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a pdms/paper/glass hybrid microfluidic biochip integrated with aptamer-functionalized graphene oxide nano-biosensors for one-step multiplexed pathogen detection.infectious pathogens often cause serious public health concerns throughout the world. there is an increasing demand for simple, rapid and sensitive approaches for multiplexed pathogen detection. in this paper we have developed a polydimethylsiloxane (pdms)/paper/glass hybrid microfluidic system integrated with aptamer-functionalized graphene oxide (go) nano-biosensors for simple, one-step, multiplexed pathogen detection. the paper substrate used in this hybrid microfluidic system facilitated the ...201323929394
neck abscess caused by salmonella enterica serotype enteritidis. 201323927985
resistance genes, phage types and pulsed field gel electrophoresis pulsotypes in salmonella enterica strains from laying hen farms in southern italy.twenty-four salmonella enterica isolates (13 serovar enteritidis and 11 typhimurium) isolated from 5,600 samples from intensive laying hen farms in italy in 1998-2007 were characterized for antimicrobial resistance genes, pulsotype and phage type. most of s. typhimurium strains were pulsotype stymxb.0147 (81.8%), phage type dt143 and resistant to sulfamethoxazole encoded by sul2. two multidrug resistant (mdr) strains were identified. one strain, stymxb.0061, was resistant to ampicillin (a), chlo ...201323924880
15-deoxy-δ12,14-prostaglandin j2 inhibits macrophage colonization by salmonella enterica serovar typhimurium.15-deoxy-δ(12,14)-prostaglandin j2 (15d-pgj2) is an anti-inflammatory downstream product of the cyclooxygenase enzymes. it has been implicated to play a protective role in a variety of inflammatory mediated diseases, including rheumatoid arthritis, neural damage, and myocardial infarctions. here we show that 15d-pgj2 also plays a role in salmonella infection. salmonella enterica typhimurium is a gram-negative facultative intracellular pathogen that is able to survive and replicate inside phagocy ...201323922794
modulators of antibiotic activity from ipomoea murucoides.reinvestigation of the chcl3-soluble extract from the flowers of ipomoea murucoides, through preparative-scale recycling hplc, yielded three pentasaccharides of 11-hydroxyhexadecanoic acid, murucoidins xvii-xix, in addition to the known murucoidin iii and v, all of which were characterized by nmr spectroscopy and mass spectrometry. these compounds were found to be macrolactones of the known pentasaccharides simonic acid b and operculinic acid a. the acylating groups corresponded to acetic, (2s)- ...201323920226
discrimination of enterobacteriaceae and non-fermenting gram negative bacilli by maldi-tof mass spectrometry.discrimination of enterobacteriaceae and non-fermenting gram negative bacilli by maldi-tof mass spectrometry matrix assisted laser desorption/ionization time of flight mass spectrometry (maldi-tof ms) has proven to be an effective identification tool in medical microbiology. discrimination to subspecies or serovar level has been found to be challenging using commercially available identification software. by forming our own reference database and using alternative analysis methods, we could reli ...201323919091
salmonella enterica serovar typhimurium baesr two-component system positively regulates soda in response to ciprofloxacin.in response to antibiotics, bacteria activate regulatory systems that control the expression of genes that participate in detoxifying these compounds, like multidrug efflux systems. we previously demonstrated that the baesr two-component system from salmonella enterica serovar typhimurium (s. typhimurium) participates in the detection of ciprofloxacin, a bactericidal antibiotic, and in the positive regulation of mdta, an efflux pump implicated in antibiotic resistance. in the present work, we pr ...201323918818
a phase i, dose-escalation trial in adults of three recombinant attenuated salmonella typhi vaccine vectors producing streptococcus pneumoniae surface protein antigen pspa.live, attenuated, orally-administered salmonella strains are excellent vectors for vaccine antigens and are attractive as vaccines based on previous use of s. typhimurium in animals. a phase i dose escalation trial was conducted to evaluate the safety and immunogenicity of three newly constructed recombinant attenuated salmonella enterica serovar typhi vaccine (rasv) vectors synthesizing streptococcus pneumoniae surface protein a (pspa).201323916987
outbreak of salmonella enterica serotype i 4,5,12:i:- infections: the challenges of hypothesis generation and microwave cooking.we investigated an outbreak of 396 salmonella enterica serotype i 4,5,12:i:- infections to determine the source. after 7 weeks of extensive hypothesis-generation interviews, no refined hypothesis was formed. nevertheless, a case-control study was initiated. subsequently, an iterative hypothesis-generation approach used by a single interviewing team identified brand a not-ready-to-eat frozen pot pies as a likely vehicle. the case-control study, modified to assess this new hypothesis, along with p ...201423916064
in vitro and in vivo investigation on genomic stability of salmonella enterica typhimurium dt41 obtained from broiler breeders in denmark.salmonella enterica serovar typhimurium phage type dt41 has previously been identified from salmonella-positive broiler breeder flocks in denmark and isolates obtained from different flocks have demonstrated major diversity by multiple-locus variable-number tandem-repeats analysis (mlva) typing. to elucidate whether the high diversity observed by mlva was related to multiple independent introductions at farm level or genetic instability of markers, we investigated the genomic stability of differ ...201323915994
ramr mutations affecting fluoroquinolone susceptibility in epidemic multidrug-resistant salmonella enterica serovar kentucky st198.a screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant salmonella enterica serovar kentucky st198. among a panel of representative isolates (n = 27), covering the epidemic, only three showed distinct mutations in ramr resulting in enhanced expression of genes encoding the acrab-tolc efflux system and low increase in ciprofloxacin mic. no mutations were detected in other regulatory regions of this efflux system. ciprofloxacin re ...201323914184
the virulence of salmonella typhimurium in the insect model galleria mellonella is impaired by mutations in endoribonucleases e and iii.salmonella enterica serovar typhimurium is a gram-negative bacterium able to invade and replicate inside eukaryotic cells. to cope with the host defense mechanisms, the bacterium has to rapidly remodel its transcriptional status. regulatory rnas and ribonucleases are the factors that ultimately control the fate of mrnas and final protein levels in the cell. there is growing evidence of the direct involvement of these factors in bacterial pathogenicity. in this report, we validate the use of gall ...201323913419
