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first report of liver abscess caused by salmonella enterica serovar dublin.this is the first reported case of liver abscess attributable to salmonella serovar dublin infection and also the fourth case of salmonella liver abscess complicated with hepatocellular carcinoma reported since 1990. drainage combined with intravenous antibiotics resulted in improvement, but recovery regressed again. subsequent hepatic left lobectomy led to full recovery.201323784127
salmonella enterica serotype choleraesuis infection of the knee and femur in a nonbacteremic diabetic patient.osteoarticular infections caused by salmonella are rare. the rates of osteomyelitis and septic arthritis due to salmonella are estimated to be less than 1% and 0.1%-0.2%, respectively (kato et al., 2012). salmonella enterica serotype choleraesuis is a nontyphoidal salmonella, highly pathogenic in humans, usually causing septicemic disease with little or no intestinal involvement. serotype choleraesuis accounts for a small percentage of published studies of salmonella infections in the united sta ...201323781356
a colanic acid operon deletion mutation enhances induction of early antibody responses by live attenuated salmonella vaccine strains.colanic acid (ca) is a common exopolysaccharide produced by many genera in the enterobacteriaceae. it is critical for biofilm formation on hep-2 cells and on chicken intestinal tissue by salmonella. in this study, we generated different ca synthesis gene mutants and evaluated the immune responses induced by these mutants. one of these mutations, δ(wza-wcam)8, which deleted the whole operon for ca synthesis, was introduced into two salmonella vaccine strains attenuated by auxotrophic traits or by ...201323774599
risk factors associated with sporadic salmonellosis in adults: a case-control study.in order to identify and assess recent risk factors for sporadic human infections with salmonella enterica, we conducted a case-control study in lower saxony, germany. the data collection was based on standardized telephone interviews with 1017 cases and 346 controls aged >14 years. odds ratios were calculated in single-factor and multi-factor analyses for salmonella cases and two different control groups, i.e. population controls and controls with rotavirus infection. multi-factor analysis reve ...201322717173
salmonella prevalence among reptiles in a zoo education setting.clinically healthy reptiles may shed salmonella and therefore act as a potential zoonotic threat. most people in northern european countries are rarely exposed to reptiles, but many zoos have education departments where children have direct contact with this group of animals. the objectives of this study were to determine the prevalence and serotype distribution of salmonella among reptiles in the education department (n = 55) at copenhagen zoo and compare it to the zoo's main reptile collection ...201322835051
extremely drug-resistant salmonella enterica serovar senftenberg infections in patients in zambia.two cases of extremely drug-resistant salmonella enterica serovar senftenberg isolated from patients in zambia were investigated by utilizing mic determinations and whole-genome sequencing. the isolates were resistant to, and harbored genes toward, nine drug classes, including fluoroquinolones and extended-spectrum cephalosporins, contained two plasmid replicons, and differed by 93 single-nucleotide polymorphisms.201323077128
impacts of salmonella enteritidis infection on liver transcriptome in broilers.salmonella enterica serovar enteritidis is an enteric bacterium that can contaminate chicken eggs and meat, resulting in production losses and consumer illness. to provide insight into the systemic metabolic effects of s. enteritidis infection, liver samples were harvested 10-days postinfection from broiler hens. hepatic global gene expression levels were assessed using a chicken 44k agilent microarray. forty-four genes were differentially expressed at a significance level of q value < 0.05. one ...201323097340
influence of salmonella enterica serovar enteritidis infection on the development of the cecum microbiota in newly hatched chicks.terminal restriction fragment length polymorphism and quantitative pcr showed that the cecal microbiota of chicks up to the age of 21 days was dominated by representatives of the orders enterobacteriales, clostridiales, and lactobacillales. salmonella enterica serovar enteritidis infection caused the greatest changes in the gut microbiota when 1-day-old chicks were infected, compared with the infection of 4- and 16-day-old chicks.201323144133
immunogenicity of salmonella enterica serovar enteritidis virulence protein, invh, and cross-reactivity of its antisera with salmonella strains.acellular vaccines containing bacterial immunodominant components such as surface proteins may be potent alternatives to live attenuated vaccines in order to reduce salmonellosis risk to human health. invh gene, an important part of needle complex in type three secretion system (ttss) plays important role in efficient bacterial adherence and entry into epithelial cells. in this work we hypothesize that use of a 15 kda recombinant invh as salmonella enterica serovar enteritidis surface protein co ...201323141708
on the evolutionary history, population genetics and diversity among isolates of salmonella enteritidis pfge pattern jegx01.0004.facile laboratory tools are needed to augment identification in contamination events to trace the contamination back to the source (traceback) of salmonella enterica subsp. enterica serovar enteritidis (s. enteritidis). understanding the evolution and diversity within and among outbreak strains is the first step towards this goal. to this end, we collected 106 new s. enteriditis isolates within s. enteriditis pulsed-field gel electrophoresis (pfge) pattern jegx01.0004 and close relatives, and de ...201323383127
pathogenicity of dodecyltrimethylammonium chloride-resistant salmonella enterica.salmonella infection causes a self-limiting gastroenteritis in humans but can also result in a life-threatening invasive disease, especially in old, young, and/or immunocompromised patients. the prevalence of antimicrobial and multidrug-resistant salmonella has increased worldwide since the 1980s. however, the impact of antimicrobial resistance on the pathogenicity of salmonella strains is not well described. in our study, a microarray was used to screen for differences in gene expression betwee ...201323377943
differential protein expression patterns between planktonic and biofilm cells of salmonella enterica serovar enteritidis pt4 on stainless steel surface.in the present study, the proteome of a strain of s. enterica serovar enteritidis pt4, grown either as biofilm on stainless steel surface or as free-floating (planktonic) in brain heart (bh) broth, was investigated in order to detect the strong differences in whole-cell protein expression patterns between the two growth styles. the proteins extracted from both types of cells were subjected to 2-d page, followed by in-gel tryptic digestion, extraction, subsequent maldi-tof mass spectrometry (ms) ...201323376784
thermal inactivation of salmonella enteritidis pt 30 in almond kernels as influenced by water activity.salmonellosis outbreaks related to consumption of raw almonds have encouraged the scientific community to study the inactivation kinetics of pathogens in this dry commodity. however, the low moisture content of the product presents a challenge for thermal control, because the time required to achieve the desired thermal inactivation of microorganisms increases sharply with reduced moisture content and water activity. in this study, we explored and modeled the heat inactivation of salmonella ente ...201323317853
