Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| investigating site-specific effects of the -x glutamate in a parvalbumin cd site model peptide. | the -x glutamate in a 33-residue model peptide comprising the cd site of carp parvalbumin 4.25 (parvcd) was replaced with aspartate (parvcd-xd) and the effect on calcium-dependent dimerization and calcium affinity assessed. the peptide parvcd demonstrates a 10(5)-fold lower calcium affinity than the same site in the native protein. both the parvcd and parvcd-xd model peptides fail to bind magnesium. the low calcium affinity and failure of the model parvcd site to bind magnesium may be due to hig ... | 1999 | 10562419 |
| experimental infection of calves with escherichia coli o157:h7. | three 3-month-old japanese black calves were experimentally infected with escherichia coli o157:h7 to define the magnitude (cfu/g) and duration of fecal shedding of the organism. in two of the three calves, fecal shedding of e. coli o157:h7 ceased in 5 and 9 weeks. the remaining calf continued shedding e. coli o157:h7 for more than 31 weeks, and the magnitude of the shedding ranged from 10(1) to 10(4) cfu/g of feces. the possibility is suggested that a percentage of animals naturally infected wi ... | 1999 | 10563303 |
| comparative sensitivity of immunoassays for haptens using monomeric and dimeric antibody fragments. | a single-chain anti-atrazine antibody fragment, scab (single-chain fv with a ck domain), was expressed in escherichia coli, and monomeric and dimeric species were preferentially purified from periplasmic extracts by chromatography upon nickel chelate immunosorbent columns or by immunoaffinity purification using a constant domain (ck) tag. recombinant monomeric and dimeric antibody fragments, fab, and intact monoclonal antibodies were compared in assays by competition between free atrazine in sol ... | 1999 | 10563896 |
| [fecal shedding and serum antibody responses of cattle experimentally infected with enterohaemorrhagic escherichia coli o157:h7]. | 1999 | 10565127 | |
| genotoxic effects of benzyl isothiocyanate, a natural chemopreventive agent. | benzyl isothiocyanate (bitc) is contained in cruciferous plants which are part of the human diet. numerous reports indicate that bitc prevents chemically induced cancer in laboratory animals and it has been postulated that bitc might also be chemoprotective in humans. on the other hand, evidence is accumulating that this compound is a potent genotoxin in mammalian cells by itself. to further elucidate the potential hazards of bitc, we investigated its genotoxic effects in different in vitro geno ... | 1999 | 10567035 |
| autoantibodies to brain components and antibodies to acinetobacter calcoaceticus are present in bovine spongiform encephalopathy. | bovine spongiform encephalopathy (bse) is a neurological disorder, predominantly of british cattle, which belongs to the group of transmissible spongiform encephalopathies together with creutzfeldt-jakob disease (cjd), kuru, and scrapie. autoantibodies to brain neurofilaments have been previously described in patients with cjd and kuru and in sheep affected by scrapie. spongiform-like changes have also been observed in chronic experimental allergic encephalomyelitis, at least in rabbits and guin ... | 1999 | 10569779 |
| occurrence of escherichia coli o157:h7 in hamburgers produced in brazil. | the occurrence of escherichia coli o157:h7 was evaluated in 886 samples of hamburgers produced by eight manufacturers in the south and southeast of brazil from january to september of 1997. the pathogen was not detected in any of the samples analyzed, although 17 (1.9%) showed the presence of e. coli strains, which presented agglutination with o157 antiserum. these strains were not confirmed, since a subsequent identification indicated that they were fermentation positive for sorbitol, incapable ... | 1999 | 10571325 |
| the effect of alpha-lactalbumin and beta-lactoglobulin hydrolysates on the metabolic activity of escherichia coli jm103. | bovine milk proteins alpha-lactalbumin (alpha-la) and beta-lactoglobulin (beta-lg) were hydrolysed with seven different proteolytic enzymes, and the effect of various hydrolysates on a genetically modified luminous escherichia coli jm103 was tested in vitro with a bioluminescence assay for bacterial growth and metabolism. undigested proteins did not inhibit the activity of tested e. coli jm103 at a concentration as high as 0.1 g ml-1. at the same concentrations, alpha-la hydrolysed with pepsin o ... | 1999 | 10583682 |
| agar underlay method for recovery of sublethally heat-injured bacteria. | a method of recovering sublethally heat-injured bacteria was developed. the procedure (termed the agar underlay method) uses a nonselective agar underlaid with a selective medium. in a two-chambered petri dish, the lutri plate (lp), a nonselective agar is inoculated with a population of sublethally heat-injured bacteria. after a 2-h repair incubation period, selective agar is added to the bottom chamber of the lp and incubated. by diffusing through the nonselective top agar, selective agents fro ... | 1999 | 10583985 |
| unusual amino acid usage in the variable regions of mercury-binding antibodies. | monoclonal antibodies (mab) specific for mercuric ions were isolated from balb/c mice injected with a mercury-containing, hapten-carrier complex. the antibodies reacted by enzyme-linked immunosorbent assay with bovine serum albumin-glutathione-mercuric chloride (bsa-gsh-hgcl) but not with bsa-gsh without mercury. nucleotide sequences from polymerase chain reaction products encoding six of the antibody heavy-chain variable regions and seven light-chain variable regions revealed that all the antib ... | 1999 | 10591102 |
| high occurrence of shiga toxin-producing escherichia coli (stec) in healthy cattle in rio de janeiro state, brazil. | in order to evaluate the prevalence of shiga toxin-producing escherichia coli (stec) strains, 197 fecal samples of healthy cattle from 10 dairy farms, four beef farms and one slaughterhouse at rio de janeiro state, brazil, were examined for shiga toxin (stx) gene sequences by polymerase chain reaction (pcr). for presumptive isolation of o157:h7 e. coli, the cefixime-potassium tellurite-sorbitol macconkey agar (ct-smac) was used. a high occurrence (71%) of stx was detected, and was more frequentl ... | 1999 | 10591502 |
| characterization of two fungal-elicitor-induced rice cdnas encoding functional homologues of the rab-specific gdp-dissociation inhibitor. | by using the mrna differential display approach to isolate defense signaling genes active at the early stage of fungal infection two cdna fragments with high sequence homology to rab-specific gdp-dissociation inhibitors (gdis) were identified in rice (oryza sativa l.) suspension cells. using polymerase-chain-reaction products as probes, two full-length cdna clones were isolated from a cdna library of fungal-elicitor-treated rice, and designated as osgdi1 and osgdi2. the deduced amino acid sequen ... | 1999 | 10592042 |
| mammalian mitochondrial ribosomal proteins (2). amino acid sequencing, characterization, and identification of corresponding gene sequences. | four different classes of mammalian mitochondrial ribosomal proteins were identified and characterized. mature proteins were purified from bovine liver and subjected to n-terminal or matrix-assisted laser-desorption mass spectroscopic amino acid sequencing after tryptic in-gel digestion and high pressure liquid chromatography separation of the resulting peptides. peptide sequences obtained were used to virtually screen expressed sequence tag data bases from human, mouse, and rat. consensus cdnas ... | 1999 | 10593885 |
