| use of inverse pcr for analysis of class 1 integrons carrying an unusual 3' conserved segment structure. | by using inverse pcr and dna sequencing, 13 sul3-associated mutational integrons, 2 defective class 1 integrons, and 1 qnrb2-associated complex sul1-type class 1 integrons were identified in salmonella enterica serovar choleraesuis, pseudomonas aeruginosa, and enterobacter cloacae, respectively. in addition, conjugation and southern hybridization demonstrated that unusual class 1 integrons were located on plasmids or integrated into chromosomal dna. thus, an inverse pcr assay can be a valuable t ... | 2010 | 21098251 |
| high prevalence of integron-mediated resistance in clinical isolates of salmonella enterica. | salmonella enterica has become progressively resistant to antimicrobial agents worldwide as a result of genes carried on different classes of integrons. the aim of the current study was to investigate the molecular diversity of these integrons and their association with antimicrobial resistance in clinical s. enterica isolates from tehran, iran. antimicrobial susceptibility testing was performed according to the clinical and laboratory standards institute. the presence of integrons was investiga ... | 2010 | 21099092 |
| bactericidal activity of mouse α-defensin cryptdin-4 predominantly affects noncommensal bacteria. | mouse paneth cell α-defensins, termed cryptdins, are secreted into the intestinal lumen, have microbicidal activity, and contribute to intestinal innate immunity. among them, cryptdin-4 (crp4) has the most potent microbicidal activity. in the intestinal lumen, commensal bacteria colonize and elicit beneficial effects in the host. however, the effects of crp4 against commensal bacteria are poorly understood. thus, we investigated the bactericidal activities of crp4 against commensal bacteria comp ... | 2010 | 21099205 |
| modulation of salmonella gene expression by subinhibitory concentrations of quinolones. | approximately 2.7% of a collection of salmonella enterica var. typhimurium promoter-lux reporter strains showed altered transcriptional patterns when exposed to low concentrations of nine different fluoroquinolones (fqs). even at the subinhibitory concentrations employed, all nine fqs upregulated genes involved in the sos response, umud, lexa, sbmc and dinp. in addition, transcriptional regulators, genes putatively associated with membrane integrity (spr), virulence (sica) and metabolism (plsb) ... | 2010 | 21102598 |
| mlva and phage typing as complementary tools in the epidemiological investigation of salmonella enterica serovar typhimurium clusters. | in south australia serotyping and phage typing are employed for routine salmonella surveillance. molecular techniques such as multiple-locus variable number tandem repeat analysis (mlva) are increasingly utilized to aid outbreak investigations. during 2007 three salmonella enterica serovar typhimurium outbreaks involving phage types dt9, dt29, and dt44 were investigated. human, food and environmental isolates were also typed by mlva. in the dt9 outbreak cluster mlva demonstrated distinct groupin ... | 2010 | 21104081 |
| [typhoid fever: facing the challenge of resistant strains]. | the introduction of chloramphenicol in 1948 revolutionised the outcome of typhoid fever but chloramphenicol-resistant strains of salmonella enterica serotype typhi were reported just two years later. resistance followed also the introduction of ampicillin and co-trimoxazole. during the second half of the 1980s, strains resistant to the three first-line antimicrobial agents, chloramphenicol, ampicillin and co-trimoxazole emerged and spread rapidly throughout the indian subcontinent and south east ... | 2010 | 21106179 |
| an externally modulated, noise-driven switch for the regulation of spi1 in salmonella enterica serovar typhimurium. | in this work we consider the regulation system present on the spi1 pathogenicity island of salmonella enterica serovar typhimurium. it is well-known that hila is the central regulator in the overall scheme of spi1 regulation and directly binds to virulence operons and activates their expression. the regulation of the expression of hila is via a complex feed-forward loop involving three transcriptional activators: hilc, hild and rtsa, and the negative regulator hile. our aim is to model this regu ... | 2010 | 21107576 |
| inactivation of cronobacter sakazakii by ultrasonic waves under pressure in buffer and foods. | the objective of this research was to characterize the resistance of cronobacter sakazakii to ultrasonic waves under pressure (manosonication, ms). the d(ms) value (decimal reduction time value) of c. sakazakii in standard conditions (35°c, 117 μm, 200 kpa, citrate-phosphate buffer ph 7.0) was 0.41 min. this value was higher than that of yersinia enterocolitica (d(ms)=0.19 min) and lower than those of salmonella enterica serovar enteritidis (d(ms)=0.61 min), listeria monocytogenes (d(ms)=0.86 mi ... | 2010 | 21111503 |
| analysis of psc138, the multidrug resistance plasmid of salmonella enterica serotype choleraesuis sc-b67. | salmonella enterica serotype choleraesuis (s. choleraesuis) usually causes systemic infections in man and needs antimicrobial treatment. multidrug resistance (mdr) in s. choleraesuis is thus a great concern in the treatment of systemic non-typhoid salmonellosis. a large plasmid, psc138, was identified in 2002 from a s. choleraesuis strain sc-b67 that was resistant to all antimicrobial agents commonly used to treat salmonellosis, including ciprofloxacin and ceftriaxone. complete dna sequence of t ... | 2010 | 21111756 |
| differential identification of salmonella enterica subsp. enterica serovar gallinarum biovars gallinarum and pullorum based on polymorphic regions of glgc and spec genes. | salmonella enterica subsp. enterica serovar gallinarum biovars gallinarum and pullorum cause fowl typhoid and pullorum disease in avian species, respectively, and have been of considerable economic importance to the poultry industry in parts of the world. the definitive diagnosis of these diseases can be made only by isolation and identification of the causative agent. however, rapid identification of biovars gallinarum and pullorum is not easily feasible due to their common antigenic structure ... | 2010 | 21111918 |
| gram negative shuttle bac vector for heterologous expression of metagenomic libraries. | bacterial artificial chromosome (bac) vectors enable stable cloning of large dna fragments from single genomes or microbial assemblages. a novel shuttle bac vector was constructed that permits replication of bac clones in diverse gram-negative species. the "gram-negative shuttle bac" vector (pgns-bac) uses the f replicon for stable single-copy replication in e. coli and the broad-host-range rk2 mini-replicon for high-copy replication in diverse gram-negative bacteria. as with other bac vectors c ... | 2010 | 21112378 |
| chronic and acute infection of the gall bladder by salmonella typhi: understanding the carrier state. | despite major treatment and prevention efforts, millions of new typhoid infections occur worldwide each year. for a subset of infected individuals, salmonella enterica subsp. enterica serovar typhi colonizes the gall bladder and remains there long after symptoms subside, serving as a reservoir for the further spread of the disease. in this progress article, we explore recent advances in our understanding of the mechanisms by which salmonella spp.--predominantly s. typhi--colonize and persist in ... | 2010 | 21113180 |
| immunization with salmonella enterica serovar typhimurium-derived outer membrane vesicles delivering the pneumococcal protein pspa confers protection against challenge with streptococcus pneumoniae. | gram-negative bacteria produce outer membrane vesicles (omvs) that serve a variety of functions related to survival and pathogenicity. periplasmic and outer membrane proteins are naturally captured during vesicle formation. this property has been exploited as a method to derive immunogenic vesicle preparations for use as vaccines. in this work, we constructed a salmonella enterica serovar typhimurium strain that synthesized a derivative of the pneumococcal protein pspa engineered to be secreted ... | 2010 | 21115718 |
