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vaccines for typhoid fever and other salmonelloses.this review summarizes the recent advances in vaccination against salmonella enterica serovar typhi and highlights the data supporting the development of next generation vaccines to address paratyphoid fever and invasive nontyphoidal salmonella (ints) disease.201222825288
assessment of root uptake and systemic vine-transport of salmonella enterica sv. typhimurium by melon (cucumis melo) during field production.among melons, cantaloupes are most frequently implicated in outbreaks and surveillance-based recalls due to salmonella enterica. there is limited but compelling evidence that associates irrigation water quality as a significant risk of preharvest contamination of melons. however, the potential for root uptake from water and soil and subsequent systemic transport of salmonella into melon fruit is uncharacterized. the aim of this work was to determine whether root uptake of s. enterica results in ...201222824339
spi-1 encoded genes of salmonella typhimurium influence differential polarization of porcine alveolar macrophages in vitro.within the last decade, macrophages have been shown to be capable of differentiating toward a classically activated phenotype (m1) with a high antimicrobial potential or an alternatively activated phenotype (m2). some pathogens are capable of interfering with differentiation in order to down-regulate the anti-microbial activity and enhance their survival in the host.201222817641
development of an improved selective and differential medium for isolation of salmonella spp.we describe an improved selective, differential, and cost-effective medium, xa medium, which contains d-arabinose, to facilitate the selective isolation of salmonella spp. the sensitivity and the specificity of xa medium were compared to those of xylose lysine desoxycholate agar (xld) using stock cultures and naturally contaminated food samples. xa medium and xld were evaluated with a total of 82 salmonella and 69 non-salmonella stock cultures. of 82 strains of salmonella spp. tested, 76 produce ...201222814469
thymus maroccanus essential oil, a membranotropic compound active on gram-negative bacteria and resistant isolates.the effects of thymus maroccanus essential oil (eo) on the integrity of the cell membranes and the permeability of the outer membrane (om) and inner membrane (im) of escherichia coli, enterobacter aerogenes and salmonella enterica typhimurium were investigated.201222809088
the antimicrobial effects of propolis collected in different regions in the basque country (northern spain).the antimicrobial activity of 19 propolis extracts prepared in different solvents (ethanol and propylene glycol) (eep/pep), was evaluated against some bacterial and fungal isolates using the agar-well diffusion method. it was verified that all the samples tested showed antimicrobial activity, although results varied considerably between samples. results revealed that both types of propolis extracts showed highly sensitive antimicrobial action against gram-positive bacteria and fungi at a concent ...201122805915
salmonella enterica serovar ohio septic arthritis and bone abscess in an immunocompetent patient: a case report.non-typhi salmonella species cause severe extra-intestinal focal infection after occult bacteremia. although the number of cases of non-typhi salmonellosis is increasing worldwide among patients with immunocompromising conditions such as human immunodeficiency virus infection, infection is uncommon in immunocompetent subjects. we report a case of septic arthritis and bone abscess due to a rare non-typhi salmonella organism that developed after a prolonged asymptomatic period.201222804866
leuo is a global regulator of gene expression in salmonella enterica serovar typhimurium.we report the first investigation of the binding of the salmonella enterica leuo lysr-type transcription regulator to its genomic targets in vivo. chromatin-immunoprecipitation-on-chip identified 178 leuo binding sites on the chromosome of s. enterica serovar typhimurium strain sl1344. these sites were distributed across both the core and the horizontally acquired genome, and included housekeeping genes and genes known to contribute to virulence. sixty-eight leuo targets were co-bound by the glo ...201222804842
early strains of multidrug-resistant salmonella enterica serovar kentucky sequence type 198 from southeast asia harbor salmonella genomic island 1-j variants with a novel insertion sequence.salmonella genomic island 1 (sgi1) is a 43-kb integrative mobilizable element that harbors a great diversity of multidrug resistance gene clusters described in numerous salmonella enterica serovars and also in proteus mirabilis. the majority of sgi1 variants contain an in104-derivative complex class 1 integron inserted between resolvase gene res and open reading frame (orf) s044 in sgi1. recently, the international spread of ciprofloxacin-resistant s. enterica serovar kentucky sequence type 198 ...201222802251
numbers of salmonella recovered by sponge or low volume whole carcass rinse sampling of inoculated commercial turkey carcasses.processed turkey carcasses are sampled for salmonella via sponge sampling, whereas broilers are sampled via whole carcass rinses. because different sampling methods have been reported to produce different results, sponge sampling and whole carcass rinsing (wcr) were performed on turkey hen carcasses inoculated with a known amount of nalidixic acid-resistant salmonella enterica serovar enteritidis. five turkey hen carcasses were collected from the shackle line in a commercial processing plant in ...201222802199
salmonella enterica serovar enteritidis phage type 4 outbreak associated with eggs in a large prison, london 2009: an investigation using cohort and case/non-case study methodology.in september 2009, an outbreak of salmonella enterica serovar enteritidis affected 327 of 1419 inmates at a london prison. we applied a cohort design using aggregated data from the kitchen about portions of food distributed, aligned this with individual food histories from 124 cases (18 confirmed, 106 probable) and deduced the exposures of those remaining well. results showed that prisoners eating egg cress rolls were 26 times more likely to be ill [risk ratio 25.7, 95% confidence interval (ci) ...201322800644
characterization of osmotically induced filaments of salmonella enterica.salmonella enterica forms aseptate filaments with multiple nucleoids when cultured in hyperosmotic conditions. these osmotic-induced filaments are viable and form single colonies on agar plates even though they contain multiple genomes and have the potential to divide into multiple daughter cells. introducing filaments that are formed during osmotic stress into culture conditions without additional humectants results in the formation of septa and their division into individual cells, which could ...201222798362
a new methodology for differentiation and typing of closely related salmonella enterica serovar heidelberg isolates.this study describe the use of a combination of two recently proposed typing approaches, multiple amplification of prophage locus typing (maplt) and multiple-locus variable-number tandem-repeat analysis (mlva) for subdividing within salmonella enterica serovar heidelberg (s. heidelberg). the combined typing method was compared with pulsed-field gel electrophoresis (pfge) by simpson's index of diversity (di). pfge was shown to have a di = 0.84 and was poor at differentiation of the predominant pt ...201222797864
