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hfq and arca are involved in the stationary phase-dependent activation of salmonella pathogenicity island 1 (spi1) under shaking culture conditions.in salmonella enterica serovar typhimurium, many genes encoded within salmonella pathogenicity island 1 (spi1) are required to induce intestinal/diarrheal disease. in this study, we compared the expression of four spi1 genes (hila, invf, prgh, and sipc) under shaking and standing culture conditions and found that the expression of these genes was highest during the transition from the exponential to stationary phase under shaking conditions. to identify regulators associated with the stationary ...201324018968
novel determinants of intestinal colonization of salmonella enterica serotype typhimurium identified in bovine enteric infection.cattle are naturally infected with salmonella enterica serotype typhimurium and exhibit pathological features of enteric salmonellosis that closely resemble those in humans. cattle are the most relevant model of gastrointestinal disease resulting from nontyphoidal salmonella infection in an animal with an intact microbiota. we utilized this model to screen a library of targeted single-gene deletion mutants to identify novel genes of salmonella typhimurium required for survival during enteric inf ...201324019407
a non-classical assembly pathway of escherichia coli pore-forming toxin cytolysin a.cytolysin a (clya) is an α-pore forming toxin from pathogenic escherichia coli (e. coli) and salmonella enterica. here, we report that e. coli clya assembles into an oligomeric structure in solution in the absence of either bilayer membranes or detergents at physiological temperature. these oligomers can rearrange to create transmembrane pores when in contact with detergents or biological membranes. intrinsic fluorescence measurements revealed that oligomers adopted an intermediate state found d ...201324019520
the genomic blueprint of salmonella enterica subspecies enterica serovar typhi p-stx-12.salmonella enterica subspecies enterica serovar typhi is a rod-shaped, gram-negative, facultatively anaerobic bacterium. it belongs to the family enterobacteriaceae in the class gammaproteobacteria, and has the capability of residing in the human gallbladder by forming a biofilm and hence causing the person to become a typhoid carrier. here we present the complete genome of salmonella enterica subspecies enterica serotype typhi strain p-stx-12, which was isolated from a chronic carrier in varana ...201324019994
tetracycline accelerates the temporally-regulated invasion response in specific isolates of multidrug-resistant salmonella enterica serovar typhimurium.multidrug-resistant (mdr) salmonella isolates are associated with increased morbidity compared to antibiotic-sensitive strains and are an important health and safety concern in both humans and animals. salmonella enterica serovar typhimurium is a prevalent cause of foodborne disease, and a considerable number of s. typhimurium isolates from humans and livestock are resistant to three or more antibiotics. the majority of these mdr s. typhimurium isolates are resistant to tetracycline, a commonly ...201324020473
conformational changes of the bacterial type i atp-binding cassette importer hisqmp2 at distinct steps of the catalytic cycle.prokaryotic solute binding protein-dependent atp-binding cassette import systems are divided into type i and type ii and mechanistic differences in the transport process going along with this classification are under intensive investigation. little is known about the conformational dynamics during the catalytic cycle especially concerning the transmembrane domains. the type i transporter for positively charged amino acids from salmonella enterica serovar typhimurium (lao-hisqmp2) was studied by ...201424021237
a novel insight on signal transduction mechanism of rcscdb system in salmonella enterica serovar typhimurium.the rcscdb system of salmonella enterica serovar typhimurium is implicated in the control of capsule and flagella synthesis. the hybrid sensor rcsc, the phosphotransferase rcsd and the rcsb regulator, constitute the main components of the rcscdb system. the proposed rcs signaling cascade involves the autophosphorylation of rcsc and the transfer of the phosphate group to rcsb, mediated by rcsd. we previously reported that the overexpression of rcsb repress the transcription of rcsd by an autoregu ...201324023746
sustained broad-spectrum antibacterial effects of nanoliposomes loaded with silver nanoparticles.the emergence of microbial resistance to antibiotics warrants the search for effective broad-spectrum antibacterial agents. silver nanoparticles (agnps) have been used as antimicrobial agents. agnps encapsulated in nanolipososmes have been developed as effective antimicrobial agents.201424024570
survival of foodborne pathogens on inshell walnuts.the survival of salmonella enterica enteritidis pt 30 or five-strain cocktails of s. enterica, escherichia coli o157:h7, and listeria monocytogenes was evaluated on inshell walnuts during storage. inshell walnuts were separately inoculated with an aqueous preparation of the pathogens at levels of 10 to 4 log cfu/nut, dried for 24 h, and then stored at either 4 °c or ambient conditions (23-25 °c, 25-35% relative humidity) for 3 weeks to more than 1 year. during the initial 24-h drying period, bac ...201324026009
cytotoxic t cell adjuvant effects of three salmonella enterica flagellins.bacterial flagellins are important virulence-associated factors and strong inducers of inflammatory responses in mammalian hosts. flagellins have also been investigated as potential vaccine adjuvants, either for induction of humoral or cellular immune responses, to different target antigens. in this study we investigated the adjuvant properties of three salmonella enterica flagellins types (flicd, flici and fljb) to an ovalbumin-derived cd8(+) t cell-restricted epitope (ova257-264). although mic ...200824031176
control of salmonella enterica serovar enteritidis in laying hens by inactivated salmonella enteritidis vaccines.salmonella enteritidis is one of the agents that is responsible for outbreaks of human foodborne salmonellosis caused by salmonella enteritidis and is generally associated with the consumption of poultry products. inactivated salmonella enteritidis cell vaccine is one of the available methods to control salmonella enteritidis in breeders and laying hens, however results in terms of efficacy vary. this vaccine has never been tested in brazil, therefore, the present work was carried out to assess ...200824031235
validation of a predictive model describing growth of salmonella in enteral feeds.the growth of salmonella enterica subs. enterica sorovar typhimurium at 25ºc was monitored in industrialized and hospital formulated enteral feeds and the results were used to validate the mathematical model of salmonella growth presented by the pathogen modeling program (pmp) 7.0 (usda-usa). the generation time of salmonella in enteral feeds ranged from 21 to 34.8 min and, the maximum growth rate (μmax) varied from 1.28 to 1.95 h(-1), resulting in a population increase from 5 to 6 log10 cycles ...200924031335