infectious diseases in humanized mice.despite many theoretical incompatibilities between mouse and human cells, mice with reconstituted human immune system components contain nearly all human leukocyte populations. accordingly, several human-tropic pathogens have been investigated in these in vivo models of the human immune system, including viruses such as human immunodeficiency virus (hiv) and epstein barr virus (ebv), as well as bacteria such as mycobacterium tuberculosis (mtb) and salmonella enterica typhi (s. typhi). while thes ...201323913412
evaluation of the immunogenicity of campylobacter jejuni cjaa protein delivered by salmonella enterica sv. typhimurium strain with regulated delayed attenuation in chickens.campylobacter spp. are regarded as the most common bacterial cause of gastroenteritis worldwide, and consumption of chicken meat contaminated by campylobacter is considered to be one of the most frequent sources of human infection in developed countries. here we evaluated the immunogenicity and protective efficacy of salmonella typhimurium χ9718 producing the campylobacter jejuni cjaa protein as a chicken anti-campylobacter vaccine. in this study chickens were orally immunized with a new generat ...201323913025
on-chip microbial culture for the specific detection of very low levels of bacteria.microbial culture continues to be the most common protocol for bacterial detection and identification in medicine and agronomics. using this process may take days to identify a specific pathogen for most bacterial strains. surface plasmon resonance (spr) detection is an emerging alternative technology that can be used for the detection of bacteria using protein microarrays although typical limits of detection are in the range of 10(3)-10(6) cfu ml(-1), which is not compatible with most food safe ...201323912527
the antimicrobial effects of cinnamon leaf oil against multi-drug resistant salmonella newport on organic leafy greens.there is generally no kill-step when preparing salad vegetables, so there is a greater risk for foodborne illness from contaminated vegetables. some essential oils have antimicrobial activities and could provide a natural way to reduce pathogens on fresh produce. the objective of this study was to investigate the antimicrobial activity of cinnamon oil wash against salmonella enterica serotype newport on organic leafy greens. organic romaine and iceberg lettuce, and organic baby and mature spinac ...201323911760
mig-14 plays an important role in influencing gene expression of salmonella enterica serovar typhi, which contributes to cell invasion under hyperosmotic conditions.mig-14 is a horizontally acquired host-induced virulence gene in salmonella enterica serovar typhi. the molecular function of mig-14 is still unknown; sequence analysis showed that mig-14 shared homology with the helix-loop-helix motif of the arac family of transcriptional regulatory proteins. in our previous microarray-based studies, mig-14 was upregulated at the early stage of high osmotic stress, indicating a potential role under this condition. therefore, we compared growth and the global tr ...201323911675
fimh adhesin from host unrestricted salmonella enteritidis binds to different glycoprotein ligands expressed by enterocytes from sheep, pig and cattle than fimh adhesins from host restricted salmonella abortus-ovis, salmonella choleraesuis and salmonella dublin.adhesion to gut tissues and colonization of the alimentary tract, two important stages in the pathogenesis of salmonella, are mediated by fimh adhesin of type 1 fimbriae. it was suggested that minor differences in the structure of fimh are most likely associated with differences in adhesion specificities, and may determine the tropism of various salmonella serovars to different species and tissues. we investigated this hypothesis by comparing the binding properties of fimh proteins from three sa ...201323910950
development of a magnetic nanoparticles microarray for simultaneous and simple detection of foodborne pathogens.foodborne diseases are a widespread and growing public health problem affecting both developed and developing countries, microbiologically contaminated food and water are the major causes of diarrhoeal diseases. methods based on polymerase chain reaction (pcr) and microarrays are rapid and sensitive enough to detect very small quantities of microorganisms, however, the requirement for expensive equipments limits their application. in the present paper, we describe a method based on multiplex pcr ...201323909141
an outbreak of gastroenteritis caused by salmonella enterica serotype enteritidis traced to cream cakes.this paper describes the epidemiological, microbiological and environmental investigations conducted during an outbreak of salmonella gastroenteritis in singapore.201123908880
the selectable antibiotic marker, teta(c), increases pseudomonas aeruginosa susceptibility to the herbicide/superoxide generator, paraquat.the presence of the widely used selectable antibiotic marker, teta(c), unexpectedly increased the sensitivity of pseudomonas aeruginosa pao1 to the superoxide-generating herbicide, paraquat. a dna fragment spanning the first 99 amino acids of teta(c) was sufficient to confer paraquat sensitivity. the teta(c)-induced paraquat sensitive phenotype was observed in other gram-negative bacteria such as agrobacterium tumefaciens, salmonella enterica ser. typhimurium and xanthomonas campestris suggestin ...201323907582
prevalence and characterization of apramycin-resistant salmonella enterica serotype typhimurium isolated from healthy and diseased pigs in korea during 1998 through 2009.apramycin resistance was observed in 22.8% (81 of 355) of salmonella typhimurium isolates collected from pigs from 1998 through 2009 in korea. all apramycin-resistant salmonella typhimurium isolates also were cross-resistant to gentamicin and tobramycin. among the seven types of aminoglycoside resistance genes tested, only four types were detected in the apramycin-resistant salmonella typhimurium isolates: aac (3)-iv, aac (3)-ii, aac (3)-iii, and ant (2'')-i. although the aac (3)-iv gene was fou ...201323905803
comparing the roles of antibodies to nontyphoidal salmonella enterica in high- and low-income countries and implications for vaccine development. 201323904457
[antimicrobial susceptibility of animal and food isolates of salmonella enterica].bacterial resistance to one or more antimicrobiak is worrisome.201323900319
combined stimulation of toll-like receptor 5 and nod1 strongly potentiates activity of nf-κb, resulting in enhanced innate immune reactions and resistance to salmonella enterica serovar typhimurium infection.pathogen recognition receptors (prrs) are essential components of host innate immune systems that detect specific conserved pathogen-associated molecular patterns (pamps) presented by microorganisms. members of two families of prrs, transmembrane toll-like receptors (tlrs 1, 2, 4, 5, and 6) and cytosolic nod receptors (nod1 and nod2), are stimulated upon recognition of various bacterial pamps. such stimulation leads to induction of a number of immune defense reactions, mainly triggered via activ ...201323897616