detection of salmonella enterica serovar enteritidis using real time pcr, immunocapture assay, pna fish and standard culture methods in different types of food samples.several methods for the rapid and specific detection of salmonella in food samples have been described. here, we compare 4 of those methods in terms of assay time, procedure complexity, detection limit, sensitivity, specificity and accuracy. milk, eggs and mayonnaise samples were artificially contaminated with salmonella enterica serovar enteritidis cell concentrations ranging from 1×10(-2) to 1×10(2) cfu per 25 g or ml of food. samples were then pre-enriched and analyzed by either: i) real-time ...201323246608
role of stda in adhesion of salmonella enterica serovar enteritidis phage type 8 to host intestinal epithelial cells.salmonella is often implicated in foodborne outbreaks, and is a major public health concern in the united states and throughout the world. salmonella enterica serovar enteritidis (se) infection in humans is often associated with the consumption of contaminated poultry products. adhesion to epithelial cells in the intestinal mucosa is a major pathogenic mechanism of salmonella in poultry. transposon mutagenesis identified stda as a potential adhesion mutant of se. therefore, we hypothesize stda p ...201324367906
complete genome of salmonella enterica serovar enteritidis myophage marshall.salmonella enterica serovar enteritidis is a food-borne pathogen that causes salmonellosis in the united states. bacteriophages are emerging as viable biocontrol agents against this pathogen. here, we present the complete annotated genome sequence of salmonella enteritidis t4-like myophage marshall, which has potential as a phage therapy agent.201324309732
salmonella in liquid eggs and other foods in fukuoka prefecture, japan.the study aimed to evaluate the prevalence of salmonella in retail and wholesale foods in fukuoka prefecture, japan. a total of 2,021 samples collected between 1999 and 2010 were tested using a culture method. samples consisted of liquid eggs (n = 30), meat (beef and pork) (n = 781), offal (n = 69), processed meats (n = 2), seafood (n = 232), processed seafood (dried fish) (n = 76), vegetables (n = 481), processed vegetables (n = 87), fruits (n = 167), and herbs (n = 96) from 574 outlets and who ...201324288539
reduction of salmonella enteritidis number after infections by immunization of liposome-associated recombinant sefa.in order to generate salmonella enterica serovar enteritidis (salmonella enteritidis) fimbriae, sef14, the sefa gene, which encodes the main subunit of the sef14 fimbrial protein, was amplified from salmonella enteritidis by polymerase chain reaction (pcr) and subcloned into a prokaryotic expression vector pet-28a(+) to yield pet-28a(+)-sefa. the recombinant sefa (rsefa) protein was highly expressed and purified by nickel-affinity chromatography. liposome-associated rsefa was prepared for oral i ...201324283128
a comparison of subtyping methods for differentiating salmonella enterica serovar enteritidis isolates obtained from food and human sources.to evaluate the abilities of these subtyping methods, we distinguished salmonella enteritidis (s. enteritidis) isolated from food products and human clinical samples between 2009 and 2010 in seoul using five subtyping methods.201324159526
molecular characterization showed limited genetic diversity among salmonella enteritidis isolated from humans and animals in malaysia.salmonella enterica serovar enteritidis (s. enteritidis) is the most common causative agent of non-typhoidal salmonellosis in malaysia. we aimed to characterize s. enteritidis isolated from humans and animals by analyzing their antimicrobial resistance profiles and genotypes. a total of 111 strains were characterized using multiple-locus variable-number tandem repeat analysis, pulsed-field gel electrophoresis, and antimicrobial susceptibility testing. both typing methods revealed that geneticall ...201324139970
evaluation of virulence and antimicrobial resistance in salmonella enterica serovar enteritidis isolates from humans and chicken- and egg-associated sources.salmonella enterica serovar enteritidis is a leading cause of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated poultry and egg products. salmonella enteritidis has enhanced ability to colonize and persist in extraintestinal sites within chickens. in this study, 54 salmonella enteritidis isolates from human patients (n=28), retail chicken (n=9), broiler farms (n=9), and egg production facilities (n=8) were characterized by antimicrobial susce ...201324102082
[salmonella is a rare cause of meningitis in infants].in developed countries, invasive disease caused by non typhoidal salmonella spp. is rare. here we present a danish case of salmonella enterica serovar enteritidis (s. enteritidis) meningitis in an infant who had no underlying diseases. the child had had no known expositions, and the source of the infection was never identified. the chance of finding uncommon microorganisms as cause of invasive infections such as meningitis and the choice of initial empiric antimicrobial treatments is discussed.201323937875
modulation of chicken intestinal immune gene expression by small cationic peptides as feed additives during the first week posthatch.we have been investigating modulation strategies tailored around the selective stimulation of the host's immune system as an alternative to direct targeting of microbial pathogens by antibiotics. one such approach is the use of a group of small cationic peptides (bt) produced by a gram-positive soil bacterium, brevibacillus texasporus. these peptides have immune modulatory properties that enhance both leukocyte functional efficiency and leukocyte proinflammatory cytokine and chemokine mrna trans ...201323863505
influence of salmonella enterica serovar enteritidis infection on the composition of chicken cecal microbiota.infection of newly hatched chicks with salmonella enterica serovar enteritidis (s. enteritidis) results in an inflammatory response in the intestinal tract which may influence the composition of gut microbiota. in this study we were therefore interested whether s. enteritidis induced inflammation results in changes in the cecal microbiota. to reach this aim, we compared the cecal microbiota of non-infected chickens and those infected by s. enteritidis by pyrosequencing the v3/v4 variable regions ...201323856245
the rna chaperone hfq regulates expression of fimbrial-related genes and virulence of salmonella enterica serovar enteritidis.salmonella enteritidis is an intracellular pathogen that causes enteritis and systemic disease in humans and other animals. the rna chaperone protein hfq mediates the binding of small noncoding rnas to target mrna and assists in post-transcriptional gene regulation in bacteria. in this study, we constructed an hfq deletion mutant in s. enteritidis se50336 and analyzed the expression of major fimbrial subunits sefa, bcfa, fima, safa, stba, stha, csga, csgd, and pega using quantitative real-time p ...201323808344
vaccination of chickens with spi1-lon and spi1-lon-flic mutant of salmonella enterica serovar enteritidis.the prevalence of salmonella enterica serovar enteritidis is gradually decreasing in poultry flocks in the eu, which may result in the demand for a vaccine that allows for the differentiation of vaccinated flocks from those infected by wild-type s. enteritidis. in this study, we therefore constructed a (salmonella pathogenicity island 1) spi1-lon mutant with or without flic encoding for s. enteritidis flagellin. the combination of spi1-lon mutations resulted in attenuated but immunogenic mutant ...201323785484