| lactoferrin concentration in milk of bovine clinical mastitis. | the lactoferrin (lf) concentration in the milk from dairy cows with clinical mastitis was determined to evaluate the relationship between the lf concentration (lfc) in milk and the non-specific defensive capability of the udder. the mean lfc in 368 milk samples from 319 cows with clinical mastitis was significantly higher (p < 0.01) than that of normal cows. the mean lfc in milk from quarters infected with mycoplasma bovis or staphylococcus aureus was significantly higher (p < 0.05) than that of ... | 1999 | 10598071 |
| characterization of monoclonal antibodies against bovine herpesvirus 1 gd fusion protein expressed in e. coli. | a total of 20 hybridoma cell lines secreting monoclonal antibodies (mabs) against e. coli expressed bovine herpesvirus-1 (bhv-1) gd fusion protein were produced following the fusion of sp2/0 myeloma cells with splenocytes from balb/c mice immunized previously with immunoaffinity purified bhv-1 gd fusion protein. an indirect fluorescent antibody test (ifat) using bhv-1 infected mdbk cells was used for the selection of positive hybridomas secreting specific antibody. the monoclonal antibody isotyp ... | 1999 | 10598086 |
| protective cultures inhibit growth of listeria monocytogenes and escherichia coli o157:h7 in cooked, sliced, vacuum- and gas-packaged meat. | contamination of cooked meat products with listeria monocytogenes poses a constant threat to the meat industry. the aim of this study was therefore to investigate the use of indigenous lactic acid bacteria (lab) as protective cultures in cooked meat products. cooked, sliced, vacuum- or gas-packaged ham and servelat sausage from nine meat factories in norway were inoculated with 10(3) cfu/g of a mixture of three rifampicin resistant (rif-mutant) strains of l. monocytogenes and stored at 8 degrees ... | 1999 | 10598113 |
| crystal structure of the purine nucleoside phosphorylase (pnp) from cellulomonas sp. and its implication for the mechanism of trimeric pnps. | the three-dimensional structure of the trimeric purine nucleoside phosphorylase (pnp) from cellulomonas sp. has been determined by x-ray crystallography. the binary complex of the enzyme with orthophosphate was crystallized in the orthorhombic space group p212121 with unit cell dimensions a=64.1 a, b=108.9 a, c=119.3 a and an enzymatically active trimer in the asymmetric unit. x-ray data were collected at 4 degrees c using synchrotron radiation (embl/desy, hamburg). the structure was solved by m ... | 1999 | 10600382 |
| recurrent clinical mastitis caused by escherichia coli in dairy cows. | in this study, the occurrence of persistent intramammary infections caused by escherichia coli with recurrent episodes of clinical mastitis caused by e. coli are described for a cohort of 300 dutch dairy herds. calculations on the recurrent episodes were based on data collected by dairy farmers. the genotype of the e. coli strains was determined by means of a polymerase chain reaction using enterobacterial repetitive intergenic consensus (eric) primers, resulting in a dna fingerprint. quarters i ... | 1999 | 10022009 |
| influence of oxygen availability on physiology, verocytotoxin expression and adherence of escherichia coli o157. | a strain of escherichia coli serotype o157 was grown in steady state chemostat culture under aerobic, oxygen-limited and anaerobic conditions. the growth and metabolic efficiency of oxygen-limited and anaerobic cultures was impaired, with biomass yield and the molar growth yield for glucose, yglucose, reduced markedly in comparison with aerobic cultures. steady state cells were typically short rods 2-3 microns long, and were encapsulated by a layer of extracellular material. the majority of cell ... | 1999 | 10030015 |
| escherichia coli o157:h7 in retail ground beef in seattle: results of a one-year prospective study. | escherichia coli o157:h7 was sought systematically in 1,400 samples of retail ground beef in seattle in a 1-year prospective study. sorbitol-nonfermenting, lactose-fermenting, indole-positive colonies isolated after enrichment culture were probed for the presence of shiga toxin genes. totals of 67,040 sorbitol-nonfermenting and 66,705 sorbitol-fermenting colonies were characterized, but e. coli o157:h7 was not identified. the sensitivity of this technique was usually sufficient to detect e. coli ... | 1999 | 10030631 |
| cytochrome p450c17-expressing escherichia coli as a first-step screening system for 17alpha-hydroxylase-c17,20-lyase inhibitors. | we have designed and synthesized a number of cytochrome p450 17alpha-hydroxylase-c17,20-lyase (p450c17) inhibitors with the aim of inhibiting androgen synthesis. to select the most potent inhibitors, we initially used human testicular microsomes, which have a high level of expression of this enzyme. however, due to lack of availability of human tissue and variability among the samples, we utilized recombinant human enzyme expressed in escherichia coli. we designed a simple and economical protoco ... | 1999 | 10036137 |
| assessment of the adequacy of cleaning of equipment used for breaking beef carcasses. | enumeration of bacteria on product entering or leaving a beef carcass breaking process showed that the meat was being contaminated with escherichia coli during the process. the equipment used in the process appeared to be well cleaned, and few bacteria were recovered from meat-contacting surfaces of cleaned equipment. however, careful inspection of the cleaned equipment revealed obscured locations in the equipment which harboured detritus that carried large numbers of aerobic bacteria including ... | 1999 | 10050680 |
| collaborative evaluation of detection methods for escherichia coli o157:h7 from radish sprouts and ground beef. | for the evaluation of plating and immunological methods applicable to the detection of escherichia coli o157:h7 from ground beef and radish sprouts, a collaborative study was conducted. it focused on a comparison of the efficiency of the plating and immunological methods using various plating agars and immuno-kits in combination with enrichment in modified e. coli broth supplemented with novobiocin (mec + n), and using immunomagnetic separation. the plating media tested were sorbitol macconkey a ... | 1999 | 10050682 |
| characterization of rpos alleles in escherichia coli o157:h7 and in other e. coli serotypes. | the rpos nucleotide and predicted amino acid sequences from three escherichia coli o157:h7 isolates were compared with those from three other e. coli isolates, including the likely o157:h7 progenitor, e. coli o55:h7. these clinical and environmental isolates all had identical sigma s amino acid sequences, while laboratory strains k12 and dh1 had three and one amino acid alterations, respectively, in comparison with the majority sequence. to extend the analysis of sigma s sequence conservation to ... | 1999 | 10063629 |
| vaccines and diagnostic methods for bovine mastitis: fact and fiction. | a number of problems are uniquely associated with vaccination of dairy cows for mastitis. one of these is that the number of mastitis pathogens is numerous and heterogeneous. vaccine efforts have concentrated mainly on the major mastitis pathogens. while at least one s. aureus bacterin has been commercially available for a number of years, no large-scale, independent field trials have been published in refereed journals which support the efficacy of this vaccine. experimental vaccines for s. aur ... | 1999 | 9890021 |
| transcriptional inhibition of the operon for the spermidine uptake system by the substrate-binding protein potd. | inhibition of spermidine uptake in escherichia coli, which occurs in the presence of accumulated polyamines, has been studied using the spermidine uptake operon consisting of the pota, -b, -c, and -d genes. transcription of the potabcd operon was inhibited by potd, a spermidine-binding protein usually found in the periplasm, and the inhibitory effect of potd was increased by spermidine. transcription was not affected by bovine serum albumin, pota, or potf, suggesting that the effects of potd are ... | 1999 | 9890949 |
