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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
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
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
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
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
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 can reach tomato fruits on plants exposed to aerosols formed by rain.outbreaks of salmonella enterica have been associated with tomatoes and traced back to production areas but the spread of salmonella in agricultural fields is still poorly understood. post-rain salmonella transfer from a point source to the air and then to tomato plants was evaluated. gfp-labeled kanamycin-resistant s. enterica serovar typhimurium (10(8)cfu/ml) with and without expression of the rdar morphotype (rough colonies; cells with fimbriae and cellulose) was used as the point source in t ...201222831820
vaccines for typhoid fever and other salmonelloses.this review summarizes the recent advances in vaccination against salmonella enterica serovar typhi and highlights the data supporting the development of next generation vaccines to address paratyphoid fever and invasive nontyphoidal salmonella (ints) disease.201222825288
assessment of root uptake and systemic vine-transport of salmonella enterica sv. typhimurium by melon (cucumis melo) during field production.among melons, cantaloupes are most frequently implicated in outbreaks and surveillance-based recalls due to salmonella enterica. there is limited but compelling evidence that associates irrigation water quality as a significant risk of preharvest contamination of melons. however, the potential for root uptake from water and soil and subsequent systemic transport of salmonella into melon fruit is uncharacterized. the aim of this work was to determine whether root uptake of s. enterica results in ...201222824339
salmonella enterica serovar ohio septic arthritis and bone abscess in an immunocompetent patient: a case report.non-typhi salmonella species cause severe extra-intestinal focal infection after occult bacteremia. although the number of cases of non-typhi salmonellosis is increasing worldwide among patients with immunocompromising conditions such as human immunodeficiency virus infection, infection is uncommon in immunocompetent subjects. we report a case of septic arthritis and bone abscess due to a rare non-typhi salmonella organism that developed after a prolonged asymptomatic period.201222804866
characterization of osmotically induced filaments of salmonella enterica.salmonella enterica forms aseptate filaments with multiple nucleoids when cultured in hyperosmotic conditions. these osmotic-induced filaments are viable and form single colonies on agar plates even though they contain multiple genomes and have the potential to divide into multiple daughter cells. introducing filaments that are formed during osmotic stress into culture conditions without additional humectants results in the formation of septa and their division into individual cells, which could ...201222798362
a new methodology for differentiation and typing of closely related salmonella enterica serovar heidelberg isolates.this study describe the use of a combination of two recently proposed typing approaches, multiple amplification of prophage locus typing (maplt) and multiple-locus variable-number tandem-repeat analysis (mlva) for subdividing within salmonella enterica serovar heidelberg (s. heidelberg). the combined typing method was compared with pulsed-field gel electrophoresis (pfge) by simpson's index of diversity (di). pfge was shown to have a di = 0.84 and was poor at differentiation of the predominant pt ...201222797864
drug resistance in salmonella enterica serotype typhi isolated from chronic typhoid carriers. 201222789724
panm, an acetyl-coenzyme a sensor required for maturation of l-aspartate decarboxylase (pand).coenzyme a (coa) is essential for cellular chemistry in all forms of life. the pantothenate moiety of coa is generated from the condensation of pantoate and β-alanine. β-alanine is formed by decarboxylation of l-aspartate catalyzed by pand, a pyruvoyl enzyme that is synthesized by the cell as an inactive precursor (pro-pand). maturation of pro-pand into pand occurs via a self-cleavage event at residue ser25, which forms the catalytic pyruvoyl moiety. we recently reported that salmonella enterica ...201222782525
selection-driven gene loss in bacteria.gene loss by deletion is a common evolutionary process in bacteria, as exemplified by bacteria with small genomes that have evolved from bacteria with larger genomes by reductive processes. the driving force(s) for genome reduction remains unclear, and here we examined the hypothesis that gene loss is selected because carriage of superfluous genes confers a fitness cost to the bacterium. in the bacterium salmonella enterica, we measured deletion rates at 11 chromosomal positions and the fitness ...201222761588
