| comparative analysis of salmonella susceptibility and tolerance to the biocide chlorhexidine identifies a complex cellular defense network. | chlorhexidine is one of the most widely used biocides in health and agricultural settings as well as in the modern food industry. it is a cationic biocide of the biguanide class. details of its mechanism of action are largely unknown. the frequent use of chlorhexidine has been questioned recently, amidst concerns that an overuse of this compound may select for bacteria displaying an altered susceptibility to antimicrobials, including clinically important anti-bacterial agents. we generated a sal ... | 2014 | 25136333 |
| synthesis of metallo-β-lactamase vim-2 is associated with a fitness reduction in salmonella enterica serovar typhimurium. | antibiotic resistance, especially due to β-lactamases, has become one of the main obstacles in the correct treatment of salmonella infections; furthermore, antibiotic resistance determines a gain of function that may encompass a biological cost, or fitness reduction, to the resistant bacteria. the aim of this work was to determine in vitro if the production of the class b β-lactamase vim-2 determined a fitness cost for salmonella enterica serovar typhimurium. to that end the gene blavim-2 was cl ... | 2014 | 25136026 |
| coptidis rhizome and si jun zi tang can prevent salmonella enterica serovar typhimurium infection in mice. | salmonella, a common zoonotic pathogen, causes gastroenteritis in both humans and animals. traditional chinese medicine (tcm) has been used to improve gastrointestinal dysfunction and to modify the immune response to inflammation for centuries. this study used six herbal plants and four tcm formulae to rate their efficacy in preventing s. typhimurium infection via mouse model. minimum bactericidal concentration (mbc) of coptidis rhizome (cr) against the reference strain tallied 12.5 mg/ml and ag ... | 2014 | 25133542 |
| understanding the basis of antibiotic resistance: a platform for drug discovery. | there are numerous genes in salmonella enterica serovar typhimurium that can confer resistance to fluoroquinolone antibiotics, including those that encode topoisomerase proteins, the primary targets of this class of drugs. however, resistance is often multifactorial in clinical isolates and it is not uncommon to also detect mutations in genes that affect the expression of proteins involved in permeability and multi-drug efflux. the latter mechanism, mediated by tripartite efflux systems, such as ... | 2014 | 25122880 |
| a small intestinal organoid model of non-invasive enteric pathogen-epithelial cell interactions. | organoids mirror in vivo tissue organization and are powerful tools to investigate the development and cell biology of the small intestine. however, their application for the study of host-pathogen interactions has been largely unexplored. we have established a model using microinjection of organoids to mimic enteric infection, allowing for direct examination of pathogen interactions with primary epithelial cells in the absence of confounding variables introduced by immune cells or the commensal ... | 2015 | 25118165 |
| stress response of salmonella enterica serovar typhimurium to acidified nitrite. | the antimicrobial action of the curing agent sodium nitrite (nano2), which is added as a preservative to raw meat products, depends on its conversion to nitric oxide and other reactive nitrogen species under acidic conditions. in this study, we used rna sequencing to analyze the acidified-nano2 shock and adaptive responses of salmonella enterica serovar typhimurium, a frequent contaminant in raw meat, considering parameters relevant for the production of raw-cured sausages. upon a 10-min exposur ... | 2014 | 25107963 |
| interaction of the carbon monoxide-releasing molecule ru(co)3cl(glycinate) (corm-3) with salmonella enterica serovar typhimurium: in situ measurements of carbon monoxide binding by integrating cavity dual-beam spectrophotometry. | carbon monoxide (co) is a toxic gas that binds to haems, but also plays critical signalling and cytoprotective roles in mammalian systems; despite problems associated with systemic delivery by inhalation of the gas, it may be employed therapeutically. co delivered to cells and tissues by co-releasing molecules (co-rms) has beneficial and toxic effects not mimicked by co gas; co-rms are also attractive candidates as novel antimicrobial agents. salmonella enterica serovar typhimurium is an enterop ... | 2014 | 25085864 |
| iron at the interface of immunity and infection. | both, mammalian cells and microbes have an essential need for iron, which is required for many metabolic processes and for microbial pathogenicity. in addition, cross-regulatory interactions between iron homeostasis and immune function are evident. cytokines and the acute phase protein hepcidin affect iron homeostasis leading to the retention of the metal within macrophages and hypoferremia. this is considered to result from a defense mechanism of the body to limit the availability of iron for e ... | 2014 | 25076907 |
| mucosal inflammatory response to salmonella typhimurium infection. | the human intestinal epithelium consists of a single layer of epithelial cells that forms a barrier against food antigens and the resident microbiota within the lumen. this delicately balanced organ functions in a highly sophisticated manner to uphold the fidelity of the intestinal epithelium and to eliminate pathogenic microorganisms. on the luminal side, this barrier is fortified by a thick mucus layer, and on the serosal side exists the lamina propria containing a resident population of immun ... | 2014 | 25071772 |
| dissecting the cyclic di-guanylate monophosphate signalling network regulating motility in salmonella enterica serovar typhimurium. | flagella-mediated swimming and swarming motility in salmonella enterica serovar typhimurium is intercalated with the cyclic di-guanylate monophosphate (c-di-gmp) signalling network. in this study, we identified the ggdef domain proteins stm2672, stm4551 and stm1987 as key di-guanylate cyclases involved in regulation of motility in a δyhjh phosphodiesterase gene deletion mutant with elevated c-di-gmp levels inhibiting motility. surprisingly, these di-guanylate cyclases distinctively inhibited mot ... | 2015 | 25059628 |
| salmonella enterica serovar typhimurium multidrug efflux pumps emrab and acref support the major efflux system acrab in decreased susceptibility to triclosan. | | 2014 | 25059442 |
| the salmonella typhimurium effector protein sope transiently localizes to the early scv and contributes to intracellular replication. | salmonella enterica serovar typhimurium (s. tm) is a facultative intracellular pathogen that induces entry into non-phagocytic cells by a type iii secretion system (ttss) and cognate effector proteins. upon host cell entry, s. tm expresses a second ttss and subverts intracellular trafficking to create a replicative niche - the salmonella-containing vacuole (scv). sope, a guanidyl exchange factor (gef) for rac1 and cdc42, is translocated by the ttss-1 upon host cell contact and promotes entry thr ... | 2014 | 25052734 |