molecular differentiation between salmonella enterica subsp enterica serovar pullorum and salmonella enterica subsp enterica serovar gallinarum.s. pullorum (sp) and s. gallinarum (sg) are very similar. they are the agents of pullorum disease and fowl typhoid, respectively, and the two diseases are responsible for economic losses in poultry production. although sp and sg are difficult to be differentiated in routine laboratory procedures, the ability to metabolize ornithine is a biochemical test that may be used to achieve this aim. while sp is able to decarboxylate this amino acid, sg is not. however, the isolation of strains showing at ...200924031341
mannanoligosaccharide agglutination by salmonella enterica strains isolated from carrier pigs.type-1 fimbriae are associated with most salmonella enterica serovars and are an essential factor for host colonization. mannanoligosaccharides (mos), a prebiotic that is agglutinated by type-1 fimbriae, are proposed for the control of enterobacteria colonization and may be an alternative to salmonella control in pigs. the aim of this study was to evaluate the capability of porcine salmonella strains to adhere to mos in vitro. a total of 108 strains of salmonella sp. isolated from carrier pigs w ...200924031388
a defective mutant of salmonella enterica serovar gallinarum in cobalamin biosynthesis is avirulent in chickens.salmonella enterica serovar gallinarum (sg) is a fowl typhoid agent in chickens and is a severe disease with worldwide economic impact as its mortality may reach up to 80%. it is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. the survival mechanisms are not considered to be virulent mechanisms but are essential for the life of the bacterium. mutants of salmonella gal ...200924031393
the contribution of genes required for anaerobic respiration to the virulence of salmonella enterica serovar gallinarum for chickens.salmonella enterica serovar gallinarum (sg) is an intracellular pathogen of chickens. to survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. the fumarate reductase (frdabcd), dimethyl sulfoxide (dmso)-trimethylamine n-oxide (tmao) reductase (dmsabc), and nitrate reductase (narghij) operons in salmonella typhimurium (stm) encode enzymes involved in anaerobic respiration to the electron acceptors fumara ...200924031452
yields from blood cultures of patients with suspected paratyphoid fever a.the yield and speed of detection of salmonella enterica serotype paratyphi a from the blood of patients with suspected paratyphoid fever a in 13 500 paired aerobic and anaerobic bottles (aeb, anb) that were each filled with 5 ml of blood by the bact/alert 3d system were compared, and the blood bacterial counts of 1 000 probable patients were estimated by pour plate method. a total of 4 060 isolates were recovered, of these, 3 149 were recovered from both aeb and anb, 461 from the aeb only, and 4 ...201024031492
effects of myrcia ovata cambess. essential oil on planktonic growth of gastrointestinal microorganisms and biofilm formation of enterococcus faecalis.the essential oil from the leaves of myrcia ovata cambess., commonly used in brazil for the treatment of gastric illnesses, was screened for antimicrobial activity and action in the formation of microbial biofilms by enterococcus faecalis. the oil was obtained by hydrodistillation using a clevenger-type system. its chemical composition was analyzed using gc and gc-ms. both mic and mbc of the essential oil were determined by broth microdilution techniques and agar dilution method. the essential o ...201024031537
expression of fljb:z66 on a linear plasmid of salmonella enterica serovar typhi is dependent on flia and flhdc and regulated by ompr.salmonella enterica serovar typhi z66-positive strains have two different flagellin genes, flic:d/j and fljb:z66, located on the chromosome and on a linear plasmid, respectively. to investigate the mechanism underlying the expressional regulation of fljb:z66, gene deletion mutants of the regulators flia, flhdc, and ompr were constructed in this study. the expression levels of flic and fljb:z66 were analyzed by qrt-pcr in the wild-type strain and mutants at high and low osmolarity. the results sh ...201024031550
characterization of class 1 integrons and antibiotic resistance genes in multidrug-resistant salmonella enterica isolates from foodstuff and related sources.in recent years, an increase in the occurrence of antimicrobial resistance among salmonella enterica has been observed in several countries, which is worrisome because s. enterica is one of the most common causes of human gastroenteritis worldwide. the aim of this study was to characterize class 1 integrons and antibiotic resistance genotypes in salmonella enterica isolates recovered from foodstuff and related sources. nineteen multidrug-resistant (mdr) salmonella enterica isolates were recovere ...201124031680
identification and biological activity of potential probiotic bacterium isolated from the stomach mucus of breast-fed lamb.the lactic acid bacterium e isolated from the stomach mucus of breast-fed lamb was identified by sequencing of 16s rdna fragment and species-specific pcr as lactobacillus reuteri. its potential antimicrobial activity and ability to modulate immune system in vitro and in vivo was determined. the growth inhibition of potential pathogens decreased from staphylococcus aureus, pseudomonas aeruginosa, salmonella enterica ser. minnesota to escherichia coli. the lowest inhibition activity was observed i ...201124031741
requirement for cobalamin by salmonella enterica serovars typhimurium, pullorum, gallinarum and enteritidis during infection in chickens.salmonella enterica serovar typhimurium synthesizes cobalamin (vitamin b12) only during anaerobiosis. two percent of the s. typhimurium genome is devoted to the synthesis and uptake of vitamin b12 and to b12-dependent reactions. to understand the requirement for cobalamin synthesis better, we constructed mutants of salmonella serovars enteritidis and pullorum that are double-defective in cobalamin biosynthesis (δcobsδcbia). we compared the virulence of these mutants to that of their respective w ...201124031771
sandwich assay for mixed-sequence recognition of double-stranded dna: invader-based detection of targets specific to foodborne pathogens.a 96-well plate sandwich assay based on invader capture/signalling probes is used to recognize 28-mer mixed-sequence dsdna targets specific to salmonella enterica, campylobacter jejuni, escherichia coli. targets are detected down to 20-55 pm concentration with excellent binding specificity.201324036937
stochastic simulation of endemic salmonella enterica serovar typhi: the importance of long lasting immunity and the carrier state.typhoid fever caused by salmonella enterica serovar typhi (s. typhi) remains a serious burden of disease, especially in developing countries of asia and africa. it is estimated that it causes 200,000 deaths per year, mainly in children. s. typhi is an obligate pathogen of humans and although it has a relatively complex life cycle with a long lived carrier state, the absence of non-human hosts suggests that well targeted control methods should have a major impact on disease. newer control methods ...201324040177
commensal akkermansia muciniphila exacerbates gut inflammation in salmonella typhimurium-infected gnotobiotic mice.excessive mucin degradation by intestinal bacteria may contribute to inflammatory bowel diseases because access of luminal antigens to the intestinal immune system is facilitated. this study investigated how the presence of a mucin degrading commensal bacterium affects the severity of an intestinal salmonella enterica typhimurium-induced gut inflammation. using a gnotobiotic c3h mouse model with a background microbiota of eight bacterial species (sihumi) the impact of the mucin-degrading commens ...201324040367
