Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| evaluation of dna extraction methods for use in combination with sybr green i real-time pcr to detect salmonella enterica serotype enteritidis in poultry. | the objective of this study was to develop a rapid, reproducible, and robust method for detecting salmonella enterica serotype enteritidis in poultry samples. first, for the extraction and purification of dna from the preenrichment culture, four methods (boiling, alkaline lysis, nucleospin, and dynabeads dna direct system i) were compared. the most effective method was then combined with a real-time pcr method based on the double-stranded dna binding dye sybr green i used with the abi prism 7700 ... | 2003 | 12788750 |
| rapid detection of campylobacter coli, c. jejuni, and salmonella enterica on poultry carcasses by using pcr-enzyme-linked immunosorbent assay. | contamination of retail poultry by campylobacter spp. and salmonella enterica is a significant source of human diarrheal disease. isolation and identification of these microorganisms require a series of biochemical and serological tests. in this study, campylobacter ceue and salmonella inva genes were used to design probes in pcr-enzyme-linked immunosorbent assay (elisa), as an alternative to conventional bacteriological methodology, for the rapid detection of campylobacter jejuni, campylobacter ... | 2003 | 12788755 |
| [effect of disinfectants on surface hydrophobicity and mobility in salmonella enterica serovar typhimurium dt104]. | the paper evaluated antibacterial efficacy of 12 disinfectants on the basis of quaternary ammonium compounds (kaz) on the isolates of salmonella enterica serovar typhimurium of the definitive phage type 104 (dt104). one isolate--5551/99--represented the multiresistant phenotype, resistant to ampicillin (a), chloramphenicol (c), streptomycin (s), and tetracycline (t). the second isolate--577/99--was sensitive to all antibiotics tested. the present study further examined the capability of sub-mic ... | 2003 | 12789775 |
| global regulation by csra in salmonella typhimurium. | csra is a regulator of invasion genes in salmonella enterica serovar typhimurium. to investigate the wider role of csra in gene regulation, we compared the expression of salmonella genes in a csra mutant with those in the wild type using a dna microarray. as expected, we found that expression of salmonella pathogenicity island 1 (spi-1) invasion genes was greatly reduced in the csra mutant, as were genes outside the island that encode proteins translocated into eukaryotic cells by the spi-1 type ... | 2003 | 12791144 |
| longitudinal study of salmonella enterica aerotype typhimurium infection in three danish farrow-to-finish swine herds. | a longitudinal study of the infection dynamics of salmonella enterica was carried out with three danish farrow-to-finish swine herds. to account for variations in salmonella shedding over time, litters from each herd were divided into two cohorts. each cohort consisted of 30 pigs, for a total of 180 pigs. pigs were individually monitored by monthly bacteriologic and serologic examinations from weaning to slaughter. at weaning, individual sows were examined bacteriologically and serologically. at ... | 2003 | 12791837 |
| prevalence of enteroaggregative escherichia coli among children with and without diarrhea in switzerland. | in a prospective study between july 1999 and september 2000, stool specimens of children below the age of 16 years with (n = 187) and without (n = 137) diarrhea were tested for the presence of enterovirulent bacteria by standard culture methods and by pcr. targets for the pcr were the plasmid pcvd432 for enteroaggregative escherichia coli (eaec), the verotoxin 1 and verotoxin 2 genes for enterohemorrhagic e. coli, ipah for enteroinvasive e. coli (eiec) and shigella spp., genes coding for heat-st ... | 2003 | 12791838 |
| the world health organization's external quality assurance system proficiency testing program has improved the accuracy of antimicrobial susceptibility testing and reporting among participating laboratories using nccls methods. | a total of 150 laboratories in 33 countries that followed the nccls testing procedures participated in the world health organization's external quality assurance system for antimicrobial susceptibility testing (eqas-ast) from january 1998 through march 2001. laboratories tested seven bacterial isolates for antimicrobial resistance and reported the results to the centers for disease control and prevention (cdc) in atlanta, ga. the results were compared to the results generated at the cdc with the ... | 2003 | 12791851 |
| several salmonella enterica subsp. enterica serotype 4,5,12:i:- phage types isolated from swine samples originate from serotype typhimurium dt u302. | pulsed-field gel electrophoresis, plasmid profiling, and phage typing were used to characterize and determine possible genetic relationships between 48 salmonella enterica subsp. enterica isolates of pig origin collected in catalonia, spain, from 1998 to 2000. the strains were grouped into 23 multidrug-resistant fljb-lacking s. enterica serovar 4,5,12:i:- isolates, 24 s. enterica serovar typhimurium isolates, and 1 s. enterica serovar 4,5,12:-:- isolate. after combining the xbai and blni macrore ... | 2003 | 12791855 |
| oral immunisation with live aroa attenuated salmonella enterica serovar typhimurium expressing the yersinia pestis v antigen protects mice against plague. | bubonic and pneumonic plague are caused by the bacterium yersinia pestis. the v antigen of y. pestis is a protective antigen against plague. in this study, an aroa attenuated strain of salmonella enterica serovar typhimurium (sl3261) has been used to deliver the y. pestis v antigen as a candidate oral plague vaccine. sl3261 was transformed with the expression plasmid ptrc-lcrv, containing the lcrv gene encoding v antigen. immunoblot analysis showed v antigen expression in sl3261 in vitro and int ... | 2003 | 12798649 |
| identification, cloning and characterization of rfae of actinobacillus pleuropneumoniae serotype 1, a gene involved in lipopolysaccharide inner-core biosynthesis. | actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia and its lipopolysaccharides (lps) have been identified as important adhesins involved in adherence to host cells. to better understand the role of lps core in the virulence of this organism, the aim of the present study was to identify and clone genes involved in lps core biosynthesis by complementation with salmonella enterica serovar typhimurium mutants (rfac, rfad, rfae and rfaf). complementation with an a. pleu ... | 2003 | 12798993 |
| tetratricopeptide-like repeats in type-iii-secretion chaperones and regulators. | efficient type-iii secretion depends on cytosolic molecular chaperones, which bind specifically to the translocators and effectors. in the past there has been a tendency to shoe-horn all type-iii-secretion chaperones into a single structural and functional class. however, we have shown that the lcrh/sycd-like chaperones consist of three central tetratricopeptide-like repeats that are predicted to fold into an all-alpha-helical array that is quite distinct from the known structure of the syce cla ... | 2003 | 12799000 |
| salmonella dna adenine methylase mutants elicit early and late onset protective immune responses in calves. | salmonellosis is an important disease of livestock and salmonella contamination of livestock-derived food products and effluents pose a significant risk to human health. salmonella vaccines currently available to prevent salmonellosis in cattle have limited efficacy. here we evaluated a salmonella enterica serovar typhimurium vaccine strain lacking the dna adenine methylase (dam) for safety and efficacy in calves. vaccination was safe in calves, and following challenge with virulent typhimurium ... | 2003 | 12804855 |
