Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| influence of eggshell condensation on eggshell penetration and whole egg contamination with salmonella enterica serovar enteritidis. | shells of agar-filled and whole eggs were inoculated with 10(3) to 10(4) cfu of salmonella enterica serovar enteritidis per eggshell. the agar-filled eggs were used to study bacterial eggshell penetration, and the whole egg results were used to characterize contamination of the egg contents. in each group, half of the eggs were stored for 21 days at 20 degrees c and 60% relative humidity (rh), and the other half was stored for 24 h at 6 degrees c and then for 20 days at 20 degrees c. the latter ... | 2006 | 16865883 |
| protection conferred by a live salmonella enteritidis vaccine against fowl typhoid in laying hens. | fowl typhoid is under control in poultry farms of developed countries, but it still endemically subsists in commercial laying hen farms of some countries. it has been demonstrated that salmonella live vaccines can elicit cross-immunity against members of the same kauffmann-white scheme serogroup. in this work, we explored the protection conferred by tad salmonella vac e, a live salmonella enterica serovar enteritidis vaccine, against fowl typhoid. three groups of laying hens were vaccinated with ... | 2006 | 16863082 |
| preliminary evaluation of the use of the sefa fimbrial gene to elicit immune response against salmonella enterica serotype enteritidis in chickens. | in the last 2 decades, the prevalence of salmonella enterica serotype enteritidis (salmonella enteritidis) has dramatically increased worldwide, becoming the leading cause of food-borne illnesses and an important public health issue. many studies have suggested the role of the sef14 fimbrial protein in the adhesion of salmonella enteritidis to the host. in the present study, the sefa gene, which encodes the main subunit of the sef14 fimbrial protein, was cloned into a temperature-sensitive expre ... | 2006 | 16863065 |
| caspase-1-mediated activation of interleukin-1beta (il-1beta) and il-18 contributes to innate immune defenses against salmonella enterica serovar typhimurium infection. | caspase-1 (casp-1) mediates the processing of the proinflammatory cytokines interleukin-1beta (il-1beta) and il-18 to their mature forms. casp-1-deficient mice succumb more rapidly to salmonella challenge than do wild-type animals. both casp-1 substrates, il-18 and il-1beta, are relevant for control of salmonella enterica serovar typhimurium. we used il-18-/- and il-1beta-/- mice in addition to administration of recombinant il-18 to casp-1-/- mice to demonstrate that il-18 is important for resis ... | 2006 | 16861683 |
| antibiotic resistance of salmonella enterica serovar paratyphi a in india: emerging and reemerging problem. | antibiotic resistance pattern and r-plasmid of salmonella enterica serovar paratyphi a isolates from kolkata, india are not well documented. | 2006 | 16855314 |
| arginine-dependent acid resistance in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium does not survive a ph 2.5 acid challenge under conditions similar to those used for escherichia coli. here, we provide evidence that s. enterica serovar typhimurium can display arginine-dependent acid resistance (ar) provided the cells are grown under anoxic conditions and not under the microaerobic conditions used for assessment of ar in e. coli. the role of the arginine decarboxylase pathway in salmonella ar was shown by the loss of ar in mutants lacking ... | 2006 | 16855258 |
| crystal structure of tdp-fucosamine acetyltransferase (wecd) from escherichia coli, an enzyme required for enterobacterial common antigen synthesis. | enterobacterial common antigen (eca) is a polysaccharide found on the outer membrane of virtually all gram-negative enteric bacteria and consists of three sugars, n-acetyl-d-glucosamine, n-acetyl-d-mannosaminuronic acid, and 4-acetamido-4,6-dideoxy-d-galactose, organized into trisaccharide repeating units having the sequence -->3)-alpha-d-fuc4nac-(1-->4)-beta-d-mannaca-(1-->4)-alpha-d-glcnac-(1-->. while the precise function of eca is unknown, it has been linked to the resistance of shiga-toxin- ... | 2006 | 16855251 |
| the mgtc virulence factor of salmonella enterica serovar typhimurium activates na(+),k(+)-atpase. | the mgtc gene of salmonella enterica serovar typhimurium encodes a membrane protein of unknown function that is important for full virulence in the mouse. since mgtc is part of an operon with mgtb which encodes a mg(2+)-transporting p-type atpase, mgtc was hypothesized to function in ion transport, possibly in mg(2+) transport. consequently, mgtc was expressed in xenopus laevis oocytes, and its effect on ion transport was evaluated using ion selective electrodes. oocytes expressing mgtc did not ... | 2006 | 16855249 |
| the fad-dependent tricarballylate dehydrogenase (tcua) enzyme of salmonella enterica converts tricarballylate into cis-aconitate. | tricarballylate is the causative agent of grass tetany, a ruminant disease characterized by acute magnesium deficiency. tricarballylate toxicity has been attributed to its ability to chelate magnesium and to inhibit aconitase, a krebs cycle enzyme. neither the ruminant nor the normal rumen flora can catabolize tricarballylate to ameliorate its toxic effects. however, the gram-negative enterobacterium salmonella enterica can use tricarballylate as a carbon and energy source, providing an opportun ... | 2006 | 16855237 |
| differences in resistance to salmonella enterica serovar gallinarum infection among indigenous local chicken ecotypes in tanzania. | a study was conducted to evaluate the disease resistance potential in 105 chickens of six indigenous local chicken ecotypes in tanzania by orally challenging 1-week-old chicks with 2.5 x 10(8) colony-forming units of virulent s. gallinarum. for 14 days post infection, clinical signs, necropsy findings, antibody titres, packed cell volume, leukocyte population count, and viable bacterial cell counts in the liver and spleen were recorded. clinical signs were recorded daily but other parameters wer ... | 2006 | 16854638 |
| a connection between iron-sulfur cluster metabolism and the biosynthesis of 4-amino-5-hydroxymethyl-2-methylpyrimidine pyrophosphate in salmonella enterica. | several cellular pathways have been identified which affect the efficiency of thiamine biosynthesis in salmonella enterica. mutants defective in iron-sulfur (fe-s) cluster metabolism are less efficient at synthesis of the pyrimidine moiety of thiamine. these mutants are compromised for the conversion of aminoimidazole ribotide (air) to 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate (hmp-p), not the synthesis of air. the gene product thic contains potential ligands for an fe-s cluster that ... | 2006 | 16849799 |
| mutational analysis of salmonella translocated effector members sifa and sopd2 reveals domains implicated in translocation, subcellular localization and function. | salmonella enterica serovar typhimurium is a facultative intracellular pathogen causing disease in several hosts. these bacteria use two distinct type iii secretion systems that inject effector proteins into the host cell for invasion and to alter maturation of the salmonella-containing vacuole. members of the salmonella translocated effector (ste) family contain a conserved n-terminal translocation signal of approximately 140 aa. in this study, the ste family member sifa was examined using dele ... | 2006 | 16849798 |
