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caveolar endocytosis of simian virus 40 is followed by brefeldin a-sensitive transport to the endoplasmic reticulum, where the virus disassembles.simian virus 40 (sv40) enters cells by atypical endocytosis mediated by caveolae that transports the virus to the endoplasmic reticulum (er) instead of to the endosomal-lysosomal compartment, which is the usual destination for viruses and other cargo that enter by endocytosis. we show here that sv4o is transported to the er via an intermediate compartment that contains beta-cop, which is best known as a component of the copi coatamer complexes that are required for the retrograde retrieval pathw ...200211967331
molecular evolution of human immunodeficiency virus env in humans and monkeys: similar patterns occur during natural disease progression or rapid virus passage.neonatal rhesus macaque 95-3 was inoculated with nonpassaged simian-human immunodeficiency virus strain shiv-vpu(+), which encodes env of the laboratory-adapted human immunodeficiency virus (hiv) strain iiib and is considered nonpathogenic. cd4(+) t-cell counts dropped to <200 cells/microl within 4.6 years, and monkey 95-3 died with opportunistic infections 5.9 years postinoculation. transfer of blood from 95-3 to two naive adult macaques resulted in high peak viral loads and rapid, persistent t ...200211967343
the exopolyphosphatase gene from sulfolobus solfataricus: characterization of the first gene found to be involved in polyphosphate metabolism in archaea.inorganic polyphosphate (polyp) polymers are widely distributed in all kinds of organisms. although the presence of polyp in members of the domain archaea has been described, at present nothing is known about the enzymology of polyp metabolism or the genes involved in this domain. we have cloned, sequenced, and overexpressed an exopolyphosphatase (ppx) gene (ppx) from thermophilic sulfolobus solfataricus. the gene codes for a functional ppx and possesses an open reading frame for 417 amino acids ...200212324325
bacterial hemoglobins and flavohemoglobins for alleviation of nitrosative stress in escherichia coli.escherichia coli mg1655 cells expressing novel bacterial hemoglobin and flavohemoglobin genes from a medium-copy-number plasmid were grown in shake flask cultures under nitrosative and oxidative stress. e. coli cells expressing these proteins display enhanced resistance against the no(.) releaser sodium nitroprusside (snp) relative to that of the control strain bearing the parental plasmid. expression of bacterial hemoglobins originating from campylobacter jejuni (chb) and vitreoscilla sp. (vhb) ...200212324328
double-staining method for differentiation of morphological changes and membrane integrity of campylobacter coli cells.we developed a double-staining procedure involving nanoorange dye (molecular probes, eugene, oreg.) and membrane integrity stains (live/dead baclight kit; molecular probes) to show the morphological and membrane integrity changes of campylobacter coli cells during growth. the conversion from a spiral to a coccoid morphology via intermediary forms and the membrane integrity changes of the c. coli cells can be detected with the double-staining procedure. our data indicate that young or actively gr ...200212324366
selection and characterization of fluoroquinolone-resistant mutants of campylobacter jejuni using enrofloxacin.significant levels of fluoroquinolone resistance were obtained in campylobacterjejuni isolates after an unique step of selection using enrofloxacin. an asp90-to-asn and a thr86-to-ile change in the gyrase subunit gyra were found associated with a low (mic < or = 8 /microg/ml) or a high (mic > or = 16 microg/ml) level of resistance to ciprofloxacin, respectively. an association of both mutations conferred a higher level of resistance (mic > or = 128 microg/ml). further steps of selection increase ...200212523631
detection of campylobacter jejuni in healthy monkeys and monkeys with enteric infections by pcr.campylobacter were detected by pcr in feces of monkeys of different species (clinically healthy, with diarrhea, and dead from acute enteric infections). high prevalence of these bacteria in monkeys was revealed. the incidence of c. jejuni dna in monkeys with acute enteric infections was higher than in healthy animals (69.6 and 51.3%, respectively). the highest percentage (92.3) of positive results was observed in macaca mulatta with enteric diseases and in macaque dead of these diseases. the pre ...200212512007
investigation on the inhibition of campylobacter jejuni growth with the applications of some preservatives, medicines, herbs and herb preparations.the aim of this study was to determine the influence of chosen preservatives, medicines, herbs and herb preparations on 39 campylobacter jejuni strains, which were isolated from fresh poultry carcasses. de-nol and ventrisol were used in the original concentration. propolis, propolan, artecholin and aukalen were of pharmacies origin. the rest of substances examined were 10% water solutions. out of 11 substances examined, potassium sorbate, sodium benzoate, de-nol and ventrisol exerted the stronge ...200212512554
the tetracycline resistance protein tet(o) perturbs the conformation of the ribosomal decoding centre.tet(o) is an elongation factor-like protein found in clinical isolates of campylobacter jejuni that confers resistance to the protein-synthesis inhibitor tetracycline. tet(o) interacts with the 70s ribosome and promotes the release of bound tetracycline, however, as shown here, it does not form the same functional interaction with the 30s subunit. chemical probing demonstrates that tet(o) changes the reactivity of the 16s rrna to dimethyl sulphate (dms). these changes cluster within the decoding ...200212354218
detection in escherichia coli of the genes encoding the major virulence factors, the genes defining the o157:h7 serotype, and components of the type 2 shiga toxin family by multiplex pcr.strains of shiga toxin-producing escherichia coli (stec) have been associated with outbreaks of diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome in humans. most clinical signs of disease arise as a consequence of the production of shiga toxin 1 (stx1), stx2 or combinations of these toxins. other major virulence factors include enterohemorrhagic e. coli hemolysin (ehec hlya), and intimin, the product of the eaea gene that is involved in the attaching and effacing adherence phenotype. ...200212354854
right atrial mobile thrombus and pulmonary thromboembolism complicating hemorrhagic campylobacter jejuni colitis. 200212356127
ciprofloxacin resistance in campylobacter jejuni: case-case analysis as a tool for elucidating risks at home and abroad.to determine factors independently associated with the acquisition of a ciprofloxacin-resistant campylobacter jejuni infection.200212356802