| a subtractively optimized dna microarray using non-sequenced genomic probes for the detection of food-borne pathogens. | in this study, we present the successful detection of food-borne pathogens using randomly selected non-sequenced genomic dna probes-based dna microarray chips. three food-borne pathogens, staphylococcus aureus, salmonella enterica subsp. enterica serovar typhimurium (s. typhimurium), and bacillus cereus, were subjected for the preparation of the dna microarray probes. initially, about 50 dna probes selected randomly from non-sequenced genomic dna of each pathogen were prepared by using a set of ... | 2010 | 21116735 |
| il-17a/f-signaling does not contribute to the initial phase of mucosal inflammation triggered by s. typhimurium. | salmonella enterica subspecies 1 serovar typhimurium (s. typhimurium) causes diarrhea and acute inflammation of the intestinal mucosa. the pro-inflammatory cytokines il-17a and il-17f are strongly induced in the infected mucosa but their contribution in driving the tissue inflammation is not understood. we have used the streptomycin mouse model to analyze the role of il-17a and il-17f and their cognate receptor il-17ra in s. typhimurium enterocolitis. neutralization of il-17a and il-17f did not ... | 2010 | 21124903 |
| orally administered p22 phage tailspike protein reduces salmonella colonization in chickens: prospects of a novel therapy against bacterial infections. | one of the major causes of morbidity and mortality in man and economically important animals is bacterial infections of the gastrointestinal (gi) tract. the emergence of difficult-to-treat infections, primarily caused by antibiotic resistant bacteria, demands for alternatives to antibiotic therapy. currently, one of the emerging therapeutic alternatives is the use of lytic bacteriophages. in an effort to exploit the target specificity and therapeutic potential of bacteriophages, we examined the ... | 2010 | 21124920 |
| pcr identification of salmonella serogroups based on specific targets obtained by comparative genomics. | comparative genomic approaches provide abundant information to reveal the diversity among salmonella serogroups. in a local genomic sequence database, twenty-five salmonella whole genomic sequences were divided into 6 (a, b, c1, c2, d and others) serogroups for mining the dna fragments specific for serogroups a through d. for each serogroup, a reference sequence was selected and split into 1000-bp fragments in silico to align against all the other genomic sequences to obtain one or more serogrou ... | 2010 | 21131088 |
| induction of fatty acid composition modifications and tolerance to biocides in salmonella enterica serovar typhimurium by plant-derived terpenes. | to enhance food safety and stability, the food industry tends to use natural antimicrobials such as plant-derived compounds as an attractive alternative to chemical preservatives. nonetheless, caution must be exercised in light of the potential for bacterial adaptation to these molecules, a phenomenon previously observed with other antimicrobials. the aim of this study was to characterize the adaptation of salmonella enterica serovar typhimurium to sublethal concentrations of four terpenes extra ... | 2010 | 21131520 |
| antimicrobial resistance in generic escherichia coli isolates from wild small mammals living in swine farm, residential, landfill, and natural environments in southern ontario, canada. | to assess the impacts of different types of human activity on the development of resistant bacteria in the feces of wild small mammals, we compared the prevalences and patterns of antimicrobial resistance and resistance genes in generic escherichia coli and salmonella enterica isolates from fecal samples collected from wild small mammals living in four environments: swine farms, residential areas, landfills, and natural habitats. resistance to antimicrobials was observed in e. coli isolates from ... | 2010 | 21131524 |
| development of pcr primers for the detection of salmonella enterica serovar choleraesuis based on the flic gene. | salmonella enterica serovar choleraesuis may cause swine salmonellosis and human infection. because the conventional method for detection of this salmonella serovar may take 3 to 5 days, a pcr method for detection was evaluated. by comparing the sequence of the phase 1 flagellin (flic) gene of salmonella choleraesuis with that of other salmonella serovars and of other bacteria species available in genbank, two pcr primers (flinc-f and flinc-r) were designed. using these primers, all 97 salmonell ... | 2005 | 21132962 |
| resting pigs on transport trailers as an intervention strategy to reduce salmonella enterica prevalence at slaughter. | recent research has shown that much preharvest salmonella enterica infection in pigs occurs immediately before slaughter during this rest period in the contaminated abattoir holding pens. the objective of this study was to evaluate a potential intervention strategy to reduce the prevalence of s. enterica-positive pigs at slaughter, which consisted of resting pigs prior to slaughter on their transport vehicle, instead of in the abattoir holding pen. additionally, the effect of transportation of p ... | 2005 | 21132985 |
| prevalence of salmonella enterica and listeria monocytogenes contamination in foods of animal origin in italy. | the present survey collected and analyzed the results of routine testing for salmonella enterica and listeria monocytogenes on foods of animal origin submitted for official controls in italy during 2001 to 2002. salmonella was detected in 2.2% of 71,643 food samples examined, and the isolation rates ranged from 9.9% for raw poultry meat to less than 0.1% for dairy products. isolation rates were also high in raw pork (4.9%) and processed meats (5.3%), which often involved pork. low rates were obs ... | 2005 | 21132987 |
| plasticity in the purine-thiamine metabolic network of salmonella. | in salmonella enterica, 5-aminoimidazole ribonucleotide (air) is the precursor of the 4-amino-5-hydroxymethyl-2-methylpyrimidine (hmp) pyrophosphate moiety of thiamine and the last intermediate in the common hmp/purine biosynthetic pathway. air is synthesized de novo via five reactions catalyzed by the purf, -d, -t, -g, and -i gene products. in vivo genetic analysis demonstrated that in the absence of these gene products air can be generated if (i) methionine and lysine are in the growth medium, ... | 2010 | 21135073 |
| separation and detection of multiple pathogens in a food matrix by magnetic sers nanoprobes. | a rapid and sensitive method was developed here for separation and detection of multiple pathogens in food matrix by magnetic surface-enhanced raman scattering (sers) nanoprobes. silica-coated magnetic probes (mnps@sio(2)) of ~100 nm in diameter were first prepared via the reverse microemulsion method using cetyltrimethylammonium bromide as a surfactant and tetraethyl orthosilicate as the silica precursor. the as-prepared mnps@sio(2) were functionalized with specific pathogen antibodies to first ... | 2010 | 21136046 |
| s. typhimurium ssej gene decreases the s. typhi cytotoxicity toward cultured epithelial cells. | salmonella enterica serovar typhi and typhimurium are closely related serovars as indicated by >96% dna sequence identity between shared genes. nevertheless, s. typhi is a strictly human-specific pathogen causing a systemic disease, typhoid fever. in contrast, s. typhimurium is a broad host range pathogen causing only a self-limited gastroenteritis in immunocompetent humans. we hypothesize that these differences have arisen because some genes are unique to each serovar either gained by horizonta ... | 2010 | 21138562 |
