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modelling the epidemiology of verocytotoxin-producing escherichia coli serogroups in young calves.we investigate the epidemiology of 12 verocytotoxin-producing escherichia coli (vtec) serogroups observed in a calf cohort on a scottish beef farm. fitting mathematical models to the observed time-course of infections reveals that there is significant calf-to-calf transmission of vtec. our models suggest that 40% of all detected infections are from calf-to-calf transmission and 60% from other sources. variation in the rates at which infected animals recover from infection by different vtec serog ...200515962551
using national microbiological data to set meaningful performance criteria for slaughter and dressing of animals at australian export abattoirs.slaughter establishments in australia that export meat to the usa are required by the controlling authority, the australian quarantine and inspection service (aqis), to test carcases under the escherichia coli and salmonella monitoring (esam) program and to use statistical process control techniques to ensure meat is produced hygienically. however, analysing the esam database for e. coli using standard statistical techniques proved difficult because of inter-plant variability and because the vas ...200515964649
prevalence and risk-factor analysis of shiga toxigenic escherichia coli in faecal samples of organically and conventionally farmed dairy cattle.cattle are a natural reservoir for shiga toxigenic escherichia coli (stec), however, no data are available on the prevalence and their possible association with organic or conventional farming practices. we have therefore studied the prevalence of stec and specifically o157:h7 in swiss dairy cattle by collecting faeces from approximately 500 cows from 60 farms with organic production (op) and 60 farms with integrated (conventional) production (ip). ip farms were matched to op farms and were comp ...200515964720
specific detection and semi-quantitative analysis of trpc4 protein expression by antibodies.in mouse tissues two variants of the transient receptor potential (canonical) (trpc) 4 protein are expressed: the "full-length" trpc4 protein and a slightly smaller variant, called trpc4delta(761-864), which lacks 84 amino acid residues. although the presence of mrna encoding the trpc4 protein in mammalian cells and the detection of the heterologously expressed trpc4 protein by western blot analysis have been reported, the unequivocal detection of endogenous trpc4 proteins has proven difficult. ...200515965705
the bovine innate immune response during experimentally-induced pseudomonas aeruginosa mastitis.almost half of all clinical cases of mastitis are caused by gram-negative bacteria. among these bacteria, intramammary infection by pseudomonas aeruginosa remains one of the most refractory to antibiotic therapy. the ability to recognize potentially harmful pathogens whether previously encountered or not, as well as the induction of an initial pro-inflammatory response to these pathogens, are critical components of host innate immunity. although the innate immune response to another gram-negativ ...200515970335
hplc purification of recombinant ncgra6 antigen improves enzyme-linked immunosorbent assay for serodiagnosis of bovine neosporosis.the gene for a dense granule protein (ncgra6) of neospora caninum was expressed in escherichia coli as a his-tag fusion protein and purified by ninta affinity chromatography. in a preliminary study, high binding of antibodies from n. caninum-negative cows was observed in enzyme-linked immunosorbent assay (elisa) using ninta-purified ncgra6. analysis of ninta eluates revealed a significant number of e. coli proteins that co-purified with recombinant ncgra6. in an attempt to improve the relative s ...200515970387
changes of viability and composition of the escherichia coli flora in faecal samples during long time storage.long-time storage of faecal samples is necessary for investigations of intestinal microfloras. the aim of the present study was to evaluate how the viability and the composition of the escherichia coli flora are affected in faecal samples during different storage conditions. four fresh faecal samples (two from calves and two from infants) were divided into sub-samples and stored in four different ways: with and without addition of glycerol broth at -20 degrees c and at -70 degrees c. the viabili ...200515979748
antimicrobial and chemoattractant activity, lipopolysaccharide neutralization, cytotoxicity, and inhibition by serum of analogs of human cathelicidin ll-37.antimicrobial peptides have been evaluated in vitro and in vivo as alternatives to conventional antibiotics. apart from being antimicrobial, the native human cathelicidin-derived peptide ll-37 (amino acids [aa] 104 to 140 of the human cathelicidin antimicrobial peptide) also binds and neutralizes bacterial lipopolysaccharide (lps) and might therefore have beneficial effects in the treatment of septic shock. however, clinical trials have been hampered by indications of toxic effects of ll-37 on m ...200515980359
effect of leukotoxin of mannheimia haemolytica and lps of e. coli on secretory response of bovine neutrophils in vitro.to evaluate the role of leukotoxin (lkt) of mannheimia haemolytica and lipopolysaccharide (lps) of e. coli 055:b5 in pathogenesis of bovine respiratory disease (brd) we investigated their in vitro effects on cultured bovine neutrophils. functional parameters of neutrophils including degranulation, generation of superoxide, and nitric oxide were distorted in response to both toxins. the most essential reaction of neutrophils was found in respect to release of elastase after addition of lkt as wel ...200515989128
concentration of ascorbic acid in the blood of cows with subclinical mastitis.the aim of the investigations was evaluation of ascorbic acia concentration in the blood or cows in the subclinical form of mastitis. the research was conducted on 56 cows. the cows were divided into 4 groups: a, b, and c with subclinical form of mastitis caused by staphylococcus aureus, streptococcus agalactiae and escherichia col, and d control. the ascorbic acid concentration in the serum of cows was measured by the hydrazine method. we observed a marked decrease in ascorbic acid concentratio ...200515989131
cloning, expression, purification, crystallization and preliminary crystallographic study of the protein module (biv2-helix) in the fusion core of bovine immunodeficiency-like virus (biv) gp40.the fusion core of bovine immunodeficiency virus (biv) gp40 is proposed to be involved in membrane fusion. however, no crystal structures are yet available. a predicted protein module biv2-helix of bivgp40 has been expressed in escherichia coli and purified by chromatography. recombinant biv2-helix was crystallized using the hanging-drop vapour-diffusion technique at 291 k. the crystals were grown in mpd and belonged to the primitive rhombohedral space group r3, with unit-cell parameters a = 39. ...200516511008
identification of escherichia coli o157:h7 meat processing indicators for fresh meat through comparison of the effects of selected antimicrobial interventions.fresh meat products can become contaminated with the pathogen escherichia coli o157:h7 during the slaughter process; therefore, an e. coli o157:h7 indicator to verify the effectiveness of process controls in slaughter establishments would be extremely useful. the hides of 20 beef cattle were sampled, and 113 bacterial isolates were obtained. thirteen of these isolates representing four genera, escherichia, enterobacter, providencia, and serratia, were selected based on growth and biochemical cha ...200516355829
