Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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 |
| molecular and biochemical characterization of oxa-45, an extended-spectrum class 2d' beta-lactamase in pseudomonas aeruginosa. | as part of the cancer antimicrobial surveillance program in north america, a clinical strain of pseudomonas aeruginosa, strain 07-406, isolated in texas was found to be resistant to all antimicrobials except polymyxin b. genetic analysis of this isolate identified two unique extended-spectrum beta-lactamase genes. one, bla(vim-7), encoded a metallo-beta-lactamase (unpublished data), and the other, bla(oxa-45), described here, encoded a class d extended-spectrum beta-lactamase. bla(oxa-45) was is ... | 2003 | 12936985 |
| a new serovar and a new serological variant belonging to salmonella enterica subspecies diarizonae. | description of a new serovar (s. iiib 16:k:e,n,x,z15) and a new serological variant (s. iiib 42:z10:e,n,x,z15:z60 ) belonging to the genus salmonella isolated from stool specimens of brazilian snakes (crotalus durissus). | 2003 | 12937762 |
| lateral gene transfer in salmonella. | comparative genomics and microarrays reveal that the genomes of different salmonella enterica serovars are distinguished from each other by the presence or absence of hundreds of genes. the distribution of these variable genome regions is often not clonal. therefore, lateral gene transfer (lgt) plays an important role in diversity among salmonella. overall, almost one quarter of the entire s. enterica sv typhimurium genome may have been introduced by lgt. | 2003 | 12941390 |
| norfloxacin and azithromycin for treatment of nontyphoidal salmonella carriers. | there has been inadequate evaluation of an antibiotic for eradication of nontyphoidal salmonellae (nts) in asymptomatic carriers. in a randomized, placebo-controlled trial, such efficacy was evaluated using 2 five-day regimens (norfloxacin, 400 mg twice per day, and azithromycin, 500 mg once per day) compared with placebo. the study included 265 food workers in an area of thailand where nts are endemic who were asymptomatic nts carriers. the presence of nts in stool samples was assessed on days ... | 2003 | 12942401 |
| avoidance of false pcr results with the integron-retron junction in multiple antibiotic resistant salmonella enterica serotype typhimurium. | salmonella infections continue to cause gastrointestinal and systemic disease throughout the world. another concern with this pathogen is the ability to acquire integrons that confer resistance to multiple antibiotics. for multiresistant salmonella enterica serotype typhimurium, the most common multiresistant salmonella serotype, an integron structure can be found between thdf and a retron. our objective was to investigate the utility of a 450 bp thdf-retron amplicon as an indicator of an insert ... | 2003 | 12944121 |
| drug resistance genes encoded in integrons and in extra-integrons: their distribution and lateral transfer among pathogenic enterobacteriaceae including enterohemorrhagic escherichia coli and salmonella enterica serovars typhimurium and infantis. | 2003 | 12944682 | |
| factors associated with the serological prevalence of salmonella enterica in greek finishing swineherds. | blood samples were taken from 50 finishing pigs at 90-105 kg in each of 59 randomly selected farrow-to-finish herds. the sera were tested for antibodies to salmonella enterica by the danish mix-elisa. samples with an optical density of > 10% were considered to be positive. associations between the odds of seropositivity of pigs and possible risk factors were evaluated in multivariable logistic regression models. the results of the analysis indicated that pigs fed non-pelleted dry or wet ration h ... | 2003 | 12948357 |
| molecular epidemiology of salmonella enteritidis phage type 1b and 6a isolates in portugal. | salmonella enterica serotype enteritidis is an important serovar comprising 76 % of salmonella isolates in portugal in 2001. for better understand the epidemiology of salmonellosis, a total of 47 isolates of s. enteritidis phage type (pt) 1b and 6a were analysed by pulsed-field gel electrophoresis (pfge) and genomic dna was subjected to macro restriction with xbai. for pt 1b isolates, only three different patterns were observed, and pt6a showed a total of 10 digestion patterns. curiously, the ma ... | 2003 | 12948358 |
| extracellular polysaccharides associated with thin aggregative fimbriae of salmonella enterica serovar enteritidis. | lipopolysaccharide (lps) o polysaccharide was identified as the principle factor impeding intercellular formation of intact thin aggregative fimbriae (tafi) in salmonella enterica serovar enteritidis. the extracellular nucleation-precipitation assembly pathway for these organelles was investigated by quantifying fimbrial formation between deltaagfa (agfa recipient) and deltaagfb (agfa donor) cells harboring mutations in lps (gale::tn10) and/or cellulose (deltabcsa) synthesis. intercellular compl ... | 2003 | 12949092 |
| lactobacillus reuteri crl1098 produces cobalamin. | we found that lactobacillus reuteri crl1098, a lactic acid bacterium isolated from sourdough, is able to produce cobalamin. the sugar-glycerol cofermentation in vitamin b(12)-free medium showed that this strain was able to reduce glycerol through a well-known cobalamin-dependent reaction with the formation of 1,3-propanediol as a final product. the cell extract of l. reuteri corrected the coenzyme b12 requirement of lactobacillus delbrueckii subsp. lactis atcc 7830 and allowed the growth of salm ... | 2003 | 12949118 |
| neutral mutations and neutral substitutions in bacterial genomes. | molecular evolutionary biologists usually assess the underlying spectrum of mutations within a bacterial genome by examining substitutions that occur at sites believed to be under no selective constraints. alternatively, bacterial mutation rates can also be estimated in a variety of experimental systems. the two classes of changes occurring in dna sequences-i.e., mutations and neutral substitutions-are, in theory, identical; however, the rates and patterns of mutations in bacteria, as inferred f ... | 2003 | 12949125 |