evaluation of a commercial diagnostic pcr for the identification of campylobacter jejuni and campylobacter coli.aims: dupont qualicon recently developed a new pcr assay for the identification of campylobacter jejuni and campylobacter coli. we evaluated the selectivity and utility of this assay compared with a pcr method already in use in our laboratory. methods and results: a group of 133 campylobacter isolates from poultry carcass rinse samples were screened using the commercial pcr and standard pcr. identical results were found for 89.5% (119/133) of the isolates. however, 10.5% (14/133) gave conflictin ...200212358702
genetic diversity and relationships of campylobacter species and subspecies.the existence of tremendous genetic diversity within campylobacter species has been well documented. to analyse the population structure of campylobacter and determine whether or not a clonal population structure could be detected, genetic diversity was assessed within the genus campylobacter by multilocus enzyme electrophoresis of 156 isolates representing 11 species and subspecies from disparate sources. analyses of electrophoretic mobility of 11 enzymes revealed 109 electrophoretic types (ets ...200212361288
interactions among strategies associated with bacterial infection: pathogenicity, epidemicity, and antibiotic resistance.infections have been the major cause of disease throughout the history of human populations. with the introduction of antibiotics, it was thought that this problem should disappear. however, bacteria have been able to evolve to become antibiotic resistant. nowadays, a proficient pathogen must be virulent, epidemic, and resistant to antibiotics. analysis of the interplay among these features of bacterial populations is needed to predict the future of infectious diseases. in this regard, we have r ...200212364374
[antiganglioside autoantibody profiles in guillain-barré syndrome].we established anti-ganglioside antibody profiles in gbs and studied the frequency, fine specificity and clinical correlate. igg and igm antibodies to 8 gangliosides were tested by immunodot-blot in 249 consecutive patients with guillain-barré syndrome with large variability in clinical expression, referred to our laboratory over a 8-year period. igg and igm anti-gm1 antibodies were measured by elisa. thin-layer chromatography overlayed by serum was used to control positivity. 89/249 gbs (36%) h ...200212368145
conservation of the biotin regulon and the bira regulatory signal in eubacteria and archaea.biotin is a necessary cofactor of numerous biotin-dependent carboxylases in a variety of microorganisms. the strict control of biotin biosynthesis in escherichia coli is mediated by the bifunctional bira protein, which acts both as a biotin-protein ligase and as a transcriptional repressor of the biotin operon. little is known about regulation of biotin biosynthesis in other bacteria. using comparative genomics and phylogenetic analysis, we describe the biotin biosynthetic pathway and the bira r ...200212368242
causative pathogens of severe diarrhea in children.to investigate the enteropathogens in children with diarrhea attending salmaniya medical complex, bahrain.200212370713
asymmetric directional mutation pressures in bacteria.when there are no strand-specific biases in mutation and selection rates (that is, in the substitution rates) between the two strands of dna, the average nucleotide composition is theoretically expected to be a = t and g = c within each strand. deviations from these equalities are therefore evidence for an asymmetry in selection and/or mutation between the two strands. by focusing on weakly selected regions that could be oriented with respect to replication in 43 out of 51 completely sequenced b ...200212372146
evaluation of an immunochromatography strip assay for the detection of salmonella sp. from poultry.the present study was conducted to evaluate the sensitivity and specificity of an immunochromatography-based diagnostic kit for salmonella. the analytical sensitivity of the test when using pure colonies of different salmonella species was in the range of 1 x 10(4) to 1 x 10(5) colony-forming units per milliliter. the strip detected 19 of 22 strains of salmonella spp. but failed to detect s. worthington, s. choleraesuis var. kunzendorf and s. johannesburg. the strip did not detect 27 different e ...200212296399
long-term antibody responses following human infection with campylobacter jejuni.epidemiological evidence suggests prior infection of humans by campylobacter jejuni leads to protection against disease following further exposure. it is known that infections elicit strong antibody responses following the onset of disease and that antibody levels are elevated in putatively immune populations. to determine if systemic and mucosal antibodies induced by a confirmed infection remain at elevated levels for prolonged periods, repeat serum, saliva and urine samples were taken from cam ...200212296859
surveillance of bacterial pathogens of diarrhea disease in indonesia.emerging or reemerging infections due to bacterial disease may be a local, regional or global problem. bacterial acute gastroenteritis is a potential cause of substantial morbidity in travelers and deployed u.s. military personnel. a surveillance study was conducted over a two-year period in indonesia among 6760 patients with debilitating diarrheal diseases. of the 6,760 patients, 587 (9%) of the patient stools were positive for bacteria. the proportions of bacteria isolated from the 587 patient ...200212493168
increasing fluoroquinolone resistance in campylobacter jejuni, pennsylvania, usa,1982-2001.fluoroquinolone-resistant campylobacter jejuni has been observed worldwide and is now being seen in the united states. among patients in our health-care system in pennsylvania, fluoroquinolone-resistant c. jejuni were not observed from 1982 to 1992; however, resistance increased to 40.5% in 2001. resistance to erythromycin remains at a low level (<5%).200212498672
high resolution genotyping of campylobacter jejuni strains by macrorestriction analysis with xhoi and polymerase chain reaction targeting enterobacterial repetitive intergenic consensus sequences: can we predict the zoonotic potential of strains?campylobacter jejuni isolates of human, canine, feline, bovine and poultry origin were investigated for their genomic diversity using o-antigen typing (n = 271), smai (n = 158) and xhoi (n = 158) macrorestriction analysis and eric-pcr (n = 107). the o-antigens o:1/44, o:2, o:4 complex, o:37. o:40 were identified and 53.7% of the human and 56.1% of the animal strains were typable with the available antisera. two eric-pcr pattern groups were generated representing human and animal strains as well ...200212558325
coagglutination test for rapid noncultural diagnosis of human campylobacteriosis.forty diarrhoeic stool samples of domestic animal handlers in a rural area of india were cultured and screened for detection of campylobacter jejuni by co-agglutination technique (coa). seven c. jejuni strains were isolated by culture and 6 faecal samples gave positive coa test. the specificity and sensitivity for negative and positive culture were 96.9% and 85.7% respectively. this is first report of detection of campylobacter enteritis of human beings using coa technique directly from stool sa ...200212608651