| delayed expansion and contraction of cd8+ t cell response during infection with virulent salmonella typhimurium. | ag presentation to cd8(+) t cells often commences immediately after infection, which facilitates their rapid expansion and control of infection. subsequently, the primed cells undergo rapid contraction. we report that this paradigm is not followed during infection with virulent salmonella enterica, serovar typhimurium (st), an intracellular bacterium that replicates within phagosomes of infected cells. although susceptible mice die rapidly (approximately 7 days), resistant mice (129 x 1svj) harb ... | 2006 | 16849458 |
| gene expression profiling in salmonella choleraesuis-infected porcine lung using a long oligonucleotide microarray. | understanding the transcriptional response to pathogenic bacterial infection within food animals is of fundamental and applied interest. to determine the transcriptional response to salmonella enterica serovar choleraesuis (sc) infection, a 13,297-oligonucleotide swine array was used to analyze rna from control, 24-h postinoculation (hpi), and 48-hpi porcine lung tissue from pigs infected with sc. in total, 57 genes showed differential expression (p < 0.001; false discovery rate = 12%). quantita ... | 2006 | 16845603 |
| multidrug-resistance efflux pumps - not just for resistance. | it is well established that multidrug-resistance efflux pumps encoded by bacteria can confer clinically relevant resistance to antibiotics. it is now understood that these efflux pumps also have a physiological role(s). they can confer resistance to natural substances produced by the host, including bile, hormones and host-defence molecules. in addition, some efflux pumps of the resistance nodulation division (rnd) family have been shown to have a role in the colonization and the persistence of ... | 2006 | 16845433 |
| regulatory protein that inhibits both synthesis and use of the target protein controls flagellar phase variation in salmonella enterica. | flagellin is a major surface antigen for many bacterial species. the pathogen salmonella enterica switches between two alternative, antigenic forms of its flagellin filament protein, either type b or c. this switching (flagellar phase variation) is achieved by stochastic inversion of a promoter that produces both type b flagellin (fljb) and an inhibitor (flja) of type c flagellin formation. when the fljb-flja operon is expressed, only type b flagella are produced; when the operon is not transcri ... | 2006 | 16844786 |
| isolation of bacteriocinogenic lactobacillus plantarum strains from ben saalga, a traditional fermented gruel from burkina faso. | a collection of lactic acid bacteria isolated from ben saalga, a traditional fermented gruel from burkina faso, was screened for bacteriocin production. seven isolates were selected for their broad antimicrobial spectra, which overall included strains of bacillus cereus, bacillus licheniformis, enterococcus faecalis, listeria innocua, listeria monocytogenes, staphylococcus aureus, escherichia coli and salmonella enterica. cluster analysis of rapd-pcr patterns revealed that six of the isolates re ... | 2006 | 16844251 |
| regulatory components at the csgd promoter--additional roles for ompr and integration host factor and role of the 5' untranslated region. | csgd is a master regulator of multicellular behaviour in salmonella enterica serovar typhimurium. expression of csgd is highly regulated on the transcriptional level. a nucleo-protein complex had been defined where the global regulators ompr and integration host factor (ihf) bind up- and downstream of the csgd core promoter. in this study, the nucleo-protein complex of pcsgd was extended through characterization of additional ompr and ihf binding sites that influence the transcriptional activity ... | 2006 | 16842367 |
| characterization of the sigmae-dependent rpoep3 promoter of salmonella enterica serovar typhimurium. | using a two-plasmid system, we recently identified sigma(e)-dependent promoters directing expression of the sigma(e) regulon genes in salmonella enterica serovar typhimurium (s. typhimurium). comparison of the promoters revealed a consensus sequence almost identical to the sigma(e)-dependent rpoep3 promoter directing expression of rpoe. this two-plasmid system was previously optimized to identify nucleotides critical for the rpoep3 promoter activity. however, two highly conserved nucleotides in ... | 2006 | 16842358 |
| the salmonella enterica serovar typhi vi capsule and self-association pili share controls on expression. | salmonella enterica serovar typhi uses type ivb pili to facilitate eukaryotic cell invasion. here, we compare environmental and genetic controls on pil operon transcription with those regulating viab genes required for vi antigen expression. transcription of pil occurs only in the late logarithmic and stationary phases of bacterial growth while viab expression occurs in the logarithmic growth phase. expression of both viab and pil was, however, optimal at 100 mm nacl, and mutations in envz/ompr, ... | 2006 | 16842356 |
| multi-drug resistance in salmonella enterica: efflux mechanisms and their relationships with the development of chromosomal resistance gene clusters. | bacterial drug resistance represents one of the most crucial problems in present day antibacterial chemotherapy. of particular concern to public health is the continuing worldwide epidemic spread of salmonella enterica serovar typhimurium phage type dt104 harbouring a genomic island called salmonella genomic island i (sgi-1). this island contains an antibiotic gene cluster conferring resistance to ampicillin, chloramphenicol, florfenicol, streptomycin, sulfonamides and tetracyclines. these resis ... | 2006 | 16842216 |
| pyrolysis mass spectrometry for distinguishing potential hoax materials from bioterror agents. | pyrolysis mass spectrometry (pyms) was investigated as a rapid tool to distinguish potential bioterror hoax materials from samples containing pathogenic bacteria. a pyrolysis time-of-flight (tof) mass spectrometer equipped with an alternative ionization technique, metastable atom bombardment (mab), was used to produce sample spectra. these spectra were analyzed by principal component and discriminant analysis for pattern recognition. materials investigated were two strains of vibrio parahaemolyt ... | 2006 | 16841357 |
| salmonella enterica serotype enteritidis and eggs: a national epidemic in the united states. | beginning in the 1970s, the incidence of salmonella enterica serotype enteritidis (se) infection and the number of related outbreaks in the united states has increased dramatically. by 1994, se was the most commonly reported salmonella serotype, with an incidence of >10 laboratory-confirmed infections per 100,000 population in the northeast. intensive epidemiologic and laboratory investigations identified shell eggs as the major vehicle for se infection in humans, and that the eggs had been inte ... | 2006 | 16838242 |
| interpolated variable order motifs for identification of horizontally acquired dna: revisiting the salmonella pathogenicity islands. | there is a growing literature on the detection of horizontal gene transfer (hgt) events by means of parametric, non-comparative methods. such approaches rely only on sequence information and utilize different low and high order indices to capture compositional deviation from the genome backbone; the superiority of the latter over the former has been shown elsewhere. however even high order k-mers may be poor estimators of hgt, when insufficient information is available, e.g. in short sliding win ... | 2006 | 16837528 |
