Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| role of plasma filtration in the intestinal fluid secretion mediated by infection with salmonella typhimurium. | the mechanisms whereby invasive enteropathogens, e.g., salmonella typhimurium, induce intestinal secretion are largely unknown. since these organisms penetrate the intestinal epithelium, disrupt the brush border, and evoke an acute inflammatory reaction, increased plasma filtration through a damaged, more permeable epithelium might contribute to the secretory process. to examine this possibility, the plasma-to-lumen clearance of two different sized molecules, [51cr]albumin and [14c]mannitol, was ... | 1976 | 816744 |
| hypertriglyceridemia produced by endotoxin: role of impaired triglyceride disposal mechanisms. | the role of salmonella typhimurium endotoxin in producing hypertriglyceridemia was investigated in 70 male rhesus monkeys. dose-response studies were performed with 0.3-9.0 mg of endotoxin/kg injected intravenously; free fatty acids and triglycerides were measured during the subsequent 8 hr. the effect of endotoxin on lipid disposal mechanisms was assessed by both intravenous lipid-loading tests and total plasma lipolytic activity after administration of heparin. the possible interference of end ... | 1976 | 816977 |
| screening of pesticides for mutagenic potential using salmonella typhimurium mutants. | 1976 | 818141 | |
| cell-mediated immune response to salmonella typhimurium infection in mice: development of nonspecific bactericidal activity against listeria monocytogenes. | generation of the cell-mediated immune response of cba/h mice against salmonella typhimurium (c5s) was monitored by measuring the nonspecifically increased bactericidal activity of macrophages against listeria monocytogenes. the appearance of detectable levels of macrophage activation was inversely related to the initiating infectious dose. with 3 x 10(3) infecting c5s organisms, significant activity was demonstrable after day 3. immunity controlled a challenge with a streptomycin-resistant stra ... | 1976 | 819372 |
| direct transfer of the phosphoryl moiety of mannitol 1-phosphate to [14c]mannitol catalyzed by the enzyme ii complexes of the phosphoenolpyruvate: mannitol phosphotransferase systems in spirochaeta aurantia and salmonella typhimurium. | spirochaeta aurantia possesses a phosphoenolpyruvate:mannitol phosphotransferase system which catalyzes the transmembrane transport and phosphorylation of mannitol. in vitro studies showed that both phosphoenolpyruvate and mannitol 1-phosphate could serve as phosphate donors. the phosphoenolpyruvate-dependent reaction required two soluble proteins, enzyme si and hpr, and an integral membrane complex, enzyme sii. only enzyme sii was required for the mannitol 1-phosphate-dependent reaction. enzyme ... | 1976 | 819432 |
| mutagenicity of 8-hydroxyquinoline and related compounds in the salmonella typhimurium bioassay. | 1976 | 820351 | |
| outer membrane of salmonella typhimurium: accessibility of phospholipid head groups to phospholipase c and cyanogen bromide activated dextran in the external medium. | whole cells of salmonella typhimurium were treated with bacillus cereus phospholipase c or with cnbr-activated dextran. if phosphatidylethanolamine head groups are exposed and accessible on the outer surface of the outer membrane of these cells, it was expected that these groups would be hydrolyzed by the former agent, and become covalently coupled to the latter agent. with strains producing lipopolysaccharides of s or rc type, results did not indicate the presence of any accessible head groups ... | 1976 | 820368 |
| metabolism of benzo(a)pyrene and benzo (a)pyrene derivatives to mutagenic products by highly purified hepatic microsomal enzymes. | a highly purified and reconstituted hepatic microsomal monooxygenase system, completely free of epoxide hydrase and consisting of cytochrome p-448 from 3-methylcholanthrene-treated rats, nadph-cytochrome c reductase, phosphatidylcholine, and nadph, metabolizes benzo (a)pyrene to products highly mutagenic in strains ta 98 and ta 1538 of salmonella typhimurium. the formation of mutagenic metabolites is completely dependent on the presence of benzo (a)pyrene, nadph, nadph-cytochrome c reductase, an ... | 1976 | 821945 |