| persistent silver disinfectant for the environmental control of pathogenic bacteria. | contaminated surfaces can act as a reservoir for pathogenic microorganisms and potentially exacerbate the risk of infection. surface disinfection and decontamination provide temporary amelioration against bacterial colonization. disinfected surfaces eventually become contaminated, thus, mitigating the benefit of the initial disinfection. it is hypothesized that to improve on the current state of the art, a disinfectant should not only immediately disinfect a surface but also provide persistent a ... | 2003 | 12806357 |
| reducing colonization of salmonella enteritidis in chicken by targeting outer membrane proteins. | to evaluate the ability of salmonella enterica ser. enteritidis outer membrane proteins (omps) of 75.6 and 82.3 kda to inhibit or reduce in vivo colonization of s. enteritidis on intestinal mucosa in chickens. | 2003 | 12807464 |
| a virulent strain of salmonella enterica serovar london isolated in infants with enteritis traced by active surveillance and molecular epidemiological study. | a total of 74 isolates of salmonella enterica serovar london were collected through the laboratory-based diarrheal diseases surveillance in 2000-2001. in order to characterize the isolates and investigate the source of the epidemic, we performed antimicrobial susceptibility tests and xbai pulsed-field gel electrophoresis (pfge) of 44 salmonella london isolates. forty isolates were from feces of infants and four isolates were from adults aged 30, 52, 54, and 59 yr. two subtypes were identified: a ... | 2003 | 12808316 |
| [primary abscess of the psoas due to salmonella enterica, serogroup g, serotype friedenau]. | 2003 | 12809589 | |
| competitive exclusion by bacillus subtilis spores of salmonella enterica serotype enteritidis and clostridium perfringens in young chickens. | cost effective control of avian diseases and food borne pathogens remains a high priority for all sectors of the poultry industry with cleansing and disinfection, vaccination and competitive exclusion approaches being used widely. previous studies showed that bacillus subtilis py79(hr) was an effective competitive exclusion agent for use in poultry to control avian pathogenic escherichia coli serotype o78:k80. here we report experiments that were undertaken to test the efficacy of b. subtilis py ... | 2003 | 12814892 |
| molting and salmonella enterica serovar enteritidis infection: the problem and some solutions. | induced molting is an important economic tool used by the egg industry to recycle an aging layer flock. it is estimated that approximately 70% of the flocks nationwide and almost 100% in california are molted annually. considering that there are approximately 240 million hens in production in the u.s., a rough estimate of the numbers of hens molted every year would be between 144 and 168 million birds, a substantial number. there are many methods to induce molt, but feed removal until hens lose ... | 2003 | 12817457 |
| detection of a nosocomial outbreak of salmonellosis may be delayed by application of a protocol for rejection of stool cultures. | in october 2001 an outbreak of salmonella enterica serovar enteritidis phage-type 6 occurred in a hospital and a nursing home, both served by the same hospital kitchen. five nursing home residents died during the outbreak. s. enteritidis was isolated from three of them. of 231 stool samples from nursing home residents, hospital patients and employees, 82 were culture-positive. all symptomatic patients were treated with oral ciprofloxacin. inspection of the kitchen showed that during preparation ... | 2003 | 12818580 |
| selection of small-colony variants of salmonella enterica serovar typhimurium in nonphagocytic eucaryotic cells. | salmonella enterica strains are enteropathogenic bacteria that survive and proliferate within vacuolar compartments of epithelial and phagocytic cells. recently, it has been reported that fibroblast cells are capable of restricting s. enterica serovar typhimurium intracellular growth. here, we show that prolonged residence of bacteria in the intracellular environment of fibroblasts results in the appearance of genetically stable small-colony variants (scv). a total of 103 scv isolates, obtained ... | 2003 | 12819049 |
| salmonella enterica serovar typhimurium expressing a chromosomally integrated copy of the bacillus anthracis protective antigen gene protects mice against an anthrax spore challenge. | protective immunity against infection with bacillus anthracis is almost entirely based on a response to the protective antigen (pa), the binding moiety for the two other toxin components. we cloned the pa gene into an auxotrophic mutant of salmonella enterica serovar typhimurium as a fusion with the signal sequence of the hemolysin (hly) a gene of escherichia coli to allow the export of pa via the hly export system. to stabilize the export cassette, it was also integrated into the chromosome of ... | 2003 | 12819066 |
| glutamine synthetase glna1 is essential for growth of mycobacterium tuberculosis in human thp-1 macrophages and guinea pigs. | to assess the role of glutamine synthetase (gs), an enzyme of central importance in nitrogen metabolism, in the pathogenicity of mycobacterium tuberculosis, we constructed a glna1 mutant via allelic exchange. the mutant had no detectable gs protein or gs activity and was auxotrophic for l-glutamine. in addition, the mutant was attenuated for intracellular growth in human thp-1 macrophages and avirulent in the highly susceptible guinea pig model of pulmonary tuberculosis. based on growth rates of ... | 2003 | 12819079 |
| the c-terminal domain of salmonella enterica serovar typhimurium ompa is an immunodominant antigen in mice but appears to be only partially exposed on the bacterial cell surface. | we examined the way the major outer membrane protein ompa of salmonella enterica serovar typhimurium is recognized by the mouse immune system, by raising a panel of 12 monoclonal antibodies (mabs) against this protein. interaction between ompa and these mabs is competitively inhibited with several-hundredfold dilutions of mouse polyclonal sera obtained by immunization with live or heat-killed whole cells, suggesting that ompa is one of the immunodominant antigens of serovar typhimurium. all of t ... | 2003 | 12819080 |
| a salmonella enterica serovar typhimurium translocated leucine-rich repeat effector protein inhibits nf-kappa b-dependent gene expression. | nontyphoidal salmonellae are enteric pathogens that cause acute gastroenteritis and colonize the intestinal tract for prolonged periods. in the intestinal epithelia, these bacteria induce secretion of proinflammatory cytokines, such as interleukin-8 (il-8), which leads to a profound inflammatory response through recruitment of polymorphonuclear leukocytes. production of il-8 induced by salmonella spp. is due to the activation of the transcription factors nuclear factor kappa b (nf-kappa b) and a ... | 2003 | 12819095 |
| cd44-regulated intracellular proliferation of listeria monocytogenes. | cd44 has been implicated in immune and inflammatory processes. we have analyzed the role of cd44 in the outcome of listeria monocytogenes infection in murine bone marrow-derived macrophages (bmm). surprisingly, a dramatically decreased intracellular survival of l. monocytogenes was observed in cd44(-/-) bmm. cd44(-/-) heart or lung fibroblast cultures also showed reduced bacterial levels. moreover, livers from cd44(-/-)-infected mice showed diminished levels of l. monocytogenes. in contrast, int ... | 2003 | 12819101 |