| effect of immune serum and role of individual fcgamma receptors on the intracellular distribution and survival of salmonella enterica serovar typhimurium in murine macrophages. | immune serum has a protective role against salmonella infections in mice, domestic animals and humans. in this study, the effect of antibody on the interaction between murine macrophages and s. enterica serovar typhimurium was examined. detailed analysis at the single-cell level demonstrated that opsonization of the bacteria with immune serum enhanced bacterial uptake and altered bacterial distribution within individual phagocytic cells. using gene-targeted mice deficient in individual fc gamma ... | 2006 | 16836651 |
| consumer-phase salmonella enterica serovar enteritidis risk assessment for egg-containing food products. | we describe a one-dimensional probabilistic model of the role of domestic food handling behaviors on salmonellosis risk associated with the consumption of eggs and egg-containing foods. six categories of egg-containing foods were defined based on the amount of egg contained in the food, whether eggs are pooled, and the degree of cooking practiced by consumers. we used bootstrap simulation to quantify uncertainty in risk estimates due to sampling error, and sensitivity analysis to identify key so ... | 2006 | 16834632 |
| the newly isolated lytic bacteriophages st104a and st104b are highly virulent against salmonella enterica. | to screen irish faecal samples from a variety of sources with a view to isolating novel anti-salmonella phages and to subsequently evaluate their lytic capability. | 2006 | 16834613 |
| antimicrobial potential of four lactobacillus strains isolated from breast milk. | the antimicrobial potential of four lactobacilli (lactobacillus salivarius cect5713, lactobacillus gasseri cect5714, l. gasseri cect5715 and lactobacillus fermentum cect5716), isolated from fresh human breast milk, was evaluated in this study and compared with lactobacillus coryniformis cect5711, a reuterin-producing strain isolated from an artisan goat's cheese. | 2006 | 16834593 |
| tumour necrosis factor alpha mediated apoptosis in murine macrophages by salmonella enterica serovar typhi under oxidative stress. | invasive salmonella has been reported to induce apoptosis of macrophages as part of its infection process, which may allow it to avoid detection by the innate immune system. however, the induction of apoptosis under the different host environments remains to be examined, including the oxidative stress experienced by pathogens in the macrophage milieu. to simulate in vivo oxidative conditions, salmonella enterica serovar typhi was grown in the presence of hydrogen peroxide and its ability to indu ... | 2006 | 16831216 |
| herd-level risk factors for salmonella enterica subsp. enterica in u.s. market pigs. | midwest u.s. herds (n=63) were studied to identify risk factors for harboring salmonella enterica among slaughter-weight pigs. samples collected on farms (feces) and at slaughter (distal colonic content, cecal content and ileocolic lymph nodes) were cultured using conventional means. approximately 15 pigs were studied per herd, for a total of 3754 samples. the proportion of pigs positive in one or more samples was calculated for each herd. herd characteristics were described by a combination of ... | 2006 | 16828183 |
| complete nucleotide sequences of 84.5- and 3.2-kb plasmids in the multi-antibiotic resistant salmonella enterica serovar typhimurium u302 strain g8430. | the multi-antibiotic resistant (mr) salmonella enterica serovar typhimurium phage type u302 strain g8430 exhibits the penta-resistant acssut-phenotype (ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline), and is also resistant to carbenicillin, erythromycin, kanamycin, and gentamicin. two plasmids, 3.2- and 84.5-kb in size, carrying antibiotic resistance genes were isolated from this strain, and the nucleotide sequences were determined and analyzed. the 3.2-kb plasmid, pu30 ... | 2007 | 16828159 |
| molecular typing reveals a unique clone of salmonella enterica serotype typhi among indian strains. | 2006 | 16825414 | |
| comparison of multilocus sequence typing, pulsed-field gel electrophoresis, and antimicrobial susceptibility typing for characterization of salmonella enterica serotype newport isolates. | in the united states, multidrug-resistant phenotypes of salmonella enterica serotype newport (commonly referred to as mdr-ampc) have emerged in animals and humans and have become a major public health problem. although pulsed-field gel electrophoresis (pfge) is the current "gold standard" typing method for salmonella, multilocus sequence typing (mlst) may be more relevant to investigations exploring evolutionary and population biology relationships. in this study, 81 salmonella enterica serotype ... | 2006 | 16825363 |
| detection of multidrug-resistant salmonella enterica serovar typhimurium phage types dt102, dt104, and u302 by multiplex pcr. | salmonella enterica serovar typhimurium is a common cause of nontyphoidal salmonellosis in humans and animals. multidrug-resistant serovar typhimurium phage type dt104, which emerged in the 1990s, has become widely distributed in many countries. a total of 104 clinical isolates of salmonella serogroup b were collected from three major hospitals in taiwan during 1997 to 2003 and were examined by a multiplex pcr targeting the resistance genes and the spv gene of the virulence plasmid. a total of 5 ... | 2006 | 16825349 |
| safety and immunogenicity of attenuated salmonella enterica serovar typhimurium delivering an hiv-1 gag antigen via the salmonella type iii secretion system. | cks257 (salmonella typhimurium sl1344 deltaphop/phoqdelta aroa deltaasd deltastra/strb psb2131) is a live oral vaccine vector expressing hiv gag. | 2006 | 16824652 |
| caspase-1-dependent pore formation during pyroptosis leads to osmotic lysis of infected host macrophages. | salmonella enterica serovar typhimurium invades host macrophages and induces a unique caspase-1-dependent pathway of cell death termed pyroptosis, which is activated during bacterial infection in vivo. we demonstrate dna cleavage during pyroptosis results from caspase-1-stimulated nuclease activity. although poly(adp-ribose) polymerase (parp) activation by fragmented dna depletes cellular atp to cause lysis during oncosis, the rapid lysis characteristic of salmonella-infected macrophages does no ... | 2006 | 16824040 |
| the o-antigen affects replication of salmonella enterica serovar typhimurium in murine macrophage-like j774-a.1 cells through modulation of host cell nitric oxide production. | o-antigen-proficient and defined o-antigen-deficient mutants of salmonella enterica serovar typhimurium were compared for intracellular replication and induction of nitric oxide (no) expression in the murine macrophage-like cell line j774-a.1. while o-antigen-proficient bacteria replicated and provoked induction of host cell no synthesis to expected levels, deltawaak, deltawaal and deltawaakl mutants displayed increased growth yields and induction of significantly lower levels of macrophage no p ... | 2006 | 16822688 |
| comparison of antagonistic ability against enteropathogens by g+ and g- anaerobic dominant components of human fecal microbiota. | to confirm if anaerobic g+-components are those responsible for the function of colonization resistance, obligate anaerobic g+- and g- -bacteria from normal dominant microbiota of human feces were isolated from three successive collections and then used in in vitro assays for antagonism against two enteropathogenic bacteria. the production of inhibitory diffusible compounds was determined on supplemented bhi agar and mrs agar media for g- - and g+-bacteria, respectively. salmonella enterica subs ... | 2006 | 16821725 |