campylobacter colonization in poultry: sources of infection and modes of transmission.since its recognition as a human pathogen in the early 1970s, campylobacter jejuni has now emerged as the leading bacterial cause of food-borne gastroenteritis in developed countries. poultry, particularly chickens, account for the majority of human infections caused by campylobacter. reduction or elimination of this pathogen in the poultry reservoir is an essential step in minimizing the public health problem; however, farm-based intervention measures are still not available because of the lack ...200212665109
immunological characterization of the campylobacter jejuni 72dz/92 cjad gene product and its fusion with b subunit of e. coli lt toxin.campylobacter jejuni 72dz/92 cjad gene, orthologue of c. jejuni nctc 11168 cj0113, c. jejuni m275 omp18 and c. jejuni atcc 29428 omp18, has been cloned, sequenced and analysed from the viewpoint of its immunological attributes. neither the 5' nor 3' fragment of the cjad encodes protein capable of reacting with anti-campylobacter antibodies. several fusions of the cjad with eltb, which encodes b subunit of the e. coli lt toxin, have been constructed. the hybrid proteins, which differ in respect t ...200212708820
[campylobacter jejuni and c. coli in aborted swine: comparison between phenotypic identification and polyacrylamide gel protein profiles].campylobacter jejuni and campylobacter coli were isolated from aborted pig fetuses which proceeded from different animals and farms between february 2000 and march 2001. seven campylobacter jejuni biotype ii, three biotype i and one campylobacter coli biotype i were identified by phenotypic tests and lior's scheme. to corroborate and compare the phenotypic results, 7.5, 10 and 12.5% polyacrilamide gel electrophoresis (sds-page) were used under reducing conditions. characteristic bands of hyperva ...200212600003
campylobacter colonization of the crops of newly hatched leghorn chicks.we have studied colonization of crops in newly hatched leghorn chicks (a layer breed) by wild-type and mutant strains of campylobacter jejuni. we established that the wild-type parent strain forms a stable population level within the crop and that the mutant strains will do likewise. concentrations of mutant strains in the crop were usually below that of the wild-type parent strain and ranged from 10(3) to 10(5) colony-forming units. these results differ from results we have previously reported ...200212495061
role of campylobacter jejuni/coli in diarrhoea in ile-ife, nigeria.campylobacter jejuni/coli are well established causative agents of diarrhoea. in nigeria, gastroenteritis due to c. jejuni was first reported in northern part of the country in 1981 and the south-western part in ile-ife in 1983.200212638844
a comparison of campylobacter jejuni enteritis incidence rates in high- and low-poultry-density counties: michigan 1992-1999.to compare the incidence of campylobacter jejuni enteritis in high- and low-poultry-density counties in michigan between the years 1992 and 1999, an ecological study was conducted in the state of michigan. a log-linear model was used to compare yearly, seasonal, age, and gender-specific incidence rates between county groupings. counties with a high poultry density had a higher overall incidence of c. jejuni enteritis, particularly among children and young adults, compared with counties with low ...200212737543
new born chicks can serve as an experimental animal model for human campylobacteriosis.campylobacter enteritis is an emerging food borne zoonotic disease. improperly cooked chicken serve as a potential source for this infection. diarrheogenic potential of campylobacter jejuni is tested either by in-vivo rat ileal loop (ril) test or by molecular methods. this study reveals that 3-day-old chicks can serve as an animal model for toxigenic c. jejuni.200212776802
[aetiology and antibiotic sensitivity of the most frequent outpatient infections, except those of the lower respiratory tract].reporting of antimicrobial susceptibility profiles is recommended in order to improve antibiotic prescribing policies and to avoid the emergence of bacterial resistance. during 2001, susceptibility data from bacterial isolates collected from urine, faeces and ear swabs and antimicrobial susceptibility for streptococcus pyogenes during the first five months in 2002 were recorded in the health area of pamplona (389,489 inhabitants) and compared against data for antibiotic prescriptions. more than ...200212861284
the genetic bases for the variation in the lipo-oligosaccharide of the mucosal pathogen, campylobacter jejuni. biosynthesis of sialylated ganglioside mimics in the core oligosaccharide.we have compared the lipo-oligosaccharide (los) biosynthesis loci from 11 campylobacter jejuni strains expressing a total of 8 different ganglioside mimics in their los outer cores. based on the organization of the genes, the 11 corresponding loci could be classified into three classes, with one of them being clearly an intermediate evolutionary step between the other two. comparative genomics and expression of specific glycosyltransferases combined with in vitro activity assays allowed us to id ...200211689567
plasmid-encoded autolysin in bacillus anthracis: modular structure and catalytic properties.a bacillus anthracis virulence plasmid-encoded peptidoglycan hydrolase (amia) with sequence similarity to n-acetylmuramoyl-l-alanine amidases hydrolyzes peptidoglycan independently of cell wall binding. residues h341, e355, h415, and e486 are absolutely required for catalysis. many amia paralogs are fused to different sorting signals, suggesting that these modular proteins result from domain shuffling.200211741877
use of a multiplex pcr-based assay to differentiate campylobacter jejuni and campylobacter coli strains isolated from human and animal sources. 200211749144
the dioxin crisis as experiment to determine poultry-related campylobacter enteritis.in june 1999, the dioxin crisis, caused by dioxin-contaminated feed components, exploded in belgium, resulting in withdrawal of chicken and eggs from the market. through the sentinel surveillance system, a decrease in campylobacter infections during june 1999 was noticed. a model was generated with the reports from preceding years (1994 to 1998), and a prediction of the number of infections in 1999 was calculated. the model shows a significant decline (40%) in the number of infections, mainly be ...200211749743
biosynthesis pathway of adp-l-glycero-beta-d-manno-heptose in escherichia coli.the steps involved in the biosynthesis of the adp-l-glycero-beta-d-manno-heptose (adp-l-beta-d-heptose) precursor of the inner core lipopolysaccharide (lps) have not been completely elucidated. in this work, we have purified the enzymes involved in catalyzing the intermediate steps leading to the synthesis of adp-d-beta-d-heptose and have biochemically characterized the reaction products by high-performance anion-exchange chromatography. we have also constructed a deletion in a novel gene, gmhb ...200211751812