convergent molecular evolution of genomic cores in salmonella enterica and escherichia coli.one of the strongest signals of adaptive molecular evolution of proteins is the occurrence of convergent hot spot mutations: repeated changes in the same amino acid positions. we performed a comparative genome-wide analysis of mutation-driven evolution of core (omnipresent) genes in 17 strains of salmonella enterica subspecies i and 22 strains of escherichia coli. more than 20% of core genes in both salmonella and e. coli accumulated hot spot mutations, with a predominance of identical changes h ...201222797756
caspase-1 activity is required to bypass macrophage apoptosis upon salmonella infection.here we report awp28, an activity-based probe that can be used to biochemically monitor caspase-1 activation in response to proinflammatory stimuli. using awp28, we show that apoptosis is triggered upon salmonella enterica var. typhimurium infection in primary mouse bone marrow macrophages lacking caspase-1. furthermore, we report that upon salmonella infection, inflammasome-mediated caspase-1 activity is required to bypass apoptosis in favor of proinflammatory pyroptotic cell death.201222797665
the in vivo extracellular life of facultative intracellular bacterial parasites: role in pathogenesis.classically labeled facultative intracellular pathogens are characterized by the ability to have an intracellular phase in the host, which is required for pathogenicity, while capable of extracellular growth in vitro. the ability of these bacteria to replicate in cell-free conditions is usually assessed by culture in artificial bacteriological media. however, the extracellular growth ability of these pathogens may also be expressed by a phase of extracellular infection in the natural setting of ...201322795971
comparative genome analysis of the high pathogenicity salmonella typhimurium strain uk-1.salmonella enterica serovar typhimurium, a gram-negative facultative rod-shaped bacterium causing salmonellosis and foodborne disease, is one of the most common isolated salmonella serovars in both developed and developing nations. several s. typhimurium genomes have been completed and many more genome-sequencing projects are underway. comparative genome analysis of the multiple strains leads to a better understanding of the evolution of s. typhimurium and its pathogenesis. s. typhimurium strain ...201222792393
a single residue determines the cooperative binding property of a primosomal dna replication protein, prib, to single-stranded dna.prib is a primosomal protein required for re-initiation of replication in bacteria. we characterized and compared the dna-binding properties of prib from salmonella enterica serovar typhimurium lt2 (stprib) and escherichia coli (ecprib). only one residue of ecprib, v6, was different in stprib (replaced by a6). previous structural information revealed that this residue is located on the putative dimer-dimer interface of prib and is not involved in single-stranded dna (ssdna) binding. the cooperat ...201222790931
drug resistance in salmonella enterica serotype typhi isolated from chronic typhoid carriers. 201222789724
the campylobacter jejuni dps homologue is important for in vitro biofilm formation and cecal colonization of poultry and may serve as a protective antigen for vaccination.in this work, we investigated the campylobacter jejuni dps (dna binding protein from starved cells) gene for a role in biofilm formation and cecal colonization in poultry. in vitro biofilm formation assays were conducted with stationary-phase cells in cell culture plates under microaerophilic conditions. these studies demonstrated a significant (>50%) reduction in biofilm formation by the c. jejuni dps mutant compared to that by the wild-type strain. studies in poultry also demonstrated the impo ...201222787197
antimicrobial and synergistic effects of silver nanoparticles synthesized using soil fungi of high altitudes of eastern himalaya.fifty three fungi isolated from soils of different microhabitats of eastern himalayan range (3,400~3,600 msl) were screened for mycosynthesis of silver nanaoparticles (agnps) and their efficacy as antimicrobials were assessed in combination with commonly used antibiotics. three isolates aspergillus terreus sp5, paecilomyces lilacinus sf1 and fusarium sp. mp5 identified based on morphological and 18s rrna gene sequences were found to synthesize agnps. these nanoparticles were characterized by vis ...201222783131
diversity and biological activities of endophytic fungi of emblica officinalis, an ethnomedicinal plant of india.in the present study, an attempt to evaluate the antimicrobial and antioxidant activity of fungal endophytes inhabiting emblica officinalis has been made keeping in view the medicinal importance of the selected host plant in indian traditional practices. a total of four endophytic fungi belonging to phylum ascomycetes were isolated from different parts of the plant which were characterized morphologically and by using rdna-internal transcribed spacer. the most frequently isolated endophyte was p ...201222783128
panm, an acetyl-coenzyme a sensor required for maturation of l-aspartate decarboxylase (pand).coenzyme a (coa) is essential for cellular chemistry in all forms of life. the pantothenate moiety of coa is generated from the condensation of pantoate and β-alanine. β-alanine is formed by decarboxylation of l-aspartate catalyzed by pand, a pyruvoyl enzyme that is synthesized by the cell as an inactive precursor (pro-pand). maturation of pro-pand into pand occurs via a self-cleavage event at residue ser25, which forms the catalytic pyruvoyl moiety. we recently reported that salmonella enterica ...201222782525
diarrhea and colitis in mice require the salmonella pathogenicity island 2-encoded secretion function but not sifa or spv effectors.we investigated the roles of salmonella pathogenicity island 2 (spi-2) and two spi-2 effectors in salmonella colitis and diarrhea in genetically resistant balb/c.d2(slc11a1) congenic mice with the wild-type nramp1 locus. wild-type salmonella enterica serovar typhimurium 14028s caused a pan-colitis, and the infected mice developed frank diarrhea with a doubling of the fecal water content. an ssav mutant caused only a 26% increase in fecal water content, without producing the pathological changes ...201222778101
fima, fimf, and fimh are necessary for assembly of type 1 fimbriae on salmonella enterica serovar typhimurium.salmonella enterica serovar typhimurium is a gram-negative member of the family enterobacteriaceae and is a common cause of bacterial food poisoning in humans. the fimbrial appendages are found on the surface of many enteric bacteria and enable the bacteria to bind to eukaryotic cells. s. typhimurium type 1 fimbriae are characterized by mannose-sensitive hemagglutination and are assembled via the chaperone/usher pathway. s. typhimurium type 1 fimbrial proteins are encoded by the fim gene cluster ...201222778099
