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toward an international standard for pcr-based detection of food-borne thermotolerant campylobacters: assay development and analytical validation.as part of a european research project (food-pcr), we developed a standardized and robust pcr detection assay specific for the three most frequently reported food-borne pathogenic campylobacter species, c. jejuni, c. coli, and c. lari. fifteen published and unpublished pcr primers targeting the 16s rrna gene were tested in all possible pairwise combinations, as well as two published primers targeting the 23s rrna gene. a panel of 150 strains including target and nontarget strains was used in an ...200312957958
toward an international standard for pcr-based detection of food-borne thermotolerant campylobacters: validation in a multicenter collaborative trial.as part of a european research project, the performance of a pcr assay to detect food-borne thermotolerant campylobacters (campylobacter jejuni, c. coli, and c. lari) was evaluated through an international collaborative trial involving 12 participating laboratories. dna from 10 target and 8 nontarget strains was tested, and the results were reported as the presence of a positive signal after gel electrophoresis. the overall inclusivity (sensitivity) was 93.7%, and the exclusivity (specificity) w ...200312957959
microarray-based identification of thermophilic campylobacter jejuni, c. coli, c. lari, and c. upsaliensis.dna microarrays are an excellent potential tool for clinical microbiology, since this technology allows relatively rapid identification and characterization of microbial and viral pathogens. in the present study, an oligonucleotide microarray was developed and used for the analysis of thermophilic campylobacter spp., the primary food-borne pathogen in the united states. we analyzed four campylobacter species: campylobacter jejuni, c. coli, c. lari, and c. upsaliensis. our assay relies on the pcr ...200312958228
production of cytolethal distending toxins by pathogenic escherichia coli strains isolated from human and animal sources: establishment of the existence of a new cdt variant (type iv).three types of cytolethal distending toxin (cdt), namely, cdt-i, cdt-ii, and cdt-iii, have been described in escherichia coli. using primers designed for the detection of sequences common to the cdtb genes, we analyzed by pcr a set of 21 cdt-producing e. coli strains of intestinal and extraintestinal origins isolated from human and different animal species in several european countries and in the united states. on the basis of the existing differences in the cdtb genes, cdt-i-, cdt-ii-, and cdt- ...200312958258
pcr-restriction fragment length polymorphism analysis for detection of point mutations associated with macrolide resistance in campylobacter spp.a 23s rrna gene fragment in domain v was sequenced from 30 clinical isolates of campylobacter spp., including 22 resistant to macrolides. two point mutations associated with erythromycin resistance were identified at positions 2074 and 2075 on the 23s rrna gene (homologous to a2142c and a2143g mutations in helicobacter pylori) in which an adenine residue is also replaced with a cytosine and a guanine residue, respectively. a combined pcr-restriction fragment length polymorphism technique was dev ...200312604552
molecular characterization of fluoroquinolone-resistant campylobacter spp. isolated from poultry.campylobacteriosis, an infectious disease caused by campylobacter jejuni and campylobacter coli, is treated by fluoroquinolone antibiotics in clinical practices. however, use of these drugs in animal husbandry may select for fluoroquinolone-resistant campylobacters and, thereby, compromise the clinical treatment of infection. in this study, 21 fluoroquinolone-resistant campylobacters were isolated from poultry samples. morphological and biochemical characteristics indicated that 19 isolates were ...200312619802
a real-time pcr assay for the detection of campylobacter jejuni in foods after enrichment culture.a real-time pcr assay was developed for the quantitative detection of campylobacter jejuni in foods after enrichment culture. the specificity of the assay for c. jejuni was demonstrated with a diverse range of campylobacter species, related organisms, and unrelated genera. the assay had a linear range of quantification over six orders of magnitude, and the limit of detection was approximately 12 genome equivalents. the assay was used to detect c. jejuni in both naturally and artificially contami ...200312620820
detection and typing of campylobacter jejuni and campylobacter coli and analysis of indicator organisms in three waterborne outbreaks in finland.waterborne outbreaks associated with contamination of drinking water by campylobacter jejuni are rather common in the nordic countries sweden, norway, and finland, where in sparsely populated districts groundwater is commonly used without disinfection. campylobacters, escherichia coli, or other coliforms have rarely been detected in potential sources. we studied three waterborne outbreaks in finland caused by c. jejuni and used sample volumes of 4,000 to 20,000 ml for analysis of campylobacters ...200312620821
comparison of broth microdilution, e test, and agar dilution methods for antibiotic susceptibility testing of campylobacter jejuni and campylobacter coli.a standardized broth microdilution method was compared to the e test and an agar dilution method for the antimicrobial susceptibility testing of campylobacter jejuni and c. coli isolates. a group of 47 human clinical isolates, 37 isolates from retail poultry, and 29 isolates from living turkeys (total, 113 isolates) was included in the study. these encompassed 92 c. jejuni and 21 c. coli strains. the mics of six antimicrobial agents were determined by the broth microdilution and e test methods, ...200312624030
molecular typing of campylobacter jejuni and campylobacter coli. 200312624086
cecal colonization of chicks by bovine-derived strains of campylobacter.campylobacter jejuni and campylobacter coli strains were isolated from feces of dairy cattle at farms with no known problem due to campylobacteria. farms were located in the northeast, desert southwest, and pacific west. twenty isolates were identified by ribotyping with a riboprinter. the ability of these bovine isolates to colonize the ceca of chicks was determined by challenge inoculation and reisolation of the challenge strain from the ceca at 1 and 2 wk after challenge. isolates recovered f ...200314708992
antimicrobial susceptibility trends in campylobacter jejuni and campylobacter coli isolated from a rural egyptian pediatric population with diarrhea.comparative and trend analysis was conducted on annual prevalence of antimicrobial susceptibility among campylobacter jejuni and campylobacter coli recovered from rural egyptian children from 1995 through 2000. c. jejuni and c. coli demonstrated significant decreasing trends in ciprofloxacin susceptibility over the study period (p < 0.001 for both). in general, c. coli demonstrated a higher degree of susceptibility than c. jejuni, however, there was no statistical difference (p = 0.2) comparing ...200314711482
