| localization of the site of adenylylation of glutamine synthetase by electron microscopy of an enzyme-antibody complex. | antibodies to the nucleosidel,n(6)-ethenoadenosine have been used to localize the site of adenylylation of the glutamine synthetase [l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2] of escherichia coli. antibodies were induced in rabbits by injection of a bovine albumin-ethenoadenosine conjugate. the resulting antisera strongly bound ethenoadenosine, its 5'-nucleotide, or protein conjugates of the nucleoside; little or no crossreaction was seen to adenosine, amp, or the protein carrier. eth ... | 1978 | 32536 |
| some effects of the administration of endotoxin in mice. specific cleavage of serum albumin by an acid protease and the generation of amyloid serum component. | endotoxin has been shown to induce amyloidosis in mice and to result in the appearance in serum of large amounts of amyloidrelated protein (saa). after injection of 300 mug lipopolysaccharide escherichia coli, saa behaves as an acute phase reactant with levels reaching a peak of >600 mug/ml at 18-22 h and returning to base line (<50 mug/ml) by 48 h in each of four strains tested; only the endotoxin-resistant c3h/hej strain showed a smaller response. lesser, though significant, elevations were al ... | 1979 | 34628 |
| diastereoisomeric glucuronides of oxazepam. isolation and stereoselective enzymic hydrolysis. | oxazepam glucuronide isolated from swine urine by previously published methods was separated into its diastereoisomers by ion-exchange chromatography on a preparative scale. quantitative high-performance liquid chromatography was used to monitor the separation. the two isomers were obtained in analytically pure form and then characterized by elemental analysis, oxazepam content, mass spectrometry, ultraviolet spectroscopy, optical rotation and optical rotatory dispersion-circular dichroism. the ... | 1979 | 35325 |
| review: ethidium fluorescence assays. part 1. physicochemical studies. | dna and rna can be assayed rapidly and very sensitively by exploiting the enhanced fluorescence of ethidium intercalated into duplex regions. by assaying at different phs and introducing a heating/cooling cycle, a great many physicochemical aspects of dna and rna can be studied avoiding the use of radiolabels, and often giving information not otherwise readily obtainable. studies are described on duplex dna which involve measurement of extinction coefficients, cross-linking by chemicals, cot cur ... | 1979 | 41222 |
| resistance of gram-negative bacteria to antibiotics in large calf agglomerations. | the antibiotic resistance of e. coli, citrobacter, enterobacter-klebsiella and pseudomonas aeruginosa strains isolated from calves was tested. a high proportion of multiresistance was found even in e. coli strains isolated from newborn calves. gram-negative bacteria isolated from animals in three large calfhouses were almost 100% resistant to ampicillin, tetracyclines and sulphonamides. multiresistance was general and varied from 5 to 12 antibiotics among different strains. initial high sensitiv ... | 1979 | 41425 |
| an attempt to identify the intestinal receptor for the k88 adhesin by means of a haemagglutination inhibition test using glycoproteins and fractions from sow colostrum. | the k88 antigen of escherichia coli specifically adheres to the piglet intestinal cell; a solution of this antigen agglutinates guinea-pig red cells at 4 degrees c. the latter reaction was used as a model of the former, using inhibition of haemagglutination as an index of specific combination with the k88 adhesin. inhibition was found with mucous glycoproteins and chemical modification of their heterosaccharide residues by mild acid hydrolysis, periodate oxidation or the smith degradation proced ... | 1975 | 46271 |
| mucosal adherence of human enteropathogenic escherichia coli. | an in-vitro assay system has been developed to measure bacterial adhesion to the mucosa of human fetal small intestine. two strains of escherichia coli that are proven human enteropathogens (e.p.e.c.) have been shown to adhere in large numbers, compared with control organisms. the attachment mechanism is species specific and is not caused by common fimbriae. mucosal adhesion may be as important as enterotoxin production or invasiveness in determining the virulence of some strains of human e.p.e. ... | 1975 | 53431 |
| the transfer of bacterial biotin genes to escherichia coli k-12 cells by transfection with lambda bio phage dna. | the transfection of biotin genes to biotin negative escherichia coli k-12 cells with donor dna isolated from transducing lambda bio phages was examined. the transfection of the cells was performed in the presence of bovine serum albumin and sucrose (osowiecki and skalińska, 1974). | 1977 | 70968 |
| new surface-associated heat-labile colonization factor antigen (cfa/ii) produced by enterotoxigenic escherichia coli of serogroups o6 and o8. | enterotoxigenic escherichia coli (etec) belonging to serogroups o6 and o8 do not possess the h-10407-type colonization factor antigen (cfa/i). however, these frequently isolated etec were found to possess a second and distinct heat-labile surface-associated colonization factor antigen, termed cfa/ii. whereas cfa/i mediates mannose-resistant hemagglutination of human group a erythrocytes, cfa/ii does not. cfa/ii mediates mannose-resistant hemagglutination of bovine erythrocytes, and mannose-resis ... | 1978 | 80383 |
| enzymic polyadenylation of 5s ribosomal ribonucleic acid and synthesis of a complementary deoxyribonucleic acid. | the 5s ribosomal rna has been isolated, pure and intact, from rat liver (5 mg of 5s rna from 150g of liver). the 5s rna serves as a primer for calf thymus poly(a) polymerase with 20% of the efficiency of (ap)3a. bacterial 5s rna and transfer rna also serve as primers; rat liver 18s and 28s ribosomal rnas support poly(a) synthesis poorly. neither the 5s rna primer nor the appended poly(a) tract is nicked or degraded by poly(a) polymerase, and initiation of poly(a) tracts on 5s rna primers continu ... | 1979 | 88957 |
| hygiene in the prevention of udder infections. iv. evaluation of teat dips with excised cows' teats. | suspensions of staphylococcus aureus, streptococcus agalactiae, escherichia coli, and pseudomonas aeruginosa were used to contaminate teats excised from cows. commercially available teat dips were applied for evaluation of comparative germicidal activity. iodophors, sodium hypochlorite, and sodium dichloro-s-triazenetrione were highly effective against all four test organisms. quarternary ammonium, chlorhexidine, and cetylpyridinium chloride were effective against staphylococcus aureus, and stre ... | 1978 | 100535 |
| [microbiological studies on bacterial spectra of milk samples from healthy udder quarters and from those with increased cell counts and/or conductivity values]. | the germ levels of 2,182 milk samples obtained from udder quarters with subclinical mastitis were compared to milk sampled from 2,061 udder quarters with physiological cell counts or conductivity values. three cattle herds were involved in the test programme. no germ growth was established from 9.5 per cent of all samples taken from udder quarters with increased cell counts and conductivities and from 4.1 per cent of those samples taken from intact udder quarters. samples taken from udder quarte ... | 1978 | 104694 |
