Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| putting salmonella contamination in perspective. | 2003 | 12652398 | |
| global regulation of the salmonella enterica serovar typhimurium major porin, ompd. | the ompd porin is the most abundant outer membrane protein in salmonella enterica serovar typhimurium and represents about 1% of total cell protein. unlike the case with the less abundant ompc and ompf porins, the stoichiometry of ompd in the outer membrane does not change in response to changes in osmolarity. the abundance of ompd increases in response to anaerobiosis and decreases in response to low ph, conditions encountered by serovar typhimurium during the infection of its murine host. by c ... | 2003 | 13129964 |
| a new pathway for salvaging the coenzyme b12 precursor cobinamide in archaea requires cobinamide-phosphate synthase (cbib) enzyme activity. | the ability of archaea to salvage cobinamide has been under question because archaeal genomes lack orthologs to the bacterial nucleoside triphosphate:5'-deoxycobinamide kinase enzyme (cobu in salmonella enterica). the latter activity is required for cobinamide salvaging in bacteria. this paper reports evidence that archaea salvage cobinamide from the environment by using a pathway different from the one used by bacteria. these studies demanded the functional characterization of two genes whose p ... | 2003 | 14645280 |
| pathways leading from bara/sira to motility and virulence gene expression in salmonella. | the bara and sira genes of salmonella enterica serovar typhimurium encode a two-component sensor kinase and a response regulator, respectively. this system increases the expression of virulence genes and decreases the expression of motility genes. in this study, we examined the pathways by which sira affects these genes. we found that the master regulator of flagellar genes, flhdc, had a positive regulatory effect on the primary regulator of intestinal virulence determinants, hila, but that hila ... | 2003 | 14645287 |
| invb is a type iii secretion-associated chaperone for the salmonella enterica effector protein sope. | sope is a bacteriophage-encoded effector protein of salmonella enterica serovar typhimurium that is translocated into the cytosol of eukaryotic cells by a type iii secretion system (ttss) (w.-d. hardt, h. urlaub, and j. e. galán, proc. natl. acad. sci. usa 95:2574-2579, 1998; m. w. wood, r. rosqvist, p. b. mullan, m. h. edwards, and e. e. galyov, mol. microbiol. 22:327-338, 1996). in this study, we provide evidence that an unlinked gene carried within the salmonella pathogenicity island 1 (spi-1 ... | 2003 | 14645290 |
| [case report: porcine circovirus type 2 infection in an european wild boar (sus scrofa) in the state of brandenburg, germany]. | this case represents the first case of porcine circovirus type 2 (pcv-2)--infection in a free living european wild boar associated with morphological lesions, which are regarded as characteristic for postweaning multisystemic wasting syndrome (pmws) in domestic pigs. the animal, an approximately 10 month old male, was found dead in a rural area within the state of brandenburg, germany. the closest commercial pig farm is located in 3 km distance from the spot where the carcass was found. at necro ... | 2003 | 14650740 |
| clonal circulation of salmonella enterica serotype heidelberg in italy? | phenotypic and genetic characteristics of 21 strains of salmonella serotype heidelberg isolated in the years 1999-2003 from different sources in italy were studied. susceptibility patterns, plasmid analysis, and pfge were used as epidemiological markers. although non-homogeneous drug resistance patterns and plasmid profiles had been detected, pfge patterns suggest the hypothesis of a nationwide clonal spread of this serotype associated with poultry. | 2003 | 14684884 |
| genes responsible for anaerobic fumarate and arginine metabolism are involved in growth suppression in salmonella enterica serovar typhimurium in vitro, without influencing colonisation inhibition in the chicken in vivo. | from a collection of over 2800 salmonella enterica subspecies enterica serotype typhimurium f98 tn5-tc1 insertion mutants 14 were identified as expressing growth-non-suppressive phenotype under strict anaerobic conditions. sequence analysis of regions flanking the tn insertions revealed that most of the selected mutants were defective in genes contributing to the anaerobic fumarate uptake and generation (insertions in dcua, dcub and aspa), or to the anaerobic l-arginine utilisation pathway (inse ... | 2003 | 14654290 |
| recovery of salmonella enterica from seropositive finishing pig herds. | the aim of this study was to assess the probability of detecting salmonella from pen faecal samples in seropositive classified finishing pig herds. the study involved 77 herds from denmark (20), the netherlands (20), greece (17) and germany (20). the serological herd status was determined by the blood-sampling of 50 finishing pigs. bacteriological sampling was performed by 20 pen faecal samples per herd. over-all, 47% of the blood samples had an od% larger than 10 and 23% larger than 40. salmone ... | 2003 | 14654291 |
| the attenuated sopb mutant of salmonella enterica serovar typhimurium has the same tissue distribution and host chemokine response as the wild type in bovine peyer's patches. | salmonella enterica serovar typhimurium is an important cause of enteric infections in farm animals and it is one of the most frequent food borne infections worldwide. serovar typhimurium lacking the sopb gene is attenuated for induction of host inflammatory response and fluid accumulation into the intestinal lumen, which correlates with clinical diarrhea. sopb is an inositol phosphate phosphatase, but its exact role in the pathogenesis of salmonellosis is still unclear. we employed the bovine i ... | 2003 | 14654296 |
| [genetic fingerprinting (pfge) of bacterial isolates for their molecular epidemiology]. | the determination of fragment patterns of bacterial genomic dna after digestion with long-range-cutting restriction enzymes and their separation in pulsed-field-gelelectrophoresis is currently regarded as reliable fingerprinting tool for surveillance and identification of infectious sources and routes of bacterial pathogens. the pfge based molecular fingerprinting has been applied and used for a broad range of bacterial species. as a prerequisite for its application in national and international ... | 2003 | 14655625 |
| th1-th2 response in hyperprolactinemic mice infected with salmonella enterica serovar typhimurium. | prolactin (prl) is a pituitary hormone and a cytokine known to regulate several physiological functions. it plays a role in modulating the immune system of rodents and humans. a hormonal protection against listeria and salmonella infections has been previously ascribed to effects of prl on immunocompetent cells. here, the role of prl in the th1-th2 response was evaluated based on the pattern of cytokines release by splenocytes from hyperprolactinemic mice infected with salmonella enterica serova ... | 2003 | 14656695 |
| lightcycler gyra mutation assay (gama) identifies heterogeneity in gyra in salmonella enterica serotypes typhi and paratyphi a with decreased susceptibility to ciprofloxacin. | mutations in gyra in strains of salmonella enterica serotypes typhi and paratyphi a have been characterised by a lightcycler-based pcr-hybridisation gyra mutation assay (gama) and by dna sequencing. four mutations (ser-83 to phe, asp-87 to asn, ser-83 to tyr and asp-87 to gly) have been identified in 13 strains of typhi and three strains of paratyphi a resistant to nalidixic acid (=nal(r)) and with decreased susceptibility to ciprofloxacin (=cp(l)), with the mutation ser-83 to phe predominating. ... | 2003 | 14659662 |