prevalence of campylobacter within a swine slaughter and processing facility.in this work, the occurrence of campylobacter in a swine slaughter and processing facility was studied. thirty composite carcass samples, representing 360 swine carcasses, were taken immediately after exsanguination, immediately after polishing, after the final wash, and after overnight chilling at 2 degrees c. thirty matching composite rectal samples were also taken immediately after exsanguination, and 60 nonmatching individual colon samples were collected from the same lot of swine during evi ...200314503704
detection and enumeration of campylobacter jejuni and campylobacter coli by indirect impedimetry with an oxygen scavenging system.six strains of campylobacter jejuni and campylobacter coli were shown to grow in a variety of media, but, with one exception, they were unable to produce sufficient change in the electrical properties of the medium to allow their detection by impedance monitoring. with the use of an indirect method based on absorption of evolved carbon dioxide and a medium containing the oxygen scavenger oxyrase, all strains were detectable, and correlations between time to detection and the logarithm of the ino ...200314503735
disinfectant susceptibility testing of avian and swine campylobacter isolates by a filtration method.the susceptibility testing of disinfectants against campylobacter jejuni and campylobacter coli strains from broilers and pigs was investigated. the filtration method european standard en 1040 was adapted to campylobacter cultures and validated with reference strains. two disinfectants were tested: 1% benzalkonium chloride active matter, as quaternary ammonium compound, and 0.63% sodium hypochlorite as chlorine-releasing agent. both disinfectants were effective against the 34 campylobacter strai ...200314516706
simultaneous detection of mutations associated with resistance to macrolides and quinolones in campylobacter jejuni and c. coli using a pcr-line probe assay.quinolone and macrolide resistance of campylobacter jejuni and campylobacter coli mainly depend on a mutation in gyra and in 23s rdna, respectively. in order to detect quinolone and/or macrolide resistant c. jejuni and c. coli strains, a macrolide and quinolone line probe assay (mq-lipa) was developed and 42 c. jejuni and c. coli strains were tested to evaluate the efficiency of the assay. profiles of the mutations in 23s rdna and in gyra characterized by mq-lipa agreed with resistance to macrol ...200314522100
ribotyping characterisation of campylobacter isolates randomly collected from different sources in italy.in this study the potential for using the automated psti ribotyping as a primary library typing method to survey campylobacter and for identification of two thermophilic campylobacter jejuni and campylobacter coli species was evaluated. a total of 158 isolates randomly collected in italy from different sources were analyzed. a large percentage of chicken (28%), turkey (27%) and turkey meat (25%) isolates shared their ribotyping profiles (ribotypes) with those of humans, whereas the swine isolate ...200314522511
the iron-responsive regulator fur is transcriptionally autoregulated and not essential in neisseria meningitidis.fur is a well-known iron-responsive repressor of gene transcription, which is used by many bacteria to respond to the low-iron environment that pathogens encounter during infection. the fur gene in neisseria meningitidis has been described as an essential gene that may regulate a broad array of genes. we succeeded in obtaining an n. meningitidis mutant with the fur gene knocked out and used it to undertake studies of fur-mediated iron regulation. we show that expression of both fur and the trans ...200314526014
comparison of the bax system with a multiplex pcr method for simultaneous detection and identification of campylobacter jejuni and campylobacter coli in environmental samples.the campylobacter detection is performed by conventional culture methods and the identification of campylobacter jejuni and campylobacter coli is principally based on the hippurate hydrolysis test. the two major drawbacks of this biochemical test for species identification include the inconsistency of the results and the presence of atypical strains, which can lead to the misidentification of an isolate. as an alternative, multiplex polymerase chain reaction (mpcr) protocols for the simultaneous ...200314527799
application of host-specific bacteriophages to the surface of chicken skin leads to a reduction in recovery of campylobacter jejuni.retail poultry products are widely purported as the major infection vehicle for human campylobacteriosis. numerous intervention strategies have sought to reduce campylobacter contamination on broiler carcasses in the abattoir. this study reports the efficacy of bacteriophage in reducing the number of recoverable campylobacter jejuni cells on artificially contaminated chicken skin.200314532096
comparison of campylobacter isolates from poultry and humans: association between in vitro virulence properties, biotypes, and pulsed-field gel electrophoresis clusters.the in vitro virulence properties of 197 temporally and geographically related campylobacter isolates from chicken broilers and humans were compared. comparisons of the virulence properties associated with genotypes and biotypes were made. all isolates adhered to, and 63% invaded, int-407 cells, whereas 13% were cytotoxic for cho cells. cho cell-cytotoxic extracts were also cytotoxic for int-407 cells, but the sensitivity for vero cells was variable. the proportion of isolates demonstrating a hi ...200314532099
antimicrobial resistance in campylobacter from broilers: association with production type and antimicrobial use.the isolation and antimicrobial resistance of campylobacter jejuni and campylobacter coli strains from broilers arriving in french slaughterhouses, were analysed according to production types (i.e. standard, export or free-range) and antimicrobial (i.e. coccidiostats, growth promoters or therapeutic agents) administration in flocks. prevalence was 56.6% in standard, 51.3% in export and 80.0% in free-range broilers. three hundred and ninety-three strains were identified. two-thirds of the strains ...200314559174
deletion of helicobacter pylori vacuolating cytotoxin gene by introduction of directed mutagenesis.to construct a vaca-knockout helicobacter pylori mutant strain, whose only difference from the wild strain is its disrupted vaca gene.200314562387
flagellin glycosylation island in pseudomonas syringae pv. glycinea and its role in host specificity.the deduced amino acid sequences of the flagellins of pseudomonas syringae pv. tabaci and p. syringae pv. glycinea are identical; however, their abilities to induce a hypersensitive reaction are clearly different. the reason for the difference seems to depend on the posttranslational modification of the flagellins. to investigate the role of this posttranslational modification in the interactions between plants and bacterial pathogens, we isolated genes that are potentially involved in the postt ...200314594840
