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hla-b27 modulates intracellular growth of salmonella pathogenicity island 2 mutants and production of cytokines in infected monocytic u937 cells.salmonella enterica serovar enteritidis pt4 ks8822/88 replicates rapidly in hla-b27-transfected human monocytic u937 cells. in this process, salmonella pathogenicity island 2 (spi-2) genes play a crucial role. our previous study indicated that 118 salmonella genes, including 8 spi-2 genes were affected by hla-b27 antigen during salmonella infection of u937 cells.201222470519
ssef, a type iii effector protein from the mammalian pathogen salmonella enterica, requires resistance-gene-mediated signalling to activate cell death in the model plant nicotiana benthamiana.type iii effector proteins (t3es) of many gram-negative pathogenic bacteria manipulate highly conserved cellular processes, indicating conservation in virulence mechanisms during the infection of hosts of divergent evolutionary origin. in order to identify conserved effector functions, we used a cross-kingdom approach in which we expressed selected t3es from the mammalian pathogen salmonella enterica in leaves of nicotiana benthamiana and searched for possible virulence or avirulence phenotypes. ...201222471508
association of a protective monoclonal iga with the o antigen of salmonella enterica serovar typhimurium impacts type 3 secretion and outer membrane integrity.invasion of intestinal epithelial cells by salmonella enterica serovar typhimurium is an energetically demanding process, involving the transfer of effector proteins from invading bacteria into host cells via a specialized organelle known as the salmonella pathogenicity island 1 (spi-1) type 3 secretion system (t3ss). by a mechanism that remains poorly understood, entry of s. typhimurium into epithelial cells is inhibited by sal4, a monoclonal, polymeric iga antibody that binds an immunodominant ...201222473607
immune dynamics following infection of avian macrophages and epithelial cells with typhoidal and non-typhoidal salmonella enterica serovars; bacterial invasion and persistence, nitric oxide and oxygen production, differential host gene expression, nf-κb signalling and cell cytotoxicity.poultry-derived food is a common source of infection of human with the non-host-adapted salmonellae while fowl typhoid and pullorum disease are serious diseases in poultry. development of novel immune-based control strategies against salmonella infection necessitates a better understanding of the host-pathogen interactions at the cellular level. intestinal epithelial cells are the first line of defence against enteric infections and the role of macrophages is crucial in salmonella infection and ...201222475571
efficacy of antimicrobials for the disinfection of pathogen contaminated green bell pepper and of consumer cleaning methods for the decontamination of knives.while there is strong focus on eliminating pathogens from produce at a commercial level, consumers can employ simple methods to achieve additional pathogen reductions in the domestic kitchen. to determine the ability of antimicrobials to decontaminate peppers, samples of green bell pepper were inoculated with salmonella enterica and escherichia coli o157:h7 and then immersed in 3% (v/v) hydrogen peroxide (h₂o₂), 2.5% (v/v) acetic acid (aa), 70% (v/v) ethyl alcohol (etoh), or sterile distilled wa ...201222476008
analysis of hilc/d-dependent invf promoter expression under different culture conditions.in salmonella enterica serovar typhimurium, many of the genes required for intestinal penetration and invasion of host cells are encoded within the salmonella pathogenicity island 1 (spi1). the expression of invf, which is a positive transcriptional activator of spi1, is controlled by hila-dependent (invf-1) and hilc/d-dependent (invf-2) promoters. transcriptional analysis of invf revealed that the invf-2 promoter (p(invf-2)) was not activated when cells were grown in standing culture conditions ...201222480973
impact of a mutator phenotype on motility and cell adherence in salmonella heidelberg.in this study, we investigated adherence and motility of the hypermutator salmonella enterica heidelberg b182 bovine strain related to a 12bp deletion in muts. this mutator phenotype was associated with increased adherence to epithelial cells and with high expression of fima as shown by real-time rt-pcr. motility studies showed that flic were up-regulated in the b182 strain, while flja and fljb were down-regulated. in order to determine if mutated muts is implicated in this genes expression, iso ...201222483239
salmonellosis in cattle: advantages of being an experimental model.salmonellosis is an important disease of cattle caused predominantly by salmonella enterica serotypes typhimurium (s. typhimurium) and dublin (s. dublin). s. typhimurium causes acute enteritis and exudative diarrhea in calves. in addition to enteric disease, s. dublin can cause systemic infections, and may cause abortion in pregnant cows. calves are considered a relevant model for non-typhoidal salmonellosis in humans. experimental oral infections or inoculation of ligated ileal loops in calves ...201222483382
salmonella chemoreceptors mcpb and mcpc mediate a repellent response to l-cystine: a potential mechanism to avoid oxidative conditions.chemoreceptors mcpb and mcpc in salmonella enterica have been reported to promote chemotaxis in lb motility-plate assays. of the chemicals tested as potential effectors of these receptors, the only response was towards l-cysteine and its oxidized form, l-cystine. although enhanced radial migration in plates suggested positive chemotaxis to both amino acids, capillary assays failed to show an attractant response to either, in cells expressing only these two chemoreceptors. in vivo fluorescence re ...201222486902
inflammation induced by phytomodulatory proteins from the latex of calotropis procera (asclepiadaceae) protects against salmonella infection in a murine model of typhoid fever.laticifer proteins (lp) of calotropis procera were fractionated by ion-exchange chromatography, and the influence of a sub-fraction (lp(pi)) on the inflammatory response of swiss mice challenged by salmonella enterica ser. typhimurium was investigated.201222487850
prevalence and antimicrobial susceptibility of salmonella isolated from a variety of raw meat sausages in gaborone (botswana) retail stores.the objective of the study was to provide baseline data on the prevalence and antimicrobial susceptibility of salmonella in different types of raw meat sausages directly accessible to the consumers in gaborone, botswana. a total of 300 raw sausages comprising 79 beef, 78 pork, 72 chicken, and 71 mutton samples were concurrently analyzed for the presence of salmonella using a conventional culture method and a validated pcr method. the pcr assay results were in full concordance with those of the c ...201222488050
novel genomic tools for specific and real-time detection of biothreat and frequently encountered foodborne pathogens.the bacterial genera escherichia, salmonella, shigella, vibrio, yersinia, and francisella include important food safety and biothreat agents. by extensive mining of the whole genome and protein databases of diverse, closely and distantly related bacterial species and strains, we have identified novel genome regions, which we utilized to develop a rapid detection platform for these pathogens. the specific genomic targets we have identified to design the primers in francisella tularensis subsp. tu ...201222488053