| single-copy green fluorescent protein gene fusions allow accurate measurement of salmonella gene expression in vitro and during infection of mammalian cells. | we developed a reliable and flexible green fluorescent protein (gfp)-based system for measuring gene expression in individual bacterial cells. until now, most systems have relied upon plasmid-borne gfp gene fusions, risking problems associated with plasmid instability. we show that a recently developed gfp variant, gfp+, is suitable for assessing bacterial gene expression. various gfp+ transcriptional fusions were constructed and integrated as single copies into the chromosome of salmonella ente ... | 2003 | 14660401 |
| detection of a salmonella enterica serovar california strain spreading in spanish feed mills and genetic characterization with dna microarrays. | we performed an epidemiological study on salmonella isolated from raw plant-based feed in spanish mills. overall, 32 different salmonella serovars were detected. despite its rare occurrence in humans and animals, salmonella enterica serovar california was found to be the predominant serovar in spanish feed mills. different typing techniques showed that isolates of this serovar were genetically closely related, and comparative genomic hybridization using microarray technology revealed 23 s. enter ... | 2003 | 14660409 |
| a salmonella protein causes macrophage cell death by inducing autophagy. | salmonella enterica, the causative agent of food poisoning and typhoid fever, induces programmed cell death in macrophages, a process found to be dependent on a type iii protein secretion system, and sipb, a protein with membrane fusion activity that is delivered into host cells by this system. when expressed in cultured cells, sipb caused the formation of and localized to unusual multimembrane structures. these structures resembled autophagosomes and contained both mitochondrial and endoplasmic ... | 2003 | 14662750 |
| salmonella rapidly kill dendritic cells via a caspase-1-dependent mechanism. | dendritic cells provide a critical link between innate and acquired immunity. in this study, we demonstrate that the bacterial pathogen salmonella enterica serovar typhimurium can efficiently kill these professional phagocytes via a mechanism that is dependent on sipb and the salmonella pathogenicity island 1-encoded type iii protein secretion system. rapid phosphatidylserine redistribution, caspase activation, and loss of plasma membrane integrity were characteristic of dendritic cells infected ... | 2003 | 14662878 |
| characterization of salmonella enterica serotype newport isolated from humans and food animals. | salmonella enterica serotype newport isolates resistant to at least nine antimicrobials (including extended-spectrum cephalosporins), known as serotype newport mdr-ampc isolates, have been rapidly emerging as pathogens in both animals and humans throughout the united states. resistance to extended-spectrum cephalosporins is associated with clinical failures, including death, in patients with systemic infections. in this study, 87 salmonella serotype newport strains were characterized by pulsed-f ... | 2003 | 14662912 |
| salmonella enterica pneumonia in a patient with lung cancer. | a case of life-threatening salmonella enterica serotype enteritidis pneumonia in a febrile patient with lung cancer is described. the organism was isolated from the sputum, the protected specimen brush material of bronchial secretions, and the stool. despite the early administration of appropriate and adequate treatment, the patient died 7 days after the onset of the infection. | 2003 | 14662992 |
| fatal case of salmonella enterica subsp. arizonae gastroenteritis in an infant with microcephaly. | salmonella enterica subsp. arizonae is a common gut inhabitant of reptiles, with snakes as the most common reservoir. though human cases due to this organism are exceedingly rare, it may infect young infants and immunocompromised individuals with a history of intimate associations with reptiles. gastroenteritis is the most common presentation; others include peritonitis, pleuritis, osteomyelitis, meningitis, and bacteremia. we report a fatal case of s. enterica subsp. arizonae gastroenteritis in ... | 2003 | 14662995 |
| helicobacter pylori flagellins have very low intrinsic activity to stimulate human gastric epithelial cells via tlr5. | helicobacter pylori is a flagellated chronic pathogen, which colonizes the gastric mucus and mucosal cell surfaces. flagella and motility are essential for the survival of this bacterium in the stomach environment. flagellins of several bacterial species are potent activators of the human innate immune system by binding to toll-like receptor 5 (tlr5). the possible role of the two h. pylori flagellins flaa and flab in stimulation of the innate immune system and induction of il-8 release by human ... | 2003 | 14670447 |
| biosynthesis of o-antigens: genes and pathways involved in nucleotide sugar precursor synthesis and o-antigen assembly. | the o-antigen is an important component of the outer membrane of gram-negative bacteria. it is a repeat unit polysaccharide and consists of a number of repeats of an oligosaccharide, the o-unit, which generally has between two and six sugar residues. o-antigens are extremely variable, the variation lying in the nature, order and linkage of the different sugars within the polysaccharide. the genes involved in o-antigen biosynthesis are generally found on the chromosome as an o-antigen gene cluste ... | 2003 | 14670712 |
| limited boundaries for extensive horizontal gene transfer among salmonella pathogens. | recombination is thought to be rare within salmonella, as evidenced by absence of gene transfer among sarc strains that represent the broad genetic diversity of the eight primary subspecies of this common facultative intracellular pathogen. we adopted a phylogenetic approach to assess recombination within the muts gene of 70 sarb strains, a genetically homogeneous population of salmonella enterica subspecies i strains, which have in common the ability to infect warm-blooded animals. we report he ... | 2003 | 14671318 |
| transfer of salmonella and campylobacter from stainless steel to romaine lettuce. | the degree of transfer of campylobacter jejuni and salmonella enterica serovar typhimurium was evaluated from a stainless steel contact surface to a ready-to-eat food (lettuce). stainless steel coupons (25 cm2) were inoculated with a 20-microl drop of either c. jejuni or salmonella typhimurium to provide an inoculum level of approximately 10(6) cfu/28 mm2. wet and dry lettuce (lactuca sativa var. longifolia) pieces (9 cm2) were placed onto the inoculated stainless steel surface for 10 s after th ... | 2003 | 14672218 |
| detection of salmonella enterica somatic groups c1 and e1 by pcr-enzyme-linked immunosorbent assay. | objectives of this study were to develop a pcr-based enzyme-linked immunosorbent assay (pcr-elisa) for identification of salmonella enterica somatic groups c1 and e1 and to evaluate this procedure along with a pcr-elisa procedure for s. enterica somatic groups b, c2, and d in a masked study. primers were selected from the rfb gene cluster, which is responsible for biosynthesis of o antigens of salmonella lipopolysaccharide. previously serogrouped salmonella isolates (n = 169) were used to determ ... | 2003 | 14672240 |
