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application of pyrosequencing for salmonella enterica rapid identification.application of pyrosequencing of six salmonella-specific genes as a rapid salmonella identification method was tested. primers for hns, hisj and hila had non-specific reactions with non-salmonella strains. primers for inva, irob and fimy had specific pcr products and pyrosequences of salmonella, suggesting that they were suitable for salmonella rapid identification.201222342525
comparative genomic analysis of salmonella enterica subsp. enterica serovar weltevreden foodborne strains with other serovars.salmonella enterica subsp. enterica serovar weltevreden is a dominant serovar associated with foodborne gastroenteritis in south-east asia and emerging in europe associated with fresh vegetables. here we compared the genome of strain 2007-60-3289-1 linked to an alfalfa sprout outbreak in scandinavia with a s. weltevreden strain isolated from scallops in the usa and with other s. enterica serovars. a unique plasmid psw82 was identified for s. weltevreden carrying a two-component type ii non-ribos ...201222341936
antimicrobial resistance in non-typhi salmonella enterica isolated from humans and poultry in palestine.the efficacy of chemotherapy can be compromised by drug resistance. this study was undertaken to describe the resistance profiles and fluoroquinolone resistance mechanism of non-typhoidal salmonella (nts) isolated from humans and poultry in west bank, palestine.201222337841
salmonella's long-term relationship with its host.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 s. enterica serovar typhi (s. typhi) and nontyphoidal 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 reservoir f ...201222335190
comparison of 2 culture methods and pcr assays for salmonella detection in poultry feces.the present work compared 2 culture methods and the combinations of pre-enrichment and enrichment culture methods with pcr assays [buffered peptone water-pcr and tetrathionate-pcr or modified semisolid rappaport-vassiliadis (msrv)-pcr] for motile and nonmotile salmonella strain detection using artificially contaminated poultry feces. the specificity and positive predictive values were equal to one in both culture methods. specificity and positive predictive values, accuracy, sensitivity, and neg ...201222334736
evolution of inchi2 plasmids via acquisition of transposons carrying antibiotic resistance determinants.to investigate the relationships between inchi2 plasmids conferring resistance to antibiotics isolated in australia and those from other countries.201222334605
prevalence, enumeration, serotypes, and antimicrobial resistance phenotypes of salmonella enterica isolates from carcasses at two large united states pork processing plants.the objective of this study was to characterize salmonella enterica contamination on carcasses in two large u.s. commercial pork processing plants. the carcasses were sampled at three points, before scalding (prescald), after dehairing/polishing but before evisceration (preevisceration), and after chilling (chilled final). the overall prevalences of salmonella on carcasses at these three sampling points, prescald, preevisceration, and after chilling, were 91.2%, 19.1%, and 3.7%, respectively. at ...201222327585
intrinsic negative feedback governs activation surge in two-component regulatory systems.phop and phoq comprise a two-component system in the bacterium salmonella enterica. phoq is the sensor kinase/phosphatase that modifies the phosphorylation state of the regulator phop in response to stimuli. the amount of phosphorylated phop surges after activation, then declines to reach a steady-state level. we now recapitulate this surge in vitro by incubating phop and phoq with atp and adp. mathematical modeling identified phoq's affinity for adp as the key parameter dictating phosphorylated ...201222325356
real-time evolution of new genes by innovation, amplification, and divergence.gene duplications allow evolution of genes with new functions. here, we describe the innovation-amplification-divergence (iad) model in which the new function appears before duplication and functionally distinct new genes evolve under continuous selection. one example fitting this model is a preexisting parental gene in salmonella enterica that has low levels of two distinct activities. this gene is amplified to a high copy number, and the amplified gene copies accumulate mutations that provide ...201223087246
live oral typhoid vaccine salmonella typhi ty21a - a surrogate vaccine against non-typhoid salmonella?non-typhoid salmonella (nts) is a leading cause of food-borne illness with more than 90 million annual cases and an emerging antimicrobial resistance among the strains worldwide. paradoxically, no vaccines are available against these pathogens. numerous nts strains share surface o-antigens with salmonella enterica serotype typhi. as intestinal antibodies against o-antigens have proven protective against nts in animal experiments, it appears conceivable that the oral whole-cell typhoid vaccine, s ...201223084770
social networks and the spread of salmonella in a sleepy lizard population.although theoretical models consider social networks as pathways for disease transmission, strong empirical support, particularly for indirectly transmitted parasites, is lacking for many wildlife populations. we found multiple genetic strains of the enteric bacterium salmonella enterica within a population of australian sleepy lizards (tiliqua rugosa), and we found that pairs of lizards that shared bacterial genotypes were more strongly connected in the social network than were pairs of lizards ...201222845647
combined genomarkers approach to salmonella characterization reveals that nucleotide sequence differences in the phase 1 flagellin gene flic are markers for variation within serotypes.the characterization and tracking of pathogenic micro-organisms in the clinical laboratory and public health environment demand schemes that are easy to standardize and use, are automated and high-throughput, and provide portable data. a combined genomarkers approach for salmonella enterica based on comparative sequence analysis by mass spectrometry has been developed. the scheme targets genes encoding synthesis and assembly of antigens, metabolic pathway enzymes, virulence factors and fluoroqui ...201222837220
differential identification of salmonella enterica serovar gallinarum biovars gallinarum and pullorum and the biovar gallinarum live vaccine strain 9r.salmonella enterica serovar gallinarum biovar gallinarum causes fowl typhoid in chickens and has been of economic importance to the chicken industry in many countries. the biovar gallinarum live vaccine strain 9r (sg 9r) has been used to control fowl typhoid in many areas where the disease is endemic. therefore, a definitive diagnosis of this disease may require differentiation of wild-type field isolates of biovar gallinarum from the live vaccine strain sg 9r. here, we report the development of ...201222728122
