Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| azide-induced mutagenesis in gram-negative bacteria is reca-and lexa-independent. | azide-induced mutagenesis was investigated in salmonella typhimurium and escherichia coli. azide was highly effective in inducing mutation in uvrb, uvrb reca and uvrb recb mutants of s. typhimurium. the mutagenic effect of azide was also observed in uvra lexa mutants of e. coli k12 and e. coli b/r. these results suggest that azide-induced mutagenesis is due to mis-replication of dna. | 1979 | 388210 |
| [laboratory and clinical studies on cefamandole (author's transl)]. | the authors have carried out the laboratory and clinical studies of cefamandole (cmd). the results are as follows: the sensitivity was measured by plate dilution method on 26 strains of staphylococcus aureus, escherichia coli, klebsiella pneumoniae and 14 strains of salmonella typhimurium isolated from patients. the distribution of sensitivity of s. aureus was 0.39 approximately 3.13 micrograms/ml and the peak of distribution was 1.56 micrograms/ml. the distribution of sensitivity of e. coli was ... | 1979 | 387993 |
| salmonella bacteriophage glycanases: endorhamnosidases of salmonella typhimurium bacteriophages. | twelve bacteriphages lysing only smooth salmonella typhimurium strains were shown to have similar morphology--an icosahedric head to which a short, noncontractile tail carrying six spikes was attached. all phages degraded their lipopolysaccharide (lps) receptors as shown by their ability to cleave off [14c]galactosyl-containing oligosaccharides from s. typhimurium cells labeled in their lps. the oligosaccharides inhibited the alpha-d-galactosyl-specific bandeiraea simplicifolia lectin agglutinat ... | 1979 | 387979 |
| interference of azide with cysteine biosynthesis in salmonella typhimurium. | the growth inhibition of salmonella typhimurium azia mutants by sodium azide is reversed by cystine and related compounds. nadph-sulphite reductase (hydrogen-sulphide:nadp+ oxidoreductase; ec 1.8.1.2), an enzyme of cysteine biosynthesis, is inhibited in cell extracts by sodium azide. azib mutants which are able to grow in the presence of the inhibitor without cystine were isolated. about half of them were mapped in the cysk gene and have only residual activity of its product, o-acetylserine sulp ... | 1979 | 387913 |
| pyridine nucleotide cycle of salmonella typhimurium: in vitro demonstration of nicotinamide mononucleotide deamidase and characterization of pnua mutants defective in nicotinamide mononucleotide transport. | the enzyme nicotinamide mononucleotide deamidase, an integral component of the proposed four-membered pyridine nucleotide cycle (pnc iv), has been demonstrated in extracts of salmonella typhimurium lt2. the enzyme has an optimum ph of 8.7 and deamidates nicotinamide mononucleotide, forming nicotinic acid mononucleotide. sigmoidal kinetic data suggest that this enzyme may be allosteric and therefore an important regulatory component of pyridine nucleotide cycle metabolism. mutants previously desi ... | 1979 | 387742 |
| deoxyribonucleic acid adenine and cytosine methylation in salmonella typhimurium and salmonella typhi. | the methylations of adenine in the sequence -gatc- and of the second cytosine in the sequence - [formula: see text] - were studied in salmonella typhimurium and in salmonella typhi. the study was carried out by using endonucleases which restrict the plasmid pbr322 by cleavage at the sequences -gatc- (dpni and mboi) and - [formula: see text] - (ecorii). the restriction patterns obtained for this plasmid isolated from transformed s. typhimurium and s. typhi were compared with those of pbr322 isola ... | 1979 | 387741 |
| electron acceptor taxis and blue light effect on bacterial chemotaxis. | salmonella typhimurium and escherichia coli from anaerobic cultures displayed tactic responses to gradients of nitrate, fumarate, and oxygen when the appropriate electron transport pathway was present. such responses were named "electron acceptor taxis" because they are elicited by terminal electron acceptors. mutant strains of s. typhimurium and e. coli were used to establish that functioning electron transport pathways to nitrate and fumarate are required for taxis to these compounds. aerotaxi ... | 1979 | 387740 |
| chemotaxis of salmonella typhimurium toward citrate. | salmonella, but not escherichia coli, was attracted to citrate, a distinction that is understandable in view of the inability of e. coli to transport tricarboxylic acids. the salmonella response to citrate and to two previously described attractants, aspartate and malate, was mutually noncompetitive. citrate taxis different from citrate uptake in that it did not require na+, was constitutive, and was not repressible by glucose. | 1979 | 387726 |
| role of gene flafv on flagellar hook formation in salmonella typhimurium. | nine temperature-sensitive nonflagellate mutants defective in flafv were isolated from a strain of salmonella typhimurium. among them three mutants were found to produce flagella with abnormally shaped (either straight or irregularly curved) hooks at the permissive temperature. two mutations that rendered hooks straight were located in one of the eight segments of flafv defined by deletion mapping. the mutation that rendered hooks irregularly curved was located in a different segment. an flar mu ... | 1979 | 387724 |
| immuno-electron microscopic localization of lipopolysaccharide antigens on ultrathin sections of salmonella typhimurium. | lipopolysaccharide antigens were demonstrated on ultrathin sections of styrene-embedded salmonella typhimurium by direct postembedding staining with ferritin-labeled antibodies. the antigenicity, partially masked in the embedding process, could be satisfactorily recovered by treatment of ultrathin sections with nonspecific protease. as judged from the reaction site of the ferritin-labeled antibodies, the lipopolysaccharides were localized in two zones. the broader zone of densely distributed fer ... | 1979 | 387723 |
| regulation of o-acetylserine sulfhydrylase b by l-cysteine in salmonella typhimurium. | a technique based on resistance to azaserine was used to isolate mutants lacking o-acetylserine sulfhydrylase b, one of two enzymes in salmonella typhimurium capable of synthesizing l-cysteine from o-acetyl-l-serine and sulfide. the mutant locus responsible for this defect has been designated cysm, and genetic mapping suggests that cysm is very close to and perhaps contiguous with cysa. strains lacking either o-acetylserine sulfhydrylase b or the second sulfhydrylase, o-acetylserine sulfhydrylas ... | 1979 | 387718 |