| molecular cloning and characterization of a large subunit of salmonella typhimurium glutamate synthase (gogat) gene in escherichia coli. | two pathways of ammonium assimilation and glutamate biosynthesis have been identified in microorganisms. one pathway involves the nadp-linked glutamate dehydrogenase, which catalyzes the amination of 2-oxoglutarate to form glutamate. an alternative pathway involves the combined activities of glutamine synthetase, which aminates glutamate to form glutamine, and glutamate synthase, which transfers the amide group of glutamine to 2-oxoglutarate to yield two molecules of glutamate. we have cloned th ... | 2006 | 16820760 |
| alteration of the rugose phenotype in waag and ddhc mutants of salmonella enterica serovar typhimurium dt104 is associated with inverse production of curli and cellulose. | the rugose (also known as wrinkled or rdar) phenotype in salmonella enterica serovar typhimurium dt104 rv has been associated with cell aggregation and the ability, at low temperature under low-osmolarity conditions, to form pellicles and biofilms. two tn5 insertion mutations in genes that are involved in lipopolysaccharide (lps) synthesis, ddhc (a1-8) and waag (a1-9), of rv resulted in diminished expression of colony rugosity. scanning electron micrographs revealed that the ddhc mutant showed r ... | 2006 | 16820499 |
| generating tetracycline-inducible auxotrophy in escherichia coli and salmonella enterica serovar typhimurium by using an insertion element and a hyperactive transposase. | we report the construction and application of a novel insertion element for transposase-mediated mutagenesis in gram-negative bacteria. besides km(r) as a selectable marker, the insertion element instet(g-)1 carries the anhydrotetracycline (atc)-regulated outward-directed pa promoter so that atc-dependent conditional gene knockouts or knockdowns are generated. the complex formed between the purified hyperactive transposase and instet(g-)1 was electroporated into escherichia coli or salmonella en ... | 2006 | 16820464 |
| phylogenetic relationships among clonal groups of extraintestinal pathogenic escherichia coli as assessed by multi-locus sequence analysis. | the evolutionary origins of extraintestinal pathogenic escherichia coli (expec) remain uncertain despite these organisms' relevance to human disease. a valid understanding of expec phylogeny is needed as a framework against which the observed distribution of virulence factors and clinical associations can be analyzed. accordingly, phylogenetic relationships were defined by multi-locus sequence analysis among 44 representatives of selected expec clonal groups and the e. coli reference (ecor) coll ... | 2006 | 16820314 |
| comparison of the concentrations of phenolic compounds in olive oils and other plant oils: correlation with antimicrobial activity. | the antimicrobial activity of different edible vegetable oils was studied. in vitro results revealed that the oils from olive fruits had a strong bactericidal action against a broad spectrum of microorganisms, this effect being higher in general against gram-positive than gram-negative bacteria. thus, olive oils showed bactericidal activity not only against harmful bacteria of the intestinal microbiota (clostridium perfringens and escherichia coli) also against beneficial microorganisms such as ... | 2006 | 16819902 |
| identification of the proteasome inhibitor mg262 as a potent atp-dependent inhibitor of the salmonella enterica serovar typhimurium lon protease. | lon is a homo-oligomeric atp-dependent serine protease which functions in the degradation of damaged and certain regulatory proteins. the importance of lon activity in bacterial pathogenicity has led to its emergence as a target in the development of novel antibiotics. as no potent inhibitors of lon activity have been reported to date, we sought to identify an inhibitor which could serve as a lead compound in the development of a potent lon-specific inhibitor. to determine whether a nucleotide- ... | 2006 | 16819825 |
| osmotic upshift transiently inhibits uptake via abc transporters in gram-negative bacteria. | atp-binding cassette transporters from several rhizobia and salmonella enterica serovar typhimurium, but not secondarily coupled systems, were inhibited by high concentrations (100 to 500 mm) of various osmolytes, an effect reversed by the removal of the osmolyte. abc systems were also inactivated in isolated pea bacteroids, probably due to the obligatory use of high-osmolarity isolation media. measurement of nutrient cycling in isolated pea bacteroids is impeded by this effect. | 2006 | 16816205 |
| sigma28-dependent transcription in salmonella enterica is independent of flagellar shearing. | the flgm anti-sigma28 factor is secreted in response to flagellar hook-basal body completion to allow sigma28-dependent transcription of genes needed late in flagellar assembly, such as the flagellin structural gene, flic. a long-standing hypothesis was that one role of flgm secretion was to allow rapid expression of flagellin in response to shearing. we tested this hypothesis by following flgm secretion and flic transcription in response to flagellar shearing. experiments showed that the level ... | 2006 | 16816191 |
| limited role for the dsra and rpra regulatory rnas in rpos regulation in salmonella enterica. | rpos, the sigma factor of enteric bacteria that responds to stress and stationary phase, is subject to complex regulation acting at multiple levels, including transcription, translation, and proteolysis. increased translation of rpos mrna during growth at low temperature, after osmotic challenge, or with a constitutively activated rcs phosphorelay depends on two trans-acting small regulatory rnas (srnas) in escherichia coli. the dsra and rpra srnas are both highly conserved in salmonella enteric ... | 2006 | 16816180 |
| protection of neonatal mice from lethal enterovirus 71 infection by maternal immunization with attenuated salmonella enterica serovar typhimurium expressing vp1 of enterovirus 71. | this study describes the potential use of attenuated salmonella enterica serovar typhimurium strains to express and deliver vp1 of enterovirus 71 (ev71) as a vaccination strategy to prevent ev71 infection in mice. when orally administered to balb/c mice, both attenuated carrier strains, cnp101 and sl7207, were able to efficiently invade livers and spleens, while only the virulence plasmid-carrying strain sl7207 persisted for more than 30 days in these organs. a recombinant in vivo-regulated prom ... | 2006 | 16815726 |
| long polar fimbriae and tissue tropism in escherichia coli o157:h7. | in vitro organ culture has demonstrated the human intestinal tropism of enterohaemorrhagic escherichia coli o157:h7 for follicle associated epithelium overlying peyer's patches of the terminal ileum. long polar (lp) fimbriae are considered to mediate the attachment of salmonella enterica serovar typhimurium to peyer's patch epithelium and, as homologous genes have been identified in o157:h7, we hypothesised that lp fimbriae in o157:h7 may perform the same function. however, mutation of lp fimbri ... | 2006 | 16815722 |