| roles of pilc and pile proteins in pilus-mediated adherence of neisseria gonorrhoeae and neisseria meningitidis to human erythrocytes and endothelial and epithelial cells. | unlike other type 4 pili, the neisserial pili consist of at least two distinct proteins, the highly variable major subunit pile forming the pilus fiber and the tip-associated adhesin pilc. pilc protein purified either from gonococci or from escherichia coli interacted with different human epithelial cell lines, primary epithelial and endothelial cells. the binding of pilc protein efficiently prevented the attachment of piliated neisseria gonorrhoeae and neisseria meningitidis to these cell types ... | 1999 | 9916098 |
| role of carboxyl-terminal charges on s-modulin membrane affinity and inhibition of rhodopsin phosphorylation. | s-modulin shows a higher affinity for urea-stripped frog rod outer segment membranes than s26 (a cone homologue of s-modulin). nacl at a concentration of several hundred millimolar reduced the membrane affinity of s-modulin to the s26 level. chimeric s-modulin and s26 whose respective 23 and 29 amino acids at the carboxyl terminus were swapped showed membrane affinites similar to those of s26 and s-modulin, respectively. the membrane affinity of an s-modulin mutant lacking c-terminal positive ch ... | 1999 | 9930992 |
| cryptosporidium and concurrent infections with other major enterophatogens in 1 to 30-day-old diarrheic dairy calves in central spain. | faeces samples from 218, 1 to 30-day-old, diarrheic dairy calves in 65 dairy herds were screened for the presence of cryptosporidium and concurrent infections with rotavirus, coronavirus, f5 escherichia coli and salmonella spp. calves were grouped according to their age as follows: 1-7, 8-14, 15-21 and 22-30 days. cryptosporidium infection was detected in 43.8%, 71.9%, 63.2% and 6.9% of the calves in the respective age groups. significant differences in the detection rate of cryptosporidium were ... | 1999 | 9950342 |
| pregnancy-associated glycoprotein and decreased polymorphonuclear leukocyte function in early post-partum dairy cows. | phagocytosis and oxidative burst activity of polymorphonuclear neutrophil leukocytes (pmn) isolated from blood and pregnancy-associated glycoprotein (bpag) concentrations in plasma were evaluated in two longitudinal studies in dairy cows from 3 weeks before until 5 weeks after calving, carried out in the united states and in europe. ingestion of staphylococcus aureus by blood pmn increased during the first week after calving and normalised 3 weeks post-partum. phagocytosis of escherichia coli di ... | 1999 | 9950353 |
| detection of escherichia coli o157:h7 from musca domestica (diptera: muscidae) at a cattle farm in japan. | enterohemorrhagic escherichia coli (ehec) o157:h7 was isolated for the first time from musca domestica l. a total of 310 fly samples was collected from 4 different farms in obihiro-city, hokkaido, in the summer and autumn of 1997;5 samples carried e. coli serotype o157:h7. using elisa and vero cell cytotoxicity assay, 3 isolates from 1 cattle farm produced both active shiga-toxin type 1 (stx1) and 2 (stx2). these isolates also carried hemolysin and eaea genes and harbored the 90-kb virulence pla ... | 1999 | 10071501 |
| modulation of the remote heme site geometry of recombinant mouse neuronal nitric-oxide synthase by the n-terminal hook region. | the role of two essential residues at the n-terminal hook region of neuronal nitric-oxide synthase (nnos) in nitric-oxide synthase activity was investigated. full-length mouse nnos proteins containing single-point mutations of thr-315 and asp-314 to alanine were produced in the escherichia coli and baculovirus-insect cell expression systems. the molecular properties of the mutant proteins were analyzed in detail by biochemical, optical, and electron paramagnetic resonance spectroscopic technique ... | 1999 | 10075660 |
| pattern of diarrhoea in newborn beef calves in south-west france. | a prospective study was carried out on 94 randomly selected beef herds in the midi-pyrénées region in france. the objective was to describe diarrhoea and mortality in beef calves from birth to 30 days of age. calves (3,080) were followed from december 1995 to april 1996, and a total of 700 visits allowed records of herd management practices, individual data and environmental conditions to be collected. the incidence rate for diarrhoea during the neonatal period was 14.6%, and varied markedly bet ... | 1999 | 10081113 |
| expression of bovine cytokines in escherichia coli. | glutathione s-transferase fusion proteins of bovine interleukin-2 (il-2), il-4, il-6 and interferon-gamma (ifn-gamma) were expressed in escherichia coli. complementary dna (cdna) for open reading frame of each cytokine without signal peptide encoding region was amplified by reverse transcriptional polymerase chain reaction method and was subcloned into pgex-5x-1. in result, il-6 and ifn-gamma fusion proteins in bacteria were soluble, but il-2 and il-4 fusion proteins were insoluble. the insolubl ... | 1999 | 10081758 |
| lipopolysaccharide enhances the production of vascular endothelial growth factor by human pulp cells in culture. | we investigated whether vascular endothelial growth factor (vegf) production by human pulp cells (hpc) is regulated by lipopolysaccharide (lps) in relation to the pathogenesis of pulpitis. although hpc incubated with medium alone only marginally expressed vegf mrna and produced a low level of vegf as detected by enzyme-linked immunosorbent assay, the vegf mrna expression and vegf production were markedly enhanced upon stimulation with lps from escherichia coli. prevotella intermedia lps, phorbol ... | 1999 | 10084996 |
| characterization of the cardiac holotroponin complex reconstituted from native cardiac troponin t and recombinant i and c. | cardiac troponin i (ctni), the inhibitory subunit of cardiac troponin (ctn), is phosphorylated by the camp-dependent protein kinase a at two adjacently located serine residues within the heart-specific n-terminal elongation. four different phosphorylation states can be formed. to investigate each monophosphorylated form ctni mutants, in which each of the two serine residues is replaced by an alanine, were generated. these mutants, as well as the wild-type cardiac troponin i (ctni-wt) have been e ... | 1999 | 10103031 |
| real-time monitoring of escherichia coli o157:h7 adherence to beef carcass surface tissues with a bioluminescent reporter. | a method for studying bacteria that are attached to carcass surfaces would eliminate the need for exogenous sampling and would facilitate understanding the interaction of potential human food-borne pathogens with food animal tissue surfaces. we describe such a method in which we used a bioluminescent reporter strain of escherichia coli o157:h7 that was constructed by transformation with plasmid pcgls1, an expression vector that contains a complete bacterial luciferase (lux) operon. beef carcass ... | 1999 | 10103275 |
| catalase hpii from escherichia coli exhibits enhanced resistance to denaturation. | catalase hpii from escherichia coli is a homotetramer of 753 residue subunits. the multimer displays a number of unusual structural features, including interwoven subunits and a covalent bond between tyr415 and his392, that would contribute to its rigidity and stability. as the temperature of a solution of hpii in 50 mm potassium phosphate buffer (ph 7) is raised from 50 to 92 degrees c, the enzyme begins to lose activity at 78 degrees c and 50% inactivation has occurred at 83 degrees c. the ina ... | 1999 | 10194300 |