the plague of athens: an ancient act of bioterrorism?recent data implicate salmonella enterica serovar typhi as a causative pathogen of the plague of athens during the peloponnesian war (430-426 bc). according to thucydides, the sudden outbreak of the disease may link to poisoning of the water reservoirs by the spartans. the siege of a city was aimed at exhausting the supplies of a population, which often led to the outbreak and spread of epidemics. poisoning of the water reservoirs of a besieged city as an act of bioterrorism would probably short ...201324041196
quantification and efficiency of lactobacillus sakei strain mixtures used as protective cultures in ground beef.lactobacillus sakei is a lactic acid bacterium, naturally associated with long term storage of fresh meat at low temperature. here we investigated the effect, on the evolution of pathogenic and spoilage microorganisms in ground beef, of l. sakei cocktails used as bioprotective cultures. we selectively developed a real time quantitative pcr method, allowing the quantification of individual l. sakei strains inoculated in ground meat with specific probes. six cocktails of three strains were tested ...201424041591
new decontamination method based on caprylic acid in combination with citric acid or vanillin for eliminating cronobacter sakazakii and salmonella enterica serovar typhimurium in reconstituted infant formula.the antimicrobial effects of natural compounds (caprylic acid, ca; citric acid, cta; and vanillin, vnl) on the inactivation of cronobacter sakazakii and salmonella enterica serovar typhimurium were examined in reconstituted infant formula. the samples were treated with: 1) ca, cta, or vnl alone (0, 10, 20, 30, 40, 60, and 80 mm); 2) a combination of ca (10 and 20 mm) and cta (15 and 30 mm); and 3) a combination of ca (10 and 20 mm) and vnl (15 and 30 mm), at mild feeding temperatures (40 °c and ...201324042002
fimy does not interfere with fimz-fimw interaction during type 1 fimbria production by salmonella enterica serovar typhimurium.the production of type 1 fimbriae in salmonella enterica serovar typhimurium is controlled, in part, by three proteins, fimz, fimy, and fimw. amino acid sequence analysis indicates that fimz belongs to the family of bacterial response regulators of two-component systems. in these studies, we have demonstrated that introducing a mutation mimicking phosphorylation of fimz is necessary for activation of its target gene, fima. in addition, the interaction of fimz with fimw, a repressor of fima expre ...201324042120
inflammatory responses induced by lipopolysaccharide are amplified in primary human monocytes but suppressed in macrophages by complement protein c5a.monocytes and macrophages are important innate immune cells equipped with danger-sensing receptors, including complement and toll-like receptors. complement protein c5a, acting via c5ar, is shown in this study to differentially modulate lps-induced inflammatory responses in primary human monocytes versus macrophages. whereas c5a enhanced secretion of lps-induced il-6 and tnf from primary human monocytes, c5a inhibited these responses while increasing il-10 secretion in donor-matched human monocy ...201324043889
trends in the antibiotic resistance patterns of enteric fever isolates - a three year report from a tertiary care centre.the incidence of multidrug resistant enteric fever is increasing alarmingly. this study was planned to determine the rate of isolation of salmonella spp. and to compare the isolates for their epidemiological parameters and antimicrobial susceptibility patterns at our center.201324043999
probing the arca regulon under aerobic/ros conditions in salmonella enterica serovar typhimurium.hydrogen peroxide (h₂o₂) is a reactive oxygen species (ros), which is part of the oxidative burst encountered upon internalization of salmonella enterica serovar typhimurium (s. typhimurium) by phagocytic cells. it has previously been established that, the arcab two-component system plays a critical role in ros resistance, but the genes regulated by the system remained undetermined to date. we therefore investigated the arca regulon in aerobically growing s. typhimurium before and after exposure ...201324044554
the calcium-stimulated lipid a 3-o deacylase from rhizobium etli is not essential for plant nodulation.the lipid a component of lipopolysaccharide from the nitrogen-fixing plant endosymbiont, rhizobium etli, is structurally very different from that found in most enteric bacteria. the lipid a from free-living r. etli is structurally heterogeneous and exists as a mixture of species which are either pentaacylated or tetraacylated. in contrast, the lipid a from r. etli bacteroids is reported to consist exclusively of tetraacylated lipid a species. the tetraacylated lipid a species in both cases lack ...201324046865
studies on extended spectrum beta lactamase (esbl) producing salmonella isolates from clinical samples of nepal.present study was carried out among the patients of age 2-60 years from november 2009 to november 2011 to assess the production of extended spectrum beta lactamase (esbl) by salmonella enterica serotype (typhi and paratyphi a) at kanti children's hospital (kch), nepal medical college (nmc), kathmandu medical college (kmc), national public health laboratory (nphl) and sankata laboratory (skl) of nepal. blood cultures were obtained from 4,820 patients with febrile illnesses. 400 strains of salmone ...201224047016
design of a core-shell type immuno-magnetic separation system and multiplex pcr for rapid detection of pathogens from food samples.we report an immuno-magnetic separation system developed by the immobilization of pathogen-specific antibodies on the core-shell magnetic beads. the magnetic beads were grafted with glycidylmethacrylate (gma) using surface-initiated atom transfer radical polymerization (si-atrp). for immuno-magnetic separation (ims) of target bacterial cells from others, antibodies for escherichia coli and salmonella enterica serovar typhimurium cells were immobilized on the magnetic beads via glutaraldehyde cou ...201324048640
effects of cyclophosphamide on the immune response of pigs to salmonella cholerae-suis var kunzendorf.the effects of the immunosuppressive agent cyclophosphamide (cy) on the immune response of pigs given im challenge inoculations of a moderately virulent strain of salmonella cholerae-suis var kunzendorf were examined. five groups of yorkshire-cross pigs (approx 6 kg) were given salmonella, cy, or both at various times after the 1st of a series of doses of cy was given. the drug was administered subcutaneously in 3 doses, 2 days between doses, at a rate of 20 mg/kg of body weight. cyclophosphamid ...198424049894
relationship between the antibody-complement susceptibility of smooth salmonella cholerae-suis var kunzendorf strains and their virulence for mice and pigs.in the present work, we attempted to characterize 4 field strains of salmonella cholerae-suis var kunzendorf susceptible to antibody and complement (ab-c), and 4 strains not susceptible to ab-c, with respect to their virulence for mice and pigs. in vivo growth of an ab-c-susceptible, mouse-virulent strain in the spleens of mice exceeded that of 2 ab-c-susceptible, but mouse-avirulent strains by at least 10(4) organisms. comparison of ab-c susceptibility with virulence for pigs seemed to indicate ...198424049895