antimicrobial effects of silver nanoparticles against bacterial cells adhered to stainless steel surfaces.given the increasing number of antibiotic-resistant bacteria and the need to synthesize new antimicrobials, silver has attracted interest in the scientific community because of its recognized antimicrobial activity. this study aimed to evaluate the antimicrobial effects of silver nanoparticles (np) obtained by a new method and tested at concentrations of 6 μg/ml and 60 μg/ml against the species staphylococcus aureus, listeria innocua, salmonella choleraesuis, pseudomonas aeruginosa, escherichia ...201222488058
comparison of a real-time pcr method with a culture method for the detection of salmonella enterica serotype enteritidis in naturally contaminated environmental samples from integrated poultry houses.conventional culture methods have traditionally been considered the "gold standard" for the isolation and identification of foodborne bacterial pathogens. however, culture methods are labor-intensive and time-consuming. a salmonella enterica serotype enteritidis-specific real-time pcr assay that recently received interim approval by the national poultry improvement plan for the detection of salmonella enteritidis was evaluated against a culture method that had also received interim national poul ...201222488064
factors associated with encephalopathy in patients with salmonella enterica serotype typhi bacteremia presenting to a diarrheal hospital in dhaka, bangladesh.to characterize clinical correlates of typhoid fever-associated encephalopathy, we performed a retrospective chart review of patients with salmonella enterica serotype typhi bacteremia who were hospitalized at the international centre for diarrhoeal disease research, bangladesh, from february of 2009 to june of 2011. of 207 patients bacteremic with salmonella typhi who were ≥ 5 years of age, we identified 43 (21%) patients with encephalopathy. univariate analysis revealed that patients with ence ...201222492156
live oral typhoid vaccine ty21a induces cross-reactive humoral immune responses against salmonella enterica serovar paratyphi a and s. paratyphi b in humans.enteric fever caused by salmonella enterica serovar paratyphi a infection has emerged as an important public health problem. recognizing that in randomized controlled field trials oral immunization with attenuated s. enterica serovar typhi live vaccine ty21a conferred significant cross-protection against s. paratyphi b but not s. paratyphi a disease, we undertook a clinical study to ascertain whether humoral immune responses could explain the field trial results. ty21a immunization of adult resi ...201222492745
salmonella enterica induces joint inflammation and expression of interleukin-17 in draining lymph nodes early after onset of enterocolitis in mice.in developing countries, one-third of reactive arthritis (rea) cases are associated with salmonella enterocolitis; nevertheless, there is no animal model for studying this pathology. here we induced a self-limiting salmonella enterica serovar enteritidis enterocolitis in mice to analyze the onset of rea. balb/c mice received orally 20 μg of streptomycin 24 h before intragastric inoculation of a low dose (3 × 10(3) to 4 × 10(3) cfu) of s. enteritidis. in response to salmonella infection, a 30-fol ...201222493084
type vi secretion system-associated gene clusters contribute to pathogenesis of salmonella enterica serovar typhimurium.the enteropathogen salmonella enterica serovar typhimurium employs a suite of tightly regulated virulence factors within the intracellular compartment of phagocytic host cells resulting in systemic dissemination in mice. a type vi secretion system (t6ss) within salmonella pathogenicity island 6 (spi-6) has been implicated in this process; however, the regulatory inputs and the roles of noncore genes in this system are not well understood. here we describe four clusters of noncore t6ss genes in s ...201222493086
genome sequence of the persistent salmonella enterica subsp. enterica serotype senftenberg strain ss209.salmonella enterica subsp. enterica serotype senftenberg is an emerging serotype in poultry production which has been found to persist in animals and the farm environment. we report the genome sequence and annotation of the ss209 strain of s. senftenberg, isolated from a hatchery, which was identified as persistent in broiler chickens.201222493197
genome sequence of the invasive salmonella enterica subsp. enterica serotype enteritidis strain la5.salmonella enterica subsp. enterica serotype enteritidis is one of the major causes of gastroenteritis in humans due to consumption of poultry derivatives. here we report the whole-genome sequence and annotation, including the virulence plasmid, of s. enteritidis la5, which is a chicken isolate used by numerous laboratories in virulence studies.201222493198
use of urine with nested pcr targeting the flagellin gene (flic) for diagnosis of typhoid fever.this study was planned to evaluate the efficacy of the use of nested pcr with a large volume of easily available urine as an effort to devise a test that can meet the levels necessary to be considered a gold standard for the diagnosis of typhoid fever. a total of 60 subjects with suspected cases of typhoid fever and 20 apparently healthy control subjects were included in the study. the study period extended from march 2010 to june 2011. blood, urine, and stool specimens were collected from the p ...201222493333
salmonella transiently reside in luminal neutrophils in the inflamed gut.enteric pathogens need to grow efficiently in the gut lumen in order to cause disease and ensure transmission. the interior of the gut forms a complex environment comprising the mucosal surface area and the inner gut lumen with epithelial cell debris and food particles. recruitment of neutrophils to the intestinal lumen is a hallmark of non-typhoidal salmonella enterica infections in humans. here, we analyzed the interaction of gut luminal neutrophils with s. enterica serovar typhimurium (s. tm) ...201222493718
selective enrichment media bias the types of salmonella enterica strains isolated from mixed strain cultures and complex enrichment broths.for foodborne outbreak investigations it can be difficult to isolate the relevant strain from food and/or environmental sources. if the sample is contaminated by more than one strain of the pathogen the relevant strain might be missed. in this study mixed cultures of salmonella enterica were grown in one set of standard enrichment media to see if culture bias patterns emerged. nineteen strains representing four serogroups and ten serotypes were compared in four-strain mixtures in salmonella-only ...201222496847
chronic infection drives expression of the inhibitory receptor cd200r, and its ligand cd200, by mouse and human cd4 t cells.certain parasites have evolved to evade the immune response and establish chronic infections that may persist for many years. t cell responses in these conditions become muted despite ongoing infection. upregulation of surface receptors with inhibitory properties provides an immune cell-intrinsic mechanism that, under conditions of chronic infection, regulates immune responses and limits cellular activation and associated pathology. the negative regulator, cd200 receptor, and its ligand, cd200, ...201222496920
