| construction and use of new cloning vectors for the rapid isolation of recombinant proteins from escherichia coli. | we describe the construction and use of two sets of vectors for the over-expression and purification of protein from escherichia coli. the set of ptev plasmids (ptev3, 4, 5) directs the synthesis of a recombinant protein with a n-terminal hexahistidine (his(6)) tag that is removable by the tobacco etch virus (tev) protease. the set of pkld plasmids (pkld66, 116) directs the synthesis of a recombinant protein that contains a n-terminal his(6) and maltose-binding protein tag in tandem, which can a ... | 2008 | 18295882 |
| yjgf is required for isoleucine biosynthesis when salmonella enterica is grown on pyruvate medium. | the yjgf/yer057c/uk114 family of proteins is conserved across the three domains of life, yet no biochemical function has been clearly defined for any member of this family. in salmonella enterica, a deletion of yjgf results in a requirement for isoleucine when the mutant strain is grown in glucose-serine or pyruvate medium. feedback inhibition of ilva is required for the curative effect of isoleucine on glucose-serine medium. on pyruvate medium, yjgf mutants are unable to synthesize enough isole ... | 2008 | 18296521 |
| microcompartments for b12-dependent 1,2-propanediol degradation provide protection from dna and cellular damage by a reactive metabolic intermediate. | salmonella enterica grows on 1,2-propanediol (1,2-pd) in a coenzyme b(12)-dependent fashion. prior studies showed that a bacterial microcompartment (mcp) is involved in this process and that an mcp-minus mutant undergoes a 20-h period of growth arrest during 1,2-pd degradation. it was previously proposed that growth arrest resulted from propionaldehyde toxicity, but no direct evidence was presented. here, high-pressure liquid chromatography analyses of culture medium were used to show that the m ... | 2008 | 18296526 |
| viability of zoonotic pathogens escherichia coli and salmonella in swine manure slurries with and without a urease inhibitor and thymol. | to determine the effects of urine, a urease inhibitor and/or an odour-reducing antimicrobial compound, on zoonotic pathogens in swine manure slurries. | 2008 | 18298450 |
| display of heterologous proteins on the surface of lactococcus lactis using the h and w domain of prtb from lactobacillus delburueckii subsp. bulgaricus as an anchoring matrix. | the aim of this study was to develop a cell-surface display system for foreign antigens on the surface of a lactococcus lactis strain using an h and w domain of prtb from lactobacillus delburueckii subsp. bulgaricus as an anchoring matrix. | 2008 | 18298534 |
| caspase-3-dependent phagocyte death during systemic salmonella enterica serovar typhimurium infection of mice. | growth of salmonella enterica in mammalian tissues results from continuous spread of bacteria to new host cells. our previous work indicated that infective s. enterica are liberated from host cells via stochastic necrotic burst independently of intracellular bacterial numbers. here we report that liver phagocytes can undergo apoptotic caspase-3-mediated cell death in vivo, with apoptosis being a rare event, more prevalent in heavily infected cells. the density-dependent apoptotic cell death is l ... | 2008 | 18298550 |
| inactivation of salmonella enterica ser. enteritidis in tomato juice by combining of high-intensity pulsed electric fields with natural antimicrobials. | the effect of high-intensity pulsed electric field (hipef) treatment (35kv/cm, 4 mus pulse length in bipolar mode without exceeding 38 degrees c) as influenced by treatment time (200, 600, and 1000 micros) and pulse frequency (100, 150, and 200 hz) for inactivating salmonella enterica ser. enteritidis inoculated in tomato juice was evaluated. similarly, the effect of combining hipef treatment with citric acid (0.5%, 1.0%, 1.5%, and 2.0%[wt/vol]) or cinnamon bark oil (0.05%, 0.10%, 0.2%, and 0.3% ... | 2008 | 18298735 |
| detection of sublethal thermal injury in salmonella enterica serotype typhimurium and listeria monocytogenes using fourier transform infrared (ft-ir) spectroscopy (4000 to 600 cm(-1)). | fourier transform infrared (ft-ir) spectroscopy (4000 to 600 cm(-1)) was utilized to detect sublethally heat-injured microorganisms: salmonella enterica serotype typhimurium atcc 14028, a gram-negative bacterium, and listeria monocytogenes atcc 19113, a gram-positive bacterium. a range of heat treatments (n= 2) at 60 degrees c were evaluated: 0d (control), 2d, 4d, 6d, and 8d using a d(60 degrees c) (s. enterica serotype typhimurium atcc 14028 = 0.30 min, l. monocytogenes atcc 19113 = 0.43 min). ... | 2008 | 18298736 |
| role of soil, crop debris, and a plant pathogen in salmonella enterica contamination of tomato plants. | in the u.s., tomatoes have become the most implicated vehicle for produce-associated salmonellosis with 12 outbreaks since 1998. although unconfirmed, trace backs suggest pre-harvest contamination with salmonella enterica. routes of tomato crop contamination by s. enterica in the absence of direct artificial inoculation have not been investigated. | 2008 | 18301739 |
| the salmonella-containing vacuole: moving with the times. | salmonella pathogenesis is dependent on its ability to invade and replicate within host cells. following invasion the bacteria remain within a modified phagosome known as the salmonella-containing vacuole (scv), within which they will survive and replicate. invasion and scv biogenesis are dependent on two type iii secretion systems, t3ss1 and t3ss2, which are used to translocate distinct cohorts of bacterial effector proteins into the host cell. elucidating the roles of individual effector prote ... | 2008 | 18304858 |
| the pdux enzyme of salmonella enterica is an l-threonine kinase used for coenzyme b12 synthesis. | here, the pdux enzyme of salmonella enterica is shown to be an l-threonine kinase used for the de novo synthesis of coenzyme b(12) and the assimilation of cobyric acid (cby). pdux with a c-terminal his tag (pdux-his(6)) was produced at high levels in escherichia coli, purified by nickel affinity chromatography, and partially characterized. (31)p nmr spectroscopy established that purified pdux-his(6) catalyzed the conversion of l-threonine and atp to l-threonine-o-3-phosphate and adp. enzyme assa ... | 2008 | 18308727 |
| small outer-membrane lipoprotein, smpa, is regulated by sigmae and has a role in cell envelope integrity and virulence of salmonella enterica serovar typhimurium. | smpa is a small outer-membrane lipoprotein that is a component of the essential yaet outer-membrane protein assembly complex. in salmonella enterica serovar typhimurium (s. typhimurium), expression of the smpa gene was shown to be directed by two promoters, smpap1 and smpap2. the more distal promoter, smpap1, is dependent upon the extracytoplasmic stress response sigma factor sigma(e). an smpa null mutant was constructed in s. typhimurium sl1344 and was shown to be more sensitive than its wild-t ... | 2008 | 18310044 |