| a mutation in the heterotrimeric stimulatory guanine nucleotide binding protein alpha-subunit with impaired receptor-mediated activation because of elevated gtpase activity. | it has been reported that substitution of arg258, a residue within the gtpase domain of the heterotrimeric guanine nucleotide binding protein (g protein) alpha-subunit (alphas), to alanine (alphas-r258a) results in decreased activation by receptor or aluminum fluoride (alf4-) and increased basal gdp release. arg258 interacts with gln170 in the helical domain, and, presumably, loss of this interaction between the gtpase and helical domain leads to more rapid gdp release, resulting in decreased ac ... | 1999 | 10200251 |
| chloroplast nadh dehydrogenase from pisum sativum: characterization of its activity and cloning of ndhk gene. | the pea chloroplast ndhk gene coding for a component of a nadh-plastoquinone oxidoreductase has been cloned and sequenced. this gene codes for a polypeptide of 227 amino acids and a predicted molecular mass of 25,495 da which belongs to the family of the 20 kda psst subunit of the bovine mitochondrial complex i. a fragment of this gene has been overexpressed in escherichia coli, and antibodies against the expressed polypeptide recognize a protein of the predicted molecular mass from pea thylakoi ... | 1999 | 10202810 |
| detection of multidrug-resistant salmonella enterica serotype typhimurium dt104 based on a gene which confers cross-resistance to florfenicol and chloramphenicol. | salmonella enterica serotype typhimurium (s. typhimurium) dt104 (dt104) first emerged as a major pathogen in europe and is characterized by its pentadrug-resistant pattern. it has also been associated with outbreaks in the united states. the organism typically carries resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline. the mechanism of chloramphenicol resistance in dt104 was determined by producing antibiotic-resistant escherichia coli host strain clones from ... | 1999 | 10203484 |
| effect of antibiotic induced bacterial clearance in the udder on l-selectin shedding of blood neutrophils in cows with escherichia coli mastitis. | bacterial clearance, l-selectin adhesion receptor expression and neutrophil recruitment during experimentally induced escherichia coli mastitis were investigated. acute mastitis was induced by injection of 10(4) cfu e. coli into both left quarters of 12 clinically healthy lactating cows, 2-6 weeks after parturition. half the cows were treated intravenously 10 h after infection, and subcutaneously 30 h after infection with enrofloxacin. in both groups, bacterial count, milk serum albumin, milk so ... | 1999 | 10206204 |
| antibacterial activity of gentamicin and ciprofloxacin against gram-negative bacteria: interactions with pig and calf sera. | the antibacterial activity of pig and calf serum and its ability to interact with gentamicin and ciprofloxacin were studied in vitro using escherichia coli k-12, proteus rettgeri (sanelli) and klebsiella pneumoniae atcc 10031. the antimicrobial activity of the above drugs, alone or in combination with serum, was investigated by the checkerboard method and expressed as the minimal inhibitory concentration (microg ml-1). pig serum (25%) with gentamicin had a synergistic antibacterial effect agains ... | 1999 | 10208763 |
| unusual sites of arginine methylation in poly(a)-binding protein ii and in vitro methylation by protein arginine methyltransferases prmt1 and prmt3. | arginine methylation is a post-translational modification found mostly in rna-binding proteins. poly(a)-binding protein ii from calf thymus was shown by mass spectrometry and sequencing to contain ng, ng-dimethylarginine at 13 positions in its amino acid sequence. two additional arginine residues were partially methylated. almost all of the modified residues were found in arg-xaa-arg clusters in the c terminus of the protein. these motifs are distinct from arg-gly-gly motifs that have been previ ... | 1999 | 10224081 |
| molecular cloning of a novel human collectin from liver (cl-l1). | collectins are a c-lectin family with collagen-like sequences and carbohydrate recognition domains. these proteins can bind to carbohydrate antigens of microorganisms and inhibit their infection by direct neutralization and agglutination, the activation of complement through the lectin pathway, and opsonization by collectin receptors. here we report the cloning of a cdna encoding human collectin from liver (cl-l1 (collectin liver 1)) that has typical collectin structural characteristics, consist ... | 1999 | 10224141 |
| shiga toxin 1 from escherichia coli blocks activation and proliferation of bovine lymphocyte subpopulations in vitro. | shiga toxin-producing escherichia coli (stec) is widespread in the cattle population, but the clinical significance of shiga toxins (stx's) for the bovine species remains obscure. since stx's exert immunomodulating effects in other species, we examined the effect of purified stx1 on a bovine b lymphoma cell line (bl-3) and peripheral blood mononuclear cells (pbmc) isolated from adult bovine blood by viability assays and flow cytometry analysis. stx1 markedly induced apoptosis in stimulated bl-3 ... | 1999 | 10225876 |
| some emerging food and water borne pathogens. | emerging pathogens are those infective organisms whose incidence has recently increased or is likely to increase during the next two decades due to changes in demography, food habits, food technology, commerce, water sources and environmental factors. some important emerging food and water borne bacterial pathogens include listeria monocytogenes, campylobacter jejuni, yersinia enterocolitica, salmonella enteritidis, escherichia coli o157: h7, vibrio cholerae biotype e1 tor serotype 0139, vibrio ... | 1999 | 10810592 |
| virulence factors of avian escherichia coli associated with swollen head syndrome. | virulence characteristics of 50 strains of escherichia coli isolated from chickens with swollen head syndrome were examined. the results were the following: in the absence of d-mannose, 74% of strains agglutinated guinea pig erythrocytes, but in the presence of d-mannose 32% agglutinated guinea-pig erythrocytes and 62% agglutinated human erythrocytes. when slide agglutination assays were carried out with antisera to adhesin of bovine and swine origin (k88, k99, f41, f42 987p and 2134p), only 14% ... | 1998 | 18483979 |
| ribotyping of fusobacterium necrophorum strains isolated from bovine and ovine hepatic abscesses. | a microbiological study was made of 100 strains of fusobacterium necrophorum isolated from hepatic abscesses in bovine and ovine herds. differences between the biological activity and ribotypes within the two f. necrophorum subspecies were studied. conventional methods identified 89 isolates as f. necrophorum subsp. necrophorum and 11 as f. necrophorum subsp. funduliforme. for ribotyping, 50 strains (35 f.n. subsp. necrophorum, 11 f.n. subsp. funduliforme and 4 reference strains) were digested w ... | 1998 | 16887645 |
| synthesis and serological characterization of l-glycero-alpha-d-manno-heptopyranose-containing di- and tri-saccharides of the non-reducing terminus of the escherichia coli k-12 lps core oligosaccharide. | synthesis of the title trisaccharide was accomplished by sugar chain extension starting from the non-reducing terminus: coupling of glcp nac with ld-hepp, then adding glcp-oall. an alternative route started from the reducing end: coupling of ld-hepp with glcp-oall, then addition of glcp nac. in the synthesis of the title disaccharide a modification of the first approach was employed. the allyl glycosides were coupled with cysteamine, activated with thiophosgene and conjugated to bovine serum alb ... | 1998 | 10230038 |