assessment of accuracy of disk diffusion tests for the determination of antimicrobial susceptibility of common bovine mastitis pathogens: a novel approach.a novel approach was used to assess disk diffusion accuracy for determination of antibiotic susceptibility of various bovine mastitis pathogens (escherichia coli, staphylococcus aureus, staphylococcus chromogenes, and streptococcus dysgalactiae). mic and disk diffusion diameters were compared for 587 bovine mastitis bacterial isolates collected in israel and 3,186 drug-organism combinations. results were analyzed by roc curves, bayesian statistics, and standard descriptive methods. low correlati ...200516359193
a comparison of the antimicrobial activity of garlic, ginger, carrot, and turmeric pastes against escherichia coli o157:h7 in laboratory buffer and ground beef.the antimicrobial effects of garlic, ginger, carrot and turmeric pastes against escherichia coli o157:h7 in laboratory buffer and model food system were investigated. turmeric paste, fresh carrot, ginger and garlic pastes from roots, and commercial ginger and garlic paste were heated alone or with buffered peptone water (bpw) or ground beef at 70 degrees c for 7 min. all samples were inoculated with a three strain cocktail of overnight cultures of e. coli o157: h7 and stored at 4 degrees c and 8 ...200516366855
characterization of escherichia coli and salmonella enterica from cattle feed ingredients.the objectives of this study were (1) to evaluate the frequency with which feed ingredients or mixed feeds in cattle feedlots were contaminated with escherichia coli and salmonella spp. and (2) to evaluate the antimicrobial susceptibility patterns of non-type-specific escherichia coli and salmonella spp. recovered from feed ingredients or mixed feeds. approximately 30 individual samples were collected from each of several feed commodities present on two cattle feedlots each month for 1 year. hal ...200516366856
antimicrobial resistance and class 1 integrons in pathogenic escherichia coli from dairy farms.the goal of this study was to assess the prevalence of antimicrobial resistance and class 1 integrons, including integron-associated genes, in 24 escherichia coli isolates from dairy farms. escherichia coli isolates (n = 14) from dairy cows with mastitis (ecdm), shiga toxin-producing (stec) o157:h7 from cull dairy cow fecal samples (n = 9) and bulk tank milk (n = 1) were evaluated for sensitivity to 19 antimicrobial agents used commonly in human and/or veterinary medicine. multiplex pcr was used ...200516366857
[expression, purification and antigen activity analysis of the n-terminal domain of lipoprotein lppq of mycoplasma mycoide subsp. mycoides sc].the gene sequence coding the n-terminal domain of lppq was amplified from mycoplasma mycoides subsp. mycoides sc (mmmsc) hvri x strain by pcr using special primers and was cloned into the ecor i /sal i sites of pet32a vector to construct the expression recombinant plasmids. the recombinant plasmids were indentified by restriction digestion, pcr and sequence analysis. the gene was overexpressed in escherichia coli bl21 (de3) host cell and the soluble protein was purified with ni-nta his. bind pur ...200516342778
identification of putative adhesin genes in shigatoxigenic escherichia coli isolated from different sources.shiga toxin-producing escherichia coli (stec) is an important pathogen responsible for severe human intestinal and systemic infections. the bacterial factors required for colonization of the hosts are still not well defined. in this study, the prevalence of seven putative adhesive genes that are not encoded in the locus of enterocyte effacement (lee) in 74 stec strains isolated from humans (n=39), food (n=6), cattle (n=11), and pigs (n=18) was investigated by pcr. in addition, shiga toxin (stx) ...200516125342
inhibition of secretory phospholipase a(2) enzyme by bilirubin: a new role as endogenous anti-inflammatory molecule.bilirubin is a powerful antioxidant that suppresses the inflammatory process. however its interaction with proinflammatory pla(2) enzyme is not known. inhibition of several secretory phospholipase a(2) (spla(2)) enzyme activities by bilirubin was studied using (14)c-oleate labeled escherichia coli as substrate. bilirubin inhibits purified spla(2) enzyme from vipera russellii and naja naja venom and partially purified spla(2) enzymes from human ascitic fluid, pleural fluid and normal serum in a d ...200516132704
short report: isolation of escherichia coli o157:h7 from fecal samples of cows in vietnam.enterohemorrhagic escherichia coli o157:h7 was isolated for the first time in vietnam. shiga toxin-producing e. coli were isolated from 8 of 100 cows examined. the two strains showing serotype o157:h7 carried the eae, ehxa, and stx2c genes, but the other six were negative for the eae gene.200516172486
[identification on the immunogenic activity of recombinant rltb/ctb-lipl41/ 1 to leptospira interrogans and detection of lipl41 gene with its production].to construct prokaryotic expression systems of ltb/ctb-lipl41/1 fusion genes, identify immunogenic and adjuvant activities of the products as well as to understand the frequencies of lipl41 gene that carrying and expressing in l. interrogans wild strains and specific antibody levels in sera from patients with leptospirosis.200516390012
[isolation of shiga toxin-producing escherichia coli strains from healthy cattle of the region of lower silesia].the aim of the study was to determine if cattle from the region of lower silesia is the reservoir of shiga toxin-producing e. coli strains (stec) and the analysis of virulence factors of isolated stec strains. the ability of tested animal strains to shiga toxin synthesis was analysed in cytotoxicity assay in vitro on vero cell line and then confirmed by detection of shiga toxin-encoding genes by pcr. stec strains were isolated from 12 (15,2%) of animals examined, 21,4% of these strains were obta ...200516773830
evaluation of culture- and pcr-based detection methods for escherichia coli o157:h7 in inoculated ground beeft.currently, several beef processors employ test-and-hold systems for increased quality control of ground beef. in such programs, each lot of product must be tested and found negative for escherichia coli o157:h7 prior to release of the product into commerce. optimization of three testing attributes (detection time, specificity, and sensitivity) is critical to the success of such strategies. because ground beef is a highly perishable product, the testing methodology used must be as rapid as possib ...200521132961
reduction of escherichia coli o157:h7 and salmonella in ground beef using lactic acid bacteria and the impact on sensory properties.studies were conducted to determine whether four strains of lactic acid bacteria (lab) inhibited escherichia coli o157: h7 and salmonella in ground beef at 5 degrees c and whether these bacteria had an impact on the sensory properties of the beef. the lab consisted of frozen concentrated cultures of four lactobacillus strains, and a cocktail mixture of streptomycin-resistant e. coli o157:h7 and salmonella were used as pathogens. individual lab isolates at 10(7) cfu/ml were added to tryptic soy b ...200521132964