| characterization of the periplasmic domain of motb and implications for its role in the stator assembly of the bacterial flagellar motor. | mota and motb are integral membrane proteins that form the stator complex of the proton-driven bacterial flagellar motor. the stator complex functions as a proton channel and couples proton flow with torque generation. the stator must be anchored to an appropriate place on the motor, and this is believed to occur through a putative peptidoglycan-binding (pgb) motif within the c-terminal periplasmic domain of motb. in this study, we constructed and characterized an n-terminally truncated variant ... | 2008 | 18310339 |
| identification of novel genes and pathways affecting salmonella type iii secretion system 1 using a contact-dependent hemolysis assay. | we screened 5,700 salmonella enterica serovar typhimurium mutants for defects in type iii secretion system 1 (t3ss-1)-mediated contact-dependent hemolysis to identify novel genes and pathways affecting the activity of t3ss-1. our data suggest that previously unrecognized factors such as type i fimbriae may modulate the expression, activity, or deployment of this key virulence factor. | 2008 | 18310344 |
| aro mutations in salmonella enterica cause defects in cell wall and outer membrane integrity. | in this study we characterized aro mutants of salmonella enterica serovars enteritidis and typhimurium, which are frequently used as live oral vaccines. we found that the aroa, arod, and aroc mutants were sensitive to blood serum, albumen, edta, and ovotransferrin, and this defect could be complemented by an appropriate aro gene cloned in a plasmid. subsequent microarray analysis of gene expression in the arod mutant in serovar typhimurium indicated that the reason for this sensitivity might be ... | 2008 | 18310348 |
| interactions between food-borne pathogens and protozoa isolated from lettuce and spinach. | the survival of salmonella enterica was recently shown to increase when the bacteria were sequestered in expelled food vacuoles (vesicles) of tetrahymena. because fresh produce is increasingly linked to outbreaks of enteric illness, the present investigation aimed to determine the prevalence of protozoa on spinach and lettuce and to examine their interactions with s. enterica, escherichia coli o157:h7, and listeria monocytogenes. glaucoma sp., colpoda steinii, and acanthamoeba palestinensis were ... | 2008 | 18310421 |
| leaf age as a risk factor in contamination of lettuce with escherichia coli o157:h7 and salmonella enterica. | outbreaks of escherichia coli o157:h7 infections have been linked increasingly to leafy greens, particularly to lettuce. we present here the first evidence that this enteric pathogen can multiply on the leaves of romaine lettuce plants. the increases in population size of e. coli o157:h7 in the phyllosphere of young lettuce plants ranged from 16- to 100-fold under conditions of warm temperature and the presence of free water on the leaves and varied significantly with leaf age. the population si ... | 2008 | 18310433 |
| the prpz gene cluster encoding eukaryotic-type ser/thr protein kinases and phosphatases is repressed by oxidative stress and involved in salmonella enterica serovar typhi survival in human macrophages. | the prpz gene cluster consists of three orfs coding for proteins with homology to eukaryotic-type ser/thr protein phosphatases 2c (prpz) and ser/thr protein kinases (prky and prkx). this cluster is present in the sequenced genomes of salmonella enterica serovar typhi (s. typhi) strains ty2 and ct18. this study investigated the genetic organization of this gene cluster, its regulation and its putative involvement in virulence. the three genes are transcribed as a polycistronic mrna as demonstrate ... | 2008 | 18312574 |
| role of outer membrane lipopolysaccharides in the protection of salmonella enterica serovar typhimurium from desiccation damage. | the ability to survive desiccation between hosts is often essential to the success of pathogenic bacteria. the bacterial outer membrane is both the cellular interface with hostile environments and the focus of much of the drying-induced damage. this study examined the contribution of outer membrane-associated polysaccharides to the survival of salmonella enterica serovar typhimurium in air-dried blood droplets following growth in high and low osmolarity medium and under conditions known to induc ... | 2008 | 18312578 |
| salmonella enterica serovar choleraesuis derivatives harbouring deletions in rpos and phop regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively. | live attenuated salmonella enterica strains have been extensively studied as potential vectors for the oral delivery of heterologous antigens. due to its ability to target immune cells, its specific mechanism for crossing the intestinal barrier, and its swine-restricted tropism, s. enterica subspecies enterica serovar choleraesuis (s. choleraesuis) has attracted a great deal of interest for the production of bacterial-based oral carriers specifically adapted to swine. in this study, two mutants ... | 2008 | 18313237 |
| heterologous prime-boost immunizations with different salmonella serovars for enhanced antigen-specific cd8 t-cell induction. | pre-existing anti-vector immunity can severely compromise the ability of salmonella enterica serovar typhimurium live vaccines to induce protective cd8 t-cell frequencies after type iii secretion system-mediated heterologous protein translocation in orally immunized mice. in the present study, we demonstrate that heterologous prime-boost immunizations using attenuated serovar typhimurium and serovar dublin strains for foreign antigen delivery can be employed to bypass anti-salmonella immunity re ... | 2008 | 18313813 |
| efficient immobilization and patterning of live bacterial cells. | a monolayer of live bacterial cells has been patterned onto substrates through the interaction between cfa/i fimbriae and the corresponding antibody. patterns of live bacteria have been prepared with cellular resolution on silicon and gold substrates for salmonella enterica serovar typhimurium as a model with high specificity and efficiency. the immobilized cells are capable of dividing in growth medium to form a self-sustaining bacterial monolayer on the patterned areas. interestingly, the immo ... | 2008 | 18321142 |
| characterization of salmonella enterica serovar agona slaughter isolates from the animal arm of the national antimicrobial resistance monitoring system-enteric bacteria (narms): 1997 through 2003. | a total of 499 salmonella enterica serovar agona isolates from cattle, swine, chicken, and turkey samples were assayed for antimicrobial susceptibility and subtyped using pulsed-field gel electrophoresis (pfge). salmonella agona isolates exhibited increased resistance to amoxicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, cephalothin, and chloramphenicol, and a single isolate was resistant to ceftriaxone. multiple drug resistance (mdr; resistance >or= 2 antimicrobials) was exhibited i ... | 2008 | 18321206 |
| high-throughput genotyping of salmonella enterica serovar typhi allowing geographical assignment of haplotypes and pathotypes within an urban district of jakarta, indonesia. | high-throughput epidemiological typing systems that provide phylogenetic and genotypic information are beneficial for tracking bacterial pathogens in the field. the incidence of salmonella enterica serovar typhi infection in indonesia is high and is associated with atypical phenotypic traits such as expression of the j and the z66 flagellum antigens. utilizing a high-throughput genotyping platform to investigate known nucleotide polymorphisms dispersed around the genome, we determined the haplot ... | 2008 | 18322069 |