occurrence of plasmid-mediated quinolone resistance determinants and rmtb gene in salmonella enterica serovar enteritidis and typhimurium isolated from food-animal products in tunisia.four hundred and thirty salmonella isolates, recovered from various food-animal products, were tested for nalidixic acid resistance, plasmid-mediated quinolone resistance, and genetic relationship. one hundred fifteen isolates (113 salmonella serovar enteritidis and two salmonella serovar typhimurium isolates) of 430 (26.7%) salmonella isolates exhibited nalidixic acid resistance. polymerase chain reaction screening for qnra, qnrb, qnrs, qepa (encoding fluoroquinolones resistance) and rmtb (enco ...201323767853
high pressure homogenization vs heat treatment: safety and functional properties of liquid whole egg.this research investigated the potential of multi-pass homogenization treatment for the inactivation of salmonella enterica serovar enteritidis inoculated at different levels in liquid whole egg (lwe) comparing the efficacy of this treatment with a traditional thermal one performed at 65 °c. moreover, the effects of high pressure treatment (hph) on structural and functional properties such as viscosity, microstructure and foaming abilities of lwe were investigated. the data obtained suggested th ...201323764221
chromosomal excision of a new pathogenicity island modulates salmonella virulence in vivo.although the excision of unstable pathogenicity islands is a phenomenon that has been described for several virulent bacteria, whether this process directly affects the capacity of these microorganisms to cause disease in their hosts remains unknown. salmonella enterica serovar enteritidis (s. enteritidis) is an enterobacterium that harbors several unstable pathogenicity islands that can excise from the main bacterial chromosome. here we have evaluated whether excision of one of these pathogenic ...201323746206
chicken innate immune response to oral infection with salmonella enterica serovar enteritidis.the characterization of the immune response of chickens to salmonella infection is usually limited to the quantification of expression of genes coding for cytokines, chemokines or antimicrobial peptides. however, processes occurring in the cecum of infected chickens are likely to be much more diverse. in this study we have therefore characterized the transcriptome and proteome in the chicken cecum after infection with salmonella enteritidis. using a combination of 454 pyrosequencing, protein mas ...201323687968
surveillance of salmonella enteritidis in layer houses: a retrospective comparison of the food and drug administration's egg safety rule (2010-2011) and the california egg quality assurance program (2007-2011).between july 2007 and december 2011, 2660 environmental drag swab samples were collected in total from california layer flocks on behalf of the california egg quality assurance program (ceqap), the egg safety rule (21 cfr parts 16 and 118) of the food and drug administration (fda), or both. the samples were processed by the california animal health and food safety lab, and positive or negative results for salmonella enterica serovar enteritidis (se) were recorded. this study retrospectively comp ...201323678729
reducing salmonella horizontal transmission during egg incubation by phage therapy.salmonella is a serious problem for both animal production and public health worldwide. contaminated poultry is the main vehicle of salmonella and the most important serotype is salmonella enterica serovar enteritidis. in order to test the efficiency of bacteriophages to treat salmonella enterica serovar enteritidis infections in poultry, a cocktail of two phages, f1055s and f12013s, isolated from chicken litter was applied by aerosol spray on fertile eggs challenged with salmonella enteritidis. ...201323672473
incidence, distribution, seasonality, and demographic risk factors of salmonella enteritidis human infections in ontario, canada, 2007-2009.in canada, surveillance systems have highlighted the increasing trend of salmonella enterica serovar enteritidis (s. enteritidis) human infections. our study objectives were to evaluate the epidemiology of s. enteritidis infections in ontario using surveillance data from january 1, 2007 through december 31, 2009.201323663256
a mathematical model representing cellular immune development and response to salmonella of chicken intestinal tissue.the aim of this study was to create a dynamic mathematical model of the development of the cellular branch of the intestinal immune system of poultry during the first 42 days of life and of its response towards an oral infection with salmonella enterica serovar enteritidis. the system elements were grouped in five important classes consisting of intra- and extracellular s. enteritidis bacteria, macrophages, cd4+, and cd8+ cells. twelve model variables were described by ordinary differential equa ...201323603730
nitric oxide as a biomarker of intracellular salmonella viability and identification of the bacteriostatic activity of protein kinase a inhibitor h-89.salmonella enterica serovar enteritidis is one of the most prevalent salmonella serovars in poultry and is often associated with human salmonellosis. s. enteritidis is known to suppress nitric oxide (no) production in infected chicken macrophage hd11 cells, while dead s. enteritidis stimulates a high level of no production, suggesting a bacterial inhibitory effect on no production. based on these observations, the present study was conducted to evaluate whether no production in s. enteritidis-in ...201323554945
o-antigen repeat number in salmonella enterica serovar enteritidis is important for egg contamination, colonisation of the chicken reproductive tract and survival in egg albumen.salmonella enterica serovar enteritidis is a major cause of human gastrointestinal disease, infection being due in large part to consumption of contaminated eggs. the lipopolysaccharide (lps) of salmonella is known to play a role in colonisation of the host and survival in hostile conditions including egg albumen. we investigated the contribution of lps o-antigen length to colonisation of the reproductive tract of laying hens, contamination of eggs and survival in albumen. we show that expressio ...201323551176
denaturing gradient gel electrophoresis analysis of 16s ribosomal dna to monitor changes in mouse gut bacterial communities during salmonella enterica serovar enteritidis latent infection.changes in intestinal microbial flora during a 4-week period of salmonella enterica serovar enteritidis colonization in resistant mice (latent carrier animals) were evaluated using a culture independent method involving denaturing gradient gel electrophoresis. the contents of the ileocecal portion of the intestines produced 26 bands. fifty-seven percent of the bands were expressed in more than 80% of the samples. forty percent of the bands present in the negative control were common to all sampl ...201323546981
the effects of polymorphisms in 7 candidate genes on resistance to salmonella enteritidis in native chickens.salmonella enterica serovar enteritidis infection is a common concern in poultry production for its negative effects on growth as well as food safety for humans. identification of molecular markers that are linked to resistance to salmonella enteritidis may lead to appropriate solutions to control salmonella infection in chickens. this study investigated the association of candidate genes with resistance to salmonella enteritidis in young chickens. two native breeds of malaysian chickens, namely ...201323472012