identification of salmonella enterica serovar typhimurium genes regulated during biofilm formation on cholesterol gallstone surfaces.salmonella spp. are able to form biofilms on abiotic and biotic surfaces. in vivo studies in our laboratory have shown that salmonella can form biofilms on the surfaces of cholesterol gallstones in the gallbladders of mice and human carriers. biofilm formation on gallstones has been demonstrated to be a mechanism of persistence. the purpose of this work was to identify and evaluate salmonella sp. cholesterol-dependent biofilm factors. differential gene expression analysis between biofilms on gla ...201323897604
an rpos-dependent srna regulates the expression of a chaperone involved in protein folding.small noncoding rnas (srnas) are usually expressed in the cell to face a variety of stresses. in this report we disclose the first target for sral (also known as ryja), a srna present in many bacteria, which is highly induced in stationary phase. we also demonstrate that this srna is directly transcribed by the major stress σ factor σ(s) (rpos) in salmonella enterica serovar typhimurium. we show that sral srna down-regulates the expression of the chaperone trigger factor (tf), encoded by the tig ...201323893734
diversity and antimicrobial susceptibility of salmonella enterica serovars isolated from pig farms in ibadan, nigeria.animals including food animals play a significant role in the epidemiology of salmonella enterica. the control requires identification of sources and institution of targeted interventions. this study investigates the diversity of s. enterica serovars, antimicrobial susceptibility, and occurrence of plasmid-mediated quinolone resistance (pmqr) genes in pigs in ibadan, nigeria. pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the salmonella isolates were sero ...201423893398
posttranslational maturation of the invasion acyl carrier protein of salmonella enterica serovar typhimurium requires an essential phosphopantetheinyl transferase of the fatty acid biosynthesis pathway.salmonella pathogenicity island 1 (spi-1) carries genes required for the formation of a type 3 secretion system, which is necessary for the invasion process of salmonella. among the proteins encoded by spi-1 is iacp, a homolog of acyl carrier proteins. acyl carrier proteins are mainly involved in fatty acid biosynthesis, and they require posttranslational maturation by addition of a 4'-phosphopantetheine prosthetic group to be functional. in this study, we analyzed iacp maturation in vivo. by pe ...201323893113
a chemical biology approach to interrogate quorum-sensing regulated behaviors at the molecular and cellular level.small molecule probes have been used extensively to explore biologic systems and elucidate cellular signaling pathways. in this study, we use an inhibitor of bacterial communication to monitor changes in the proteome of salmonella enterica serovar typhimurium with the aim of discovering unrecognized processes regulated by ai-2-based quorum-sensing (qs), a mechanism of bacterial intercellular communication that allows for the coordination of gene expression in a cell density-dependent manner. in ...201323890008
complete genome sequence of salmonella enterica serovar typhimurium u288.salmonella enterica serovar typhimurium u288 has firmly established itself within the united kingdom pig production industry. the prevalence of this highly pathogenic multidrug-resistant serovar at such a critical point in the food chain is therefore of great concern. to enhance our understanding of this microorganism, whole-genome and plasmid sequencing was performed.201323887910
rapid, sensitive recovery of recombinant attenuated salmonella enterica serovar typhi vaccine strains from human blood.prior to initiating a phase 1 dose escalation trial of the safety and immunogenicity of live, oral, recombinant, attenuated salmonella enterica serovar typhi vaccine strains in human subjects, the suitability of conventional blood culture procedures to rapidly and reliably detect the organisms in human blood was investigated. blood culture specimens, with and without added growth supplements, were inoculated with study organism concentrations ranging from approximately 300 to as few as 1 to 2 cf ...201323885029
survey of culture, goldengate assay, universal biosensor assay, and 16s rrna gene sequencing as alternative methods of bacterial pathogen detection.cultivation-based assays combined with pcr or enzyme-linked immunosorbent assay (elisa)-based methods for finding virulence factors are standard methods for detecting bacterial pathogens in stools; however, with emerging molecular technologies, new methods have become available. the aim of this study was to compare four distinct detection technologies for the identification of pathogens in stools from children under 5 years of age in the gambia, mali, kenya, and bangladesh. the children were ide ...201323884998
antimicrobial resistance of human salmonella enterica serovar typhimurium u302 strains: prevalence of r-type assut in slovakia, 2006-2011.salmonella enterica serovar typhimurium is a common cause of non-typhoid salmonellosis in humans. since 2006, an increase in the human infections caused by u302 phage type in slovakia has been documented and, from 2006 to 2011, a total of 291 u302 human strains were isolated. antimicrobial susceptibility testing demonstrated that these strains had a high overall antimicrobial resistance and 244 (83.8%) of the tested strains were multidrug-resistant (mdr). the most prevalent resistance was to amp ...201323883849
prevalence of salmonella in wild snakes in japan.a total of 87 wild snakes of 6 species in 2 families collected in japan were examined for the presence of salmonella. the prevalence of salmonella was 58.6%, and that of salmonella enterica subspecies i, which includes most human pathogenic serotypes, accounted for 12.6%. s. enterica subspecies i was isolated from japanese grass snakes and japanese four-striped snakes, and the isolates belonged to 6 serotypes: s. enterica subspecies enterica serotypes eastbourne, mikawashima, narashino, newport, ...201323883839
effects of subtherapeutic concentrations of antimicrobials on gene acquisition events in yersinia, proteus, shigella, and salmonella recipient organisms in isolated ligated intestinal loops of swine.to assess antimicrobial resistance and transfer of virulence genes facilitated by subtherapeutic concentrations of antimicrobials in swine intestines.201323879845
a riboswitch-regulated antisense rna in listeria monocytogenes.riboswitches are ligand-binding elements located in 5' untranslated regions of messenger rnas, which regulate expression of downstream genes. in listeria monocytogenes, a vitamin b12-binding (b12) riboswitch was identified, not upstream of a gene but downstream, and antisense to the adjacent gene, pocr, suggesting it might regulate pocr in a nonclassical manner. in salmonella enterica, pocr is a transcription factor that is activated by 1,2-propanediol, and subsequently activates expression of t ...201323878253