| pyrosequencing analysis of the gyrb gene to differentiate bacteria responsible for diarrheal diseases. | pathogens causing acute diarrhea include a large variety of species from enterobacteriaceae and vibrionaceae. a method based on pyrosequencing was used here to differentiate bacteria commonly associated with diarrhea in china; the method is targeted to a partial amplicon of the gyrb gene, which encodes the b subunit of dna gyrase. twenty-eight specific polymorphic positions were identified from sequence alignment of a large sequence dataset and targeted using 17 sequencing primers. of 95 isolate ... | 2008 | 18324428 |
| ciprofloxacin-resistant salmonella enterica serotype typhimurium, china. | we characterized 44 salmonella enterica serotype typhimurium isolates from tongji hospital outpatients in wuhan, china, may 2002-october 2005. all 31 ciprofloxacin-resistant isolates were also resistant to > or = 8 other antimicrobial drugs and carried > or = 2 mutations in gyra and 1 mutation in parc. class 1 integrons were identified in 37 isolates. | 2008 | 18325271 |
| hypoxia-independent activation of hif-1 by enterobacteriaceae and their siderophores. | hypoxia inducible factor-1 (hif-1) is the key transcriptional regulator during adaptation to hypoxia. recent studies provide evidence for hif-1 activation during bacterial infections. however, molecular details of how bacteria activate hif-1 remain unclear. here, we pursued the role of bacterial siderophores in hif-1 activation during infection with enterobacteriaceae. | 2008 | 18325389 |
| chronic enteric salmonella infection in mice leads to severe and persistent intestinal fibrosis. | intestinal fibrosis and stricture formation are serious complications of crohn's disease, often requiring surgical intervention. unfortunately, the mechanisms underlying intestinal fibrosis development are poorly understood, in part because of the lack of relevant animal models. here, we present a novel murine model of severe and persistent intestinal fibrosis caused by chronic bacterial-induced colitis. | 2008 | 18325390 |
| epidemiological analysis of salmonella enterica from beef sampled in the slaughterhouse and retailers in dakar (senegal) using pulsed-field gel electrophoresis and antibiotic susceptibility testing. | seventy-eight isolates of salmonella spp. isolated from beef sampled from the official city slaughterhouse and from retailers in dakar, senegal were analyzed using serotyping, antimicrobial testing and macrorestriction profiling by pulsed-field gel electrophoresis (pfge). these analyses were done to identify clonal relationships and potential transmission routes in beef channel. xbai macrorestriction allowed defining 17 genotypes among the six main analyzed serotypes: salmonella bredeney (3 geno ... | 2008 | 18325615 |
| salmonella michigan soft tissue infection in an immunocompromised child. | a rare case of soft tissue infection due to salmonella michigan in an immunocompromised child is reported. the same organism was isolated from a tortoise kept in the home. immunocompromised patients are especially susceptible to reptile-associated salmonellosis and should be advised appropriately. | 2008 | 18326014 |
| optimization and validation of a simple method using p22::luxab bacteriophage for rapid detection of salmonella enterica serotypes a, b, and d in poultry samples. | a simple method was developed for the fast and inexpensive detection of salmonella typhimurium using a recombinant p22::luxab phage. all the steps from phage production to detection were considered. a strain of salmonella typhimurium harboring the prophage p22::luxab was grown in batch culture to produce spontaneously the recombinant bacteriophage. batch production to stationary phase was better for propagation of the phage and led to a total population of 4.3 x 10(9) (+/-4.3 x 10(9)) pfu/ml of ... | 2008 | 18326191 |
| migration of salmonella enteritidis phage type 30 through almond hulls and shells. | the ability of salmonella to migrate from an external aqueous environment through the almond hull and shell, and to colonize the kernel, was evaluated in two ways. first, the outer surface of shell halves from five varieties of almonds that differed in shell hardness were placed in contact with a suspension of salmonella enterica serovar enteritidis phage type 30 for 24 h at 24 degrees c. salmonella enteritidis was isolated from the inside of these almond shells in 46 and 100% of the samples, by ... | 2008 | 18326194 |
| class 1 integrons and salmonella genomic island 1 among salmonella enterica isolated from poultry and swine. | two hundred eleven salmonella enterica strains representing 35 serotypes isolated from healthy poultry (n=103) and swine (n=108) were used in this study. the occurrence and characteristics of class 1 integrons were investigated. salmonella genomic islands (sgis) and the horizontal transfer of integrons were assessed. one hundred eighty-six isolates (88%) were resistant to at least one antimicrobial and 140 isolates (66%) were multidrug resistant. the inti1 gene was present in 54 isolates (25.6%) ... | 2008 | 18328001 |
| crystal structure of yihs in complex with d-mannose: structural annotation of escherichia coli and salmonella enterica yihs-encoded proteins to an aldose-ketose isomerase. | the three-dimensional structure of a salmonella enterica hypothetical protein yihs is significantly similar to that of n-acyl-d-glucosamine 2-epimerase (age) with respect to a common scaffold, an alpha6/alpha6-barrel, although the function of yihs remains to be clarified. to identify the function of yihs, escherichia coli and s. enterica yihs proteins were overexpressed in e. coli, purified, and characterized. both proteins were found to show no age activity but showed cofactor-independent aldos ... | 2008 | 18328504 |
| cross-protective immunity conferred by a dna adenine methylase deficient salmonella enterica serovar typhimurium vaccine in calves challenged with salmonella serovar newport. | intensive livestock production and management systems are associated with increased fecal-oral pathogen transmission and a resultant high prevalence of multiple salmonella serovars in many large dairy farms and feedlots. thus, it is imperative to develop livestock vaccines that are capable of eliciting potent states of cross-protective immunity against a diversity of serovars of a given species. immunization with modified live salmonella enterica serovar typhimurium vaccine strains, that lack th ... | 2008 | 18329764 |
| low-level resistance to ciprofloxacin in non-typhi salmonella enterica isolated from human gastroenteritis in dakar, senegal (2004--2006). | | 2008 | 18329856 |
| rose represses std fimbrial expression in salmonella enterica serotype typhimurium. | the salmonella enterica serotype typhimurium (s. typhimurium) genome contains a large repertoire of putative fimbrial operons that remain poorly characterized because they are not expressed in vitro. in this study, insertions that induced expression of the putative stdabcd fimbrial operon were identified from a random bank of transposon mutants by screening with immuno-magnetic particles for ligand expression (simple). transposon insertions upstream of csgc and lrha or within dam, setb and stm44 ... | 2008 | 18331470 |