increasing rates of salmonella paratyphi a and the current status of its vaccine development.enteric fever caused by salmonella enterica serovar typhi and salmonella enterica serovar paratyphi is still a major disease burden mainly in developing countries. previously, s. typhi was believed to be the major cause of enteric fever. the real situation is now becoming clear with reports emerging from many asian countries of s. paratyphi, mostly s. paratyphi a, causing a substantial number of cases of enteric fever. although there have been advances in the use of the currently available typho ...201324053396
baer protein from salmonella enterica serovar paratyphi a induces inflammatory response in murine and human cell lines.baer is the response regulator of the two-component system, baesr, found in escherichia coli (e. coli) and salmonella. several biological functions of baer, related to multidrug efflux and bacterial virulence, have been described. herein, we report a putative function of baer during inflammatory response of the host by using baer protein of salmonella enterica paratyphi a (s. paratyphi a) origin overexpressed in e. coli, and raw 264.7 and thp-1 cells as in vitro models. baer (3 μg/ml) upregulate ...201324055826
preadaptation to cold stress in salmonella enterica serovar typhimurium increases survival during subsequent acid stress exposure.salmonella is an important cause of bacterial food-borne gastroenteritis. salmonella encounters multiple abiotic stresses during pathogen elimination methods used in food processing, and these stresses may influence its subsequent survivability within the host or in the environment. upon ingestion, salmonella is exposed to gastrointestinal acidity, a first line of the host innate defense system. this study tested the hypothesis that abiotic stresses encountered during food processing alter the m ...201324056458
a novel csra titration mechanism regulates fimbrial gene expression in salmonella typhimurium.a hierarchical control of fimbrial gene expression limits laboratory grown cultures of salmonella enterica serovar typhimurium (s. typhimurium) to the production of type i fimbriae encoded by the fimaicdhf operon. here we show that an unlikely culprit, namely the 5'-untranslated region (5'-utr) of a messenger (m)rna, coordinated the regulation. binding of csra to the 5'-utr of the pefacdef transcript was required for expression of plasmid-encoded fimbriae. the 5'-utr of the fimaicdhf transcript ...201324056837
salmonella enterica prevalence in leatherback sea turtles (dermochelys coriacea) in st. kitts, west indies.salmonella spp. are gram-negative bacteria capable of causing diseases in a wide range of aquatic and terrestrial animals, including humans. sea and terrestrial turtles have been recognized as carriers of this zoonotic pathogen. in this project, conventional and molecular diagnostic methods were combined to investigate the prevalence of salmonella enterica in leatherback sea turtles (dermochelys coriacea) that used the island of st. kitts, west indies as a nesting ground during 2011 (n = 21). is ...201324063110
study of the role of efflux pump in ciprofloxacin resistance in salmonella enterica serotype typhi.there are increasing reports on failure of clinical response to ciprofloxacin in typhoid fever despite the strain being sensitive to drug in in-vitro using standard guidelines and showing mutations in dna gyrase. but this increased mic and clinical failures with ciprofloxacin are not always co-related with mutations presently identified in gyra and parc genes. this shows that there may be other mechanisms such as an active drug efflux pump responsible as has been shown in other enterobacteriacea ...201324064645
unusual manifestation of salmonella enterica serotype enteritidis infection in a case of langerhans cell histiocytosis.nontyphoidal salmonella (nts) are established foodborne pathogens, most commonly reported in cases of gastroenteritis. these pathogens are however, increasingly being implicated in cases of bacteraemia and other extraintestinal manifestations. we report a case of a scalp abscess due to salmonella enterica serotype enteritidis, which is a serotype of nts, in a child suffering from a haematologic malignancy. the child was on steroid and anticancer chemotherapy and developed the abscess secondary t ...201324064654
development of a novel hexa-plex pcr method for identification and serotyping of salmonella species.salmonella is one of the most important foodborne pathogens, which causes a huge economic burden worldwide. to detect salmonella rapidly is very meaningful in preventing salmonellosis and decreasing economic losses. currently, isolation of salmonella is confirmed by biochemical and serobased serotyping methods, which are time consuming, labor intensive, and complicated. to solve this problem, a hexa-plex polymerase chain reaction (pcr) method was developed using comparative genomics analysis and ...201424066904
lymph node colonization dynamics after oral salmonella typhimurium infection in mice.an understanding of how pathogens colonize their hosts is crucial for the rational design of vaccines or therapy. while the molecular factors facilitating the invasion and systemic infection by pathogens are a central focus of research in microbiology, the population biological aspects of colonization are still poorly understood. here, we investigated the early colonization dynamics of salmonella enterica subspecies 1 serovar typhimurium (s. tm) in the streptomycin mouse model for diarrhea. we f ...201324068916
genetic characterization of atypical citrobacter freundii.the ability of a bacterial population to survive in different niches, as well as in stressful and rapidly changing environmental conditions, depends greatly on its genetic content. to survive such fluctuating conditions, bacteria have evolved different mechanisms to modulate phenotypic variations and related strategies to produce high levels of genetic diversity. laboratories working in microbiological diagnosis have shown that citrobacter freundii is very versatile in its colony morphology, as ...201324069274
enhancement of host immune responses by oral vaccination to salmonella enterica serovar typhimurium harboring both flic and fljb flagella.flagellin, the structural component of the flagellar filament in various motile bacteria, can contribute to the activation of nf-κb and proinflammatory cytokine expression during the innate immune response in host cells. thus, flagellin proteins represent a particularly attractive target for the development of vaccine candidates. in this study, we investigated the immune response by increasing the flagella number in the iacp mutant strain and the adjuvant activity of the flagellin component fljb ...201324069357
bioengineered 2'-fucosyllactose and 3-fucosyllactose inhibit the adhesion of pseudomonas aeruginosa and enteric pathogens to human intestinal and respiratory cell lines.human milk oligosaccharides help to prevent infectious diseases in breastfed infants. larger scale testing, particularly in animal models and human clinical studies, is still limited due to shortened availability of more complex oligosaccharides. the purpose of this study was to evaluate 2'-fucosyllactose (2'-fl) and 3-fucosyllactose (3-fl) synthesized by whole-cell biocatalysis for their biological activity in vitro. therefore, we have tested these oligosaccharides for their inhibitory potentia ...201324074741
