Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| subversion of antimicrobial calprotectin (s100a8/s100a9 complex) in the cytoplasm of tr146 epithelial cells after invasion by listeria monocytogenes. | expressed by squamous mucosal keratinocytes, calprotectin is a complex of two ef-hand calcium-binding proteins of the s100 subfamily (s100a8 and s100a9) with significant antimicrobial activity. calprotectin-expressing cells resist invasion by porphyromonas gingivalis, listeria monocytogenes, and salmonella enterica serovar typhimurium (s. typhimurium). to understand the interactions between calprotectin and invasive bacteria, we studied the distribution of calprotectin in the cytoplasm of tr146 ... | 2009 | 19079333 |
| a dynamic view of the spread and intracellular distribution of salmonella enterica. | the events that determine the dynamics of proliferation, spread and distribution of microbial pathogens within their hosts are surprisingly heterogeneous and poorly understood. we contend that understanding these phenomena at a sophisticated level with the help of mathematical models is a prerequisite for the development of truly novel, targeted preventative measures and drug regimes. we describe here recent studies of salmonella enterica infections in mice which suggest that bacteria resist the ... | 2009 | 19079353 |
| molecular characterisation of class 1 integrons in salmonella enterica serovar choleraesuis isolates from southern taiwan. | integron-mediated multidrug resistance in salmonellaenterica serovar choleraesuis poses a major concern in human salmonellosis in taiwan. in this study, 71 strains of s. choleraesuis harbouring a class 1 integron from humans and animals were characterised for detection of integrons, gene cassettes and the spvc virulence gene using molecular genetic techniques. all 71 strains tested were negative for class 2 and 3 integrons. fifty-eight (81.7%) of the isolates harboured a class 1 integron with di ... | 2009 | 19084383 |
| characterization of antimicrobial resistance in salmonella enterica serotype heidelberg isolated from food animals. | fifty-eight salmonella enterica serovar heidelberg isolates isolated from food animals were tested for antimicrobial susceptibilities and further characterized for select antimicrobial resistance genes, plasmid carriage, class 1 integrons, and genetic relatedness using pulsed-field gel electrophoresis (pfge). seventy-two percent of isolates displayed resistance to at least one of the antimicrobial agents tested, while 24% exhibited resistance to eight or more antimicrobial agents. resistance was ... | 2009 | 19099358 |
| mucosal immunization with attenuated salmonella enterica serovar typhi expressing protective antigen of anthrax toxin (pa83) primes monkeys for accelerated serum antibody responses to parenteral pa83 vaccine. | salmonella enterica serovar typhi vaccine strain cvd 908-htra was genetically engineered for stable plasmid-based expression of protective antigen of anthrax toxin (pa83) fused with the export protein clya (clya-pa83). the priming potential of cvd 908-htra expressing clya-pa83 was assessed in 12 rhesus and 20 cynomolgus macaques that were immunized mucosally (i.e., intranasally) on days 0 and 14. a parenteral booster with purified pa83 plus alum was given to rhesus macaques on days 42 and 225; c ... | 2009 | 19099487 |
| salmonella-containing vacuoles display centrifugal movement associated with cell-to-cell transfer in epithelial cells. | intracellular salmonella enterica serovar typhimurium (serovar typhimurium) occupies a salmonella-containing vacuole (scv) where bacterial effector proteins are secreted into the host cell using type iii secretion systems (t3ss). cytoskeletal motor proteins and t3ss-delivered effector proteins facilitate scv positioning to juxtanuclear positions where bacterial replication occurs. here, we show that this characteristic scv positioning is not maintained by all scvs during infection of hela cells. ... | 2009 | 19103768 |
| salmonella enterica serovar typhimurium strains with regulated delayed attenuation in vivo. | recombinant bacterial vaccines must be fully attenuated for animal or human hosts to avoid inducing disease symptoms while exhibiting a high degree of immunogenicity. unfortunately, many well-studied means for attenuating salmonella render strains more susceptible to host defense stresses encountered following oral vaccination than wild-type virulent strains and/or impair their ability to effectively colonize the gut-associated and internal lymphoid tissues. this thus impairs the ability of reco ... | 2009 | 19103774 |
| multiple regulatory pathways associated with high-level ciprofloxacin and multidrug resistance in salmonella enterica serovar enteritidis: involvement of rama and other global regulators. | mechanisms of antibiotic resistance were examined in nalidixic acid-resistant salmonella enterica serovar enteritidis field isolates displaying decreased susceptibility to ciprofloxacin and in in vitro-derived ciprofloxacin-resistant mutants (104-cip and 5408-cip). all field isolates harbored a single gyra mutation (d87y). deletion of acrb and complementation with wild-type gyra increased quinolone susceptibility. selection for ciprofloxacin resistance was associated with the development of an a ... | 2009 | 19104017 |
| cmy-31 and cmy-36 cephalosporinases encoded by cole1-like plasmids. | two cmy-2 derivatives, cmy-31 (gln(215)-->arg) from salmonella enterica serotype newport and cmy-36 (ala(77)-->cys and gln(193)-->glu) from klebsiella pneumoniae, were characterized. both cephalosporinases functionally resembled cmy-2. bla(cmy) alleles occurred as parts of a putative transposon comprising isecp1b and a citrobacter freundii-derived sequence carried by cole1-like plasmids similar to cmy-5-encoding ptkh11 from klebsiella oxytoca. | 2009 | 19104021 |
| reaction of adomet with thic generates a backbone free radical. | thic is an [4fe-4s] cluster protein that catalyzes the formation of 4-amino-5-hydroxymethyl-2-methylpyrimidine. epr spectroscopic studies demonstrate that, upon interaction with adomet, active thic from salmonella enterica generates a persistent free radical on the alpha-carbon of an amino acid residue. the epr properties of the radical are consistent with any residue other than a gly or ala. exposure to oxygen was accompanied by a fission of the radical-carrying polypeptide chain between the gl ... | 2009 | 19113839 |
| salmonella enterica typhimurium sipa induces cxc-chemokine expression through p38mapk and jun pathways. | the role of salmonella typhimurium type iii secretion system (t3ss-1)-translocated proteins in chemokines' expression and protein phosphorylation was investigated in hela cells. infection of hela cells with s. typhimurium activated il-8 and gro-alpha expression at higher levels than infection with a s. typhimurium sipasopabde2 mutant, confirming that t3ss-1-secreted proteins are required to fully induce chemokine expression in hela cells. a s. typhimurium sipasopabde2 mutant complemented with si ... | 2009 | 19114119 |
| archaeal apbc/nbp35 homologs function as iron-sulfur cluster carrier proteins. | iron-sulfur clusters may have been the earliest catalytic cofactors on earth, and most modern organisms use them extensively. although members of the archaea produce numerous iron-sulfur proteins, the major cluster assembly proteins found in the bacteria and eukarya are not universally conserved in archaea. free-living archaea do have homologs of the bacterial apbc and eukaryotic nbp35 genes that encode iron-sulfur cluster carrier proteins. this study exploits the genetic system of salmonella en ... | 2009 | 19114487 |