| pcrh of pseudomonas aeruginosa is essential for secretion and assembly of the type iii translocon. | pseudomonas aeruginosa harbors a type iii secretion system that translocates antihost effectors into an infected eukaryotic cell. pcrh is a key component of type iii secretion in this essential virulence strategy. in the absence of pcrh, p. aeruginosa is translocation deficient because of a specific reduction in presecretory stability and subsequent secretion of popb and popd, 2 proteins essential for the translocation process. pcrh exerts this chaperone function by binding directly to popb and ... | 2003 | 14673772 |
| increased lymphocyte subpopulations and macrophages in the ovaries and oviducts of laying hens infected with salmonella enterica serovar enteritidis. | salmonella enterica serovar enteritidis (se) is a causative agent for human food poisoning cases throughout the world. the ovaries and the oviducts of the laying hens are the major sites of se colonization from which vertical transmission to eggs occurs. in this study, salmonella-induced changes in t lymphocytes, b lymphocytes and macrophages in the ovaries and oviducts were assessed after primary and secondary experimental inoculations of laying hen with se. statistically significant increases ... | 2003 | 14676008 |
| fluoroquinolone resistance linked to gyra, gyrb, and parc mutations in salmonella enterica typhimurium isolates in humans. | we report two cases of infection with clonally unrelated, high-level ciprofloxacin-resistant, b-lactamase-producing strains of salmonella enterica typhimurium. resistance was caused by four topoisomerase mutations, in gyra, gyrb, and parc and increased drug efflux. ciprofloxacin treatment failed in one case. in the second case, reduced susceptibility to third-generation cephalosporins occurred after initial treatment with these drugs and may explain the treatment failure with ceftriaxone. | 2003 | 14718091 |
| effect of disinfectants on the metabolism of salmonella enterica serovar enteritidis. | antimicrobial activity of 19 commercially manufactured disinfectant substances on a salmonella enteritidis strain was determined. the substances represented 8 quaternary ammonium salts (qas) and 10 qas combined with other additives. the antimicrobial efficacy was characterized by influencing the growth of bacterial cells expressed as mic and ed50 values as well as by the inhibition of the incorporation rate of 14c-adenine and 14c-leucine. according to their efficacy the disinfectants were divide ... | 2003 | 14976722 |
| 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 |
| treatment of experimental sepsis-induced immunoparalysis with tnf. | following a severe septic abdominal infection induced by sublethal cecal ligation and puncture (clp) in mice, a phase of depressed immune reactivity occurred two days after clp characterized by a reduced capacity to produce tnf. to determine whether this reduced tnf production causes immunoparalysis as determined by increased susceptibility to bacterial infection and whether therapeutic tnf substitution can be beneficial during this phase, a super-infection with salmonella enterica serovar typhi ... | 2003 | 14748511 |
| a multistate outbreak of salmonella enterica serotype newport infection linked to mango consumption: impact of water-dip disinfestation technology. | fresh produce increasingly is recognized as an important source of salmonellosis in the united states. in december 1999, the centers for disease control and prevention detected a nationwide increase in salmonella serotype newport (sn) infections that had occurred during the previous month. sn isolates recovered from patients in this cluster had indistinguishable pulsed-field gel electrophoresis (pfge) patterns (which identified the outbreak strain), suggesting a common source. seventy-eight pati ... | 2003 | 14689335 |
| a fluorescent amplified fragment length polymorphism study of salmonella enterica serovar sofia, the major salmonella serovar isolated from chickens in australia. | fluorescent amplified fragment length polymorphism (faflp) analysis was performed on 68 isolates of salmonella enterica subsp. salamae serovar sofia (s. sofia). fifty eight isolates were obtained over a period of approximately 15 years from a range of human, chicken industry and environmental sources throughout australia. a further ten isolates were identified from human and poultry sources in israel from 1972 to 1987. analysis of faflp profiles for fragments between 50 to 500 base pairs in leng ... | 2003 | 14695065 |
| ofloxacin minimum inhibitory concentration versus disk diffusion zone diameter for salmonella enterica serovar typhi isolates: problems in the detection of ofloxacin resistance. | using the guidelines of the national committee for clinical laboratory standards (nccls), a total of 421 blood culture isolates of salmonella enterica serovar typhi obtained during 1991-2001 were tested for susceptibility to ofloxacin (ofx) by the disc diffusion method, and for the determination of minimum inhibitory concentration (mic) values of ofx by the agar dilution method. among 421 isolates, 248 were fully ofx-sensitive showing mics of 0.0125-0.075 microg/ml and inhibitory zone diameters ... | 2003 | 14695432 |
| chromosomal transferable multidrug resistance genes of salmonella enterica serovar infantis. | 2003 | 14695434 | |
| a microcantilever-based pathogen detector. | the ability to detect small amounts of materials, especially bacterial organisms, is important for medical diagnostics and national security issues. engineered micromechanical systems provide one approach for constructing multifunctional, highly sensitive, real-time, immunospecific biological detectors. we present qualitative detection of specific salmonella enterica strains using a functionalized silicon nitride microcantilever. detection is achieved due to a change in the surface stress on the ... | 2003 | 14696978 |
| molecular characterization of plasmids with antimicrobial resistant genes in avian isolates of pasteurella multocida. | the complete nucleotide sequences of two plasmids from avian isolates of pasteurella multocida that caused outbreaks of fowl cholera in taiwan were determined. the entire sequences of the two plasmids, designated as pjr1 and pjr2, were 6792 bp and 5252 bp. sequence analysis showed that the plasmid pjr1 contained six major genes: the first gene (sulii) encoded a type ii sulfonamide resistant dihydropteroate synthase, the second gene (tetg) encoded a tetracycline resistance protein, the third gene ... | 2003 | 14708986 |
| salmonella enterica serovar enteritidis, japan. | 2003 | 14725308 | |
| screening method for salmonella enterica serovar typhi and serovar paratyphi a with reduced susceptibility to fluoroquinolones by pcr-restriction fragment length polymorphism. | salmonella enterica serovar typhi and serovar paratyphi a with reduced susceptibility to fluoroquinolones (mics of ciprofloxacin, 0.25 to 2 microg/ml) have a mutation at codon either ser-83 or asp-87 of gyra gene. a screening method by pcr-restriction fragment length polymorphism (pcr-rflp) was designed to screen the mutations at codon ser-83 and asp-87 of the gyra gene of s. enterica serovar typhi and serovar paratyphi a clinical isolates. this method successfully screened the gyra mutations of ... | 2003 | 12680720 |
