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a holin remnant protein encoded by sty1365 is involved in envelope stability of salmonella enterica serovar typhi.we characterized sty1365, a small orf of salmonella enterica serovar typhi. this 174-bp orf encodes a putative product of 57 amino acid residues with a premature stop codon. nevertheless, bioinformatic analyses revealed that the predicted product of sty1365 has similarity to putative holin genes of escherichia coli and bacteriophage φp27. sty1365 showed a high-level expression at the early log phase and a small corresponding protein product was detected mainly in the inner membrane fraction. clo ...201121592194
oral and nasal dna vaccines delivered by attenuated salmonella typhimurium induce protective immune response against infectious bronchitis in chickens.several studies have reported that intramuscular injection of dna vaccines against infectious bronchitis virus (ibv) induces protective immune responses. in the present study, we developed oral and nasal dna vaccines that carried the s1 gene and n gene of ibv delivered by attenuated salmonella typhimurium strains, sl/pv-s1 and sl/pv-n, respectively. the safety and stability of recombinant salmonella vaccine were evaluated. following oral and nasal administration of chickens, the serum and mucosa ...201121593235
the population of a high-virulence strain of salmonella enterica serovar enteritidis in subcutaneously infected partridge: a quantitative time-course study using real-time pcr.this research was undertaken to determine the population of a high-virulence strain of salmonella enterica serovar enteritidis in partridge by a fluorescent quencher pcr assay and to correlate these findings with the results obtained from the immunohistochemical localization and histopathological examinations of selected salmonella enterica serovar enteritidis-infected tissues. to make the results meaningful, a side-by-side bacteriology method (indirect immuno-fluorescent antibody staining) was ...201121594642
a shigella boydii bacteriophage which resembles salmonella phage vii.abstract: background: lytic bacteriophages have been applied successfully to control the growth of various foodborne pathogens. sequencing of their genomes is considered as an important preliminary step to ensure their safety prior to food applications. results: the lytic bacteriophage, phisbom-ag3, targets the important foodborne pathogen, shigella. it is morphologically similar to phage vii of salmonella enterica serovar typhi and a series of phages of acinetobacter calcoaceticus and rhizobium ...201121595934
comparative genomics of 28 salmonella enterica isolates: evidence for crispr-mediated adaptive sublineage evolution.despite extensive surveillance, foodborne salmonella enterica infections continue to cause a significant burden on public health systems worldwide. as the s. enterica species comprises sublineages with greatly differing antigenic representation, virulence and antimicrobial resistance phenotypes, a better understanding of the species evolution is critical for the prediction and prevention of future outbreaks. the role that virulence and resistance phenotype acquisition, exchange and loss play for ...201121602358
the long-term persistence of blacmy-2 positive, inca/c plasmids requires selection pressure.multidrug resistance (mdr), bla(cmy-2) plasmids that confer resistance to third-generation cephalosporins have been found in multiple bacterial species collected from different hosts worldwide. the widespread distribution of bla(cmy-2) plasmids may be driven by antibiotic use that selects for the dissemination and persistence of these plasmids. alternatively, these plasmids may persist and spread in bacterial populations in the absence of selection pressure if a balance exists between conjugativ ...201121602382
the spectrin cytoskeleton is crucial for adherent and invasive bacterial pathogenesis.various enteric bacterial pathogens target the host cell cytoskeletal machinery as a crucial event in their pathogenesis. despite thorough studies detailing strategies microbes use to exploit these components of the host cell, the role of the spectrin-based cytoskeleton has been largely overlooked. here we show that the spectrin cytoskeleton is a host system that is hijacked by adherent (entropathogenic escherichia coli [epec]), invasive triggering (salmonella enterica serovar typhimurium [s. ty ...201121603579
allb, allantoin utilisation and salmonella enterica serovar enteritidis and typhimurium colonisation of poultry and mice.natural variation in the presence or the absence of stm0517-0529 genes allowing allantoin utilisation has been described in field isolates of the multidrug resistant salmonella enterica serovar typhimurium belonging to the phage type dt104. interestingly, s. enterica subspecies enterica serovar typhimurium dt104 is quite frequent in pigs and cattle, but rarely present in egg-laying hens. taking into account the different mode of allantoin metabolism in birds and mammals, we were interested in wh ...201121611691
a method to generate recombinant salmonella typhi ty21a strains expressing multiple heterologous genes using an improved recombineering strategy.live attenuated salmonella enterica serovar typhi ty21a (ty21a) is an important vaccine strain used in clinical studies for typhoid fever and as a vaccine vector for the expression of heterologous antigens. to facilitate the use of ty21a in such studies, it is desirable to develop improved strategies that enable the stable chromosomal integration and expression of multiple heterologous antigens. the phage λ red homologous recombination system has previously been used in various gram-negative bac ...201121611798
comprehensive analysis of salmonella sequence polymorphisms and development of a ldr-ua assay for the detection and characterization of selected serotypes.salmonella is a major cause of food-borne disease, and salmonella enterica subspecies i includes the most clinically relevant serotypes. salmonella serotype determination is important for the disease etiology assessment and contamination source tracking. this task will be facilitated by the disclosure of salmonella serotype sequence polymorphisms, here annotated in seven genes (sefa, safa, safc, biga, inva, fima, and phsb) from 139 s. enterica strains, of which 109 belonging to 44 serotypes of s ...201121611799
molecular epidemiological investigation of a diffuse outbreak caused by salmonella enterica serotype montevideo isolates in osaka prefecture, japan.abstract in osaka prefecture, japan, three foodborne outbreaks were caused by salmonella enterica serotype montevideo in rapid succession between september 2007 and may 2008. further, salmonella montevideo was also isolated from several sporadic diarrhea patients and asymptomatic carriers examined during approximately the identical period. to investigate the relatedness of the isolates, we performed antimicrobial susceptibility testing, pulsed-field gel electrophoresis (pfge) analysis, and multi ...201121612424
mycobacterium avium subsp. avium and salmonella enterica serotype typhimurium var. copenhagen phage type dt2 in pigeons.abstract we report on a coinfection of mycobacterium avium subsp. avium and salmonella enterica serotype typhimurium var. copenhagen phage type dt2 in pigeons from one flock, from which squabs were occasionally consumed by humans. triplex quantitative real-time pcr and culture methods were used for m. a. avium detection in livers and culture method was used for the detection of salmonella sp. in samples of liver and caecum of 33 examined birds. m. a. avium was detected in a total of 31 (93.9%) a ...201121612426