| enrichment for isolating salmonella choleraesuis and other salmonella spp. from pigs. | the growth of salmonella choleraesuis was examined in rappaport vassiliadis broth (rv) and hajna-tetrathionate broth (htt) at 37 and 42 degrees c. as the enrichment in rv at 37 degrees c was satisfactory for isolating s. choleraesuis, we used this enrichment for isolation from the samples collected from 15 asymptomatic pigs reared on a s. choleraesuis contaminated farm. s. choleraesuis was frequently isolated from six pigs (40.0%) under field conditions. the isolation of other salmonella serovar ... | 2003 | 12951433 |
| toward an international standard for pcr-based detection of food-borne thermotolerant campylobacters: validation in a multicenter collaborative trial. | as part of a european research project, the performance of a pcr assay to detect food-borne thermotolerant campylobacters (campylobacter jejuni, c. coli, and c. lari) was evaluated through an international collaborative trial involving 12 participating laboratories. dna from 10 target and 8 nontarget strains was tested, and the results were reported as the presence of a positive signal after gel electrophoresis. the overall inclusivity (sensitivity) was 93.7%, and the exclusivity (specificity) w ... | 2003 | 12957959 |
| molecular properties of salmonella enterica serotype paratyphi b distinguish between its systemic and its enteric pathovars. | salmonella enterica serotype o1,4,5,12:hb:1,2, designated according to the current kauffmann-white scheme as s. enterica serotype paratyphi b, is a very diverse serotype with respect to its clinical and microbiological properties. pcr and blot techniques, which identify the presence, polymorphism, and expression of various effector protein genes, help to distinguish between strains with systemic and enteric outcomes of disease. all serotype paratyphi b strains from systemic infections have been ... | 2003 | 12958256 |
| phage-based typing scheme for salmonella enterica serovar heidelberg, a causative agent of food poisonings in canada. | salmonella enterica serovar heidelberg is perhaps the second most frequent salmonella serovar isolated from humans and the most common isolated from animals in canada. this pathogen has shown increasing resistance to antimicrobial agents and mimics the multidrug resistance observed in s. enterica serovar typhimurium strain dt 104. however, unlike for serovar typhimurium, a rapid and inexpensive subtyping method has not been available for large-scale surveillance efforts. we developed a phage typ ... | 2003 | 12958257 |
| discrimination of d-tartrate-fermenting and -nonfermenting salmonella enterica subsp. enterica isolates by genotypic and phenotypic methods. | a multiplex pcr and an improved lead acetate test were developed to discriminate d-tartrate-fermenting and -nonfermenting salmonella enterica subsp. enterica strains. both methods showed an accuracy of 100% when 125 salmonella strains belonging to 15 serovars were tested. special emphasis was given to s. enterica subsp. enterica serovar paratyphi b isolates because of the clinical importance of its d-tartrate-nonfermenting variant and the recently increasing numbers of cases of human outbreaks c ... | 2003 | 12958259 |
| molecular typing of salmonella enterica serovar typhi isolates from various countries in asia by a multiplex pcr assay on variable-number tandem repeats. | a multiplex pcr method incorporating primers flanking three variable-number tandem repeat (vntr) loci (arbitrarily labeled tr1, tr2, and tr3) in the ct18 strain of salmonella enterica serovar typhi has been developed for molecular typing of s. enterica serovar typhi clinical isolates from several asian countries, including singapore, indonesia, india, bangladesh, malaysia, and nepal. we have demonstrated that the multiplex pcr could be performed on crude cell lysates and that the vntr banding pr ... | 2003 | 12958274 |
| in vivo development of quinolone resistance in salmonella enterica serotype typhimurium dt104. | salmonella enterica serotype typhimurium definitive phage type 104 was isolated several times from the same patient over a period of 2 years. the strain developed reduced sensitivity to fluoroquinolones, and a mutation in the gyra gene that is associated with reduced sensitivity to quinolones was identified. | 2003 | 12958295 |
| activity of dermaseptin k4-s4 against foodborne pathogens. | dermaseptin s4 and its substituted derivative k(4)-s4 were investigated against various food-related pathogenic bacteria in culture media. k(4)-s4, but not the native peptide displayed significant growth inhibitory activity against all bacteria tested. next, activity of k(4)-s4 against escherichia coli o157:h7 was defined in terms of milieu dependencies. salt-dependent kinetic studies in growth medium indicated that the peptide's antibacterial activity is maintained at fairly high (up to 600mm) ... | 2003 | 15019214 |
| outbreak of neonatal meningitis caused by salmonella enterica serotype worthington. | we report an outbreak of salmonella meningitis in a nursery unit due to serotype worthington. the organism was isolated from blood and csf samples of five babies. the isolates were found to be resistant to commonly used antibiotics such as ampicillin, cefotaxime, cefiriaxone and amikacin but were sensitive to ciprofloxacin. serotype worthington appears to be an emerging pathogen in neonatal units. | 2003 | 15022937 |
| harmonization of antimicrobial susceptibility testing among veterinary diagnostic laboratories in the five nordic countries. | a total of 100 bacterial strains (25 escherichia coli, 25 salmonella enterica, 25 staphylococcus aureus, and 25 enterococcus strains) and four reference strains were tested for susceptibility toward 8-12 antimicrobial agents in 12 veterinary diagnostic laboratories in the five nordic countries using routine methodology. in addition, the 25 enterococcus strains were identified to species level. a total of 22,598 (97.2%) out of 23,259 test results were in accordance when the data were categorized ... | 2003 | 15000745 |
