| genotypic characterization of salmonella by multilocus sequence typing, pulsed-field gel electrophoresis and amplified fragment length polymorphism. | molecular typing is an important tool in surveillance and outbreak investigations of human salmonella infections. in this study, three molecular typing methods were used to investigate the discriminatory ability, reproducibility and the genetic relationship between 110 salmonella enterica subspecies enterica isolates. a total of 25 serotypes were investigated that had been isolated from humans or veterinary sources in denmark between 1995 and 2001. all isolates were genotyped by multilocus seque ... | 2005 | 16226640 |
| molecular mechanisms of resistance in multidrug-resistant serovars of salmonella enterica isolated from foods in germany. | the objectives of this study were to determine antimicrobial susceptibility and to characterize the molecular mechanisms of multidrug resistance among german food-borne salmonella isolates of different serovars. | 2005 | 16227350 |
| recurrent infections caused by cefotaxime- and ciprofloxacin-resistant salmonella enterica serotype choleraesuis treated successfully with imipenem. | we present a case of recurrent infection (infective spondilitis, psoas abscess, and bacteraemia) caused by a single strain of cefotaxime- and ciprofloxacin-resistant and bla(cmy-2)-containing salmonella enterica serotype choleraesuis during a 4-month period in a patient with uremia. the patient was successfully treated with imipenem for 7 weeks. our observation indicates that a carbapenem might be considered as a drug of choice for the treatment of infections caused by this emerging multi-resist ... | 2005 | 16230198 |
| stationary-phase regulation of rpos translation in escherichia coli. | in enteric bacteria, adaptation to a number of different stresses is mediated by the rpos protein, one of several sigma factors that collectively allow a tailored transcriptional response to environmental cues. stress stimuli including low temperature, osmotic shock, nutrient limitation, and growth to stationary phase (sp) all result in a substantial increase in rpos abundance and activity. the mechanism of regulation depends on the specific signal but may occur at the level of transcription, tr ... | 2005 | 16237004 |
| resolvase-in vivo expression technology analysis of the salmonella enterica serovar typhimurium phop and pmra regulons in balb/c mice. | salmonella enterica modulates resistance to antimicrobial peptides in part via covalent modifications of the lipopolysaccharide (lps). the two-component systems phop/phoq and pmra/pmrb are activated during infection and regulate several genes involved in lps modifications by responding to signals such as ph, iron, magnesium, and antimicrobial peptides. a recombination-based in vivo expression technology approach was adopted to analyze the spatial-temporal patterns of in vivo expression of genes ... | 2005 | 16237024 |
| analysis of the contribution of salmonella pathogenicity islands 1 and 2 to enteric disease progression using a novel bovine ileal loop model and a murine model of infectious enterocolitis. | we have developed a novel ileal loop model for use in calves to analyze the contribution of salmonella enterica serovar typhimurium type iii secretion systems to disease processes in vivo. our model involves constructing ileal loops with end-to-end anastamoses to restore the patency of the small intestine, thereby allowing experimental animals to convalesce following surgery for the desired number of days. this model overcomes the time constraint imposed by ligated ileal loop models that have pr ... | 2005 | 16239510 |
| cd4+-t-cell responses generated during murine salmonella enterica serovar typhimurium infection are directed towards multiple epitopes within the natural antigen flic. | the flagellar filament protein flic is a natural antigen recognized by memory cd4+ t cells recovered from salmonella enterica serovar typhimurium-infected humans and mice. to further investigate t-cell responses to flic, we derived flic-specific cd4+-t-cell clones from mice of two different haplotypes following oral s. enterica serovar typhimurium infection. using c-terminal truncations of male-flic recombinant fusion proteins, we mapped antigenic activity to four different regions of flic; thre ... | 2005 | 16239517 |
| a strong antigen-specific t-cell response is associated with age and genetically dependent resistance to avian enteric salmonellosis. | chicken genetics and age affect resistance to enteric infection with salmonella enterica serovar typhimurium and were used to identify the immune responses that may contribute to rapid clearance. when birds were infected at 40 days of age, line 6(1) chickens cleared the infection more effectively than line n chickens, whereas when birds were infected at 10 days of age, both chicken lines were highly susceptible to infection. antibody levels, t-cell responsiveness, and cytokine mrna levels were a ... | 2005 | 16239553 |
| loop-mediated isothermal amplification for the rapid detection of salmonella. | loop-mediated isothermal amplification (lamp) assay detected salmonella within 60 min. the 220 strains of 39 serotypes of salmonella subsp. enterica and 7 strains of salmonella enterica subsp. arizonae were amplified, but not 62 strains of 23 bacterial species other than salmonella. the sensitivity of the lamp assay was found to be >2.2 cfu/test tube using nine serotypes. the specificity was similar to that of a pcr assay, but the sensitivity of lamp was greater. both fluorescence and turbidity ... | 2005 | 16242860 |
| bacterial histidine kinase as signal sensor and transducer. | adaptation to an environmental stress is essential for cell survival in all organisms, from e. coli to human. to respond to changes in their surroundings, bacteria utilize two-component systems (tcss), also known as histidyl-aspartyl phosphorelay (hap) systems that consist of a histidine kinase (hk) sensor and a cognate response regulator (rr). while mammals developed complex signaling systems involving serine/threonine/tyrosine kinases in stress response mechanisms, bacterial tcs/hap systems re ... | 2006 | 16242988 |
| increasing incidence of quinolone resistance in human non-typhoid salmonella enterica isolates in korea and mechanisms involved in quinolone resistance. | we investigated the trends of nalidixic acid resistance in human non-typhoid salmonella enterica in a korean population, and examined some possible mechanisms involved in this resistance. | 2005 | 16244086 |
| transgenic tobacco plants expressing a dimeric single-chain variable fragment (scfv) antibody against salmonella enterica serotype paratyphi b. | transgenic tobacco plants were produced that express an anti-salmonella enterica single-chain variable fragment (scfv) antibody that binds to the lipopolysaccharide (lps) of s. enterica paratyphi b. the coding sequence of this scfv was optimized for expression in tobacco, synthesized and subsequently placed behind three different promoters: an enhanced tobacco constitutive ubiquitous promoter (entcup4), and single- and double-enhancer versions of the cauliflower mosaic virus 35s promoter (camv 3 ... | 2005 | 16245169 |
