon, ydci or stm1625, encodes a highly conserved dna binding protein with related homologs present in a range of gram-negative bacterial genera. gene expression analysis shows that ydci is expressed in diff ...201121398541
at home with hostility: how do pathogenic bacteria evade mammalian immune surveillance to establish persistent infection?bacterial persistence is of major concern as persistent bacterial infections involving bacteria such as helicobacter pylori, salmonella enterica serotype typhi, and mycobacterium tuberculosis pose significant public health problems worldwide. this report discusses the recent advances in understanding the strategies used by bacteria during persistent infection that allow them to colonize specific sites in the host and evade immune surveillance.201121399762
in vivo regulation of the vi antigen in salmonella and induction of immune responses with an in vivo-inducible promoter.salmonella enterica serovar typhi, the agent of typhoid fever in humans, expresses the surface vi polysaccharide antigen that contributes to virulence. however, vi expression can also be detrimental to some key steps of s. typhi infectivity, for example, invasion, and vi is the target of protective immune responses. we used a strain of s. typhimurium carrying the whole salmonella pathogenicity island 7 (spi-7) to monitor in vivo vi expression within phagocytic cells of mice at different times af ...201121402763
evaluation of recombinant salmonella expressing the flagellar protein flic for persistence and enhanced antibody response in commercial turkeys.salmonella enterica serovar enteritidis (se) is one of the most common causes of human foodborne illness in the united states. previous research indicates that antibodies against the flic protein can provide protection against salmonella challenge in mice. to generate a vaccine that effectively protects poultry against multiple salmonella serotypes, novel attenuated strains of se were developed to express a flic peptide sequence on the outer membrane protein lamb in association with an m2e (mark ...201121406359
transcriptional profiling of cecal gene expression in probiotic- and salmonella-challenged neonatal chicks.probiotics are currently used to improve health and reduce enteric pathogens in poultry. however, the mechanisms by which they reduce or prevent disease are not known. salmonella are intracellular pathogens that cause acute gastroenteritis in humans, and infections by nontyphoid species of salmonella also can result in diarrhea, dehydration, and depression in poultry. frequently, however, no clinical signs of infection are apparent in poultry flocks. in this study, day-of-hatch chicks were chall ...201121406379
a comparative study on the effectiveness of chlorine dioxide gas, ozone gas and e-beam irradiation treatments for inactivation of pathogens inoculated onto tomato, cantaloupe and lettuce seeds.the increase in reported food-borne outbreaks linked with consumption of raw fruits and vegetables has motivated new research focusing on prevention of pre-harvest produce contamination. this study evaluates and compares the effectiveness of three non-thermal technologies, chlorine dioxide gas, ozone gas and e-beam irradiation, for inactivation of salmonella enterica and escherichia coli o157:h7 on pre-inoculated tomato, lettuce and cantaloupe seeds, and also their corresponding effect on seeds ...201121411164
a novel real-time polymerase chain reaction for identification of salmonella enterica subspecies enterica.salmonella enterica subspecies enterica (subspecies i) causes the majority of infections in humans and homeothermic animals. we present a real-time polymerase chain reaction assay targeting the hila gene that demonstrates 97.9% specificity and 99.9% sensitivity for rapid and reliable identification of subspecies i, offering savings in time and labor over traditional methods.201121411262
the vi conjugate typhoid vaccine is safe, elicits protective levels of igg anti-vi, and is compatible with routine infant vaccines.typhoid fever remains a serious problem in developing countries. current vaccines are licensed for individuals who are 5 years old or older. a conjugate of the capsular polysaccharide (cp) of salmonella enterica serovar typhi (vi) bound to recombinant exoprotein a of pseudomonas aeruginosa (vi-repa) enhanced vi immunogenicity and protected 2- to 5-year-olds in vietnam. in this study, vi-repa was evaluated for use in infants. a total of 301 full-term vietnamese infants received expanded program o ...201121411598