| the art of serendipity: killing of caenorhabditis elegans by human pathogens as a model of bacterial and fungal pathogenesis. | the nematode worm, caenorhabditis elegans, has been used to develop a facile model system of host-pathogen interactions to identify basic evolutionarily conserved pathways associated with microbial pathogenesis. the model involves the killing of caenorhabditis elegans by a variety of human pathogens. several virulence-related genes in a variety of pathogens previously shown to be involved in mammalian infection have also been shown to play a role in caenorhabditis elegans killing. screening of l ... | 2003 | 15482109 |
| structure-function discrimination of the n- and c- catalytic domains of human angiotensin-converting enzyme: implications for cl- activation and peptide hydrolysis mechanisms. | human somatic angiotensin i-converting enzyme (sace) has two active sites present in two sequence homologous protein domains (ace_n and ace_c) possessing several biochemical features that differentiate the two active sites (i.e. chloride ion activation). based on the recently solved x-ray structure of testis angiotensin-converting enzyme (tace), the 3d structure of ace_n was modeled. electrostatic potential calculations reveal that the ace_n binding groove is significantly more positively charge ... | 2003 | 14983080 |
| fresh garlic: a possible vehicle for salmonella virchow. | a sustained increase in salmonella enterica serovar virchow notifications in south eastern australia between september 1997 and may 1998 instigated a case-control study and environmental investigations. cases were defined as having locally acquired culture-confirmed s. virchow phage-type 8 infection and diarrhoeal disease. matched controls were selected by progressive digit dialling based on cases' telephone numbers. an exposure and food history questionnaire was administered by telephone. phage ... | 2003 | 14959768 |
| a preliminary report on current antibiogram of salmonella enterica serotype typhi in nagpur. | 2003 | 17643050 | |
| salmonella enterica subsp. enterica serovar agona infections in commercial pheasant flocks. | infections in pheasant flocks due to salmonella enterica subsp. enterica serovar agona occurred in a commercial pheasant farm in 1995 and 2000. s. enterica serovar agona isolates obtained from the affected birds in both years and an environmental sample from 1998 showed an identical pulsed-field gel electrophoresis pattern, indicating that the farm was continually contaminated with the strain during this period. nine hundred and seventy-three of 1850 birds (56.2%) died at 4 to 5 days of age in 1 ... | 2003 | 17585459 |
| granulomatous myocarditis and coelomic effusion due to salmonella enterica arizonae in a madagascar dumerili's boa (acrantophis dumerili, jan. 1860). | a granulomatous myocarditis due to salmonella enterica arizonae was diagnosed in an 8-year-old madagascar dumerili's boa (acrantophis dumerili) based on positive coelomic effusion culture, ultrasound visualization of abnormal ventricular myocardium, necropsy and cardiac histological examination. | 2003 | 19081357 |
| molecular epidemiology of salmonella enterica serovar enteritidis isolated in taiwan. | incidence of salmonella enterica serovar enteritidis infection seems to be on the rise in taiwan, and therefore, the characteristics of the isolate, including genotypes, were epidemiologically investigated. of the 71 clinical strains isolated in 1997-1999, 61 (86%) remained susceptible to the eight antibiotics tested, while the remaining ten, eight of which were isolated in 1999, were resistant to one to three of the agents including three multiply resistant strains. the majority, 69 or 97% of t ... | 2002 | 12597357 |
| development of a mucosal complex vaccine against oral salmonella infection in mice. | we examined the immunogenicity of a salmonella enterica complex vaccine (cv), consisting of flagellin and polysome purified from serotype typhimurium lt2. cv plus cholera toxin (ct), in three oral doses given at 7-day intervals, conferred complete protection on c57bl/6 mice against lethal oral infection with a wild-type strain. it elicited mucosal iga > igg2a > igg1 and systemic igg2a > igg1 > iga antibodies to flagellin and polysome, and delayed footpad response (dfr) to both antigens. in peyer ... | 2002 | 12597365 |
| a statewide outbreak of salmonella bovismorbificans phage type 32 infection in queensland. | between 30 may and 1 june 2001, 10 cases of salmonella bovismorbificans infection were reported to public health services, queensland health. investigations included enhanced surveillance, case interviews, a matched case control study, environmental audit and microbiological testing of faecal isolates (phage typing) and implicated food products. forty-one cases of s. bovismorbificans infection were detected, 36 cases were phage type 32. a matched case control study identified that illness was as ... | 2002 | 12549525 |
| characterization of a highly attenuated salmonella enterica serovar typhimurium mutant strain. | salmonella enterica serovar typhimurium atcc 13311 is virulent at a dose as low as 10(2) colony-forming units when administered intraperitoneally to balb/c mice. in order to develop highly attenuated mutant strain through the combination of 2 phenotypically attenuated markers, we constructed a number of amino acid requiring auxotrophic strains of s. enterica serovar typhimurium by means of uv-induced mutations. one of them, strain ndmc-b1, was highly attenuated for mice, with an ld50-value of 6 ... | 2002 | 12542248 |
| structural and biological characterization of highly purified hepta-acyl lipid a present in the lipopolysaccharide of the salmonella enterica sv. minnesota re deep rough mutant strain r595. | one major component of the salmonella enterica sv. minnesota re deep rough mutant (strain r595) lipopolysaccharide is hepta-acyl lipid a (la(hepta)). in a recent publication [tanamoto k-i, azumi s. salmonella-type heptaacylated lipid a is inactive and acts as an antagonist of lipopolysaccharide action on human line cells. j immunol 2000; 164: 3149-3156] the corresponding synthetic hepta-acyl lipid a (compound 516) was reported to be agonistically inactive but to rather suppress pro-inflammatory ... | 2002 | 12537693 |