gene expression analysis of salmonella enterica spi in macrophages indicates differences between serovars that induce systemic disease from those normally causing enteritis.global gene expression of the invasive salmonella serovars s. enteritidis and s. typhimurium, and the less-invasive s. infantis and s. hadar was studied during infection of a chicken macrophage cell line. major functional gene groups responsible for intracellular physiological changes were regulated similarly in all four serovars. however, spi1 and spi4 genes of s. enteritidis and s. typhimurium were strongly repressed in the macrophages whereas s. infantis, s. hadar and other similar serovars m ...201324080352
growth-inhibiting and morphostructural effects of constituents identified in asarum heterotropoides root on human intestinal bacteria.the growth-inhibiting and morphostructural effects of seven constituents identified in asarum heterotropoides root on 14 intestinal bacteria were compared with those of the fluoroquinolone antibiotic ciprofloxacin.201324083511
fate of escherichia coli o157:h7 and salmonella enterica in the manure-amended soil-plant ecosystem of fresh vegetable crops: a review.enterohemorrhagic escherichia coli (ehec) and salmonella enterica have been implicated in several disease outbreaks linked to consumption of fresh vegetables. both ruminant and non-ruminant animals carry ehec and s. enterica in their gastrointestinal tracts and can shed the pathogens in the faecal matter both in symptomatic and asymptomatic states. application of animal waste in soil fertility management and irrigation of crops with contaminated waste water has been recognised as an important ro ...201524083946
treatment of infected abdominal aortic aneurysm caused by salmonella.we reviewed the outcomes of patients treated for nontyphoidal salmonella-infected abdominal aortic aneurysm (aaa) treatment at a single center.201424084275
salmonella prostatitis in a man with spinal cord injury.prostatitis is a very unusual manifestation of salmonella urinary tract infection and has not been reported in men with spinal cord injury (sci).201424090046
the ssec translocon component in salmonella enterica serovar typhimurium is chaperoned by ssca.salmonella enterica is a causative agent of foodborne gastroenteritis and the systemic disease known as typhoid fever. this bacterium uses two type three secretion systems (t3sss) to translocate protein effectors into host cells to manipulate cellular function. salmonella pathogenicity island (spi)-2 encodes a t3ss required for intracellular survival of the pathogen. genes in spi-2 include apparatus components, secreted effectors and chaperones that bind to secreted cargo to coordinate their rel ...201324090070
the gdac1 locus modifies spontaneous and salmonella-induced colitis in mice deficient in either gpx2 or gpx1 gene.we previously identified the gdac1 (gpx-deficiency-associated colitis 1) locus, which influences the severity of spontaneous colitis in gpx1- and gpx2-double-knockout (gpx1/2-dko) mice. congenic gpx1/2-dko mice in the 129s1/svimj (129) background but carrying the gdac1(b6) allele have milder spontaneous colitis than 129 gpx1/2-dko mice carrying the gdac1(129) allele. here, we evaluated the effect of the gdac1(b6) allele on 129 strain non-dko mice that had a wild-type (wt) gpx1 or gpx2 allele and ...201324090658
carbapenemase-producing enterobacteriaceae and non-enterobacteriaceae from animals and the environment: an emerging public health risk of our own making?acquired carbapenemases pose one of the most pressing public health threats relating to antibiotic resistance. in most countries, the number of carbapenemase-producing bacteria from human clinical specimens is rising, and the epidemiological status of these multiresistant bacteria is progressively worsening. furthermore, there is a growing number of reports of carbapenemases found either in bacteria isolated from non-human sources or in salmonella enterica subsp. enterica, a zoonotic species. ho ...201424092657
draft genome sequences of two salmonella strains from the sara collection, sara64 (muenchen) and sara33 (heidelberg), provide insight into their antibiotic resistance.the salmonella enterica strains that are representatives of the s. enterica serovar typhimurium complex in reference collection a (sara) are closely related but exhibit differences in antibiotic resistance, which could have public health consequences. to better understand the mechanisms behind these resistances, we sequenced the genomes of two multidrug-resistant strains: sara64 (muenchen) and sara33 (heidelberg).201324092796
increase in salmonella enterica serovar paratyphi a infections in phnom penh, cambodia, january 2011 to august 2013.we report an increased number of salmonella enterica paratyphi a infections in adults in cambodia. between january 2011 and august 2013, 71 s. paratyphi a isolates were recovered from blood cultures, representing a 44-fold increase compared to july 2007 to december 2010, while monthly numbers of cultures did not change. infections with s. typhi increased two-fold in the same period. most cases came from the capital phnom penh. these findings warrant epidemiological investigation to support publi ...201324094060
impact of plasmids, including those encodingvirb4/d4 type iv secretion systems, on salmonella enterica serovar heidelberg virulence in macrophages and epithelial cells.salmonella enterica serovar heidelberg (s. heidelberg) can cause foodborne illness in humans following the consumption of contaminated meat and poultry products. recent studies from our laboratory have demonstrated that certain s. heidelberg isolated from food-animal sources harbor multiple transmissible plasmids with genes that encode antimicrobial resistance, virulence and a virb4/d4 type-iv secretion system. this study examines the potential role of these transmissible plasmids in bacterial u ...201324098597
structure of the periplasmic copper-binding protein cuep from salmonella enterica serovar typhimurium.cuep was initially identified as a copper-resistance gene in salmonella enterica serovar typhimurium, which has evolved to survive in the phagosomes of macrophages. recently, cuep was determined to be a periplasmic copper-binding protein and has been implicated in the transfer of copper ions to sodcii in the periplasm. in this study, the crystal structure of cuep has been determined, revealing a v-shaped dimeric structure. the conserved cysteine and histidine residues are clustered on the surfac ...201324100307
characterization of drug resistance and virulotypes of salmonella strains isolated from food and humans.the virulence of bacteria can be evaluated through both phenotypic and molecular assays. we applied these techniques to 114 strains of salmonella enterica subsp. enterica collected from july 2010 to june 2012. salmonella strains were of human origin (71/114) or isolated from food (43/114). the strain set included only the three predominant salmonella serovars isolated in italy from humans (s. enteritidis, s. typhimurium, s. 4,[5],12:i:-). these strains were screened via polymerase chain reaction ...201324102078
