Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the long polar fimbriae genes identified in shiga toxin-producing escherichia coli are present in other diarrheagenic e. coli and in the standard e. coli collection of reference (ecor) strains. | long polar fimbriae (lpf) are related to type i fimbriae in genetic organization and were first identified in salmonella enterica serovar typhimurium. four lpfa genetic variants designated lpfa(o157/oi-141), lpfa(o157/oi-154), lpfa(o26) and lpfa(o113) have been identified in shiga toxin-producing escherichia coli (stec). in this study, pcr was employed to determine the distribution of stec-lpfas in enteropathogenic, enteroaggregative, enterotoxigenic and enteroinvasive e. coli (epec, eaec, etec ... | 2006 | 16125910 |
| insertion-duplication mutagenesis of salmonella enterica and related species using a novel thermosensitive vector. | we constructed a novel temperature-sensitive vector as a tool for gene disruption by insertion-duplication mutagenesis (idm) in salmonella enterica and related species. a phon insertion mutant was proven highly stable during growth in lb medium and during infection of macrophage cells in the absence of selection pressure. by progressive shortening of a phon fragment, the minimal length for effective insertional mutagenesis driven by homologous recombination was determined to be 50 bp, allowing t ... | 2006 | 16125236 |
| delivery of heterologous protein antigens via hemolysin or autotransporter systems by an attenuated ler mutant of rabbit enteropathogenic escherichia coli. | in this report, we describe the use of an attenuated regulatory mutant of a rabbit enteropathogenic escherichia coli (repec) as a live vaccine vector to deliver heterologous protein antigens using two dedicated transport systems, a salmonella autotransporter and the e. coli hemolysin apparatus. we previously reported that an isogeneic ler (lee encoded regulator) mutant of repec o103:h2 is attenuated and immunogenic in rabbits. we first evaluated the salmonella autotransporter misl containing the ... | 2006 | 16098637 |
| salmonella enterica serovar choleraesuis infection of the porcine jejunal peyer's patch rapidly induces il-1beta and il-8 expression. | salmonella enterica serovar choleraesuis is an enteric pathogen of swine, producing septicemia, enterocolitis, pneumonia, and hepatitis. the initial molecular events at the site of salmonella infection are hypothesized to be critical in the initiation of innate and adaptive immune responses; however, the acute immune response elicited by porcine intestinal tissues is not well understood. to address this need, we employed explants of jejunal peyer's patch (jpp) mucosa from pigs to examine salmone ... | 2006 | 16115691 |
| porcine liver-expressed antimicrobial peptides, hepcidin and leap-2: cloning and induction by bacterial infection. | hepcidin is a liver-expressed iron-regulating hormone that also is an antimicrobial peptide. here we report the full-length cdna sequences of porcine hepcidin and liver-expressed antimicrobial peptide-2 (leap-2). porcine hepcidin and leap-2 cdna sequences contain 411 and 525 bp, and encode predicted peptides of 82 and 77 amino acid residues, respectively. both porcine hepcidin and leap-2 are highly expressed in liver and leap-2 also is expressed in intestinal tissues and kidney. pigs infected wi ... | 2006 | 16051358 |
| production and characterisation of monoclonal antibodies specific for escherichia coli o157:h7. | seven monoclonal antibodies (mabs) specific for escherichia coli o157:h7, one of the major causes of haemorrhagic colitis in humans, were produced by immunising balb/c mice with the strain e. coli o157:h7. these monoclonal antibodies do not cross-react with other bacteria such as salmonella enterica serovar typhimurium, e. coli o14, e. coli jm109, s. enterica serovar enteritidis, s. panama, s. saintpaul, s. derby, s. muenchen, s. bredeney, s. hadar, yersinia enterocolitica, proteus vulgaris, shi ... | 2006 | 20429059 |
| biosynthesis of proline. | proline was among the last biosynthetic precursors to have its biosynthetic pathway unraveled. this review recapitulates the findings on the biosynthesis and transport of proline. glutamyl kinase (gk) catalyzes the atp-dependent phosphorylation of l-glutamic acid. purification of γ-gk from escherichia coli was facilitated by the expression of the prob and proa genes from a high-copy-number plasmid and the development of a specific coupled assay based on the nadph-dependent reduction of gp by γ-g ... | 2007 | 26443591 |
| regulation of fimbrial expression. | fimbria-mediated interaction with the host elicits both innate and adaptive immune responses, and thus their expression may not always be beneficial in vivo. furthermore, the metabolic drain of producing fimbriae is significant. it is not surprising, therefore, to find that fimbrial production in escherichia coli and salmonella enterica is under extensive environmental regulation. in many instances, fimbrial expression is regulated by phase variation, in which individual cells are capable of swi ... | 2007 | 26443581 |
| nadh as donor. | the number of nadh dehydrogenases and their role in energy transduction in escherchia coli have been under debate for a long time. now it is evident that e. coli possesses two respiratory nadh dehydrogenases, or nadh:ubiquinone oxidoreductases, that have traditionally been called ndh-i and ndh-ii. this review describes the properties of these two nadh dehydrogenases, focusing on the mechanism of the energy converting nadh dehydrogenase as derived from the high resolution structure of the soluble ... | 2007 | 26443579 |
| epidemiological investigation of an outbreak of enteric fever. | ninety five cases of enteric fever among military recruits from a regimental training centre at maharastra were admitted to the local military hospital in a few weeks time. | 2007 | 27408039 |
| reemergence of chloramphenicol sensitivity in enteric fever. | enteric fever is a global health problem and rapidly developing resistance to various drugs makes the situation more alarming. drug sensitivity in salmonella enterica serovar typhi and salmonella enterica serovar paratyphi a isolated from 45 blood culture positive cases of enteric fever was tested to determine in-vitro susceptibility pattern of prevalent strains in northern india. | 2007 | 27407999 |
| complete nucleotide sequences of 84.5- and 3.2-kb plasmids in the multi-antibiotic resistant salmonella enterica serovar typhimurium u302 strain g8430. | the multi-antibiotic resistant (mr) salmonella enterica serovar typhimurium phage type u302 strain g8430 exhibits the penta-resistant acssut-phenotype (ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline), and is also resistant to carbenicillin, erythromycin, kanamycin, and gentamicin. two plasmids, 3.2- and 84.5-kb in size, carrying antibiotic resistance genes were isolated from this strain, and the nucleotide sequences were determined and analyzed. the 3.2-kb plasmid, pu30 ... | 2007 | 16828159 |
| invasive non-typhoidal salmonellosis in immunocompetent infants and children. | to investigate the extraintestinal manifestations of non-typhoidal salmonellae (nts) infection in immunocompetent infants and children. | 2007 | 16564718 |