| incidence and relationship of group d streptococci with other indicator organisms in meats. | raw and processed meats were analyzed for presumptive group d streptococci using kf streptococcus agar. counts were compared with coliform, presumptive escherichia coli, and enterobacteriaceae counts but no meaningful relationships were observed. results indicated that group d streptococci and e. coli type i were principally contaminants from the packing plant, rather than at retail level. the predominating group d streptococcus in both beef and pork cuts was streptococcus faecalis, while in pro ... | 1978 | 106944 |
| bacteriological quality of runoff water from pastureland. | runoff from a cow-calf pasture in eastern nebraska was monitored for total coliforms (tc), fecal coliforms (fc), and fecal streptococci (fs) during 1976, 1977, and 1978. bacteriological counts in runoff from both grazed and ungrazed areas generally exceeded recommended water quality standards. the fc group was the best indicator group of the impact of grazing. rainfall runoff from the grazed area contained 5 to 10 times more fc than runoff from the fenced, ungrazed area. there was little differe ... | 1979 | 114112 |
| [aanalysis of resistance and its transferability in microflora from primary meat production]. | resistance spectra and their transferability were studied in g- strains isolated from the primary production of meat by the method after bohus (1974). out of the set of strains, 93% were resistant, and out of these, 65% were multiresistant. thirty-five per cent of the resistant strains were r plasmid donors. of the two recipients, the laboratory strain of e. coli ihe nx was significantly better. among the 21 determined resistance spectra, the following were the most frequent: tc, smtcsu, and tca ... | 1979 | 117592 |
| thermal denaturation and template activities of reconstituted dna-histone complexes. | reconstituted complexes of dna with histone were prepared by salt-and-urea step gradient dialysis. the dna was complexed with histone h1, with the combination of the other four histones h2a, h2b, h3 and h4, and with whole histones. these dna-histone complexes were purified by bio-gel column chromatography, and the weight ratio of histone-to-dna was determined in each complex. the thermal denaturation profile and nuclease digestion pattern of dna-histone h2a, h2b, h3 and h4 complex were compatibl ... | 1977 | 146400 |
| inhibition of e coli atpase activity by a troponin component, tn-i, and by mitochondrial atpase inhibitor. | the enzymic activity of mg2+- or ca2+-stimulated atpase from escherichia coli was inhibited by one of the troponin components, tn-i, and by mitochondrial atpase inhibitor (f1-inhibitor). the inhibitory ability of component tn-i against mg2+-stimulated atpase activity was lost after digestion of component tn-i with trypsin. the mg2+-stimulated atpase activity inhibited by component tn-i was completely restored by the addition of another troponin component tn-c. | 1979 | 160325 |
| replication of polyoma dna in isolated nuclei. v. complementation of in vitro dna replication. | nuclei from polyoma-infected 3t6 fibroblasts elongate in vitro the progeny strands of the replicative intermediates of polyoma dna. when high concentrations of such nuclei were incubated, short dna fragments were formed and subsequently added onto growing progeny strands. when nuclei were repeatedly washed with buffer containing detergent and then incubated at low concentrations. dna synthesis was decreased. in particular, the joining process was reduced, resulting in an accumulation of short dn ... | 1975 | 163354 |
| demonstation that thymine dimers are excised as oligonucleotides from specifically incised ultraviolet-irradiated deoxyribonucleic acid. | the average size of the dimer-containing acid-soluble oligonucleotides after incubation of specifically incised dna with two dimer excising nuclease activities has been determined to be about 8 nucleotides. | 1975 | 164436 |
| isolation and characterization of cytidine diphosphate diglyceride from beef liver. | cytidine diphosphate diglyceride was isolated from beef liver by a combination of silicic acid column, deae-cellulose column, and this layer chromatography. the product (5.8 to 17.4 mumol/kg of liver) contained cytidine/phosphate/fatty acids in the molar proportions 1.05/2.0/2.05 (theoretical, 1.0/2.0/2.0) (average for three preparations). the liponucleotide was split quantitatively by a partially purified hydrolase from escherichia coli, specific for cdp-diglyceride, (raetz, c. r. h., hirschber ... | 1975 | 169258 |
| the interaction of bovine erythrocyte superoxide dismutase with hydrogen peroxide: chemiluminescence and peroxidation. | reaction of bovine erythrocyte superoxide dismutase with h2o2 was accompanied by a luminescence whose intensity was a function of the concentration of h2o2 and whose duration was coincident with the inactivation of the enzyme by this reagent. oxygen, which protected against inactivation, also diminished the luminescence. several other compounds which prevented the inactivation by h2o2 also modified the luminescence. thus urate, formate, and triethylamine inhibited luminescence whereas imidazole ... | 1975 | 172122 |
| a study of the enzymic dephosphorylation of beta-casein and a derived phosphopeptide. | beta-casein, and the phosphate containing peptide derived from it by tryptic digestion, have been dephosphorylated by the action of two phosphatases. escherichia coli alkaline phosphatase (ec 3.1.3.1) has been shown to remove the phosphates from these substrates in two distinct stages. substrate molecules retaining three of the original phosphoseryl residues accumulate during the reaction and are resistant to further dephosphorylation at low enzyme concentrations. in contrast bovine spleen phosp ... | 1976 | 187232 |
| changes in intestinal structure and function of neonatal calves infected with reovirus-like agent and eschericia coli. | measurements of villus/crypt length ratio and mucosal beta-galactosidase activity were made on calves less than 3 weeks of age which had diarrhoea associated with reovirus-like agent and e. coli. in calves with diarrhoea, the villus/crypt length ratios at all sites examined along the small intestine were less than in normal calves of similar age. this was attributed to a reduction in length of vili in calves infected with the reovirus-like agent. the activity of mucosal beta-galactosidase in the ... | 1976 | 189746 |
| proposed calfhood immunization program for the commercial dairy herd. | immunization programs never will usurp the central role of sound management practices and good nutrition in the disease prevention program of the commercial dairy operation. however, certain immunizations against diseases such as brucellosis, leptospirosis, and clostridial infections should be routine. other diseases such as infectious bovine rhinotracheitis, bovine virus diarrhea, parainfluenza-3, colibacillosis, and pasteurellosis should be considered if it can be determined that the herd is i ... | 1977 | 190280 |