characterization of comq and comx, two genes required for production of comx pheromone in bacillus subtilis.many microbes use secreted peptide-signaling molecules to stimulate changes in gene expression in response to high population density, a process called quorum sensing. comx pheromone is a modified 10-amino-acid peptide used by bacillus subtilis to modulate changes in gene expression in response to crowding. comq and comx are required for production of comx pheromone. we found that accumulation of comx pheromone in culture supernatant paralleled cell growth, indicating that there was no autoinduc ...200211751817
occurrence and strain diversity of thermophilic campylobacters in cattle of different age groups in dairy herds.to investigate the occurrence and numbers of thermophilic campylobacters excreted by cattle in dairy herds, and to assess the strain diversity within herds.200212081556
hyperreflexia in axonal guillain-barré syndrome subsequent to campylobacter jejuni enteritis.we describe a patient with the acute motor axonal neuropathy (aman) form of guillain-barré syndrome (gbs), who showed generalized hyperreflexia. a 24-year-old man developed acute paralysis following campylobacter jejuni enteritis. he showed exaggerated tendon reflexes with abnormal reflex spread to other segments, and was initially diagnosed as having post-infectious myelitis. nerve conduction studies showed motor axonal degeneration (the aman pattern), and increased soleus h-reflex amplitudes. ...200212084449
fitness of salmonella enterica serovar thompson in the cilantro phyllosphere.the epiphytic fitness of salmonella enterica was assessed on cilantro plants by using a strain of s. enterica serovar thompson that was linked to an outbreak resulting from cilantro. salmonella serovar thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (clsm) at high densities on the veins and in natural lesions. the population sizes of two common colonizers of plant surfaces, pantoea agglomerans and pseudomonas chloro ...200212089050
transmission of campylobacter hyointestinalis from a pig to a human.we report on a case of human gastroenteritis caused by the pathogen campylobacter hyointestinalis. recurrent watery diarrhea and intermittent vomiting were the most significant symptoms of the previously healthy patient. whole-cell protein electrophoresis and 16s rrna gene sequencing were used to identify this campylobacter species. investigation of the patient's surroundings led to the recovery of a second c. hyointestinalis strain originating from porcine feces. subsequent typing of the human ...200212089284
pcr for detection of cdt-iii and the relative frequencies of cytolethal distending toxin variant-producing escherichia coli isolates from humans and cattle.a pcr assay that uses primers whose sequences were obtained from the published sequence of the cdt-iii gene was developed to determine the frequencies of the cdt-i, cdt-ii, and cdt-iii genes in escherichia coli isolates from humans and animals. e. coli isolates producing cytolethal distending toxin (cdt) were infrequently detected. the cdt-i gene was preferentially detected in strains with the cnf1 gene, while the cdt-iii gene was found in strains carrying the cnf2 gene. the cdt-iii genotype was ...200212089305
quality control strains used in susceptibility testing of campylobacter spp. 200212089316
catalase, a specific antigen in the feces of human subjects infected with helicobacter pylori.recently, we reported the production of three new monoclonal antibodies with high specificity for a helicobacter pylori antigen suitable for diagnosis of h. pylori infection. the aim of the present study was to identify the antigen recognized by these monoclonal antibodies concerning both h. pylori and the feces of human subjects infected with h. pylori. the cellular antigen was purified from an h. pylori cell extract by immunoaffinity column chromatography with the monoclonal antibody as a liga ...200212093673
effect of esculentoside a on autoimmunity in mice and its possible mechanisms.to investigate the influence of esculentoside a (esa) on autoimmunity in mice and its possible mechanisms.200212100759
growth of campylobacter jejuni supported by respiration of fumarate, nitrate, nitrite, trimethylamine-n-oxide, or dimethyl sulfoxide requires oxygen.the human gastrointestinal pathogen campylobacter jejuni is a microaerophilic bacterium with a respiratory metabolism. the genome sequence of c. jejuni strain 11168 reveals the presence of genes that encode terminal reductases that are predicted to allow the use of a wide range of alternative electron acceptors to oxygen, including fumarate, nitrate, nitrite, and n- or s-oxides. all of these reductase activities were present in cells of strain 11168, and the molybdoenzyme encoded by cj0264c was ...200212107136
survival of campylobacter jejuni in biofilms isolated from chicken houses.campylobacter jejuni is a thermophilic and microaerophilic enteric pathogen associated with poultry. biofilms may be a source of c. jejuni in poultry house water systems since they can protect constituent microorganisms from environmental stress. in this study, the viability of c. jejuni in biofilms of gram-positive chicken house isolates (p1, y1, and w1) and a pseudomonas sp. was determined using a cultural method (modified brucella agar) and direct viable count (dvc). two-day biofilms grown on ...200212117243
effectiveness of chemical sanitizers against campylobacter jejuni-containing biofilms.survival of campylobacter jejuni in mixed-culture biofilms was determined after treatment with chemical sanitizers including chlorine, quaternary ammonia, peracetic acid (paa), and a paa/peroctanoic acid mixture (paa/poa). biofilm-producing bacteria (gram-positive rods, y1 and w1) were isolated from chicken house nipple drinkers. a meat plant isolate (pseudomonas sp.) was also included as a biofilm producer. two-day-old biofilms grown on polyvinyl chloride (pvc) plastic coupons in r2a broth at 1 ...200212117244
generation and characterization of human monoclonal scfv antibodies against helicobacter pylori antigens.infection with helicobacter pylori is chronic despite a vigorous cellular and humoral immune response and causes severe pathology in some patients. in this study, phage display was used as a new approach in order to investigate the role of the host's humoral immune response in the pathogenesis of h. pylori gastritis. human monoclonal single-chain fv (scfv) antibody fragments against h. pylori cell lysate and the h. pylori urease were isolated from an immune phage display library, constructed fro ...200212117924
characterization of pit, a streptococcus pneumoniae iron uptake abc transporter.bacteria frequently have multiple mechanisms for acquiring iron, an essential micronutrient, from the environment. we have identified a four-gene streptococcus pneumoniae operon, named pit, encoding proteins with similarity to components of a putative brachyspira hyodysenteriae iron uptake abc transporter, bit. an s. pneumoniae strain containing a defined mutation in pit has impaired growth in medium containing the iron chelator ethylenediamine di-o-hydroxyphenylacetic acid, reduced sensitivity ...200212117949