a whole-cell phenotypic screening platform for identifying methylerythritol phosphate pathway-selective inhibitors as novel antibacterial agents.isoprenoid biosynthesis is essential for survival of all living organisms. more than 50,000 unique isoprenoids occur naturally, with each constructed from two simple five-carbon precursors: isopentenyl diphosphate (ipp) and dimethylallyl diphosphate (dmapp). two pathways for the biosynthesis of ipp and dmapp are found in nature. humans exclusively use the mevalonate (mva) pathway, while most bacteria, including all gram-negative and many gram-positive species, use the unrelated methylerythritol ...201222777049
enhancement of th1-biased protective immunity against avian influenza h9n2 virus via oral co-administration of attenuated salmonella enterica serovar typhimurium expressing chicken interferon-α and interleukin-18 along with an inactivated vaccine.control of currently circulating re-assorted low-pathogenicity avian influenza (lpai) h9n2 is a major concern for both animal and human health. thus, an improved lpai h9n2 vaccination strategy is needed to induce complete immunity in chickens against lpai h9n2 virus strains. cytokines play a crucial role in mounting both the type and extent of an immune response generated following infection with a pathogen or after vaccination. to improve the efficacy of inactivated lpai h9n2 vaccine, attenuate ...201222776696
functional analysis of bacillus subtilis genes involved in the biosynthesis of 4-thiouridine in trna.thii has been identified as an essential enzyme involved in the biosynthesis of thiamine and the trna thionucleoside modification, 4-thiouridine. in escherichia coli and salmonella enterica, thii acts as a sulfurtransferase, receiving the sulfur donated from the cysteine desulfurase iscs and transferring it to the target molecule or additional sulfur carrier proteins. however, in bacillus subtilis and most species from the firmicutes phylum, thii lacks the rhodanese domain that contains the site ...201222773787
significance of the bacteriophage treatment schedule in reducing salmonella colonization of poultry.salmonella remains the major cause of food-borne diseases worldwide, with chickens known to be the main reservoir for this zoonotic pathogen. among the many approaches to reducing salmonella colonization of broilers, bacteriophage offers several advantages. in this study, three bacteriophages (uab_phi20, uab_phi78, and uab_phi87) obtained from our collection that exhibited a broad host range against salmonella enterica serovar enteritidis and salmonella enterica serovar typhimurium were characte ...201222773654
evaluation of near-infrared pasteurization in controlling escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in ready-to-eat sliced ham.this study was conducted to investigate the efficacy of near-infrared (nir) heating to reduce salmonella enterica serovar typhimurium, escherichia coli o157:h7, and listeria monocytogenes in ready-to-eat (rte) sliced ham compared to conventional convective heating, and the effect of nir heating on quality was determined by measuring the color and texture change. a cocktail of three pathogens was inoculated on the exposed or protected surfaces of ham slices, followed by nir or conventional heatin ...201222773635
phosphorothioate dna as an antioxidant in bacteria.diverse bacteria contain dna with sulfur incorporated stereo-specifically into their dna backbone at specific sequences (phosphorothioation). we found that in vitro oxidation of phosphorothioate (pt) dna by hydrogen peroxide (h(2)o(2)) or peracetic acid has two possible outcomes: dna backbone cleavage or sulfur removal resulting in restoration of normal dna backbone. the physiological relevance of this redox reaction was investigated by challenging pt dna hosting salmonella enterica cells using ...201222772986
bacterial tir-containing proteins and host innate immune system evasion.the innate immune system provides the first line of host defence against invading pathogens. key to upregulation of the innate immune response are toll-like receptors (tlrs), which recognize pathogen-associated molecular patterns (pamps) and trigger a signaling pathway culminating in the production of inflammatory mediators. central to this tlr signaling pathway are heterotypic protein-protein interactions mediated through toll/interleukin-1 receptor (tir) domains found in both the cytoplasmic r ...201322772799
structural characterization of the h-ns protein from xylella fastidiosa and its interaction with dna.the nucleoid-associated protein h-ns is a major component of the bacterial nucleoid involved in dna compaction and transcription regulation. the nmr solution structure of the xylella fastidiosa h-ns c-terminal domain (residues 56-134) is presented here and consists of two beta-strands and two alpha helices, with one loop connecting the two beta-strands and a second loop connecting the second beta strand and the first helix. the amide (1)h and (15)n chemical shift signals for a sample of xfh-ns(5 ...201222772065
rapid discrimination of salmonella enterica serovar typhi from other serovars by maldi-tof mass spectrometry.systemic infections caused by salmonella enterica are an ongoing public health problem especially in sub-saharan africa. essentially typhoid fever is associated with high mortality particularly because of the increasing prevalence of multidrug-resistant strains. thus, a rapid blood-culture based bacterial species diagnosis including an immediate sub-differentiation of the various serovars is mandatory. at present, maldi-tof based intact cell mass spectrometry (icms) advances to a widely used rou ...201222768195
accessibility and conservation: general features of bacterial small rna-mrna interactions?bacterial small rnas (srnas) are a class of structural rnas that often regulate mrna targets via post-transcriptional base pair interactions. we determined features that discriminate functional from non-functional interactions and assessed the influence of these features on genome-wide target predictions. for this purpose, we compiled a set of 71 experimentally verified srna-target pairs from escherichia coli and salmonella enterica. furthermore, we collected full-length 5' untranslated regions ...201222767260
selection-driven gene loss in bacteria.gene loss by deletion is a common evolutionary process in bacteria, as exemplified by bacteria with small genomes that have evolved from bacteria with larger genomes by reductive processes. the driving force(s) for genome reduction remains unclear, and here we examined the hypothesis that gene loss is selected because carriage of superfluous genes confers a fitness cost to the bacterium. in the bacterium salmonella enterica, we measured deletion rates at 11 chromosomal positions and the fitness ...201222761588
immunostimulatory effects of recombinant erysipelothrix rhusiopathiae expressing porcine interleukin-18 in mice and pigs.interleukin-18 (il-18), which was originally called gamma interferon (ifn-γ)-inducing factor, has been shown to play an important role in innate and acquired immune responses. in this study, attenuated erysipelothrix rhusiopathiae strains were engineered to produce porcine il-18 (poil-18) and evaluated for their potential immunostimulatory effect in animals. recombinant poil-18 was successfully expressed in the recombinant e. rhusiopathiae strains ys-1/il-18 and ko/il-18. the culture supernatant ...201222761300