babies and bearded dragons: sudden increase in reptile-associated salmonella enterica serovar tennessee infections, germany 2008.abstract introduction: in 2008 a marked increase in salmonella enterica serovar tennessee infections in infants occurred in germany. in march and april 2008, eight cases were notified compared to a median of 0-1 cases in 2001-2006. materials and methods: we carried out an investigation including a case-control study to identify the source of infection. a patient was a child <3 years of age with salmonella tennessee isolated from stool from september 1, 2007, through december 31, 2008, identified ...201121612527
salmonella genomic island 1-j variants associated with change in the antibiotic resistance gene cluster in multidrug-resistant salmonella enterica serovar virchow isolated from humans, taiwan, 2004-2006.clin microbiol infect abstract: salmonella genomic island 1 (variant sgi1-j3) has been previously identified in multi-drug resistant (mdr) salmonella enterica serovar virchow isolated from humans in 1994. in this study, antimicrobial resistance, genotypes and genetic relationship were investigated in 96 s. virchow isolates collected from humans in 2004-2006. xbai-pfge analysis separated 96 isolates into two main related clusters, i and ii, which consisted of four major pulsotypes differing in pr ...201121615827
impact of a probiotic fermented milk in the gut ecosystem and in the systemic immunity using a non-severe protein-energy-malnutrition model in mice.abstract: background: malnutrition affects the immune response, causing a decrease of defence mechanisms and making the host more susceptible to infections. probiotics can reconstitute the intestinal mucosa and stimulate local and systemic immunity. the aim of this work was evaluate the effects of a probiotic fermented milk as a complement of a re-nutrition diet, on the recovery of the intestinal barrier, and mucosal and systemic immune functions in a murine model of non-severe protein-energy-ma ...201121615956
mouse models to assess the efficacy of non-typhoidal salmonella vaccines: revisiting the role of host innate susceptibility and routes of challenge.non-typhoidal salmonella enterica (nts) serovars typhimurium and enteritidis are important causes of bacterial gastroenteritis in the usa and worldwide. in sub-saharan africa these two serovars are emerging as agents associated with lethal invasive disease (e.g., bacteremia, meningitis). the development of nts vaccines, based on mucosally administered live attenuated strains and parenteral non-living antigens, could diminish the nts disease burden globally. mouse models of s. typhimurium and s. ...201121616112
phosphorylation of the autophagy receptor optineurin restricts salmonella growth.selective autophagy can be mediated via receptor molecules that link specific cargoes to the autophagosomal membranes decorated by ubiquitin-like lc3 (microtubule-associated protein light chain 3) modifiers. although several autophagy receptors have been identified, little is known about mechanisms controlling their functions in vivo. here, we found that phosphorylation of an autophagy receptor, optineurin, promoted selective autophagy of ubiquitin-coated cytosolic salmonella enterica. the prote ...201121617041
complete genome sequence of the universal killer, salmonella enterica serovar typhimurium uk-1 (atcc 68169).the salmonella enterica serovar typhimurium strain uk-1 presents the highest invasion and virulence attributes among the most frequently studied strains. s. typhimurium uk-1 has been used as the foundation for developing recombinant vaccines and been extensively used on virulence and colonization studies in chickens and mice. we describe here the complete genome sequence of s. typhimurium uk-1. comparative genomics of salmonella typhimurium will provide insight into factors that determine virule ...201121622747
humanized mice for salmonella typhi infection: new tools for an old problem.salmonella enterica serovar typhi (s. typhi), is a human restricted pathogen and the causal agent of typhoid fever. although the use of antimicrobial drugs or vaccines has served as an effective therapeutics strategy against typhoid fever, the recent surge in multidrug resistant strains of s. typhi presents a major health concern worldwide. progress on typhoid research has been limited in the past due to the lack of a suitable animal model that recapitulates the hallmark immunological features o ...201121623167
the salmonella enterica phop directly activates the horizontally acquired spi-2 gene ssel and is functionally different from a s. bongori ortholog.to establish a successful infection within the host, a pathogen must closely regulate multiple virulence traits to ensure their accurate temporal and spatial expression. as a highly adapted intracellular pathogen, salmonella enterica has acquired during its evolution various virulence genes via numerous lateral transfer events, including the acquisition of the salmonella pathogenicity island 2 (spi-2) and its associated effectors. beneficial use of horizontally acquired genes requires that their ...201121625519
β-glucan plus ascorbic acid in neonatal calves modulates immune functions with and without salmonella enterica serovar dublin.to determine if β-glucan plus ascorbic acid affects adherence and pathogenicity of salmonella dublin and innate immune response in neonatal calves, 20 calves were fed control or supplemented diets (β-glucan, 0.9g/d, plus ascorbic acid, 500mg/d) until d 23. on d 21, 5 calves per treatment received 2.4×10(8)cfu of s. dublin orally. s. dublin spread through intestinal tissues into mesenteric lymph nodes (mln), spleen, and lung tissues within 48h. all supplemented calves had less mrna expression of ...201121628075
antibodies in action: the role of human opsonins in killing salmonella enterica serovar typhi.although vaccines have been available for over a century, a correlate of protection for typhoid fever has yet to be identified. antibodies are produced in response to typhoid infection and vaccination, and are generally used as the gold standard for determining vaccine immunogenicity even though their role in clearance of s. typhi infections is poorly defined. herein, we describe the first functional characterization of s. typhi-specific antibodies following vaccination with a new vaccine, m01zh ...201121628517
expression of tlr4 and downstream effectors in selected cecal cell sub-populations of chicks resistant or susceptible to salmonella carrier-state.toll-like receptor 4 (tlr4), which recognizes lipopolysaccharide from gram negative bacteria plays a major role in resistance of mice and humans to salmonella infection. in chicken, salmonella may establish a carrier-state whereby bacteria are able to persist in the organism without triggering clinical signs. based on cellular morphological parameters, we developed a method, without using antibodies, to separate three cecal cell sub-populations: lymphocytes, enterocytes, and a population encompa ...201121628520
multidrug-resistant typhoid fever: a review.multidrug-resistant typhoid fever (mdrtf) is defined as typhoid fever caused by salmonella enterica serovar typhi strains (s. typhi), which are resistant to the first-line recommended drugs for treatment such as chloramphenicol, ampicillin and trimethoprim-sulfamethoxazole. since the mid-1980s, mdrtf has caused outbreaks in several countries in the developing world, resulting in increased morbidity and mortality, especially in affected children below five years of age and those who are malnouris ...201121628808