| vinyl chloride mutagenicity via the metabolites chlorooxirane and chloroacetaldehyde monomer hydrate. | mutagenicity tester strains of bacillus and salmonella were used to assay vinyl chloride in nutrient broth at a practical concentration level. also screened without exogenous activation were seven potential metabolites of vinyl chloride in their pure forms as well as the related epichlorohydrin. chlorooxirane, chloroacetaldehyde, chloroacetaldehyde monomer hydrate, chloroacetaldehyde dimer hydrate, chloroacetaldehyde trimer, and epichlorohydrin produced significant mutagenic acitivity in salmone ... | 1976 | 822875 |
| enzymatic activities leading to pyrimidine nucleotide biosynthesis from cell-free extracts of rickettsia typhi. | cell-free extracts from rickettsia typhi were examined for the presence or absence of pyrimidine phosphotransferase enzymes and compared with the enzymes of mouse l cells and salmonella typhimurium. the organisms were grown in mouse l cells and in the yolk sacs of chicken embryos, purified by renografin density gradient centrifugation, and ruptured in a french pressure cell. the enzymes for the reutilization of uridine and thymidine, uridine kinase (ec 2.7.1.48) and thymidine kinase (ec 2.7.1.21 ... | 1976 | 823112 |
| basic characterization of w-pili. | the bacterial drug-resistance plasmids sa, r388 and r7k that comprise the w compatability group were transferred by conjugation to species in the genera escherichia, salmonella, shigella and pseudomonas, chosen for their lack of common pili. on receiving the w plasmids, all strains produced pili, which were similar morphologically, at average frequencies of up to 3-0 pila/cell. the pili determined by the w plasmids were also related serologically, but unrelated to those of other plasmids. r- seg ... | 1976 | 825614 |
| the in vitro metabolism, macromolecular binding and bacterial mutagenicity of 4-chloribiphenyl, a model pcb substrate. | the in vitro metabolism of 4-chlorobiphenyl, a model polychlorinated biphenyl (pcb) substrate, proceeds via an arene oxide intermediate to give the observed in vivo hydroxylated metabolites. the rabbit liver microsomal fraction mediates binding between the pcb and the endogenous microsomal protein and rna and the major part of the pcb was bound to the light 3s-10s rna fraction. the lower chlorinated 4-chlorobiphenyl isomer was highly mutagenic to the salmonella typhimurium strain ta1538 (sensiti ... | 1976 | 825937 |
| the function and activity of certain membrane enzymes when localized on- and off- the membrane. | a group of enzymes known to be involved in group translocation-type transport mechanisms for the uptake of a variety of nucleotide precursors are enzymatically active both in their natural membrane milieu and in aqueous solution. the activity in aqueous solution markedly differ, however, from the enzymatic activity when the enzyme is membrane localized. the adenine phosphoribosyltransferase (prt) of e. coli (hochstadt-ozer and stadtman, 71a) is capable of carrying out an exchange reaction betwee ... | 1976 | 827551 |
| mutagenicity of carcinogenic azo dyes and their derivatives. | the mutagenicity of n,n-dimethyl-4-aminoazobenzene and n-methyl-4-aminoazobenzene and their derivatives was shown on salmonella typhimurium ta100 and ta98. s-9 mix, obtained from rat liver after injection of polychlorinated biphenyl, was abligatory for their mutagenic action. n-acetoxy-n-methyl-4-aminoazobenzene and n-benzoyloxy-n-methyl-4-aminoazobenzene and their 4'-methoxycarbonyl derivatives were also mutagenic on ta100 and ta98 and did not require metabolic activation by s-9 mix. it is sugg ... | 1975 | 828073 |
| the pathogenesis of porcine rectal stricture. i. the naturally occurring disease and its association with salmonellosis. | rectal stricture occurred in each of 23 pigs submitted for necropsy from eight indiana farms. each stricture was an annular cicatrization of the rectal wall, 2.0-5.0 cm anterior to the anorectal junction. emaciation, colonic dilatation and compression atrophy of abdominal and thoracic viscera were a result of chronic obstipation and inanition. most pigs with strictures had severe enteric disease 4-8 weeks before the strictures occurred. salmonella typhimurium was isolated from seven of the eight ... | 1977 | 850993 |
| the pathogenesis rectal stricture. ii. experimental salmonellosis and ischemic proctitis. | experimentally induced oral salmonella typhimurium infection in pigs resulted in a severe, prolonged enterocolitis with ulcerative proctitis a constant feature. healed lesions were annular cicatricial ulcers in the part of the rectum affected with rectal strictures. strictures indistinguishable from the naturally occurring lesion were produced by injecting chlorpromazine into the cranial hemorrhoidal artery of three pigs. dye injected into the cranial hemorrhoidal artery perfused the entire rect ... | 1977 | 850994 |