molecular structure and evolution of the conjugative multiresistance plasmid pre25 of enterococcus faecalis isolated from a raw-fermented sausage.plasmid pre25 from enterococcus faecalis transfers resistances against kanamycin, neomycin, streptomycin, clindamycin, lincomycin, azithromycin, clarithromycin, erythromycin, roxithromycin, tylosin, chloramphenicol, and nourseothricin sulfate by conjugation in vitro to e. faecalis jh2-2, lactococcus lactis bu2, and listeria innocua l19. its nucleotide sequence of 50237 base pairs represents the largest, fully sequenced conjugative multiresistance plasmid of enterococci (plasmid 46 (2001) 170). t ...200314597005
diversity and succession of the intestinal bacterial community of the maturing broiler chicken.the diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16s rrna gene sequences. nearly 70% of sequences from the ileum were related to those of lactobacillus, with the majority of the rest being related to clostridiaceae (11%), streptococcus (6.5%), and enterococcus (6.5%). in contrast, clostridiaceae-related sequences (65%) were the most abundant group detected in the ...200314602645
hazards of healthy living: bottled water and salad vegetables as risk factors for campylobacter infection. 200314609455
characterization of waterborne outbreak-associated campylobacter jejuni, walkerton, ontario. 200314609457
evaluation of the prospect microplate assay for detection of campylobacter: a routine laboratory perspective.to evaluate the use of the new enzyme-linked immunosorbent assay, the prospect campylobacter microplate assay (alexon-trend, minneapolis, mn, usa), which allows 2-h detection of both campylobacter jejuni and campylobacter coli antigen directly in stool specimens.200314616724
pseudaminic acid, the major modification on campylobacter flagellin, is synthesized via the cj1293 gene.flagellins from campylobacter jejuni 81-176 and campylobacter coli vc167 are heavily glycosylated. the major modifications on both flagellins are pseudaminic acid (pse5ac7ac), a nine carbon sugar that is similar to sialic acid, and an acetamidino-substituted analogue of pseudaminic acid (pseam). previous data have indicated that pseam is synthesized via pse5ac7ac in c. jejuni 81-176, but that the two sugars are synthesized using independent pathways in c. coli vc167. the cj1293 gene of c. jejuni ...200314617187
effect of temperature on viability of campylobacter jejuni and campylobacter coli on raw chicken or pork skin.to determine growth and survival of campylobacter jejuni and campylobacter coli on chicken and pork, campylobacter spp. (10(4) cfu/cm2) were inoculated on pieces of raw, irradiated chicken or pork skin and exposed to temperatures ranging from -20 to 42 degrees c under either microaerobic or aerobic conditions. viable counts over 48 h declined 2 to 3 log cfu/cm2 at -20 degrees c and 1 to 2 log cfu/cm2 at 25 degrees c regardless of skin type, species of campylobacter, or level of oxygen. at 4 degr ...200314627278
isolation of campylobacter jejuni and campylobacter coli from the gall bladder samples of sheep and identification by polymerase chain reaction.in this study, 100 gall bladder samples of sheep slaughtered at an abattoir in elaziğ province were examined for campylobacter jejuni and campylobacter coli by culture and polymerase chain reaction (pcr). preston campylobacter agar supplemented with 7% horse blood and preston selective supplement (oxoid, hampshire, uk) were used for isolation of the agents. campylobacter spp. were isolated in 66 samples, and they were identified as 34% c. jejuni and 32% c. coli. a multiplex pcr based upon the us ...200314629001
antimicrobial resistance in campylobacter jejuni and campylobacter coli strains isolated in 1991 and 2001-2002 from poultry and humans in berlin, germany.the susceptibilities of 430 campylobacter jejuni strains and 79 c. coli strains to six antimicrobial agents were tested and analyzed. the two sets of strains originated from retail market chicken and turkey samples and from humans, respectively, in berlin, germany. two groups of isolates, one dating from 1991 and the other dating from 2001-2002, were tested. of the campylobacter sp. isolates recovered from humans in 2001-2002, 45.1% were resistant to ciprofloxacin, 37.8% were resistant to tetrac ...200314638490
risk factors for sporadic campylobacter jejuni infections in rural michigan: a prospective case-control study.this case-control study investigated risk factors for campylobacteriosis in a rural population. exposure to live farm animals was hypothesized to increase the risk for campylobacter jejuni enteritis.200314652344
genetic diversity of campylobacter jejuni isolates from farm animals and the farm environment.the genetic diversity of campylobacter jejuni isolates from farm animals and their environment was investigated by multilocus sequence typing (mlst). a total of 30 genotypes, defined by allelic profiles (assigned to sequence types [sts]), were found in 112 c. jejuni isolates originating in poultry, cattle, sheep, starlings, and slurry. all but two of these genotypes belonged to one of nine c. jejuni clonal complexes previously identified in isolates from human disease and retail food samples and ...200314660392
survival of helicobacter pylori in a natural freshwater environment.the mode by which helicobacter pylori, the causative agent of most gastric ulcers, is transmitted remains undetermined. epidemiological evidence suggests these organisms are waterborne; however, h. pylori has rarely been grown from potential water sources. this may be due to the ability of this organism to rapidly enter the viable but nonculturable (vbnc) state. our investigation examines the entrance of h. pylori into this state in laboratory cultures and a natural freshwater environment as wel ...200314660399
avian reservoirs and zoonotic potential of the emerging human pathogen helicobacter canadensis.a polyphasic identification approach was used to investigate the taxonomic position of campylobacter-like isolates recovered from barnacle geese (branta leucopsis) and canada geese (branta candensis). seven strains were selected from a collection of 21 isolates and analyzed by extensive phenotypic testing; four strains were characterized by 16s rrna gene sequence analysis. the results clearly identified the bird isolates as helicobacter canadensis, recently described as an emerging human pathoge ...200314660407
risk factors for antibiotic resistance in campylobacter spp. isolated from raw poultry meat in switzerland.the world-wide increase of foodborne infections with antibiotic resistant pathogens is of growing concern and is designated by the world health organization as an emerging public health problem. thermophilic campylobacter have been recognised as a major cause of foodborne bacterial gastrointestinal human infections in switzerland and in many other countries throughout the world. poultry meat is the most common source for foodborne cases caused by campylobacter. because all classes of antibiotics ...200314662013
risk factors associated with campylobacter jejuni infections in curaçao, netherlands antilles.a steady increase in the incidence of guillain-barré syndrome (gbs) with a seasonal preponderance, almost exclusively related to campylobacter jejuni, and a rise in the incidence of laboratory-confirmed campylobacter enteritis have been reported from curaçao, netherlands antilles. we therefore investigated possible risk factors associated with diarrhea due to epidemic c. jejuni. typing by pulsed-field gel electrophoresis identified four epidemic clones which accounted for almost 60% of the infec ...200314662945