factors affecting thermal resistance of salmonella enterica serovar enteritidis oda 99-30581-13 in shell egg contents and use of heat-ozone combinations for egg pasteurization.infection of laying hens with salmonella enterica serovar enteritidis leads to deposition of the pathogen into the albumen or yolk of forming eggs. heat treatment can inactivate internalized salmonella enteritidis in shell eggs, but factors such as the nature and location of contamination may influence the efficacy of thermal treatments. in the current research, natural contamination was mimicked by introducing small inocula of salmonella enteritidis into different locations of shell eggs and in ...201323433367
analysis of pulsed field gel electrophoresis profiles using multiple enzymes for predicting potential source reservoirs for strains of salmonella enteritidis and salmonella typhimurium isolated from humans.we reported previously on a highly discriminatory pulsed field gel electrophoresis-based (pfge) subtyping scheme for salmonella enterica serovar enteritidis (se) and salmonella typhimurium (st) that relies on combined cluster analysis of up to six restriction enzymes. this approach allowed for the high-resolution separation of numerous poultry-derived se and st isolates into several distinct clusters that sorted along several geographical and host-linked boundaries. in this study, 101 se and 151 ...201323429060
dam methylation participates in the regulation of pmra/pmrb and rcsc/rcsd/rcsb two component regulatory systems in salmonella enterica serovar enteritidis.the absence of dam in salmonella enterica serovar enteritidis causes a defect in lipopolysaccharide (lps) pattern associated to a reduced expression of wzz gene. wzz is the chain length regulator of the lps o-antigen. here we investigated whether dam regulates wzz gene expression through its two known regulators, pmra and rcsb. thus, the expression of rcsb and pmra was monitored by quantitative real-time rt-pcr and western blotting using fusions with 3×flag tag in wild type (wt) and dam strains ...201323418573
novel determinants of intestinal colonization of salmonella enterica serotype typhimurium identified in bovine enteric infection.cattle are naturally infected with salmonella enterica serotype typhimurium and exhibit pathological features of enteric salmonellosis that closely resemble those in humans. cattle are the most relevant model of gastrointestinal disease resulting from nontyphoidal salmonella infection in an animal with an intact microbiota. we utilized this model to screen a library of targeted single-gene deletion mutants to identify novel genes of salmonella typhimurium required for survival during enteric inf ...201324019407
evaluation of regulated delayed attenuation strategies for salmonella enterica serovar typhi vaccine vectors in neonatal and infant mice.we developed regulated delayed attenuation strategies for salmonella vaccine vectors. in this study, we evaluated the combination of these strategies in recombinant attenuated salmonella enterica serovar typhi and salmonella enterica serovar typhimurium vaccine vectors with similar genetic backgrounds in vitro and in vivo. our goal is to develop a vaccine to prevent streptococcus pneumoniae infection in newborns; thus, all strains delivered a pneumococcal antigen pspa and the impact of maternal ...201323616408
a multiplex real-time pcr assay for the identification and differentiation of salmonella enterica serovar typhimurium and monophasic serovar 4,[5],12:i:-.salmonella enterica subsp. enterica serovar 4,[5],12:i:- is considered to be a monophasic variant of salmonella typhimurium and is increasingly associated with human infections. the use of pcr for the unequivocal identification of strains identified by conventional serotyping as 4,[5],12:i:- has been recommended by the european food safety authority (efsa), in particular the conventional multiplex pcr developed by tennant et al. (2010). an alternative protocol for the identification and differen ...201323827807
salmonella enterica serovar enteritidis phage type 4 outbreak associated with eggs in a large prison, london 2009: an investigation using cohort and case/non-case study methodology.in september 2009, an outbreak of salmonella enterica serovar enteritidis affected 327 of 1419 inmates at a london prison. we applied a cohort design using aggregated data from the kitchen about portions of food distributed, aligned this with individual food histories from 124 cases (18 confirmed, 106 probable) and deduced the exposures of those remaining well. results showed that prisoners eating egg cress rolls were 26 times more likely to be ill [risk ratio 25.7, 95% confidence interval (ci) ...201322800644
isolation and partial characterization of φsp-1, a salmonella specific lytic phage from intestinal content of broiler chicken.salmonella enterica subsp. enterica serovar enteritidis is a major causative agent of gastroenteritis with contaminated eggs and chicken meat being the major source of infection. phages are seriously being considered as a safe and cheaper alternative to antibiotics. the intestinal content of chicken was used as source for isolating phages. phage designated as φsp-1 was selected for the study. transmission electron microscopy (tem) of phage φsp-1 revealed that it belonged to family podoviridae. t ...201322733367
identification of salmonella enterica serovar typhimurium genes regulated during biofilm formation on cholesterol gallstone surfaces.salmonella spp. are able to form biofilms on abiotic and biotic surfaces. in vivo studies in our laboratory have shown that salmonella can form biofilms on the surfaces of cholesterol gallstones in the gallbladders of mice and human carriers. biofilm formation on gallstones has been demonstrated to be a mechanism of persistence. the purpose of this work was to identify and evaluate salmonella sp. cholesterol-dependent biofilm factors. differential gene expression analysis between biofilms on gla ...201323897604
organically managed soils reduce internal colonization of tomato plants by salmonella enterica serovar typhimurium.a two-phase experiment was conducted twice to investigate the effects of soil management on movement of salmonella enterica typhimurium in tomato plants. in the first phase, individual leaflets of 84 tomato plants grown in conventional or organic soils were dip inoculated two to four times before fruiting with either of two salmonella typhimurium strains (10(9) cfu/ml; 0.025% [vol/vol] silwet l-77). inoculated and adjacent leaflets were tested for salmonella spp. densities for 30 days after each ...201323506364
complete genome sequence of a multidrug-resistant salmonella enterica serovar typhimurium var. 5- strain isolated from chicken breast.salmonella enterica subsp. enterica serovar typhimurium is a leading cause of salmonellosis. here, we report a closed genome sequence, including sequences of 3 plasmids, of salmonella serovar typhimurium var. 5- cfsan001921 (national antimicrobial resistance monitoring system [narms] strain id n30688), which was isolated from chicken breast meat and shows resistance to 10 different antimicrobials. whole-genome and plasmid sequence analyses of this isolate will help enhance our understanding of t ...201324356834
evidence of microevolution of salmonella typhimurium during a series of egg-associated outbreaks linked to a single chicken farm.the bacterium salmonella enterica serovar typhimurium (s. typhimurium) is one of the most frequent causes of foodborne outbreaks of gastroenteritis. between 2005-2008 a series of s. typhimurium outbreaks occurred in tasmania, australia, that were all traced to eggs originating from a single chicken farm. we sequenced the genomes of 12 isolates linked to these outbreaks, in order to investigate the microevolution of a pathogenic s. typhimurium clone in a natural, spatiotemporally restricted popul ...201324245509