| helicobacter pylori preferentially induces interleukin 12 (il-12) rather than il-6 or il-10 in human dendritic cells. | dendritic cells are potent antigen-presenting cells that are present in the gastrointestinal tract and are required for the induction of a th1 t-cell acquired immune response. since infection with the gastric pathogen helicobacter pylori elicits a th1 cell response, the interaction of these organisms with dendritic cells should reflect the th1 bias. we incubated h. pylori with cultured human dendritic cells and measured the cytokine induction profile, comparing the response to that induced by sa ... | 2003 | 12819109 |
| a comparison of antimicrobial susceptibilities in nontyphoidal salmonellas from humans and food animals in england and wales in 2000. | a joint study by the public health laboratory service and the veterinary laboratories agency of resistance to antimicrobials in isolates of salmonella enterica serotypes enteritidis, typhimurium, hadar, and virchow from humans and food-producing animals in england and wales in 2000 has demonstrated that resistance was most common in typhimurium, particularly in strains of definitive phage type (dt) 104. however resistance was also common in other phage types, particularly dts 193 and 208 and pha ... | 2003 | 12820804 |
| [multiresistant salmonella enterica subspecies enterica serovar typhimurium dt104 in the czech republic 2000-2001]. | salmonelloses belong to the most important alimentary diseases. from 1989 the main source of infection is s. enteritidis (95% and more). the ratio of s. typhimurium in the etiology declined gradually since 1994 from 3% in 1993 to 1.9% in 2001. the number of detected multiresistant strains stm dt104 is so far low in the czech republic. in 2000 laboratory tests confirmed 53 and in 2001 a total of 63 strains. analysis of these strains revealed: 1. the proportion of multiresistant strains stm dt104 ... | 2003 | 12822536 |
| regulation of dinucleoside polyphosphate pools by the ygdp and apah hydrolases is essential for the ability of salmonella enterica serovar typhimurium to invade cultured mammalian cells. | the ygdp and apah genes of salmonella enterica serovar typhimurium (s. typhimurium) encode two unrelated dinucleoside polyphosphate (npnn) hydrolases. for example, ygdp cleaves diadenosine tetraphosphate (ap4a) producing amp and atp, while apah cleaves ap4a producing 2adp. disruption of ygdp, apah individually, and disruption of both genes together reduced intracellular invasion of human hep-2 epithelial cells by s. typhimurium by 9-, 250-, and 3000-fold, respectively. adhesion of the mutants wa ... | 2003 | 12824172 |
| comparison of early ileal invasion by salmonella enterica serovars choleraesuis and typhimurium. | the mechanisms of salmonella serovar-host specificity are not well defined. pig ileal loops were used to compare phenotypic differences in early cellular invasion between non-host-adapted salmonella serovar typhimurium (sst) and host-adapted salmonella serovar choleraesuis (ssc). by 10 minutes postinoculation, both serovars invaded a small number of m cells, enterocytes, and goblet cells. multiple ssc organisms (up to 6 per cell) simultaneously invaded m cells, whereas sst often invaded as one t ... | 2003 | 12824508 |
| r-factor in salmonella enterica serovar typhi: transfer to and acquisition from escherichia coli. | blood culture isolates of salmonella enterica serovar typhi showing high degrees of resistance to ampicillin, chloramphenicol, cotrimoxazole and tetracycline (accot-resistance) transferred their full resistance phenotype to antibiotic-sensitive s. enterica serovar typhi strains through the primary recipient escherichia coli c600. transfer frequencies were 0.80 x 10(-5) and 0.80 x 10(-6), respectively, in the primary and secondary transfer experiments. the escherichia coli isolates from urinary t ... | 2003 | 12824689 |
| display and release of the plasmodium falciparum circumsporozoite protein using the autotransporter misl of salmonella enterica. | the salmonella enterica misl (protein of membrane insertion and secretion) is an autotransporter with high homology to aida-i (adhesin involved in diffuse adherence) of enteropathogenic escherichia coli. considering that it has been reported that the misl beta translocator domain is able to display heterologous passenger peptides to the bacterial surface, we developed a system to display proteins and release them to the external environment by means of proteolytic cleavage. plasmids were constru ... | 2003 | 12826054 |
| emerging themes in manganese transport, biochemistry and pathogenesis in bacteria. | though an essential trace element, manganese is generally accorded little importance in biology other than as a cofactor for some free radical detoxifying enzymes and in the photosynthetic photosystem ii. only a handful of other mn2+-dependent enzymes are known. recent data, primarily in bacteria, suggest that mn2+-dependent processes may have significantly greater physiological importance. two major classes of prokaryotic mn2+ uptake systems have now been described, one homologous to eukaryotic ... | 2003 | 12829271 |
| involvement of intestinal inducible nitric oxide synthase (inos) in the early stages of murine salmonellosis. | local induction of inducible nitric oxide synthase (inos) and apoptosis was examined in the intestine of mice infected with virulent salmonella enterica serovar enteritidis 5694 (s. enteritidis) and its attenuated derivative mutant e/1/3. both, intestinal inos mrna expression and inos activity showed a peak at 4 h only in animals receiving the virulent s. enteritidis. aminoguanidine treatment abrogated intestinal epithelial damage produced by virulent s. enteritidis and diminished apoptosis at t ... | 2003 | 12829292 |
| development of a novel method of lytic phage delivery by use of a bacteriophage p22 site-specific recombination system. | bacteriophage therapy represents a potential alternative to the use of antibiotics to control proliferation of pathogenic bacteria. as an alternative to the strategy where a limited number of doses of large numbers of lytic bacteriophages are administered, a novel method delivery system was developed so that phages are continually released into the culture. specifically, a non-pathogenic escherichia coli strain was constructed that was lysogenic for a lytic mutant of bacteriophage lambda. this l ... | 2003 | 12829296 |
| retron reverse transcriptase rrtt is ubiquitous in strains of salmonella enterica serovar typhimurium. | bacterial retron reverse transcriptases are unusual enzymes which utilise the same rna molecule as a template and also as a primer for initiation of the reverse transcription. except for their relatively frequent presence in myxococcus spp., they are considered as quite rare proteins. however, in this study we proved that retron reverse transcriptase is frequently found in certain serovars of salmonella enterica. using polymerase chain reaction (pcr), in strains of serovar typhimurium, the rrtt ... | 2003 | 12829299 |
| inhibition of bacterial dna replication by zinc mobilization during nitrosative stress. | phagocytic cells inhibit the growth of intracellular pathogens by producing nitric oxide (no). no causes cell filamentation, induction of the sos response, and dna replication arrest in the gram-negative bacterium salmonella enterica. no also induces double-stranded chromosomal breaks in replication-arrested salmonella lacking a functional recbcd exonuclease. this dna damage depends on actions of additional dna repair proteins, the recg helicase, and ruvc endonuclease. introduction of a recg mut ... | 2003 | 12829799 |