evaluation of virulence and antimicrobial resistance in salmonella enterica serovar enteritidis isolates from humans and chicken- and egg-associated sources.salmonella enterica serovar enteritidis is a leading cause of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated poultry and egg products. salmonella enteritidis has enhanced ability to colonize and persist in extraintestinal sites within chickens. in this study, 54 salmonella enteritidis isolates from human patients (n=28), retail chicken (n=9), broiler farms (n=9), and egg production facilities (n=8) were characterized by antimicrobial susce ...201324102082
c-jun nh2 -terminal kinase is a critical node in the death of cd4+ cd8+ thymocytes during salmonella enterica serovar typhimurium infection.thymic atrophy, due to the depletion of cd4(+) cd8(+) thymocytes, is observed during infections with numerous pathogens. several mechanisms, such as glucocorticoids and inflammatory cytokines, are known to be involved in this process; however, the roles of intracellular signaling molecules have not been investigated. in this study, the functional role of c-jun nh2 -terminal kinase (jnk) during infection-induced thymic atrophy was addressed. the levels of phosphorylated jnk in immature cd4(+) cd8 ...201424105651
distribution of serotypes and genotypes of salmonella enterica species in french pig production.the population of salmonella found at various stages of pig production in france was characterised to analyse the distribution and spread of salmonella in the pig production chain. we serotyped and genotyped by pfge 174 isolates collected from breeding pigs from breeding farms, 163 collected from breeding pigs from production farms, and 325 collected from fattening pigs. forty-seven serovars and 110 genotypes were identified. the major serovars were s derby (263 isolates) and s typhimurium (162 ...201324106251
identification of diverse salmonella serotypes, virulotypes, and antimicrobial resistance phenotypes in waterfowl from chile.salmonella enterica is a pathogen with a wide host-range that presents great concern in developed and developing countries. to determine and characterize salmonella strains found in chile's waterfowl, we sampled 758 birds along 2000 km of the chilean coast. in this sample, 46 isolates from 10 serotypes were detected, several with multidrug resistance phenotypes and different combinations of virulence-associated genes (virulotypes). these results suggest that salmonella infection in waterfowl in ...201324107205
campylobacter spp., yersinia enterocolitica, and salmonella enterica and their simultaneous occurrence in german fattening pig herds and their environment.campylobacter spp., salmonella enterica, and yersinia enterocolitica are common causes of foodborne infections in humans with pork as a potential source. monitoring programs at farm level are, to date, only implemented for s. enterica, while epidemiological knowledge of the other two pathogens is still lacking. this study aimed to assess the pathogen load (in the pigs' environment) in fattening pig herds, their simultaneous occurrence, and the occurrence of campylobacter spp. and y. enterocoliti ...201324112569
evaluation of levulinic acid and sodium dodecyl sulfate as a sanitizer for use in processing georgia-grown cantaloupes.freshly harvested georgia-grown cantaloupes (cucumis melo l. var. reticulatus cv. athena and atlantis) were spot inoculated with 100 μl of a five-strain mixture of salmonella enterica serovar poona (9 log cfu/ml) at the stem scar and on the netted rind and then subjected to no treatment (control) or a 6-min treatment (tank only) in water, 120 ppm of chlorine (ph 7.0), 1% levulinic acid plus 0.1% sodium dodecyl sulfate (sds; ph 3.0), or 2% levulinic acid plus 0.2% sds (ph 3.0). the log reduction ...201324112578
biofilm formation of salmonella serotypes in simulated meat processing environments and its relationship to cell characteristics.salmonella attached to meat contact surfaces encountered in meat processing facilities may serve as a source of cross-contamination. in this study, the influence of serotypes and media on biofilm formation of salmonella was investigated in a simulated meat processing environment, and the relationships between biofilm formation and cell characteristics were also determined. all six serotypes (salmonella enterica serotype heidelberg, salmonella derby, salmonella agona, salmonella indiana, salmonel ...201324112581
identification of an iron acquisition machinery in flavobacterium columnare.flavobacterium columnare, a fastidious gram-negative pathogen and the causative agent of columnaris disease, is one of the most harmful pathogens in the freshwater fish-farming industry. nevertheless the virulence mechanisms of f. columnare are not well understood. bacterial iron uptake from the host during infection is an important mechanism of virulence. here we identified and analyzed part of the iron uptake machinery of f. columnare. under iron-limited conditions during in vitro growth, synt ...201324113246
value addition in the efficacy of conventional antibiotics by nisin against salmonella.frequent and indiscriminate use of existing battery of antibiotics has led to the development of multi drug resistant (mdr) strains of pathogens. as decreasing the concentration of the antibiotic required to treat salmonellosis might help in combating the development of resistant strains, the present study was designed to assess the synergistic effects, if any, of nisin, in combination with conventional anti-salmonella antibiotics against salmonella enterica serovar typhimurium. minimum inhibito ...201324116175
postharvest transfer and survival of salmonella enterica serotype enteritidis on living lettuce.the potential for postharvest transfer of salmonella to 'living lettuce' is not well understood. in this study, the transfer of salmonella enterica enteritidis (6 log cfu g(-1) ) from worker hands or contaminated roots to leaves of living lettuce was quantified. transfer rates of salmonella from contaminated gloves to sequentially handled lettuce heads ranged from 94% to head 1, 82% to head 2 and 69% to head 3. on average, 2.9 ± 0.1 log cfu g(-1) (64%) salmonella was transferred from inoculated ...201424117925
siia and siib are novel type i secretion system subunits controlling spi4-mediated adhesion of salmonella enterica.the giant non-fimbrial adhesin siie is essential to establish intimate contact between salmonella enterica and the apical surface of polarized epithelial cells. siie is secreted by a type i secretion system (t1ss) encoded by salmonella pathogenicity island 4 (spi4). we identified siia and siib as two regulatory proteins encoded by spi4. mutant strains in siia or siib still secrete siie, but are highly reduced in adhesion to, and invasion of polarized cells. siia and siib are inner membrane prote ...201424119191
clonal spread of salmonella enterica serovar infantis in serbia: acquisition of mutations in the topoisomerase genes gyra and parc leads to increased resistance to fluoroquinolones.quinolone-resistant salmonella infantis (n = 64) isolated from human stool samples, food and poultry during the years 2006-2011 were analysed for their resistance phenotypes, macrorestriction patterns and molecular mechanisms of decreased susceptibility to fluoroquinolones. minimum inhibitory concentrations (mics) of nalidixic acid (nal) and ciprofloxacin (cip) were determined by the agar dilution procedure, and the susceptibility to additional antimicrobial agents was determined by the disc dif ...201424119387
