Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| molecular analysis of inchi1 antimicrobial resistance plasmids from salmonella serovar typhi strains associated with typhoid fever. | the first outbreak of multidrug-resistant (mdr) typhoid fever in vietnam was in 1993, and by 1995 nearly 90% of cases were mdr. plasmid hcm1, sequenced in full, is an inchi1 plasmid from salmonella enterica serovar typhi strain ct18, isolated in vietnam in 1993. restriction analysis shows that phcm1 shares a restriction fragment length polymorphism (rflp) pattern with plasmids isolated from the first outbreak and 10 of 17 mdr plasmids isolated from sporadic cases occurring at the same time in vi ... | 2003 | 12936967 |
| feedstuffs as a vehicle of cattle exposure to escherichia coli o157:h7 and salmonella enterica. | feed has been reported as a vehicle for transmission of salmonella enterica in cattle and several lines of evidence suggest that feed can be a vehicle for transmitting escherichia coli o157:h7 as well. to show whether microbial contamination of feeds could contribute to the populations of s. enterica and e. coli o157:h7 on a farm, we compared isolates from feed samples to bovine fecal isolates from the same farm using pulsed-field gel electrophoresis (pfge). four of 2365 component feed samples ( ... | 2003 | 12935747 |
| the small nucleoid-binding proteins h-ns, hu, and fis affect hila expression in salmonella enterica serovar typhimurium. | hila encodes an activator of salmonella enterica serovar typhimurium virulence genes and is transcriptionally modulated by environmental conditions. we show that h-ns represses hila under low-osmolarity conditions. h-ns, hu, and fis also appear to affect the derepression of hila by hild. modulation of hila by counteracting repressing and derepressing mechanisms may allow salmonella serovar typhimurium to regulate its virulence genes in response to different situations in vivo. | 2003 | 12933899 |
| role of periplasmic peptidylprolyl isomerases in salmonella enterica serovar typhimurium virulence. | fkpa is a peptidylprolyl isomerase whose expression is regulated by the alternative sigma factor, sigma factor e (sigma(e)). in contrast to the results of a previous report, inactivation of fkpa was found to have only a minor effect on the ability of salmonella enterica serovar typhimurium to invade and survive within epithelial and macrophage cell lines and cause infection in mice. however, an effect of the fkpa mutation on serovar typhimurium virulence was seen if the mutation was combined wit ... | 2003 | 12933889 |
| unusual interaction of a lipopolysaccharide isolated from burkholderia cepacia with polymyxin b. | we have demonstrated that lipopolysaccharide (lps) obtained from burkholderia cepacia, an important opportunistic pathogen, has unique characteristics in both structure and activity. one of the structural characteristics is that the b. cepacia lps has 4-amino-4-deoxy-l-arabinose (ara4n) in its inner core region. polymyxin b (pmxb) is known to act as an lps antagonist, but lps with ara4n is suggested to be pmxb resistant by decreasing the binding capability of pmxb. interaction of b. cepacia lps ... | 2003 | 12933868 |
| role of toll-like receptor 4 in macrophage activation and tolerance during salmonella enterica serovar typhimurium infection. | toll-like receptors (tlrs) play an important role in the innate immune response, particularly in the initial interaction between the infecting microorganism and phagocytic cells, such as macrophages. we investigated the role of tlr4 during infection of primary murine peritoneal macrophages with salmonella enterica serovar typhimurium. we found that macrophages from the c3h/hej mouse strain, which carries a functionally inactive tlr4 gene, exhibit marked impairment of tumor necrosis factor alpha ... | 2003 | 12933828 |
| distribution of virulence genes in salmonella serovars isolated from man & animals. | pathogenesis of salmonellosis depends upon a large number of factors controlled by an array of genes that synergise into the actual virulence of salmonella. a study was undertaken to observe the distribution of three such genes, namely, salmonella enterotoxin (stn), salmonella enteritidis fimbrial (sef and plasmid encoded fimbrial (pef genes, among different serovars of salmonella enterica isolated from man and animals. | 2003 | 12931840 |
| spread of bacterial pathogens during preparation of freshly squeezed orange juice. | to study the potential of three bacterial pathogens to cross-contaminate orange juice during extraction, normal operation conditions during juice preparation at food service establishments were simulated. the spread of salmonella enterica serovar typhimurium, escherichia coli o157:h7, and listeria monocytogenes from inoculated oranges to work surfaces and to the final product was determined. the transference of these three bacterial pathogens to orange juice made from uninoculated oranges with t ... | 2003 | 12929844 |
| potential of a plant-parasitic nematode to facilitate internal contamination of tomato plants by salmonella. | the objective of this study was to determine whether tomato plants infested with a plant-parasitic nematode, meloidogne incognita, can internalize salmonella. tomato plants (lycopersicon esculentum mill. 'rutgers') were grown in soil infested with m. incognita and/or inoculated with a six-serotype mixture of salmonella enterica. m. incognita, upon wounding roots when parasitizing the tomato plant, does not result in the entry and survival of salmonella. analysis of roots, galls, stems, and leave ... | 2003 | 12929836 |
| sensitization of outer-membrane mutants of salmonella typhimurium and pseudomonas aeruginosa to antimicrobial peptides under high pressure. | high pressure can sensitize gram-negative bacteria to antimicrobial peptides or proteins through the permeabilization of their outer membranes; however, the range of compounds to which sensitivity is induced is species and strain dependent. we studied the role of outer-membrane properties in this sensitization by making use of a series of rough and deep rough mutants of salmonella enterica serovar typhimurium that show an increased degree of lipopolysaccharide (lps) truncation, along with pseudo ... | 2003 | 12929820 |
| competitive exclusion of salmonella from the gut of neonatal and weaned pigs. | our laboratory has developed a bacterial competitive-exclusion (ce) culture against enteropathogens (which are considered human foodborne pathogens) for use in swine. in this article, we document the effects of this ce culture, pcf1, on cecal colonization by and fecal shedding of salmonella choleraesuis in neonatal and weaned pigs and its effects on the horizontal transmission of this pathogen between weaned penmates. piglets treated with the pcf1 culture twice within their first day of life and ... | 2003 | 12929819 |
| dynamics of bacterial growth and distribution within the liver during salmonella infection. | salmonella enterica causes severe systemic diseases in humans and animals and grows intracellularly within discrete tissue foci that become pathological lesions. because of its lifestyle salmonella is a superb model for studying the in vivo dynamics of bacterial distribution. using multicolour fluorescence microscopy in the mouse typhoid model we have studied the interaction between different bacterial populations in the same host as well as the dynamic evolution of foci of infection in relation ... | 2003 | 12925129 |