construction and immunological evaluation of dual cell surface display of hiv-1 gag and salmonella enterica serovar typhimurium flic in lactobacillus acidophilus for vaccine delivery.oral vaccines that elicit a mucosal immune response may be effective against human immunodeficiency virus type 1 (hiv-1) because its transmission occurs mainly at the mucosa. the aim of this study was to construct recombinant lactobacillus for oral delivery of oral vaccines against hiv-1 and to evaluate their immunogenicity. a recombinant lactobacillus acidophilus strain expressing the hiv-1 gag on the bacterial cell surface was established by fusion with the signal peptide and anchor motif of a ...201222761297
molecular characterization of salmonella strains in individuals with acute diarrhea syndrome in the state of sucre, venezuela.in venezuela, acute diarrheic syndrome (ads) is a primary cause of morbi-mortality, often involving the salmonella genus. salmonella infections are associated with acute gastroenteritis, one of the most common alimentary intoxications, and caused by the consumption of contaminated water and food, especially meat.201222760131
characterization of extended-spectrum cephalosporin-resistant salmonella enterica serovar heidelberg isolated from food animals, retail meat, and humans in the united states 2009.salmonella enterica is one of the most common causes of foodborne illness in the united states. although salmonellosis is usually self-limiting, severe infections typically require antimicrobial treatment, and ceftriaxone, an extended-spectrum cephalosporin (esc), is commonly used in both adults and children. surveillance conducted by the national antimicrobial resistance monitoring system (narms) has shown a recent increase in esc resistance among salmonella heidelberg isolated from food animal ...201222755514
a novel phage element of salmonella enterica serovar enteritidis p125109 contributes to accelerated type iii secretion system 2-dependent early inflammation kinetics in a mouse colitis model.salmonella enterica subsp. i serovar enteritidis exhibits type iii secretion system 2 (ttss2)-dependent early colonization and inflammation kinetics faster than those of closely related s. enterica serovar typhimurium. to investigate the accelerated ttss-2-dependent pathogenic potential of s. enteritidis, we focused on its genome. results of a previously published comparative genomic study revealed the presence of mutually exclusive genes in both serovars. in this study, we investigated the role ...201222753379
phosphate groups of lipid a are essential for salmonella enterica serovar typhimurium virulence and affect innate and adaptive immunity.lipid a is a key component of the outer membrane of gram-negative bacteria and stimulates proinflammatory responses via the toll-like receptor 4 (tlr4)-md2-cd14 pathway. its endotoxic activity depends on the number and length of acyl chains and its phosphorylation state. in salmonella enterica serovar typhimurium, removal of the secondary laurate or myristate chain in lipid a results in bacterial attenuation and growth defects in vitro. however, the roles of the two lipid a phosphate groups in b ...201222753374
antibiotic resistance and probiotic properties of dominant lactic microflora from tungrymbai, an ethnic fermented soybean food of india.the present investigation was conducted to assess lactic acid bacteria present in traditionally fermented food of ethnic tribes in india for probiotic properties, antibacterial activity, and antibiotic tolerance behavior. enterococcus sp., lactobacillus sp., and lactococcus sp. showed antibacterial activity against bacillus cereus mtcc 430, staphylococcus aureus subsp. aureus mtcc 740, and salmonella enterica ser. paratyphi a mtcc 735. lactococcus sp. and lactobacillus sp. could tolerate acidic ...201222752919
identification of a new bacillus licheniformis strain producing a bacteriocin-like substance.the emergence of antibiotic resistance has spurred a great number of studies for development of new antimicrobials in the past decade. the purpose of this study was to screen environmental samples for bacillus strains producing potent antimicrobial agents. a new strain, which showed strong antimicrobial activity against staphylococcus aureus and salmonella enterica ser. pullorum, was isolated from soil and designated as b116. this new isolate was identified as bacillus licheniformis by morpholog ...201222752909
in vitro susceptibility testing of fluoroquinolone activity against salmonella: recent changes to clsi standards.fluoroquinolone (fq) resistance in salmonella enterica is a significant clinical concern. recognition of resistance by the clinical laboratory is complicated by the multiple fq resistance mechanisms found in salmonella. the clinical laboratory standards institute (clsi) recently addressed this issue by revising the ciprofloxacin break points for salmonella species. it is critical for clinicians and laboratory workers to be aware of the multiple technical issues surrounding these revised break po ...201222752519
enhanced inactivation of salmonella and pseudomonas biofilms on stainless steel by use of t-128, a fresh-produce washing aid, in chlorinated wash solutions.the effect of the washing aid t-128 (generally recognized as safe [gras] formulation, composed mainly of phosphoric acid and propylene glycol) on inactivation of salmonella and pseudomonas populations in biofilms on stainless steel was evaluated under conditions of increasing organic matter loads in chlorinated wash solutions dominated by hypochlorous acid. biofilms were formed statically on stainless steel coupons suspended in 2% lettuce extract after inoculation with salmonella enterica serova ...201222752180
differential expression of the transcription factors mara, rob, and soxs of salmonella typhimurium in response to sodium hypochlorite: down-regulation of rob by mara and soxs.to survive, salmonella enterica serovar typhimurium (s. typhimurium) must sense signals found in phagocytic cells and modulate gene expression. in the present work, we evaluated the expression and cross-regulation of the transcription factors mara, rob, and soxs in response to naocl. we generated strains δsoxs and δmara, which were 20 times more sensitive to naocl as compared to the wild-type strain; while δrob only 5 times. subsequently, we determined that mara and soxs transcript and protein l ...201222752112
construction of recombinant e. coli nissle 1917 (ecn) strains for the expression and secretion of defensins.the probiotic escherichia coli strain nissle 1917 (ecn) is one of the few probiotics licensed as a medication in several countries. best documented is its effectiveness in keeping patients suffering from ulcerative colitis (uc) in remission. this might be due to its ability to induce the production of human β-defensin 2 (hbd2) in a flagellin-dependent way in intestinal epithelial cells. in contrast to ulcerative colitis, for crohn's disease (cd) convincing evidence is lacking that ecn might be c ...201222748509
long-amplicon propidium monoazide-pcr enumeration assay to detect viable campylobacter and salmonella.the effect of amplicon length on the ability of propidium monoazide-pcr (pma-pcr) to reliably quantify viable cells without interference from dead cells was tested on heat- and ultraviolet (uv)-killed salmonella enterica and campylobacter jejuni, two important enteric pathogens of concern in environmental, food and clinical samples.201222747901