outbreak of campylobacter jejuni infections associated with drinking unpasteurized milk procured through a cow-leasing program--wisconsin, 2001.on december 7, 2001, the sawyer county department of health and human services in northwestern wisconsin notified the wisconsin division of public health about five cases of campylobacter jejuni enteritis. all of the ill persons drank unpasteurized milk obtained at a local dairy farm. this report summarizes the investigation of these and other cases and of a cow-leasing program used to circumvent regulations prohibiting the sale of unpasteurized milk in wisconsin. the outbreak highlights the haz ...200212118535
clinical dysentery in hospitalized children.clinical dysentery is a severe presentation of an enteric infection. the aim of the study was to evaluate the impact of a serious bacterial etiology in clinical dysentery in hospitalized children and determine if children at high risk can be identified on the basis of clinical or laboratory parameters.200212120936
detection of cytolethal distending toxin activity and cdt genes in actinobacillus actinomycetemcomitans isolates from geographically diverse populations.a cytolethal distending toxin (cdt) found in actinobacillus actinomycetemcomitans inhibits the eukaryotic cell cycle, which may contribute to the pathogenic potential of the bacterium. the presence of the cdtabc genes and cdt activity were examined in 40 clinical isolates of a. actinomycetemcomitans from brazil, kenya, japan and sweden. thirty-nine of 40 cell lysates caused distension of chinese hamster ovary cells. at least one of the cdt genes was detected in all strains examined. the three cd ...200212121473
kinetics of kb and hep-2 cell responses to an invasive, cytolethal distending toxin-producing strain of actinobacillus actinomycetemcomitans.the periodontal pathogen actinobacillus actinomycetemcomitans produces cytolethal distending toxin (cdt), a complex multicomponent toxin that arrests the growth of many types of eukaryotic cell. the kinetics of the effects of cdt-containing extracts, from an invasive strain of this bacterium, were examined on epithelial-like cells routinely used in invasion studies. both kb and hep-2 cells were exquisitely sensitive to the effects of the cdt with td50 of 30 and 300 pg of total bacterial protein, ...200212121475
helicobacter pylori induces apoptosis of rat gastric parietal cells.gastric helicobacter pylori infection may lead to multifocal atrophic corpus gastritis associated with loss of epithelial cells as well as glandular structures. the current work investigated h. pylori effects on cell death of isolated, nontransformed rat parietal cells (pc). highly enriched rat pc (>97%) were isolated from gastric mucosa and cultured in serum-free medium over 24 h. the cells were cocultured over 8 h with cytotoxin-associated immunodominant protein (caga)(+)/vacuolating toxin (va ...200212121877
gyra polymorphism in campylobacter jejuni: detection of gyra mutations in 162 c. jejuni isolates by single-strand conformation polymorphism and dna sequencing.mutations in the quinolone resistance-determining region of the gyra gene from 138 ciprofloxacin-resistant (mic, > or =4 microg/ml) and 24 ciprofloxacin-susceptible (mic, < or =1 microg/ml) clinical campylobacter jejuni isolates were subjected to single-strand conformation polymorphism analysis and sequencing. all of the isolates could be assigned to three genotypic clusters based on silent mutations. all resistant isolates had a point mutation at codon 86.200212121947
multifocal motor neuropathy and campylobacter jejuni reactivity.in some patients, campylobacter jejuni infection has been associated with the development of multifocal motor neuropathy (mmn) and high titers of antiganglioside antibodies. the authors measured anti-c. jejuni antibodies by elisa and immunoblot in 20 patients with mmn, and correlated their presence with antiganglioside reactivity and a history of recent diarrhea. only one patient had high titers of anti-c. jejuni antibodies, indicating that c. jejuni is unlikely to be involved in the pathogenesi ...200212136073
regulation of riboflavin biosynthesis and transport genes in bacteria by transcriptional and translational attenuation.the riboflavin biosynthesis in bacteria was analyzed using comparative analysis of genes, operons and regulatory elements. a model for regulation based on formation of alternative rna structures involving the rfn elements is suggested. in gram-positive bacteria including actinomycetes, thermotoga, thermus and deinococcus, the riboflavin metabolism and transport genes are predicted to be regulated by transcriptional attenuation, whereas in most gram-negative bacteria, the riboflavin biosynthesis ...200212136096
suppressive subtractive hybridization detects extensive genomic diversity in thermotoga maritima.comparisons between genomes of closely related bacteria often show large variations in gene content, even between strains of the same species. such studies have focused mainly on pathogens; here, we examined thermotoga maritima, a free-living hyperthermophilic bacterium, by using suppressive subtractive hybridization. the genome sequence of t. maritima msb8 is available, and dna from this strain served as a reference to obtain strain-specific sequences from thermotoga sp. strain rq2, a very clos ...200212142418
genome-wide transcriptional profiling in a histidine kinase mutant of helicobacter pylori identifies members of a regulon.to identify putative members of a regulon controlled by the h. pylori sensory histidine kinase hp0164 (hk0164), we constructed hk0164 null mutant h. pylori strains and analyzed bacterial gene transcription using dna arrays. seven genes were differentially expressed in multiple hk0164 mutant strains compared to their expression in control strains. strain-dependent variations in differential expression were also detected. these results indicate that the signal transduction circuit utilizing hk0164 ...200212142435
crystal structure of an mrna-binding fragment of moorella thermoacetica elongation factor selb.selb is an elongation factor needed for the co-translational incorporation of selenocysteine. selenocysteine is coded by a uga stop codon in combination with a specific downstream mrna hairpin. in bacteria, the c-terminal part of selb recognizes this hairpin, while the n-terminal part binds gtp and trna in analogy with elongation factor tu (ef-tu). we present the crystal structure of a c-terminal fragment of selb (selb-c) from moorella thermoacetica at 2.12 a resolution, solved by a combination ...200212145214
helicobacter pylori impairs dna mismatch repair in gastric epithelial cells.helicobacter pylori infection is a major gastric cancer risk factor. h. pylori gastritis occurs more frequently in individuals with microsatellite instability-positive than those with microsatellite instability-negative gastric cancers, raising the possibility that h. pylori infection affects dna mismatch repair (mmr). the aim of this study was to determine the effect of h. pylori on the expression of dna mmr proteins and rna in gastric epithelial cells.200212145807