| role of the hya hydrogenase in recycling of anaerobically produced h2 in salmonella enterica serovar typhimurium. | double and triple uptake-type hydrogenase mutants were used to determine which hydrogenase recycles fermentatively produced hydrogen. the deltahyb deltahya and deltahyd deltahya double mutants evolved h(2) at rates similar to that of the triple mutant strain, so hya alone oxidizes the bulk of h(2) produced during fermentation. when only hya was present, no hydrogen production was observed in nutrient-limited medium. h(2) uptake assays showed that hya can oxidize both exogenously added h(2) and f ... | 2009 | 19114523 |
| poultry-associated salmonella enterica subsp. enterica serovar 4,12:d:- reveals high clonality and a distinct pathogenicity gene repertoire. | a european baseline survey during the years 2005 and 2006 has revealed that the monophasic salmonella enterica subsp. enterica serovar 4,12:d:- was, with a prevalence of 23.6%, the most frequently isolated serovar in german broiler flocks. in denmark and the united kingdom, its serovar prevalences were 15.15% and 2.8%, respectively. although poultry is a major source of human salmonellosis, serovar 4,12:d:- is rarely isolated in humans (approximately 0.09% per year). molecular typing studies usi ... | 2009 | 19114530 |
| evaluation of new generation salmonella enterica serovar typhimurium vaccines with regulated delayed attenuation to induce immune responses against pspa. | increasing the immunogenicity to delivered antigens by recombinant attenuated salmonella vaccines (rasv) has been the subject of intensive study. with this goal in mind, we have designed and constructed a new generation of rasv that exhibit regulated delayed attenuation. these vaccine strains are phenotypically wild type at the time of immunization and become attenuated after colonization of host tissues. the vaccine strains are grown under conditions that allow expression of genes required for ... | 2009 | 19114649 |
| variation in antimicrobial resistance in sporadic and outbreak-related salmonella enterica serovar typhimurium. | the prevalence of different antimicrobial resistance profiles and variants of the salmonella genomic island 1 (sgi1) was reported for salmonella enterica serovar typhimurium dt104 strains isolated from patients in denmark. variation in antimicrobial resistance and corresponding changes of sgi1 were shown among isolates from a foodborne outbreak. | 2009 | 19116064 |
| deletion of tola in salmonella typhimurium generates an attenuated strain with vaccine potential. | the gram-negative tol-pal system of envelope proteins plays a key role in maintaining outer membrane integrity and contributes to the virulence of several pathogens. we have investigated the role of one of these proteins, tola, in the biology of salmonella enterica serovar typhimurium. deletion of tola rendered strain sl1344 more susceptible to killing by bile and human serum. in addition the mutant had impaired membrane integrity and displayed alterations in lps production. the tola mutant was ... | 2009 | 19118362 |
| osmoregulated periplasmic glucans of salmonella enterica serovar typhimurium are required for optimal virulence in mice. | we purified osmoregulated periplasmic glucans (opgs) from salmonella enterica serovar typhimurium and found them to be composed of 100 % glucose with 2-linked glucose as the most abundant residue, with terminal glucose, 2,3-linked and 2,6-linked glucose also present in high quantities. the two structural genes for opg biosynthesis, opgg and opgh, form a bicistronic operon, and insertion of a kanamycin resistance gene cassette into this operon resulted in a strain devoid of opgs. the opggh mutant ... | 2009 | 19118363 |
| oxidative stress and disruption of labile iron generate specific auxotrophic requirements in salmonella enterica. | the response of a cell to integrated stresses was investigated using environmental and/or genetic perturbations that disrupted labile iron homeostasis and increased oxidative stress. the effects of the perturbations were monitored as nutritional requirements, and were traced to specific enzymic targets. a yggx gsha cyay mutant strain required exogenous thiamine and methionine for growth. the thiamine requirement, which had previously been linked to the fe-s cluster proteins thih and thic, was re ... | 2009 | 19118370 |
| citrate-mediated iron uptake in pseudomonas aeruginosa: involvement of the citrate-inducible feca receptor and the feob ferrous iron transporter. | in an attempt to identify components of a ferric citrate uptake system in pseudomonas aeruginosa, a mutant library of a siderophore-deficient strain (ia614) was constructed and screened for defects in citrate-promoted growth in an fe-restricted medium. a mutant disrupted in gene pa3901, encoding a homologue of the outer-membrane ferric citrate receptor, feca, of escherichia coli (feca(e.c.)), was recovered and shown to be deficient in citrate-promoted growth and citrate-mediated fe uptake. a mut ... | 2009 | 19118371 |
| evaluation of the control of pathogen load by an anti-salmonella bacterium in a herd of cattle with persistent salmonella infection. | to determine whether an anti-salmonella bacterium is involved in control of pathogen load in persistently infected cattle herds. | 2009 | 19119953 |
| regulators of g-protein signalling are modulated by bacterial lipopeptides and lipopolysaccharide. | regulators of g-protein signalling accelerate the gtpase activity of g(alpha) subunits, driving g proteins in their inactive gdp-bound form. this property defines them as gtpase activating proteins. here the effect of different toll-like receptor agonists on rgs1 and rgs2 expression in murine bone marrow-derived macrophages and j774 cells was analysed. after stimulation with tlr2/1 or tlr2/6 lipopeptide ligands and the tlr4/md2 ligand lipopolysaccharide, microarray analyses show only modulation ... | 2009 | 19120454 |
| regulation of expression of the tricarballylate utilization operon (tcuabc) of salmonella enterica. | the tricarballylate utilization locus (tcurabc) of salmonella enterica serovar typhimurium is comprised of a 3-gene operon (tcuabc) that encodes functions that allow this bacterium to use tricarballylate as a source of carbon and energy, and the tcur gene, which encodes a putative lysr-type transcriptional regulator. in our studies, transcription of the tcuabc operon peaked at mid-log phase, and declined moderately during stationary phase. this pattern was not due to a change in the amount of tc ... | 2009 | 19284970 |
| an increase in enteric fever cases due to salmonella paratyphi a in & around chandigarh. | enteric fever is a major public health problem in india. it is classically caused by salmonella enterica serotype typhi. salmonella enterica serotype paratyphi a which had been reported less frequently from cases of enteric fever has shown an increasing trend since 1996 in india. there is also variation in the antimicrobial susceptibility of salmonella paratyphi a from different parts of the country. an attempt is therefore made to study the rate of isolation and antimicrobial susceptibility pat ... | 2009 | 19287065 |
