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isolation of lactic acid bacteria from swine milk and characterization of potential probiotic strains with antagonistic effects against swine-associated gastrointestinal pathogens.probiotics are usually isolated from the gastrointestinal tract of humans and animals. the search of probiotics in human milk is a recent field of research, as the existence of the human milk microbiome was discovered only about a decade ago. to our knowledge, no reports regarding the potential probiotic effect of bacteria from swine milk have been published. in this work, we isolated several lactic acid bacteria from swine milk and evaluated them for them potential as probiotics. among the isol ...201627149540
the global regulatory system csr senses glucose through the phosphoenolpyruvate: carbohydrate phosphotransferase system.a novel connection between two regulatory systems controlling crucial biological processes in bacteria, the carbon storage regulator (csr) system and the glucose-specific phosphotransferase system (pts), is reported by leng et al. in this issue. this involves the interaction of unphosphorylated eiia(glc), a component of the glucose-specific pts, with the csrd protein, which accelerates the decay of the csrb and csrc small rnas via rnase e in escherichia coli. as unphosphorylated eiia(g) (lc) is ...201626593223
modulation of the interaction of enteric bacteria with intestinal mucosa by stress-related catecholamines.stress associated with parturition, transport or mixing has long been correlated with enhanced faecal excretion of diarrhoeal zoonotic pathogens in animals such as salmonella enterica and escherichia coli. it may also predispose humans to infection and/or be associated with more severe outcomes. one possible explanation for this phenomenon is the ability of enteric bacterial pathogens to sense and respond to host stress-related catecholamines. this article reviews evidence of the ability of cate ...201626589217
characterization of the novel t4-like salmonella enterica bacteriophage stp4-a and its endolysin.while screening for new antimicrobial agents for multidrug-resistant salmonella enterica, the novel lytic bacteriophage stp4-a was isolated and characterized. phage morphology revealed that stp4-a belongs to the family myoviridae. bacterial challenge assays showed that different serovars of salmonella enterica were susceptible to stp4-a infection. the genomic characteristics of stp4-a, containing 159,914 bp of dsdna with an average gc content of 36.86 %, were determined. furthermore, the endolys ...201626563319
plasma nanotextured polymeric lab-on-a-chip for highly efficient bacteria capture and lysis.we describe the design, fabrication, and successful demonstration of a sample preparation module comprising bacteria cell capture and thermal lysis on-chip with potential applications in food sample pathogen analysis. plasma nanotexturing of the polymeric substrate allows increase of the surface area of the chip and the antibody binding capacity. three different anti-salmonella antibodies were directly and covalently linked to plasma treated chips without any additional linker chemistry or other ...201626556673
a microbiological assay to estimate the antimicrobial activity of parenteral tildipirosin against foodborne pathogens and commensals in the colon of beef cattle and pigs.tildipirosin (tip) is a novel 16-membered-ring macrolide authorized for the treatment of bovine and swine respiratory disease. the ph dependency of macrolide antimicrobial activity is well known. considering that the ph in the colon contents of growing beef cattle and pigs is usually below ph 7.0, the minimum inhibitory concentrations (mic) of tip against foodborne bacterial pathogens such as campylobacter (c.) coli, c. jejuni and salmonella enterica and commensal species including enterococcus ...201626538405
lactobacillus plantarum lb95 impairs the virulence potential of gram-positive and gram-negative food-borne pathogens in ht-29 and vero cell cultures.listeria monocytogenes, salmonella enterica and verocytotoxigenic escherichia coli (vtec) are amongst the most important agents responsible for food outbreaks occurring worldwide. in this work, two lactobacillus spp. strains (labs), lactobacillus plantarum (lb95) and lactobacillus paraplantarum (lb13), previously isolated from spontaneously fermenting olive brines, and two reference probiotic strains, lactobacillus casei shirota and lactobacillus rhamnosus gg, were investigated for their ability ...201626506821
expression of iron, the salmochelin siderophore receptor, requires mrna activation by ryhb small rna homologues.the iron gene of salmonella enterica and uropathogenic escherichia coli encodes the outer membrane receptor of fe(3+) -bound salmochelin, a siderophore tailored to evade capture by the host's immune system. the iron gene is under negative control of the fur repressor and transcribed under iron limiting conditions. we show here that transcriptional de-repression is not sufficient to allow iron expression, as this also requires activation by either of two partially homologous small rnas (srnas), r ...201626710935
rapid determination of β-lactam antimicrobial resistance in bacteria by a liquid chromatography-mass spectrometry-based method.conventional antimicrobial susceptibility tests (asts) are very time consuming and insufficiently precise to promptly select a proper antimicrobial treatment. this difficulty disrupts the management of infections and exacerbates the development of antimicrobial resistance. generally, antimicrobial resistance involves the chemical modification of an antimicrobial compound to an inactive form by an enzyme released by bacteria. this modification causes a structural change and is followed by a chara ...201627744479
the occurrence of salmonella in raw and ready-to-eat bean sprouts and sprouted seeds on retail sale in england and northern ireland.a total of 554 samples of bean sprouts or other sprouted seeds were collected at retail sale and submitted to nine official control laboratories in england and northern ireland during january to march 2011. samples (100 g) were tested for the presence of salmonella using the en iso 6579:2002 method. products labelled as ready-to-eat comprised 23% of the samples and 61% were labelled as raw or to-cook: the remaining 12% had no indication if the food was intended as ready-to-eat or ready-to-cook, ...201626661563
lytic action of the truncated ynce gene in escherichia coli.we recently found lytic action of the truncated ynce gene. when the truncated ynce gene of salmonella enterica serovar paratyphi a was expressed in escherichia coli dh5α under the control of the ara promoter, bacterial growth was markedly inhibited. in the present study, we characterized this lytic action. the n-terminal 103 aa of ynce, containing a signal peptide, was demonstrated to be essential for inhibition. microscopic observation showed that the bacterial envelope of e. coli was damaged b ...201626687463