| epidemiology of plasmid-mediated quinolone resistance in salmonella enterica serovar typhimurium isolates from food-producing animals in japan. | abstract: a total of 225 isolates of salmonella enterica serovar typhimurium from food-producing animals collected between 2003 and 2007 were examined for the prevalence of plasmid-mediated quinolone resistance (pmqr) determinants, namely qnra, qnrb, qnrc, qnrd, qnrs, qepa and aac(6')ib-cr, in japan. two isolates (0.8%) of s. typhimurium dt104 from different dairy cows on a single farm in 2006 and 2007 were found to have qnrs1 on a plasmid of approximately 9.6-kbp. none of the s. typhimurium iso ... | 2010 | 21138594 |
| potential application of spice and herb extracts as natural preservatives in cheese. | this study investigated the antibacterial efficiency of five spice and herb extracts (cinnamon stick, oregano, clove, pomegranate peel, and grape seed) against listeria monocytogenes, staphylococcus aureus, and salmonella enterica in cheese at room temperature (∼23°c). the lipid oxidation (thiobarbituric acid-reactive substances) of cheese was periodically tested by oxidative analyses. the results showed that all five plant extracts were effective against three foodborne pathogens in cheese. tre ... | 2010 | 21142945 |
| dna topology of highly transcribed operons in salmonella enterica serovar typhimurium. | bacteria differ from eukaryotes by having the enzyme dna gyrase, which catalyses the atp-dependent negative supercoiling of dna. negative supercoils are essential for condensing chromosomes into an interwound (plectonemic) and branched structure known as the nucleoid. topo-1 removes excess supercoiling in an atp-independent reaction and works with gyrase to establish a topological equilibrium where supercoils move within 10 kb domains bounded by stochastic barriers along the sequence. however, t ... | 2010 | 21143310 |
| the interaction dynamics of a negative feedback loop regulates flagellar number in salmonella enterica serovar typhimurium. | each salmonella enterica serovar typhimurium cell produces a discrete number of complete flagella. flagellar assembly responds to changes in growth rates through flhd(4) c(2) activity. flhd(4) c(2) activity is negatively regulated by the type 3 secretion chaperone flit. flit is known to interact with the flagellar filament cap protein flid as well as components of the flagellar type 3 secretion apparatus. flid is proposed to act as an anti-regulator, in a manner similar to flgm inhibition of σ(2 ... | 2010 | 21143315 |
| response regulator arca of salmonella enterica serovar typhimurium downregulates expression of ompd, a porin facilitating uptake of hydrogen peroxide. | here we demonstrate that ompd, the most abundant porin in salmonella enterica serovar typhimurium, facilitates uptake of hydrogen peroxide (h₂o₂) and that its expression is negatively regulated by arca upon peroxide exposure. when exposed to sublethal concentrations of h₂o₂, a s. typhimurium ompd mutant showed decreased peroxide levels compared to those observed in the wild type strain, suggesting that h₂o₂ could be channeled inside the cell through ompd. further evidence came from in vitro stud ... | 2010 | 21144897 |
| the prevalence of salmonella enterica in spanish feed mills and potential feed-related risk factors for contamination. | a cross-sectional study was conducted in spain to estimate the prevalence of salmonella enterica in feed mills and to identify and evaluate potential risk factors associated with feed contamination. a total of 3844 samples were collected from 523 different feed mills using a stratified sampling method. samples were tested for the presence of salmonella using conventional culture methods. when the presence of salmonella was detected, samples were further characterised using serotyping at the nati ... | 2010 | 21145122 |
| virulence plasmid interchange between strains atcc 14028, lt2, and sl1344 of salmonella enterica serovar typhimurium. | strains atcc 14028 and sl1344 of salmonella enterica serovar typhimurium are more virulent than lt2 in the balb/c mouse model. virulence plasmid swapping between strains atcc 14208, lt2, and sl1344 does not alter their competitive indexes during mouse infection, indicating that the three plasmids are functionally equivalent, and that their contribution to virulence is independent from the host background. strains atcc 14028 and lt2 are more efficient than sl1344 as conjugal donors of the virulen ... | 2010 | 21145349 |
| effects on salmonella shell contamination and trans-shell penetration of coating hens' eggs with chitosan. | chitosan is a biopolymer with antimicrobial activity and film-forming properties. in this study, the effects on salmonella shell contamination and trans-shell penetration of coating hens' eggs with chitosan was evaluated. a chitosan was selected from eight types (four non-commercial and four commercial) based on its antimicrobial activity against salmonella enterica serovar enteritidis (s. enteritidis). for this purpose, a contact plate method was developed and chitosans were applied at a concen ... | 2010 | 21146239 |
| comparison of multilocus variable-number tandem repeat analysis and pulsed-field gel electrophoresis in molecular subtyping of salmonella enterica serovars paratyphi a. | salmonella enterica serotype paratyphi a is a highly clonal organism; pulsed-field gel electrophoresis (pfge) is insufficient in discriminating isolates. a multilocus variable-number tandem repeat analysis (mlva) was developed, and its usefulness in discriminating isolates was compared. pfge analysis with xbai and blni discriminated 55 isolates into 14 types, with a discriminatory index (di) of 0.741 (confidence interval [ci], 0.635-0.847). mlva divided the isolates into 23 types, with a di of 0 ... | 2011 | 21146707 |
| gcpa (stm1987) is critical for cellulose production and biofilm formation on polystyrene surface by salmonella enterica serovar weltevreden in both high and low nutrient medium. | biofilm formation by salmonella is a serious concern in the food-processing industry and the persistence of the organism in biofilms becomes a constant source of contamination. since there is zero tolerance for salmonella in foods, it is important to understand the mechanism of biofilm formation and to prevent the formation. therefore, this study aimed at investigating the biofilm-forming ability of seafood isolates of salmonella enterica serovar weltevreden (s. weltevreden) under two different ... | 2010 | 21147214 |
| regulation of the acrab multidrug efflux pump in salmonella enterica serovar typhimurium in response to indole and paraquat. | salmonella enterica serovar typhimurium has at least nine multidrug efflux pumps. among these, acrab is constitutively expressed and is the most efficient, playing a role in both drug resistance and virulence. the acrab locus is induced by indole, escherichia coli-conditioned medium, and bile salts. this induction is dependent on rama through the binding sequence in the upstream region of acra that binds rama. in the present study, we made a detailed investigation of the rama and acrab induction ... | 2010 | 21148208 |
| camp receptor protein (crp) positively regulates the yihu-ysha operon in salmonella enterica serovar typhi. | salmonella enterica serovar typhi (s. typhi) is the aetiological agent of typhoid fever in humans. this bacterium is also able to persist in its host, causing a chronic disease by colonizing the spleen, liver and gallbladder, in the last of which the pathogen forms biofilms in order to survive the bile. several genetic components, including the yihu-ysha genes, have been suggested to be involved in the survival of salmonella in the gallbladder. in this work we describe how the yihu-ysha gene clu ... | 2010 | 21148209 |