salmonella enterica serovars typhimurium and typhi as model organisms: revealing paradigm of host-pathogen interactions.the lifestyle of intracellular pathogens has always questioned the skill of a microbiologist in the context of finding the permanent cure to the diseases caused by them. the best tool utilized by these pathogens is their ability to reside inside the host cell, which enables them to easily bypass the humoral immunity of the host, such as the complement system. they further escape from the intracellular immunity, such as lysosome and inflammasome, mostly by forming a protective vacuole-bound niche ...201222722237
early immune dynamics following infection with salmonella enterica serovars enteritidis, infantis, pullorum and gallinarum: cytokine and chemokine gene expression profile and cellular changes of chicken cecal tonsils.salmonella enterica subspecies enterica infection remains a serious problem in a wide range of animals and in man. poultry-derived food is the main source of human infection with the non-host-adapted serovars while fowl typhoid and pullorum disease are important diseases of poultry. we have assessed cecal colonization and immune responses of newly hatched and older chickens to salmonella serotypes enteritidis, infantis, gallinarum and pullorum. s. enteritidis and s. infantis colonized the ceca m ...201222512820
a case of urinary tract infection due to salmonella enterica serovar virchow and review of the related literature.nontyphoid salmonella (nts) serotypes can cause gastroenteritis, bacteriemia, and focal infections. however, these focal infections, including urinary tract infections (uti), are occasionally observed; in particular, the presence of several predisposing factors, such as immunodeficiency and structural abnormality in the urinary tract, increase the possibility of the occurrence of infection. we present a case of uti caused by salmonella enterica serovar virchow in an elderly and debilitated patie ...201222510290
system-wide studies of n-lysine acetylation in rhodopseudomonas palustris reveal substrate specificity of protein acetyltransferases.n-lysine acetylation is a posttranslational modification that has been well studied in eukaryotes and is likely widespread in prokaryotes as well. the central metabolic enzyme acetyl-coa synthetase is regulated in both bacteria and eukaryotes by acetylation of a conserved lysine residue in the active site. in the purple photosynthetic α-proteobacterium rhodopseudomonas palustris, two protein acetyltransferases (rppat and the newly identified rpkata) and two deacetylases (rpldaa and rpsrtn) regul ...201222416131
dispersal of salmonella typhimurium by rain splash onto tomato plants.outbreaks of salmonella enterica have increasingly been associated with tomatoes and traced back to production areas, but the spread of salmonella from a point source onto plants has not been described. splash dispersal by rain could be one means of dissemination. green fluorescent protein-labeled, kanamycin-resistant salmonella enterica sv. typhimurium dispensed on the surface of plastic mulch, organic mulch, or soil at 10⁸ cfu/cm² was used as the point source in the center of a rain simulator. ...201222410220
survival and growth of epidemically successful and nonsuccessful salmonella enterica clones after freezing and dehydration.the spread of epidemically successful nontyphoidal salmonella clones has been suggested as the most important cause of salmonellosis in industrialized countries. factors leading to the emergence of success clones are largely unknown, but their ability to survive and grow after physical stress may contribute. during epidemiological studies, a mathematical model was developed that allowed estimation of a factor (q) accounting for the relative ability of salmonella serovars with different antimicro ...201222410218
genomic variation in salmonella enterica core genes for epidemiological typing.technological advances in high throughput genome sequencing are making whole genome sequencing (wgs) available as a routine tool for bacterial typing. standardized procedures for identification of relevant genes and of variation are needed to enable comparison between studies and over time. the core genes--the genes that are conserved in all (or most) members of a genus or species--are potentially good candidates for investigating genomic variation in phylogeny and epidemiology.201222409488
occurrence and antibiotic resistance of multiple salmonella serotypes recovered from water, sediment and soil on mid-atlantic tomato farms.salmonella outbreaks associated with the consumption of raw tomatoes have been prevalent in recent years. however, sources of salmonella contamination of tomatoes remain poorly understood. the objectives of this study were to identify ecological reservoirs of salmonella on tomato farms, and to test antimicrobial susceptibilities of recovered salmonella isolates. fourteen mid-atlantic tomato farms in the u.s. were sampled in 2009 and 2010. groundwater, irrigation pond water, pond sediment, irriga ...201222406288
clonal dissemination of salmonella enterica serovar infantis in germany.salmonella enterica serovar infantis (salmonella infantis) is consistently isolated from broiler chickens, pigs, and humans worldwide. this study investigated 93 epidemiologically unrelated salmonella infantis strains isolated in germany between 2005 and 2008 in respect to their transmission along the food chain. various phenotypic and genotypic methods were applied, and the pathogenicity and resistance gene repertoire was determined. phenotypically, 66% of the strains were susceptible to all 17 ...201222401270
an evaluation of the effect of sodium bisulfate as a feed additive on salmonella enterica serotype enteritidis in experimentally infected broilers.the colonization of broiler chickens with salmonella can pose serious health and economic risks for both consumers and the poultry industry. because colonization with salmonella can lead to subsequent contamination of chicken carcasses during processing, preemptive control measures should include the reduction of this pathogen in chickens before slaughter. in this study, we evaluated the effect of sodium bisulfate, a potential antimicrobial feed additive, on salmonella colonization of experiment ...201222399744
development and clinical verification of a loop-mediated isothermal amplification method for detection of salmonella species in suspect infected ducks.to detect salmonella spp. in suspect infected ducks, a loop-mediated isothermal amplification (lamp) assay was developed. with the help of this assay, we can detect salmonella enterica serovar enteriditis and salmonella enterica serovar anatis above 6.0 cfu/test and 4.8 cfu/test, respectively, in pure-culture conditions, even in the existence of 0.01 g of duck liver or spleen homogenates; the detection thresholds were still achieved at 6.0 cfu per test tube. further experiments of the test strai ...201222399738