| antimicrobial susceptibilities of salmonella isolates obtained from layer chicken houses on a commercial egg-producing farm in japan, 1997 to 2002. | susceptibility to antimicrobial agents was examined for 325 isolates of salmonella enterica serotypes cerro, infantis, livingstone, and montevideo isolated from layer houses on a commercial egg-production farm in the western region of japan between 1997 and 2002. no antimicrobials were used for therapeutic purposes on the farm during this period. from 1.8 to 3.1% of the isolates were resistant to ampicillin, chloramphenicol, and tetracycline. resistance to streptomycin and sulfisoxazole was foun ... | 2005 | 16245703 |
| antimicrobial effect of thai spices against listeria monocytogenes and salmonella typhimurium dt104. | the objective of this study was to determine the potential antimicrobial activity of extracts and essential oils of spices from thailand against foodborne pathogenic bacteria. the antimicrobial efficacy of ginger (zingiber officinale), fingerroot (boesenbergia pandurata), and turmeric (curcuma longa) was evaluated against five strains of listeria monocytogenes and four strains of salmonella enterica ssp. enterica serovar typhimurium dt104. antimicrobial activity was investigated in microbiologic ... | 2005 | 16245707 |
| effect of temperature, ph, and water activity on biofilm formation by salmonella enterica enteritidis pt4 on stainless steel surfaces as indicated by the bead vortexing method and conductance measurements. | an assay was developed in an effort to elucidate the effect of important environmental parameters (temperature, ph, and water activity [aw]) on salmonella enteritidis biofilm formation on stainless steel surfaces. to achieve this, a modified microbiological technique used for biofilm studying (the bead vortexing method) and a rapid method based on conductivity measurements were used. the ability of the microorganism to generate biofilm on the stainless surfaces was studied at three temperatures ... | 2005 | 16245722 |
| dna sequence and comparative genomics of papec-o2-r, an avian pathogenic escherichia coli transmissible r plasmid. | in this study, a 101-kb incf plasmid from an avian pathogenic escherichia coli (apec) strain (apec o2) was sequenced and analyzed, providing the first completed apec plasmid sequence. this plasmid, papec-o2-r, has functional transfer and antimicrobial resistance-encoding regions. the resistance-encoding region encodes resistance to eight groups of antimicrobial agents, including silver and other heavy metals, quaternary ammonium compounds, tetracycline, sulfonamides, aminoglycosides, trimethopri ... | 2005 | 16251312 |
| visualization of vacuolar acidification-induced transcription of genes of pathogens inside macrophages. | the objective of these studies was to analyze the role of the ionic environment of phagosomal vacuoles in the control of pathogens by macrophages. digital imaging and flow cytometry were used to follow the induction of the phop promoter of salmonella enterica typhimurium within live macrophages. manipulating the mg2+ concentration within the salmonella-containing vacuole (scv) was without effect on the early induction of phopq. moreover, direct measurement of [mg2+] within the scv using nanosens ... | 2006 | 16251362 |
| isolation, phage typing and antibiogram of salmonella from man and animals in northeastern india. | salmonella is an important zoonotic pathogen and its prevalence in the animals acts as a continuous threat to man. the present study was carried out to report the isolation along with the serotypes, phage types and antibiogram pattern of salmonella among man, livestock and poultry in the northeastern india. | 2005 | 16251781 |
| complete nucleotide sequence of pscv50, the virulence plasmid of salmonella enterica serovar choleraesuis sc-b67. | we carried out comparative analysis on the sequences of two 50-kb virulence plasmids of salmonella enterica serovar choleraesuis strains sc-b67 (pscv50) and rf-1 (pkdsc50). the two plasmids share over 99% sequence similarity. ninety-two nucleotide variations at 42 sites were detected between the two plasmids; pscv50 contains 24 nucleotide substitutions, 6 deletions, and 62 insertions, compared to pkdsc50. two regions in pscv50 appeared to be more susceptible to changes: one is the non-virulence- ... | 2006 | 16257053 |
| kinetic analysis of the antibacterial activity of probiotic lactobacilli towards salmonella enterica serovar typhimurium reveals a role for lactic acid and other inhibitory compounds. | six lactobacillus strains including commercial probiotic ones (l. acidophilus ibb 801, l. amylovorus dce 471, l. casei shirota, l. johnsonii la1, l. plantarum aca-dc 287 and l. rhamnosus gg) were investigated, through batch fermentations under controlled conditions, for their capacity to inhibit salmonella enterica serovar typhimurium sl1344. all lactobacilli displayed strong antibacterial activity toward this gram-negative pathogen and significantly inhibited invasion of the pathogen into cultu ... | 2006 | 16266797 |
| functional selection of a type iv pili-binding peptide that specifically inhibits salmonella typhi adhesion to/invasion of human monocytic cells. | salmonella enterica serovar typhi (s. typhi) is an important pathogen which infects humans exclusively and causes typhoid or enteric fever. recently it has been discovered that type ivb pili, encoded by the s. typhi pil operon located in the major pathogenicity island, may be important in the pathogenesis of epidemic enteric fever. to further investigate the roles of type ivb pili of s. typhi, a 12-mer peptide (rqersslskpvv), binding to the structural protein pils of the type ivb pili of s. typh ... | 2005 | 16269342 |
| cora affects tolerance of escherichia coli and salmonella enterica serovar typhimurium to the lactoperoxidase enzyme system but not to other forms of oxidative stress. | the enzyme lactoperoxidase is part of the innate immune system in vertebrates and owes its antimicrobial activity to the formation of oxidative reaction products from various substrates. in a previous study, we have reported that, with thiocyanate as a substrate, the lactoperoxidase system elicits a distinct stress response in escherichia coli mg1655. this response is different from but partly overlapping with the stress responses to hydrogen peroxide and to superoxide. in the current work, we c ... | 2005 | 16269676 |
| detection of salmonella enterica in naturally contaminated liquid eggs by loop-mediated isothermal amplification, and characterization of salmonella isolates. | loop-mediated isothermal amplification (lamp) assay was effective in detecting salmonella enterica in naturally contaminated liquid egg samples. salmonella was detected in 110 samples taken from four egg-breaking plants. the egg samples were pre-enriched in buffered peptone water (bpw) at 37 degrees c for 20 h. the selective enrichment was done in rappaport-vassiliadis or tetrathionate broth and plated onto xylose lysine deoxycholate agar and brilliant green agar, modified. in addition, the pcr ... | 2005 | 16269703 |
| development of a rapid method for simultaneous recovery of diverse microbes in drinking water by ultrafiltration with sodium polyphosphate and surfactants. | the ability to simultaneously concentrate diverse microbes is an important consideration for sample collection methods that are used for emergency response and environmental monitoring when drinking water may be contaminated with an array of unknown microbes. this study focused on developing a concentration method using ultrafilters and different combinations of a chemical dispersant (sodium polyphosphate [napp]) and surfactants. tap water samples were seeded with bacteriophage ms2, escherichia ... | 2005 | 16269722 |