| collaborative studies on the salmonella/microsome mutagenicity assay. | although the salmonella/plate test has been used extensively, a collaborative study was undertaken to determine the interlaboratory reproducibility of this microbial mutagenicity assay. four laboratories participating in the study have completed testing, under code, of 61 carcinogens and noncarcinogens. all chemicals were tested both with and without metabolic activation in salmonella typhimurium strains ta1535, 1537, 1538, 98, and 100. the metabolic activation systems used were derived from the ... | 1979 | 387710 |
| artificial salmonella vaccines: o-antigenic oligosaccharide-protein conjugates induce protection against infection with salmonella typhimurium. | outbred mice were vaccinated with various artificial salmonella vaccines and subsequently challenged intraperitoneally with graded doses of virulent salmonella typhimurium. the salmonella vaccines used were: (i) octasaccharide, obtained by hydrolysis of the o-antigenic polysaccharide chain of s. typhimurium strain sh 4809 with phage p22-associated endo-rhamnosidase and covalently linked to either diphtheria toxin or edestine; (ii) purified outer membrane proteins (porins) from s. typhimurium; an ... | 1979 | 387597 |
| immunization with major outer membrane proteins in experimental salmonellosis of mice. | porin (outer membrane protein) preparations extracted from a rough (rb2) mutant of salmonella typhimurium proved to be good immunogens in mice and rabbits. the antibody response achieved was measured by using enzyme-linked immunosorbent assay techniques. high titers of both antiporin and antilipopolysaccharide were detected in both species. the rabbit antiserum raised against the porins and the porin preparations themselves had a highly significant protective capacity against intraperitoneal sal ... | 1979 | 387596 |
| absence of mutagenic activity in salmonella typhimurium of some impurities found in saccharin. | 1979 | 387554 | |
| [acute renal failure and hypocomplementemia associated with salmonella typhimurium infection]. | 1979 | 387548 | |
| [effect of bacterial insecticides on soil self-purification processes and on the survival in the soil of pathogenic enterobacteria with the example of salmonella typhimurium]. | 1979 | 387535 | |
| a refined map of the hisg gene of salmonella typhimurium. | the hisg gene is the most operator-proximal structural gene of the histidine operon; it encodes the feedback-inhibitable first enzyme of the biosynthetic pathway. previously, hisg mutants were mapped into seven intervals defined by the availble deletion mutations having endpoints in the hisg gene. the map has been refined using over 60 new deletion mutants. the new map divides the gene into 40 deletion intervals, which average approximately 30 base pairs in length. the map has been used to analy ... | 1979 | 387517 |
| histidine mutants requiring adenine: selection of mutants with reduced hisg expression in salmonella typhimurium. | a method is described for the selection of salmonella typhimurium mutants with reduced levels of hisg enzyme activity. this method is based on the fact that the hisg enzyme catalyzes the consumption of atp in the first step of histidine biosynthesis. normally, this reaction is closely regulated, both by feedback inhibition and by repression of the operon. however, conditions can be set up that result in the uncontrolled use of adenine in histidine biosynthesis. cells grown under these conditions ... | 1979 | 387516 |
| transfer of f'lac+ plasmid from salmonella typhimurium to shigella flexneri. | 1978 | 387348 | |
| experimental klebsiella and salmonella infection in neonatal swine. | twenty colostrum-fed piglets from three sows were separated from the sows 24 hours after birth and were randomly divided into five groups of four piglets each. every piglet in each of four test groups was orally inoculated with about 10(10) colony forming units of salmonella typhimurium, salmonella choleraesuis var kunzendorf or one of two isolates of klebsiella pneumoniae. one group served as uninoculated controls. piglets infected with k. pneumoniae developed severe diarrhea beginning about 12 ... | 1979 | 387185 |
| permeabilization of cells for studies on the biochemistry of bacterial chemotaxis. | the cell membranes of salmonella typhimurium and escherichia coli have been made permeable in order to introduce s-adenosylmethionine into the cell for study of the course of methylation. a series of protein bands in the mr 60,000 region were methylated, the specific bands and the extent of methylation depending on the attractant used. the change in levels of methylation was essentially the same as the in vivo responses, indicating that the permeabilization procedure maintains the relative relat ... | 1979 | 386344 |
| isolation and mapping of plasmids containing the salmonella typhimurium origin of dna replication. | a purified ecori restriction endonuclease fragment that determines resistance to kanamycin and is incapable of self-replication was used to select autonomously replicating fragments from an ecori digest of a salmonella typhimurium f' plasmid containing the chromosomal region believed to include the s. typhimurium origin of dna replication. both the f factor and s. typhimurium chromosome replication origins were cloned by this procedure. the ecori fragmentment containing the s. typhimurium origin ... | 1979 | 386330 |
| [sepsis and peritonitis caused by salmonella typhimurium in a patient splenectomized for pancytopenia]. | 1979 | 386167 | |
| mutagenic activity of thiram in ames tester strains of salmonella typhimurium. | the mutagenic activity of thiram was investigated in 4 histidine-requiring strains of salmonella typhimurium (ta1535, ta100, ta1538, ta98) with and without activation by liver microsomes. in strains ta1535 and ta100, thiram induces mutations without metabolic activation. the presence of rat-liver microsome fraction, cysteine or glutathione abolish its mutagenic activity in these strains. in contrast, thiram requires metabolic activation for the expression of its mutagenic activity in ta1538 and ... | 1979 | 386113 |