| complete genome sequence of salmonella enterica serovar typhimurium vnp20009, a strain engineered for tumor targeting. | a mutagenized and genetically modified derivative of salmonella enterica serovar typhimurium 14028s, vnp20009 (atcc 202165), is attenuated in host virulence and accumulates preferentially in tumors. here, we report the complete genome of this anticancer therapy agent consisting of one chromosome and one virulence plasmid. the major genetic features that distinguish vnp20009 from its parental strain are: an engineered msbb deletion, a 3'-extension in pyka, a tn10-caused 16.6-kbp inversion leading ... | 2014 | 25046822 |
| the ins and outs of bacterial iron metabolism. | iron is a critical nutrient for the growth and survival of most bacterial species. accordingly, much attention has been paid to the mechanisms by which host organisms sequester iron from invading bacteria and how bacteria acquire iron from their environment. however, under oxidative stress conditions such as those encountered within phagocytic cells during the host immune response, iron is released from proteins and can act as a catalyst for fenton chemistry to produce cytotoxic reactive oxygen ... | 2014 | 25040830 |
| the rcscdb regulatory system plays a crucial role in the protection of salmonella enterica serovar typhimurium against oxidative stress. | dps, the most abundant protein during the stationary growth phase, in salmonella enterica is required for resistance to reactive oxygen species produced by the host during infection. it has been reported that in salmonella dps expression is controlled by rpos and fur proteins. however, the regulation and function of dps remain to be resolved. in the present work we demonstrate that activation of the complex rcscdb regulatory system increases dps expression during exponential growth of salmonella ... | 2014 | 25028458 |
| phenotypic evolution of therapeutic salmonella enterica serovar typhimurium after invasion of tramp mouse prostate tumor. | salmonella has been of interest in cancer research due to its intrinsic ability to selectively target and colonize within tumors, leading to tumor cell death. current research indicates promising use of salmonella in regular administrations to remove tumors in mouse models while minimizing toxic side effects. however, selection of mutants during such long-term tumor colonization is a safety concern, and understanding selection of certain phenotypes within a tumor is an important consideration in ... | 2014 | 24987088 |
| salmonella methylglyoxal detoxification by stm3117-encoded lactoylglutathione lyase affects virulence in coordination with salmonella pathogenicity island 2 and phagosomal acidification. | intracellular pathogens such as salmonella enterica serovar typhimurium (s. typhimurium) manipulate their host cells through the interplay of various virulence factors. a multitude of such virulence factors are encoded on the genome of s. typhimurium and are usually organized in pathogenicity islands. the virulence-associated genomic stretch of stm3117-3120 has structural features of pathogenicity islands and is present exclusively in non-typhoidal serovars of salmonella. it encodes metabolic en ... | 2014 | 24961952 |
| suppression of conformation-compromised mutants of salmonella enterica serovar typhimurium melb. | the crystal structure of the na(+)-coupled melibiose permease of salmonella enterica serovar typhimurium (melbst) demonstrates that melb is a member of the major facilitator superfamily of transporters. arg residues at positions 295, 141, and 363 are involved in interdomain interactions at the cytoplasmic side by governing three clusters of electrostatic/polar interactions. insertion of (one at a time) glu, leu, gln, or cys at positions r295, r141, and r363, or lys at position r295, inhibits act ... | 2014 | 24957620 |
| analysis of salmonella enterica serovar typhimurium variable-number tandem-repeat data for public health investigation based on measured mutation rates and whole-genome sequence comparisons. | variable-number tandem repeats (vntrs) mutate rapidly and can be useful markers for genotyping. while multilocus vntr analysis (mlva) is increasingly used in the detection and investigation of food-borne outbreaks caused by salmonella enterica serovar typhimurium (s. typhimurium) and other bacterial pathogens, mlva data analysis usually relies on simple clustering approaches that may lead to incorrect interpretations. here, we estimated the rates of copy number change at each of the five loci co ... | 2014 | 24957617 |
| dam methylation regulates the expression of spi-5-encoded sopb gene in salmonella enterica serovar typhimurium. | dna adenine methylation is an essential factor in salmonella virulence. here, we investigate the involvement of dna adenine methylase (dam) in the expression and translocation of a spi-5-encoded effector of s. typhimurium. sopb expression and secretion were determined using sopb-flag-tagged wild type and dam strains of s. typhimurium. western blot and quantitative reverse transcriptase pcr analysis showed that the dam mutant expresses lower levels of sopb protein and sopb mrna than the wild type ... | 2014 | 24947562 |
| unique helicase determinants in the essential conjugative trai factor from salmonella enterica serovar typhimurium plasmid pcu1. | the widespread development of multidrug-resistant bacteria is a major health emergency. conjugative dna plasmids, which harbor a wide range of antibiotic resistance genes, also encode the protein factors necessary to orchestrate the propagation of plasmid dna between bacterial cells through conjugative transfer. successful conjugative dna transfer depends on key catalytic components to nick one strand of the duplex dna plasmid and separate the dna strands while cell-to-cell transfer occurs. the ... | 2014 | 24936053 |
| identification and characterization of outer membrane vesicle-associated proteins in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium is a primary cause of enteric diseases and has acquired a variety of virulence factors during its evolution into a pathogen. secreted virulence factors interact with commensal flora and host cells and enable salmonella to survive and thrive in hostile environments. outer membrane vesicles (omvs) released from many gram-negative bacteria function as a mechanism for the secretion of complex mixtures, including virulence factors. we performed a proteomic anal ... | 2014 | 24935973 |
| gene co-expression network analysis identifies porcine genes associated with variation in salmonella shedding. | salmonella enterica serovar typhimurium is a gram-negative bacterium that can colonise the gut of humans and several species of food producing farm animals to cause enteric or septicaemic salmonellosis. while many studies have looked into the host genetic response to salmonella infection, relatively few have used correlation of shedding traits with gene expression patterns to identify genes whose variable expression among different individuals may be associated with differences in salmonella cle ... | 2014 | 24912583 |