| binding of phosphorylated histone h1 to dna. | a chromatin associated protein kinase was used to add 3 moles of phosphate to seryl side chains of 1 mole of histone h1. the dna binding properties of this in vitro phosphorylated h1 were compared with those of unmodified h1. considerably more radioactive superhelical dna was retained on nitrocellulose filters at 20mm-40mm nacl by phosphorylated h1 than by unmodified h1. however, zone velocity sedimentation analysis of histone-dna complexes indicated that similar amounts of phosphorylated and un ... | 1978 | 209406 |
| glycoproteins of natural origin with an affinity for hepatitis b surface antigen. | sera from certain animal species contain a substance(s) which binds hepatitis b surface antigen. the hepatitis b binding substance found in animals is not antibody, but appears to be a glycoprotein which reacted with antigen-coated beads and produced a "false positive" test for antibody. this glycoprotein could be selectively and quantitatively removed by reaction with purified hepatitis b surface antigen and centrifugation. pili fractions isolated from neisseria gonorrhoeae and escherichia coli ... | 1978 | 213390 |
| elisa: enzyme-linked immunosorbent assay. | similar in design to radioimmunoassay, comparable in sensitivity and specificity but easier, safer, and less expensive, this new diagnostic technique uses enzyme-labeled rather than isotope-labeled reagents. the end point is a color change that can be assessed by colorimetry or with the naked eye. various techniques of elisa are described, along with examples of current and potential clinical applications. | 1978 | 215505 |
| transcription of nucleosomal dna in sv40 minichromosomes by eukaryotic and prokaryotic rna polymerases. | sv 40 minichromosomes can be transcribed by prokaryotic and eukaryotic rna polymerases. size analysis of transcripts indicated that dna in nucleosomes was accessible for transcription by both enzymes. sedimentation of the transcription complex showed that minichromosomes which were being transcribed had a full complement of nucleosomes. strand selection by e. coli rna polymerase was reduced by the presence of nucleosomes. no region of sv 40 dna was preferentially transcribed on minichromosomes b ... | 1979 | 223131 |
| studies on the substrate specificity of the dna methylase activity from escherichia coli k-12. | a partially purified extract of dna methylases from e. coli k-12 containing dna-adenine as well as dna-cytosine methylase activities has been examined with respect to different dna species as substrates. the results show that the natural content of 6-map) in the applied dna represses the dna-adenine methylase activity. on the other hand, 5-mc, already present in the substrate does not influence the activity of the dna-cytosine methylase. dna from micrococcus radiodurans, which is completely free ... | 1979 | 232591 |
| properties of a dna-adenylate complex formed in the reaction between mammalian dna ligase i and dna containing single-strand breaks. | the major dna ligase from calf thymus (mammalian dna ligase i) forms a covalent enzyme-amp complex on incubation with atp [söderhäll & lindahl, j. biol. chem. 248, 672-675, (1973)]. the reaction of this complex with dna has now been studied. when the ligase-adenylate complex is incubated at 0 degrees c for short time periods with dna containing single-strand breaks, a dna-amp complex can be isolated from the reaction mixture by isopycnic centrifugation in cscl. incubation at ph 6.5 increased the ... | 1975 | 235425 |
| specific limited cleavage of bihelical deoxyribonucleic acid by wheat seedling nuclease. | wheat seedling nuclease catalyzes the hydrolysis of intact, bihelical viral dna or high molecular weight, native escherichia coli dna to produce limit polymers which are resistant to further hydrolysis by additional enzyme. these limit products are double-stranded polymers free of single strand interruptions and are terminated at their 5' ends with equal amounts of either deoxycytidylate or deoxyguanylate residues. the average size of the duplex limit products, as determined by (a) alkaline and ... | 1975 | 236302 |
| the radiometric assay of alkaline phosphatase activity with 125-i-labelled phenolphthalein monophosphate. | the coupling of 125-i to phenolphthalein monophosphate is described. hydrolytic cleavage of the phosphate group by alkaline phosphatases (ec 3.1.-3.1) releases labelled phenolphthalein which is extracted into ethyl acetate at ph 10. this forms the basis of a sensitive assay for the enzyme with the advantages of sensitivity and rapidity from the use of a gamma-emitter. results with escherichia coli and calf intestine alkaline phosphatases are presented. | 1975 | 237639 |
| studies on indoleamine 2,3-dioxygenase. i. superoxide anion as substrate. | indoleamine 2,3-dioxygenase purified to apparent homogeneity from rabbit intestine was inhibited by scavengers for superoxide anion such as superoxide dismutase and 1,2-dihydroxybenzene-3,5-disulfonic acid (tiron). on the other hand, beta-carotene and 1,4-diazobicyclo-(2,2,2)-octane, scavengers for singlet oxygen, did not affect the enzyme activity significantly. the degree of inhibition of the dioxygenase by superoxide dismutase preparations from bovine erythrocytes, green peas, spinach leaves, ... | 1975 | 238993 |
| transcription of double-stranded rna by escherichia coli dna-dependent rna polymerase. | double-stranded rna of some virus genomes can be used as template for the dna-dependent rna polymerase purified from escherichia coli. the rna synthesis requires all four nucleoside triphosphates and manganese ions and is dependent on the presence of sigma subunit. the reaction is inhibited by rifampicin, streptolydigin and ethidium bromide, but not by dnase and actinomycin d which does not bind to double-stranded rna. the template activity of double-stranded rna from various viruses is differen ... | 1977 | 320006 |
| occurrence of k99 antigen on escherichia coli isolated from pigs and colonization of pig ileum by k99+ enterotoxigenic e. coli from calves and pigs. | several strains of enterotoxigenic escherichia coli (etec) isolated from pigs were found to have an antigen (k99) previously reported only on strains of calf and lamb origin and which facilitates intestinal colonization in the latter two species. several human etec were also tested for k99; however, none were positive. each of four k99-positive etec strains of calf origin and one of pig origin produced k99 in pig ileum in vivo, adhered to villous epithelium in pig ileum, colonized pig ileum, and ... | 1977 | 321356 |
| methodology for recognition of invasive potential of escherichia coli. | surveillance for dysentery-related invasive potential in bacteria using the sereny keratoconjunctivitis test is restricted by expense, time factor, and necessity for confirmation. primary screening of isolates in a standardized mammalian cell culture system is recommended. bacteria are grown 20 hr in veal infusion, washed, and resuspended in 20% heat-inactivated fetal bovine serum (fbs) supplemented with 0.12% brain heart infusion and 0.1% bile salts. the hela culture is grown 20 hr as a monolay ... | 1977 | 323215 |
| acute undifferentiated neonatal diarrhea of beef calves: the prevalence of enterotoxigenic e. coli, reo-like (rota) virus and other enteropathogens in cow-calf herds. | | 1977 | 326373 |