the missing link in coenzyme a biosynthesis: panm (formerly yhhk), a yeast gcn5 acetyltransferase homologue triggers aspartate decarboxylase (pand) maturation in salmonella enterica.coenzyme a (coa) is an essential cofactor for all forms of life. the biochemistry underpinning the assembly of coa in escherichia coli and other enterobacteria is well understood, except for the events leading to maturation of the l-aspartate-α-decarboxylase (pand) enzyme that converts pantothenate to β-alanine. pand is synthesized as pro-pand, which undergoes an auto-proteolytic cleavage at residue ser25 to yield the catalytic pyruvoyl moiety of the enzyme. since 1990, it has been known that e. ...201222497218
the wzx translocases for salmonella enterica o-antigen processing have unexpected serotype specificity.most gram-negative bacteria have an o antigen, a polysaccharide with many repeats of a short oligosaccharide that is a part of the lipopolysaccharide, the major lipid in the outer leaflet of the outer membrane. lipopolysaccharide is variable with 46 forms in salmonella enterica that underpin the serotyping scheme. repeat units are assembled on a lipid carrier that is embedded in the cell membrane, and are then translocated by the wzx translocase from the cytoplasmic face to the outer face of the ...201222497246
genetic analysis of multiple antimicrobial resistance in salmonella isolated from diseased broilers in egypt.to date, no information has been available on the molecular bases of antimicrobial resistance in salmonella spp. from poultry in egypt or even in africa. therefore, the objective of this study was to analyze, at the molecular level, the mechanisms of multidrug-resistance in isolates of salmonella recovered from diseased broilers in egypt. twenty-one salmonella isolates were identified; 13 of these isolates were salmonella enterica serovar enteritidis and eight salmonella enterica serovar typhimu ...201222500933
mitsuokella jalaludinii inhibits growth of salmonella enterica serovar typhimurium.salmonella continues to be a significant human health threat, and the objective of this study was to identify microorganisms with the potential to improve porcine food-safety through their antagonism of salmonella. anaerobic culture supernatants of 973 bacterial isolates from the gastrointestinal tract and feces of swine were screened for their capacity to inhibit the growth of salmonella enterica serovar typhimurium. growth inhibition of 1000-fold or greater was observed from 16 isolates, and 1 ...201222503601
tigecycline therapy for bacteremia and aortitis caused by salmonella enterica serotype choleraesuis: a case report.non-typhoid salmonella species represent a significant cause of aortitis. few antimicrobial agents can be used when the patient is allergic or intolerable to cephalosporins or fluoroquinolones. here, we report a case of bacteremia and aortitis caused by salmonella enterica serotype choleraesuis. this patient was cured by initial parenteral tigecycline and subsequent oral ciprofloxacin without surgical intervention.201622503800
three-axis model for atg recruitment in autophagy against salmonella.salmonella enterica serovar typhimurium enter epithelial cells and take up residence there. within epithelial cells, a portion of the bacteria are surrounded by an autophagosome-like double-membrane structure, and they are still residing within the salmonella-containing vacuole (scv). in this paper, we will discuss how the autophagy machinery is recruited in proximity to salmonella. the formation of this double membrane requires atg9l1 and fip200; these proteins are important for autophagy-speci ...201222505927
quantifying ligand binding to large protein complexes using electrospray ionization mass spectrometry.an electrospray ionization mass spectrometry (esi-ms) method for quantifying protein-ligand complexes that cannot be directly detected by esi-ms is described. the proxy protein esi-ms method combines direct esi-ms binding measurements with competitive protein-ligand binding. to implement the method, a proxy protein (p(proxy)), which interacts specifically with the ligand of interest with known affinity and can be detected directly by esi-ms, is used to quantitatively monitor the extent of ligand ...201222507285
a case of urinary tract infection due to salmonella enterica serovar virchow and review of the related literature.nontyphoid salmonella (nts) serotypes can cause gastroenteritis, bacteriemia, and focal infections. however, these focal infections, including urinary tract infections (uti), are occasionally observed; in particular, the presence of several predisposing factors, such as immunodeficiency and structural abnormality in the urinary tract, increase the possibility of the occurrence of infection. we present a case of uti caused by salmonella enterica serovar virchow in an elderly and debilitated patie ...201222510290
high incidence of campylobacter concisus in gastroenteritis in north jutland, denmark: a population-based study.the incidence of non-thermophilic campylobacter species was assessed in an unselected population-based study in a mixed urban and rural community in north jutland, denmark. in a 2-year study period, 11,314 faecal samples from 8302 patients with gastroenteritis were cultured with supplement of the filter method. we recovered a high incidence of campylobacter concisus (annual incidence 35/100,000 inhabitants), almost as high as the common campylobacter jejuni/coli. in contrast, there was a very lo ...201322512739
improved immune responses against avian influenza virus following oral vaccination of chickens with ha dna vaccine using attenuated salmonella typhimurium as carrier.this study evaluates the immune responses of single avian influenza virus (aiv) ha dna vaccine immunization using attenuated salmonella enterica sv. typhimurium as an oral vaccine carrier and intramuscular (im) dna injection. one-day-old specific-pathogen-free (spf) chicks immunized once by oral gavage with 10(9) salmonella colony-forming units containing plasmid expression vector encoding the ha gene of a/ck/malaysia/5858/04 (h5n1) (pcdna3.1.h5) did not show any clinical manifestations. serum h ...201222512819
early immune dynamics following infection with salmonella enterica serovars enteritidis, infantis, pullorum and gallinarum: cytokine and chemokine gene expression profile and cellular changes of chicken cecal tonsils.salmonella enterica subspecies enterica infection remains a serious problem in a wide range of animals and in man. poultry-derived food is the main source of human infection with the non-host-adapted serovars while fowl typhoid and pullorum disease are important diseases of poultry. we have assessed cecal colonization and immune responses of newly hatched and older chickens to salmonella serotypes enteritidis, infantis, gallinarum and pullorum. s. enteritidis and s. infantis colonized the ceca m ...201222512820
detection and characterization of pct-like plasmid vectors for blactx-m-14 in escherichia coli isolates from humans, turkeys and cattle in england and wales.to detect and characterize escherichia coli strains and pct-like plasmids implicated in the dissemination of the ctx-m-14 gene in animals and humans, in england and wales.201222514265
[highly ciprofloxacin resistant salmonella enterica serovar kentucky isolates in turkey meat and a human patient].in recent years in france, england, wales, denmark and the usa about 500 human infections occurred, which were caused by multidrug-resistant salmonella enterica serovar (s.) kentucky isolates displaying high-level resistance to fluoroquinolones (ciprofloxacin, mic > or = 4 mg/l). the responsible clone was referred to as st198-x1.to determine whether this clone is also present in german s. kentucky isolates, the national reference laboratory for salmonella (nrl-salm) at the bfr analyzed the trend ...201322515025