effect of xylanase and a blend of essential oils on performance and salmonella colonization of broiler chickens challenged with salmonella heidelberg.the present experiment examined the influence of xylanase supplementation and a blend of essential oils (eo; cinnamaldehyde and thymol) on performance and salmonella horizontal transmission in broiler chickens challenged with salmonella. two thousand 1-d-old broiler chicks were randomly assigned to 5 dietary treatments (8 pens/treatment of 50 male broilers each). four dietary treatments were challenged with salmonella: 1) control, 2) basal diets supplemented with eo, 3) basal diet supplemented w ...201222399734
synthesis of a tetrasaccharide analog corresponding to the repeating unit of the o-polysaccharide of salmonella enterica o59: unexpected stereo outcome in glycosylation.convergent synthesis of a tetrasaccharide analog corresponding to the repeating unit of the o-polysaccharide of salmonella enterica o59 is presented. a thioglycoside disaccharide donor was prepared by the glycosylation of two thioglycosides by tuning their relative reactivity. an unexpected stereochemical outcome was observed in a glycosylation using an ethyl 2-o-acetyl-3-o-benzyl-4,6-o-bensylidene-thio-galactoside donor, where the alpha-galactoside was formed in spite of the presence of the 2-o ...201222398254
salmonella enterica shedding in hospitalized horses and associations with diarrhea occurrence among their stablemates and gastrointestinal-related illness or death following discharge.to evaluate the potential association between salmonella enterica shedding in hospitalized horses and the risk of diarrhea among stablemates, and to characterize gastrointestinal-related illness and death following discharge among horses that shed s. enterica while hospitalized.201222380811
ydiv: a dual function protein that targets flhdc for clpxp-dependent degradation by promoting release of dna-bound flhdc complex.ydiv is an eal-like protein that acts as a post-transcriptional, negative regulator of the flagellar master transcriptional activator complex, flhd(4)c(2), in salmonella enterica to couple flagellar gene expression to nutrient availability. mutants defective in clpxp protease no longer exhibit ydiv-dependent inhibition of flhd(4)c(2)-dependent transcription under moderate ydiv expression conditions. clpxp protease degrades flhd(4)c(2), and this degradation is accelerated in the presence of ydiv. ...201222380597
transient gut retention and persistence of salmonella through metamorphosis in the lesser mealworm, alphitobius diaperinus (coleoptera: tenebrionidae).this study was undertaken to determine the retention of salmonella through alphitobius diaperinus metamorphosis and its contribution, through defecation, to external contamination.201222380581
highly resistant salmonella enterica serovar typhi with a novel gyra mutation raises questions about the long-term efficacy of older fluoroquinolones for treating typhoid fever.as a consequence of multidrug resistance, clinicians are highly dependent on fluoroquinolones for treating the serious systemic infection typhoid fever. while reduced susceptibility to fluoroquinolones, which lessens clinical efficacy, is becoming ubiquitous, comprehensive resistance is exceptional. here we report ofloxacin treatment failure in typhoidal patient infected with a novel, highly fluoroquinolone-resistant isolate of salmonella enterica serovar typhi. the isolation of this organism ha ...201222371897
genomic comparison of the closely related salmonella enterica serovars enteritidis and dublin.the enteritidis and dublin serovars of salmonella enterica are closely related, yet they differ significantly in pathogenicity and epidemiology. s. enteritidis is a broad host range serovar that commonly causes gastroenteritis and infrequently causes invasive disease in humans. s. dublin mainly colonizes cattle but upon infecting humans often results in invasive disease.to gain a broader view of the extent of these differences we conducted microarray-based comparative genomics between several fi ...201222371816
copper redistribution in murine macrophages in response to salmonella infection.the movement of key transition metal ions is recognized to be of critical importance in the interaction between macrophages and intracellular pathogens. the present study investigated the role of copper in mouse macrophage responses to salmonella enterica sv. typhimurium. the copper chelator bcs (bathocuproinedisulfonic acid, disodium salt) increased intracellular survival of s. typhimurium within primary mouse bmm (bone-marrow-derived macrophages) at 24 h post-infection, implying that copper co ...201222369063
efficacy of biocides used in the modern food industry to control salmonella enterica, and links between biocide tolerance and resistance to clinically relevant antimicrobial compounds.biocides play an essential role in limiting the spread of infectious disease. the food industry is dependent on these agents, and their increasing use is a matter for concern. specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. in this study, we investigated the tolerance of a collection of susceptible and mult ...201222367085
notes from the field: outbreak of salmonellosis associated with pet turtle exposures--united states, 2011.cdc is collaborating with the pennsylvania state health department in an ongoing investigation of an outbreak of human salmonella enterica serotype paratyphi b var. l (+) tartrate + infections associated with pet turtle exposures. turtles have long been recognized as sources of human salmonella infections and are a particular risk to young children. although the sale or distribution of small turtles (those with carapace lengths <4 inches [<10.2 cm]) has been prohibited in the united states since ...201222298304
wound-healing potential of an ethanol extract of carica papaya (caricaceae) seeds.carica papaya l. (linn) (caricaceae) is traditionally used to treat various skin disorders, including wounds. it is widely used in developing countries as an effective and readily available treatment for various wounds, particularly burns. this study evaluated the wound-healing and antimicrobial activity of c. papaya seed extract. ethanol extract of c. papaya seed (50 mg/kg/day) was evaluated for its wound-healing activity in sprague-dawley rats using excision wound model. animals were randomly ...201222296524
first human isolate of salmonella enterica serotype enteritidis harboring blactx-m-14 in south america.we studied a clinical isolate of salmonella enterica serotype enteritidis showing resistance to oxyiminocephalosporins. pcr analysis confirmed the presence of bla(ctx-m-14) linked to is903 in a 95-kb inci1 conjugative plasmid. such a plasmid is maintained on account of the presence of a pndac addiction system. multilocus sequence typing (mlst) analysis indicated that the strain belongs to st11. this is the first report of bla(ctx-m-14) in salmonella enteritidis of human origin in south america.201222290976