salmonella enterica in semi-aquatic turtles in colombia.turtles can be hosts of salmonella enterica serovars which can cause disease both in the animals themselves and in people they come into contact with, especially when the turtles are kept as pets. to investigate the prevalence of salmonella in turtles in colombia, we studied animals at a wildlife protection centre. the turtles had either been confiscated or donated to the centre.201121628812
in vitro activity of azithromycin in salmonella isolates from pakistan.enteric fever is caused by salmonella enterica serovars typhi and paratyphi a, b and c. it is a significant public health issue in pakistan, which is exacerbated by a high level of resistance some isolates display to drugs routinely used in treatment. azithromycin may be a treatment option for such isolates.201121628817
prenatal exposure to lps leads to long-lasting physiological consequences in male offspring.growing evidence suggests that early life events are critical determinants for disorders later in life. according to a comprehensive number of epidemiological/animal studies, exposure to lipopolysaccharide, causes alteration in pro-inflammatory cytokine levels, hypothalamic-pituitary-adrenal functioning and the hormonal system which may contribute to behavioral and neurological injuries. in this study we investigated the effects of lipopolysaccharide administration on physiological parameters in ...201121630247
survival of salmonella newport in oysters.salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the united states and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. a 2005 epidemiological study done in our laboratory by brands et al., showed that oysters in the united states are contaminated with salmonella, and in particular, a specific strain of the newport serovar. this work sought to further investigate the host-microbe interactions between salmonella newport ...201121632135
bacteriophage selection against a plasmid-encoded sex apparatus leads to the loss of antibiotic-resistance plasmids.antibiotic-resistance genes are often carried by conjugative plasmids, which spread within and between bacterial species. it has long been recognized that some viruses of bacteria (bacteriophage; phage) have evolved to infect and kill plasmid-harbouring cells. this raises a question: can phages cause the loss of plasmid-associated antibiotic resistance by selecting for plasmid-free bacteria, or can bacteria or plasmids evolve resistance to phages in other ways? here, we show that multiple antibi ...201121632619
salmonella synthesizing 1-monophosphorylated lipopolysaccharide exhibits low endotoxic activity while retaining its immunogenicity.the development of safe live, attenuated salmonella vaccines may be facilitated by detoxification of its lps. recent characterization of the lipid a 1-phosphatase, lpxe, from francisella tularensis allowed us to construct recombinant, plasmid-free strains of salmonella that produce predominantly 1-dephosphorylated lipid a, similar to the adjuvant approved for human use. complete lipid a 1-dephosphorylation was also confirmed under low ph, low mg(2+) culture conditions, which induce lipid a modif ...201121632711
the intestinal microbiota plays a role in salmonella-induced colitis independent of pathogen colonization.the intestinal microbiota is composed of hundreds of species of bacteria, fungi and protozoa and is critical for numerous biological processes, such as nutrient acquisition, vitamin production, and colonization resistance against bacterial pathogens. we studied the role of the intestinal microbiota on host resistance to salmonella enterica serovar typhimurium-induced colitis. using multiple antibiotic treatments in 129s1/svimj mice, we showed that disruption of the intestinal microbiota alters h ...201121633507
synthesis, characterization and biological properties of thienyl derived triazole schiff bases and their oxovanadium(iv) complexes.a new series of biologically active thienyl derived triazole schiff bases and their oxovanadium(iv) complexes have been synthesized and characterized on the basis of physical (m.p., magnetic susceptibility and conductivity), spectral (ir, (1)h and (13)c nmr, electronic and mass spectrometry) and microanalytical data. all the schiff base ligands and their oxovanadium(iv) complexes have been subjected to in vitro antibacterial activity against four gram-negative (escherichia coli, shigella flexner ...201121635212
the relative efficacy of different strain combinations of lactic acid bacteria in the reduction of populations of salmonella enterica typhimurium in the livers and spleens of mice.multispecies probiotics have been reported to be more effective than monostrain probiotics in health promoting for the host. in this study, twelve lactic acid bacteria (lab) strains were selected based on the level of induction of tnf-α in raw 264.7 macrophage cells. their adherence to caco-2 cells and inhibitory effects on salmonella invasion of caco-2 cells were compared. strains with different probiotic properties were then combined and balb/c mice were fed with lab strains for 63 days, then ...201121635568
crystallization and preliminary x-ray crystallographic analysis of salmonellatyphimurium cuep.salmonella enterica serovar typhimurium (s. typhimurium) can survive in the phagosome of macrophages, causing serious medical and veterinary problems. cuep is uniquely found in s. typhimurium and has been characterized as a major periplasmic copper-binding protein. although cuep has been identified as being responsible for the copper resistance of the bacterium in vivo, the biochemical role and three-dimensional structure of cuep remain unknown. in this study, cuep from s. typhimurium was overex ...201121636909
characterization of the carbohydrate backbone of vibrio parahaemolyticus o6 lipopolysaccharides.structural characterization studies have been carried out on the carbohydrate backbone of vibrio parahaemolyticus serotype o6 lipopolysaccharides (lps). the carbohydrate backbone isolated from o6 lps by sequential derivatization, i.e., dephosphorylation, o-deacylation, pyridylamination, n-deacylation and n-acetylation, is a nonasaccharide consisting of 3 mol of d-glucosamine (glcn) (of which one is pyridylaminated), 2 mol of l-glycero-d-manno-heptose (hep), and 1 mol each of d-galactose (gal), d ...201121639862
decay of bacterial pathogens, fecal indicators, and real-time quantitative pcr genetic markers in manure amended soils.this study examined persistence and decay of bacterial pathogens, fecal indicator bacteria (fib), and emerging real-time quantitative pcr (qpcr) genetic markers for rapid detection of fecal pollution in manure-amended agricultural soils. known concentrations of transformed green fluorescent protein-expressing escherichia coli o157:h7/pzs and red fluorescent protein-expressing salmonella enterica serovar typhimurium/pds were added to laboratory-scale manure-amended soil microcosms with moisture c ...201121642395
structure-guided investigation of lipopolysaccharide o-antigen chain length regulators reveals regions critical for modal length control.the o-antigen component of the lipopolysaccharide (lps) represents a population of polysaccharide molecules with a non-random (modal) chain length distribution. the number of the repeat o-units in each individual o-antigen polymer depends on the wzz chain-length regulator, an inner membrane protein belonging to the polysaccharide co-polymerase (pcps) family. different wzz proteins confer vastly different ranges of modal lengths (4 to >100 repeat units) despite having remarkably conserved structu ...201121642455