| genetic toxicity of procarbazine in bacteria and yeast. | procarbazine [n-isopropyl-alpha-(2-methylhydrazino)-p-toluamide hydrochloride] is used to treat hodgkin's disease. this compound was tested in vitro without and with s10 fraction from mice liver (microsomal assay) using saccharomyces cerevisiae strain d7, salmonella typhimurium (strains ta98, ta100, ta1535) and in vivo in swiss albino mice (host-mediated assay) using d7. procarbazine, without s10 fraction, is highly toxic and induced mitotic crossover, gene conversion, and reverse mutation in d7 ... | 1979 | 386110 |
| mutagenicity evaluation of the two antimalarial agents chloroquine and mefloquine, using a bacterial fluctuation test. | the two antimalarial agents chloroquine and mefloquine have been tested for mutagenicity in salmonella typhimurium strains ta1535, ta1537 and ta1538. chloroquine was found to revert strain ta1537 at concentrations of 100 and 250 micrograms/ml, most likely due to intercalation. no mutagenicity was found with mefloquine at concentrations up to 2.5 micrograms/ml, neither without nor with metabolic activation by ca2+-precipitated rat liver microsomes. higher concentrations of mefloquine and chloroqu ... | 1979 | 386109 |
| mutagenic cholesterol preparations. | naturally air-aged commercial samples of usp or reagent-grade cholesterol contain components which are mutagenic towards salmonella typhimurium strains ta1537, ta1538 and ta98. these mutagenic components are associated with the polar cholesterol autoxidation products, but identity of the mutagenic components has not been achieved. pure crystalline nonmutagenic cholestrol free from autoxidation products becomes mutagenic towards these strains upon heating at 70 degrees in air or following exposur ... | 1979 | 386108 |
| in vivo conversion of sodium azide to a stable mutagenic metabolite in salmonella typhimurium. | salmonella typhimurium ta1530 and g46 strains growing in minimal medium supplemented with sodium azide produce a stable mutagenic metabolite which is not azide. the production of this metabolite is restricted to the log phase of bacteria grown in the presence of azide. the metabolite is highly mutagenic in dna-repair defective base-substitution strains ta1530 and ta1535, but ineffective in frameshift strains ta1538 and ta1537. the metabolite induces mutations in resting cells of the ta1530 strai ... | 1979 | 386107 |
| the mutagenicity of nitrosamides in salmonella typhimurium. | 34 nitrosamides (10 nitrosoalkylcarbamates, 2 nitrosoalkylnitroguanidines, 12 nitrosoalkylureas, 6 substituted nitrosoalkylureas, and 4 cyclic nitrosoalkylureas) were tested for mutagenicity in salmonella. all were direct-acting mutagens of varying potency. | 1979 | 386106 |
| mutagenic effects of benzo[a]pyrene after metabolic activation by hepatic 9000 g supernatants or intact hepatocytes. | the activating capacities of isolated rat hepatocytes and 9000 g supernatant from these cells with respect to the mutagenic effect of benzo[a]pyrene on salmonella typhimurium ta100 were investigated. no mutagenicity of benzo[a]pyrene was found with the cell-mediated assay, unless the hepatocytes were disrupted after pre-incubation with benzo[a]pyrene or the intracellular glutathione content was reduced. it is suggested that a retention of active metabolites and an effective detoxication may acco ... | 1979 | 386101 |
| the effect on the virulence and infectivity of salmonella typhimurium and salmonella gallinarum of acquiring antibiotic resistance plasmids from organisms that had caused serious outbreaks of disease. | antibiotic resistance plasmids from organisms that had caused serious epidemics, including those responsible for epidemics of chloramphenicol-resistant typhoid fever and dysentery in central america, were transferred to a strain of salmonella typhimurium and of salmonella gallinarum. the virulence and infectivity of these r(+) forms were then compared with the r(-) parent forms in orally inoculated chickens.none of the r(+) forms were more virulent than their r(-) parent forms. the mortality rat ... | 1979 | 385769 |
| in vivo methylation of prokaryotic elongation factor tu. | in salmonella typhimurium and escherichia coli, elongation factor tu (ef-tu) is methylated as shown by its incorporation of labeled methyl residues from [methyl-3h]methionine. analysis of the nature of the methyl-containing residues by protein hydrolysis, followed by paper chromatography and high voltage electrophoresis showed that both mono- and dimethyllysine are present. eighty per cent of the ef-tu molecules are methylated if methylation occurs at a unique lysine residue. the ef-tu fraction ... | 1979 | 385603 |
| membrane receptors for aspartate and serine in bacterial chemotaxis. | high affinity binding sites for serine and aspartate have been characterized in membranes from salmonella typhimurium and escherichia coli. greater than 80% of these sites have been identified as chemotaxis receptors. mutants lacking binding sites for these amino acids have been shown to have corresponding defects in taxis. the substrate specificity of each of the receptors in salmonella is very high; most analogs of serine and aspartate do not bind to these receptor sites and do not affect chem ... | 1979 | 385590 |
| bactericidal activity of fractionated granule contents from human polymorphonuclear leukocytes: antagonism of granule cationic proteins by lipopolysaccharide. | granule extracts from human polymorphonuclear leukocytes (pmn) were prepared with 0.2 m (ph 4.0) acetate. a fraction (valley ab) with distinctive bactericidal activity against cell wall mutants of salmonella typhimurium lt-2 was obtained after fractionation of the granule extracts by sephadex g-100 column chromatography. the smooth parent lt-2 strain was less sensitive to the bactericidal action. susceptibility of the rough mutants to bactericidal action increased as sugar residues decreased in ... | 1979 | 385501 |
| characterization of a mutator dna polymerase i from salmonella typhimurium. | 1979 | 385235 | |
| locating salmonella resistance gene on mouse chromosome 1. | the inherited resistance of inbred mouse strains to salmonella typhimurium injected subcutaneously has been reported to be controlled primarily by a single gene designated ity. resistant mice have the dominant allele ityr and sensitive mice are homozygous for the recessive allele itys. this paper describes studies undertaken to locate the gene using readily distinguishable phenotypes as chromosome markers. appropriate f1 backcross and f2 generations of hybrids between resistant and susceptible i ... | 1979 | 385184 |