| production, crystallization and diffraction to atomic resolution of an antibody fv specific for the blood-group a oligosaccharide antigen. | the histoblood-group abo carbohydrate antigens are well known as important factors in blood transfusions, but they can also act as receptors for infectious agents and have been implicated in susceptibility to certain carcinomas. a single-chain variable-domain antigen-binding fragment (scfv) gene based on the known sequence of an anti-blood-group-a monoclonal antibody (ac1001) has been synthesized and expressed in escherichia coli. the purified scfv preparation existed primarily in the monomeric ... | 1998 | 10089537 |
| the susceptibility of gram-negative rods and their adaptive forms resistant to colistine to the bactericidal action of sera. | the susceptibility of escherichia coli k1, salmonella enteritidis, salmonella typhimurium strains and their adaptative forms resistant to colistine (colr forms) was compared with respect to their sensitivity to the bactericidal action of normal cord serum and normal bovine serum. it has been shown that the colr forms are more susceptible to sera as compared to initial strains. the increase of sensitivity of the colr forms is connected with structural changes within bacterial cell wall which is t ... | 1998 | 9990711 |
| lactoferricin of bovine origin is more active than lactoferricins of human, murine and caprine origin. | the antimicrobial peptide lactoferricin is generated by gastric pepsin cleavage of lactoferrin. we have examined the antimicrobial activity of lactoferricins derived from lactoferrin of human, murine, caprine and bovine origin with minimal inhibitory concentration (mic) and minimal bactericidal concentration (mbc) against e. coli atcc 25922 and s. aureus atcc 25923. we found that lactoferricin of bovine origin (lf-cin b) was the most efficacious of the lactoferricins tested. by comparing the lin ... | 1998 | 10066056 |
| mechanisms of dna damage by chromium(v) carcinogens. | reactions of bis(2-ethyl-2-hydroxy-butanato)oxochromate(v) with puc19 dna, single-stranded calf thymus dna (ss-ctdna), a synthetic oligonucleotide, 5'-gatctatggacttacttcaaggccgggtaatgcta-3' (35mer), deoxyguanosine and guanine were carried out in bis-tris buffer at ph 7.0. the plasmid dna was only nicked, whereas the single-stranded dna suffered extensive damage due to oxidation of the ribose moiety. the primary oxidation product was characterized as 5-methylene-2-furanone. although all four base ... | 1998 | 9512527 |
| evaluation of an enzyme-linked immunosorbent assay using recombinant major surface protein 5 for serological diagnosis of bovine anaplasmosis in venezuela. | an indirect enzyme-linked immunosorbent assay (elisa) was developed for the serological diagnosis of bovine anaplasmosis with purified recombinant major surface protein 5 (msp5) of anaplasma marginale produced in escherichia coli. serum antibody responses against msp5 were detected in calves experimentally infected with a. marginale as early as 21 days postinfection and reached maximum titers at 28 days postinfection. the msp5 elisa performed with serum samples taken from field cattle from diffe ... | 1998 | 9521155 |
| one-headed kinesin derivatives move by a nonprocessive, low-duty ratio mechanism unlike that of two-headed kinesin. | a single molecule of the "two-headed" motor enzyme kinesin can move along a microtubule continuously for many enzymatic turnovers (processive movement), and the velocity produced by one kinesin molecule is the same as that produced by many kinesin molecules (high duty ratio). we studied the microtubule movement driven at 1 mm atp by biotinated n-terminal fragments of drosophila kinesin heavy chain attached to streptavidin-coated coverslips at various surface densities. k448-bio has velocity at a ... | 1998 | 9521668 |
| risk factors for clinical mastitis in a random sample of dairy herds from the southern part of the netherlands. | the incidence of clinical mastitis in dairy cows was estimated in 171 randomly selected dairy herds from the southern part of the netherlands. a total of 1103 quarter cases was reported. the mean annual incidence rate was 12.7 quarter cases/yr per 100 cows. the modeling incidence rate of clinical mastitis at the herd level indicated that a number of risk factors were associated with a higher rate of clinical mastitis: one or more cows that were leaking milk, one or more cows with trampled teats, ... | 1998 | 9532495 |
| alteration in immune responsiveness during the peripartum period and its ramification on dairy cow and calf health. | substantial evidence indicates that innate and acquired defense mechanisms are lowest from 3 wk precalving to 3 wk postcalving. this lowered responsiveness includes aspects of systemic and mammary gland immunity that may account, at least in part, for the increased incidence of peripartum disease. the physical and metabolic stresses of pregnancy, calving, and lactation may contribute to this decrease in host resistance and the subsequent increase in disease incidence. however, variation among co ... | 1998 | 9532513 |
| studies of the presence of verocytotoxic escherichia coli o157 in bovine faeces submitted for diagnostic purposes in england and wales and on beef carcases in abattoirs in the united kingdom. | a survey of beef carcases in abattoirs in the uk was carried out in order to estimate the prevalence of contamination with verocytotoxin-producing escherichia coli (vtec) serogroup o157. contamination with verocytotoxin-producing e. coli (vtec) o157 was confirmed in 0.47% of the 4067 (95% confidence limits 0.22-1.00%) of neck muscle samples. a significant tendency for carcases present in the same abattoir on the same day to have similar results was found, thus suggesting cross contamination. vte ... | 1998 | 9593489 |
| the occurrence and replication of escherichia coli in cattle feeds. | sixty-three of 209 (30.1%) samples of cattle feed that were collected from multiple commercial sources and from farms were found to contain escherichia coli. however, none of the feed samples examined were culture-positive for e. coli o157. replication of fecal e. coli, including e. coli o157, was demonstrated in a variety of feeds at temperatures that were similar to those found on farms in summer months. fresh mixed rations containing corn silage were sampled from 16 dairies. rations from 12 o ... | 1998 | 9594399 |
| on-line dual microdialysis with esi-ms for direct analysis of complex biological samples and microorganism lysates. | a novel dual-microdialysis approach has been developed for fast and efficient fractionation and cleanup for esi-ms and esi ms/ms analyses of biological samples. a modified dynamic microdialyzer utilizing two mirror-image serpentine channels, which sandwich a regenerated cellulose membrane of selected molecular weight cutoff, serves as the first stage for the removal of high-molecular-weight components and cellular residue. the second stage employs a hollow microdialysis capillary to remove low-m ... | 1998 | 9599580 |
| mammalian mitochondrial methionyl-trna transformylase from bovine liver. purification, characterization, and gene structure. | the mammalian mitochondrial methionyl-trna transformylase (mtfmt) was partially purified 2,200-fold from bovine liver mitochondria using column chromatography. the polypeptide responsible for mtfmt activity was excised from a sodium dodecyl sulfate-polyacrylamide gel and the amino acid sequences of several peptides were determined. the cdna encoding bovine mtfmt was obtained and its nucleotide sequence was determined. the deduced amino acid sequence of the mature form of mtfmt consists of 357 am ... | 1998 | 9614118 |
| lipofection of cultured mouse muscle cells: a direct comparison of lipofectamine and dosper. | cationic lipid-dna complexes (lipoplexes) have been widely used as gene transfer vectors which avoid the adverse immunogenicity and potential for viraemia of viral vectors. with the long-term aim of gene transfer into skeletal muscle in vivo, we describe a direct in vitro comparison of two commercially available cationic lipid formulations, lipofectamine and dosper. optimisation of transfection was performed in the c2c12 mouse muscle cell line, before further studies in primary mouse myoblasts a ... | 1998 | 9614580 |