| a recurring salmonellosis epidemic in new zealand linked to contact with sheep. | one strain of salmonella brandenburg began causing large numbers of human infections in new zealand in 1998. we investigated the emergence of this strain using combined notification and laboratory data on human and animal disease and a case-control study. s. brandenburg infection in humans was characterized by spring peaks and high rates in the southern half of the south island. this epidemic pattern followed very closely that seen in sheep. the case-control study found that infection was signif ... | 2007 | 16740191 |
| the early transcriptional response of pig small intestinal mucosa to invasion by salmonella enterica serovar typhimurium dt104. | salmonella enterica serovar typhimurium (s. typhimurium) species are a leading cause of human invasive gastroenteritis. there is increasing in vitro evidence about salmonella interaction with isolated cells or cell lines (macrophages, and enterocytes) on the molecular level, however, very little is known about in vivo interactions during actual invasion. we investigated the early interaction of s. typhimurium with intact small intestinal mucosa, in a pig model. intestinal segments were infected ... | 2007 | 16884775 |
| rapid detection of gyra and parc mutations in quinolone-resistant salmonella enterica using pyrosequencing technology. | fluoroquinolones are broad-spectrum antimicrobials highly effective in the treatment of a wide variety of clinical infections. salmonella gastroenteritis is usually only treated with fluoroquinolones when the patient is elderly or immunocompromised. fluoroquinolones are also used for the treatment of systemic salmonella infection or for long-term salmonella carriage. resistance to quinolones is commonly mediated by point mutations within the topoisomerase genes gyra and parc. pyrosequencing tech ... | 2007 | 16934351 |
| ancient typhoid epidemic reveals possible ancestral strain of salmonella enterica serovar typhi. | in contrast to other serotypes of salmonella enterica, s. typhi is exclusively adapted to human hosts. recently, s. typhi was identified in ancient skeletal material, thereby incriminating typhoid fever for the plague of athens. since, according to thucydides' report, animals were also affected by the disease, a working hypothesis is constituted that the causative agent of the plague might be the anticipated original strain of s. typhi, purportedly capable of infecting animals as well as humans. ... | 2007 | 16765652 |
| phage typing, biotyping & antimicrobial resistance profile of salmonella enterica serotype typhi from kolkata. | kolkata and its suburbs in eastern india are known to be endemic for typhoid fever. the objective of this study was to determine phage types, biotypes and antimicrobial resistance patterns of salmonella enterica serotype typhi isolated during the period 2003-2005 from a prospective surveillance for typhoid fever in two urban slums in kolkata. | 2007 | 17642505 |
| ctx-m-14 type beta-lactamase producing salmonella enterica serovar enteritidis isolated from imported chicken meat. | 2007 | 17642544 | |
| sunlight inactivation of campylobacter jejuni and salmonella enterica, compared with escherichia coli, in seawater and river water. | the inactivation of campylobacter jejuni and salmonella enterica, compared with escherichia coli, was determined in 100 l chambers of seawater and river water located at an outdoor site. the chambers (paired with dark controls) were seeded with waste stabilization pond effluent and laboratory-cultured pathogens, and exposed to sunlight in summer and winter experiments. all sunlight inactivation (k(s)) rates, as a function of cumulative global solar radiation (insolation), were far higher than th ... | 2007 | 17878550 |
| development of flexible antimicrobial films using essential oils as active agents. | the antimicrobial activity in the vapor-phase of laboratory-made flexible films of polypropylene (pp) and polyethylene/ethylene vinyl alcohol copolymer (pe/evoh) incorporating essential oil of cinnamon ( cinnamomum zeylanicum), oregano ( origanum vulgare), clove ( syzygium aromaticum), or cinnamon fortified with cinnamaldehyde was evaluated against a wide range of microorganisms: the gram-negative bacteria escherichia coli, yersinia enterocolitica, pseudomonas aeruginosa, and salmonella cholerae ... | 2007 | 17880148 |
| prolonged treatment of salmonella enterica serovar typhimurium with commercial disinfectants selects for multiple antibiotic resistance, increased efflux and reduced invasiveness. | to study how disinfectants affect antimicrobial susceptibility and phenotype of salmonella enterica serovar typhimurium sl1,344. | 2007 | 17855722 |
| flagella facilitate escape of salmonella from oncotic macrophages. | the intracellular parasite salmonella enterica serovar typhimurium causes a typhoid-like systemic disease in mice. whereas the survival of salmonella in phagocytes is well understood, little has been documented about the exit of intracellular salmonella from host cells. here we report that in a population of infected macrophages salmonella induces "oncosis," an irreversible progression to eukaryotic cell death characterized by swelling of the entire cell body. oncotic macrophages (onmphis) are t ... | 2007 | 17873035 |
| salmonella enterica serovar typhi: molecular analysis of strains with decreased susceptibility and resistant to ciprofloxacin in india from 2001-2003. | chromosomally-mediated reduced susceptibility to ciprofloxacin narrows the therapeutic options in enteric fever. we made a molecular comparison of clinical isolates of fluoroquinolone-resistant strains of salmonella enterica serotype typhi from january 2001 to may 2003; 178 isolates were subjected to antimicrobial susceptibility testing by the kirby-bauer method of disk diffusion, and agar dilution was used to determine the minimum inhibitory concentration (mic) to ciprofloxacin. nalidixic-acid ... | 2007 | 17873998 |
| gamma interferon-independent effects of interleukin-12 on immunity to salmonella enterica serovar typhimurium. | interleukin-12 (il-12) and il-18 are both central to the induction of gamma interferon (ifn-gamma), and various roles for il-12 and il-18 in control of intracellular microbial infections have been demonstrated. we used il-12p40(-/-) and il-18(-/-) mice to further investigate the role of il-12 and il-18 in control of salmonella enterica serovar typhimurium. while c57bl/6 and il-18(-/-) mice were able to resolve attenuated s. enterica serovar typhimurium infections, the il-12p40(-/-) mice succumbe ... | 2007 | 17875635 |
| peptidase n encoded by salmonella enterica serovar typhimurium modulates systemic infection in mice. | the cytosolic protein degradation pathway, involving atp-dependent proteases and atp-independent peptidases, is important for modulating several cellular responses. the involvement of pathogen-encoded atp-dependent proteases is well established during infection. however, the roles of atp-independent peptidases in this process are not well studied. the functional role of peptidase n (pepn), an atp-independent enzyme belonging to the m1 family, during systemic infection of mice by salmonella enter ... | 2007 | 17877733 |