| a novel mucosal vaccine targeting peyer's patch m cells induces protective antigen-specific iga responses. | mucosal vaccines can induce mucosal immunity, including antigen-specific secretory iga production, to protect from invasion by pathogens and to neutralize toxins at mucosal surfaces. we established an effective antigen-delivering fusion protein, anti-gp2-sa, as a mucosal vaccine. the anti-gp2-sa consists of streptavidin (sa) fused to the antigen-binding fragment region from a mab against glycoprotein 2 (gp2), an antigen-uptake receptor specifically expressed on m cells. anti-gp2-sa targets antig ... | 2014 | 24908678 |
| parenteral administration of attenuated salmonella typhimurium δznuabc is protective against salmonellosis in piglets. | a major cause of salmonellosis in humans is the contamination of pork products. infection in pigs can be controlled using bio-security programs, but they are not sufficient in countries where a high level of infection is recorded. in this context, the use of vaccines can represent a valid supplementary method of control. recently, we have demonstrated that an attenuated strain of salmonella enterica serovar typhimurium (salmonella typhimurium δznuabc) is protective against systemic and enteric s ... | 2014 | 24907486 |
| molecular characterization of thai salmonella enterica serotype typhimurium and serotype 4,5,12:i:- reveals distinct genetic deletion patterns. | in order to better understand the relationship between salmonella serotypes typhimurium and its monophasic variant 4,5,12:i:- found in thailand, a total of 138 isolates from various sources were characterized using different molecular subtyping methods (i.e., pulsed-field gel electrophoresis [pfge] and polymerase chain reaction [pcr]) and antibiotic resistance (abr) patterns. pfge revealed 52 distinct band patterns among these isolates, 3 of which were shared between the two serotypes. pcr chara ... | 2014 | 24906076 |
| comparison of the sensitivity of strains of salmonella enterica serovar typhimurium in the detection of mutagenicity induced by nitroarenes. | the use of strains of salmonella enterica serovar typhimurium with different metabolic capacities can indicate the class or classes of compounds present in an environmental sample and enable the diagnosis of the mutagenic activity of these pollutants adsorbed on particulate matter (pm) in the air. in the present study, the sensitivity of salmonella strains ta98nr, ta98/1,8-dnp₆, yg1021, and yg1024 to detect nitro compounds adsorbed on samples of pm 2.5 was compared from three sites in rio de jan ... | 2014 | 24854446 |
| fusaric acid modulates type three secretion system of salmonella enterica serovar typhimurium. | natural small-molecule products are promising lead compounds for developing a generation of novel antimicrobials agents to meet the challenge of antibiotic-resistant pathogens. to facilitate the search for novel anti-virulence agents, we chose a virulence factor of type three secretion system (t3ss) as a drug target to screen candidates from a small-molecule library in our laboratory. this study demonstrated fusaric acid had dramatically inhibitory effects on secretion of salmonella island 1 (sp ... | 2014 | 24853802 |
| salmonella enterica serovar typhimurium immunotherapy for b-cell lymphoma induces broad anti-tumour immunity with therapeutic effect. | despite the efficacy of current immune-chemotherapy for treatment of b-cell non-hodgkin lymphoma, a substantial proportion of patients relapse, highlighting the need for new therapeutic modalities. the use of live microorganisms to develop anti-tumoural therapies has evolved since coley's toxin and is now receiving renewed attention. salmonella typhimurium has been shown to be highly effective as an anti-tumour agent in many solid cancer models, but it has not been used in haemato-oncology. here ... | 2014 | 24834964 |
| bile-mediated activation of the acrab and tolc multidrug efflux genes occurs mainly through transcriptional derepression of rama in salmonella enterica serovar typhimurium. | in salmonella typhimurium, the genes encoding the acrab-tolc multidrug efflux system are mainly regulated by the ramra locus, composed of the divergently transcribed rama and ramr genes. the acrab and tolc genes are transcriptionally activated by rama, the gene for which is itself transcriptionally repressed by ramr. previous studies have reported that bile induces acrab in a rama-dependent manner, but none provided evidence for an induction of rama expression by bile. therefore, the objective o ... | 2014 | 24816212 |
| expanding the rpos/σs-network by rna sequencing and identification of σs-controlled small rnas in salmonella. | the rpos/σs sigma subunit of rna polymerase (rnap) controls a global adaptive response that allows many gram-negative bacteria to survive starvation and various stresses. σs also contributes to biofilm formation and virulence of the food-borne pathogen salmonella enterica serovar typhimurium (s. typhimurium). in this study, we used directional rna-sequencing and complementary assays to explore the σs-dependent transcriptome of s. typhimurium during late stationary phase in rich medium. this stud ... | 2014 | 24810289 |
| nutritional and metabolic requirements for the infection of hela cells by salmonella enterica serovar typhimurium. | salmonella is the causative agent of a spectrum of human and animal diseases ranging from gastroenteritis to typhoid fever. it is a food--and water--borne pathogen and infects via ingestion followed by invasion of intestinal epithelial cells and phagocytic cells. in this study we employed a mutational approach to define the nutrients and metabolic pathways required by salmonella enterica serovar typhimurium during infection of a human epithelial cell line (hela). we deleted the key glycolytic ge ... | 2014 | 24797930 |
| the salmonella effector stea contributes to the control of membrane dynamics of salmonella-containing vacuoles. | salmonella enterica serovar typhimurium is a bacterial pathogen causing gastroenteritis in humans and a typhoid-like systemic disease in mice. s. typhimurium virulence is related to its capacity to multiply intracellularly within a membrane-bound compartment, the salmonella-containing vacuole (scv), and depends on type iii secretion systems that deliver bacterial effector proteins into host cells. here, we analyzed the cellular function of the salmonella effector stea. we show that, compared to ... | 2014 | 24778114 |
| emergence of clinical salmonella enterica serovar typhimurium isolates with concurrent resistance to ciprofloxacin, ceftriaxone, and azithromycin. | salmonella infection is an important public health issue for which the needs of antimicrobial treatment are increasing. a total of 546 human clinical s. enterica serovar typhimurium isolates were recovered from patients in hospitals in china during the period of 2005 to ∼ 2011. twenty percent of the isolates exhibited resistance to ciprofloxacin, and 4% were resistant to ceftriaxone. importantly, for the first time, 12 (2%) s. typhimurium isolates resistant to both ciprofloxacin and ceftriaxone ... | 2014 | 24752251 |