| role for salmonella enterica enterobacterial common antigen in bile resistance and virulence. | passage through the digestive tract exposes salmonella enterica to high concentrations of bile salts, powerful detergents that disrupt biological membranes. mutations in the wecd or weca gene, both of which are involved in the synthesis of enterobacterial common antigen (eca), render s. enterica serovar typhimurium sensitive to the bile salt deoxycholate. competitive infectivity analysis of wecd and weca mutants in the mouse model indicates that eca is an important virulence factor for oral infe ... | 2003 | 12923112 |
| thin pilus pilv adhesins of plasmid r64 recognize specific structures of the lipopolysaccharide molecules of recipient cells. | inci1 plasmid r64 encodes a type iv pilus called a thin pilus, which includes pilv adhesins. seven different sequences for the c-terminal segments of pilv adhesins can be produced by shufflon dna rearrangement. the expression of the seven pilv adhesins determines the recipient specificity in liquid matings of plasmid r64. salmonella enterica serovar typhimurium lt2 was recognized by the pilva' and pilvb' adhesins, while escherichia coli k-12 was recognized by the pilva', pilvc, and pilvc' adhesi ... | 2003 | 12923092 |
| the sopephi phage integrates into the ssra gene of salmonella enterica serovar typhimurium a36 and is closely related to the fels-2 prophage. | salmonella spp. are enteropathogenic gram-negative bacteria that use a large array of virulence factors to colonize the host, manipulate host cells, and resist the host's defense mechanisms. even closely related salmonella strains have different repertoires of virulence factors. bacteriophages contribute substantially to this diversity. there is increasing evidence that the reassortment of virulence factor repertoires by converting phages like the gifsy phages and sopephi may represent an import ... | 2003 | 12923091 |
| anthranilate synthase can generate sufficient phosphoribosyl amine for thiamine synthesis in salmonella enterica. | in bacteria, the biosynthetic pathway for the hydroxymethyl pyrimidine moiety of thiamine shares metabolic intermediates with purine biosynthesis. the two pathways branch after the compound aminoimidazole ribotide. past work has shown that the first common metabolite, phosphoribosyl amine (pra), can be generated in the absence of the first enzyme in purine biosynthesis, purf. purf-independent pra synthesis is dependent on both strain background and growth conditions. standard genetic approaches ... | 2003 | 12923085 |
| rtsa and rtsb coordinately regulate expression of the invasion and flagellar genes in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium encounters numerous host environments and defense mechanisms during the infection process. the bacterium responds by tightly regulating the expression of virulence genes. we identified two regulatory proteins, termed rtsa and rtsb, which are encoded in an operon located on an island integrated at trna(pheu) in s. enterica serovar typhimurium. rtsa belongs to the arac/xyls family of regulators, and rtsb is a helix-turn-helix dna binding protein. in a random ... | 2003 | 12923082 |
| protein content of polyhedral organelles involved in coenzyme b12-dependent degradation of 1,2-propanediol in salmonella enterica serovar typhimurium lt2. | salmonella enterica forms polyhedral organelles during coenzyme b(12)-dependent growth on 1,2-propanediol (1,2-pd). previously, these organelles were shown to consist of a protein shell partly composed of the pdua protein, the majority of the cell's b(12)-dependent diol dehydratase, and additional unidentified proteins. in this report, the polyhedral organelles involved in b(12)-dependent 1,2-pd degradation by s. enterica were purified by a combination of detergent extraction and differential an ... | 2003 | 12923081 |
| composition, acquisition, and distribution of the vi exopolysaccharide-encoding salmonella enterica pathogenicity island spi-7. | vi capsular polysaccharide production is encoded by the viab locus, which has a limited distribution in salmonella enterica serovars. in s. enterica serovar typhi, viab is encoded on a 134-kb pathogenicity island known as spi-7 that is located between partially duplicated trna(pheu) sites. functional and bioinformatic analysis suggests that spi-7 has a mosaic structure and may have evolved as a consequence of several independent insertion events. analysis of viab-associated dna in vi-positive s. ... | 2003 | 12923078 |
| plasmid-mediated antimicrobial resistance in salmonella enterica. | the selective pressure imposed by the use of antimicrobials in both human and veterinary medicine promotes the spread of multiple antimicrobial resistance. the dissemination of antimicrobial resistance in salmonella enterica strains, causing severe enteritis in human, has been reported worldwide and is largely attributed to conjugative dna exchange. in the present review, the relevance of plasmids to the dissemination of antimicrobial resistance in s. enterica is discussed. recent examples of pl ... | 2003 | 12921226 |
| aflp analysis of salmonella enterica serovar typhimurium isolates of phage types dt 9 and dt 135: diversity within phage types and its epidemiological significance. | amplified fragment length polymorphism (aflp) was applied to 35 and 34 isolates, respectively, of salmonella enterica serovar typhimurium phage types dt 9 and dt 135, using eight primer pair combinations. eight and 17 aflp types were observed in dt 9 and dt 135, respectively. dt 9 is rare in the uk and common in australia, but one aflp form dominated with 28 isolates, comprising 22 of 25 uk isolates, four of five australian isolates, one jamaican and one spanish isolate. of the others, two uk is ... | 2003 | 12919852 |
| clinical coccidiosis in a boar stud. | this report describes an outbreak of coccidiosis in a boar stud. a live, untreated, adult boar with a history of diarrhea was submitted to the iowa state university veterinary diagnostic laboratory, ames, ia. for a 3-month period, approximately 40% of the boars in this stud had developed gray to brown diarrhea that lasted 1-3 days. affected boars did not lose condition, and antibiotic therapy did not appear to affect the clinical course ofthe disease. at necropsy, the distal ileum was palpably t ... | 2003 | 12918824 |
| comparison of phenotypic traits and genetic relatedness of salmonella enterica subspecies arizonae isolates from a colony of ridgenose rattlesnakes with osteomyelitis. | reptiles are well-known sources of human salmonella infections; however, little is known about the ability of salmonella to cause disease in reptiles. thirty-seven isolates of salmonella enterica subspecies arizonae (s. arizonae) were obtained from retrospective and prospective studies of a closed colony of ridgenose rattlesnakes (crotalus willardi) with osteomyelitis. all isolates (n = 7) from bone lesions were of a single serotype, 56:z4,z23, and this serotype was found on only 1 occasion amon ... | 2003 | 12918823 |
| activity of faropenem and imipenem for ciprofloxacin-resistant bacteria. | to determine whether an association exists between ciprofloxacin and faropenem resistance in bacteria including multiply drug-resistant isolates. | 2003 | 12917244 |
| taking possession: biogenesis of the salmonella-containing vacuole. | the gram-negative pathogen salmonella enterica can survive and replicate within a variety of mammalian cells. regardless of the cell type, internalized bacteria survive and replicate within the salmonella-containing vacuole, the biogenesis of which is dependent on bacterially encoded virulence factors. in particular, type iii secretion systems translocate bacterial effector proteins into the eukaryotic cell where they can specifically interact with a variety of targets. salmonella has two distin ... | 2003 | 12911813 |