| differentiation of selected salmonella enterica serovars by fourier transform mid-infrared spectroscopy. | salmonella enterica serovars include pathogens responsible for high numbers of foodborne salmonellosis. fourier transform infrared (ft-ir) spectroscopy can be used to rapidly and accurately identify microorganisms based on unique spectra of bacterial cell components. the objectives of this study were to discriminate closely related salmonella enterica serovars by using ft-ir spectroscopy and multivariate analysis and to compare the performance of three techniques for differentiating among salmon ... | 2006 | 16808859 |
| flagellin in combination with curli fimbriae elicits an immune response in the gastrointestinal epithelial cell line ht-29. | flagellin is the major cytokine-releasing factor when salmonella enterica serovar typhimurium (s. typhimurium) infects intestinal epithelial cells. in this work it is shown that curli, an adhesive proteinaceous surface component of enterobacteriaceae involved in biofilm formation of s. typhimurium and escherichia coli strains can bind flagellin and thus elicit an immune response by the intestinal epithelial cell line ht-29. | 2006 | 16807036 |
| plasmid-mediated quinolone resistance in non-typhi serotypes of salmonella enterica. | serious infections with salmonella species are often treated with fluoroquinolones or extended-spectrum beta-lactams. increasingly recognized in enterobacteriaceae, plasmid-mediated quinolone resistance is encoded by qnr genes. here, we report the presence of qnr variants in human isolates of non-typhi serotypes of salmonella enterica (hereafter referred to as non-typhi salmonella) from the united states national antimicrobial resistance monitoring system for enteric bacteria. | 2006 | 16804843 |
| distribution of prophages and sgi-1 antibiotic-resistance genes among different salmonella enterica serovar typhimurium isolates. | recently, the authors identified salmonella enterica serovar typhimurium (s. typhimurium) definitive type (dt)104-specific sequences of mainly prophage origin by genomic subtractive hybridization. in the present study, the distribution of the prophages identified, st104 and st64b, and the novel prophage remnant designated prophage st104b, was tested among 23 non-dt104 s. typhimurium isolates of different phage types and 19 isolates of the dt104 subtypes dt104a, dt104b low and dt104l, and the dt1 ... | 2006 | 16804187 |
| in vivo, flic expression by salmonella enterica serovar typhimurium is heterogeneous, regulated by clpx, and anatomically restricted. | flic is a natural antigen recognized by the innate and adaptive immune systems during salmonella infection in mice and humans; however, the regulatory mechanisms governing its expression in vivo are incompletely understood. here, we use flow cytometry to quantify flic gene expression in single bacteria. in vitro, flic transcription was not uniformly positive; a viable flic-negative subpopulation was also identified. intracellular salmonella repressed transcription of flic and its positive regula ... | 2006 | 16803592 |
| identification of the lipopolysaccharide modifications controlled by the salmonella pmra/pmrb system mediating resistance to fe(iii) and al(iii). | iron is an essential metal but can be toxic in excess. while several homeostatic mechanisms prevent oxygen-dependent killing promoted by fe(ii), little is known about how cells cope with fe(iii), which kills by oxygen-independent means. several gram-negative bacterial species harbour a regulatory system - termed pmra/pmrb - that is activated by and required for resistance to fe(iii). we now report the identification of the pmra-regulated determinants mediating resistance to fe(iii) and al(iii) i ... | 2006 | 16803591 |
| functional dissection of ssef, a type iii effector protein involved in positioning the salmonella-containing vacuole. | intracellular replication of salmonella enterica requires the formation of a unique organelle termed salmonella-containing vacuole (scv). the type iii secretion system (t3ss) encoded by salmonella pathogenicity island 2 (spi2-t3ss) has a crucial role in the formation and maintenance of the scv. the spi2-t3ss translocates a large number of effector proteins that interfere with host cell functions such as microtubule-dependent transport. we investigated the function of the effector ssef and observ ... | 2006 | 16800847 |
| berry phenolics: antimicrobial properties and mechanisms of action against severe human pathogens. | antimicrobial activity and mechanisms of phenolic extracts of 12 nordic berries were studied against selected human pathogenic microbes. the most sensitive bacteria on berry phenolics were helicobacter pylori and bacillus cereus. campylobacter jejuni and candida albicans were inhibited only with phenolic extracts of cloudberry, raspberry, and strawberry, which all were rich in ellagitannins. cloudberry extract gave strong microbicidic effects on the basis of plate count with all studied strains. ... | 2006 | 16800770 |
| a mechanical role for the chemotaxis system in swarming motility. | the chemotaxis system, but not chemotaxis, is essential for swarming motility in salmonella enterica serovar typhimurium. mutants in the chemotaxis pathway exhibit fewer and shorter flagella, downregulate class 3 or 'late' motility genes, and appear to be less hydrated when propagated on a surface. we show here that the output of the chemotaxis system, chey approximately p, modulates motor bias during swarming as it does during chemotaxis, but for a distinctly different end. a constitutively act ... | 2006 | 16796690 |
| donor-strand exchange in chaperone-assisted pilus assembly proceeds through a concerted beta strand displacement mechanism. | gram-negative pathogens commonly use the chaperone-usher pathway to assemble adhesive multisubunit fibers on their surface. in the periplasm, subunits are stabilized by a chaperone that donates a beta strand to complement the subunits' truncated immunoglobulin-like fold. pilus assembly proceeds through a "donor-strand exchange" (dse) mechanism whereby this complementary beta strand is replaced by the n-terminal extension (nte) of an incoming pilus subunit. using x-ray crystallography and real-ti ... | 2006 | 16793551 |
| an sopb-mediated immune escape mechanism of salmonella enterica can be subverted to optimize the performance of live attenuated vaccine carrier strains. | salmonellae have evolved several mechanisms to evade host clearance. here, we describe the influence on bacterial immune escape of the effector protein sopb, which is translocated into the cytosol through a type iii secretion system. wild-type bacteria, as well as the ssec and aroa attenuated mutants exerted a stronger cytotoxic effect on dendritic cells (dc) than their sopb-deficient derivatives. cells infected with the double ssec sopb, phop sopb and aroa sopb mutants also exhibited higher exp ... | 2006 | 16793312 |
| stabilization of a plasmid coding for a heterologous antigen in salmonella enterica serotype typhi vaccine strain cvd908-htra by using site-specific recombination. | a gene cassette incorporating the crs-rsd site-specific recombination system from the salmonella enterica subsp. enterica serovar dublin virulence plasmid improved the inheritance in s. enterica serotype typhi strain cvd908-htra of a multicopy plasmid expression vector. use of this recombination cassette may improve expression of heterologous antigens from multicopy plasmid expression vectors in attenuated bacterial vaccine strains. | 2006 | 16790817 |