| n-lysine propionylation controls the activity of propionyl-coa synthetase. | reversible protein acetylation is a ubiquitous means for the rapid control of diverse cellular processes. acetyltransferase enzymes transfer the acetyl group from acetyl-coa to lysine residues, while deacetylase enzymes catalyze removal of the acetyl group by hydrolysis or by an nad(+)-dependent reaction. propionyl-coenzyme a (coa), like acetyl-coa, is a high energy product of fatty acid metabolism and is produced through a similar chemical reaction. because acetyl-coa is the donor molecule for ... | 2007 | 17684016 |
| assessment of contamination potential of lettuce by salmonella enterica serovar newport added to the plant growing medium. | the capacity of salmonella enterica serovar newport to contaminate romaine lettuce (lactuca sativa l. cv. nogal) via the root system was evaluated in 17-, 20-, and 33-day-old plants. apparent internalization of salmonella via the root to the above-ground parts was identified in 33- but not 17- or 20-day-old plants and was stimulated by root decapitation. leaves of lettuce plants with intact and damaged roots harbored salmonella at 500 +/- 120 and 5,130 +/- 440 cfu/g of leaf, respectively, at 2 d ... | 2007 | 17685348 |
| outbreaks where food workers have been implicated in the spread of foodborne disease. part 1. description of the problem, methods, and agents involved. | food workers in many settings have been responsible for foodborne disease outbreaks for decades, and there is no indication that this is diminishing. the committee on control of foodborne illnesses of the international association for food protection was tasked with collecting and evaluating any data on worker-associated outbreaks. a total of 816 reports with 80,682 cases were collected from events that occurred from 1927 until the first quarter of 2006. most of the outbreaks reviewed were from ... | 2007 | 17685355 |
| protective role of hemidesmus indicus r. br. root extract against salmonella typhimurium-induced cytotoxicity in int 407 cell line. | the present investigation deals with the effect of the chloroform fraction composed of sterols and fatty acids isolated from hemidesmus indicus root extract (chi) on salmonella enterica serovar typhimurium (s. typhimurium)-induced cytotoxicity in a human intestinal epithelial cell line (int 407). the optimum dose was fixed as 100 microg/ml for chi against s. typhimurium, which was quite safe for int 407 cells as the cd(50) concentration (50% cell death) of chi was determined to be 500 microg/ml ... | 2007 | 17685386 |
| protective action of lactobacillus kefir carrying s-layer protein against salmonella enterica serovar enteritidis. | eight lactobacillus kefir strains isolated from different kefir grains were tested for their ability to antagonize salmonella enterica serovar enteritidis (salmonella enteritidis) interaction with epithelial cells. l. kefir surface properties such as autoaggregation and coaggregation with salmonella and adhesion to caco-2/tc-7 cells were evaluated. l. kefir strains showed significantly different adhesion capacities, six strains were able to autoaggregate and four strains coaggregated with salmon ... | 2007 | 17719671 |
| monocyte and dendritic cell recruitment and activation during oral salmonella infection. | immunity to bacterial infection involves the joint effort of the innate and adaptive immune systems. the innate immune response is triggered when the body senses bacterial components, such as lipopolysaccharide, that alarm the body of the invader. an array of cell types function in the innate response. these cells are rapidly recruited to the infection site and activated to optimally perform their functions. the adaptive immune response follows the innate response, and one cell type in particula ... | 2007 | 17720254 |
| spontaneous zygogenesis, a wide-ranging mating process in bacteria. | spontaneous zygogenesis (or z-mating) in escherichia coli, unlike f-mediated conjugation, promotes formation of complete zygotes. most z-mating products have proven to be phenotypically unstable, losing part of the phenotype for which they were selected. persistent z-mating products appear as stable genetic recombinants or yield subclones of two types: either both parental types or one of them plus a recombinant type, and the ability to promote spontaneous zygogenesis can appear in all emerging ... | 2007 | 17720456 |
| cobalt targets multiple metabolic processes in salmonella enterica. | cobalt is essential for growth of salmonella enterica and other organisms, yet this metal can be toxic when present in excess. wild-type salmonella exhibits several metabolic defects when grown in the presence of cobalt, some of which generate visible growth consequences. work herein identifies sulfur assimilation, iron homeostasis, and fe-s cluster metabolism as targets for cobalt toxicity. in each case it is proposed that cobalt exerts its effect by one of two mechanisms: direct competition wi ... | 2007 | 17720790 |
| systemic translocation of salmonella enterica serovar dublin in cattle occurs predominantly via efferent lymphatics in a cell-free niche and requires type iii secretion system 1 (t3ss-1) but not t3ss-2. | salmonella enterica is an important diarrheal pathogen, and infections may involve severe systemic sequelae depending on serovar- and host-specific factors. the molecular mechanisms underlying translocation of host-restricted and -specific serovars of s. enterica from the intestines to distal organs are ill defined. by surgical cannulation of lymph and blood vessels draining the distal ileum in cattle, s. enterica serovar dublin was observed to translocate predominantly via mesenteric lymph node ... | 2007 | 17724072 |
| evaluation of phop and rpos mutants of salmonella enterica serovar typhi as attenuated typhoid vaccine candidates: virulence and protective immune responses in intranasally immunized mice. | the attenuation and immunoenhancing effects of rpos and phop salmonella enterica serovar strain typhi (salmonella typhi) mutants have not been compared. here, three s. typhi deletion mutants (phop, rpos, and rpos-phop double mutant) are constructed and these mutants are characterized with respect to invasiveness, virulence, and protective immune response compared with wild-type ty2. it was found that phop and phop-rpos deletion mutants are less invasive to ht-29 cells than the wild-type ty2 and ... | 2007 | 17725620 |
| the role of ubix in escherichia coli coenzyme q biosynthesis. | the reversible redox chemistry of coenzyme q serves a crucial function in respiratory electron transport. biosynthesis of q in escherichia coli depends on the ubi genes. however, very little is known about ubix, an enzyme thought to be involved in the decarboxylation step in q biosynthesis in e. coli and salmonella enterica. here we characterize an e. coli ubix gene deletion strain, ll1, to further elucidate e. coli ubix function in q biosynthesis. lli produces very low levels of q, grows slowly ... | 2007 | 17889824 |