the extradomain a of fibronectin enhances the efficacy of lipopolysaccharide defective salmonella bacterins as vaccines in mice.the extradomain a from fibronectin (eda) has an immunomodulatory role as fusion protein with viral and tumor antigens, but its effect when administered with bacteria has not been assessed. here, we investigated the adjuvant effect of eda in mice immunizations against salmonella enterica subspecies enterica serovar enteritidis (salmonella enteritidis). since lipopolysaccharide (lps) is a major virulence factor and the lps o-polysaccharide (o-ps) is the immunodominant antigen in serological diagno ...201222515195
distribution of salmonella serovars and antimicrobial susceptibility of salmonella enteritidis from poultry in zimbabwe.a study was carried out to determine the distribution and antimicrobial susceptibility profiles of salmonella serovars from chickens from large-scale commercial (lsc), small-scale commercial (ssc), and rural free-range (rfr) farms of zimbabwe. pooled cloacal swabs were collected for culture and isolation of salmonella spp. a chi-square test was used to assess distribution differences of salmonellas among the farming sectors. approximately 10% (283/2833) of the swabs were positive for salmonella ...201222515540
antioxidant and antibacterial activities of the leaf essential oil and its constituents furanodienone and curzerenone from lindera pulcherrima (nees.) benth. ex hook. f.lindera pulcherrima (nees.) benth. ex hook. f. (family: lauraceae), an evergreen shrub, is an important medicinal plant distributed in temperate himalayan regions. the leaves and bark are used as spice in cold, fever, and cough.201222518079
requirement of siderophore biosynthesis for plant colonization by salmonella enterica.contaminated fresh produce has become the number one vector of nontyphoidal salmonellosis to humans. however, salmonella enterica genes essential for the life cycle of the organism outside the mammalian host are for the most part unknown. screening deletion mutants led to the discovery that an aroa mutant had a significant root colonization defect due to a failure to replicate. aroa is part of the chorismic acid biosynthesis pathway, a central metabolic node involved in aromatic amino acid and s ...201222522683
storing drinking-water in copper pots kills contaminating diarrhoeagenic bacteria.microbially-unsafe water is still a major concern in most developing countries. although many water-purification methods exist, these are expensive and beyond the reach of many people, especially in rural areas. ayurveda recommends the use of copper for storing drinking-water. therefore, the objective of this study was to evaluate the effect of copper pot on microbially-contaminated drinking-water. the antibacterial effect of copper pot against important diarrhoeagenic bacteria, including vibrio ...201222524115
variability of rna quality extracted from biofilms of foodborne pathogens using different kits impacts mrna quantification by qpcr.the biofilm formation by foodborne pathogens is known to increase the problem related with surface disinfection procedure in the food processing environment and consequent transmission of these pathogens into the population. messenger rna has been increasingly used to understand the action and the consequences of disinfectants in the virulence on such biofilms. rna quality is an important requirement for any rna-based analysis since the quality can impair the mrna quantification. therefore, we e ...201222526569
development of an antigen-capture monoclonal antibody-based enzyme-linked immunosorbent assay and comparison with culture for detection of salmonella enterica serovar enteritidis in poultry hatchery environmental samples.an antigen-capture enzyme-linked immunosorbent assay (elisa) was developed for use as a presumptive screening test for detection of salmonella enterica serovar enteritidis and other group d salmonella in poultry hatchery environments. a mixture of 2 monoclonal antibodies that recognize different forms of the lipopolysaccharide o-antigen was used for specific detection of group d salmonella. the performance of the elisa was evaluated in comparison to standard salmonella culture procedures. cultur ...201222529117
functional dissection of ssef, a membrane-integral effector protein of intracellular salmonella enterica.during intracellular life, the bacterial pathogen salmonella enterica translocates a complex cocktail of effector proteins by means of the spi2-encoded type iii secretions system. the effectors jointly modify the endosomal system and vesicular transport in host cells. ssef and sseg are two effectors encoded by genes within salmonella pathogenicity island 2 and both effector associate with endosomal membranes and microtubules and are involved in the formation of salmonella-induced filaments. our ...201222529968
high pressure inactivation of salmonella on jalapeño and serrano peppers destined for direct consumption or as ingredients in mexican salsa and guacamole.in summer of 2008, the united states witnessed one of the largest multi-state salmonellosis outbreak linked to the consumption of jalapeño and serrano peppers tainted with salmonella enterica serovar saintpaul. the first objective of this study was to assess the application of high hydrostatic pressure (hhp) to decontaminate jalapeño and serrano peppers from this pathogen. jalapeño and serrano peppers were inoculated with a five-strain cocktail of salmonella to a final level of ca. ~6 log cfu/g ...201222534353
conversion of viable but nonculturable enteric bacteria to culturable by co-culture with eukaryotic cells.viable but nonculturable (vbnc) vibrio cholerae non-o1/non-o139, v. parahaemolyticus, enterohemorrhagic escherichia coli, enterotoxigenic e. coli, enteropathogenic e. coli, shigella flexneri, and salmonella enterica were converted to the culturable state by co-culture with selected eukaryotic cells, e.g., ht-29, caco-2, t84, hela, intestine 407, and cho cells.201222537150
the transcriptional landscape and small rnas of salmonella enterica serovar typhimurium.more than 50 y of research have provided great insight into the physiology, metabolism, and molecular biology of salmonella enterica serovar typhimurium (s. typhimurium), but important gaps in our knowledge remain. it is clear that a precise choreography of gene expression is required for salmonella infection, but basic genetic information such as the global locations of transcription start sites (tsss) has been lacking. we combined three rna-sequencing techniques and two sequencing platforms to ...201222538806
in vitro inhibition of expression of virulence genes responsible for colonization and systemic spread of enteric pathogens using bifidobacterium bifidum secreted molecules.enteric pathogens such as salmonella enterica serovar typhimurium and enterohaemorrhagic escherichia coli require an initial indispensable step of attachment or invasion of enterocytes before they can produce systemic disease and translocate to their target organs. prevention of either of these steps will result in an avirulent state and limit their pathogenicity. in vitro tests demonstrated that molecules secreted by bifidobacterium bifidum interfere with both attachment and invasion. the main ...201222541391