a salmonella typhimurium-translocated glycerophospholipid:cholesterol acyltransferase promotes virulence by binding to the rhoa protein switch regions.salmonella enterica serovar typhimurium translocates a glycerophospholipid:cholesterol acyltransferase (ssej) into the host cytosol after its entry into mammalian cells. ssej is recruited to the cytoplasmic face of the host cell phagosome membrane where it is activated upon binding the small gtpase, rhoa. ssej is regulated similarly to cognate eukaryotic effectors, as only the gtp-bound form of rhoa family members stimulates enzymatic activity. using nmr and biochemistry, this work demonstrates ...201222740689
multilocus sequence typing as a replacement for serotyping in salmonella enterica.salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. we used multilocus sequence typing (mlst) to assign 4,257 isolates from 554 serovars to 1092 sequence types (sts). the majority of the isolates and many sts were grouped into 138 genetically closely related clusters called eburstgroups (ebgs). many ebgs correspond to a serovar, for example most typhimurium are in ebg1 and most enteritidis are in ebg4, but many ebgs co ...201222737074
a polymer coating applied to salmonella prevents the binding of salmonella-specific antibodies.the use of salmonella as a potential antitumor agent has been investigated, but innate immunity against this bacterium reduces the efficacy of its tumor-targeting and antitumor activities. the purpose of this study was to investigate the modulation of the tumor-targeting efficiency of salmonella enterica serovar choleraesuis by modifying the immune response to these bacteria by coating them with poly(allylamine hydrochloride) (pah), designated pah-s.c. to evaluate this modulation, we used naïve ...201322736433
complete genomic sequence of salmonella enterica serovar enteritidis phage se2.salmonella enterica serovar enteritidis has remained a major food-borne pathogen in humans. we isolated a virulent s. enterica serovar enteritidis bacteriophage, se2, which belongs to the family siphoviridae. phage se2 could lyse s. enterica serovar enteritidis pt-4, and its virulence was maintained even at ambient temperature. the genomic sequence of phage se2 was composed of 43,221 bp with close similarity to those of salmonella phage setp3 and salmonella phage ss3e. the strong and stable lyti ...201222733878
loss of or inhibition of all multidrug resistance efflux pumps of salmonella enterica serovar typhimurium results in impaired ability to form a biofilm.to investigate the contribution of multidrug efflux pump systems of salmonella enterica serovar typhimurium to the formation of a competent biofilm.201222733653
isolation and partial characterization of φsp-1, a salmonella specific lytic phage from intestinal content of broiler chicken.salmonella enterica subsp. enterica serovar enteritidis is a major causative agent of gastroenteritis with contaminated eggs and chicken meat being the major source of infection. phages are seriously being considered as a safe and cheaper alternative to antibiotics. the intestinal content of chicken was used as source for isolating phages. phage designated as φsp-1 was selected for the study. transmission electron microscopy (tem) of phage φsp-1 revealed that it belonged to family podoviridae. t ...201322733367
molecular characterization of the flagellar hook in bacillus subtilis.the structure of the gram-positive flagellum is poorly understood, and bacillus subtilis encodes three proteins homologous to the flagellar hook protein from salmonella enterica. here we generated a modified b. subtilis hook protein that could be fluorescently stained using a cysteine-reactive dye. we used the fluorescently labeled hook to demonstrate that flge is the hook structural protein and that flik regulated hook length. we further demonstrate that two proteins of unknown function, flho a ...201222730131
virulence and metabolic characteristics of salmonella enterica serovar enteritidis strains with different sefd variants in hens.salmonella enterica serovar enteritidis is one of a few salmonella enterica serotypes that has sef14 fimbriae encoded by the sef operon, which consists of 4 cotranscribed genes, sefabcd, regulated by sefr. a parental strain was used to construct a sefd mutant and its complement, and all 3 strains were compared for gene expression, metabolic properties, and virulence characteristics in hens. transcription of sefd by wild type was suppressed at 42°c and absent for the mutant under conditions where ...201222729535
salmonella enterica serovar typhi plasmid pr st98 enhances intracellular bacterial growth and s. typhi-induced macrophage cell death by suppressing autophagy.plasmid pr st98 is a hybrid resistance-virulence plasmid isolated from salmonella enterica serovar typhi (s. typhi). previous studies demonstrated that pr st98 could enhance the virulence of its host bacteria. however, the mechanism of pr st98-increased bacterial virulence is still not fully elucidated. this study was designed to gain further insight into the roles of pr st98 in host responses.201722729194
campylobacter jejuni is highly susceptible to killing by chicken host defense peptide cathelicidin-2 and suppresses intestinal cathelicidin-2 expression in young broilers.little is known about the interactions of chicken host defense peptides (hdps) with campylobacter jejuni in young chicks. to examine the role of the chicken hdp, cathelicidin-2 (cath-2) in host-pathogen interactions we challenged 4-day-old ross 308 broilers with a chicken-derived c. jejuni isolate (ws356) and used the chicken pathogen salmonella enterica enteritidis phage type 4 (fgt1) as a reference. immunohistochemical staining was used to localize cath-2, c. jejuni and salmonella enteritidis. ...201222728124
differential identification of salmonella enterica serovar gallinarum biovars gallinarum and pullorum and the biovar gallinarum live vaccine strain 9r.salmonella enterica serovar gallinarum biovar gallinarum causes fowl typhoid in chickens and has been of economic importance to the chicken industry in many countries. the biovar gallinarum live vaccine strain 9r (sg 9r) has been used to control fowl typhoid in many areas where the disease is endemic. therefore, a definitive diagnosis of this disease may require differentiation of wild-type field isolates of biovar gallinarum from the live vaccine strain sg 9r. here, we report the development of ...201222728122
salmonella enterica serovars typhimurium and typhi as model organisms: revealing paradigm of host-pathogen interactions.the lifestyle of intracellular pathogens has always questioned the skill of a microbiologist in the context of finding the permanent cure to the diseases caused by them. the best tool utilized by these pathogens is their ability to reside inside the host cell, which enables them to easily bypass the humoral immunity of the host, such as the complement system. they further escape from the intracellular immunity, such as lysosome and inflammasome, mostly by forming a protective vacuole-bound niche ...201222722237