| an additional novel antimicrobial resistance gene cluster in salmonella genomic island 1 of a salmonella enterica serovar typhimurium dt104 human isolate. | the multi-antimicrobial resistance gene cluster and its derivatives have been detected in salmonella genomic island 1 (sgi1), which has been identified in the salmonella enterica serovar typhimurium, phage types dt104, dt12, dt120, and u302, as well as other salmonella serovars, including agona, paratyphi b, albany, meleagridis, newport, cerro, derby, dusseldorf, infantis, kiambu, and emek. we acquired 53 salmonella typhimurium dt104 isolates from diarrheal patients in korea. from these isolates ... | 2009 | 19292580 |
| emergence, distribution, and molecular and phenotypic characteristics of salmonella enterica serotype 4,5,12:i:-. | salmonella spp. represent one of the most common causes of bacterial foodborne illnesses around the world. the species salmonella enterica contains more than 2500 serotypes, and emergence of new human pathogenic salmonella strains and serotypes represents a major public health issue. salmonella enterica subsp. enterica serotype 4,5,12:i:- represents a monophasic variant of salmonella typhimurium, which has rarely been identified before the mid-1990 s. the prevalence of this serotype among human ... | 2009 | 19292687 |
| characterization of pathogenic and resistant genome repertoire reveals two clonal lines in salmonella enterica subsp. enterica serovar paratyphi b (+)-tartrate positive. | a total of 36 contemporary human, animal, and environmental (+)-tartrate-fermenting (dt+) salmonella enterica serovar paratyphi b isolates, formerly called salmonella serovar java, and five related monophasic s. enterica serovar 4,5,12:b:- isolates from belgium, germany, the netherlands, and the united kingdom were investigated for clonality and antimicrobial resistance profiles, as well as their virulence and resistance gene repertoire. two major clonal lines, which could be phenotypically diff ... | 2009 | 19292689 |
| investigation of an outbreak of salmonella enterica serovar newport infection. | a large outbreak of salmonella enterica serotype newport infection occurred in northern ireland during september and october 2004. typing of isolates from patients confirmed that this strain was indistinguishable from that in concurrent outbreaks in regions of england, in scotland and in the isle of man. a total of 130 cases were distributed unequally across local government district areas in northern ireland. the epidemic curve suggested a continued exposure over about 4 weeks. a matched case-c ... | 2009 | 19296871 |
| differential il-23 requirement for il-22 and il-17a production during innate immunity against salmonella enterica serovar enteritidis. | early activation of the il-12/ifn-gamma axis has been shown following salmonella enterica serovar enteritidis (s. enteritidis) infection. we were interested to study whether il-22 and il-17a production is initiated early in response to s. enteritidis. we demonstrate here that il-22 was strongly elevated in the peritoneal lavage fluid and in serum already 1 day post-intraperitoneal infection (d.p.i.) of mice; not only il-22 but also il-17a was produced ex vivo by activated peritoneal exudate cell ... | 2009 | 19297659 |
| novel approach to control salmonella enterica by modern biophotonic technology: photosensitization. | salmonellosis is one of the most common foodborne diseases in the world. the aim of this study was to evaluate the antibacterial efficiency of 5-aminolevulinic acid (ala) based photosensitization against one of food pathogens salmonella enterica. | 2009 | 19302098 |
| phagocytic superoxide specifically damages an extracytoplasmic target to inhibit or kill salmonella. | the phagocytic oxidative burst is a primary effector of innate immunity that protects against bacterial infection. however, the mechanism by which reactive oxygen species (ros) kill or inhibit bacteria is not known. it is often assumed that dna is a primary target of oxidative damage, consistent with known effects of endogenously produced ros in the bacterial cytoplasm. but most studies fail to distinguish between effects of host derived ros versus damage caused by endogenous bacterial sources. ... | 2009 | 19305502 |
| mesoscopic and microstructural characterization of liposomes formed by the lipooligosaccharide from salmonella minnesota strain 595 (re mutant). | large unilamellar liposomes formed by the re lps (from here below named los) from salmonella enterica serotype minnesota strain 595 (re mutant) have been prepared by the extrusion techniques. the physico-chemical investigation of these systems has been performed by a combined experimental strategy, which has allowed a characterization at different observation scales, from the morphological to the micro-structural level. particularly, dynamic light scattering (dls) measurements have revealed the ... | 2009 | 19305906 |
| unusual class 1 integron-associated gene cassette configuration found in inca/c plasmids from salmonella enterica. | inca/c plasmids carrying an unusual cassette configuration in a class 1 integron and five further shared resistance genes, aacc4, apha1, hph, sul2, and teta(d) were found in salmonella enterica serovars senftenberg and ohio. a deletion formed using a short region of homology in the 5' conserved segment and the orff cassette created an array with only part of orff followed by the aada2 cassette. the inca/c plasmids were not recoverable by conjugation, but additional conjugative resistance plasmid ... | 2009 | 19307357 |
| omeprazole antagonizes virulence and inflammation in salmonella enterica-infected raw264.7 cells. | the proton pump inhibitor omeprazole reduced the intracellular replication of salmonella enterica serovar typhimurium in raw264.7 cells without affecting bacterial growth in vitro or the viability of the host cells. the mechanism was bacteriostatic and interfered with replication mediated by the virulence-associated spi2 type iii secretion system. the proton pump inhibitor bafilomycin a(1), in contrast, mediated killing of intracellular bacteria and imposed a marked cytotoxicity on raw264.7 cell ... | 2009 | 19307359 |
| invited review: breaking barriers--attack on innate immune defences by omptin surface proteases of enterobacterial pathogens. | the omptin family of gram-negative bacterial transmembrane aspartic proteases comprises surface proteins with a highly conserved beta-barrel fold but differing biological functions. the omptins ompt of escherichia coli, pgte of salmonella enterica, and pla of yersinia pestis differ in their substrate specificity as well as in control of their expression. their functional differences are in accordance with the differing pathogenesis of the infections caused by e. coli, salmonella, and y. pestis, ... | 2009 | 19318417 |
| microarray analysis of antimicrobial resistance genes in salmonella enterica from preharvest poultry environment. | to detect antimicrobial resistance genes in salmonella isolates from turkey flocks using the microarray technology. | 2009 | 19320942 |
| functions exerted by the virulence-associated type-three secretion systems during salmonella enterica serovar enteritidis invasion into and survival within chicken oviduct epithelial cells and macrophages. | salmonella enterica serovar enteritidis (se) infection of chickens is a major contributing factor to non-typhoidal salmonellosis. the roles of the type-three secretion systems (t3ss-1 and t3ss-2) in the pathogenesis of se infection of chickens are poorly understood. in this study, the functions of t3ss-1 and t3ss-2 during se infection of primary chicken oviduct epithelial cells (coec) and macrophages were characterized. the t3ss-1 and t3ss-2 mutants (sipb and ssav), impaired in translocation and ... | 2009 | 19322708 |