tubal factor infertility is associated with antibodies against chlamydia trachomatis heat shock protein 60 (hsp60) but not human hsp60.background serum antibodies against major outer membrane protein (momp) and heat shock protein 60 (hsp60) from chlamydia trachomatis are correlated with sequelae following infection. since bacterial and human hsp60 share considerable sequence homology, cross-reactivity to human hsp60 is suggested as being involved in tubal factor infertility (tfi). the aim was to investigate whether antibodies to human hsp60 are associated with tfi, and to evaluate antibody testing in tfi diagnosis. methods seru ...201121642639
the salmonella enterica pan-genome.salmonella enterica is divided into four subspecies containing a large number of different serovars, several of which are important zoonotic pathogens and some show a high degree of host specificity or host preference. we compare 45 sequenced s. enterica genomes that are publicly available (22 complete and 23 draft genome sequences). of these, 35 were found to be of sufficiently good quality to allow a detailed analysis, along with two escherichia coli strains (k-12 substr. dh10b and the avian p ...201121643699
gene expression pattern in swine neutrophils after lipopolysaccharide exposure: a time course comparison.experimental exposure of swine neutrophils to bacterial lipopolysaccharide (lps) represents a model to study the innate immune response during bacterial infection. neutrophils can effectively limit the infection by secreting lipid mediators, antimicrobial molecules and a combination of reactive oxygen species (ros) without new synthesis of proteins. however, it is known that neutrophils can modify the gene expression after lps exposure. we performed microarray gene expression analysis in order t ...201121645290
multi-comparative systems biology analysis reveals time-course biosignatures of in vivo bovine pathway responses to b.melitensis, s.enterica typhimurium and m.avium paratuberculosis.to decipher the complexity and improve the understanding of host-pathogen interactions, biologists must adopt new system level approaches in which the hierarchy of biological interactions and dynamics can be studied. this paper presents the application of systems biology for the cross-comparative analysis and interactome modeling of three different infectious agents, leading to the identification of novel, unique and common molecular host responses (biosignatures).201121645321
molecular characterization of salmonella enterica serovar saintpaul isolated from imported seafood, pepper, environmental and clinical samples.a total of 39 salmonella enterica serovar saintpaul strains from imported seafood, pepper and from environmental and clinical samples were analyzed for the presence of virulence genes, antibiotic resistance, plasmid and plasmid replicon types. pulsed-field gel electrophoresis (pfge) fingerprinting using the xbai restriction enzyme and plasmid profiling were performed to assess genetic diversity. none of the isolates showed resistance to ampicillin, chloramphenicol, gentamicin, kanamycin, strepto ...201121645810
prevalence and counts of salmonella spp. in minimally processed vegetables in são paulo, brazil.minimally processed vegetables (mpv) may be important vehicles of salmonella spp. and cause disease. this study aimed at detecting and enumerating salmonella spp. in mpv marketed in the city of são paulo, brazil. a total of 512 samples of mpv packages collected in retail stores were tested for salmonella spp. and total coliforms and escherichia coli as indication of the hygienic status. salmonella spp. was detected in four samples, two using the detection method and two using the counting method ...201121645825
the pmrcab operon mediates polymyxin resistance in acinetobacter baumannii atcc 17978 and clinical isolates through phosphoethanolamine modification of lipid a.the emergence of multidrug resistance amongst acinetobacter baumannii is leading to an increasing dependence on the use of polymyxins as last hope antibiotics. here we utilized genetic and biochemical methods to define the involvement of the pmrcab operon in polymyxin resistance in this organism. sequence analysis of 16 polymyxin b resistant strains, including six spontaneous mutants derived from strain atcc 17978 and 10 clinical isolates from diverse sources, revealed that they had independent ...201121646482
the expression levels of outer membrane proteins stm1530 and ompd, which are influenced by the cpxar and baesr two-component systems, play important roles in the ceftriaxone resistance of salmonella enterica serovar typhimurium.significant increases in stm3031, stm1530 and acrd protein levels and significant decreases in ompc and ompd protein levels are present when the ceftriaxone-resistant s. enterica serovar typhimurium r200 strain is compared with the ceftriaxone-susceptible strain 01-4. acrd is known to be involved in drug export and stm3031 seems to play a key role in ceftriaxone resistance. here, we examine the role of stm1530, ompc and ompd in ceftriaxone resistance. an ompd gene deletion mutant showed a 4-fold ...201121646491
enhancing the role of veterinary vaccines reducing zoonotic diseases of humans: linking systems biology with vaccine development.the aim of research on infectious diseases is their prevention, and brucellosis and salmonellosis as such are classic examples of worldwide zoonoses for application of a systems biology approach for enhanced rational vaccine development. when used optimally, vaccines prevent disease manifestations, reduce transmission of disease, decrease the need for pharmaceutical intervention, and improve the health and welfare of animals, as well as indirectly protecting against zoonotic diseases of people. ...201121651944
chromosomal rearrangements in salmonella enterica serovar typhi strains isolated from asymptomatic human carriers.host-specific serovars of salmonella enterica often have large-scale chromosomal rearrangements that occur by recombination between rrn operons. two hypotheses have been proposed to explain these rearrangements: (i) replichore imbalance from horizontal gene transfer drives the rearrangements to restore balance, or (ii) the rearrangements are a consequence of the host-specific lifestyle. although recent evidence has refuted the replichore balance hypothesis, there has been no direct evidence for ...201121652779
an infrequent molecular ruler controls flagellar hook length in salmonella enterica.the bacterial flagellum consists of a long external filament connected to a membrane-embedded basal body at the cell surface by a short curved structure called the hook. in salmonella enterica, the hook extends 55 nm from the cell surface. flik, a secreted molecular ruler, controls hook length. upon hook completion, flik induces a secretion-specificity switch to filament-type substrate secretion. here, we demonstrate that an infrequent ruler mechanism determines hook length. flik is intermittent ...201121654632
inverse regulation in the metabolic genes pcka and mete revealed by proteomic analysis of the salmonella rcscdb regulon.the rcsc, rcsd, and rcsb proteins compose a system used by enteric bacteria to sense envelope stress. signal transmission occurs from the sensor rcsc to the transcriptional regulator rcsb. accessory proteins, such as igaa, are known to adjust the response level. in a previous transcriptomic study, we uncovered 85 genes differentially expressed in salmonella enterica serovar typhimurium igaa mutants. here, we extended these observations to proteomics by performing differential isotope-coded prote ...201121657791