sensitive quantification of escherichia coli o157:h7, salmonella enterica , and campylobacter jejuni by combining stopped polymerase chain reaction with chemiluminescence flow-through dna microarray analysis.rapid analysis of pathogenic bacteria is essential for food and water control to preserve the public health. therefore, we report on a chemiluminescence (cl) flow-through dna microarray assay for the rapid and sensitive quantification of the pathogenic bacteria escherichia coli o157:h7, salmonella enterica , and campylobacter jejuni in water. using the stopped polymerase chain reaction (pcr) strategy, the amount of amplified target dna was strongly dependent on the applied cell concentration. th ...201121417213
antibacterial activity of the enniatin b, produced by fusarium tricinctum in liquid culture, and cytotoxic effects on caco-2 cells.the enniatins (ens) are bioactive compounds of hexadepsipeptidic structure produced by several strains of fusarium sp. the en b was purified from extracts of fusarium tricinctum growth on liquid culture of potato dextrose broth (pdb), using a semipreparative liquid chromatography (lc) followed by an analytical lc. the purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (esi-ms) stud ...201121417626
analysis of the arca regulon in anaerobically grown salmonella enterica sv. typhimurium.salmonella enterica serovar typhimurium (s. typhimurium) is a gram-negative pathogen that must successfully adapt to the broad fluctuations in the concentration of dissolved dioxygen encountered in the host. in escherichia coli, arca (aerobic respiratory control) helps the cells to sense and respond to the presence of dioxygen. the global role of arca in e. coli is well characterized; however, little is known about its role in anaerobically grown s. typhimurium.201121418628
development of a libs assay for the detection of salmonella enterica serovar typhimurium from food.laser-induced breakdown spectroscopy (libs) is used for the identification of the presence of hazardous bacteria in food. in this study, our main focus was centered on the identification of s. enterica serovar typhimurium, a gram-negative foodborne pathogen, in various liquids such as milk, chicken broth, and brain heart infusion due to the infection being most prevalent in raw meat and dairy products. a nd:yag laser of operating wavelength 266 nm was used to obtain the spectra from the artifici ...201121424774
analysis of mechanisms involved in reduced susceptibility to ciprofloxacin in salmonella enterica serotypes typhi and paratyphi a isolates from travellers to southeast asia.owing to multidrug resistance, quinolones and third-generation cephalosporins are currently used as key antibiotics to combat salmonella organisms. therapy failure due to reduced ciprofloxacin susceptibility has been reported in endemic areas, but also in imported disease. different bacterial resistance mechanisms may result in reduced ciprofloxacin susceptibility. in this study, the presence and expression of different resistance mechanisms resulting in reduced minimum inhibitory concentrations ...201121227657
characterization of salmonella enterica isolates from turkeys in commercial processing plants for resistance to antibiotics, disinfectants, and a growth promoter.salmonella enterica isolates from turkeys in two commercial processing plants (1 and 2) were characterized for susceptibility to antibiotics, disinfectants, and the organoarsenical growth promoter, 4-hydroxy-3-nitrophenylarsonic acid (3-nhpaa, roxarsone), and it's metabolites, naaso(2) (as(iii)) and na(2)haso(4) • 7h(2)o (as(v)). the 130 salmonella serovars tested demonstrated a low incidence of resistance to the antibiotics gentamicin (gen), kanamycin (kan), sulfamethoxazole (smx), streptomycin ...201121235389
prevalence and characterization of extended-spectrum beta-lactamases-producing salmonella enterica isolates in saragossa, spain (2001-2008).we analyzed the prevalence of resistance to extended-spectrum cephalosporins (escs) among clinical strains of salmonella enterica collected by the laboratory of clinical microbiology in the university clinical hospital lozano blesa in the region of aragón (spain), for which very few epidemiological information exists. a total of 2,092 strains of s. enterica were identified in stool samples from patients with gastroenteritis. five isolates showed an extended-spectrum beta-lactamase (esbl) phenoty ...201121235396