| fad binding by apbe protein from salmonella enterica: a new class of fad-binding proteins. | the periplasmic protein apbe was identified through the analysis of several mutants defective in thiamine biosynthesis and was implicated as having a role in iron-sulfur cluster biosynthesis or repair. while mutations in apbe cause decreased activity of several iron-sulfur enzymes in vivo, the specific role of apbe remains unknown. members of the abpe family include nosx and rnff, which have been implicated in oxidation-reduction associated with nitrous oxide and nitrogen metabolism, respectivel ... | 2010 | 21148731 |
| analysis of salmonella enterica serotype paratyphi a gene expression in the blood of bacteremic patients in bangladesh. | salmonella enterica serotype paratyphi a is a human-restricted cause of paratyphoid fever, accounting for up to a fifth of all cases of enteric fever in asia. | 2010 | 21151879 |
| multilocus variable number tandem repeat analysis for salmonella enterica subspecies. | genomic analysis of salmonella enterica revealed the existence of a variable number of tandem repeats (vntr) at multiple loci. some s. enterica strains are considered as references (typhi ty2, typhi ct18, typhimurium lt2, enteritidis lk5, pt4, and enteritidis 07-2642, and newport). these allowed the selection of markers to develop the genotyping technique, multiple-locus vntr analysis (mlva). these markers were used to discriminate s. enterica isolated from humans, food, or the environment. in t ... | 2010 | 21153561 |
| bacterial gold sensing and resistance. | gold ions are mobilized and disseminated through the environment and enter into the cells by non-specific intake. to avoid deleterious effect that occurs even at very low concentrations, bacteria such as salmonella enterica and cupriavidus metallidurans use au-specific merr-type transcriptional regulators to detect the presence of these toxic ions, and control the expression of specific resistance factors. in contrast to the related copper sensor cuer, the au-selective metalloregulatory proteins ... | 2010 | 21153861 |
| interference of bifidobacterium choerinum or escherichia coli nissle 1917 with salmonella typhimurium in gnotobiotic piglets correlates with cytokine patterns in blood and intestine. | the colonization, translocation and protective effect of two intestinal bacteria - pr4 (pig commensal strain of bifidobacterium choerinum) or ecn (probiotic escherichia coli strain nissle 1917) - against subsequent infection with a virulent lt2 strain of salmonella enterica serovar typhimurium were studied in gnotobiotic pigs after oral association. the clinical state of experimental animals correlated with bacterial translocation and levels of inflammatory cytokines [a chemokine, interleukin (i ... | 2010 | 21155989 |
| the hyb hydrogenase permits hydrogen-dependent respiratory growth of salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium contains three distinct respiratory hydrogenases, all of which contribute to virulence. addition of h(2) significantly enhanced the growth rate and yield of s. typhimurium in an amino acid-containing medium; this occurred with three different terminal respiratory electron acceptors. based on studies with site-specific double-hydrogenase mutant strains, most of this h(2)-dependent growth increase was attributed to the hyb hydrogenase, rather than to the hya ... | 2010 | 21157514 |
| enhancement of immune responses by an attenuated salmonella enterica serovar typhimurium strain secreting an escherichia coli heat-labile enterotoxin b subunit protein as an adjuvant for a live salmonella vaccine candidate. | a plasmid harboring eltb, the gene encoding heat-labile enterotoxin (ltb), was constructed by insertion of eltb into an asd(+) β-lactamase signal plasmid (pmmp65). this was introduced into the δlon δcpxr δasd salmonella enterica serovar typhimurium strain and designated the ltb adjuvant strain. ltb protein production and secretion from the strain were demonstrated with an immunoblot assay and enzyme-linked immunosorbent assay. the ltb strain was evaluated for enhancement of immunity and protecti ... | 2010 | 21159921 |
| sub-clinical infection with salmonella in chickens differentially affects behaviour and welfare in three inbred strains. | 1. much evidence exists detailing how animals respond to pathogen challenge, yet information explaining how the various behavioural, immunological, and physiological systems in chickens interplay during such challenges remains limited. 2. to gain an understanding of this interplay while controlling for genetic variation, the current study collected a variety of behavioural, physiological and immunological measures from three inbred lines (p, o and n) of laying hens before and after a sub-clinica ... | 2010 | 21161776 |
| high prevalence of plasmid-mediated quinolone resistance determinant aac(6')-ib-cr amongst salmonella enterica serotype typhimurium isolates from hospitalised paediatric patients with diarrhoea in china. | in this study, the antimicrobial susceptibilities and prevalence of plasmid-mediated quinolone resistance determinants amongst salmonella enterica serotype typhimurium isolates from hospitalised paediatric patients with diarrhoea in china were investigated. in total, 40 (64.5%) of 62 s. typhimurium isolates were resistant to ciprofloxacin (minimum inhibitory concentration ≥0.5 μg/ml), comprising 28 isolates with low-level resistance and 12 isolates with high-level resistance. all ciprofloxacin-r ... | 2010 | 21163630 |
| salmonella serovars from foodborne and waterborne diseases in korea, 1998-2007: total isolates decreasing versus rare serovars emerging. | salmonella enterica has been one of the most widespread foodborne pathogens in korea. between 1998 and 2007, a total of 9,472 salmonella isolates were identified from foodborne and waterborne illness patients. during that time, korea was transitioning into a developed country in industry as well as in its hygiene system. although the isolation number of total salmonella including serovar typhi has decreased since 1999, the isolation of rare salmonella serovars has emerged. three most prevalent s ... | 2010 | 21165281 |
| inactivation of salmonella in organic soil by cinnamaldehyde, eugenol, ecotrol, and sporan. | salmonella can survive in soil for months to years; consequently, soil can be a preharvest source of contamination of produce. elimination of salmonella with natural products and processes such as essential oils is important to prevent infection among consumers. essential oils (distilled extract from plants) have been mainly evaluated in liquid medium and foods in which minimum inhibitory concentration is determined. however, there are no reports describing the impact of essential oils in soil, ... | 2010 | 21166519 |
| effect of e-beam treatment on the safety and shelf life of mayonnaise potato salad. | the radioresistance of listeria monocytogenes, salmonella enterica serovar enteritidis, and s. enterica serovar typhimurium has been studied in a complex matrix like mayonnaise potato salad. d(10)-values of 0.56, 0.32-0.35, and 0.41-0.42 kgy were calculated for each organism, respectively. keeping in mind these values, the microbiological criteria, the characteristics of the microorganisms, and a shelf life of the products of 20 days stored at 4°c, an irradiation treatment of 1 kgy was calculate ... | 2010 | 21166582 |
| continuous control of flagellar gene expression by the σ28-flgm regulatory circuit in salmonella enterica. | the flagellar genes in salmonella enterica are expressed in a temporal hierarchy that mirrors the assembly process itself. the σ(28)-flgm regulatory circuit plays a key role in controlling this temporal hierarchy. this circuit ensures that the class 3 genes are expressed only when the hook-basal body (hbb), a key intermediate in flagellar assembly, is complete. in this work, we investigated the role of the σ(28)-flgm regulatory circuit in controlling the timing and magnitude of class 3 gene expr ... | 2010 | 21166907 |