| in vitro evaluation of a new cefixime-clavulanic acid combination for gram-negative bacteria. | the study was conducted to evaluate a new cefixime-clavulanic acid combination for in vitro susceptibility towards gram-negative bacteria. a total of 220 isolates of escherichia coli, klebsiella pneumoniae, pseudomonas aeroginosa, acinetobacter spp, salmonella enterica serovar typhi and salmonella enterica serovar typhimurium were included in the study. the isolates were tested for susceptibility towards the new combination antimicrobial molecule cefixime with clavulanic acid by disk diffusion a ... | 2009 | 19323045 |
| role of pre-a motif in nitric oxide scavenging by truncated hemoglobin, hbn, of mycobacterium tuberculosis. | mycobacterium tuberculosis truncated hemoglobin, hbn, is endowed with a potent nitric-oxide dioxygenase activity and has been found to relieve nitrosative stress and enhance in vivo survival of a heterologous host, salmonella enterica typhimurium, within the macrophages. these findings implicate involvement of hbn in the defense of m. tuberculosis against nitrosative stress. the protein carries a tunnel system composed of a short and a long tunnel branch that has been proposed to facilitate diat ... | 2009 | 19329431 |
| interaction of candida albicans with an intestinal pathogen, salmonella enterica serovar typhimurium. | candida albicans is an opportunistic human fungal pathogen that normally resides in the gastrointestinal tract and on the skin as a commensal but can cause life-threatening invasive disease. salmonella enterica serovar typhimurium is a gram-negative bacterial pathogen that causes a significant amount of gastrointestinal infection in humans. both of these organisms are also pathogenic to the nematode caenorhabditis elegans, causing a persistent gut infection leading to worm death. in the present ... | 2009 | 19329669 |
| myxinidin, a novel antimicrobial peptide from the epidermal mucus of hagfish, myxine glutinosa l. | fish epidermal mucus contains innate immune components that provide a first line of defense against various infectious pathogens. this study reports the bioassay-guided fractionation and characterization of a novel antimicrobial peptide, myxinidin, from the acidic epidermal mucus extract of hagfish (myxine glutinosa l.). edman sequencing and mass spectrometry revealed that myxinidin consists of 12 amino acids and has a molecular mass of 1,327.68 da. myxinidin showed activity against a broad rang ... | 2009 | 19330556 |
| aquaculture and florfenicol resistance in salmonella enterica serovar typhimurium dt104. | 2009 | 19331756 | |
| emergence and evolution of multiply antibiotic-resistant salmonella enterica serovar paratyphi b d-tartrate-utilizing strains containing sgi1. | the first australian isolate of salmonella enterica serovar paratyphi b d-tartrate-utilizing (dt(+)) that is resistant to ampicillin, chloramphenicol, florfenicol, streptomycin, spectinomycin, sulfonamides, and tetracycline (apcmflsmspsutc) and contains sgi1 was isolated from a patient with gastroenteritis in early 1995. this is the earliest reported isolation globally. the incidence of infections caused by these sgi1-containing multiply antibiotic-resistant s. enterica serovar paratyphi b dt(+) ... | 2009 | 19332668 |
| genetic analysis of colistin resistance in salmonella enterica serovar typhimurium. | colistin is a cyclic cationic peptide that kills gram-negative bacteria by interacting with and disrupting the outer membrane. we isolated 44 independent mutants in salmonella enterica serovar typhimurium with reduced susceptibility to colistin and identified 27 different missense mutations located in the pmra and pmrb genes (encoding the regulator and sensor of a two-component regulatory system) that conferred increased resistance. by comparison of the two homologous sensor kinases, pmrb and en ... | 2009 | 19332669 |
| a simple broth-disk method to determine the minimum inhibitory concentration of ceftriaxone on salmonella enterica serovar typhi and paratyphi. | resistance to fluoroquinolones and cephalosporins is a major problem with salmonella enterica serovar typhi and paratyphi. an accurate determination of antibiotic susceptibility requires tests for minimum inhibitory concentration (mic) of antibiotics. we describe a simple broth-disk method to determine the mic of ceftriaxone on s. typhi and s. paratyphi. | 2009 | 19332908 |
| deep sequencing of salmonella rna associated with heterologous hfq proteins in vivo reveals small rnas as a major target class and identifies rna processing phenotypes. | the bacterial sm-like protein, hfq, is a key factor for the stability and function of small non-coding rnas (srnas) in escherichia coli. homologues of this protein have been predicted in many distantly related organisms yet their functional conservation as srna-binding proteins has not entirely been clear. to address this, we expressed in salmonella the hfq proteins of two eubacteria (neisseria meningitides, aquifex aeolicus) and an archaeon (methanocaldococcus jannaschii), and analyzed the asso ... | 2009 | 19333007 |
| identification of a flja gene on a linear plasmid as the repressor gene of flic in salmonella enterica serovar typhi. | salmonella enterica serovar typhi z66-positive strain contains an fljba-like operon on a linear plasmid and the flic gene on the chromosome encoding d or j antigen. the fljb-like gene has been identified as the gene encoding z66 antigen. to investigate the function of the flja-like gene in s. enterica serovar typhi, a z66-positive wild-type strain gifu10007 and its phase variation j positive strain 007j+ were used in the present study. after deletion of the flja-like gene, the wild-type strain t ... | 2009 | 19341422 |
| a novel hybrid yeast-human network analysis reveals an essential role for fnbp1l in antibacterial autophagy. | autophagy is a conserved cellular process required for the removal of defective organelles, protein aggregates, and intracellular pathogens. we used a network analysis strategy to identify novel human autophagy components based upon the yeast interactome centered on the core yeast autophagy proteins. this revealed the potential involvement of 14 novel mammalian genes in autophagy, several of which have known or predicted roles in membrane organization or dynamics. we selected one of these membra ... | 2009 | 19342671 |
| humoral immune responses inhibit the antitumor activities mediated by salmonella enterica serovar choleraesuis. | salmonella is a powerful antitumor agent owing to its tumor-targeting potential, antitumor capability, and ability to deliver therapeutic genes. host factors including innate and adaptive immune responses play roles in salmonella-induced antitumor activity. an emerging realization from animal models that host immune system responses to salmonella remains uncertain. herein, we used naive mice and salmonella enterica serovar choleraesuis (s. choleraesuis) immunized mice to study the role of humora ... | 2009 | 19342967 |
| an accelerated method for isolation of salmonella enterica serotype typhimurium from artificially contaminated foods, using a short preenrichment, immunomagnetic separation, and xylose-lysine-desoxycholate agar (6ix method). | rapid isolation of salmonella from food is essential for faster typing and source tracking in an outbreak. the objective of this study was to investigate a rapid isolation method that would augment the standard u.s. food and drug administration's bacteriological analytical manual (bam) method. food samples with low microbial load, including egg salad and ice cream, moderately high-microbial-load tomatoes, and high-microbial-load ground beef were intentionally inoculated with 2 to 48 cfu of salmo ... | 2009 | 19343948 |