invasive non-typhoidal salmonella typhimurium st313 are not host-restricted and have an invasive phenotype in experimentally infected chickens.salmonella enterica serovar typhimurium sequence type (st) 313 is a major cause of invasive non-typhoidal salmonellosis in sub-saharan africa. no animal reservoir has been identified, and it has been suggested that st313 is adapted to humans and transmission may occur via person-to-person spread. here, we show that st313 cause severe invasive infection in chickens as well as humans. oral infection of chickens with st313 isolates d23580 and q456 resulted in rapid infection of spleen and liver wit ...201324130915
use of a bacteriophage cocktail to control salmonella in food and the food industry.the use of lytic bacteriophages for the biocontrol of food-borne pathogens in food and in the food industry is gaining increasing acceptance. in this study, the effectiveness of a bacteriophage cocktail composed of three different lytic bacteriophages (uab_phi 20, uab_phi78, and uab_phi87) was determined in four different food matrices (pig skin, chicken breasts, fresh eggs, and packaged lettuce) experimentally contaminated with salmonella enterica serovar typhimurium and s. enterica serovar ent ...201323735218
dissemination of clonal salmonella enterica serovar typhimurium isolates causing salmonellosis in mauritius.salmonella enterica serotype typhimurium is one of the leading causes of salmonellosis in mauritius, where it has also been associated with outbreaks of foodborne illness. however, little is known about its molecular epidemiology in the country. this study was therefore undertaken to investigate the clonality and source of salmonella typhimurium in mauritius by studying human, food, and poultry isolates by pulsed-field gel electrophoresis (pfge) and antibiotic minimum inhibitory concentration de ...201323705985
the type vi secretion system encoded in spi-6 plays a role in gastrointestinal colonization and systemic spread of salmonella enterica serovar typhimurium in the chicken.the role of the salmonella pathogenicity islands (spis) in pathogenesis of salmonella enterica typhimurium infection in the chicken is poorly studied, while many studies have been completed in murine models. the type vi secretion system (t6ss) is a recently described protein secretion system in gram-negative bacteria. the genus salmonella contains five phylogenetically distinct t6ss encoded in differentially distributed genomic islands. s. typhimurium harbors a t6ss encoded in spi-6 (t6ssspi-6), ...201323691117
salmonella enterica typhimurium infection causes metabolic changes in chicken muscle involving ampk, fatty acid and insulin/mtor signaling.salmonella enterica serovar typhimurium (salmonella typhimurium) infection of chickens that are more than a few days old results in asymptomatic cecal colonization with persistent shedding of bacteria. we hypothesized that while the bacterium colonizes and persists locally in the cecum it has systemic effects, including changes to metabolic pathways of skeletal muscle, influencing the physiology of the avian host. using species-specific peptide arrays to perform kinome analysis on metabolic sign ...201323682635
deletions in the pyruvate pathway of salmonella typhimurium alter spi1-mediated gene expression and infectivity.salmonella enterica serovar typhimurium is a major foodborne pathogen worldwide. s. typhimurium encodes type iii secretion systems via salmonella pathogenicity islands (spi), producing the major effector proteins of virulence. previously, we identified two genes of salmonella pyruvate metabolism that were up-regulated during chicken cell infection: pyruvate formate lyase i (pflb) and bifunctional acetaldehyde-coa/alcohol dehydrogenase (adhe). we were therefore interested in examining the role th ...201323442379
simultaneous near-infrared radiant heating and uv radiation for inactivating escherichia coli o157:h7 and salmonella enterica serovar typhimurium in powdered red pepper (capsicum annuum l.).this study was conducted to investigate the efficacy of the simultaneous application of near-infrared (nir) heating and uv irradiation for reducing populations of food-borne pathogens, including salmonella enterica serovar typhimurium and escherichia coli o157:h7 in red pepper powder and to clarify the mechanisms of the lethal effect of the nir-uv combined treatment. also, the effect of the combination treatment on quality was determined by measuring changes in color and pungency constituents. s ...201323956394
mixed biofilm formation by shiga toxin-producing escherichia coli and salmonella enterica serovar typhimurium enhanced bacterial resistance to sanitization due to extracellular polymeric substances.shiga toxin-producing escherichia coli o157:h7 and salmonella enterica serovar typhimurium are important foodborne pathogens capable of forming single-species biofilms or coexisting in multispecies biofilm communities. bacterial biofilm cells are usually more resistant to sanitization than their planktonic counterparts, so these foodborne pathogens in biofilms pose a serious food safety concern. we investigated how the coexistence of e. coli o157:h7 and salmonella typhimurium strains would affec ...201323992495
effect of frequency and waveform on inactivation of escherichia coli o157:h7 and salmonella enterica serovar typhimurium in salsa by ohmic heating.the effect of frequency of alternating current during ohmic heating on electrode corrosion, heating rate, inactivation of food-borne pathogens, and quality of salsa was investigated. the impact of waveform on heating rate was also investigated. salsa was treated with various frequencies (60 hz to 20 khz) and waveforms (sine, square, and sawtooth) at a constant electric field strength of 12.5 v/cm. electrode corrosion did not occur when the frequency exceeded 1 khz. the heating rate of the sample ...201323023752
mlva as a tool for public health surveillance of human salmonella typhimurium: prospective study in belgium and evaluation of mlva loci stability.surveillance of salmonella enterica subsp. enterica serovar typhimurium (s. typhimurium) is generally considered to benefit from molecular techniques like multiple-locus variable-number of tandem repeats analysis (mlva), which allow earlier detection and confinement of outbreaks. here, a surveillance study, including phage typing, antimicrobial susceptibility testing and the in europe most commonly used 5-loci mlva on 1,420 s. typhimurium isolates collected between 2010 and 2012 in belgium, was ...201324391880
genetic types, gene repertoire, and evolution of isolates of the salmonella enterica serovar 4,5,12:i:- spanish clone assigned to different phage types.salmonella enterica subsp. enterica 4,[5],12:i:- is one of the most prevalent serovars associated with human infections worldwide. two multidrug-resistant clones, designated spanish and european clones, are recognized as having importance for public health and are subject to control measures in the european union. in this study, 23 clinical isolates belonging to the spanish clone were characterized by multilocus sequence typing, multiple-locus variable number tandem repeat analysis (mlva), pcr a ...201323325816
comparison of heat stress responses of immobilized and planktonic salmonella enterica serovar typhimurium.salmonellae are often present as immobilized cells in food products in the form of micro-colonies. despite this, most research into salmonella physiology has been performed with bacteria grown as planktonic cultures. in the current study, we compared the transcriptome of planktonic and immobilized salmonella enterica subsp. enterica serovar typhimurium (s. typhimurium) subjected to 30 min of heat stress at 45 °c. the expression of 538 genes was differently regulated between the two conditions af ...201323200655