dietary proteins extend the survival of salmonella dublin in a gastric acid environment.the ph of the human stomach is dynamic and changes over time, depending on the composition of the food ingested and a number of host-related factors such as age. to evaluate the number of bacteria surviving the gastric acid barrier, we have developed a simple gastric acid model, in which we mimicked the dynamic ph changes in the human stomach. in the present study, model gastric fluid was set up to imitate ph dynamics in the stomachs of young and elderly people after ingestion of a standard meal ...201222289597
effects of tomato variety, temperature differential, and post-stem removal time on internalization of salmonella enterica serovar thompson in tomatoes.tomatoes have been implicated in salmonellosis outbreaks due to possible contamination through bacterial internalization during postharvest handling. this study was conducted to determine the effects of tomato variety, temperature differential between tomato pulp and bacterial suspension, and the time delay between stem removal and immersion in bacterial suspension on internalization of salmonella enterica serovar thompson in tomato fruit. mature green tomatoes at 32.2°c were immersed in water c ...201222289590
analysis of gene expression responses to a salmonella infection in rugao chicken intestine using genechips.poultry products are an important source of salmonella enterica. an effective way to reduce food poisoning due to salmonella would be to breed chickens more resistant to infection. unfortunately host responses to salmonella are complex with many factors involved. to learn more about responses to salmonella in young chickens of 2 wk old, a cdna microarray containing 13,319 probes was performed to compare gene expression profiles between two chicken groups under control and salmonella infected con ...201225049563
capacities of migrating cd1b+ lymph dendritic cells to present salmonella antigens to naive t cells.dendritic cells (dcs) are well known as professional antigen-presenting cells (apc) able to initiate specific t-cell responses to pathogens in lymph nodes (ln) draining the site of infection. however, the respective contribution of migratory and ln-resident dcs in this process remains unclear. as dc subsets represent important targets for vaccination strategies, more precise knowledge of dc subsets able to present vaccine antigens to t cells efficiently is required. to investigate the capacities ...201222279590
population-based incidence of typhoid fever in an urban informal settlement and a rural area in kenya: implications for typhoid vaccine use in africa.high rates of typhoid fever in children in urban settings in asia have led to focus on childhood immunization in asian cities, but not in africa, where data, mostly from rural areas, have shown low disease incidence. we set out to compare incidence of typhoid fever in a densely populated urban slum and a rural community in kenya, hypothesizing higher rates in the urban area, given crowding and suboptimal access to safe water, sanitation and hygiene.201222276105
adaptation and preadaptation of salmonella enterica to bile.bile possesses antibacterial activity because bile salts disrupt membranes, denature proteins, and damage dna. this study describes mechanisms employed by the bacterium salmonella enterica to survive bile. sublethal concentrations of the bile salt sodium deoxycholate (doc) adapt salmonella to survive lethal concentrations of bile. adaptation seems to be associated to multiple changes in gene expression, which include upregulation of the rpos-dependent general stress response and other stress res ...201222275872
complete genome sequence of salmonella enterica serovar pullorum rks5078.salmonella enterica serovar pullorum is a chicken-adapted pathogen, causing pullorum disease. its strict host adaptation has been suspected to result in gene decay. to validate this hypothesis and identify the decayed genes, we sequenced the complete genome of s. pullorum rks5078. we found 263 pseudogenes in this strain and conducted functional analyses of the decayed genes.201222247537
septicemic salmonellosis caused by salmonella hessarek in wintering and migrating song thrushes (turdus philomelos) in spain.we investigated two mortality events in wintering and migrating song thrushes (turdus philomelos) in catalonia, northeastern spain in 2009 and 2010. both episodes occurred in late february to mid-march during the spring migration. salmonellosis produced by the serotype salmonella enterica subsp. enterica serotype hessarek (s. hessarek) was identified as the cause of death in both episodes. poor body condition, marked splenomegaly, and microscopic disseminated intravascular coagulation with numer ...201222247379
use of high hydrostatic pressure to inactivate escherichia coli o157:h7 and salmonella enterica internalized within and adhered to preharvest contaminated green onions.green onions grown in soil and hydroponic medium contaminated with escherichia coli o157:h7 and salmonella were found to take up the pathogens in their roots, bulbs, stems, and leaves. pressure treatment at 400 to 500 mpa for 2 min at 20 to 40°c eliminated both pathogens that were internalized within green onions during plant growth.201222247156
nationwide outbreak of salmonella enterica serotype 4,[5],12:i:- infection associated with consumption of dried pork sausage, france, november to december 2011.an outbreak of the monophasic variant of salmonella enterica serotype 4,[5],12:i:- occurred in november and december 2011 in france. epidemiological investigation and food investigation with the help of supermarket loyalty cards suggested dried pork sausage from one producer as the most likely source of the outbreak. despite the absence of positive food samples, control measures including withdrawal and recall were implemented.201222321138
addition of a surfactant to tryptic soy broth allows growth of a lactic acid bacteria food antimicrobial, escherichia coli o157:h7, and salmonella enterica.this study aimed to determine the survival and growth of escherichia coli o157:h7 and salmonella enterica subsp. enterica in a medium supporting the growth of a lactic acid bacteria (lab) food antimicrobial culture.201222313253
investigations of salmonella enterica serovar newport infections of oysters by using immunohistochemistry and knockout mutagenesis.the consumption of raw oysters is an important risk factor in the acquisition of food-borne disease, with salmonella being one of a number of pathogens that have been found in market oysters. previous work by our lab found that salmonella was capable of surviving in oysters for over 2 months under laboratory conditions, and this study sought to further investigate salmonella's tissue affinity and mechanism of persistence within the oysters. immunohistochemistry was used to show that salmonella w ...201222307286
enhancing chloramphenicol and trimethoprim in vitro activity by ocimum sanctum linn. (lamiaceae) leaf extract against salmonella enterica serovar typhi.to evaluate the antibacterial activity of ocimum sanctum (o. sanctum) leaf extract, alone, and in combination with chloramphenicol (c) and trimethoprim (tm) against salmonella enterica serovar typhi (s. typhi).201222305788