| capsular polysaccharide surrounds smooth and rugose types of salmonella enterica serovar typhimurium dt104. | the biofilms and rugose colony morphology of salmonella enterica serovar typhimurium strains are usually associated with at least two different exopolymeric substances (eps), curli and cellulose. in this study, another eps, a capsular polysaccharide (cp) synthesized constitutively in s. enterica serovar typhimurium strain dt104 at 25 and 37 degrees c, has been recognized as a biofilm matrix component as well. fluorophore-assisted carbohydrate electrophoresis (face) analysis indicated that the cp ... | 2005 | 16269777 |
| typhoid and paratyphoid fever. | | 2005 | 16271634 |
| peptidoglycan degradation by specialized lytic transglycosylases associated with type iii and type iv secretion systems. | specialized lytic transglycosylases are muramidases capable of locally degrading the peptidoglycan meshwork of gram-negative bacteria. specialized lytic transglycosylase genes are present in clusters encoding diverse macromolecular transport systems. this paper reports the analysis of selected members of the specialized lytic transglycosylase family from type iii and type iv secretion systems. these proteins were analysed in vivo by assaying their ability to complement the dna transfer defect of ... | 2005 | 16272370 |
| acetate excretion during growth of salmonella enterica on ethanolamine requires phosphotransacetylase (eutd) activity, and acetate recapture requires acetyl-coa synthetase (acs) and phosphotransacetylase (pta) activities. | this report shows that salmonella enterica catabolizes ethanolamine to acetyl-coa (ac-coa), which enters the glyoxylate bypass and tricarboxylic acid cycle for the generation of energy and central metabolites. during growth on ethanolamine, s. enterica excreted acetate, whose recapture depended on ac-coa synthetase (acs) and the housekeeping phosphotransacetylase (pta) enzyme activities. the pta enzyme did not play a role in acetate excretion during growth of s. enterica on ethanolamine. it is p ... | 2005 | 16272400 |
| use of biochemical kinetic data to determine strain relatedness among salmonella enterica subsp. enterica isolates. | classical biotyping characterizes strains by creating biotype profiles that consider only positive and negative results for a predefined set of biochemical tests. this method allows salmonella subspecies to be distinguished but does not allow serotypes and phage types to be distinguished. the objective of this study was to determine the relatedness of isolates belonging to distinct salmonella enterica subsp. enterica serotypes by using a refined biotyping process that considers the kinetics at w ... | 2005 | 16272463 |
| new quinolone resistance phenomenon in salmonella enterica: nalidixic acid-susceptible isolates with reduced fluoroquinolone susceptibility. | we describe the emergence of a new quinolone resistance pattern in salmonella enterica isolates from southeast asia. these isolates are susceptible to nalidixic acid but exhibit reduced susceptibility to ciprofloxacin. the increase of such strains may threaten the value of the nalidixic acid disk test to screen for reduced fluoroquinolone susceptibility in salmonellas. | 2005 | 16272517 |
| detection of a bla(shv) extended-spectrum {beta}-lactamase in salmonella enterica serovar newport mdr-ampc. | salmonella enterica serovar newport mdr-ampc expressing tem-1b and extended-spectrum beta-lactamase shv-12 was isolated from affected animals during an outbreak of salmonellosis that led to a 3-month closure of one of the largest equine hospitals in the united states. | 2005 | 16272522 |
| finding the sources of korean salmonella enterica serovar enteritidis pt 4 isolates by pulsed-field gel electrophoresis. | in previous studies, it has been reported that both s. enteritidis, the most common serotype, and s. enteritidis phage type 4 (sept 4) isolates were identified as the most prevalent pt in domestic poultry and also in humans in korea until 2002. the aim of this study was to analyze the genetic diversity and epidemiological properties of both pt isolates, and also to trace the source of sept 4 isolates from domestic poultry and humans by pulsed-field gel electrophoresis (pfge). in order to underst ... | 2005 | 16273034 |
| feline cholecystitis and acute neutrophilic cholangitis: clinical findings, bacterial isolates and response to treatment in six cases. | clinicopathological findings from six cats with confirmed cholecystitis or acute neutrophilic cholangitis are presented. historical findings included lethargy and anorexia or inappetence of up to five days duration. on physical examination all cats were pyrexic and four out of six were jaundiced and had cranial abdominal pain. bile samples were obtained by cholecystocentesis at exploratory coeliotomy (two cases) or by percutaneous, ultrasound-guided cholecystocentesis (four cases). gall bladder ... | 2006 | 16278090 |
| expression of cellulose and curli fimbriae by escherichia coli isolated from the gastrointestinal tract. | escherichia coli colonizes the gastrointestinal tract of humans; however, little is known about the features of commensal strains. this study investigated whether expression of the biofilm extracellular matrix components cellulose and curli fimbriae is found among commensal isolates. fifty-two e. coli strains were isolated from faecal samples and, as a control, 24 strains from urinary tract infections were also used. faecal isolates were characterized by serotyping and phylogenetically grouped b ... | 2005 | 16278431 |
| quenched autoligation probes allow discrimination of live bacterial species by single nucleotide differences in rrna. | quenched autoligation (qual) probes are a class of self-reacting nucleic acid probes that give strong fluorescence signal in the presence of fully complementary rnas and selectivity against single nucleotide differences in solution. here, we describe experiments designed to test whether qual probes can discriminate between bacterial species by the detection of small differences in their 16s rrna sequences. probes were introduced into live cells using small amounts of detergent, thus eliminating ... | 2005 | 16284198 |
| molecular epidemiology of emergent multidrug-resistant salmonella enterica serotype typhimurium strains carrying the virulence resistance plasmid puo-stvr2. | to evaluate the incidence of a distinct multidrug-resistant (mdr) grouping of salmonella serotype typhimurium strains carrying the hybrid virulence resistance plasmid puo-stvr2, and its possible evolution in the region where it was first detected [principality of asturias (pa), spain]. | 2006 | 16286360 |
| retron reverse transcriptase (rrtt) can be lost in multidrug resistant salmonella enterica serovar typhimurium dt 104 strains and influences virulence for mice. | in salmonella enterica serovar typhimurium, retron reverse transcriptase (rrtt), which is part of st 85 retron, is quite ubiquitous and is located in the thdf -yidy intergenic region. in this study, we showed that rrtt is relatively unstable in multidrug resistant, salmonella genomic island 1 (sgi 1) positive strains. out of 365 field strains, 55 were free of retron. in 54 of the rrtt negative strains, the excision must have occurred by the same mechanism in which the rrtt together with five oth ... | 2005 | 16289543 |