| sub-inhibitory fosmidomycin exposures elicits oxidative stress in salmonella enterica serovar typhimurium lt2. | fosmidomycin is a time-dependent nanomolar inhibitor of methylerythritol phosphate (mep) synthase, which is the enzyme that catalyzes the first committed step in the mep pathway to isoprenoids. importantly, fosmidomycin is one of only a few mep pathway-specific inhibitors that exhibits antimicrobial activity. most inhibitors identified to date only exhibit activity against isolated pathway enzymes. the mep pathway is the sole route to isoprenoids in many bacteria, yet has no human homologs. the ... | 2014 | 24751777 |
| the sdia-regulated gene srge encodes a type iii secreted effector. | salmonella enterica serovar typhimurium is a food-borne pathogen that causes severe gastroenteritis. the ability of salmonella to cause disease depends on two type iii secretion systems (t3sss) encoded in two distinct salmonella pathogenicity islands, 1 and 2 (spi1 and spi2, respectively). s. typhimurium encodes a solo luxr homolog, sdia, which can detect the acyl-homoserine lactones (ahls) produced by other bacteria and upregulate the rck operon and the srge gene. srge is predicted to encode a ... | 2014 | 24727228 |
| integrative analysis of salmonellosis in israel reveals association of salmonella enterica serovar 9,12:l,v:- with extraintestinal infections, dissemination of endemic s. enterica serovar typhimurium dt104 biotypes, and severe underreporting of outbreaks. | salmonella enterica is the leading etiologic agent of bacterial food-borne outbreaks worldwide. this ubiquitous species contains more than 2,600 serovars that may differ in their host specificity, clinical manifestations, and epidemiology. to characterize salmonellosis epidemiology in israel and to study the association of nontyphoidal salmonella (nts) serovars with invasive infections, 48,345 salmonella cases reported and serotyped at the national salmonella reference center between 1995 and 20 ... | 2014 | 24719441 |
| persistent salmonellosis causes pancreatitis in a murine model of infection. | pancreatitis, a known risk factor for the development of pancreatic ductal adenocarcinoma, is a serious, widespread medical condition usually caused by alcohol abuse or gallstone-mediated ductal obstruction. however, many cases of pancreatitis are of an unknown etiology. pancreatitis has been linked to bacterial infection, but causality has yet to be established. here, we found that persistent infection of mice with the bacterial pathogen salmonella enterica serovar typhimurium (s. typhimurium) ... | 2014 | 24717768 |
| removal of the phage-shock protein pspb causes reduction of virulence in salmonella enterica serovar typhimurium independently of nramp1. | the phage-shock protein (psp) system is believed to manage membrane stress in all enterobacteriaceae and has recently emerged as being important for virulence in several pathogenic species of this phylum. the core of the psp system consists of the pspa-d operon and the distantly located pspg gene. in salmonella enterica serovar typhimurium (s. typhimurium), it has recently been reported that pspa is essential for systemic infection of mice, but only in nramp1(+) mice, signifying that attenuation ... | 2014 | 24713356 |
| cd11b+ ly6chi ly6g- immature myeloid cells recruited in response to salmonella enterica serovar typhimurium infection exhibit protective and immunosuppressive properties. | immature myeloid cells in bone marrow are a heterogeneous population of cells that, under normal conditions, provide tissues with protective cell types such as granulocytes and macrophages. under certain pathological conditions, myeloid cell homeostasis is altered and immature forms of these cells appear in tissues. murine immature myeloid cells that express cd11b and ly6c or ly6g (two isoforms of gr-1) have been associated with immunosuppression in cancer (in the form of myeloid-derived suppres ... | 2014 | 24711563 |
| arginine and vitamin e improve the immune response after a salmonella challenge in broiler chicks. | two experiments were conducted to evaluate the effects of arg, vitamin e (ve), and mannanoligosaccharide (mos) on the immune response and clearance of salmonella in broiler chickens. in each experiment, 1-d-old chicks (n = 160) were randomly distributed into 4 groups: antibiotic-free diet (negative control, ctl-), antibiotic-supplemented diet (positive control, ctl+), antibiotic free-diet plus arg and ve (ave), or antibiotic-free diet plus arg, ve, and mos (avm). birds were orally challenged wit ... | 2014 | 24706965 |
| effects of dietary clays on performance and intestinal mucus barrier of broiler chicks challenged with salmonella enterica serovar typhimurium and on goblet cell function in vitro. | in vivo and in vitro experiments were conducted to test for beneficial effects of dietary clays on broiler chicks challenged with salmonella enterica serovar typhimurium and to explore potential mechanisms. first, two hundred forty 1-d-old male broilers (initial bw: 41.6 ± 0.4 g) were allotted in a 2 × 4 factorial arrangement in a randomized complete block design. there were 2 infection treatments (with or without salmonella) and 4 diets: basal (bas), 0.3% smectite a (sma), 0.3% smectite b, and ... | 2014 | 24706960 |
| rig-i detects mrna of intracellular salmonella enterica serovar typhimurium during bacterial infection. | the cytoplasmic helicase rig-i is an established sensor for viral 5'-triphosphorylated rna species. recently, rig-i was also implicated in the detection of intracellular bacteria. however, little is known about the host cell specificity of this process and the bacterial pathogen-associated molecular pattern (pamp) that activates rig-i. here we show that rna of salmonella enterica serovar typhimurium activates production of beta interferon in a rig-i-dependent fashion only in nonphagocytic cells. ... | 2014 | 24692634 |
| selection of orphan rhs toxin expression in evolved salmonella enterica serovar typhimurium. | clonally derived bacterial populations exhibit significant genotypic and phenotypic diversity that contribute to fitness in rapidly changing environments. here, we show that serial passage of salmonella enterica serovar typhimurium lt2 (stlt2) in broth, or within a mouse host, results in selection of an evolved population that inhibits the growth of ancestral cells by direct contact. cells within each evolved population gain the ability to express and deploy a cryptic "orphan" toxin encoded with ... | 2014 | 24675981 |
| salmonella transfer during pilot plant scale washing and roller conveying of tomatoes. | salmonella transfer during washing and roller conveying of inoculated tomatoes was quantified using a pilot scale tomato packing line equipped with plastic, foam, or brush rollers. red round tomatoes (2.3 kg) were dip inoculated with salmonella enterica serovar typhimurium lt2 (avirulent) (4 log cfu/g), air dried for 2 h, and then washed in sanitizer-free water for 2 min. inoculated tomatoes were then passed single file over a 1.5-m conveyor equipped with plastic, foam, or brush rollers followed ... | 2014 | 24674428 |