a comparison of aflp and eric-pcr analyses for discriminating escherichia coli from cattle, pig and human sources.amplified fragment length polymorphism (aflp) and enterobacterial repetitive intergenic consensus polymerase chain reaction (eric-pcr) genomic fingerprinting assays were compared for their ability to differentiate escherichia coli isolates obtained from various host sources, and with respect to their pathogenicity. one hundred and ten verotoxigenic, enterotoxigenic and non-pathogenic e. coli isolates obtained from cattle, humans and pigs were used in this study. the aflp assay was shown to be hi ...200419712352
cloning and expression of recombinant mpb70 protein antigen from mycobacterium bovis bcg for diagnosis of tuberculosis.in a search for developing new skin test reagents, mpb70 protein antigen was a candidate antigen for the diagnosis of bovine tuberculosis. first m. bovis bcg genomic dna was extracted purified and the mpb70 gene was amplified by pcr. the gene was then ligated to an expression vector, pqe. after transformation of the expression e. coil m15 host strain with the pqe plasmid, the expression was induced using 10 mm of iptg. two bands were seen in the sds-page analysis the 44 and 50 kda represents the ...200416734114
evaluation of universal pre-enrichment broth for isolation of salmonella spp., escherichia coli o157:h7, and listeria monocytogenes from dairy farm environmental samples.use of universal pre-enrichment broth (upb) as a primary enrichment medium for detection of salmonella spp., escherichia coli o157:h7, and listeria monocytogenes from dairy farm environmental samples was evaluated. there were no differences in bacterial growth between upb and selective primary enrichment broths for each pathogen inoculated individually or in combination at 10(1) and 10(2) colony forming units/ml. in addition, no differences were observed when upb and selective primary enrichment ...200415992260
examination of heat stress and stage of lactation (early versus late) on fecal shedding of e. coli o157:h7 and salmonella in dairy cattle.mature, healthy lactating dairy cattle were sampled on two farms in the southwestern united states to examine the effects of heat stress (experiment i) and stage of lactation (experiment ii) on the fecal shedding of e. coli o157:h7 and salmonella. to examine the effects of heat stress, fecal samples were collected from 45 cows at 7:00 am (coolest part of the day) and 5:00 pm (hottest part of the day) in august 2002 on a 250 cow dairy. the study was replicated one month later (n = 170 total sampl ...200415992270
comparison of escherichia coli isolates from humans, food, and farm and companion animals for presence of shiga toxin-producing e. coli virulence markers.the objective of this study was to characterize escherichia coli isolates from dairy cows/feedlots, calves, mastitis, pigs, dogs, parrot, iguana, human disease, and food products for prevalence of shiga toxin-producing e. coli (stec) virulence markers. the rationale of the study was that, isolates of the same serotypes that were obtained from different sources and possessed the same marker profiles, could be cross-species transmissible. multiplex polymerase chain reaction (pcr) was used to detec ...200415992278
characterization of recombinant antibodies developed for capturing enterohemorrhagic escherichia coli o157:h7.escherichia coli o157:h7, an emerging cause of food-borne disease with the occurrence of an estimated 20,000 illnesses and 250 deaths each year in the united states, has now been reported from several countries worldwide. infections with this bacteria, which follows the ingestion of contaminated food by humans, causes bloody diarrhea, hemolytic uremic syndrome (hus), and renal disease, that can have serious health implications. the source of food contamination is usually associated with animals, ...200415916089
possible animal origin of human-associated, multidrug-resistant, uropathogenic escherichia coli.the multistate occurrence of cases of urinary tract infection (uti) caused by trimethoprim-sulfamethoxazole (tmp-smz)-resistant escherichia coli strains belonging to a single clonal group (designated as clonal group a [cga]) in the united states has raised an intriguing hypothesis that these infections may have been spread by contaminated food products. the present study attempted to determine if cga strains could be traced to food animals.200415655743
serotypes and virulence markers of shiga toxin-producing escherichia coli (stec) isolated from dairy cattle in são paulo state, brazil.in order to determine the occurrence, serotypes and virulence markers of shiga toxin-producing escherichia coli (stec) strains, 153 fecal samples of cattle randomly selected from six dairy farms in sao paulo state, brazil, were examined for shiga toxin (stx) production by the vero cell assay. feces were directly streaked onto macconkey sorbitol agar and incubated at 37 degrees c overnight. sorbitol-negative colonies (maximum 20) and up to 10 sorbitol-positive colonies from each plate were subcul ...200415607081
bile-induced dna damage in salmonella enterica.in the absence of dna adenine methylase, growth of salmonella enterica serovar typhimurium is inhibited by bile. mutations in any of the muth, mutl, and muts genes suppress bile sensitivity in a dam(-) background, indicating that an active muthls system renders dam(-) mutants bile sensitive. however, inactivation of the muthls system does not cause bile sensitivity. an analogy with escherichia coli, in which the muthls system sensitizes dam(-) mutants to dna-injuring agents, suggested that bile ...200415611156
role of s fimbriae in escherichia coli k1 binding to brain microvascular endothelial cells in vitro and penetration into the central nervous system in vivo.bacterial binding to host cell surface is considered an important initial step in the pathogenesis of many infectious diseases including meningitis. previous studies using a laboratory escherichia coli (e. coli) strain hb101 possessing a recombinant plasmid carrying the cloned s fimbriae gene cluster have shown that s fimbriae are the major contributor to binding to bovine brain microvascular endothelial cells (bmec) for hb101. our present study, however, revealed that s fimbriae did not play a ...200415619424
[hazard evaluation of livestock-derived, verotoxin-producing escherichia coli by enterohemolysin production assay and eaea gene detection].we examined enterohemolysin (ehly) production, and detected the hlya gene and the eaea gene for the intestinal mucosal adherence factor intimin in 131 strains of human-derived verotoxin-producing escherichia coli (vtec) and 140 strains of livestock (cattle and swine) -derived vtec to evaluate their hazards to humans. the hlya gene was confirmed in 98.5% of human-derived, in 50.5% of cattle-derived, and in 10.3% of swine-derived vtec strains. ehly-positive rates were 96.2-97.7%, 45.9-55.0%, and 1 ...200415628530
high level production of bovine angiogenin in e. coli by an efficient refolding procedure.recombinant bovine angiogenin (rbang) was expressed in e. coli at up to 30% of total cell proteins but was produced as inclusion bodies. by investigating the effect of various factors on the refolding yield, we obtained about 60% refolding. after chromatographic purification, about 60 mg purified angiogenin was obtained from 1 l culture. the purified recombinant bovine angiogenin was identical to native bovine angiogenin (nbang) obtained from cow's milk. our approach is highly efficient and can ...200415604787
factors associated with the presence of escherichia coli o157 in feedlot-cattle water and feed in the midwestern usa.our objective was to generate hypotheses about associations between management, climate, and the presence of escherichia coli o157 in feedlot-cattle water tanks and in feedlot-cattle feed. water samples from 710 tanks on 73 feedlots, and feed-samples from a subset of 504 pens on 54 feedlots, in four us states were tested for e. coli o157. management and climate factors were ascertained by survey and observation. escherichia coli o157 were isolated from 13% of the water tanks and at least one wat ...200415579344