the mucin muc2 limits pathogen burdens and epithelial barrier dysfunction during salmonella enterica serovar typhimurium colitis.salmonella enterica serovar typhimurium is a model organism used to explore the virulence strategies underlying salmonella pathogenesis. although intestinal mucus is the first line of defense in the intestine, its role in protection against salmonella is still unclear. the intestinal mucus layer is composed primarily of the muc2 mucin, a heavily o-glycosylated glycoprotein. the core 3-derived o-glycans of muc2 are synthesized by core 3 β1,3-n-acetylglucosaminyltransferase (c3gnt). mice lacking t ...201323876803
outbreak-associated salmonella enterica serotypes and food commodities, united states, 1998-2008.salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. to clarify links between salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998-2008. more than 80% of outbreaks caused by serotypes enteritidis, heidelberg, and hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes javiana, l ...201323876503
rflm functions as a transcriptional repressor in the autogenous control of the salmonella flagellar master operon flhdc.motility of bacteria like salmonella enterica is a highly regulated process that responds to a variety of internal and external stimuli. a hierarchy of three promoter classes characterizes the salmonella flagellar system, and the onset of flagellar gene expression depends on the oligomeric regulatory complex and class 1 gene product flhd(4)c(2). the flhdc promoter is a target for a broad range of transcriptional regulators that bind within the flhdc promoter region and either negatively or posit ...201323873910
compound(s) secreted by lactobacillus casei strain shirota yit9029 irreversibly and reversibly impair the swimming motility of helicobacter pylori and salmonella enterica serovar typhimurium, respectively.we conducted experiments in order to examine whether the probiotic lactobacillus casei strain shirota yit9029 (lcs) in vitro and in vivo antagonism of helicobacter pylori and salmonella, involves inhibition of the swimming motility of these pathogens. we report the irreversible inhibition of the swimming motility of h. pylori strain 1101 and reversible inhibition of salmonella enterica serovar typhimurium (s. typhimurium) strain sl1344 by compound(s) secreted by lcs. in h. pylori 1101, irreversi ...201323873784
impact of 6 different intestinal bacteria on broiler breeder sperm motility in vitro.male fertility is often evaluated by measuring sperm parameters, including concentration, viability, and motility. this is important because after copulation occurs, sperm must overcome many barriers in the female reproductive tract to fertilize the ovum. in mammalian species, sperm have been shown to have reduced motility when bacteria are present. in male broiler breeders, bacteria have been associated with spermatozoa, but their effect on motility has not been investigated. the sperm quality ...201323873566
use of allyl isothiocyanate and carbon nanotubes in an antimicrobial film to package shredded, cooked chicken meat.we developed antimicrobial packaging incorporated with allyl isothiocyanate (ait) and carbon nanotube (cnt), and this packaging was used for shredded cooked chicken meat inoculated with salmonella choleraesuis. the following parameters were analysed during the 40 days of storage: microbial counts, colour characteristics and changes in the oxidation of the meat as well as changes in the mechanical properties of the film, the structure of the antimicrobial film and the diffusion of the antimicrobi ...201323871073
probiotic bacteria reduce salmonella typhimurium intestinal colonization by competing for iron.host inflammation alters the availability of nutrients such as iron to limit microbial growth. however, salmonella enterica serovar typhimurium thrives in the inflamed gut by scavenging for iron with siderophores. by administering escherichia coli strain nissle 1917, which assimilates iron by similar mechanisms, we show that this nonpathogenic bacterium can outcompete and reduce s. typhimurium colonization in mouse models of acute colitis and chronic persistent infection. this probiotic activity ...201323870311
distribution of salmonella enterica isolates from human cases in italy, 1980 to 2011. 201323870078
salmonella enterica delivers its genotoxin through outer membrane vesicles secreted from infected cells.cytolethal-distending toxins (cdts) belong to a family of dna damage inducing exotoxins that are produced by several gram-negative bacteria. salmonella enterica serovar typhi expresses its cdt (named as typhoid toxin) only in the salmonella-containing vacuole (scv) of infected cells, which requires its export for cell intoxication. the mechanisms of secretion, release in the extracellular space and uptake by bystander cells are poorly understood. we have addressed these issues using a recombinan ...201323869968
emergence of a multidrug-resistant (assuttm) strain of salmonella enterica serovar typhimurium dt120 in england in 2011 and the use of multiple-locus variable-number tandem-repeat analysis in supporting outbreak investigations.in summer 2011, two outbreaks of a unique, multidrug-resistant strain of salmonella enterica serovar typhimurium phage type 120 (dt120) occurred mainly in the midlands, england. the first outbreak occurred among guests attending a wedding in july 2011 ('wedding outbreak'), followed by a more geographically dispersed outbreak in august and september 2011 ('midlands outbreak'). fifty-one cases were confirmed. detailed epidemiological and environmental health investigations suggested that pork was ...201323869962
performance of stool cultures before and after a 3-day hospitalization: fewer cultures, better for patients and for money.we evaluated retrospectively the yield of stool culture (sc) depending on the length of hospitalization, and we characterized the patients missed by the 3-day rejection rule. sc detects bacterial enteric pathogens (campylobacter spp., salmonella enterica, yersinia spp., shigella spp.). during this 5-year study period, 13,039 scs were requested, and 376 were positive (2.9%). the yield of sc dropped from 11.7% before 3 days of hospitalization to 0.7% after 3 days in children and 4.3% to 0.3% in ad ...201323867328
[metabolism of salmonella enterica serovar typhi influenced by rpoe and rpos under hyperosmosis].to study the role of rpoe and rpos on the influence of the metabolism and growth of bacterial under hyperosmotic stress.201323866755
modulation of chicken intestinal immune gene expression by small cationic peptides as feed additives during the first week posthatch.we have been investigating modulation strategies tailored around the selective stimulation of the host's immune system as an alternative to direct targeting of microbial pathogens by antibiotics. one such approach is the use of a group of small cationic peptides (bt) produced by a gram-positive soil bacterium, brevibacillus texasporus. these peptides have immune modulatory properties that enhance both leukocyte functional efficiency and leukocyte proinflammatory cytokine and chemokine mrna trans ...201323863505