| transfer of salmonella enterica serovar typhimurium from contaminated irrigation water to parsley is dependent on curli and cellulose, the biofilm matrix components. | enteric pathogens can contaminate fresh produce, and this contaminated produce can be a significant potential source of human illness. the objective of this study was to determine a possible mode of transfer of salmonella typhimurium from contaminated irrigation water to mature parsley plants and to investigate the role of bacterial cellulose and curli. parsley plants were drip irrigated with water containing green fluorescent protein-labeled salmonella typhimurium. stems and leaves were harvest ... | 2009 | 19343953 |
| roles of the outer membrane protein asma of salmonella enterica in the control of marrab expression and invasion of epithelial cells. | a genetic screen for suppressors of bile sensitivity in dna adenine methylase (dam) mutants of salmonella enterica serovar typhimurium yielded insertions in an uncharacterized locus homologous to the escherichia coli asma gene. disruption of asma suppressed bile sensitivity also in phop and wec mutants of s. enterica and increased the mic of sodium deoxycholate for the parental strain atcc 14028. increased levels of mara mrna were found in asma, asma dam, asma phop, and asma wec strains of s. en ... | 2009 | 19346309 |
| escherichia coli and salmonella enterica are protected against acetic acid, but not hydrochloric acid, by hypertonicity. | chapman et al. (b. chapman, n. jensen, t ross, and m. b. cole, appl. environ. microbiol. 72:5165-5172, 2006) demonstrated that an increased nacl concentration prolongs survival of escherichia coli o157 serl 2 in a broth model simulating the aqueous phase of a food dressing or sauce containing acetic acid. we examined the responses of five other e. coli strains and four salmonella enterica strains to increasing concentrations of nacl under conditions of lethal acidity and observed that the averag ... | 2009 | 19346344 |
| salmonella infection after surgery of small intestine foreign bodies. | to report the first case of salmonella enterica serotype choleraesuis infection after surgery for small intestine foreign bodies. | 2009 | 19349730 |
| effects of in-feed egg yolk antibodies on salmonella shedding, bacterial antibiotic resistance, and health of pigs. | to determine effects of anti-salmonella egg yolk antibodies on shedding and antibiotic resistance of salmonella enterica typhimurium, newly weaned pigs were randomly assigned to six dietary treatments. these treatment groups were (i) a control (basal) diet without additives and similar diets with (ii) egg yolk powder derived from chickens challenged with salmonella typhimurium antigens, (iii) a commercial egg yolk powder control, (iv) apramycin for 14 days followed by carbadox, (v) oxytetracycli ... | 2009 | 19350971 |
| contamination of bottles used for feeding reconstituted powdered infant formula and implications for public health. | microbial contamination of powdered infant formula (pif) is known to cause gastrointestinal infections in infants. of concern is intrinsic contamination of the formula with (for example) salmonella enterica as well as extrinsic contamination from inappropriate handling or ineffective disinfection. the aim of this study was to evaluate organic and microbial contamination of 'in-use' bottles used for feeding infants powdered formula milk in south wales, uk. | 2009 | 19354201 |
| characterisation of antibiotic resistance in host-adapted salmonella enterica. | salmonella enterica serovars dublin, choleraesuis and pullorum are host-adapted serovars that cause disease primarily in cattle, swine and poultry, respectively. in addition, serovars dublin and choleraesuis are important human pathogens that are disproportionately associated with severe invasive infections that require antimicrobial therapy. because of the potential increased emergence and spread of antimicrobial resistance, isolates of 42 s. enterica serovars dublin, choleraesuis and pullorum ... | 2009 | 19356907 |
| [molecular biological and phenotypical characterization of human isolates of salmonella enterica serovar paratyphi b dt+ or salmonella java]. | salmonella paratyphi b dt+ (or salmonella java) is an emerging public health problem. the study objective was to characterize phenotypically and genotypically 13 human isolates from sporadic cases of infection. | 2009 | 19358450 |
| reduction of salmonella enterica var. enteritidis colonization and invasion by bacillus cereus var. toyoi inclusion in poultry feeds. | the effect of continuously feeding the probiotic microorganism toyocerin to birds inoculated with salmonella enteritidis field-isolated strains on salmonella enteritidis prevalence, and performance variables were studied in 2 experiments. the experiments were performed with 1) broiler chickens in floor pens until slaughter 42 d of age, challenge was performed on d 3, 7, or 14 with 2 x 10(6) cfu per chick, and 2) single comb white leghorn chickens in cages until 28 d of age, challenge was perform ... | 2009 | 19359685 |
| salmonella enterica serovar enteritidis pathogenicity island 1 is not essential for but facilitates rapid systemic spread in chickens. | salmonella enterica subsp. enterica serovar enteritidis is a leading cause of human food-borne illness that is mainly associated with the consumption of contaminated poultry meat and eggs. to cause infection, s. enteritidis is known to use two type iii secretion systems, which are encoded on two salmonella pathogenicity islands, spi-1 and spi-2, the first of which is thought to play a major role in invasion and bacterial uptake. in order to study the role of spi-1 in the colonization of chicken, ... | 2009 | 19364835 |
| salmonella enterica serovar typhimurium pathogenicity island 1-encoded type iii secretion system translocases mediate intimate attachment to nonphagocytic cells. | delivery of bacterial proteins into mammalian cells by type iii secretion systems (ttss) is thought to require the intimate association of bacteria with target cells. the molecular bases of this intimate association appear to be different in different bacteria involving ttss components, as well as surface determinants not associated with ttss. we show here that the protein translocases sipb, sipc, and sipd of the salmonella enterica serovar typhimurium pathogenicity island 1 (spi-1)-encoded ttss ... | 2009 | 19364837 |
| o-antigen-negative salmonella enterica serovar typhimurium is attenuated in intestinal colonization but elicits colitis in streptomycin-treated mice. | lipopolysaccharide (lps) is a major constituent of the outer membrane and an important virulence factor of salmonella enterica subspecies 1 serovar typhimurium (serovar typhimurium). to evaluate the role of lps in eliciting intestinal inflammation in streptomycin-treated mice, we constructed an o-antigen-deficient serovar typhimurium strain through deletion of the wbap gene. the resulting strain was highly susceptible to human complement activity and the antimicrobial peptide mimic polymyxin b. ... | 2009 | 19364844 |