| nationwide surveillance of salmonella in the faeces of pigs in japan. | the prevalence of faecal carriage of salmonella in 5393 pigs reared on 218 pig farms located in 31 of 47 prefectures in japan over the period july 2003 to june 2005 was investigated. we isolated 172 strains belonging to 20 serovars and one untypable salmonella enterica from 169 pig faecal samples (3.1%) collected from 48 farms (22.0%). the most prevalent type of s. enterica was untypable o4,12:d:- which lacks phase 2 flagellar antigen, representing 29.1% (50/172) of all isolates. of 26 s. enteri ... | 2008 | 18331516 |
| intravaginal immunization of mice with recombinant salmonella enterica serovar typhimurium expressing human papillomavirus type 16 antigens as a potential route of vaccination against cervical cancer. | cervical cancer, the second leading cause of cancer deaths in women, is the consequence of high-risk human papillomavirus (hpv) infections. toward the development of therapeutic vaccines that can induce both innate and adaptive mucosal immune responses, we analyzed intravaginal (ivag) vaccine delivery of live attenuated salmonella enterica serovar typhimurium expressing hpv16l1 as a model antigen. innate immune responses were examined in cervicovaginal tissues by determining gene expression patt ... | 2008 | 18332214 |
| complete nucleotide sequence of a virulence plasmid of salmonella enterica serovar dublin and its phylogenetic relationship to the virulence plasmids of serovars choleraesuis, enteritidis and typhimurium. | the complete nucleotide sequence of pou1113 (psdvu), one of the two types of virulence plasmids of salmonella enterica serovar dublin, was determined. it contained 80 156 bp with 53.8 mol% g+c content. approximately 70 genes could be discerned. compared with pstv, the virulence plasmid of serovar typhimurium, pou1113 was shorter owing to a missing region amounting to c. 10 kb; furthermore, except for a unique 10 849-bp region, the nucleotide as well as deduced amino acid sequences of pou1113 wer ... | 2008 | 18336553 |
| recombinant attenuated salmonella enterica serovar typhimurium expressing the carboxy-terminal domain of alpha toxin from clostridium perfringens induces protective responses against necrotic enteritis in chickens. | clostridium perfringens-induced necrotic enteritis (ne) is a widespread disease in chickens that causes high mortality and reduced growth performance. traditionally, ne was controlled by the routine application of antimicrobials in the feed, a practice that currently is unpopular. consequently, there has been an increase in the occurrence of ne, and it has become a threat to the current objective of antimicrobial-free farming. the pathogenesis of ne is associated with the proliferation of c. per ... | 2008 | 18337376 |
| synergistic antitumoral effects of human telomerase reverse transcriptase-mediated dual-apoptosis-related gene vector delivered by orally attenuated salmonella enterica serovar typhimurium in murine tumor models. | salmonella enterica serovar typhimurium (s. typhimurium), a facultative anaerobe, has been reported to be capable of both selectively amplifying and expressing exogenous genes within tumors. in addition, previous studies have demonstrated that the human telomerase reverse transcriptase (htert) promoter could confine gene expression strictly to the telomerase-positive cancer cells. in the present study, we used attenuated s. typhimurium as a carrier to deliver a eukaryotic expression vector (psnh ... | 2008 | 18338832 |
| comparison of antimicrobial activity in the epidermal mucus extracts of fish. | the mucus layer on the surface of fish consists of several antimicrobial agents that provide a first line of defense against invading pathogens. to date, little is known about the antimicrobial properties of the mucus of arctic char (salvelinus alpinus), brook trout (s. fontinalis), koi carp (cyprinus carpio sub sp. koi), striped bass (morone saxatilis), haddock (melanogrammus aeglefinus) and hagfish (myxine glutinosa). the epidermal mucus samples from these fish were extracted with acidic, orga ... | 2008 | 18342561 |
| detection of salmonella enterica in food using two-step enrichment and real-time polymerase chain reaction. | a new real-time polymerase chain reaction-based method was developed for the detection of salmonella enterica in food. | 2008 | 18346136 |
| t cells help to amplify inflammatory responses induced by salmonella enterica serotype typhimurium in the intestinal mucosa. | salmonella enterica serotype typhimurium causes an acute inflammatory reaction in the ceca of streptomycin-pretreated mice. we determined global changes in gene expression elicited by serotype typhimurium in the cecal mucosa. the gene expression profile was dominated by t-cell-derived cytokines and genes whose expression is known to be induced by these cytokines. markedly increased mrna levels of genes encoding gamma interferon (ifn-gamma), interleukin-22 (il-22), and il-17 were detected by quan ... | 2008 | 18347048 |
| toll-like receptor 4 mediates an antitumor host response induced by salmonella choleraesuis. | we have shown tumor-targeting and antitumor activities of an attenuated salmonella choleraesuis in various tumor models. meanwhile, host factors, including innate and adaptive immune responses, play roles in salmonella-induced antitumor activity. toll-like receptor 4 (tlr4) is identified as a signaling receptor for lipopolysaccharide derived from gram-negative bacteria. however, the detailed mechanism of the s. choleraesuis-induced antitumor immune response via tlr4 remained uncertain. | 2008 | 18347194 |
| distribution of salmonella pathogenicity island (spi)-8 and spi-10 among different serotypes of salmonella. | many virulence phenotypes of salmonella enterica are encoded by genes located on pathogenicity islands. based on genome analysis, it is predicted that salmonella pathogenicity island (spi)-8 is restricted to salmonella serovars typhi and paratyphi a, and spi-10 to salmonella serovars typhi, paratyphi, enteritidis, dublin and gallinarum. this study was conducted to investigate the distribution of spi-8 and spi-10 among salmonella isolates from sprouts, fish, water and blood. a total of 110 salmon ... | 2008 | 18349359 |
| nitric oxide antagonizes the acid tolerance response that protects salmonella against innate gastric defenses. | reactive nitrogen species (rns) derived from dietary and salivary inorganic nitrogen oxides foment innate host defenses associated with the acidity of the stomach. the mechanisms by which these reactive species exert antimicrobial activity in the gastric lumen are, however, poorly understood. | 2008 | 18350168 |
| salmonella secreted factor l deubiquitinase of salmonella typhimurium inhibits nf-kappab, suppresses ikappabalpha ubiquitination and modulates innate immune responses. | salmonella enterica translocates virulent factors into host cells using type iii secretion systems to promote host colonization, intracellular bacterial replication and survival, and disease pathogenesis. among many effectors, the type iii secretion system encoded in salmonella pathogenicity island 2 translocates a salmonella-specific protein, designated salmonella secreted factor l (ssel), a putative virulence factor possessing deubiquitinase activity. in this study, we attempt to elucidate the ... | 2008 | 18354230 |