| unusual susceptibility of erwinia amylovora to antibacterial agents in relation to the barrier function of its cell envelope. | wild-type strains of the bacterial phytopathogen erwinia amylovora (the cause of fire blight disease of apples and pears) are markedly susceptible to novobiocin, deoxycholate, and sodium dodecyl (= lauryl) sulfate. the inhibitory concentration, expressed as the concentration causing a 99% inhibition of growth, of these three antibacterial agents were 15 to 100, 40 to 800, and 50 to 800 mug/ml, respectively, depending on the e. amylovora strain. growth of strains of other erwinia spp. and salmone ... | 1977 | 879740 |
| zeatin ribonucleosides in the transfer ribonucleic acid of rhizobium leguminosarum, agrobacterium tumefaciens, corynebacterium fascians, and erwinia amylovora. | until recently, the presence in transfer ribonucleic acid (trna) of the hydroxylated cytokinin ribosylzeatin [n6-(4-hydroxy-3-methylbut-2-enyl)adenosine]was thought to be unique to higher plants. this extension of work from several laboratories indicates the presence of 2-methylthioribosylzeatin in the trna of the plant-associated bacteria rhizobium leguminosarum, agrobacterium tumefaciens, and corynebacterium fascians, but not in that of erwinia amylovora. this cytokinin has the cis configurati ... | 1977 | 893341 |
| effects of enrichment media and incubation conditions on isolating salmonellae from ground-meat filtrate. | forty-eight combinations of enrichment media, secondary enrichment, incubation times and temperatures, and atmospheres were examined for their efficacy in recovering different serovars of salmonella that had been inoculated into ground-meat extract. variations included three selective-enrichment media, two (37 and 43 degrees c) incubation temperatures, two (24 and 48 h) incubation times, two (aerobic and anaerobic) incubation atmospheres, and secondary enrichment to two of the selective-enrichme ... | 1977 | 911161 |
| in vitro evaluation of the new oral cephalosporin cefatrizine: comparison with other cephalosporins. | cefatrizine (bl-s640), a semisynthetic, orally administered cephalosporin, was found to have an in vitro spectrum of activity comparable to those of four other cephalosporins tested. it is as effective as cephalexin, the other orally administered cephalosporin evaluated, against most species, and it appears to be more effective than cephalexin against many enterobacter, haemophilus, and proteus strains isolated in our hospital. it is not inactivated by the plasmid-determined beta-lactamases of 1 ... | 1976 | 984771 |
| comparison of six methods of detecting salmonella typhimurium infection of chickens. | six methods were used in testing for prior exposure of chickens to salmonella typhimurium (st). the most sensitive and reliable was the microantiglobulin (mag) test; less reliable were the tube agglutination, microagglutination, rapid-whole-blood, and rapid-serum-plate tests. it was assumed that the agglutinins demonstrated by the mag test method were the direct result of exposure to st, and that the mag test detected the maximum number of birds previously exposed to st. the cloacal swab culture ... | 1976 | 985271 |
| salmonellosis in wild mammals. | one thousand two hundred and sixty-nine freeliving, wild mammals, representative of 16 species from estates in berkshire, oxfordshire and surrey, were examined for the presence of salmonellas. salmonella typhimurium was isolated from 1 and s. dublin from 7 house mice (mus musculus). there were no isolations from the other species examined. it was concluded that the house-mice infected with s. dublin acquired the organism from experimentally infected cattle. the wild mammal population does not at ... | 1976 | 1068191 |
| histidine regulation in salmonella typhimurium. xvi. a sensitive radiochemical assay for histidinol dehydrogenase. | 1975 | 1089301 | |
| association of salmonella typhimurium with, and its invasion of, the ileal mucosa in mice. | a wild-type strain of salmonella typhimurium and three mutant rough colonial variants of the wild type were compared for their ability to become associated with and invade the ileal mucosa of germfree and specific-pathogen-free mice. the rough-mutant strains differed from the wild type in having incomplete lipopolysaccharides lacking one or more sugars in the polysaccharide moiety. the wild-type and mutant strains also differed one from the other in the types of appendages (flagella, pili) on th ... | 1975 | 1089603 |