| inhibitory action of galactose on phagocytes from normal and hypergalactosemic chicks. | the inhibitory effect of galactose on phagocyte function was investigated in normal and hypergalactosemic chicks by monitoring the in vitro killing of escherichia coli by leukocytes and the in vivo clearance of colloidal 125i-labeled bovine serum albumin ([125i]bsa) from the circulation. elevated levels of galactose (30 mm) significantly impaired the bactericidal activities of leukocytes from both control and hypergalactosemic chicks. however, the latter cells were more susceptible to the galact ... | 1977 | 326668 |
| lutropin stimulation of rna synthesis in corpus luteum chromatin. | lutropin and human choriogonadotropin stimulated the endogenous chromatin-associated polymerase activity in purified chromatin prepared from nuclei of bovine corpus luteum. chromatin was incubated in two different buffer systems: one that mainly supports the activity of polymerase i, another that supports the activity of polymerase ii and is largely alpha-amanitin sensitive. the hormones lutropin and chorigonadotropin stimulated an increase in the rate of incorporation of [14c]atp or [14c]utp in ... | 1977 | 329886 |
| blastogenic transformation by lipopolysaccharide of blood leukocytes from immunized but not normal cattle. | escherichia coli lipopolysaccharide produced blastogenic transformation in whole-blood leukocytes from heifers that had been infected and immunized with campylobacter fetus, but not in cells from control animals. this suggests that lipopolysaccharide dose not function as a b-cell mitogen in cattle and that its stimulation of cells from immunized animals occurred through another mechanism. | 1977 | 330414 |
| in vitro packaging of uv radiation-damaged dna from bacteriophage t7. | when dna from bacteriophage t7 is irradiated with uv light, the efficiency with which this dna can be packaged in vitro to form viable phage particles is reduced. a comparison between irradiated dna packaged in vitro and irradiated intact phage particles shows almost identical survival as a function of uv dose when escherichia coli wild type or pola or uvra mutants are used as the host. although uvra mutants perform less host cell reactivation, the pola strains are identical with wild type in th ... | 1977 | 330877 |
| [studies of immunity in mastitis in cows]. | studies were carried out to establish the specific antibodies in the milk and blood sera of cows recovered from a spontaneous infection of the udder caused by streptococci, staphylocci, corynebacteria, and some representatives of escherichia coli as well as of cows immunized with a polybacterial vaccine. followed up was likewise the resistance of the udder in vaccinated cows to bacterial infections. it was found that in both groups of animals the specific antibodies' titer ranged from 1:80 to 1: ... | 1977 | 331658 |
| effect of tetracycline upon transfer of an r plasmid from calves to human beings. | fecal specimens from human subjects in daily contact with calves shedding escherichia coli containing an r plasmid were analyzed for the presence of e coli and the plasmid. a low level of crossover was found to occur unrelated to whether or not the calves were receiving tetracycline. | 1977 | 333999 |
| [escherichia coli cell competence induced by calcium cations]. | escherichia coli k-12 cells grown to early and late exponential, and early and late stationary phases were treated with ca2+ and analysed for the ability of exogenous 14c-dna uptake and genetic transformation. dna-membrane complexes were detected detected by isopicnic centrifugation of cell lysates in sucrose density gradient. it is found that 1) during all the tested phases of the growth cycle, e. coli cells attain the ability of enhanced dna uptake after ca2+ treatment; 2) exogenous and host d ... | 1977 | 334632 |
| resistance of neonatal calves given colostrum diet to oral challenge with a septicemia-producing escherichia coli. | twenty holstein-friesian male calves were obtained within 4 hours after bith (colostrum deprived) and allotted to 1 of 4 groups, each given a different feeding: colostrum, milk replacer, polyvinylpyrrolidone (pvp), and saline solution (0.85% nacl). each calf was fed 2 l of the respective diets every 12 hours. rectal temperatures were recorded and blood samples were collected immediately before each feeding. at approximately 27 hours of age, all calves were inoculated orally with 1.5 x 10(10) via ... | 1977 | 335927 |
| [dynamics of agglutinins following vaccination against coli-bacteriosis in calves]. | a bivalent vaccine, produced with strains escherichia coli 078 and 0117 to control colibacteriosis in calves, was used to vaccinate experimentally 20 cows following up the agglutinin dynamics in the serum of calves born later on. it was found that the agglutinin titers of the 0 antibodies were lower than those of ok, and varied within the range of from 1:10 to 1:320, the titers of 1:20-1:40 values being prevalent. highest level of titers was observed by the third day following birth. ok antibodi ... | 1977 | 337649 |
| mammary blood flow during experimental escherichia coli endotoxin induced mastitis in goats and cows. | the effect of intramammary infusion of escherichia coli endotoxin upon mammary blood flow was studied in lactating goats and cows. blood flow was recorded by means of an electromagnetic flow probe chronically implanted around one mammary artery. endotoxin mastatis was always accompanied by a significant increase in mammary blood flow, characterized by 2 conspicuous peaks. the flow returned to control values by the thirteenth hour after infusion. other symptoms of acute mastitis were: fever, incr ... | 1977 | 338650 |
| studies on the immunity of the calf to colibacillosis--vii: the experimental reproduction of enteric colibacillosis in colostrum-fed calves. | eight newborn calves were challenged orally with a known enteropathogenic strain of escherichia coli 0101 k?(a) and two to six hours later each calf was fed a minimum of three pints colostrum. all calves suffered from acute diarrhoea of varying severity within 24 to 48 hours of infection. immunofluorescent and histological examination of the small intestine demonstrated adherence of the challenge organism to the epithelium and the presence of pathological lesions similar to those seen in colostr ... | 1977 | 339479 |
| biochemical characteristics of enterotoxigenic and nonenterotoxigenic escherichia coli isolated from calves with diarrhea. | eighteen isolates of enterotoxigenic escherichia coli (etec) and 15 isolates of nonenterotoxigenic e coli (netec) obtained from calves with diarrheal disease were characterized biochemically. of 64 biochemical tests employed, none allowed making differentiation of etec from netec. eleven tests were used to separate etec isolates into 1 of 5 biotypes, although the ability to ferment dulcitol, salicin, sucrose, and sorbose gave sufficient information to identify the 5 biotypes of etec. the biotype ... | 1977 | 339791 |
| the sources of "oh" serotypes of escherichia coli. | the sources from which different "oh" serotypes of escherichia coli have been isolated are listed in a series of tables. it is considered that these tables should provide a basis for obtaining a greater understanding of the ecology of e. coli. | 1978 | 340583 |