adaptation of salmonella enterica hadar under static magnetic field: effects on outer membrane protein pattern.salmonella enterica serovar hadar (s. hadar) is a highly prevalent foodborne pathogen and therefore a major cause of human gastroenteritis worldwide. outer membrane proteins whose production is often regulated by environmental conditions also play important roles in the adaptability of bacterial pathogens to various environments.201222304719
high-resolution genotyping of the endemic salmonella typhi population during a vi (typhoid) vaccination trial in kolkata.typhoid fever, caused by salmonella enterica serovar typhi (s. typhi), is a major health problem especially in developing countries. vaccines against typhoid are commonly used by travelers but less so by residents of endemic areas.201222303491
dynamics of salmonella serotype shifts in an endemically infected dairy herd.salmonella is a leading cause of foodborne illness in the united states. it is a zoonotic pathogen found in many species of food animals, and contamination of foodstuffs by strains of salmonella found on farms is an important source of human exposure. here we describe a long-term (2004-2010) study of salmonella colonization on a typical dairy farm in the northeastern united states. the fecal shedding prevalence in the herd ranged from 8% to 97%, and greater than 50% of the herd was shedding salm ...201222300223
tentative colistin epidemiological cut-off value for salmonella spp.the objective of this research was to determine minimal inhibitory concentration (mic) population distributions for colistin for salmonella on subtype level. furthermore, we wanted to determine if differences in mic for colistin could be explained by mutations in pmra or pmrb encoding proteins involved in processes that influence the binding of colistin to the cell membrane. during 2008-2011, 6,583 salmonella enterica subsp. enterica isolates of human origin and 1931 isolates of animal/meat orig ...201222300222
a large outbreak of typhoid fever associated with a high rate of intestinal perforation in kasese district, uganda, 2008-2009.salmonella enterica serovar typhi (salmonella typhi) causes an estimated 22 million typhoid fever cases and 216 000 deaths annually worldwide. in africa, the lack of laboratory diagnostic capacity limits the ability to recognize endemic typhoid fever and to detect outbreaks. we report a large laboratory-confirmed outbreak of typhoid fever in uganda with a high proportion of intestinal perforations (ips).201222357703
multidrug-resistant typhoid fever with neurologic findings on the malawi-mozambique border.salmonella enterica serovar typhi causes an estimated 22 million cases of typhoid fever and 216 000 deaths annually worldwide. we investigated an outbreak of unexplained febrile illnesses with neurologic findings, determined to be typhoid fever, along the malawi-mozambique border.201222357702
gene expression analysis of salmonella enterica enteritidis nal(r) and salmonella enterica kentucky 3795 exposed to hcl and acetic acid in rich medium.in the united states, serovar kentucky has become one of the most frequently isolated salmonella enterica serovars from chickens. the reasons for this prevalence are not well understood. phenotypic comparisons of poultry salmonella isolates belonging to various serovars demonstrated that serovar kentucky isolates differed from those of most other serovars in their response to acid. microarray and qpcr analyses were performed with aerated exponentially growing poultry isolates, salmonella enteric ...201222356573
wild birds as sentinels for multiple zoonotic pathogens along an urban to rural gradient in greater chicago, illinois.wild birds are important in the maintenance and transmission of many zoonotic pathogens. with increasing urbanization and the resulting emergence of zoonotic diseases, it is critical to understand the relationships among birds, vectors, zoonotic pathogens, and the urban landscape. here, we use wild birds as sentinels across a gradient of urbanization to understand the relative risk of diseases caused by three types of zoonotic pathogens: salmonella pathogens, mosquito-borne west nile virus (wnv) ...201222353581
effect of wheat distillers dried grains with solubles or sugar beet pulp on prevalence of salmonella enterica typhimurium in weaned pigs.salmonella enterica typhimurium (st) is of concern in the swine industry with relevance for animal health and consumer safety. nutritional strategies might help to reduce st infection and transmission. this study examined the potential of wheat (triticum aestivum) distillers dried grains with solubles (ddgs) and sugar beet (beta vulgaris) pulp (sbp) to alter intestinal microbial communities and st shedding using a trojan model. weaned pigs (n = 105; 28.5 ± 3.5 d of age) were separated into 3 tre ...201223365269
pitfalls of interpreting ciprofloxacin minimum inhibitory concentrations in salmonella enterica serovar typhi. 201223287141
early diagnosis of typhoid fever by nested pcr for flagellin gene of salmonella enterica serotype typhi.typhoid fever caused by salmonella typhi continues to be a major health problem in spite of the use of antibiotics and the development of newer antibacterial drugs. inability to make an early laboratory diagnosis and resort to empirical therapy, often lead to increased morbidity and mortality in cases of typhoid fever. this study was aimed to optimize a nested pcr for early diagnosis of typhoid fever and using it as a diagnostic tool in culture negative cases of suspected typhoid fever.201223287134
molecular serotyping of salmonella enterica by complete rpob gene sequencing.serotyping has been the gold standard for identifying salmonella, but it requires large amounts of standard antisera. multilocus sequence typing (mlst) has been applied to identify salmonella serovars, but the recombination of 4-7 housekeeping genes and multiple analytic steps diminish its applicability. in the present study, we determined the complete sequences of the rna polymerase beta subunit gene (rpob) and 7 housekeeping genes (aroc, dnan, hemd, hisd, pure, suca, and thra) for 76 strains o ...201223274983
an allele of an ancestral transcription factor dependent on a horizontally acquired gene product.changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. in bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. here, we identify an allele of the ancestral transcription factor pmra that requires the horizontally acquired pmrd gene product to promote gene expression. we determined that a single amino acid difference between the pmra proteins from the hu ...201223300460
attenuated salmonella typhimurium lacking the pathogenicity island-2 type 3 secretion system grow to high bacterial numbers inside phagocytes in mice.intracellular replication within specialized vacuoles and cell-to-cell spread in the tissue are essential for the virulence of salmonella enterica. by observing infection dynamics at the single-cell level in vivo, we have discovered that the salmonella pathogenicity island 2 (spi-2) type 3 secretory system (t3ss) is dispensable for growth to high intracellular densities. this challenges the concept that intracellular replication absolutely requires proteins delivered by spi-2 t3ss, which has bee ...201223236281