| metabiosis of proteolytic moulds and salmonella in raw, ripe tomatoes. | the aim of this study was to determine the survival and growth characteristics of salmonella enterica in sound and chill-injured tomatoes as influenced by co-infection with proteolytic moulds. | 2003 | 12911690 |
| simple and rapid detection of salmonella strains by direct pcr amplification of the hila gene. | the suitability of a pcr procedure using a pair of primers targeting the hila gene was evaluated as a means of detecting salmonella species. a total of 33 salmonella strains from 27 serovars and 15 non-salmonella strains from eight different genera were included. pcr with all the salmonella strains produced a 784 bp dna fragment that was absent from all the non-salmonella strains tested. the detection limit of the pcr was 100 pg with genomic dna and 3 x 10(4) c.f.u. ml(-1) with serial dilutions ... | 2003 | 12909653 |
| anaerobiosis-induced virulence of salmonella enterica subsp. enterica serovar typhimurium: role of phospholipase cgamma signalling cascade. | salmonella enterica subsp. enterica serovar typhimurium (s. typhimurium) can initiate entry into non-phagocytic epithelial cells by triggering certain signal transduction pathways, thereby allowing the pathogen to invade and establish a niche within host cells. anaerobiosis has been shown to be an important inducer of the invasion process of s. typhimurium. however, the effect of anaerobiosis on modulation of cell signalling cascades by s. typhimurium is not known. in the present study, the phos ... | 2003 | 12909648 |
| typing of salmonella enterica subsp. enterica serovars choleraesuis, typhimurium, dublin and laboratory strains of escherichia coli using subtracted restriction fingerprinting (srf). | the aim of the present study was to evaluate the usefulness of a new typing technique called subtracted restriction fingerprinting (srf) for bacterial strain and isolate discrimination. the technique was applied to isolates of salmonella enterica subsp. enterica (s.) serovars choleraesuis, typhimurium, dublin and to two laboratory strains of e. coli. srf is based on the selective removal of excess fragments from a restriction digest using magnetic particles. subsequently, the remaining subset of ... | 2003 | 12906386 |
| clinical review of nontyphoid salmonella infections from 1991 to 1999 in a danish county. | to determine outcomes of nontyphoid salmonella infections, we reviewed all 3328 cases of infection registered in a large danish county from 1991 to 1999. the hospitalization rate was 27% among patients <5 years old, 22% among patients 5-59 years old, and 54% among patients > or =60 years old; complications were present in 7% and extraintestinal disease in 4% of patients. we conclude that nontyphoid salmonella infections may frequently cause severe disease even among patients without predisposing ... | 2003 | 12905152 |
| effect of edta on salmonella enterica serovar typhimurium involves a component not assignable to lipopolysaccharide release. | the effect of edta on salmonella enterica serovar typhimurium was studied in different growth phases with cells grown with or without ca(2+) and mg(2+) supplementation. edta affected the outer membrane much more strongly in the early exponential phase than in the mid- or late exponential phase, as indicated by uptake of 1-n-phenylnaphthylamine (a nonpolar hydrophobic probe, m(r) 219), and detergent (sds) susceptibility. this effect was, however, not paralleled by lps release (determined by measu ... | 2003 | 12904541 |
| failure to detect salmonella enterica serovar dublin on aes laboratoire salmonella agar plate. | 2003 | 12904443 | |
| differences in gene content among salmonella enterica serovar typhi isolates. | we used a nonredundant microarray of the salmonella enterica serovar typhimurium lt2 and typhi ct18 genomes to assess the genomic content of a diverse set of isolates of serovar typhi. comparative genomic hybridization revealed 13 regions of absent or divergent gene content in the eight typhi strains examined compared to typhi ct18. in particular, two typhi ct18 prophage regions, sty1048 to sty1077 and sty2038 to sty2077, as well as a five-gene islet (sty3188 to sty3193) were absent or divergent ... | 2003 | 12904395 |
| antimicrobial susceptibilities of salmonella strains isolated from humans, cattle, pigs, and chickens in the netherlands from 1984 to 2001. | we monitored antimicrobial susceptibility data for salmonella strains isolated from humans, cattle, pigs, and chickens in the netherlands from 1984 to 2001 in order to provide insight into the dynamics of resistance over time. the strains were tested for their susceptibilities to seven antimicrobial agents by the agar diffusion method. resistance was most common in salmonella enterica subsp. enterica serovar typhimurium. among the strains from humans, pigs, and chickens, it was found that the le ... | 2003 | 12904357 |
| reduction of experimental salmonella and campylobacter contamination of chicken skin by application of lytic bacteriophages. | lytic bacteriophages, applied to chicken skin that had been experimentally contaminated with salmonella enterica serovar enteritidis or campylobacter jejuni at a multiplicity of infection (moi) of 1, increased in titer and reduced the pathogen numbers by less than 1 log(10) unit. phages applied at a moi of 100 to 1,000 rapidly reduced the recoverable bacterial numbers by up to 2 log(10) units over 48 h. when the level of salmonella contamination was low (< log(10) 2 per unit area of skin) and th ... | 2003 | 12902308 |
| colonization of arabidopsis thaliana with salmonella enterica and enterohemorrhagic escherichia coli o157:h7 and competition by enterobacter asburiae. | enteric pathogens, such as salmonella enterica and escherichia coli o157:h7, have been shown to contaminate fresh produce. under appropriate conditions, these bacteria will grow on and invade the plant tissue. we have developed arabidopsis thaliana (thale cress) as a model system with the intention of studying plant responses to human pathogens. under sterile conditions and at 100% humidity, s. enterica serovar newport and e. coli o157:h7 grew to 10(9) cfu g(-1) on a. thaliana roots and to 2 x 1 ... | 2003 | 12902287 |
| survival of salmonella enterica in freshwater and sediments and transmission by the aquatic midge chironomus tentans (chironomidae: diptera). | survival of a nalidixic acid-resistant strain of salmonella enterica serovar typhimurium mr-dt-104 in water and sediments was tested using artificially contaminated aquaria. water samples remained culture positive for salmonella for up to 54 days. sediment samples were culture positive up to 119 days. in addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. we evaluated the acquisition of mr-dt-104 by chironomids from contaminate ... | 2003 | 12902242 |
| preslaughter holding environment in pork plants is highly contaminated with salmonella enterica. | the objective of this study was to determine whether abattoir pens can provide a salmonella enterica infection source during the 2 to 4 h of preharvest holding. previous work has suggested that pigs may be getting infected, but little has been reported on the environmental contamination of abattoir holding pens. for 24 groups of pigs studied ( approximately 150 animals/group) at two high-capacity abattoirs, six pooled fecal samples (n, 10 per pool) were collected from each transport trailer imme ... | 2003 | 12902233 |
| characterization of the rpos status of clinical isolates of salmonella enterica. | the stationary-phase-inducible sigma factor, sigma(s) (rpos), is the master regulator of the general stress response in salmonella and is required for virulence in mice. rpos mutants can frequently be isolated from highly passaged laboratory strains of salmonella: we examined the rpos status of 116 human clinical isolates of salmonella, including 41 salmonella enterica serotype typhi strains isolated from blood, 38 s. enterica serotype typhimurium strains isolated from blood, and 37 salmonella s ... | 2003 | 12902215 |
