Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| comparison of deltarela strains of escherichia coli and salmonella enterica serovar typhimurium suggests a role for ppgpp in attenuation regulation of branched-chain amino acid biosynthesis. | the growth recovery of escherichia coli k-12 and salmonella enterica serovar typhimurium deltarela mutants were compared after nutritional downshifts requiring derepression of the branched-chain amino acid pathways. because wild-type e. coli k-12 and s. enterica serovar typhimurium lt2 strains are defective in the expression of the genes encoding the branch point acetohydroxy acid synthetase ii (ilvgm) and iii (ilvih) isozymes, respectively, deltarela derivatives corrected for these mutations we ... | 2001 | 11591661 |
| formation of intermediate transcription initiation complexes at pflid and pflgm by sigma(28) rna polymerase. | the sigma subunit of prokaryotic rna polymerase is an important factor in the control of transcription initiation. primary sigma factors are essential for growth, while alternative sigma factors are activated in response to various stimuli. expression of class 3 genes during flagellum biosynthesis in salmonella enterica serovar typhimurium is dependent on the alternative sigma factor sigma(28). previously, a novel mechanism of transcription initiation at the flic promoter by sigma(28) holoenzyme ... | 2001 | 11591667 |
| structures of bacterial flagellar motors from two flif-flig gene fusion mutants. | flagella purified from salmonella enterica serovar typhimurium contain flig, flim, and flin, cytoplasmic proteins that are important in torque generation and switching, and flif, a transmembrane structural protein. the motor portion of the flagellum (the basal body complex) has a cytoplasmic c ring and a transmembrane m ring. incubation of purified basal bodies at ph 4.5 removed flim and flin but not flig or flif. these basal bodies lacked c rings but had intact m rings, suggesting that flim and ... | 2001 | 11591685 |
| effect of attenuated salmonella enterica serovar typhimurium expressing a streptococcus mutans antigen on secondary responses to the cloned protein. | attenuated salmonella enterica serovar typhimurium has been used for targeted delivery of recombinant antigens to gut- and nose-associated lymphoid tissues. contradictory reports have described the effect of preexisting immunity to the antigen delivery vehicle. we decided to examine this discrepancy by studying the effect of immunizing mice by the intranasal (i.n.) route with salmonella expressing an insoluble protein and to study the ability to augment recall responses by boosting with either s ... | 2001 | 11598028 |
| salmonella dna adenine methylase mutants confer cross-protective immunity. | salmonella isolates that lack or overproduce dna adenine methylase (dam) elicited a cross-protective immune response to different salmonella serovars. the protection afforded by the salmonella enterica serovar typhimurium dam vaccine was greater than that elicited in mice that survived a virulent infection. s. enterica serovar typhimurium dam mutant strains exhibited enhanced sensitivity to mediators of innate immunity such as antimicrobial peptides, bile salts, and hydrogen peroxide. also, s. e ... | 2001 | 11598044 |
| three-dimensional tissue assemblies: novel models for the study of salmonella enterica serovar typhimurium pathogenesis. | the lack of readily available experimental systems has limited knowledge pertaining to the development of salmonella-induced gastroenteritis and diarrheal disease in humans. we used a novel low-shear stress cell culture system developed at the national aeronautics and space administration in conjunction with cultivation of three-dimensional (3-d) aggregates of human intestinal tissue to study the infectivity of salmonella enterica serovar typhimurium for human intestinal epithelium. immunohistoc ... | 2001 | 11598087 |
| the deltauvrb mutations in the ames strains of salmonella span 15 to 119 genes. | the deltauvrb mutations present in strains of salmonella enterica typhimurium used commonly in the salmonella (ames) mutagenicity assay were isolated independently for at least five different his mutants. these deletions all involved the galactose operon, biotin operon, nucleotide-excision-repair uvrb gene, and chlorate-resistance genes. beyond this, the size of the deletions and the number and type of genes deleted have remained unknown for nearly 30 years. here, we have used genomic hybridizat ... | 2001 | 11600126 |
| clearance of infection with mycobacterium bovis bcg in mice is enhanced by treatment with s28463 (r-848), and its efficiency depends on expression of wild-type nramp1 (resistance allele). | the mouse bcg host resistance gene is known to control the activation of host macrophages for killing of intracellular parasites like leishmania donovani as well as intracellular bacteria, including mycobacterium bovis bcg and salmonella enterica serovar typhimurium. the nramp1 gene has been mapped to this locus and affects the efficiency of macrophage activation. it has been shown that imidazoquinoline compounds, including s28463, are able to improve the clearance of a number of intracellular p ... | 2001 | 11600356 |
| families of restriction enzymes: an analysis prompted by molecular and genetic data for type id restriction and modification systems. | current genetic and molecular evidence places all the known type i restriction and modification systems of escherichia coli and salmonella enterica into one of four discrete families: type ia, ib, ic or id. stysbli is the founder member of the id family. similarities of coding sequences have identified restriction systems in e.coli and klebsiella pneumoniae as probable members of the type id family. we present complementation tests that confirm the allocation of ecor9i and kpnai to the id family ... | 2001 | 11600708 |
| improving recovery of salmonella enterica serovar typhimurium dt104 cells injured by heating at different water activity values. | this study describes the evaluation of potentially more sensitive methods for the recovery of salmonella cells injured by heating (54 to 60 degrees c) at different water activity values (0.65 to 0.90, reduced using equal portions of glucose and fructose). these methods included gradual rehydration, the use of diluting media with added solutes or blood, the addition of blood to plating agar, and the use of different incubation temperatures and times. gradual rehydration of cells that had been cha ... | 2001 | 11601692 |
| efficacy of chitosan, carvacrol, and a hydrogen peroxide-based biocide against foodborne microorganisms in suspension and adhered to stainless steel. | the ability of natural compounds to inactivate foodborne organisms adhered to surfaces was investigated with the ultimate aim of replacing synthetic biocides by more environmentally friendly, natural alternatives. the antimicrobial efficacy of 0.5, 1.0, and 2.0% chitosan and spor-klenz rtu (a commercial biocide based on hydrogen peroxide and peroxyacetic acid) and 0.5, 1.25, and 2.0 mm carvacrol was determined at 20 degrees c against listeria monocytogenes, salmonella enterica serovar typhimuriu ... | 2001 | 11601703 |