| relative transport behavior of escherichia coli o157:h7 and salmonella enterica serovar pullorum in packed bed column systems: influence of solution chemistry and cell concentration. | the influence of solution chemistry and cell concentration on bacterial transport has been examined using salmonella pullorum sa1685 and escherichia coli o157:h7. a column was employed to determine the transport behavior and deposition kinetics with aquifer sand over a range of ionic strengths and cell concentrations. o157:h7 was found to be more adhesive than sa1685, with calculated deposition rate coefficients higher than those of sa1685. comprehensive cell surface characterization techniques ... | 2009 | 19368180 |
| identification of resistance and virulence factors in an epidemic enterobacter hormaechei outbreak strain. | bacterial strains differ in their ability to cause hospital outbreaks. using comparative genomic hybridization, enterobacter cloacae complex isolates were studied to identify genetic markers specific for enterobacter cloacae complex outbreak strains. no outbreak-specific genes were found that were common in all investigated outbreak strains. therefore, the aim of our study was to identify specific genetic markers for an enterobacter hormaechei outbreak strain (ehos) that caused a nationwide outb ... | 2009 | 19372158 |
| [active efflux as the multidrug resistance mechanism]. | active efflux is a common resistance mechanism in a wide range of bacterial pathogens. it is responsible for the transport of such toxic compounds as drugs, toxins, and detergents. pumps with broad substrate profiles promote the emergence of multidrug-resistant bacterial pathogens that are a particular threat to contemporary medicine, such as pseudomonas aeruginosa, escherichia coli, staphylococcus aureus, and salmonella enterica sv typhimurium. one can distinguish five major class of transport ... | 2009 | 19373193 |
| genetic basis of multidrug resistance in salmonella enterica serovars enteritidis and typhimurium isolated from diarrheic calves in egypt. | up to this date, nothing is known about the molecular basis of antimicrobial resistance in salmonella isolated from animals in africa. therefore, this study was carried out to screen the incidence of multidrug-resistant (mdr) strains of salmonella from neonatal calf diarrhea in egypt and also to characterize the molecular basis of this resistance. nine unique salmonella isolates were obtained from 220 fecal samples, and six of these showed multidrug resistance phenotypes and harbored at least tw ... | 2009 | 19375408 |
| salmonella induces flagellin- and myd88-dependent migration of bacteria-capturing dendritic cells into the gut lumen. | intestinal dendritic cells (dcs) sample bacteria, such as salmonella, by extending cellular processes into the lumen to capture bacteria and shuttle them across the epithelium; however, direct evidence of bacteria-loaded dcs travelling back into the tissue is lacking. we hypothesized that sampling is paralleled by migration of dcs into the lumen prior to or following the internalization of salmonella. | 2009 | 19375423 |
| effect of long chain fatty acids on salmonella killing, superoxide and nitric oxide production by chicken macrophages. | the objective of this study was to investigate the effect of uptake of different commonly consumed long chain fatty acids on superoxide (o(2)(-)), nitric oxide (no) production, and ability to kill salmonella enterica serotype typhimurium (s. typhimurium) by chicken macrophages (hd11 cells). all the fatty acids were taken up by hd11 cells with stearic acid uptake higher than polyunsaturated fatty acids. uptake of green fluorescent protein-labeled bacteria and the viability of hd11 cells (measured ... | 2009 | 19375809 |
| prevalence and concentration of verocytotoxigenic escherichia coli, salmonella enterica and listeria monocytogenes in the beef production chain: a review. | this review examines the prevalence of three important pathogens, verocytotoxigenic escherichia coli (vtec), salmonella enterica and listeria monocytogenes, in cattle and beef from the farm to the final, ready-to-eat product. factors affecting prevalence of pathogens in the beef chain, such as the season and cattle rearing method, are examined. data from many key surveys are summarized in table form. the observed prevalence of pathogens in cattle and beef varies considerably from survey to surve ... | 2009 | 19376457 |
| mutations in flk, flgg, flha, and flhe that affect the flagellar type iii secretion specificity switch in salmonella enterica. | upon completion of the flagellar hook-basal body (hbb) structure, the flagellar type iii secretion system switches from secreting rod/hook-type to filament-type substrates. the secretion specificity switch has been reported to occur prematurely (prior to hbb completion) in flk-null mutants (p. aldridge, j. e. karlinsey, e. becker, f. f. chevance, and k. t. hughes, mol. microbiol. 60:630-643, 2006) and in distal rod gene gain-of-function mutants (flgg* mutants) that produce filamentous rod struct ... | 2009 | 19376867 |
| a role for the eal-like protein stm1344 in regulation of csgd expression and motility in salmonella enterica serovar typhimurium. | the bacterial second messenger cyclic di-gmp (c-di-gmp) regulates the transition between sessility and motility. in salmonella enterica serovar typhimurium, the expression of csgd, the regulator of multicellular rdar morphotype behavior, is a major target of c-di-gmp signaling. csgd expression is positively regulated by at least two diguanylate cyclases, ggdef domain proteins, and negatively regulated by at least four phosphodiesterases, eal domain proteins. here, we show that in contrast to eal ... | 2009 | 19376870 |
| detection of live salmonella sp. cells in produce by a taqman-based quantitative reverse transcriptase real-time pcr targeting inva mrna. | salmonella enterica contamination in foods is a significant concern for public health. when dna detection methods are used for analysis of foods, one of the major concerns is false-positive results from the detection of dead cells. to circumvent this crucial issue, a taqman quantitative real-time rt-pcr (qrt-pcr) assay with an rna internal control was developed. inva rna standards were used to determine the detection limit of this assay as well as to determine inva mrna levels in mid-exponential ... | 2009 | 19376910 |
| role of ceftiofur in selection and dissemination of blacmy-2-mediated cephalosporin resistance in salmonella enterica and commensal escherichia coli isolates from cattle. | third-generation cephalosporin resistance of salmonella and commensal escherichia coli isolates from cattle in the united states is predominantly conferred by the cephamycinase cmy-2, which inactivates beta-lactam antimicrobial drugs used to treat a wide variety of infections, including pediatric salmonellosis. the emergence and dissemination of bla(cmy-2)(-)-bearing plasmids followed and may in part be the result of selection pressure imposed by the widespread utilization of ceftiofur, a third- ... | 2009 | 19376926 |
| glucose and glycolysis are required for the successful infection of macrophages and mice by salmonella enterica serovar typhimurium. | salmonella is a widespread zoonotic enteropathogen that causes gastroenteritis and fatal typhoidal disease in mammals. during systemic infection of mice, salmonella enterica serovar typhimurium resides and replicates in macrophages within the "salmonella-containing vacuole" (scv). it is surprising that the substrates and metabolic pathways necessary for growth of s. typhimurium within the scv of macrophages have not been identified yet. to determine whether s. typhimurium utilized sugars within ... | 2009 | 19380470 |