applicability of a rapid duplex real-time pcr assay for speciation of campylobacter jejuni and campylobacter coli directly from culture plates.a rapid duplex real-time polymerase chain reaction (pcr) assay for speciation of campylobacter jejuni and campylobacter coli using the abi prism 7700 sequence detection system (applied biosystems) was developed based on two of the genes used in a conventional multiplex pcr. a rapid turnaround time of 3 h was achieved with the use of boiled cell lysates. applicability of the assay was tested with 6015 random campylobacter strains referred to the campylobacter reference unit, with 97.6% being iden ...200314680705
fluoroquinolone-resistant campylobacter in animal reservoirs: dynamics of development, resistance mechanisms and ecological fitness.thermophilic campylobacter species, including campylobacter jejuni and campylobacter coli, are responsible for foodborne campylobacteriosis in humans and are increasingly resistant to fluoroquinolone (fq) antimicrobials. the therapeutic use of fq antimicrobial agents in food animal production, particularly in poultry, has become a concern for public health, because the practice may promote the emergence of fq-resistant campylobacter that can be transmitted to humans through the food chain. recen ...200315134291
routes for campylobacter contamination of poultry meat: epidemiological study from hatchery to slaughterhouse.from april 1998 to march 2000, 18 broiler flocks were followed from the hatchery to the slaughterhouse. campylobacter was not found in the hatchery, 1-day-old chicks or in the rearing house before the arrival of the chicks. the infection of broiler flocks increased continuously during the rearing time, with a total of seven positive flocks at the end of rearing. farms with campylobacter-positive broilers were characterized by the circulation of campylobacter in the environment (puddles, dung hil ...200314959785
a survey of campylobacter species shed in faeces of beef cattle using polymerase chain reaction.a polymerase chain reaction (pcr)-based survey of campylobacters associated with faeces collected from 382 beef cattle was undertaken. to ensure the removal of pcr inhibitors present in faeces and determine if adequate extraction was achieved, faeces were seeded with internal control dna (i.e., dna designed to amplify with the campylobacter genus primer set, but provide a smaller amplicon) before the extraction procedure. in only two samples (0.5%) were the internal control or campylobacter genu ...200314735214
birds, migration and emerging zoonoses: west nile virus, lyme disease, influenza a and enteropathogens.wild birds are important to public health because they carry emerging zoonotic pathogens, either as a reservoir host or by dispersing infected arthropod vectors. in addition, bird migration provides a mechanism for the establishment of new endemic foci of disease at great distances from where an infection was acquired. birds are central to the epidemiology of west nile virus (wnv) because they are the main amplifying host of the virus in nature. the initial spread of wnv in the u.s. along the ea ...200315931279
resistance to quinolones in campylobacter jejuni and campylobacter coli from danish broilers at farm level.to investigate the prevalence of quinolone resistance among campylobacter jejuni and camp. coli isolates from danish poultry at the farm level, as well as for the whole country.200312492931
association of helicobacter pylori antioxidant activities with host colonization proficiency.to assess the importance of two separate antioxidant activities in helicobacter pylori, we tested the abilities of strains with mutations in either tpx (encoding thiolperoxidase) or ahpc (encoding alkyl hydroperoxide reductase [ahpc]) to colonize the stomachs of mice. the tpx strain was clearly more sensitive than the parent strain to both oxygen and cumene hydroperoxide. the strain colonized only 5% of the inoculated mice. two different classes of oxygen-sensitive ahpc mutants in the type strai ...200312496216
antimicrobial susceptibilities of campylobacter strains isolated from finnish subjects infected domestically or from those infected abroad.the in vitro susceptibilities of 678 campylobacter jejuni and campylobacter coli strains isolated from stool samples of the same number of finnish subjects were studied. a total of 523 patients, representing inhabitants from throughout finland, had not traveled abroad within the 2 weeks prior to becoming ill, whereas 155 persons had presumably acquired their infections abroad. the antimicrobial agents studied were erythromycin, ciprofloxacin, levofloxacin, trovafloxacin, and moxifloxacin. the mi ...200312499176
enhanced surveillance of campylobacter infection in the north west of england 1997-1999.to identify sources and routes of infection for sporadic cases of campylobacter infection in the north west of england.200312504607
survival and resuscitation of ten strains of campylobacter jejuni and campylobacter coli under acid conditions.the culturability of 10 strains of campylobacter jejuni and campylobacter coli was studied after the bacteria were exposed to acid conditions for various periods of time. campylobacter cells could not survive 2 h under acid conditions (formic acid at ph 4). the 10 campylobacter strains could not be recovered, even when enrichment media were used. viable cells, however, could be detected by a double-staining (5-cyano-2,3-ditolyl tetrazolium chloride [ctc]-4',6'-diamidino-2-phenylindole [dapi]) te ...200312514068
comparative genotyping of campylobacter jejuni by amplified fragment length polymorphism, multilocus sequence typing, and short repeat sequencing: strain diversity, host range, and recombination.three molecular typing methods were used to study the relationships among 184 campylobacter strains isolated from humans, cattle, and chickens. all strains were genotyped by amplified fragment length polymorphism (aflp) analysis, multilocus sequence typing (mlst), and sequence analysis of a genomic region with short tandem repeats designated clustered regularly interspaced short palindromic repeats (crisprs). mlst and aflp analysis yielded more than 100 different profiles and patterns, respectiv ...200312517820
molecular assays for detection of human metapneumovirus.the recent description of the respiratory pathogen human metapneumovirus (hmpv) has highlighted a deficiency in current diagnostic techniques for viral agents associated with acute lower respiratory tract infections. we describe two novel approaches to the detection of viral rna by use of reverse transcriptase pcr (rt-pcr). the pcr products were identified after capture onto a solid-phase medium by hybridization with a sequence-specific, biotinylated oligonucleotide probe. the assay was applied ...200312517833
epidemiology and antimicrobial susceptibilities of 111 campylobacter fetus subsp. fetus strains isolated in québec, canada, from 1983 to 2000.the epidemiology and antimicrobial susceptibilities of 111 campylobacter fetus subsp. fetus strains isolated from 103 patients from 1983 to 2000 in québec, canada, were determined. the median number of patients infected annually with this bacteria was seven, with an incidence of 0.1 per 100,000 population. the male-to-female ratio was 1.1 to 1.0. the patients originated from 13 of the 18 québec socioeconomic regions. the age range of the patients was 6 months to 90 years old, 53% being > or = 70 ...200312517895