| the flavoprotein component of the escherichia coli sulfite reductase can act as a cytochrome p450c17 reductase. | the flavoprotein component (sir-fp) of the e. coli sulfite reductase was found to support 17 alpha-hydroxylation of pregnenolone in the presence of cytochrome p450c17. half maximum activity is obtained for a 1:1 ratio of sir-fp, expressed as monomer concentration, to p450c17. when compared to bovine nadph-cytochrome p450 reductase, sir-fp is about 12-15 times less efficient. p450c17 was demonstrated to interact specifically with the fmn-binding domain of the protein and the n-terminal part of si ... | 1998 | 9618257 |
| the dinuclear center of cytochrome bo3 from escherichia coli. | for the study of the dinuclear center of heme-copper oxidases cytochrome bo3 from escherichia coli offers several advantages over the extensively characterized bovine cytochrome c oxidase. the availability of strains with enhanced levels of expression allows purification of the significant amounts of enzyme required for detailed spectroscopic studies. cytochrome bo3 is readily prepared as the fast form, with a homogeneous dinuclear center which gives rise to characteristic broad epr signals not ... | 1998 | 9623806 |
| association of genes encoding p fimbriae, cs31a antigen and east 1 toxin among cnf1-producing escherichia coli strains from cattle with septicemia and diarrhea. | fifty-six cnf1-producing escherichia coli strains isolated from cattle with diarrhea or septicemia were screened by pcr for the detection of pap, sfa, afa, clpg, or f17 adherence factor and east 1 toxin genes. all the isolates were pap-positive, in accordance with the close association of pap, cnf1 and alpha-hemolysin genes observed on human and porcine e. coli. only the gene encoding the p adhesin of class iii (prsg) was detected. genes encoding cs31a antigen (71%) and s fimbriae (34%) (but not ... | 1998 | 9627958 |
| research notes: prevalence of selected microbial pathogens in processed poultry waste used as dairy cattle feed. | processed poultry litter intended for dairy cattle feed was collected on 13 dairy ranches in the san joaquin valley of california and analyzed for the presence of significant bacterial pathogens associated with clinical disease in cattle or foodborne disease in humans. litter samples were collected from the surface and interior of the litter piles upon arrival on the dairies and 2 to 4 wk later. litter samples were cultured for salmonella, escherichia coli, campylobacter, and other bacteria. the ... | 1998 | 9628527 |
| adhesion of some probiotic and dairy lactobacillus strains to caco-2 cell cultures. | the adhesion of 12 different lactobacillus strains was studied using caco-2 cell line as an in vitro model for intestinal epithelium. some of the strains tested have been used as probiotics, and most of them are used in the dairy and food industry. human and bovine enterotoxigenic escherichia coli strains were used as positive and negative control, respectively. bacterial adhesion to caco-2 cell cultures was quantitated using radiolabelled bacteria. the adherence of bacteria was also observed mi ... | 1998 | 9631336 |
| novel recombinant analogues of bovine placental lactogen. g133k and g133r provide a tool to understand the difference between the action of prolactin and growth hormone receptors. | two new analogues of bovine placental lactogen (bpl), bpl(g133k) and bpl(g133r), were expressed in escherichia coli, refolded, and purified to a native form. binding experiments, which are likely to represent the binding to site 1 only, to intact fdc-p1 cells transfected with rabbit (rb) growth hormone receptor (ghr) or with human (h) ghr, to nb2 rat lymphoma cells, or to rabbit mammary gland membranes prolactin receptor (prlr), revealed only small or no reduction in binding capacity. the comple ... | 1998 | 9632658 |
| factors affecting the heat resistance of escherichia coli o157:h7. | escherichia coli o157:h7 has been reported as being not particularly heat resistant. however, several factors which might increase its heat resistance have been investigated in this study using five strains. increase in growth temperature to 40 degrees c, as found in the cow gut, heat-shock at sub-lethal temperatures of 42, 45, 48 and 50 degrees c, and variable heating rate (1 degree c min-1 to 23 degrees c min-1) had no dramatic effect on heat resistance. growth phase had a marked impact on hea ... | 1998 | 9633099 |
| compensation of preliminary blood phagocyte immaturity in the newborn calf. | to estimate the functional maturity of the phagocytic defence in neonatal calves, we analyzed the characteristics of blood phagocytes from calves (n = 10) 1 h post partum (p.p.) and 4 h p.p. at 1 h p.p., all calves were colostrum-deprived, while 5 calves had received colostrum before the 4 h p.p. sampling. the results were compared to those obtained from 3-9-week-old calves (n = 10). phagocytic and oxidative burst activity of polymorphonuclear leukocytes (pmnl) and monocytes were determined in w ... | 1998 | 9646436 |
| endocytosis and mhc class ii expression by human oviductal epithelium according to stage of the menstrual cycle. | the epithelium is the first barrier against pathogens invading the lumen of the human oviduct. its expression of class ii major histocompatibility complex (mhc class ii) proteins suggests that it might play a role in antigen presentation during the local immune response. to study the role of the oviductal epithelium in antigen processing, its endocytic properties and mhc class ii expression were examined. for assay of endocytosis, fluorescein isothiocyanate-labelled bovine serum albumin (bsa-fit ... | 1998 | 9647540 |
| potent enzyme inhibitors derived from dromedary heavy-chain antibodies. | evidence is provided that dromedary heavy-chain antibodies, in vivo-matured in the absence of light chains, are a unique source of inhibitory antibodies. after immunization of a dromedary with bovine erythrocyte carbonic anhydrase and porcine pancreatic alpha-amylase, it was demonstrated that a considerable amount of heavy-chain antibodies, acting as true competitive inhibitors, circulate in the bloodstream. in contrast, the conventional antibodies apparently do not interact with the enzyme's ac ... | 1998 | 9649422 |
| detection of verotoxin-producing escherichia coli o157:h7 by multiplex polymerase chain reaction. | we constructed primers for multiplex polymerase chain reaction (pcr) to detect verotoxin-producing escherichia coli (vtec) o157:h7. the multiplex pcr primers were designed from the sequence of the flagellin structural gene of escherichia coli flagellar type h7 (genbank under accession number l07388), and from the sequence of the rfbe gene of escherichia coli o157:h7 (genbank under accession number s83460). in addition to these primers, we used a primer pair reported by karch and meyer (j. clin. ... | 1998 | 9654369 |
| u1 snrnp inhibits pre-mrna polyadenylation through a direct interaction between u1 70k and poly(a) polymerase. | it has previously been shown in vivo that bovine papillomavirus represses its late gene expression via a 5' splice site sequence located upstream of the late polyadenylation signal. here, the mechanism of repression is determined by in vitro analysis. u1 snrnp binding to the 5' splice site results in inhibition of polyadenylation via a direct interaction with poly(a) polymerase (pap). although the inhibitory mechanism is similar to that used in u1a autoregulation, u1a within the u1 snrnp does no ... | 1998 | 9659922 |