| molecular analysis of salmonella enterica subsp. enterica serovar agona isolated from slaughter pigs. | salmonella enterica subsp. enterica (s.) serovar agona plays an important role in brazil as causative agent of salmonellosis in food-producing animals - in particular, pigs and poultry - as well as in humans. a total of 45 s. agona isolates collected from slaughter pigs at three different slaughterhouses in southern brazil was investigated in this study for their phenotypic and genotypic relatedness. for this, the antimicrobial susceptibility patterns and the phage types were determined. molecul ... | 2006 | 16289951 |
| increased excision of the salmonella prophage st64b caused by a deficiency in dam methylase. | salmonella enterica mutants defective in dam methylase are strongly attenuated in virulence and release a large amount of proteins to the extracellular medium. the extent to which these two phenotypes are linked is unknown. using a proteomic approach, we identified sb6, sb13, and sb36 as proteins present in larger amounts in culture supernatants of an s. enterica serovar typhimurium dam mutant than in those of the wild-type strain. these three proteins are encoded in the salmonella prophage st64 ... | 2005 | 16291663 |
| minimal functions and physiological conditions required for growth of salmonella enterica on ethanolamine in the absence of the metabolosome. | during growth on ethanolamine, salmonella enterica synthesizes a multimolecular structure that mimics the carboxysome used by some photosynthetic bacteria to fix co(2). in s. enterica, this carboxysome-like structure (hereafter referred to as the ethanolamine metabolosome) is thought to contain the enzymatic machinery needed to metabolize ethanolamine into acetyl coenzyme a (acetyl-coa). analysis of the growth behavior of mutant strains of s. enterica lacking specific functions encoded by the 17 ... | 2005 | 16291677 |
| a degenerate type iii secretion system from septicemic escherichia coli contributes to pathogenesis. | the type iii secretion system (t3ss) is an important virulence factor used by several gram-negative bacteria to deliver effector proteins which subvert host cellular processes. enterohemorrhagic escherichia coli o157 has a well-defined t3ss involved in attachment and effacement (ett1) and critical for virulence. a gene cluster potentially encoding an additional t3ss (ett2), which resembles the spi-1 system in salmonella enterica, was found in its genome sequence. the ett2 gene cluster has since ... | 2005 | 16291689 |
| acute renal failure likely due to acute nephritic syndrome associated with typhoid fever. | a 45-year-old woman was admitted to our hospital because of high fever and malaise. she also presented abnormal urine findings including macrohematuria and proteinuria with transient renal insufficiency. salmonella typhi was isolated from her blood and stool culture, and then she was diagnosed as having typhoid fever. salmonella enterica serotype typhi infection can be complicated by renal involvement, although rare. in japan, few cases have been reported about acute nephritic syndrome in typhoi ... | 2005 | 16293920 |
| host restriction of salmonella enterica serotype typhi is not caused by functional alteration of sipa, sopb, or sopd. | salmonella enterica serotype typhi is a strictly human adapted pathogen that does not cause disease in nonprimate vertebrate hosts, while salmonella enterica serotype typhimurium is a broad-host-range pathogen. serotype typhi lacks some of the proteins (effectors) exported by the invasion-associated type iii secretion system that are required by serotype typhimurium for eliciting fluid secretion and inflammation in bovine ligated ileal loops. we investigated whether the remaining serotype typhi ... | 2005 | 16299271 |
| identification of core and variable components of the salmonella enterica subspecies i genome by microarray. | we have performed microarray hybridization studies on 40 clinical isolates from 12 common serovars within salmonella enterica subspecies i to identify the conserved chromosomal gene pool. we were able to separate the core invariant portion of the genome by a novel mathematical approach using a decision tree based on genes ranked by increasing variance. all genes within the core component were confirmed using available sequence and microarray information for s. enterica subspecies i strains. the ... | 2005 | 16299280 |
| increased sensitivity to salmonella enterica serovar typhimurium infection in mice undergoing withdrawal from morphine is associated with suppression of interleukin-12. | we have shown previously that withdrawal from morphine induces immunosuppression in mice. the present study reports the effects of morphine withdrawal on infection with salmonella enterica serovar typhimurium. mice were made dependent on morphine by the implantation of a slow-release morphine pellet for 96 h. controls received a placebo pellet. withdrawal was induced by pellet removal. mice were inoculated intraperitoneally with salmonella 24 h postwithdrawal. morphine withdrawal sensitized mice ... | 2005 | 16299287 |
| h2-m3 major histocompatibility complex class ib-restricted cd8 t cells induced by salmonella enterica serovar typhimurium infection recognize proteins released by salmonella serovar typhimurium. | salmonella enterica serovar typhimurium causes a typhoid-like disease in mice which has been studied extensively as a model for typhoid fever in humans. cd8 t cells contribute to protection against s. enterica serovar typhimurium in mice, but little is known about the specificity and major histocompatibility complex (mhc) restriction of the response. we report here that cd8 t-cell lines derived from s. enterica serovar typhimurium-infected balb/c mice lysed bone marrow macrophages infected with ... | 2005 | 16299293 |
| novel attenuated salmonella enterica serovar choleraesuis strains as live vaccine candidates generated by signature-tagged mutagenesis. | salmonella enterica serovar choleraesuis is a host-adapted pathogen that causes swine paratyphoid. signature-tagged mutagenesis (stm) was used to understand the pathogenicity of s. enterica serovar choleraesuis in its natural host and also to develop novel attenuated live vaccine candidates against this disease. a library of 960 signature-tagged mutants of s. enterica serovar choleraesuis was constructed and screened for attenuation in pigs. thirty-three mutants were identified by the stm screen ... | 2005 | 16299315 |
| attenuation of salmonella enterica serovar typhimurium by altering biological functions of murein lipoprotein and lipopolysaccharide. | we constructed salmonella enterica serovar typhimurium double-knockout mutants in which either the lipoprotein a (lppa) or the lipoprotein b (lppb) gene was deleted from an msbb-negative background strain by marker exchange mutagenesis. these mutants were highly attenuated when tested with in vitro and in vivo models of salmonella pathogenesis. | 2005 | 16299345 |
| a simple method for the direct detection of salmonella and escherichia coli o157:h7 from raw alfalfa sprouts and spent irrigation water using pcr. | the u.s. food and drug administration recognizes that raw seed sprouts are an important cause of foodborne disease and is now recommending that either spent irrigation water or final product be screened for salmonella and escherichia coli o157:h7 as a means of assuring the safety of product intended for consumption. in an effort to streamline such testing efforts, a simple method to preconcentrate pathogens from sprouts and spent irrigation water was investigated to facilitate the direct (withou ... | 2005 | 16300060 |