| bacteremia associated with naturally occuring acute coliform mastitis in dairy cows. | to determine the incidence of bacteremia in dairy cows with naturally occurring acute coliform mastitis (acm) with a wide range of disease severity. | 2001 | 11601796 |
| transfer of eukaryotic expression plasmids to mammalian host cells by bacterial carriers. | the concept of transkingom transfer of dna from bacteria to other organisms has recently been extended to include eukaryotic host cells. intracellular bacteria have been shown to transfer eukaryotic expression plasmids to mammalian host cells in vitro and in vivo. this can be used to induce immune responses towards protein antigens encoded by the plasmid, to complement genetic defects or even to direct the production of proteins in appropriate organs. the ease of generating such vehicles makes t ... | 2001 | 11604322 |
| [multidrug-resistant and fluoroquinolone-resistant salmonella enterica serotype typhimurium definitive phage type 12 isolated from infantile diarrhea]. | a 35-day-old male infant was admitted to our hospital, presenting a high fever, vomiting, and diarrhea. multidrug-resistant and fluoroquinolon-resistant salmonella serotype typhimurium was isolated from his stool. the phage type of the strain was dt12. the strain was resistant to ampicillin, streptomycin, gentamicin, tetracycline, chloramphenicol, sulfamethoxazole-trimethoprim, and fluoroquinolones (levofloxacin; mic 8 micrograms/ml, norfloxacin; 24 micrograms/ml, ciprofloxacin; 16 micrograms/ml ... | 2001 | 11605192 |
| the isolation of antibiotic-resistant salmonella from retail ground meats. | salmonella is a leading cause of foodborne illness. the emergence of antimicrobial-resistant salmonella is associated with the use of antibiotics in animals raised for food; resistant bacteria can be transmitted to humans through foods, particularly those of animal origin. we identified and characterized strains of salmonella isolated from ground meats purchased in the washington, d.c., area. | 2001 | 11642230 |
| [five cases of gastroenteritis with multiresistant salmonella enterica serovar typhimurium dt104 related to farm animals in denmark]. | whereas the overall incidence of human salmonella infections in denmark has fallen during the past three years, the number of infections with multidrug-resistant salmonella typhimurium definitive type 104 (dt104) has risen. we report five cases of human infection with dt104 in patients living on farms, in which cattle and mixed herds of cattle and pigs were infected with dt104. transmission from the animals to the patients in the cases described is likely to have occurred. these cases emphasize ... | 2001 | 11665472 |
| [outbreak of salmonella bovismorbificans infection]. | 2001 | 11665476 | |
| in vivo expression from the rpos-dependent p1 promoter of the osmotically regulated prou operon in escherichia coli and salmonella enterica serovar typhimurium: activation by rho and hns mutations and by cold stress. | unlike the sigma(70)-controlled p2 promoter for the osmotically regulated prou operon of escherichia coli and salmonella enterica serovar typhimurium, the sigma(s)-controlled p1 promoter situated further upstream appears not to contribute to expression of the prou structural genes under ordinary growth conditions. for s. enterica prou p1, there is evidence that promoter crypticity is the result of a transcription attenuation phenomenon which is relieved by the deletion of a 22-base c-rich segmen ... | 2001 | 11673423 |
| hha is a negative modulator of transcription of hila, the salmonella enterica serovar typhimurium invasion gene transcriptional activator. | an early step in the establishment of salmonella enterica serovar typhimurium murine infection is the penetration of the intestinal mucosa of the small intestine. the majority of the genes responsible for the salmonella invasive phenotype are encoded on salmonella pathogenicity island 1, and their transcription is controlled by the hila transcriptional activator. the expression of hila is regulated by environmental signals including oxygen, osmolarity, ph, and growth phase such that the presence ... | 2001 | 11673432 |
| evolution of antibiotic resistance of non-typhoidal salmonellae in greece during 1990-97. | susceptibility to 15 antibiotics was determined in 1548 non-typhoidal salmonella strains isolated in greece from l990 to l997. the overall prevalence of resistance of both salmonella enterica serotype enteritidis and salmonella enterica serotype typhimurium increased during the first years of the study. a decrease was observed from 1996, especially for s. enteritidis, which showed the highest overall antibiotic resistance. s. typhimurium was the serotype with the highest multiresistance to antib ... | 2001 | 11673638 |
| complete genome sequence of a multiple drug resistant salmonella enterica serovar typhi ct18. | salmonella enterica serovar typhi (s. typhi) is the aetiological agent of typhoid fever, a serious invasive bacterial disease of humans with an annual global burden of approximately 16 million cases, leading to 600,000 fatalities. many s. enterica serovars actively invade the mucosal surface of the intestine but are normally contained in healthy individuals by the local immune defence mechanisms. however, s. typhi has evolved the ability to spread to the deeper tissues of humans, including liver ... | 2001 | 11677608 |
| complete genome sequence of salmonella enterica serovar typhimurium lt2. | salmonella enterica subspecies i, serovar typhimurium (s. typhimurium), is a leading cause of human gastroenteritis, and is used as a mouse model of human typhoid fever. the incidence of non-typhoid salmonellosis is increasing worldwide, causing millions of infections and many deaths in the human population each year. here we sequenced the 4,857-kilobase (kb) chromosome and 94-kb virulence plasmid of s. typhimurium strain lt2. the distribution of close homologues of s. typhimurium lt2 genes in e ... | 2001 | 11677609 |
| fluorescent amplified fragment length polymorphism genotyping of salmonella enteritidis: a method suitable for rapid outbreak recognition. | to perform fluorescent amplified fragment length polymorphism (faflp) analysis on phage type (pt) reference strains of salmonella enterica subsp. enterica serotype enteritidis (s. enteritidis), and s. enteritidis pt 6 and 6a recent clinical isolates to determine its usefulness for primary characterization of clinical s. enteritidis isolates, and then to determine whether faflp is suitable for rapid characterization of strains in an outbreak situation. | 2001 | 11678930 |
| identification by subtractive hybridization of sequences specific for salmonella enterica serovar enteritidis. | salmonella enterica serovar enteritidis, a major cause of food poisoning, can be transmitted to humans through intact chicken eggs when the contents have not been thoroughly cooked. infection in chickens is asymptomatic; therefore, simple, sensitive, and specific detection methods are crucial for efforts to limit human exposure. suppression subtractive hybridization was used to isolate dna restriction fragments present in salmonella serovar enteritidis but absent in other bacteria found in poult ... | 2001 | 11679316 |