the gam protein of bacteriophage mu is an orthologue of eukaryotic ku.mu bacteriophage inserts its dna into the genome of host bacteria and is used as a model for dna transposition events in other systems. the eukaryotic ku protein has key roles in dna repair and in certain transposition events. here we show that the gam protein of phage mu is conserved in bacteria, has sequence homology with both subunits of ku, and has the potential to adopt a similar architecture to the core dna-binding region of ku. through biochemical studies, we demonstrate that gam and the ...200312524520
characterization of helicobacter pylori nickel metabolism accessory proteins needed for maturation of both urease and hydrogenase.previous studies demonstrated that two accessory proteins, hypa and hypb, play a role in nickel-dependent maturation of both hydrogenase and urease in helicobacter pylori. here, the two proteins were purified and characterized. hypa bound two ni(2+) ions per dimer with positive cooperativity (hill coefficient, approximately 2.0). the dissociation constants k(1) and k(2) for ni(2+) were 58 and 1.3 microm, respectively. studies on purified site-directed mutant proteins in each of the five histidin ...200312533448
the iron-binding protein dps confers hydrogen peroxide stress resistance to campylobacter jejuni.we identified and characterized the iron-binding protein dps from campylobacter jejuni. electron microscopic analysis of this protein revealed a spherical structure of 8.5 nm in diameter, with an electron-dense core similar to those of other proteins of the dps (dna-binding protein from starved cells) family. cloning and sequencing of the dps-encoding gene (dps) revealed that a 450-bp open reading frame (orf) encoded a protein of 150 amino acids with a calculated molecular mass of 17,332 da. ami ...200312533477
evaluation of broiler litter with reference to the microbial composition as assessed by using 16s rrna and functional gene markers.very little is known about the microbial composition of animal bedding wastes, including poultry litter, and what is known has been deduced from standard culture methods, by which some fastidious organisms that exist in the environment may not be detected. we evaluated the bacterial composition of poultry litter by using a combination of culture and molecular detection. total aerobic bacteria in poultry litter were detected by culture at 10(9) cfu/g of material. enteric bacteria such as enteroco ...200312571010
specific detection of arcobacter and campylobacter strains in water and sewage by pcr and fluorescent in situ hybridization.the aim of this study was to evaluate pcr and fluorescent in situ hybridization (fish) techniques for detecting arcobacter and campylobacter strains in river water and wastewater samples. both 16s and 23s rrna sequence data were used to design specific primers and oligonucleotide probes for pcr and fish analyses, respectively. in order to assess the suitability of the methods, the assays were performed on naturally and artificially contaminated samples and compared with the isolation of cells on ...200312571045
occurrence and resistance to antibiotics of campylobacter jejuni and campylobacter coli in animals and meat in northeastern italy.a study was carried out in northeastern italy during 2000 and 2001 to investigate the occurrence of campylobacter jejuni and campylobacter coli in animals, cattle, pigs, and broilers, and raw meat, beef, pork, and chicken. campylobacter spp. were detected in 53.9% of the cattle, 63.5% of the pigs, and 82.9% of the broilers examined. chicken meat was frequently contaminated (81.3%), while lower rates were found in pork meat (10.3%) and beef (1.3%). the resistance to antibiotics of the strains was ...200312593931
gastroenteritis in nf-kappab-deficient mice is produced with wild-type camplyobacter jejuni but not with c. jejuni lacking cytolethal distending toxin despite persistent colonization with both strains.campylobacter jejuni continues to be a leading cause of bacterial enteritis in humans. however, because there are no readily available animal models to study the pathogenesis of c. jejuni-related diseases, the significance of potential virulence factors, such as cytolethal distending toxin (cdt), in vivo are poorly understood. mice deficient in nf-kappab subunits (p50(-/-) p65(+/-)) in a c57bl/129 background are particularly susceptible to colitis induced by another enterohepatic microaerobe, he ...200414742559
proteomic analysis of the sarcosine-insoluble outer membrane fraction of helicobacter pylori strain 26695.helicobacter pylori causes gastroduodenal disease, which is mediated in part by its outer membrane proteins (omps). to identify omps of h. pylori strain 26695, we performed a proteomic analysis. a sarcosine-insoluble outer membrane fraction was resolved by two-dimensional electrophoresis with immobilized ph gradient strips. most of the protein spots, with molecular masses of 10 to 100 kda, were visible on the gel in the alkaline pi regions (6.0 to 10.0). the proteome of the omps was analyzed by ...200414761989
genotypic and antibiotic susceptibility characteristics of a campylobacter coli population isolated from dairy farmland in the united kingdom.campylobacter infections are the most common cause of bacterial enteritis in humans, and nearly 8% of such infections are caused by campylobacter coli. most studies have concentrated on campylobacter jejuni, frequently isolated from intensively farmed poultry and livestock production units, and few studies have examined the spread and relatedness of campylobacter across a range of geographical and host boundaries. systematic sampling of a 100-km2 area of mixed farmland in northwest england yield ...200414766560
comparison of survival of campylobacter jejuni in the phyllosphere with that in the rhizosphere of spinach and radish plants.campylobacter jejuni has been isolated previously from market produce and has caused gastroenteritis outbreaks linked to produce. we have tested the ability of this human pathogen to utilize organic compounds that are present in leaf and root exudates and to survive in the plant environment under various conditions. carbon utilization profiles revealed that c. jejuni can utilize many organic acids and amino acids available on leaves and roots. despite the presence of suitable substrates in the p ...200414766604
simultaneous presence of multiple campylobacter species in dogs.the prevalence of coinfection of campylobacter species in dogs was determined using four isolation methods. in 26% of the positive-testing stools, multiple campylobacter species were identified. the use of multiple isolation methods as well as the time lapse between sampling and processing are important for detection of coinfection.200414766860