| advances in the development of bacterial vector technology. | the demand for new and improved vaccines against human diseases has continued unabated over the past century. while the need continues for traditional vaccines in areas such as infectious diseases, there is an increasing demand for new therapies in nontraditional areas, such as cancer treatment, bioterrorism and food safety. prompted by these changes, there has been a renewed interest in the application and development of live, attenuated bacteria expressing foreign antigens as vaccines. the app ... | 2003 | 12901595 |
| longitudinal serological responses to salmonella enterica of growing pigs in a subclinically infected herd. | a longitudinal survey was conducted in france in a subclinically salmonella-infected farrow-to-finish pig farm to describe the time-course of the serological response to salmonella enterica in growing pigs. we used three batches of sows and their corresponding litters (n = 31 litters). among these, 256 pigs randomly selected and individually identified were followed from the first week of age until slaughter. serial individual blood samples were submitted to indirect salmonella-elisa testing. sa ... | 2003 | 12900159 |
| the agreement in isolation of salmonella enterica iiib 61:k:1,5,(7) from rectal swabs, faecal samples and ileo-caecal lymph nodes from sheep. | the agreements between various culturing-method combinations and specimens to detect sheep naturally infected by salmonella enterica iiib 61:k:1,5,(7) were tested. rectal swabs, faecal samples and ileo-caecal lymph nodes were collected from each individual. rectal swabs called "group i" (n = 54) were cultured directly on selective media (selenite cysteine, sc). rectal swabs called "group ii" (n = 47) were pre-incubated in buffered peptone water. the four other combinations of culturing-method an ... | 2003 | 12900156 |
| single versus double testing of meat-juice samples for salmonella antibodies, in the danish pig-herd surveillance programme. | in denmark, a national serological surveillance-and-control programme for salmonella in pigs has been in operation since 1995. the programme is based on the danish mix-elisa and uses double testing (two elisa-wells used per sample) of meat-juice samples taken in relation to slaughter. all herds are classified monthly into one of the three levels; the classification is based on the percentage of positive serological results in the previous 3 months. in connection with evaluation of the programme ... | 2003 | 12900155 |
| the gyr genes of salmonella enterica serovar typhimurium are repressed by the factor for inversion stimulation, fis. | the dna sequence of the gyr genes from salmonella enterica serovar typhimurium revealed strong similarity between gyrb and its counterpart in escherichia coli. however, the gyra gene showed similarity to the e. coli homologue only downstream from the pribnow box of the promoter, with the sequence upstream diverging markedly. since this region encompasses the binding sites for the fis dna binding protein in e. coli, we investigated the possibility that the gyra genes in the two species might diff ... | 2003 | 12898222 |
| a burkholderia pseudomallei type iii secreted protein, bope, facilitates bacterial invasion of epithelial cells and exhibits guanine nucleotide exchange factor activity. | we report the characterization of bope, a type iii secreted protein that is encoded adjacent to the burkholderia pseudomallei bsa locus and is homologous to salmonella enterica sope/sope2. inactivation of bope impaired bacterial entry into hela cells, indicating that bope facilitates invasion. consistent with this notion, bope expressed in eukaryotic cells induced rearrangements in the subcortical actin cytoskeleton, and purified bope exhibited guanine nucleotide exchange factor activity for cdc ... | 2003 | 12897019 |
| genomic profiling of iron-responsive genes in salmonella enterica serovar typhimurium by high-throughput screening of a random promoter library. | the importance of iron to bacteria is shown by the presence of numerous iron-scavenging and transport systems and by many genes whose expression is tightly regulated by iron availability. we have taken a global approach to gene expression analysis of salmonella enterica serovar typhimurium in response to iron by combining efficient, high-throughput methods with sensitive, luminescent reporting of gene expression using a random promoter library. real-time expression profiles of the library were g ... | 2003 | 12897017 |
| residues c123 and d58 of the 2-methylisocitrate lyase (prpb) enzyme of salmonella enterica are essential for catalysis. | the prpb gene of salmonella enterica serovar typhimurium lt2 encodes a protein with 2-methylisocitrate (2-mic) lyase activity, which cleaves 2-mic into pyruvate and succinate during the conversion of propionate to pyruvate via the 2-methylcitric acid cycle. this paper reports the isolation and kinetic characterization of wild-type and five mutant prpb proteins. wild-type prpb protein had a molecular mass of approximately 32 kda per subunit, and the biologically active enzyme was comprised of fou ... | 2003 | 12897003 |
| dape can function as an aspartyl peptidase in the presence of mn2+. | extracts of a multiply peptidase-deficient (pepnabdpqte iada iaaa) salmonella enterica serovar typhimurium strain contain an aspartyl dipeptidase activity that is dependent on mn(2+). purification of this activity followed by n-terminal sequencing of the protein suggested that the mn(2+)-dependent peptidase is dape (n-succinyl-l,l-diaminopimelate desuccinylase). a dape chromosomal disruption was constructed and transduced into a multiply peptidase-deficient (mpd) strain. crude extracts of this s ... | 2003 | 12896993 |
| msdna-st85, a multicopy single-stranded dna isolated from salmonella enterica serovar typhimurium lt2 with the genomic analysis of its retron. | bacterial reverse transcriptase is responsible for the production of a small satellite dna-rna complex called multicopy single-stranded dna (msdna) that has been found in a wide variety of gram-negative bacteria. here we describe the isolation and characterization of a novel msdna, msdna-st85, from salmonella enterica serovar typhimurium lt2. we determined the nucleotide sequence of msdna-st85 and the location of retron-st85 on the chromosome that is responsible for msdna-st85 production by anal ... | 2003 | 12892895 |
| transcription increases multiple spontaneous point mutations in salmonella enterica. | the spontaneous rate of g.c-->a.t mutations and a hotspot t.a-->g.c transversion are known to increase with the frequency of transcription-increases that have been ascribed primarily to processes that affect only these specific mutations. to investigate how transcription induces other spontaneous point mutations, we tested for its effects in repair-proficient salmonella enterica using reversion assays of chromosomally inserted alleles. our results indicate that transcription increases rates of a ... | 2003 | 12888512 |
| the effect of nitric oxide combined with fluoroquinolones against salmonella enterica serovar typhimurium in vitro. | two regulons, soxrs and marrab, are associated with resistance to quinolones or multiple antibiotic in salmonella enterica serovar typhimurium. these regulons are activated by nitric oxide and redox-cycling drugs, such as paraquat and cause on activation of the acrab-encoded efflux pump. in this study, we investigated the effect of nitric oxide (no) alone and in combination with ofloxacin, ciprofloxacin, and pefloxacin against s. typhimurium clinical isolates and mutant strains in vitro. we did ... | 2003 | 12886427 |