| detection of decreased in vitro susceptibility to ciprofloxacin in salmonella enterica serotypes typhi and paratyphi a. | 2001 | 11679569 | |
| the rfah gene, which affects lipopolysaccharide synthesis in salmonella enterica serovar typhi, is differentially expressed during the bacterial growth phase. | we have cloned and sequenced the rfah gene from salmonella enterica serovar typhi strain ty2. the gene showed a high degree of similarity to the rfah genes from escherichia coli k-12 and s. enterica serovar typhimurium. a rfah mutant was constructed by site-directed mutagenesis. this mutant produced a rough lipopolysaccharide (lps), with an incomplete core region. the defect in lps expression that results from the rfah mutation was corrected by a plasmid carrying the intact gene. the plasmid-bor ... | 2001 | 11682190 |
| characterization of salmonella associated with pig ear dog treats in canada. | in the summer of 1999, the incidence of salmonella enterica serotype infantis infections in alberta rose dramatically. subsequent laboratory and epidemiological investigations established that an outbreak of human disease caused by this organism was occurring across canada and was associated with pet treats for dogs produced from processed pig ears. laboratory investigations using phage typing and pulsed-field gel electrophoresis (pfge) established that isolates of salmonella serotype infantis f ... | 2001 | 11682515 |
| structural and biochemical characterization of the type iii secretion chaperones cest and sige. | several gram-negative bacterial pathogens have evolved a type iii secretion system to deliver virulence effector proteins directly into eukaryotic cells, a process essential for disease. this specialized secretion process requires customized chaperones specific for particular effector proteins. the crystal structures of the enterohemorrhagic escherichia coli o157:h7 tir-specific chaperone cest and the salmonella enterica sigd-specific chaperone sige reveal a common overall fold and formation of ... | 2001 | 11685226 |
| evaluation of two enzyme-linked immunosorbent assays for detecting salmonella enterica subsp. enterica serovar dublin antibodies in bulk milk. | two enzyme-linked immunosorbent assays (elisas) for the detecting salmonella enterica subsp. enterica serovar dublin antibodies in bulk milk were developed and evaluated for potential use in control programs. the elisas were based on either lipopolysacharide (lps elisa) or flagellar antigen (gp elisa). sensitivity was determined with 79 case herds with a wide range of clinical signs. specificity was determined with 125 dutch and 200 swedish control herds. the relation between antibodies in bulk ... | 2001 | 11687438 |
| salmonella interactions with host cells: type iii secretion at work. | the bacterial pathogen salmonella enterica has evolved a very sophisticated functional interface with its vertebrate hosts. at the center of this interface is a specialized organelle, the type iii secretion system, that directs the translocation of bacterial proteins into the host cell. salmonella spp. encode two such systems that deliver a remarkable array of bacterial proteins capable of modulating a variety of cellular functions, including actin cytoskeleton dynamics, nuclear responses, and e ... | 2001 | 11687484 |
| purification and characterization of waap from escherichia coli, a lipopolysaccharide kinase essential for outer membrane stability. | in escherichia coli, salmonella enterica, and pseudomonas aeruginosa, the waap (rfap) gene product is required for the addition of phosphate to o-4 of the first heptose residue of the lipopolysaccharide (lps) inner core region. this phosphate substitution is particularly important to the biology of these bacteria; it has previously been shown that waap is necessary for resistance to hydrophobic and polycationic antimicrobials in e. coli and that it is required for virulence in invasive strains o ... | 2001 | 11069912 |
| identification of residues involved in catalytic activity of the inverting glycosyl transferase wbbe from salmonella enterica serovar borreze. | synthesis of the o:54 o antigen of salmonella enterica is initiated by the nonprocessive glycosyl transferase wbbe, assigned to family 2 of the glycosyl transferase enzymes (gt2). gt2 enzymes possess a characteristic n-terminal domain, domain a. based on structural data from the gt2 representative spsa (s. j. charnock and g. j. davies, biochemistry 38:6380-6385, 1999), this domain is responsible for nucleotide binding. it possesses two invariant asp residues, the first forming a hydrogen bond to ... | 2001 | 11114903 |
| alternative pathways for siroheme synthesis in klebsiella aerogenes. | siroheme, the cofactor for sulfite and nitrite reductases, is formed by methylation, oxidation, and iron insertion into the tetrapyrrole uroporphyrinogen iii (uro-iii). the cysg protein performs all three steps of siroheme biosynthesis in the enteric bacteria escherichia coli and salmonella enterica. in either taxon, cysg mutants cannot reduce sulfite to sulfide and require a source of sulfide or cysteine for growth. in addition, cysg-mediated methylation of uro-iii is required for de novo synth ... | 2001 | 11114933 |
| methionine-to-cysteine recycling in klebsiella aerogenes. | in the enteric bacteria escherichia coli and salmonella enterica, sulfate is reduced to sulfide and assimilated into the amino acid cysteine; in turn, cysteine provides the sulfur atom for other sulfur-bearing molecules in the cell, including methionine. these organisms cannot use methionine as a sole source of sulfur. here we report that this constraint is not shared by many other enteric bacteria, which can use either cysteine or methionine as the sole source of sulfur. the enteric bacterium k ... | 2001 | 11114934 |
| analysis of expression of flagella by salmonella enterica serotype typhimurium by monoclonal antibodies recognising both phase specific and common epitopes. | monoclonal antibodies specific for phase 1 ("i" antigen), phase 2 ("1,2" antigen) and common epitopes of the flagellins of salmonella enterica serotype typhimurium were raised. having confirmed their specificity, the monoclonal antibodies were used to develop semi-quantitative elisas in order to assess the relative expression of the two phases by strains of typhimurium. the majority of typhimurium strains representative of a wide cross-section of definitive types from animal and environmental so ... | 2001 | 11118742 |
| salmonella enterica serotype typhimurium elicits cross-immunity against a salmonella enterica serotype enteritidis strain expressing lp fimbriae from the lac promoter. | the biological significance of fimbrial phase variation in salmonella serotypes is currently unknown. exposure to long polar (lp) fimbriae of salmonella enterica serotype typhimurium results in selection against lpf phase on cells of serotype enteritidis during a subsequent challenge, suggesting that fimbrial phase variation may be a mechanism to evade cross-immunity between salmonella serotypes. this notion was tested by assessing the effect of an immune response against serotype typhimurium lp ... | 2001 | 11119507 |
