Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| dietary lipid-dependent activation of the carcinogen n-2-fluorenylacetamide in rats as monitored by salmonella typhimurium. | 1978 | 354780 | |
| mutagenic and recombinogenic effects of the antitumor antibiotic anthramycin. | anthramycin, one of the pyrrolo(1,4)benzodiazepine antibiotics with potent antitumor activity, was tested for its effects on a number of genetic parameters. the results show that this antibiotic is nonmutagenic in the ames strains of salmonella typhimurium while mutagenic in only one and antimutagenic in the rest of the genes tested in the eukaryotic organism saccharomyces cerevisiae. the antibiotic is, however, a potent recombinogen inasmuch as it induced mitotic crossing over, mitotic gene con ... | 1978 | 354779 |
| an evaluation of 6 short-term tests for detecting organic chemical carcinogens. | a number of tests have been described which are thought to be capable of identifying carcinogens without using the actual induction of cancer as an endpoint. this study compared the performance of 6 such tests on a selection of 120 organic chemicals. the tests studies were: (1) mutation of salmonella typhimurium; (2) cell transformation; (3) degranulation of endoplasmic reticulum; (4) sebaceous gland suppression; (5) tetrazolium reduction and (6) subcutaneous implant. a further 4 tests were exam ... | 1978 | 354672 |
| [observed metabolic changes in the polymorphonucleocytes and macrophages of guinea pigs injected with salmonella typhimurium s neurotoxin]. | 1977 | 354587 | |
| survival of a salmonella typhimurium experimental contaminant during cooking of beef roasts. | twenty-one raw boneless beef roasts were experimentally injected with 2 x 10(7) cells of a nalidixic acid-resistant strain of salmonella typhimurium per roast. contaminated roasts were cooked to center internal temperatures of 137.0 to 147.5 degrees f (58.3 to 64.1 degrees c) in a gas-fired pilot plant food-processing oven. viable experimental contaminants were recovered from two core samples of the 21 roasts (one cooked to 137.0 degrees f [58.3 degrees c] and one cooked to 141.5 degrees f [ca 6 ... | 1978 | 354529 |
| detection of mutagens produced by fungi with the salmonella typhimurium assay. | forty-one fungal isolates (one isolate per species) representing common plant pathogens and food crop contaminants were grown on sterile, polished rice and assayed for mutagenic activity in the salmonella typhimurium-microsome system. initially, single doses of aqueous and chloroform extracts of the moldy rice were assayed against the ta100 tester strain by incorporating extracts into the growth medium and by applying small quantities on disks placed on the agar surface. suspected activity was e ... | 1978 | 354528 |
| nonmutagenic action of cannabinoids in vitro. | under the specific conditions reported for the separate tests delta9-tetrahydrocannabinol (thc) did not elicit a mutagenic response in microbial and eukaryotic in vitro test systems. thc treatment to histidine auxotrophs of salmonella typhimurium strains ta 98 (susceptible to frame shift mutation) and ta 100 (susceptible to base pair substitution) were investigated. analysis for possible revertance in the presence and absence of s9 microsomal activation system indicated an absence of induction o ... | 1978 | 353830 |
| [post-salmonella rheumatism: case report]. | a twenty seven year old man had polyarthritis following diarrhoea due to salmonella typhimurium. the role of the salmonella infection in the pathogenesis of this joint problem would appear to be confirmed by the detection of the organism on stool culture and a positive reaction for specific antigens in the blood. the arthritis was cured in six weeks under the influence of non-steroid anti-inflammatory agents. | 1978 | 353717 |
| microbiological mutagenicity studies of pesticides in vitro. | 14 pesticides were tested as pure compounds for the induction of point mutations in four strains of salmonella typhimurium--ta1535, ta1536, ta1537 and ta1538--in the presence and in the absence of rat-liver microsomal fractions and for the induction of resistance to low concentrations of streptomycin in the filamentous bacterium, streptomyces coelicolor. the technique used was essentially the so-called "spot test". the pesticides investigated were: aminotriazole, benomyl, captafol, captan, dichl ... | 1978 | 353549 |
| analytical and biological analyses of test materials from the synthetic fuel technologies. i. mutagenicity of crude oils determined by the salmonella typhimurium/microsomal activation system. | we have assayed the mutagenicity of crude industrial products and effluents with the salmonella/microsomal activation system. test materials (crude products from coal-conversion processes and natural crude oils) were initially fractionated into primary classes by liquid--liquid extraction and then further fractionated by column chromatography. prescreening was accomplished over a wide concentration range with the ames tester strains. active fractions (mainly the neutral fractions containing poly ... | 1978 | 353548 |
| microbial assays for mutagenicity: a modified liquid culture method compared with the agar plate system for precision and sensitivity. | a microbial assay system for mutagenicity was developed in which bacterial cells divided in liquid culture. the statistical and practical problems associated with dividing cells were avoided or reduced, whilst the advantages in precision and reliability resulting from the determination of mutation per colony-forming unit (survivor) and of separating the mutation and selection systems were retained. seven mutagens, two of which required microsomal activation, were evaluated by this liquid-medium ... | 1978 | 353542 |
| arginine regulon control in a salmonella typhimurium--escherichia coli hybrid merodiploid. | the regulation of synthesis of arg enzymes was studied in a hybrid merodiploid in which an episome of escherichia coli carrying the argr+ allele was transfered to salmonella typhimurium argr strain. the arg enzyme levels of the hybrid merodiploid were compared to that found in argr and argr+ haploids of s. typhimurium. the results showed that repression of synthesis of arg enzymes was effected through the introduction of the e. coli argr+ allele but significant quantitative differences of arg en ... | 1978 | 353519 |