| dna fingerprinting of salmonella enterica subsp. enterica serovar typhimurium with emphasis on phage type dt104 based on variable number of tandem repeat loci. | seventy-eight human and environmental strains of salmonella enterica subsp. enterica serovar typhimurium, as well as 18 isolates of other salmonella serovars and 6 isolates of escherichia coli, were subjected to a novel variable number of tandem repeats (vntr)-based fingerprinting method that showed high discrimination and reproducibility for typing serovar typhimurium isolates. the method is based on capillary separation of pcr products from fluorescence-labeled vntr in the serovar typhimurium ... | 2003 | 12682132 |
| analysis of molecular epidemiology of chilean salmonella enterica serotype enteritidis isolates by pulsed-field gel electrophoresis and bacteriophage typing. | human salmonella enterica serotype enteritidis infections emerged in chile in 1994. s. enterica serotype enteritidis phage type 1 isolates predominated in the north, and phage type 4 isolates predominated in the central and southern regions. a study was planned to characterize this epidemic using the best discriminatory typing technique. research involved 441 s. enterica serotype enteritidis isolates, including clinical preepidemic samples (n = 74; 1975 to 1993) and epidemic (n = 199), food (n = ... | 2003 | 12682153 |
| genetic modulation of shigella flexneri 2a lipopolysaccharide o antigen modal chain length reveals that it has been optimized for virulence. | the lipopolysaccharide (lps) molecules of shigella flexneri 2a have o antigen (oag) polysaccharides with two modal chain length distributions. the chromosomal wzz(sf) gene results in short (s) type oag chains [11-17 oag repeat units (rus)], and the phs-2 plasmid-located wzz(phs2) gene results in very long (vl) type oag chains (>90 oag rus). s. flexneri wzz(sf) mutants are unable to form plaques on hela cell monolayers and f-actin comet tails, indicating that icsa/virg function in actin-based mot ... | 2003 | 12686635 |
| attenuated salmonella enterica serovar typhi and shigella flexneri 2a strains mucosally deliver dna vaccines encoding measles virus hemagglutinin, inducing specific immune responses and protection in cotton rats. | measles remains a leading cause of child mortality in developing countries. residual maternal measles antibodies and immunologic immaturity dampen immunogenicity of the current vaccine in young infants. because cotton rat respiratory tract is susceptible to measles virus (mv) replication after intranasal (i.n.) challenge, this model can be used to assess the efficacy of mv vaccines. pursuing a new measles vaccine strategy that might be effective in young infants, we used attenuated salmonella en ... | 2003 | 12692223 |
| adhesion of salmonella enterica serotype enteritidis isolates to chicken isthmal glandular secretions. | the ability of salmonella enterica serotype enteritidis isolates to adhere to immobilized secretions of the isthmus of the laying hen was determined in an elisa-type assay. one-third of the 56 isolates tested in the logarithmic growth phase, adhered to the isthmal secretions. using a binding assay of the isolates to thin paraffin sections of the oviduct, we demonstrated that the receptor of the adhesion was localized inside the tubular gland cells of the isthmus. the adhesion to immobilized isth ... | 2003 | 12695046 |
| incubation of supplemented egg contents pools to support rapid detection of salmonella enterica serovar enteritidis. | detecting internal contamination of eggs with salmonella enterica serovar enteritidis (salmonella enteritidis) is an important aspect of efforts to identify infected laying flocks. when egg contents pools are tested for salmonella enteritidis, a preliminary incubation step is often employed to allow small initial populations of contaminants to multiply to more easily detectable numbers. consistent detection of salmonella enteritidis in egg pools by direct plating requires the presence of at leas ... | 2003 | 12696691 |
| significance analysis of lexical bias in microarray data. | genes that are determined to be significantly differentially regulated in microarray analyses often appear to have functional commonalities, such as being components of the same biochemical pathway. this results in certain words being under- or overrepresented in the list of genes. distinguishing between biologically meaningful trends and artifacts of annotation and analysis procedures is of the utmost importance, as only true biological trends are of interest for further experimentation. a numb ... | 2003 | 12697067 |
| propionyl coenzyme a is a common intermediate in the 1,2-propanediol and propionate catabolic pathways needed for expression of the prpbcde operon during growth of salmonella enterica on 1,2-propanediol. | the studies reported here identify propionyl coenzyme a (propionyl-coa) as the common intermediate in the 1,2-propanediol and propionate catabolic pathways of salmonella enterica serovar typhimurium lt2. growth on 1,2-propanediol as a carbon and energy source led to the formation and excretion of propionate, whose activation to propionyl-coa relied on the activities of the propionate kinase (pduw)/phosphotransacetylase (pta) enzyme system and the cobb sirtuin-controlled acetyl-coa and propionyl- ... | 2003 | 12700259 |
| species-wide variation in the escherichia coli flagellin (h-antigen) gene. | escherichia coli is a clonal species. the best-understood components of its clonal variation are the flagellar (h) and polysaccharide (o) antigens, both well documented since the mid-1930s because of their use in serotyping. flagellin is the protein subunit of the flagellum that carries h-antigen specificity. we show that 43 of the 54 h-antigen specificities of e. coli map to the flagellin gene at flic and sequenced all 43 forms and confirmed specificity of each by cloning and expression. this i ... | 2003 | 12700273 |
| alfalfa seed decontamination in a salmonella outbreak. | based on in vitro data, the u.s. food and drug administration recommends chemical disinfection of raw sprout seeds to reduce enteric pathogens contaminating the seed coats. however, little is known about the effectiveness of decontamination at preventing human disease. in 1999, an outbreak of salmonella enterica serotype mbandaka occurred in oregon, washington, idaho, and california. based on epidemiologic and pulsed-field gel electrophoresis evidence from 87 confirmed cases, the outbreak was li ... | 2003 | 12702229 |
| first incursion of salmonella enterica serotype typhimurium dt160 into new zealand. | an outbreak of human salmonella enterica serotype typhimurium dt160 infection in new zealand was investigated from may to august 2001. handling of dead wild birds, contact with persons with diarrheal illness, and consumption of fast food were associated with infection. contaminated roof-collected rainwater was also detected. | 2003 | 12702234 |
| automated ribotyping and pulsed-field gel electrophoresis for rapid identification of multidrug-resistant salmonella serotype newport. | in a series of 116 salmonella enterica newport isolates that included 64 multidrug-resistant (mdr) isolates, automated ribotyping and pulsed-field gel electrophoresis (pfge) discriminated mdr s. newport with a sensitivity of 100% and 98% and specificity of 76% and 89%, respectively. clustering of pfge patterns (but not ribotyping) linked human and bovine cases. automated ribotyping rapidly identified the mdr strain, and pfge detected associations that aided epidemiologic investigations. | 2003 | 12702235 |