characterization of campylobacter isolates recovered from clinically healthy pigs and from sporadic cases of campylobacteriosis in humans.campylobacter spp. were recovered from 660 (77.6%) of 850 swine cecal contents at the abattoir and from 24 (8.6%) of 278 specimens from sporadic cases of human diarrhea during the same period in the same geographical area. campylobacter coli represented 95.7% of campylobacter isolates recovered from pigs and 8.3% of those isolated from humans. genetic profiles were determined by pulsed-field gel electrophoresis (pfge) using kpni enzyme to characterize the isolates in combination with phenotypic ...200414968951
distribution and characterization of campylobacter spp. from russian poultry.the distribution of campylobacter spp. on 13 poultry farms (broiler chicken, quail, pheasant, peacock, and turkey) from eight regions (vladimir, vologda, voronezh, kaluga, liptsk, moscow, orenburg, and orel) in russia was surveyed. intestinal materials were plated onto campylobacter-selective medium and plates were incubated microaerobically at 42 degrees c for 24 or 48 h. identification was based on colonial morphology, microscopic examination, and biochemical tests; latex agglutination assays ...200414968953
optimization of pcr-based methods for rapid detection of campylobacter jejuni, campylobacter coli and yersinia enterocolitica serovar 0:3 in wastewater samples.pcr-based methods were evaluated for their adequacy to assess the removal of pathogens from wastewater samples. for the development and optimization of the methods, samples were taken at two different sites from two different constructed wetlands. campylobacter jejuni/coli and yersinia enterocolitica serogroup 0:3 were selected as model pathogens and enterococcus faecalis as a standard microbiological indicator. the chosen pcr protocols were optimized for wastewater dna extracts in order to obta ...200414975667
transcriptional phase variation at the flhb gene of pseudomonas putida dot-t1e is involved in response to environmental changes and suggests the participation of the flagellar export system in solvent tolerance.frameshift mutations in a poly(g) track at the flhb gene of pseudomonas putida dot-t1e are responsible for the diminished swimming of this strain on semisolid medium, which contrasts with the high swimming ability of p. putida kt2440, which does not exhibit a poly(g) track at the flhb gene. we previously showed that a mutant lacking flhb was more sensitive to solvents than the wild-type strain (segura et al., j. bacteriol., 183:4127-4133, 2001). in this study, we show that swimming ability corre ...200414996824
multiplex pcr assay for differentiation of helicobacter felis, h. bizzozeronii, and h. salomonis.helicobacter felis, helicobacter bizzozeronii, and helicobacter salomonis are frequently found in the gastric mucous membrane of dogs and cats. these large spiral organisms are phylogenetically highly related to each other. their fastidious nature makes it difficult to cultivate them in vitro, hampering traditional identification methods. we describe here a multiplex pcr test based on the trna intergenic spacers and on the urease gene, combined with capillary electrophoresis, that allows discrim ...200415004062
occurrence of campylobacter jejuni in pets living with human patients infected with c. jejuni.campylobacter jejuni was recovered from four dogs (11%) and four cats (33%) living with danish human patients infected with c. jejuni. pulsed-field gel electrophoresis (pfge) analysis revealed the occurrence of the same quinolone-resistant strain in a girl and her dog. c. jejuni isolates with closely related (>95% similarity) pfge profiles occurred in humans and pets from different danish counties.200415004120
[the role of certain campylobacter types in the etiology of enterocolitis].in recent decades, medical community has increasingly been calling attention to the importance of campylobacter as an disease-causing agent in humans. nowadays, campylobacter jejuni (c. jejuni) is known as the most frequent bacterial cause of diarrhea worldwide. epidemiological differences of the infections caused by campylobacter, present in the developed and the developing countries, are attributed to the differences of the types of virulence. due to the specificity, and the demanding features ...200415022385
emergence of fluoroquinolone resistance in the native campylobacter coli population of pigs exposed to enrofloxacin.the effect of a single 5 day enrofloxacin treatment on the native campylobacter coli population in conventionally weaned 5-week-old pigs was investigated.materials: twelve pigs were split into two groups of six: one group was treated with a therapeutic dose (15 mg/pig/day) of enrofloxacin and the other remained untreated to act as the control. campylobacter coli were isolated from faecal samples and tested for ciprofloxacin resistance by measuring mic values. mutations in the quinolone resistanc ...200415028665
sequence polymorphism in the glycosylation island and flagellins of pseudomonas aeruginosa.a genomic island consisting of 14 open reading frames, orfa to orfn was previously identified in pseudomonas aeruginosa strain pak and shown to be essential for glycosylation of flagellin. dna microarray hybridization analysis of a number of p. aeruginosa strains from diverse origins showed that this island is polymorphic. pcr and sequence analysis confirmed that many p. aeruginosa strains carry an abbreviated version of the island (short island) in which orfd, -e and -h are polymorphic and orfi ...200415028697
prevalence and characteristics of shiga toxin-producing escherichia coli, salmonella spp. and campylobacter spp. isolated from slaughtered sheep in switzerland.caecum samples collected from 653 slaughtered sheep from two swiss abattoirs were examined. the aim of this study was: (i) to determine the prevalence of shiga toxin-producing escherichia coli (stec), salmonella spp. and campylobacter spp.; (ii) to further characterize isolated strains; and (iii) to discuss the results obtained with their relevance to food safety. the percentage of samples testing positive for stec by a polymerase chain reaction was 29.9%. the prevalence of positive salmonella s ...200415033267
development of a multiplex microarray microsystem.a hybrid multiplex microarray microsystem has been developed that consists of 32 individually addressable array reaction chambers, supporting the use of multichannel pipettes for addition of up to 8 samples simultaneously. discrimination between campylobacter jejuni and campylobacter coli bacteria was observed in dna samples containing campylobacter spp., with the same specificity and sensitivity as when compared to a full-size microarray. the spinloaded multiplex microarray microsystem describe ...200415052357
direct quantification of campylobacter jejuni and campylobacter lanienae in feces of cattle by real-time quantitative pcr.campylobacter species are fastidious to culture, and the ability to directly quantify biomass in microbiologically complex substrates using real-time quantitative (rtq) pcr may enhance our understanding of their biology and facilitate the development of efficacious mitigation strategies. this study reports the use of nested rtq-pcr to directly quantify campylobacter jejuni and campylobacter lanienae in cattle feces. for c. jejuni, the single-copy mapa gene was selected. for c. lanienae, the thre ...200415066825