activation of type iii interferon genes by pathogenic bacteria in infected epithelial cells and mouse placenta.bacterial infections trigger the expression of type i and ii interferon genes but little is known about their effect on type iii interferon (ifn-λ) genes, whose products play important roles in epithelial innate immunity against viruses. here, we studied the expression of ifn-λ genes in cultured human epithelial cells infected with different pathogenic bacteria and in the mouse placenta infected with listeria monocytogenes. we first showed that in intestinal lovo cells, induction of ifn-λ genes ...201222720036
the bimodal lifestyle of intracellular salmonella in epithelial cells: replication in the cytosol obscures defects in vacuolar replication.salmonella enterica serovar typhimurium invades and proliferates within epithelial cells. intracellular bacteria replicate within a membrane bound vacuole known as the salmonella containing vacuole. however, this bacterium can also replicate efficiently in the cytosol of epithelial cells and net intracellular growth is a product of both vacuolar and cytosolic replication. here we have used semi-quantitative single-cell analyses to investigate the contribution of each of these replicative niches ...201222719929
the salmonella deubiquitinase ssel inhibits selective autophagy of cytosolic aggregates.cell stress and infection promote the formation of ubiquitinated aggregates in both non-immune and immune cells. these structures are recognised by the autophagy receptor p62/sequestosome 1 and are substrates for selective autophagy. the intracellular growth of salmonella enterica occurs in a membranous compartment, the salmonella-containing vacuole (scv), and is dependent on effectors translocated to the host cytoplasm by the salmonella pathogenicity island-2 (spi-2) encoded type iii secretion ...201222719249
assessment of whole-genome mapping in a well-defined outbreak of salmonella enterica serotype saintpaul.we investigated the use of whole-genome mapping and pulsed-field gel electrophoresis (pfge) with isolates from an outbreak of salmonella enterica serotype saintpaul. pfge and whole-genome mapping were concordant with 22 of 23 isolates. whole-genome mapping is a viable alternative tool for the epidemiological analysis of salmonella food-borne disease investigations.201222718933
human milk mucin 1 and mucin 4 inhibit salmonella enterica serovar typhimurium invasion of human intestinal epithelial cells in vitro.many human milk glycans inhibit pathogen binding to host receptors and their consumption by infants is associated with reduced risk of disease. salmonella infection is more frequent among infants than among the general population, but the incidence is lower in breast-fed babies, suggesting that human milk could contain components that inhibit salmonella. this study aimed to test whether human milk per se inhibits salmonella invasion of human intestinal epithelial cells in vitro and, if so, to id ...201222718031
traditional copper water storage vessels and sub-lethal injury of salmonella enterica serovar typhi and vibrio cholerae.recent studies on escherichia coli have demonstrated sub-lethal injury-sensitivity to oxygen and selective agents prior to irreversible inactivation when kept in water in a brass vessel. the present study was carried out to investigate whether equivalent responses occur in copper vessels using the pathogens salmonella enterica serovar typhi and vibrio cholerae. bacterial suspensions were stored in water in a traditional copper vessel for up to 24 h at 30 °c. samples were withdrawn and plated on ...201222717752
molecular typing of salmonella enterica serotype typhimurium and serotype 4,5,12:i:- isolates from cattle by multiple-locus variable-number tandem-repeats analysis.to evaluate the usefulness of multiple-locus variable-number tandem-repeats analysis (mlva) as a tool for the epidemiological analysis of bovine salmonellosis, salmonella enterica serotype typhimurium and serotype 4,5,12:i:- isolates (544 and 18, respectively) obtained from cattle in hokkaido, japan, between 1977 and 2009, were characterised by mlva. mlva identified 184 profiles versus 121 profiles identified by pulsed-field gel electrophoresis (pfge). cluster analysis of the mlva profiles demon ...201222717391
risk factors associated with sporadic salmonellosis in adults: a case-control study.in order to identify and assess recent risk factors for sporadic human infections with salmonella enterica, we conducted a case-control study in lower saxony, germany. the data collection was based on standardized telephone interviews with 1017 cases and 346 controls aged >14 years. odds ratios were calculated in single-factor and multi-factor analyses for salmonella cases and two different control groups, i.e. population controls and controls with rotavirus infection. multi-factor analysis reve ...201322717173
a previously uncharacterized gene stm0551 plays a repressive role in the regulation of type 1 fimbriae in salmonella enterica serotype typhimurium.salmonella enterica serotype typhimurium produces surface-associated fimbriae that facilitate adherence of the bacteria to a variety of cells and tissues. type 1 fimbriae with binding specificity to mannose residues are the most commonly found fimbrial type. in vitro, static-broth culture favors the growth of s. typhimurium with type 1 fimbriae, whereas non-type 1 fimbriate bacteria are obtained by culture on solid-agar media. previous studies demonstrated that the phenotypic expression of type ...201222716649
the importance of motility and chemotaxis for extra-animal survival of salmonella enterica serovar typhimurium and dublin.this study investigated the importance of flagella and motility of salmonella enterica serovar typhimurium and dublin in models of extra-animal survival.201222716502
refractory salmonella enterica serotype choleraesuis-related renal cyst infection in a patient with autosomal dominant polycystic kidney disease undergoing hemodialysis treated successfully with intracystic ciprofloxacin infusion.to report a potential salvage therapy for refractory renal cyst infection secondary to salmonellaenterica serotype choleraesuis (s. choleraesuis).201222710499
analyzing cellular internalization of nanoparticles and bacteria by multi-spectral imaging flow cytometry.nanoparticulate systems have emerged as valuable tools in vaccine delivery through their ability to efficiently deliver cargo, including proteins, to antigen presenting cells. internalization of nanoparticles (np) by antigen presenting cells is a critical step in generating an effective immune response to the encapsulated antigen. to determine how changes in nanoparticle formulation impact function, we sought to develop a high throughput, quantitative experimental protocol that was compatible wi ...201222710268
association of extended-spectrum β-lactamase veb-5 and 16s rrna methyltransferase arma in salmonella enterica from the united kingdom. 201222710120
potential international spread of multidrug-resistant invasive salmonella enterica serovar enteritidis.in developing countries, salmonella enterica serovar enteritidis causes substantial illness and death, and drug resistance is increasing. isolates from the united kingdom containing virulence-resistance plasmids were characterized. they mainly caused invasive infections in adults linked to africa. the common features in isolates from these continents indicate the role of human travel in their spread.201222709653