| circulating gamma delta t cells in response to salmonella enterica serovar enteritidis exposure in chickens. | gammadelta t cells are considered crucial to the outcome of various infectious diseases. the present study was undertaken to characterize gammadelta (t-cell receptor 1(+) [tcr1(+)]) t cells phenotypically and functionally in avian immune response. day-old chicks were orally immunized with salmonella enterica serovar enteritidis live vaccine or s. enterica serovar enteritidis wild-type strain and infected using the s. enterica serovar enteritidis wild-type strain on day 44 of life. between days 3 ... | 2006 | 16790770 |
| phenotypic and genotypic characterization of salmonella enterica serotype paratyphi b isolates from environmental and human sources in galicia, spain. | salmonella serotype paratyphi b isolates obtained from shellfish and human infections in galicia (northwest spain) from 1998 were investigated by different phenotypic and genetic methods to evaluate their systemic or enteric nature. isolates were investigated for d-tartrate fermentation, presence of genes encoding the effector proteins sope1 and avra, pulsed-field gel electrophoresis profile, and antimicrobial susceptibility. systemic variant strains (dt-) were the dominant among the marine envi ... | 2006 | 16786846 |
| isolation of different serovars of salmonella enterica from wild birds in great britain between 1995 and 2003. | postmortem examinations were carried out on the carcases of 779 wild birds. salmonellosis was a common cause of death in greenfinches (carduelis chloris), house sparrows (passer domesticus) and chaffinches (fringilla coelebs), and was also responsible for the deaths of other birds such as goldfinches (carduelis carduelis), feral pigeons and different species of gulls. most cases of salmonellosis in finches occurred between january and march, whereas salmonellosis in house sparrows tended to occu ... | 2006 | 16782854 |
| occurrence of integrons and antimicrobial resistance genes among salmonella enterica from brazil. | to determine the occurrence of antimicrobial resistance genes and role of integrons among 135 antimicrobial-resistant salmonella enterica from brazil. | 2006 | 16782743 |
| characterization of antimicrobial resistance and class 1 and 2 integrons in salmonella enterica isolates from different sources in portugal. | the antimicrobial resistance profiles of 1183 salmonella isolates collected during 2002-2003 from several sources (human, food products and environment) were evaluated. the occurrence, distribution and cassette content of class 1 and 2 integrons among the sulphonamide-resistant population, as well as the role of particular clones to the spread of these genetic elements, were investigated. | 2006 | 16782741 |
| the temperature-sensing protein tlpa is repressed by phop and dispensable for virulence of salmonella enterica serovar typhimurium in mice. | tlpa is a temperature-sensing, coiled-coil protein, encoded on the pslt virulence plasmid of salmonella enterica serovar typhimurium. tlpa was previously presumed to play a role in the pathogenicity of salmonella. herein we show that tlpa is tightly regulated, differentially expressed in response to environmental and physiological signals, and can be secreted in vitro. expression of tlpa was found to be repressed in modified minimal medium containing limiting concentrations of mg2+ and in the st ... | 2006 | 16782389 |
| class 1 integrons in dutch salmonella enterica serovar dublin isolates from clinical cases of bovine salmonellosis. | fifty-nine salmonella enterica serovar dublin (salmonella dublin) isolates from clinical cases of bovine salmonellosis between 1993 and 2004 were tested for their susceptibility to 15 antimicrobial agents and the presence of class 1 integrons. integrons were further analyzed by conserved segment pcr-rflp. dna sequencing was used to identify the inserted gene cassette. twelve (20.3%) isolates were multidrug-resistant. a combination of resistance against chloramphenicol, streptomycin and sulphonam ... | 2006 | 16781090 |
| emergence of multidrug-resistant salmonella enterica serotype newport in minnesota. | we report a concurrent increase in the number of isolates of salmonella enterica serotype newport and the rate of multidrug resistance in s. newport isolates from animal and human populations in minnesota. antimicrobial susceptibility and pulsed-field gel electrophoresis analysis demonstrated heterogeneity of isolates and showed that 1 pulsed-field gel electrophoresis cluster contained most of the multidrug-resistant isolates with a resistance pattern and most class 1 integron isolates, implying ... | 2006 | 16779749 |
| 55 kda outer-membrane protein from short-chain fatty acids exposed salmonella enterica serovar typhi induces apoptosis in macrophages. | various pathogens including salmonella species are known to induce apoptosis in host cell types during their infection processes. however, the bacterial components capable of inducing apoptosis have not been fully understood. it is now known that in vivo expression of virulence determinants differ from the expression under in vitro conditions. therefore, in the present study, attempts were made to evaluate the apoptotic potential of outer-membrane protein (omp) from short-chain fatty acids (scfa ... | 2006 | 16779627 |
| fis is required for proper regulation of ssag expression in salmonella enterica serovar typhimurium. | salmonella pathogenicity island 2 (spi2) encodes a type iii secretion system (ttss) necessary for bacterial survival and replication in intracellular environment of host cells. spi2 genes are transcribed preferentially after salmonella enters the host cells. transcriptional regulation of ssag encoding the component of spi2-ttss apparatus was studied in vivo and in vitro. fis, one of the major components of bacterial nucleoid, activated the stationary phase-specific expression of ssag when salmon ... | 2006 | 16777370 |
| effects of ractopamine hcl on escherichia coli o157:h7 and salmonella in vitro and on intestinal populations and fecal shedding in experimentally infected sheep and pigs. | the effects of the beta-agonist ractopamine, approved for use in finishing swine and cattle to improve carcass quality and performance, were examined on two important foodborne pathogens, escherichia coli o157:h7 and salmonella. ractopamine, administered to sheep before and after oral inoculation with e. coli o157:h7, increased (p < 0.01) fecal shedding and tended to increase (p = 0.08) cecal populations of the challenge strain. pigs receiving ractopamine in the diet and then experimentally infe ... | 2006 | 16775793 |
| a survey of foodborne pathogens in bulk tank milk and raw milk consumption among farm families in pennsylvania. | a 2-part study was conducted to determine the risk of exposure to human pathogens from raw milk. the first part of the study focused on determining raw milk consumption habits of dairy producers. a total of 248 dairy producers from 16 counties in pennsylvania were surveyed. overall, 105 (42.3%) of the 248 dairy producers consumed raw milk and 170 (68.5%) of the 248 dairy producers were aware of foodborne pathogens in raw milk. dairy producers who were not aware of foodborne pathogens in raw milk ... | 2006 | 16772561 |
| ciprofloxacin resistance in salmonella enterica serotype typhi/paratyphi and antimicrobial agent quality and bioavailability. | 2006 | 16772428 | |
| oral dna vaccination with the polyprotein gene of infectious bursal disease virus (ibdv) delivered by the attenuated salmonella elicits protective immune responses in chickens. | our previous study showed that vaccination with plasmid dna containing infectious bursal disease virus (ibdv) gene which encodes complete polyprotein (vp2/4/3) induced protective immune responses. in this study, we examined the efficacy of an oral dna vaccine carrying the ibdv polyprotein antigen delivered by attenuated salmonella enterica sv. typhimurium (s. typhimurium). the recombinant plasmid pci-vp2/4/3 was transformed by electroporation into an attenuated s.typhimurium strain (dam phop) (d ... | 2006 | 16769159 |