immunogenicity of recombinant proteins consisting of plasmodium vivax circumsporozoite protein allelic variant-derived epitopes fused with salmonella enterica serovar typhimurium flagellin.a plasmodium falciparum circumsporozoite protein (csp)-based recombinant fusion vaccine is the first malaria vaccine to reach phase iii clinical trials. resistance to infection correlated with the production of antibodies to the immunodominant central repeat region of the csp. in contrast to p. falciparum, vaccine development against the csp of plasmodium vivax malaria is far behind. based on this gap in our knowledge, we generated a recombinant chimeric protein containing the immunodominant cen ...201323863502
salmonella enterica serovar typhi cutf is upregulated during environmental stress. 201323863294
loss of very-long o-antigen chains optimizes capsule-mediated immune evasion by salmonella enterica serovar typhi.expression of capsular polysaccharides is a variable trait often associated with more-virulent forms of a bacterial species. for example, typhoid fever is caused by the capsulated salmonella enterica serovar typhi, while nontyphoidal salmonella serovars associated with gastroenteritis are noncapsulated. here we show that optimization of the immune evasive properties conferred by the virulence-associated (vi) capsular polysaccharide involved an additional alteration to the cell envelope of s. typ ...201323860765
influence of salmonella enterica serovar enteritidis infection on the composition of chicken cecal microbiota.infection of newly hatched chicks with salmonella enterica serovar enteritidis (s. enteritidis) results in an inflammatory response in the intestinal tract which may influence the composition of gut microbiota. in this study we were therefore interested whether s. enteritidis induced inflammation results in changes in the cecal microbiota. to reach this aim, we compared the cecal microbiota of non-infected chickens and those infected by s. enteritidis by pyrosequencing the v3/v4 variable regions ...201323856245
evaluation of an electricity-free, culture-based approach for detecting typhoidal salmonella bacteremia during enteric fever in a high burden, resource-limited setting.in many rural areas at risk for enteric fever, there are few data on salmonella enterica serotypes typhi (s. typhi) and paratyphi (s. paratyphi) incidence, due to limited laboratory capacity for microbiologic culture. here, we describe an approach that permits recovery of the causative agents of enteric fever in such settings. this approach involves the use of an electricity-free incubator based upon use of phase-change materials. we compared this against conventional blood culture for detection ...201323853696
salmonella typhi rib osteomyelitis with abscess mimicking a 'cold abscess'.salmonella enterica serovar typhi (salmonella typhi) causing typhoid fever is common in many parts of the world particularly in developing countries. extra-intestinal manifestations such as osteomyelitis are rare in immunocompetent individuals. we report a case of salmonella typhi osteomyelitis of a rib with overlying abscess mimicking a 'cold abscess', treatment outcomes and discuss relevant literature.201323853436
transport and catabolism of the sialic acids n-glycolylneuraminic acid and 3-keto-3-deoxy-d-glycero-d-galactonononic acid by escherichia coli k-12.escherichia coli can transport and catabolize the common sialic acid, n-acetylneuraminic acid (neu5ac), as a sole source of carbon and nitrogen, which is an important mucus-derived carbon source in the mammalian gut. herein we demonstrate that e. coli can also grow efficiently on the related sialic acids, n-glycolylneuraminic acid (neu5gc) and 3-keto-3-deoxy-d-glycero-d-galactonononic acid (kdn), which are transported via the sialic acid transporter nant and catabolized using the sialic acid ald ...201323848303
structure and function of the salmonella typhi chimaeric a(2)b(5) typhoid toxin.salmonella enterica serovar typhi (s. typhi) differs from most other salmonellae in that it causes a life-threatening systemic infection known as typhoid fever. the molecular bases for its unique clinical presentation are unknown. here we find that the systemic administration of typhoid toxin, a unique virulence factor of s. typhi, reproduces many of the acute symptoms of typhoid fever in an animal model. we identify specific carbohydrate moieties on specific surface glycoproteins that serve as ...201323842500
outbreak of salmonella heidelberg infections linked to a single poultry producer -- 13 states, 2012-2013.in june 2012, the oregon health authority and the washington state department of health noted an increase in the number of salmonella enterica serotype heidelberg clinical isolates sharing an identical pulsed-field gel electrophoresis (pfge) pattern. in 2004, this pattern had been linked to chicken from foster farms by the washington state department of health; preliminary 2012 interviews with infected persons also indicated exposure to foster farms chicken. on august 2, 2012, cdc's pulsenet* de ...201323842445
a multi-omic view of host-pathogen-commensal interplay in salmonella-mediated intestinal infection.the potential for commensal microorganisms indigenous to a host (the 'microbiome' or 'microbiota') to alter infection outcome by influencing host-pathogen interplay is largely unknown. we used a multi-omics "systems" approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen salmonella enterica serovar typhimurium (s. typhimurium), and commensal gut microorganisms during intestinal infection with s. typh ...201323840608
comparison of five molecular subtyping methods for differentiation of salmonella kentucky isolates in tunisia.salmonellosis is one of the most common causes of food-borne infection worldwide. in the last decade, salmonella enterica serovar kentucky has shown an increase in different parts of the world with the concurrent emergence of multidrug-resistant isolates. these drug-resistant types spread from africa and the middle east to europe and asia. although s. kentucky serovar is of potential human relevance, there is currently no standardized fingerprinting method for it, in tunisia. in the present stud ...201423839713
salmonella utilizes d-glucosaminate via a mannose family phosphotransferase system permease and associated enzymes.salmonella enterica is a globally significant bacterial food-borne pathogen that utilizes a variety of carbon sources. we report here that salmonella enterica subsp. enterica serovar typhimurium (s. typhimurium) uses d-glucosaminate (2-amino-2-deoxy-d-gluconic acid) as a carbon and nitrogen source via a previously uncharacterized mannose family phosphotransferase system (pts) permease, and we designate the genes encoding the permease dgaabcd (d-glucosaminate pts permease components eiia, eiib, e ...201323836865
il-10 produced by trophoblast cells inhibits phagosome maturation leading to profound intracellular proliferation of salmonella enterica typhimurium.salmonella enterica typhimurium (st) is a phagosomal pathogen that can infect placental trophoblast cells leading to abortion and severe maternal illness. it is unclear how the trophoblast cells promote profound bacterial proliferation.201323834952