molecular characterization of salmonella strains in individuals with acute diarrhea syndrome in the state of sucre, venezuela.in venezuela, acute diarrheic syndrome (ads) is a primary cause of morbi-mortality, often involving the salmonella genus. salmonella infections are associated with acute gastroenteritis, one of the most common alimentary intoxications, and caused by the consumption of contaminated water and food, especially meat.201222760131
characterization of extended-spectrum cephalosporin-resistant salmonella enterica serovar heidelberg isolated from food animals, retail meat, and humans in the united states 2009.salmonella enterica is one of the most common causes of foodborne illness in the united states. although salmonellosis is usually self-limiting, severe infections typically require antimicrobial treatment, and ceftriaxone, an extended-spectrum cephalosporin (esc), is commonly used in both adults and children. surveillance conducted by the national antimicrobial resistance monitoring system (narms) has shown a recent increase in esc resistance among salmonella heidelberg isolated from food animal ...201222755514
in vitro susceptibility testing of fluoroquinolone activity against salmonella: recent changes to clsi standards.fluoroquinolone (fq) resistance in salmonella enterica is a significant clinical concern. recognition of resistance by the clinical laboratory is complicated by the multiple fq resistance mechanisms found in salmonella. the clinical laboratory standards institute (clsi) recently addressed this issue by revising the ciprofloxacin break points for salmonella species. it is critical for clinicians and laboratory workers to be aware of the multiple technical issues surrounding these revised break po ...201222752519
draft genome sequences of eight salmonella enterica serotype newport strains from diverse hosts and locations.salmonellosis is a major contributor to the global public health burden. salmonella enterica serotype newport has ranked among three salmonella serotypes most commonly associated with food-borne outbreaks in the united states. it was thought to be polyphyletic and composed of independent lineages. here we report draft genomes of eight strains of s. newport from diverse hosts and locations.201222933769
insights from the genome sequence of a salmonella enterica serovar typhi strain associated with a sporadic case of typhoid fever in malaysia.salmonella enterica serovar typhi is the causative agent of typhoid fever, which causes nearly 21.7 million illnesses and 217,000 deaths globally. herein, we describe the whole-genome sequence of the salmonella typhi strain st0208, isolated from a sporadic case of typhoid fever in kuala lumpur, malaysia. the whole-genome sequence and comparative genomics allow an in-depth understanding of the genetic diversity, and its link to pathogenicity and evolutionary dynamics, of this highly clonal pathog ...201222933756
whole-genome sequences and comparative genomics of salmonella enterica serovar typhi isolates from patients with fatal and nonfatal typhoid fever in papua new guinea.many of the developing countries of the southeast asian region are significantly affected by endemic typhoid fever, possibly as a result of marginal living standards. it is an important public health problem in countries such as papua new guinea, which is geographically close to some of the foci of endemicity in asia. the severity of the disease varies in different regions, and this may be attributable to genetic diversity among the native strains. genome sequence data on strains from different ...201222933755
salmonella enterica serovar agbeni, british columbia, canada, 2011. 201222932699
interactions between the termini of lumen enzymes and shell proteins mediate enzyme encapsulation into bacterial microcompartments.bacterial microcompartments (mcps) are a widespread family of proteinaceous organelles that consist of metabolic enzymes encapsulated within a protein shell. for mcps to function specific enzymes must be encapsulated. we recently reported that a short n-terminal targeting sequence of propionaldehyde dehydrogenase (pdup) is necessary and sufficient for the packaging of enzymes into a mcp that functions in 1,2-propanediol (1,2-pd) utilization (pdu) by salmonella enterica. here we show that encapsu ...201222927404
prevalence of quinolone resistance and mutations in the topoisomerase genes in salmonella enterica serotype enteritidis isolates from serbia.the prevalence of quinolone resistance was studied in salmonella enterica serotype enteritidis isolates collected during 2005-2010 in southern bačka county, serbia. a total of 878 clinical isolates were examined, among which 19 (2.2%) nalidixic acid (nal)-resistant s. enteritidis were detected by selection on agar plates containing 64 mg/l nal. antimicrobial susceptibility of the isolates was tested by the agar dilution method. according to clinical and laboratory standards institute (clsi) brea ...201222999768