salmonellosis outbreak traced to playground sand, australia, 2007-2009.a community outbreak of gastroenteritis in australia during 2007-2009 was caused by ingestion of playground sand contaminated with salmonella enterica paratyphi b, variant java. the bacterium was also isolated from local wildlife. findings support consideration of nonfood sources during salmonellosis outbreak investigations and indicate transmission through the animal-human interface.201222709539
expression and delivery of tetanus toxin fragment c fused to the n-terminal domain of sipb enhances specific immune responses in mice.live attenuated bacteria can be used as a carrier for the delivery of foreign antigens to a host's immune system. the n-terminal domain of sipb, a translocon protein of the type iii secretion system of salmonella enterica serovar typhimurium, is required for secretion and outer membrane localization. in the present study, vaccine plasmids for antigen delivery in which the non-toxic tetanus toxin fragment c (ttfc), which contains a t cell epitope, is fused to the n-terminal 160 amino acids of sip ...201222708880
slc11a1 (nramp1) impairs growth of salmonella enterica serovar typhimurium in macrophages via stimulation of lipocalin-2 expression.the expression of the cation transporter nramp1 (slc11a1) in late phagolysosomes confers resistance to infection with several intracellular pathogens, such as salmonella enterica, in mice. the antimicrobial actions of nramp1 are attributable, in part, to modulation of macrophage immune function and cellular iron metabolism--the latter affecting the availability of the essential nutrient iron for intraphagosomal bacteria. here, we provide novel evidence that nramp1 functionality increases the exp ...201222706314
emergence of an sgi1-bearing salmonella enterica serotype kentucky isolated from septic poultry in nigeria.salmonella enterica serotype kentucky was isolated from septic poultry in nigeria. the objective of this study was to characterize this isolate by screening for sgi1 and hyper-virulence.201222706190
scano-magneto immunoassay based on carbon nanotubes/gold nanoparticles nanocomposite for salmonella enterica serovar typhimurium detection.to improve sensitivity of s. enterica serovar typhimurium detection, multiwalled carbon nanotubes (mwcnts) and gold nanoparticles (aunps) were combined and used as a label to amplify signal in a scanometric based assay. in this study, the mwcnts/aunps nanocomposite was fabricated by directly assemble of au(3+) to mwcnts and allowed growing of aunps along the mwcnts surface. this mwcnts/aunps nanocomposite was then attached to anti-s. typhimurium antibody (mwcnts/aunps/ab(1)) and used as a detect ...201222705403
the feoa protein is necessary for the feob transporter to import ferrous iron.in many bacterial feo loci, the feoa gene is associated with the feob gene. while the feob-encoded feob protein has been demonstrated as a ferrous iron [fe(ii)] transporter, the function of the feoa gene product, feoa, is unknown. in the present study, we report that the feoa protein interacts with the feob fe(ii) transporter, which is required for feob-mediated fe(ii) uptake in salmonella enterica. iron uptake assay revealed that in the absence of feoa, feob import of fe(ii) is impaired. bacter ...201222705302
mechanisms used by virulent salmonella to impair dendritic cell function and evade adaptive immunity.innate and adaptive immunity are inter-related by dendritic cells (dcs), which directly recognize bacteria through the binding of pathogen-associated molecular patterns (pamps) to specialized receptors on their surface. after capturing and degrading bacteria, dcs present their antigens as small peptides bound to mhc molecules and prime naive bacteria-specific t cells. in response to pamp recognition dcs undergo maturation, which is a phenotypic change that increases their immunogenicity and prom ...201222703384
assessment of pathogen survival potential during managed aquifer recharge with diffusion chambers.to evaluate the efficacy of using in situ diffusion chambers for pathogen decay studies in the aquifer.201222702409
human genome-wide rnai screen for host factors that modulate intracellular salmonella growth.salmonella enterica is a bacterial pathogen of humans that can proliferate within epithelial cells as well as professional phagocytes of the immune system. while much has been learned about the microbial genes that influence the infectious process through decades of intensive research, relatively little is known about the host factors that affect infection. we performed a genome-wide sirna screen to identify host genes that salmonella enterica serovar typhimurium (s. typhimurium) utilizes to fac ...201222701604
caprylic acid reduces salmonella enteritidis populations in various segments of digestive tract and internal organs of 3- and 6-week-old broiler chickens, therapeutically.we investigated the efficacy of feed supplemented with caprylic acid (ca), a natural, 8-carbon fatty acid for reducing salmonella enterica serovar enteritidis colonization in commercial broiler chickens. in separate 3- and 6-wk trials, 1-d-old straight-run broiler chicks (n = 70 birds/trial) were assigned to a control group (challenged with salmonella enteritidis, no ca) and 2 replicates of 0.7 and 1% ca (n = 14 birds/group). water and feed were provided ad libitum. on d 1, birds were tested for ...201222700516
control of a salmonella virulence locus by an atp-sensing leader messenger rna.the facultative intracellular pathogen salmonella enterica resides within a membrane-bound compartment inside macrophages. this compartment must be acidified for salmonella to survive within macrophages, possibly because acidic ph promotes expression of salmonella virulence proteins. we reasoned that salmonella might sense its surroundings have turned acidic not only upon protonation of the extracytoplasmic domain of a protein sensor but also by an increase in cytosolic atp levels, because condi ...201222699622
characterization of the salmonella bacteriophage vb_sens-ent1.the bacteriophage vb_sens-ent1 (ent1) is a member of the family siphoviridae of tailed bacteriophages and infects a broad range of serovars of the enteric pathogen salmonella enterica. the virion particle is composed of an icosahedral head 64 nm in diameter and a flexible, non-contractile tail of 116 × 8.5 nm possessing terminal fibres. the adsorption rate constant at 37 °c is 6.73 × 10(-9) ml min(-1). latent and eclipse periods are 25 and 20 min, respectively, and the burst size is 35 progeny p ...201222694898
glycerol supplementation enhances l. reuteri's protective effect against s. typhimurium colonization in a 3-d model of colonic epithelium.the probiotic effects of lactobacillus reuteri have been speculated to partly depend on its capacity to produce the antimicrobial substance reuterin during the reduction of glycerol in the gut. in this study, the potential of this process to protect human intestinal epithelial cells against infection with salmonella enterica serovar typhimurium was investigated. we used a three-dimensional (3-d) organotypic model of human colonic epithelium that was previously validated and applied to study inte ...201222693569