| isolated splenic infarction owing to group b salmonella: case report. | the clinical spectrum of extra-intestinal salmonellosis, comprising enteric fever and invasive infections owing to non-typhoidal salmonellae, is well known. we report an otherwise healthy patient with isolated splenic infarction caused by group b salmonella. she was seropositive for the o antigen of salmonella group b and stool cultures were positive for group b salmonellae. after appropriate antimicrobial therapy, her complaints disappeared and microbiological tests for salmonellae became negat ... | 2002 | 12530289 |
| evolution of multiresistance in nontyphoid salmonella serovars from 1984 to 1998 in argentina. | molecular evolution of multiresistance in nontyphoid salmonella spp. was investigated with 155 isolates obtained in argentina from 1984 to 1998. in 74 isolates obtained from 1984 to 1988 resistance was associated with the presence of tn3, tn9, class i (in0) and ii (tn7) integrons, and the aac(3)-iia gene. extended-spectrum cephalosporin (esc) resistance in salmonella spp. emerged in 1989, and 81 isolates resistant to at least one esc and one aminoglycoside were collected thereafter. among these, ... | 2002 | 12435702 |
| the salmonella enterica subspecies i specific centisome 7 genomic island encodes novel protein families present in bacteria living in close contact with eukaryotic cells. | we have determined the genetic structure of the salmonella enterica centisome 7 genomic island (sci) located at the aspv loci in s. enterica subspecies i strains. the 47-kb long genomic island encodes 37 putative proteins, including the previously described saf fimbrial operon and the sinr transcriptional regulator. other open reading frames (designated sci a to z) in the island encode putative proteins with homologies to virulence-associated proteins in a number of gram-negative bacteria such a ... | 2002 | 12437215 |
| identification and genetic characterization of pmra-regulated genes and genes involved in polymyxin b resistance in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium encounters antimicrobial peptides (ap) within the phagosomes of professional phagocytes and at intestinal mucosal surfaces. salmonella serovar typhimurium utilizes the two-component regulatory system pmra-pmrb, which is activated in response to the environmental conditions encountered in vivo, to regulate resistance to several ap, including polymyxin b (pm). random mudj transposon mutagenesis was used to identify pmra-pmrb-regulated genes, as well as genet ... | 2002 | 12438352 |
| analysis of salmonella enterica serotype-host specificity in calves: avirulence of s. enterica serotype gallinarum correlates with bacterial dissemination from mesenteric lymph nodes and persistence in vivo. | host and bacterial factors that determine whether salmonella serotypes remain restricted to the gastrointestinal tract or penetrate beyond the mucosa and cause systemic disease remain largely undefined. here, factors influencing salmonella host specificity in calves were assessed by characterizing the pathogenesis of different serotypes. salmonella enterica serotype dublin was highly virulent intravenously, whereas s. enterica serotype choleraesuis was moderately virulent. both serotypes were vi ... | 2002 | 12438354 |
| concomitant cytosolic delivery of two immunodominant listerial antigens by salmonella enterica serovar typhimurium confers superior protection against murine listeriosis. | during its interaction with host cells, salmonella enterica serovar typhimurium employs a type iii secretion system for cytosolic targeting of virulence factors. this protein translocation mechanism is a useful tool for heterologous antigen delivery by attenuated salmonella vaccine carrier strains. in the present study, we used the yersinia outer protein e (yope) as a carrier molecule for salmonella type iii-dependent cytosolic delivery of the immunodominant cd8 t-cell antigens listeriolysin o ( ... | 2002 | 12438393 |
| genetic requirements for salmonella-induced cytopathology in human monocyte-derived macrophages. | infection of human macrophages with salmonella enterica serovar typhimurium or salmonella enterica serovar dublin produces delayed cytotoxicity characterized by cell detachment and associated apoptosis. using a site-specific mutant in the spvb active site, we verify that the adp-ribosylation activity of spvb is required for delayed cytotoxicity in human macrophages infected with salmonella: sipb and the type iii protein secretion system (ttss) encoded by salmonella pathogenicity island 1 (spi1) ... | 2002 | 12438395 |
| the acrb multidrug transporter plays a major role in high-level fluoroquinolone resistance in salmonella enterica serovar typhimurium phage type dt204. | salmonella enterica serovar typhimurium phage type dt204 strains isolated from cattle and animal feed in belgium were characterized for high-level fluoroquinolone resistance mechanisms [mics to enrofloxacin (enr) and ciprofloxacin (cip), 64 and 32 microg/ml, respectively]. these strains isolated during the periods 1991-1994, and in 2000 were clonally related as shown by pulsed-field gel electrophoresis (pfge). selected strains studied carried several mutations in the quinolone target genes, i.e. ... | 2002 | 12523625 |
| phenotypic and genotypic characterization of food animal isolates of salmonella with reduced sensitivity to ciprofloxacin. | reports of nontyphoidal salmonella enterica subsp. enterica showing reduced sensitivity to ciprofloxacin (rsc) have increased rapidly during the past decade. infection in humans with salmonella possessing rsc may compromise the effectiveness of ciprofloxacin therapy. nineteen among 4,357 salmonella strains isolated from food animals in canada from 1998 to 1999 showed rsc; 17 were from turkeys and 2 from chickens. all were resistant to nalidixic acid and sulfisoxazole and possessed rsc at a level ... | 2002 | 12523636 |