a new plant-derived antibacterial is an inhibitor of efflux pumps in staphylococcus aureus.an in-depth evaluation was undertaken of a new antibacterial natural product (1) recently isolated and characterised from the plant hypericum olympicum l. cf. uniflorum. minimum inhibitory concentrations (mics) were determined for a panel of bacteria, including: meticillin-resistant and -susceptible strains of staphylococcus aureus, staphylococcus epidermidis and staphylococcus haemolyticus; vancomycin-resistant and -susceptible enterococcus faecalis and enterococcus faecium; penicillin-resistan ...201324119569
dissecting cobamide diversity through structural and functional analyses of the base-activating cobt enzyme of salmonella enterica.cobamide diversity arises from the nature of the nucleotide base. nicotinate mononucleotide (namn):base phosphoribosyltransferases (cobt) synthesize α-linked riboside monophosphates from diverse nucleotide base substrates (e.g., benzimidazoles, purines, phenolics) that are incorporated into cobamides.201424121107
oral vaccination with inhibin dna delivered using attenuated salmonella choleraesuis for improving reproductive traits in mice.the objective of this study was to examine the efficacy and safety of a novel inhibin vaccine containing inhibin α (1-32) fragments in mice. a recombinant plasmid pvax-asd-is was constructed by inserting recombinant inhibin α (1-32) and the hepatitis b surface antigen s into the plasmid in which the asd gene, rather than the kanamycin gene, was a selection marker. ninety kuming mice were divided into six groups consisting of 15 mice each. first group was (c1) injected with 200 µl of pbs, second ...201424123188
salmonella infection induces recruitment of caspase-8 to the inflammasome to modulate il-1β production.nucleotide-binding oligomerization domain-like receptors (nlrs) detect pathogens and danger-associated signals within the cell. salmonella enterica serovar typhimurium, an intracellular pathogen, activates caspase-1 required for the processing of the proinflammatory cytokines, pro-il-1β and pro-il-18, and pyroptosis. in this study, we show that salmonella infection induces the formation of an apoptosis-associated specklike protein containing a card (asc)-caspase-8-caspase-1 inflammasome in macro ...201324123685
dimethyl adenosine transferase (ksga) deficiency in salmonella enterica serovar enteritidis confers susceptibility to high osmolarity and virulence attenuation in chickens.dimethyl adenosine transferase (ksga) performs diverse roles in bacteria, including ribosomal maturation and dna mismatch repair, and synthesis of ksga is responsive to antibiotics and cold temperature. we previously showed that a ksga mutation in salmonella enterica serovar enteritidis results in impaired invasiveness in human and avian epithelial cells. in this study, we tested the virulence of a ksga mutant (the ksga::tn5 mutant) of s. enteritidis in orally challenged 1-day-old chickens. the ...201324123731
role of salmonella enterica exposure in chilean crohn's disease patients.to study the association between exposure to salmonella enterica (se) and crohn's disease (cd) and its clinical implications in chilean patients.201324124330
identification of virulence properties in salmonella typhimurium dt104 using caenorhabditis elegans.salmonella enterica serover typhimurium definitive phage type dt104, resistant to multiple antibiotics, is one of the most widespread salmonella species in human infection worldwide. although several cohort studies indicate that dt104 carrying the multidrug resistance (mdr) locus on salmonella genomic island 1 is a possible hyper-virulent strain compared to dt104 strains without mdr, or other salmonella enterica serotypes, existing experimental evidence regarding virulence properties associated ...201324124587
[current situation and problems associated with inactivation of microorganisms in water using copper].the current situation and problems associated with inactivation of microorganisms in water using copper were elucidated.201324125817
polynucleotide phosphorylase (pnpase) is required for salmonella enterica serovar typhimurium colonization in swine.the pnp gene encodes polynucleotide phosphorylase, an exoribonuclease involved in rna processing and degradation. a mutation in the pnp gene was previously identified by our group in a signature-tagged mutagenesis screen designed to search for salmonella enterica serovar typhimurium genes required for survival in an ex vivo swine stomach content assay. in the current study, attenuation and colonization potential of a s. typhimurium pnp mutant in the porcine host was evaluated. following intranas ...201324126127
yersinia enterocolitica inhibits salmonella enterica serovar typhimurium and listeria monocytogenes cellular uptake.yersinia enterocolitica biovar 1b employs two type three secretion systems (t3ss), ysa and ysc, which inject effector proteins into macrophages to prevent phagocytosis. conversely, salmonella enterica serovar typhimurium uses a t3ss encoded by salmonella pathogenicity island 1 (spi1) to actively invade cells that are normally nonphagocytic and a second t3ss encoded by spi2 to survive within macrophages. given the distinctly different outcomes that occur with regard to host cell uptake of s. typh ...201424126528
extracellular dna inhibits salmonella enterica serovar typhimurium and s. enterica serovar typhi biofilm development on abiotic surfaces.extracellular dna (edna) was identified and characterized in a 2-day-old biofilms developed by salmonella enterica ser. typhimurium sr-11 and s. enterica ser. typhi st6 using confocal laser scanning microscopy (clsm) and enzymatic extraction methods. results of microtitre plate assay and clsm analysis showed both salmonella strains formed significantly more biofilms in the presence of dnase i; furthermore, a remarkable decrease of biofilm formation was observed when edna was added in the inocula ...201424126602
the salmonella enterica zint structure, zinc affinity and interaction with the high-affinity uptake protein znua provide insight into the management of periplasmic zinc.in gram-negative bacteria the znuabc transporter ensures adequate zinc import in zn(ii)-poor environments, like those encountered by pathogens within the infected host. recently, the metal-binding protein zint was suggested to operate as an accessory component of znuabc in periplasmic zinc recruitment. since zint is known to form a zint-znua complex in the presence of zn(ii) it was proposed to transfer zn(ii) to znua. the present work was undertaken to test this claim.201424128931
genomics of an emerging clone of salmonella serovar typhimurium st313 from nigeria and the democratic republic of congo.salmonella enterica serovar typhimurium st313 is an invasive and phylogenetically distinct lineage present in sub-saharan africa. we report the presence of s. typhimurium st313 from patients in the democratic republic of congo and nigeria.201324129621
mait cells detect and efficiently lyse bacterially-infected epithelial cells.mucosal associated invariant t cells (mait) are innate t lymphocytes that detect a large variety of bacteria and yeasts. this recognition depends on the detection of microbial compounds presented by the evolutionarily conserved major-histocompatibility-complex (mhc) class i molecule, mr1. here we show that mait cells display cytotoxic activity towards mr1 overexpressing non-hematopoietic cells cocultured with bacteria. the nk receptor, cd161, highly expressed by mait cells, modulated the cytokin ...201324130485