| reevaluating fluoroquinolone breakpoints for salmonella enterica serotype typhi and for non-typhi salmonellae. | salmonella enterica infections cause considerable morbidity and mortality worldwide. antimicrobial therapy may be life-saving for patients with extraintestinal infections with s. enterica serotype typhi or non-typhi salmonellae. because antimicrobial resistance to several classes of traditional first-line drugs has emerged in the past several decades, the quinolone antimicrobial agents, particularly the fluoroquinolones, have become the drugs of choice. recently, resistance to nalidixic acid has ... | 2003 | 12830411 |
| sexual transmission of typhoid fever: a multistate outbreak among men who have sex with men. | in august 2000, the ohio department of health reported a cluster of men with typhoid fever who denied having traveled abroad. to determine the cause and the extent of the outbreak, an epidemiological investigation was initiated in which 7 persons in ohio, kentucky, and indiana with culture-confirmed salmonella enterica serotype typhi infection and 2 persons with probable typhoid fever were evaluated; all were men, and all but one reported having had sex with 1 asymptomatic male s. typhi carrier. ... | 2003 | 12830419 |
| synergistic effects of lipopolysaccharide and interferon-gamma in inducing interleukin-8 production in human monocytic thp-1 cells is accompanied by up-regulation of cd14, toll-like receptor 4, md-2 and myd88 expression. | lipopolysaccharide (lps) and interferon (ifn)-gamma synergistically induced interleukin-8 (il-8) production in human monocytic thp-1 cells. ifn-gamma-primed thp-1 cells produced higher levels of il-8 on stimulation with lps than non-primed cells and the level correlated with duration of priming up to 24 h, although the level of il-8 induced was most comparable to that induced by co-stimulation with lps and ifn-gamma. unstimulated thp-1 cells were shown by flow cytometry to be practically devoid ... | 2003 | 12831455 |
| the role of membrane-bound lbp, endotoxin aggregates, and the maxik channel in lps-induced cell activation. | we have previously shown in patch-clamp experiments on excised outside-out cytoplasmic membrane patches from human macrophages that the activation of a high-conductance ca(2+)- and voltage-dependent potassium channel, the maxik channel, is an early step in lps-induced transmembrane signal transduction in macrophages. maxik can be activated by agonistically active lps, and activation can be completely inhibited by lps antagonists (e.g. synthetic compound 406) and by anti-cd14 antibodies. furtherm ... | 2003 | 12831460 |
| in vitro and in vivo stability of recombinant plasmids in a vaccine strain of salmonella enterica var. typhimurium. | this study examined the ability of different plasmid vectors encoding h(c) fragment, the non-toxic binding portion of tetanus toxin, to be stably retained by salmonella enterica var. typhimurium (salmonella typhimurium) vaccine strain brd509 and, upon immunisation, to induce an antibody response against the carried antigen. the h(c) fragment expression cassette containing the transcription/translation signals, h(c) fragment open reading frame and the downstream trpa terminator, was excised from ... | 2003 | 12832114 |
| structural study of binding of flagellin by toll-like receptor 5. | in order to predict the binding regions within the complex formed by toll-like receptor 5 (tlr-5) and flagellin, a complementary hydropathy between the two proteins was sought. a region common to the flagellins of salmonella enterica serovar typhimurium, pseudomonas aeruginosa, and listeria monocytogenes was shown to be hydropathically complementary to the 552-to-561 fragment of tlr-5, whose sequence is eildisrnql. the hydrophobicity profile of this region is shared with flagellins of 377 bacter ... | 2003 | 12837800 |
| [in vitro susceptibility of salmonella enterica serovar typhimurium to reactive oxygen and nitrogen products]. | the aim of this study was to investigate the in-vitro susceptibility of salmonella enterica serovar typhimurium against reactive oxygen and nitrogen intermediates, on five different strains. sh5014 as a parental strain, pp120 as a soxrs mutant, sh7616 as a acrab efflux pump mutant, szh kuen 557 as a standard strain and a clinical isolate, were included to the study. hydrogen peroxide (at 0.125, 0.25, 0.5 mm concentrations) as reactive oxygen intermediate (roi) and deta-no (at 1, 2, 4 mg/ml conce ... | 2003 | 12838675 |
| salmonella enterica serovar typhimurium and listeria monocytogenes acid tolerance response induced by organic acids at 20 degrees c: optimization and modeling. | an acid tolerance response (atr) has been demonstrated in listeria monocytogenes and salmonella enterica serovar typhimurium in response to low ph poised (i.e., adapted) with acetic or lactic acids at 20 degrees c and modeled by using dynamic differential equations. the atr was not immediate or prolonged, and optimization occurred after exposure of l. monocytogenes for 3 h at ph 5.5 poised with acetic acid and for 2 h at ph 5.5 poised with lactic acid and after exposure of s. enterica serovar ty ... | 2003 | 12839765 |
| optimization of a reusable hollow-fiber ultrafilter for simultaneous concentration of enteric bacteria, protozoa, and viruses from water. | the detection and identification of pathogens from water samples remain challenging due to variations in recovery rates and the cost of procedures. ultrafiltration offers the possibility to concentrate viral, bacterial, and protozoan organisms in a single process by using size-exclusion-based filtration. in this study, two hollow-fiber ultrafilters with 50,000-molecular-weight cutoffs were evaluated to concentrate microorganisms from 2- and 10-liter water samples. when known quantities (10(5) to ... | 2003 | 12839786 |
| ingestion of salmonella enterica serotype poona by a free-living mematode, caenorhabditis elegans, and protection against inactivation by produce sanitizers. | free-living nematodes are known to ingest food-borne pathogens and may serve as vectors to contaminate preharvest fruits and vegetables. caenorhabditis elegans was selected as a model to study the effectiveness of sanitizers in killing salmonella enterica serotype poona ingested by free-living nematodes. aqueous suspensions of adult worms that had fed on s. enterica serotype poona were treated with produce sanitizers. treatment with 20 microg of free chlorine/ml significantly (alpha = 0.05) redu ... | 2003 | 12839787 |
| use of pulsed-field gel electrophoresis to characterize the heterogeneity and clonality of salmonella isolates obtained from the carcasses and feces of swine at slaughter. | salmonella enterica isolates were recovered from swine at a collaborating processing plant over a 2-month period in the spring of 2000. in the present study, molecular subtyping by pulsed-field gel electrophoresis (pfge) was performed on the 581 confirmed salmonella isolates from the 84 salmonella-positive samples obtained from the previous study. a total of 32 different pfge pulsotypes were observed visually, and a bionumerics software analysis clustered those pulsotypes into 12 pfge groups. th ... | 2003 | 12839796 |
| nontyphoidal salmonellae in united kingdom badgers: prevalence and spatial distribution. | eighteen (72%) of 25 badger social groups were found to excrete salmonella enterica serovar ried, s. enterica serovar binza, s. enterica serovar agama, or s. enterica serovar lomita. each serovar was susceptible to a panel of antimicrobials. based on results of pulsed-field gel electrophoresis, the s. enterica serovar agama and s. enterica serovar binza isolates were very similar, but two clones each of s. enterica serovar lomita and s. enterica serovar ried were found. badgers excreting s. ente ... | 2003 | 12839821 |