comparison of dkgb-linked intergenic sequence ribotyping to dna microarray hybridization for assigning serotype to salmonella enterica.two dna-based methods were compared for the ability to assign serotype to 139 isolates of salmonella enterica ssp. i. intergenic sequence ribotyping (isr) evaluated single nucleotide polymorphisms occurring in a 5s ribosomal gene region and flanking sequences bordering the gene dkgb. a dna microarray hybridization method that assessed the presence and the absence of sets of genes was the second method. serotype was assigned for 128 (92.1%) of submissions by the two dna methods. isr detected mixt ...201222998607
[meningitis due to salmonella enterica]. 201222987268
reptile pets-associated salmonella enterica subspecies diarizonae gastroenteritis in a neonate. 201222982955
[salmonella multiphasic flagellar antigen].in the salmonella antigenic pattern, more than one phase of flagellar antigen is observed. the phase of flagellar antigen depends of the gene which encodes the protein building the filament of flagella. the flic gene encodes the 1st phase of flagellar antigen and the fljb gene encodes the 2nd phase of flagellar antigen. the third phase of flagellar antigen is encoded by one of the genes localized on the plasmid. expression of the fljb gene (part of the hinfljba operon) is regulated by a mechanis ...201222922144
oral administration of a combination of select lactic acid bacteria strains to reduce the salmonella invasion and inflammation of broiler chicks.one-day-old chicks are susceptible to infection by strains of salmonella enterica subspecies. because multistrain probiotics are suggested to be more effective than monostrain probiotics due to the additive and synergistic effects, in this study, we prepared a multistrain formula a (mfa) consisting of 4 lactic acid bacteria (lab) strains selected by enhancing the tnf-α production for mouse macrophage 264.7 cells. the antagonistic effect of this mfa against the cecal colonization, viscera invasiv ...201222912447
fis is essential for the stability of linear plasmid pbssb1 and affects the motility of salmonella enterica serovar typhi.pbssb1 is a 27 kb non-bacteriophage-related linear plasmid first found in salmonella enterica serovar typhi (s. typhi), but the mechanism underlying the replication of pbssb1 is currently unknown. previous reports showed that the factor for inversion stimulation (fis) encoded by fis can affect the replication, transcription and other processes through binding dna. here, a fis deletion mutant of s. typhi (δfis) was prepared through the homologous recombination mediated by suicide plasmid and the ...201222911678
immediate after birth transmission of epidemic salmonella enterica typhimurium monophasic strains in pigs is a likely event. 201222904242
a comprehensive subcellular proteomic survey of salmonella grown under phagosome-mimicking versus standard laboratory conditions.towards developing a systems-level pathobiological understanding of salmonella enterica, we performed a subcellular proteomic analysis of this pathogen grown under standard laboratory and phagosome-mimicking conditions in vitro. analysis of proteins from cytoplasmic, inner membrane, periplasmic, and outer membrane fractions yielded coverage of 25% of the theoretical proteome. confident subcellular location could be assigned to over 1000 proteins, with good agreement between experimentally observ ...201222900174
suppressor analyses identify threonine as a modulator of rida mutant phenotypes in salmonella enterica.the rida (yjgf/yer057c/uk114) family of proteins is broadly conserved in the three domains of life yet the functional understanding of these proteins is at an early stage. physiological studies of rida mutant strains of salmonella enterica provided a framework to inform in vitro studies and led to the description of a conserved biochemical activity for this family. rida mutant strains of s. enterica have characteristic phenotypes including new synthesis of thiamine biosynthetic intermediate phos ...201222900093
pathways of genetic adaptation: multistep origin of mutants under selection without induced mutagenesis in salmonella enterica.in several bacterial systems, mutant cell populations plated on growth-restricting medium give rise to revertant colonies that accumulate over several days. one model suggests that nongrowing parent cells mutagenize their own genome and thereby create beneficial mutations (stress-induced mutagenesis). by this model, the first-order induction of new mutations in a nongrowing parent cell population leads to the delayed accumulation of visible colonies. in an alternative model (selection only), sel ...201222887815