the peptidyl-prolyl isomerase motif is lacking in pmpa, the prsa-like protein involved in the secretion machinery of lactococcus lactis.the prsa-like gene from lactococcus lactis encoding its single homologue to prsa, an essential protein triggering the folding of secreted proteins in bacillus subtilis, was characterized. this gene, annotated pmpa, encodes a lipoprotein of 309 residues whose expression is increased 7- to 10-fold when the source of nitrogen is limited. a slight increase in the expression of the prsa-like protein (plp) in l. lactis removed the degradation products previously observed with the staphylococcus hyicus ...200212147493
combined use of two genetic fingerprinting methods, pulsed-field gel electrophoresis and ribotyping, for characterization of escherichia coli o157 isolates from food animals, retail meats, and cases of human disease.two genetic fingerprinting techniques, pulsed-field gel electrophoresis (pfge) and ribotyping, were used to characterize 207 escherichia coli o157 isolates from food animals, foods of animal origin, and cases of human disease (206 of the isolates were from the united kingdom). in addition, 164 of these isolates were also phage typed. the isolates were divided into two general groups: (i) unrelated isolates not known to be epidemiologically linked (n = 154) and originating from food animals, food ...200212149334
molecular epidemiology of caliciviruses causing outbreaks and sporadic cases of acute gastroenteritis in spain.the molecular epidemiology of human caliciviruses (hucvs) causing sporadic cases and outbreaks of acute gastroenteritis around eastern spain (catalonia and the valencian community) was studied by reverse transcription-pcr (rt-pcr) and by sequencing part of the rna polymerase gene in open reading frame 1. hucvs were detected in 44 of 310 stool specimens (14.19%) negative for other enteric pathogens obtained from children with acute gastroenteritis. norwalk-like viruses (nlvs) were the most common ...200212149342
hypogammaglobulinaemia: cumulative experience in 49 patients in a tertiary care institution.in this paper, clinical data of 49 adult patients with agammaglobulinaemia (syn. hypogammaglobulinaemia), 15 cases of x-linked agammaglobulinaemia (xla) and 34 of common variable immunodeficiency (cvid) are reviewed. although immunoglobulin substitution largely abolished life-threatening respiratory tract infections, considerable infectious and non-infectious morbidity was still encountered in these patients. almost all patients suffered from chronic or recurrent upper and lower airway infection ...200212164371
occupational health and safety in small animal veterinary practice: part i--nonparasitic zoonotic diseases.zoonotic diseases are an ever-present concern in small animal veterinary practice and are often overlooked. a variety of nonparasitic zoonotic diseases may be encountered in small animal practice, including cat scratch disease (bartonellosis), cat bite abscesses, rabies, leptospirosis, methicillin-resistant staphylococcus aureus, clostridium difficile-associated diarrhea, salmonellosis, avian chlamydiosis, campylobacteriosis, dermatophytosis, and blastomycosis. these may cause human disease rang ...200212170843
pervasive properties of the genomic signature.the dinucleotide relative abundance profile can be regarded as a genomic signature because, despite diversity between species, it varies little between 50 kilobase or longer windows on a given genome. both the causes and the functional significance of this phenomenon could be illuminated by determining if it persists on smaller scales. the profile is computed from the base step "odds ratios" that compare dinucleotide frequencies to those expected under the assumption of stochastic equilibrium (t ...200212171605
evidence that plant-like genes in chlamydia species reflect an ancestral relationship between chlamydiaceae, cyanobacteria, and the chloroplast.an unusually high proportion of proteins encoded in chlamydia genomes are most similar to plant proteins, leading to proposals that a chlamydia ancestor obtained genes from a plant or plant-like host organism by horizontal gene transfer. however, during an analysis of bacterial-eukaryotic protein similarities, we found that the vast majority of plant-like sequences in chlamydia are most similar to plant proteins that are targeted to the chloroplast, an organelle derived from a cyanobacterium. we ...200212176923
peptide linkage mapping of the agrobacterium tumefaciens vir-encoded type iv secretion system reveals protein subassemblies.numerous bacterial pathogens use type iv secretion systems (t4ss) to deliver virulence factors directly to the cytoplasm of plant, animal, and human host cells. here, evidence for interactions among components of the agrobacterium tumefaciens vir-encoded t4ss is presented. the results derive from a high-resolution yeast two-hybrid assay, in which a library of small peptide domains of t4ss components was screened for interactions. the use of small peptides overcomes problems associated with assay ...200212177441
flaa-like sequences containing internal termination codons (tag) in urease-positive thermophilic campylobacter isolated in japan.to demonstrate two flaa-like sequences containing two internal termination codons (tag) in two japanese strains of urease-positive thermophilic campylobacter (uptc).200212180938
prevalence of thermophilic campylobacter spp. in ready-to-eat foods and raw poultry in northern ireland.although there have been numerous studies investigating the prevalence of campylobacters in animals and raw meats, there are limited data on the persistence of these organisms in ready-to-eat (rte) foodstuffs. although poultry is now well established as a major reservoir of thermophilic campylobacters, it is widely assumed that hazard analysis critical control point (haccp) controls in commercial and industrial settings are effective in eliminating this hazard through thorough cooking of rte pro ...200212182488
the regulator perr is involved in oxidative stress response and iron homeostasis and is necessary for full virulence of streptococcus pyogenes.ferric uptake regulator (fur) and fur-like proteins form an important family of transcriptional regulators in many bacterial species. in this work we have characterized a fur-like protein, the peroxide regulator perr, in an m1 serotype of streptococcus pyogenes. to determine the role of perr in s. pyogenes, we inactivated the gene by allelic replacement. perr-deficient bacteria showed 48% reduction of (55)fe incorporation from the culture medium. transcriptional analysis revealed that mtsa, enco ...200212183543
tolerance to self gangliosides is the major factor restricting the antibody response to lipopolysaccharide core oligosaccharides in campylobacter jejuni strains associated with guillain-barré syndrome.guillain-barré syndrome following campylobacter jejuni infection is frequently associated with anti-ganglioside autoantibodies mediated by molecular mimicry with ganglioside-like oligosaccharides on bacterial lipopolysaccharide (lps). the regulation of antibody responses to these t-cell-independent antigens is poorly understood, and only a minority of campylobacter-infected individuals develop anti-ganglioside antibodies. this study investigates the response to gangliosides and lps in strains of ...200212183547