prevalence, serovars, and antimicrobial susceptibility of salmonella isolated from blue land crabs (cardisoma guanhumi) in grenada, west indies.samples of intestine and hepatopancreas from 65 blue land crabs (cardisoma guanhumi), a crustacean commonly consumed as a food item in grenada, were collected from six geographic sites in grenada and tested for salmonella by enrichment and selective culture. the individual animal prevalence of salmonella based on isolation was 17% (11 of 65), and all infected crabs were from three of the six sampled locations. isolates were identified by serotyping as salmonella enterica serovars saintpaul (n = ...201323834805
antimicrobial activity of plant compounds against salmonella typhimurium dt104 in ground pork and the influence of heat and storage on the antimicrobial activity.salmonella enterica is a predominant foodborne pathogen that causes diarrheal illness worldwide. a potential method of inhibiting pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. the objectives of this study were to investigate the influence of heat (70°c for 5 min) and subsequent cold storage (4°c up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against salmonella enterica serovar typh ...201323834804
determination of 5-log reduction times for escherichia coli o157:h7, salmonella enterica, or listeria monocytogenes in acidified foods with ph 3.5 or 3.8 3.a critical factor in ensuring the safety of acidified foods is the establishment of a thermal process that assures the destruction of acid-resistant vegetative pathogenic and spoilage bacteria. for acidified foods such as dressings and mayonnaises with ph values of 3.5 or higher, the high water phase acidity (acetic acid of 1.5 to 2.5% or higher) can contribute to lethality, but there is a lack of data showing how the use of common ingredients such as acetic acid and preservatives, alone or in c ...201323834800
postharvest handling conditions affect internalization of salmonella in baby spinach during washing.internalization of foodborne pathogens in fruits and vegetables is an increasing safety concern. the aim of this research was to assess the potential for internalization of an enteric pathogen (salmonella enterica serotype typhimurium) in a leafy vegetable (baby spinach) during washing as influenced by three postharvest handling conditions: (i) illumination, (ii) negative temperature differential, and (iii) relative humidity (rh). to compare these potential postharvest handling conditions, leave ...201323834788
electrochemical immunoassay for salmonella typhimurium based on magnetically collected ag-enhanced dna biobarcode labels.we describe a sensitive electrochemical immunoassay for salmonella enterica serovar typhimurium, a common foodborne pathogen which can cause infection at extremely small doses. the assay is based on the recognition of dna biobarcode labels by differential pulse anodic stripping voltammetry (dpasv), following ag enhancement. the biobarcodes consist of latex spheres (mean diameter 506 nm ± 22 nm) modified by ferromagnetic fe3o4 particles. each biobarcode is loaded by adsorption with approx. 27 mol ...201323833764
protective immunity to salmonella enterica is partially serogroup specific.pre-harvest reduction of salmonella carriage by swine would benefit both animal health and food quality. while vaccination is an attractive pre-harvest intervention to reduce salmonella levels in swine, the large number of potential salmonella enterica serovars found in swine makes it critical that vaccines provide broad serotype efficacy. in order to directly compare the relative efficacy of salmonella vaccines against serogroup-matched and serogroup-unmatched salmonella, we vaccinated pigs wit ...201323830894
a multiplex real-time pcr assay for the identification and differentiation of salmonella enterica serovar typhimurium and monophasic serovar 4,[5],12:i:-.salmonella enterica subsp. enterica serovar 4,[5],12:i:- is considered to be a monophasic variant of salmonella typhimurium and is increasingly associated with human infections. the use of pcr for the unequivocal identification of strains identified by conventional serotyping as 4,[5],12:i:- has been recommended by the european food safety authority (efsa), in particular the conventional multiplex pcr developed by tennant et al. (2010). an alternative protocol for the identification and differen ...201323827807
a bacterial virulence protein promotes pathogenicity by inhibiting the bacterium's own f1fo atp synthase.several intracellular pathogens, including salmonella enterica and mycobacterium tuberculosis, require the virulence protein mgtc to survive within macrophages and to cause a lethal infection in mice. we now report that, unlike secreted virulence factors that target the host vacuolar atpase to withstand phagosomal acidity, the mgtc protein acts on salmonella's own f1fo atp synthase. this complex couples proton translocation to atp synthesis/hydrolysis and is required for virulence. we establish ...201323827679
identification of salmonella enterica serovar typhi genotypes by use of rapid multiplex ligation-dependent probe amplification.salmonella enterica serovar typhi, the causative agent of typhoid fever, is highly clonal and genetically conserved, making isolate subtyping difficult. we describe a standardized multiplex ligation-dependent probe amplification (mlpa) genotyping scheme targeting 11 key phylogenetic markers of the s. typhi genome. the mlpa method demonstrated 90% concordance with single nucleotide polymorphism (snp) typing, the gold standard for s. typhi genotyping, and had the ability to identify isolates of th ...201323824765
horizontally acquired glycosyltransferase operons drive salmonellae lipopolysaccharide diversity.the immunodominant lipopolysaccharide is a key antigenic factor for gram-negative pathogens such as salmonellae where it plays key roles in host adaptation, virulence, immune evasion, and persistence. variation in the lipopolysaccharide is also the major differentiating factor that is used to classify salmonella into over 2600 serovars as part of the kaufmann-white scheme. while lipopolysaccharide diversity is generally associated with sequence variation in the lipopolysaccharide biosynthesis op ...201323818865
rbrothers: r package for bayesian multiple change-point recombination detection.phylogenetic recombination detection is a fundamental task in bioinformatics and evolutionary biology. most of the computational tools developed to attack this important problem are not integrated into the growing suite of r packages for statistical analysis of molecular sequences. here, we present an r package, rbrothers, that makes a bayesian multiple change-point model, one of the most sophisticated model-based phylogenetic recombination tools, available to r users. moreover, we equip the bay ...201323818749
ndm-1 carbapenemase-producing salmonella enterica subsp. enterica serovar corvallis isolated from a wild bird in germany. 201323818284