| antimicrobial resistance in salmonella serotypes isolated from slaughter animals in kenya. | to isolate salmonella from food animals and characterise the antimicrobial resistance of the isolates. | 2007 | 17892198 |
| alternate slya and h-ns nucleoprotein complexes control hlye expression in escherichia coli k-12. | haemolysin e is a cytolytic pore-forming toxin found in several escherichia coli and salmonella enterica strains. expression of hlye is repressed by the global regulator h-ns (histone-like nucleoid structuring protein), but can be activated by the regulator slya. expression of a chromosomal hlye-lacz fusion in an e. coli slya mutant was reduced to 60% of the wild-type level confirming a positive role for slya. dnase i footprint analysis revealed the presence of two separate slya binding sites, o ... | 2007 | 17892462 |
| comparison of tissue-selective proinflammatory gene induction in mice infected with wild-type, dna adenine methylase-deficient, and flagellin-deficient salmonella enterica. | mutants of salmonella enterica serovar typhimurium deficient in dna adenine methylase (dam) are attenuated for virulence in mice and confer heightened immunity in vaccinated animals. in contrast, infection of mice with wild-type (wt) strains or flagellin-deficient mutants of salmonella causes typhoid fever. here we examined the bacterial load and spatiotemporal kinetics of expression of several classes of host genes in peyer's patches, the liver, and the spleen following oral infection of mice w ... | 2007 | 17893133 |
| cytokine response of porcine cell lines to salmonella enterica serovar typhimurium and its hila and ssra mutants. | salmonella enterica serovar typhimurium (s. typhimurium) is a facultative intracellular bacterium which can infect and colonize pigs. after contact with enterocytes and macrophages, s. typhimurium induces production of cytokines thus triggering the innate immune response. in this study we evaluated the cytokine response of two porcine cell lines, ipi-2i and 3d4/31, of epithelial or macrophage origins, respectively, to the wild-type s. typhimurium and its hila and ssra mutants. we observed that t ... | 2007 | 17894638 |
| salmonella enterica infections in spanish swine fattening units. | the present study is the first conducted in spain to estimate the bacteriological herd prevalence of salmonella enterica in fattening units and to describe the salmonella serovar diversity on these farms using a sample representative of the entire swine population. for this purpose, 10 faecal samples were collected from 10 different pens containing pigs close to market weight in a total of 232 fattening units. total sample size was proportionally distributed according to the fattener census in e ... | 2007 | 17894639 |
| thermosensing coordinates a cis-regulatory module for transcriptional activation of the intracellular virulence system in salmonella enterica serovar typhimurium. | the expression of bacterial virulence genes is tightly controlled by the convergence of multiple extracellular signals. as a zoonotic pathogen, virulence gene regulation in salmonella enterica serovar typhimurium must be responsive to multiple cues from the general environment as well as from multiple niches within animal and human hosts. previous work has identified combined magnesium and phosphate limitation as an environmental cue that activates genes required for intracellular virulence. one ... | 2007 | 17895240 |
| endocarditis due to salmonella enterica subsp. arizonae in a patient with sickle cell disease: a case report and review of the literature. | human cases due to salmonella enterica subsp. arizonae are especially rare, but it may affect immunocompromised patients and infants. we present a case of endocarditis in a patient with sickle cell disease and a review of earlier cases caused by this rare human pathogen. the patient was successfully treated with ceftriaxone and ciprofloxacin. there are only few cases of salmonella endocarditis reported in the last six decades and it is the first case of salmonella enterica subsp. arizonae endoca ... | 2007 | 17896960 |
| novel pcr assay for identification of salmonella enterica serovar infantis. | we developed, optimized and tested two novel pcr assays specific for salmonella enterica subspecies enterica serovar infantis. | 2007 | 17897386 |
| commonly used farm disinfectants can select for mutant salmonella enterica serovar typhimurium with decreased susceptibility to biocides and antibiotics without compromising virulence. | to determine if one passage of salmonella enterica serovar typhimurium in the presence of farm disinfectants selected for mutants with decreased susceptibility to disinfectants and/or antibiotics. | 2007 | 17897935 |
| oligonucleotide microarray for molecular characterization and genotyping of salmonella spp. strains. | to characterize and subtype multidrug-resistant salmonella isolates by determining the virulence factors, prophage sequences and antimicrobial resistance genes using a novel salmonella-specific oligonucleotide microarray. | 2007 | 17897936 |
| high-pressure resistance variation of escherichia coli o157:h7 strains and salmonella serovars in tryptic soy broth, distilled water, and fruit juice. | the effect of high pressure on the log reduction of six strains of escherichia coli o157:h7 and five serovars of salmonella enterica was investigated in tryptic soy broth, sterile distilled water, and commercially sterile orange juice (for salmonella) and apple cider (for e. coli). samples were subjected to high-pressure processing treatment at 300 and 550 mpa for 2 min at 6 degrees c. samples were plated onto tryptic soy agar directly after pressurization and after being held for 24 h at 4 degr ... | 2007 | 17900085 |
| characterization of a waaf mutant of helicobacter pylori strain 26695 provides evidence that an extended lipopolysaccharide structure has a limited role in the invasion of gastric cancer cells. | an ld-heptosyltransferase gene, hp1191 (waaf), involved in biosynthesis of the inner-core region of helicobacter pylori strain 26695 lipopolysaccharide (lps), has been cloned and its function established by complementation of salmonella enterica serovar typhimurium waaf mutant strain, strain 3789. insertional inactivation of the hp1191 open reading frame in strain 26695 resulted in the formation of a deeply truncated lps molecule, as observed using sds-page. subsequent compositional and fatty ac ... | 2007 | 17901900 |
| the wetting agent required for swarming in salmonella enterica serovar typhimurium is not a surfactant. | we compared the abilities of media from agar plates surrounding swarming and nonswarming cells of salmonella enterica serovar typhimurium to wet a nonpolar surface by measuring the contact angles of small drops. the swarming cells were wild type for chemotaxis, and the nonswarming cells were nonchemotactic mutants with motor biases that were counterclockwise (chey) or clockwise (chez). the latter strains have been shown to be defective for swarming because the agar remains dry (q. wang, a. suzuk ... | 2007 | 17905988 |