detection of salmonella enterica isolates producing ctx-m cephalosporinase in u.s. livestock populations.we report the detection of salmonella carrying bla(ctx-m) in u.s. livestock populations. we identified 12 of 2,034 (0.6%) salmonella isolates originating from turkeys, horses, and pigs from at least 6 u.s. states, all carrying bla(ctx-m-1), many on a pandemic sequence type 1 incn plasmid.201222885753
human infections attributable to the d-tartrate-fermenting variant of salmonella enterica serovar paratyphi b in germany originate in reptiles and, on rare occasions, poultry.in this study, the population structure, incidence, and potential sources of human infection caused by the d-tartrate-fermenting variant of salmonella enterica serovar paratyphi b [s. paratyphi b (dt+)] was investigated. in germany, the serovar is frequently isolated from broilers. therefore, a selection of 108 epidemiologically unrelated s. enterica serovar paratyphi b (dt+) strains isolated in germany between 2002 and 2010 especially from humans, poultry/poultry meat, and reptiles was investig ...201222885742
emergence of fluoroquinolone resistance in salmonella enterica serovar typhi in andaman and nicobar islands, india. 201222885270
genome-wide detection of spontaneous chromosomal rearrangements in bacteria.genome rearrangements have important effects on bacterial phenotypes and influence the evolution of bacterial genomes. conventional strategies for characterizing rearrangements in bacterial genomes rely on comparisons of sequenced genomes from related species. however, the spectra of spontaneous rearrangements in supposedly homogenous and clonal bacterial populations are still poorly characterized. here we used 454 pyrosequencing technology and a 'split mapping' computational method to identify ...201222880062
characterization of extended-spectrum beta-lactamase-producing salmonella enterica serotype brunei and heidelberg at the hussein dey hospital in algiers (algeria).the purpose of this work was to study the genetic determinants responsible for extended-spectrum cephalosporin (esc) resistance of salmonella collected during the period of 1995-2008 at the hussein dey hospital in algiers (algeria). fourteen esc-resistant salmonella isolates were tested towards 22 antimicrobial agents. polymerase chain reaction (pcr) and sequencing were used to determine the underlying genetic determinants responsible for the extended-spectrum beta-lactamase (esbl) phenotypes. e ...201222871227
farm-level associations with the shedding of salmonella and antimicrobial-resistant salmonella in u.s. dairy cattle.salmonella enterica is the leading cause of foodborne-related deaths and hospitalizations within the united states. infections caused by antimicrobial-resistant (amr) strains are associated with higher hospital costs and case fatality. the objective for this study was to determine the association of management practices with the recovery of salmonella and amr salmonella on dairy herds. individual adult cow fecal samples and/or composite fecal samples were collected from 265 dairy herds in 17 sta ...201222870913
multiple pathways of duplication formation with and without recombination (reca) in salmonella enterica.duplications are often attributed to "unequal recombination" between separated, directly repeated sequence elements (>100 bp), events that leave a recombinant element at the duplication junction. however, in the bacterial chromosome, duplications form at high rates (10(-3)-10(-5)/cell/division) even without recombination (reca). here we describe 1800 spontaneous lac duplications trapped nonselectively on the low-copy f'(128) plasmid, where lac is flanked by direct repeats of the transposable ele ...201222865732
cross-reactive gut-directed immune response against salmonella enterica serovar paratyphi a and b in typhoid fever and after oral ty21a typhoid vaccination.there are no vaccines against paratyphoid fever in clinical use. the disease has become more wide-spread and there is a growing problem of antibiotic resistance among the strains. previous reports suggest that the oral live salmonella typhi ty21a-vaccine confers protection against paratyphoid b fever. data on efficacy against paratyphoid a fever are somewhat contentious. the present study investigated the immunological basis for such efficacy reports at a single-cell level: plasmablasts (identif ...201222858557
increased resistance to multiple antimicrobials and altered resistance gene expression in cmy-2-positive salmonella enterica following a simulated patient treatment with ceftriaxone.salmonellosis is one of the most common causes of food-borne disease in the united states. increasing antimicrobial resistance and corresponding increases in virulence present serious challenges. currently, empirical therapy for invasive salmonella enterica infection includes either ceftriaxone or ciprofloxacin (e. l. hohmann, clin. infect. dis. 32:263-269, 2001). the bla(cmy-2) gene confers resistance to ceftriaxone, the antimicrobial of choice for pediatric patients with invasive salmonella en ...201222961898