| free flying sparrows as carriers of salmonellosis. | salmonella typhimurium was isolated from nine of 60 wild sparrows trapped in the guelph area. while this organism was isolated from birds trapped at several different locations, the highest prevalence was in sparrows trapped in close proximity to an animal clinic. the significance of these findings in relation to human and animal salmonellosis is discussed. | 1979 | 385137 |
| the influence of cations on the permeability of the outer membrane of salmonella typhimurium and other gram-negative bacteria. | the high sensitivity of rough mutants of salmonella typhimurium, s. minnesota, and escherichia coli 08 (i.e. with defects in the carbohydrate core of the lipopolysaccharide) to several antibiotics and to the dye gentian violet could be substantially reduced by the addition of cations (mg2+, na+) into the growth medium. one heptoseless mutant of s. typhimurium (chemotype re) and its isogenic smooth parent strain were studied in more detail. the uptake of gentian violet was about 20% in the smooth ... | 1979 | 385129 |
| studies on experimental enteric salmonellosis in ponies. | clinical, bacteriological, serological and haematological observations were made on 13 adult ponies orally inoculated with salmonella typhimurium. the results were compared to two control ponies and four others infected by accidental transmission. the clinical responses in inoculated ponies included pyrexia lasting four days and neutropaenia during the first five days after inoculation followed by a neutrophilia. pyrexia and neutropaenia was associated with maximal shedding of organisms in the r ... | 1979 | 385122 |
| a single amino acid substitution in a histidine-transport protein drastically alters its mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. | mutation hisj5625 has altered the histidine-binding protein j of salmonella typhimurium such that histidine transport is impaired, even though binding of histidine by the j protein is unimpaired [kustu, s.g., & ames, g.f. (1974) j. biol. chem. 249, 6976--6983]. we have determined by protein analytical methods that the only effect of this mutation has been the substitution of a cysteine residue for an arginine at a site in the interior of the polypeptide chain. this arginine residue is therefore ... | 1979 | 385047 |
| covalent linkage of lipoprotein to peptidoglycan is not essential for outer membrane stability in proteus mirabilis. | isolated rigis layers from proteus mirabilis harvested at different growth phases were degraded by endo-n-acetylmuramidase from chalaropsis b, and the degradation products were investigated. the results show the complete absence of covalently linked lipoprotein in exponential-phase cultures. stationary cells, however, possess covalently linked lipoprotein in amounts similar to those found in escherichia coli or salmonella typhimurium during all growth phases. the overall peptidoglycan structure ... | 1979 | 384953 |
| [geographic distribution of biotypes of salmonella typhimurium var. copenhagen in belgium]. | 1978 | 384913 | |
| mutagenic activity of fusarium moniliforme isolates in the salmonella typhimurium assay. | a total of 33 isolates of fusarium moniliforme from several food or feed crops were grown on sterile cracked corn, and chloroform-isopropanol extracts were assayed for mutagenic activity in the salmonella typhimurium-microsome system by using tester strain ta98 or ta100 or both. extracts of 21 (64%) of the isolates assayed against ta100 were mutagenic. activities of seven of these extracts were increased markedly with incorporation of the liver homogenate (s-9) into the assay. seven (33%) of the ... | 1979 | 384905 |
| [the anodically moving thermolabile antigen (ata) of gram negative bacteria. protection of mice by immunization with ata (author's transl)]. | mice are protected against lethal doses of salmonella typhi-murium by vaccination with ata extracted from providencia. no protective effect is observed when the s. typhi-murium strains are enterotoxigenic. thus protection is antibacterial, but not antitoxic. | 1979 | 384750 |
| derivatives of side-chain hydroxylated nitrosamines direct acting mutagens in salmonella typhimurium. | methyl-(beta-tosyloxyethyl)nitrosamine and 3-methyl-4,5-dihydro-1,2,3-oxadiazolium tosylate are potent direct acting mutagens in the ames assay, as is n-nitrosoprolinyl tosylate. these compounds are derived from beta-hydroxylated nitrosamines. the closely related methyl-(gamma-tosyloxypropyl)nitrosamine is not mutagenic without activation. these data are consistent with the chemical behavior of these substances, which suggest that suitable derivatives of beta-hydroxylated nitrosamines, such as o ... | 1979 | 384234 |
| platinum(ii) complexes generate frame-shift mutations in test strains of salmonella typhimurium. | cis-diamminodichloroplatinum(ii) (cis-pdd) and diaquoethylenediamineplatinum(ii) induce histidine revertants in salmonella typhimurium strains ta98 (frame-shift mutation) and ta100 (base-pair substitution mutation). a linear dose--response relationship is found with cis-pdd acting on ta98 and ta100. salmonella typhimurium strains ta1535, ta1537 and ta1538 are not sensitive to the mutagenic action of cis-pdd. all 5 strains are sensitive to the toxic effect of cis-pdd. platinum(ii) complexes induc ... | 1979 | 384231 |
| the l-arabinose-resistance test with salmonella typhimurium strain sv3 selects forward mutations at several ara genes. | a new assay has been described for mutagenicity testing using an l-arabinose-sensitive strain of salmonella typhimurium. the test strain sv3 and several l-arabinose-resistant mutants selected therefrom are characterized in the present study by 3 different criteria: inhibition of growth by l-arabinose, accumulation of keto-sugars, and activities of the enzymes involved in l-arabinose catabolism. strain sv3 (ara-531) shows high levels of inducible l-arabinose isomerase (ec 5.3.1.4) and l-ribulokin ... | 1979 | 384229 |
| mutagens in the feces of 3 south-african populations at different levels of risk for colon cancer. | the incidence of mutagens in the feces of 3 south-african populations at different risk levels for colon cancer has been determined. lyophilized fecal samples were extracted with ether and the mutagenicity of the extracts determined using the salmonella/mammalian microsome mutagenicity test. 19% of the samples from urban white south-africans, a population at a high risk for colon cancer, were mutagenic using salmonella typhimurium strain ta100. this incidence was significantly greater (p less th ... | 1979 | 384227 |