| virulence determinants of escherichia coli isolated from milk of sows with coliform mastitis. | escherichia coli isolates recovered from the milk of sows with coliform mastitis were examined to determine their biochemical and serologic characteristics, serum resistance and ability to adhere to fibronectin and bovine fetal fibroblasts. no common biotype was identified, and a variety of serovars were detected. ninety-five per cent of the investigated strains were serum resistant in swine serum. binding to fibronectin was demonstrated in most of the strains. at a binding level above 13% of th ... | 1998 | 9673580 |
| differentiation and quantification of theileria sergenti piroplasm types using type-specific monoclonal antibodies. | antigenic properties of two representative allelic products of the major piroplasm surface protein (mpsp) of theileria sergenti were studied. sera from cattle infected with either of ikeda and chitose types of the parasite reacted strongly with homologous but weakly with heterologous recombinant antigens in immunoblotting. monoclonal antibodies (moabs) produced against the both allelic products of mpsp parasites reacted only to the immunizing antigen. these results suggested that crossreactivity ... | 1998 | 9673935 |
| association of herd management factors with colonization of dairy cattle by shiga toxin-positive escherichia coli o157. | management factors in 36 pacific northwest dairy herds were evaluated for their association with the prevalence of shiga toxin-positive escherichia coli o157 (e. coli o157) in dairy cattle. the within-herd prevalence of e. coli o157 was estimated by bacteriological culture of fecal pat samples, collected monthly for 6 months (approximately 60 per visit), from heifer cattle. during the first visit to each farm, a management questionnaire was administered that covered a broad range of animal husba ... | 1998 | 9678159 |
| enhancement by copper, zinc superoxide dismutase of dna damage and mutagenicity with hydrogen peroxide. | oxidative dna damage caused by hydrogen peroxide was enhanced by copper, zinc superoxide dismutase (cuznsod) in a concentration-dependent manner, as reflected by the formation of 8-hydroxy-2'-deoxyguanosine (8-oh-dg) and strand breaks. hydroxyl radical scavengers such as sodium azide, mannitol and 5,5-dimethyl-1-pyrroline n-oxide (dmpo), a metal chelator, diethylenetriamine-pentaacetic acid, and catalase decreased strand breaks and 8-oh-dg formation in dna. the deoxyribose assay showed that hydr ... | 1998 | 9679665 |
| the region of alpha-lactalbumin recognized by groel. | the binding constants between disulfide-intact or various disulfide-reduced bovine alpha-lactalbumins and an escherichia coli chaperonin, groel, were determined by using the equilibrium dialysis method. the disulfide-intact and one-disulfide (cys6-cys120)-reduced alpha-lactalbumins were shown not to bind with groel both in the presence and absence of ca2+. the two-disulfide (cys6-cys120 and cys28-cys111)-reduced alpha-lactalbumin, which has the native-like tertiary structure in its beta-domain r ... | 1998 | 9685721 |
| role of phe120 in the activity and structure of bovine pancreatic ribonuclease a. | phenylalanine120 is a candidate residue juxtaposing catalytic his12 and his119 in ribonuclease a (rnase a). to clarify its role in construction of the catalytic center, phe120 was replaced by alanine, tryptophan, leucine, or glutamic acid by site-directed mutagenesis. the transphosphorylation and hydrolysis activities of the mutant rnase as, respectively, toward cytidinyl 3',5' adenosine (cpa) and cytidine 2',3' cyclic monophosphate (c>p) were compared with those of the wild type enzyme. the km ... | 1998 | 9685734 |
| expression and equilibrium denaturation of cardiac troponin i: stabilization of a folding intermediate during denaturation by urea. | human cardiac troponin i has been expressed at high level in escherichia coli as a fusion protein by using the expression vector ptac114. the expressed protein forms primarily intracellular inclusion bodies that are solubilized in the presence of 8 m urea. the purified troponin i is recognized by anti-(human cardiac troponin i) monoclonal antibodies. equilibrium denaturation of recombinant human troponin i and bovine troponin i is compared by monitoring changes in the protein's fluorescence and ... | 1998 | 9693083 |
| actin enhances the haemolytic activity of escherichia coli. | actin is a major cytoskeletal protein of mammalian muscle and non-muscle cells. exposure of cells to soluble factors that damage cell membranes results in the release of actin into the extracellular spaces. the alpha-haemolysin (hlya) of escherichia coli is the prototype rtx (repeat in toxin) toxin and is thought to be important in virulence because of its ability to lyse cells by formation of pores in the cell membrane. these studies were conducted to determine if actin influences growth and ha ... | 1998 | 9695917 |
| influence of escherichia coli endotoxin induced fever on the pharmacokinetics and dosage regimen of oxytetracycline in cross-bred calves. | the pharmacokinetics and dosage regimen of oxytetracycline were determined in healthy and febrile cross-bred calves following its single intravenous administration (10 mg kg-1). fever was induced by a single intravenous injection of e. coli endotoxin (1 microgram kg-1 i.v.). the elimination half-life (t1/2 beta) and the apparent volume of distribution [vd(area)] were slightly increased in febrile calves, as compared to healthy animals. the values of t1/2 beta and vd(area) were 3.22 +/- 0.20 h an ... | 1998 | 9704514 |
| use of hot water for beef carcass decontamination. | hot water treatment of beef carcass surfaces for reduction of escherichia coli o157:h7, salmonella typhimurium, and various indicator organisms was studied using a model carcass spray cabinet. paired hot carcass surface regions with different external fat characteristics (inside round, outside round, brisket, flank, and clod) were removed from carcasses immediately after the slaughter and dressing process. all cuts were inoculated with bovine feces containing 10(6)/g each of rifampicin-resistant ... | 1998 | 9708247 |
| a representative microbial sampling method for large commercial containers of raw beef based on purge. | the purge from beef combos ( a boxed collection of beef trimmings) was tested as a means of representatively sampling the microbial content of this raw product. in the first experiment, purge was sampled from model beef combos that had been inoculated with bovine feces.. data from this experiment indicated a strong correlation (r = 0.94) between the total aerobic bacteria counts derived from the purge samples of a model beef combo and the total aerobic bacteria present in a rinse sample of the e ... | 1998 | 9708274 |
| thermal inactivation of escherichia coli o157:h7 isolated from ground beef and bovine feces, and suitability of media for enumeration. | rates of thermal inactivation of five strains of escherichia coli o157:h7 isolated from ground beef implicated in outbreaks of hemorrhagic colitis and five strains isolated from bovine feces were determined. ground beef (22% fat, 10 g), inoculated with individual test strains at populations ranging from 6.85 to 7.40 log10 cfu g-1 of beef, was formed into patties (0.3 cm thick and 8.0 cm in diameter) and sealed in polyethylene bags. for each strain and treatment temperature (54.4, 58.9, 62.8, 65. ... | 1998 | 9708297 |
| long-term effect of alkaline, organic acid, or hot water washes on the microbial profile of refrigerated beef contaminated with bacterial pathogens after washing. | the effect of 2% (vol/vol) lactic acid, 2% (vol/vol) acetic acid, 12% (wt/vol) trisodium phosphate, water at 72 degrees c and water at 32 degrees c washes on bacterial populations introduced onto beef carcass surfaces after treatment was determined for up to 21 days at 4 degrees c storage in vacuum packaging. beef carcass short plates were collected from cattle immediately after slaughter and subjected to the above treatments or left untreated (c). short plates were then inoculated with low leve ... | 1998 | 9708300 |