| salmonella pathogenicity island 2 influences both systemic salmonellosis and salmonella-induced enteritis in calves. | we have used signature-tagged mutagenesis to identify mutants of the host-specific salmonella enterica serotype dublin which were avirulent in calves and/or balb/c mice. a mutant with a transposon insertion in the ssed gene of salmonella pathogenicity island 2 (spi-2), which encodes a putative secreted effector protein, was identified. this mutant was recovered from the bovine host but not from the murine host following infection with a pool of serotype dublin mutants. however, a pure inoculum o ... | 2001 | 11119526 |
| improved innate immunity of endotoxin-tolerant mice increases resistance to salmonella enterica serovar typhimurium infection despite attenuated cytokine response. | during infection with gram-negative bacteria, exposure of immune cells to lipopolysaccharide (lps) from the bacterial cell membrane induces a rapid cytokine response which is essential for the activation of host defenses against the invading pathogens. administration of lps to mice induces a state of hyporesponsiveness, or tolerance, characterized by reduced cytokine production upon subsequent lps challenge. in the model of experimental salmonella enterica serovar typhimurium infection of mice, ... | 2001 | 11119538 |
| aromatic compound-dependent brucella suis is attenuated in both cultured cells and mouse models. | the aroc gene of the facultative intracellular pathogen brucella suis was cloned and sequenced. the cloned aroc gene complements escherichia coli and salmonella enterica serovar typhimurium aroc mutants. a b. suis aroc mutant was found to be unable to grow in a defined medium without aromatic compounds. the mutant was highly attenuated in tissue culture (thp1 macrophages and hela cells) and murine virulence models. | 2001 | 11119550 |
| immunity against helicobacter pylori: significance of interleukin-4 receptor alpha chain status and gender of infected mice. | vaccination of interleukin-4 (il-4) receptor alpha (il-4ralpha) chain-deficient balb/c mice with helicobacter pylori urease and cholera toxin or with urease-expressing, live attenuated salmonella enterica serovar typhimurium cells revealed that protection against h. pylori infection is independent of il-4- or il-13-mediated signals. a comparison of male and female mice suggests a sexual dimorphism in the extent of bacterial colonization that is particularly evident in the absence of the il-4ralp ... | 2001 | 11119552 |
| a soxrs-constitutive mutation contributing to antibiotic resistance in a clinical isolate of salmonella enterica (serovar typhimurium). | the soxrs regulon is activated by redox-cycling drugs such as paraquat and by nitric oxide. the >15 genes of this system provide resistance to both oxidants and multiple antibiotics. an association between clinical quinolone resistance and elevated expression of the soxrs regulon has been observed in escherichia coli, but this association has not been explored for other enteropathogenic bacteria. here we describe a soxrs-constitutive mutation in a clinical strain of salmonella enterica (serovar ... | 2001 | 11120941 |
| development and optimization of a novel immunomagnetic separation- bacteriophage assay for detection of salmonella enterica serovar enteritidis in broth. | salmonella is the second-leading cause of food-borne illness in most developed countries, causing diarrhea, cramps, vomiting, and often fever. many rapid methods are available for detection of salmonella in foods, but these methods are often insensitive or expensive or require a high degree of technical ability to perform. in this paper we describe development and characterization of a novel assay that utilizes the normal infection cycle of bacteriophage sj2 for detection of salmonella enterica ... | 2001 | 11133448 |
| inactivation of gram-negative bacteria by lysozyme, denatured lysozyme, and lysozyme-derived peptides under high hydrostatic pressure. | we have studied the inactivation of six gram-negative bacteria (escherichia coli, pseudomonas fluorescens, salmonella enterica serovar typhimurium, salmonella enteritidis, shigella sonnei, and shigella flexneri) by high hydrostatic pressure treatment in the presence of hen egg-white lysozyme, partially or completely denatured lysozyme, or a synthetic cationic peptide derived from either hen egg white or coliphage t4 lysozyme. none of these compounds had a bactericidal or bacteriostatic effect on ... | 2001 | 11133464 |
| relative distribution and conservation of genes encoding aminoglycoside-modifying enzymes in salmonella enterica serotype typhimurium phage type dt104. | pcr was used to identify genes encoding aminoglycoside-modifying enzymes in 422 veterinary isolates of salmonella enterica serotype typhimurium. the identities of extra-integron genes encoding resistance to streptomycin, gentamicin, kanamycin, and apramycin were evaluated. gentamicin resistance was conferred by the aadb gene. kanamycin resistance was encoded by either the apha1-iab gene or the kn gene. apramycin resistance was determined by the aacc4 gene. analysis of gene distribution did not r ... | 2001 | 11133477 |
| application of rapid dot blot immunoassay for detection of salmonella enterica serovar enteritidis in eggs, poultry, and other foods. | salmonella enterica serovar enteritidis was detected in artificially inoculated eggs within 24 h through a rapid monoclonal antibody-based dot blot immunoassay. detection in poultry and other products required 28 h. samples were directly enriched in homogenized egg without the need for pre- or postenrichment steps. serovar enteritidis was detected in the presence of other bacteria when outcompeted 1:400. | 2001 | 11133480 |
| fimw is a negative regulator affecting type 1 fimbrial expression in salmonella enterica serovar typhimurium. | type 1 fimbriae are proteinaceous surface appendages that carry adhesins specific for mannosylated glycoproteins. these fimbriae are found on most members of the family enterobacteriaceae and are known to facilitate binding to a variety of eukaryotic cells, including those found on the mucosal surfaces of the alimentary tract. we have shown that the regulation of type 1 fimbrial expression in salmonella enterica serovar typhimurium is controlled, in part, by the products of four genes found with ... | 2001 | 11133935 |
| characterization of grva, an antivirulence gene on the gifsy-2 phage in salmonella enterica serovar typhimurium. | the lambdoid phage gifsy-2 contributes significantly to salmonella enterica serovar typhimurium virulence. the phage carries the periplasmic superoxide dismutase gene, sodci, and other unidentified virulence factors. we have characterized the gene grva, a single open reading frame inserted in the opposite orientation in the tail operon of the gifsy-2 phage. contrary to what is observed with classic virulence genes, grva null mutants were more virulent than wild type as measured by intraperitonea ... | 2001 | 11133955 |