| genetic control of defective cell shape and osmotic-sensitivity in a mutant of salmonella typhimurium. | 1978 | 353491 | |
| linkage map of salmonella typhimurium, edition v. | 1978 | 353483 | |
| mutagenic action of triose reductone and ascorbic acid on salmonella typhimurium at 100 strain. | 1978 | 353232 | |
| bacteriophage p22 is not a likely probe for zones of adhesion between the inner and outer membranes of salmonella typhimurium. | thin-section electron micrographs of plasmolyzed salmonella typhimurium infected with bacteriophage p22 demonstrated that phage adsorbed to cells over sites of inner- and outer-membrane contact. efforts were made to isolate such adsorption sites by infection of cells with 35s- and 32p-labeled phage and by separation of the membranes on sucrose gradients. at 37 degrees c, about 75% of the 35s radioactivity could be recovered in a region of intermediate density between the inner and outer membrane ... | 1978 | 353032 |
| production and partial purification of salmonella enterotoxin. | by using a strain of salmonella typhimurium, we detected the presence of an enterotoxin, as determined by the rabbit ileal loop assay, in various complex and defined media. the enterotoxin was concentrated by ultrafiltration of culture supernatant fluids and eluted in and adjacent to the void volume of a sephadex g-100 column. this suggested that the enterotoxic factor was of a relatively high molecular weight, and additional evidence indicated it was heterogeneous in size. further chromatograph ... | 1978 | 352941 |
| [mutagenic activity of dioxydine]. | a previous evaluation of mutagenic activity of some drugs and perspective substances is carried out using indicator microorganisms. the mutagenicity of dioxydine, a drag with discovered antibacterial activity, is investigated. dioxydine is shown to induce reversions in mutant of salmonella typhimurium ta-1950, the indicator strain which demonstrates mutagenic activity of agents, producing mutations of base pair substitution type. dioxydine proved to affect logariphmiically growing bacterial cult ... | 1978 | 352806 |
| [intergeneric conjugational hybridization of escherichia coli and salmonella typhimurium. 1. obtaining a salmonella hybrid possessing greater recipient activity in crosses with escherichia coli]. | intergeneric hybrids were selected from mating hfrh escherichia coli with f- salmonella typhimurium. the hybrid obtained from e. coli leu+ and pro+ genes possessed the increased recipient ability in the mating with e. coli hfrr1 (o--ilv--mete--ara). this hybrid lacked the ability to restrict the phage p1 dna propagated on e. coli k-12. the replacement of mutated uvra gene of salmonella for uvra+ gene of e. coli restore uvr+ phenotype of salmonella mutant. | 1977 | 352802 |
| the nature of genetic instability in auxotrophs of salmonella typhimurium requiring cysteine or methionine and resistant to inhibition by 1,2,4-triazole. | we tested the hypothesis that unstable suppression of auxotrophy in triazole-resistant derivatives of cym- mutants of salmonella typhimurium is due to reversible insertion at the cym- site of genetic material originating in the cysalkptshi region. we have shown that the unstable phenotype was co-transducible with markers in the cyscdhij region. the suppression of the cym phenotype was reca dependent and frequencies of segregation were affected by uv irradiation. restored enzyme activity in suppr ... | 1978 | 352799 |
| genetic instability in auxotrophs of salmonella typhimurium requiring cysteine or methionine and resistant to inhibition by 1,2,4-triazole. | triazole-resistant (trz(r)) derivatives of six cysteine- or methionine-requiring (cym(-)) mutants of salmonella typhimurium were isolated. some of the derivatives of each mutant (cts) were prototrophic, i.e., cym(-) was suppressed. in every case suppression was initially unstable, cym(-) auxotrophs being segregated at high frequency, although trz(r) was stable. after several subcultures on selective medium, cts strains were classified as either persistently unstable or stabilized. the unstable s ... | 1978 | 352798 |
| a mutant of escherichia coli which accumulates large amounts of coproporphyrin. | a mutant of escherichia coli which accumulates a large amount of coproporphyrin, presumably because of a block in heme biosynthesis, has been isolated after nitrosoguanidine mutagenesis. on rich media, the mutant forms colonies which give bright orange fluorescence when illuminated with ultraviolet light. the mutant appears to be similar to a salmonella typhimurium mutant, deficient in uroporphyrinogen iii cosynthase, described by sasarman and desrochers ((1976) j. bacteriol. 128, 717--721). a s ... | 1978 | 352406 |
| [atypical strains of salmonella typhimurium isolated during hospital infection]. | 1978 | 352044 | |
| potentiation, desensitization, and inversion of response in bacterial sensing of chemical stimuli. | behavior patterns of chemotactic mutants of salmonella typhimurium were compared to those of the wild type by using the quantitative tumble frequency assay. some cheu mutants were completely inverted in their responses--e.g., attractants produce responses expected for repellents and repellents produce responses expected for attractants. still others swam smoothly and did not respond to any stimuli. mutants of other complementation groups were found to exhibit exact additivity or potentiation in ... | 1978 | 351616 |
| mutagenicity of n-nitrosopiperazine derivatives in salmonella typhimurium. | mutagenicity of several nitroso derivatives of piperazine was assayed using histidine auxotrophic strains of salmonella typhimurium. nitroso derivatives of piperazine required metabolic activation with preference to phenobarbital induced rat-liver microsomal enzymes. we observed a good correlation between a positive effect in the mutation assay and the carcinogenic potency of the compound. even though our results are not in complete agreement with earlier published work using several microbial m ... | 1978 | 351385 |