a novel salmonella serovar isolated from peregrine falcon (falco peregrinus) nestlings in sweden: salmonella enterica enterica serovar pajala (salmonella pajala).a novel salmonella serovar was isolated from peregrine falcon (falco peregrinus) nestlings in northern sweden in 2006. three isolates of the same clone was retrieved from three falcon siblings and characterized as salmonella enterica sub-species enterica: o-phase 13, 23:-: e, n, z 15 and the h-phase was not present. we propose the geographical name salmonella enterica, sub-species enterica serovar pajala to this novel salmonella.201222957136
prevalence of salmonella cerro in laboratory-based submissions of cattle and comparison with human infections in pennsylvania, 2005-2010.the aim of this study was to identify salmonella serotypes infecting cattle in pennsylvania, to compare infection rates for the predominant serotype, salmonella enterica serotype cerro, with the infection rates for the same serotype in humans, and to study the clonal diversity and antimicrobial resistance for this serotype in cattle from 2005 to 2010. clonal diversity among the selected isolates was studied using pulsed-field gel electrophoresis (pfge) and repetitive (rep)-polymerase chain react ...201222953739
longitudinal dissemination of salmonella enterica clonal groups through the slaughter process of salmonella-positive pig batches.this study was conducted to assess the dissemination of salmonella clonal groups in slaughterhouses that received batches of salmonella -positive pigs and used different routine processing procedures. eight serial sampling sessions were conducted in three slaughterhouses (a, b, and c). blood was collected randomly (n = 25) from each batch of pigs and processed for serology. carcasses (n = 12) were identified and sampled after dehairing, after singeing, after evisceration, and before chilling. a ...201222947464
increasing quinolone resistance and multidrug resistant isolates among salmonella enterica in hong kong.to study the antimicrobial susceptibility and molecular epidemiology of salmonella enterica isolates from 2005 to 2010 in hong kong.201222947244
comparative proteome and transcriptome analyses of wild-type and live vaccine strains of salmonella enterica serovar gallinarum.salmonella enterica serovar gallinarum causes fowl typhoid in chickens and is of economic importance to the chicken industry. a serovar gallinarum live vaccine strain 9r (sg 9r) has been used to control fowl typhoid in many areas where the disease is endemic. because the attenuation mechanism of sg 9r was not defined, there has been continued concern about reversion to virulence. in this study, we examined the molecular characteristics, which might provide better insight into attenuation of sg 9 ...201222944630
intracontinental spread of human invasive salmonella typhimurium pathovariants in sub-saharan africa.a highly invasive form of non-typhoidal salmonella (ints) disease has recently been documented in many countries in sub-saharan africa. the most common salmonella enterica serovar causing this disease is typhimurium (salmonella typhimurium). we applied whole-genome sequence-based phylogenetic methods to define the population structure of sub-saharan african invasive salmonella typhimurium isolates and compared these to global salmonella typhimurium populations. notably, the vast majority of sub- ...201223023330
development of a custom 16s rrna gene library for the identification and molecular subtyping of salmonella enterica.the use of 16s rrna gene sequencing within the regulatory workflow may help to reduce the time and labor involved in the identification and differentiation of salmonella enterica isolates. however, a comprehensive, standardized reference library is needed in order to use this method with regulatory samples. the goal of this project was to acquire 16s rrna partial and full gene sequences for a variety of s. enterica isolates and to use these sequences to build a custom 16s rrna reference library. ...201223022443
studies on the substrate specificity of a gdp-mannose pyrophosphorylase from salmonella enterica.a series of methoxy and deoxy derivatives of mannopyranose-1-phosphate (manp-1p) were chemically synthesized, and their ability to be converted into the corresponding guanosine diphosphate mannopyranose (gdp-manp) analogues by a pyrophosphorylase (gdp-manpp) from salmonella enterica was studied. evaluation of methoxy analogues demonstrated that gdp-manpp is intolerant of bulky substituents at the c-2, c-3, and c-4 positions, in turn suggesting that these positions are buried inside the enzyme ac ...201223019451
multidrug-resistant salmonella enterica, democratic republic of the congo. 201223017665
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
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