| reversal of sodium-azide mutagenicity by liver preparations and by gastric juice. | sodium azide was found to be mutagenic for salmonella typhimurium by inducing base-pair substitutions that were not enhanced by pkm101 plasmid (r factor). however, the mutagenicity of sodium azide was decreased by enzyme proteins contained in rat-liver post-mitochondrial fractions, depending on the nadph-generating system. pre-incubation with human gastric juice also decreased azide mutagenicity. these metabolic effects might explain the conflicting nature of the mutagenicity and carcinogenicity ... | 1979 | 384225 |
| dna--benzo[a]pyrene adducts formed in a salmonella typhimurium mutagenesis assay system. | the dna adducts formed in salmonella typhimurium when bacteria are incubated with radioactive benzo[a]pyrene and liver microsomal enzymes from several sources has been investigated. when enzyme preparations from aroclor i254 or 3-methylcholanthrene induced c57bl/6n (b6) mice were used to mediate activation, the predominant product was an adduct between the 10 position of 7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene and the n-2 position of deoxyguanosine. si ... | 1979 | 384221 |
| mutagenicity of 8-ethoxycaffeine in vitro. induction of point mutations in the salmonella/microsome test and of sister-chromatid exchanges as well as chromosomal aberrations in chinese hamster ovary cells (cho line). | the caffeine derivative 8-ethoxycaffeine (eoc) was tested in 3 different test systems in vitro. each experiment was carried out with and without s9 mix. incubation temperatures were 20 and 37 degrees c. (1) in the salmonella/microsome test, eoc behaved as a pro-mutagen in the salmonella typhimurium strain ta1535. no mutagenic activity was found in experiments without s9 mix. the influence of temperature was negligible. the mutagenic activity of eoc depended mainly on the mammals used to prepare ... | 1979 | 384216 |
| the in vitro detection of defects in temperature sensitive rna polymerases from mutants of salmonella typhimurium. | 1979 | 384150 | |
| assay for mutagenicity of bile in sprague-dawley rats treated subcutaneously with intestinal carcinogens. | to investigate the mode of action of sc injected intestinal carcinogens, the mutagenicity assay of bile collected from noninbred sprague-dawley rats treated sc with carcinogens was conducted in the presence and absence of beta-glucuronidase. the bile samples from rats inoculated with 4-aminobiphenyl were mutagenic for salmonella typhimurium ta100 only in the presence of beta-glucuronidase, whereas those from the 3,2'-dimethyl-4-aminobiphenyl-treated rats did not require the enzyme for mutagenici ... | 1979 | 384011 |
| concentration-dependent mutation by alkylating agents in human lymphoblasts and salmonella typhimurium: n-methyl-n-nitrosourethane and beta-propiolactone. | the toxic and mutagenic effects of the alkylating agents n-methyl-n-nitrosourethane (mnut) and beta-propiolactone (bpl) were quantitatively measured in human lymphoblasts and salmonella typhimurium. forward mutation to 6-thioguanine resistance was measured in the human lymphoblasts, and forward mutation to 8-azaguanine resistance was measured in the bacterial cells after equigenerational (1.5 doubling times) exposures. in both systems, the induced mutant fraction rose linearly as a function of c ... | 1979 | 384009 |
| inhibition of 2-fluorenamine-induced mutagenesis in salmonella typhimurium by vitamin a. | vitamin a alcohol (retinol) completely inhibited the mutagenicity of the carcinogen 2-fluorenamine (2-fa) in salmonella typhimurium ta98 when the mutagen was activated by liver microsomes from cfn rats. the mutagenicity of 2-fa activated by 9,000xg rat liver supernatant s9 was inhibited by retinol to a lesser degree. the decline in the number of his+ revertants was not an artifact due to bacterial killing, inasmuch as retinol was not toxic to the bacteria at levels that totally inhibited mutagen ... | 1979 | 384006 |
| transduction of fimbriation demonstrating common ancestry in firn strains of salmonella typhimurium. | the production of fimbriate (fim+) recombinants was observed in transductional crosses between different pairs of wild-type strains of different biotypes of salmonella typhimurium. fim+ recombinants were readily produced in transductions from fim+ donor strains to fim- recipient strains and, less frequently, between some pairs of fim- strains, for example, between almost any strain of the firn biogroup (fim- inl- rha- bxyl-) and many strains of the non-firn fim- biogroup. none of numerous crosse ... | 1979 | 383900 |
| differences between the anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferases of salmonella typhimurium strains lt2 and lt7. | the anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferases (prt), coded by the second structural gene (trpb) of the tryptophan (trp) operon in strains lt2 and lt7 of salmonella typhimurium, differ from each other in a number of parameters. these include the apparent km values for their substrates anthranilic acid and 5-phosphoribosylpyrophosphate, thermostability, sensitivity to substrate inhibition by anthranilic acid, as well as end-product inhibition by tryptophan and specific ... | 1979 | 383894 |
| mutation spot of escherichia coli increases expression of the histidine operon deleted for the attenuator. | f'-episomes carrying the salmonella typhimurium wild-type or attenuator-deleted histidine (his) operons were introduced into escherichia coli strains containing rela or spot single and double mutations known to affect guanosine 3'-diphosphate 5'-diphosphate (ppgpp) and guanosine 3'-triphosphate 5'-diphosphate (pppgpp) levels. expression of the his operon and expression of the gene for 6-phosphogluconate dehydrogenase (gnd) were measured during balanced growth in amino acid-rich and minimal media ... | 1979 | 383702 |
| two mutations which affect the barrier function of the escherichia coli k-12 outer membrane. | two genetically distinct classes of novobiocin-supersensitive mutants were isolated from escherichia coli k-12. one class, given the phenotypic name nbsa, lies at 10 min on the e. coli chromosome. the order of the genes in this region, based on transductional analyses, is proc nbsa plsa pure. the second, nbsb, lies at 80 min. the order of the genes in this region, based on transduction analyses, is xyl cyse nbsb pyre. both classes of mutants show increased sensitivity to hydrophobic drugs but ar ... | 1979 | 383699 |