| diversity of strains of salmonella enterica serotype enteritidis from english poultry farms assessed by multiple genetic fingerprinting. | reliable and sufficiently discriminative methods are needed for differentiating individual strains of salmonella enterica serotype enteritidis beyond the phenotypic level; however, a consensus has not been reached as to which molecular method is best suited for this purpose. in addition, data are lacking on the molecular fingerprinting of serotype enteritidis from poultry environments in the united kingdom. this study evaluated the combined use of classical methods (phage typing) with three well ... | 2001 | 11136764 |
| fluorescent amplified-fragment length polymorphism subtyping of the salmonella enterica serovar enteritidis phage type 4 clone complex. | fluorescent amplified-fragment length polymorphism (faflp) analysis, a high-resolution pcr-based genome fingerprinting method, was used to subtype salmonella enterica serovar enteritidis phage type 4. this single phage type is responsible for the majority of salmonellosis in europe. twenty strains isolated from nine outbreaks, five isolates from sporadic cases of human infection, four strains of poultry origin, and one laboratory-derived strain were comparatively studied by pulsed-field gel elec ... | 2001 | 11136771 |
| new insights into endotoxin-induced activation of macrophages: involvement of a k+ channel in transmembrane signaling. | lps (endotoxins) activate cells of the human immune system, among which are monocytes and macrophages, to produce endogenous mediators. these regulate the immune response, but may also cause severe harm leading to septic shock. the activation of monocytes/macrophages by lps is mediated by a membrane-bound lps receptor, mcd14. as mcd14 lacks a transmembrane domain, a further protein is required for the signal transducing step to the cell interior. here we show, using excised outside-out membrane ... | 2001 | 11145680 |
| data-quality issues and alternative variable-screening methods in a questionnaire-based study on subclinical salmonella enterica infection in danish pig herds. | our aim was to determine risk factors for subclinical salmonella enterica infection in danish finishing-pig herds. in this paper, the evaluation, combining and initial reduction of variables is presented, along with assessment of the hypotheses in the preliminary statistical testing. the first group of herds was selected at random with no former knowledge of s. enterica infection. both the herd prevalence and the within-herd prevalence among these herds turned out to be low; hence, some addition ... | 2001 | 11150633 |
| genetic mapping by duplication segregation in salmonella enterica. | mudp and mudq elements were used to induce duplications in salmonella enterica by formation of a triple crossover between two transduced fragments and the host chromosome. the large size (36 kb) of mudp and mudq is a favorable trait for duplication formation, probably because homology length is a limiting factor for the central crossover. additional requirements are a multiplicity of infection of 2 or higher in the infecting phage suspensions (which reflects the need of two transduced fragments) ... | 2001 | 11156973 |
| genetic analysis of assembly of the salmonella enterica serovar typhimurium type iii secretion-associated needle complex. | several pathogenic bacteria have evolved a specialized protein secretion system termed type iii to secrete and deliver effector proteins into eukaryotic host cells. salmonella enterica serovar typhimurium uses one such system to mediate entry into nonphagocytic cells. this system is composed of more than 20 proteins which are encoded within a pathogenicity island (spi-1) located at centisome 63 of its chromosome. a subset of these components form a supramolecular structure, termed the needle com ... | 2001 | 11157927 |
| one of two hemn genes in bradyrhizobium japonicum is functional during anaerobic growth and in symbiosis. | previously, we screened the symbiotic gene region of the bradyrhizobium japonicum chromosome for new nifa-dependent genes by competitive dna-rna hybridization (a. nienaber, a. huber, m. göttfert, h. hennecke, and h. m. fischer, j. bacteriol. 182:1472-1480, 2000). here we report more details on one of the genes identified, a hemn-like gene (now called hemn(1)) whose product exhibits significant similarity to oxygen-independent coproporphyrinogen iii dehydrogenases involved in heme biosynthesis in ... | 2001 | 11157943 |
| sige is a chaperone for the salmonella enterica serovar typhimurium invasion protein sigd. | sigd is translocated into eucaryotic cells by a type iii secretion system. in this work, evidence that the putative chaperone sige directly interacts with sigd is presented. a bacterial two-hybrid system demonstrated that sige can interact with itself and sigd. in addition, sigd was specifically copurified with sige-his(6) on a nickel column. | 2001 | 11157959 |
| ompc is the receptor for gifsy-1 and gifsy-2 bacteriophages of salmonella. | mutations in the salmonella enterica serovar typhimurium ompc gene conferred resistance to gifsy-1 and gifsy-2 bacteriophages. selection for complementing plasmids yielded clones of ompc. introduction of an ompc clone into escherichia coli conferred the ability to adsorb gifsy phage. these data show that ompc is the receptor for gifsy-1 and gifsy-2 phages. | 2001 | 11157969 |
| characterization of extended-spectrum beta-lactamase (tem-52)-producing strains of salmonella enterica serovar typhimurium with diverse resistance phenotypes. | two salmonella enterica serovar typhimurium strains from different clonal origins, both producing an extended-spectrum beta-lactamase (tem-52), were isolated from a patient. this enzyme was encoded on a single plasmid and was found at very low levels in one strain, while being encoded on multiple plasmids and in multiple different ecori fragments in the other strain. | 2001 | 11158154 |
| salmonella pathogenicity island 2-encoded proteins ssec and ssed are essential for virulence and are substrates of the type iii secretion system. | survival of salmonella enterica serovar typhimurium within host phagocytic cells is a critical step in establishing systemic infection in mice. genes within salmonella pathogenicity island 2 (spi-2) encode a type iii secretion system that is required for establishment of systemic infection. several proteins encoded by spi-2 have homology to type iii secreted proteins from enteropathogenic escherichia coli and yersinia and, based on that homology, are predicted to be secreted through the spi-2 ty ... | 2001 | 11159962 |
| gene discovery through genomic sequencing of brucella abortus. | brucella abortus is the etiological agent of brucellosis, a disease that affects bovines and human. we generated dna random sequences from the genome of b. abortus strain 2308 in order to characterize molecular targets that might be useful for developing immunological or chemotherapeutic strategies against this pathogen. the partial sequencing of 1,899 clones allowed the identification of 1,199 genomic sequence surveys (gsss) with high homology (blast expect value < 10(-5)) to sequences deposite ... | 2001 | 11159979 |
