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innate immunity: unfolding the neuro-immuno connections.the innate immune system maintains health and fitness during infection by eliminating infectious agents and by limiting damage caused by pathogens or immune activation. the nervous system contributes to innate immunity by modulating the expression of antimicrobial peptides and by regulating the unfolded protein response.201121683903
secretory nucleoside diphosphate kinases from both intra- and extracellular pathogenic bacteria are functionally indistinguishable.nucleoside diphosphate kinase (ndk), responsible for the maintenance of ntp pools, is an atp-utilizing enzyme secreted by different pathogens. we found that ndk from salmonella enterica serovar typhimurium (s. typhimurium) is also secretory in nature. secretory ndk is known to play a crucial role in the survival of pathogenic microbes within host cells through their interaction with extracellular atp. to elucidate this aspect, we assessed the contribution of secretory products containing ndk fro ...201121816881
antisense inhibition of gene expression and growth in gram-negative bacteria by cell-penetrating peptide conjugates of peptide nucleic acids targeted to rpod gene.gram-negative bacteria (gnb) cause common and severe hospital- and community-acquired infections with a high incidence of multidrug resistance (mdr) and mortality. the emergence and spread of mdr-gnb strains limit therapeutic options and highlight the need to develop new therapeutic strategies. in this study, the peptide (rxr)(4)xb- and (kff)(3)k-conjugated peptide nucleic acids (ppnas) were developed to target rpod, which encodes an rna polymerase primary σ(70) that is thought to be essential f ...201122000398
specific detection of campylobacter jejuni using the bacteriophage nctc 12673 receptor binding protein as a probe.campylobacter jejuni is found in the intestines of poultry, cattle, swine, wild birds and pet animals and is the major cause of foodborne gastroenteritis in developed countries. we report the use of the receptor binding protein (rbp) of campylobacter bacteriophage nctc 12673 for the specific capture of campylobacter jejuni bacteria using rbp-derivatized capturing surfaces. the gp48 rbp was expressed as a glutathione s-transferase-gp48 (gst-gp48) fusion protein and immobilized onto surface plasmo ...201121955997
associations among pathogenic bacteria, parasites, and environmental and land use factors in multiple mixed-use watersheds.over a five year period (2004-08), 1171 surface water samples were collected from up to 24 sampling locations representing a wide range of stream orders, in a river basin in eastern ontario, canada. water was analyzed for cryptosporidium oocysts and giardia cyst densities, the presence of salmonella enterica subspecies enterica, campylobacter spp., listeria monocytogenes, and escherichia coli o157:h7. the study objective was to explore associations among pathogen densities/occurrence and objecti ...201121889781
small heat shock protein agsa forms dynamic fibrils.as a class of molecular chaperones, small heat shock proteins (shsps) usually exist as multi-subunit spherical oligomers. in this study, we report that agsa, a shsp of salmonella enterica serovar typhimurium, spontaneously forms fibrils in vitro. these fibrils tend to be formed at elevated temperature and do not share the characteristics of amyloid. interestingly, the fibril-forming agsa is able to suppress the dithiothreitol-induced aggregation of insulin efficiently within a certain range of t ...201122001209
innate immune response to salmonella typhimurium, a model enteric pathogen.the innate immune system provides the first line of defense against invading microorganisms by inducing a variety of inflammatory and antimicrobial responses. these responses are particularly important in the gastrointestinal tract, where the needs for efficient nutrient uptake and host defense collide. many pathogens have evolved to specifically colonize the intestine, causing millions of cases of enteric infections a year. a paradigm of an enteric pathogen is salmonella enterica, a gram-negati ...201122198618
a1-giardin based live heterologous vaccine protects against Giardia lamblia infection in a murine model.Giardia lamblia is a leading protozoan cause of diarrheal disease worldwide, yet preventive medical strategies are not available. A crude veterinary vaccine has been licensed for cats and dogs, but no defined human vaccine is available. We tested the vaccine potential of three conserved antigens previously identified in human and murine giardiasis, a1-giardin, a-enolase, and ornithine carbamoyl transferase, in a murine model of G. lamblia infection. Live recombinant attenuated Salmonella enteric ...201122001876
a regional salmonella enterica serovar typhimurium outbreak associated with raw beef products, the netherlands, 2010.abstract between april and may 2010, several medical microbiological laboratories in the netherlands notified a total of 90 cases of salmonella enterica serovar typhimurium with the same antibiogram type (resistant for ampicillin, tetracycline, and co-trimoxazol) and the same multiple locus variable number tandem repeats analysis pattern (03-16-09-na-311) or single locus variants. date of illness onset ranged from end of march to mid-may with a peak in the second week of april. almost half of ...201122047057
antimicrobial activity of lemongrass oil against salmonella enterica on organic leafy greens.aims:  we investigated the antimicrobial effectiveness of lemongrass essential oil on organic leafy greens, romaine and iceberg lettuces and mature and baby spinach, inoculated with salmonella newport. the influences of exposure times and abuse temperatures on bacterial survival were also investigated. methods and results:  leaf samples were washed, inoculated with salm. newport (6-log cfu ml(-1) ) and dried. inoculated leaves were immersed in solutions containing 0·1, 0·3 or 0·5% lemongrass oil ...201122188296
role of spi-1 secreted effectors in acute bovine response to salmonella enterica serovar typhimurium: a systems biology analysis approach.salmonella enterica serovar typhimurium (s. typhimurium) causes enterocolitis with diarrhea and polymorphonuclear cell (pmn) influx into the intestinal mucosa in humans and calves. the salmonella type iii secretion system (t3ss) encoded at pathogenicity island i translocates salmonella effector proteins sipa, sopa, sopb, sopd, and sope2 into epithelial cells and is required for induction of diarrhea. these effector proteins act together to induce intestinal fluid secretion and transcription of c ...201122096503
porcine ipec-j2 intestinal epithelial cells in microbiological investigations.ipec-j2 cells are porcine intestinal columnar epithelial cells that were isolated from neonatal piglet mid-jejunum. this cell line forms polarized monolayers with high transepithelial electrical resistance when cultured on 0.4μm pore-size filters. the cell line is unique in that it is derived from small intestinal tissue (compared to the common human colon-derived lines ht-29, t84, and caco-2) and is not transformed (compared to the porcine small intestinal line, ipi-2i). porcine intestinal epit ...201122074860