genome sequencing and analysis of salmonella enterica serovar typhi strain cr0063 representing a carrier individual during an outbreak of typhoid fever in kelantan, malaysia.salmonella typhi is a human restricted pathogen with a significant number of individuals as asymptomatic carriers of the bacterium. salmonella infection can be effectively controlled if a reliable method for identification of these carriers is developed. in this context, the availability of whole genomes of carrier strains through high- throughput sequencing and further downstream analysis by comparative genomics approaches is very promising. herein we describe the genome sequence of a salmonell ...201223234298
ensuring safety of home-produced eggs to control salmonellosis in poland: lessons from an outbreak in september 2011.implementation of control measures in line with european commission regulations has led to a decrease in salmonellosis in the european union since 2004. however, control programmes do not address laying hens whose eggs are produced for personal consumption or local sale. this article reports an investigatxion of a salmonellosis outbreak linked to home-produced eggs following a family event held in a farm in september 2011 near warsaw, poland. in the outbreak, 34 people developed gastroenteritis ...201223231857
neurologic manifestations associated with an outbreak of typhoid fever, malawi--mozambique, 2009: an epidemiologic investigation.the bacterium salmonella enterica serovar typhi causes typhoid fever, which is typically associated with fever and abdominal pain. an outbreak of typhoid fever in malawi-mozambique in 2009 was notable for a high proportion of neurologic illness.201223226492
interactions of salmonella enterica with dendritic cells.dendritic cells (dcs) form an important link between innate and adaptive immunity. however, dcs are also deployed as vehicles for systemic spread of pathogens. salmonella is an important gastrointestinal pathogen causing diseases ranging from gastroenteritis to typhoid fever. dcs play an important role in the immunity against salmonella infection, but this pathogen has also evolved efficient mechanisms to persist after phagocytosis by dcs, to spread using dcs as vehicles and to interfere with th ...201223221476
pleural empyema due to salmonella typhi.salmonella serotypes most often produce gastroenteritis, enteric fever, bacteremia, vascular infection and chronic carrier state. localized infection may occur at any site after salmonella bacteremia. pulmonary involvement due to salmonella infection is rare. empyema occurs usually in elderly patients or in patients with underlying diseases such as diabetes mellitus, malignancy, or pulmonary disease. we report the case of an 83-year-old male diabetic patient who presented with fever, productive ...201223217492
detection of escherichia coli o157:h7 and salmonella enterica in air and droplets at three u.s. commercial beef processing plants.bacteria are known to be present in the air at beef processing plants, but published data regarding the prevalences of airborne escherichia coli o157:h7 and salmonella enterica are very limited. to determine if airborne pathogens were present in beef processing facilities, we placed sedimentation sponges at various locations in three commercial beef plants that processed cattle from slaughter through fabrication. for the 291 slaughter area air samples, e. coli o157:h7 was isolated from 15.8% and ...201223212019
modeling to predict growth/no growth boundaries and kinetic behavior of salmonella on cutting board surfaces.this study developed models to predict the growth probabilities and kinetic behavior of salmonella enterica strains on cutting boards. polyethylene coupons (3 by 5 cm) were rubbed with pork belly, and pork purge was then sprayed on the coupon surface, followed by inoculation of a five-strain salmonella mixture onto the surface of the coupons. these coupons were stored at 13 to 35°c for 12 h, and total bacterial and salmonella cell counts were enumerated on tryptic soy agar and xylose lysine deox ...201223212007
salmonella and campylobacter baseline in retail ground beef and whole-muscle cuts purchased during 2010 in the united states.salmonella enterica and campylobacter spp. cause a considerable number of human illnesses each year, and the vast majority of cases are foodborne. the purpose of this study was to establish the baseline of salmonella and campylobacter in beef products purchased from u.s. retail markets. sampling was carried out in 38 american cities. retail raw ground and whole-muscle beef (n = 2,885) samples were purchased and examined for the presence of salmonella. samples testing positive for salmonella were ...201223212006
salmonella enterica serovar typhi plasmid pr st98 -mediated inhibition of autophagy promotes bacterial survival in infected fibroblasts.pr (st98) is a chimeric plasmid isolated from salmonella enterica serovar typhi (s. typhi) and mediates both drug-resistance and virulence of s. typhi. autophagy has been recently reported as an important component of the innate immune response against intracellular pathogen. in this study, we investigated the effect of pr (st98) on cellular autophagy, apoptosis and bacterial survival in infected fibroblasts. s. typhi strain st 8 carrying pr (st98) , salmonella typhimurium strain sr-11 carrying ...201223183467
extended-spectrum β-lactamase- and ampc β-lactamase-producing salmonella enterica strains isolated from domestic retail chicken meat from 2006 to 2011. 201223183214
failure of oral antibiotic therapy, including azithromycin, in the treatment of a recurrent breast abscess caused by salmonella enterica serotype paratyphi a.we report a case of recurrent, multifocal salmonella enterica serotype paratyphi a breast abscesses, resistant to ciprofloxacin, which relapsed despite surgery, aspiration and multiple courses of antibiotics, including co-trimoxazole and azithromycin. the patient was cured after a prolonged course of intravenous ceftriaxone.201223182142
dna sequence analysis of plasmids from multidrug resistant salmonella enterica serotype heidelberg isolates.salmonella enterica serovar heidelberg is among the most detected serovars in swine and poultry, ranks among the top five serotypes associated with human salmonellosis and is disproportionately associated with invasive infections and mortality in humans. salmonella are known to carry plasmids associated with antimicrobial resistance and virulence. to identify plasmid-associated genes in multidrug resistant s. enterica serovar heidelberg, antimicrobial resistance plasmids from five isolates were ...201223251446