evidence for lack of acquisition of tolerance in salmonella enterica serovar typhimurium atcc 14028 after exposure to subinhibitory amounts of origanum vulgare l. essential oil and carvacrol.overnight exposure of salmonella enterica serovar typhimurium to sublethal amounts of origanum vulgare essential oil (ov) and carvacrol (car) did not result in direct and cross-bacterial protection. cells subcultured with increasing amounts of ov or car survived up to the mic of either compound, revealing few significant changes in bacterial susceptibility.201222544235
no beneficial effects evident for enterococcus faecium ncimb 10415 in weaned pigs infected with salmonella enterica serovar typhimurium dt104.salmonella enterica serovar typhimurium dt 104 is the major pathogen for salmonellosis outbreaks in europe. we tested if the probiotic bacterium enterococcus faecium ncimb 10415 can prevent or alleviate salmonellosis. therefore, piglets of the german landrace breed that were treated with e. faecium (n = 16) as a feed additive and untreated controls (n = 16) were challenged with s. typhimurium 10 days after weaning. the presence of salmonellae in feces and selected organs, as well as the immune r ...201222544257
heterogeneity of persistence of salmonella enterica serotype senftenberg strains could explain the emergence of this serotype in poultry flocks.salmonella enterica serotype senftenberg (s. senftenberg) has recently become more frequent in poultry flocks. moreover some strains have been implicated in severe clinical cases. to explain the causes of this emergence in farm animals, 134 s. senftenberg isolates from hatcheries, poultry farms and human clinical cases were analyzed. persistent and non-persistent strains were identified in chicks. the non-persistent strains disappeared from ceca a few weeks post inoculation. this lack of persist ...201222545136
comparison of the prevalence of salmonella infection in layer hens from commercial layer farms with high and low rodent densities.a comparison on the prevalence of salmonella infection in layer hens from commercial layer farms with high and low rodent densities was investigated. out of 280 laying hens sampled from three commercial layer farms with high rodent densities, salmonella enterica subsp. enterica serovar enteritidis (salmonella enteritidis) was isolated from 20 (7.14%) hens and salmonella enterica subsp. enterica serovar infantis (salmonella infantis) from three (1.07%) hens. in contrast, layer hens sampled from f ...201222545525
identification of genes responsible for biofilm formation or virulence in salmonella enterica serovar pullorum.salmonella living in biofilms are more resistant to chemical and physical stresses. however, information regarding the regulation of genes involved in biofilm formation for salmonella enterica serovar pullorum remains limited. in this study, eight mutants with knockout of genes ompr, rpos, rfag, rfbh, rhle, mete, spia, or steb from the salmonella enterica serovar pullorum strain s6702 were constructed. phenotypic analysis revealed that all mutants were similar to the wild-type strain in growth r ...201222545539
hypochlorous acid and hydrogen peroxide-induced negative regulation of salmonella enterica serovar typhimurium ompw by the response regulator arca.hydrogen peroxide (h2o2) and hypochlorous acid (hocl) are reactive oxygen species that are part of the oxidative burst encountered by salmonella enterica serovar typhimurium (s. typhimurium) upon internalization by phagocytic cells. in order to survive, bacteria must sense these signals and modulate gene expression. growing evidence indicates that the arcab two component system plays a role in the resistance to reactive oxygen species. we investigated the influx of h2o2 and hocl through ompw and ...201222545862
glutathione deficiency in type 2 diabetes impairs cytokine responses and control of intracellular bacteria.individuals with type 2 diabetes are at increased risk of acquiring melioidosis, a disease caused by burkholderia pseudomallei infection. although up to half of melioidosis patients have underlying diabetes, the mechanisms involved in this increased susceptibility are unknown. we found that b. pseudomallei-infected pbmcs from diabetic patients were impaired in il-12p70 production, which resulted in decreased ifn-γ induction and poor bacterial killing. the defect was specific to the il-12-ifn-γ a ...201222546856
srnas and the virulence of salmonella enterica serovar typhimurium.the combination of genomics and high-throughput cdna sequencing technologies has facilitated the identification of many small rnas (srnas) that play a central role in the post-transcriptional gene regulation of salmonella enterica serovar typhimurium. to date, most of the functionally characterized srnas have been involved in the regulation of processes which are not directly linked to virulence. just five srnas have been found to affect the ability of salmonella to replicate within mammalian ce ...201222546935
characterization of salmonella enterica and detection of the virulence genes specific to diarrheagenic escherichia coli from poultry carcasses in ouagadougou, burkina faso.one hundred chicken carcasses purchased from three markets selling poultry in ouagadougou, burkina faso, between june 2010 and october 2010 were examined for their microbiological quality. the presence of salmonella was investigated using standard bacteriological procedures, and the isolates obtained were serotyped and tested for antimicrobial susceptibility. the presence of virulence-associated genes of the five main pathogroups of diarrheagenic escherichia coli-shiga toxin-producing e. coli (s ...201222551070
sanitation of selected ready-to-eat intermediate-moisture foods of animal origin by e-beam irradiation.to optimize the sanitation treatment of ready-to-eat (rte) intermediate-moisture foods (imf), the behavior of listeria monocytogenes scott a (cip 103575), l. innocua (ntc 11288), salmonella enterica serovar typhimurium (cect 443), and escherichia coli o157:h7 (cect 4972) following treatment with electron-beam irradiation has been studied. as food matrixes, three rte vacuum-packed products (iberian dry-cured ham, dry beef [cecina], and smoked tuna) were used. although an irradiation treatment is ...201222551071
co-administration of live attenuated salmonella enterica serovar typhimurium expressing swine interleukin-18 and interferon-α provides enhanced th1-biased protective immunity against inactivated vaccine of pseudorabies virus.the co-administration of two or more cytokines may generate additive or synergistic effects for controlling infectious diseases. however, the practical use of cytokine combinations for the modulation of immune responses against inactivated vaccine has not been demonstrated in livestock yet, primarily due to protein stability, production, and costs associated with mass administration. in light of the current situation, we evaluated the immunomodulatory functions of the combined administration of ...201222551253
dynamics of salmonella infection of macrophages at the single cell level.salmonella enterica causes a range of diseases. salmonellae are intracellular parasites of macrophages, and the control of bacteria within these cells is critical to surviving an infection. the dynamics of the bacteria invading, surviving, proliferating in and killing macrophages are central to disease pathogenesis. fundamentally important parameters, however, such as the cellular infection rate, have not previously been calculated. we used two independent approaches to calculate the macrophage ...201222552918