| expression, extracellular secretion, and immunogenicity of the plasmodium falciparum sporozoite surface protein 2 in salmonella vaccine strains. | deleting transmembrane alpha-helix motifs from plasmodium falciparum sporozoite surface protein (ssp-2) allowed its secretion from salmonella enterica serovar typhimurium sl3261 and s. enterica serovar typhi cvd 908-htra by the hly type i secretion system. in mice immunized intranasally, serovar typhimurium constructs secreting ssp-2 stimulated greater gamma interferon splenocyte responses than did nonsecreting constructs (p = 0.04). | 2001 | 11160021 |
| mice lacking interleukin-2 (il-2)/il-15 receptor beta chain are susceptible to infection with avirulent salmonella enterica subsp. enterica serovar choleraesuis but mice lacking il-2 are resistant. | interleukin-2 (il-2)/il-15 receptor beta (il-15r beta)(-/-) mice were susceptible to infection with avirulent salmonella enterica subsp. enterica serovar choleraesuis, whereas il-2(-/-) mice were resistant. a natural killer cell response was not evident for both types of deficient mice. a th1 response was detected in il-2(-/-) but not in il-2/il-15r beta(-/-) mice infected with salmonella, suggesting that il-2/il-15r beta signaling is important for the generation of protective th1 cells. | 2001 | 11160028 |
| functional genomic, biochemical, and genetic characterization of the salmonella pduo gene, an atp:cob(i)alamin adenosyltransferase gene. | salmonella enterica degrades 1,2-propanediol by a pathway dependent on coenzyme b12 (adenosylcobalamin [adocb1]). previous studies showed that 1,2-propanediol utilization (pdu) genes include those for the conversion of inactive cobalamins, such as vitamin b12, to adocbl. however, the specific genes involved were not identified. here we show that the pduo gene encodes a protein with atp:cob(i)alamin adenosyltransferase activity. the main role of this protein is apparently the conversion of inacti ... | 2001 | 11160088 |
| the apee gene of salmonella enterica serovar typhimurium is induced by phosphate limitation and regulated by phobr. | mutations in aper, a regulatory locus of the outer membrane esterase apee from salmonella enterica serovar typhimurium, were shown to be alleles of the pstscab-phou high-affinity phosphate transport operon. expression of apee was induced by phosphate limitation, and this induction required the phobr phosphate regulatory system. | 2001 | 11160112 |
| characterization of the catalytic activities of the phoq histidine protein kinase of salmonella enterica serovar typhimurium. | studies of escherichia coli membranes that were highly enriched in the salmonella enterica serovar typhimurium phoq protein showed that the presence of atp and divalent cations such as mg2+, mn2+, ca2+, or ba2+ resulted in phoq autophosphorylation. however, when mg2) or mn2+ was present at concentrations higher than 0.1 mm, the kinetics of phoq autophosphorylation were strongly biphasic, with a rapid autophosphorylation phase followed by a slower dephosphorylation phase. a fusion protein lacking ... | 2001 | 11160113 |
| a flagellar gene fliz regulates the expression of invasion genes and virulence phenotype in salmonella enterica serovar typhimurium. | we previously reported that the fliz gene encodes a positive regulatory factor for the class 2 flagellar operons in salmonella enterica serovar typhimurium. in this study, we found that the fliz mutation reduced not only the amounts of excreted flagellar proteins, but also those of several secreted invasion proteins encoded by the genes within salmonella pathogenicity island 1. using the lacz gene fused to a subset of virulence-associated genes, we show that this downregulation was caused by a d ... | 2001 | 11162188 |
| the best defense is a good offense--salmonella deploys an adp-ribosylating toxin. | the dramatic clinical manifestations of toxigenic infections such as cholera and diphtheria occur without substantial bacterial invasion. disease is mediated by the secretion of potent toxins that use adp-ribosylation as the catalytic mechanism underlying their action. adp-ribosylating toxins comprise a large family, including the cholera, diphtheria, pertussis and escherichia coli heat-labile (lt) toxins, and all produce disease by altering key metabolic processes after transfer of an adp-ribos ... | 2001 | 11166220 |
| novel use of anaerobically induced promoter, dmsa, for controlled expression of fragment c of tetanus toxin in live attenuated salmonella enterica serovar typhi strain cvd 908-htra. | the anaerobically induced promoter dmsa (pdmsa) was adapted to optimize in vivo expression of foreign antigens in attenuated salmonella enterica serovar typhi live vector vaccines cvd 908-htra. pdmsa from escherichia coli and two derivatives, pdmsa2 and pdmsa3 were cloned into a plasmid driving the expression of a gene encoding tetanus toxin fragment c. expression of fragment c varied from a low level induced by ptetdmsa, to moderate and high levels induced, respectively, by ptetdmsa2 and ptetdm ... | 2001 | 11166893 |
| evolution of antibiotic resistance of non-typhoidal salmonellae in greece during 1990-97. | susceptibility to 15 antibiotics was determined in 1548 non-typhoidal salmonella strains isolated in greece from l990 to l997. the overall prevalence of resistance of both salmonella enterica serotype enteritidis and salmonella enterica serotype typhimurium increased during the first years of the study. a decrease was observed from 1996, especially for s. enteritidis, which showed the highest overall antibiotic resistance. s. typhimurium was the serotype with the highest multiresistance to antib ... | 2001 | 12631956 |
| [salmonella bacteremia]. | non-typhi salmonellae are invasive bacteria, which can, in certain conditions, get into the blood stream, and course bacteriemia or localized infections in different organ systems. incidence of salmonella bacteriemia varied in different studies between 5.2-13.7%. the incidence is higher in patients younger than 1 year and the elderly. among different serotypes, the most invasive are salmonella typhimurium, salmonella choleraesuis and salmonella virchow. the aim of our study was to determine the ... | 2001 | 11905187 |
| increased resistance of mice to salmonella enterica serovar typhimurium infection by synbiotic administration of bifidobacteria and transgalactosylated oligosaccharides. | the anti-infectious activity of bifidobacteria in combination with transgalactosylated oligosaccharides (tos) against salmonella enterica serovar typhimurium lt-2 in an opportunistic antibiotic-induced murine infection model in mice was examined. | 2001 | 11851805 |
| single-enzyme amplified fragment length polymorphism and its applicability for salmonella epidemiology. | amplified fragment length polymorphism (aflp) is a pcr-based dna fingerprinting technique whereby restriction fragments may be visualized without prior knowledge of nucleotide sequences. in aflp analysis, bacterial genomic dna is digested with a restriction enzyme and ligated to adapter oligonucleotides. a subset of dna fragments are then amplified using primers which contain adapter-defined sequences. selective amplification is achieved by the use of primers containing adapter-defined sequences ... | 2001 | 11822676 |