epidemic of salmonellosis in passerine birds in switzerland with spillover to domestic cats.a die-off of passerine birds, mostly eurasian siskins (carduelis spinus), occurred in multiple areas of switzerland between february and march 2010. several of the dead birds were submitted for full necropsy. bacteriological examination was carried out on multiple tissues of each bird. at gross examination, common findings were light-tan nodules, 1 to 4 mm in diameter, scattered through the esophagus/crop. histologically, a necroulcerative transmural esophagitis/ingluvitis was observed. bacteria ...201323125146
ifnγ expression by an attenuated strain of salmonella enterica serovar typhimurium improves vaccine efficacy in susceptible tlr4-defective c3h/hej mice.c3h/hej mice carry a mutated allele of tlr4 gene (tlr4 ( d )) and thus are hyporesponsive to the lethal effects of lipopolysaccharide (lps). characteristically, however, the mice are also hypersusceptible to infections, particularly by gram-negative bacteria such as salmonella enterica serovar typhimurium (s. typhimurium) and are known to be difficult to vaccinate against virulent exposure. this is observed despite the expression of wild-type allele of nramp1 gene, another important determinant ...201322684724
[model of chronic salmonellosis: parameters of infection and immune response in inbred mice genetically variable in susceptibility to salmonellosis].study parameters of chronic infection and immune response in i/st and a/sn line mice in the model of per oral infection of mice with salmonella enterica serovar typhimurium.201322937698
genetic analysis of non-hydrogen sulfide-producing salmonella enterica serovar typhimurium and s. enterica serovar infantis isolates in japan.whole-genome sequencing of non-h(2)s-producing salmonella enterica serovar typhimurium and s. enterica serovar infantis isolates from poultry meat revealed a nonsense mutation in the phsa thiosulfate reductase gene and carriage of a cmy-2 β-lactamase. the lack of production of h(2)s might lead to the incorrect identification of s. enterica isolates carrying antimicrobial resistance genes.201323135931
inactivation of salmonella enterica serovar typhimurium on fresh produce by cold atmospheric gas plasma technology.cold atmospheric gas plasma treatment (cap) is an alternative approach for the decontamination of fresh and minimally processed food. in this study, the effects of growth phase, growth temperature and chemical treatment regime on the inactivation of salmonella enterica serovar typhimurium (s. typhimurium) by nitrogen cap were examined. furthermore, the efficacy of cap treatment for decontaminating lettuce and strawberry surfaces and potato tissue inoculated with s. typhimurium was evaluated. it ...201323122497
phenotypic analysis of salmonella enterica serovar typhimurium rpoe mutants encoding rna polymerase extracytoplasmic stress response sigma factors σ(e) with altered promoter specificity.we previously identified mutants in the rpoe gene of salmonella enterica serovar typhimurium (s. typhimurium) encoding rna polymerase extracytoplasmic stress response sigma factors σ(e) with altered promoter specificity. the replacement of the conserved r171 residue in the conserved region 4.2 of σ(e) by different amino acid residues exhibited different phenotypes. while r171a almost completely abolished sigma factor activity, r171g and r171c mutant changes imparted a relaxed recognition phenoty ...201322972381
impact of maternally-derived antibodies against salmonella enterica serovar typhimurium on the bacterial load in suckling piglets.the significance of maternal immunity against non-typhoid salmonella spp. acquired by piglets via colostrum and milk was evaluated in a salmonella enterica serovar typhimurium challenge experiment. piglets from sows vaccinated with an experimental inactivated vaccine exhibited high levels of serum immunoglobulins g and a against s. typhimurium 4 days after birth, just prior to experimental oral challenge. the s. typhimurium load in the ileal and caecal wall of piglets 3 days after experimental i ...201322967925
deletion of invh gene in salmonella enterica serovar typhimurium limits the secretion of sip effector proteins.the type-iii secretion system-i (t3ss-i) of salmonella enterica serovar typhimurium (s. typhimurium) is an essential component to mediate active invasion and subsequent inflammation in genetically susceptible c57bl/6 mice. s. typhimurium translocates its effector proteins through salmonella pathogenicity island-i (spi-i) encoded t3ss-i needle complex. this study focuses on invh gene of s. typhimurium, which plays an active role in spi-i mediated effector protein translocation. the deletion of in ...201323159244
polynucleotide phosphorylase (pnpase) is required for salmonella enterica serovar typhimurium colonization in swine.the pnp gene encodes polynucleotide phosphorylase, an exoribonuclease involved in rna processing and degradation. a mutation in the pnp gene was previously identified by our group in a signature-tagged mutagenesis screen designed to search for salmonella enterica serovar typhimurium genes required for survival in an ex vivo swine stomach content assay. in the current study, attenuation and colonization potential of a s. typhimurium pnp mutant in the porcine host was evaluated. following intranas ...201324126127
value addition in the efficacy of conventional antibiotics by nisin against salmonella.frequent and indiscriminate use of existing battery of antibiotics has led to the development of multi drug resistant (mdr) strains of pathogens. as decreasing the concentration of the antibiotic required to treat salmonellosis might help in combating the development of resistant strains, the present study was designed to assess the synergistic effects, if any, of nisin, in combination with conventional anti-salmonella antibiotics against salmonella enterica serovar typhimurium. minimum inhibito ...201324116175
exposure of salmonella enterica serovar typhimurium to a protective monoclonal iga triggers exopolysaccharide production via a diguanylate cyclase-dependent pathway.sal4 is a monoclonal polymeric iga antibody directed against the o antigen (o-ag) of salmonella enterica serovar typhimurium (s. typhimurium), which is sufficient to protect mice against intestinal infections from s. typhimurium. we recently reported that the exposure of s. typhimurium to sal4 results in the immediate loss of flagellum-based motility, in alterations to the outer membrane (om) integrity, and in the concomitant appearance of a mucoid phenotype that is reminiscent of cells in the e ...201323230292
effects of natural mutations in the ramra locus on invasiveness of epidemic fluoroquinolone-resistant salmonella enterica serovar typhimurium isolates.fluoroquinolone (fq) resistance is increasing worldwide among salmonella species. among the mechanisms involved, increased efflux via the tripartite acrab-tolc efflux system is mainly modulated through control of expression via the ramra regulatory locus gene products. interestingly, in some reference strains these have also been experimentally shown to regulate cell invasion-related genes of the type iii secretion system 1 (t3ss-1). in this study, we investigated whether natural mutations occur ...201323230062