| cross-protective immunity in calves conferred by a dna adenine methylase deficient salmonellaenterica serovar typhimurium vaccine. | the global trend towards intensive livestock production is associated with increased fecal oral pathogen transmission resulting in a high prevalence of salmonella. since many pathogenic salmonella serovars are often endemic to livestock production systems, it is desirable to develop a vaccine that is capable of eliciting immunity to more than one serovar. here we examined whether immunization with a modified live salmonella enterica serovar typhimurium vaccine strain lacking the dna adenine meth ... | 2006 | 16300866 |
| negative regulation of salmonella pathogenicity island 2 is required for contextual control of virulence during typhoid. | salmonella enterica relies on a type iii secretion system encoded in salmonella pathogenicity island-2 (spi-2) to survive and replicate within macrophages at systemic sites during typhoid. spi-2 virulence is induced upon entry into macrophages, but the mechanisms of spi-2 gene control in vivo remain unclear, particularly with regard to negative regulators that control the contextual activation of spi-2. here, we identified and characterized ydgt as a negative modulator of the spi-2 pathogenicity ... | 2005 | 16301528 |
| evidence for the requirement for cd40-cd154 interactions in resistance to infections with attenuated salmonella. | salmonella species include facultative intracellular pathogens which reside preferentially within cells of the host's reticulo-endothelial system. resistance to salmonella involves a collaboration between cells of the innate and adaptive immune systems, and protective immunity requires cell-mediated and humoral-immune responses. cd40-cd154 interactions are of central importance in the induction of cellular immune responses. in the present study, cd154-deficient (cd154(-/-)) mice were used to ass ... | 2005 | 16303097 |
| distribution and function of plasmids in salmonella enterica. | plasmids of salmonella enterica vary in size from 2 to more than 200 kb. the best described group of plasmids are the virulence plasmids (50-100 kb in size) present in serovars enteritidis, typhimurium, dublin, cholerae-suis, gallinarum, pullorum and abortus-ovis. they all encode spvrabcd genes involved in intra-macrophage survival of salmonella. another group of high molecular weight plasmids are plasmids responsible for antibiotic resistance. since most of these plasmids are conjugative, besid ... | 2006 | 16303262 |
| salmonella pathogenicity island 2 is expressed prior to penetrating the intestine. | salmonella enterica serovar typhimurium is a facultative intracellular pathogen that causes disease in mice that resembles human typhoid. typhoid pathogenesis consists of distinct phases in the intestine and a subsequent systemic phase in which bacteria replicate in macrophages of the liver and spleen. the type iii secretion system encoded by salmonella pathogenicity island 2 (spi-2) is a major virulence factor contributing to the systemic phase of typhoid pathogenesis. understanding how pathoge ... | 2005 | 16304611 |
| thermal tolerance of acid-adapted and unadapted salmonella, escherichia coli o157:h7, and listeria monocytogenes in cantaloupe juice and watermelon juice. | a study was performed to determine d values of acid-adapted and unadapted cells of salmonella, escherichia coli o157:h7, and listeria monocytogenes in cantaloupe juice and watermelon juice. | 2005 | 16305669 |
| resuscitation of acid-injured salmonella in enrichment broth, in apple juice and on the surfaces of fresh-cut cucumber and apple. | to investigate the resuscitation of acid-injured salmonella enterica in selected enrichment broths, in apple juice and on cut surfaces of apple and cucumber slices. | 2005 | 16305675 |
| pulsed-field gel electrophoresis, plasmid profiles and phage types for the human isolates of salmonella enterica serovar enteritidis obtained over 13 years in taiwan. | plasmid profile, phage typing, and pulsed-field gel electrophoresis (pfge) patterns of 124 salmonella enteritidis strains isolated in 1998-2002 in taiwan were analysed and the results were compared with those of the 63 strains obtained in 1991-1997, so that molecular subtypes and epidemic strains for salmonella enteritidis over a 13-year period (1991-2002) could be elucidated. | 2005 | 16313420 |
| bapa, a large secreted protein required for biofilm formation and host colonization of salmonella enterica serovar enteritidis. | in environmental settings, biofilms represent the common way of life of microorganisms. salmonella enterica serovar enteritidis, the most frequent cause of gastroenteritis in developed countries, produces a biofilm whose matrix is mainly composed of curli fimbriae and cellulose. in contrast to other bacterial biofilms, no proteinaceous compound has been reported to participate in the formation of this matrix. here, we report the discovery of bapa, a large cell-surface protein required for biofil ... | 2005 | 16313619 |
| vaccination of pregnant ewes against infection with salmonella brandenburg. | to develop a challenge model for salmonella brandenburg infection in pregnant ewes. to compare efficacies of a live attenuated salmonella typhimurium mutant, a subunit preparation from a virulent s. brandenburg isolate, and a commercial multivalent inactivated vaccine in their ability to prevent experimental s. brandenburg infection. to assess the efficacy of the live attenuated s. typhimurium mutant against natural s. brandenburg infection in lambs. | 2005 | 16317442 |
| infections associated with cantaloupe consumption: a public health concern. | fresh produce is an important part of a healthy diet and is consumed in greater quantity in the united states than ever before. consumption of cantaloupe has recently been associated with several large outbreaks of infections in north america, highlighting the need for a better understanding of practices and processes that may contribute to contamination. we reviewed all cantaloupe-associated outbreaks that were reported to the centers for disease control and prevention (cdc) and published in th ... | 2006 | 16318654 |
| salmonella paratyphi a rates, asia. | little is known about the causes of enteric fever in asia. most cases are believed to be caused by salmonella enterica serovar typhi and the remainder by s. paratyphi a. we compared their incidences by using standardized methods from population-based studies in china, indonesia, india, and pakistan. | 2005 | 16318734 |
| 1-deoxy-d-xylulose 5-phosphate reductoisomerase (ispc) from mycobacterium tuberculosis: towards understanding mycobacterial resistance to fosmidomycin. | 1-deoxy-d-xylulose 5-phosphate reductoisomerase (ispc) catalyzes the first committed step in the mevalonate-independent isopentenyl diphosphate biosynthetic pathway and is a potential drug target in some pathogenic bacteria. the antibiotic fosmidomycin has been shown to inhibit ispc in a number of organisms and is active against most gram-negative bacteria but not gram positives, including mycobacterium tuberculosis, even though the mevalonate-independent pathway is the sole isopentenyl diphosph ... | 2005 | 16321944 |
| multiresistant shv-2-producing salmonella enterica serotype corvallis in bulgaria. | | 2005 | 16323450 |