| screening of safrole, eugenol, their ninhydrin positive metabolites and selected secondary amines for potential mutagenicity. | the mutagenicity of safrole, eugenol, the secondary amines, with which they combine during metabolism, and the ninhydrin positive urinary metabolites of safrole and eugenol was tested. the panel of tests included the direct bacterial assay, a microsomal mutagenesis assay and a host-mediated assay. with the direct bacterial assay employing four mutant strains of salmonella typhimurium (ta1530, ta1531, ta1532, ta1964), all the compounds gave negative results. in the microsomal mutagenesis assay, ... | 1978 | 351383 |
| comparison of the nucleotide sequences of the initial transcribed regions of the tryptophan operons of escherichia coli and salmonella typhimurium. | 1978 | 351195 | |
| rna polymerase interaction at the promoter--operator region of the tryptophan operon of escherichia coli and salmonella typhimurium. | 1978 | 351193 | |
| nucleotide sequence of the promoter--operator region of the tryptophan operon of salmonella typhimurium. | 1978 | 351192 | |
| immunochemistry of salmonella o-antigens: preparation of an octasaccharide-bovine serum albumin immunogen representative of salmonella serogroup b o-antigen and characterization of the antibody response. | the o-antigenic polysaccharide of phenol-water extracted salmonella typhimurium (o antigens 4, 12) lipopolysaccharide was enzymatically cleaved by phage p22 endorhamnosidase. an octasaccharide with the (formula: see text) structure gal-man-rha-gal-man-rha was isolated and shown to retain the o-antigen 4 specificity of the native polysaccharide. after oxidation of the terminal reducing rhamnose residue to the corresponding aldonic acid, the octasaccharide was covalently linked to bovine serum alb ... | 1978 | 351058 |
| characterization of a salmonella typhimurium hisu mutant defective in trna precursor processing. | the da11 mutant of salmonella typhimurium, originally isolated as derepressed for the histidine operon, carries a temperature-dependent alteration in a nucleolytic enzyme specifically involved in the maturation of trna. as a consequence of this alteration, no detectable synthesis of any mature trna species occurs in da11 upon shift at 43 degrees c, whereas many trna precursors, whose sizes range between 80 and 750 nucleotides, do accumulate. kinetic studies on the synthesis and processing of the ... | 1978 | 350829 |
| isolation of salmonella typhimurium from cephalhematoma and osteomyelitis. | 1978 | 350769 | |
| [exerimental study of enterotoxic activity in some strains of salmonella typhimurium: observations on the model of adp-induced platelet aggregation]. | in a previous report it has been shown that enterotoxin preparations (cholera and e. coli) able to activate adenylatecyclase system, abrogated platelet aggregation induced by adp. in the present study the same experimental model has been applied to some purified filtrates from salmonella typhimurium strains. preparations from 986 and tlm (invasive strains causing also fluid secretion) interfere with platelet aggregation, while 1027 strain (invasive but not evoking fluid secretion) didn't show su ... | 1977 | 350683 |
| the acceptor for polar head groups of the lipid a component of salmonella lipopolysaccharides. | we describe here experiments which determine at which stage in the lipid a biosynthesis the polar head groups 4-aminoarabinose, phosphorylethanolamine and 3-deoxy-d-manno-octulosonic acid are transferred to the diphosphorylated glucosamine backbone of the lipid a structure. use was made of a conditional lethal mutant of salmonella typhimurium (ts1) which is defective in the synthesis of 3-deoxy-d-manno-octulosonic acid 8-phosphate and accumulates under nonpermissive conditions an underacylated l ... | 1978 | 350584 |
| 1,2-dihydro-1,2-dihydroxy-5-methylchrysene, a major activated metabolite of the environmental carcinogen 5-methylchrysene. | the metabolic activation of the environmental carcinogen 5-methylchrysene was studied by combining high-pressure liquid chromatographic analysis of metabolites formed in vitro with assays of these metabolites for mutagenic activity toward salmonella typhimurium. metabolites were formed by incubation of 5-methylchrysene with the 9000 x g supernatant from aroclor-treated rat livers. with the use of reverse-phase columns, the metabolites were resolved into nine peaks, a to i. each peak was collecte ... | 1978 | 350385 |
| mutagenicity of several classes of antitumor agents to salmonella typhimurium ta98, ta100, and ta92. | the mutagenic activities of antitumor agents, including 5 antibiotics, 19 antimetabolites, 5 alkylating agents, 2 alkaloids, 1 enzyme, and 1 adrenal steroid hormone, were tested on salmonella tyhimurium ta100, ta98, and ta92. four of these, busulfan, carbazilquinone, 1-(4-amino-2-methylpyrimidine-5-yl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride, and pipobroman were shown for the first time to be mutagenic. further, the known mutagenicities of five others, daunomycin hydrochloride, adria ... | 1978 | 350383 |
| allosteric inhibition and catabolite inactivation of purified biodegradative threonine dehydratase of salmonella typhimurium. | 1978 | 350274 | |
| oral administration of neomycin to chickens experimentally infected with salmonella typhimurium. | groups of healthy chickens with a light experimental salmonella typhimurium infection were fed on a diet containing 225 g per ton (1016 kg) of neomycin for two days. this brought about only a slight reduction in the incidence of chickens that were excreting s typhimurium in their faeces. examination of caecal contents two days after the cessation of treatment revealed the neomycin had not had any effect in eliminating infection. in one experiment, the neomycin administration resulted in the emer ... | 1978 | 349853 |