extreme antimicrobial peptide and polymyxin b resistance in the genus burkholderia.cationic antimicrobial peptides and polymyxins are a group of naturally occurring antibiotics that can also possess immunomodulatory activities. they are considered a new source of antibiotics for treating infections by bacteria that are resistant to conventional antibiotics. members of the genus burkholderia, which includes various human pathogens, are inherently resistant to antimicrobial peptides. the resistance is several orders of magnitude higher than that of other gram-negative bacteria s ...201122919572
effect of the salmonella pathogenicity island 2 type iii secretion system on salmonella survival in activated chicken macrophage-like hd11 cells.in order to better identify the role of the salmonella pathogenicity island 2 (spi-2) type iii secretion system (t3ss) in chickens, we used the well-known gentamicin protection assay with activated hd11 cells. hd11 cells are a macrophage-like chicken cell line that can be stimulated with phorbol 12-myristate 13-acetate (pma) to exhibit more macrophage-like morphology and greater production of reactive oxygen species (ros). activated hd11 cells were infected with a wild-type salmonella enterica s ...201122216355
development of a novel in-water vaccination protocol for dna adenine methylase deficient salmonella enterica serovar typhimurium vaccine in adult sheep.intensive livestock production is associated with an increased incidence of salmonellosis. the risk of infection and the subsequent public health concern is attributed to increased pathogen exposure and disease susceptibility due to multiple stressors experienced by livestock from farm to feedlot. traditional parenteral vaccine methods can further stress susceptible populations and cause carcass damage, adverse reactions, and resultant increased production costs. as a potential means to address ...201122214887
application of a mouse ligated peyer’s patch intestinal loop assay to evaluate bacterial uptake by m cells.the inside of our gut is inhabited with enormous number of commensal bacteria. the mucosal surface of the gastrointestinal tract is continuously exposed to them and occasionally to pathogens. the gut-associated lymphoid tissue (galt) play a key role for induction of the mucosal immune response to these microbes(1, 2). to initiate the mucosal immune response, the mucosal antigens must be transported from the gut lumen across the epithelial barrier into organized lymphoid follicles such as peyer's ...201122215009
palmitoylation state impacts induction of innate and acquired immunity by the salmonella enterica serovar typhimurium msbb mutant.lipopolysaccharide (lps), composed of lipid a, core, and o-antigen, is a major virulence factor of salmonella enterica serovar typhimurium, with lipid a being a major stimulator to induce the proinflammatory response via the toll-like receptor 4 (tlr4)-md2-cd14 pathway. while salmonella msbb mutants lacking the myristate chain in lipid a were investigated widely as an anticancer vaccine, inclusion of the msbb mutation in a salmonella vaccine to deliver heterologous antigens has not yet been inve ...201121930761
purification and characterization of the acetyl-coa synthetase from mycobacterium tuberculosis.acetyl-coa (accoa) synthetase (acs) catalyzes the conversion of acetate into accoa, which is involved in many catabolic and anabolic pathways. although this enzyme has been studied for many years in many organisms, the properties of mycobacterium tuberculosis acs and the regulation of its activity remain unknown. here, the putative acs gene of m. tuberculosis h37rv (mt-acs) was expressed as a fusion protein with 6×his-tag on the c-terminus in escherichia coli. the recombinant mt-acs protein was ...201121896569
oxysterol-binding protein (osbp) enhances replication of intracellular salmonella and binds the salmonella spi-2 effector ssel via its n-terminus.effectors translocated into the host cell by salmonella enterica serovar typhimurium are critical for bacterial virulence. for many effectors, the mechanisms of their interactions with host pathways are not yet understood. we have recently found an interaction between the spi-2 effector ssel and oxysterol-binding protein (osbp). we show here that ssel binds the n-terminus of osbp and that s. typhimurium infection results in redistribution of osbp. we furthermore demonstrate that osbp is required ...201121988961
Identification of environmental reservoirs of nontyphoidal salmonellosis: aptamer-assisted bioconcentration and subsequent detection of salmonella typhimurium by quantitative polymerase chain reaction.In this study, identification of environmental reservoirs of Salmonella enterica subsp. enterica serovar Typhimurium (abbreviated as Salmonella Typhimurium) in sediments, water, and aquatic flora collected from the Ganges River (Ganges riverine material) was carried out by adopting a two-step strategy. Step 1 comprised a selective serovar-specific capture of Salmonella Typhimurium from potential reservoirs. Step 2 involved culture-free detection of selectively captured Salmonella Typhi ...201121875107
Isolation and Characterization of small qnrS1-carrying plasmids from imported seafood isolates of Salmonella enterica that are highly similar to plasmids of clinical isolates.Dissemination of plasmid-mediated quinolone resistance among pathogenic bacteria is a concern for public health due to decreased sensitivity to fluoroquinolones and increased potentials to develop high fluoroquinolone resistance. Two qnrS1-positive isolates of Salmonella enterica, Corvallis (468) and Typhimurium (484) from imported seafood (Thailand and Vietnam) were tested for quinolone sensitivity using disk agar diffusion and the Sensititre(®) system. The presence of qnr genes, qnr-carrying ...201122151215
evasion of host immunity by virulent salmonella: implications for vaccine design.dendritic cells (dcs) are professional antigen presenting cells (apcs) capable of linking innate and adaptive immunity during infection. after recognition of pathogen-associated molecular patterns (pamps), dcs can engulf, process and present bacteria-derived antigens on mhc molecules to t cells. because of the key role that dcs play on the initiation of innate and adaptive immunity, alterations in their function could render the host susceptible to bacterial dissemination. consistent with this n ...201122172071
antimicrobial activity of apple, hibiscus, olive, and hydrogen peroxide formulations against salmonella enterica on organic leafy greens.salmonella enterica is one of the most common bacterial pathogens implicated in foodborne outbreaks involving fresh produce in the last decade. in an effort to discover natural antimicrobials for use on fresh produce, the objective of the present study was to evaluate the effectiveness of different antimicrobial plant extract-concentrate formulations on four types of organic leafy greens inoculated with s. enterica serovar newport. the leafy greens tested included organic romaine and iceberg le ...201122004815
interaction of concanavalin a with bacterial lipopolysaccharides in agarose gel.binding of fluorescein isothiocyanate-labeled concanavalin a to a series of molecular species of lipopolysaccharide (lps), purified from pathogenic bacteria, was studied via agarose gel precipitation experiments and the results were compared with available structural data.the lps species could be divided into cona-reactive and non-reactive ones. reactivity resided in the o-specific chain of lps, and binding to the lipid a or core moieties of lps could not be demonstrated by the present methods. ...201121983321