| the h box-harboring domain is key to the function of the salmonella enterica phoq mg2+-sensor in the recognition of its partner phop. | in two-component signaling systems, the transduction strategy relies on a conserved his-asp phosphoryl exchange between the sensor histidine kinase and its cognate response-regulator, and structural and functional consensus motifs are found when comparing either the diverse histidine kinases or response regulators present in a single cell. therefore, the mechanism that guarantees the specific recognition between partners of an individual pair is essential to unequivocally generate the appropriat ... | 2003 | 12702718 |
| pretreatment of mice with streptomycin provides a salmonella enterica serovar typhimurium colitis model that allows analysis of both pathogen and host. | salmonella enterica subspecies 1 serovar typhimurium is a principal cause of human enterocolitis. for unknown reasons, in mice serovar typhimurium does not provoke intestinal inflammation but rather targets the gut-associated lymphatic tissues and causes a systemic typhoid-like infection. the lack of a suitable murine model has limited the analysis of the pathogenetic mechanisms of intestinal salmonellosis. we describe here how streptomycin-pretreated mice provide a mouse model for serovar typhi ... | 2003 | 12704158 |
| coordinate regulation of salmonella enterica serovar typhimurium invasion of epithelial cells by the arp2/3 complex and rho gtpases. | salmonella enterica serovar typhimurium can infect epithelial cells via the basolateral surface after breaching the intestinal epithelium, yet little is known about this process. here, we show that actin polymerization driven by the arp2/3 complex is critical to both basolateral and apical bacterial invasion of polarized mdck cells. while there is also a dependence upon toxin b-sensitive rho gtpases, none of the four gtpases known to be activated by s. enterica serovar typhimurium sope are indiv ... | 2003 | 12704163 |
| a 5-year study of the bacterial pathogens associated with acute diarrhoea on the island of crete, greece, and their resistance to antibiotics. | during a 5-year period (1995-1999) a total of 7090 stool samples obtained from patients with acute diarrhoea, mostly community-acquired, were examined for bacterial pathogens, in the greek island of crete. one or more enteric pathogens were isolated from 987 patients (14%). salmonella enterica were the most commonly isolated bacteria (6%), followed by campylobacter spp. (4.2%), and enteropathogenic escherichia coli (epec) (1.8%). yersinia enterocolitica (0.6%), shigella spp. (0.3%), and aeromona ... | 2003 | 12705628 |
| a conductometric biosensor for biosecurity. | the paper describes the development of a conductometric biosensor for detecting foodborne pathogens. the biosensor consists of two components: an immunosensor that is based on electrochemical sandwich immunoassay, and a reader for signal measurement. the architecture of the immunosensor utilizes a lateral flow system that allows the liquid sample to move from one pad to another. the biosensor provides a specific, sensitive, low volume, and near real-time detection mechanism. results are presente ... | 2003 | 12706596 |
| crystal structure of 2-methylisocitrate lyase (prpb) from escherichia coli and modelling of its ligand bound active centre. | following acetate, propionate is the second most abundant low molecular mass carbon compound found in soil. many microorganisms, including most, if not all fungi, as well as several aerobic bacteria, such as escherichia coli and salmonella enterica oxidize propionate via the methylcitrate cycle. the enzyme 2-methylisocitrate lyase (prpb) from escherichia coli catalysing the last step of this cycle, the cleavage of 2-methylisocitrate to pyruvate and succinate, was crystallised and its structure d ... | 2003 | 12706720 |
| antimicrobial resistance in clinical isolates of salmonella enterica serotype enteritidis: relationships between mutations conferring quinolone resistance, integrons, plasmids and genetic types. | in 481 clinical isolates of salmonella enterica serotype enteritidis collected from a spanish region in 2000, 108, 83 and four isolates were resistant, respectively, to nalidixic acid, ampicillin or both. nalidixic acid resistance was the result of dna gyrase mutations involving the codons asp-87 (97 isolates) and ser-83 (15 isolates) of the gyra gene; no mutations in parc were detected. in ampicillin-resistant strains, blatem genes located on plasmids and/or the chromosome were implicated. five ... | 2003 | 12668577 |
| the yggx protein of salmonella enterica is involved in fe(ii) trafficking and minimizes the dna damage caused by hydroxyl radicals: residue cys-7 is essential for yggx function. | previous work from our laboratory identified yggx as a protein whose accumulation increased the resistance of salmonella enterica to superoxide stress, reversed defects attributed to oxidized [fe-s] clusters, and decreased the spontaneous mutation frequency of the cells. here we present work aimed at determining why the accumulation of yggx correlates with reduced mutation frequency. genetic and biochemical data showed that accumulation of yggx reduced the damage to dna by hydroxyl radicals. the ... | 2003 | 12670952 |
| acid shock accumulation of sigma s in salmonella enterica involves increased translation, not regulated degradation. | enteric pathogens such as salmonella enterica and escherichia coli face the daunting task of surviving passage through the extremely acid ph of the stomach in order to establish an infection in the host intestinal tract. these organisms have evolved elaborate stress response systems that aid in survival. the alternative sigma factor sigma(s) is a key regulator of many stress responses in s. enterica and is regulated at the levels of transcription, translation, and protein stability. of these con ... | 2003 | 12673058 |
| virk, soma and rcsc are important for systemic salmonella enterica serovar typhimurium infection and cationic peptide resistance. | salmonella must express and deploy a type iii secretion system located in salmonella pathogenicity island 2 (spi-2) in order to survive in host phagocytic vacuoles and to cause systemic infection in mouse models of typhoid fever. a genome-wide approach to screening for salmonella genes that are transcriptionally co-regulated in vitro with spi-2 genes was used to identify bacterial loci that might function in a mouse model of systemic disease. strains with mutations in three spi-2 co-expressed ge ... | 2003 | 12675799 |
| turnover of flhd and flhc, master regulator proteins for salmonella flagellum biogenesis, by the atp-dependent clpxp protease. | in enterobacteria such as salmonella, flagellar biogenesis is dependent upon the master operon flhdc at the apex of the flagellar gene hierarchy, which is divided into three classes 1, 2 and 3. previously we reported that depletion of the clpxp atp-dependent protease results in dramatic enhancement of class 2 and class 3 gene transcription, whereas the transcription level of the flhdc operon remains normal in salmonella enterica serovar typhimurium. this suggests that the clpxp protease may be r ... | 2003 | 12675803 |
| the role of dna base excision repair in the pathogenesis of salmonella enterica serovar typhimurium. | the intracellular pathogen, salmonella enterica serovar typhimurium, is able to proliferate in phagocytes, although reactive oxygen and nitrogen intermediates are lethal to most phagocytosed bacteria. to determine whether repair of oxidatively damaged dna is involved in s. typhimurium intramacrophage proliferation, null mutants of the dna base excision repair (ber) system were generated. these mutants were deficient in discrete enzymes (deltanth, deltanei, deltaxth, deltanfo) or in the defined g ... | 2003 | 12675811 |