development of a rapid pcr method using the insertion sequence is1203 for genotyping shiga toxin-producing escherichia coli o157.we developed a rapid pcr method utilizing the diversity of the insertion site is1203 for genotyping shiga toxin-producing escherichia coli (stec) o157 (is1203 pcr typing). dna fragments digested by pvuii, which cut is1203 at one site, were ligated with themselves and detected by pcr with outward-facing primer pairs for is1203. to minimize nonspecific bands, nested pcr was also performed. two fingerprinting patterns produced from the upstream or downstream regions of is1203 were obtained within 1 ...200415583266
[the prevalence of antimicrobial susceptibility of veterinary pathogens isolated from cattle and pigs: national antibiotic resistance monitoring 2002/2003 of the bvl].the national antimicrobial resistance monitoring determines the current quantitative resistance level of life-stock pathogens, in order to permit the evaluation and surveillance of the distribution of resistances on a valid basis. during the examination period from june 2002 to july 2003, a total of 1849 pathogens was collected, following a representative german-wide pattern in collaboration with 29 laboratories. the selection of examined bacterial strains included different specimen causing res ...200415584430
the nano-tag, a streptavidin-binding peptide for the purification and detection of recombinant proteins.we present a new streptavidin-binding peptide for both the purification and the detection of recombinant proteins. the peptide possesses nanomolar-affinity for streptavidin and therefore was termed nano-tag. the nano-tag(15) is 15 amino acids long and binds to streptavidin with a dissociation constant of 4 nm and the nano-tag(9) is a 9-mer peptide with a dissociation constant of 17 nm. we demonstrate the one-step purification of nano-tagged proteins, namely bovine heart fatty acid-binding protei ...200414680960
plant cell-based intimin vaccine given orally to mice primed with intimin reduces time of escherichia coli o157:h7 shedding in feces.intimin is the primary adhesin of escherichia coli o157:h7, the most common infectious cause of bloody diarrhea in the united states and the leading cause of acute kidney failure in children who develop hemolytic uremic syndrome. cattle are the primary reservoir of e. coli o157:h7. indeed, most cases of e. coli o157:h7 infection in the united states occur after ingestion of contaminated undercooked hamburger or produce that had contact with bovine manure. because intimin is required for persiste ...200414688094
a phosphoprotein from the archaeon sulfolobus solfataricus with protein-serine/threonine kinase activity.sulfolobus solfataricus contains a membrane-associated protein kinase activity that displays a strong preference for threonine as the phospho-acceptor amino acid residue. when a partially purified detergent extract of the membrane fraction from the archaeon s. solfataricus that had been enriched for this activity was incubated with [gamma-(32)p]atp, radiolabeled phosphate was incorporated into roughly a dozen polypeptides, several of which contained phosphothreonine. one of the phosphothreonine- ...200414702316
a gapc chimera retains the properties of the streptococcus uberis wild-type gapc protein.the gapc products of streptococcus agalactiae, streptococcus dysgalactiae, and streptococcus uberis share considerable homology at the dna and amino acid levels. the high similarity at the protein level suggests that one gapc protein might be used as a single antigen to protect dairy cows against infections with the contagious s. agalactiae and the environmental s. dysgalactiae and s. uberis strains. despite their similarities, immunization with the s. dysgalactiae gapc did not protect dairy cow ...200414711517
frozen storage of escherichia coli o157 in buffered peptone water and its detection on bovine carcasses.the adaptation of a standard escherichia coli o157 isolation method involving immunomagnetic separation and a period of frozen storage was investigated. a series of experiments was designed to test the recovery of a bovine strain of e. coli o157 from buffered peptone water after a period of frozen storage at -80 degrees c. the effects of the addition of glycerol at 5 and 10%, freezing time, the number of freeze-thaw cycles, the method of freezing and the method of thawing, the inclusion of a res ...200414717349
genotypes and phenotypes of shiga toxin producing-escherichia coli isolated from healthy cattle in thailand.shiga toxin producing-escherichia coli (stec) has not yet been identified as an important aetiologic agent of human disease in thailand. to evaluate the potential for stec to contribute to human disease in thailand, 139 fecal samples were collected from healthy cattle from five different provinces and analysed by genotypic and phenotypic methods for stec. of 139 samples, 27 (19.4%) were positive for stx1 and/or stx2 by multiplex polymerase chain reaction, or for o157 lipopolysaccharide (lps) by ...200414720491
effect of phosphophoryn on rhbmp-2-induced bone formation.in the present study, dentin phosphophoryn (dpp) derived from fresh bovine dentin was evaluated as a co-factor for recombinant human bone morphogenetic protein-2 (rhbmp-2) in rhbmp-2-induced bone formation in rats. a 5 microg amount of escherichia coli-derived rhbmp-2 variant was combined with dpp cross-linked to type i collagen (2.4 microg dpp/360 microg collagen), acting as carrier. next, rhbmp-2/dpp/collagen composites were implanted by onlay-grafting beneath the cranial periosteum in 4-week- ...200414725816
antimicrobial resistance of commensal escherichia coli from dairy cattle associated with recent multi-resistant salmonellosis outbreaks.the use of antimicrobial drugs in livestock is suspected to contribute to bacterial antimicrobial resistance (ar) development. dairy farms experiencing recent outbreaks of salmonellosis involving multi-resistant (mr) salmonella strains were compared to control farms with respect to ar among bovine commensal e. coli isolates. for most antimicrobials tested, the percentage of ar e. coli isolated from salmonellosis-affected farms was significantly higher than that from control farms. calf e. coli f ...200414738782
virulence genes and intimin types of shiga-toxin-producing escherichia coli isolated from cattle and beef products in argentina.a total of 153 shiga-toxin-producing escherichia coli (stec) isolates from feces of cattle and beef products (hamburgers and ground beef) in argentina were characterized in this study. pcr showed that 22 (14%) isolates carried stx1 genes, 113 (74%) possessed stx2 genes and 18 (12%) both stx1 and stx2. intimin (eae), enterohemolysin (ehxa), and stec autoagglutinating adhesin (saa) virulence genes were detected in 36 (24%), 70 (46%) and in 34 (22%) of the isolates, respectively. none of 34 saa-pos ...200415666247
isolation of escherichia coli o157 from human and bovine faeces in the urbino area, italy.we examined 476 faecal samples from subjects aged from 0 to >60 years, 283 with diarrhoea and 193 with illnesses involving other sites or clinically healthy, and 154 samples of faeces of healthy cattle, in order to define the diffusion of e. coli o157 in the urbino area. the samples were seeded by both direct streaking onto cefixime tellurite sorbitol mac conkey agar (ct-smac) and previous enrichment in cefixime tellurite tryptone soya broth for human specimens and in cefixime vancomicin trypton ...200415729839