| structures of the o-polysaccharides of salmonella enterica o59 and escherichia coli o15. | the o-polysaccharide of salmonella enterica o59 was studied using sugar analysis and 2d (1)h and (13)c nmr spectroscopy, and the following structure of the tetrasaccharide repeating unit was established: →2)-β-d-galp-(1→3)-α-d-glcpnac-(1→4)-α-l-rhap-(1→3)-β-d-glcpnac-(1→ accordingly, the o-antigen gene cluster of s. enterica o59 includes all genes necessary for the synthesis of this o-polysaccharide. earlier, another structure has been reported for the o-polysaccharide of salmonella arizonae (s. ... | 2010 | 21167479 |
| structure of the o-polysaccharide and characterization of the o-antigen gene cluster of salmonella enterica o53. | the o-polysaccharide (o-antigen) of salmonella enterica o53 was isolated by mild acid degradation of the lipopolysaccharide and studied by sugar analysis and (1)h and (13)c nmr spectroscopy before and after o-deacetylation. the following structure of the tetrasaccharide o-unit was established: sequencing of the o-antigen gene cluster of s. enterica o53 revealed 11 open reading frames having the same transcriptional direction. the functions were tentatively assigned to the genes based on their si ... | 2010 | 21168829 |
| transcriptional and proteomic responses of pseudomonas aeruginosa pao1 to spaceflight conditions involve hfq regulation and reveal a role for oxygen. | assessing bacterial behavior in microgravity is important for risk assessment and prevention of infectious diseases during spaceflight missions. furthermore, this research field allows the unveiling of novel connections between low-fluid-shear regions encountered by pathogens during their natural infection process and bacterial virulence. this study is the first to characterize the spaceflight-induced global transcriptional and proteomic responses of pseudomonas aeruginosa, an opportunistic path ... | 2010 | 21169425 |
| evolution in a family of chelatases facilitated by the introduction of active site asymmetry and protein oligomerization. | the class ii chelatases associated with heme, siroheme, and cobalamin biosynthesis are structurally related enzymes that insert a specific metal ion (fe(2+) or co(2+)) into the center of a modified tetrapyrrole (protoporphyrin or sirohydrochlorin). the structures of two related class ii enzymes, cbix(s) from archaeoglobus fulgidus and cbik from salmonella enterica, that are responsible for the insertion of cobalt along the cobalamin biosynthesis pathway are presented in complex with their metall ... | 2010 | 21173279 |
| the yfer gene of salmonella enterica serovar typhimurium encodes an osmoregulated lysr-type transcriptional regulator. | a genetic screening for osmoregulated genes allowed us to identify the yfer gene of salmonella enterica serovar typhimurium. the yfer gene product encodes a novel lysr-type transcriptional regulator (lttr), the expression of which decreases when external osmolarity increases. out of the adjacent gene yfeh, yfer modulates expression of several genes that may be required for optimal growth under low osmolarity conditions. | 2010 | 21175741 |
| comparative proteomic analysis of salmonella enterica serovar typhimurium ppgpp-deficient mutant to identify a novel virulence protein required for intracellular survival in macrophages. | the global ppgpp-mediated stringent response in pathogenic bacteria plays an important role in the pathogenesis of bacterial infections. in salmonella enterica serovar typhimurium (s. typhimurium), several genes, including virulence genes, are regulated by ppgpp when bacteria are under the stringent response. to understand the control of virulence genes by ppgpp in s. typhimurium, agarose 2-dimensional electrophoresis (2-de) combined with mass spectrometry was used and a comprehensive 2-de refer ... | 2010 | 21176126 |
| untangling metabolic and communication networks: interactions of enterics with phytobacteria and their implications in produce safety. | recent outbreaks of vegetable-borne gastrointestinal illnesses across the globe demonstrate that human enteric pathogens can contaminate produce at any stage of production. interactions of enterics with native plant-associated microbiota influence the microbiological safety of produce by affecting the attachment, persistence and proliferation of human pathogens on plants. supermarket surveys have revealed that bacteria, but not fungi or mechanical damage, promote the growth of salmonella enteric ... | 2010 | 21177108 |
| effect of heating and aging of poultry litter on the persistence of enteric bacteria. | food-borne illnesses have rarely been associated with the reuse of poultry litter as an organic fertilizer and soil amendment in agriculture. yet farming practices in many countries have come under increased scrutiny because of heightened consumer awareness of food safety and environmental issues. this study was conducted to determine whether simple on-farm management practices could improve the microbiological safety of poultry litter. first, the effects of heat and moisture on the survival of ... | 2011 | 21177438 |
| salmonella typhimurium oral challenge model in mature broilers: bacteriological, immunological, and growth performance aspects. | in this study, salmonella enterica serovar typhimurium challenge models were tested to identify the best conditions under which to perform the experimental infection of 3-wk-old broilers. such a model would be useful to study the efficiency of therapeutic treatments that could take place at the end of the grow-out period. salmonella-free chicks were obtained from a breeder flock vaccinated with salmonella. intestinal maternal immunity was monitored by elisa analyses at 2, 9, and 16 d of age. dat ... | 2011 | 21177444 |
| the impact of different housing systems on egg safety and quality. | a move from conventional cages to either an enriched cage or a noncage system may affect the safety or quality, or both, of the eggs laid by hens raised in this new environment. the safety of the eggs may be altered either microbiologically through contamination of internal contents with salmonella enterica serovar enteritidis (salmonella enteritidis) or other pathogens, or both, or chemically due to contamination of internal contents with dioxins, pesticides, or heavy metals. quality may be aff ... | 2011 | 21177467 |
| two groups of phenylalanine biosynthetic operon leader peptides genes: a high level of apparently incidental frameshifting in decoding escherichia coli phel. | the bacterial phel gene encodes the leader peptide for the phenylalanine biosynthetic operon. translation of phel mrna controls transcription attenuation and, consequently, expression of the downstream phea gene. fifty-three unique phel genes have been identified in sequenced genomes of the gamma subdivision. there are two groups of phel genes, both of which are short and contain a run(s) of phenylalanine codons at an internal position. one group is somewhat diverse and features different termin ... | 2010 | 21177642 |
| inca/c plasmids mediate antimicrobial resistance linked to virulence genes in the spanish clone of the emerging salmonella enterica serotype 4,[5],12:i:-. | to broaden knowledge of the molecular bases and genetics of multidrug resistance in clinical isolates of salmonella enterica serotype 4,5,12:i:- belonging to the spanish clone. | 2010 | 21177672 |
| comparison of salmonella enterica serovar heidelberg isolates from human patients with those from animal and food sources. | seventy-eight salmonella enterica serovar heidelberg isolates from humans were tested for antimicrobial susceptibility, resistance genes, and plasmids and genotyped by pulsed-field gel electrophoresis (pfge). most (88%) contained plasmids, and 47% were resistant to antimicrobials. the overall results were compared to those of previous s. heidelberg studies of food- and animal-related sources, and multiple similarities were observed. | 2010 | 21177888 |