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
structural insights into the function of the nicotinate mononucleotide:phenol/p-cresol phosphoribosyltransferase (arsab) enzyme from sporomusa ovata.cobamides (cbas) are cobalt (co) containing tetrapyrrole-derivatives involved in enzyme-catalyzed carbon skeleton rearrangements, methyl-group transfers, and reductive dehalogenation. the biosynthesis of cobamides is complex and is only performed by some bacteria and achaea. cobamides have an upper (coβ) ligand (5'-deoxyadenosyl or methyl) and a lower (coα) ligand base that contribute to the axial co coordinations. the identity of the lower coα ligand varies depending on the organism synthesizin ...201223039029
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
optimized culturing and nucleic acid-based methods for the detection of salmonella enterica in poultry environments.the main objective of this trial was to set up a series of assays following quantified inoculation of salmonella samples in 2 initial enrichment methods to ultimately determine the most effective and fastest detection method for recovery of salmonella in a poultry environment matrix. samples were randomly split into 2 different containers containing either buffered peptone water (bpw) + yeast extract, or tetrathionate broth (tt) with added iodine and brilliant green solution 0.1%. a frozen stock ...201223091129
modification of salmonella typhimurium motility by the probiotic yeast strain saccharomyces boulardii.motility is an important component of salmonella enterica serovar typhimurium (st) pathogenesis allowing the bacteria to move into appropriate niches, across the mucus layer and invade the intestinal epithelium. in vitro, flagellum-associated motility is closely related to the invasive properties of st. the probiotic yeast saccharomyces boulardii biocodex (s.b-b) is widely prescribed for the prophylaxis and treatment of diarrheal diseases caused by bacteria or antibiotics. in case of salmonella ...201222442723
β-galactomannan and saccharomyces cerevisiae var. boulardii modulate the immune response against salmonella enterica serovar typhimurium in porcine intestinal epithelial and dendritic cells.salmonella enterica serovar typhimurium is a facultative intracellular pathogen that causes inflammation, necrosis, and diarrhea in pigs, as well as being an important source of food-borne diseases in humans. probiotics and prebiotics are promising alternatives to antibiotics to control and prevent intestinal infections. the present work investigated a recently developed β-galactomannan (βgm) prebiotic compared to the proven probiotic saccharomyces cerevisiae var. boulardii on porcine ileum inte ...201222301691
early strains of multidrug-resistant salmonella enterica serovar kentucky sequence type 198 from southeast asia harbor salmonella genomic island 1-j variants with a novel insertion sequence.salmonella genomic island 1 (sgi1) is a 43-kb integrative mobilizable element that harbors a great diversity of multidrug resistance gene clusters described in numerous salmonella enterica serovars and also in proteus mirabilis. the majority of sgi1 variants contain an in104-derivative complex class 1 integron inserted between resolvase gene res and open reading frame (orf) s044 in sgi1. recently, the international spread of ciprofloxacin-resistant s. enterica serovar kentucky sequence type 198 ...201222802251
a novel capture compound for the identification and analysis of cyclic di-gmp binding proteins.the second messenger cyclic di-gmp is a near-ubiquitous signaling molecule that globally alters bacterial cell physiology to promote biofilm formation and community behavior. much progress was made in recent years towards the identification and characterization of diguanylate cyclases and phosphodiersterases, enzymes involved in the synthesis and degradation of this signaling compound. in contrast, our knowledge of the nature and mechanistic details of c-di-gmp effector proteins lags behind, pri ...201222652488
effects of x-ray treatments on pathogenic bacteria, inherent microflora, color, and firmness on whole cantaloupe.inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole cantaloupes using x-ray at different doses (0.1, 0.5, 1.0, 1.5, and 2.0 kgy) was studied. the effect of x-ray on quality parameters (color and texture) of untreated and treated whole cantaloupes was instrumentally determined. the effect of x-ray on microflora counts (mesophilic counts, psychrotrophic counts and yeast and mold counts) of untreated and treated whole canta ...201222560020
sanitation of selected ready-to-eat intermediate-moisture foods of animal origin by e-beam irradiation.to optimize the sanitation treatment of ready-to-eat (rte) intermediate-moisture foods (imf), the behavior of listeria monocytogenes scott a (cip 103575), l. innocua (ntc 11288), salmonella enterica serovar typhimurium (cect 443), and escherichia coli o157:h7 (cect 4972) following treatment with electron-beam irradiation has been studied. as food matrixes, three rte vacuum-packed products (iberian dry-cured ham, dry beef [cecina], and smoked tuna) were used. although an irradiation treatment is ...201222551071