| a rapid and direct real time pcr-based method for identification of salmonella spp. | the aim of this work was the validation of a rapid, real-time pcr assay based on taqman technology for the unequivocal identification of salmonella spp. to be used directly on an agar-grown colony. a real-time pcr system targeting at the salmonella spp. inva gene was optimized and validated through a four times repeated blind experiment performed in two different laboratories including 50 salmonella spp. with representative strains from each of the 5 different salmonella subgenera and 30 non-sal ... | 2003 | 12842485 |
| molecular epidemiology and characterization of plasmid-encoded beta-lactamases produced by tunisian clinical isolates of salmonella enterica serotype mbandaka resistant to broad-spectrum cephalosporins. | we studied 31 clinical isolates of salmonella enterica serotype mbandaka resistant to broad-spectrum cephalosporins and recovered in tunisia over a 5-year period. the transferability of this resistance was demonstrated by conjugation experiments. thirty of the 31 isolates were positive in the double-disk synergy test. by isoelectric focusing analysis, all of the isolates were found to produce a band of beta-lactamase activity with a pi of 5.9. three of these isolates produced an additional band ... | 2003 | 12843024 |
| multistate outbreak of salmonella serotype typhimurium infections associated with drinking unpasteurized milk--illinois, indiana, ohio, and tennessee, 2002-2003. | on december 10, 2002, the clark county combined health district and the ohio department of health (odh) were notified of two hospitalized children infected with salmonella enterica serotype typhimurium. initial investigation implicated consumption of raw, unpasteurized milk purchased at a local combination dairy-restaurant (dairy) during november 27-december 13, 2002, as the cause. this report summarizes the subsequent investigation. because 27 states still allow the sale of raw milk, and organi ... | 2003 | 12844078 |
| bacterial lipopolysaccharide signaling through toll-like receptor 4 suppresses asthma-like responses via nitric oxide synthase 2 activity. | asthma results from an intrapulmonary allergen-driven th2 response and is characterized by intermittent airway obstruction, airway hyperreactivity, and airway inflammation. an inverse association between allergic asthma and microbial infections has been observed. microbial infections could prevent allergic responses by inducing the secretion of the type 1 cytokines, il-12 and ifn-gamma. in this study, we examined whether administration of bacterial lps, a prototypic bacterial product that activa ... | 2003 | 12847273 |
| salmonella septicemia in rheumatoid arthritis patients receiving anti-tumor necrosis factor therapy: association with decreased interferon-gamma production and toll-like receptor 4 expression. | patients treated with antibodies to tumor necrosis factor alpha (tnfalpha) have an increased susceptibility to intracellular infections. we describe 2 patients with rheumatoid arthritis (ra) who developed salmonella septicemia during anti-tnf treatment. the aim of this study was to identify the mechanisms involved in the increased susceptibility of anti-tnf-treated patients to intracellular microorganisms. | 2003 | 12847679 |
| regional dissemination of salmonella enterica serovar enteritidis is season dependent. | to carry out epidemiological typing of clinical isolates of salmonella enterica serovar enteritidis by pulsed-field gel electrophoresis (pfge), random amplified polymorphic dna (rapd) and analysis of their antibiotic resistance. | 2003 | 12848748 |
| investigation of the distribution and control of salmonella enterica serovar enteritidis pt6 in layer breeding and egg production. | investigations were carried out in a layer breeder hatchery, a layer parent rearing farm, a layer parent farm and in a commercial pullet rearing and cage layer farm where salmonella enterica serovar enteritidis (s. enteritidis) pt6 had become established. pt6 was initially found in focal points in the hatchery, such as hatcher ventilation ducting, tray wash areas and waste areas, but improved disinfection was followed by a rapid disappearance of contamination. several different phage types of s. ... | 2003 | 12850912 |
| adrenomedullin expression by gastric epithelial cells in response to infection. | many surface epithelial cells express adrenomedullin, a multifunctional peptide found in a wide number of body and cell systems. recently, we and others have proposed that adrenomedullin has an important novel role in host defense. this peptide has many properties in common with other cationic antimicrobial peptides, including the human beta-defensins. upon exposure of human gastric epithelial cells to viable cells of invasive or noninvasive strains of helicobacter pylori, escherichia coli, salm ... | 2003 | 12853384 |
| immune responses against salmonella enterica serovar enteritidis infection in virally immunosuppressed chickens. | to understand the role of immune mechanisms in protecting chickens from salmonella infections, we examined the immune responses of salmonella enterica serovar enteritidis-infected chickens and the effect of chicken anemia virus (cav), a t-cell-targeted virus, on s. enterica serovar enteritidis-induced immune responses. one-day-old chicks were orally inoculated with s. enterica serovar enteritidis with or without intramuscular injection of cav. the bacterial infection, pathology, and immune respo ... | 2003 | 12853403 |
| vaccination of mice with bacteria carrying a cloned herpesvirus genome reconstituted in vivo. | bacterial delivery systems are gaining increasing interest as potential vaccination vectors to deliver either proteins or nucleic acids for gene expression in the recipient. bacterial delivery systems for gene expression in vivo usually contain small multicopy plasmids. we have shown before that bacteria containing a herpesvirus bacterial artificial chromosome (bac) can reconstitute the virus replication cycle after cocultivation with fibroblasts in vitro. in this study we addressed the question ... | 2003 | 12857893 |
| intracellular expression of the salmonella plasmid virulence protein, spvb, causes apoptotic cell death in eukaryotic cells. | the spv genes carried on the salmonella virulence plasmid are commonly associated with severe systemic infection in experimental animals. the spvb virulence-associated protein has been shown to adp-ribosylate actin, and this enzymatic activity is essential for virulence in mice. here, we present evidence that intracellular expression of spvb protein induces not only disruption of actin filaments but also apoptotic cell death in eukaryotic cells. | 2003 | 12860458 |
| the role of mutators in the emergence of antibiotic-resistant bacteria. | bacteria contain a number of error prevention and error correction systems that maintain genome stability. however, strains exhibiting elevated mutation frequencies have recently been reported amongst natural populations of pathogenic escherichia coli, salmonella enterica, pseudomonas aeruginosa, neisseria meningitidis, helicobacter pylori and streptococcus pneumoniae. the majority of naturally occurring, strong mutators contain defects in the methyl-directed mismatch repair (mmr) system, with m ... | 2003 | 12860461 |
| real-time pcr duplex assay for rickettsia prowazekii and borrelia recurrentis. | rickettsia prowazekii, the etiologic agent for epidemic typhus, and borrelia recurrentis, the etiologic agent of relapsing fever, both utilize the same vector, the human body louse (pediculus humanus), to transmit human disease. we have developed an assay to detect both bacterial pathogens in a single tube utilizing real-time pcr. assays for both agents are specific. the r. prowazekii and b. recurrentis assays do not detect nucleic acid from r. typhi, r. canada, or any of eight spotted fever ric ... | 2003 | 12860643 |