| the rcscdb signaling system and swarming motility in salmonella enterica serovar typhimurium: dual regulation of flagellar and spi-2 virulence genes. | the rcs phosphorelay is a multicomponent signaling system that positively regulates colanic acid synthesis and negatively regulates motility and virulence. we have exploited a spontaneously isolated mutant, igaa(t191p), that is nearly maximally activated for the rcs system to identify a vast set of genes that respond to the stimulation, and we report new regulatory properties of this signaling system in salmonella enterica serovar typhimurium. microarray data show that the rcs system normally fu ... | 2007 | 17905992 |
| the gatc-binding protein seqa is required for bile resistance and virulence in salmonella enterica serovar typhimurium. | disruption of the seqa gene of salmonella enterica serovar typhimurium causes defects similar to those described in e. coli: filament formation, aberrant nucleoid segregation, induction of the sos response, envelope instability, and increased sensitivity to membrane-damaging agents. differences between seqa(-) mutants of e. coli and s. enterica, however, are found. seqa(-) mutants of s. enterica form normal colonies and do not exhibit alterations in phage plaquing morphology. lack of seqa causes ... | 2007 | 17905993 |
| differential expression of nife uptake-type hydrogenase genes in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium possesses three similar nife hydrogenases important to its virulence. here we show that the three hydrogenase operons hyb, hya and hyd are expressed under different environmental conditions and are subject to control by different regulatory proteins. hydrogenase promoter-lacz fusion plasmids were transferred into the wild-type strain or into arca, fnr, iscr, narl and narp deletion mutants, or into a fnr/arca double mutant. the hyb promoter had highest beta ... | 2007 | 17906148 |
| src homology domain 2 adaptors affect adherence of salmonella enterica serovar typhimurium to non-phagocytic cells. | the ability of salmonella enterica serovar typhimurium (s. typhimurium) to penetrate the intestinal epithelium is key to its pathogenesis. bacterial invasion can be seen as a two-step process initially requiring adherence to the host cell surface followed by internalization into the host cell. evidence suggests that adherence of s. typhimurium to host cells is receptor-mediated; however, the host cell receptor(s) has/have not been identified. internalization of s. typhimurium absolutely requires ... | 2007 | 17906149 |
| infertility associated with sub clinical salmonellosis. | subclinical infection of guinea pigs with isogenic wild type and aroa, htra and aroa-htra mutants of salmonella enterica subspecies enterica serovar abortusequi (s. abortusequi) induced infertility, while mutants had little or no effect on conception rate in guinea pigs. conception rate was significantly lower in guinea pigs inoculated with wild type (s-787) and aroa mutant of s. abortusequi than those inoculated with intracellular survival deficient htra or aroa-htra mutants of s. abortusequi. ... | 2007 | 17907752 |
| induction of rpos degradation by the two-component system regulator rsta in salmonella enterica. | bacterial survival in diverse and changing environments relies on the accurate interplay between different regulatory pathways, which determine the design of an adequate adaptive response. the proper outcome depends on a precise gene expression profile generated from the finely tuned and concerted action of transcriptional factors of distinct regulatory hierarchies. salmonella enterica serovar typhimurium harbors multiple regulatory systems that are crucial for the bacterium to cope with harsh e ... | 2007 | 17704217 |
| influence of lactic acid bacteria on longevity of caenorhabditis elegans and host defense against salmonella enterica serovar enteritidis. | this study aimed to develop a convenient model to investigate the senescence of host defenses and the influence of food and nutrition. a small soil nematode, caenorhabditis elegans, was grown for 3 days from hatching on a lawn of escherichia coli op50 as the normal food source, and subsequently some of the nematodes were fed lactic acid bacteria (lab). the life spans of worms fed lab were significantly longer than the life spans of those fed op50. to investigate the effect of age on host defense ... | 2007 | 17704266 |
| ability of bacteriophages isolated from different sources to reduce salmonella enterica serovar enteritidis in vitro and in vivo. | salmonella enterica serovar enteritidis-lysing bacteriophages isolated from poultry or human sewage sources were used to reduce salmonella enteritidis in vitro and in experimentally infected chicks. cocktails of 4 different bacteriophages obtained from commercial broiler houses (cb4ø) and 45 bacteriophages from a municipal wastewater treatment plant (wt45ø) were evaluated. in experiment 1, an in vitro crop assay was conducted with selected bacteriophage concentrations (10(5) to 10(9) pfu/ml) to ... | 2007 | 17704377 |
| trends in salmonella enterica serotypes isolated from human, food, animal, and environment in tunisia, 1994-2004. | the present study was conducted to investigate, for the first time in tunisia, the current trends in salmonella enterica serotypes in tunisia (human, food, animal, and environment) which would help to improve the control and prevention of salmonella infections. | 2007 | 17706289 |
| chicken cecum immune response to salmonella enterica serovars of different levels of invasiveness. | day-old chicks are very susceptible to infections with salmonella enterica subspecies. the gut mucosa is the initial site of host invasion and provides the first line of defense against the bacteria. to study the potential of different s. enterica serovars to invade the gut mucosa and trigger an immune response, day-old chicks were infected orally with salmonella enterica serovar enteritidis, s. enterica serovar typhimurium, s. enterica serovar hadar, or s. enterica serovar infantis, respectivel ... | 2007 | 17709416 |
| contribution of the stg fimbrial operon of salmonella enterica serovar typhi during interaction with human cells. | salmonella serovars contain a wide variety of putative fimbrial systems that may contribute to colonization of specific niches. salmonella enterica serovar typhi is the etiologic agent of typhoid fever and is a pathogen specific to humans. in a previous study, we identified a gene, sty3920 (stgc), encoding the predicted usher of the stg fimbrial operon, that was expressed by serovar typhi during infection of human macrophages. the stg genes are located in the glms-psts intergenic region in serov ... | 2007 | 17709421 |
| omptin proteins: an expanding family of outer membrane proteases in gram-negative enterobacteriaceae. | the escherichia coli k-12 outer membrane protein ompt is a prototype of a unique family of bacterial endopeptidases known as the omptins. this family includes ompt and ompp of e. coli, sopa of shigella flexneri, pgte of salmonella enterica, and pla of yersinia pestis. despite their sequence similarities, the omptins vary in their reported functions. the ompt protease is characterized by narrow cleavage specificity defined by the extracellular loops of the beta-barrel protruding above the lipid b ... | 2007 | 17710644 |