| antimicrobial resistance of salmonella serotypes isolated from slaughter-age pigs and environmental samples. | the aim of this study was to determine the antimicrobial resistance patterns of salmonella strains isolated from slaughter-age pigs and environmental samples collected at modern swine raising facilities in brazil. seventeen isolates of six serotypes of salmonella enterica subsp. enterica were isolated out of 1,026 collected samples: salmonella typhimurium (1), salmonella agona (5), salmonella sandiego (5), salmonella rissen (1), salmonella senftenberg (4), and salmonella javiana (1). resistance ... | 2002 | 12523640 |
| regulation of capsule synthesis and cell motility in salmonella enterica by the essential gene igaa. | mutants of salmonella enterica carrying the igaa1 allele, selected as able to overgrow within fibroblast cells in culture, are mucoid and show reduced motility. mucoidy is caused by derepression of wca genes (necessary for capsule synthesis); these genes are regulated by the rcsc/yojn/rcsb phosphorelay system and by the rcsa coregulator. the induction of wca expression in an igaa1 mutant is suppressed by mutations in rcsa and rcsc. reduced motility is caused by lowered expression of the flagella ... | 2002 | 12524328 |
| [community-acquired bacterial infections]. | corticosteroids in bacterial meningitis: a randomised multicentre study on meningitis in adults versus a placebo showed significant benefits of corticoids in terms of reduction in mortality and neurological complications. these results were essentially observed in pneumococcal infections. the interest in monitoring blood cultures: several works on staphylococcus aureus bacteremia have confirmed the necessity of monitoring hemocultures, 48-72 hours following initiation of treatment. the persisten ... | 2002 | 12497721 |
| sir2-dependent activation of acetyl-coa synthetase by deacetylation of active lysine. | acetyl-coenzyme a (coa) synthetase (acs) is an enzyme central to metabolism in prokaryotes and eukaryotes. acs synthesizes acetyl coa from acetate, adenosine triphosphate, and coa through an acetyl-adenosine monophosphate (amp) intermediate. immunoblotting and mass spectrometry analysis showed that salmonella enterica acs enzyme activity is posttranslationally regulated by acetylation of lysine-609. acetylation blocks synthesis of the adenylate intermediate but does not affect the thioester-form ... | 2002 | 12493915 |
| prevalence and antimicrobial susceptibility of salmonella serotypes in patients from ribeirão preto, são paulo, brazil, between 1985 and 1999. | salmonella strains isolated from 1,138 samples representing 28,199 biological materials (stool, urine, blood and other fluids), collected between january 1985 and january 1999 at a reference university hospital in ribeirão preto, são paulo, brazil, were studied. the most frequently detected serotypes were salmonella enterica subspecies enterica serotype 4,5,12:i:- (s. i 4,5,12:i:) (21.2%), s. agona (15.8%) and s. enteritidis (11.3%). a changing pattern of salmonella serotypes was observed betwee ... | 2002 | 12495606 |
| cytopathic effects observed upon expression of a repressed collagenase gene present in salmonella and related pathogens: mimicry of a cytotoxin from multiple antibiotic-resistant salmonella enterica serotype typhimurium phagetype dt104. | recently, we reported that certain strains of salmonella enterica serovar typhimurium phagetype dt104 (dt104) secrete a putative cytotoxin. while searching for the gene that encodes this toxin, we noted a previously reported but uncharacterized dna fragment (clg) in salmonella that could be potentially relevant to cytotoxin-like activity. therefore, we cloned and expressed clg in cytotoxin-negative escherichia coli and salmonella and subsequently assessed the bioactivity of clg in vitro and in v ... | 2002 | 12495674 |
| combined application of simulated reuse and quantitative carrier tests to assess high-level disinfection: experiments with an accelerated hydrogen peroxide-based formulation. | heat-sensitive medical devices require chemical disinfection between patients, and certain formulations for this purpose can be reused for several days. because dilution, evaporation, and breakdown or neutralization of active ingredients can occur during reuse, it is vital to ensure that the solution retains its broad-spectrum germicidal activity even at the end of the recommended reuse period. | 2002 | 12461509 |
| results of a 5-year prospective surveillance study of antibiotic resistance among salmonella enterica isolates and ceftriaxone therapy among children hospitalized for acute diarrhea. | the spread of resistant salmonella strains continues to increase worldwide. it is necessary to establish epidemiologic information to determine an appropriate empiric antibiotic regimen (when indicated) in infants and children with suspected salmonella infections for whom the results of susceptibility tests are not yet available. | 2002 | 12462288 |
| alive but non-infectious. | 2002 | 12467699 | |
| identification of the gene responsible for the cblb complementation group of vitamin b12-dependent methylmalonic aciduria. | the methylmalonic acidurias are metabolic disorders resulting from deficient methylmalonyl-coa mutase activity, a vitamin b(12)-dependent enzyme. we have cloned the gene for the cblb complementation group caused by deficient activity of a cob(i)alamin adenosyltransferase. this was accomplished by searching bacterial genomes for genes in close proximity to the methylmalonyl-coa mutase gene that might encode a protein with the properties of an adenosyltransferase. a candidate was identified in the ... | 2002 | 12471062 |