phage-mediated acquisition of a type iii secreted effector protein boosts growth of salmonella by nitrate respiration.information on how emerging pathogens can invade and persist and spread within host populations remains sparse. in the 1980s, a multidrug-resistant salmonella enterica serotype typhimurium clone lysogenized by a bacteriophage carrying the sope virulence gene caused an epidemic among cattle and humans in europe. here we show that phage-mediated horizontal transfer of the sope gene enhances the production of host-derived nitrate, an energetically highly valuable electron acceptor, in a mouse colit ...201222691391
salmonella meningitis in a paediatric patient caused by salmonella enterica serotype houtenae.the authors report a case of a 6-week-old baby girl who was admitted to the paediatric ward due to a high fever for 2 days. the patient experienced three fits which took place while in the ward. a brain sonogram showed subdural heterogeneous collection consistent with focal empyema; however, no hydrocephalus or infarction was detected. an urgent burr hole procedure was performed to remove the collected pus. both blood and cerebrospinal fluid (csf) culture grew salmonella species which remain sen ...201122689601
the application of stem and in situ controlled dehydration to bacterial systems using esem.transmission imaging with an environmental scanning electron microscope (esem) (wet stem) is a recent development in the field of electron microscopy, combining the simple preparation inherent to esem work with an alternate form of contrast available through a stem detector. because the technique is relatively new, there is little information available on how best to apply this technique and which samples it is best suited for. this work is a description of the sample preparation and microscopy ...201222689513
genetic fine structure of a salmonella enterica serovar typhi strain associated with the 2005 outbreak of typhoid fever in kelantan, malaysia.among enteric pathogens, salmonella enterica serovar typhi is responsible for the largest number of food-borne outbreaks and fatalities. the ability of the pathogen to cause systemic infection for extended durations leads to a high cost of disease control. chronic carriers play important roles in the evolution of salmonella typhi; therefore, identification and in-depth characterization of isolates from clinical cases and carriers, especially those from zones of endemicity where the pathogen has ...201222689247
complete genome sequence of the strong mutator salmonella enterica subsp. enterica serotype heidelberg strain b182.in bacteria, normal mutation frequencies are mostly around 10(-10) per base pair. however, there exists natural isolates, called "mutators," that exhibit permanent mutation occurrences up to 1,000-fold greater than usual. as mutations play essential roles, particularly in the evolution of antibiotic resistance, bacteria showing elevated mutation rates could have an important responsibility in the emergence of antibiotic resistance, especially in the clinical background. in this announcement, we ...201222689230
granulomatous typhlocolitis, lymphangitis, and lymphadenitis in a horse infected with listeria monocytogenes, salmonella typhimurium, and cyathostomes.a 15-year-old american quarter horse mare was euthanized because of poor response to therapy for severe diarrhea. significant gross findings were limited to the large intestines. the walls of the cecum and colon were thickened with widely scattered nodules in the mucosa and submucosa that extended into the enlarged colic lymph nodes. microscopically, there was severe granulomatous typhlocolitis, lymphangitis, and lymphadenitis, with many intralesional gram-positive, non-acid-fast coccobacilli an ...201322688587
receptor-independent interaction of bacterial lipopolysaccharide with lipid and lymphocyte membranes; the role of cholesterol.lipopolysaccharide (lps) is a major constituent of bacterial outer membranes where it makes up the bulk of the outer leaflet and plays a key role as determinant of bacterial interactions with the host. membrane-free lps is known to activate t-lymphocytes through interactions with toll-like receptor 4 via multiprotein complexes. in the present study, we investigate the role of cholesterol and membrane heterogeneities as facilitators of receptor-independent lps binding and insertion, which underpi ...201222685597
evolution of salmonella enterica virulence via point mutations in the fimbrial adhesin.whereas the majority of pathogenic salmonella serovars are capable of infecting many different animal species, typically producing a self-limited gastroenteritis, serovars with narrow host-specificity exhibit increased virulence and their infections frequently result in fatal systemic diseases. in our study, a genetic and functional analysis of the mannose-specific type 1 fimbrial adhesin fimh from a variety of serovars of salmonella enterica revealed that specific mutant variants of fimh are co ...201222685400
effect of iacp mutation on flagellar phase variation in salmonella enterica serovar typhimurium strain uk-1.flagella are surface appendages that are important for bacterial motility and invasion of host cells. two flagellin subunits in salmonella enterica serovar typhimurium, flic and fljb, are alternatively expressed by a site-specific dna inversion mechanism called flagellar phase variation. although this inversion mechanism is understood at the molecular level, the key factor controlling the expression of the two flagellin subunits has not been determined. in this study, we found that a putative ac ...201222685287
cysteine catabolism and cysteine desulfhydrase (cdsh/stm0458) in salmonella enterica serovar typhimurium.cysteine is potentially toxic and can affect diverse functions such as oxidative stress, antibiotic resistance, and swarming motility. the contribution of cysteine catabolism in modulating responses to cysteine has not been examined, in part because the genes have not been identified and mutants lacking these genes have not been isolated or characterized. we identified the gene for a previously described cysteine desulfhydrase, which we designated cdsh (formerly stm0458). we also identified a di ...201222685283
ifnγ expression by an attenuated strain of salmonella enterica serovar typhimurium improves vaccine efficacy in susceptible tlr4-defective c3h/hej mice.c3h/hej mice carry a mutated allele of tlr4 gene (tlr4 ( d )) and thus are hyporesponsive to the lethal effects of lipopolysaccharide (lps). characteristically, however, the mice are also hypersusceptible to infections, particularly by gram-negative bacteria such as salmonella enterica serovar typhimurium (s. typhimurium) and are known to be difficult to vaccinate against virulent exposure. this is observed despite the expression of wild-type allele of nramp1 gene, another important determinant ...201322684724
heterogeneity of multifunctional il-17a producing s. typhi-specific cd8+ t cells in volunteers following ty21a typhoid immunization.salmonella enterica serovar typhi (s. typhi), the causative agent of typhoid fever, continues to cause significant morbidity and mortality world-wide. cd8+ t cells are an important component of the cell mediated immune (cmi) response against s. typhi. recently, interleukin (il)-17a has been shown to contribute to mucosal immunity and protection against intracellular pathogens. to investigate multifunctional il-17a responses against s. typhi antigens in t memory subsets, we developed multiparamet ...201222679502
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