| contribution of spi-4 genes to the virulence of salmonella enterica. | salmonella pathogenicity island-4 (spi-4) is a 27-kb region that carries six genes designated siiabcdef. siic, siid, and siif form a type i secretion apparatus for the secretion of siie, a huge (approximately 600 kda) protein contributing to the colonization of the bovine intestines. here it is shown that loss of spi-4 attenuates the oral virulence of salmonella enterica serovars typhimurium and enteritidis in mice. fifty percent lethal doses were elevated in both serovars upon the loss of spi-4 ... | 2007 | 17711458 |
| late recurrent salmonella sacroiliac osteomyelitis with psoas abscess in a non-sickle cell adult: case report. | 2007 | 17712436 | |
| predictive models for reduction of salmonella hadar on chicken skin during single and double sequential spraying treatments with acetic acid. | the response surface methodology was used to evaluate the effect of acetic acid concentration, spraying time and temperature on the reduction of salmonella hadar on poultry skin in a laboratory spraying process, and to identify the best conditions required to develop this operation. | 2007 | 17714385 |
| multiple-locus variable-number tandem repeat analysis of salmonella enterica subsp. enterica serovar typhimurium: comparison of isolates from pigs, poultry and cases of human gastroenteritis. | pulsed-field gel electrophoresis (pfge) and variable number tandem repeat (vntr) profiles of 195 epidemiologically unrelated salmonella typhimurium strains isolated in 1997-2004 from pigs were analysed and the results compared to establish the discriminatory ability of each method. in order to investigate the epidemiology of s. typhimurium from different populations, the vntr profiles from pigs were compared with those obtained from 190 s. typhimurium strains isolated from poultry and 186 strain ... | 2007 | 17714389 |
| growth inhibitory factors in bovine faeces impairs detection of salmonella dublin by conventional culture procedure. | to analyse the relative importance of different biological and technical factors on the analytical sensitivity of conventional culture methods for detection of salmonella dublin in cattle faeces. | 2007 | 17714398 |
| the lactobacillus plantarum strain aca-dc287 isolated from a greek cheese demonstrates antagonistic activity in vitro and in vivo against salmonella enterica serovar typhimurium. | the purpose of this study was to investigate the antibacterial activity of the xynotyri cheese isolate lactobacillus plantarum aca-dc287 using a set of in vitro and in vivo assays. | 2007 | 17714399 |
| identification and characterization of starter lactic acid bacteria and probiotics from columbian dairy products. | considering the significant rise in the probiotic market in columbia, and given the lack of reports concerning the microbial population and strain performance in products from different producers, this study aims at determining the number of viable starter bacteria and probiotics in bio-yoghurts available at the columbian market, identifying the species and analysing the performance of the isolated strains in bile acid resistance, antagonistic activity against pathogens, and adherence capacity t ... | 2007 | 17714400 |
| pyroptosis and host cell death responses during salmonella infection. | salmonella enterica are facultatively intracellular pathogens causing diseases with markedly visible signs of inflammation. during infection, salmonella interacts with various host cell types, often resulting in death of those cells. salmonella induces intestinal epithelial cell death via apoptosis, a cell death programme with a notably non-inflammatory outcome. in contrast, macrophage infection triggers caspase-1-dependent proinflammatory programmed cell death, a recently recognized process ter ... | 2007 | 17714514 |
| it's not easy being green. | 2007 | 17714671 | |
| salmonella pathogenicity islands in host specificity, host pathogen-interactions and antibiotics resistance of salmonella enterica. | salmonella enterica is a pathogen highly successful in causing a variety of gastrointestinal and systemic diseases in animals and humans. while some serovars of s. enterica are able to infect a broad range of host organisms, other serovars are highly restricted to specific host species. the colonization of hosts by s. enterica depends on the function of a large number of virulence determinants. the molecular analyses of virulence genes demonstrated that most of these loci are clustered within sa ... | 2007 | 17715824 |
| one step engineering of t7-expression strains for protein production: increasing the host-range of the t7-expression system. | the t7-expression system has been very useful for protein expression in escherichia coli. however, it is often desirable to over-express proteins in species other than e. coli. here, we constructed an inducible broad-host-range t7-expression transposon, which allows simple one-step construction of t7-expression strains in various species, providing the option to over-express proteins of interest in a broader host-range. this transposon contains the t7 rna polymerase driven by the lacuv5 promoter ... | 2007 | 17716915 |
| temporal fragmentation of speciation in bacteria. | because bacterial recombination involves the occasional transfer of small dna fragments between strains, different sets of niche-specific genes may be maintained in populations that freely recombine at other loci. therefore, genetic isolation may be established at different times for different chromosomal regions during speciation as recombination at niche-specific genes is curtailed. to test this model, we separated sequence divergence into rate and time components, revealing that different reg ... | 2007 | 17717188 |
| the pattern of pleiomorphism in stressed salmonella virchow populations is nutrient and growth phase dependent. | to describe the interactions of imposed osmotic and nutritional stress on the morphology of stationary and exponential phase s. virchow cells. | 2007 | 17718839 |
| a role for natural killer cells in intestinal inflammation caused by infection with salmonella enterica serovar typhimurium. | acute gastroenteritis caused by salmonella infection is a significant public health problem. using a mouse model of this condition, the authors demonstrated previously that the cytokine gamma interferon (ifn-gamma) is required for a normal intestinal inflammatory response to the pathogen. in the present study, these experiments are extended to show that natural killer (nk) cells constitute an early source of intestinal ifn-gamma during salmonella infection, and that these cells have a significan ... | 2007 | 17727655 |