a novel peptidoglycan d,l-endopeptidase induced by salmonella inside eukaryotic cells contributes to virulence.bacteria remodel peptidoglycan structure in response to environmental changes. many enzymes are involved in peptidoglycan metabolism; however, little is known about their responsiveness in a defined environment or the modes they assist bacteria to adapt to new niches. here, we focused in peptidoglycan enzymes that intracellular bacterial pathogens use inside eukaryotic cells. we identified a peptidoglycan enzyme induced by salmonella enterica serovar typhimurium in fibroblasts and epithelial cel ...201626462856
shotgun analysis of rough-type lipopolysaccharides using ultraviolet photodissociation mass spectrometry.detailed structural characterization of intact rough-type lipopolysaccharides (r-lps) was accomplished using a multi-stage mass spectrometry (ms(3)) strategy consisting of collision-induced dissociation (cid) followed by 193 ultraviolet photodissociation (uvpd) implemented on an orbitrap fusion mass spectrometer. complex mixtures of r-lps from either escherichia coli or salmonella enterica were directly infused into the mass spectrometer using static source nanoelectrospray ionization (nanoesi). ...201626616388
temperate phages promote colicin-dependent fitness of salmonella enterica serovar typhimurium.bacteria employ bacteriocins for interference competition in microbial ecosystems. colicin ib (colib), a pore-forming bacteriocin, confers a significant fitness benefit to salmonella enterica serovar typhimurium (s. tm) in competition against commensal escherichia coli in the gut. colib is released from s. tm into the environment, where it kills susceptible competitors. however, colicin-specific release proteins, as they are known for other colicins, have not been identified in case of colib. th ...201626439675
development of ceftriaxone resistance in salmonella enterica serotype oranienburg during therapy for bacteremia.the majority of nontyphoid salmonella infection is identified in children. when an invasive or severe salmonella infection is encountered, ceftriaxone is recommended for such patients. a 2-year-old girl was hospitalized for the treatment of salmonella bacteremia and discharged with standard ceftriaxone treatment. she was readmitted to the hospital after 2 days due to the recurrence of the salmonella bacteremia. the study aimed to unveil the mechanism for the relapse.201624657069
frequency of blood culture isolates and their antibiogram in a teaching hospital.bloodstream infections are associated with significant patient morbidity and mortality. antimicrobial susceptibility patterns should guide the choice of empiric antimicrobial regimens for patients with bacteremia.201626905550
stall no more at polyproline stretches with the translation elongation factors ef-p and if-5a.synthesis of polyproline proteins leads to translation arrest. to overcome this ribosome stalling effect, bacteria depend on a specialized translation elongation factor p (ef-p), being orthologous and functionally identical to eukaryotic/archaeal elongation factor e/aif-5a (recently renamed 'ef5'). ef-p binds to the stalled ribosome between the peptidyl-trna binding and trna-exiting sites, and stimulates peptidyl-transferase activity, thus allowing translation to resume. in their active form, bo ...201626416626
antibacterial and antiviral effectiveness of two household water treatment devices that use monobrominated hydantoinylated polystyrene.many different household water treatment (hwt) methods have been researched and promoted to mitigate the serious burden of diarrheal disease in developing countries. however, hwt methods using bromine have not been extensively evaluated. two gravity-fed hwt devices (aquasure™ and waterbird™) were used to test the antimicrobial effectiveness of halopure(®) br beads (monobrominated hydantoinylated polystyrene) that deliver bromine. as water flows over the beads, reactive bromine species are eluted ...201627959873
prophylactic administration of vector-encoded porcine granulocyte-colony stimulating factor reduces salmonella shedding, tonsil colonization, and microbiota alterations of the gastrointestinal tract in salmonella-challenged swine.salmonella colonization of food animals is a concern for animal health and public health as a food safety risk. various obstacles impede the effort to reduce asymptomatic salmonella carriage in food animals, including the existence of numerous serovars and the ubiquitous nature of salmonella. to develop an intervention strategy that is non-specific yet effective against diverse salmonella serovars, we explored the prophylactic use of a cytokine to decrease salmonella in swine by boosting the hos ...201627610361
molecular detection of legionella spp. and their associations with mycobacterium spp., pseudomonas aeruginosa and amoeba hosts in a drinking water distribution system.this study investigated waterborne opportunistic pathogens (ops) including potential hosts, and evaluated the use of legionella spp. for indicating microbial water quality for ops within a full-scale operating drinking water distribution system (dwds).201626535924
what's on the outside matters: the role of the extracellular polymeric substance of gram-negative biofilms in evading host immunity and as a target for therapeutic intervention.biofilms are organized multicellular communities encased in an extracellular polymeric substance (eps). biofilm-resident bacteria resist immunity and antimicrobials. the eps provides structural stability and presents a barrier; however, a complete understanding of how eps structure relates to biological function is lacking. this review focuses on the eps of three gram-negative pathogens: pseudomonas aeruginosa, nontypeable haemophilus influenzae, and salmonella enterica serovar typhi/typhimurium ...201627129225
regulation of rac1 and reactive oxygen species production in response to infection of gastrointestinal epithelia.generation of reactive oxygen species (ros) during infection is an immediate host defense leading to microbial killing. ape1 is a multifunctional protein induced by ros and after induction, protects against ros-mediated dna damage. rac1 and napdh oxidase (nox1) are important contributors of ros generation following infection and associated with gastrointestinal epithelial injury. the purpose of this study was to determine if ape1 regulates the function of rac1 and nox1 during oxidative stress. g ...201626761793
clinical predictors of the leading pathogens in human immunodeficiency virus-infected adults with community-onset bacteremia in the emergency department: the importance of transmission routes.to investigate the clinical characteristics and pathogens of community-onset bacteremia among human immunodeficiency virus (hiv)-infected adults as well as to establish the clinical predictors of the major microorganisms.201628082067
genomic analysis of salmonella enterica serovar typhimurium characterizes strain diversity for recent u.s. salmonellosis cases and identifies mutations linked to loss of fitness under nitrosative and oxidative stress.salmonella enterica serovar typhimurium is one of the most common s. enterica serovars associated with u.s. foodborne outbreaks. s. typhimurium bacteria isolated from humans exhibit wide-ranging virulence phenotypes in inbred mice, leading to speculation that some strains are more virulent in nature. however, it is unclear whether increased virulence in humans is related to organism characteristics or initial treatment failure due to antibiotic resistance. strain diversity and genetic factors co ...201626956590