horizontal transmission of escherichia coli o157:h7 during cattle housing.ruminant livestock, particularly cattle, is considered the primary reservoir of escherichia coli o157:h7. this study examines the transmission of e. coli o157:h7 within groups of cattle during winter housing. holstein friesian steers were grouped in six pens of five animals. an animal inoculated with and proven to be shedding a marked strain of e. coli o157: h7 was introduced into each pen. fecal (rectal swabs) and hide samples (900 cm2 from the right rump) were taken from the 36 animals through ...200415633666
coliform and pathologic bacteria in sierra nevada national forest wilderness area lakes and streams.to analyze backcountry-area water quality in us department of agriculture forest service-designated wilderness areas for the presence of coliform and potentially pathogenic bacteria.200415636374
variation of high mannose chains of tamm-horsfall glycoprotein confers differential binding to type 1-fimbriated escherichia coli.tamm-horsfall glycoprotein (thp), the most abundant protein in mammalian urine, has been implicated in defending the urinary tract against infections by type 1-fimbriated escherichia coli. recent experimental evidence indicates that the defensive capability of thp relies on its single high mannose chain, which binds to e. coli fimh lectin and competes with mannosylated uroplakin receptors on the bladder surface. here we describe several major differences, on both structural and functional levels ...200414570881
properties of recombinant human cytosolic sialidase hsneu2. the enzyme hydrolyzes monomerically dispersed gm1 ganglioside molecules.recombinant human cytosolic sialidase (hsneu2), expressed in escherichia coli, was purified to homogeneity, and its substrate specificity was studied. hsneu2 hydrolyzed 4-methylumbelliferyl alpha-neuac, alpha 2-->3 sialyllactose, glycoproteins (fetuin, alpha-acid glycoprotein, transferrin, and bovine submaxillary gland mucin), micellar gangliosides gd1a, gd1b, gt1b, and alpha 2-->3 paragloboside, and vesicular gm3. alpha 2-->6 sialyllactose, colominic acid, gm1 oligosaccharide, whereas micellar ...200414613940
changes in vitamin c concentrations in plasma and milk from dairy cows after an intramammary infusion of escherichia coli.plasma and milk concentrations of ascorbic acid and dehydro-l-ascorbic acid (dhaa) were measured before and after 21 holstein cows (approximately 26 dim) were given an intramammary infusion of escherichia coli. blood, milk from the unchallenged quarters, and milk from the challenged gland were sampled immediately before challenge (d 0) and 24 h and 7 d postchallenge. plasma vitamin c (ascorbic acid + dhaa) concentrations decreased 39%, and concentrations of vitamin c and ascorbic acid in milk fr ...200414765807
associations between pathogen-specific cases of clinical mastitis and somatic cell count patterns.associations were estimated between pathogen-specific cases of clinical mastitis (cm) and somatic cell count (scc) patterns based on deviations from the typical curve for scc during lactation and compared with associations between pathogen-specific cm and lactation average scc. data from 274 dutch herds recording cm over an 18-mo period were used. pathogens found were staphylococcus aureus, coagulase-negative staphylococci, escherichia coli, streptococcus dysgalactiae, streptococcus uberis, stre ...200414765815
pharmacokinetics of marbofloxacin in lactating cows after repeated intramuscular administrations and pharmacodynamics against mastitis isolated strains.the plasma and milk pharmacokinetics of marbofloxacin, a fluoroquinolone antibacterial compound, were evaluated in dairy cows, as well as its pharmacodynamic characteristics against mastitis-isolated pathogens. marbofloxacin was given intramuscularly as a 10% aqueous solution to dairy cows either at a single dose or at repeated doses of 2 mg/kg once daily for 3 d. blood and milk samples were collected for the determination of the concentration of marbofloxacin and of its putative metabolites: n- ...200414765828
oxidized groel can function as a chaperonin.here, we report on the facilitated reactivation (85%) of oxidatively inactivated rhodanese by an oxidized form of the molecular chaperone groel (ox-groel). reactivation by ox-groel required a reductant, and the enzyme substrate, sodium thiosulfate. also, we found that ox-groel formed a complex with oxidatively inactivated rhodanese as shown by differential centrifugation and fluorescence spectroscopy. ox-groel was obtained upon incubation of native groel for 16 h with 5 mm hydrogen peroxide. und ...200414766403
role of calf-adapted escherichia coli in maintenance of antimicrobial drug resistance in dairy calves.the prevalence of antimicrobial drug-resistant bacteria is typically highest in younger animals, and prevalence is not necessarily related to recent use of antimicrobial drugs. in dairy cattle, we hypothesize that antimicrobial drug-resistant, neonate-adapted bacteria are responsible for the observed high frequencies of resistant escherichia coli in calves. to explore this issue, we examined the age distribution of antimicrobial drug-resistant e. coli from holstein cattle at a local dairy and co ...200414766551
cmp-n-acetylneuraminic acid synthetase from escherichia coli k1 is a bifunctional enzyme: identification of minimal catalytic domain for synthetase activity and novel functional domain for platelet-activating factor acetylhydrolase activity.escherichia coli cmp-neuac synthetase (ec 2.7.7.43) catalyzes the synthesis of cmp-neuac from ctp and neuac, which is essential for the formation of capsule polysialylate for strain k1. alignment of the amino acid sequence of e. coli cmp-neuac synthetase with those from other bacterial species revealed that the conserved motifs were located in its n termini, whereas the c terminus appeared to be redundant. based on this information, a series of deletions from the 3'-end of the cmpneuac synthetas ...200414960566
protocol for evaluating the efficacy of cetylpyridinium chloride as a beef hide intervention.the objective of this study was to establish the necessary protocols and assess the efficacy of cetylpyridinium chloride (cpc) as an antimicrobial intervention on beef cattle hides. experiments using cpc were conducted to determine (i) the methods of neutralization needed to obtain valid efficacy measurements, (ii) the effect of concentration and dwell time after treatment, (iii) the effect of cpc on hide and carcass microbial populations when cattle were treated at a feedlot and then transporte ...200414968962
escherichia coli o157:h7 in the gallbladders of experimentally infected calves.fifteen weaned calves (age 89-141 days) were treated with dexamethasone (0.25 mg/kg, iv) for 3 days before, the day of, and the day after inoculation with 10 colony-forming units of either escherichia coli o157:h7 (strain 86-24, which produces shiga toxin 2 and intimin; n = 13) or nonpathogenic e. coli (strain 123, which does not produce shiga toxin or intimin; n = 2). all calves were necropsied 4 days after inoculation. histologic lesions of attaching and effacing bacteria were observed in the ...200414974852