| mutagenicity of nitrosourea compounds for salmonella typhimurium. | the nitrosourea derivatives 1,3-bis(2-chloroethyl)-1-nitrosourea (nsc-409962), 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (ccnu; nsc-79037), 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (me-ccnu; nsc-95441), and 1-methyl-1-nitrosourea (mnu; nsc-23909) were screened for mutagenic potential with salmonella typhimurium strains g46 and ta1530 in vitro and in vivo. alu were also mutagenic in the host-mediated assay. four additional chemotherapeutic nitrosoureas were tested in vitro, three ... | 1978 | 349171 |
| [reparation of the damages induced by uv light in salmonellae]. | the survival of salmonella typhimurium wild type strains after uv-irradiation is studied. it is demonstrated that many of these are more sensitive to uv-irradiation than escherichia coli of the wild type. alkaline sucrose density gradient centrifugation has demonstrated a deficiency of these strains in normal excision repair of uv-damaged dna. this deficiency is not a feature of salmonella genus, because a strain is found of the same resistance and reparation ability as e. coli wild type strain. | 1977 | 348575 |
| [specific mutagenic effectiveness of 1,4-bis-diazoacetylbutane in relation to individual genes]. | a selective effect of 1,4-bis-diazoacetylbutane (dab) with respect to individual genes is observed when studying its mutagenic action on bacterial strains. escherichia coli and salmonella typhimurium. the frequency of mutations to thr+ exceeded in three orders the background of spontaneous variability for this marker. no induced mutations to trp+ and his+ leu+, which might be the result of transition, transversions, suppressor mutations and frame shift mutations, were detected. mutagenic effect ... | 1977 | 348566 |
| an epizootic of salmonella typhimurium var. copenhagen in broilers and the use of cultured chicken interestinal flora for its control. | 1. an epizootic caused by salmonella typhimurium var. copenhagen and occurring on the farms of one company was examined with the following factors in mind: the spread of the epizootic, the infection rate of the flocks and the role of the food, hatchery and parent stock. 2. a microbiological technique was used the aim of preventing infection on the farms. 3. the method of control was not as effective the field as in the laboratory; the possible reasons for this are discussed. | 1978 | 348270 |
| lack of mutagenicity to salmonella typhimurium of some fusarium mycotoxins. | the mutagenicity of eight fusarium toxins (mono-, di-, and triacetoxyscirpenol, t-2 toxin, deoxynivalenol, 3-acetyl-deoxynivalenol, zearalenone, and moniliformin) and of two positive controls (aflatoxin b1 and sterigmatocystin) to histidine-requiring strains ta 98, 100, 1535, and 1537 of salmonella typhimurium was tested both with and without metabolic activation. both aflatoxin b1 and sterigmatocystin, but none of the eight fusarium toxins, were mutagenic to s. typhimurium. the lack of mutageni ... | 1978 | 348106 |
| salmonella serotypes isolated from the aquatic environment (wabash river, indiana, 1973-1976). | during 1973-1976, 833 isolations of salmonellae were made from the aquatic biosphere of the wabash river, lafayette, ind. of the isolants, 643 were definitively serotyped. salmonella typhimurium represented 34.4% of the cultures. salmonella eimsbuettel previously had not been recognized in indiana. a total of 35 serotypes and 1 untypable group c1 was obtained from the aquatic samples, ie, river water, river bottom sediment, fish, and mussels. most of the isolants were presumed to be of human ori ... | 1978 | 347997 |
| detection of salmonella typhimurium infection of chickens. | the serological response of two groups of chickens was followed by three techniques after experimental infection of one group with salmonella typhimurium. results obtained illustrate the greater sensitivity of the microantiglobulin (coombs) test over more conventional methods for detecting salmonella agglutinins. the possibilities of the diagnostic use of the microantiglobulin test in the field are discussed. | 1978 | 347688 |
| the identification of the trna substrates for the supk trna methylase. | purified preparations of the trna methylase deficient in supk strains of salmonella typhimurium transfer methyl groups from s-adenosylmethionine (sam) to at least two trna species, an alanine trna and a serine trna. the identity of the trna substrates for this enzyme was determined by a change in the elution position of the methyl-labeled trna from bnd-cellulose columns before and after aminoacylation with a specific amino acid followed by derivatization of the free primary amino group with phen ... | 1978 | 347399 |
| tinidazole (tnz) ethyl[2-(2-methyl-5-nitro-1-imidazolyl) ethyl]sulphone) is mutagenic in a salmonella typhimurium assay. | 1978 | 347287 | |
| the mutagenicity of n-nitrosopiperidines for salmonella typhimurium. | 1978 | 347286 | |
| genetic activity of allyl chloride. | allyl chloride (3-chloroprene) is mutagenic for salmonella typhimurium and it induces gene conversions in saccharomyces cerevisiae. it also displays dna-modifying activity for e. coli. this is in contrast to a recent study which reported its lack of genetic activity for salmonella typhimurium. | 1978 | 347285 |
| the mutagenicity of heterocyclic n-nitrosamines for salmonella typhimurium. | 14 carcinogenic and noncarcinogenic heterocyclic n-nitrosamines were evaluated for mutagenicity to salmonella typhimurium ta-1535, which responds to mutagens inducing base-pair substitutions. both suspension and plate tests were used, with mouse and rat liver in vitro metabolic activation systems. all carcinogenic nitrosamines showed a positive response in at least one test system, as did the noncarcinogens. in general, the mutagenic responses obtained with mouse liver were equal to, or greater ... | 1978 | 347283 |