| antimicrobial resistance of salmonella enterica serotype typhi in dakar, senegal. | 2003 | 12884182 | |
| systemic and local cytokine response of young piglets to oral infection with salmonella enterica serotype typhimurium. | one-week-old breast-fed miniature piglets were orally infected either with virulent lt2 strain or with a non-virulent sf1591 rough mutant of salmonella typhimurium for 1 d. both microorganisms were cultivated from mesenteric lymph nodes but not from the blood of infected piglets. interleukins (il) 1 beta, 8, 18, tumor necrosis factor alpha (tnf-alpha) and interferon gamma (ifn-gamma) were quantified by elisa in plasma and washes of a terminal part of the small bowel. in plasma, cytokines were mo ... | 2003 | 12879755 |
| secreted effector proteins of salmonella enterica serotype typhimurium elicit host-specific chemokine profiles in animal models of typhoid fever and enterocolitis. | infection of bovine ligated loops with the salmonella enterica serotype typhimurium wild type but not a sipa sopabde2 mutant resulted in fluid accumulation, polymorphonuclear cell infiltration, and expression of cxc chemokines, particularly gro alpha. none of these sipa sopabde2-dependent responses was observed in murine-ligated loops. the majority of gro alpha transcripts localized to bovine intestinal epithelium. thus, different disease outcomes between mice (i.e., no diarrhea) and calves (i.e ... | 2003 | 12874363 |
| induction of antimicrobial pathways during early-phase immune response to salmonella spp. in murine macrophages: gamma interferon (ifn-gamma) and upregulation of ifn-gamma receptor alpha expression are required for nadph phagocytic oxidase gp91-stimulated oxidative burst and control of virulent salmonella spp. | the effect of gamma interferon (ifn-gamma) on elevation of reactive oxygen species and the viability of virulent wild-type and avirulent mutants of salmonella enterica serovar typhimurium and s. enterica serovar infantis was studied in a murine macrophage cell line (j774.2 cells). s. enterica serovar typhimurium 14028 phop and a rough lipopolysaccharide mutant of s. enterica serovar infantis 1326/28 (phi(r)) (avirulent mutants) induced nadph phagocytic oxidase gp91 (gp91(phox)) activity and a si ... | 2003 | 12874355 |
| construction, characterization, and immunogenicity of an attenuated salmonella enterica serovar typhimurium pgte vaccine expressing fimbriae with integrated viral epitopes from the spic promoter. | transmissible gastroenteritis virus (tgev) is a porcine coronavirus that causes diarrhea, leading to near 100% mortality in neonatal piglets with corresponding devastating economic consequences. for the protection of neonatal and older animals, oral live vaccines present the attractive property of inducing desired mucosal immune responses, including colostral antibodies in sows--an effective means to passively protect suckling piglets. newly attenuated salmonella vaccine constructs expressing tg ... | 2003 | 12874347 |
| human alveolar macrophages infected by virulent bacteria expressing sipb are a major source of active interleukin-18. | recent publications have demonstrated that the protease caspase-1 is responsible for the processing of pro-interleukin 18 (il-18) into the active form. studies on cell lines and murine macrophages have shown that the bacterial invasion factor sipb activates caspase-1, triggering cell death. thus, we investigated the role of sipb in the activation and release of il-18 in human alveolar macrophages (am), which are the first line of defense against inhaled pathogens. under steady-state conditions, ... | 2003 | 12874316 |
| evaluation of treatment and prophylaxis with nitrofurans and comparison with alternative antimicrobial agents in experimental salmonella enterica serovar enteritidis infection in chicks. | the ability of the nitrofuran antimicrobial agents furazolidone and furaltadone to prevent, reduce or eliminate salmonella enterica serovar enteritidis pt4 infection in artificially challenged day-old chicks was evaluated. treating the birds with the nitrofurans failed to eliminate established infections with either furazolidone-resistant (fzr) or furazolidone-sensitive (fzs) strains. simultaneous administration of the nitrofurans to day-old chicks challenged with fzs failed to prevent infection ... | 2003 | 12872826 |
| multiplex pcr for the direct detection of salmonella enterica from chicken, lamb and beef food products. | three sets of known salmonella enterica-specific primers were used collectively, for the first time, to evaluate the use of multiplex polymerase chain reaction (m-pcr) as a diagnostic tool to detect salmonella enterica in naturally contaminated meat and poultry products. for this purpose a total of 300 samples representing the most frequently used fresh and frozen meat (beef and lamb) and poultry (chicken) products (whole, cut, ground, and processed) were collected from eight locations within ir ... | 2003 | 12872313 |
| impact of commercial preharvest transportation and holding on the prevalence of salmonella enterica in cull sows. | the objective of this study was to examine the prevalence of salmonella enterica in cull sows at various stages from the farm to the abattoir. cull sows (n=181) were sampled over 10 weeks. fecal samples (10 g each) were collected on the farm ca. 24 h before loading and at the live-hog market ca. 3 h before loading. samples (ileocecal lymph nodes, cecal contents, feces from the transverse colon, ventral thoracic lymph nodes, subiliac lymph nodes, sponge swabs of the left and right carcass section ... | 2003 | 12870744 |
| tolerance to stress and ability of acid-adapted and non-acid-adapted salmonella enterica serovar typhimurium dt104 to invade and survive in mammalian cells in vitro. | the ability of acid-adapted (aa) and non-acid-adapted (na) salmonella enterica serovar typhimurium definitive type 104 (dt104) strains to invade and multiply in mammalian cells in vitro and to survive stress conditions was examined. dt104 and non-dt104 strains were grown in tryptic soy broth without glucose (na) or in tryptic soy broth containing 1% glucose (aa) for 18 h at 37 degrees c. the invasiveness of dt104 strains in j774a.1 macrophage and int407 intestinal cell lines was not more extensi ... | 2003 | 12870742 |
| analysis of the clonal relationship among clinical isolates of salmonella enterica serovar infantis by different typing methods. | salmonella infantis has been the second most common serovar in argentina in the last two years, being isolated mostly from paediatric hospitalised patients. in order to determine the clonal relationship among salmonella infantis strains, we examined 15 isolates from paediatric patient faeces in argentina (12 geographically related and 3 geographically non-related) by using antimicrobial susceptibility, plasmid profiling, repetitive extragenic palindromic (rep) pcr, enterobacterial repetitive int ... | 2003 | 12870059 |
| molecular epidemiology of ampicillin-resistant clinical isolates of salmonella enterica serovar typhimurium. | thirty-nine multiresistant salmonella enterica serovar typhimurium (s. typhimurium) isolates were obtained from 33 children and 6 adults hospitalized from 1996 to 1999 in the university hospital of amiens (france). s. typhimurium was cultured from stools (n=36), blood samples (n=2) and peritoneal fluid (n=1). these isolates were characterized by biotyping, antibiotic susceptibility test, rapd-pcr, and pfge typing. emergence of pentaresistant s. typhimurium isolates (phenotype acssute) was observ ... | 2003 | 12868659 |