| threonine deaminase from salmonella typhimurium. relationship between regulatory sites. | kinetic analysis of the biosynthetic threonine deaminase, ec 4.2.1.16, from samonella typhimurium yields hyperbolic substrate saturation curves in the absence of, and higher order substrate saturation curves in the presence of, l-isoleucine. l-valine reverses this effect of l-isoleucine by restoring the hyperbolic substrate saturation curves. the inhibition of enzyme activity and the reversal of valine stimulation is a function of a second order concentration of l-isoleucine, whereas antagonism ... | 1975 | 1089662 |
| polarity of the cysjih operon of salmonella typhimurium. | certain point and deletion mutants with lesions in the cysj gene of salmonella typhimurium have low levels of enzymes coded by the cysi and cysh genes. these results support the hypothesis that an operon exists comprising genes cysj, i and h which is transcribed in the direction from cysj to h. the nearby cysc and cysd genes do not form part of this cysjih operon. | 1975 | 1089759 |
| reduced maximal levels of derepression of the isoleucine-valine and leucine enzymes in hist mutants of salmonella typhimurium. | 1975 | 1089896 | |
| in vitro metabolism and microsome-mediated mutagenicity of dialkylnitrosamines in rat, hamster, and mouse tissues. | rates of conversion of 14c-labeled dimethyl-and diethylnitrosamine by rat and hamster tissue slices to 14co2 and/or into mutagenic reactants were measured using salmonella typhimurium g-46 r ta 1530 and fortified tissue fractions in vitro. a correlation between the co2 production from dimethyl- or diethylnitrosamine in liver or lung and the organ distribution of induced tumors in vivo was observed. as an exception, hamster lung, which is a major target organ in diethylnitrosamine carcinogenesis, ... | 1975 | 1090363 |
| serum zinc, iron, and copper concentrations during typhoid fever in man: effect of chloramphenicol therapy. | in volunteers experimentally infected with salmonella typhi, serum iron and zinc concentrations became significantly depressed and there was a concomitant rise in serum copper before the onset of overt clinical illness. however, after several days of fever and the initiation of chloramphenicol therapy, serum iron and zinc concentrations significantly increased. additional studies--in volunteers with typhoid fever treated with chloramphenicol, in a volunteer with typhoid fever receiving cefazolin ... | 1975 | 1090399 |
| control of salmonellosis pacifarin biosynthesis by iron. | enterobacter cloacae strain ss4-56 produced salmonellosis pacifarins when grown in an iron-depleted synthetic medium to which 3.16 x 10-7 g-atom of iron had been added per liter, but did not do so when grown in iron-depleted medium supplemented with 3.16 x 10-4 g-atom of iron per liter. the addition of 3.16 x 10-4 g-atom of ferric iron per liter to a pacifarin-containing culture supernatant fluid had no significant effect upon the ability of the active pacifarins present, when administered per o ... | 1975 | 1090527 |
| effect of water activity on heat survival of staphylococcus aureus, salmonella typhimurium and salm. senftenberg. | 1975 | 1090567 | |
| positive selection of mutants with deletions of the gal-chl region of the salmonella chromosome as a screening procedure for mutagens that cause deletions. | we have developed a convenient and specific positive selection for long deletions through the gal region of the chromosomes of salmonella typhimurium and escherichia coli. through simultaneous selection for mutations in the two closely linked genes, gal and chla, a variety of deletions of varying length, some extending through as much as 1 min of the chromosome, could be readily obtained. many of these deletions resulted in the loss of a gene, which we named dhb, concerned with the ability of th ... | 1975 | 1090571 |
| genetic modification of substrate specificity of hypoxanthine phosphoribosyltransferase in salmonella typhimurium. | salmonella typhimurium strain gp660 (proab-gpt deletion, pure) lacks guanine phosphoribosyltransferase and hence cannot utilize guanine as a purine source and is resistant to inhibition by 8-azaguanine. strain gp660 was mutagenized and a derivative strain (gp36) was isolated for utilization of guanine and hypoxanthine, but not xanthine, as purine sources. this alteration was designated sug. the strain was then sensitive to inhibition by 8-azaguanine. column chromatographic analysis revealed the ... | 1975 | 1090579 |