| role of murein lipoprotein in morphogenesis of the bacterial division septum: phenotypic similarity of lkyd and lpo mutants. | phenotypes were compared in two different classes of mutants with defects in murein-lipoprotein (lkyd mutants of salmonella typhimurium and an lpo mutant of escherichia coli). both mutations are associated with the same triad of phenotypic abnormalities, consisting of defective formation of the division septum, leakage of periplasmic proteins during growth, and increased sensitivity to several unrelated external toxic agents. the abnormality in septum formation consists of a defect in invaginati ... | 1978 | 346575 |
| transmembrane permeability channels in vesicles reconstituted from single species of porins from salmonella typhimurium. | aggregates of the "major" outer membrane proteins, "porins," of salmonella typhimurium form diffusion channels in reconstituted vesicle membranes. the aggregate consists of three species of porins with apparent molecular weights of 34,000, 35,000, and 36,000 when active aggregates are subjected to sodium dodecyl sulfate-acrylamide gel electrophoresis after heating in the presence of sodium dodecyl sulfate (nakae, j. biol. chem. 251:2176-2178, 1976). single species of porins were isolated by solu ... | 1978 | 346571 |
| permease-specific mutations in salmonella typhimurium and escherichia coli that release the glycerol, maltose, melibiose, and lactose transport systems from regulation by the phosphoenolpyruvate:sugar phosphotransferase system. | several carbohydrate permease systems in salmonella typhimurium and escherichia coli are sensitive to regulation by the phosphoenolpyruvate:sugar phosphotransferase system. mutant salmonella strains were isolated in which individual transport systems had been rendered insensitive to regulation by sugar substrates of the phosphotransferase system. in one such strain, glycerol uptake was insensitive to regulation; in another, the maltose transport system was resistant to inhibition; and in a third ... | 1978 | 346569 |
| isolation and characterization of mutants of the plasmid pkm101 deficient in their ability to enhance mutagenesis and repair. | a screening procedure was developed for identifying mutants of the plasmid pkm101 no longer capable of enhancing mutagenesis. the test was based on the large pkm101-mediated increase in the number of gal+ papillae observed on colonies of salmonella typhimurium gal mutants plated on tetrazolium-galactose plates in the presence of a mutagen. the pkm101 mutant plasmids transferred normally, were stably maintained in cells, caused normal levels of ampicillin resistance, and still imparted sensitivit ... | 1978 | 346562 |
| a survey of argentine and lebanese bone for salmonellas with particular reference to the isolation of salmonella typhimurium. | 1978 | 346551 | |
| influence of the growth phase and fimbriae on the gradient elution of salmonella typhimurium from deae-cellulose. | 1978 | 346548 | |
| selection of salmonella typhimurium mutants with altered serine transhydroxymethylase regulation. | in salmonella typhimurium the glya gene product, serine transhydroxymethylase (e.c. 2.1.2.1.; l-serine:tetrahydrofolate-5,10-hydroxymethyltransferase) is responsible for the interconversion of serine and glycine. this reaction also provides the cell with one-carbon units from the 5,10-methylene-tetrahydrofolate formed during glycine synthesis. despite the importance of this enzyme, however, no mutants in which its regulation has been specificially altered have been isolated. to isolate such muta ... | 1978 | 346438 |
| inhibitory effect of reducing agents on n-acetoxy- and n-hydroxy-2-acetylaminofluorene-induced mutagenesis. | the effect of cysteine (alpha-amino-beta-mercaptopropionic acid) on the mutagenic activities of the proximate carcinogen, n-hydroxy-2-acetylaminofluorene, and the ultimate carcinogen, n-acetoxy-2-acetylaminofluorene, was examined by estimating the frequency of his+ revertants of salmonella typhimurium. nontoxic concentrations of cysteine significantly reduced the formation of revertants when it was applied concurrently with the two carcinogens. cysteine showed no detectable effect on mutagenesis ... | 1978 | 346207 |
| the measurement of bacterial translation by photon correlation spectroscopy. | photon correlation spectroscopy is shown to be a practical technique for the accurate determination of translational speeds of bacteria. though other attempts have been made to use light scattering as a probe of various aspects of bacterial motility, no other comprehensive studies to establish firmly the basic capabilities and limitations of the technique have been published. the intrinsic accuracy of the assay of translational speeds by photon correlation spectroscopy is investigated by analysi ... | 1978 | 346073 |
| mechanisms of bacterial mutagenesis and properties of mutagenesis tester strains. | bacterial tester strains are available which can detect base pair substitution, frameshift and deletion mutations. i consider possible mechanisms for these types of event. i describe the four main types of dna repair process operating in escherichia coli and salmonella typhimurium and how they may influence mutation: means of modifying repair processes to increase the sensitivity of tester strains are discussed. the properties of some current strains are briefly described. i comment adversely on ... | 1978 | 346007 |
| recovery of sublethally heat-injured salmonella typhimurium on supplemented plating media. | the efficacy of 32 additives to levine eosin-methylene blue-salts agar medium (embs) for the recovery of sublethally heat-injured salmonella typhimurium was evaluated. in order of decreasing effectiveness, lactate, mannitol, and alpha-glycerophosphate mediated 90% or more recovery of injured cells; similar levels of recovery were obtained on embs supplemented with 1% (wt/vol) tryptic soy broth, protease peptone, or plate count agar. other additives showed little or no capacity for repair or stro ... | 1978 | 345969 |
| salmonella typhimurium pancreatic abscess: report of a case. | a case of pancreatic abscess from salmonella typhimurium is reported. after surgical drainage of the abscess, positive stool cultures persisted. finally, after intensive antimicrobial therapy with tetracycline and chloramphenicol, and cholecystectomy, stool cultures became negative. this is, to our knowledge, the first published case of s. typhimurium pancreative abscess. | 1978 | 345903 |