cell-associated flagella enhance the protection conferred by mucosally-administered attenuated salmonella paratyphi a vaccines.antibiotic-resistant salmonella enterica serovar paratyphi a, the agent of paratyphoid a fever, poses an emerging public health dilemma in endemic areas of asia and among travelers, as there is no licensed vaccine. integral to our efforts to develop a s. paratyphi a vaccine, we addressed the role of flagella as a potential protective antigen by comparing cell-associated flagella with exported flagellin subunits expressed by attenuated strains.201122069504
evidence of significant synergism between antibiotics and the antipsychotic, antimicrobial drug flupenthixol.previously, the antipsychotic, non-antibiotic compound flupenthixol dihydrochloride (fp) was shown to exhibit distinct in vitro antibacterial activity against gram-positive and gram-negative bacteria and to significantly protect swiss albino mice challenged with a known mouse virulent salmonella. the present study was designed to ascertain whether this drug could efficiently augment the action of an antibiotic or a non-antibiotic when tested in combination. a total of 12 bacterial strains belong ...201121997771
Bacterial rejuvenation: lag phase is a distinct growth phase that prepares bacteria for exponential growth and involves transient metal accumulation.Lag phase represents the earliest and most poorly understood stage of the bacterial growth cycle. We developed a reproducible experimental system and conducted functional genomic and physiological analyses of a 2 hour lag phase in Salmonella enterica serovar Typhimurium. Adaptation began within four minutes of inoculation into fresh LB media, with the transient expression of genes involved in phosphate uptake. The main lag phase transcriptional programme initiated at twenty minutes with the up-r ...201122139505
meta-analytic approach to the accurate prediction of secreted virulence effectors in gram-negative bacteria.many pathogens use a type iii secretion system to translocate virulence proteins (called effectors) in order to adapt to the host environment. to date, many prediction tools for effector identification have been developed. however, these tools are insufficiently accurate for producing a list of putative effectors that can be applied directly for labor-intensive experimental verification. this also suggests that important features of effectors have yet to be fully characterized.201122078363
characterization of class i integrons among salmonella enterica serovar enteritidis isolated from humans and poultry.a total of 84 salmonella enterica serovar enteritidis (s. enteritidis) isolates, 42 of human and 42 of poultry origin, were characterized for antimicrobial resistance patterns and class i integrons. among them, 58 (69%) s. enteritidis were multidrug-resistant (mdr) and showed resistance to two or more antibiotic classes. by pcr assays and dna sequencing, 50 (59.5%) s. enteritidis isolates were found to carry class i integrons. amplification of internal variable regions of class i integrons revea ...201122066813
Deletion of yncD gene in Salmonella enterica subsp. enterica serovar Typhi leads to attenuation in mouse model.TonB-dependent transporters (TBDTs) are bacterial outer membrane proteins that usually involve in uptake of certain key nutrients, for example, iron. In the genome of Salmonella enterica subsp. enterica serovar Typhi, yncD gene encodes a putative TBDT and was identified as an in vivo induced antigen recently. In the present study, a yncD-deleted mutant was constructed to evaluate the role of the yncD gene in virulence. Our results showed that the mutant is attenuated to a mouse model by intraper ...201122150228
Differential gene expression of antimicrobial peptides ß defensins in the gastrointestinal tract of Salmonella serovar Pullorum infected broiler chickens.Salmonella enterica serovar Pullorum causes substantial mortality in chicks as well as results in persistent infection and vertical transmission in layer birds. An effective innate immune response in the early stages of infection could reduce bacterial colonization and mortality in chicks and persistency of infection in later stages. ß Defensins (AvBDs) are now considered as one of the key components of innate immunity in avian species. In the present study, we quantified the mRNA expression lev ...201122170093
Use of bioinformatic SNP predictions in differentially expressed genes to find SNPs associated with Salmonella colonization in swine.Asymptomatic Salmonella-carrier pigs present a major problem in preharvest food safety, with a recent survey indicating >50% of swine herds in the United States have Salmonella-positive animals. Salmonella-carrier pigs serve as a reservoir for contamination of neighbouring pigs, abattoir pens and pork products. In addition, fresh produce as well as water can be contaminated with Salmonella from manure used as fertilizer. Control of Salmonella at the farm level could be through genetic improvemen ...201121906181
change in antimicrobial resistance pattern in salmonella enterica serovar typhimurium isolates detected in a beef cattle farm.multidrug-resistant salmonella enterica serovar typhimurium (s. typhimurium) isolates with four different antimicrobial resistance patterns obtained from a beef cattle farm were characterized to determine their clonality. macrorestriction analysis of genomic dna revealed that these four isolates are closely related to each other and can be classified as a newly emerged pulsed-field gel electrophoresis type among cattle: cluster vii. three of the four isolates showed resistance to extended-spectr ...201121869573
hydrogen-stimulated carbon acquisition and conservation in salmonella enterica serovar typhimurium.salmonella enterica serovar typhimurium can utilize molecular hydrogen for growth and amino acid transport during anaerobic growth. via microarray we identified h(2) gas-affected gene expression changes in salmonella. the addition of h(2) caused altered expression of 597 genes, of which 176 genes were upregulated and 421 were downregulated. the significantly h(2)-upregulated genes include those that encode proteins involved in the transport of iron, manganese, amino acids, nucleosides, and sugar ...201121856852
[surveillance of nalidixic acid-resistant and extended-spectrum beta-lactamase-producing salmonella spp. isolated from human feces].nalidixic acid (na)-resistant and extended-spectrum beta-lactamase (esbl)-producing salmonella sp. isolates from human specimens are associated with clinical failure or delayed response in subjects treated with fluoroquinolone or third-generation cephalosporins. we studied drug susceptibility in 604 salmonella enterica isolates from human feces in 2007. of these, 39 (6.5%) were resistat to na. of these, 46% were resistant to two or more drugs and 2% susceptible to na were resistant to multiple d ...201121861438