| enhanced recovery of salmonella typhimurium dt104 from exposure to stress at low temperature. | salmonella enterica serovar typhimurium remains an important cause of food-borne infection in the developed world. in order to establish infection within a host, salmonella must survive and recover from a range of environmental stresses. s. typhimurium strain sl1344 is among the most extensively studied pathogenic salmonella strains, while s. typhimurium phage type dt104 is an important type that has been associated with pandemic spread and a high number of food-borne disease outbreaks over the ... | 2010 | 21178168 |
| identification of bacterial dna in noninfectious pleural fluid with a highly sensitive pcr method. | background: bacterial dna due to bacterial translocation has been identified in noninfectious ascitic fluid samples. objective: this study investigated the possible presence of bacterial dna in the pleural fluid of patients with pleural effusions of noninfectious origin, using a highly sensitive pcr-based method. methods: pleural fluid samples from 175 patients (average age ± sd: 69 ± 14 years) with noninfectious pleural effusion (62 transudates, 113 exudates) were analyzed. bacterial dna was de ... | 2010 | 21178326 |
| eukaryotic signaling pathways targeted by salmonella effector protein avra in intestinal infection in vivo. | the salmonella avra gene is present in 80% of salmonella enterica serovar strains. avra protein mimics the activities of some eukaryotic proteins and uses these activities to the pathogen's advantage by debilitating the target cells, such as intestinal epithelial cells. therefore, it is important to understand how avra works in targeting eukaryotic signaling pathways in intestinal infection in vivo. in this study, we hypothesized that avra interacts with multiple stress pathways in eukaryotic ce ... | 2010 | 21182782 |
| penetration and activation of brain endothelium by salmonella enterica serovar typhimurium. | salmonella meningitis is a serious disease of the central nervous system, common particularly in africa. here, we show that salmonella enterica serovar typhimurium is able to adhere, invade, and penetrate human brain microvascular endothelial cells (hbmecs), the single-cell layer constituting the blood-brain barrier (bbb). cellular invasion was dependent on host actin cytoskeleton rearrangements, while expression of a functional type iii secretion system was not essential. in addition, salmonell ... | 2010 | 21186258 |
| the salmonella genomic island 1 is specifically mobilized in trans by the inca/c multidrug resistance plasmid family. | the salmonella genomic island 1 (sgi1) is a salmonella enterica-derived integrative mobilizable element (ime) containing various complex multiple resistance integrons identified in several s. enterica serovars and in proteus mirabilis. previous studies have shown that sgi1 transfers horizontally by in trans mobilization in the presence of the inca/c conjugative helper plasmid pr55. | 2010 | 21187963 |
| mechanism of bactericidal activity of microcin l in escherichia coli and salmonella enterica. | for the first time, the mechanism of action of microcin l (mccl) was investigated in live bacteria. mccl is a gene-encoded peptide produced by escherichia coli lr05 that exhibits a strong antibacterial activity against related enterobacteriaceae, including salmonella enterica serovars typhimurium and enteritidis. we first subcloned the mccl genetic system to remove the sequences not involved in mccl production. we then optimized the mccl purification procedure to obtain large amounts of purified ... | 2010 | 21189348 |
| foreign travel and decreased ciprofloxacin susceptibility in salmonella enterica infections. | to determine antimicrobial drug resistance patterns, we characterized nontyphoidal salmonella enterica strains isolated in liverpool, uk, january 2003 through december 2009. decreased susceptibility to ciprofloxacin was found in 103 (20.9%) of 492 isolates. the lower susceptibility was associated with ciprofloxacin treatment failures and with particular serovars and phage types often acquired during foreign travel. | 2011 | 21192872 |
| lag phase of salmonella enterica under osmotic stress conditions. | salmonella enterica serovar typhimurium was grown at salt concentrations ranging from 0.5 to 7.5% in minimal medium with and without added osmoprotectant and in a rich medium. in minimal medium, the cells showed an initial decline period, and consequently the definition of the lag time of the resultant log count curve was revised. the model of baranyi and roberts (int. j. food microbiol. 23:277-294, 1994) was modified to take into account the initial decline period, based on the assumption that ... | 2010 | 21193660 |
| medicinal plant extracts with efflux inhibitory activity against gram-negative bacteria. | it was hypothesised that extracts from plants that are used as herbal medicinal products contain inhibitors of efflux in gram-negative bacteria. extracts from 21 plants were screened by bioassay for synergy with ciprofloxacin against salmonella enterica serotype typhimurium, including mutants in which acrb and tolc had been inactivated. the most active extracts, fractions and purified compounds were further examined by minimum inhibitory concentration testing with five antibiotics for activity a ... | 2010 | 21194895 |
| assessment of 2 salmonella enterica serovar typhimurium-based vaccines against necrotic enteritis in reducing colonization of chickens by salmonella serovars of different serogroups. | this study assessed the protective efficacy of oral vaccination with 2 experimental attenuated salmonella typhimurium-vectored vaccines for necrotic enteritis in protecting chickens against intestinal colonization by common serovars of salmonella belonging to the 4 major serogroups affecting chickens. birds were vaccinated orally with 1 × 10⁸ colony-forming units (cfu) of 1 of the vaccine strains χ9241 and χ9352, which express a plasmid-encoded partial recombinant hypothetical protein gene (thp) ... | 2010 | 21197226 |
| characterisation of proteins extracted from the surface of salmonella typhimurium grown under spi-2-inducing conditions by lc-esi/ms/ms sequencing. | salmonella enterica has two pathogenicity islands encoding separate type three secretion systems (t3ss). proteins secreted through these systems facilitate invasion and survival. after entry, salmonella reside within a membrane bound vacuole, the salmonella containing vacuole (scv), where translocation of a second set of effectors by the salmonella pathogenicity island 2 (spi-2) t3ss is initiated. spi-2 secretion in vitro can be induced by conditions that mimic the salmonella containing vacuole. ... | 2010 | 21197671 |
| antimicrobial resistance among invasive nontyphoidal salmonella enterica isolates in the united states: national antimicrobial resistance monitoring system, 1996 to 2007. | nontyphoidal salmonellae (nts) are important causes of community-acquired bloodstream infection. we describe patterns of antimicrobial resistance among invasive nts in the united states. we compared bloodstream nts isolates with those from stool submitted to the national antimicrobial resistance monitoring system (narms) from 1996 to 2007. we describe antimicrobial resistance among invasive strains by serogroup and serotype. of the 19,302 nts isolates, 17,804 (92.2%) were from stool or blood. of ... | 2011 | 21199924 |