complete nucleotide sequence of ph11, an inchi2 plasmid conferring multi-antibiotic resistance and multi-heavy metal resistance genes in a clinical klebsiella pneumoniae isolate.the complete 284,628bp sequence of ph11, an inchi2 plasmid, was determined through single-molecule, real-time (smrt) sequencing. harbored by a clinical klebsiella pneumoniae strain h11, and isolated in beijing, this plasmid contains multiple antibiotic resistance genes, including cata2, aac(6')-ib, strb, stra, dfra19, blatem-1, blashv-12, sul1, qace delta 1, erea, arr2, and aac3. the aac(6')-ib is carried by a class i integron. plasmid ph11 also carries several genes associated with resistance t ...201627101788
at the crossroads: communication of bacteria-containing vacuoles with host organelles.invasive bacterial pathogens are engulfed upon host cell entry in a vacuolar environment called the bacteria-containing vacuole (bcv). bcvs directly contact with numerous host compartments, mainly vesicles of the endocytic pathway, such as endosomes or lysosomes. in addition, they also interact with the endoplasmic reticulum and endomembranes of the secretory pathway. these connections between the pathogen and the host occur either through heterotypic membrane fusions or through membrane contact ...201626762760
a simple integrated microfluidic device for the multiplexed fluorescence-free detection of salmonella enterica.rapid, inexpensive and simplistic nucleic acid testing (nat) is pivotal in delivering biotechnology solutions at the point-of-care (poc). we present a poly(methylmethacrylate) (pmma) microdevice where on-board infrared-mediated pcr amplification is seamlessly integrated with a particle-based, visual dna detection for specific detection of bacterial targets in less than 35 minutes. fluidic control is achieved using a capillary burst valve laser-ablated in a novel manner to confine the pcr reagent ...201626658961
the horizontally-acquired response regulator ssrb drives a salmonella lifestyle switch by relieving biofilm silencing.a common strategy by which bacterial pathogens reside in humans is by shifting from a virulent lifestyle, (systemic infection), to a dormant carrier state. two major serovars of salmonella enterica, typhi and typhimurium, have evolved a two-component regulatory system to exist inside salmonella-containing vacuoles in the macrophage, as well as to persist as asymptomatic biofilms in the gallbladder. here we present evidence that ssrb, a transcriptional regulator encoded on the spi-2 pathogenicity ...201626880544
a critical role of bacterioferritin in salmonella pullorum-induced ifn-β expression in df-1 cells.salmonella enterica serovar pullorum (s. pullorum) causes pullorum disease in poultry and results in great economic losses to the poultry industry. although an eradication program has been successfully performed in some countries, it remains a major threat to countries with poor poultry disease surveillance. currently there are no effective control measures for pullorum disease except eradication. in particular, the pathogenesis of s. pullorum infection is still largely unknown. here we identifi ...201626870001
sos system induction inhibits the assembly of chemoreceptor signaling clusters in salmonella enterica.swarming, a flagellar-driven multicellular form of motility, is associated with bacterial virulence and increased antibiotic resistance. in this work we demonstrate that activation of the sos response reversibly inhibits swarming motility by preventing the assembly of chemoreceptor-signaling polar arrays. we also show that an increase in the concentration of the reca protein, generated by sos system activation, rather than another function of this genetic network impairs chemoreceptor polar clus ...201626784887
production of recombinant salmonella flagellar protein, flgk, and its uses in detection of anti-salmonella antibodies in chickens by automated capillary immunoassay.conventional immunoblot assays are a useful tool for specific protein identification, but tedious, labor-intensive and time-consuming. a capillary electrophoresis-based immunoblot assay so-called "simple western" was developed to enable the protein identification in an automatic manner. this communication describes the use of simple western for detecting anti-salmonella flgk antibodies from chicken sera.201626784737
classification of salmonella enterica serotypes with selective bands using visible/nir hyperspectral microscope images.optical detection of foodborne bacteria such as salmonella classifies bacteria by analysing spectral data, and has potential for rapid detection. in this experiment hyperspectral microscopy is explored as a means for classifying five salmonella serotypes. initially, the microscope collects 89 spectral measurements between 450 and 800 nm. here, the objective was to develop correct classification of five serotypes with optimal spectral bands selected through multivariate data analysis (mvda), thus ...201626695128
oxyr-dependent formation of dna methylation patterns in opvaboff and opvabon cell lineages of salmonella enterica.phase variation of the salmonella enterica opvab operon generates a bacterial lineage with standard lipopolysaccharide structure (opvab(off)) and a lineage with shorter o-antigen chains (opvab(on)). regulation of opvab lineage formation is transcriptional, and is controlled by the lysr-type factor oxyr and by dna adenine methylation. the opvab regulatory region contains four sites for oxyr binding (obsa-d), and four methylatable gatc motifs (gatc1-4). opvab(off) and opvab(on) cell lineages displ ...201626687718
quinolone resistance mechanisms among salmonella enterica in malaysia.the prevalence of quinolone-resistant salmonella enterica is on the rise worldwide. salmonella enterica is one of the major foodborne pathogens in malaysia. therefore, we aim to investigate the occurrence and mechanisms of quinolone resistance among salmonella strains isolated in malaysia. a total of 283 salmonella strains isolated from food, humans, and animals were studied. the disk diffusion method was used to examine the quinolone susceptibility of the strains, and the minimum inhibitory con ...201626683630
modelling biofilm formation of salmonella enterica ser. newport as a function of ph and water activity.the effect of ph and water activity (aw) on the formation of biofilm by salmonella enterica ser. newport, previously identified as a strong biofilm producer, was assessed. biofilm formation was evaluated in tryptone soy broth at 37 °c and at different combinations of ph (3.3-7.8) and aw (0.894-0.997). in total, 540 biofilm formation tests in 108 ph and aw combinations were carried out in polystyrene microtiter plates using crystal violet staining and optical density (od; 580 nm) measurements. si ...201626678133
inactivation of salmonella senftenberg, salmonella typhimurium and salmonella tennessee in peanut butter by 915 mhz microwave heating.this study evaluated the efficacy of a 915 mhz microwave with 3 different levels to inactivate 3 serovars of salmonella in peanut butter. peanut butter inoculated with salmonella enterica serovar senftenberg, s. enterica serovar typhimurium and s. enterica serovar tennessee were treated with a 915 mhz microwave with 2, 4 and 6 kw and acid and peroxide values and color changes were determined after 5 min of microwave heating. salmonella populations were reduced with increasing treatment time and ...201626678129