| sulphate permease of escherichia coli k12. | some properties of the sulphate transport system and the isolation of sulphate permease mutants in e. coli k12 are described. the gene coding for sulphate permease is located in the same region as the cysa gene in salmonella typhimurium. | 1977 | 345700 |
| [transfer of multi-drug resistance in vivo by salmonellae and shigella in white mice]. | the oral infection accomplished by 0.3 cm3 x 10(10) microbial bodies of salmonella heidelberg and shigella sonnei in albino mice the pathogens were found to localize in the intestines. the salmonellae were detected up to the 10th day, and the shigellae--up to the 14th day. both shigella and salmonella transferred multi-drug resistance to some enterobacteria--e. coli and proteus as well as to salmonella typhimurium when the latter was also present in the intestinal tract; of these some 10--40 per ... | 1977 | 345607 |
| chloramphenicol-resistant salmonella typhimurium. | 1978 | 345599 | |
| superinfection exclusion and changes in cellular transport processes in phage infected salmonella typhimurium. | the changes induced by bacteriophage p22 in the cellular transport process(es) of the host salmonella typhimurium (taneja et al., 1975; khandekar et al., 1975; bandyopadhyay and chakravorty, 1976) involve interactions between the superinfection exclusion system of the resident prophage and the c immunity region of the superinfecting phage. the sie a gene of the prophage interferes with the changes in the cellular transport process induced by the superinfecting phage. however, if the superinfecti ... | 1978 | 345099 |
| molecular studies of fime resistance plasmids, particularly in epidemic salmonella typhimurium. | 1978 | 345079 | |
| tandem chromosomal duplications in salmonella typhimurium: fusion of histidine genes to novel promoters. | 1978 | 344891 | |
| the effect of antimicrobial feed additives on the colonization of the alimentary tract of chickens by salmonella typhimurium. | groups of 33 chickens were fed continuously on diets containing feed additives that are employed commercially for a variety of purposes, and were infected orally when 4 days old with a nalidixic acid-resistant mutant of salmonella typhimurium. the amount of s. typhimurium organisms excreted in their faeces was estimated by culturing them at intervals and in a standard manner on brilliant green agar containing sodium nalidixate; when the chickens were killed their caecal contents were examined by ... | 1978 | 344789 |
| comparative efficacy and toxicity of a ribosomal vaccine, acetone-killed cells, lipopolysaccharide, and a live cell vaccine prepared from salmonella typhhimurium. | the protective and toxic properties of a ribosomal vaccine prepared from salmonella typhimurium w118-2 were systematicaly compared with those of an acetone-killed whole cell vaccine, purified lipopolysaccharide, and living cells in cd-1 mice. tests of graded immunizing doses of each vaccine against several challenge doses of live strain w118-2 showed that, although the protection given by ribosomes approached the levels of protection conferred by living organisms, acetone-killed cells administe ... | 1978 | 344216 |
| experimental infection of point-of-lay and in-lay pullets with salmonella typhimurium. | 1978 | 343883 | |
| vaccination control of an outbreak of salmonella typhimurium infection in suckler cows and calves. | 1977 | 343876 | |
| [ulterior acquisitions regarding the salmonellosis (author's transl)]. | the authors report the results of the bacteriological researches on the incidence of the salmonella of our zone, after a brief consideration of general aspects salmonellosis. our observations are refered to 1005 samples of feces of which 84 cases proved positive to salmonella. it is pointed out that morbidity, represented by salmonella typhi, paratyphi a and b is low, while it is high for the salmonella typhimurium and salmonella enteritidis. the authors conclude stating that epidemiological sit ... | 1977 | 343729 |
| nematospiroides dubius as a vector for salmonella typhimurium. | salmonella typhimurium within the 3rd stage larvae of nematospiroides dubius was shown to infect mice, evidenced by prolonged shedding of salmonellae in the feces. numbers of s typhimurium needed to infect mice were approximately 1,000- fold less if incorporated within the 3rd-stage larvae of n dubius. results of these experiments demonstrate that nematode parasites may act as a vector for pathogenic species of enteric bacteria. | 1978 | 343664 |
| [further studies on the metabolic changes in salmonella typhimurium and yersinia pseudotuberculosis strains after treatment with detergents and lipid solvents]. | 1977 | 343513 | |
| quantitative forward mutation assay in salmonella typhimurium using 8-azaguanine resistance as a genetic marker. | we have developed a quantitative forward mutation assay using salmonella typhimurium, in which resistance to the purine analog 8-azaguanine is used as a genetic marker. we present the assay protocol, the concentration-dependent toxicity and mutagenicity of five known mutagens (n-methyl-n'-nitro-n-nitrosoguanidine, icr-191, 9-aminoacridine, dimethylnitrosamine, and benzo[a]pyrene), and reconstruction experiments testing the assay for possible bias. the relative merits of forward versus reverse mu ... | 1978 | 343109 |
| effect of low level feeding chlortetracycline on subsequent therapy of chicks infected with salmonella typhimurium. | a six-week trial was conducted to determine if therapeutic use of chlortetracycline (ctc) would be affected by previous use of the same antibiotics at subtherapeutic levels in the feed. results indicated therapeutic effect of ctc on mortality was not compromised by the previous use of the low level antibiotic. | 1977 | 343088 |