| activation of guinea pig macrophages by bacterial lipopolysaccharide requires bone marrow-derived lymphocytes. | the activation of guinea pig peritoneal macrophages by salmonella typhimurium lipopolysaccharide (lps) was studied by using 14c-glucosamine uptake. peritoneal exudate cells incorporated significant amounts of 14c-glucosamine when stimulated with lps but neither purified macrophages nor nonadherent lymphocytes by themselves incorporated glucosamine. the activation of macrophages could be restored by adding nonadherent peritoneal lymphocytes, spleen cells, and lymph node cells but not thymocytes. ... | 1975 | 1090657 |
| induction of base-pair substitution and frameshift mutations in wild-type and repair-deficient strains of salmonella typhimurium by the photodynamic action of methylene blue. | induction of back mutations to prototrophy by methylene blue (mb)-sensitized photodynamic (pd) treatment has been studied in wild-type and repair-deficient strains of salmonella typhimurium carrying either the base-pair substitution mutation hisg46 or the frameshift mutation hisd30529 we found that reversion of the hisg46 mutation was increased in a strain carrying a uvrb deletion and decreased in a strain carrying a reca-type mutation. reversion of the hisd3052 (frameshift) mutation, on the oth ... | 1975 | 1090811 |
| quantitative relationship between carcinogenicity and mutagenicity of polyaromatic hydrocarbons in salmonella typhimurium mutants. | mutagenic activities of various polyaromatic hydrocarbons (pahs) in air pollutants, which are different in carcinogenic activities from each other, were examined with a set of four strains of salmonella typhimurium (tai535 series; deep rough strains without excision repair). all the compounds tested were converted to frameshift mutagens when they were metabolized by rat liver homogenate. there was a clear quantitative correlation between carcinogenicity and mutagenicity of pahs tested in strain ... | 1975 | 1090818 |
| [use of 2 bacteriophages for salmonella typhimurium bacilli in the evaluation of homogeneity of a food poisoning epidemic]. | 1975 | 1090981 | |
| studies on the development of chloramphenicol resistance in salmonella typhimurium. | chloramphenicol therapy of acute and chronic salmonella typhimurium infection in mice did not lead to the development of chloramphenicol resistant mutants of this organism. however, chloramphenicol resistant organisms were readily produced in vitro. transfer of chloramphenicol resistance from a donor strain of escherichia coli x12 to a suitable recipient strain of s typhimurium 5235 occurred readily in the intestine of 15 out of 20 conventional mice, following oral administration of large doses ... | 1975 | 1090986 |
| effect of aeration on minimal medium recovery of heated salmonella typhimurium. | the effect of presence or absence of air on minimal medium recovery of heated salmonella typhimurium was investigated. it was determined that the expression of minimal medium recovery is not only dependent on heat and a nutritionally complex medium but also on air. unlike in the presence of air, in the presence of nitrogen, cells were able to recover their ability to grow on trypticase soy agar enriched with 0.5% yeast extract (tsy) when incubated in tsy broth. it was established that in the pre ... | 1975 | 1091616 |
| gentic mapping of salmonella typhimurium peptidase mutations. | the map positions of three loci, each specifying a different peptidase, have been determined in salmonella typhimurium. mutations in pepn (leading to loss of peptidase n [1974] are co-transducible with pyrd. the order of markers in this region is put pyrd pepn. mutations in pepa (leading to loss of peptidase a [1974] are co-transducible with pyrb and argi. the relative orientation of these markers is pepa argi pyrb. mutations in pepdp (leading to loss of dipeptidase, peptidase d) are co-transduc ... | 1975 | 1091621 |
| purification and properties of a periplasmic glutamate-aspartate binding protein from escherichia coli k12 strain w3092. | a protein which binds both glutamate (k-d = 0.8 mum) and aspartate (k-d = 1.2 mum) has been purified to homogeneity (290-fold) from the periplasmic fraction released from escherichia coli w3092 by the cold osmotic shock procedure. the apparent molecular weight of the glutamate-aspartate binding protein is approximately 31,000 as judged by gel electrophoresis, gel filtration, and sedimentation equilibrium centrifugation; and the protein has a pi of 9.69. this protein contains 2 half-cystine resid ... | 1975 | 1091635 |