increased persistence of salmonella enterica serovar typhi in the presence of acanthamoeba castellanii.salmonella enterica serovar typhi (s. typhi) is the etiological agent of the systemic disease typhoid fever. transmission occurs via ingestion of contaminated food or water. s. typhi is specific to humans, and no animal or environmental reservoirs are known. as the free-living amoeba acanthamoeba castellanii is an environmental host for many pathogenic bacteria, this study investigates interactions between s. typhi and a. castellanii by using cocultures. growth of both organisms was estimated by ...201121926221
salmonella persistence and transmission strategies.host-adapted strains of salmonella enterica cause systemic infections and have the ability to persist systemically for long periods of time and pose significant public-health problems. multidrug-resistant salmonella enteric serovar typhi (s. typhi) and non-typhoidal salmonella (nts) are on the increase, and are often associated with hiv infection. chronically infected hosts are often asymptomatic and transmit disease to naïve hosts via fecal shedding of bacteria, thereby serving as a critical re ...201122137596
multi-locus variable-number tandem repeat profiling of salmonella enterica serovar typhi isolates from blood cultures and gallbladder specimens from makassar, south-sulawesi, indonesia.multi-locus variable-number tandem repeat analysis differentiated 297 salmonella enterica serovar typhi blood culture isolates from makassar in 76 genotypes and a single unique s. typhi genotype was isolated from the cholecystectomy specimens of four patients with cholelithiasis. the high diversity in s. typhi genotypes circulating in makassar indicates that the number of carriers could be very large, which may complicate disease prevention and control.201121949819
the antimicrobial effects of propolis collected in different regions in the basque country (northern spain).the antimicrobial activity of 19 propolis extracts prepared in different solvents (ethanol and propylene glycol) (eep/pep), was evaluated against some bacterial and fungal isolates using the agar-well diffusion method. it was verified that all the samples tested showed antimicrobial activity, although results varied considerably between samples. results revealed that both types of propolis extracts showed highly sensitive antimicrobial action against gram-positive bacteria and fungi at a concent ...201122805915
[detection of salmonella and mycobacterium species in seagulls captured in talcahuano, chile].salmonella can be isolated from the feces of seagulls. therefore these birds can be a vector for dissemination of this pathogen.201122446658
[epidemiology, microbiology, and outcomes of septicemia in children treated at the charles de gaulle university pediatric hospital in burkina faso].the aim of this study is to describe the epidemiological and microbiological characteristics and outcome of children with septicemia at the charles de gaulle university pediatric hospital of ouagadougou to help improve probabilistic antibiotic therapy in this type of infection. this retrospective descriptive study covered all the children from 0 to 15 years old seen over a period of 7 years in any hospital department with suspected bacteriemia and for whom the bacteriology laboratory performed a ...201122407247
antimicrobial and safety properties of lactobacilli isolated from two cameroonian traditional fermented foods.twenty-one lactobacillus isolates from "sha'a" (a maize - based fermented beverage) and "kossam" (traditionally fermented cow milk) were selected in accordance with their antagonistic activities and tested for their bacteriocinogenic potential as well as safety properties. these isolates were preliminarily identified as lactobacillus plantarum (62%), lactobacillus rhamnosus (24%), lactobacillus fermentum (10%) and lactobacillus coprophilus (4%) based on phenotypic characteristics and rep-pcr gen ...201122396914
oral co-administration of live attenuated salmonella enterica serovar typhimurium expressing chicken interferon-α and interleukin-18 enhances the alleviation of clinical signs caused by respiratory infection with avian influenza virus h9n2.the combined use of cytokines has shown synergistic and/or additive effects in controlling several viral infections of livestock animals. however, little is known concerning the practical use of chicken cytokine combinations to control avian diseases. here, we investigated the antiviral efficacy of oral co-administration of chicken interferon-α (chifn-α) and chicken interleukin-18 (chil-18) using attenuated salmonella enterica serovar typhimurium in chickens infected with avian influenza virus ( ...201122245401
curtailed short-term and long-term survival following infection with non-typhoid salmonella in israel.among bacterial foodborne pathogens, non-typhoid salmonella enterica (nts) is a leading cause of death worldwide. this study assessed short-term and long-term mortality following nts infection in israel, and evaluated the effects of age, sex, source of isolation and different serotypes on mortality. the source of data was a national registry of nts isolates submitted to the salmonella reference center, government central laboratories, in jerusalem, israel, during 1997-2006. vital status was deri ...201120132249
evaluation of pet-related management factors and the risk of salmonella spp. carriage in pet dogs from volunteer households in ontario (2005-2006).the purpose of this study was to determine pet-related management factors that may be associated with the presence of salmonella spp. in feces of pet dogs from volunteer households. from october 2005 until may 2006, 138 dogs from 84 households in ontario were recruited to participate in a cross-sectional study. five consecutive daily fecal samples were collected from each dog and enrichment culture for salmonella spp. was performed. a higher than expected number of the dogs (23.2%; 32/138) had a ...201120163574
peptidomic analysis of the skin secretions of the frog pachymedusa dacnicolor.high-resolution mass spectrometry-based peptidomics has been used to characterize several components in electro-stimulated skin secretions of the endemic mexican frog pachymedusa dacnicolor. peptide mass screening performed in an orbitrap-xl mass spectrometer showed that p. dacnicolor skin secretions possess 194 different components with molecular masses ranging mainly from 500 to 6,000 da. dozens of molecules were partially sequenced including two novel protease inhibitors. additionally, one po ...201120352461
culture-independent quantification of salmonella enterica in carcass gauze swabs by flotation prior to real-time pcr.to facilitate quantitative risk assessment in the meat production chain, there is a need for culture-independent quantification methods. the aim of this study was to evaluate the use of flotation, a non-destructive sample preparation method based on traditional buoyant density centrifugation, for culture-independent quantification of intact salmonella in pig carcass gauze swabs (100 cm(2)) prior to quantitative pcr (qpcr). a novel approach was investigated, excluding the homogenization step prio ...201120417982
comparative virulence genotyping and antimicrobial susceptibility profiling of environmental and clinical salmonella enterica from cochin, india.salmonella enterica serotype newport is an important cause of non-typhoidal salmonellosis, a clinically less severe infection than typhoid fever caused by s. enterica serotype typhi. in this investigation, the virulence genotypes of s. enterica newport isolated from a backwater environment were compared with salmonella typhi from clinical cases in the same region where salmonellosis is endemic. genotyping was done by pcr screening for virulence markers associated with salmonella pathogenicity is ...201120490498