outbreak of salmonella enterica serotype infantis producing arma 16s rna methylase and ctx-m-15 extended-spectrum +¦-lactamase in a neonatology ward in constantine, algeria.plasmid-mediated 16s rrna methylases such as arma, which confer high levels of resistance to aminoglycosides, are increasingly reported in enterobacteriaceae. this study investigated the molecular mechanism of +¦-lactam and aminoglycoside resistance in extended-spectrum +¦-lactamase (esbl)-producing salmonella enterica serotype infantis isolated at the 53-bed neonatology ward of university hospital benabib in constantine, algeria. from september 2008 to january 2009, 200 s. enterica isolates wer ...201121658916
the effects of brazilian and bulgarian propolis in vitro against salmonella typhi and their synergism with antibiotics acting on the ribosome.salmonella enterica serovar typhi is the causative agent of typhoid fever in humans, and the use of antibiotics is essential for controlling this infection; however, the excessive use of antibiotics may select resistant strains. propolis is a honeybee product and its antimicrobial activity has been intensively investigated. thus, the objective of this study was to investigate a possible synergism between propolis (collected in brazil and bulgaria) and antibiotics acting on the ribosome (chloramp ...201121660841
a retrospective study of post-mortem examination findings in takahe (porphyrio hochstetteri).to identify the major diseases or disease processes affecting both captive and wild populations of takahe (porphyrio hochstetteri) in birds submitted for post-mortem examination between 1992 and 2007, and to survey archived wild dead takahe for the presence of erysipelothrix rhusiopathiae.201121660844
interferon-╬│ and proliferation responses to salmonella enterica serotype typhi proteins in patients with s. typhi bacteremia in dhaka, bangladesh.salmonella enterica serotype typhi is a human-restricted intracellular pathogen and the cause of typhoid fever. cellular immune responses are required to control and clear salmonella infection. despite this, there are limited data on cellular immune responses in humans infected with wild type s. typhi.201121666798
prevalence and characterization of salmonella serovars isolated from oysters served raw in restaurants.to determine if salmonella-contaminated oysters are reaching consumer tables, a survey of raw oysters served in eight tucson restaurants was performed from october 2007 to september 2008. salmonella spp. were isolated during 7 of the 8 months surveyed and were present in 1.2% of 2,281 oysters tested. this observed prevalence is lower than that seen in a previous study in which u.s. market oysters were purchased from producers at bays where oysters are harvested. to test whether the process of re ...201121669086
iceberg lettuce as suggested source of a nationwide outbreak caused by two salmonella serotypes, newport and reading, in finland in 2008.a nationwide outbreak of salmonella enterica serotypes newport and reading occurred between 17 october and 28 november 2008 in finland. a total of 77 culture-confirmed salmonella newport and 30 salmonella reading cases, including one case with a double infection, were reported. all strains isolated from the patients were subtyped using serotyping, microbial resistance profiling, and pulsed-field gel electrophoresis (pfge). here, the pfge patterns of the studied salmonella newport strains were id ...201121669088
multi-locus sequence typing of salmonella enterica subsp. enterica serovar enteritidis strains in japan between 1973 and 2004.salmonella enterica subsp. enterica serovar enteritidis (s. enteritidis) was responsible for a worldwide pandemic during the 1980s and 1990s; however, changes in the dominant lineage before and after this event remain unknown. this study determined s. enteritidis lineages before and after this pandemic event in japan using multilocus sequence typing (mlst). thirty s. enteritidis strains were collected in japan between 1973 and 2004, consisting of 27 human strains from individual episodes, a bovi ...201121672260
horizontal transmission of salmonella enteritidis in groups of experimentally infected laying hens housed in different housing systems.concerns regarding the welfare of laying hens have led to the ban of conventional battery cages in europe from 2012 onward and to the development of alternative housing systems that allow hens to perform a broader range of natural behaviors. limited information is available about the consequences of alternative housing systems on transmission of zoonotic pathogens such as salmonella enteritidis. however, salmonella enterica serovar enteritidis continues to be one of the leading causes of bacteri ...201121673153
sodium alginate oligosaccharides from brown algae inhibit salmonella enteritidis colonization in broiler chickens.the effects of sodium alginate oligosaccharides (sao) on growth performance, cecal microbiota, salmonella translocation to internal organs, and mucosal immune responses to challenge with salmonella enterica serovar enteritidis in broiler chickens were investigated. we designed an experiment with a 2 × 3 factorial arrangement, in which 3 feed treatments with supplementation of sao at 0 (controls), 0.04, or 0.2% were provided in the diet for birds not challenged or challenged with salmonella ente ...201121673159
assessment of salmonella spp. in feces, cloacal swabs, and eggs (eggshell and content separately) from a laying hen farm.microbial pathogens of the genus salmonella are among the leading causes of foodborne illness in the world. the present study was done on a laying hen farm with a salmonella enterica serovar enteritidis-positive result according to the testing specified by european regulation 2160/2003. the aim of this study was to compare the salmonella contamination on a laying hen farm with the salmonella presence in the hen eggs. the strains were isolated by iso method 6579:2002 (standard method for the dete ...201121673175
prevalence and antimicrobial resistance profiles of salmonella enterica serovars isolated from slaughtered cattle in bahir dar, ethiopia.a study was undertaken from october 2006 to march 2007 to determine the prevalence and antimicrobial resistance patterns of salmonella serovars. liver, mesenteric lymph nodes, intestinal content, and carcass swab samples (each n = 186) were collected from 186 apparently healthy slaughtered cattle at bahir dar abattoir. bacteriological analysis was done according to the international organization for standardization (iso 6579 2002). isolates were serotyped at agence française de securite sanitair ...201121814750
challenges and opportunities to identifying and controlling the international spread of salmonella. 201121813513
international spread of an epidemic population of salmonella enterica serotype kentucky st198 resistant to ciprofloxacin.national salmonella surveillance systems from france, england and wales, denmark, and the united states identified the recent emergence of multidrug-resistant isolates of salmonella enterica serotype kentucky displaying high-level resistance to ciprofloxacin. a total of 489 human cases were identified during the period from 2002 (3 cases) to 2008 (174 cases). these isolates belonged to a single clone defined by the multilocus sequence type st198, the xbai-pulsed-field gel electrophoresis cluster ...201121813512
roles of salmonella enterica serovar typhimurium encoded peptidase n during systemic infection of ifnγ(-/-) mice.pathogen encoded peptidases are known to be important during infection; however, their roles in modulating host responses in immunocompromised individuals are not well studied. the roles of s. typhimurium (wt) encoded peptidase n (pepn), a major aminopeptidase and sole m1 family member, was studied in mice lacking interferon-γ (ifnγ), a cytokine important for immunity. s. typhimurium lacking pepn (δpepn) displays enhanced colony forming units (cfu) compared to wt in peripheral organs during syst ...201121813203