| leveraging management strategies for seedborne plant diseases to reduce salmonella enterica serovar typhimurium incidence on tomato seed and seedlings. | tomatoes have been linked to many outbreaks of salmonellosis over the last decade, but the routes of contamination have yet to be discerned. many phytopathogens of tomato are seedborne and are effectively managed using seed sanitizers. seed sanitizers effective against bacterial phytopathogens were evaluated for their efficacy in killing bioluminescent salmonella enterica serovar typhimurium strain set-a14 on tomato seed infested with moderately high and high levels of pathogen. set-a14 incidenc ... | 2014 | 24674425 |
| the mucosal inflammatory response to non-typhoidal salmonella in the intestine is blunted by il-10 during concurrent malaria parasite infection. | coinfection can markedly alter the response to a pathogen, thereby changing its clinical presentation. for example, non-typhoidal salmonella (nts) serotypes are associated with gastroenteritis in immunocompetent individuals. in contrast, individuals with severe pediatric malaria can develop bacteremic infections with nts, during which symptoms of gastroenteritis are commonly absent. here we report that, in both a ligated ileal loop model and a mouse colitis model, malaria parasites caused a glob ... | 2014 | 24670425 |
| the primary transcriptome of salmonella enterica serovar typhimurium and its dependence on ppgpp during late stationary phase. | we have used differential rna-seq (drna-seq) to characterise the transcriptomic architecture of s. typhimurium sl1344, and its dependence on the bacterial alarmone, guanosine tetraphosphate (ppgpp) during late stationary phase, (lsp). under lsp conditions we were able to identify the transcriptional start sites (tsss) for 53% of the s. typhimurium open reading frames (orfs) and discovered 282 candidate non-coding rnas (ncrnas). the mapping of lsp tsss enabled a detailed comparison with a previou ... | 2014 | 24664308 |
| invasive salmonella enterica serotype typhimurium infections, democratic republic of the congo, 2007-2011. | infection with salmonella enterica serotype typhimurium sequence type (st) 313 is associated with high rates of drug resistance, bloodstream infections, and death. to determine whether st313 is dominant in the democratic republic of the congo, we studied 180 isolates collected during 2007-2011; 96% belonged to crispol type ct28, which is associated with st313. | 2014 | 24655438 |
| nisin/β-lactam adjunct therapy against salmonella enterica serovar typhimurium: a mechanistic approach. | multidrug resistance exhibited by salmonella strains has proved to be a big hurdle in the development of an effective anti-salmonella therapy. in this context, we had previously demonstrated strong synergism of nisin/ceftriaxone and nisin/cefotaxime combinations against salmonella enterica serovar typhimurium. however, the mechanism remained unexplored. the present study was therefore planned in order to evaluate the underlying mechanisms responsible for the synergistic effect of nisin in combin ... | 2014 | 24633205 |
| salmonella enterica serovar typhimurium-infected pigs with different shedding levels exhibit distinct clinical, peripheral cytokine and transcriptomic immune response phenotypes. | foodborne salmonellosis costs the us $2.7 billion/year, including $100.0 million in annual losses to pork producers. pigs colonized with salmonella are usually asymptomatic with varied severity and duration of fecal shedding. thus, understanding the responses that result in less shedding may provide a mechanism for control. fifty-four pigs were inoculated with salmonella enterica serovar typhimurium (st) and clinical signs, fecal st shedding, growth performance, peripheral cytokines and whole bl ... | 2015 | 24632525 |
| the oxido-reductase enzyme glutathione peroxidase 4 (gpx4) governs salmonella typhimurium-induced neutrophil transepithelial migration. | neutrophil (polymorphonuclear leucocytes; pmn) transmigration across mucosal surfaces contributes to dysfunction of epithelial barrier properties, a characteristic underlying many mucosal inflammatory diseases. using salmonella enterica serovar typhimurium (s. typhimurium) as a prototypic proinflammatory insult, we have previously reported that the eicosanoid hepoxilin a3 (hxa3 ), an endogenous product of 12-lipoxygenase (12-lox) activity, is secreted from the apical surface of the intestinal ep ... | 2014 | 24617613 |
| immune response of pigs to salmonella enterica serovar derby and typhimurium infections. | interaction between pigs and salmonella enterica serovar derby (salmonella derby) is much less understood in comparison with salmonella enterica serovar typhimurium (salmonella typhimurium). to study interactions of weaned piglets with salmonella derby, we compared the course of infections with salmonella derby de1 and salmonella typhimurium dt104 strains, both isolated from pig herds with a long history of asymptomatic infection. salmonella derby strain used was shed during the 28-day experimen ... | 2014 | 24613290 |
| whole-genome sequences of six salmonella enterica serovar bovismorbificans isolates associated with a 2011 multistate hummus-borne outbreak. | we present six draft genome sequences of salmonella enterica serovar bovismorbificans from isolates associated with the 2011 hummus-borne multistate outbreak. all six genome sequences indicate the presence of two plasmids, one of which demonstrates similarity to the 93-kb pslt2 incf-type plasmid of salmonella enterica serovar typhimurium. | 2014 | 24604659 |
| highly specific salt bridges govern bacteriophage p22 icosahedral capsid assembly: identification of the site in coat protein responsible for interaction with scaffolding protein. | icosahedral virus assembly requires a series of concerted and highly specific protein-protein interactions to produce a proper capsid. in bacteriophage p22, only coat protein (gp5) and scaffolding protein (gp8) are needed to assemble a procapsid-like particle, both in vivo and in vitro. in scaffolding protein's coat binding domain, residue r293 is required for procapsid assembly, while residue k296 is important but not essential. here, we investigate the interaction of scaffolding protein with a ... | 2014 | 24600011 |
| direct ros scavenging activity of cuep from salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium (s. typhimurium) is an intracellular pathogen that has evolved to survive in the phagosome of macrophages. the periplasmic copper-binding protein cuep was initially known to confer copper resistance to s. typhimurium. crystal structure and biochemical studies on cuep revealed a putative copper binding site surrounded by the conserved cysteine and histidine residues. a recent study reported that cuep supplies copper ions to periplasmic cu, zn-superoxide dis ... | 2014 | 24598994 |