| degeneration of the mucosal surface of the small intestine of the chicken in salmonella infection. | day-old chicks were infected with salmonella typhimurium. the impact on the intestinal mucosa was observed by scanning and transmission electron microscopy. salmonella infected birds were characterized as having areas on their intestinal mucosal cells devoid of microvilli. the absence of microvilli probably interferes with absorption of the digesta. | 1977 | 343083 |
| mutagenicity induced by lyophilization or storage of urine from isoniazid-treated rats. | urine collected during 24 h after treatment of rats with 90--550 mg/kg isonicotinic acid hydrazide (isoniazid, inh) was after lyophilization, mutagenic for salmonella typhimurium ta1535. urine collected directly from bladders of inh-treated rats was not mutagenic, and solutions of inh in water or urine became mutagenic only after lyophilization. in the absence of lyophilization, sterile urine from inh-treated rats became mutagenic after 8--14 days' storage at room temperature. | 1978 | 342946 |
| mutagenicities of the pyrolyzates of peptides and proteins. | pyrolyzates of 10 peptides, 10 proteins and 5 naturally-occurring materials were tested for mutagenicity in the histidine-requiring mutants salmonella typhimurium ta98 and ta100. significant mutagenic activity was detected with pyrolyzates of most of these materials. the pyrolyzates requred a liver microsomal fraction, as representative of mammalian metabolism, for their detection as mutagens. among the pyrolyzates tested, the highest mutagenic activity was observed with that of a tryptophan-con ... | 1978 | 342945 |
| mutagenicity in salmonella typhimurium mutants of the benzene-soluble organic matter derived from air-borne particulate matter and its five fractions. | air-borne particulate matter was collected on a filter, then extracted with benzene. the benzene-soluble material was separated into 5 fractions, namely acidic, basic, alipathic, polyaromatic and oxygenated fractions. the mutagenic activities of these fractions were examined with a set of salmonella typhimurium mutants. the 6 mutants were from the ta1535 series, deep rough strains without excision repair, namely ta100 and ta98 (having a resistance-transfer factor) and the standard strain ta1535, ... | 1978 | 342944 |
| mutagenic effect of dichloromethane on salmonella typhimurium. | the possible mutagenicity of the organic solvent dichloromethane was investigated with the mutation test as described by ames et al. the compound was mutagenic in both tester strains used, namely ta98 and ta100. the administration of rat-liver homogenate did not appear to be essential though it slightly increased the number of mutations. | 1978 | 342942 |
| mutagenicity of alkyl-(omega-hydroxyalkyl) nitrosamines related to dibutylnitrosamine. | various alkyl-(omega-hydroxyalkyl) derivatives related to dibutylnitrosamine (dbn) were investigated for mutagenicity in the absence of liver-activation system. butyl-(4-hydroxybutyl)-, butyl-(3-hydroxypropyl)-, and butyl-(2-hydroxyethyl)-nitrosamines were so tested and found to be mutagenic for ta 1535 strain of salmonella typhimurium. in all cases, a simple dose-response relationship was observed. furthermore, no significant (p less than 0.05) differences in the mutagenicity of the various tes ... | 1978 | 342939 |
| evaluation of the mutagenic potential of mycotoxins using salmonella typhimurium and saccharomyces cerevisiae. | the mutagenic effects of fiteen mycotoxins on salmonella typhimurium strains ta1535, ta1537 and ta1538 and saccharomyces cerevisiae strain d-3 were tested. only aflatoxin b1 and sterigmatocystin were mutagenic. both were active against s. typhimurium strain ta1538 and s. cerevisiae strain d-3; however, both required activation by the hepatic s-9 enzyme preparation. a positive correlation between the other mycotoxins reported to be carcinogenic and the two in vitro test systems employed was not d ... | 1978 | 342938 |
| high mutagenicity of n-(alpha-acyloxy)alkyl-n-alkylnitrosamines in s. typhimurium: model compounds for metabolically activated n,n-dialkylnitrosamines. | a series of n,n-dialkylnitrosamines (alkyl means methyl, ethyl, n-propyl, n-butyl or tert-butyl group) mono-substituted at the alpha-carbon with an acetoxy group, were tested for their mutagenic action in salmonella typhimurium ta1530 in the presence or absence of a rat-liver supernatant from 9000 x g. the presumed released of methyl, ethyl, n-butyl and n-propyl carbonium ions from the corresponding alpha-acetoxy derivatives, either by enzymic cleavage or by non-enzymic hydrolysis of the ester g ... | 1978 | 342933 |
| re-initiation of tryptophan operon expression in a promoter deletion strain of salmonella typhimurium. | a genetic and enzymological study was made of five spontaneous prototrophic revertants of a tryptophan auxotroph of salmonella typhimurium which carries a deletion extending from the closely linked supx locus into the trp operator-promoter region. the revertants were found to have regained initiation of expression of all five trp genes. recombinational tests showed that in each case the genetic change responsible for re-initiation is cotransducible with the trp-cysb region of the chromosome. two ... | 1978 | 342912 |
| immunological properties of vibrio cholerae lipopolysaccharides. | immunological effects of wall lipopolysaccharide (lps) preparations obtained from vibrio cholerae inaba 569b, ogawa nih 41 and nag 4715 strains by the hot phenol-water procedure were examined in mice. although these lps lack kdo, which are basic components of the core region of most gram-negative lps, they still have potencies as b-cell mitogens, adjuvants, immunosuppressants, polyclonal b-cell activators and phagocytic stimulants for macrophages. the activities of these v. cholerae lps on murin ... | 1977 | 342874 |
| the use of strain lt2-ml in identifying the protective antigens in a salmonella typhimurium-derived ribosomal vaccine. | 1978 | 342689 | |