| an efficient sampling technique used to detect four foodborne pathogens on pork and beef carcasses in nine belgian abattoirs. | the method presented in this paper should prove useful in assessing the effectiveness of haccp plans developed in slaughterhouses. samples were collected by swabbing well-defined areas of pork and beef carcasses with sterile gauze. between 160 and 420 half-carcasses were swabbed in each of nine pork or beef slaughterhouses. swabs from five carcasses were placed in the same sterile stomacher bag, constituting a single composite sample. standard or validated analytical methods were used to isolate ... | 1998 | 9709223 |
| steam pasteurization of commercially slaughtered beef carcasses: evaluation of bacterial populations at five anatomical locations. | a steam pasteurization process (patent pending) has been shown to effectively reduce pathogenic bacterial populations on beef tissue and to significantly reduce naturally occurring bacterial populations on commercially slaughtered beef carcasses. the objective of this study was to determine the effectiveness of the steam pasteurization treatment for reducing bacterial populations at several anatomical locations on commerically slaughtered carcasses. before and after pasteurization treatment (82. ... | 1998 | 9709229 |
| mutagenicity of p-aminophenol in e. coli wp2uvra/pkm101 and its relevance to oxidative dna damage. | it was recently reported that p-aminophenol (p-ap) induces dna cleavage in mouse lymphoma cells, cho cells and human lymphoblastoid cells. the mutagenicity of p-ap has not, however, been detected by reverse mutation assays. the purpose of this study was to assess the mutagenicity of p-ap by reverse mutation assay using escherichia coli wp2uvra/pkm101, which has a spectrum for detecting mutations different from those of other strains in the family with an at base pair at the mutation site and has ... | 1998 | 9711270 |
| bovine herpesvirus type 1 glycoprotein h is essential for penetration and propagation in cell culture. | bovine herpesvirus type 1 (bhv-1) glycoprotein h (gh) is a structural component of the virion which forms a complex with glycoprotein gl. to study the role of bhv-1 gh in the virus infectious cycle, a gh null mutant was constructed in which the gh coding sequences were deleted and replaced by the escherichia coli lacz cassette. the bhv-1 gh null mutant was propagated in trans-complementing mdbk cells, stably transfected with plasmid pmep4 containing the bhv-1 gh gene under the control of the ind ... | 1998 | 9714247 |
| surveillance of antimicrobial resistance in bacteria isolated from food animals to antimicrobial growth promoters and related therapeutic agents in denmark. | this study was conducted to describe the occurrence of acquired resistance to antimicrobials used for growth promotion among bacteria isolated from swine, cattle and poultry in denmark. resistance to structurally related therapeutic agents was also examined. three categories of bacteria were tested: 1) indicator bacteria (escherichia coli, enterococcus faecalis, enterococcus faecium), 2) zoonotic bacteria (campylobacter, salmonella, yersinia enterocolitica), and 3) animal pathogens (e. coli, sta ... | 1998 | 9725794 |
| analysis of escherichia coli o157:h7 survival in ovine or bovine manure and manure slurry. | farm animal manure or manure slurry may disseminate, transmit, or propagate escherichia coli o157:h7. in this study, the survival and growth of e. coli o157:h7 in ovine or bovine feces under various experimental and environmental conditions were determined. a manure pile collected from experimentally inoculated sheep was incubated outside under fluctuating environmental conditions. e. coli o157:h7 survived in the manure for 21 months, and the concentrations of bacteria recovered ranged from <10( ... | 1998 | 9726855 |
| pcr-based dna amplification and presumptive detection of escherichia coli o157:h7 with an internal fluorogenic probe and the 5' nuclease (taqman) assay. | presumptive identification of escherichia coli o157:h7 is possible in an individual, nonmultiplexed pcr if the reaction targets the enterohemorrhagic e. coli (ehec) eaea gene. in this report, we describe the development and evaluation of the sensitivity and specificity of a pcr-based 5' nuclease assay for presumptively detecting e. coli o157:h7 dna. the specificity of the eaea-based 5' nuclease assay system was sufficient to correctly identify all e. coli o157:h7 strains evaluated, mirroring the ... | 1998 | 9726887 |
| structural and functional consequences of substitutions at the pro108-arg14 hydrogen bond in bovine adrenodoxin. | elimination of pro108 in bovine adrenodoxin is known to result in the formation of a misfolded protein that is not able to incorporate a [2fe-2s] cluster and rapidly degrades upon expression in e. coli. however, no experimental explanation for this phenomenon has been demonstrated so far. using the recently obtained 3d structure of the truncated mutant adx(4-108) we have studied the reasons of the protein stabilization by the proline residue by means of site-directed muta-genesis. two main resul ... | 1998 | 9731239 |
| grain feeding and the dissemination of acid-resistant escherichia coli from cattle. | the gastric stomach of humans is a barrier to food-borne pathogens, but escherichia coli can survive at ph 2.0 if it is grown under mildly acidic conditions. cattle are a natural reservoir for pathogenic e. coli, and cattle fed mostly grain had lower colonic ph and more acid-resistant e. coli than cattle fed only hay. on the basis of numbers and survival after acid shock, cattle that were fed grain had 10(6)-fold more acid-resistant e. coli than cattle fed hay, but a brief period of hay feeding ... | 1998 | 9733511 |
| rna polymerase ii is an essential mrna polyadenylation factor. | production of messenger rna in eukaryotic cells is a complex, multistep process. mrna polyadenylation, or 3' processing, requires several protein factors, including cleavage/polyadenylation-specificity factor (cpsf), cleavage-stimulation factor, two cleavage factors and poly(a) polymerase. these proteins seem to be unnecessary for other steps in mrna synthesis such as transcription and splicing, and factors required for these processes were not considered to be essential for polyadenylation. non ... | 1998 | 9738505 |
| immunization of cows with ferric enterobactin receptor from coliform bacteria. | the serum and milk immunoglobulin (ig) g responses of lactating dairy cows were determined following immunization with ferric enterobactin receptor fepa. escherichia coli 471 was cultured in iron-depleted medium, and outer membrane proteins were extracted by 2% n-lauroylsarcosine sodium salt and 2% triton x-100. the fepa was isolated from the outer membrane proteins by ion-exchange chromatography. twenty cows were assigned to four treatment groups of 5 cows blocked by breed and days in milk. tre ... | 1998 | 9749380 |
| partial budget of the discounted annual benefit of mastitis control strategies. | the objective of this study was to rank the benefits associated with various mastitis control strategies in simulated herds with intramammary infections caused by streptococcus agalactiae, streptococcus spp. other than strep. agalactiae, staphylococcus aureus, coagulase-negative staphylococci, and escherichia coli. the control strategies tested were prevention, vaccination for e. coli, lactation therapy, and dry cow antibiotic therapy. partial budgets were based on changes caused by mastitis con ... | 1998 | 9749395 |