| sublethal amounts of origanum vulgare l. essential oil and carvacrol cause injury and changes in membrane fatty acid of salmonella typhimurium cultivated in a meat broth. | this study aimed to evaluate whether sublethal concentrations of the essential oil of origanum vulgare l. (oveo) and its major compound carvacrol (car) cause injury to the cell membrane and outer membrane of salmonella enterica serovar typhimurium atcc 14028 grown in a meat broth and to assess the effect of these substances on membrane fatty acid (fa) composition. exposure of salmonella typhimurium atcc 14028 to sublethal concentrations of oveo or car caused damage to the cytoplasmic membrane an ... | 2014 | 24588810 |
| conformational changes of the histidine atp-binding cassette transporter studied by double electron-electron resonance spectroscopy. | the conformational dynamics of the histidine abc transporter hisqmp2 from salmonella enterica serovar typhimurium, reconstituted into liposomes, is studied by site-directed spin labeling and double electron-electron resonance spectroscopy in the absence of nucleotides, in the atp-bound, and in the post-hydrolysis state. the results show that the inter-dimer distances as measured between the q-loops of hisp2 in the intact transporter resemble those determined for the maltose transporter in all th ... | 2014 | 24583084 |
| il-35-producing b cells are critical regulators of immunity during autoimmune and infectious diseases. | b lymphocytes have critical roles as positive and negative regulators of immunity. their inhibitory function has been associated primarily with interleukin 10 (il-10) because b-cell-derived il-10 can protect against autoimmune disease and increase susceptibility to pathogens. here we identify il-35-producing b cells as key players in the negative regulation of immunity. mice in which only b cells did not express il-35 lost their ability to recover from the t-cell-mediated demyelinating autoimmun ... | 2014 | 24572363 |
| the flagellar soluble protein flik determines the minimal length of the hook in salmonella enterica serovar typhimurium. | the length of the flagellar hook is controlled by the soluble protein flik. flik is structurally divided into two halves with distinct functions; the n-terminal half determines hook length, while the c-terminal half switches the secretion substrate specificity, consequently terminating hook elongation. flik properly achieves both functions only when it is secreted. in a previous paper, we showed that a temperature-sensitive flge mutant of salmonella enterica serovar typhimurium, sjw2219, produce ... | 2014 | 24563036 |
| novel synergistic approach to exploit the bactericidal efficacy of commercial disinfectants on the biofilms of salmonella enterica serovar typhimurium. | combined effect of malic acid and ozone as sanitizer to inhibit the biofilm formation by salmonella typhimurium on different food contact surfaces was investigated in this study. different surfaces used in food industry including pvc pipes, polyethylene bags, plastic surfaces and fresh produce were analyzed for the biofilm formation by s. typhimurium st1 and st2. malic acid alone was not able to inhibit biofilm formation in all the samples. however, combination of malic acid with ozone reduced t ... | 2014 | 24560666 |
| salmonella enterica serovar typhimurium slows down to dodge antibiotics. | | 2014 | 24558352 |
| structure and expression of propanediol utilization microcompartments in acetonema longum. | numerous bacteria assemble proteinaceous microcompartments to isolate certain biochemical reactions within the cytoplasm. the assembly, structure, contents, and functions of these microcompartments are active areas of research. here we show that the gram-negative sporulating bacterium acetonema longum synthesizes propanediol utilization (pdu) microcompartments when starved or grown on 1,2-propanediol (1,2-pd) or rhamnose. electron cryotomography of intact cells revealed that pdu microcompartment ... | 2014 | 24532773 |
| experimental salmonellosis challenge model in older calves. | non-typhoidal salmonella serovars (nts) are the leading cause of foodborne illnesses worldwide and the leading cause of hospitalization and death due to foodborne illnesses in the united states. while there has been some progress in vaccine development against salmonella spp., there are no broadly protective vaccines. a compounding factor in the development of these vaccines is the lack of a natural model. most vaccine research is performed utilizing a mouse typhoid model. unlike mice, calves in ... | 2014 | 24529790 |
| toll-like receptor-deficient mice reveal how innate immune signaling influences salmonella virulence strategies. | pathogens utilize features of the host response as cues to regulate virulence gene expression. salmonella enterica serovar typhimurium (st) sense toll-like receptor (tlr)-dependent signals to induce salmonella pathogenicity island 2 (spi2), a locus required for intracellular replication. to examine pathogenicity in the absence of such cues, we evaluated st virulence in mice lacking all tlr function (tlr2(-/-)xtlr4(-/-)xunc93b1(3d/3d)). when delivered systemically to tlr-deficient mice, st do not ... | 2014 | 24528866 |
| nosocomial outbreak of salmonella enterica serovar typhimurium primarily affecting a pediatric ward in south africa in 2012. | we describe a nosocomial outbreak of diarrheal disease caused by extended-spectrum β-lactamase-producing multidrug-resistant salmonella enterica serovar typhimurium, focused on a pediatric ward in south africa. the outbreak peaked between may 2012 and july 2012. person-to-person transmission was the most likely mechanism of spread of the infection, expedited due to a breakdown in hand-washing and hygiene, suboptimal infection control practices, overcrowding of hospital wards, and an undesirable ... | 2014 | 24478499 |
| absence of intestinal pparγ aggravates acute infectious colitis in mice through a lipocalin-2-dependent pathway. | to be able to colonize its host, invading salmonella enterica serovar typhimurium must disrupt and severely affect host-microbiome homeostasis. here we report that s. typhimurium induces acute infectious colitis by inhibiting peroxisome proliferator-activated receptor gamma (pparγ) expression in intestinal epithelial cells. interestingly, this pparγ down-regulation by s. typhimurium is independent of tlr-4 signaling but triggers a marked elevation of host innate immune response genes, including ... | 2014 | 24465207 |
| fimy of salmonella enterica serovar typhimurium functions as a dna-binding protein and binds the fimz promoter. | salmonella enterica serovar typhimurium produces type 1 fimbriae with binding specificity to mannose residues. elements involved in fimbrial structural biosynthesis, transport, and regulation are encoded by the fim gene cluster. fimz, fimy, fimw, stm0551, and an arginine transfer rna (fimu) were previously demonstrated to regulate fimbrial expression. the amino acid sequences of the c-terminal portion of fimy revealed similarity with those of luxr-like proteins. electrophoretic mobility shift as ... | 2014 | 24462182 |
| female partner preferences enhance offspring ability to survive an infection. | it is often suggested that mate choice enhances offspring immune resistance to infectious diseases. to test this hypothesis, we conducted a study with wild-derived house mice (mus musculus musculus) in which females were experimentally mated either with their preferred or non-preferred male, and their offspring were infected with a mouse pathogen, salmonella enterica (serovar typhimurium). | 2014 | 24450606 |