| the epidemiology and genetics of antibiotic resistance of salmonella typhimurium isolated from diseases animals in new york. | only 12% of 249 strains of salmonella typhimurium isolated during the period 1973-1976 from diseased animals were sensitive to six commonly used antibiotics. isolates from calves exhibited the highest frequency of resistance as well as a steadily increasing frequency of resistance to ampicillin and chloramphenicol. the majority of strains from horses, dogs, and cats were also resistant to more than one antibiotic, a finding which was interpreted as primarily an effect of therapeutic rather than ... | 1978 | 342636 |
| biosynthesis of lipid a. enzymatic incorporation of 3-deoxy-d-mannooctulosonate into a precursor of lipid a in salmonella typhimurium. | the cell envelope fraction of salmonella typhimurium contains an enzyme system which catalyzes transfer of 3-deoxyoctulosonate (kdo) from cmp-kdo to an incomplete, kdo-deficient precursor of lipid a. the enzyme system is firmly membrane-bound, but has been solubilized by treatment with nonionic detergent at alkaline ph and partially purified. both the particulate and partially purified fractions catalyzed formation of a single reaction product containing 2 residues of kdo. periodate oxidation of ... | 1978 | 342527 |
| threonine deaminase from salmonella typhimurium. effect of regulatory ligands on the binding of substrates and substrate analogues to the active sites and the differentiation of the activator and inhibitor sites from the active sites. | 1978 | 342520 | |
| incomplete flagellar structures in nonflagellate mutants of salmonella typhimurium. | incomplete flagellar structures were detected in osmotically shocked cells or membrane-associated fraction of many nonflagellate mutants of salmonella typhimurium by electron microscopy. the predominant types of these structures in the mutants were cistron specific. the incomplete basal bodies were detected in flafi, flafiv, flafviii, and flafix mutants, the structure homologous to a basal body in flafv mutants, the polyhook-basal body complex in flar mutants, and the hook-basal body complex in ... | 1978 | 342514 |
| promoter- and attenuator-related metabolic regulation of the salmonella typhimurium histidine operon. | expression of the histidine (his) operon in salmonella typhimurium was found to be positively correlated with the intracellular level of guanosine tetraphosphate (ppgpp). limitation for amino acids other than histidine elicited a histidine-independent metabolic regulation of the operon. in bacteria grown at decreased growth rates, his operon expression was metabolically regulated up to a point, after which further decreases in growth rate no longer resulted in further enhancement of operon expre ... | 1978 | 342509 |
| cluster of genes controlling proline degradation in salmonella typhimurium. | a cluster of genes essential for degradation of proline to glutamate (put) is located between the pyrc and pyrd loci at min 22 of the salmonella chromosome. a series of 25 deletion mutants of this region have been isolated and used to construct a fine-structure map of the put genes. the map includes mutations affecting the proline degradative activities, proline oxidase and pyrroline-5-carboxylic dehydrogenase. also included are mutations affecting the major proline permease and a regulatory mut ... | 1978 | 342507 |
| regulation of the major proline permease gene of salmonella typhimurium. | the structural gene for the major proline permease is located in a tight cluster with genes coding for the proline degradative enzymes, proline oxidase and pyrroline-5-carboxylic acid dehydrogenase. expression of the permease is regulated in parallel with the two degradative enzymes, and all three functions are subject to catabolite repression. regulatory mutants (putc) have constitutively high levels of all three activities, suggesting that all are regulated by a single mechanism. | 1978 | 342506 |
| chemotaxis of salmonella typhimurium to amino acids and some sugars. | patterns of chemotaxis by salmonella typhimurium strain lt-2 to l-amino acids and to several sugars were quantitated by the adler capillary procedure. competition experiments indicated that lt-2 possesses three predominant receptors, or interacting sets of receptors, for amino acids. these were termed the aspartate, serine, and alanine classes, respectively. studies with strains carrying point and deletion mutations affecting components of the phosphoenolpyruvate: glycose phosphotransferase syst ... | 1978 | 342504 |
| expression of escherichia coli fol alleles in salmonella typhimurium. | studies of the expression of escherichia coli fol alleles in salmonella typhimurium indicated that fol regulatory functions are highly conserved between these bacterial species. | 1978 | 342487 |
| influence of oral antibiotic feeding on the duration and severity of clinical disease, growth performance, and pattern of shedding in swine inoculated with salmonella typhimurium. | 1978 | 342469 | |
| o antigen as virulence factor in mouse typhoid: effect of b-cell suppression. | immunosuppression by cyclophosphamide was used to make mice incapable of b-lymphocyte responses; they could not make an antibody response to nip-ficoll. these mice, as well as untreated mice, were challenged intraperitoneally with graded doses of isogenic o-4,12 or o-6,7 salmonella typhimurium derivatives. the 50% lethal dose of the o-6,7 strains was 35- to 70-fold higher than that of the o-4,12 strains, both in the normal and the immunosuppressed animals, although the latter were approximately ... | 1978 | 342413 |
| antimutagenic effects of caffeine during nitrosoguanidine-induced mutagenesis of salmonella typhimurium cells and phages. | the effect of caffeine on nitrosoguanidine-induced mutagenesis of salmonella typhimurium and its p22 and l phages was studied. the detected mutations included phage "clear" mutations, reversions of phage "amber" mutation, and prototrophic reversions of the his- auxotroph of salmonella typhimurium. neither the reca mutation of the host nor the erf mutation of the phage genome were found to affect the nitrosoguanidine-induced mutagenesis of the phage during vegetative growth. beginning with a conc ... | 1978 | 342372 |