rapid emergence and clonal dissemination of ctx-m-15-producing salmonella enterica serotype virchow, south korea.the prevalence of cefotaxime-resistant salmonella enterica serotype virchow has dramatically increased in south korea since the first isolation in 2011. of 68 isolates collected over 10 years, 28 cefotaxime-resistant isolates harbored the bla(ctx-m-15) extended-spectrum β-lactamase gene and were closely related genetically, demonstrating the clonal dissemination of ctx-m-15-producing salmonella virchow in south korea.201626674083
comparison of immunomodulatory properties of mannose-binding lectins from canavalia brasiliensis and cratylia argentea in a mice model of salmonella infection.the immunomodulatory properties of mannose-binding lectins conbr (canavalia brasiliensis) and cfl (cratylia argentea) were investigated comparatively in a model of salmonella infection. the lectins were intraperitoneally (i.p.) administered to mice daily for three days before the bacterial challenge with salmonella enterica ser. typhimurium (0.2 ml i.p.; 10(7) cfu/ml). in vivo assays have shown that both lectins induced a significant leukocyte infiltration into the peritoneal cavity of uninfecte ...201626773770
complete genome and plasmid sequences of three canadian isolates of salmonella enterica subsp. enterica serovar heidelberg from human and food sources.isolates of salmonella enterica subsp. enterica serovar heidelberg are often associated with poultry products and may cause severe human illness. here, we report the fully assembled genome and plasmid sequences of three s. heidelberg strains with phage types 9, 29, and 41.201626769926
type-iii secretion filaments as scaffolds for inorganic nanostructures.nanostructured materials exhibit unique magnetic, electrical and catalytic properties. these characteristics are determined by the chemical composition, size and shape of the nanostructured components, which are challenging to modulate on such small size scales and to interface with living cells. to address this problem, we are using a self-assembling filament protein, prgi, as a scaffold for bottom-up inorganic nanostructure synthesis. prgi is a small protein (80 amino acids) that oligomerizes ...201626763334
molecular epidemiology of monophasic salmonella enterica serovar o7: -: 1, 5 isolates in akita prefecture, japan. 201626743153
differential killing of salmonella enterica serovar typhi by antibodies targeting vi and lipopolysaccharide o:9 antigen.salmonella enterica serovar typhi expresses a capsule of vi polysaccharide, while most salmonella serovars, including s. enteritidis and s. typhimurium, do not. both s. typhi and s. enteritidis express the lipopolysaccharide o:9 antigen, yet there is little evidence of cross-protection from anti-o:9 antibodies. vaccines based on vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against vi confer protection. here we investigate the role of vi capsule and antibodies ...201626741681
persistent infections by nontyphoidal salmonella in humans: epidemiology and genetics.although chronic infections by typhoidal salmonella are well-known, prolonged human infections by nontyphoidal salmonella (nts) are poorly characterized.201626740515
development and evaluation of an elime assay to reveal the presence of salmonella in irrigation water: comparison with real-time pcr and the standard culture method.a reliable, low-cost and easy-to-use elime (enzyme-linked-immuno-magnetic-electrochemical) assay for detection of salmonella enterica in irrigation water is presented. magnetic beads (mbs), coupled to a strip of eight-magnetized screen-printed electrodes localized at the bottom of eight wells (8-well/spe strip), effectively supported a sandwich immunological chain. enzymatic by-product is quickly measured by chronoamperometry, using a portable instrument. with the goal of developing a method abl ...201626717832
on the use of the electrospinning coating technique to produce antimicrobial polyhydroxyalkanoate materials containing in situ-stabilized silver nanoparticles.electro-hydrodynamic processing, comprising electrospraying and electrospinning techniques, has emerged as a versatile technology to produce nanostructured fiber-based and particle-based materials. in this work, an antimicrobial active multilayer system comprising a commercial polyhydroxyalkanoate substrate (pha) and an electrospun pha coating containing in situ-stabilized silver nanoparticles (agnps) was successfully developed and characterized in terms of morphology, thermal, mechanical, and b ...201628336838
gatifloxacin versus ceftriaxone for uncomplicated enteric fever in nepal: an open-label, two-centre, randomised controlled trial.because treatment with third-generation cephalosporins is associated with slow clinical improvement and high relapse burden for enteric fever, whereas the fluoroquinolone gatifloxacin is associated with rapid fever clearance and low relapse burden, we postulated that gatifloxacin would be superior to the cephalosporin ceftriaxone in treating enteric fever.201626809813
core proteomic analysis of unique metabolic pathways of salmonella enterica for the identification of potential drug targets.infections caused by salmonella enterica, a gram-negative facultative anaerobic bacteria belonging to the family of enterobacteriaceae, are major threats to the health of humans and animals. the recent availability of complete genome data of pathogenic strains of the s. enterica gives new avenues for the identification of drug targets and drug candidates. we have used the genomic and metabolic pathway data to identify pathways and proteins essential to the pathogen and absent from the host.201626799565
complete genome sequences of salmonella enterica serovars anatum and anatum var. 15+, isolated from retail ground turkey.the complete genome sequences of two isolates of salmonella enterica serovars anatum and anatum var. 15+ revealed the presence of two plasmids of 112 kb and 3 kb in size in each. the chromosome of salmonella anatum (4.83 mb) was slightly smaller than that of salmonella anatum var. 15+ (4.88 mb).201626798111
whole-genome sequencing of salmonella enterica subsp. enterica serovar ouakam isolated from ground turkey.in this report, we announce the first whole-genome sequencing of salmonella enterica subsp. enterica serovar ouakam strain gnt-01, isolated from ground turkey retail meat. the strain has a chromosome of 5,088,451 bp long, with a g+c content of 52.3%, and a plasmid of 109,715 bp.201626798110
complete genome and methylome sequences of two salmonella enterica spp.salmonella enterica is responsible for major foodborne outbreaks worldwide. it can cause gastroenteritis characterized by diarrhea, vomiting, and fever. salmonella infections raise public health concerns along with consequential economic impacts. in this report, we announce the first complete genome sequences of salmonella enterica subsp. enterica serovar choleraeuis (s. choleraeuis) atcc 10708 and salmonella enterica subsp. enterica serovar pullorum (s. pullorum) atcc 9120, isolated from patien ...201626798102