| fitness cost of fluoroquinolone resistance in salmonella enterica serovar typhimurium. | high-level fluoroquinolone (fq) resistance is still infrequent in salmonellae, compared with other pathogenic enterobacteria. data provided in this work support the hypothesis that the mechanisms that confer high-level fq resistance on salmonellae have a prohibitive fitness cost and may thus limit the emergence of highly resistant clones. in vitro mutants that were highly resistant to ciprofloxacin (mic = 8 and 16 micro g ml(-1)) showed generation times 1.4- and 2-fold longer than their parent s ... | 2003 | 12867565 |
| an unusually high occurrence of salmonella enterica serotype paratyphi a in patients with enteric fever. | salmonella enterica serotype paratyphi a has been reported less frequently as a causative agent of enteric fever. reports on the antimicrobial susceptibility of this pathogen are few and varied. an unusually high occurrence of s. paratyphi a was noted in a tertiary care hospital at nagpur, maharashtra during april 2001-september 2002. an effort was made to study the antimicrobial susceptibility pattern and phage types of the isolates. | 2003 | 12866820 |
| catecholamines and in vitro growth of pathogenic bacteria: enhancement of growth varies greatly among bacterial species. | the purpose of this study was to examine the effects of catecholamines on in vitro growth of a range of bacterial species, including anaerobes. bacteria tested included: porphyromonas gingivalis, bacteriodes fragilis, shigella boydii, shigella sonnie, enterobacter sp, and salmonella choleraesuis. the results of the current study indicated that supplementation of bacterial cultures in minimal medium with norepinephrine or epinephrine did not result in increased growth of bacteria. positive contro ... | 2003 | 12865092 |
| current trends in typhoid fever. | typhoid fever, a systemic infection caused by salmonella enterica serotype typhi, remains an important worldwide cause of morbidity and mortality. endemic cases in the united states are unusual, with most following foreign travel to the indian subcontinent, africa, asia, or latin america. the classic findings of typhoid fever include rose spots, relative bradycardia, and stepwise fevers, but unfortunately these signs are frequently absent. gastrointestinal manifestations may include diffuse abdo ... | 2003 | 12864957 |
| salmonella type iii effectors pipb and pipb2 are targeted to detergent-resistant microdomains on internal host cell membranes. | the intracellular pathogen, salmonella enterica, translocates type iii effectors across its vacuolar membrane into host cells. herein we describe a new salmonella effector, pipb2, which has sequence similarity to another type iii effector, pipb. in phagocytic cells, pipb2 localizes to the salmonella-containing vacuole (scv) and tubular extensions from the scv, salmonella-induced filaments (sifs). we used the specific targeting of pipb2 in macrophages to characterize sifs in phagocytic cells for ... | 2003 | 12864852 |
| functions and effectors of the salmonella pathogenicity island 2 type iii secretion system. | salmonella enterica uses two functionally distinct type iii secretion systems encoded on the pathogenicity islands spi-1 and spi-2 to transfer effector proteins into host cells. a major function of the spi-1 secretion system is to enable bacterial invasion of epithelial cells and the principal role of spi-2 is to facilitate the replication of intracellular bacteria within membrane-bound salmonella-containing vacuoles (scvs). studies of mutant bacteria defective for spi-2-dependent secretion have ... | 2003 | 12864810 |
| real-time pcr duplex assay for rickettsia prowazekii and borrelia recurrentis. | rickettsia prowazekii, the etiologic agent for epidemic typhus, and borrelia recurrentis, the etiologic agent of relapsing fever, both utilize the same vector, the human body louse (pediculus humanus), to transmit human disease. we have developed an assay to detect both bacterial pathogens in a single tube utilizing real-time pcr. assays for both agents are specific. the r. prowazekii and b. recurrentis assays do not detect nucleic acid from r. typhi, r. canada, or any of eight spotted fever ric ... | 2003 | 12860643 |
| the role of mutators in the emergence of antibiotic-resistant bacteria. | bacteria contain a number of error prevention and error correction systems that maintain genome stability. however, strains exhibiting elevated mutation frequencies have recently been reported amongst natural populations of pathogenic escherichia coli, salmonella enterica, pseudomonas aeruginosa, neisseria meningitidis, helicobacter pylori and streptococcus pneumoniae. the majority of naturally occurring, strong mutators contain defects in the methyl-directed mismatch repair (mmr) system, with m ... | 2003 | 12860461 |
| intracellular expression of the salmonella plasmid virulence protein, spvb, causes apoptotic cell death in eukaryotic cells. | the spv genes carried on the salmonella virulence plasmid are commonly associated with severe systemic infection in experimental animals. the spvb virulence-associated protein has been shown to adp-ribosylate actin, and this enzymatic activity is essential for virulence in mice. here, we present evidence that intracellular expression of spvb protein induces not only disruption of actin filaments but also apoptotic cell death in eukaryotic cells. | 2003 | 12860458 |
| vaccination of mice with bacteria carrying a cloned herpesvirus genome reconstituted in vivo. | bacterial delivery systems are gaining increasing interest as potential vaccination vectors to deliver either proteins or nucleic acids for gene expression in the recipient. bacterial delivery systems for gene expression in vivo usually contain small multicopy plasmids. we have shown before that bacteria containing a herpesvirus bacterial artificial chromosome (bac) can reconstitute the virus replication cycle after cocultivation with fibroblasts in vitro. in this study we addressed the question ... | 2003 | 12857893 |
| immune responses against salmonella enterica serovar enteritidis infection in virally immunosuppressed chickens. | to understand the role of immune mechanisms in protecting chickens from salmonella infections, we examined the immune responses of salmonella enterica serovar enteritidis-infected chickens and the effect of chicken anemia virus (cav), a t-cell-targeted virus, on s. enterica serovar enteritidis-induced immune responses. one-day-old chicks were orally inoculated with s. enterica serovar enteritidis with or without intramuscular injection of cav. the bacterial infection, pathology, and immune respo ... | 2003 | 12853403 |
| adrenomedullin expression by gastric epithelial cells in response to infection. | many surface epithelial cells express adrenomedullin, a multifunctional peptide found in a wide number of body and cell systems. recently, we and others have proposed that adrenomedullin has an important novel role in host defense. this peptide has many properties in common with other cationic antimicrobial peptides, including the human beta-defensins. upon exposure of human gastric epithelial cells to viable cells of invasive or noninvasive strains of helicobacter pylori, escherichia coli, salm ... | 2003 | 12853384 |
| investigation of the distribution and control of salmonella enterica serovar enteritidis pt6 in layer breeding and egg production. | investigations were carried out in a layer breeder hatchery, a layer parent rearing farm, a layer parent farm and in a commercial pullet rearing and cage layer farm where salmonella enterica serovar enteritidis (s. enteritidis) pt6 had become established. pt6 was initially found in focal points in the hatchery, such as hatcher ventilation ducting, tray wash areas and waste areas, but improved disinfection was followed by a rapid disappearance of contamination. several different phage types of s. ... | 2003 | 12850912 |