| mucosal innate immune response to intragastric infection by salmonella enterica serovar choleraesuis. | the innate immune response is critical to enteric disease resistance and the induction of mucosal adaptive immunity. in mucosae of the small intestine, peyer's patches play a central role in immune surveillance and sampling of bacteria by specialized m cells. the innate immune response to salmonella enterica serovar choleraesuis, an enteric pathogen of swine, involves il-1beta and il-8 mrna induction but not that of il-6 and tnfalpha, in contrast to salmonella serovar typhimurium infection of mu ... | 2006 | 16325910 |
| differential effects of clathrin and actin inhibitors on internalization of escherichia coli and salmonella choleraesuis in porcine jejunal peyer's patches. | peyer's patches constitute both an inductive immune site and an enteropathogen invasion route. peyer's patch mucosae from porcine jejunum were mounted in ussing chambers, and either salmonella choleraesuis vaccine strain sc-54 or non-pathogenic rodent and porcine escherichia coli strains contacted the peyer's patch mucosa for 90 min. internalized bacteria were quantified by a gentamicin resistance assay. monodansylcadaverine (300 microm, luminal addition), an inhibitor of clathrin-mediated endoc ... | 2006 | 16326046 |
| solution structure of yggx: a prokaryotic protein involved in fe(ii) trafficking. | we report the three-dimensional structure of yggx from salmonella enterica, determined by solution nuclear magnetic resonance (nmr) spectroscopy from protein labeled with carbon-13 and nitrogen-15 produced by escherichia coli cells. the protein has a beta1beta2alpha1alpha2alpha3 fold that is unique to yggx and one of its homologs, a protein from pseudomonas aeruginosa with 45% sequence identity whose x-ray structure [protein data bank (pdb) 1t07] was determined by a structural genomics center. t ... | 2006 | 16329120 |
| [mechanism of acrab-tolc system mediated multiple antimicrobial resistance in salmonella typhimurium]. | to confirm acrab-tolc system mediated the multiple antimicrobial resistance in salmonella typhimurium. | 2005 | 16329607 |
| cost-effective application of pulsed-field gel electrophoresis to typing of salmonella enterica serovar typhimurium. | salmonella enterica serovar typhimurium is frequently isolated from humans and animals. phage typing is historically the first-line reference typing technique in europe. it is rapid and convenient for laboratories with appropriate training and experience, and costs of consumables are low. phage typing and pulsed-field gel electrophoresis (pfge) were performed on 503 isolates of serovar typhimurium. twenty-nine phage types and 53 pfge patterns were observed. most isolates of phage types dt104, dt ... | 2005 | 16332808 |
| timing of induction of osmotically controlled genes in salmonella enterica serovar typhimurium, determined with quantitative real-time reverse transcription-pcr. | the signals that control the transcription of osmoregulated genes are not understood satisfactorily. the "turgor control model" suggested that the primary osmoregulatory signal in enterobacteriaceae is turgor loss, which induces the kdp k+ transport operon and activates the trk k+ permease. the ensuing increase in cytoplasmic k+ concentration was proposed to be the signal that turns on all secondary responses, including the induction of the prou (proline-glycine betaine transport) operon. the "i ... | 2005 | 16332813 |
| waterborne pathogen detection by use of oligonucleotide-based microarrays. | a small-oligonucleotide microarray prototype was designed with probes specific for the universal 16s rrna and cpn60 genes of several pathogens that are usually encountered in wastewaters. in addition to these two targets, wece-specific oligonucleotide probes were included in the microarray to enhance its discriminating power within the enterobacteriaceae family. universal pcr primers were used to amplify variable regions of 16s rrna, cpn60, and wece genes directly in escherichia coli and salmone ... | 2005 | 16332846 |
| propionate-regulated high-yield protein production in escherichia coli. | a new expression system containing the salmonella enterica prpbcde promoter (p(prpb)) responsible for expression of the propionate catabolic genes (prp bcde) and prpr encoding the positive regulator of this promoter has been developed and tested. the main features of the expression system compared to those based on the bacteriophage t7 promoter are low background expression and high induced expression in escherichia coli strains bl21, bl21(de3), mg1655, and w3110. in addition, propionate is an i ... | 2006 | 16333863 |
| distribution of salmonella enterica serovars from humans, livestock and meat in vietnam and the dominance of salmonella typhimurium phage type 90. | epidemiologically unrelated non-typhoid salmonella isolates from humans (n = 56) and animal origin (n = 241, from faeces, carcasses and meat) in vietnam were investigated. salmonella typhimurium, s. anatum, s. weltevreden, s. emek, and s. rissen were the most prevalent serovars. s. typhimurium phage type 90 was predominant among s. typhimurium isolates. the serotype and phage type distribution of the salmonella isolates was different from that in europe and america. many sero- and phage types fo ... | 2006 | 16337754 |
| glycogen production by different salmonella enterica serotypes: contribution of functional glgc to virulence, intestinal colonization and environmental survival. | in enteric bacteria, the contribution of endogenous energy sources to survival both inside and outside the host is poorly understood. the contribution of glycogen production to the virulence, colonization and environmental survival of different salmonella enterica serotypes was assessed. of 19 serotypes (339 strains) tested for glycogen production, 17 (256 strains) were positive. the avian-specific serovars s. gallinarum (62 strains) and s. pullorum (21 strains) did not produce glycogen. the seq ... | 2005 | 16339941 |
| dimerization and dna binding of the salmonella enterica phop response regulator are phosphorylation independent. | in salmonella enterica, phop is the response regulator of the phop/phoq two-component regulatory system that controls the expression of various virulence factors in response to external mg2+. previous studies have shown that phosphorylation of a phop variant with a c-terminal his tag (phop(his)) enhances dimerization and binding to target dna. here, the effect of phosphorylation on the oligomerization and dna binding properties of both wild-type phop (phop) and phop(his) are compared. gel filtra ... | 2005 | 16339942 |
| a slow, tight-binding inhibitor of the zinc-dependent deacetylase lpxc of lipid a biosynthesis with antibiotic activity comparable to ciprofloxacin. | the zinc-dependent enzyme lpxc catalyzes the deacetylation of udp-3-o-acyl-glcnac, the first committed step of lipid a biosynthesis. lipid a is an essential component of the outer membranes of most gram-negative bacteria, including escherichia coli, salmonella enterica, and pseudomonas aeruginosa, making lpxc an attractive target for antibiotic design. the inhibition of lpxc by a novel n-aroyl-l-threonine hydroxamic acid (chir-090) from a recent patent application (international patent wo 2004/0 ... | 2005 | 16342948 |
| salmonella infections in the setting of aids: a serpentine course. | | 2005 | 16351025 |
| mural endocarditis caused by salmonella virchow: survival with conservative treatment. | we describe a case of endocarditis caused by salmonella enterica serotype virchow, which was treated conservatively with antibiotics alone. it is the only reported case of survival from salmonella endocarditis with conservative treatment, and the first reported case of endocarditis caused by salmonella virchow. the changing prevalence, virulence patterns and importance of salmonella species in endocarditis are discussed. | 2001 | 16352056 |