strain variability of the biofilm-forming ability of salmonella enterica under various environmental conditions.the biofilm-forming ability of 60 salmonella enterica strains was assessed at different ph values (3.8-7.0), nacl concentrations (0.5-8.0%) and temperatures (4-37°c). a total of 4320 biofilm formation tests (60 strains×12 different environmental conditions×6 replicates) were carried out. biofilm formation was evaluated in tryptone soy broth after 48h of incubation in polystyrene microtiter plates using crystal violet staining, and its quantification was based on the difference between the optica ...201223177057
multistate outbreak of salmonella serotype bovismorbificans infections associated with hummus and tahini--united states, 2011.on september 27, 2011, three clinical isolates of salmonella enterica serotype bovismorbificans with indistinguishable pulsed-field gel electrophoresis (pfge) patterns were identified by the district of columbia public health laboratory (phl). human infection with s. bovismorbificans is rare in the united states. through query of pulsenet, the national molecular subtyping network for foodborne disease surveillance, six additional cases with indistinguishable pfge patterns were identified in thre ...201223169315
expression of hila in response to mild acid stress in salmonella enterica is serovar and strain dependent.salmonella enterica is the leading cause of foodborne illness with poultry and poultry products being primary sources of infection. the 2 most common s. enterica serovars associated with human infection are typhimurium and enteritidis. however, kentucky and heidelburg and the 2 most prevalent serovars isolated from poultry environments. given the prevalence of other serovars in poultry products and environments, research is needed to understand virulence modulation in response to stress in serov ...201223163946
salmonella inhibits retrograde trafficking of mannose-6-phosphate receptors and lysosome function.salmonella enterica is an intracellular bacterial pathogen that replicates within membrane-bound vacuoles through the action of effector proteins translocated into host cells. salmonella vacuoles have characteristics of lysosomes but are reduced in hydrolytic enzymes transported by mannose-6-phosphate receptors (mprs). we found that the effector sifa subverted rab9-dependent retrograde trafficking of mprs, thereby attenuating lysosome function. this required binding of sifa to its host cell targ ...201223162002
[pyopneumothorax caused by salmonella choleraesuis: a case report and review of the literature].to improve understanding of the clinical features, diagnosis and treatment of pyopneumothorax caused by salmonella choleraesuis.201223158072
structural insights into the mechanism of four-coordinate cob(ii)alamin formation in the active site of the salmonella enterica atp:co(i)rrinoid adenosyltransferase enzyme: critical role of residues phe91 and trp93.atp:co(i)rrinoid adenosyltransferases (acats) are enzymes that catalyze the formation of adenosylcobalamin (adocbl, coenzyme b(12)) from cobalamin and atp. there are three families of acats, namely, coba, eutt, and pduo. in salmonella enterica, coba is the housekeeping enzyme that is required for de novo adocbl synthesis and for salvaging incomplete precursors and cobalamin from the environment. here, we report the crystal structure of coba in complex with atp, four-coordinate cobalamin, and fiv ...201223148601
salmonella typhi in the democratic republic of the congo: fluoroquinolone decreased susceptibility on the rise.drug resistance of salmonella enterica serovar typhi (salmonella typhi) to first-line antibiotics is emerging in central africa. although increased use of fluoroquinolones is associated with spread of resistance, salmonella typhi with decreased ciprofloxacin susceptibility (dcs) has rarely been reported in central africa.201223166855
o:2-crm(197) conjugates against salmonella paratyphi a.enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. salmonella enterica serovar typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of s. paratyphi a, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against s. paratyphi a. the o-specific polysaccharide (o:2) of s. paraty ...201223144798
adhesion and splash dispersal of salmonella enterica typhimurium on tomato leaflets: effects of rdar morphotype and trichome density.salmonella enterica strains with rdar (red dry and rough) and saw (smooth and white) morphotypes have previously been associated with tomato outbreaks but the dispersal mechanisms of these morphotypes are still poorly understood. in this study, salmonella adhesion was distinguished from attachment by comparing different contact periods. initial adhesion of rdar and saw morphotypes of salmonella was compared in relation to tomato plants with different leaf trichome densities. trichome densities w ...201223141646
phenotypic and genotypic features of antibiotic resistance in salmonella enterica isolated from chicken meat and chicken and quail carcasses.one hundred and twenty-three salmonella enterica isolated in italy from chicken meat and carcasses and from quail carcasses were analyzed to determine their levels of antibiotic resistance using antibiograms (phenotypic method) and pcr amplification of antimicrobial resistance-associated genes (genotypic method). the isolates were screened for the ability to grow in the presence of antibiotics (ampicillin, gentamicin, sulfamethoxazole and tetracycline) and for the presence of the following genes ...201223141641
perturbations in histidine biosynthesis uncover robustness in the metabolic network of salmonella enterica.phosphoribosylamine (pra) is an intermediate in the biosynthetic pathway that is common to thiamine and purines. glutamine phosphoribosyl pyrophosphate (prpp) amidotransferase is the product of the purf gene in salmonella enterica and catalyzes the synthesis of pra from prpp and glutamine. strains lacking purf require exogenous addition of purines for growth. however, under some growth conditions or with specific secondary mutations these strains grow in the absence of exogenous thiamine. mutant ...201223133571
polythiophene synthesis coupled to quartz crystal microbalance and raman spectroscopy for detecting bacteria.a simple electrochemical procedure was used for the synthesis of a polythiophene containing para-benzenesulfonyl chloride groups. the obtained polymer was shown to be very reactive and directly able to covalently bind nucleophile biomolecules. protein a and a specific antibody were then successively immobilized on the conductive polymer through a covalent bonding of protein a with the as-prepared linker for bacteria trapping purpose. all reactions were controlled in situ by cyclic voltammetry, q ...201223129343
enteric fever in cambodian children is dominated by multidrug-resistant h58 salmonella enterica serovar typhi with intermediate susceptibility to ciprofloxacin.infections with salmonella enterica serovar typhi isolates that are multidrug resistant (mdr: resistant to chloramphenicol, ampicillin, trimethoprim-sulphamethoxazole) with intermediate ciprofloxacin susceptibility are widespread in asia but there is little information from cambodia. we studied invasive salmonellosis in children at a paediatric hospital in siem reap, cambodia. between 2007 and 2011 salmonella was isolated from a blood culture in 162 children. there were 151 children with enteric ...201223122884