| regional dissemination of salmonella enterica serovar enteritidis is season dependent. | to carry out epidemiological typing of clinical isolates of salmonella enterica serovar enteritidis by pulsed-field gel electrophoresis (pfge), random amplified polymorphic dna (rapd) and analysis of their antibiotic resistance. | 2003 | 12848748 |
| salmonella septicemia in rheumatoid arthritis patients receiving anti-tumor necrosis factor therapy: association with decreased interferon-gamma production and toll-like receptor 4 expression. | patients treated with antibodies to tumor necrosis factor alpha (tnfalpha) have an increased susceptibility to intracellular infections. we describe 2 patients with rheumatoid arthritis (ra) who developed salmonella septicemia during anti-tnf treatment. the aim of this study was to identify the mechanisms involved in the increased susceptibility of anti-tnf-treated patients to intracellular microorganisms. | 2003 | 12847679 |
| bacterial lipopolysaccharide signaling through toll-like receptor 4 suppresses asthma-like responses via nitric oxide synthase 2 activity. | asthma results from an intrapulmonary allergen-driven th2 response and is characterized by intermittent airway obstruction, airway hyperreactivity, and airway inflammation. an inverse association between allergic asthma and microbial infections has been observed. microbial infections could prevent allergic responses by inducing the secretion of the type 1 cytokines, il-12 and ifn-gamma. in this study, we examined whether administration of bacterial lps, a prototypic bacterial product that activa ... | 2003 | 12847273 |
| multistate outbreak of salmonella serotype typhimurium infections associated with drinking unpasteurized milk--illinois, indiana, ohio, and tennessee, 2002-2003. | on december 10, 2002, the clark county combined health district and the ohio department of health (odh) were notified of two hospitalized children infected with salmonella enterica serotype typhimurium. initial investigation implicated consumption of raw, unpasteurized milk purchased at a local combination dairy-restaurant (dairy) during november 27-december 13, 2002, as the cause. this report summarizes the subsequent investigation. because 27 states still allow the sale of raw milk, and organi ... | 2003 | 12844078 |
| molecular epidemiology and characterization of plasmid-encoded beta-lactamases produced by tunisian clinical isolates of salmonella enterica serotype mbandaka resistant to broad-spectrum cephalosporins. | we studied 31 clinical isolates of salmonella enterica serotype mbandaka resistant to broad-spectrum cephalosporins and recovered in tunisia over a 5-year period. the transferability of this resistance was demonstrated by conjugation experiments. thirty of the 31 isolates were positive in the double-disk synergy test. by isoelectric focusing analysis, all of the isolates were found to produce a band of beta-lactamase activity with a pi of 5.9. three of these isolates produced an additional band ... | 2003 | 12843024 |
| a rapid and direct real time pcr-based method for identification of salmonella spp. | the aim of this work was the validation of a rapid, real-time pcr assay based on taqman technology for the unequivocal identification of salmonella spp. to be used directly on an agar-grown colony. a real-time pcr system targeting at the salmonella spp. inva gene was optimized and validated through a four times repeated blind experiment performed in two different laboratories including 50 salmonella spp. with representative strains from each of the 5 different salmonella subgenera and 30 non-sal ... | 2003 | 12842485 |
| nontyphoidal salmonellae in united kingdom badgers: prevalence and spatial distribution. | eighteen (72%) of 25 badger social groups were found to excrete salmonella enterica serovar ried, s. enterica serovar binza, s. enterica serovar agama, or s. enterica serovar lomita. each serovar was susceptible to a panel of antimicrobials. based on results of pulsed-field gel electrophoresis, the s. enterica serovar agama and s. enterica serovar binza isolates were very similar, but two clones each of s. enterica serovar lomita and s. enterica serovar ried were found. badgers excreting s. ente ... | 2003 | 12839821 |
| use of pulsed-field gel electrophoresis to characterize the heterogeneity and clonality of salmonella isolates obtained from the carcasses and feces of swine at slaughter. | salmonella enterica isolates were recovered from swine at a collaborating processing plant over a 2-month period in the spring of 2000. in the present study, molecular subtyping by pulsed-field gel electrophoresis (pfge) was performed on the 581 confirmed salmonella isolates from the 84 salmonella-positive samples obtained from the previous study. a total of 32 different pfge pulsotypes were observed visually, and a bionumerics software analysis clustered those pulsotypes into 12 pfge groups. th ... | 2003 | 12839796 |
| ingestion of salmonella enterica serotype poona by a free-living mematode, caenorhabditis elegans, and protection against inactivation by produce sanitizers. | free-living nematodes are known to ingest food-borne pathogens and may serve as vectors to contaminate preharvest fruits and vegetables. caenorhabditis elegans was selected as a model to study the effectiveness of sanitizers in killing salmonella enterica serotype poona ingested by free-living nematodes. aqueous suspensions of adult worms that had fed on s. enterica serotype poona were treated with produce sanitizers. treatment with 20 microg of free chlorine/ml significantly (alpha = 0.05) redu ... | 2003 | 12839787 |
| optimization of a reusable hollow-fiber ultrafilter for simultaneous concentration of enteric bacteria, protozoa, and viruses from water. | the detection and identification of pathogens from water samples remain challenging due to variations in recovery rates and the cost of procedures. ultrafiltration offers the possibility to concentrate viral, bacterial, and protozoan organisms in a single process by using size-exclusion-based filtration. in this study, two hollow-fiber ultrafilters with 50,000-molecular-weight cutoffs were evaluated to concentrate microorganisms from 2- and 10-liter water samples. when known quantities (10(5) to ... | 2003 | 12839786 |
| salmonella enterica serovar typhimurium and listeria monocytogenes acid tolerance response induced by organic acids at 20 degrees c: optimization and modeling. | an acid tolerance response (atr) has been demonstrated in listeria monocytogenes and salmonella enterica serovar typhimurium in response to low ph poised (i.e., adapted) with acetic or lactic acids at 20 degrees c and modeled by using dynamic differential equations. the atr was not immediate or prolonged, and optimization occurred after exposure of l. monocytogenes for 3 h at ph 5.5 poised with acetic acid and for 2 h at ph 5.5 poised with lactic acid and after exposure of s. enterica serovar ty ... | 2003 | 12839765 |
| [in vitro susceptibility of salmonella enterica serovar typhimurium to reactive oxygen and nitrogen products]. | the aim of this study was to investigate the in-vitro susceptibility of salmonella enterica serovar typhimurium against reactive oxygen and nitrogen intermediates, on five different strains. sh5014 as a parental strain, pp120 as a soxrs mutant, sh7616 as a acrab efflux pump mutant, szh kuen 557 as a standard strain and a clinical isolate, were included to the study. hydrogen peroxide (at 0.125, 0.25, 0.5 mm concentrations) as reactive oxygen intermediate (roi) and deta-no (at 1, 2, 4 mg/ml conce ... | 2003 | 12838675 |