| [biochemical and serological studies of the e. coli strains isolated from cows with subclinical mastitis]. | studies were serologically and biochemically a total of 17 strains of escherichia coli isolated from mastitis-affected cows in the districts of sofia, varna, and plovidiv. demonstrated were the serogroups 0125, 0111, 086, 025, 026, 055, and 0128, which were pathogenic for humans too. via the milk they were shown to reach both newborn animals and children and to cause severely expressed colienteritis. all investigated strains attacked glucose and manite, reduced nitrates into nitrites, and gave a ... | 1977 | 343354 |
| in vitro adhesion of escherichia coli to porcine small intestinal epithelial cells: pili as adhesive factors. | escherichia coli strains with pili (k99 or 987p) known to facilitate intestinal colonization adhered in vitro to porcine intestinal epithelial cells. these strains adhered equally to both ileal and jejunal epithelial cells. a laboratory e. coli strain that has type 1 pili also adhered to porcine intestinal epithelial cells. when nonpiliated cells derived from 987p+, k99+, or type 1 pilus+ strains were used for in vitro adhesion assays, they failed to adhere. the attachment of piliated bacteria t ... | 1978 | 357285 |
| biological evaluation of a methanol-soluble, heat-stable escherichia coli enterotoxin in infant mice, pigs, rabbits, and calves. | escherichia coli p16 was shown to produce two heat-stable toxins (st) with differing biological activity. the toxins were separated by methanol extraction, and the first, sta, was methanol soluble, partially heat stable, active in neonatal piglets (1 to 3 days old) and infant mice, but inactive in weaned pigs (7 to 9 weeks old); the second, stb, was methanol insoluble, active in weaned pigs and rabbit ligated loops, but inactive in infant mice. it is therefore suggested that use of suckling mice ... | 1978 | 357288 |
| microscopic assay for the phagocytotic-collagenolytic performance (pcp index) of human gingival fibroblasts in vitro. | using 16 human gingival fibroblasts cell lines from patients with periodontitis, dilantin hyperplasia, and nonpathological gingiva, a microscopic assay was developed to quantitate the cells' ability to lyse collagen substrates. the method employs tissue culture chambers with one cover slip partially coated with a thin layer of undenatured fibrillar bovine collagen. the assay measures the relative numbers and sizes of holes in the collagen within defined regions of the cover slips effected by the ... | 1978 | 363754 |
| incidence of colicinogenic escherichia coli in sheep, goats and cattle. | | 1978 | 367012 |
| purification of 3-phosphoglycerate kinase from diverse sources by affinity elution chromatography. | 1. affinity elution chromatography was used to purify phosphoglycerate kinase from a variety of sources. the choice of buffer ph for the chromatography was made according to the relative electrophoretic mobility of the enzyme from the species concerned. 2. outlines of the methods used to isolate the enzyme from over 20 sources are presented. the enzyme was purified from the muscle tissue of a variety of mammals, fish and birds, from liver of several animals, from yeast, escherichia coli, and pla ... | 1978 | 367367 |
| antibiotic resistance and transferable antibiotica resistance escherichia coli isolated from calves on a modern farm with therapeutic problems and unsatisfactory management conditions. | on a farm with therapeutic problems and unsatisfactory management conditions, the occurrence of antibiotic resistance and transferable antibiotic resistance has been studied in e. coli isolated from calves which were 5 and 30 days old. strains with resistance to up to seven antibiotics as well as transferable resistance against up to five antibiotics were recorded. on an average, 4.2 strains with different patterns and 4.0 different strains with transferable resistance were isolated from each ca ... | 1979 | 370760 |
| use of polyvalent cow colostrum in the prevention of enteric infections in calves and piglets. | colostrum of cows immunized with a polyvalent vaccine against enteropathogenic strains of escherichia coli gave good protection to piglets and calves against enteric coli infections. bovine immunoglobulin (igg1) and its precipitable fragments persisted in the small intestine of piglets for 6 hours after oral administration. the proteolytic breakdown of porcine colostral igg2, which occurs predominantly in the small intestine proceeded at a higher rate than that of heterologous bovine colostral i ... | 1978 | 371506 |
| biochemical and topographical studies on escherichia coli cell surface. iv. giant spheroplast formation from a filamentous cell. | long, nonseptate filamentous cells consisting of 5 to 40 single-cell unit lengths were formed from escherichia coli surface mutant ont-3 by treatment with a sublethal concentration of sodium dodecyl sylfate. as distinct from several other elongated cells (e.g., thymine-starved filaments), it was found here that stable giant spheroplasts, 5 to 10 micrometers in diameter, were produced by the action of lysozyme in the presence of bovine serum albumin via the gradual fusion of distinct spheroplasti ... | 1979 | 374397 |
| leucocytic changes in cows given intravenous injections of e coli endotoxin. | | 1979 | 380122 |
| early mitochondrial damage in the induction of haemorrhagic necrosis in the crocker sarcoma (s 180) by endotoxin. | disturbances in the functional properties of tumor mitochondria have been studied during the course of induction of haemorrhage brought about by endotoxin in the murine crocker sarcoma (s 180). extensive impairment of function was already present in mitochondria isolated from control tumors, as shown by low respiratory control ratios. the existing mitochondrial damage intensified promptly in response to injection of endotoxin long before the onset of haemorrhage at 4 h. the nature of the additio ... | 1979 | 381316 |
| [interaction of oligophosphates of pyridoxal with certain enzymes of polynucleotide synthesis]. | the interaction of pyridoxal, pyridoxal-5'-mono-, di- and triphosphate with certain enzymes of polynucleotide synthesis (dna-dependent rna polymerase, dna-dependent dna polymerase i and polynucleotide phosphorylase from escherichia coli and terminal deoxyribonucleotide transferase from calf thymus) was studied. all compounds tested was found to be reversible and competitive inhibitors of these enzymes. the reduction of the enzyme-inhibitor complex with nabh4 gives rise to the complete irreversib ... | 1979 | 381898 |
| the survival of serum resistant escherichia coli in the bovine mammary gland following experimental infection. | serum resistant strains of escherichia coli were injected into one or two quarters of the udders of eight healthy dairy cows. animals receiving infection into two quarters showed variation in their ability to eliminate the bacteria. this variation extended from elimination from both glands to complete failure to remove the organisms from either gland. in most cases, the organisms were removed from one gland before the clinical signs of infection were observed, but persisted in the other gland fo ... | 1979 | 382316 |