| oxidation of propionate to pyruvate in escherichia coli. involvement of methylcitrate dehydratase and aconitase. | the pathway of the oxidation of propionate to pyruvate in escherichia coli involves five enzymes, only two of which, methylcitrate synthase and 2-methylisocitrate lyase, have been thoroughly characterized. here we report that the isomerization of (2s,3s)-methylcitrate to (2r,3s)-2-methylisocitrate requires a novel enzyme, methylcitrate dehydratase (prpd), and the well-known enzyme, aconitase (acnb), of the tricarboxylic acid cycle. acnb was purified as 2-methylaconitate hydratase from e. coli ce ... | 2002 | 12473114 |
| co-localization of quantitative trait loci regulating resistance to salmonella typhimurium infection and specific antibody production phenotypes. | salmonella enterica serotype typhimurium is a facultative intracellular bacteria that induces systemic infection in mice. resistance to this pathogen is under polygenic control in which nramp1 is the major gene involved. lines of mice obtained by selective breeding for high (hiii) or low (liii) antibody response to flagellar antigens of salmonellae showed significant susceptibility differences, although both the lines display nramp1(r) alleles. the hiii line was extremely susceptible to infectio ... | 2002 | 12475631 |
| phage mediated horizontal transfer of the sope1 gene increases enteropathogenicity of salmonella enterica serotype typhimurium for calves. | epidemiological evidence shows that the sope1 gene is associated with salmonella typhimurium phage types causing epidemics in cattle. in this study we demonstrate that horizontal transfer of the sope1 gene by lysogenic conversion with the sopephi increased enteropathogenicity of s. typhimurium in the bovine ligated ileal loop model. these data support the hypothesis that phage mediated horizontal transfer of the sope1 gene contributes to the emergence of epidemic cattle-associated s. typhimurium ... | 2002 | 12480111 |
| o-antigen expression in salmonella enterica serovar typhi is regulated by nitrogen availability through rpon-mediated transcriptional control of the rfah gene. | the authors previously reported increased expression of the salmonella enterica serovar typhi (s. typhi) rfah gene when the bacterial cells reach stationary phase. in this study, using a lacz fusion to the rfah promoter region, they demonstrate that growth-dependent regulation of rfah expression occurs at the level of transcription initiation. it was also observed that production of the lipopolysaccharide (lps) o-antigen by s. typhi ty2 correlated with the differential expression of rfah during ... | 2002 | 12480883 |
| host-pathogen interactions: host resistance factor nramp1 up-regulates the expression of salmonella pathogenicity island-2 virulence genes. | nramp1 (natural resistance-associated macrophage protein-1; also known as slc11a1) is a host resistance gene that provides protection against several intracellular pathogens, including salmonella enterica serovar typhimurium. little is known about the dynamic interplay that occurs between mammalian host resistance determinants such as nramp1 and pathogens during infection. to explore these interactions, we examined the effect of nramp1 on expression of salmonella typhimurium (stm) virulence fact ... | 2002 | 12441401 |
| cuid is a crucial gene for survival at high copper environment in salmonella enterica serovar typhimurium. | copper ion is an essential micronutrient but it is also extremely cytotoxic when it exists in excess. our studies have shown that salmonella enterica serovar typhimurium can survive potentially lethal copper exposures by the way of copper efflux system. a copper ion inducible gene was identified in virulent s. typhimurium by using the technique of mudj (km, lac)-directed laczya operon fusions. a copper ion inducible strain lf153 (cuid::mudj) has been identified. the cuid mutant exhibits a copper ... | 2002 | 12442888 |
| the cysteine desulfurase iscs is required for synthesis of all five thiolated nucleosides present in trna from salmonella enterica serovar typhimurium. | deficiency of a modified nucleoside in trna often mediates suppression of +1 frameshift mutations. in salmonella enterica serovar typhimurium strain tr970 (hisc3737), which requires histidine for growth, a potential +1 frameshifting site, ccc-caa-uaa, exists within the frameshifting window created by insertion of a c in the hisc gene. this site may be suppressed by peptidyl-trnaprocmo5ugg (cmo(5)u is uridine-5-oxyacetic acid), making a frameshift when decoding the near-cognate codon ccc, provide ... | 2002 | 12446633 |
| ribosylnicotinamide kinase domain of nadr protein: identification and implications in nad biosynthesis. | nad is an indispensable redox cofactor in all organisms. most of the genes required for nad biosynthesis in various species are known. ribosylnicotinamide kinase (rnk) was among the few unknown (missing) genes involved with nad salvage and recycling pathways. using a comparative genome analysis involving reconstruction of nad metabolism from genomic data, we predicted and experimentally verified that bacterial rnk is encoded within the 3' region of the nadr gene. based on these results and previ ... | 2002 | 12446641 |
| repression of glutamate dehydrogenase formation in klebsiella aerogenes requires two binding sites for the nitrogen assimilation control protein, nac. | in klebsiella aerogenes, the gdha gene codes for glutamate dehydrogenase, one of the enzymes responsible for assimilating ammonia into glutamate. expression of a gdhap-lacz transcriptional fusion was strongly repressed by the nitrogen assimilation control protein, nac. this strong repression (>50-fold under conditions of severe nitrogen limitation) required the presence of two separate nac binding sites centered at -89 and +57 relative to the start of gdha transcription. mutants lacking either o ... | 2002 | 12446647 |
| influence of enrofloxacin and chloramphenicol on the level of igy in serum and egg yolk after immunostimulation of hens with salmonella enteritidis antigens. | in the chicken, maternal antibodies are transferred into the egg and subsequently transported into the developing embryo. igg (called igy) is the primary immunoglobulin isotype of the egg yolk. their level in serum depends on the correct function of immunological system in laying hens. many factors have a direct or indirect influence on antibody level in fowl. one of them is a commonly used antibiotic, but its influence on avian immune system is still unknown. the objective of the study was to d ... | 2002 | 12448078 |