composition and antimicrobial activity of the skin peptidome of russian brown frog rana temporaria.a nano-hplc-esi-orbitrap study involving hcd and etd spectra has been carried out to clarify the composition of the skin peptidome of brown russian frogs rana temporaria. this approach allowed determinantion of 76 individual peptides, increasing 3-fold the identified portion of the peptidome in comparison to that obtained earlier with fticr ms. a search for the new bradykinin related peptides (brps) was carried out by reconstructing mass chromatograms based on the ion current of characteristic b ...201223121565
invasive salmonellosis in humans.human salmonellosis is generally associated with salmonella enterica from subspecies enterica (subspecies i). acute infections can present in one of four ways: enteric fever, gastroenteritis, bacteremia, or extraintestinal focal infection. as with other infectious diseases, the course and outcome of the infection depend on a variety of factors, including the infecting organism, the inoculating dose, and the immune status and genetic background of the host. for serovarstyphi and paratyphi a there ...201226442824
a tollgate for typhoid.humans are uniquely susceptible to typhoid fever caused by infection with salmonella enterica serovar typhi. mathur et al. now report that mice lacking toll-like receptor 11, which is absent in humans, can be lethally infected with s. typhi, a breakthrough that promises to speed the development of better vaccines.201223101620
inactivation of salmonella enterica on tomato stem scars by antimicrobial solutions and vacuum perfusion.a study was conducted to identify sanitizing solutions effective at inactivating ca. 5logcfu of salmonella enterica inoculated onto the stem scar of red round tomatoes during two-minute immersion treatments. sixty-three antimicrobial combinations were tested. vacuum perfusion was applied to tomatoes during selected treatments to promote infiltration of sanitizer into porous tomato stem scar tissue. red round tomatoes were inoculated to ca. 6.9logcfu/stem scar with a four-serovar composite of sal ...201223072692
fast dna serotyping and antimicrobial resistance gene determination of salmonella enterica with an oligonucleotide microarray-based assay.salmonellosis caused by salmonella (s.) belongs to the most prevalent food-borne zoonotic diseases throughout the world. therefore, serotype identification for all culture-confirmed cases of salmonella infection is important for epidemiological purposes. as a standard, the traditional culture method (iso 6579:2002) is used to identify salmonella. classical serotyping takes 4-5 days to be completed, it is labor-intensive, expensive and more than 250 non-standardized sera are necessary to characte ...201223056321
host-pathogen interaction in invasive salmonellosis.salmonella enterica infections result in diverse clinical manifestations. typhoid fever, caused by s. enterica serovar typhi (s. typhi) and s. paratyphi a, is a bacteremic illness but whose clinical features differ from other gram-negative bacteremias. non-typhoidal salmonella (nts) serovars cause self-limiting diarrhea with occasional secondary bacteremia. primary nts bacteremia can occur in the immunocompromised host and infants in sub-saharan africa. recent studies on host-pathogen interactio ...201223055923
human infections due to salmonella blockley, a rare serotype in south africa: a case report.infections due to nontyphoidal salmonella have increased worldwide over the last couple of decades. salmonella enterica serotype blockley (salmonella blockley) infections is associated with chickens and is a rarely isolated serotype in human infections in most countries.201223050633
genome sequence and comparative pathogenomics analysis of a salmonella enterica serovar typhi strain associated with a typhoid carrier in malaysia.salmonella enterica serovar typhi is a human pathogen that causes typhoid fever predominantly in developing countries. in this article, we describe the whole genome sequence of the s. typhi strain cr0044 isolated from a typhoid fever carrier in kelantan, malaysia. these data will further enhance the understanding of its host persistence and adaptive mechanism.201223045488
effect of chemical sanitizers on salmonella enterica serovar poona on the surface of cantaloupe and pathogen contamination of internal tissues as a function of cutting procedure.survival of salmonella enterica subsp. enterica serovar poona on surface and stem scar portions of inoculated cantaloupe following sanitizer application, transfer of pathogen from the rind to the flesh during cutting, and growth of salmonella poona on cantaloupe cubes over 15 days of refrigerated storage were investigated. cantaloupes inoculated with a rifampin-resistant strain of salmonella poona (10(7) cfu/ml) for 3 min and dried for 12 h were washed with chlorine (200 mg free chlorine per lit ...201223043824
typhoid and paratyphoid fever in western sydney local health district, nsw, january-june 2011.we undertook a study of enteric fever, caused by salmonella enterica enterica subtypes typhi and paratyphi a, presenting in residents of the western sydney local health district for the period january-june 2011. twelve cases of s. typhi and eight of s. paratyphi a were notified. patients were predominantly young adults (median age 26 years, 70% female) who had been visiting friends and relatives in india, samoa, bangladesh or sri lanka. no cases were associated with travel for less than 3 weeks; ...201223043747
population genetic structure of 4,12:a:- salmonella enterica strains from harbor porpoises.according to pulsed-field gel electrophoresis (pfge) typing, 4,12:a:- salmonella enterica isolates from harbor porpoises are highly diverse. however, porpoise isolates belong to only two multilocus sequence types within the eburst group 18 (ebg18) genetic cluster, which also includes s. enterica serovars bispebjerg and abortusequi. isolates of other, serologically similar serovars belong to unrelated ebgs. these assignments to ebgs were supported by ebg-specific sequences of the flagellar gene f ...201223042176
interplay between fur and hns in controlling virulence gene expression in salmonella typhimurium.salmonella enterica is responsible for a large number of diseases in a wide-range of hosts. two of the global regulators involved in controlling gene expression during the infection cycle of the bacterium are fur and hns. in this paper, we demonstrate computationally that fur and hns have disproportionately high density of binding sites in the pathogenicity islands on the salmonella chromosome. moreover, the frequency of binding sites for the two proteins is correlated throughout the genome of t ...201223040276
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