oral treatment with saccharomyces cerevisiae strain ufmg 905 modulates immune responses and interferes with signal pathways involved in the activation of inflammation in a murine model of typhoid fever.salmonella spp. are gram-negative, facultative, intracellular pathogens that cause several diarrheal diseases ranging from self-limiting gastroenteritis to typhoid fever. previous results from our laboratory showed that saccharomyces cerevisiae strain ufmg 905 isolated from 'cachaça' production presented probiotic properties due to its ability to protect against experimental infection with salmonella enterica serovar typhimurium. in this study, the effects of oral treatment with s. cerevisiae 90 ...201121236729
diversity of multidrug-resistant salmonella enterica strains associated with cattle at harvest in the united states.the prevalence and diversity of multidrug-resistant (mdr) salmonella enterica strains associated with cattle at harvest in the united states were examined. hides and carcasses of cattle were sampled at processing plants (n = 6) located in four geographically distant regions from july 2005 to april 2006. the mean prevalences of salmonella on hides, preevisceration carcasses (immediately after hide removal), and postintervention carcasses (in the chiller and after the full complement of interventi ...201121239549
molecular epidemiology of salmonella enterica serovar typhimurium isolates from cattle in hokkaido, japan: evidence of clonal replacement and characterization of the disseminated clone.the molecular epidemiology of 545 salmonella enterica serovar typhimurium isolates collected between 1977 and 2009 from cattle in hokkaido, japan, was investigated using pulsed-field gel electrophoresis (pfge). nine main clusters were identified from 116 pfge patterns. cluster i comprised 248 isolates, 243 of which possessed a sequence specific to definitive phage type 104 (dt104) or u302. the cluster i isolates were dominant in 1993 to 2003, but their numbers declined beginning in 2004. beginni ...201121239560
bistability in myo-inositol utilization by salmonella enterica serovar typhimurium.the capability of salmonella enterica serovar typhimurium strain 14028 (s. typhimurium 14028) to utilize myo-inositol (mi) is determined by the genomic island gei4417/4436 carrying the iol genes that encode enzymes, transporters, and a repressor responsible for the mi catabolic pathway. in contrast to all bacteria investigated thus far, s. typhimurium 14028 growing on mi as the sole carbon source is characterized by a remarkable long lag phase of 40 to 60 h. we report here that on solid medium w ...201121239589
structural-dynamical investigation of the znua histidine-rich loop: involvement in zinc management and transport.comparative homology modelling techniques have been used to model the protein znua from salmonella enterica serovar typhimurium using the 3d structure of the homologous protein from escherichia coli. these two-domain proteins bind one zn(2+) atom, with high affinity, in the inter-domain cleft and possess a histidine-rich loop in the n-terminal domain. alternative structures of the znua histidine-rich loop, never resolved by the x-ray diffraction method, have been modelled. a model of the apo for ...201121240623
a community effort towards a knowledge-base and mathematical model of the human pathogen salmonella typhimurium lt2.metabolic reconstructions (mrs) are common denominators in systems biology and represent biochemical, genetic, and genomic (bigg) knowledge-bases for target organisms by capturing currently available information in a consistent, structured manner. salmonella enterica subspecies i serovar typhimurium is a human pathogen, causes various diseases and its increasing antibiotic resistance poses a public health problem.201121244678
temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of vietnam.typhoid fever remains a public health problem in vietnam, with a significant burden in the mekong river delta region. typhoid fever is caused by the bacterial pathogen salmonella enterica serovar typhi (s. typhi), which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. we used a goldengate (illumina) assay to type 1,500 single nucleotide polymorphisms (snps) and analyse the genetic variation of s. ty ...201121245916
Refresh
firstprev
...61626364656667686970...
nextlast
Displaying items 6701 - 6800 of 11731