| the pathogenesis of experimental escherichia coli mastitis in newly calved dairy cows. | experimental infections of the mammary gland of newly calved cows with 500 serum resistant escherichia coli produced a very severe form of mastitis when compared with animals in mid-lactation. ten hours after infection the bacteria had multiplied in the milk to very high numbers (10(6)--10(7)/ml) and the animals showed signs of pyrexia, anorexia and diarrhoea. initially the gland and milk showed little or no clinical signs of mastitis, but later the secretion became a viscous, serous fluid with ... | 1979 | 382318 |
| circular dichroism anisotrophy of dna with different modifications at n7 of guanine. | the complexex dna-ag1+, dna-cu1+, protonated dna and dna methylated at n7 of guanine were oriented by pumping the solutions through a multicapillary cell in the direction of a light beam. the cd components along the dna axis, delta epsilon parallel, and normal to it, 2 delta epsilon perpendicular, were calculated from the cd spectra of the oriented samples by the method of chung and holzwarth, (1975) j. mol. biol. 92, 449--466. it was shown that in most cases, except that of the protonated dna, ... | 1979 | 385054 |
| the origin of yolk-dna in xenopus laevis. | xenopus laevis serum and plasma was found to contain an average of 25 microgram dna/ml. isolated x. laevis oocytes incubated in medium containing 25 microgram dna/ml labeled with either 125i, 32p or 14c and from three different sources (bovine, e. coli and x. laevis), incorporated the label at an average rate of 0.11 ng.mm-2.hr-1. sucrose gradient fractionation of oocytes revealed that 40-75% of the acid-precipitable label incorporated was associated with the yolk platelets. additional incubatio ... | 1979 | 385804 |
| ribosome structure: localization of 3' end of rna in small subunit by immunoelectronmicroscopy. | the 3' end of the rna in the 30s ribosomal subunit of escherichia coli has been modified by oxidation with sodium periodate and conjugation with the (mono) dinitrophenyl derivative of ethylenediamine. antibodies, induced with dinitrophenyl-bovine serum albumin, interact with the modified ribosomal subunits. electron micrographs of negatively stained antibody-subunit complexes show individual ribosomal subunits to which a single antibody molecule is bound and subunit dimers cross-linked by an igg ... | 1979 | 386348 |
| a rhelogical separator for very large dna molecules. | we present a rheological separation method for dna molecules in which their deformability is used to advantage. this is the "radial migration method"; here we present experimental verification of the principle, theory having been reported elsewhere. the main conclusions are: (1) the theory is reasonably good; (2) radial migration is highly sensitive to the molecular weight, as predicted, and (3) intact t2 dna (1.25 x 108 daltons) can be made to migrate about three centimeters in less than three ... | 1979 | 388346 |
| the effect of an intramammary infusion of endotoxin on experimentally induced mycoplasmal mastitis. | the infusion of 10 microgram of endotoxin lipopolysaccharide from escherichia coli into the mammary gland of four cows 16 h before inoculation with ureaplasmas did not prevent, or even diminish, the subsequent ureaplasmal mastitis. there was no reduction in the severity or duration of the inflammatory cell response in milk or in the clinical appearance of the resulting mastitis. also, the excretion of ureaplasmas was not reduced. a similar experiment with mycoplasma dispar in two cows demonstrat ... | 1979 | 390046 |
| recurrent coliform mastitis in the dairy cow. | daily monitoring of milk over a 120-day period for bacteria and neutrophil counts revealed that following experimental e coli mastitis, five out of 28 infections resulted in the development of a long continued and recurring condition. intermittent periods of acute inflammation were observed in the gland, pyrexia was noted, and if bacteria were isolated they were always of the same serotype as the original infecting strain. failure to isolate bacteria and the lack of overt inflammation during per ... | 1979 | 390847 |
| the pathogenesis of enteric colibacillosis in neonatal unsuckled calves. | the development of pathological lesions in the small intestine of neonatal calves is described. seven newborn calves were challenged orally with a known enteropathogenic strain of e coli 0101k?(a) and killed at varying times after inoculation. adhesion of bacteria to the mucosa of the small intestine was observed in all calves. a few organisms were seen in the distal small intestine at three hours after inoculation and thereafter adhesion progressed anteriorly along the intestine in calves kille ... | 1979 | 390852 |
| vaccination of the dam by the intramuscular or deep subcutaneous route to prevent neonatal calf enteric colibacillosis. | comparison of colostrum-induced immunities in calves was made by challenge exposure with escherichia coli. these calves were delivered of cows which were vaccinated intramuscularly or deep subcutaneously (in the region of the mammary lymph nodes) with strain b44 e coli bacterin during the last trimester of pregnancy. the calf of each cow was allowed to nurse colostrum naturally after birth. cows vaccinated by either route of administration were capable of providing increased resistance to their ... | 1979 | 393149 |
| [immunobiological activity of various blood serum fractions from cattle and swine. the dynamics of ig in specific serum against colibacillosis in pigs]. | the level of the igm and igg agglutinating antibody specific hyperimmune serum against coli-bacteriosis and its fractions were studied. the serum was obtained at various stages of the preparation, hyperimmunization and exploitation of serum producing swine by using the 2-mercapto-ethanol test. it was established that serum of the total globulin, alpha-beta-globulin and gamma-globulin fractions contains igm and igg agglutinating antibodies against e. coli. these immunoglobulin classes are synthet ... | 1979 | 396718 |
| diethylaminoalkyloxycoumarin and -furocoumarin derivatives. | four series of diethylaminoalkoxyderivatives of coumarin (at the positions 4 and 7) and furocoumarin (at the positions 5 and 8) have been prepared, in order to study their complexing capacity with dna, these compounds having a double possibility of interaction, that is intercalation of the aromatic moiety between two base pairs and formation of an electrostatic bond between their terminal amino group and a phosphoric group of dna. some biological effects connected with the interaction with dna h ... | 1979 | 399924 |
| anomalous reaction of 4-chloro-7-nitrobenzofurazan with thiol compounds. | the kinetics of reaction of 4-chloro-7-nitrobenzofurazan with thiol groups at ph values above 5 cannot be accounted for solely on the basis of formation of a single product, the 4-thio derivative. spectroscopic observations indicate that, in addition to the 4-thio derivative, at least two other products are formed. one of these, referred to as p1, is most likely a reversible complex of thiol compound and 4-chloro-7-nitrobenzofurazan of the meisenheimer type. the other product, p2, which forms pr ... | 1979 | 435240 |