bacterial pathogen incidences in sludge from swedish sewage treatment plants.this study surveyed the presence of bacterial pathogens in eight swedish sewage treatment plants (stps), with four different treatment methods, focusing on detection of zoonotic bacteria in raw and treated sludge. salmonella spp., listeria monocytogenes, campylobacter coli and jejuni, escherichia coli o157 and indicator bacteria were investigated. samplings were performed from july 2000 to june 2002, resulting in 64 raw sludge samples and 69 treated sludge samples. the samples from raw sludge (6 ...200415087179
in vitro and in vivo characterization of helicobacter hepaticus cytolethal distending toxin mutants.helicobacter hepaticus expresses a member of the cytolethal distending toxin (cdt) family of bacterial cytotoxins. to investigate the role of cdt in the pathogenesis of h. hepaticus, transposon mutagenesis was used to generate a series of isogenic mutants in and around the cdtabc gene cluster. an h. hepaticus transposon mutant with a disrupted cdtabc coding region no longer produced cdt activity. conversely, a transposon insertion outside of the cluster did not affect the cdt activity. an examin ...200415102759
cloning and characterization of the gene encoding the major cell-associated phospholipase a of legionella pneumophila, plab, exhibiting hemolytic activity.legionella pneumophila, the causative agent of legionnaires' disease, is an intracellular pathogen of amoebae, macrophages, and epithelial cells. the pathology of legionella infections involves alveolar cell destruction, and several proteins of l. pneumophila are known to contribute to this ability. by screening a genomic library of l. pneumophila, we found an additional l. pneumophila gene, plab, which coded for a hemolytic activity and contained a lipase consensus motif in its deduced protein ...200415102773
relative contribution of target gene mutation and efflux to fluoroquinolone and erythromycin resistance, in french poultry and pig isolates of campylobacter coli.thirty-eight avian and swine french isolates of campylobacter coli were studied for their mechanisms of co-resistance to fluoroquinolones and erythromycin. a thr86ile modification of gyra, responsible for fluoroquinolone resistance, was found in all the strains. two different levels of resistance to erythromycin (mic of 8-16 or >/=256 mg/l) were observed. a a2075g mutation in the 23s rrna genes was found only in the highly-resistant strains. phe-arg-beta-naphthylamide, an efflux pump inhibitor, ...200415120725
dual control of helicobacter pylori heat shock gene transcription by hspr and hrca.the hspr repressor regulates transcription of the groesl, hrca-grpe-dnak, and cbpa-hspr-orf operons of helicobacter pylori. here we show that two of the hspr-regulated operons, namely, the groesl and dnak operons, encoding the major cellular chaperone machineries are also regulated by the h. pylori homologue of the hrca repressor. similarly to the hspr mutation, deletion of the hrca gene also leads to complete derepression of the pgro and phrc promoters. the presence of both hspr and hrca is the ...200415126455
molecular characterization of class 1 integrons from irish thermophilic campylobacter spp.in this study a large random collection (n = 378) of irish thermophilic campylobacter isolates were investigated for the presence of integrons, genetic elements associated with the dissemination of antimicrobial resistance.200415128721
longitudinal study of the excretion patterns of thermophilic campylobacter spp. in young pet dogs in denmark.the campylobacter excretion patterns of 26 domestic pet dogs were described in a longitudinal study. the dogs entered the study between 3 and 8 months of age and were monitored until 2 years of age. they were tested monthly for campylobacter carriage in stool samples that were cultured on the campylobacter-selective media cat and modified ccda agar at 37 and 42 degrees c. this study comprised 366 fecal swab samples, of which 278 (76.2%) were found to be campylobacter positive, with the following ...200415131162
use of the omp50 gene for identification of campylobacter species by pcr.we studied the prevalence of the omp50 gene and the omp50 protein in campylobacter strains. immunodetection assays and dna-dna hybridizations showed that most c. coli strains tested were negative and most c. jejuni and c. lari strains tested were positive. a pcr assay was developed, using the omp50 gene as a species-specific target. we propose a combination of a hippurate test and an omp50 assay to perform identification of campylobacter species.200415131219
l-serine catabolism via an oxygen-labile l-serine dehydratase is essential for colonization of the avian gut by campylobacter jejuni.campylobacter jejuni is a microaerophilic, asaccharolytic bacterium. the identity of the carbon and energy sources used by c. jejuni in vivo is unknown, but the genome sequence of strain nctc11168 indicates the presence of genes for catabolism of a limited range of amino acids, including serine. specific omission of l-serine from a defined medium containing a mixture of amino acids led to a dramatic decrease in cell yields. as c. jejuni does not have a biosynthetic serine requirement, this suppo ...200414688104
characterization of a haemolytic phospholipase a(2) activity in clinical isolates of campylobacter concisus.a membrane-bound, haemolytic phospholipase a(2) (pla(2)) activity was detected in clinical strains of campylobacter concisus isolated from children with gastroenteritis. the clinical strains were assigned into two molecular groups (genomospecies) based on pcr amplification of their 23s rdna. this calcium-dependent, heat-stable, haemolytic pla(2) activity was detected in strains from both genomospecies. a crude haemolysin extract (che) was initially prepared from cellular outer-membrane proteins ...200415150326
prevalence and antimicrobial resistance of campylobacter coli isolated from fattening pigs in france.campylobacter are a leading cause of human diarrhea. the usual source of infection is contaminated food, particularly poultry but pork has also been described. the veterinary use of antimicrobial drugs has been suggested to be largely responsible for resistance in human isolates of this zoonotic pathogen. a study was carried out to investigate the occurrence and antimicrobial resistance of campylobacter isolated from french fattening pigs. from march 1998 to june 1999, stomach samples were colle ...200415172691
antimicrobial resistance among enteric pathogens.diarrhea is a major cause of morbidity and mortality in infants and children worldwide. use of antimicrobial therapy in children with bacterial diarrhea involves consideration of advantages and limitations of use of appropriate agents in the general population and in specific hosts. antimicrobial agents for bacterial diarrhea should be prescribed with an appreciation of limitations including antimicrobial resistance. studies from many countries have reported resistance to campylobacter jejuni, c ...200415185189
characterization of erythromycin resistance in campylobacter coli and campylobacter jejuni isolated from pig offal in new zealand.to determine the level and mechanism(s) of antimicrobial resistance in campylobacter isolates obtained from human and environmental sources from south canterbury, new zealand.200415186451