| differences in abilities to colonize reproductive organs and to contaminate eggs in intravaginally inoculated hens and in vitro adherences to vaginal explants between salmonella enteritidis and other salmonella serovars. | in experiment 1, mature laying hens were inoculated intravaginally with 10(6) colony-forming units of salmonella enterica serovar enteritidis (s. enteritidis), salmonella typhimurium, salmonella infantis, salmonella hadar, salmonella heidelberg, or salmonella montevideo to compare their abilities to colonize the reproductive organs of chickens and to contaminate eggs. salmonella enteritidis was more frequently recovered (from 11 of 40 eggs, 27.5%) than the other serovars, and especially the inne ... | 2001 | 11785900 |
| environmental contamination and detection of salmonella enterica serovar enteritidis in laying flocks. | faecal, dust and other environmental samples were collected from the floors, droppings belts, egg-collection systems and other areas of 14 cage-layer flocks, 10 barn egg production flocks and seven free-range flocks, and cultured for salmonella species. the distribution of the organism varied with its prevalence and with the vaccination status of the birds. no one sample type was found to be suitable for identifying all contaminated houses. salmonella was also frequently found on egg-packing equ ... | 2001 | 11787781 |
| outbreak of salmonella serotype anatum infection associated with unpasteurized orange juice. | in march 1999, a patient was infected with salmonella serotype anatum after having consumed unpasteurized orange juice from a manufacturer in florida. we conducted a cohort study among customers of the manufacturer, performed pulsed-field gel electrophoresis (pfge) on isolates, and inspected the manufacturing plant. surveillance data identified three additional patients infected with salmonella anatum showing indistinguishable or closely related pfge patterns. three of the four patients had cons ... | 2001 | 11811854 |
| growth-dependent dna breakage and cell death in a gyrase mutant of salmonella. | a class of gyrase mutants of salmonella enterica mimics the properties of bacteria exposed to quinolones. these mutants suffer spontaneous dna breakage during normal growth and depend on recombinational repair for viability. unlike quinolone-treated bacteria, however, they do not show accumulation of cleavable gyrase-dna complexes. in reca or recb mutant backgrounds, the temperature-sensitive (ts) allele gyra208 causes rapid cell death at 43 degrees. here, we isolated "suppressor-of-death" mutat ... | 2001 | 11779784 |
| [multidrug resistance to antibacterial drugs of salmonella enterica subsp. enterica strains isolated in poland in the 1998-1999 period]. | a total of 510 salmonella enterica subsp. enterica strains representing 56 serotypes, isolated from human stool specimens during 1998-2000 in sanitary-epidemiological units in poland were tested for their susceptibility by a standard disk diffusion method for: ampicillin, cefotaxime, chloramphenicol, tetracycline, streptomycin, gentamicin, kanamycin, nalidixic acid, ciprofloxacin, furazolidone, cotrimoxazole, sulfonamides and trimethoprim. for 201 of the investigated strains, belonging to 5 most ... | 2001 | 11757401 |
| [phage types, plasmid profiles and chromosomal restriction profiles of salmonella enterica subsp. enterica ser. enteritidis (s. enteritidis) isolated in poland in 1999-2000]. | salmonella enteritidis strains are the most often isolated salmonella serovars in poland. in the present study, phage typing, plasmid profile analysis, and pfge have been applied to characterize 140 polish s. enteritidis isolates originated from human cases of salmonellosis and from other sources. the typing phages of ward and colleagues scheme were used to type a total of 140 s. enteritidis strains coming from poland. all 140 strains were typable and six different phage types were observed. a t ... | 2001 | 11757428 |
| survival and distribution of cell-free sef 21 of salmonella enterica serovar enteritidis in the stomach and various compartments of the rat gastrointestinal tract in vivo. | rats were dosed for 6 days with purified sef 21 fimbriae of salmonella enterica serovar enteritidis 10360. the levels of fimbriae in gut contents associated with tissues and in the faeces were quantified by direct non-competitive elisa. sef 21 was distributed throughout the gut. the majority was found in the large intestine where it was primarily in the luminal contents. in contrast, a high proportion of sef 21 detected in the ileum, the main site of salmonella colonisation and invasion, was tis ... | 2001 | 11761188 |
| an unusual serotype of salmonella from a case of meningitis in a neonate. | 2001 | 11770251 | |
| monitoring of chicken houses and an attached egg-processing facility in a laying farm for salmonella contamination between 1994 and 1998. | two chicken houses and an attached egg-processing facility in a laying farm were sampled between 1994 and 1998 to investigate salmonella contamination. each of the houses was environmentally controlled and fitted with egg belts that transported eggs from the houses to the egg-processing facility. four hundred twenty-eight salmonella isolates were obtained from 904 environmental samples collected from the houses. two hundred fifty-two of the 428 (58.9%) isolates yielded five serotypes as follows: ... | 2001 | 11770616 |
| introduction: microbiology and immunology: lessons learned from salmonella. | salmonella enterica, a gram-negative bacterium, causes significant morbidity and mortality worldwide, and is an excellent model to study bacterial pathogenesis and cellular immune responses. with the development of powerful new technologies, there has been a fusion of research on immunology, molecular biology and cellular microbiology of s. enterica infections. this multidisciplinary research will enhance our understanding of the basic mechanisms of bacterial infections and immunity; it also pro ... | 2001 | 11755405 |
| host-salmonella interaction: human trials. | human clinical trials, including experimental challenges of volunteers with pathogenic salmonella enterica serovar typhi, small phase i and ii trials that monitor the immune responses to vaccines, and large-scale controlled field trials that assess vaccine efficacy under conditions of natural challenge, have helped elucidate the interactions between salmonella typhi and human hosts. | 2001 | 11755415 |
| salmonella entry into host cells: the work in concert of type iii secreted effector proteins. | upon contact with intestinal epithelial cells, salmonella enterica serovar spp. inject a set of bacterial proteins into host cells via the bacterial spi-1 type iii secretion system. sope, sope2 and sopb, activate cdc42 and rac to initiate actin cytoskeleton rearrangements. sipa and sipc, two salmonella actin-binding proteins, directly modulate host actin dynamics to facilitate bacterial uptake. sptp promotes the recovery of the actin cytoskeleton rearrangements by antagonizing cdc42 and rac. the ... | 2001 | 11755417 |
| animal models of salmonella infections: enteritis versus typhoid fever. | the most common disease syndromes caused by salmonella serotypes in humans, typhoid fever and enteritis, can be modeled using salmonella enterica serotype typhimurium infections in mice and calves, respectively. this article reviews murine typhoid and bovine enteritis and discusses strengths, limitations and distinctive features of these animal models. | 2001 | 11755423 |