| humanized mice are susceptible to salmonella typhi infection. | salmonella enterica serovar typhi is a pathogen that only infects humans. currently, there is no animal model for studying this pathogen. recently, alymphoid rag-2(-/-)/γ(c)(-/-) mice engrafted with human leukocytes, known as humanized mice, have been successfully utilized to develop experimental models for several human-specific viral infections, including hiv, human-like dengue fever and hepatitis c virus. little is known about the usefulness and feasibility of the humanized mouse model for th ... | 2010 | 21200387 |
| horizontal gene transfer of a colv plasmid has resulted in a dominant avian clonal type of salmonella enterica serovar kentucky. | salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. a wide variety of salmonella serovars have been isolated from production birds and from retail poultry meat. recently, though, s. enterica subsp. enterica serovar kentucky has emerged as one of the prominent salmonella serovars isolated from broiler chickens. recent work suggests that its emergence apparently coincides with its acquisition of a colv virulence plasmid. in the present study, we ... | 2010 | 21203520 |
| structural and genetic relationships of two pairs of closely related o-antigens of escherichia coli and salmonella enterica: e. coli o11/s. enterica o16 and e. coli o21/s. enterica o38. | the o-antigen is a part of the lipopolysaccharide molecule present in the outer membrane of gram-negative bacteria, and is essential for the full function of the microorganisms. salmonella enterica and escherichia coli are taxonomically closely related species. in this study, the o-antigen structures of s. enterica o16 and o38 and e. coli o11 were determined. salmonella enterica o38 and e. coli o21 were found to have identical o-antigen structures, whereas s. enterica o16 and e. coli o11 had clo ... | 2011 | 21205000 |
| inactivation of salmonella in liquid egg albumen by antimicrobial bottle coatings infused with allyl isothiocyanate, nisin and zinc oxide nanoparticles. | to develop an antimicrobial bottle coating effective at inhibiting the growth of salmonella in liquid egg albumen (egg white) and reduce the risk of human salmonellosis. | 2011 | 21205106 |
| structures of the sep22 dodecamer, a dps-like protein from salmonella enterica subsp. enterica serovar enteritidis. | the crystal structure of sep22, a dna-binding protein from starved cells from salmonella enterica subsp. enterica serovar enteritidis, has been determined in two forms: the native state at 1.25 å resolution and an iron-soaked form at 1.30 å resolution. the sep22 protomers form a dodecameric shell with 23 symmetry and a single iron ion per protomer was found at the ferroxidase centre in the iron-soaked form. along the threefold axes of the 23 symmetry, hydrophilic asp channels that consist of asp ... | 2010 | 21206015 |
| analysis of interactions of salmonella type three secretion mutants with 3-d intestinal epithelial cells. | the prevailing paradigm of salmonella enteropathogenesis based on monolayers asserts that salmonella pathogenicity island-1 type three secretion system (spi-1 t3ss) is required for bacterial invasion into intestinal epithelium. however, little is known about the role of spi-1 in mediating gastrointestinal disease in humans. recently, spi-1 deficient nontyphoidal salmonella strains were isolated from infected humans and animals, indicating that spi-1 is not required to cause enteropathogenesis an ... | 2010 | 21206750 |
| multilocus variable-number of tandem-repeats analysis of salmonella enterica serotype gallinarum and comparison with pulsed-field gel electrophoresis genotyping. | salmonella enterica serovar gallinarum is the causative agent of fowl typhoid, a severe disease of poultry, responsible for heavy economic losses. epidemiologic investigation of fowl typhoid significantly benefits from molecular typing tools, rapd and pfge have been proposed for this purpose. pfge, a well established technique, is still the gold standard among typing methods for most bacteria, including salmonella. nevertheless, it has some limitations regarding execution and reproducibility, in ... | 2010 | 21208755 |
| phenotypic and molecular characterization of salmonella enterica serovar sofia, an avirulent species in australian poultry. | salmonella enterica serovar sofia (s. sofia) is often isolated from chickens in australia. however, despite its high frequency of isolation from chicken and chicken meat products, s. sofia is rarely associated with animal or human salmonellosis, presumably because this serovar is avirulent in nature. the objective of this work was to investigate the phenotypic and molecular properties of s. sofia in order to assess its pathogenic potential. our in vivo studies support the observation that this s ... | 2011 | 21212118 |
| nucleoid-associated protein hu controls three regulons that coordinate virulence, response to stress and general physiology in salmonella enterica serovar typhimurium. | the role of the hu nucleoid-associated proteins in gene regulation was examined in salmonella enterica serovar typhimurium. the dimeric hu protein consists of different combinations of its α and β subunits. transcriptomic analysis was performed with cultures growing at 37 °c at 1, 4 and 6 h after inoculation with mutants that lack combinations of hu α and hu β. distinct but overlapping patterns of gene expression were detected at each time point for each of the three mutants, revea ... | 2011 | 21212121 |
| effect of desiccation on tolerance of salmonella enterica to multiple stresses. | reducing the available water in food is a long-established method for controlling bacterial growth in the food industry. nevertheless, food-borne outbreaks of salmonellosis due to consumption of dry foods have been continuously reported. previous studies showed that dried salmonella cells acquire high tolerance to heat and ethanol. in order to examine if dehydration also induces tolerance to other stressors, dried salmonella enterica serotype typhimurium cells were exposed to multiple stresses, ... | 2011 | 21216905 |
| efficacy of an anaerobic swab transport system to maintain aerobic and anaerobic microorganism viability after storage at -80 degrees c. | an amies agar gel swab transport system was evaluated for its ability to maintain bacterial viability and relative quantity after freezing at -80°c. nine american type culture collection (atcc) bacterial strains were used: 3 anaerobic strains (propionibacterium acnes, peptostreptococcus anaerobius, and clostridium sporogenes) and 6 facultative or strict aerobic bacterial strains (stenotrophomonas maltophilia, escherichia coli ([atcc 25922 and atcc 11775], salmonella enterica subsp. enterica sero ... | 2011 | 21217035 |
| analysis of tomato and jalapeño and serrano pepper imports into the united states from mexico before and during a national outbreak of salmonella serotype saintpaul infections in 2008. | case-control studies conducted during a multistate outbreak of salmonella enterica serotype saintpaul infections in 2008 revealed associations between illness and the consumption of jalapeño peppers, serrano peppers, and tomatoes. traceback investigations of implicated jalapeño and serrano peppers led to farms in tamaulipas and nuevo león, mexico. we conducted a novel analysis of a u.s. food and drug administration database of tomatoes and jalapeño and serrano peppers imported from mexico during ... | 2010 | 21219707 |
| reduction of salmonella enterica contamination on grape tomatoes by washing with thyme oil, thymol, and carvacrol as compared with chlorine treatment. | in recent years, multistate outbreaks of salmonella enterica serovars were traced to tomatoes and resulted in serious economic loss for the tomato industry and decreased consumer confidence in the safety of tomato produce. purified compounds derived from essential oils such as thymol and carvacrol had wide inhibitory effects against foodborne pathogens including salmonella. the objective of this study was to determine the antimicrobial activities of thymol, carvacrol, and thyme oil against salmo ... | 2010 | 21219747 |