| [report on salmonella nomenclature of judicial commission during iums general meeting in paris]. | 2002 | 12448841 | |
| early epithelial invasion by salmonella enterica serovar typhimurium dt104 in the swine ileum. | salmonella enterica serovar typhimurium is an important intestinal pathogen in swine. this study was performed to document the early cellular invasion of salmonella serovar typhimurium in swine ileum. ileal gut-loops were surgically prepared in ten 4- to 5-week-old mixed-breed pigs and inoculated for 0-60 minutes. loops were harvested and prepared for both scanning and transmission electron microscopy (sem and tem, respectively). preferential bacterial adherence to microfold cells (m cells) was ... | 2002 | 12450202 |
| bile stress response in listeria monocytogenes lo28: adaptation, cross-protection, and identification of genetic loci involved in bile resistance. | bile is one of many barriers that listeria monocytogenes must overcome in the human gastrointestinal tract in order to infect and cause disease. we demonstrated that stationary-phase cultures of l. monocytogenes lo28 were able to tolerate concentrations of bovine, porcine, and human bile and bile acids well in excess of those encountered in vivo. strain lo28 was relatively bile resistant compared with other clinical isolates of l. monocytogenes, as well as with listeria innocua, salmonella enter ... | 2002 | 12450822 |
| salmonella enterica subspecies enterica serotype typhimurium and escherichia coli o86 in wild birds at two garden sites in south-west scotland. | salmonella enterica subspecies enterica serotype typhimurium and escherchia coli o86:k61:nm are two bacteria that can cause outbreaks of mortality in garden birds visiting bird tables and other feeding stations. two sites in south-west scotland were monitored for the two organisms for 12 months. at site a, large numbers of birds fed throughout the year, and at site b smaller numbers of birds fed only in the winter months. samples of composite faeces were collected from the feeding stations and s ... | 2002 | 12452355 |
| molecular diversity of the genetic loci responsible for lipopolysaccharide core oligosaccharide assembly within the genus salmonella. | the waa locus on the chromosome of salmonella enterica encodes enzymes involved in the assembly of the core oligosaccharide region of the lipopolysaccharide (lps) molecule. to date, there are two known core structures in salmonella, represented by serovars typhimurium (subspecies i) and arizonae (subspecies iiia). the waa locus for serovar typhimurium has been characterized. here, the corresponding locus from serovar arizonae is described, and the molecular basis for the distinctive structures i ... | 2002 | 12453217 |
| multiple genetic typing of salmonella enterica serotype typhimurium isolates of different phage types (dt104, u302, dt204b, and dt49) from animals and humans in england, wales, and northern ireland. | salmonella enterica serotype typhimurium is a common cause of salmonellosis among humans and animals in england, wales, and northern ireland. phage types dt104 and u302 were the most prevalent types in both livestock and humans in 2001. in addition, salmonella serotype typhimurium dt204b was responsible for a recent international outbreak involving england. a total of 119 isolates from humans (n = 28) and animals or their environment (n = 91), belonging to dt104 (n = 66), u302 (n = 33), dt204b ( ... | 2002 | 12454135 |
| molecular characterization of cephalosporin-resistant salmonella enterica serotype newport isolates from animals in pennsylvania. | multidrug-resistant (mdr) strains of salmonella enterica serotype newport have been described for many years. however, the recognition of newport strains with resistance to cephalosporin antibiotics is more recent. plasmid-mediated cmy-2 ampc beta-lactamases have been identified in salmonella in the united states, and the bla(cmy-2) gene has been shown to be present in salmonella serotype newport. this organism is currently undergoing epidemic spread in both animals and humans in the united stat ... | 2002 | 12454172 |
| quantitative comparison of intestinal invasion of zoonotic serotypes of salmonella enterica in poultry. | the aim of the present study was to compare the invasion of selected zoonotic salmonella serotypes of poultry in an in vivo chicken intestinal loop model and also in vitro in epithelial cell cultures. invasion was measured relative to a reference strain, salmonella typhimurium 4/74 invh201::tnphoa. two serotypes demonstrated intracellular log(10) counts that differed significantly from all other serotypes tested: salmonella enteritidis pt4 being 1.5 log(10) colony forming units (cfu) (31-fold) h ... | 2002 | 12425791 |
| dietary mannan-oligosaccharides and their effect on chicken caecal microflora in relation to salmonella enteritidis colonization. | this study first investigates the effects of mash diet, or mash supplemented with either 2.5% mannose-oligosaccharide (mos) or palm kernel meal (pkm), on the microflora of the hen caecal contents. second, it investigates the effect of caecal contents of hens (hcc) fed mash or mash supplemented with mos or pkm on the major microflora groups of chicks, and their inhibitory effect on salmonella enterica serovar enteritidis (pt4) colonization. finally, this study investigates the effect over time of ... | 2002 | 12425792 |
| identification of a nipsnap homologue as host cell target for salmonella virulence protein spic. | salmonella enterica uses a type iii secretion system encoded by spi-2 to target specific virulence factors into the host cytosol of macrophages to inhibit the phagosomal-lysosomal maturation pathway. this ensures survival of salmonella inside its intracellular niche, the salmonella-containing vacuole (scv). one such virulence factor is spic, which was previously shown to interfere with intracellular vesicular trafficking. in this study we have used a yeast two-hybrid assay to identify a nipsnap ... | 2002 | 12427096 |