| a new concept to stimulate mucosal as well as systemic immunity by parenteral vaccination as applied to the development of a live attenuated salmonella enterica serovar dublin vaccine. | a new concept of slow "drip feeding" that enables activation of mucosal as well as systemic immunity following parenteral vaccination was demonstrated using salmonella dublin in a mouse model. the live vaccine candidate, n-rm25, generated from a wild s. dublin strain utilising metabolic-drift (spontaneous chromosomal) mutations had a unique sensitivity to bile and restricted growth in the presence of a very low concentration of bile salts no. 3 (0.075% (w/v)) but also had the ability to survive ... | 2007 | 17727804 |
| pulmonary colonization with salmonella enterica serovar kentucky in an intensive care unit. | 2007 | 17728015 | |
| single-nucleotide-polymorphism typing and genetic relationships of salmonella enterica serovar typhi isolates. | salmonella enterica serovar typhi is a clone with a low level of variation. we developed a molecular typing method for serovar typhi using 38 genome-wide single-nucleotide polymorphisms (snps) as markers detected by pcr-restriction enzyme digestion. the 73 worldwide serovar typhi isolates studied were separated into 23 snp profiles and four distinct genetic groups. serovar typhi isolates expressing the unique flagellar antigen z66 were found to cluster together and branch off from the ancestral ... | 2007 | 17728466 |
| clonal expansion and microevolution of quinolone-resistant salmonella enterica serotype typhi in vietnam from 1996 to 2004. | salmonella enterica serotype typhi clinical isolates (n = 91) resistant to nalidixic acid (nal(r)) were collected from sporadic cases and minor outbreaks throughout vietnam between 1996 and 2004. these isolates were typed and compared by four methods: vi phage typing, psti ribotyping, xbai and spei pulsed-field gel electrophoresis (pfge), and single-nucleotide polymorphism (snp) analysis. the results indicated that 65% of the isolates were not typeable by vi phage typing. in contrast, the riboty ... | 2007 | 17728470 |
| salmonella: clinical importance and evolution of nomenclature. | salmonella is an important pathogen for both humans and animals. although the organism has been intensively studied during the last century, much remains to be learned about this pathogen. the complicated nomenclature system of salmonella has long been a subject of discussion. in 2005, "salmonella enterica" finally gained official approval as the type species of the genus salmonella. the genus salmonella also contains the species "salmonella bongori" in addition to a new species, "salmonella sub ... | 2007 | 17760271 |
| salmonella enterica serovar typhimurium exploits inflammation to compete with the intestinal microbiota. | most mucosal surfaces of the mammalian body are colonized by microbial communities ("microbiota"). a high density of commensal microbiota inhabits the intestine and shields from infection ("colonization resistance"). the virulence strategies allowing enteropathogenic bacteria to successfully compete with the microbiota and overcome colonization resistance are poorly understood. here, we investigated manipulation of the intestinal microbiota by the enteropathogenic bacterium salmonella enterica s ... | 2007 | 17760501 |
| serodiagnosis of salmonella enterica serovar typhi and s. enterica serovars paratyphi a, b and c human infections. | the aim of this study was to evaluate an immunoassay for the detection of human serum antibodies to the lps and flagellar antigens of salmonella typhi and salmonella paratyphi a, b and c, and to the vi capsular polysaccharide of s. typhi and s. paratyphi c. a total of 330 sera were used; these originated from 15 patients who were culture-positive for s. typhi and 15 healthy controls, together with 300 sera submitted to the laboratory of enteric pathogens for salmonella serodiagnosis. by sds-page ... | 2007 | 17761477 |
| the role of gene fusions in the evolution of metabolic pathways: the histidine biosynthesis case. | histidine biosynthesis is one of the best characterized anabolic pathways. there is a large body of genetic and biochemical information available, including operon structure, gene expression, and increasingly larger sequence databases. for over forty years this pathway has been the subject of extensive studies, mainly in escherichia coli and salmonella enterica, in both of which details of histidine biosynthesis appear to be identical. in these two enterobacteria the pathway is unbranched, inclu ... | 2007 | 17767732 |
| dissecting the salmonella response to copper. | intracellular copper homeostasis in bacteria is maintained as the result of a complex ensemble of cellular processes that in escherichia coli involve the coordinated action of two systems, cue and cus. in contrast, the pathogenic bacterium salmonella harbours only the cue regulon, including copa, which is shown here to be transcriptionally controlled by cuer. mutant strains in the cuer-regulated genes were constructed to characterize the response of salmonella enterica serovar typhimurium to hig ... | 2007 | 17768242 |
| expression of the fis protein is sustained in late-exponential- and stationary-phase cultures of salmonella enterica serovar typhimurium grown in the absence of aeration. | the classic expression pattern of the fis global regulatory protein during batch culture consists of a high peak in the early logarithmic phase of growth, followed by a sharp decrease through mid-exponential growth phase until fis is almost undetectable at the end of the exponential phase. we discovered that this pattern is contingent on the growth regime. in salmonella enterica serovar typhimurium cultures grown in non-aerated spi1-inducing conditions, fis can be detected readily in stationary ... | 2007 | 17784910 |
| vertical transmission of salmonella paratyphi a. | neonatal enteric fever is a rare but life-threatening illness. patients may present with varying severity, salmonella enterica serotype typhi causing more severe illness than salmonella enterica serotype paratyphi a. salmonella enterica serotype paratyphi a is considered to cause milder infection with fewer complications. we report a rare case of vertical transmission of salmonella enterica serotype paratyphi a with severe complications and high mortality. even though there are case reports of v ... | 2007 | 17785907 |
| splenic abscesses caused by a reptile-associated salmonella infection. | salmonella infections are not very uncommon. the source generally has to be looked for in food. the syndrome concerns mostly gastro-enteritis. we present a 17-year-old girl with sepsis caused by splenic abscesses which was successfully treated with splenectomy and antibiotics. after analysis (blood and surgical specimen samples), she appeared to be infected with salmonella type telelkebir, a rare variant that is associated with exotic animal species, mainly reptiles. the same variant was cultiva ... | 2007 | 17785987 |
| oral sodium chlorate, topical disinfection, and younger weaning age reduce salmonella enterica shedding in pigs. | salmonella enterica subsp. enterica can cause swine illness or human foodborne disease. although nontoxic to mammalian cells, chlorate can be converted to cytotoxic chlorite by salmonellae. to test whether chlorate is effective at reducing salmonella shedding in weaned pigs exposed to shedding dams, a chlorate-nitrate-lactate (chlorate) oral dose was administered daily for 5 days following weaning, and this treatment was evaluated in combination with two weaning ages and a topical disinfectant. ... | 2007 | 17803134 |