the copper supply pathway to a salmonella cu,zn-superoxide dismutase (sodcii) involves p(1b)-type atpase copper efflux and periplasmic cuep.periplasmic cu,zn-superoxide dismutases (cu,zn-sods) are implicated in bacterial virulence. it has been proposed that some bacterial p(1b)-type atpases supply copper to periplasmic cupro-proteins and such transporters have also been implicated in virulence. here we show that either of two p(1b)-type atpases, copa or golt, is needed to activate a periplasmic cu,zn-sod (sodcii) in salmonella enterica serovar typhimurium. a δcopa/δgolt mutant accumulates inactive zn-sodcii which can be activated by ...201323171030
hr-mas nmr reveals a ph-dependent lps alteration by de-o-acetylation at abequose in the o-antigen of salmonella enterica serovar typhimurium.nmr spectroscopy can detect biomolecules like lipopolysaccharide directly on the surface of the cell, thus avoiding isolation and purification, and providing a more realistic description than the one derived from in vitro studies. here we present a high-resolution magic-angle spinning nmr study of the o-antigen of salmonella enterica serovar typhimurium (s. typhimurium) performed directly on the cells showing the alteration of its acetylation state over time. the o-antigen region of s. typhimuri ...201324211643
salmonella typhimurium ttss-2 deficient mig-14 mutant shows attenuation in immunocompromised mice and offers protection against wild-type salmonella typhimurium infection.development of salmonella enterica serovar typhimurium (s. typhimurium) live attenuated vaccine carrier strain to prevent enteric infections has been a subject of intensive study. several mutants of s. typhimurium have been proposed as an effective live attenuated vaccine strain. unfortunately, many such mutant strains failed to successfully complete the clinical trials as they were suboptimal in delivering effective safety and immunogenicity. however, it remained unclear, whether the existing l ...201324148706
genomic diversity and adaptation of salmonella enterica serovar typhimurium from analysis of six genomes of different phage types.salmonella enterica serovar typhimurium (or simply typhimurium) is the most common serovar in both human infections and farm animals in australia and many other countries. typhimurium is a broad host range serovar but has also evolved into host-adapted variants (i.e. isolated from a particular host such as pigeons). six typhimurium strains of different phage types (defined by patterns of susceptibility to lysis by a set of bacteriophages) were analysed using illumina high-throughput genome seque ...201324138507
genome sequences of salmonella enterica serotype typhimurium blood clinical isolate st4848/06 and stool isolate st1489/06.salmonella enterica serotype typhimurium human blood strains isolated from outside africa are rarely sequenced. here, we report the draft genome sequences of two s. typhimurium clinical strains isolated in the same year, one from blood and another from stool, in order to gain insights into the genetic basis leading to invasive diseases.201324136846
genomics of an emerging clone of salmonella serovar typhimurium st313 from nigeria and the democratic republic of congo.salmonella enterica serovar typhimurium st313 is an invasive and phylogenetically distinct lineage present in sub-saharan africa. we report the presence of s. typhimurium st313 from patients in the democratic republic of congo and nigeria.201324129621
complete genome of salmonella enterica serovar typhimurium myophage maynard.salmonella enterica serovar typhimurium is a pathogenic bacterium that has been a major concern for food and public safety. phages infecting s. typhimurium may prove to be useful therapeutics against this harmful bacterium. here, we announce the complete genome of s. typhimurium t4-like myophage maynard and describe its features.201324356822
non-essential genes form the hubs of genome scale protein function and environmental gene expression networks in salmonella enterica serovar typhimurium.salmonella typhimurium is an important pathogen of human and animals. it shows a broad growth range and survives in harsh conditions. the aim of this study was to analyze transcriptional responses to a number of growth and stress conditions as well as the relationship of metabolic pathways and/or cell functions at the genome-scale-level by network analysis, and further to explore whether highly connected genes (hubs) in these networks were essential for growth, stress adaptation and virulence.201324345035
an infection-relevant transcriptomic compendium for salmonella enterica serovar typhimurium.bacterial transcriptional networks consist of hundreds of transcription factors and thousands of promoters. however, the true complexity of transcription in a bacterial pathogen and the effect of the environments encountered during infection remain to be established. we present a simplified approach for global promoter identification in bacteria using rna-seq-based transcriptomic analyses of 22 distinct infection-relevant environmental conditions. individual rna samples were combined to identify ...201324331466
evaluation of genotoxic effects of new molecules with possible trypanocidal activity for chagas disease treatment.chagas disease is responsible for a large number of human infections and many are also at risk of infection. there is no effective drug for chagas disease treatment. the institute of pharmaceutical technology at fiocruz, brazil, has designed three nitro analogs of the nitroimidazole-thiadiazole, megazol: two triazole analogs ptal 05-02 and pamt 09 and a pyrazole analog ptal 04-09. a set of salmonella enterica serovar typhimurium strains were used in the bacterial reverse mutation test (ames test ...201324311974
pyroptosis and adaptive immunity mechanisms are promptly engendered in mesenteric lymph-nodes during pig infections with salmonella enterica serovar typhimurium.in this study, we explored the transcriptional response and the morphological changes occurring in porcine mesenteric lymph-nodes (mln) along a time course of 1, 2 and 6 days post infection (dpi) with salmonella typhimurium. additionally, we analysed the expression of some salmonella effectors in tissue to complete our view of the processes triggered in these organs upon infection. the results indicate that besides dampening apoptosis, swine take advantage of the flagellin and prgj expression by ...201324308825
salmonella neck abscess as an opportunistic infection in diabetes mellitus.salmonella neck infections represent an uncommon cause of focal salmonellosis. while the incidence of nontyphoid salmonellosis is estimated at over 2 million cases annually, extraintestinal manifestations account for less than 1% of cases. this paper describes two patients with salmonella neck abscesses as the initial presentation of diabetes mellitus. the first patient was diagnosed as having salmonella enterica serotype enteritidis sternocleidomastoid pyomyositis and the second patient salmone ...201324307959
a link between gut community metabolism and pathogenesis: molecular hydrogen-stimulated glucarate catabolism aids salmonella virulence.glucarate, an oxidized product of glucose, is a major serum organic acid in humans. still, its role as a carbon source for a pathogen colonizing hosts has not been studied. we detected high-level expression of a potential glucarate permease encoding gene gudt when salmonella enterica serovar typhimurium are exposed to hydrogen gas (h(2)), a gaseous by-product of gut commensal metabolism. a gudt strain of salmonella is deficient in glucarate-dependent growth, however, it can still use other monos ...201324307595
effects of quaternary benzo(c)phenanthridine alkaloids on growth performance, shedding of organisms, and gastrointestinal tract integrity in pigs inoculated with multidrug-resistant salmonella spp.to evaluate effects of quaternary benzo(c)phenanthridine alkaloids (qbas) against salmonella spp and determine effects on growth performance, organism shedding, and gastrointestinal tract integrity in pigs inoculated with salmonella enterica serovar typhimurium.201324274891