[isolation of salmonella enterica serovar typhi in a mesenteric adenopathy]. 201323817655
decreased coenzyme a levels in rida mutant strains of salmonella enterica result from inactivated serine hydroxymethyltransferase.the rida/yer057/uk114 family of proteins is well represented across the domains of life and recent work has defined both an in vitro activity and an in vivo role for rida. rida proteins have enamine deaminase activity, and in their absence the reactive 2-aminoacrylate (2-aa) accumulates and inactivates at least some pyridoxal 5'-phosphate (plp)-containing enzymes in salmonella enterica. the conservation of rida suggested that 2-aa was a ubiquitous cellular stressor that was generated in central ...201323815688
antimicrobial resistance of salmonella enterica serovar heidelberg isolated from poultry in alberta.salmonella enterica serovar heidelberg is one of the top three serovars implicated in human infections in canada. in 2003, the canadian integrated program for antimicrobial resistance surveillance reported antimicrobial resistance (amr) in s. heidelberg in canada. the study objective was to investigate the amr of s. heidelberg isolated from poultry in alberta. we examined 951 s. heidelberg poultry isolates obtained during 1996 to 2010 and tested against 18 antibiotics using the sensititre avian1 ...201323815674
evaluation of the adjuvant effect of salmonella-based escherichia coli heat-labile toxin b subunits on the efficacy of a live salmonella-delivered avian pathogenic escherichia coli vaccine.the present study evaluated the adjuvant effect of live attenuated salmonella organisms expressing the heat-labile toxin of escherichia coli b subunit (ltb) on the efficacy of an avian pathogenic escherichia coli (apec) vaccine. the asd(+) (aspartate semialdehyde dehydrogenase) plasmid pmmp906 containing the ltb gene was introduced into a salmonella enterica typhimurium strain lacking the lon, cpxr and asd genes to generate the adjuvant strain. live recombinant salmonella-delivered apec vaccine ...201323815619
lipid-rich enteral nutrition regulates mucosal mast cell activation via the vagal anti-inflammatory reflex.nutritional stimulation of the cholecystokinin-1 receptor (cck-1r) and nicotinic acetylcholine receptor (nachr)-mediated vagal reflex was shown to reduce inflammation and preserve intestinal integrity. mast cells are important early effectors of the innate immune response; therefore modulation of mucosal mast cells is a potential therapeutic target to control the acute inflammatory response in the intestine. the present study investigates intestinal mast cell responsiveness upon nutritional acti ...201323812038
dnase i and proteinase k eliminate dna from injured or dead bacteria but not from living bacteria in microbial reference systems and natural drinking water biofilms for subsequent molecular biology analyses.molecular techniques, such as polymerase chain reaction (pcr) and quantitative pcr (qpcr), are very sensitive, but may detect total dna present in a sample, including extracellular dna (edna) and dna coming from live and dead cells. dnase i is an endonuclease that non-specifically cleaves single- and double-stranded dna. this enzyme was tested in this study to analyze its capacity of digesting dna coming from dead cells with damaged cell membranes, leaving dna from living cells with intact cell ...201323811209
short communication: survey of animal-borne pathogens in the farm environment of 13 dairy operations.a survey was conducted on 13 dairies to determine the occurrence of 5 animal-borne pathogens (salmonella enterica, escherichia coli o157:h7, campylobacter jejuni, mycobacterium avium ssp. paratuberculosis, and cryptosporidium parvum) and their distributions across farm elements (feces, bedding, milk filters, stored manure, field soil, and stream water). presence of c. parvum was measured only in feces and stored manure. all but one farm were positive for at least one pathogen species, and 5 farm ...201323810596
salmonella enterica serovar typhimurium virulence-resistance plasmids derived from the pslt carrying nonconventional class 1 integrons with dfra12 gene in their variable region and sul3 in the 3' conserved segment.drug-resistant derivatives of serovar-specific virulence plasmids, such as pslt, in clinically-relevant salmonella enterica serovar typhimurium strains, represent a threat for human health. we have analysed 14 s. typhimurium isolates recovered in italy and the united kingdom from swine and from cases of human infection for the presence of virulence-resistance (vr) plasmids. they were negative for the multidrug resistance (mdr) region of the salmonella genomic island 1 (sgi1), but expressed resis ...201323808958
the rna chaperone hfq regulates expression of fimbrial-related genes and virulence of salmonella enterica serovar enteritidis.salmonella enteritidis is an intracellular pathogen that causes enteritis and systemic disease in humans and other animals. the rna chaperone protein hfq mediates the binding of small noncoding rnas to target mrna and assists in post-transcriptional gene regulation in bacteria. in this study, we constructed an hfq deletion mutant in s. enteritidis se50336 and analyzed the expression of major fimbrial subunits sefa, bcfa, fima, safa, stba, stha, csga, csgd, and pega using quantitative real-time p ...201323808344
[rapid methods for the genus salmonella bacteria detection in food and raw materials].the article considers sanitary and epidemiological aspects and the impact of salmonella food poisoning in russia and abroad. the main characteristics of the agent (salmonella enterica subsp. enteritidis) are summarized. the main sources of human salmonella infection are products of poultry and livestock (poultry, eggs, dairy products, meat products, etc.). standard methods of identifying the causative agent, rapid (alternative) methods of analysis of salmonella using differential diagnostic medi ...201323808276
an antioxidant role for catecholate siderophores in salmonella.iron acquisition is an important aspect of the host-pathogen interaction. in the case of salmonella it is established that catecholate siderophores are important for full virulence. in view of their very high affinity for ferric iron, functional studies of siderophores have been almost exclusively focused on their role in acquisition of iron from the host. in the present study, we investigated whether the siderophores (enterobactin and salmochelin) produced by salmonella enterica sv. typhimurium ...201323805839
role of antilipopolysaccharide antibodies in serum bactericidal activity against salmonella enterica serovar typhimurium in healthy adults and children in the united states.recent observations from africa have rekindled interest in the role of serum bactericidal antibodies in protecting against systemic infection with salmonella enterica serovar typhimurium. to determine whether the findings are applicable to other populations, we analyzed serum samples collected from healthy individuals in the united states. we found that all but 1 of the 49 adult samples tested had robust bactericidal activity against s. typhimurium in a standard in vitro assay. the activity was ...201323803904