| protein-peptidoglycan interactions modulate the assembly of the needle complex in the salmonella invasion-associated type iii secretion system. | the invasion-associated type iii secretion system of salmonella enterica assembles as a supra-molecular structure, termed needle complex, which spans the bacterial envelope. here, we present evidence for protein-peptidoglycan interactions that modulate the assembly of this organelle. the presence of major membrane components of the needle complex (prgh, prgk and invg) and invh, required for efficient assembly of the organelle, was examined in peptidoglycan purified by extensive boiling of bacter ... | 2003 | 12675813 |
| the rise and fall of salmonella enteritidis in the uk. | after rising in the early 1980s, the number of recorded human cases of salmonella enterica subsp. enterica in the uk has fallen in the last 5 years, with a particular decline in cases of infection with serovar enteritidis. this decline has been concomitant with the introduction of vaccination of egg-laying hens against serovar enteritidis. it is likely that other factors such as improved biosecurity in egg-laying flocks, a build-up of immunity in other animals and the rise in the number of lives ... | 2003 | 12675943 |
| involvement of nitric oxide donor compounds in the bactericidal activity of human neutrophils in vitro. | the bactericidal activity of human neutrophils against extracellular and facultatively intracellular bacteria was studied in the presence of the nitric oxide (no) donors sodium nitroprusside (snp) and 3-morpholinosydnonimine (sin-1), a molsidomine metabolite. snp and molsidomine are drugs commonly used as nitrovasodilators in coronary heart disease. it is demonstrated here that the no donor compounds themselves did not affect the viability and survival of the bacterial strains tested. neither sn ... | 2003 | 12676868 |
| closing the loop: the pmra/pmrb two-component system negatively controls expression of its posttranscriptional activator pmrd. | a fundamental question in biology is how an organism integrates multiple signals to mediate an appropriate cellular response. the pmrapmrb two-component system of salmonella enterica can be activated independently by fe(3+), which is sensed by the pmrb protein, and in low mg(2+), which is sensed by the phoq protein. the low-mg(2+) activation requires pmrd, a phopphoq-activated gene that activates the response regulator pmra at a posttranscriptional level. we now report that pmrd expression is ne ... | 2003 | 12676988 |
| cpg odn enhances uptake of bacteria by mouse macrophages. | unmethylated cpg motif in synthetic oligodeoxynucleotide (cpg odn) or bacterial dna is well recognized for its role in innate immunity, including enhancing production of no and cytokines by macrophages. in the present study, we demonstrated the effect of cpg odn on the phagocytic uptake of bacteria by macrophages. flow cytometric analysis of mouse macrophages (raw 264.7) incubated with fluorescein isothiocyanate (fitc)-labelled burkholderia pseudomallei, salmonella enterica serovar typhi or esch ... | 2003 | 12653838 |
| the use of nasba for the detection of microbial pathogens in food and environmental samples. | the isothermal amplification method nucleic acid sequence-based amplification (nasba), which amplifies rna, has been reported as useful for the detection of microbial pathogens in food and environmental samples. methods have been published for campylobacter spp., listeria monocytogenes and salmonella enterica ser. enteritidis in various foods and for cryptosporidium parvum in water. both 16s rrna and various mrnas have been used as target molecules for detection; the latter may have advantages i ... | 2003 | 12654488 |
| detection of pathogenic bacteria in shellfish using multiplex pcr followed by covalink nh microwell plate sandwich hybridization. | outbreak of diseases associated with consumption of raw shellfish especially oysters is a major concern to the seafood industry and public health agencies. a multiplex pcr amplification of targeted gene segments followed by dna-dna sandwich hybridization was optimized to detect the etiologic agents. first, a multiplex pcr amplification of hns, spvb, vvh, ctx and tl was developed enabling simultaneous detection of total salmonella enterica serotype typhimurium, vibrio vulnificus, vibrio cholerae ... | 2003 | 12654491 |
| imipenem resistance in a salmonella clinical strain due to plasmid-mediated class a carbapenemase kpc-2. | a salmonella enterica serotype cubana isolate exhibiting resistance to most beta-lactam antibiotics, including oxyimino-cephalosporins and imipenem, was isolated from a 4-year-old boy with gastroenteritis in maryland. beta-lactam resistance was mediated by a conjugative plasmid that encoded kpc-2, a class a carbapenemase previously found in a klebsiella pneumoniae isolate from the maryland area as well. sequence analysis of the flanking regions indicated a potential association of bla(kpc-2) wit ... | 2003 | 12654661 |
| integron-associated antibiotic resistance in salmonella enterica serovar typhi from asia. | eighteen of 25 isolates of salmonella enterica serovar typhi were multidrug resistant and contained class 1 integrons with a single cassette, dfrvii or aada1. the dfrvii-containing integron was likely borne on an inchi1 plasmid. salmonella serovar typhi could become resistant to broad-spectrum cephalosporins by integrating cassettes, such as veb-1, a common cassette in asia. | 2003 | 12654684 |
| florfenicol resistance in salmonella enterica serovar newport mediated by a plasmid related to r55 from klebsiella pneumoniae. | florfenicol resistance has emerged over the past few years in multidrug-resistant salmonella enterica serovars typhimurium, agona and paratyphi b. the flor gene encoding florfenicol resistance is chromosomally located in these serovars within a genomic island of 43 kb called sgi1 (salmonella genomic island 1). in the present study, we characterized florfenicol resistance in a strain of s. enterica serovar newport isolated from a turkey in 1990 and that lacked sgi1. florfenicol resistance was med ... | 2003 | 12654754 |
| contribution of the shigella flexneri sit, iuc, and feo iron acquisition systems to iron acquisition in vitro and in cultured cells. | shigella flexneri possesses multiple iron acquisition systems, including proteins involved in the synthesis and uptake of siderophores and the feo system for ferrous iron utilization. we identified an additional s. flexneri putative iron transport gene, sita, in a screen for s. flexneri genes that are induced in the eukaryotic intracellular environment. sita was present in all shigella species and in most enteroinvasive escherichia coli strains but not in any other e. coli isolates tested. the s ... | 2003 | 12654809 |
| autodisplay: development of an efficacious system for surface display of antigenic determinants in salmonella vaccine strains. | to optimize antigen delivery by salmonella vaccine strains, a system for surface display of antigenic determinants was established by using the autotransporter secretion pathway of gram-negative bacteria. a modular system for surface display allowed effective targeting of heterologous antigens or fragments thereof to the bacterial surface by the autotransporter domain of aida-i, the escherichia coli adhesin involved in diffuse adherence. a major histocompatibility complex class ii-restricted epi ... | 2003 | 12654812 |