oral administration of a probiotic lactobacillus modulates cytokine production and tlr expression improving the immune response against salmonella enterica serovar typhimurium infection in mice.abstract: background: diarrheal infections caused by salmonella, are one of the major causes of childhood morbidity and mortality in developing countries. salmonella causes various diseases that range from mild gastroenteritis to enteric fever, depending on the serovar involved, infective dose, species, age and immune status of the host. probiotics are proposed as an attractive alternative possibility in the prevention against this pathogen infection. previously we demonstrated that continuous l ...201121813005
emergence of a globally dominant inchi1 plasmid type associated with multiple drug resistant typhoid.typhoid fever, caused by salmonella enterica serovar typhi (s. typhi), remains a serious global health concern. since their emergence in the mid-1970s multi-drug resistant (mdr) s. typhi now dominate drug sensitive equivalents in many regions. mdr in s. typhi is almost exclusively conferred by self-transmissible inchi1 plasmids carrying a suite of antimicrobial resistance genes. we identified over 300 single nucleotide polymorphisms (snps) within conserved regions of the inchi1 plasmid, and geno ...201121811646
genetic characterization of conserved charged residues in the bacterial flagellar type iii export protein flha.for assembly of the bacterial flagellum, most of flagellar proteins are transported to the distal end of the flagellum by the flagellar type iii protein export apparatus powered by proton motive force (pmf) across the cytoplasmic membrane. flha is an integral membrane protein of the export apparatus and is involved in an early stage of the export process along with three soluble proteins, flih, flii, and flij, but the energy coupling mechanism remains unknown. here, we carried out site-directed ...201121811603
extreme antimicrobial peptide and polymyxin b resistance in the genus burkholderia.cationic antimicrobial peptides and polymyxins are a group of naturally occurring antibiotics that can also possess immunomodulatory activities. they are considered a new source of antibiotics for treating infections by bacteria that are resistant to conventional antibiotics. members of the genus burkholderia, which includes various human pathogens, are inherently resistant to antimicrobial peptides. the resistance is several orders of magnitude higher than that of other gram-negative bacteria s ...201121811491
ancestral genes can control the ability of horizontally acquired loci to confer new traits.horizontally acquired genes typically function as autonomous units conferring new abilities when introduced into different species. however, we reasoned that proteins preexisting in an organism might constrain the functionality of a horizontally acquired gene product if it operates on an ancestral pathway. here, we determine how the horizontally acquired pmrd gene product activates the ancestral pmra/pmrb two-component system in salmonella enterica but not in the closely related bacterium escher ...201121811415
an allelotyping pcr for identifying <em>salmonella enterica</em> serovars enteritidis, hadar, heidelberg, and typhimurium.current commercial pcrs tests for identifying salmonella target genes unique to this genus. however, there are two species, six subspecies, and over 2,500 different salmonella serovars, and not all are equal in their significance to public health. for example, finding s. enterica subspecies iiia arizona on a table egg layer farm is insignificant compared to the isolation of s. enterica subspecies i serovar enteritidis, the leading cause of salmonellosis linked to the consumption of table eggs. s ...201121808227
engineering and pre-clinical evaluation of attenuated non-typhoidal salmonella strains serving as live oral vaccines and as reagent strains.while non-typhoidal salmonella (nts) have long been recognized as a cause of self-limited gastroenteritis, it is becoming increasingly evident that multiple antibiotic-resistant strains are also emerging as important causes of invasive bacteremia and focal infections, resulting in hospitalizations and deaths. we have constructed attenuated salmonella enterica serovar typhimurium and enteritidis strains that can serve as live oral vaccines and as "reagent strains" for subunit vaccine production i ...201121807911
salmonella enteritidis core-o polysaccharide (cops) conjugated to h:g,m flagellin as a candidate vaccine for protection against invasive infection with salmonella enteritidis.non-typhoidal salmonella serovars enteritidis and typhimurium are a common cause of gastroenteritis but also cause invasive infections and enteric fever in certain hosts (young children in sub-saharan africa, the elderly and immunocompromised). salmonella o polysaccharides (ops) and flagella proteins are virulence factors and protective antigens. the surface polysaccharides of salmonella are poorly immunogenic and do not confer immunologic memory, limitations overcome by covalently attaching the ...201121807909
fliz acts as a repressor of the ydiv gene which encodes an anti-flhd4c2 factor of the flagellar regulon in salmonella enterica serovar typhimurium.ydiv acts as an anti-flhd(4)c(2) factor, which regulates negatively the class 2 flagellar operons in poor medium in salmonella enterica serovar typhimurium. on the other hand, one of the class 2 flagellar genes fliz encodes a positive regulator of the class 2 operons. in this study, we found that the fliz-dependent activation of the class 2 expression was more profound in poor medium than in rich medium and not observed in the ydiv-mutant background. transcription of the ydiv gene was shown to i ...201121804009
detection of viable cryptosporidium parvum in soil by reverse transcription real time pcr targeting hsp70 mrna.extraction of high-quality mrna from cryptosporidium parvum is a key step in pcr detection of viable oocysts in environmental samples. current methods for monitoring oocysts are limited to water samples; therefore, the goal of this study was to develop a rapid and sensitive procedure for cryptosporidium detection in soil samples. the effectiveness of five rna extraction methods were compared (mrna extraction with the dynabeads® mrna direct™ kit after chemical and physical sample treatments, and ...201121803904
co-production of acetaldehyde and hydrogen from glucose fermentation by escherichia coli.escherichia coli k12 strain mg1655 was engineered to co-produce acetaldehyde and hydrogen during glucose fermentation using an exogenous acetyl-coa reductase (for the conversion of acetyl-coa to acetaldehyde) and the native formate hydrogen lyase. a putative acetaldehyde dehydrogenase/acetyl-coa reductase from salmonella enterica (seeute) was cloned, produced at high levels and purified by nickel affinity chromatography. in vitro assays showed that this enzyme had both acetaldehyde dehydrogenase ...201121803884
salmonella carriage in adopted children from mali: 2001-08.objectives salmonella spp. are among the most frequently encountered bacterial pathogens in children adopted abroad, especially from developing countries. the aim of this study was to investigate the carriage of salmonella in international adoptees over an 84 month period. this screening programme was initiated after serious infections occurred in adopted children. material and methods stool samples taken at the first visit to the outpatient adoption practice and subsequently every month from ch ...201121803770