| pseudomembranous colitis due to salmonella enterica serotype infantis. | 2006 | 16767602 | |
| age-related clinical and microbiological characteristics of enteric fever in india. | a retrospective, hospital-based study at safdarjang hospital, india, was undertaken between january 1999 and december 2003 to estimate age-related epidemiological, clinical and microbiological characteristics in enteric fever cases. a total of 750 blood-culture-proven cases of enteric fever were studied. the majority of cases occurred in children aged 5-12 years and 24.8% of cases were in children up to 5 years of age. salmonella serotypes showed an age-related predilection, with paratyphoid fev ... | 2006 | 16766005 |
| ancient typhoid epidemic reveals possible ancestral strain of salmonella enterica serovar typhi. | in contrast to other serotypes of salmonella enterica, s. typhi is exclusively adapted to human hosts. recently, s. typhi was identified in ancient skeletal material, thereby incriminating typhoid fever for the plague of athens. since, according to thucydides' report, animals were also affected by the disease, a working hypothesis is constituted that the causative agent of the plague might be the anticipated original strain of s. typhi, purportedly capable of infecting animals as well as humans. ... | 2007 | 16765652 |
| broad-spectrum microbicidal activity, toxicologic assessment, and materials compatibility of a new generation of accelerated hydrogen peroxide-based environmental surface disinfectant. | concerns on human and environmental safety and label claims of many microbicides point to the need for safer, faster acting, and broad-spectrum substitutes. accel tb, a 0.5% accelerated h(2)o(2) (ahp)-based disinfectant described here, is a potential candidate. | 2006 | 16765201 |
| eila, a hila-like regulator in enteroaggregative escherichia coli. | enteroaggregative escherichia coli (eaec) is increasingly recognized as a diarrhoeal pathogen in developing and industrialized countries. most eaec virulence factors thus far described are encoded on virulence plasmid paa, yet recent completion of the eaec genome has suggested the presence of additional factors encoded on chromosomal islands. previous reports have recognized the presence of a type iii secretion system (t3ss), designated ett2, at the glyu locus of prototype eaec strain 042, along ... | 2006 | 16762026 |
| impact of heat stress on the fecal shedding patterns of salmonella enterica typhimurium dt104 and salmonella enterica infantis by 5-week-old male broilers. | the objective of this study was to determine if there is an impact of heat stress of broiler chickens on number and survival of two types of salmonella shed in the chicken's feces after an oral challenge. the data from this study indicate that heat stress did not result in higher levels or longer survival of salmonella spp. shed in feces. it is possible that the duration or intensity of the heat stress employed was not sufficient or that heat stress does not alter the number or survivability for ... | 2006 | 16761943 |
| dissemination of salmonella enterica serotype agona and multidrug-resistant salmonella enterica serotype typhimurium in cuba. | the molecular epidemiology, antimicrobial susceptibility, and mechanisms of resistance of 34 salmonella spp. strains causing acute gastroenteritis, isolated from different provinces in cuba, were determined. sixty-four percent of the strains showed multiresistance. salmonella typhimurium was the most frequent with 15 strains (44%), 13 of which belonged to phagotype 104 and presented similar genetic profiles of pulsed field gel electrophoresis. high levels of resistance to tetracycline (53%), spe ... | 2006 | 16760518 |
| alterations in the virulence potential of enteric pathogens and bacterial-host cell interactions under simulated microgravity conditions. | host immune mechanisms were proposed to decline under microgravity conditions during spaceflights, which might result in severe infections in astronauts. therefore, it was important to investigate the effects of microgravity on infecting organisms and their interaction with host cells. data showed that simulated microgravity (smg) conditions markedly increased production of the enterotoxigenic escherichia coli (etec) heat-labile enterotoxin, which induced fluid secretory responses in a mouse mod ... | 2006 | 16760141 |
| enhanced immune response by amphotericin b following ns1 protein prime-oral recombinant salmonella vaccine boost vaccination protects mice from dengue virus challenge. | a recombinant vaccine strain sl3261/plt105 of attenuated aroa salmonella enterica serovar typhimurium sl3261 strain expressing a secreted dengue virus type 2 non-structural ns1 and yersinia pestis f1 (caf1) fusion protein, rns1:caf1, was generated. immunological evaluation was performed by prime-boost vaccine regimen. oral immunization of mice with 1 x 10(9)cfu of sl3261/plt105 only induced low levels of ns1-specific antibody response and protective immunity following dengue virus challenge. the ... | 2006 | 16759760 |
| genetic determinants and polymorphisms specific for human-adapted serovars of salmonella enterica that cause enteric fever. | salmonella enterica serovars typhi, paratyphi a, and sendai are human-adapted pathogens that cause typhoid (enteric) fever. the acute prevalence in some global regions and the disease severity of typhoidal salmonella have necessitated the development of rapid and specific detection tests. most of the methodologies currently used to detect serovar typhi do not identify serovars paratyphi a or sendai. to assist in this aim, comparative sequence analyses were performed at the loci of core bacterial ... | 2006 | 16757591 |
| [construction and characterization of delta crp delta asd mutant host-vector balanced lethal system of salmonella choleraesuis c500 strain]. | salmonella choleraesuis c500 strain was an attenuated vaccine strain to prevent piglet paratyphoid, attenuated by chemical method. although the vaccine has good immunogenicity, it remains some residual virulence. in order to develop a safer vaccine strain and exploit c500 as a live vaccine vector for mucosal immunization, delta crp delta asd double deletion mutant was constructed. firstly, the recombination suicide vector with 320 bp-deleted crp (camp receptor protein) gene and sacb (sucrose-sen ... | 2006 | 16755912 |
| direct quantitation and detection of salmonellae in biological samples without enrichment, using two-step filtration and real-time pcr. | a new two-step filtration protocol followed by a real-time pcr assay based on sybr green i detection was developed to directly quantitate salmonellae in two types of biological samples: i.e., chicken rinse and spent irrigation water. four prefiltration filters, one type of final filter, and six protocols for recovery of salmonellae from the final filter were evaluated to identify an effective filtration protocol. this method was then combined with a real-time pcr assay based on detection of the ... | 2006 | 16751494 |