| cloning, expression and purification of a glycosylated form of the dna-binding protein dps from salmonella enterica typhimurium. | dps, found in many eubacterial and archaebacterial species, appears to protect cells from oxidative stress and/or nutrient-limited environment. dps has been shown to accumulate during the stationary phase, to bind to dna non-specifically, and to form a crystalline structure that compacts and protects the chromosome. our previous results have indicated that dps is glycosylated at least for a certain period of the bacterial cell physiology and this glycosylation is thought to be orchestrated by so ... | 2008 | 18358740 |
| first report of ctx-m-15 in salmonella enterica serotype kedougou recovered from an algerian hospital. | | 2008 | 18360298 |
| molecular epidemiological analysis and microbial source tracking of salmonella enterica serovars in a preharvest turkey production environment. | epidemiological studies were conducted to source track and delineate horizontal transmission pathways of salmonella serovars in a turkey production environment. salmonella enterica serovar heidelberg (n = 111), salmonella senftenberg (n = 14), salmonella muenster (n = 10), unidentifiable "roughs" (n = 5), salmonella anatum (n = 3), and salmonella worthington (n = 2) were isolated from the birds' cecal and crop contents, litter, environmental swabs, drinkers, and feed samples. these strains (n = ... | 2008 | 18361686 |
| induction of guanylate binding protein 5 by gamma interferon increases susceptibility to salmonella enterica serovar typhimurium-induced pyroptosis in raw 264.7 cells. | the regulation of caspase-1 activation in macrophages plays a central role in host defense against bacterial pathogens. the activation of caspase-1 by the detection of bacterial products through nod-like receptors leads to the secretion of mature interleukin-1beta (il-1beta) and il-18 and the induction of rapid host cell death (pyroptosis). here, we report that pyroptosis induced by salmonella enterica serovar typhimurium can be positively regulated by prior gamma interferon (ifn-gamma) stimulat ... | 2008 | 18362138 |
| regulatory and structural differences in the cu,zn-superoxide dismutases of salmonella enterica and their significance for virulence. | many of the most virulent strains of salmonella enterica produce two distinct cu,zn-superoxide dismutases (sodci and sodcii). the bacteriophage-encoded sodci enzyme makes the greater contribution to salmonella virulence. we have performed a detailed comparison of the functional, structural, and regulatory properties of the salmonella sodc enzymes. here we demonstrate that sodci and sodcii differ with regard to specific activity, protease resistance, metal affinity, and peroxidative activity, wit ... | 2008 | 18362154 |
| salmonella enterica serotype typhimurium infection causing mortality in eurasian tree sparrows (passer montanus) in hokkaido. | | 2008 | 18362416 |
| synthesis and biological activity of analogues of vanchrobactin, a siderophore from vibrio anguillarum serotype o2. | several analogues of vanchrobactin, a catechol siderophore isolated from the bacterial fish pathogen vibrio anguillarum serotype o2 strain rv22, have been synthesized. the biological evaluation of these novel compounds showed that most of them are active as siderophores, as determined by growth promotion assays using the producer strain, as well as v. anguillarum serotype o1, salmonella enterica, and erwinia chrysanthemi. these compounds also gave a positive chrome azurol-s (cas) test. on the ba ... | 2008 | 18362969 |
| cloth-based hybridization array system for the identification of antibiotic resistance genes in salmonella. | a simple macroarray system based on the use of polyester cloth as the solid phase for dna hybridization has been developed for the identification and characterization of bacteria on the basis of the presence of various virulence and toxin genes. in this approach, a multiplex polymerase chain reaction (pcr) incorporating digoxigenin-dutp is used to simultaneously amplify different marker genes, with subsequent rapid detection of the amplicons by hybridization with an array of probes immobilized o ... | 2007 | 18363231 |
| genome-based identification and molecular analyses of pathogenicity islands and genomic islands in salmonella enterica. | pathogenicity islands and genomic islands (gi) are key elements in the evolution of bacterial virulence and environmental adaptation. in salmonella enterica, salmonella pathogenicity islands ispi) confer important virulence traits; however, many of these loci have not been characterized in molecular detail. in this chapter, procedures for the identification and molecular characterization of spi and gi are described. based on genome sequence data, bioinformatics approaches allow the identificatio ... | 2007 | 18363232 |
| determination of the gene content of salmonella genomes by microarray analysis. | microarray technology provides a convenient and relatively inexpensive way of investigating the genetic content of bacterial genomes by comparative genomic hybridization. in this method, genomic dna of an unknown bacterial strain of interest and that of a closely related sequenced isolate are hybridized to the same array. hybridization signals are subsequently translated into gene absence and presence predictions for the experimental strain. our nonredundant microarray of pcr products representi ... | 2007 | 18363233 |
| amplified fragment length polymorphism analysis of salmonella enterica. | amplified fragment length polymorphism (aflp) is a powerful pcr-based fingerprinting method and has the capacity to reveal variation around the whole genome by selectively amplifying a subset of restriction fragments for comparison. the restriction fragments analyzed are small, and even mutation of 1 bp can be detected. the use of different sets of restriction enzymes or different primer combinations can generate large numbers of different aflp fingerprints. aflp is of particular value for studi ... | 2007 | 18363235 |
| applications of cell imaging in salmonella research. | salmonella enterica is a gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in both humans and warm-blooded animals. understanding the mechanisms by which salmonella induce disease has been the focus of intensive research. this has revealed that salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cel ... | 2007 | 18363239 |
| analysis of kinesin accumulation on salmonella-containing vacuoles. | salmonella enterica is an intracellular bacterial pathogen that causes gastroenteritis and typhoid fever. inside host cells, the bacterium is enclosed in a membrane bound compartment, the salmonella-containing vacuole (scv). intracellular replication of salmonella requires the translocation of effector proteins into the host cytosol. the sifa effector protein is important for the membrane stability of the scv. recently, we have shown that the salmonella sifa- mutant presents on its vacuole an im ... | 2007 | 18363240 |