| a high-performance liquid chromatography-tandem mass spectrometry method for quantitation of nitrogen-containing intracellular metabolites. | a comprehensive method of quantifying intracellular metabolite concentrations would be a valuable addition to the arsenal of tools for holistic biochemical studies. here, we describe a step toward the development of such method: a quantitative assay for 90 nitrogen-containing cellular metabolites. the assay involves reverse-phase high-performance liquid chromatography separation followed by electrospray ionization and detection of the resulting ions using triple-quadrupole mass spectrometry in s ... | 2006 | 16352439 |
| genetic relatedness of a rarely isolated salmonella: salmonella enterica serotype niakhar from narms animal isolates. | in the united states, salmonella enterica serotype niakhar is infrequently isolated. between 1997 and 2000, the animal arm of the national antimicrobial resistance monitoring system-enteric bacteria (narms) assayed a total of 22,383 salmonella isolates from various animal sources (swine, cattle, chickens, turkeys, cats, horses, exotics and dogs) for antimicrobial susceptibility. isolates originated from diagnostic and non-diagnostic submissions. | 2006 | 16352736 |
| genetic transplantation: salmonella enterica serovar typhimurium as a host to study sigma factor and anti-sigma factor interactions in genetically intractable systems. | in salmonella enterica serovar typhimurium, sigma(28) and anti-sigma factor flgm are regulatory proteins crucial for flagellar biogenesis and motility. in this study, we used s. enterica serovar typhimurium as an in vivo heterologous system to study sigma(28) and anti-sigma(28) interactions in organisms where genetic manipulation poses a significant challenge due to special growth requirements. the chromosomal copy of the s. enterica serovar typhimurium sigma(28) structural gene flia was exchang ... | 2006 | 16352826 |
| role of salmonella enterica serovar typhimurium two-component system prea/preb in modulating pmra-regulated gene transcription. | the pmra/pmrb two-component system encoded by the pmrcab operon regulates the modification of salmonella enterica serovar typhimurium lipopolysaccharide leading to polymyxin b resistance. pmra and phop are the only known activators of pmrcab. a transposon mutagenesis screen for additional regulators of a pmrc::mudj fusion led to the identification of a two-component system, termed prea/preb (pmrcab regulators a and b), that controls the transcription of the pmrcab operon in response to unknown s ... | 2006 | 16352830 |
| the pseudomonas aeruginosa lipid a deacylase: selection for expression and loss within the cystic fibrosis airway. | lipopolysaccharide (lps) is the major surface component of gram-negative bacteria, and a component of lps, lipid a, is recognized by the innate immune system through the toll-like receptor 4/md-2 complex. pseudomonas aeruginosa, an environmental gram-negative bacterium that opportunistically infects the respiratory tracts of patients with cystic fibrosis (cf), can synthesize various structures of lipid a. lipid a from p. aeruginosa strains isolated from infants with cf has a specific structure t ... | 2006 | 16352835 |
| comparative and functional genomic analysis of prokaryotic nickel and cobalt uptake transporters: evidence for a novel group of atp-binding cassette transporters. | the transition metals nickel and cobalt, essential components of many enzymes, are taken up by specific transport systems of several different types. we integrated in silico and in vivo methods for the analysis of various protein families containing both nickel and cobalt transport systems in prokaryotes. for functional annotation of genes, we used two comparative genomic approaches: identification of regulatory signals and analysis of the genomic positions of genes encoding candidate nickel/cob ... | 2006 | 16352848 |
| salmonella enterica serotypes isolated from imported frozen chicken meat in the canary islands. | to determine the prevalence of salmonella enterica serotypes in imported frozen chicken meat, 406 samples (whole chicken, legs, and breast meat) were analyzed for salmonella according to iso6579 rules, serotypes were assigned, and phage typing was conducted for salmonella serotypes enteritidis, typhimurium, and heidelberg. the overall frequency of salmonella isolation was 16.5%. by country of origin, the highest percentage of cases was found among the samples from france followed by samples from ... | 2005 | 16355846 |
| virulence and drug resistance roles of multidrug efflux systems of salmonella enterica serovar typhimurium. | drug efflux systems play a major role in resistance to a wide range of noxious compounds in several gram negative species. here, we report the drug resistance and virulence phenotypes of salmonella mutants defective in either resistance-nodulation-division (rnd)-type systems and/or in drug efflux systems belonging to the major facilitator (mfs), multidrug and toxic compound extrusion (mate), and atp-binding cassette (abc) superfamilies. we determined that nine potential drug transporters contrib ... | 2006 | 16359323 |
| coordinated expression and immunogenicity of an outer membrane protein from salmonella enterica serovar typhi under iron limitation, oxidative stress and anaerobic conditions. | successful pathogens overcome the environmental stresses by the coordinated expression of various genes and eventually proteins. since, the surface of the microbe is likely to come in contact with the host initially, an attempt was made to identify the outer membrane proteins (omps), if any, which may get expressed under more than one environmental conditions simulating the in vivo ones. in the present study, salmonella enterica serovar typhi was grown under iron-limited, oxidative stress as wel ... | 2006 | 16362827 |
| identification of an aada2 gene cassette from salmonella enterica subsp. enterica serovar derby. | during a study on salmonella enterica subsp. enterica serovar derby from slaughter-age pigs in brazil, two epidemiologically unrelated multi-resistant s. derby isolates were found to carry a class 1 integron with a single gene cassette. sequence analysis confirmed that this gene cassette harboured an aada2 gene. the aada2 gene codes for an aminoglycoside adenyltransferase, which mediates resistance to the aminoglycoside streptomycin and the aminocyclitol spectinomycin. although aada2 gene casset ... | 2005 | 16364021 |
| analysis of porcine differential gene expression following challenge with salmonella enterica serovar choleraesuis using suppression subtractive hybridization. | swine-adapted salmonella enterica subsp. enterica serovar choleraesuis (s. choleraesuis) is the pathogen most frequently isolated from diseased pigs and may affect host gene expression in a species-specific manner. to characterize the porcine transcriptional response to s. choleraesuis infection, the mrna profiles from the mesenteric lymph nodes of three non-infected and three experimentally infected pigs at 24 h post-inoculation were analyzed by suppression subtractive hybridization (ssh). fort ... | 2006 | 16364571 |