| neutrophils are a source of gamma interferon during acute salmonella enterica serovar typhimurium colitis. | gamma interferon (ifn-γ) is an important driver of intestinal inflammation during colitis caused by salmonella enterica serovar typhimurium. here we used the mouse colitis model to investigate the cellular sources of ifn-γ in the cecal mucosa during the acute phase of an s. typhimurium infection. while ifn-γ staining was detected in t cells, nk cells, and inflammatory monocytes at 2 days after infection, the majority of ifn-γ-positive cells in the cecal mucosa were neutrophils. furthermore, neut ... | 2014 | 24421037 |
| bacterial flagellin-specific chaperone flis interacts with anti-sigma factor flgm. | flagella are extracellular organelles that propel bacteria. each flagellum consists of a basal body, a hook, and a filament. the major protein of the filament is flagellin. induction of flagellin gene expression coincides with secretion of flgm. the role of flgm is to inhibit flia (σ(28)), a flagellum-specific rna polymerase responsible for flagellin transcription. to prevent premature polymerization of newly synthesized flagellin molecules, flis, the flagellin-specific chaperone, binds flagelli ... | 2014 | 24415724 |
| the role of the st313-td gene in virulence of salmonella typhimurium st313. | multidrug-resistant salmonella enterica serovar typhimurium st313 has emerged in sub-saharan africa causing severe infections in humans. therefore, it has been speculated that this specific sequence type, st313, carries factors associated with increased pathogenicity. we assessed the role in virulence of a gene with a yet unknown function, st313-td, detected in st313 through comparative genomics. additionally, the structure of the genomic island st313-gi, harbouring the gene was determined. the ... | 2014 | 24404174 |
| ttss2-deficient hha mutant of salmonella typhimurium exhibits significant systemic attenuation in immunocompromised hosts. | non-typhoidal salmonella (nts) infections are emerging as leading problem worldwide and the variations in host immune status append to the concern of nts. salmonella enterica serovar typhimurium is one of the causative agents of nts infections and has been extensively studied. the inactivation of salmonella pathogenicity island 2 (spi2) encoded type-iii secretion system 2 (ttss2) has been reported rendering the strain incapable for systemic dissemination to host sites and has also been proposed ... | 2014 | 24401482 |
| outbreak of salmonellosis associated with consumption of pulled pork at a church festival - hamilton county, ohio, 2010. | on june 18, 2010, hamilton county public health (hcph), a local health department in ohio, began receiving reports of gastrointestinal illness from persons who attended a church festival held during june 11-13 in a suburban community of hamilton county. hcph investigated and confirmed the existence of a foodborne outbreak associated with consumption of pulled pork prepared in a private home and sold at the church festival. sixty-four attendees with gastroenteritis were identified. salmonella ent ... | 2014 | 24381078 |
| iron-induced virulence of salmonella enterica serovar typhimurium at the intestinal epithelial interface can be suppressed by carvacrol. | oral iron therapy can increase the abundance of bacterial pathogens, e.g., salmonella spp., in the large intestine of african children. carvacrol is a natural compound with antimicrobial activity against various intestinal bacterial pathogens, among which is the highly prevalent salmonella enterica serovar typhimurium. this study aimed to explore a presumed interaction between carvacrol and bacterial iron handling and to assess the potential of carvacrol in preventing the increase of bacterial p ... | 2014 | 24379194 |
| differential timing of antibody-mediated phagocytosis and cell-free killing of invasive african salmonella allows immune evasion. | nontyphoidal salmonellae commonly cause fatal bacteraemia in african children lacking anti-salmonella antibodies. these are facultative intracellular bacteria capable of cell-free and intracellular survival within macrophages. to better understand the relationship between extracellular and intracellular infection in blood and general mechanisms of ab-related protection against salmonella, we used human blood and sera to measure kinetics of ab and complement deposition, serum-mediated bactericida ... | 2014 | 24375424 |
| identification of hild-regulated genes in salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium (s. typhimurium) pathogenicity island 1 (spi-1) encodes a type iii secretion system required for invasion of host gut epithelial cells. expression of spi-1 virulence genes is controlled by a complex hierarchy of transcription factors encoded within and outside spi-1. the master regulator of spi-1, hila, is itself regulated by three homologous transcription factors, hild, hilc, and rtsa. hild activates transcription of hila and other target genes in respons ... | 2014 | 24375101 |
| an rfah mutant of salmonella enterica serovar typhimurium is attenuated in swine and reduces intestinal colonization, fecal shedding, and disease severity due to virulent salmonella typhimurium. | swine are often asymptomatic carriers of salmonella spp., and interventions are needed to limit colonization of swine to enhance food safety and reduce environmental contamination. we evaluated the attenuation and potential vaccine use in pigs of a salmonella enterica serovar typhimurium mutant of rfah, the gene encoding the rfah antiterminator that prevents premature termination of long mrna transcripts. pigs inoculated with wild-type s. typhimurium exhibited a significant elevation in average ... | 2014 | 26664915 |
| multiresistance to antibiotics of salmonella enterica serovar typhimurium strains producing extended spectrum beta-lactamases (esbls). | the purpose of the study is to give the rising incidence of salmonellosis and the continuous decrease of sensitivity of salmonella to a range of antibiotics, the prime importance of the choice of optimal anti-infective chemotherapy in order to prevent the selection of multidrug-resistant strains (mdr). we have studied 54 strains of salmonella sent for further investigation to "cantacuzino" nirdmi bucharest. the statistical analysis was based on the interpretation pathogen susceptibility and anal ... | 2014 | 25870680 |
| 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. | 2013 | 24356822 |
| regulation of salmonella enterica pathogenicity island 1 (spi-1) by the lysr-type regulator leuo. | leuo is a quiescent lysr-type regulator belonging to the h-ns regulon. activation of leuo transcription represses expression of pathogenicity island 1 (spi-1) in salmonella enterica serovar typhimurium and inhibits invasion of epithelial cells. loss of hile suppresses leuo-mediated downregulation of spi-1. activation of leuo transcription reduces the level of hild protein, and loss of hile restores the wild type hild level. hence, leuo-mediated downregulation of spi-1 may involve inhibition of h ... | 2014 | 24354910 |