| comparison of methods of extracting salmonella enterica serovar enteritidis dna from environmental substrates and quantification of organisms by using a general internal procedural control. | this paper compares five commercially available dna extraction methods with respect to dna extraction efficiency of salmonella enterica serovar enteritidis from soil, manure, and compost and uses an escherichia coli strain harboring a plasmid expressing green fluorescent protein as a general internal procedural control. inclusion of this general internal procedural control permitted more accurate quantification of extraction and amplification of s. enterica serovar enteritidis in these samples a ... | 2006 | 16751492 |
| antibiotic sensitivity profiles of salmonella organisms isolated from presumptive typhoid patients in zaria, northern nigeria. | a hundred and ten salmonella organisms (comprising 38 salm. typhi, 13 salm. paratyphi and 59 non-typhi salmonella spp.) isolated from blood of patients diagnosed of typhoid fever in zaria, northern, nigeria were evaluated for their in-vitro susceptibility to eighteen antibiotics. a high percentage of the salmonella spp. exhibited resistance to the various test antibiotics. while ceftriaxone, ciprofloxacin and the aminoglycosides exhibited the greatest in-vitro activity against the isolates (82.7 ... | 2005 | 16749332 |
| transcriptional and translational control of the salmonella flic gene. | the flagellin gene flic encodes the major component of the flagellum in salmonella enterica serovar typhimurium. this study reports the identification of a signal within the 5' untranslated region (5'utr) of the flic transcript required for the efficient expression and assembly of flic into the growing flagellar structure. primer extension mapping determined the transcription start site of the flic flagellin gene to be 62 bases upstream of the aug start codon. using teta-flic operon fusions, we ... | 2006 | 16740955 |
| whole-genome transcription profiling reveals genes up-regulated by growth on fucose in the human gut bacterium "roseburia inulinivorans". | "roseburia inulinivorans" is an anaerobic polysaccharide-utilizing firmicute bacterium from the human colon that was identified as a producer of butyric acid during growth on glucose, starch, or inulin. r. inulinivorans a2-194 is also able to grow on the host-derived sugar fucose, following a lag period, producing propionate and propanol as additional fermentation products. a shotgun genomic microarray was constructed and used to investigate the switch in gene expression that is involved in chan ... | 2006 | 16740940 |
| the cbis gene of the archaeon methanopyrus kandleri av19 encodes a bifunctional enzyme with adenosylcobinamide amidohydrolase and alpha-ribazole-phosphate phosphatase activities. | here we report the initial biochemical characterization of the bifunctional alpha-ribazole-p (alpha-rp) phosphatase, adenosylcobinamide (adocbi) amidohydrolase cbis enzyme from the hyperthermophilic methanogenic archaeon methanopyrus kandleri av19. the cbis gene encodes a 39-kda protein with two distinct segments, one of which is homologous to the adocbi amidohydrolase (cbiz, ec 3.5.1.90) enzyme and the other of which is homologous to the recently discovered archaeal alpha-rp phosphatase (cobz, ... | 2006 | 16740929 |
| a recurring salmonellosis epidemic in new zealand linked to contact with sheep. | one strain of salmonella brandenburg began causing large numbers of human infections in new zealand in 1998. we investigated the emergence of this strain using combined notification and laboratory data on human and animal disease and a case-control study. s. brandenburg infection in humans was characterized by spring peaks and high rates in the southern half of the south island. this epidemic pattern followed very closely that seen in sheep. the case-control study found that infection was signif ... | 2007 | 16740191 |
| pcr detection of salmonella spp. using primers targeting the quorum sensing gene sdia. | bacteria communicate with one another and with their host using chemical signalling molecules. this phenomenon is generally described as quorum sensing. a set of primers for pcr detection of salmonella spp. has been designed using as target the sdia gene which encodes a signal receptor of the luxr family. the pcr product (274 bp) was confirmed by sequencing. a number of 81 non-salmonella strains (representing 24 different species) were tested and gave negative results, while a total of 101 diffe ... | 2006 | 16734780 |
| identification of the plasmid-borne quinolone resistance gene qnrs in salmonella enterica serovar infantis. | a salmonella enterica serovar infantis isolate of avian origin was investigated for the presence of the gene qnrs, its transferability and its association with other resistance genes. | 2006 | 16720566 |
| magnesium transporters: properties, regulation and structure. | the chemistry of mg2+ is unique amongst biological cations, and the properties of mg2+ transport systems reflect this chemistry. prokaryotes carry three classes of mg2+ transport systems: cora, mgta/b and mgte. cora and mgte are widely distributed in both eubacteria and archaea, while the mgta/b class is found primarily in the eubacteria. eukaryotic homologs of cora, although clearly functional as mg2+ transporters, have minimal sequence homology and include the mrs2p mitochondrial mg2+ channel ... | 2006 | 16720382 |
| salmonella enterica serotype choleraesuis infections in pediatric patients. | among >2500 nontyphoid salmonella serotypes, salmonella enterica serotype choleraesuis shows a high predilection to cause systemic infections in humans. the objective of this study was to delineate the clinical and microbiologic features of pediatric patients with salmonella choleraesuis infections. | 2006 | 16717121 |
| multiplication and motility of salmonella enterica serovars enteritidis, infantis, and montevideo in in vitro contamination models of eggs. | the invasive ability of salmonella enterica serovars enteritidis, infantis, and montevideo in eggs was examined. strains of these serovars originating from egg contents, laying chicken houses, and human patients were experimentally inoculated (0.1-ml dose containing 78 to 178 cells) onto the vitelline membrane of eggs collected from specific-pathogen-free chickens and incubated at 25 degrees c. the test strains were detected in 25 of 138 yolk contents by day 6, indicating the penetration of salm ... | 2006 | 16715797 |
| analyses of five gallinacin genes and the salmonella enterica serovar enteritidis response in poultry. | gallinacins in poultry are functional equivalents of mammalian beta-defensins, which constitute an integral component of the innate immune system. salmonella enterica serovar enteritidis is a gram-negative bacterium that negatively affects both human and animal health. to analyze the association of genetic variations of the gallinacin genes with the phenotypic response to s. enterica serovar enteritidis, an f1 population of chickens was created by crossing four outbred broiler sires to dams of t ... | 2006 | 16714567 |
| salmonella enterica serovar typhimurium requires the lpf, pef, and tafi fimbriae for biofilm formation on hep-2 tissue culture cells and chicken intestinal epithelium. | recent work has demonstrated that salmonella enterica serovar typhimurium forms biofilms on hep-2 tissue culture cells in a type 1 fimbria-dependent manner. to investigate how biofilm growth of hep-2 tissue culture cells affects gene expression in salmonella, we compared global gene expression during planktonic growth and biofilm growth. microarray results indicated that the transcription of approximately 100 genes was substantially altered by growth in a biofilm. these genes encode proteins wit ... | 2006 | 16714543 |