| isolation of salmonella enterica serotypes from children with diarrhoea in calcutta, india. | the prevalence of salmonella enterica serotypes, antimicrobial susceptibility, and phage typing of serovers were studied. clinical presentations of the infected cases were also examined. the study was carried out during august 1993-september 1996 in and around calcutta, india. in total, 1,025 faecal samples from hospitalized diarrhoeal children were screened for enteropathogens. four s. enterica serotypes were identified in 157 (15.3%) cases as a single pathogen. s. enterica serotype typhimurium ... | 2001 | 11855352 |
| nitric oxide metabolites in gnotobiotic piglets orally infected with salmonella enterica serovar typhimurium. | reactive no metabolites play a distinct role in the control of salmonella enterica serovar typhimurium (st; a facultative intracellular pathogen) in susceptible host. a significant increase of nitrite and/or nitrate plasma levels, 3-nitro-tyrosine expression and pathological changes in mesenteric lymph nodes have been observed in gnotobiotic piglets orally infected for 1 d with a virulent strain of st but not in piglets infected with a rough mutant of st. | 2001 | 11830949 |
| community-acquired bacteremia among hospitalized children in rural central africa. | to describe the epidemiology of community-acquired bacteremia in children admitted to a rural hospital in central africa and to identify useful diagnostic signs or symptoms. | 2001 | 11953214 |
| ordinary and opportunistic enteropathogens associated with diarrhea in senegalese adults in relation to human immunodeficiency virus serostatus. | a survey was conducted in dakar, senegal, to identify major types and prevalences of bacteria, parasites, fungi, and rotaviruses associated with diarrhea in relation to human immunodeficiency virus (hiv) serostatus with the goal to provide guidance to physicians for case management. | 2001 | 11953215 |
| acute terminal ileitis mimicking crohn's disease caused by salmonella veneziana. | 2001 | 11953223 | |
| global aspects of antimicrobial-resistant enteric bacteria. | antibiotics have been considered to be safe and effective 'magic bullets', with no disadvantages to their widespread use. this has been proven to be a complacent attitude, with ever-increasing prevalences of resistance now evident. the present review covers aspects of the development, mechanisms and genetics of antimicrobial resistance in enteric commensals and pathogens. | 2001 | 11964879 |
| mural endocarditis caused by salmonella virchow: survival with conservative treatment. | we describe a case of endocarditis caused by salmonella enterica serotype virchow, which was treated conservatively with antibiotics alone. it is the only reported case of survival from salmonella endocarditis with conservative treatment, and the first reported case of endocarditis caused by salmonella virchow. the changing prevalence, virulence patterns and importance of salmonella species in endocarditis are discussed. | 2001 | 16352056 |
| [infective etiology of diarrhea in adults with hiv infection in dakar: a case-control study on 594 patients]. | a survey was conducted in dakar, senegal from may 1997 to may 1999, to identify major types and prevalences of bacteria, parasites, fungi and rotaviruses associated with diarrhea in relation to human immunodeficiency virus serostatus with the aim to provide guidance to physicians for case management. etiologic agents were identified in a case-control study: cases were hiv-infected patients with diarrhea (hiv+ d+) and hiv seronegative patients with diarrhea (hiv- d+); controls were hiv-infected p ... | 2001 | 15773157 |
| molecular mechanisms of salmonella pathogenesis. | the success of a pathogen depends on its capacity to enter a host, circumvent host defense barriers and establish infection. the gram-negative bacterium salmonella enterica has evolved different strategies to subvert normal host cellular functions, which allow it to enter into and proliferate within host cells. | 2000 | 11964823 |
| resistance mechanism for a number of non-typhoidic salmonella strains isolated in iaşi, romania. | the aim of this study was to find a possible explanation for the resistance pattern of the selected strains and to evaluate the impact in case of isolating such strains. during the period february-march 1998, in the pediatric hospital "sf. maria" from iasi, romania, 12 non-typhoidic salmonella strains, non-duplicates were isolated from stools of newborns and, in one case, from mother as well. identification was done by standard methods, and sensitivity testing by disk diffusion method, against t ... | 2000 | 12089972 |
| surveillance of antimicrobial resistance in denmark. | recent data of the danish integrated antimicrobial resistance monitoring and research programme (danmap) show that, in denmark, resistance levels among salmonella enterica are modest and that resistance in escherichia coli isolates causing disease in anim | 2000 | 12631958 |
| salmonella enterica serotype oranienburg infections associated with consumption of locally produced tyrolean cheese. | sixteen culture confirmed cases of enteric infection with salmonella enterica serotype oranienburg were detected between august 10 and september 29 1999 in tyrol (austria). ten of them suffered bloody diarrhoea and six were asymptomatic carriers. intervie | 2000 | 12631963 |
| endemic presence of salmonella enterica serotype cerro in southern italy. | molecular typing of salmonella strains isolated between 1997 and 1999 in southern italy and carried out by the southern italy centre for enteric pathogens, has shown a high frequency of salmonella enterica serotype cerro. this serotype is extremely rare i | 2000 | 12631854 |
| high rate of resistance to nalidixic acid in salmonella enterica: its role as a marker of resistance to fluoroquinolones. | 2000 | 11168127 | |
| the emergence and spread of antibiotic resistance in food-borne bacteria. | since the early 1990s there has been a dramatic increase in resistance to antimicrobial drugs in salmonella enterica and campylobacter spp., and to a lesser extent in vero cytotoxin-producing escherichia coli o157 from cases of human infection in developed countries. for s. typhimurium a particularly important aspect of this increase has been the widespread dissemination of a multiply drug-resistant (mr) strain of definitive phage type (dt) 104 in food animals since the early 1990s. the use of a ... | 2000 | 11139009 |
| comparison of the escherichia coli k-12 genome with sampled genomes of a klebsiella pneumoniae and three salmonella enterica serovars, typhimurium, typhi and paratyphi. | the escherichia coli k-12 genome (eco) was compared with the sampled genomes of the sibling species salmonella enterica serovars typhimurium, typhi and paratyphi a (collectively referred to as sal) and the genome of the close outgroup klebsiella pneumoniae (kpn). there are at least 160 locations where sequences of >400 bp are absent from eco but present in the genomes of all three sal and 394 locations where sequences are present in eco but close homologs are absent in all sal genomes. the 394 s ... | 2000 | 11121489 |