| antimicrobial drug resistance in human nontyphoidal salmonella isolates in europe 2000-2004: a report from the enter-net international surveillance network. | a 5-year survey, from 2000 to 2004, of results of antimicrobial susceptibility testing for 11 antimicrobials for 134,310 isolates of nontyphoidal salmonellas from cases of human infection in 10 european countries has demonstrated an overall increase in the occurrence of resistance, from 57% to 66% over the period of study. in contrast, multiple resistance (to four or more antimicrobial drugs) has declined from 18% to 15%. the most significant increase in resistance has been to nalidixic acid (14 ... | 2008 | 18366323 |
| slc41a1 is a novel mammalian mg2+ carrier. | the molecular biology of mammalian magnesium transporters and their interrelations in cellular magnesium homeostasis are largely unknown. recently, the mouse slc41a1 protein was suggested to be a candidate magnesium transporter with channel-like properties when overexpressed in xenopus laevis oocytes. here, we demonstrate that human slc41a1 overexpressed in hek293 cells forms protein complexes and locates to the plasma membrane without, however, giving rise to any detectable magnesium currents d ... | 2008 | 18367447 |
| pcr method to identify salmonella enterica serovars typhi, paratyphi a, and paratyphi b among salmonella isolates from the blood of patients with clinical enteric fever. | pcr methodology was developed to identify salmonella enterica serovars typhi, paratyphi a, and paratyphi b. one multiplex pcr identifies serogroup d, a, and b and vi-positive strains; another confirms flagellar antigen "d," "a," or "b." blinded testing of 664 malian and chilean salmonella blood isolates demonstrated 100% sensitivity and specificity. | 2008 | 18367574 |
| salicylic acid-based poly(anhydride esters) for control of biofilm formation in salmonella enterica serovar typhimurium. | bacterial biofilms generally are more resistant to stresses as compared with free planktonic cells. therefore, the discovery of antimicrobial stress factors that have strong inhibitory effects on bacterial biofilm formation would have great impact on the food, personal care, and medical industries. | 2008 | 18373656 |
| investigating the function of rho family gtpases during salmonella/host cell interactions. | salmonella enterica comprise a family of pathogenic gram-negative bacteria that have evolved sophisticated virulence mechanisms to enter non-phagocytic cells. the entry event is the result of a carefully orchestrated modulation of rho family gtpase activity within the host cell, which in turn triggers localized remodeling of the actin cytoskeleton. these cytoskeletal rearrangements drive profuse membrane ruffling and lamellipodial extensions that envelop bacteria and trigger their internalizatio ... | 2008 | 18374162 |
| do salmonella carry spare tyres? | salmonellae are enterobacteria that have the unique ability to change their flagellar composition by switching expression among two loci that encode the major flagellin protein. this property is not available to all salmonella, but is species, subspecies and serotype specific. curiously, the subsequent loss of the second locus in some lineages of salmonella has apparently been tolerated and, indeed, has led to considerable success for some lineages. we discuss here an evolutionary model for main ... | 2008 | 18375124 |
| transferable, multiple antibiotic and mercury resistance in atlantic canadian isolates of aeromonas salmonicida subsp. salmonicida is associated with carriage of an inca/c plasmid similar to the salmonella enterica plasmid psn254. | the aim of this study was to examine the molecular basis for multiple antibiotic and mercury resistance in canadian isolates of aeromonas salmonicida subsp. salmonicida. | 2008 | 18375380 |
| a combination of cytochrome c nitrite reductase (nrfa) and flavorubredoxin (norv) protects salmonella enterica serovar typhimurium against killing by no in anoxic environments. | the enteric bacterium salmonella enterica serovar typhimurium is a pathogen that is highly adapted for both intracellular and extracellular survival in a range of oxic and anoxic environments. the cytotoxic radical nitric oxide (no) is encountered in many of these environments. protection against no may involve reductive detoxification in low-oxygen environments, and three enzymes, flavorubredoxin (norv), flavohaemoglobin (hmpa) and cytochrome c nitrite reductase (nrfa), have been shown to reduc ... | 2008 | 18375814 |
| antimicrobial resistance of salmonella enterica isolates from apparently healthy and clinically ill finishing pigs in spain. | this study was the first conducted in spain to evaluate the occurrence of antimicrobial resistance and multi-resistance in salmonella isolates recovered from finishing pigs from spanish swine farms distributed over the whole country. for this purpose, 290 salmonella isolates recovered from apparently healthy finishing pigs in a farm-based cross-sectional study and 192 salmonella isolates recovered from faecal samples of finishing pigs suffering from diarrhoea were investigated. resistance to a p ... | 2008 | 18387141 |
| longitudinal study of salmonella infection in italian farrow-to-finish swine herds. | a longitudinal study of salmonella enterica infection was carried out in five italian farrow-to-finish swine herds previously known to be infected by salmonella. five litters were randomly selected from each herd and in each litter six piglets were randomly selected and individually identified. thus, the study included 30 pigs from each farm. at weaning, individual blood samples were collected for serological examination from all selected piglets and on the same day from all sows in the farrowin ... | 2008 | 18387144 |
| a comparison of sugar indicators enables a universal high-throughput sugar-1-phosphate nucleotidyltransferase assay. | a systematic comparison of six sugar indicators for their sensitivity, specificity, cross-reactivity, and suitability in the context of crude lysates revealed para-hydroxybenzoic acid hydrazide (phbh) to be best suited for application in a plate-based phosphatase-assisted universal sugar-1-phosphate nucleotidyltransferase assay. the addition of a general phosphatase to nucleotidyltransferase reaction aliquots enabled the conversion of remaining sugar-1-phosphate to free sugar, the concentration ... | 2008 | 18387352 |
| structural investigations into the interaction of hemoglobin and part structures with bacterial endotoxins. | an understanding of details of the interaction mechanisms of bacterial endotoxins (lipopolysaccharide, lps) with the oxygen transport protein hemoglobin is still lacking, despite its high biological relevance. here, a biophysical investigation into the endotoxin:hemoglobin interaction is presented which comprises the use of various rough mutant lps as well as free lipid a; in addition to the complete hemoglobin molecule from fetal sheep extract, also the partial structure alpha-chain and the hem ... | 2008 | 18387918 |
| proteomic analysis of triclosan resistance in salmonella enterica serovar typhimurium. | the aim of this study was to determine and compare the proteomes of three triclosan-resistant mutants of salmonella enterica serovar typhimurium in order to identify proteins involved in triclosan resistance. | 2008 | 18388111 |