therapeutic effects of bacteriophages against salmonella gallinarum infection in chickens.in this study the isolation and characterization of three bacteriophages (st4, l13, and sg3) infecting salmonella gallinarum were carried out. they were further tested for their in vivo efficacy in phage therapy. all three phages belong to the siphoviridae family with isometric heads and non-contractile tails. they have a broad host range among serovars of salmonella enterica. the burst sizes were observed to be 1670, 80, and 28 for st4, l13, and sg3, respectively. the in vivo efficacy of the ph ...201323801253
the biology of the pmra/pmrb two-component system: the major regulator of lipopolysaccharide modifications.the ability of gram-negative bacteria to resist killing by antimicrobial agents and to avoid detection by host immune systems often entails modification to the lipopolysaccharide (lps) in their outer membrane. in this review, we examine the biology of the pmra/pmrb two-component system, the major regulator of lps modifications in the enteric pathogen salmonella enterica. we examine the signals that activate the sensor pmrb and the targets controlled by the transcriptional regulator pmra. we disc ...201323799815
species-dependent blood-brain barrier disruption of lipopolysaccharide: amelioration by colistin in vitro and in vivo.the aim of this study was to use in vitro and in vivo models to assess the impact of lipopolysaccharide (lps) from two different bacterial species on blood-brain barrier (bbb) integrity and brain uptake of colistin. following repeated administration of lps from pseudomonas aeruginosa, the brain-to-plasma ratio of [(14)c]sucrose in swiss outbred mice was not significantly increased. furthermore, while the brain uptake of colistin in mice increased 3-fold following administration of lps from salmo ...201323796941
expansion of salmonella enterica serovar typhimurium st34 clone carrying multiple resistance determinants in china. 201323796940
antibiotic resistance in salmonella typhimurium associates with crispr sequence type.salmonella enterica subspecies enterica serovar typhimurium is a leading cause of foodborne salmonellosis in the united states. the number of antibiotic resistant isolates identified in humans is steadily increasing, suggesting that the spread of antibiotic resistant strains is a major threat to public health. s. typhimurium is commonly identified in a wide range of animal hosts, food sources, and environments, but little is known about the factors mediating the spread of antibiotic resistance i ...201323796925
immune response variations to salmonella enterica serovar typhi recombinant porin proteins in mice.typhoid fever is caused by salmonella enterica serovar typhi. ompc, ompf and ompa, the three major outer membrane proteins (omps), could serve as vaccine candidates.201323796754
comparative molecular dynamics simulation studies for determining factors contributing to the thermostability of chemotaxis protein "chey".comparative molecular dynamics simulations of chemotaxis protein "chey" from thermophilic origin thermotoga maritima and its mesophilic counterpart salmonella enterica have been performed for 10 ns each at 300 and 350 k, and 20 ns each at 400 and 450 k. the trajectories were analyzed in terms of different factors like root-mean-square deviation, root-mean-square fluctuation, radius of gyration, solvent accessible surface area, h-bonds, salt bridge content, and protein-solvent interactions which ...201423796004
longitudinal study of distributions of similar antimicrobial-resistant salmonella serovars in pigs and their environment in two distinct swine production systems.the aim of this longitudinal study was to determine and compare the prevalences and genotypic profiles of antimicrobial-resistant (ar) salmonella isolates from pigs reared in antimicrobial-free (abf) and conventional production systems at farm, at slaughter, and in their environment. we collected 2,889 pig fecal and 2,122 environmental (feed, water, soil, lagoon, truck, and floor swabs) samples from 10 conventional and eight abf longitudinal cohorts at different stages of production (farrowing, ...201323793629
substantial within-animal diversity of salmonella isolates from lymph nodes, feces, and hides of cattle at slaughter.lymph nodes (mandibular, mesenteric, mediastinal, and subiliac; n = 68) and fecal (n = 68) and hide (n = 35) samples were collected from beef carcasses harvested in an abattoir in mexico. samples were analyzed for salmonella, and presumptive colonies were subjected to latex agglutination. of the isolates recovered, a subset of 91 was characterized by serotyping, pulsed-field gel electrophoresis (pfge), and antimicrobial susceptibility phenotyping. salmonella was isolated from 100% (hide), 94.1% ...201323793628
population structure of salmonella enterica serovar 4,[5],12:b:- strains and likely sources of human infection.salmonella enterica serovar 4,[5],12:b:- is a monophasic serovar not able to express the second-phase flagellar antigen (h2 antigen). in germany, the serovar is occasionally isolated from poultry, reptiles, fish, food, and humans. in this study, a selection of 67 epidemiologically unrelated salmonella enterica serovar 4,[5],12:b:- strains isolated in germany between 2000 and 2011 from the environment, animal, food, and humans was investigated by phenotypic and genotypic methods to better underst ...201323793625
draft genome sequences for ten salmonella enterica serovar typhimurium phage type 135 variants.salmonella enterica serovar typhimurium (s. typhimurium) is a common cause of gastroenteritis in humans. here, we report the draft genome sequences of 10 isolates of an s. typhimurium phage type 135 variant that is linked to egg-associated outbreaks in tasmania, australia.201323792739
cloning, expression, and purification of the hemolysin/cytolysin (hlye antigen) from salmonella enterica serovar typhi: potential application for immunoassay development.the hemolysin (hlye) protein of salmonella enterica serovar typhi was reported to be antigenic. this work describes the cloning, expression, and purification of a hexahistidine-tagged hlye protein under native conditions. immunoblot analysis and a competitive enzyme-linked immunosorbent assay using sera from typhoid patients showed the presence of hlye-specific antibodies in circulation.201323790417
an outbreak of foodborne gastroenteritis caused by dual pathogens, salmonella enterica serovar weltevreden and vibrio fluvialis in kolkata, india.salmonella enterica serovar weltevreden and vibrio fluvialis were identified as etiological agents of a foodborne gastroenteritis outbreak after an iftar feast in north dumdum. of the 278 cases admitted to the infectious diseases hospital, kolkata, 44 stool samples were tested for the enteric pathogens. six were positive for salmonella weltevreden, 5 for vibrio fluvialis, and 8 contained both of the pathogens. consumption of mutton-ghogni might have been the likely vehicle of this outbreak. in t ...201323789767
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