ganglioside mimicry of campylobacter jejuni lipopolysaccharides determines antiganglioside specificity in rabbits.the core oligosaccharides of campylobacter jejuni lipopolysaccharides (lps) display molecular mimicry with gangliosides. cross-reactive anti-lps-antiganglioside antibodies have been implicated to show a crucial role in the pathogenesis of the guillain-barré and miller fisher syndrome. the specificity of the antiganglioside response is thought to depend on the oligosaccharide structure of the ganglioside mimic. to test this hypothesis and to investigate the potential of lps from campylobacter str ...200212183556
campylobacter jejuni from patients with guillain-barré syndrome preferentially expresses a gd(1a)-like epitope.gm(1)- and gd(1a)-like ganglioside mimicry in campylobacter jejuni lipooligosaccharide (los) is considered to be involved in the pathogenesis of campylobacter-induced guillain-barré syndrome (gbs). compared with gastroenteritis-related isolates, gbs-related c. jejuni isolates were strongly associated with the expression of gd(1a)-like mimicry. the presence of a few genes involved in los ganglioside mimicry, cst-ii, cgta, and cgtb, was also associated with gbs-related strains. gd(1a)-like epitope ...200212183587
structure of the n-linked glycan present on multiple glycoproteins in the gram-negative bacterium, campylobacter jejuni.mass spectrometry investigations of partially purified campylobacter jejuni protein peb3 showed it to be partially modified with an asn-linked glycan with a mass of 1406 da and composed of one hexose, five n-acetylhexosamines and a species of mass 228 da, consistent with a trideoxydiacetamidohexose. by means of soybean lectin affinity chromatography, a mixture of glycoproteins was obtained from a glycine extract, and two-dimensional gel proteomics analysis led to the identification of at least 2 ...200212186869
a novel cell entry pathway for a daf-using human enterovirus is dependent on lipid rafts.the glycosylphosphatidylinositol (gpi)-anchored complement regulatory protein decay-accelerating factor (daf) is used by a number of enteroviruses as a receptor during infection. daf and other gpi-anchored proteins can be found in cholesterol-rich ordered domains within the plasma membrane that are known as "lipid rafts." we have shown, by using drugs to specifically inhibit various endocytosis routes, that infection by a daf-using strain of echovirus 11 (ev11) is dependent upon cholesterol and ...200212186914
a case-case comparison of campylobacter coli and campylobacter jejuni infection: a tool for generating hypotheses.preventing campylobacteriosis depends on a thorough understanding of its epidemiology. we used case-case analysis to compare cases of campylobacter coli infection with cases of c. jejuni infection, to generate hypotheses for infection from standardized, population-based sentinel surveillance information in england and wales. persons with c. coli infection were more likely to have drunk bottled water than were those with c. jejuni infection and, in general, were more likely to have eaten pâté. im ...200212194770
molecular characterization of campylobacter jejuni clones: a basis for epidemiologic investigation.a total of 814 isolates of the foodborne pathogen campylobacter jejuni were characterized by multilocus sequence typing (mlst) and analysis of the variation of two cell-surface components: the heat-stable (hs) serotyping antigen and the flagella protein flaa short variable region. we identified 379 combinations of the mlst loci (sequence types) and 215 combinations of the cell-surface components among these isolates, which had been obtained from human disease, animals, food, and the environment. ...200212194772
response of intestinal epithelial cells to trichuris suis excretory-secretory products and the influence on campylobacter jejuni invasion under in vitro conditions.we previously developed a swine animal model in which natural host resistance to campylobacter jejuni is altered by experimental infection with low numbers of the nematode trichuris suis. pigs naturally colonized with c. jejuni experience colitis because of the invasion of the bacterium approximately 21 days after exposure to t. suis. to better understand the mechanism of t. suis-dependent c. jejuni colitis, we evaluated the effects of t. suis excretory-secretory products (esps) on intestinal ep ...200212197123
from the farm to the kitchen table: the negative impact of antimicrobial use in animals on humans.antimicrobials used as growth promotion agents in the livestock and poultry industries appear to result in the spread of drug-resistant pathogens to humans such as vancomycin-resistant enterococci, fluoroquinolone-resistant campylobacter jejuni, and multidrug-resistant strains of salmonella enterica. we present some epidemiologic evidence supporting this link and suggest that the use of antimicrobial agents for nontherapeutic purposes in food animals should be severely limited, if not banned alt ...200212199302
environmental regulation of campylobacter jejuni major outer membrane protein porin expression in escherichia coli monitored by using green fluorescent protein.porins allow exchanges between bacteria and their environment. in the gram-negative food-borne pathogen campylobacter jejuni two porins, major outer membrane protein (momp) and omp50, have been identified. momp is synthesized at a very high level under laboratory culture conditions, suggesting that its promoter functions very efficiently under these conditions. in campylobacter samples, we observed that momp porin expression increased at a high temperature (42 degrees c) or a high ph (ph 8.5) co ...200212200267
quorum sensing and production of autoinducer-2 in campylobacter spp., escherichia coli o157:h7, and salmonella enterica serovar typhimurium in foods.autoinducer molecules are utilized by gram-negative and gram-positive bacteria to regulate density-dependent gene expression by a mechanism known as quorum sensing. pcr and dna sequencing results showed that campylobacter jejuni and campylobacter coli possessed luxs, which is responsible for autoinducer-2 (ai-2) production. using a vibrio harveyi luminescence assay, the production of ai-2 was observed in milk, chicken broth, and brucella broth by c. coli, c. jejuni, salmonella enterica serovar t ...200212200329
rational design of dna sequence-based strategies for subtyping listeria monocytogenes.the ability to differentiate bacteria beyond the species level is essential for identifying and tracking infectious disease outbreaks and to improve our knowledge of the population genetics, epidemiology, and ecology of bacterial pathogens. commonly used subtyping methods, such as serotyping, phage typing, ribotyping, and pulsed-field gel electrophoresis, can yield ambiguous results that are difficult to standardize and share among laboratories. dna sequence-based subtyping strategies can reduce ...200212202573