| ribosomal ribonucleic acid isolated from salmonella typhimurium: absence of the intact 23s species. | ribonucleic acid (rna) isolated by four distinct methods and from a variety of salmonella typhimurium strains lacked intact 23s ribosomal rna (rrna). on sucrose gradients which minimize aggregation, the vast majority of s. typhimurium rrna sedimented as a 16s peak with a 14s shoulder. rna from this region of the gradient was resolved into three discrete bands by electrophoresis in formamide. two very minor s. typhimurium rna peaks were resolved at 21s and 10s on sucrose gradients, and each peak ... | 1979 | 383696 |
| the ends of tn10 are not is3. | by heteroduplex and hybridization analysis we showed that the inverted repetition (here called is10) at the ends of the translocatable tetracycline resistance element tn10 is not is3, as had previously been reported by ptashne and cohen (j. bacteriol. 122:776--781, 1975). further analysis confirmed the homology between is3 and the alpha beta sequence of f and demonstrated that is10 was not present in the genomes of salmonella typhimurium lt2 or escherichia coli k-12. | 1979 | 383689 |
| his-linked hydrogen sulfide locus of salmonella typhimurium and its expression in escherichia coli. | a his-linked h2s locus of salmonella typhimurium has been further defined by direct isolation of h2s mutants. expression of this locus in escherichia coli has been demonstrated. | 1979 | 383686 |
| a morphological study in germfree mice (salmonella infection). | the morphological manifestation of the intestinal infections of salmonella typhimurium by the intestine rolled method in both conventional dki and germfree mice have been investigated in our laboratory. in the conventional mice, the morphological manifestation of intestinal infection shows no difference from the general features of infection, while in the germfree mice, the manifestation is characterized by the so-called non-reactive necrotizing enteritis without cellular reaction. when infectio ... | 1979 | 383491 |
| [do pigeons play a part in human infections with salmonella typhimurium var. copenhagen (author's transl)]. | 1979 | 383458 | |
| mutagenicity of the naturally occurring carcinogen cycasin and synthetic methylazoxymethanol conjugates in salmonella typhimurium. | the aglycone methylazoxymethanol of the naturally occurring carcinogenic glucoside, cycasin, has previously been shown to be mutagenic, but cycasin per se has not. in this work, cycasin was demonstrated to be mutagenic using a modification of the ames salmonella test in which it was preincubated with beta-glucosidase and the tester strain in liquid medium. the mutagenicity of cycasin to six histine-depedent salmonella strains varied considerably with strain hisg46 being the most susceptible. met ... | 1979 | 383289 |
| chemical characterization of 465 known or suspected carcinogens and their correlation with mutagenic activity in the salmonella typhimurium system. | since chemicals exhibiting mutagenic activity pose a potential hazard to their users, there is increasing acceptance of mutagenicity testing as an integral part of a premarketing toxicological evaluation of chemicals. in vitro testing has gained much notoriety as quick and relatively inexpensive means to assess the mutagenic potential of chemicals. however, the innovative use of microsomes to simulate metabolism has not changed the fact that in vitro activation cannot duplicate faithfully the me ... | 1979 | 383284 |
| mutagenicity of soot and associated polycyclic aromatic hydrocarbons to salmonella typhimurium. | 1979 | 383281 | |
| tryptophan-requiring parental strains yield salmonella typhimurium x escherichia coli hybrid recombinants with functional tryptophan operons. | crosses between an escherichia coli hfr trp strain and three salmonella typhimurium f- trp strains produced some trp+ hybrids in which the tryptophan operon is composed of genes from both parental species. | 1979 | 383245 |
| purification and properties of a citrate-binding transport component, the c protein of salmonella typhimurium. | salmonella typhimurium was shown to contain a citrate-binding protein (c protein) which was purified to homogeneity from the periplasmic fraction released by cold osmotic shock. the protein is dimeric, has an apparent molecular weight of 28 000 and an isoelectric point of 6.1. sodium ions were required for optimum substrate binding, however, the divalent cations zn2+, mg2+, and co2+ were inhibitory. the c protein was relatively stable but sensitive to various detergents and chaotropic agents. ap ... | 1979 | 383235 |
| bacteriophage p22 development is temperature sensitive in thiolutin resistant mutants of salmonella typhimurium. | 1979 | 383075 | |
| mutagenic activity of cytostatic methyl hydrazones with different strains of salmonella typhimurium. | experiments are performed to ascertain the mutagenic properties of four new cytostatic methyl-hydrazones in the ames test using different strains of salmonella typhimurium. as could be demonstrated all four hydrazones are mutagenic per se without a metabolic activation through rat liver microsomes (s-9 fraction). whereas the beta-chloroethyl hydrazones b1 and b2 cause a base-pair substitution with the strains ta100 and ta1535 the methyl-hydrazones eb4 and cyb4 both cause base-pair substitution w ... | 1979 | 383045 |
| immunogenic complexes obtained from salmonella typhi-murium and salmonella typhi ty2 by the bacterial acetone powder method. | an immunogenic complex was isolated from salmonella typhi-murium and another one from salmonella typhi ty2. both were prepared by the bacterial acetone powder method which eliminated the cell wall, the dna almost completely and the membrane phospholipids. the complexes were denominated "new vaccines". the s. typhi-murium new vaccine induced, even at doses of 0.5 microgram dry weight per mouse, a high degree of protection against the challenge of the virulent microorganism. by immunoelectrophores ... | 1979 | 382951 |
| the mutagenic activity of anti-cancer drugs and the urine of rats given these drugs. | twenty-one anti-cancer drugs have been tested for their ability to cause mutations in salmonella typhimurium test strains in the salmonella/microsome mutagenicity test. nine of the 21 anticancer drugs showed this ability: cyclophosphmide, nitromin, thio-tepa, busulfan, 6-mercaptopurine, neocarzinostatin, daunomycin, adriamycin and estramustine phosphate. seven of these 9 mutagenic drugs were injected continuously into the jugular veins of rats. urine was collected through a cystostomy tube and t ... | 1979 | 382571 |