| functions and effectors of the salmonella pathogenicity island 2 type iii secretion system. | salmonella enterica uses two functionally distinct type iii secretion systems encoded on the pathogenicity islands spi-1 and spi-2 to transfer effector proteins into host cells. a major function of the spi-1 secretion system is to enable bacterial invasion of epithelial cells and the principal role of spi-2 is to facilitate the replication of intracellular bacteria within membrane-bound salmonella-containing vacuoles (scvs). studies of mutant bacteria defective for spi-2-dependent secretion have ... | 2003 | 12864810 |
| salmonella type iii effectors pipb and pipb2 are targeted to detergent-resistant microdomains on internal host cell membranes. | the intracellular pathogen, salmonella enterica, translocates type iii effectors across its vacuolar membrane into host cells. herein we describe a new salmonella effector, pipb2, which has sequence similarity to another type iii effector, pipb. in phagocytic cells, pipb2 localizes to the salmonella-containing vacuole (scv) and tubular extensions from the scv, salmonella-induced filaments (sifs). we used the specific targeting of pipb2 in macrophages to characterize sifs in phagocytic cells for ... | 2003 | 12864852 |
| current trends in typhoid fever. | typhoid fever, a systemic infection caused by salmonella enterica serotype typhi, remains an important worldwide cause of morbidity and mortality. endemic cases in the united states are unusual, with most following foreign travel to the indian subcontinent, africa, asia, or latin america. the classic findings of typhoid fever include rose spots, relative bradycardia, and stepwise fevers, but unfortunately these signs are frequently absent. gastrointestinal manifestations may include diffuse abdo ... | 2003 | 12864957 |
| catecholamines and in vitro growth of pathogenic bacteria: enhancement of growth varies greatly among bacterial species. | the purpose of this study was to examine the effects of catecholamines on in vitro growth of a range of bacterial species, including anaerobes. bacteria tested included: porphyromonas gingivalis, bacteriodes fragilis, shigella boydii, shigella sonnie, enterobacter sp, and salmonella choleraesuis. the results of the current study indicated that supplementation of bacterial cultures in minimal medium with norepinephrine or epinephrine did not result in increased growth of bacteria. positive contro ... | 2003 | 12865092 |
| an unusually high occurrence of salmonella enterica serotype paratyphi a in patients with enteric fever. | salmonella enterica serotype paratyphi a has been reported less frequently as a causative agent of enteric fever. reports on the antimicrobial susceptibility of this pathogen are few and varied. an unusually high occurrence of s. paratyphi a was noted in a tertiary care hospital at nagpur, maharashtra during april 2001-september 2002. an effort was made to study the antimicrobial susceptibility pattern and phage types of the isolates. | 2003 | 12866820 |
| fitness cost of fluoroquinolone resistance in salmonella enterica serovar typhimurium. | high-level fluoroquinolone (fq) resistance is still infrequent in salmonellae, compared with other pathogenic enterobacteria. data provided in this work support the hypothesis that the mechanisms that confer high-level fq resistance on salmonellae have a prohibitive fitness cost and may thus limit the emergence of highly resistant clones. in vitro mutants that were highly resistant to ciprofloxacin (mic = 8 and 16 micro g ml(-1)) showed generation times 1.4- and 2-fold longer than their parent s ... | 2003 | 12867565 |
| molecular epidemiology of ampicillin-resistant clinical isolates of salmonella enterica serovar typhimurium. | thirty-nine multiresistant salmonella enterica serovar typhimurium (s. typhimurium) isolates were obtained from 33 children and 6 adults hospitalized from 1996 to 1999 in the university hospital of amiens (france). s. typhimurium was cultured from stools (n=36), blood samples (n=2) and peritoneal fluid (n=1). these isolates were characterized by biotyping, antibiotic susceptibility test, rapd-pcr, and pfge typing. emergence of pentaresistant s. typhimurium isolates (phenotype acssute) was observ ... | 2003 | 12868659 |
| analysis of the clonal relationship among clinical isolates of salmonella enterica serovar infantis by different typing methods. | salmonella infantis has been the second most common serovar in argentina in the last two years, being isolated mostly from paediatric hospitalised patients. in order to determine the clonal relationship among salmonella infantis strains, we examined 15 isolates from paediatric patient faeces in argentina (12 geographically related and 3 geographically non-related) by using antimicrobial susceptibility, plasmid profiling, repetitive extragenic palindromic (rep) pcr, enterobacterial repetitive int ... | 2003 | 12870059 |
| tolerance to stress and ability of acid-adapted and non-acid-adapted salmonella enterica serovar typhimurium dt104 to invade and survive in mammalian cells in vitro. | the ability of acid-adapted (aa) and non-acid-adapted (na) salmonella enterica serovar typhimurium definitive type 104 (dt104) strains to invade and multiply in mammalian cells in vitro and to survive stress conditions was examined. dt104 and non-dt104 strains were grown in tryptic soy broth without glucose (na) or in tryptic soy broth containing 1% glucose (aa) for 18 h at 37 degrees c. the invasiveness of dt104 strains in j774a.1 macrophage and int407 intestinal cell lines was not more extensi ... | 2003 | 12870742 |
| impact of commercial preharvest transportation and holding on the prevalence of salmonella enterica in cull sows. | the objective of this study was to examine the prevalence of salmonella enterica in cull sows at various stages from the farm to the abattoir. cull sows (n=181) were sampled over 10 weeks. fecal samples (10 g each) were collected on the farm ca. 24 h before loading and at the live-hog market ca. 3 h before loading. samples (ileocecal lymph nodes, cecal contents, feces from the transverse colon, ventral thoracic lymph nodes, subiliac lymph nodes, sponge swabs of the left and right carcass section ... | 2003 | 12870744 |
| multiplex pcr for the direct detection of salmonella enterica from chicken, lamb and beef food products. | three sets of known salmonella enterica-specific primers were used collectively, for the first time, to evaluate the use of multiplex polymerase chain reaction (m-pcr) as a diagnostic tool to detect salmonella enterica in naturally contaminated meat and poultry products. for this purpose a total of 300 samples representing the most frequently used fresh and frozen meat (beef and lamb) and poultry (chicken) products (whole, cut, ground, and processed) were collected from eight locations within ir ... | 2003 | 12872313 |
| evaluation of treatment and prophylaxis with nitrofurans and comparison with alternative antimicrobial agents in experimental salmonella enterica serovar enteritidis infection in chicks. | the ability of the nitrofuran antimicrobial agents furazolidone and furaltadone to prevent, reduce or eliminate salmonella enterica serovar enteritidis pt4 infection in artificially challenged day-old chicks was evaluated. treating the birds with the nitrofurans failed to eliminate established infections with either furazolidone-resistant (fzr) or furazolidone-sensitive (fzs) strains. simultaneous administration of the nitrofurans to day-old chicks challenged with fzs failed to prevent infection ... | 2003 | 12872826 |