| major histocompatibility complex heterozygote superiority during coinfection. | genes of the major histocompatibility complex (mhc) play a critical role in immune recognition, and many alleles confer susceptibility to infectious and autoimmune diseases. how these deleterious alleles persist in populations is controversial. one hypothesis postulates that mhc heterozygote superiority emerges over multiple infections because mhc-mediated resistance is generally dominant and many allele-specific susceptibilities to pathogens will be masked by the resistant allele in heterozygot ... | 2003 | 12654829 |
| salmonella infection induces a hypersecretory phenotype in human intestinal xenografts by inducing cyclooxygenase 2. | enteric salmonella infection is accompanied by inflammation and diarrhea, and yet little is known about its effects on intestinal epithelial physiology. since species differences limit the utility of animal tissues and cell lines lack relevant cell-cell interactions, we have used a human model of fetal intestine grown as xenografts in scid mice. we investigated here the effects of salmonella enterica serovar typhimurium sl1344 on xenograft ion transport. harvested xenografts were stripped of ser ... | 2003 | 12654832 |
| rapid protection of gnotobiotic pigs against experimental salmonellosis following induction of polymorphonuclear leukocytes by avirulent salmonella enterica. | oral inoculation of 5-day-old gnotobiotic pigs with salmonella enterica serovar typhimurium strain f98 resulted in severe enteritis and invasive disease. preinoculation 24 h earlier with an avirulent mutant of salmonella enterica serovar infantis (1326/28) completely prevented disease for up to 14 days (when the experiment was terminated). s. enterica serovar infantis colonized the alimentary tract well, with high bacterial counts in the intestinal lumen but with almost no invasion into the tiss ... | 2003 | 12654840 |
| vector priming reduces the immunogenicity of salmonella-based vaccines in nramp1+/+ mice. | the present studies in nramp1(-/-) balb/c and nramp1(+/+) cba mice question the significance of this genotype as a determinant of the level of gut colonization following oral administration of naturally attenuated or highly virulent salmonella strains. in line with previous results in balb/c hosts, vector priming of cba mice with salmonella enterica serovar stanley was found to significantly compromise the immunogenicity of a recombinant construct expressing a foreign pilus protein. | 2003 | 12654852 |
| a non-redundant microarray of genes for two related bacteria. | a microarray with sequences from the annotated open reading frames (orfs) in salmonella enterica subspecies 1, serovar typhimurium was supplemented with annotated chromosomal orfs from serovar typhi that are divergent from typhimurium (>10% dna sequence divergence). this non- redundant array was used to (i) measure changes in gene copy number in dna from actively growing versus stationary typhi and (ii) to reveal the transcriptional response of typhi to peroxide, a stress similar to that experie ... | 2003 | 12655003 |
| salmochelins, siderophores of salmonella enterica and uropathogenic escherichia coli strains, are recognized by the outer membrane receptor iron. | members of a family of catecholate siderophores, called salmochelins, were isolated by reversed-phase hplc from salmonella enterica serotype typhimurium and structurally characterized by fourier transform ion cyclotron resonance-msms and gc-ms. the tentative structure of salmochelin 1 contained two 2,3- dihydroxybenzoylserine moieties bridged by a glucose residue, bound to the serine hydroxyl group of one moiety and the carboxylate of the second moiety. salmochelin 2 contained in addition a seco ... | 2003 | 12655053 |
| subtracted restriction fingerprinting--a tool for bacterial genome typing. | reproducible, discriminative, high-throughput methods are required for the identification of bacterial strains and isolates in a clinical environment. a new molecular typing method for bacteria was developed and tested on salmonella and e. coli species. the technique is called subtracted restriction fingerprinting and is based on double restriction enzyme digestion of genomic dna followed by end labeling. the "detection" enzyme produces ttaa overhangs that are filled in with digoxigenated nucleo ... | 2003 | 12613253 |
| short-chain fatty acid activation by acyl-coenzyme a synthetases requires sir2 protein function in salmonella enterica and saccharomyces cerevisiae. | sir2 proteins have nad(+)-dependent histone deacetylase activity, but no metabolic role has been assigned to any of these proteins. in salmonella enterica, sir2 function was required for activity of the acetyl-coa synthetase (acs) enzyme. a greater than two orders of magnitude increase in the specific activity of acs enzyme synthesized by a sirtuin-deficient strain was measured after treatment with homogeneous s. enterica sir2 protein. human sir2a and yeast sir2 proteins restored growth of sir2- ... | 2003 | 12618394 |
| mutational analysis of the residue at position 48 in the salmonella enterica serovar typhimurium phoq sensor kinase. | the phop/phoq two-component regulatory system of salmonella enterica serovar typhimurium plays an essential role in controlling virulence by mediating the adaptation to mg(2+) depletion. the pho-24 allele of phoq harbors a single amino acid substitution (t48i) in the periplasmic domain of the phoq histidine kinase sensor. this mutation has been shown to increase net phosphorylation of the phop response regulator. we analyzed the effect on signaling by phop/phoq of various amino acid substitution ... | 2003 | 12618457 |
| histopathological study of rabbit intestinal mucosa infected with a hybrid strain of shigella dysenteriae 1 carrying lps biosynthesis genes of salmonella enterica serovar typhimurium. | the rfb gene cluster and the rfc gene of salmonella enterica were introduced earlier into an invasive shigella dysenteriae 1 strain by triparental cross. antiserum was raised in rabbit against lipopolysaccharide isolated from the hybrid strain. both the hybrid and the invasive s. dysenteriae 1 strain were found to have a titer of 1:2560 while for s. enterica, it was 1:640. ligated ileal loops were prepared in rabbit, which were inoculated with 10(8) cfu ml(-1) each of the hybrid strain, and inva ... | 2003 | 12620623 |
| survival of bacterial indicator species and bacteriophages after thermal treatment of sludge and sewage. | the inactivation of naturally occurring bacterial indicators and bacteriophages by thermal treatment of a dewatered sludge and raw sewage was studied. the sludge was heated at 80 degrees c, and the sewage was heated at 60 degrees c. in both cases phages were significantly more resistant to thermal inactivation than bacterial indicators, with the exception of spores of sulfite-reducing clostridia. somatic coliphages and phages infecting bacteroides fragilis were significantly more resistant than ... | 2003 | 12620828 |
| kinetics and strain specificity of rhizosphere and endophytic colonization by enteric bacteria on seedlings of medicago sativa and medicago truncatula. | the presence of human-pathogenic, enteric bacteria on the surface and in the interior of raw produce is a significant health concern. several aspects of the biology of the interaction between these bacteria and alfalfa (medicago sativa) seedlings are addressed here. a collection of enteric bacteria associated with alfalfa sprout contaminations, along with escherichia coli k-12, salmonella enterica serotype typhimurium strain atcc 14028, and an endophyte of maize, klebsiella pneumoniae 342, were ... | 2003 | 12620870 |