| natulan induces forward mutations to l-arabinose-resistance in salmonella typhimurium. | 1979 | 381917 | |
| chemicals which revert all commonly used salmonella typhimurium tester strains. | 1979 | 381916 | |
| diethylstilbestrol and 11 derivatives: a mutagenicity study with salmonella typhimurium. | diethylstilbestrol was tested for mutagenicity with his- s. typhimurium strains under 10 different matabolic situations (no exogenous metabolizing system; s9 mix from liver homogenate of rats induced with aroclor 1254, with or without inhibition of epoxide hydratase; liver and/or kidney s9 mix from control or hamsters treated with aroclor 1254; horse-radish peroxidase + h2o2). under none of these conditions did diethylstilbestrol give any indication of a mutagenic effect. furthermore, 11 metabol ... | 1979 | 381911 |
| mutagenic activity of propylene oxide in bacterial and mammalian systems. | propylene oxide is used extensively in the chemical and food manufacturing industries, but relatively little is known of its ability to interact with genetic material. studies were undertaken to investigate its ability to induce gene mutations and primary dna damage in bacteria and chromosomal damage in mammalian cells. the induction of base-substitution mutations was demonstrated in spot tests with strains of salmonella typhimurium and escherichia coli at 700 micrograms/plate of propylene oxide ... | 1979 | 381910 |
| evaluation of three metabolic activation systems by a forward mutation assay in salmonella. | the strain sv3 of salmonella typhimurium was used as the indicator bacterium in the intrasanguineous host-mediated mutagenicity assay. bacterial distribution and spontaneous mutation frequency were determined after intravenous injection of sv3 into cd1 male mice. bacteria were cleared at an exponential rate from the blood stream and recovered mainly from the liver and in smaller quantities from the lungs and kidneys. no bactericidal effect was observed during incubation within the animal, and ba ... | 1979 | 381907 |
| a longitudinal epizootiological study of salmonella infection on a piggery: a study on the mode of contamination by biotyping of salmonella typhimurium and by the antibiogram. | 1979 | 381741 | |
| nucleotide sequence of the trpc-trpb intercistronic region from salmonella typhimurium. | 1979 | 381671 | |
| biotyping and colicine typing of salmonella typhimurium strains of phage type 141 isolated in scotland. | cultures of salmonella typhimurium (551 strains) of phage type 141 isolated in scotland from 1965 to 1977 were examined for biotype and colicine type. three main biotype clones were recognised: if (30 strains), 9f (507 strains) and 31bd (11 strains) with subtype variants 9bf (1 strain), 9cf (1 strain) and 31b (1 strain). the contribution made by each biotype clone to outbreaks in scotland was analysed. the findings confirmed the distinctness of the three biotype clones within the single phage ty ... | 1979 | 381665 |
| evaluation of the mutagenicity of aminoglycoside antibiotics in salmonella typhimurium and saccharomyces cerevisiae. | the mutagenicity of aminoglycoside antibiotics (km, akm, dkb, rsm, amk, gm, tob) has been studied in cells of the bacteria salmonella typhimurium and in the yeast saccharomyces cerevisiae. the bacterial strains (ames') monitor reverse mutation (point mutation) and the yeast strain d5 monitors mitotic crossing-over, mitotic gene conversion and point mutation. none of these antibiotics demonstrated any mutagenic activities in either the bacteria or the yeast. | 1979 | 381273 |
| the removal of 14c labeled endotoxin by activated charcoal. | endotoxin shock due to gram-negative enteric bacteria is of major medical concern with an estimated 100,000 fatalities in the united states per year. an effective therapy for endotoxin shock, particularly in combination with significant liver damage, has not been available to date. since activated charcoal is known as a universal sorbent, the use of activated charcoal in a hemoperfusion apparatus to remove endotoxin has interesting possibilities. current assays for endotoxin are inadequate. the ... | 1979 | 381215 |
| immunotherapy of guinea pig line 10 hepatoma with nonliving bcg cells in aqueous medium. | killed bcg cells suspended in 1.5% carboxymethylcellulose cured guinea pigs with established line 10 tumors in a high percentage of cases. the bacterial preparation of bcg in carboxymethylcellulose displayed a stronger tumor regressive activity and the process of healing was accelerated when endotoxin from a rough (re) strain of salmonella typhimurium was added to the bcg bacilli. | 1979 | 381203 |
| identification of protective cell surface proteins in ribosomal fractions from salmonella typhimurium. | cell surface antigen preparations from salmonella typhimurium sr-11 prepared by either trichloroacetic acid extraction or boiling in sodium dodecyl sulfate were able to protect c3h/hej, c3h/hedub, and a/j mice. some of the proteins found in these preparations were shown to exist in the protective ribosomal fraction isolated from s. typhimurium sr-11. passage of ribosomes isolated from s. typhimurium sr-11 and 6707 through a sepharose 2b column removed the protective immunogen from 6707 ribosomes ... | 1979 | 381202 |
| the natural resistance of radiation chimeras to s. typhimurium c5. | differences in the in vivo net growth rate of salmonella typhimurium c5 during the first week of infection in different mouse strains are controlled by a single autosomal gene. in lethally irradiated mice repopulated with semi-allogeneic bone marrow, the early net growth rate shows the phenotype of the donor of the bone marrow cell and not the phenotype of the irradiated recipient. thus, genetically controlled differences in in vivo bacterial net growth rate are a consequence of mechanisms opera ... | 1979 | 381180 |
| genetics of natural resistance to salmonellae in mice. | the genetics of natural resistance to salmonellae were studied in f1 hybrid and backcross mice. overall resistance to salmonella typhimurium c5 is complex, but one parameter, the early net growth rate of the organism in vivo, is controlled by a single autosomal gene or cluster of genes. 'slow' net growth rate is necessary but insufficient, for resistance to s. typhimurium c5. resistance requires the participation of other mechanisms, detectable by the end of the first week, which presumably invo ... | 1979 | 381179 |