| salmonella enterica serovar pullorum requires the salmonella pathogenicity island 2 type iii secretion system for virulence and carriage in the chicken. | functional mutations were made in the type iii secretion systems encoded by salmonella pathogenicity island 1 (spi 1) and salmonella pathogenicity island 2 (spi 2) of salmonella enterica serovar pullorum, the cause of pullorum disease in poultry. their role in cell invasion in vitro, and in virulence in vivo was determined. the spi 1 mutant showed decreased invasiveness for chicken cells but was capable of causing disease in orally infected 1-day-old chicks, although it showed some reduction in ... | 2002 | 12427344 |
| specificity of respiratory pathways involved in the reduction of sulfur compounds by salmonella enterica. | the tetrathionate (ttr) and thiosulfate (phs) reductases of salmonella enterica lt2, together with the polysulfide reductase (psr) of wolinella succinogenes, are unusual examples of enzymes containing a molybdopterin active-site cofactor since all formally catalyse sulfur-sulfur bond cleavage. this is in contrast to the oxygen or hydrogen transfer reactions exhibited by other molybdopterin enzymes. here the catalytic specificity of ttr and phs has been compared using both physiological and synth ... | 2002 | 12427953 |
| magnetized carbonyl iron and insoluble zirconium hydroxide mixture facilitates bacterial concentration and separation from nonfat dry milk. | a mixture of magnetized carbonyl iron and insoluble zirconium hydroxide was investigated for its ability to concentrate various foodborne pathogens from 25-ml samples of reconstituted nonfat dry milk. each sample was artificially contaminated with 10(3) to 10(6) cfu/25 ml of representative foodborne pathogens (salmonella enterica serovar enteritidis, listeria monocytogenes, and bacillus cereus spores) and processed for bacterial concentration with high-speed centrifugation for the primary concen ... | 2002 | 12430708 |
| the invasion-associated type iii secretion system of salmonella enterica serovar typhimurium is necessary for intracellular proliferation and vacuole biogenesis in epithelial cells. | type iii secretion systems (ttss) are used by gram-negative pathogens to translocate proteins into eukaryotic host cells. salmonella enterica serovar typhimurium (s. typhimurium) has two of these specialized systems, which are encoded on separate salmonella pathogenicity islands (spi-1 and spi-2) and translocate unique sets of effectors. the specific roles of these systems in salmonella pathogenesis remain undefined, although spi-1 is required for bacterial invasion of epithelial cells and spi-2 ... | 2002 | 11856172 |
| immunogenicity of chi4127 phop- salmonella enterica serovar typhimurium in dogs. | salmonellae are commonly isolated from dogs. the number of dogs infected with salmonella spp. is surprisingly high and greater than the incidence of clinical disease would suggest. salmonellosis is common in greyhound kennels. morbidity can approach 100% in puppies and the mortality ranges to nearly 40%. to date, there has been little effort to evaluate the feasibility of a vaccine for control of this disease in dogs. in the studies described here, an attenuated strain of salmonella enterica ser ... | 2002 | 11858870 |
| serotype and phage type distribution of salmonella strains isolated from humans, cattle, pigs, and chickens in the netherlands from 1984 to 2001. | we studied serotypes and phage types of salmonella strains isolated from humans and animals in the netherlands over the period 1984 to 2001. all human strains (n = 59,168) were clinical isolates. the animal strains (n = 65,567) were from clinical and nonclinical infections. all isolates were serotyped, and salmonella enterica serovar typhimurium and serovar enteritidis strains were further phage typed. the most prevalent serotypes were as follows: in humans, serovars typhimurium and enteritidis; ... | 2002 | 12409362 |
| detection of gyra mutations in quinolone-resistant salmonella enterica by denaturing high-performance liquid chromatography. | denaturing high-performance liquid chromatography (dhplc) was evaluated as a rapid screening and identification method for dna sequence variation detection in the quinolone resistance-determining region of gyra from salmonella serovars. a total of 203 isolates of salmonella were screened using this method. dhplc analysis of 14 isolates representing each type of novel or multiple mutations and the wild type were compared with lightcycler-based pcr-gyra hybridization mutation assay (gama) and sing ... | 2002 | 12409384 |
| increasing genetic diversity of salmonella enterica serovar typhi isolates from papua new guinea over the period from 1992 to 1999. | pulsed-field gel electrophoresis (pfge) of xbai-digested chromosomal dna was performed on 133 strains of salmonella enterica serovar typhi obtained from papua new guinea, with the objective of assessing the temporal variation of these strains. fifty-two strains that were isolated in 1992 and 1994 were of one phage type, d2, and only two predominant pfge profiles, x1 and x2, were present. another 81 strains isolated between 1997 and 1999 have shown divergence, with four new phage types, uvs i (n ... | 2002 | 12409390 |
| expanded-spectrum cephalosporin-resistant salmonella strains in romania. | thirteen salmonella enterica serotype typhimurium and one salmonella enterica serotype heidelberg strain resistant to expanded-spectrum cephalosporins were isolated from october 2000 to february 2001 from infants with gastroenteritis in iasi, romania. in all but one serotype typhimurium isolate, resistance was due to the production of a cmy-2 cephalosporinase encoded by a nonconjugative plasmid. the remaining isolate produced an shv-5-type beta-lactamase. typing by pulsed-field gel electrophores ... | 2002 | 12409424 |