structural and genetic characterization of the closely related o-antigens of escherichia coli o85 and salmonella enterica o17.o-antigen is a part of the lipopolysaccharide present in the outer membrane of gram-negative bacteria, which confers major antigenic variability to the cell surface. in this study, we report on a previously undefined pair of escherichia coli and salmonella enterica with closely related o-antigens. the o-polysaccharides were isolated from the lipopolysaccharides of e. coli o85 and s. enterica o17 by mild acid degradation and studied by sugar analysis and nmr spectroscopy. the following structure ...201120501518
hemorrhagic colitis as the onset of wegener's granulomatosis. 201120544207
antibacterial activity of extracts from plants of central argentina--isolation of an active principle from achyrocline satureioides.the great increase in bacterial infections is fueling interest in the search for antibacterial products of plant origin. extracts obtained from 51 native and naturalized plants from central argentina were therefore evaluated for their in vitro inhibitory activity on pathogenic bacteria with the aim of selecting the most active ones as new sources of effective antibiotics. the susceptibility of reference and clinical strains of enterococcus faecalis, escherichia coli, proteus mirabilis, pseudomon ...201120645245
on-farm multi-contamination of pigs by food-borne bacterial zoonotic hazards: an exploratory study.application of risk analysis to control pork-borne zoonoses on farms is a major aim of the current european food safety legislation. the prevalence, levels of contamination and variations in pig contaminations according to herds and batches must therefore be studied to define relevant methods for control of zoonoses. the aims of this exploratory study were to provide information on the prevalence and levels of infection of finisher/fattening pigs by campylobacter spp., clostridium perfringens, l ...201120655671
salmonella transcriptional signature in tetrahymena phagosomes and role of acid tolerance in passage through the protist.salmonella enterica typhimurium remains undigested in the food vacuoles of the common protist, tetrahymena. contrary to its interaction with acanthamoeba spp., s. typhimurium is not cytotoxic to tetrahymena and is egested as viable cells in its fecal pellets. through microarray gene expression profiling we investigated the factors in s. typhimurium that are involved in its resistance to digestion by tetrahymena. the transcriptome of s. typhimurium in tetrahymena phagosomes showed that 989 and 12 ...201120686510
rpoe may promote flagellar gene expression in salmonella enterica serovar typhi under hyperosmotic stress.salmonella enterica serovar typhi z66 positive strain contains a fljba-like operon on a linear plasmid. the operon contains the gene fljb:z66 which encodes the z66 antigen. rpoe is a sigma factor σ(e) that initiates transcription of a series of genes in escherichia and salmonella under environmental stresses. to investigate whether the gene fljb:z66 is regulated by rpoe (σ(e)), a rpoe deletion mutant of s. enterica serovar typhi (δrpoe) was prepared in this study. the defective motility of the δ ...201120717675
osteomyelitis in adults: an underrecognized clinical entity in immunocompetent hosts. a report of six cases.osteomyelitis is rare in adults and typically occurs in patients with risk factors such as sickle cell disease or immune deficiency. cases in immunocompetent adults without sickle cell disease are extremely rare. the objective of this work was to describe the epidemiological, clinical, laboratory, and radiological features and the management of long-bone osteomyelitis in immunocompetent adults without sickle cell disease.201120800526
targeting tumor gene by shrna-expressing salmonella-mediated rnai.rna interference (rnai) has been established as an important research tool that carries great potential for gene therapy. however, targeted induction of rnai in vivo has met with significant challenges. in this study, a novel psls plasmid capable of expressing short hairpin rnas (shrnas) was transformed into attenuated salmonella enterica serovar typhimurium strain 7207 (sl). in vitro infection studies with the transformed s. enterica containing psls (sl-psls-cat) demonstrated that expression of ...201120811467
systematic review of animal models of post-infectious/post-inflammatory irritable bowel syndrome.post-infectious irritable bowel syndrome (pi-ibs) is a subset of ibs which occurs after an episode of acute gastrointestinal infections. the mechanisms of pi-ibs are not fully understood. currently, numerous animal models have been used in the study of pi-ibs. this article reviews the strengths and weaknesses of these models.201120848144
joint effects of topoisomerase alterations and plasmid-mediated quinolone-resistant determinants in salmonella enterica typhimurium.alterations in topoisomerases and plasmid-mediated quinolone-resistant (pmqr) determinants have been identified as main quinolone-resistant mechanisms in salmonella enterica typhimurium. but the joint effects of these mechanisms have not been thoroughly characterized in homologous salmonella typhimurium strains. in this study, isogenic topoisomerase mutants were constructed using phage λ red recombinase system and phage transduction. and the joint effects of topoisomerase mutations (gyra [s83f], ...201120818995
molecular subtypes of campylobacter spp., salmonella enterica, and escherichia coli o157:h7 isolated from faecal and surface water samples in the oldman river watershed, alberta, canada.campylobacter spp., salmonella enterica, and escherichia coli o157:h7 isolated from 898 faecal, 43 sewage, and 342 surface water samples from the oldman river were characterized using bacterial subtyping methods in order to investigate potential sources of contamination of the watershed. among these pathogens, campylobacter spp. were the most frequently isolated from faecal, sewage, and surface water samples (266/895, 11/43, and 91/342, respectively), followed by salmonella (67/898, 8/43, and 29 ...201120971491
type vi secretion regulation: crosstalk and intracellular communication.pathogens use type vi secretion systems (t6sss) to transport proteins into the environment or host cells in response to external stimuli. t6sss are tightly regulated together with other virulence determinants such as type iii secretion systems, quorum sensing (qs), and flagella synthesis. five pathogens (salmonella enterica, edwardsiella tarda, aeromonas hydrophila, vibrio cholerae, and pseudomonas aeruginosa) are examined for crosstalk proteins (global regulators) that connect t6sss to other vi ...201120971679
isolation of scfv fragments specific to ompd of salmonella typhimurium.pork meat is one of the major sources for human infections with salmonella enterica subspecies enterica serovars. further, zoonoses caused by s. enterica subspecies enterica serovars are responsible for substantial economical losses in industrial countries. quick and reliable detection of this infection is urgently needed to improve consumer security. due to its capability to identify infections independent of the species, a competitive elisa is the preferable method for the detection of anti-sa ...201120708859