shiga toxin 1 targets bovine leukemia virus-expressing cells.direct evidence that escherichia coli shiga toxin (stx) acts against bovine leukemia virus (blv)-expressing cells was obtained. the active a subunit of stx type 1 (stxa1) targeted a selected population of permeable cells expressing blv and inhibited blv replication in a culture of bovine peripheral blood mononuclear cells. cells were cultured with and without stxa1, and at various times cells expressing blv were identified by being stained with mw1 monoclonal antibody specific for the blv protei ...200414977999
effect of endotoxins on contractility of smooth muscle preparations from the bovine abomasal antrum.the effects of endotoxin (et) on spontaneous contractility and of carbachol- and alpha-methyl-5-hydroxytryptamine-(alpha-m-5-ht; 5-ht2 receptor agonist) induced contractions of smooth muscle preparations from the bovine abomasal antrum were investigated in vitro. preparations from the abomasal antrum of freshly slaughtered healthy dairy cows were cut parallel to the longitudinal and circular fibres, suspended in isolated organ baths, and contractility was recorded and analyzed, using digitalized ...200414983752
one- and two-dimensional miniaturized electrophoresis of proteins with native fluorescence detection.miniaturized electrophoresis was successfully coupled with native fluorescence detection for direct analysis of proteins in one- and two-dimensional separations. the detection setup was based on direct observation of the uv-induced fluorescence of proteins using a ccd camera and a hg (xe) lamp for sample excitation. protein mixtures were readily separated by size on a 1-cm segment of the one-dimensional gel in 8 min, and a detection limit of 0.04 ng per band was achieved. the dynamic range of th ...200414987093
four-year survey of urinary tract infections in calves in israel.the prevalence of urinary tract infections in calves aged seven days to three months in three dairy cattle herds ranged from 0.5 to 1.6 per cent, with an average of 1.1 per cent. the mortality rate reached 16.1 per cent. the morbidity rate of the female calves was 1.4 per cent and that of the male calves 0.8 per cent. the bacteria isolated from urine, and from vaginal and preputial swabs were escherichia coli (35 per cent), corynebacterium renale (14 per cent), plasma coagulase-negative staphylo ...200414994858
otitis in cattle, an aetiological review.otitis externa in cattle has a significant impact in tropical and subtropical regions, and the aetiological agents are predominantly rhabditiform nematodes and mites of the genus raillietia. its prevalence is higher in mature and zebu cattle. in advanced clinical cases there can be irreversible and fatal neural lesions. ear infection in calves has been associated with concurrent respiratory diseases and mixed infection. the principal reported agents of otitis in calves are bacteria such as actin ...200414995970
high diversity among environmental escherichia coli isolates from a bovine feedlot.approximately 280 escherichia coli isolates were isolated from a bovine feedlot at the university of connecticut campus via enrichment in lauryl tryptose broth and random selection from macconkey plates. the e. coli subspecies diversity was estimated by employing whole-cell box-pcr genomic fingerprints. a total of 89 distinct operational taxonomic units (otus) were identified by employing a criterion of 85% fingerprint similarity as a surrogate for an otu, while the chao1 index estimated the e. ...200415006775
evaluation of a real-time pcr kit for detecting escherichia coli o157 in bovine fecal samples.a commercially available real-time, rapid pcr test was evaluated for its ability to detect escherichia coli o157. both the sensitivity and specificity of the assay were 99% for isolates in pure culture. the assay detected 1 cfu of e. coli o157:h7 g(-1) in artificially inoculated bovine feces following enrichment.200415006817
cloning of bovine mail and its mrna expression in white blood cells of holstein cows.molecule possessing ankyrin-repeats induced by lipopolysaccharide (mail) is known as an ikappab protein induced after administration of bacterial lipopolysaccharide (lps) to mice. in the present study, we cloned bovine mail cdna and examined its mrna expression in white blood cells isolated from holstein cows. bovine mail had more than 80% amino acid identities with murine and human mails, highly conserved ankyrin-repeat motifs and pest-like sequences. bovine mail mrna was undetectable in isolat ...200415010226
assessment of the california mastitis test usage in smallholder dairy herds and risk of violative antimicrobial residues.this study evaluated how predictive the california mastitis test (cmt) is for sub-clinical mastitis under tropical smallholder dairy production conditions in kenya. it intended to establish whether the cmt usage could be contributing to misdiagnosis and consequent mistreatment with animal drugs resulting in residue problems. milk samples (n = 239) were aseptically collected from lactating cows in the rift valley of kenya and tested using the cmt, somatic cell counts (scc) and bacterial culture. ...200415028880
non-o157 shiga toxin-producing escherichia coli isolated from diarrhoeic calves in argentina.faecal samples from 76 diarrhoeic calves belonging to 36 farms located in the pampas plain, argentina, were examined for shiga toxin-producing escherichia coli (stec). a total of 15 stec strains were isolated from 12 (15.8%) calves which came from six different farms. all stx positive strains assayed by pcr were also positives in the vero cell cytotoxicity test. the majority (60.0%) of the stec strains carried the stx(1) gene. twelve (80.0%) of the stec isolates which belonged to serotypes o5:h- ...200415030606
fate of escherichia coli o157:h7 in manure compost-amended soil and on carrots and onions grown in an environmentally controlled growth chamber.studies were done to determine the fate of escherichia coli o157:h7 in manure compost-amended soil and on carrots and green onions grown in an environmentally controlled growth chamber. commercial dairy cattle manure compost was inoculated with a five-strain mixture of green fluorescent protein-labeled e. coli o157:h7 at 10(7) cfu g(-1) and mixed with unsterilized tifton sandy loam soil at a ratio of 1:5. baby carrot or green onion seedlings were planted into the manure compost-amended soil in p ...200415035376
testing two lactobacillus plantarum and lactobacillus acidophilus strains for their suitability as a lipoid probiotic.two strains of lactobacilli (lactobacillus acidophilus t-135 and lactobacillus plantarum 4/97) were selected in order to study their inhibitory properties against frequent udder pathogens (escherichia coli, staphylococcus aureus, streptococcus agalactiae, streptococcus uberis, salmonella enteritidis and bacillus pumilus), their production of organic acids as well as their ability to survive on the teat skin, the teat duct mucosa and in a lipoid emulsion. both strains inhibited the tested pathoge ...200415046462
the bacillus thuringiensis cry1aa toxin: effects of trypsin and chymotrypsin site mutations on toxicity and stability.the objective of the present work was to create an active cry1aa toxin showing enhanced resistance to degradation by spruce budworm (choristoneura fumiferana) midgut proteases by mutating potential chymotrypsin and trypsin sites. fourteen cry1aa mutants were created in an escherichia coli-bacillus shuttle vector and expressed in a crystal minus bacillus thuringiensis host. using spruce budworm gut juice, commercial bovine trypsin and chymotrypsin we performed protease resistance assays with cry1 ...200415050842