| human alveolar macrophages infected by virulent bacteria expressing sipb are a major source of active interleukin-18. | recent publications have demonstrated that the protease caspase-1 is responsible for the processing of pro-interleukin 18 (il-18) into the active form. studies on cell lines and murine macrophages have shown that the bacterial invasion factor sipb activates caspase-1, triggering cell death. thus, we investigated the role of sipb in the activation and release of il-18 in human alveolar macrophages (am), which are the first line of defense against inhaled pathogens. under steady-state conditions, ... | 2003 | 12874316 |
| construction, characterization, and immunogenicity of an attenuated salmonella enterica serovar typhimurium pgte vaccine expressing fimbriae with integrated viral epitopes from the spic promoter. | transmissible gastroenteritis virus (tgev) is a porcine coronavirus that causes diarrhea, leading to near 100% mortality in neonatal piglets with corresponding devastating economic consequences. for the protection of neonatal and older animals, oral live vaccines present the attractive property of inducing desired mucosal immune responses, including colostral antibodies in sows--an effective means to passively protect suckling piglets. newly attenuated salmonella vaccine constructs expressing tg ... | 2003 | 12874347 |
| induction of antimicrobial pathways during early-phase immune response to salmonella spp. in murine macrophages: gamma interferon (ifn-gamma) and upregulation of ifn-gamma receptor alpha expression are required for nadph phagocytic oxidase gp91-stimulated oxidative burst and control of virulent salmonella spp. | the effect of gamma interferon (ifn-gamma) on elevation of reactive oxygen species and the viability of virulent wild-type and avirulent mutants of salmonella enterica serovar typhimurium and s. enterica serovar infantis was studied in a murine macrophage cell line (j774.2 cells). s. enterica serovar typhimurium 14028 phop and a rough lipopolysaccharide mutant of s. enterica serovar infantis 1326/28 (phi(r)) (avirulent mutants) induced nadph phagocytic oxidase gp91 (gp91(phox)) activity and a si ... | 2003 | 12874355 |
| secreted effector proteins of salmonella enterica serotype typhimurium elicit host-specific chemokine profiles in animal models of typhoid fever and enterocolitis. | infection of bovine ligated loops with the salmonella enterica serotype typhimurium wild type but not a sipa sopabde2 mutant resulted in fluid accumulation, polymorphonuclear cell infiltration, and expression of cxc chemokines, particularly gro alpha. none of these sipa sopabde2-dependent responses was observed in murine-ligated loops. the majority of gro alpha transcripts localized to bovine intestinal epithelium. thus, different disease outcomes between mice (i.e., no diarrhea) and calves (i.e ... | 2003 | 12874363 |
| systemic and local cytokine response of young piglets to oral infection with salmonella enterica serotype typhimurium. | one-week-old breast-fed miniature piglets were orally infected either with virulent lt2 strain or with a non-virulent sf1591 rough mutant of salmonella typhimurium for 1 d. both microorganisms were cultivated from mesenteric lymph nodes but not from the blood of infected piglets. interleukins (il) 1 beta, 8, 18, tumor necrosis factor alpha (tnf-alpha) and interferon gamma (ifn-gamma) were quantified by elisa in plasma and washes of a terminal part of the small bowel. in plasma, cytokines were mo ... | 2003 | 12879755 |
| antimicrobial resistance of salmonella enterica serotype typhi in dakar, senegal. | 2003 | 12884182 | |
| the effect of nitric oxide combined with fluoroquinolones against salmonella enterica serovar typhimurium in vitro. | two regulons, soxrs and marrab, are associated with resistance to quinolones or multiple antibiotic in salmonella enterica serovar typhimurium. these regulons are activated by nitric oxide and redox-cycling drugs, such as paraquat and cause on activation of the acrab-encoded efflux pump. in this study, we investigated the effect of nitric oxide (no) alone and in combination with ofloxacin, ciprofloxacin, and pefloxacin against s. typhimurium clinical isolates and mutant strains in vitro. we did ... | 2003 | 12886427 |
| transcription increases multiple spontaneous point mutations in salmonella enterica. | the spontaneous rate of g.c-->a.t mutations and a hotspot t.a-->g.c transversion are known to increase with the frequency of transcription-increases that have been ascribed primarily to processes that affect only these specific mutations. to investigate how transcription induces other spontaneous point mutations, we tested for its effects in repair-proficient salmonella enterica using reversion assays of chromosomally inserted alleles. our results indicate that transcription increases rates of a ... | 2003 | 12888512 |
| msdna-st85, a multicopy single-stranded dna isolated from salmonella enterica serovar typhimurium lt2 with the genomic analysis of its retron. | bacterial reverse transcriptase is responsible for the production of a small satellite dna-rna complex called multicopy single-stranded dna (msdna) that has been found in a wide variety of gram-negative bacteria. here we describe the isolation and characterization of a novel msdna, msdna-st85, from salmonella enterica serovar typhimurium lt2. we determined the nucleotide sequence of msdna-st85 and the location of retron-st85 on the chromosome that is responsible for msdna-st85 production by anal ... | 2003 | 12892895 |
| dape can function as an aspartyl peptidase in the presence of mn2+. | extracts of a multiply peptidase-deficient (pepnabdpqte iada iaaa) salmonella enterica serovar typhimurium strain contain an aspartyl dipeptidase activity that is dependent on mn(2+). purification of this activity followed by n-terminal sequencing of the protein suggested that the mn(2+)-dependent peptidase is dape (n-succinyl-l,l-diaminopimelate desuccinylase). a dape chromosomal disruption was constructed and transduced into a multiply peptidase-deficient (mpd) strain. crude extracts of this s ... | 2003 | 12896993 |
| residues c123 and d58 of the 2-methylisocitrate lyase (prpb) enzyme of salmonella enterica are essential for catalysis. | the prpb gene of salmonella enterica serovar typhimurium lt2 encodes a protein with 2-methylisocitrate (2-mic) lyase activity, which cleaves 2-mic into pyruvate and succinate during the conversion of propionate to pyruvate via the 2-methylcitric acid cycle. this paper reports the isolation and kinetic characterization of wild-type and five mutant prpb proteins. wild-type prpb protein had a molecular mass of approximately 32 kda per subunit, and the biologically active enzyme was comprised of fou ... | 2003 | 12897003 |
| genomic profiling of iron-responsive genes in salmonella enterica serovar typhimurium by high-throughput screening of a random promoter library. | the importance of iron to bacteria is shown by the presence of numerous iron-scavenging and transport systems and by many genes whose expression is tightly regulated by iron availability. we have taken a global approach to gene expression analysis of salmonella enterica serovar typhimurium in response to iron by combining efficient, high-throughput methods with sensitive, luminescent reporting of gene expression using a random promoter library. real-time expression profiles of the library were g ... | 2003 | 12897017 |
| a burkholderia pseudomallei type iii secreted protein, bope, facilitates bacterial invasion of epithelial cells and exhibits guanine nucleotide exchange factor activity. | we report the characterization of bope, a type iii secreted protein that is encoded adjacent to the burkholderia pseudomallei bsa locus and is homologous to salmonella enterica sope/sope2. inactivation of bope impaired bacterial entry into hela cells, indicating that bope facilitates invasion. consistent with this notion, bope expressed in eukaryotic cells induced rearrangements in the subcortical actin cytoskeleton, and purified bope exhibited guanine nucleotide exchange factor activity for cdc ... | 2003 | 12897019 |