| natural resistance to salmonella typhimurium in different inbred mouse strains. | the mechanisms of natural resistance to intravenous challenge with salmonella typhimurium c5 are complex. ld50 determinations showed inbred mouse strains of low, intermediate and high natural resistance, with balb/c and b10 strains the most susceptible, a/j the most resistant. delayed (footpad) hypersensitivity was not by itself a measure of natural resistance. resistant mouse strains sensitized either s.c. or i.v. with an attenuated salmonella strain showed positive 48 h footpad reactions when ... | 1979 | 381178 |
| induction of thymocytotoxic autoantibodies after injection of bacterial lipopolysaccharides in mice. | the injection of bacterial lipopolysaccharides (salmonella typhimurium and escherichia coli lps) has been shown to induce thymocytotoxic autoantibodies in various strains of mice (c57bl/6, balb/c, dba/2, akr, a/j and c3heb/fej). titers up to l:16 were observed. such antibodies did not develop in c3h/hej mice which are low responders to lps. the thymocytotoxic antibodies had the following characteristics: (a) 2-mercaptoethanol sensitivity, (b) optimal reactivity at 4 degrees c, (c) cytotoxicity f ... | 1979 | 381011 |
| mechanisms of action of carcinogenic aromatic amines: an investigation using mutagenesis in bacteria. | the mutagenicities of groups of n-acetoxy-n-arylacetamides, nitroarenes, arylamides and arylamines were determined in the salmonella typhimurium tester stains ta98, ta1538, ta100, ta1535 and ta1537. three broad classes of mutagenic activity were found, interpreted as follows: class a, including 2-naphthylamine, produced essentially only base-pair substitution without induction of error-prone repair; class b, including 4-aminobiphenyl, caused consideration induction of error-prone repair, accompa ... | 1979 | 380829 |
| metabolic and mutagenicity studies on ddt and 15 derivatives. detection of 1,1-bis(p-chlorophenyl)-2,2-dichloroethane and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethyl acetate (kelthane acetate) as mutagens in salmonella typhimurium and of 1,1-bis(p-chlorophenyl) ethylene oxide, a likely metabolite, as an alkylating agent. | using a novel in vitro technique, whereby microsomal enzymes were embedded in an agar layer to prolong their viability, 1,1-bis(p-chlorophenyl) ethylene(ddnu), a mammalian metabolite of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (ddt), was converted by microsomal mono-oxygenases of mouse liver into 1,1-bis(p-chlorophenyl)-1,2-ethanediol (ddnu-diol). the putative epoxide intermediate, 1,1-bis(p-chlorophenyl)ethylene oxide (ddnu-oxide), a new compound, was synthesized; it showed weak alkylating ... | 1979 | 380827 |
| [cytophilic immunoglobulins on the surface of neutrophilic granulocytes in mice perorally immunized with a live vaccine made from the supressor revertant s. typhimurium rev 8]. | the reaction of the spleen cell migration inhibition in the presence of monospecific antisera against mouse g, a and m immunoglobulins was used to detect cytophilic antibodies on the surface of mouse granulocytes. the oral administration of acr live vaccine from suppressor revertant salmonella typhimurium rev. 8 protected the mice against infection induced by virulent species of mouse. salmonella typhimurium. the immunized mice showed an increase in cytophilic igg on the surface of neutrophile g ... | 1979 | 380686 |
| [subdural empyema due to salmonella typhimurium. analysis of a case]. | the case was that of an infant with congenital hydrocephalus who developed subdural empyema. the most outstanding items were, the age of the patient (18 months), the identification of salmonella typhimurium, a germ rarely described responsible for this pathology, the absence of anacrobe germs and the possible hematogenous dissemination from the digestive tract when the port of entry usually associated is the infection of the paranasal sinuses. the most useful method for study was the computerize ... | 1979 | 380596 |
| relaxed control of rna synthesis during nutritional shiftdowns of hisu mutant of salmonella typhimurium. | 1979 | 380566 | |
| effect of a salmonella group h1 r factor on virulence and response of infections to antimicrobial therapy. | a group h1 r factor encoding resistance to chloramphenicol, streptomycin, sulfonamide, and tetracycline was transferred into salmonella typhimurium lt-2. the virulence of lt-2 for mice, as assessed by intraperitoneal 50% lethal dose and the number of organisms in the spleen, was not affected by the r factor. on the other hand, the r factor conferred resistance in mouse infections to therapy with chloramphenicol and trimethoprim plus sulfamethoxazole. | 1979 | 380460 |
| [change in the biological properties of salmonellae in acquiring resistance to chloramphenicol]. | mutants of salmonella typhimurium and salmonella abony resistant to 40 microgram/ml of chloramphenicol were obtained during selection according to the method of szybalski on hottinger broth with increasing concentrations of the antibiotic. by the colony morphology the mutants were divided into 4 groups. the study of the mutant biological properties revealed changes in the growth rate characterized by elongation of the lag-phase and exponential phase, changes in the biochemical activity evident f ... | 1979 | 380452 |
| [effect of protein in the feed on the resistance of poultry artificially infected with salmonella galinarum pullorum and salmonella typhimurium]. | studied is the effect of the low protein level in rations of birds, experimentally infected with salmonella gallinarum-pullorum and salmonella typhimurium. birds of different ages of the leghorn and cornish breeds are included in the experiments. results obtained from the experiments indicate that the lowered level of protein in rations to young birds at the age of five months makes them more resistant to salmonella infection. this dependence is markedly demonstrated in particular in the case of ... | 1978 | 380135 |
| [mutagenicity for salmonella typhimurium (ames test) of some trichomonacides]. | 1979 | 379709 | |
| mutagenicity of 7-iodo and 7-fluoro derivatives of n-hydroxy-and n-acetoxy-n-2-acetylaminofluorene in the salmonella typhimurium assay. | 1979 | 379638 |