complete nucleotide sequence of pvqs1 containing a quinolone resistance determinant from salmonella enterica serovar virchow associated with foreign travel.nalidixic acid-resistant salmonella enterica serovars kentucky (n = 5) and virchow (n = 6) cultured from individuals were investigated for the presence of plasmid-mediated quinolone resistance (pmqr) determinants.201222553140
signature tagged mutagenesis in the functional genetic analysis of gastrointestinal pathogens.signature tagged mutagenesis is a genetic approach that was developed to identify novel bacterial virulence factors. it is a negative selection method in which unique identification tags allow analysis of pools of mutants in mixed populations. the approach is particularly well suited to functional genetic analysis of the gastrointestinal phase of infection in foodborne pathogens and has the capacity to guide the development of novel vaccines and therapeutics. in this review we outline the techni ...201222555467
targeted therapy via oral administration of attenuated salmonella expression plasmid-vectored stat3-shrna cures orthotopically transplanted mouse hcc.the development of rna interference-based cancer gene therapies has been delayed due to the lack of effective tumor-targeting delivery systems. attenuated salmonella enterica serovar typhimurium (s. typhimurium) has a natural tropism for solid tumors. we report here the use of attenuated s. typhimurium as a vector to deliver shrna directly into tumor cells. constitutively activated signal transducer and activator of transcription 3 (stat3) is a key transcription factor involved in both hepatocel ...201222555509
prevalence and characterization of motile salmonella in commercial layer poultry farms in bangladesh.salmonella is a globally widespread food-borne pathogen having major impact on public health. all motile serovars of salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. information on the prevalence of salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the south and south-east asian countries including bangladesh, where small-scale commercial farms are predominant, is limited. ...201222558269
functional and computational analysis of amino acid patterns predictive of type iii secretion system substrates in pseudomonas syringae.bacterial type iii secretion systems (t3sss) deliver proteins called effectors into eukaryotic cells. although n-terminal amino acid sequences are required for translocation, the mechanism of substrate recognition by the t3ss is unknown. almost all actively deployed t3ss substrates in the plant pathogen pseudomonas syringae pathovar tomato strain dc3000 possess characteristic patterns, including (i) greater than 10% serine within the first 50 amino acids, (ii) an aliphatic residue or proline at ...201222558318
virulence of 32 salmonella strains in mice.virulence and persistence in the balb/c mouse gut was tested for 32 strains of salmonella enterica for which genome sequencing is complete or underway, including 17 serovars within subspecies i (enterica), and two representatives of each of the other five subspecies. only serovar paratyphi c strain baa1715 and serovar typhimurium strain 14028 were fully virulent in mice. three divergent atypical enteritidis strains were not virulent in balb/c, but two efficiently persisted. most of the other str ...201222558320
polyamines are required for virulence in salmonella enterica serovar typhimurium.sensing and responding to environmental cues is a fundamental characteristic of bacterial physiology and virulence. here we identify polyamines as novel environmental signals essential for virulence of salmonella enterica serovar typhimurium, a major intracellular pathogen and a model organism for studying typhoid fever. central to its virulence are two major virulence loci salmonella pathogenicity island 1 and 2 (spi1 and spi2). spi1 promotes invasion of epithelial cells, whereas spi2 enables s ...201222558361
vulnerabilities in yersinia pestis caf operon are unveiled by a salmonella vector.during infection, yersinia pestis uses its f1 capsule to enhance survival and cause virulence to mammalian host. since f1 is produced in large quantities and secreted into the host tissues, it also serves as a major immune target. to hold this detrimental effect under proper control, y. pestis expresses the caf operon (encoding the f1 capsule) in a temperature-dependent manner. however, additional properties of the caf operon limit its expression. by overexpressing the caf operon in wild-type sa ...201222558420
effects of x-ray treatments on pathogenic bacteria, inherent microflora, color, and firmness on whole cantaloupe.inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole cantaloupes using x-ray at different doses (0.1, 0.5, 1.0, 1.5, and 2.0 kgy) was studied. the effect of x-ray on quality parameters (color and texture) of untreated and treated whole cantaloupes was instrumentally determined. the effect of x-ray on microflora counts (mesophilic counts, psychrotrophic counts and yeast and mold counts) of untreated and treated whole canta ...201222560020
salmonella enterica: a surprisingly well-adapted intracellular lifestyle.the infectious intracellular lifestyle of salmonella enterica relies on the adaptation to nutritional conditions within the salmonella-containing vacuole (scv) in host cells. we summarize latest results on metabolic requirements for salmonella during infection. this includes intracellular phenotypes of mutant strains based on metabolic modeling and experimental tests, isotopolog profiling using (13)c-compounds in intracellular salmonella, and complementation of metabolic defects for attenuated m ...201222563326
microbiological analysis of bovine lymph nodes for the detection of salmonella enterica.bovine peripheral lymph nodes (lns) have been identified as a potential source of salmonella when trim containing these nodes is incorporated into ground beef. studies examining the prevalence of salmonella in peripheral lns of cattle are few in number, and the microbiological methods used for these analyses have not been validated. given that salmonella contamination may be found on postintervention carcasses, it is important to understand the extent to which salmonella contamination from surro ...201222564933
effect of farm type on within-herd salmonella prevalence, serovar distribution, and antimicrobial resistance.salmonella represents a major challenge to the pig industry, as pork presents a risk for human salmonellosis. in this study, we have examined the effect of farm type on the prevalence of fattening pigs shedding salmonella on 12 farms at risk for harboring salmonella. on six open (grow-to-finish) and six closed (farrow-to-finish) farms, the prevalence of pigs shedding salmonella was determined on two occasions approximately 2 months apart. the serovar, phage type, and antimicrobial resistance of ...201222564934
frequency and antimicrobial resistance of salmonella serotypes on beef carcasses at small abattoirs in jalisco state, mexico.the prevalence and antimicrobial resistance of salmonella serotypes on beef carcasses from four small abattoirs in jalisco state, mexico, were investigated during a 10-month period. following u.s. department of agriculture food safety and inspection service protocols, salmonella was isolated from 78 (15.4%) beef carcasses (n = 505) after the final carcass water wash. isolation frequency differed by establishment (p < 0.05) and was higher (p < 0.05) during the wet season (may through september) f ...201222564935