| competitive inhibition bacteria of bovine origin against salmonella serovars. | studies were conducted to isolate bacteria inhibitory to salmonella enterica serovar typhimurium definitive type (dt) 104 in vitro from cattle not carrying salmonella and to determine the inhibitory activity of the isolated bacteria through competitive growth in cattle feces artificially contaminated with salmonella typhimurium dt104 and s. enterica serovar newport. fecal samples (108) were obtained from dairy and beef cows. s. enterica serovars were isolated from 9.25% of the samples and includ ... | 2007 | 17803135 |
| variation in salmonella resistance to poultry chemical decontaminants, based on serotype, phage type, and antibiotic resistance patterns. | chemical decontaminants are currently under review for final approval by the european union authorities with the aim of reducing the number and/or prevalence of pathogenic microorganisms on poultry. the purpose of the research being reported here was to determine the association, if any, of decontaminant resistance with the serotype, phage type, and antibiotic resistance of salmonella strains. sixty poultry isolates of salmonella enterica (serotypes enteritidis: phage types 1, 4, 4b, 6a, 14b, an ... | 2007 | 17803139 |
| detection and identification of salmonella typhimurium in bovine diarrhoeic fecal samples by immunomagnetic separation and multiplex pcr assay. | the aim of this study was to use the immunomagnetic separation (ims) test plus a multiplex polymerase chain reaction (m-pcr) assay to detect salmonella at genus level and also for the identification of salmonella enterica serovar typhimurium in bovine diarrhoeic fecal samples. in all, 400 bovine diarrhoeic fecal specimens were examined by conventional bacterial culture, ims, and m-pcr. for m-pcr assay, four set primers were selected: 139-141, specific for inv-a gene of salmonella spp and the rfb ... | 2007 | 17803511 |
| feasibility of a molecular screening method for detection of salmonella enterica and campylobacter jejuni in a routine community-based clinical microbiology laboratory. | conventional diagnostic methods for the detection of salmonella enterica and campylobacter jejuni are laborious and time-consuming procedures, resulting in final results, for the majority of specimens, only after 3 to 4 days. molecular detection can improve the time to reporting of the final results from several days to the next day. however, molecular assays for the detection of gastrointestinal pathogens directly from stool specimens have not made it into the routine clinical microbiology labo ... | 2007 | 17804656 |
| reinterpreting a community outbreak of salmonella enterica serotype enteritidis in the light of molecular typing. | in november 2005, a large outbreak due to salmonella enterica serotype enteritidis (s. enteritidis) was observed within children who had eaten their meals at 53 school cafeterias in florence and the surrounding area. a total of 154 isolates of s. enteritidis were recovered from human cases between november 2005 and january 2006. all strains were assigned phage type 8 (pt8) and a common xbai pulsotype. this paper reports the findings of a molecular epidemiological investigation performed on 124 s ... | 2007 | 17825103 |
| the genome of epsilon15, a serotype-converting, group e1 salmonella enterica-specific bacteriophage. | the genome sequence of the salmonella enterica serovar anatum-specific, serotype-converting bacteriophage epsilon15 has been completed. the nonredundant genome contains 39,671 bp and 51 putative genes. it most closely resembles the genome of phiv10, an escherichia coli o157:h7-specific temperate phage, with which it shares 36 related genes. more distant relatives include the burkholderia cepacia-specific phage, bcepc6b (8 similar genes), the bordetella bronchiseptica-specific phage, bpp-1 (8 sim ... | 2007 | 17825342 |
| heterologous protection in pigs induced by a plasmid-cured and crp gene-deleted salmonella choleraesuis live vaccine. | in this study, we exploited a crp (camp receptor protein) gene-deleted, virulence plasmid-cured salmonella choleraesuis mutant with decreased carbon source utilization, designated s.c.-deltacrp/vpl(-), as a live vaccine strain. normal weight gain with no clinical signs was observed in pigs immunized with high doses of s.c.-deltacrp/vpl(-) live vaccine. vaccination in pregnant sows induced high maternal antibodies, which could prevent piglets from salmonella infection. moreover, serial transmissi ... | 2007 | 17825957 |
| detailed structure of integrons and transposons carried by large conjugative plasmids responsible for multidrug resistance in diverse genomic types of salmonella enterica serovar brandenburg. | to evaluate the incidence, molecular basis and distribution among genomic types of antimicrobial drug resistance in salmonella enterica (s.) serovar brandenburg isolates recorded in the principality of asturias, spain. | 2007 | 17827139 |
| the cbib protein of salmonella enterica is an integral membrane protein involved in the last step of the de novo corrin ring biosynthetic pathway. | we report results of studies of the conversion of adenosylcobyric acid (adocby) to adenosylcobinamide-phosphate, the last step of the de novo corrin ring biosynthetic branch of the adenosylcobalamin (coenzyme b12) pathway of salmonella enterica serovar typhimurium lt2. previous reports have implicated the cbib protein in this step of the pathway. hydropathy analysis predicted that cbib would be an integral membrane protein. we used a computer-generated topology model of the primary sequence of c ... | 2007 | 17827296 |
| lysine decarboxylase-negative salmonella enterica serovar enteritidis: antibiotic susceptibility, phage and pfge typing. | one hundred twenty salmonella enteritidis isolates collected from 1992 to 2005 in nagasaki prefecture (65 isolates from 40 outbreak cases, 44 from sporadic diarrhea patients, and 11 from chicken-related products) were investigated by their antibiotic susceptibility profiles, phage typing, and pulsed-field gel electrophoresis (pfge) typing. out of them, 18 were identified as lysine decarboxylase (ldc)-negative isolates, and 15 showed resistance toward streptomycin. based on the pfge typing, the i ... | 2007 | 17827887 |
| phenotypic variations and molecular identification of salmonella enterica serovar typhimurium cells under starvation in seawater. | in seawater, enteric bacteria evolve toward a stressed state that is difficult to identify because of major alterations of their phenotype. in this study, we incubated four reference strains of s. enterica serovar typhimurium in seawater microcosms for 10 months and studied the modifications of their main phenotypic characters. all of the strains lost some key characters used for traditional identification of the salmonella genus. they became able to produce acetoin, and tryptophane deaminase ac ... | 2007 | 17828573 |