| epidemiology of tetracycline resistance determinants in shigella spp. and enteroinvasive escherichia coli: characterization and dissemination of tet(a)-1. | to make a comprehensive study of tetracycline resistance determinant distribution in the genus shigella, a collection of 577 clinical isolates of shigella spp. and enteroinvasive escherichia coli (eiec) from a variety of geographical locations was screened to identify tetracycline-resistant strains. the 459 tetracycline-resistant isolates identified were then screened by pcr analysis to determine the distribution in these strains of tetracycline efflux resistance determinants belonging to classe ... | 2003 | 12624025 |
| csgd, a regulator of curli and cellulose synthesis, also regulates serine hydroxymethyltransferase synthesis in escherichia coli k-12. | the homologous csgd and agfd proteins are members of the fixj/uhpa/luxr family and are proposed to regulate curli (thin aggregative fibres) and cellulose production by escherichia coli and salmonella enterica serovar typhimurium, respectively. a plasmid containing part of the csgd gene was isolated during a screen for multicopy suppressors of glycine auxotrophy caused by deleting the fola gene in e. coli. the sequence of the plasmid suggests it encodes a chimaeric protein. plasmids containing th ... | 2003 | 12624214 |
| the 1.75 a crystal structure of acetyl-coa synthetase bound to adenosine-5'-propylphosphate and coenzyme a. | acetyl-coenzyme a synthetase catalyzes the two-step synthesis of acetyl-coa from acetate, atp, and coa and belongs to a family of adenylate-forming enzymes that generate an acyl-amp intermediate. this family includes other acyl- and aryl-coa synthetases, firefly luciferase, and the adenylation domains of the modular nonribosomal peptide synthetases. we have determined the x-ray crystal structure of acetyl-coa synthetase complexed with adenosine-5'-propylphosphate and coa. the structure identifie ... | 2003 | 12627952 |
| adaptive responses of salmonella enterica serovar typhimurium dt104 and other s. typhimurium strains and escherichia coli o157 to low ph environments. | cattle are a known main reservoir for acid-resistant escherichia coli o157 and salmonella enterica serovar typhimurium dt104. we studied the response of s. typhimurium dt104 to extreme low ph environments and compared their response to that of acid-resistant e. coli o157 and other s. typhimurium phage types. | 2003 | 12631198 |
| construction and evaluation of a eukaryotic expression plasmid for stable delivery using attenuated salmonella. | an approach to enhancing the stability of eukaryotic expression plasmids for delivery using attenuated salmonella has been evaluated. the expression apparatus and beta-galactosidase gene from the expression plasmid, pcmvbeta, was cloned into the low copy number plasmid plg339. the resulting construct, plgbetagal, was shown to have a lower copy number than pcmvbeta in salmonella enterica var typhimurium aroa strain sl7207. furthermore, beta-galactosidase-specific antibody was induced in mice foll ... | 2003 | 12631472 |
| systemic and enteric colonization of pigs by a hila signature-tagged mutant of salmonella choleraesuis. | although host adapted to pigs, salmonella enterica serovar choleraesuis (s. choleraesuis) can induce a virulent foodborne salmonellosis in humans. to directly investigate virulence factors of s. choleraesuis, we extended the functional genomics approach of signature-tagged mutagenesis to s. choleraesuis and pigs. when a test pool of 45 randomly signature-tagged null mutants was inoculated orally and intraperitoneally in pigs, one of the mutants that failed to colonize by either route was tagged ... | 2003 | 12631476 |
| filament formation by salmonella spp. inoculated into liquid food matrices at refrigeration temperatures, and growth patterns when warmed. | in this study, the formation of multicellular filamentous salmonella cells in response to low temperatures was investigated by using isolates of salmonella enterica serovar enteritidis pt4 and s. enterica serovar typhimurium dt104 as the inocula. the formation of filamentous cells in two liquid food matrices at the recommended maximum temperature for refrigeration (8 degrees c) was monitored and compared with that in tryptone soya broth. giemsa staining was performed to locate nuclear material w ... | 2003 | 12597479 |
| suppression of salmonella growth by wild-type and large-plaque variants of bacteriophage felix o1 in liquid culture and on chicken frankfurters. | the bacteriophage felix o1, a member of myoviridae, is specific for, and possesses a broad host range within, the genus salmonella. this work explores a felix o1 phage-based intervention for salmonella enterica serotype typhimurium dt104 that is potentially applicable at several stages of animal production and processing. a variant of felix o1 was obtained that produces a larger, clearer plaque phenotype (lp) on salmonella typhi than wild-type felix o1 (wt) does, not unlike r mutants of phage t4 ... | 2003 | 12597480 |
| hsp60 specific antibodies in egg yolks from laying hens naturally infected with salmonella enterica subspecies enterica serovar enteritidis. | heat shock protein (hsp) 60 of salmonella appears to be involved in pathogenesis of infectious processes and host immune responses. eggs of laying hens from two salmonella enteritidis naturally infected flocks (i--acute outbreak of infection; ii--occasional bacteria excretion) and one control flock (iii) were tested for the presence of yolk antibodies (igy) against hsp60 by applying enzyme-linked immunosorbent assay (elisa). the levels of specific immunoglobulins were related to those against li ... | 2003 | 12602685 |
| life-threatening infantile diarrhea from fluoroquinolone-resistant salmonella enterica typhimurium with mutations in both gyra and parc. | salmonella typhimurium dt12, isolated from a 35-day-old infant with diarrhea, was highly resistant to ampicillin, tetracycline, chloramphenicol, streptomycin, gentamycin, sulfamethoxazole/trimethoprim, nalidixic acid, and fluoroquinolones. the patient responded to antibiotic therapy with fosfomycin. multidrug-resistance may become prevalent in salmonella infections in japan, as shown in this first case of a patient infected with fluoroquinolone-resistant salmonella. | 2003 | 12604000 |
| a new inhibitor of the transcription-termination factor rho. | in this study we describe bi-k0058, a new inhibitor of the transcription-termination factor rho belonging to a different chemical class from bicyclomycin, the only known antibiotic acting on rho. bi-k0058 inhibits the poly(c)-dependent atpase activity of rho with an ic(50) of 25 microm as well as in vitro transcription-termination of two natural substrates, the salmonella enterica hisg cistron and the f1 phage intergenic region. bi-k0058 does not affect photolabeling of rho by atp. the results o ... | 2003 | 12604334 |
| imipenem resistance in salmonella enterica serovar wien related to porin loss and cmy-4 beta-lactamase production. | two multidrug-resistant salmonella enterica serovar wien strains (sw468 and sw1107) were isolated in 2001 in tunis. both strains produced the beta-lactamases tem-1, shv-2a, and cmy-4, whereas strain sw1107 also produced the beta-lactamase ctx-m-3. the imipenem-resistant strain (sw468) was totally devoid of the ompf-immunorelated porin. imipenem resistance was shown as being related to porin loss and cmy-4 beta-lactamase production. | 2003 | 12604564 |