dynamic modification of microtubule-dependent transport by effector proteins of intracellular salmonella enterica.intracellular salmonella enterica translocate effector proteins that modify microtubule-dependent transport processes of the host cell and modulate the biogenesis of the salmonella-containing vacuole (scv). one functional consequence is the induction of tubular aggregates of endosomal membranes, termed salmonella-induced filaments or sifs, and further tubular membrane compartments have recently been described. sifs are unique, highly dynamic compartments that form by modification of vesicular tr ...201121803443
[expressing of porcine beta-defensin-2 mature peptide in the yeast].to construct the recombinant pichia pastoris km71 in which porcine beta-defensin-2(pbd-2) mature peptide could be stably expressed and the antimicrobial effect was evaluated.201121800634
sensing and adaptation to low ph mediated by inducible amino acid decarboxylases in salmonella.during the course of infection, salmonella enterica serovar typhimurium must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. inducible amino acid decarboxylases are known to promote adaptation to acidic environments. three low ph inducible amino acid decarboxylases were annotated in the genome of s. typhimurium, adia, cada and spef, which are specific for arginine, lysine and ornithine, respectively. in this study, we char ...201121799843
beta-lactam antibiotics prevent salmonella-mediated bovine encephalopathy regardless of the ß-lactam resistance status of the bacteria.this study assessed the capacity of ß-lactam antibiotics to prevent salmonella-mediated encephalopathy in calves given the putative neuroprotective effects of these drugs of increasing glutamate export from the brain. both ampicillin and ceftiofur prevented the development of encephalopathy despite resistance of the inoculated salmonella enterica serovar saint-paul isolate to both drugs. a glutamate receptor antagonist also prevented this salmonella-mediated encephalopathy. glutamate exporters w ...201121798771
allosteric catch bond properties of the fimh adhesin from salmonella enterica serovar typhimurium.despite sharing the name and the ability to mediate mannose-sensitive adhesion, the type 1 fimbrial fimh adhesins of salmonella typhimurium and escherichia coli share only 15% sequence identity. in the present study, we demonstrate that even with this limited identity in primary sequence, these two proteins share remarkable similarity of complex receptor-binding and structural properties. in silico simulations suggest that, like e. coli fimh, salmonella fimh has a two-domain tertiary structure t ...201121795699
a stochastic approach for integrating strain variability in modeling salmonella enterica growth as a function of ph and water activity.strain variability of the growth behavior of foodborne pathogens has been acknowledged as an important issue in food safety management. a stochastic model providing predictions of the maximum specific growth rate (µ(max)) of salmonella enterica as a function of ph and water activity (a(w)) and integrating intra-species variability data was developed. for this purpose, growth kinetic data of 60 s. enterica isolates, generated during monitoring of growth in tryptone soy broth of different ph (4.0- ...201121794942
antioxidant and antibacterial activity of six edible wild plants (sonchus spp.) in china.the total phenolic and flavonoid, antioxidant and antibacterial activities of six sonchus wild vegetables (sonchus oleraceus l., sonchus arvensis l., sonchus asper (l.) hill., sonchus uliginosus m.b., sonchus brachyotus dc. and sonchus lingianus shih) in china were investigated. the results revealed that s. arvensis extract and s. oleraceus extract contained the highest amount of phenolic and flavonoid, respectively. among the methanol extracts of six sonchus species, s. arvensis extract exhibit ...201121793765
comparison of real-time pcr with conventional pcr and culture to assess the efficacy of a live attenuated salmonella enterica serovar typhimurium vaccine against salmonella enterica serovar enteritidis in commercial leghorn chicks vaccinated under field and laboratory conditions.the efficacy of a live attenuated salmonella typhimurium megan vac 1 vaccine (mv1) was evaluated against salmonella enteritidis in chicken pullets with the use of pcr and culture methods. two hundred hyline w-32 white leghorn chicks were obtained from a local hatchery and divided into four treatment groups. two of the groups served as positive and negative controls. the mv1 vaccine was administered to the chicks in the remaining two groups at 1 and 35 days old by either the coarse spray (field) ...201121793441
emergence of salmonella enterica serovar potsdam as a major serovar in waterfowl hatcheries and chicken eggs.salmonellosis is a common food-borne illness in humans caused by salmonella-contaminated poultry and their products. in hatcheries, 110 salmonella isolates were identified, mostly from first enrichment, and few from delayed enrichment. the salmonella prevalence in goose and duck hatcheries was higher when measured by four multiplex pcr methods than by traditional culture (73.8% vs. 44.35%, p < 0.05); 97.3% of 110 isolates were salmonella potsdam of serogroup c1 and other isolates were salmonella ...201121793436
regulating iron storage and metabolism with rna: an overview of posttranscriptional controls of intracellular iron homeostasis.iron (fe) is a double-edged sword for most living organisms. although it is essential for the catalytic activity of a large number of enzymes, ferrous iron (fe(2+) ) becomes cytotoxic in the presence of normal respiratory by-products such as h(2) o(2) . because of this toxicity, intracellular iron concentrations ought to be regulated by elaborated homeostasis systems that, despite decades of extensive studies, have not yet revealed all of their surprising arrays of mechanistic details. within th ...201121793218
new generation typhoid vaccines: an effective preventive strategy to control typhoid fever in developing countries.typhoid fever is a serious systemic infection, caused by the enteric pathogen salmonella enterica serovar typhi, a highly virulent and invasive enteric bacterium. this disease occurs in all parts of world where water supplies and sanitation are substandard. these pathogens then travel to food, drinks and water through house-flies and other vectors. globally, an estimated 12 - 33 million cases of enteric fever occur with 216,000 - 600,000 deaths per year, almost exclusively in the developing coun ...201121791973
development of multiplex pcr assay for rapid detection of riemerella anatipestifer, escherichia coli, and salmonella enterica simultaneously from ducks.three pathogens, riemerella anatipestifer, escherichia coli, and salmonella enterica, are leading causes of bacterial fibrinous pericarditis and perihepatitis in ducks in china and worldwide. it is difficult to differentiate these pathogens when obtaining a diagnosis on clinical signs and pathological changes. the aim of this research was to develop a multiplex polymerase chain reaction (m-pcr) that could discriminate r. anatipestifer, e. coli, and s. enterica rapidly in field isolates, or detec ...201121791228
the two-component sensor kinase kdpd is required for salmonella typhimurium colonization of caenorhabditis elegans and survival in macrophages.the ability of enteric pathogens to perceive and adapt to distinct environments within the metazoan intestinal tract is critical for pathogenesis, however the preponderance of interactions between microbe- and host-derived factors remain to be fully understood. salmonella enterica serovar typhimurium is a medically important enteric bacterium that colonizes, proliferates, and persists in the intestinal lumen of the nematode caenorhabditis elegans. several salmonella virulence factors important i ...201121790938