| predictive value of clinical and laboratory findings in the diagnosis of the enteric fever. | although the definitive diagnosis of enteric fever requires the isolation of salmonella enterica serotype typhi or paratyphi, the diagnosis is usually made according to clinical and laboratory findings. there is usually a diagnostic dilemma. the aim of this study was to determine the minimum required parameters that could be valuable in the diagnosis of enteric fever. a retrospective study was performed to compare the clinical and laboratory findings in 60 patients who proved to have enteric fev ... | 2009 | 19382666 |
| b cell precursors are targets for salmonella infection. | we previously reported that, in mice, b cells are a reservoir for bacteria during salmonella infection. here, we show that, within the bone marrow, b cells and their precursors are targeted for infection by salmonella enterica serovar typhimurium. our data suggest that b cells within the bone marrow may be a bacterial niche during chronic salmonella infection. | 2009 | 19383536 |
| fimh alleles direct preferential binding of salmonella to distinct mammalian cells or to avian cells. | this study aimed to determine whether allelic variants of the fimh adhesin from salmonella enterica confer differential bacterial binding to different types of mammalian cells [murine bone marrow-derived dendritic cells (dcs) and hep-2 cells] and chicken leukocytes. although the type 1 fimbriated s. enterica serovar typhimurium strains ajb3 (sr-11 derivative) and sl1344 both aggregated yeast cells, only the former bound efficiently to dcs and hep-2 cells. type 1 fimbriae-mediated binding to dcs ... | 2009 | 19383701 |
| multilocus variable-number tandem-repeat method for typing salmonella enterica serovar newport. | in recent years, the proportion of salmonella enterica infections represented by s. enterica serovar newport has increased markedly among humans and animals. multilocus variable-number tandem-repeat analysis (mlva) has proven to be useful in discriminating other highly clonal salmonella serovars. here, we report on the development of a highly discriminatory mlva for salmonella serovar newport. | 2009 | 19386855 |
| adhesion and growth inhibitory effect of chicken egg yolk antibody (igy) on salmonella enterica serovars enteritidis and typhimurium in vitro. | the protective effects of powder preparation of egg yolk immunoglobulin y (igy), specific to salmonella enteritidis and salmonella typhimurium outer membrane proteins (omp), against these two salmonella sp. serovars were investigated in vitro in two different assays: adhesion-prevention and growth-inhibition. the adhesion-prevention assay was conducted using polarized monolayers of the human intestinal epithelial caco-2 cell line. first, the conditions of salmonella adherence to caco-2 cells wer ... | 2009 | 19388827 |
| ferrous iron-binding protein omb of salmonella enterica serovar choleraesuis promotes resistance to hydrophobic antibiotics and contributes to its virulence. | salmonella enterica serovar choleraesuis (sc) is an important enteric pathogen that causes serious systemic infections in swine and humans. to identify the genes required for resistance to antimicrobial peptides, we constructed a bank of sc transposon mutants and screened them for hypersensitivity to the cationic peptide polymyxin b. here we report one isolated polymyxin b-susceptible mutant that also exhibited increased sensitivity toward human neutrophil peptide alpha-defensin 1 (hnp-1) and hy ... | 2009 | 19389759 |
| proteomic analysis of the adaptive response of salmonella enterica serovar typhimurium to growth under anaerobic conditions. | in order to survive in the host and initiate infection, salmonella enterica needs to undergo a transition between aerobic and anaerobic growth by modulating its central metabolic pathways. in this study, a comparative analysis of the proteome of s. enterica serovar typhimurium grown in the presence or absence of oxygen was performed. the most prominent changes in expression were measured in a semiquantitative manner using difference in-gel electrophoresis (dige) to reveal the main protein factor ... | 2009 | 19389776 |
| accurate prediction of secreted substrates and identification of a conserved putative secretion signal for type iii secretion systems. | the type iii secretion system is an essential component for virulence in many gram-negative bacteria. though components of the secretion system apparatus are conserved, its substrates--effector proteins--are not. we have used a novel computational approach to confidently identify new secreted effectors by integrating protein sequence-based features, including evolutionary measures such as the pattern of homologs in a range of other organisms, g+c content, amino acid composition, and the n-termin ... | 2009 | 19390620 |
| search for salmonella spp. in ostrich productive chain of brazilian southeast region. | we analyzed ostriches from an equipped farm located in the brazilian southeast region for the presence of salmonella spp. this bacterium was investigated in 80 samples of ostrich droppings, 90 eggs, 30 samples of feed and 30 samples of droppings from rodents. additionally, at slaughter-house this bacterium was investigated in droppings, caecal content, spleen, liver and carcasses from 90 slaughtered ostriches from the studied farm. also, blood serum of those animals were harvested and submitted ... | 2009 | 19390983 |
| microbial co-habitation and lateral gene transfer: what transposases can tell us. | determining the habitat range for various microbes is not a simple, straightforward matter, as habitats interlace, microbes move between habitats, and microbial communities change over time. in this study, we explore an approach using the history of lateral gene transfer recorded in microbial genomes to begin to answer two key questions: where have you been and who have you been with? | 2009 | 19393086 |
| genotoxic activation of the environmental pollutant 3,6-dinitrobenzo[e]pyrene in salmonella typhimurium umu strains expressing human cytochrome p450 and n-acetyltransferase. | 3,6-dinitrobenzo[e]pyrene (dnbep) is a potent mutagen identified in surface soil in two metropolitan areas of japan. we investigated whether dnbep can cause genotoxicity through any metabolic activation pathway in bacteria using the parental strain salmonella enterica serovar typhimurium (s. typhimurium) ta1535/psk1002, nitroreductase (nr)-deficient strain nm1000, the o-acetyltransferase (o-at)-deficient strain nm2000, bacterial o-at-overexpressing strain nm2009, and bacterial nr- and o-at-overe ... | 2009 | 19393727 |
| population structure, origins and evolution of major salmonella enterica clones. | the genus salmonella consists of two species s. enterica and s. bongori. s. enterica has a well defined subspecies structure with seven subspecies consistently delineated by sequence variation. frequency of recombination between subspecies and within a subspecies is markedly different. subspecies i undergoes frequent recombination as demonstrated recently, demystifying the long-held belief that salmonella is a highly clonal organism. the majority of disease causing serovars are from subspecies i ... | 2009 | 19393770 |