bacterial infection of macrophages induces decrease in refractive index.infection of cells by pathogens leads to both biochemical and structural modifications of the host cell. to study the structural modifications in a label-free manner, we use digital holographic microscopy, dhm, to obtain the integral refractive index distribution of cells. primary murine bone marrow derived macrophages (bmdm) infected with salmonella enterica serovar typhimurium, undergo highly significant reduction in refractive index, ri, compared to uninfected cells. infected bmdm cells from ...201322887897
differential outcome of infection with attenuated salmonella in myd88-deficient mice is dependent on the route of administration.activation of the innate immune system is a prerequisite for the induction of adaptive immunity to both infectious and non-infectious agents. tlrs are key components of the innate immune recognition system and detect pathogen-associated molecular patterns. most tlrs utilize the myd88 adaptor for their signaling pathways. in the current study, we investigated innate and adaptive immune responses to primary as well as secondary salmonella infections in myd88-deficient (myd88(-/-)) mice. using i.p. ...201322386951
genome expression analysis of nonproliferating intracellular salmonella enterica serovar typhimurium unravels an acid ph-dependent phop-phoq response essential for dormancy.genome-wide expression analyses have provided clues on how salmonella proliferates inside cultured macrophages and epithelial cells. however, in vivo studies show that salmonella does not replicate massively within host cells, leaving the underlying mechanisms of such growth control largely undefined. in vitro infection models based on fibroblasts or dendritic cells reveal limited proliferation of the pathogen, but it is presently unknown whether these phenomena reflect events occurring in vivo. ...201323090959
a phosphotransferase system permease is a novel component of cadc signaling in salmonella enterica.in salmonella enterica serovar typhimurium, proteolytic cleavage of the membrane-bound transcriptional regulator cadc acts as a switch to activate genes of the lysine decarboxylase system in response to low ph and lysine signals. to identify the genetic factors required for the proteolytic activation of cadc, we performed genome-wide random mutagenesis. we show that a phosphotransferase system (pts) permease stm4538 acts as a positive modulator of cadc function. the transposon insertion in stm45 ...201323066934
structure of the periplasmic copper-binding protein cuep from salmonella enterica serovar typhimurium.cuep was initially identified as a copper-resistance gene in salmonella enterica serovar typhimurium, which has evolved to survive in the phagosomes of macrophages. recently, cuep was determined to be a periplasmic copper-binding protein and has been implicated in the transfer of copper ions to sodcii in the periplasm. in this study, the crystal structure of cuep has been determined, revealing a v-shaped dimeric structure. the conserved cysteine and histidine residues are clustered on the surfac ...201324100307
the gdac1 locus modifies spontaneous and salmonella-induced colitis in mice deficient in either gpx2 or gpx1 gene.we previously identified the gdac1 (gpx-deficiency-associated colitis 1) locus, which influences the severity of spontaneous colitis in gpx1- and gpx2-double-knockout (gpx1/2-dko) mice. congenic gpx1/2-dko mice in the 129s1/svimj (129) background but carrying the gdac1(b6) allele have milder spontaneous colitis than 129 gpx1/2-dko mice carrying the gdac1(129) allele. here, we evaluated the effect of the gdac1(b6) allele on 129 strain non-dko mice that had a wild-type (wt) gpx1 or gpx2 allele and ...201324090658
the ssec translocon component in salmonella enterica serovar typhimurium is chaperoned by ssca.salmonella enterica is a causative agent of foodborne gastroenteritis and the systemic disease known as typhoid fever. this bacterium uses two type three secretion systems (t3sss) to translocate protein effectors into host cells to manipulate cellular function. salmonella pathogenicity island (spi)-2 encodes a t3ss required for intracellular survival of the pathogen. genes in spi-2 include apparatus components, secreted effectors and chaperones that bind to secreted cargo to coordinate their rel ...201324090070
enhancement of host immune responses by oral vaccination to salmonella enterica serovar typhimurium harboring both flic and fljb flagella.flagellin, the structural component of the flagellar filament in various motile bacteria, can contribute to the activation of nf-κb and proinflammatory cytokine expression during the innate immune response in host cells. thus, flagellin proteins represent a particularly attractive target for the development of vaccine candidates. in this study, we investigated the immune response by increasing the flagella number in the iacp mutant strain and the adjuvant activity of the flagellin component fljb ...201324069357
a novel csra titration mechanism regulates fimbrial gene expression in salmonella typhimurium.a hierarchical control of fimbrial gene expression limits laboratory grown cultures of salmonella enterica serovar typhimurium (s. typhimurium) to the production of type i fimbriae encoded by the fimaicdhf operon. here we show that an unlikely culprit, namely the 5'-untranslated region (5'-utr) of a messenger (m)rna, coordinated the regulation. binding of csra to the 5'-utr of the pefacdef transcript was required for expression of plasmid-encoded fimbriae. the 5'-utr of the fimaicdhf transcript ...201324056837
preadaptation to cold stress in salmonella enterica serovar typhimurium increases survival during subsequent acid stress exposure.salmonella is an important cause of bacterial food-borne gastroenteritis. salmonella encounters multiple abiotic stresses during pathogen elimination methods used in food processing, and these stresses may influence its subsequent survivability within the host or in the environment. upon ingestion, salmonella is exposed to gastrointestinal acidity, a first line of the host innate defense system. this study tested the hypothesis that abiotic stresses encountered during food processing alter the m ...201324056458
probing the arca regulon under aerobic/ros conditions in salmonella enterica serovar typhimurium.hydrogen peroxide (h₂o₂) is a reactive oxygen species (ros), which is part of the oxidative burst encountered upon internalization of salmonella enterica serovar typhimurium (s. typhimurium) by phagocytic cells. it has previously been established that, the arcab two-component system plays a critical role in ros resistance, but the genes regulated by the system remained undetermined to date. we therefore investigated the arca regulon in aerobically growing s. typhimurium before and after exposure ...201324044554
inflammatory responses induced by lipopolysaccharide are amplified in primary human monocytes but suppressed in macrophages by complement protein c5a.monocytes and macrophages are important innate immune cells equipped with danger-sensing receptors, including complement and toll-like receptors. complement protein c5a, acting via c5ar, is shown in this study to differentially modulate lps-induced inflammatory responses in primary human monocytes versus macrophages. whereas c5a enhanced secretion of lps-induced il-6 and tnf from primary human monocytes, c5a inhibited these responses while increasing il-10 secretion in donor-matched human monocy ...201324043889
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