effective inactivation of food pathogens listeria monocytogenes and salmonella enterica by combined treatment of hypericin-based photosensitization and high power pulsed light.the aim of this study was to evaluate the inactivation efficiency of listeria monocytogenes atc(l3) c 7644 and salmonella enterica serovar typhimurium strain ds88 by combined treatment of hypericin (hyp)-based photosensitization and high power pulsed light (hppl).201222469030
a comparison of methods used to extract bacterial dna from raw milk and raw milk cheese.in this study, we compare seven different methods which have been designed or modified to extract total dna from raw milk and raw milk cheese with a view to its subsequent use for the pcr of bacterial dna.201222452460
antimicrobial activity of lauric arginate-coated polylactic acid films against listeria monocytogenes and salmonella typhimurium on cooked sliced ham.a novel type of environmentally friendly packaging with antibacterial activity was developed from lauric arginate (lae)-coating of polylactic acid (pla) films after surface activation using a corona discharge. scanning electron microscopy (sem)-based analysis of the lae/pla films confirmed the successful coating of lae on the pla surface. the mechanical properties of the lae/pla films with different levels of lae-coating (0% to 2.6%[w/w]) were essentially the same as those of the neat pla film. ...201222309353
effect of storage temperature on survival and growth of foodborne pathogens on whole, damaged, and internally inoculated jalapeños (capsicum annuum var. annuum).there is a lack of general knowledge regarding the behavior of foodborne pathogenic bacteria associated with jalapeño peppers. the survival and growth behaviors of listeria monocytogenes, escherichia coli o157:h7, and salmonella enterica on the interior and exterior of jalapeño peppers were determined under different storage conditions. jalapeños were inoculated with a five-strain cocktail of l. monocytogenes, e. coli o157:h7, or s. enterica on the intact external surface, injured external surfa ...201222289602
survival of salmonella enterica, escherichia coli o157:h7, and listeria monocytogenes on inoculated walnut kernels during storage.the survival of single strains or cocktails of salmonella, escherichia coli o157:h7, and listeria monocytogenes was evaluated on walnut kernels. kernels were separately inoculated with an aqueous preparation of the pathogens at 3 to 10 log cfu/g, dried for 7 days, and then stored at 23°c for 3 weeks to more than 1 year. a rapid decrease of 1 to greater than 4 log cfu/g was observed as the inoculum dried. in some cases, the time of storage at 23°c did not influence bacterial levels, and in other ...201222289584
modeling the growth rate and lag time of different strains of salmonella enterica and listeria monocytogenes in ready-to-eat lettuce.the growth parameters (growth rate, μ and lag time, λ) of three different strains each of salmonella enterica and listeria monocytogenes in minimally processed lettuce (mpl) and their changes as a function of temperature were modeled. mpl were packed under modified atmosphere (5% o₂, 15% co₂ and 80% n₂), stored at 7-30 °c and samples collected at different time intervals were enumerated for s. enterica and l. monocytogenes. growth curves and equations describing the relationship between μ and λ ...201222265311
effect of x-ray treatments on pathogenic bacteria, inherent microbiota, color, and texture on parsley leaves.this work is a part of systematic studies of the effect of x-ray treatments on fresh produce. the main objective of this investigation was to study the effects of x-ray treatments in reducing the concentration of artificially inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica, and shigella flexneri, and inherent microbiota on parsley leaves. the secondary objective was to study the effects of x-ray treatments on color and texture parameters on treated parsley leaves ...201223035726
annual cost of illness and quality-adjusted life year losses in the united states due to 14 foodborne pathogens.in this article we estimate the annual cost of illness and quality-adjusted life year (qaly) loss in the united states caused by 14 of the 31 major foodborne pathogens reported on by scallan et al. (emerg. infect. dis. 17:7-15, 2011), based on their incidence estimates of foodborne illness in the united states. these 14 pathogens account for 95 % of illnesses and hospitalizations and 98 % of deaths due to identifiable pathogens estimated by scallan et al. we estimate that these 14 pathogens caus ...201222980013
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