| salmonella exploits nlrp12-dependent innate immune signaling to suppress host defenses during infection. | the nucleotide-binding oligomerization domain (nod)-like receptor family pyrin domain containing 12 (nlrp12) plays a protective role in intestinal inflammation and carcinogenesis, but the physiological function of this nlr during microbial infection is largely unexplored. salmonella enterica serovar typhimurium (s. typhimurium) is a leading cause of food poisoning worldwide. here, we show that nlrp12-deficient mice were highly resistant to s. typhimurium infection. salmonella-infected macrophage ... | 2014 | 24347638 |
| 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. | 2013 | 24345035 |
| salmonella enterica serovar typhimurium infection-induced cd11b+ gr1+ cells ameliorate allergic airway inflammation. | allergies are mainly characterized as an unrestrained th2-biased immune response. epidemiological data associate protection from allergic diseases with the exposure to certain infectious agents during early stages of life. modulation of the immune response by pathogens has been considered to be a major factor influencing this protection. recent evidence indicates that immunoregulatory mechanisms induced upon infection ameliorate allergic disorders. a longitudinal study has demonstrated reduced f ... | 2014 | 24343652 |
| 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 ... | 2013 | 24331466 |
| .analysis of the contribution of bacteriophage st64b to in vitro virulence traits of salmonella enterica serovar typhimurium. | comparison of the publicly available genomes of the virulent salmonella enterica serovar typhimurium (s. typhimurium) strains sl1344, 14028s and d23580 to that of the virulence-attenuated isolate lt2 revealed the absence of a full sequence of bacteriophage st64b in the latter. four selected st64b regions of unknown function (sb7-sb11, sb46, sb49-sb50 and sb54) were mapped by pcr in two strain collections: (i) 310 isolates of s. typhimurium from human blood or stool samples, and from food, animal ... | 2014 | 24324031 |
| structure of a pathogenic type 3 secretion system in action. | type 3 secretion systems use 3.5-megadalton syringe-like, membrane-embedded 'injectisomes', each containing an ~800-å-long needle complex to connect intracellular compartments of infectious bacteria and hosts. here we identify requirements for substrate association with, transport through and exit from the injectisome of salmonella enterica serovar typhimurium. this guided the design of substrates that become trapped within the secretion path and enabled visualization of injectisomes in action i ... | 2014 | 24317488 |
| 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 ... | 2013 | 24311974 |
| 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 ... | 2013 | 24308825 |
| 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 ... | 2013 | 24307959 |
| 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 ... | 2013 | 24307595 |
| redundancy in the periplasmic adaptor proteins acra and acre provides resilience and an ability to export substrates of multidrug efflux. | the components of the acrab-tolc efflux pump function as a tripartite efflux system conferring resistance to multiple antibiotics and the individual components can also function in conjunction with other efflux pumps. this study aimed to establish whether redundancy exists between the homologous periplasmic adaptor proteins (paps) acra and acre and to measure the impact of this redundancy on antimicrobial resistance and the potential efficacy of inhibitor molecules. | 2014 | 24302652 |
| first report of a salmonella enterica serovar typhimurium isolate with carbapenemase (kpc-2) in colombia. | | 2014 | 24295970 |
| 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. | 2013 | 24274891 |
| core lipopolysaccharide-specific phage ssu5 as an auxiliary component of a phage cocktail for salmonella biocontrol. | salmonella spp. are among the major food-borne pathogens that cause mild diarrhea to severe bacteremia. the use of bacteriophages to control various food-borne pathogens, including salmonella, has emerged as a promising alternative to traditional chemotherapy. we isolated the siphoviridae family phage ssu5, which can infect only rough strains of salmonella. the blocking of ssu5 adsorption by periodate treatment of host salmonella cells and spotting and adsorption assays with mutants that contain ... | 2014 | 24271179 |
| proteomic analysis of intestinal mucosa responses to salmonella enterica serovar typhimurium in naturally infected pig. | salmonella enterica serovar typhimurium (s. typhimurium) is one of the most frequent salmonella serotypes isolated from european pigs. despite the advances in understanding the mechanisms involved in host-pathogen interactions and host cell responses to s. typhimurium, the global change that occurs in naturally exposed populations has been poorly characterized. here, we present a proteomics study on intestinal mucosa of pigs naturally infected with s. typhimurium, in order to better understand t ... | 2014 | 24268431 |
| signal-specific temporal response by the salmonella phop/phoq regulatory system. | the two-component system phop/phoq controls a large number of genes responsible for a variety of physiological and virulence functions in salmonella enterica serovar typhimurium. here we describe a mechanism whereby the transcriptional activator phop elicits expression of dissimilar gene sets when its cognate sensor phoq is activated by different signals in the periplasm. we determine that full transcription of over half of the genes directly activated by phop requires the mg(2+) transporter mgt ... | 2014 | 24256574 |
| effect of chitosan on salmonella typhimurium in broiler chickens. | public concern with the incidence of antibiotic-resistant bacteria, particularly among foodborne pathogens such as salmonella, has been challenging the poultry industry to find alternative means of control. the purposes of the present study were to evaluate in vitro and in vivo effects of chitosan on salmonella enterica serovar typhimurium (st) infection in broiler chicks. for in vitro crop assay experiments, tubes containing feed, water, and st were treated with either saline as a control or 0. ... | 2014 | 24237042 |
| 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 ... | 2013 | 24211643 |
| a thin-layer chromatography autographic method for the detection of inhibitors of the salmonella phop-phoq regulatory system. | the phop-phoq system from salmonella enterica serovar typhimurium controls the expression of factors that are critical for the bacterial entry into host cells and the bacterial intramacrophage survival. therefore it constitutes an interesting target to search for compounds that would control salmonella virulence. localisation of such compounds in complex matrixes could be facilitated by thin-layer chromatography (tlc) bioautography. | 2014 | 24185747 |