| the gyr genes of salmonella enterica serovar typhimurium are repressed by the factor for inversion stimulation, fis. | the dna sequence of the gyr genes from salmonella enterica serovar typhimurium revealed strong similarity between gyrb and its counterpart in escherichia coli. however, the gyra gene showed similarity to the e. coli homologue only downstream from the pribnow box of the promoter, with the sequence upstream diverging markedly. since this region encompasses the binding sites for the fis dna binding protein in e. coli, we investigated the possibility that the gyra genes in the two species might diff ... | 2003 | 12898222 |
| single versus double testing of meat-juice samples for salmonella antibodies, in the danish pig-herd surveillance programme. | in denmark, a national serological surveillance-and-control programme for salmonella in pigs has been in operation since 1995. the programme is based on the danish mix-elisa and uses double testing (two elisa-wells used per sample) of meat-juice samples taken in relation to slaughter. all herds are classified monthly into one of the three levels; the classification is based on the percentage of positive serological results in the previous 3 months. in connection with evaluation of the programme ... | 2003 | 12900155 |
| the agreement in isolation of salmonella enterica iiib 61:k:1,5,(7) from rectal swabs, faecal samples and ileo-caecal lymph nodes from sheep. | the agreements between various culturing-method combinations and specimens to detect sheep naturally infected by salmonella enterica iiib 61:k:1,5,(7) were tested. rectal swabs, faecal samples and ileo-caecal lymph nodes were collected from each individual. rectal swabs called "group i" (n = 54) were cultured directly on selective media (selenite cysteine, sc). rectal swabs called "group ii" (n = 47) were pre-incubated in buffered peptone water. the four other combinations of culturing-method an ... | 2003 | 12900156 |
| longitudinal serological responses to salmonella enterica of growing pigs in a subclinically infected herd. | a longitudinal survey was conducted in france in a subclinically salmonella-infected farrow-to-finish pig farm to describe the time-course of the serological response to salmonella enterica in growing pigs. we used three batches of sows and their corresponding litters (n = 31 litters). among these, 256 pigs randomly selected and individually identified were followed from the first week of age until slaughter. serial individual blood samples were submitted to indirect salmonella-elisa testing. sa ... | 2003 | 12900159 |
| advances in the development of bacterial vector technology. | the demand for new and improved vaccines against human diseases has continued unabated over the past century. while the need continues for traditional vaccines in areas such as infectious diseases, there is an increasing demand for new therapies in nontraditional areas, such as cancer treatment, bioterrorism and food safety. prompted by these changes, there has been a renewed interest in the application and development of live, attenuated bacteria expressing foreign antigens as vaccines. the app ... | 2003 | 12901595 |
| characterization of the rpos status of clinical isolates of salmonella enterica. | the stationary-phase-inducible sigma factor, sigma(s) (rpos), is the master regulator of the general stress response in salmonella and is required for virulence in mice. rpos mutants can frequently be isolated from highly passaged laboratory strains of salmonella: we examined the rpos status of 116 human clinical isolates of salmonella, including 41 salmonella enterica serotype typhi strains isolated from blood, 38 s. enterica serotype typhimurium strains isolated from blood, and 37 salmonella s ... | 2003 | 12902215 |
| preslaughter holding environment in pork plants is highly contaminated with salmonella enterica. | the objective of this study was to determine whether abattoir pens can provide a salmonella enterica infection source during the 2 to 4 h of preharvest holding. previous work has suggested that pigs may be getting infected, but little has been reported on the environmental contamination of abattoir holding pens. for 24 groups of pigs studied ( approximately 150 animals/group) at two high-capacity abattoirs, six pooled fecal samples (n, 10 per pool) were collected from each transport trailer imme ... | 2003 | 12902233 |
| survival of salmonella enterica in freshwater and sediments and transmission by the aquatic midge chironomus tentans (chironomidae: diptera). | survival of a nalidixic acid-resistant strain of salmonella enterica serovar typhimurium mr-dt-104 in water and sediments was tested using artificially contaminated aquaria. water samples remained culture positive for salmonella for up to 54 days. sediment samples were culture positive up to 119 days. in addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. we evaluated the acquisition of mr-dt-104 by chironomids from contaminate ... | 2003 | 12902242 |
| colonization of arabidopsis thaliana with salmonella enterica and enterohemorrhagic escherichia coli o157:h7 and competition by enterobacter asburiae. | enteric pathogens, such as salmonella enterica and escherichia coli o157:h7, have been shown to contaminate fresh produce. under appropriate conditions, these bacteria will grow on and invade the plant tissue. we have developed arabidopsis thaliana (thale cress) as a model system with the intention of studying plant responses to human pathogens. under sterile conditions and at 100% humidity, s. enterica serovar newport and e. coli o157:h7 grew to 10(9) cfu g(-1) on a. thaliana roots and to 2 x 1 ... | 2003 | 12902287 |
| reduction of experimental salmonella and campylobacter contamination of chicken skin by application of lytic bacteriophages. | lytic bacteriophages, applied to chicken skin that had been experimentally contaminated with salmonella enterica serovar enteritidis or campylobacter jejuni at a multiplicity of infection (moi) of 1, increased in titer and reduced the pathogen numbers by less than 1 log(10) unit. phages applied at a moi of 100 to 1,000 rapidly reduced the recoverable bacterial numbers by up to 2 log(10) units over 48 h. when the level of salmonella contamination was low (< log(10) 2 per unit area of skin) and th ... | 2003 | 12902308 |
| antimicrobial susceptibilities of salmonella strains isolated from humans, cattle, pigs, and chickens in the netherlands from 1984 to 2001. | we monitored antimicrobial susceptibility data for salmonella strains isolated from humans, cattle, pigs, and chickens in the netherlands from 1984 to 2001 in order to provide insight into the dynamics of resistance over time. the strains were tested for their susceptibilities to seven antimicrobial agents by the agar diffusion method. resistance was most common in salmonella enterica subsp. enterica serovar typhimurium. among the strains from humans, pigs, and chickens, it was found that the le ... | 2003 | 12904357 |
| differences in gene content among salmonella enterica serovar typhi isolates. | we used a nonredundant microarray of the salmonella enterica serovar typhimurium lt2 and typhi ct18 genomes to assess the genomic content of a diverse set of isolates of serovar typhi. comparative genomic hybridization revealed 13 regions of absent or divergent gene content in the eight typhi strains examined compared to typhi ct18. in particular, two typhi ct18 prophage regions, sty1048 to sty1077 and sty2038 to sty2077, as well as a five-gene islet (sty3188 to sty3193) were absent or divergent ... | 2003 | 12904395 |
| failure to detect salmonella enterica serovar dublin on aes laboratoire salmonella agar plate. | 2003 | 12904443 |