in vitro inhibitory activity of chinese leek extract against campylobacter species.three aqueous extracts of dietary materials of chinese leek (leek flower stem, soft leek and green leek) and two other reference extracts of allium plants were used to investigate the antibacterial effects against campylobacter jejuni and campylobacter coli. all the tested strains of campylobacter species were isolated from chickens. the minimum concentration of aqueous leek extracts (ales) required to inhibit the bacterial growth was 2.0 mg/ml. among the plant extracts tested, ales shared the l ...200415193803
genotyping of broiler-originated campylobacter jejuni and campylobacter coli isolates using fla typing and random amplified polymorphic dna methods.liver and intestine samples taken from 200 broilers at 20 flocks were inoculated onto preston enrichment broth and agar for selective isolation of campylobacter jejuni and campylobacter coli. the isolates were identified by both conventional and polymerase chain reaction (pcr) methods. campylobacter spp. were identified in 102 of 400 samples (200 liver and 200 intestine), 57 (14.25%) of which were identified as c. jejuni and 45 (11.25%) as c. coli. pcr-restriction fragment length polymorphism (r ...200415193806
relapsing cellulitis associated with campylobacter coli bacteremia in an agammaglobulinemic patient.campylobacter coli rarely causes bacteremia or extraintestinal infection. we report herein a case of agammaglobulinemia in which cellulitis associated with c. coli bacteremia relapsed after a disease-free interval of >5 years. pulsed field gel electrophoresis revealed that the organisms in this patient were genetically identical, suggesting a latent c. coli infection.200415194845
quinolone-resistant campylobacter infections: risk factors and clinical consequences.we integrated data on quinolone and macrolide susceptibility patterns with epidemiologic and typing data from campylobacter jejuni and c. coli infections in two danish counties. the mean duration of illness was longer for 86 patients with quinolone-resistant c. jejuni infections (median 13.2 days) than for 381 patients with quinolone-sensitive c. jejuni infections (median 10.3 days, p = 0.001). foreign travel, eating fresh poultry other than chicken and turkey, and swimming were associated with ...200415207057
adaptation of campylobacter jejuni nctc11168 to high-level colonization of the avian gastrointestinal tract.the genome sequence of the human pathogen campylobacter jejuni nctc11168 has been determined recently, but studies on colonization and persistence in chickens have been limited due to reports that this strain is a poor colonizer. experimental colonization and persistence studies were carried out with c. jejuni nctc11168 by using 2-week-old light sussex chickens possessing an acquired natural gut flora. after inoculation, nctc11168 initially colonized the intestine poorly. however, after 5 weeks ...200415213117
molecular characterization of benzimidazole resistance in helicobacter pylori.a family of benzimidazole derivatives (bi) was shown to possess potent and selective activity against helicobacter pylori, although the precise cellular target of the bis is unknown. spontaneous h. pylori mutants were isolated as resistant to a representative bi (compound a). genomic dna was isolated from a bi-resistant mutant, transformed into a bi-sensitive strain, and found to be sufficient to confer bi resistance. the resistance determinant was localized to a 17-kb clone after screening a la ...200415215104
helicobacter pylori flgr is an enhancer-independent activator of sigma54-rna polymerase holoenzyme.helicobacter pylori flgr activates transcription with sigma54-rna polymerase holoenzyme (sigma54-holoenzyme) from at least five flagellar operons. activators of sigma54-holoenzyme generally bind enhancer sequences located >70 bp upstream of the promoter and contact sigma54-holoenzyme bound at the promoter through dna looping to activate transcription. h. pylori flgr lacks the carboxy-terminal dna-binding domain present in most sigma54-dependent activators. as little as 42 bp of dna upstream of t ...200415231786
iron acquisition and regulation in campylobacter jejuni.iron affects the physiology of bacteria in two different ways: as a micronutrient for bacterial growth and as a catalyst for the formation of hydroxyl radicals. in this study, we used dna microarrays to identify the c. jejuni genes that have their transcript abundance affected by iron availability. the transcript levels of 647 genes were affected after the addition of iron to iron-limited c. jejuni cells. several classes of affected genes were revealed within 15 min, including immediate-early re ...200415231804
longitudinal study of campylobacter jejuni bacteriophages and their hosts from broiler chickens.a longitudinal study of bacteriophages and their hosts was carried out at a broiler house that had been identified as having a population of campylobacter-specific bacteriophages. cloacal and excreta samples were collected from three successive broiler flocks reared in the same barn. campylobacter jejuni was isolated from each flock, whereas bacteriophages could be isolated from flocks 1 and 2 but were not isolated from flock 3. the bacteriophages isolated from flocks 1 and 2 were closely relate ...200415240258
identification of bacterial populations in dairy wastewaters by use of 16s rrna gene sequences and other genetic markers.hydraulic flush waste removal systems coupled to solid/liquid separators and circulated treatment lagoons are commonly utilized to manage the large amounts of animal waste produced on high-intensity dairy farms. although these systems are common, little is known about the microbial populations that inhabit them or how they change as they traverse the system. using culture-based and non-culture-based methods, we characterized the microbial community structure of manure, water from the separator p ...200415240310
multiplex pcr assay for detection of streptococcus suis species and serotypes 2 and 1/2 in tonsils of live and dead pigs.a pcr assay was developed for the detection of streptococcus suis serotypes 2 and 1/2. this multiplex pcr is based on the amplification of the gene coding for 16s rrna of s. suis and on the amplification of the cps2j gene coding for the capsule of s. suis serotypes 2 and 1/2. an internal control was constructed and added in this test to monitor the efficiency of amplification in each reaction. to evaluate the specificity of the test, 31 strains of other bacterial species related to s. suis or is ...200415243078
characterization of plasmid-mediated apha-3 kanamycin resistance in campylobacter jejuni.a total of 254 isolates of campylobacter jejuni and three isolates of campylobacter coli, isolated from sweden, canada, and egypt, were screened for kanamycin resistance. eight strains of c. jejuni contained large plasmids that carried the apha-3 kanamycin-resistance marker. in six plasmids, the apha-3 gene was located downstream of an apparent insertion sequence, designated is607*, which showed a considerable similarity to is607, characterized on the chromosome of some helicobacter pylori strai ...200415256024
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