| salmonella enterica subsp. arizonae bone and joints sepsis. a case report and literature review. | osteoarticular infections caused by salmonella enterica subsp. arizonae are rarely seen in humans but young children and immunocompromised adults are at particular risk of acquiring this bacteria. reptiles and their by-products (e.g. meat preparations or medications) are particularly likely to harbor salmonella. we report on a case of septic arthritis of the hip transmitted by a reptile in a 10-month-old child. we carry out a recall of the complex nomenclature of salmonella, a review of the lite ... | 2009 | 19395336 |
| antimicrobial efficiency of essential oil and freeze-thaw treatments against escherichia coli o157:h7 and salmonella enterica ser. enteritidis in strawberry juice. | this study investigated the antimicrobial efficiency of 3 essential oils (eos), lemongrass, cinnamon leaf, and basil, and freeze-thaw treatment, alone or in combination, against escherichia coli o157:h7 and salmonella enterica ser. enteritidis inoculated in strawberry juice stored at 7 degrees c. eo of lemongrass or cinnamon leaf at 0.1 to 2 microl/ml and freezing at -23 degrees c for 24 or 48 h followed by thawing at 7 degrees c for 4 h all showed significant antimicrobial activities (p < 0.05) ... | 2009 | 19397729 |
| a typhoid fever outbreak in a slum of south dumdum municipality, west bengal, india, 2007: evidence for foodborne and waterborne transmission. | in april 2007, a slum of south dumdum municipality, west bengal reported an increase in fever cases. we investigated to identify the agent, the source and to propose recommendations. | 2009 | 19397806 |
| [molecular subtyping of salmonella enterica serotype enteritidis in a post epidemic period]. | in the last two decades, salmonella enterica serotype enteritidis has become one of the main agents causing food borne diseases worldwide. this agent is transmitted mainly by contaminated meat and poultry. | 2009 | 19399324 |
| two site-directed mutations are required for the conversion of a sugar dehydratase into an aminotransferase. | l-colitose and d-perosamine are unusual sugars found in the o-antigens of some gram-negative bacteria such as escherichia coli, vibrio cholerae, and salmonella enterica, among others. the biosynthetic pathways for these two sugars begin with the formation of gdp-mannose from d-mannose 1-phosphate and gtp followed by the subsequent dehydration and oxidation of gdp-mannose to yield gdp-4-keto-6-deoxymannose. following the production of gdp-4-keto-6-deoxymannose, the two pathways diverge. in the ca ... | 2009 | 19402712 |
| an oral recombinant salmonella enterica serovar typhimurium mutant elicits systemic antigen-specific cd8+ t cell cytokine responses in mice. | the induction of antigen-specific cd8+ t cell cytokine responses against an attenuated, oral recombinant salmonella enterica serovar typhimurium vaccine expressing a green fluorescent protein (gfp) model antigen was investigated. a gfp expression plasmid was constructed in which the gfp gene was fused in-frame with the 5' domain of the escherichia coli beta-galactosidase alpha-gene fragment with expression under the lac promoter. groups of mice were orally immunized three times with the bacteria ... | 2009 | 19402893 |
| reduced fluoroquinolone susceptibility in salmonella enterica isolates from travelers, finland. | we tested the fluoroquinolone susceptibility of 499 salmonella enterica isolates collected from travelers returning to finland during 2003-2007. among isolates from travelers to thailand and malaysia, reduced fluoroquinolone susceptibility decreased from 65% to 22% (p = 0.002). all isolates showing nonclassical quinolone resistance were from travelers to these 2 countries. | 2009 | 19402977 |
| characterization of the enzyme aac(3)-id in a clinical isolate of salmonella enterica serovar haifa causing traveler's diarrhea. | the objective of this investigation was to identify the mechanism of decreased susceptibility to gentamicin in a salmonella clinical isolate, leading to the detection of a aminoglycoside acetyltransferase gene found in a class 1 integron. | 2009 | 19403206 |
| rfab, a galactosyltransferase, contributes to the resistance to detergent and the virulence of salmonella enterica serovar enteritidis. | in this study, a deletion mutant of rfab (deltarfab) was observed to be susceptible to sodium dodecyl sulfate and less tolerant to bile salts. in addition, pre-incubation in 10% bile salts increased bacterial tolerance to 30% bile salts. we also showed that the deltarfab mutant invaded hela cells less than the wild type and resulted in a lower ratio of intracellular bacteria. competitive infection of mice showed that the deltarfab mutant was defective in the colonization of host organs and was c ... | 2009 | 19404677 |
| the dna static curvature has a role in the regulation of the omps1 porin gene in salmonella enterica serovar typhi. | the dna static curvature has been described to play a key role as a regulatory element in the transcription process of several bacterial genes. here, the role of dna curvature in the expression of the omps1 porin gene in salmonella enterica serovar typhi is described. the web server mutacurve was used to predict mutations that diminished or restored the extent of dna curvature in the 5' regulatory region of omps1. using these predictions, curvature was diminished by site-directed mutagenesis of ... | 2009 | 19406898 |
| the global consequence of disruption of the acrab-tolc efflux pump in salmonella enterica includes reduced expression of spi-1 and other attributes required to infect the host. | the mechanisms by which rnd pumps contribute to pathogenicity are currently not understood. using the acrab-tolc system as a paradigm multidrug-resistant efflux pump and salmonella enterica serovar typhimurium as a model pathogen, we have demonstrated that acra, acrb, and tolc are each required for efficient adhesion to and invasion of epithelial cells and macrophages by salmonella in vitro. in addition, acrb and tolc are necessary for salmonella to colonize poultry. mutants lacking acra, acrb, ... | 2009 | 19411325 |
| adaptation and cross-adaptation of listeria monocytogenes and salmonella enterica to poultry decontaminants. | information on the potential for acquired reduced susceptibility of bacteria to poultry decontaminants occurring is lacking. minimal inhibitory concentrations (mics) were established for assessing the initial susceptibility and the adaptative and cross-adaptative responses of four bacterial strains (listeria monocytogenes serovar l/2a, l. monocytogenes serovar 4b, salmonella enterica serotype typhimurium, and s. enterica serotype enteritidis) to four poultry decontaminants (trisodium phosphate, ... | 2009 | 19412596 |
| evaluation of iso enrichment real-time pcr methods with internal amplification control for detection of listeria monocytogenes and salmonella enterica in fresh fruit and vegetables. | to provide with a quick method for qualitative detection, in less than three days, of salmonella enterica and listeria monocytogenes in fresh fruit and vegetables. | 2009 | 19413765 |
| a genetic analysis of in vivo selenate reduction by salmonella enterica serovar typhimurium lt2 and escherichia coli k12. | the twin-arginine transport (tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. proteins are targeted to the tat system by signal peptides containing a twin-arginine motif. in salmonella enterica serovar typhimurium and escherichia coli many tat substrates are known or predicted to bind a molybdenum cofactor in the cytoplasm prior to export. in the case of n- and s-oxide reductases, co-ordination of molybdenum cofactor insertion with prote ... | 2009 | 19415239 |