novel domains and orthologues of eukaryotic transcription elongation factors.the passage of rna polymerase ii across eukaryotic genes is impeded by the nucleosome, an octamer of histones h2a, h2b, h3 and h4 dimers. more than a dozen factors in the yeast saccharomyces cerevisiae are known to facilitate transcription elongation through chromatin. in order to better understand the evolution and function of these factors, their sequences have been compared with known protein, est and dna sequences. elongator subcomplex components elp4p and elp6p are shown to be homologues of ...200212202748
predicted structure and phyletic distribution of the rna-binding protein hfq.hfq, a bacterial rna-binding protein, was recently shown to contain the sm1 motif, a characteristic of sm and lsm proteins that function in rna processing events in archaea and eukaryotes. in this report, comparative structural modeling was used to predict a three-dimensional structure of the hfq core sequence. the predicted structure aligns with most major features of the methanobacterium thermoautotrophicum lsm protein structure. conserved residues in hfq are positioned at the same structural ...200212202750
immunoglobulin g antibody response to infection with coccoid forms of helicobacter pylori.an increasing number of studies support a potential role for coccoid forms in helicobacter pylori infection. evidence for this was obtained through scanning microscopy, genetic analysis for virulence traits, examination of the presence and activity of key enzymes, and other methods. we studied the serum immunoglobulin g responses to coccoid h. pylori forms by enzyme-linked immunosorbent assay (elisa) and immunoblotting and compared them with those of bacillary cells. sera from a total of 295 inf ...200212204961
activation of the transcription factor nf-kappab by campylobacter jejuni.campylobacter jejuni is a food-borne pathogen responsible for infectious enterocolitis. the early-response transcription factor nf-kappa b triggers the expression of genes associated with cellular immune and inflammatory responses. co-incubation of hela cells with viable c. jejuni leads to the activation of the transcription factor nf-kappa b as determined by specific induction of a cellular luciferase-based reporter. boiled cell-free extracts of c. jejuni are also potent dose-dependent stimulat ...200212213922
[utility of studying feces for the diagnosis and management of infants and preschool children with acute diarrhea].to analyze the results of a stool work-up protocol in a series of infants and preschoolers with acute diarrhea.200212216520
interdependent expression of the cconoqp-rdxbhis loci in rhodobacter sphaeroides 2.4.1.the rdxbhis gene cluster of rhodobacter sphaeroides 2.4.1, located downstream of the cconoqp operon encoding the cbb(3) cytochrome c oxidase, is required for the posttranscriptional modification of the cbb(3) cytochrome c oxidase. the cbb(3) cytochrome c oxidase is the main terminal oxidase under microaerobic conditions, as well as a component of the signal transduction pathway controlling photosynthesis gene expression. because of the intimate functional and positional relationships of the ccon ...200212218019
[an outbreak of campylobacter jejuni enteritis after farm visit in haifa subdistrict].we report on an outbreak of campylobacter jejuni (c. jejuni) gastroenteritis among children residing in haifa subdistrict after a farm visit. this incident emphasizes the importance of this issue and our report suggests preventive measures to reduce the risk of transmission of enteric pathogens in such situations.200212222128
detection of escherichia coli o157:h7 using immunomagnetic separation and absorbance measurement.an assay system for detection of escherichia coli o157:h7 was developed based on immunomagnetic separation of the target pathogen from samples and absorbance measurement of p-nitrophenol at 400 nm from p-nitrophenyl phosphate hydrolysis by alkaline phosphatase (ec 3.1.3.1) on the "sandwich" structure complexes (antibodies coated onto micromagnetic beads--e. coli o157:h7-antibodies conjugated with the enzyme) formed on the microbead surface. the effects of immunoreaction time, phosphate buffer co ...200212223297
dynamic diversity of the tryptophan pathway in chlamydiae: reductive evolution and a novel operon for tryptophan recapture.complete genomic sequences of closely related organisms, such as the chlamydiae, afford the opportunity to assess significant strain differences against a background of many shared characteristics. the chlamydiae are ubiquitous intracellular parasites that are important pathogens of humans and other organisms. tryptophan limitation caused by production of interferon-gamma by the host and subsequent induction of indoleamine dioxygenase is a key aspect of the host-parasite interaction. it appears ...200212225590
cxxs: fold-independent redox motif revealed by genome-wide searches for thiol/disulfide oxidoreductase function.redox reactions involving thiol groups in proteins are major participants in cellular redox regulation and antioxidant defense. although mechanistically similar, thiol-dependent redox processes are catalyzed by structurally distinct families of enzymes, which are difficult to identify by available protein function prediction programs. herein, we identified a functional motif, cxxs (cysteine separated from serine by two other residues), that was often conserved in redox enzymes, but rarely in oth ...200212237451
identification of a new source of campylobacter contamination in poultry: transmission from breeder hens to broiler chickens.campylobacter jejuni, a foodborne pathogen closely associated with market poultry, is considered to be the most frequent agent of human gastroenteritis in the united states. the pathways involved in the contamination of poultry flocks, vertical transmission and/or horizontal transmission, are unclear. in this study, campylobacter isolates from two independent commercial broiler breeder flocks, as well as from their respective progeny, were characterized and compared by psti ribotype analysis and ...200212243515
effect of high-temperature inside-outside spray on survival of campylobacter jejuni attached to prechill chicken carcasses.prechill chicken carcasses, inoculated with campylobacter jejuni, were sprayed in an inside-outside birdwasher at 20, 55, or 60 c, with or without 50 ppm chlorine, in a poultry processing pilot plant. carcasses were sprayed for 12 s at 80 pounds per square inch (psi). next, carcasses were placed in a chiller filled with 50 ppm chlorinated ice water at 4 c for 50 min. most probable numbers of c. jejuni were determined based on chicken carcass wash water before and after the spray treatment. the s ...200212269619
multiresistant clones of salmonella enterica: the importance of dissemination.increasing anitmicrobial resistance among foodborne pathogens has prompted calls for the reduction of anitmicrobial use in livestock to prevent future emergence or resistance. in the case of salmonella enterica, clonal dissemination may play a more critical role in regional changes in antimicrobial resistance in salmonellae than antimicrobial selection pressure. multi-resistant salmonella typhimurium definitive type 104 (mr-dt104) emerged from an unknown location and was disseminated globally du ...200212271270
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