solution nmr structure of the plasmid-encoded fimbriae regulatory protein pefi from salmonella enterica serovar typhimurium. 201120979070
re-emergence of multi-drug resistant salmonella enterica serovar stanley from cattle.during 2009, salmonella enterica subspecies enterica serovar stanley isolates were recovered from cattle diagnostic specimens in southern japan, and the isolates were examined to characterize the genetic determinants involved in this new pathogenicity that associated with mortality in cattle. all the isolates were multi-drug resistance exhibited resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, oxytetracycline, and kanamycin (acssut-km) encoded by blatem, cata, aada1, su ...201121061061
the ubiquitin-binding adaptor proteins p62/sqstm1 and ndp52 are recruited independently to bacteria-associated microdomains to target salmonella to the autophagy pathway. 201121079414
comparison of multilocus variable-number tandem repeat analysis and pulsed-field gel electrophoresis in molecular subtyping of salmonella enterica serovars paratyphi a.salmonella enterica serotype paratyphi a is a highly clonal organism; pulsed-field gel electrophoresis (pfge) is insufficient in discriminating isolates. a multilocus variable-number tandem repeat analysis (mlva) was developed, and its usefulness in discriminating isolates was compared. pfge analysis with xbai and blni discriminated 55 isolates into 14 types, with a discriminatory index (di) of 0.741 (confidence interval [ci], 0.635-0.847). mlva divided the isolates into 23 types, with a di of 0 ...201121146707
effect of heating and aging of poultry litter on the persistence of enteric bacteria.food-borne illnesses have rarely been associated with the reuse of poultry litter as an organic fertilizer and soil amendment in agriculture. yet farming practices in many countries have come under increased scrutiny because of heightened consumer awareness of food safety and environmental issues. this study was conducted to determine whether simple on-farm management practices could improve the microbiological safety of poultry litter. first, the effects of heat and moisture on the survival of ...201121177438
salmonella typhimurium oral challenge model in mature broilers: bacteriological, immunological, and growth performance aspects.in this study, salmonella enterica serovar typhimurium challenge models were tested to identify the best conditions under which to perform the experimental infection of 3-wk-old broilers. such a model would be useful to study the efficiency of therapeutic treatments that could take place at the end of the grow-out period. salmonella-free chicks were obtained from a breeder flock vaccinated with salmonella. intestinal maternal immunity was monitored by elisa analyses at 2, 9, and 16 d of age. dat ...201121177444
the impact of different housing systems on egg safety and quality.a move from conventional cages to either an enriched cage or a noncage system may affect the safety or quality, or both, of the eggs laid by hens raised in this new environment. the safety of the eggs may be altered either microbiologically through contamination of internal contents with salmonella enterica serovar enteritidis (salmonella enteritidis) or other pathogens, or both, or chemically due to contamination of internal contents with dioxins, pesticides, or heavy metals. quality may be aff ...201121177467
identification and biological activity of potential probiotic bacterium isolated from the stomach mucus of breast-fed lamb.the lactic acid bacterium e isolated from the stomach mucus of breast-fed lamb was identified by sequencing of 16s rdna fragment and species-specific pcr as lactobacillus reuteri. its potential antimicrobial activity and ability to modulate immune system in vitro and in vivo was determined. the growth inhibition of potential pathogens decreased from staphylococcus aureus, pseudomonas aeruginosa, salmonella enterica ser. minnesota to escherichia coli. the lowest inhibition activity was observed i ...201124031741
development of recombinant vaccines in lactobacilli for elimination of salmonella.many lactobacillus and lactococcus strains are generally regarded as safe for consumption because they are utilized for food fermentation or inhabit the intestinal mucosa as commensals. recently, vaccine delivery systems using lactic acid bacteria (lab) have been under development. our research group has been investigating the development of oral mucosal vaccines against salmonella enterica serovar enteritidis (se) using lactobacillus casei igm393 as an antigen delivery vehicle. recombinant lact ...201125045314
bilateral breast abscesses due to salmonella enterica serotype typhi.focal infection is an uncommon complication of salmonella septicemia, particularly in immunocompetent patients. the localization of salmonella infection to breast tissue is regarded as a rare event. we report a case of bilateral breast abscesses due to salmonellaenterica serotype typhi in a nonlactating female and highlight the fact that salmonella spp. should be included in differential diagnosis of abscesses in individuals coming from endemic areas with the history of recent typhoid fever and ...201122224009
genotypic and phenotypic differentiation of salmonella enterica serovar paratyphi b in malaysia.abstract. salmonella enterica serovar paratyphi b is known to cause either paratyphoid fever or gastroenteritis. differentiation of salmonella ser. paratyphi b into biotype java (d-tartrate fermenting, dt+) and biotype paratyphi b (d-tartrate non-fermenting, dt) is important for salmonella epidemiology. this study applied a pcr approach to differentiate the two biotypes to augment the conventional biochemical method and to determine the antibiograms and genomic diversity of malaysian s. paratyph ...201122299444
widespread presence of dfra12 and its association with dfra12-aada2 cassette in salmonella enterica isolates from swine.one hundred and eighty-nine salmonella isolates from swine were tested for susceptibility to nine antimicrobial agents, presence of dfra12 and class 1 integrons containing dfra12-orff-aada2 cassette. all isolates were multidrug resistant and exhibited highest resistance prevalence to trimethoprim (93%). most isolates (89%) were intll-positive and 107 isolates (57%) carried dfra12, all of which were resistant to trimethoprim. forty-eight dfra12-harboring strains (45%) were intl1-positive together ...201122299418
characterization of class 1 integrons and antibiotic resistance genes in multidrug-resistant salmonella enterica isolates from foodstuff and related sources.in recent years, an increase in the occurrence of antimicrobial resistance among salmonella enterica has been observed in several countries, which is worrisome because s. enterica is one of the most common causes of human gastroenteritis worldwide. the aim of this study was to characterize class 1 integrons and antibiotic resistance genotypes in salmonella enterica isolates recovered from foodstuff and related sources. nineteen multidrug-resistant (mdr) salmonella enterica isolates were recovere ...201124031680