| triclosan resistance in salmonella enterica serovar typhimurium. | the aim of this study was to characterize the mechanisms of resistance to triclosan in salmonella enterica serovar typhimurium. | 2008 | 18388112 |
| a novel secretion pathway of salmonella enterica acts as an antivirulence modulator during salmonellosis. | salmonella spp. are gram-negative enteropathogenic bacteria that infect a variety of vertebrate hosts. like any other living organism, protein secretion is a fundamental process essential for various aspects of salmonella biology. herein we report the identification and characterization of a horizontally acquired, autonomous and previously unreported secretion pathway. in salmonella enterica serovar typhimurium, this novel secretion pathway is encoded by stm1669 and stm1668, designated zirt and ... | 2008 | 18389060 |
| an antibody microarray, in multiwell plate format, for multiplex screening of foodborne pathogenic bacteria and biomolecules. | intoxication and infection caused by foodborne pathogens are important problems worldwide, and screening tests for multiple pathogens are needed because foods may be contaminated with multiple pathogens and/or toxic metabolites. we developed a 96-well microplate, multiplex antibody microarray method to simultaneously capture and detect escherichia coli o157:h7 and salmonella enterica serovar typhimurium (s. typhimurium), as well as a biomolecule (chicken immunoglobulin g or igg employed as a pro ... | 2008 | 18389224 |
| insertion hot spot for horizontally acquired dna within a bidirectional small-rna locus in salmonella enterica. | in escherichia coli and salmonella enterica, ryea and ryeb rnas are encoded on opposite dna strands at the same locus. we present evidence indicating that the last 23 bp of the ryeb gene, corresponding to an internal portion of the ryea gene, served repeatedly as the integration site for exogenous dna during salmonella evolution and still act as an attachment site for present-day bacteriophages. interestingly, ryea sequence and expression are modified upon lysogenization. | 2008 | 18390661 |
| mobilization of the incq plasmid r300b with a chromosomal conjugation system in salmonella enterica serovar typhi. | salmonella pathogenicity island 7 (spi-7) in salmonella enterica serovar typhi appears to be related to other genomic islands. evidence suggests that spi-7 is susceptible to spontaneous circularization, loss, and transposition. here, we demonstrate that a region within spi-7 has the ability to mobilize the small incq plasmid r300b. | 2008 | 18390666 |
| down-modulation of tcr expression by salmonella enterica serovar typhimurium. | t cell-mediated adaptive immunity is required to help clear infection with the facultative intracellular bacterial pathogen salmonella enterica serovar typhimurium (s. typhimurium), yet development of t cell-mediated adaptive immunity to s. typhimurium has been described as slow and inefficient. a key step in inducing t cell-mediated adaptive immunity is t cell priming; the activation, proliferation, and differentiation of naive t cells following initial encounter with ag. we previously demonstr ... | 2008 | 18390741 |
| the innate immune response to salmonella enterica serovar typhimurium by macrophages is dependent on trem2-dap12. | macrophage recognition of salmonella enterica serovar typhimurium leads to a cascade of signaling events, including the activation of src family and syk kinases and the production of reactive oxygen species (ros), which are critical for host innate defense during early stages of bacterial infection. ros production depends on the nadph oxidase, but little is known about the innate immune receptors and proximal adapters that regulate salmonella-induced ros. herein, we demonstrate that serovar typh ... | 2008 | 18391000 |
| toll-like receptor gene expression in cecum and spleen of advanced intercross line chicks infected with salmonella enterica serovar enteritidis. | understanding the changes in host gene expression that occur with bacterial infection will help to elucidate the basis of molecular genetic control of disease resistance. the effect of infecting chicks with salmonella enterica serovar enteritidis on the rna expression level of toll-like receptor (tlr) genes, and the correlation between tlr rna expression level and bacterial burden in the cecum and spleen of young birds was studied. chicks from two advanced intercross lines were either infected o ... | 2008 | 18394716 |
| ultrafiltration-based techniques for rapid and simultaneous concentration of multiple microbe classes from 100-l tap water samples. | this study focused on ultrafiltration as a technique for simultaneously concentrating and recovering viruses, bacteria and parasites in 100-l drinking water samples. a chemical dispersant, sodium polyphosphate, and tween 80 were used to increase microbial recovery efficiencies. secondary concentration was performed to reduce sample volumes to 3-5 ml for analysis using tissue culture, microscopy, and real-time pcr and rt-pcr. at seeding levels of 100-1000 (cfu, pfu, oocysts, or particles), a "hig ... | 2008 | 18395278 |
| human-derived probiotic lactobacillus reuteri demonstrate antimicrobial activities targeting diverse enteric bacterial pathogens. | lactobacillus reuteri is a commensal-derived anaerobic probiotic that resides in the human gastrointestinal tract. l. reuteri converts glycerol into a potent broad-spectrum antimicrobial compound, reuterin, which inhibits the growth of gram-positive and gram-negative bacteria. in this study, we compared four human-derived l. reuteri isolates (atcc 55730, atcc pta 6475, atcc pta 4659 and atcc pta 5289) in their ability to produce reuterin and to inhibit the growth of different enteric pathogens i ... | 2008 | 18396068 |
| defective t-cell function leading to reduced antibody production in a kleisin-beta mutant mouse. | the recently described nessy (ncaph2nes/nes) mutant mouse strain has a defect in t-cell development caused by a mutation in the ubiquitous kleisin-beta (also known as ncaph2). kleisin-beta is a subunit of the condensin ii complex involved in chromosome condensation during mitosis. the nessy phenotype is characterized by cd44hi cd8+ peripheral t cells, 10-20% of normal thymocyte numbers and 2.5-fold fewer alphabeta t cells in the spleen compared with wild-type mice. in this study we examined the ... | 2008 | 18397266 |
| nramp1 expression by dendritic cells modulates inflammatory responses during salmonella typhimurium infection. | host resistance against salmonella enterica serovar typhimurium (s. typhimurium) is mediated by natural resistance-associated macrophage protein 1 (nramp1/slc11a1). nramp1 is critical to host defence, as mice lacking nramp1 fail to control bacterial replication and succumb to low doses of s. typhimurium. despite this crucial role, the mechanisms underlying nramp1's protective effects are unclear. dendritic cells (dcs) that sample the intestinal lumen are among the first cells encountered by s. t ... | 2008 | 18397382 |
| [multiplex real-time pcr detecting salmonella, shigella and diarrheagenic escherichia coli]. | to develop a multiplex real-time pcr for the detection of salmonella invasion protein a gene (inva), enterotoxigenic escherichia coli (etec) heat-labile i enterotoxin gene (elt), and shigella or enteroinvasive e. coli (eiec) invasive plasmid antigen h gene (ipah). | 2007 | 18399125 |