draft genome sequences of two salmonella enterica serotype infantis strains isolated from a captive western lowland gorilla (gorilla gorilla gorilla) and a cohabitant black and white tegu (tupinambis merianae) in brazil.the draft genome sequences of two salmonella enterica serotype infantis isolates are reported here. one of the strains was isolated from a western lowland gorilla (gorilla gorilla gorilla) with colitis. the second strain was isolated from a reptile that inhabited the same premises. whole-genome sequencing demonstrated that these isolates were not clonal.201626798099
highly drug-resistant salmonella enterica serovar indiana clinical isolates recovered from broilers and poultry workers with diarrhea in china.highly drug-resistant salmonella enterica serovar indiana became the most common serovar in broilers with diarrhea in china over the course of this study (15% in 2010 to 70% in 2014). while most s. indiana isolates (87%, 384/440) were resistant to 13 to 16 of the 16 antibiotics tested, 89% of non-s. indiana isolates (528/595) were resistant to 0 to 6 antibiotics. class 1 integrons and inchi2-type plasmids were detected in all s. indiana isolates, but only in 39% and 1% of non-s. indiana isolates ...201626824960
complete genome sequence and methylome of salmonella enterica subsp. enterica cerro, a frequent dairy cow serovar.salmonella enterica subsp. enterica serovar cerro is an infrequent pathogen of humans and other mammals but is frequently isolated from the hindgut of asymptomatic cattle in the united states. to further understand the genomic determinants of s. cerro specificity for the bovine hindgut, the genome of isolate cfsan001588 was fully sequenced and deposited in the genbank database.201626823571
recombinant plasmid-based quantitative real-time pcr analysis of salmonella enterica serotypes and its application to milk samples.the aim of the current study was to develop, a new, rapid, sensitive and quantitative salmonella detection method using a real-time pcr technique based on an inexpensive, easy to produce, convenient and standardized recombinant plasmid positive control. to achieve this, two recombinant plasmids were constructed as reference molecules by cloning the two most commonly used salmonella-specific target gene regions, inva and ttrrsbc. the more rapid detection enabled by the developed method (21 h) com ...201626820062
prevalence of nontyphoidal salmonella and salmonella strains with conjugative antimicrobial-resistant serovars contaminating animal feed in texas.the objective of this study was to characterize 365 nontyphoidal salmonella enterica isolates from animal feed. among the 365 isolates, 78 serovars were identified. twenty-four isolates (7.0%) were recovered from three of six medicated feed types. three of these isolates derived from the medicated feed, salmonella newport, salmonella typhimurium var. o 5- (copenhagen), and salmonella lexington var. 15+ (manila), displayed antimicrobial resistance. susceptibility testing revealed that only 3.0% ( ...201626818979
interaction of a live attenuated salmonella gallinarum vaccine candidate with chicken bone marrow-derived dendritic cells.salmonella enterica serovar gallinarum (sg) is a gram-negative intracellular host-adapted pathogen that causes fowl typhoid. attenuated strains of sg are proven and widely used vaccine candidates because of advantages like induction of strong humoral and cell-mediated immune responses. in the present study, we investigated the interaction of chicken bone marrow-derived dendritic cells (chbm-dcs) with an attenuated sg (jol1355) strain that secretes a heat-labile enterotoxin b subunit protein prev ...201626813292
host stress drives salmonella recrudescence.host stress is well known to result in flare-ups of many bacterial, viral and parasitic infections. the mechanism by which host stress is exploited to increase pathogen loads, is poorly understood. here we show that salmonella enterica subspecies enterica serovar typhimurium employs a dedicated mechanism, driven by the scsa gene, to respond to the host stress hormone cortisol. through this mechanism, cortisol increases salmonella proliferation inside macrophages, resulting in increased intestina ...201626857846
differences in host cell invasion and salmonella pathogenicity island 1 expression between salmonella enterica serovar paratyphi a and nontyphoidal s. typhimurium.active invasion into nonphagocytic host cells is central to salmonella enterica pathogenicity and dependent on multiple genes within salmonella pathogenicity island 1 (spi-1). here, we explored the invasion phenotype and the expression of spi-1 in the typhoidal serovars paratyphi a compared to that of the nontyphoidal serovars typhimurium. we demonstrate that while s. typhimurium is equally invasive under both aerobic and microaerobic conditions, s. paratyphi a invades only following growth unde ...201626857569
correction: genomic comparison of non-typhoidal salmonella enterica serovars typhimurium, enteritidis, heidelberg, hadar and kentucky isolates from broiler chickens. 201626854571
differentiation of uk endemic strains of salmonella enterica serovar newport from epidemic north american strains by pcr detection of a truncated bapa chromosomal gene.the aim of this study was to develop a pcr test to detect chromosomal differences between epidemic multidrug resistant (epi-mdr) strains of salmonella enterica serovar newport (s. newport) and non-epi-mdr strains of s. newport that are endemic to the united kingdom (uk). sequence analysis of the biofilm-associated protein a gene (bapa) showed that epi-mdr strains of s. newport from the united states of america (usa) had a deletion of 309 bp, which was not present in non-epi-mdr strains of s. new ...201626850548
complete closed genome sequences of salmonella enterica subsp. enterica serotypes anatum, montevideo, typhimurium, and newport, isolated from beef, cattle, and humans.salmonella enterica spp. are a diverse group of bacteria with a wide range of virulence potential. to facilitate genome comparisons across this virulence spectrum, we present eight complete closed genome sequences of four s. enterica serotypes (anatum, montevideo, typhimurium, and newport), isolated from various cattle samples and from humans.201626847891
population structure and associated phenotypes of salmonella enterica serovars derby and mbandaka overlap with host range.the salmonella enterica serovar derby is frequently isolated from pigs and turkeys whereas serovar mbandaka is frequently isolated from cattle, chickens and animal feed in the uk. through comparative genomics, phenomics and mutant construction we previously suggested possible mechanistic reasons why these serovars demonstrate apparently distinct host ranges. here, we investigate the genetic and phenotypic diversity of these two serovars in the uk. we produce a phylogenetic reconstruction and per ...201626846255
suppurative granulomatous cholecystitis in a pediatric chronic carrier with salmonella enterica serotype typhi: a case report and review of literature.bacterial infection of salmonella enterica serotype typhi is rare in the united states but endemic in many developing countries. approximately 3-5% of patients become chronic asymptomatic carriers. we describe an atypical presentation of s. enterica serotype typhi infection in a 10-year-old male, whose cholecystechtomy and bile culture revealed chronic carrier status despite negative stool tests and the absence of gallstones. the gallbladder showed marked thickening of the wall with an intense s ...201626838767