development of a polymerase chain reaction test to confirm mycobacterium avium subsp. paratuberculosis in culture.a polymerase chain reaction (pcr) assay for confirmation of mycobacterium avium subsp. paratuberculosis was developed using the primer set derived from ismav2. the pcr product was 494 base pairs (bp) and could be digested with clai, which produced 311- and 183-bp fragments. no amplification of 494-bp dna fragment was detected from dna of other mycobacterium spp., including mycobacterium avium complex, other bacteria, including escherichia coli, pseudomonas aeruginosa, actinobacillus pleuropneumo ...200415053361
variation in the faecal shedding of salmonella and e. coli o157:h7 in lactating dairy cattle and examination of salmonella genotypes using pulsed-field gel electrophoresis.to examine the variability in faecal shedding of salmonella and escherichia coli o157:h7 in healthy lactating dairy cattle and to evaluate the genetic relatedness of salmonella isolates.200415059205
a diagnostic strategy to determine the shiga toxin-producing escherichia coli o157 status of pens of feedlot cattle.although cattle are reservoirs, no validated method exists to monitor shiga toxin-producing escherichia coli o157 (stec o157) on farms. in 29 midwestern united states feedlot pens we compared culturing faeces from the individual cattle to: (1) culturing rope devices that cattle rub or chew; and (2) culturing a composite of faecal pats. eighty-six per cent (68-96%) of pens were classified correctly using rope devices to detect pens with at least 16% of the cattle shedding stec o157 [sensitivity=8 ...200415061505
interactions of lactoferricin-derived peptides with lps and antimicrobial activity.synthetic peptides derived from human and bovine lactoferricin, as well as tritrpticin sequences, were assayed for antimicrobial activity against wild-type escherichia coli and lps mutant strains. antimicrobial activity was only obtained with peptides derived from the bovine lactoferricin sequence and peptides corresponding to chimeras of human and bovine sequences. none of the peptides corresponding to different regions of native human lactoferricin showed any antimicrobial activity. the result ...200415063486
interaction of actin and its 11-amino acid c-terminal peptide as cofactors with the adenovirus proteinase.actin bound to the adenovirus proteinase (avp) with a lower equilibrium dissociation constant, 4.2 nm, than those exhibited by two viral, nuclear cofactors for avp, the 11-amino acid peptide pvic and the viral dna. the k(cat)/k(m) ratio for substrate hydrolysis by avp increased 150,000-fold in the presence of actin. the 11-amino acid residue peptide corresponding to the c-terminus of actin, which is highly homologous to pvic, bound to avp and stimulated its activity in the presence of dna. as a ...200415063751
role of neutrophil polymorphonuclear leukocytes during bovine coliform mastitis: physiology or pathology?the review compiles some major findings concerning the inflammatory reaction in the mammary gland of dairy cows within the physiological context of the lactation cycle. the dual role of the pmn leukocyte in defense and tissue damage during experimentally induced coliform mastitis, especially around parturition and during early lactation, is highlighted. this disease affects many high producing cows in dairy herds and may cause several cases of death per year in the most severe cases. most resear ...200415074078
prevalence of shiga-toxigenic escherichia coli o157:h7 in adult dairy cattle.to describe shiga-toxigenic escherichia coil o157:h7 (stec o157:h7) fecal shedding prevalence, seasonal fecal shedding patterns, and site-specific prevalence from the oral cavity, skin, and feces of dairy cattle.200415074864
novel metabolism of 1 alpha,25-dihydroxyvitamin d3 with c24-c25 bond cleavage catalyzed by human cyp24a1.our previous study revealed that human cyp24a1 catalyzes a remarkable metabolism consisting of both c-23 and c-24 hydroxylation pathways that used both 25(oh)d(3) and 1alpha,25(oh)(2)d(3) as substrates, while rat cyp24a1 showed extreme predominance of the c-24 over c-23 hydroxylation pathway [sakaki, t., sawada, n., komai, k., shiozawa, s., yamada, s., yamamoto, k., ohyama, y. and inouye, k. (2000) eur. j. biochem. 267, 6158-6165]. in this study, by using the escherichia coli expression system f ...200415078099
the expression of an r3 lipopolysaccharide-core by pathotypes of escherichia coli.to investigate the incidence of an r3 lipopolysaccharide (lps)-core amplicon in a range of pathotypes of escherichia coli, including verocytotoxin-producing e. coli (vtec), enteroaggregative e. coli (eaggec) and enteropathogenic e. coli (epec).200415078514
effect of maillard reaction products on ruminal and fecal acid-resistant e. coli, total coliforms, vfa profiles, and ph in steers.six ruminally cannulated angus-cross steers (362 kg) were used in a replicated 3 x 3 latin square design to determine effects of supplementing maillard reaction products (mrp) on acid-resistant e. coli and coliform populations. steers were fed roughage-based diets supplemented (dm basis) with either 10% soybean meal (sbm), 10% nonenzymatically browned sbm (nesbm), or 10% sbm top-dressed with 45 g of a lysine-dextrose maillard reaction product (ld-mrp). equal weights of dextrose, lysine hydrochlo ...200415080340
acid tolerance of acid-adapted and nonadapted escherichia coli o157:h7 following habituation (10 degrees c) in fresh beef decontamination runoff fluids of different ph values.this study evaluated survival of escherichia coli o157:h7 strain atcc 43895 during exposure to ph 3.5 following its habituation for 2 or 7 days at 10 degrees in fresh beef decontamination waste runoff fluid mixtures (washings) containing 0, 0.02, or 0.2% of lactic or acetic acids. meat washings and sterile water (control) were initially inoculated with approximately 5 log cfu/ml of acid- and nonadapted e. coli o157:h7 cells cultured (30 degrees c, 24 h) in broth with and without 1% glucose, resp ...200415083712
escherichia coli o157 prevalence and enumeration of aerobic bacteria, enterobacteriaceae, and escherichia coli o157 at various steps in commercial beef processing plants.the effectiveness of current antimicrobial interventions used in reducing the prevalence or load of escherichia coli o157 and indicator organisms on cattle hides and carcasses at two commercial beef processing plants was evaluated. sponge sampling of beef cattle was performed at five locations from the initial entry of the animals to the slaughter floor to the exit of carcasses from the "hotbox" cooler. for each sample, e. coli o157 prevalence was determined and total aerobic bacteria, enterobac ...200415083715
reduction of escherichia coli o157:h7 and salmonella enterica serovar enteritidis in chicken manure by larvae of the black soldier fly.green fluorescent protein-labeled escherichia coli o157:h7 and salmonella enterica serovar enteritidis were inoculated at 10(7) cfu/g into cow, hog, or chicken manure. ten- or 11-day-old soldier fly larvae (hermetia illucens l.) (7 to 10 g) were added to the manure and held at 23, 27, or 32 degrees c for 3 to 6 days. soldier fly larvae accelerated inactivation of e. coli o157:h7 in chicken manure but had no effect in cow manure and enhanced survival in hog manure. the initial ph values of the ho ...200415083719
farm visits and undercooked hamburgers as major risk factors for sporadic escherichia coli o157:h7 infection: data from a case-control study in 5 foodnet sites.in 1996, active surveillance in 5 foodborne diseases active surveillance network (foodnet) sites revealed up to a 9-fold difference in escherichia coli o157:h7 (o157) infection incidence between sites. a matched case-control study of sporadic o157 cases was conducted in these sites from march 1996 through april 1997. case subjects were patients with non-outbreak-related diarrheal illness who had o157 isolated from their stool samples. control subjects were healthy persons matched by age and tele ...200415095199