a glance at listeria and salmonella cell invasion: different strategies to promote host actin polymerization.the facultative intracellular bacterial pathogens listeria monocytogenes and salmonella enterica have evolved multiple strategies to invade a large panel of mammalian cells. these pathogens use the host cell actin system for invasion and became a paradigm for the study of host-pathogen interactions and bacterial adaptation to mammalian hosts. the key signaling component that these pathogens use to orchestrate actin remodeling is the arp2/3 complex, which is related to polymerization of actin fil ...201121783413
type iv(b) pili are required for invasion but not for adhesion of salmonella enterica serovar typhi into bhk epithelial cells in a cystic fibrosis transmembrane conductance regulator-independent manner.the cystic fibrosis transmembrane conductance regulator (cftr) has been proposed as an epithelial cell receptor for the entry of salmonella typhi but not salmonella typhimurium. the bacterial ligand recognized by cftr is thought to reside either in the s. typhi lipopolysaccharide core region or in the type iv pili. here, we assessed the ability of virulent strains of s. typhi and s. typhimurium to adhere to and invade bhk epithelial cells expressing either the wild-type cftr protein or the ?f508 ...201121782926
porcine circovirus type 2 potentiates morbidity of salmonella enterica serovar choleraesuis in cesarean-derived, colostrum-deprived pigs.problem addressed: porcine circovirus type 2 (pcv2) and salmonella enterica subspecies enterica serovar choleraesuis (s. choleraesuis) are two leading causes of economic loss in the swine industry. although s. choleraesuis infection occurs concurrently with pcv2-associated disease in many swine herds, the pathogenesis of concurrent infection with pcv2 and s. choleraesuis remains largely undefined. objective: we investigated the interactions between pcv2 and s. choleraesuis in 20 cesarean-derived ...201121782358
evaluation of different analysis and identification methods for salmonella detection in surface drinking water sources.the standard method for detecting salmonella generally analyzes food or fecal samples. salmonella often occur in relatively low concentrations in environmental waters. therefore, some form of concentration and proliferation may be needed. this study compares three salmonella analysis methods and develops a new salmonella detection procedure for use in environmental water samples. the new procedure for salmonella detection include water concentration, nutrient broth enrichment, selection of salmo ...201121782212
salmonella enterica ssp. arizonae infection in a 43-year-old italian man with hypoglobulinemia: a case report and review of the literature.abstract: introduction: salmonella enterica ssp. arizonae is an uncommon human pathogen with serious infections reported in immunocompromised hosts. in europe, only a few cases have been described. patients with this infection usually have a history of contact with reptiles or travel abroad. we present a case report of infection in a patient with hypoglobulinemia and a literature review. case presentation: we describe the case of a 43-year-old caucasian italian man with hypoglobulinemia who pres ...201121781321
activation of akt by the bacterial inositol phosphatase, sopb, is wortmannin insensitive.salmonella enterica uses effector proteins translocated by a type iii secretion system to invade epithelial cells. one of the invasion-associated effectors, sopb, is an inositol phosphatase that mediates sustained activation of the pro-survival kinase akt in infected cells. canonical activation of akt involves membrane translocation and phosphorylation and is dependent on phosphatidyl inositide 3 kinase (pi3k). here we have investigated these two distinct processes in salmonella infected hela ce ...201121779406
colombos: access port for cross-platform bacterial expression compendia.microarrays are the main technology for large-scale transcriptional gene expression profiling, but the large bodies of data available in public databases are not useful due to the large heterogeneity. there are several initiatives that attempt to bundle these data into expression compendia, but such resources for bacterial organisms are scarce and limited to integration of experiments from the same platform or to indirect integration of per experiment analysis results.201121779320
bacterial carbonic anhydrases as drug targets: toward novel antibiotics?carbonic anhydrases (cas, ec 4.2.1.1) are metalloenzymes which catalyze the hydration of carbon dioxide to bicarbonate and protons. many pathogenic bacteria encode such enzymes belonging to the a-, ß-, and/or ?-ca families. in the last decade, the a-cas from neisseria spp. and helicobacter pylori as well as the ß-class enzymes from escherichia coli, h. pylori,mycobacterium tuberculosis, brucella spp., streptococcus pneumoniae, salmonella enterica, and haemophilus influenzae have been cloned and ...201121779249
recurrent meningitis and subarachnoid hemorrhage due to salmonella in an hiv+ patient: case report and mini-review of the literature.meningitis due to non-typhi salmonella is infrequent in hiv-positive adults.we report a case of a patient with >300 cd4+ cells/mm3 who presented with five episodes of recurrent meningitis, focal subarachnoid hemorrhage and cerebral vasculitis ultimately attributed to salmonella choleraesuis infection. even within the cart era invasive salmonellosis can occur in unusual ways in hiv-infected patients.201121772932
effect of deletion of genes involved in lipopolysaccharide core and o-antigen synthesis on virulence and immunogenicity of salmonella enterica serovar typhimurium.lipopolysaccharide (lps) is a major virulence factor of salmonella enterica serovar typhimurium, and is composed of lipid a, core-oligosaccharide (c-os) and o-antigen polysaccharide (o-ps). while the functions of the gene products involved in synthesis of core and o-antigen have been elucidated, the effect of removing o-antigen and core sugars on the virulence and immunogenicity of salmonella enterica serovar typhimurium has not been systematically studied. we introduced non-polar, defined delet ...201121768282
salmonella enterica serovar typhimurium colonizing the lumen of the chicken intestine are growing slowly and up-regulate a unique set of virulence and metabolism genes.the pattern of global gene expression of s. typhimurium harvested from the chicken intestinal lumen (ceca) was compared with those of a late log lb broth culture using a whole genome microarray. levels of transcription, translation and cell division in vivo were lower than in vitro. s. typhimurium appeared to be using carbon sources such as propionate, 1,2-propanediol and ethanolamine in addition to melibiose and ascorbate, the latter possibly transformed to d-xylulose. amino acid starvation app ...201121768276
leukocytic responses and intestinal mucin dynamics of broilers protected with enterococcus faecium ef55 and challenged with salmonella enteritidis.the protective effect of enterococcus faecium ef55 in chickens challenged with salmonella enterica serovar enteritidis phage type 4 (se pt4) was assessed. the antibacterial effect on the bacterial microflora in the small intestine in relation to white blood cell count, phenotyping of peripheral blood and intestinal lymphocytes, functional activity of lymphocytes and phagocytes and mucin quantitation were investigated. day-old chicks (85) were randomly divided into four groups. the probiotic grou ...201121767856
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