attribution of salmonella enterica serotype hadar infections using antimicrobial resistance data from two points in the food supply system.a challenge to the development of foodborne illness prevention measures is determining the sources of enteric illness. microbial subtyping source-attribution models attribute illnesses to various sources, requiring data characterizing bacterial isolate subtypes collected from human and food sources. we evaluated the use of antimicrobial resistance data on isolates of salmonella enterica serotype hadar, collected from ill humans, food animals, and from retail meats, in two microbial subtyping att ...201626838291
immune protection of chickens conferred by a vaccine consisting of attenuated strains of salmonella enteritidis, typhimurium and infantis.the colonization of poultry with different salmonella enterica serovars poses an issue throughout the world. in this study we therefore tested the efficacy of a vaccine consisting of attenuated strains of salmonella enterica serovars enteritidis, typhimurium and infantis against challenge with the same serovars and with s. agona, dublin and hadar. we tested oral and aerosol administration of the vaccine, with or without co-administration of cecal microbiota from adult hens. the protective effect ...201627741950
draft genome sequences of four salmonella enterica strains isolated from turkey-associated sources.we report the draft genomes of four salmonella enterica isolates evaluated for the contribution of plasmids to virulence. strains se163a, se696a, and se710a carry plasmids demonstrated to facilitate plasmid-associated virulence, while se819 is less virulent and has been used as a recipient for conjugation experiments to assess plasmid-encoded virulence mechanisms.201627738037
construction and characterization of a cigr deletion mutant of salmonella enterica serovar pullorum.salmonella enterica serovar pullorum (s. pullorum) is the causative agent of pullorum disease (pd) and results in severe economic losses to the poultry industry. as a salmonella type iii secretion system 2 (t3ss2) effector and predicted membrane protein, cigr is encoded by the cigr gene within salmonella pathogenicity island 3 (spi3). in order to research the influence of the cigr gene on s. pullorum, a cigr mutant of s. pullorum s06004 was constructed by the lambda red recombination system, and ...201627163262
the o-antigen mediates differential survival of salmonella against communities of natural predators.antigenically-distinct members of bacterial species can be differentially distributed in the environment. predators known to consume antigenically-distinct prey with different efficiencies are also differentially distributed. here we show that antigenically-distinct, but otherwise isogenic and physiologically indistinct, strains of salmonella enterica show differential survival in natural soil, sediment and intestinal environments where they would face a community of predators. decline in overal ...201626888189
characterization of quinolone resistance in salmonella spp. isolates from food products and human samples in brazil.non-typhoidal salmonellosis is an important zoonotic disease caused by salmonella enterica. the aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance in salmonella spp. and its association with fluoroquinolone susceptibility in brazil. a total of 129 nts isolates (samples from human origin, food from animal origin, environmental, and animal) grouped as from animal (n=62) and human (n=67) food were evaluated between 2009 and 2013. these isolates were investi ...201626887245
spectroscopic studies of the eutt adenosyltransferase from salmonella enterica: mechanism of four-coordinate co(ii)cbl formation.eutt from salmonella enterica is a member of a class of enzymes termed atp:co(i)rrinoid adenosyltransferases (acats), implicated in the biosynthesis of adenosylcobalamin (adocbl). in the presence of cosubstrate atp, acats raise the co(ii)/co(i) reduction potential of their cob(ii)alamin [co(ii)cbl] substrate by >250 mv via the formation of a unique four-coordinate (4c) co(ii)cbl species, thereby facilitating the formation of a "supernucleophilic" cob(i)alamin intermediate required for the format ...201626886077
high-efficiency, two-step scarless-markerless genome genetic modification in salmonella enterica.we present a two-step method for scarless-markerless genome genetic modification in salmonella enterica based on the improved suicide plasmid pgmb152. the whole laczya gene can provide a lacz-based blue/white screening strategy for fast selection of double-crossover mutants by allelic exchange. the high efficiency of this genetic engineering strategy permits the study of gene function by gene knockin, site-directed mutagenesis, and gene knockout to construct live attenuated vaccines.201626883127
compensating the fitness costs of synonymous mutations.synonymous mutations do not change the sequence of the polypeptide but they may still influence fitness. we investigated in salmonella enterica how four synonymous mutations in the rpst gene (encoding ribosomal protein s20) reduce fitness (i.e., growth rate) and the mechanisms by which this cost can be genetically compensated. the reduced growth rates of the synonymous mutants were correlated with reduced levels of the rpst transcript and s20 protein. in an adaptive evolution experiment, these f ...201626882986
phenotypic and genotypic characterization of animal-source salmonella heidelberg isolates.salmonella enterica serotype heidelberg (s. heidelberg) is frequently implicated in human foodborne salmonella infections and often produces more severe clinical disease than other serotypes. livestock and poultry products represent a potential risk for transmission to humans. the purpose of this study was to evaluate 49 s. heidelberg veterinary isolates for exponential growth rate (egr), pfge pattern, and antimicrobial resistance to evaluate these parameters as mechanisms by which s. heidelberg ...201626881274
phenotypic and genotypic diversity of salmonella in finishing swine.salmonella enterica (nontyphoidal) is one of the major causes of foodborne diseases in the united states and worldwide. molecular typing methods are significant tools used to better understand the transmission and ecology of salmonella in order to implement pre-harvest control measures. the objectives of this study were to describe the salmonella genotypes, the distribution of isolate subtypes from different ecological niches (i.e., barn environment, nursery, and individual pigs) and their evolu ...201626977814
global mlst of salmonella typhi revisited in post-genomic era: genetic conservation, population structure, and comparative genomics of rare sequence types.typhoid fever, caused by salmonella enterica serovar typhi, remains an important public health burden in southeast asia and other endemic countries. various genotyping methods have been applied to study the genetic variations of this human-restricted pathogen. multilocus sequence typing (mlst) is one of the widely accepted methods, and recently, there is a growing interest in the re-application of mlst in the post-genomic era. in this study, we provide the global mlst distribution of s. typhi ut ...201626973639