genomic fingerprinting and serotyping of salmonella from galápagos iguanas demonstrates island differences in strain diversity.salmonella carriage patterns in wild and captive reptiles suggest that both geographical proximity and host ecological differences may determine bacterial diversity among reptile populations. in this study, we explore the relative importance of these factors on salmonella diversity in free-living galápagos iguanas. we isolated salmonella enterica from marine iguanas (amblyrhynchus cristatus) and land iguanas (conolophus subcristatus and c. pallidus) living on two islands (plaza sur and santa fe) ...201123761248
salmonella enterica serotype typhi from a case of empyema. 201123785888
an outbreak of gastroenteritis caused by salmonella enterica serotype enteritidis traced to cream cakes.this paper describes the epidemiological, microbiological and environmental investigations conducted during an outbreak of salmonella gastroenteritis in singapore.201123908880
salmonella meningitis in a paediatric patient caused by salmonella enterica serotype houtenae.the authors report a case of a 6-week-old baby girl who was admitted to the paediatric ward due to a high fever for 2 days. the patient experienced three fits which took place while in the ward. a brain sonogram showed subdural heterogeneous collection consistent with focal empyema; however, no hydrocephalus or infarction was detected. an urgent burr hole procedure was performed to remove the collected pus. both blood and cerebrospinal fluid (csf) culture grew salmonella species which remain sen ...201122689601
salmonella enterica serovar paratyphi a: an emerging cause of febrile illness in nepal.with an aim to evaluate the isolation rate and antibiotic susceptibility pattern in salmonella enterica serovar typhi and s. paratyphi a, 656 blood samples collected from clinically diagnosed enteric fever patients at national public health laboratory, nepal during january through december 2008 were processed. isolates were identified by standard microbiological procedures including serotyping. antibiotic susceptibility testing was performed by disc diffusion method and minimum inhibitory concen ...201122364084
[serotypes and antimicrobial susceptibility patterns of salmonella strains isolated from food in cuba].the serotypes of 178 isolates of salmonella enterica taken from food in different regions of cuba between january 2008 and december 2009 were identified, and the antimicrobial susceptibility pattern of 100 selected isolates was determined by strata sampling. a total of 20 salmonella serotypes were identified, with a predominance of s. enteritidis (23%), s. agona (13.5%), and s. london (11.2%). of all the strains, 75% were resistant or presented intermediate resistance to at least one of the drug ...201122358403
[characteristics of salmonella enterica serovar senftenberg lacking salmonella pathogenicity island 1].to study the characteristics of the strains of salmonella enterica (s. enterica) serovar senftenberg lacking salmonella pathogenicity island 1 (spi-1).201122321589
survival of salmonella typhi and shigella dysenteriae in dehydrated infant formula.powdered infant formula has previously been linked to the transmission of various bacterial pathogens in infants resulting in life-threatening disease and death. survival studies of 2 common foodborne pathogens, salmonella enterica serovar typhi and shigella dysenteriae, in powdered infant formula have not been previously studied despite the potentially devastating consequences from ingestion of these organisms, particularly by newborns, in case of a natural or deliberate contamination event. th ...201122417504
distribution and genetic diversity of salmonella enterica in the upper suwannee river.the suwannee river spans the florida/georgia border to the gulf of mexico, and contributes to regional irrigation and recreational activities. association of salmonella enterica with these resources may result in the contamination of produce and disease outbreaks. therefore, surface water was examined for the distribution of s. enterica at multiple time points from 4 sites on the upper suwannee river. isolates were confirmed by detection of the inva gene, and 96% of all samples were positive for ...201122347228
antimicrobial resistance profile and presence of class i integrongs among salmonella enterica serovars isolated from human clinical specimens in tehran, iran.salmonella is one of the leading causes of food-borne diseases. increasing occurrence of antimicrobial resistance, especially multidrug-resistance, in salmonella serovars is a major public health problem worldwide. this study was carried out to detect class i integrons and antibiotic resistance profiles in clinical isolates of salmonella serovars collected from seven hospitals in tehran during november 2009 to june 2010.201122347592
requirement for cobalamin by salmonella enterica serovars typhimurium, pullorum, gallinarum and enteritidis during infection in chickens.salmonella enterica serovar typhimurium synthesizes cobalamin (vitamin b12) only during anaerobiosis. two percent of the s. typhimurium genome is devoted to the synthesis and uptake of vitamin b12 and to b12-dependent reactions. to understand the requirement for cobalamin synthesis better, we constructed mutants of salmonella serovars enteritidis and pullorum that are double-defective in cobalamin biosynthesis (δcobsδcbia). we compared the virulence of these mutants to that of their respective w ...201124031771
oral and intranasal administration of somatostatin dna vaccine mediated by attenuated salmonella enterica serovar typhimurium to promote growth of piglets.an attenuated strain of salmonella typhimurium has been used as a carrier for oral and intranasal genetic immunization. here, we evaluate the efficacy of a vaccine strain of s. typhimurium. cso22 (pgm-csf/ss, plasmid granulocyte-macrophage colony-stimulating factor/somatostatin) expressing two copies of ss genes. a total of 115 piglets, aged 2 months old, were either orally or intranasally immunized against the vaccine strain cso22 (pgm-csf/ss) with three dosages (5 × 10(10) colony forming units ...201122440175
cellulose mediates attachment of salmonella enterica serovar typhimurium to tomatoes.fresh fruit and vegetables are important components of a healthy and balanced diet. however, they are increasingly being recognized as important vehicles for transmission of human pathogens that were traditionally classified as zoonotic. there is a significant gap in our knowledge and understanding of the mechanisms by which human pathogens colonize and survive on or in fruits and vegetables. in this study we investigated the binding of salmonella enterica to tomato fruits (solanum lycopersicum) ...201123761337
intestinal and chronic infections: salmonella lifestyles in hostile environments.the main disease syndromes caused by salmonella serovars in immunocompetent individuals are gastroenteritis and typhoid fever. these syndromes differ with regard to the host niches in which salmonella serovars grow and survive to ensure their transmission. during gastroenteritis, non-typhoidal salmonella serovars such as salmonella enterica serovar typhimurium (s. typhimurium) use their virulence factors to elicit acute intestinal inflammation, thereby creating a novel luminal niche. reactive ox ...201123761329