| structural study of binding of flagellin by toll-like receptor 5. | in order to predict the binding regions within the complex formed by toll-like receptor 5 (tlr-5) and flagellin, a complementary hydropathy between the two proteins was sought. a region common to the flagellins of salmonella enterica serovar typhimurium, pseudomonas aeruginosa, and listeria monocytogenes was shown to be hydropathically complementary to the 552-to-561 fragment of tlr-5, whose sequence is eildisrnql. the hydrophobicity profile of this region is shared with flagellins of 377 bacter ... | 2003 | 12837800 |
| in vitro and in vivo stability of recombinant plasmids in a vaccine strain of salmonella enterica var. typhimurium. | this study examined the ability of different plasmid vectors encoding h(c) fragment, the non-toxic binding portion of tetanus toxin, to be stably retained by salmonella enterica var. typhimurium (salmonella typhimurium) vaccine strain brd509 and, upon immunisation, to induce an antibody response against the carried antigen. the h(c) fragment expression cassette containing the transcription/translation signals, h(c) fragment open reading frame and the downstream trpa terminator, was excised from ... | 2003 | 12832114 |
| the role of membrane-bound lbp, endotoxin aggregates, and the maxik channel in lps-induced cell activation. | we have previously shown in patch-clamp experiments on excised outside-out cytoplasmic membrane patches from human macrophages that the activation of a high-conductance ca(2+)- and voltage-dependent potassium channel, the maxik channel, is an early step in lps-induced transmembrane signal transduction in macrophages. maxik can be activated by agonistically active lps, and activation can be completely inhibited by lps antagonists (e.g. synthetic compound 406) and by anti-cd14 antibodies. furtherm ... | 2003 | 12831460 |
| synergistic effects of lipopolysaccharide and interferon-gamma in inducing interleukin-8 production in human monocytic thp-1 cells is accompanied by up-regulation of cd14, toll-like receptor 4, md-2 and myd88 expression. | lipopolysaccharide (lps) and interferon (ifn)-gamma synergistically induced interleukin-8 (il-8) production in human monocytic thp-1 cells. ifn-gamma-primed thp-1 cells produced higher levels of il-8 on stimulation with lps than non-primed cells and the level correlated with duration of priming up to 24 h, although the level of il-8 induced was most comparable to that induced by co-stimulation with lps and ifn-gamma. unstimulated thp-1 cells were shown by flow cytometry to be practically devoid ... | 2003 | 12831455 |
| sexual transmission of typhoid fever: a multistate outbreak among men who have sex with men. | in august 2000, the ohio department of health reported a cluster of men with typhoid fever who denied having traveled abroad. to determine the cause and the extent of the outbreak, an epidemiological investigation was initiated in which 7 persons in ohio, kentucky, and indiana with culture-confirmed salmonella enterica serotype typhi infection and 2 persons with probable typhoid fever were evaluated; all were men, and all but one reported having had sex with 1 asymptomatic male s. typhi carrier. ... | 2003 | 12830419 |
| reevaluating fluoroquinolone breakpoints for salmonella enterica serotype typhi and for non-typhi salmonellae. | salmonella enterica infections cause considerable morbidity and mortality worldwide. antimicrobial therapy may be life-saving for patients with extraintestinal infections with s. enterica serotype typhi or non-typhi salmonellae. because antimicrobial resistance to several classes of traditional first-line drugs has emerged in the past several decades, the quinolone antimicrobial agents, particularly the fluoroquinolones, have become the drugs of choice. recently, resistance to nalidixic acid has ... | 2003 | 12830411 |
| inhibition of bacterial dna replication by zinc mobilization during nitrosative stress. | phagocytic cells inhibit the growth of intracellular pathogens by producing nitric oxide (no). no causes cell filamentation, induction of the sos response, and dna replication arrest in the gram-negative bacterium salmonella enterica. no also induces double-stranded chromosomal breaks in replication-arrested salmonella lacking a functional recbcd exonuclease. this dna damage depends on actions of additional dna repair proteins, the recg helicase, and ruvc endonuclease. introduction of a recg mut ... | 2003 | 12829799 |
| retron reverse transcriptase rrtt is ubiquitous in strains of salmonella enterica serovar typhimurium. | bacterial retron reverse transcriptases are unusual enzymes which utilise the same rna molecule as a template and also as a primer for initiation of the reverse transcription. except for their relatively frequent presence in myxococcus spp., they are considered as quite rare proteins. however, in this study we proved that retron reverse transcriptase is frequently found in certain serovars of salmonella enterica. using polymerase chain reaction (pcr), in strains of serovar typhimurium, the rrtt ... | 2003 | 12829299 |
| development of a novel method of lytic phage delivery by use of a bacteriophage p22 site-specific recombination system. | bacteriophage therapy represents a potential alternative to the use of antibiotics to control proliferation of pathogenic bacteria. as an alternative to the strategy where a limited number of doses of large numbers of lytic bacteriophages are administered, a novel method delivery system was developed so that phages are continually released into the culture. specifically, a non-pathogenic escherichia coli strain was constructed that was lysogenic for a lytic mutant of bacteriophage lambda. this l ... | 2003 | 12829296 |
| involvement of intestinal inducible nitric oxide synthase (inos) in the early stages of murine salmonellosis. | local induction of inducible nitric oxide synthase (inos) and apoptosis was examined in the intestine of mice infected with virulent salmonella enterica serovar enteritidis 5694 (s. enteritidis) and its attenuated derivative mutant e/1/3. both, intestinal inos mrna expression and inos activity showed a peak at 4 h only in animals receiving the virulent s. enteritidis. aminoguanidine treatment abrogated intestinal epithelial damage produced by virulent s. enteritidis and diminished apoptosis at t ... | 2003 | 12829292 |
| emerging themes in manganese transport, biochemistry and pathogenesis in bacteria. | though an essential trace element, manganese is generally accorded little importance in biology other than as a cofactor for some free radical detoxifying enzymes and in the photosynthetic photosystem ii. only a handful of other mn2+-dependent enzymes are known. recent data, primarily in bacteria, suggest that mn2+-dependent processes may have significantly greater physiological importance. two major classes of prokaryotic mn2+ uptake systems have now been described, one homologous to eukaryotic ... | 2003 | 12829271 |
| display and release of the plasmodium falciparum circumsporozoite protein using the autotransporter misl of salmonella enterica. | the salmonella enterica misl (protein of membrane insertion and secretion) is an autotransporter with high homology to aida-i (adhesin involved in diffuse adherence) of enteropathogenic escherichia coli. considering that it has been reported that the misl beta translocator domain is able to display heterologous passenger peptides to the bacterial surface, we developed a system to display proteins and release them to the external environment by means of proteolytic cleavage. plasmids were constru ... | 2003 | 12826054 |