presence of plasmid-mediated quinolone resistance determinants and mutations in gyrase and topoisomerase in salmonella enterica isolates with resistance and reduced susceptibility to ciprofloxacin.in recent decades, the emergence and spread of resistance to nalidixic acid are usually associated with reduced susceptibility to ciprofloxacin among salmonella serotypes. the aims of this study were to investigate the mechanisms associated with resistance to fluoroquinolone and the clonal relatedness of salmonella strains isolated from human and nonhuman origins, in a 5-year period in são paulo, brazil. antimicrobial susceptibility testing for salmonella isolates was performed. pcr and dna sequ ...201626971183
development of a simple, peripheral-blood-based lateral-flow dipstick assay for accurate detection of patients with enteric fever.enteric fever is a systemic infection caused by typhoidal strains of salmonella enterica and is a significant cause of mortality and morbidity in many parts of the world, especially in resource-limited areas. unfortunately, currently available diagnostic tests for enteric fever lack sensitivity and/or specificity. no true clinically practical gold standard for diagnosing patients with enteric fever exists. unfortunately, microbiologic culturing of blood is only 30 to 70% sensitive although 100% ...201626961857
salmonella typhimurium undergoes distinct genetic adaption during chronic infections of mice.typhoid fever caused by salmonella enterica serovar typhi (s. typhi) is a severe systemic human disease and endemic in regions of the world with poor drinking water quality and sewage treatment facilities. a significant number of patients become asymptomatic life-long carriers of s. typhi and serve as the reservoir for the disease. the specific mechanisms and adaptive strategies enabling s. typhi to survive inside the host for extended periods are incompletely understood. yet, elucidation of the ...201626955808
draft genome sequence of a salmonella enterica subsp. enterica serovar gallinarum bv. gallinarum isolate associated with fowl typhoid outbreaks in brazil.salmonella enterica subsp. enterica serovar gallinarum bv. gallinarum strains are bird pathogens causing fowl typhoid (ft). isolate br_rs12 was obtained from a poultry flock with ft in 2014. the sequencing of this genome will enable to track the origin of the recent outbreaks in brazil.201626950322
assessing the growth of escherichia coli o157:h7 and salmonella in spinach, lettuce, parsley and chard extracts at different storage temperatures.the objective of this work was to study the growth potential of escherichia coli o157:h7 and salmonella spp. in leafy vegetable extracts at different temperature conditions.201626950043
effective photosensitization-based inactivation of gram (-) food pathogens and molds using the chlorophyllin-chitosan complex: towards photoactive edible coatings to preserve strawberries.this study is focused on the novel approaches to enhance the inactivation of the gram (-) food pathogen salmonella enterica and harmful molds in vitro and on the surface of strawberries using the chlorophyllin-chitosan complex. salmonella enterica (∼1 × 10(7) cfu ml(-1)) was incubated with chlorophyllin 1.5 × 10(-5) m (chl, food additive), chitosan 0.1% (chs, food supplement) or the chlorophyllin-chitosan complex (1.5 × 10(-5) m chl-0.1% chs) and illuminated with visible light (λ = 405 nm, light ...201626947225
colonization of internal organs by salmonella enteritidis in experimentally infected laying hens housed in enriched colony cages at different stocking densities.epidemiologic analyses have linked the frequency of human infections with salmonella enterica subspecies enterica serovar enteritidis to the consumption of contaminated eggs and thus to the prevalence of this pathogen in commercial egg-laying flocks. contamination of the edible contents of eggs by salmonella enteritidis is a consequence of the colonization of reproductive tissues in systemically infected hens. the animal welfare implications of laying hen housing systems have been widely debated ...201626944976
differential antibacterial response of chicken granulosa cells to invasion by salmonella serovars.in the united states, salmonella enterica ser. enteritidis (se) is among the leading bacterial cause of foodborne illness via consumption of raw or undercooked eggs. the top salmonella serovars implicated in u.s. foodborne outbreaks associated with chicken consumption include se, typhimurium (st), heidelberg (sh), montevideo, mbandka, braenderup, and newport. while enforcement actions target the eradication of se from layer hens, there is a growing concern that other serovars could occupy this n ...201626944965
development of a loop mediated isothermal amplification (lamp) - surface enhanced raman spectroscopy (sers) assay for the detection of salmonella enterica serotype enteritidis.as a major foodborne pathogen, salmonella enterica serotype enteritidis is increasingly rising as a global health concern. here, we developed an integrated assay that combines loop mediated isothermal amplification (lamp) and surface enhanced raman spectroscopy (sers) for dna detection of s. enteritidis using specifically designed raman active au-nanoprobes. the target dna was amplified by lamp and then labeled with au-nanoprobes comprised of gold nanoparticle-modified with specific cy5/dna prob ...201626941845
study of salmonella typhimurium infection in laying hens.members of salmonella enterica are frequently involved in egg and egg product related human food poisoning outbreaks worldwide. in australia, salmonella typhimurium is frequently involved in egg and egg product related foodborne illness and salmonella mbandaka has also been found to be a contaminant of the layer farm environment. the ability possessed by salmonella enteritidis to colonize reproductive organs and contaminate developing eggs has been well-described. however, there are few studies ...201626941727
draft whole-genome sequences of 25 salmonella enterica strains representing 24 serovars.we report the draft genome sequences of 25 salmonella enterica strains representing 24 different serotypes, many of which were not available in public repositories during our selection process. these draft genomes will provide useful reference for the genetic variation between serotypes and aid in the development of molecular typing tools.201626941156
new insights about excisable pathogenicity islands in salmonella and their contribution to virulence.pathogenicity islands (pais) are regions of the chromosome of pathogenic bacteria that harbor virulence genes, which were probably acquired by lateral gene transfer. several pais can excise from the bacterial chromosome by site-specific recombination and in this review have been denominated "excisable pais". here, the characteristic of some of the excisable pais from salmonella enterica and the possible role and impact of the excision process on bacterial virulence is discussed. understanding th ...201626939722