| inactivation by detergents of the proline transport system in membrane vesicles from escherichia coli and its reactivation by bovine serum albumin. | the proline transport system of membrane vesicles from escherichia coli was inactivated by a low concentration of detergents such as deoxycholate, dodecyl sulfate and triton x-100. the addition of a large amount of bovine serum albumin to membrane vesicles which had been treated with one of these detergents resulted in the restoration of the proline transport activity. the restoration of the transport activity by bovine serum albumain was most remarkable with the deoxycholate-inactivated membran ... | 1976 | 764873 |
| [decomposition of steroids during incubation with beta-glucuronidase and during storage of urine]. | androsterone, etiocholanolone, pregnanetriol, dehydroepiandrosterone, pregnanediol, tetrahydrocortisol, 5-pregnenolone and 11-beta-oh-androsterone were incubated with beta-glucuronidase preparations (helix pomatia, bovine liver and e. coli) for 96 hrs at 37 degrees c. after extraction and silylation they were gas-chromatographed. the first 3 steroids were left practically intact. the least decomposition of the last 5 steroids occurred with the liver enzyme. testosterone and 11-ketoandrosterone w ... | 1975 | 765125 |
| experimental neonatal colibacillosis in cows: serological studies. | serological studies of passive immunity in experimentally induced bovine colibacillosis was studied in a 41-cow university herd. pregnant dams were antigenized prepartum with two injections administered by the subcutaneous and intrammamary routes with one of four vaccine preparations (killed bacteria, live bacteria, culture supernatant, or heart infusion broth [control]). the data indicate that 77% of the neonates born to vaccinated dams were strongly protected against oral challenge with escher ... | 1976 | 765285 |
| passive oral immunization with bovine immunoglobulins: enterpathogenic escherichia coli from infants and bovine anti-e. coli lactoserum assayed in the rabbit ileal loop model. | the effect of immune bovine lactoserum (bls) antipolyvalent enteropathogenic escherichia coli on bacterial growth, viability and bacteria-induced fluid accumulation was examined in rabbit ileal loops. human enteropathogenic e. coli strains 0125:k70 (b15), 0111:k58 (b4) and 055:k59 (b5) (1-3 x 10(9) per inoculum) induced secretion of 4-6 ml fluid per 10 cm loop. this effect was inhibited effectively by bls (corresponding to 50 mg igg 1 per loop) while the viability of bacteria counts decreased 2- ... | 1975 | 765710 |
| [residues of antimicrobial materials in the effluents of livestock farms (author's transl)]. | forty water samples were taken from streams of three different regions of belgium, with intensive husbandry and examined for residual microbiological activity. in some samples, activity was detected against staphylococcus aureus; none of them were active against e. coli and c. albicans. the substances in the few positive samples were not identified. with this low activity and the small proportion of positive samples (12 out of 41) any influence on the water biosphere due to the methods of farmin ... | 1976 | 766304 |
| [transcription of dna by rna polymerases of e. coli and calf thymus]. | the paper deals with the comparative investigation of initiation and in vitro rna synthesis on dna template by e. coli rna polymerase and b-form of calf thymus rna polymerase. it was shown in hybridization experiments that in the range of cot values between 10(2) and 10(4) rna synthesized by calf thymus rna polymerase was hybridized with homologous dna more effectively than rna synthesized by e. coli rna polymerase. no differences were observed in the case of low cot values. rna chains synthesiz ... | 1975 | 768744 |
| local immune responses in the bovine fetus vaccinated in utero with escherichia coli antigen. | using specific immunofluorescent examinations, the local immune responses were studied in 14 calves prenatally vaccinated (10 to 50 days before birth) with escherichia coli (o26:k60:nm) antigen or sterile saline solution. all calves were colostrum-deprived, were given oral doses of homologous organisms (killed or live), and were necropsied either at birth or within 12 days after birth. immunofluorescent plasma cells were not seen in duodenum, jejunum, jejunal lymph nodes, ileum, ileal lymph node ... | 1976 | 769610 |
| endotoxin enhancement of plasma cell tumor development in mice given injections of mineral oil. | bacterial endotoxins administered to balb/c mice given i.p. mineral oil cause an increased incidence of plasma cell tumors, compared with mice given either oil or antigens alone, or oil plus antigen other than endotoxin. endotoxin in ng doses was more effective than in mug doses. | 1976 | 773532 |
| [the effect of dna isolated from different sources and different physico-chemical conditions on candida tropicalis strain d-2 his-]. | mutagenic effect of dna, isolated from escherichia coli, actinomyces olivaceus and calf thymus, on hystidine-deficient strain of candida tropicalis d-2 is demonstrated. | 1975 | 773761 |
| antibodies to the triplet codons aaa, aac, and aug: reactions with nucleic acids. | antibodies specific for the trinucleotide codons aaa, aug, and aac were examined for their reactions with nucleic acids. anti-aug and anti-aac precipitated denatured dna. anti-aaa did not, and moreover, the binding of a tritiated aaa derivative to anti-aaa was not inhibited by denatured dna. radioligand-binding studies showed that anti-aaa was highly specific for the triplet sequence, some cross-reactions occurring with di-a and tetra-a but little with a and poly(a). the anti-codons did not prec ... | 1976 | 774989 |
| clinical pharmacology of oxolinic acid in young dairy calves. | the in vitro sensitivity to oxolinic acid shown by pathogenic gram-negative bacterial isolates from young calves with diarrhea, pneumonia, and septicemia was investigated by the bute dilution method. minimal bactericidal concentrations of the drug for 65.5% of the isolates were less than or equal to 1.56 mug/ml and for 90%, less than or equal to 6.25 mug/ml. cross resistance between oxolinic acid and chloramphenicol, streptomycin, neomycin, colistin, ampicillin, gentamicin, and oxytetracycline w ... | 1976 | 776048 |
| cytidine diphosphate diglyceride of bovine brain. positional distribution of fatty acids and analysis of major molecular species. | a method is described for the isolation of cdp-diglyceride from bovine brain. yields of the product ranged from 9.2-15.5 mumol per kilogram of tissue, which corresponds to about 1% of the level of phosphatidic acid. mild alkaline hydrolysis of the product gave three water-soluble phosphate esters which had the same electrophoretic mobilities as cmp, cdp-glycerol and glycerol 3-phosphate. the liponucleotide was quantitatively hydrolysed by cdp-diglyceride hydrolase from escherichia coli to phosph ... | 1976 | 776622 |
| occurrence and characteristics of enterotoxigenic escherichia coli isolated from calves with diarrhea. | of 1,004 isolates of escherichia coli obtained during the spring of 1975 in seven different states from calves with diarrhea, 124 isolates were enterotoxigenic based upon ability to cause distention of the calf ligated intestinal segment. isolates of enterotoxigenic e. coli (etec) were obtained from calves in six of the seven states. etec were detected in calves in 118 of 355 herds in montana during the 1974 and 1975 spring beef calving seasons. the occurrence and serotypes of etec isolated from ... | 1976 | 776828 |