effect of bovine lactoferricin on enteropathogenic yersinia adhesion and invasion in hep-2 cells.bovine lactoferricin, a pepsin-generated antimicrobial peptide from bovine lactoferrin active against a wide range of bacteria, was tested for its ability to influence the adhesion and invasion of yersinia enterocolitica and yersinia pseudotuberculosis in hep-2 cells. the addition of non-cytotoxic and non-bactericidal concentrations of lactoferricin to cell monolayers before infection, under different bacterial growth experimental conditions, was ineffective or resulted in about a 10-fold increa ...200415096550
use of florfenicol in non-human primates.studies were undertaken to determine if florfenicol, an antimicrobial agent structurally similar to chloramphenicol, could be used as an effective broad spectrum antibiotic for the treatment of bacterial infections in primates. florfenicol was developed as an injectable antibiotic for use in cattle on an every other day dosing schedule. its broad spectrum activity, long duration of action following i.m. administration, and its safety as compared with chloramphenicol made it an attractive antibio ...200415102069
vaccination with an ostertagia ostertagi polyprotein allergen protects calves against homologous challenge infection.as an alternative to antihelminthic drugs, we are exploiting vaccination to control infections with the abomasal nematode ostertagia ostertagi in cattle. our focus for vaccine targets is excretory-secretory (es) products of this parasite. one of the most abundant antigens in larval and adult ostertagia es products is a protein homologous to nematode polyprotein allergens. we found that the ostertagia polyprotein allergen (opa) is encoded by a single-copy gene. opa comprises three or more repeate ...200415102812
glycosylation of anaplasma marginale major surface protein 1a and its putative role in adhesion to tick cells.anaplasma marginale, the causative agent of bovine anaplasmosis, is a tick-borne rickettsial pathogen of cattle that multiplies in erythrocytes and tick cells. major surface protein 1a (msp1a) and msp1b form the msp1 complex of a. marginale, which is involved in adhesion of the pathogen to host cells. in this study we tested the hypothesis that msp1a and msp1b were glycosylated, because the observed molecular weights of both proteins were greater than the deduced molecular masses. we further hyp ...200415102815
role of a mutation at position 167 of ctx-m-19 in ceftazidime hydrolysis.ctx-m-19 is a recently identified ceftazidime-hydrolyzing extended-spectrum beta-lactamase, which differs from the majority of ctx-m-type beta-lactamases that preferentially hydrolyze cefotaxime but not ceftazidime. to elucidate the mechanism of ceftazidime hydrolysis by ctx-m-19, the beta-lactam mics of a ctx-m-19 producer, and the kinetic parameters of the enzyme were confirmed. we reconfirmed here that ctx-m-19 is also stable at a high enzyme concentration in the presence of bovine serum albu ...200415105092
ion exchange using poorly activated supports, an easy way for purification of large proteins.ion-exchange chromatography using commercial ionic supports is a commonly used technique for protein purification. however, selective adsorption of a target protein from a given extract onto commercial ion exchangers seems to be quite complex since they are designed to adsorb the maximum percentage of proteins with the opposite charge. in this paper, ion-exchanger supports with different activation degrees (from 1 to 40 micromol of amino groups per g of agarose) have been prepared and used for t ...200415116925
molecular conservation of msp4 and msp5 in anaplasma marginale and a. centrale vaccine strain.anaplasma centrale msp4 and msp5 genes were cloned and sequenced, and the recombinant proteins were expressed. the identity between anaplasma marginale and a. centrale msp4 was 83% in the nucleotide sequences and 91.7% in the encoded protein sequences. a. centrale msp5 nucleotide sequences shared 86.8% identity with a. marginale msp5, and there was 92.9% homology between a. centrale and a. marginale encoded amino acids of the msp5 protein. southern blots hybridized with probes derived from the m ...200415135513
effects of esculin and esculetin on the survival of escherichia coli o157 in human faecal slurries, continuous-flow simulations of the rumen and colon and in calves.the human pathogen escherichia coli o157:h7 is thought to be spread by direct or indirect contact with infected animal or human faeces. the present study investigated the effects of the plant coumarin esculin and its aglycone esculetin on the survival of a strain of e. coli o157 under gut conditions. the addition of these compounds to human faecal slurries and in vitro continuous-flow fermenter models simulating conditions in the human colon and rumen caused marked decreases in the survival of a ...200415137927
escherichia coli and staphylococcus aureus elicit differential innate immune responses following intramammary infection.staphylococcus aureus and escherichia coli are among the most prevalent species of gram-positive and gram-negative bacteria, respectively, that induce clinical mastitis. the innate immune system comprises the immediate host defense mechanisms to protect against infection and contributes to the initial detection of and proinflammatory response to infectious pathogens. the objective of the present study was to characterize the different innate immune responses to experimental intramammary infectio ...200415138171
differential activation of nitric-oxide synthase isozymes by calmodulin-troponin c chimeras.the interactions of neuronal nitric-oxide synthase (nnos) with calmodulin (cam) and mutant forms of cam, including cam-troponin c chimeras, have been previously reported, but there has been no comparable investigation of cam interactions with the other constitutively expressed nos (cnos), endothelial nos (enos), or the inducible isoform (inos). the present study was designed to evaluate the role of the four cam ef hands in the activation of enos and inos. to assess the role of cam regions on asp ...200415138276
anti-complement effects of lactoferrin-derived peptides.lactoferrin is an important biological molecule with many functions such as modulation of the inflammatory response, iron metabolism and antimicrobial defense. one effect of lactoferrin is the inhibition of the classical complement pathway. this study reports that antimicrobial peptides derived from the n-terminal region from both human and bovine lactoferrin, lactoferricin h and lactoferricin b, respectively, inhibit the classical complement pathway. no inhibitory effect of these peptides was o ...200415145458
in vitro inactivation of escherichia coli o157:h7 in bovine rumen fluid by caprylic acid.the antibacterial effect of caprylic acid (35 and 50 mm) on escherichia coli o157:h7 and total anaerobic bacteria at 39 degrees c in rumen fluid (ph 5.6 and 6.8) from 12 beef cattle was investigated. the treatments containing caprylic acid at both phs significantly reduced (p < 0.05) the population of e. coli o157:h7 compared with that in the control samples. at ph 5.6, both levels of caprylic acid killed e. coli o157:h7 rapidly, reducing the pathogen population to undetectable levels at 1 min o ...200415151222
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