salmonella enterica serovar typhi plasmid impairs dendritic cell responses to infection.salmonella enterica serovar typhi (s. typhi) evades from innate immunity by expression of a variety of pathogenic factors. the "pr(st98)" plasmid of s. typhi is involved in multidrug-resistant and virulence of s. typhi. however, its exact effect on host cell function remains elusive. dendritic cells (dcs) play an important role in shaping immune response against salmonella. for the purpose of investigation whether pr(st98) might target dcs involved in adaptive immune response, murine dcs were in ...201222569891
prevalence of human pathogens and indicators in stormwater runoff in brisbane, australia.elevated numbers of enteric pathogens in the receiving waters following a storm event can be a serious public health concern. the purpose of this study was to conduct a preliminary investigation into the presence of human pathogens of concern in urban stormwater runoff. the involvement of a human sewage as a potential source of contamination was also investigated by using microbial source tracking methods. water samples (20 l) were collected after storm events and during the dry weather from six ...201222572123
chronic proliferative rhinitis associated with salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) in sheep in spain.a chronic proliferative rhinitis in sheep associated with salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) is described. ten adult sheep from eight traditionally managed rasa aragonesa flocks located in aragon (spain) were studied. clinical signs began with bilateral thick mucus nasal discharge, wheezing and snoring and progressed to partial or complete obstruction of the nostrils. necropsy examination revealed swollen ventral nasal turbinates with a roughened mucosal surface par ...201222572396
salmonella enterica serotype enteritidis: increasing incidence of domestically acquired infections.salmonella enterica causes an estimated 1 million cases of domestically acquired foodborne illness in humans annually in the united states; enteritidis (se) is the most common serotype. public health authorities, regulatory agencies, food producers, and food processors need accurate information about rates and changes in se infection to implement and evaluate evidence-based control policies and practices.201222572674
selection of salmonella enterica serovar typhi genes involved during interaction with human macrophages by screening of a transposon mutant library.the human-adapted salmonella enterica serovar typhi (s. typhi) causes a systemic infection known as typhoid fever. this disease relies on the ability of the bacterium to survive within macrophages. in order to identify genes involved during interaction with macrophages, a pool of approximately 10(5) transposon mutants of s. typhi was subjected to three serial passages of 24 hours through human macrophages. mutants recovered from infected macrophages (output) were compared to the initial pool (in ...201222574205
c1 inhibitor suppresses the endotoxic activity of a wide range of lipopolysaccharides and interacts with live gram-negative bacteria.human c1 inhibitor (c1inh) prevents endotoxin shock via a direct interaction with gram-negative bacterial lipopolysaccharide (lps) and improves survival in animal models of sepsis. in this report, we further characterize the interaction of c1inh with lps and whole live bacteria. we investigate c1inh interactions with lps from five different strains of gram-negative enteric bacteria known to participate in the pathogenesis of human sepsis. treatment with c1inh improved survival in mice with endot ...201222576004
structures of a unique o-polysaccharide of edwardsiella tarda pcm 1153 containing an amide of galacturonic acid with 2-aminopropane-1,3-diol and an abequose-containing o-polysaccharide shared by e. tarda pcm 1145, pcm 1151 and pcm 1158.lipopolysaccharides of four strains of edwardsiella tarda were degraded by mild acid hydrolysis, and the released o-polysaccharides were isolated by gpc and studied by sugar and methylation analyses along with (1)h and (13)c nmr spectroscopy, including 2d (1)h, (1)h cosy, tocsy, roesy, (1)h, (13)c hmbc, hsqc and hsqc-tocsy experiments. the o-polysaccharide from e. tarda pcm 1153 was found to contain d-gala, d-glcnac, d-gal and 2-amino-1,3-propanediol (gron). in the tetrasaccharide repeating unit ...201222578768
comparative proteomic analysis of salmonella tolerance to the biocide active agent triclosan.concern has been expressed about the overuse of biocides in farm animal production and food industries. biocide application can create selective pressures that lead to increased tolerance to one or more of these compounds and are concomitant with the emergence of cross-resistance to antibiotics. a triclosan sensitive salmonella enterica serovar typhimurium and the isogenic triclosan tolerant mutant were studied at the proteomic level in order to elucidate cellular mechanisms that facilitate bioc ...201222579747
instability of escherichia coli r-factors in salmonella enterica serovar typhi involves formation of recombinant composite plasmid structures.in spite of a well-documented ability of samonella enterica typhi strains to receive r factors from escherichia coli and other enterobacteria, epidemiological data show that typhi is a rather poor host of antibiotic-resistance genes and in fact, of plasmids, suggesting that most of the plasmids naturally acquired by typhi strains become unstable and eventually segregate. we have previously reported evidence that each of three plasmids conjugatively transferred to s. enterica typhi experienced de ...201222579995
salmonella biofilm development depends on the phosphorylation status of rcsb.the rcs phosphorelay pathway is a complex signaling pathway involved in the regulation of many cell surface structures in enteric bacteria. in response to environmental stimuli, the sensor histidine kinase (rcsc) autophosphorylates and then transfers the phosphate through intermediary steps to the response regulator (rcsb), which, once phosphorylated, regulates gene expression. here, we show that salmonella biofilm development depends on the phosphorylation status of rcsb. thus, unphosphorylated ...201222582278
a modified weibull model for growth and survival of listeria innocua and salmonella typhimurium in chicken breasts during refrigerated and frozen storage.the potential of food-borne pathogens to survive and grow during refrigerated and frozen storage has raised serious concerns over the safety of stored poultry products. in this study, the effect of refrigeration and freezing temperatures (-20, -12, 0, 4, and 8°c) on growth and survival of listeria innocua and salmonella enterica serovar typhimurium in raw chicken breasts for storage times of 3, 7, 10, 14, and 21 d were investigated. a modified weibull model was also developed to analyze the micr ...201222582310
application of the random forest method to analyse epidemiological and phenotypic characteristics of salmonella 4,[5],12:i:- and salmonella typhimurium strains.salmonella enterica 4,[5],12:i:- is a monophasic variant of s. typhimurium. in the last decade, its prevalence rose sharply. although s. 4,[5],12:i:- and s. typhimurium are known to pose a considerable public health risk, there is no detailed information on the circulation of these serovars in italy, particularly as far as veterinary isolates are concerned. for this reason, a data set of 877 strains isolated in the north-east of italy from foodstuffs, animals and environment was analysed during ...201222583909