| effect of coliform challenge at milking time on new udder infections. | this project was designed to study rates of infection in udders of cows exposed to an escherichia coli broth culture at milking time. forty holstein cows of varied stages of lactation were divided randomly into three treatment and one control group of ten cows each. the treatment groups were exposed for 3 wk to an escherichia coli broth of 10(9) colony forming units per ml at milking time by either 1) dipping teat ends in broth before milking, 2) spraying the udder and leaving it dripping wet du ... | 1976 | 777057 |
| conjugated polyene fatty acids as fluorescent membrane probes: model system studies. | the use of conjugated polyene fatty acids as probes of membrane structure is examined, alpha- and beta-parinaric acid (cis, trans, trans, cis- and all trans-9, 11, 13, 15-octadecatetraenoic acid) and synthetic lecithins containing an alpha-parinaric acid chai in position 2 have been prepared, and their absorption and fluorescence properties have been determined. their absorption spectra are at sufficiently long wavelength to be unobscured by cellular chromophores such as nucleotides and aromatic ... | 1976 | 778493 |
| vaccination of cows with an escherichia coli bacterin for the prevention of naturally occurring diarrheal disease in their calves. | a formalin-killed escherichia coli bacterin composed of 6 enterotoxigenic strains of the organism prepared from calves with diarrheal disease with field tested for efficacy against naturally occurring diarrheal disease in young calves. the bacterin was tested in 23 privately owned beef herds in montana involving 3,508 cows and their calves. about half the cows in each herd were given 2 subcutaneous vaccinations before calving and the other half (controls) were injected twice with a placebo. almo ... | 1976 | 779544 |
| etiologic diagnosis of diarrheal disease of calves: frequency and methods for detecting enterotoxin and k99 antigen production by escherichia cola. | escherichia coli isolated from calves in minnesota and montana were tested for enterotoxigenicity via bio-assay of cell-free broth culture fluid and for k99 antigen via a serum agglutination test. infant mice were used to assay for heat-stable enterotoxin (st), and adrenal cells in culture were used to assay for heat-labile enterotoxin (lt). forty-six of the 345 e coli isolates produced st enterotoxin, but none produced lt enterotoxin. thirty-five of the 46 enterotoxigenic isolates had k99 antig ... | 1976 | 786085 |
| [artificial intranasal bacterial invasion in the newborn calf. 1. quantitative assessment of nasal secretion for certain groups of bacteria]. | a technique has been developed for quantitative assessment of nasal secretion for the presence of specified groups of bacteria, as a contribution to microbiological treatment of the problem of artificial intranasal bacterial invasion in newborn and nursed calf. some 10(6) to 10(7) bacteria were recorded from each gram of nasal secretion in calves exposed to natural bacterial invasion. micrococci and green diplococci were very rare, with only 10(3) to 10(4) or hardly up to 10(5) bacteria per gram ... | 1976 | 786200 |
| [artificial intranasal bacterial invasion in the newborn calf. 2. artificial bacterial invasion using gram-positive and gram-negative strains]. | a micrococcal and a diplocaccal strain isolated from the nasal space of a clinically intact nursed calf were used for artificial bacterial invasion in the first phase of the experiment. application of bacterial suspension prepared from those strains had no effect upon the rise of coli counts in the nasal secretion of nursed calves during their first days of age nor upon the morbidity or mortality of all 677 test animals in comparison to 665 controls. therefore, an avirulent e.-coli strain was us ... | 1976 | 786201 |
| control of rna synthesis by chromatin proteins. | the effect of chromatin proteins on template activity has been studied. using both e. coli rna polymerase and calf thymmus polymerase b we have measured the number of initiation sites on chromatin and various histone-dna complexes. chromatin can be reconstituted with histone proteins alone and this complex is still a restricted template for rna synthesis. the removal of histone f1 causes a large increase in the template activity. chromatin is then treated with micrococcal nuclease and the dna fr ... | 1976 | 787926 |
| pathogenesis and treatment of escherichia coli infections in calves. | two clearly defined types of e. coli infection are recognised and the factors predisposing and giving rise to pathogenicity are discussed. the mode of action of enterotoxins in the secretary mechanism is thought to be through stimulation of adenyl cyclase activity. treatment and prevention of the disease is considered in relation to the pathogenesis of the infection. | 1976 | 792447 |
| pathological and microbiological observations made on spontaneous cases of acute neonatal calf diarrhea. | the purpose of this report is to describe clinical signs, gross and microscopic lesions, bacteriological and immunofluorescence observations made on spontaneous cases of acute neonatal calf diarrhea (ncd) in dairy and beef herds. the following diagnostic tools were used: 1) direct smears of intestinal content, 2) escherichia coli counts, 3) aerobic bacterial cultures of the small intestine and other organs (the o serogroup and the enterotoxigenicity of the e. coli isolated was determined), 4) de ... | 1976 | 793692 |
| characterization of enterotoxigenic bovine escherichia coli. | among 300 isolates of bovine escherichia coli, 56 which had been found enterotoxigenic in calf gut loops were characterized on the basis of o and k antigens, colonial morphology and resistance to seven antimicrobial drugs. the 56 isolates enterotoxigenic in the calf were compared with the nonenterotoxigenic ones. of the 56 enterotoxigenic e. coli the majority possessed the a type of k antigen and had ok groups, o9:k(ps274) or o101:k(rvc118). fourteen of these isolates had the k99 antigen. none o ... | 1976 | 793694 |
| coliform contaminated bedding and new infections. | ten holstein cows were bedded on fresh, uncured sawdust seeded with coliform broth culture. escherichia coli concentrations were maintained at 10(6) colony-forming units/g for the 4-wk experimental period. ten control cows were bedded with dry shavings. the elevated bacterial contamination caused an increase in contamination of teat ends; however, no new coliform infections occurred. | 1976 | 795819 |
| cloning of calf thymus satellite i dna in escherichia coli. | the 1400 base pair repeat produced by digestion of calf satellite i dna (phi = 1.714 g/cm3) with ecori, was cloned in e. coli. the hybrid plasmid (pgm 214) which contains the cole1-ap vector (psf 2124) and the 1400 base pair fragment replicates stably in e. coli and can be amplified by chloramphenicol treatment. no clone was found in which more than one "repeat unit" of the satellite i dna was present in the chimaera plasmid. digestion of the original satellite i and the plasmid pgm 214 with r-s ... | 1976 | 796669 |