genome-scale screening and validation of targets for identification of salmonella enterica and serovar prediction.salmonella enterica is the most common foodborne pathogen worldwide, with 2,500 recognized serovars. detection of s. enterica and its classification into serovars are essential for food safety surveillance and clinical diagnosis. the pcr method is useful for these applications because of its rapidity and high accuracy. we obtained 412 candidate detection targets for s. enterica using a comparative genomics mining approach. gene ontology (go) functional enrichment analysis of these candidate targ ...201626939647
strain-specific survival of salmonella enterica in peanut oil, peanut shell, and chia seeds.in north america, outbreaks of salmonella have been linked to low-water activity (aw) foods, such as nuts and seeds. these outbreaks have implicated an assortment of salmonella serotypes. some salmonella serotypes (e.g., enteritidis and typhimurium) cause high proportions of salmonellosis. nevertheless, there has recently been an emergence of uncommon salmonella serotypes and strains (e.g., tennessee, hartford, and thompson) in low-aw foods. the aim of this study was to evaluate the survival cha ...201626939645
autoregulation of the tufb operon in salmonella.in salmonella enterica and related species, translation elongation factor ef-tu is encoded by two widely separated but near-identical genes, tufa and tufb. two thirds of ef-tu is expressed from tufa with the remaining one third coming from tufb. inactivation of tufa is partly compensated by a doubling in the amount of ef-tub but the mechanism of this up-regulation is unknown. by experimental evolution selecting for improved growth rate in a strain with an inactive tufa we selected six different ...201626934594
prevalence of salmonella excretion in stool: a community survey in 2 sites, guinea-bissau and senegal.chronic and convalescent carriers play an important role in the transmission and endemicity of many communicable diseases. a high incidence of salmonella enterica serovar typhi and invasive nontyphoidal salmonella (nts) infection has been reported in parts of sub-saharan africa, yet the prevalence of salmonella excretion in the general population is unknown.201626933022
a multicountry molecular analysis of salmonella enterica serovar typhi with reduced susceptibility to ciprofloxacin in sub-saharan africa.salmonella enterica serovar typhi is a predominant cause of bloodstream infections in sub-saharan africa (ssa). increasing numbers of s. typhi with resistance to ciprofloxacin have been reported from different parts of the world. however, data from ssa are limited. in this study, we aimed to measure the ciprofloxacin susceptibility of s. typhi isolated from patients with febrile illness in ssa.201626933020
challenges and opportunities for typhoid fever control: a call for coordinated action.the burden of enteric fever caused by salmonella enterica serovars typhi and paratyphi is substantial and has high impact in toddlers and young children. this burden is relatively well documented in asia, and this supplement provides new data on the substantial burden in several sub-saharan african countries. challenges in standardized surveillance and imperfect diagnostic tools have resulted in patchy local disease data, which are not well acknowledged or integrated into local country evidence ...201626933019
diagnosing salmonella enterica serovar typhi infections by polymerase chain reaction using edta blood samples of febrile patients from burkina faso.globally, there are an estimated 22 million cases of salmonella enterica serovar typhi infection each year. however, this figure is likely to be an underestimate due to the low sensitivity of blood culture in s. typhi diagnosis. the aim of this study was to diagnose s. typhi by conventional polymerase chain reaction (pcr) using patient's blood preserved with ethylenediamine tetraacetic acid (edta).201626933018
variations of invasive salmonella infections by population size in asante akim north municipal, ghana.the typhoid fever surveillance in africa program (tsap) estimated adjusted incidence rates (irs) for salmonella enterica serovar typhi and invasive nontyphoidal s. enterica serovars (ints) of >100 cases per 100 000 person-years of observation (pyo) for children aged <15 years in asante akim north municipal (aan), ghana, between march 2010 and may 2012. we analyzed how much these rates differed between rural and urban settings.201626933015
what have we learned from the typhoid fever surveillance in africa program?the typhoid fever surveillance in africa program (tsap) was established in 2009 to fill the data void concerning invasive salmonella disease in sub-saharan africa, and to specifically estimate the burden of bloodstream infections caused by the key pathogen, salmonella enterica serovar typhi. tsap has achieved this ambitious target, finding high incidences of typhoid fever in both rural and urban populations in several countries in sub-saharan africa. the results of tsap will undoubtedly dictate ...201626933014
unraveling the effects of static magnetic field stress on cytosolic proteins of salmonella by using a proteomic approach.the present study investigated the adaptation of salmonella enterica subsp. enterica serovar hadar to static magnetic field (smf) exposure (200 mt, 9 h). the proteomic analysis provides an overview of potentially important cytosolic proteins that salmonella needs to regulate to survive and adapt to magnetic stress. via 2-dimensional electrophoresis and liquid chromatography tandem mass spectrometry, we compared cytosolic proteomes before and after exposure to magnetic field. a total of 35 protei ...201626928316
mechanisms of resistance to linalool in salmonella senftenberg and their role in survival on basil.fresh produce contaminated with human pathogens raises vital and ecological questions about bacterial survival strategies. such occurrence was basil harboring salmonella enterica serovar senftenberg that caused an outbreak in 2007. this host was unanticipated due to its production of antibacterial substances, including linalool. we show that linalool perforates bacterial membranes, resulting in increased permeability and leakage of vital molecules. it also inhibits cell motility and causes bacte ...201626914987
[laboratory surveillance of salmonella enterica from human clinical cases in colombia 2005-2011].salmonella is an enteropathogen acquired through contaminated food or water. in colombia, salmonella spp. is included in the national surveillance of acute diarrhoeal diseases and typhoid fever initiated in 1997. this report shows the phenotype and genotype results obtained from 2005 to 2011.201627038678
nontyphoidal salmonella disease: current status of vaccine research and development.among more than 2500 nontyphoidal salmonella enterica (nts) serovars, s. enterica serovar typhimurium and s. enterica serovar enteritidis account for approximately fifty percent of all human isolates of nts reported globally. the global incidence of nts gastroenteritis in 2010 was estimated to be 93 million cases, approximately 80 million of which were contracted via food-borne transmission. it is estimated that 155,000 deaths resulted from nts in 2010. nts also causes severe, extra-intestinal, ...201627032517
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