| salmonella enterica enteritidis biofilm formation and viability on regular and triclosan-impregnated bench cover materials. | contamination of food contact surfaces by microbes such as salmonella is directly associated with substantial industry costs and severe foodborne disease outbreaks. several approaches have been developed to control microbial attachment; one approach is the development of food contact materials incorporating antimicrobial compounds. in the present study, salmonella enterica enteritidis adhesion and biofilm formation on regular and triclosan-impregnated kitchen bench stones (silestones) were asses ... | 2011 | 21219760 |
| inhibitory activity of cheese whey fermented with kefir grains. | we investigated the chemical and microbiological compositions of three types of whey to be used for kefir fermentation as well as the inhibitory capacity of their subsequent fermentation products against 100 salmonella sp. and 100 escherichia coli pathogenic isolates. all the wheys after fermentation with 10% (wt/vol) kefir grains showed inhibition against all 200 isolates. the content of lactic acid bacteria in fermented whey ranged from 1.04 × 10(7) to 1.17 × 10(7) cfu/ml and the level of yeas ... | 2011 | 21219767 |
| prevalence, antibiotic resistance, and molecular characterization of salmonella serovars in retail meat products. | the prevalence of salmonella was determined in chicken meat (n = 26), beef (n = 49), and pork (n = 56) collected from wholesale markets, retail stores, and traditional markets in seoul, south korea, in 2009. antibiotic resistance was assessed, and the molecular subtypes of salmonella isolates were ascertained using an automated repetitive sequence-based pcr (rep-pcr) system (diversilab). a total of 18 salmonella strains were isolated from 17 of 131 samples: 16 strains from each of 16 samples and ... | 2011 | 21219782 |
| an attenuated salmonella enterica serovar typhimurium strain lacking the znuabc transporter induces protection in a mouse intestinal model of salmonella infection. | salmonella enterica serovar typhimurium has long been recognised as a zoonotic pathogen of economic significance in animals and humans. attempts to protect humans and livestock may be based on immunization with vaccines aimed to induce a protective response. we recently demonstrated that the oral administration of a salmonella enterica serovar typhimurium strain unable to synthesize the zinc transporter znuabc is able to protect mice against systemic salmonellosis induced by a virulent homologou ... | 2011 | 21219981 |
| reduction of salmonella enterica on grape tomatoes using microwave heating. | grape tomatoes were surface inoculated with salmonella enterica serovars typhimurium, senftenburg, kentucky and enteritidis and heated for 10, 20, 30, 40 and 50 s using a household microwave oven at two different power levels (medium and high). following heating, viable counts, temperature measurements and quality measurements were performed on the tomatoes. at high power level, more than 2 log reduction of salmonella enterica was detected on grape tomatoes after 50 s but the texture were damage ... | 2010 | 21227524 |
| analysis of mechanisms involved in reduced susceptibility to ciprofloxacin in salmonella enterica serotypes typhi and paratyphi a isolates from travellers to southeast asia. | owing to multidrug resistance, quinolones and third-generation cephalosporins are currently used as key antibiotics to combat salmonella organisms. therapy failure due to reduced ciprofloxacin susceptibility has been reported in endemic areas, but also in imported disease. different bacterial resistance mechanisms may result in reduced ciprofloxacin susceptibility. in this study, the presence and expression of different resistance mechanisms resulting in reduced minimum inhibitory concentrations ... | 2011 | 21227657 |
| characterization of salmonella enterica isolates from turkeys in commercial processing plants for resistance to antibiotics, disinfectants, and a growth promoter. | salmonella enterica isolates from turkeys in two commercial processing plants (1 and 2) were characterized for susceptibility to antibiotics, disinfectants, and the organoarsenical growth promoter, 4-hydroxy-3-nitrophenylarsonic acid (3-nhpaa, roxarsone), and it's metabolites, naaso(2) (as(iii)) and na(2)haso(4) • 7h(2)o (as(v)). the 130 salmonella serovars tested demonstrated a low incidence of resistance to the antibiotics gentamicin (gen), kanamycin (kan), sulfamethoxazole (smx), streptomycin ... | 2011 | 21235389 |
| prevalence and characterization of extended-spectrum beta-lactamases-producing salmonella enterica isolates in saragossa, spain (2001-2008). | we analyzed the prevalence of resistance to extended-spectrum cephalosporins (escs) among clinical strains of salmonella enterica collected by the laboratory of clinical microbiology in the university clinical hospital lozano blesa in the region of aragón (spain), for which very few epidemiological information exists. a total of 2,092 strains of s. enterica were identified in stool samples from patients with gastroenteritis. five isolates showed an extended-spectrum beta-lactamase (esbl) phenoty ... | 2011 | 21235396 |
| oral treatment with saccharomyces cerevisiae strain ufmg 905 modulates immune responses and interferes with signal pathways involved in the activation of inflammation in a murine model of typhoid fever. | salmonella spp. are gram-negative, facultative, intracellular pathogens that cause several diarrheal diseases ranging from self-limiting gastroenteritis to typhoid fever. previous results from our laboratory showed that saccharomyces cerevisiae strain ufmg 905 isolated from 'cachaça' production presented probiotic properties due to its ability to protect against experimental infection with salmonella enterica serovar typhimurium. in this study, the effects of oral treatment with s. cerevisiae 90 ... | 2011 | 21236729 |
| diversity of multidrug-resistant salmonella enterica strains associated with cattle at harvest in the united states. | the prevalence and diversity of multidrug-resistant (mdr) salmonella enterica strains associated with cattle at harvest in the united states were examined. hides and carcasses of cattle were sampled at processing plants (n = 6) located in four geographically distant regions from july 2005 to april 2006. the mean prevalences of salmonella on hides, preevisceration carcasses (immediately after hide removal), and postintervention carcasses (in the chiller and after the full complement of interventi ... | 2011 | 21239549 |
| molecular epidemiology of salmonella enterica serovar typhimurium isolates from cattle in hokkaido, japan: evidence of clonal replacement and characterization of the disseminated clone. | the molecular epidemiology of 545 salmonella enterica serovar typhimurium isolates collected between 1977 and 2009 from cattle in hokkaido, japan, was investigated using pulsed-field gel electrophoresis (pfge). nine main clusters were identified from 116 pfge patterns. cluster i comprised 248 isolates, 243 of which possessed a sequence specific to definitive phage type 104 (dt104) or u302. the cluster i isolates were dominant in 1993 to 2003, but their numbers declined beginning in 2004. beginni ... | 2011 | 21239560 |
| bistability in myo-inositol utilization by salmonella enterica serovar typhimurium. | the capability of salmonella enterica serovar typhimurium strain 14028 (s. typhimurium 14028) to utilize myo-inositol (mi) is determined by the genomic island gei4417/4436 carrying the iol genes that encode enzymes, transporters, and a repressor responsible for the mi catabolic pathway. in contrast to all bacteria investigated thus far, s. typhimurium 14028 growing on mi as the sole carbon source is characterized by a remarkable long lag phase of 40 to 60 h. we report here that on solid medium w ... | 2011 | 21239589 |