dietary rice bran promotes resistance to salmonella enterica serovar typhimurium colonization in mice.dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as salmonella. the ability of rice bran to reduce the susceptibility of mice to a salmonella infection has not been previously investigated. therefore, we hypothesized that the incorporation of rice bra ...201222583915
caenorhabditis elegans immune conditioning with the probiotic bacterium lactobacillus acidophilus strain ncfm enhances gram-positive immune responses.although the immune response of caenorhabditis elegans to microbial infections is well established, very little is known about the effects of health-promoting probiotic bacteria on evolutionarily conserved c. elegans host responses. we found that the probiotic gram-positive bacterium lactobacillus acidophilus ncfm is not harmful to c. elegans and that l. acidophilus ncfm is unable to colonize the c. elegans intestine. conditioning with l. acidophilus ncfm significantly decreased the burden of a ...201222585961
invasive non-typhoidal salmonella disease: an emerging and neglected tropical disease in africa.invasive strains of non-typhoidal salmonellae have emerged as a prominent cause of bloodstream infection in african adults and children, with an associated case fatality of 20-25%. the clinical presentation of invasive non-typhoidal salmonella disease in africa is diverse: fever, hepatosplenomegaly, and respiratory symptoms are common, and features of enterocolitis are often absent. the most important risk factors are hiv infection in adults, and malaria, hiv, and malnutrition in children. a dis ...201222587967
shedding light on salmonella carriers.host-to-host transmission in most salmonella serovars occurs primarily via the fecal-oral route. salmonella enterica serovar typhi is a human host-adapted pathogen and some s. typhi patients become asymptomatic carriers. these individuals excrete large numbers of the bacteria in their feces and transmit the pathogen by contaminating water or food sources. the carrier state has also been described in livestock animals and is responsible for food-borne epidemics. identification and treatment of ca ...201222591832
a gold nanoparticles based immuno-bioprobe for detection of vi capsular polysaccharide of salmonella enterica serovar typhi.a rapid and sensitive gold-nanobioprobe based immunoassay format has been presented for the detection of capsular vi polysaccharide of salmonella enterica serovar typhi (surface antigen) using anti-vi antibodies. the vi antigen was extracted from serovar typhi cells, under the optimised growth conditions for its over-expression. anti-vi antibodies were produced and conjugated with gold nanoparticles (gnps) of definite size (~30 nm), which served as the nano-bioprobe in the detection system. a sa ...201222592180
stm2209-stm2208 (opvab): a phase variation locus of salmonella enterica involved in control of o-antigen chain length.stm2209 and stm2208 are contiguous loci annotated as putative protein-coding genes in the chromosome of salmonella enterica. lack of homologs in related enterobacteria and low g+c content suggest that s. enterica may have acquired stm2209-stm2208 by horizontal transfer. stm2209 and stm2208 are co-transcribed from a promoter upstream stm2209, and their products are inner (cytoplasmic) membrane proteins. analysis with the bacterial adenylate cyclase two-hybrid system suggests that stm2209 and stm2 ...201222606300
first outbreak of food poisoning caused by salmonella enterica subspecies enterica serovar berta in italy.to provide an epidemiologic interpretation of a suspected outbreak of food poisoning caused by salmonella enterica subspecies enterica serovar berta strains isolated from humans and from the leftovers of the implicated foods (cream, dairy-based desserts and eggs).201222607387
salmonella cross-contamination in swine abattoirs in portugal: carcasses, meat and meat handlers.in this study the occurrence of salmonella in swine, pork meat and meat handlers along with their clonal relatedness is evaluated at abattoir level. samples from the lymph nodes, carcass surface and meat of 100 pigs and 45 meat handlers were collected in eight abattoirs (july 2007-august 2008). salmonella isolates were serotyped and genotyped by pulsed-field gel electrophoresis (pfge). from the pigs tested, 42 produced at least one positive sample. a relatively high frequency of salmonella occur ...201222607810
influence of serotype on the growth kinetics and the ability to form biofilms of salmonella isolates from poultry.the influence of the serotype on the growth behaviour and the ability to form biofilms of salmonella enterica strains was investigated. the relationships between biofilm formation and growth kinetic parameters were also determined. a total of 69 strains (61 isolates from poultry and 8 reference strains from culture collections) belonging to 10 serotypes (s. enterica serotype typhimurium, s. newport, s. paratyphi b, s. poona, s. derby, s. infantis, s. enteritidis, s. virchow, s. agona and s. typh ...201222608221
the evaluation of a pcr-based method for identification of salmonella enterica serotypes from environmental samples and various food matrices.the most commonly used method for serotyping salmonella spp. is based on the kaufmann-white scheme, and is composed of serological reactions using antibodies to lps agglutinins. the multiplex pcr used in this investigation was established by kim et al. to serotype the 30 most common clinical salmonella serotypes, as determined by cdc. the pcr assay consists of two five-plex reactions and a single two-plex pcr reaction, based on six genetic loci from salmonella enterica serotype typhimurium and f ...201222608224
identification of a third osmoprotectant transport system, the osmu system, in salmonella enterica.the growth of salmonella enterica serovar typhimurium mutants lacking the prop and prou osmoprotectant transport systems is stimulated by glycine betaine in high-osmolarity media, suggesting that this organism has an additional osmoprotectant transport system. bioinformatic analysis revealed that the genome of this organism contains a hitherto-unidentified operon, designated osmu, consisting of four genes whose products show high similarity to abc-type transport systems for osmoprotectants in ot ...201222609924
the acyl homoserine lactone receptor, sdia, of escherichia coli and salmonella enterica serovar typhimurium does not respond to indole.in this study, we tested the hypothesis that the sdia proteins of escherichia coli and salmonella enterica serovar typhimurium respond to indole. while indole was found to have effects on gene expression and biofilm formation, these effects were not sdia dependent. however, high concentrations of indole did inhibit n-acyl-l-homoserine lactone (ahl) sensing by sdia. we conclude that sdia does not respond to indole but indole can inhibit sdia activity in e. coli and salmonella.201222610437
a retrospective study of community-acquired salmonella infections in patients attending public hospitals in lagos, nigeria.a retrospective cohort study on salmonella-associated diseases (sads) was conducted in 14 public hospitals across lagos state, nigeria, between 1999 and 2008.201222610704
plasmid-mediated quinolone resistance determinant qnrb19 in non-typhoidal salmonella enterica strains isolated in venezuela. 201222610715
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