pcr-restriction fragment length polymorphism analysis of fljb gene in salmonella enterica subspecies enterica serovar typhimurium isolated from avians.economic constraint of diseases arising from salmonella typhimurium causes the study of this zoonotic organism more important. most studies on identification and characterization of s. typhimurium are conducted at dna level. flagellin genes (flic and fljb genes encoding phase-1 and phase-2 flagella, respectively) are useful as a model system for studying genetic differentiation. the objectives of the present study were to identify the polymorphism of fljb among avians in different regions by the ...201022347569
low prevalence of salmonella enterica in australian wildlife.a total of 2489 wildlife hosts from australia were sampled in order to determine the fraction of hosts that harboured salmonella enterica as a dominant member of the host's enteric community. hosts sampled included fish, frogs, reptiles, birds and mammals from the four main climatic regions of australia: desert, grassland, temperate and tropical. salmonella enterica was predominately isolated from reptiles, in particular, lizards. it was also isolated from mammals, though not from any fish, frog ...201023766252
the stability of rrna in heat-killed salmonella enterica cells and its detection by fluorescent in situ hybridisation (fish).differentiation of viable cells from non-viable cells is a major concern in the detection of foodborne microbial pathogens. fluorescent in situ hybridisation (fish) has been utilised as a promising method in this regard. the ability of fish to differentiate viable cells from non-viable cells depends on the rapid degradation of rrna in non-viable cells. in our work, salmonella enterica that were heat-killed at 80°c, 100°c and 121°c were examined for the presence of rrna using fish at various time ...201024575189
expression of fljb:z66 on a linear plasmid of salmonella enterica serovar typhi is dependent on flia and flhdc and regulated by ompr.salmonella enterica serovar typhi z66-positive strains have two different flagellin genes, flic:d/j and fljb:z66, located on the chromosome and on a linear plasmid, respectively. to investigate the mechanism underlying the expressional regulation of fljb:z66, gene deletion mutants of the regulators flia, flhdc, and ompr were constructed in this study. the expression levels of flic and fljb:z66 were analyzed by qrt-pcr in the wild-type strain and mutants at high and low osmolarity. the results sh ...201024031550
stress and microbial endocrinology: prospects for ruminant nutrition.the feed efficiency of ruminant meat and dairy livestock can be significantly influenced by factors within their living environments. in particular, events perceived by the animals as stressful (such as parturition, transport or handling) have been found to affect susceptibility to infection. it has been well documented that even minor stress such as weighing can result in an increase in colonisation and faecal shedding of enteric pathogens such as salmonella enterica and escherichia coli o157:h ...201022444620
microfluidic channels on nanopatterned substrates: monitoring protein binding to lipid bilayers with surface-enhanced raman spectroscopy.we used surface enhanced raman spectroscopy (sers) to detect binding events between streptavidin and biotinylated lipid bilayers. the binding events took place at the surface between microfluidic channels and anodized aluminum oxide (aao) with the latter serving as substrates. the bilayers were incorporated in the substrate pores. it was revealed that non-bound molecules were easily washed away and that large suspended cells (salmonella enterica) are less likely to interfere with the monitoring ...201024932024
yields from blood cultures of patients with suspected paratyphoid fever a.the yield and speed of detection of salmonella enterica serotype paratyphi a from the blood of patients with suspected paratyphoid fever a in 13 500 paired aerobic and anaerobic bottles (aeb, anb) that were each filled with 5 ml of blood by the bact/alert 3d system were compared, and the blood bacterial counts of 1 000 probable patients were estimated by pour plate method. a total of 4 060 isolates were recovered, of these, 3 149 were recovered from both aeb and anb, 461 from the aeb only, and 4 ...201024031492
epidemic multidrug-resistant (mdr-ampc) salmonella enterica serovar newport strains contain three phage regions and a mdr resistance plasmid.multidrug-resistant (mdr-ampc) salmonella enterica serovar newport has caused serious disease in animals and humans in north america, whereas in the uk s. enterica serovar newport is not associated with severe disease and usually sensitive to antibiotics; mdr s. newport (not ampc) strains have only been isolated from poultry. we found that uk poultry strains belonged to mlst type st166 and were distinct from cattle isolates for being able to utilize d-tagotose and when compared by pulsed-field g ...201023766073
differential effect of lactobacillus johnsonii bfe 6128 on expression of genes related to tlr pathways and innate immunity in intestinal epithelial cells.probiotics have been shown to enhance immune defenses, but their mechanisms of action are only partially understood. we investigated the modulation of signal pathways involved in innate immunity in enterocytes by lactobacillus johnsonii bfe 6128 isolated from 'kule naoto', a maasai traditional fermented milk product. this lactobacillus sensitized ht29 intestinal epithelial cells toward recognition of salmonella enterica serovar typhimurium by increasing the il-8 levels released after challenge w ...201026781315
evaluation of in vitro probiotic potential of pediococcus pentosaceus ozf isolated from human breast milk.this study was conducted to evaluate the probiotic properties of pediococcus pentosaceus ozf isolated from human breast milk. the results obtained so far suggest that the strain is resistant to low ph, bile salt, pepsin and pancreatin, so it could survive while passing through the upper part of the gastrointestinal tract and reveal its potential probiotic action on host organism. the strain was non-pathogenic (γ-hemolytic), produced anti-listerial bacteriocin, exhibited a strong autoaggregating ...201026781239
antibiotic resistant salmonella and escherichia coli isolated from indigenous gallus domesticus in nairobi, kenya.to characterise and investigate antimicrobial resistance of esherichia coli and salmonella strains isolated from indigenous gallus gallus in a leading slaughterhouse/market outlet in nairobi-kenya.201023057283
effects of myrcia ovata cambess. essential oil on planktonic growth of gastrointestinal microorganisms and biofilm formation of enterococcus faecalis.the essential oil from the leaves of myrcia ovata cambess., commonly used in brazil for the treatment of gastric illnesses, was screened for antimicrobial activity and action in the formation of microbial biofilms by enterococcus faecalis. the oil was obtained by hydrodistillation using a clevenger-type system. its chemical composition was analyzed using gc and gc-ms. both mic and mbc of the essential oil were determined by broth microdilution techniques and agar dilution method. the essential o ...201024031537
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