| cd154 is essential for protective immunity in experimental salmonella infection: evidence for a dual role in innate and adaptive immune responses. | cd40-cd154 interactions are of central importance in the induction of humoral and cellular immune responses. in the present study, cd154-deficient (cd154-/-) mice were used to assess the role of cd40-cd154 interactions in regulating the immune response to a systemic salmonella infection. compared with c57bl/6 (cd154+/+) controls, cd154-/- mice were hypersusceptible to infection by an attenuated strain of salmonella enterica serovar typhimurium (s. typhimurium), as evidenced by decreased survival ... | 2006 | 16365443 |
| evaluation of the lon-deficient salmonella strain as an oral vaccine candidate. | we evaluated the efficacy of cs2022 (the lon protease-deficient mutant strain of salmonella enterica serovar typhimurium) as a candidate live oral vaccine strain against subsequent oral challenge with a virulent strain administered to balb/c and c57bl/6 mice. cs2022 persistently resided in the spleen, mesenteric lymph nodes, peyer's patches, and cecum of both strains of mice after a single oral inoculation with 1 x 10(8) colony-forming units. finally, cs2022 almost disappeared from each tissue s ... | 2005 | 16365528 |
| characterization of escherichia coli and salmonella enterica from cattle feed ingredients. | the objectives of this study were (1) to evaluate the frequency with which feed ingredients or mixed feeds in cattle feedlots were contaminated with escherichia coli and salmonella spp. and (2) to evaluate the antimicrobial susceptibility patterns of non-type-specific escherichia coli and salmonella spp. recovered from feed ingredients or mixed feeds. approximately 30 individual samples were collected from each of several feed commodities present on two cattle feedlots each month for 1 year. hal ... | 2005 | 16366856 |
| identification of csrc and characterization of its role in epithelial cell invasion in salmonella enterica serovar typhimurium. | the csr regulatory system of salmonella regulates the expression of the genes of salmonella pathogenicity island 1 (spi1) required for the invasion of epithelial cells. this system consists of the posttranscriptional regulator csra and an untranslated regulatory rna, csrb, that opposes the action of csra. here we identify and characterize the role of a second regulatory rna, csrc, whose ortholog was discovered previously in escherichia coli. we show that a mutant of csrc has only mild defects in ... | 2006 | 16368988 |
| identification and characterization of a novel bacterial virulence factor that shares homology with mammalian toll/interleukin-1 receptor family proteins. | many important bacterial virulence factors act as mimics of mammalian proteins to subvert normal host cell processes. to identify bacterial protein mimics of components of the innate immune signaling pathway, we searched the bacterial genome database for proteins with homology to the toll/interleukin-1 receptor (tir) domain of the mammalian toll-like receptors (tlrs) and their adaptor proteins. a previously uncharacterized gene, which we have named tlpa (for tir-like protein a), was identified i ... | 2006 | 16369016 |
| virulence of broad- and narrow-host-range salmonella enterica serovars in the streptomycin-pretreated mouse model. | salmonella enterica subspecies i serovars are common bacterial pathogens causing diseases ranging from enterocolitis to systemic infections. some serovars are adapted to specific hosts, whereas others have a broad host range. the molecular mechanisms defining the virulence characteristics and the host range of a given s. enterica serovar are unknown. streptomycin pretreated mice provide a surrogate host model for studying molecular aspects of the intestinal inflammation (colitis) caused by serov ... | 2006 | 16369020 |
| antibacterial activity of polygodial. | polygodial was found to possess moderate antibacterial activity against gram-positive bacteria including bacillus subtilis, staphylococcus aureus and gram-negative bacteria including escherichia coli and salmonella choleraesuis with minimum bactericidal concentrations (mbc) of 100 and 100 microg/ml (0.34 mm) and 100 and 50 microg/ml, respectively. the time kill curve study showed that polygodial was bactericidal against b. subtilis and s. choleraesuis. however, there was a difference in its bact ... | 2005 | 16372365 |
| the expression of the virulence-associated effector protein gene avra is dependent on a salmonella enterica-specific regulatory function. | although the avra gene is prevalent among 80% of the salmonella enterica serovars, only a small number of them usually express the respective virulence-associated effector protein avra. however, under culture conditions below ph 6.0 many of the avra non-producer strains (e.g. s. agona, s. bovismorbificans, s. virchow) begin to produce avra, while some others remain silent. four phenotypical classes of s. enterica were identified under defined standard culture conditions: class 1 comprises strain ... | 2006 | 16377240 |
| ciprofloxacin-resistant salmonella enterica serovar typhimurium strains are difficult to select in the absence of acrb and tolc. | it has been proposed that lack of a functional efflux system(s) will lead to a lower frequency of selection of resistance to fluoroquinolones and other antibiotics. we constructed five strains of salmonella enterica serovar typhimurium sl1344 that lacked efflux gene components of resistance nodulation cell division pumps (acrb, acrd, acrf, acrbacrf, and tolc) plus three strains that lack genes that effect efflux gene expression (mara, soxs, and rama) and a hypermutable strain (muts::aph). strain ... | 2006 | 16377664 |
| prevalence of salmonella enterica serovar typhi in bile and stool of patients with biliary diseases and those requiring biliary drainage for other purposes. | acute suppurative cholangitis is a serious complication of biliary obstructions due to infection. salmonella enterica serovar typhi is an important biliary pathogen. bile samples from 445 patients with biliary diseases as well as those requiring biliary drainage for other miscellaneous gastrointestinal diseases were investigated bacteriologically with special emphasis on salmonella. fecal samples or rectal swabs were also obtained from 402 of these patients. bactericholia was detected in 68.8% p ... | 2005 | 16377868 |
| real-time reverse transcription pcr for the quantification of the mnth expression of salmonella enterica as a function of growth phase and phagosome-like conditions. | this article presents an experimental design for measuring the mrna expression in salmonella enterica of the mnth gene in phagosome-mimicking conditions. the expression of mnth was quantified by real-time reverse transcription pcr for different s. enterica strains of porcine origin under different biological growth conditions which mimicked the environment inside the phagosome. the expression of mnth and the different control genes (16s rrna, rpod and gmk) varied according to the growth phase. f ... | 2006 | 16378650 |
| [influence of human gastrointestinal tract bacterial pathogens on host cell apoptosis]. | several pathogenic bacteria are able to trigger apoptosis in the host cell, but the mechanisms by which it occurs differ, and the resulting pathology can take different courses. induction and/or blockage of programmed cell death upon infection is a result of complex interaction of bacterial proteins with cellular proteins involved in signal transduction and apoptosis. in this review we focus on pro/anti-apoptotic activities exhibited by two enteric pathogens salmonella enterica, yersinia spp. an ... | 2005 | 16381171 |