| modelling within-host spatiotemporal dynamics of invasive bacterial disease. | mechanistic determinants of bacterial growth, death, and spread within mammalian hosts cannot be fully resolved studying a single bacterial population. they are also currently poorly understood. here, we report on the application of sophisticated experimental approaches to map spatiotemporal population dynamics of bacteria during an infection. we analyzed heterogeneous traits of simultaneous infections with tagged salmonella enterica populations (wild-type isogenic tagged strains [wits]) in wild ... | 2008 | 18399718 |
| interactions of some common pathogenic bacteria with acanthamoeba polyphaga. | protozoan grazing is a major trophic pathway whereby the biomass re-enters the food web. nonetheless, not all bacteria are digested by protozoa and the number known to evade digestion, resulting in their environmental augmentation, is increasing. we investigated the interactions of bacillus cereus, enterococcus faecalis, enteropathogenic escherichia coli (epec), listeria monocytogenes, salmonella enterica serovar typhimurium, and methicillin-sensitive staphylococcus aureus (mssa), with the amoeb ... | 2008 | 18399997 |
| optimization of vi capsular polysaccharide production during growth of salmonella enterica serotype typhi ty2 in a bioreactor. | vi capsular polysaccharide is synthesized during growth of salmonella typhi ty2 and is spontaneously released from the bacterial cells into the culture medium during culture. vi production was dependent on cell growth and the greater the cell mass the greater the production of vi. using fed batch culture to optimize bacterial growth resulted is an increase in cell mass and consequently vi production. the yield of vi obtained in fed batch culture was 415 mgl(-1), which was over three times that, ... | 2008 | 18400326 |
| competition of lactobacillus paracasei with salmonella enterica for adhesion to caco-2 cells. | competition of commensal and probiotic bacteria with pathogens for adhesion and colonization is one of the important protective mechanisms of gastrointestinal tract. in this study, we examined the ability of lactobacillus paracasei to inhibit the adhesion of pathogenic salmonella enterica to human colon adenocarcinoma caco-2 cells. caco-2 cells were grown for 6 or 21 days to obtain nondifferentiated or well-differentiated cells, respectively. in adhesion experiments, bacteria were added to the c ... | 2008 | 18401442 |
| [prevalence of salmonella sp. in foods in tamaulipas, mexico, during 2005]. | to determine the prevalence of salmonella sp. in foods obtained from tamaulipas sanitary jurisdictions during 2005. | 2007 | 18402335 |
| salmonella enterica serovar typhimurium modulates p-glycoprotein in the intestinal epithelium. | studies over the last decade have shown that salmonella enterica serovar typhimurium (s. typhimurium) is able to preferentially locate to sites of tumor growth and modulate (shrink) the growth of many cancers. given this unique association between s. typhimurium and cancer cells, the objective of this study was to investigate the capacity of this microorganism to modulate the plasma membrane multidrug resistance (mdr) protein p-glycoprotein (p-gp), an atp-binding cassette transporter responsible ... | 2008 | 18403618 |
| an agonist of toll-like receptor 5 has radioprotective activity in mouse and primate models. | the toxicity of ionizing radiation is associated with massive apoptosis in radiosensitive organs. here, we investigate whether a drug that activates a signaling mechanism used by tumor cells to suppress apoptosis can protect healthy cells from the harmful effects of radiation. we studied cblb502, a polypeptide drug derived from salmonella flagellin that binds to toll-like receptor 5 (tlr5) and activates nuclear factor-kappab signaling. a single injection of cblb502 before lethal total-body irrad ... | 2008 | 18403709 |
| composition and antimicrobial activity of the essential oil of acronychia pedunculata (l.) miq. from vietnam. | the chemical composition and the antimicrobial activity of the essential oil isolated from aerial parts of acronychia pedunculata (l.) miq. from vietnam are reported. analysis was carried out by gc (ri), gc-ms and 13c nmr. thirty-four compounds were identified, accounting for 92.8% of the oil. the major constituents were alpha-pinene (57.4%) and (e)-beta-caryophyllene (13.6%). the essential oil of a. pedunculata was shown to possess a broad spectrum of antimicrobial activity against various bact ... | 2008 | 18404559 |
| evaluation of gene expression in a single antibiotic exposure-derived isolate of salmonella enterica typhimurium 14028 possessing resistance to multiple antibiotics. | antibiotics are important tools used to control infections. unfortunately, microbes can become resistant to antibiotics, which limit the drugs' usefulness for clinical and veterinary use. it is necessary to improve our understanding of mechanisms that contribute to or enhance antibiotic resistance. using nalidixic acid (na) exposure as a sole selective agent, a resistant strain of salmonella enterica typhimurium 14028 was derived (2a) that had acquired resistance to chloramphenicol, sulfisoxazol ... | 2008 | 18407759 |
| role for myosin ii in regulating positioning of salmonella-containing vacuoles and intracellular replication. | salmonella enterica serovar typhimurium grows within host cells in a permissive compartment termed the salmonella-containing vacuole (scv). these bacteria use two distinct type iii secretion systems (t3ss) to deliver virulence proteins (effectors) into cells. effectors secreted by the salmonella pathogenicity island 1 (spi-1)-encoded t3ss mediate invasion and early scv maturation steps, while those secreted by the spi-2 t3ss affect the scv at later stages postinfection. some spi-2 effectors modu ... | 2008 | 18411289 |
| multiplex pcr for differential diagnosis of emerging typhoidal pathogens directly from blood samples. | classically salmonella enterica serovar typhi (s. typhi) is associated with typhoid, a major health problem in developing countries. however, in recent years s. paratyphi a and vi-negative variants of s. typhi have emerged rapidly. we have developed a nested multiplex pcr targeting five different genes for differential diagnosis of typhoidal pathogens which has been optimized to be directly applicable on clinical blood samples. of 42 multiplex pcr-positive blood samples, 26, nine, and two were v ... | 2009 | 18413005 |
| optimal foraging predicts the ecology but not the evolution of host specialization in bacteriophages. | we explore the ability of optimal foraging theory to explain the observation among marine bacteriophages that host range appears to be negatively correlated with host abundance in the local marine environment. we modified charnov's classic diet composition model to describe the ecological dynamics of the related generalist and specialist bacteriophages phix174 and g4, and confirmed that specialist phages are ecologically favored only at high host densities. our modified model accurately predicte ... | 2008 | 18414655 |