invasive non-typhoidal salmonella typhimurium st313 are not host-restricted and have an invasive phenotype in experimentally infected chickens.salmonella enterica serovar typhimurium sequence type (st) 313 is a major cause of invasive non-typhoidal salmonellosis in sub-saharan africa. no animal reservoir has been identified, and it has been suggested that st313 is adapted to humans and transmission may occur via person-to-person spread. here, we show that st313 cause severe invasive infection in chickens as well as humans. oral infection of chickens with st313 isolates d23580 and q456 resulted in rapid infection of spleen and liver wit ...201324130915
comparison of different preenrichment broths, egg:preenrichment broth ratios, and surface disinfection for the detection of salmonella enterica ssp. enterica serovar enteritidis in shell eggs.salmonella enterica ssp. enterica serovar enteritidis is the leading reported cause of salmonella infections. most salmonella enteritidis infections are associated with whole shell eggs and egg products. this project attempted to lay the foundation for improving the food and drug administration's current bacteriological analytical manual method for the detection of salmonella enteritidis in shell eggs. two salmonella enteritidis isolates were used for comparisons among different preenrichment an ...201324135606
occurrence of extended-spectrum β-lactamases among isolates of salmonella enterica subsp. enterica from food-producing animals and food products, in portugal.a total of 1120 salmonella spp. isolates, recovered from poultry, swine and food products of animal origin (bovine, swine and poultry) over the period of 2009-2011, were investigated in order to determine their serotype, susceptibility to a panel of eleven antimicrobials (a, ampicillin; ct, cefotaxime; cp, ciprofloxacin; tm, trimethoprim; su, sulfamethoxazole; c, chloramphenicol; s, streptomycin; g, gentamicin; t, tetracycline; na, nalidixic acid; fl, florfenicol), and the presence of resistance ...201324135677
isolation of salmonella virchow from a fruit bat (pteropus giganteus).detection of zoonotic pathogens carried by bats is important both for understanding disease ecology and for developing preventive measures. pteropus fruit bats have been identified as potential carriers of salmonella enterica serotype typhi. a cross-sectional study was conducted to determine the prevalence of salmonella typhi and other salmonella serotypes in pteropus giganteus fruit bats in bangladesh. rectal swabs were collected from 302 bats and cultured for salmonella species. the bats were ...201324136382
genome sequences of salmonella enterica serotype typhimurium blood clinical isolate st4848/06 and stool isolate st1489/06.salmonella enterica serotype typhimurium human blood strains isolated from outside africa are rarely sequenced. here, we report the draft genome sequences of two s. typhimurium clinical strains isolated in the same year, one from blood and another from stool, in order to gain insights into the genetic basis leading to invasive diseases.201324136846
genomic diversity and adaptation of salmonella enterica serovar typhimurium from analysis of six genomes of different phage types.salmonella enterica serovar typhimurium (or simply typhimurium) is the most common serovar in both human infections and farm animals in australia and many other countries. typhimurium is a broad host range serovar but has also evolved into host-adapted variants (i.e. isolated from a particular host such as pigeons). six typhimurium strains of different phage types (defined by patterns of susceptibility to lysis by a set of bacteriophages) were analysed using illumina high-throughput genome seque ...201324138507
molecular study of quinolone resistance mechanisms and clonal relationship of salmonella enterica clinical isolates.in the last few years, the number of salmonella enterica strains resistant to nalidixic acid has steadily increased. in a previous study, the quinolone susceptibility phenotype and genotype of 38 s. enterica clinical isolates (19 s. enterica serovar typhimurium and 19 s. enterica serovar enteritidis) were determined. forty-two percent of the isolates showed nalidixic acid resistance associated with a mutation in gyra together with putative overexpression of efflux pump(s). in this study, mutatio ...201424139882
molecular characterization showed limited genetic diversity among salmonella enteritidis isolated from humans and animals in malaysia.salmonella enterica serovar enteritidis (s. enteritidis) is the most common causative agent of non-typhoidal salmonellosis in malaysia. we aimed to characterize s. enteritidis isolated from humans and animals by analyzing their antimicrobial resistance profiles and genotypes. a total of 111 strains were characterized using multiple-locus variable-number tandem repeat analysis, pulsed-field gel electrophoresis, and antimicrobial susceptibility testing. both typing methods revealed that geneticall ...201324139970
binding of mgtr, a salmonella transmembrane regulatory peptide, to mgtc, a mycobacterium tuberculosis virulence factor: a structural study.mgtr, a highly hydrophobic peptide expressed in salmonella enterica serovar typhimurium, inhibits growth in macrophages through binding to the membrane protein mgtc that has been identified as essential for replication in macrophages. while the mycobacterium tuberculosis mgtc is highly homologous to its s. typhi analogue, there does not appear to be an mtb homologue for mgtr, raising significant pharmacological interest in this system. here, solid-state nmr and epr spectroscopy in lipid bilayer ...201424140750
lack of correlation between in vitro antibiosis and in vivo protection against enteropathogenic bacteria by probiotic lactobacilli.increased resistance to infection is one of the beneficial effects attributed to probiotic microorganisms. this effect may be due to several mechanisms: production of inhibitory substances, blocking of adhesion sites on the intestinal surface, competition for nutrients and stimulation of mucosal and systemic immunity. the present study aimed to investigate the correlation between in vitro and in vivo antimicrobial activity of probiotic lactobacilli. the agar spot test was used to show that twent ...201424140789
evaluating gulls as potential vehicles of salmonella enterica serotype newport (jjpx01.0061) contamination of tomatoes grown on the eastern shore of virginia.salmonella enterica serovar newport pattern jjpx01.0061 has been identified as causing several multistate outbreaks in the last 10 years, primarily due to contamination of tomatoes grown in virginia. the goal of this study was to evaluate gulls as a potential vehicle of s. newport pattern 61 contamination for tomatoes grown on the eastern shore of virginia. gull fecal samples were collected at four sites in eastern virginia for 3 months (may to july) in 2012, resulting in 360 samples, among whic ...201424141129
a small rna activates cfa synthase by isoform-specific mrna stabilization.small rnas use a diversity of well-characterized mechanisms to repress mrnas, but how they activate gene expression at the mrna level remains not well understood. the predominant activation mechanism of hfq-associated small rnas has been translational control whereby base pairing with the target prevents the formation of an intrinsic inhibitory structure in the mrna and promotes translation initiation. here, we report a translation-independent mechanism whereby the small rna rydc selectively act ...201324141880
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