| explosive outbreaks of food poisoning due to salmonella typhimurium u65. | 1975 | 1092634 | |
| hycanthone and its congeners as bacterial mutagens. | hycanthone methanesulfonate (hct) was shown to induce "forward" and "reverse" mutations in salmonella typhimurium and escherichia coli. mutational effects of hct on s. tyhhimurium ta1532 were concentration and time dependent. a comparison of mutagenic potency for ta1532 was made between hct and the frame-shift mutagens quinacrine and icr-191. an investigation of structure-activity relationships revealed the substituent in the 4-position of ring a to be critical for mutagenicity. activity was fou ... | 1975 | 1092656 |
| isolation and characterization of gal e mutant ty 21a of salmonella typhi: a candidate strain for a live, oral typhoid vaccine. | a gal e mutant of salmonella typhi was isolated; results obtained with salmonella typhimurium and the mouse as a model for human typhoid fever indicated that this mutant has the potential for use as a live, oral typhoid vaccine. the mutant, ty 21a, took up galactose from exogenous sources and accumulated sufficient quantities of galactose-1-phosphate and uridine diphosphate galactose to cause lysis of the cells, an event that resulted in the avirulence of the strain. galactose was incorporated s ... | 1975 | 1092768 |
| pigment production by bacteroides species with reference to sub-classification. | all six reference strains of bacteroides species, 36 laboratory isolates conforming to this group, and individual strains of escherichia coli, proteus mirabilis, salmonella typhimurium and clostridum welchii produced a dense black pigment, identified as ferrus sulphide, when grown in cooked-meat media containing cystine and ferrous sulphate. this was an indicator effect resulting from the production of h2s by the bacteria in the presence of ferrous ions and was unrelated to the characteristic pi ... | 1975 | 1092861 |
| a new biotyping scheme for salmonella typhimurium and its phylogenetic significance. | a new, two-tier system for biotyping salmonella typhimurium gives a finer and more reliable differentiation of strains than the kristensen scheme and is capable of future extension by the addition of new types and new tests. strains are allocated to a primary type (1-32) by their reactions in five primary tests with bitter's xylose medium, meso-inositol, l-rhamnose, d-tartrate and m-tartrate. subtypes are distinguished within the primary types by reactions in ten secondary tests, which include o ... | 1975 | 1092863 |
| mutagenicity of sodium hypochlorite for salmonella typhimurium. | sodium hypochlorite, a standard household item, induces base-substitution mutations in salmonella typhimurium. because of its potent bactericidal effect the mutagenicity of hypochlorite could best be demonstrated by short-term exposure to this chemical followed by the addition of ascorbic acid to decompose the hypochlorite. | 1975 | 1093014 |
| the influence of ethanol and carbon tetrachloride on the mutagenic effectivity of cyclophosphamide in the host-mediated assay with salmonella typhimurium. | 1975 | 1093018 | |
| experimental infection of cockerels with salmonella typhimurium. | six-month-old spf brown leghorn cockerels were experimentally infected per os with s typhimurium (1 times 1010) and slaughtered at intervals up to 42 days following infection. observations were made on the clinical pathology, bacteriology and serology during the course of infection and extensive bacteriological examinations were undertaken after post mortem examination. | 1975 | 1093242 |
| dietary modifications affecting the mutagenicity of n-nitroso compounds in the host-mediated assay. | the effects of various dietary modifications on the mutagenicity of dimethylnitrosamine (dmna), n-nitrosomorpholine, and n-methyl-n-nitrosourea for salmonella typhimurium his g-46 in the host-mediated assay were studied. the diets used were:chow, complete semisynthetic, protein-free, and all-casein, in addition to a 24-hr starvation regimen. the mutagenicity of dmna and n-nitrosomorpholine, which require metabolic activation for their biological activity, was depressed by the complete semisynthe ... | 1975 | 1093677 |
| synthesis of escherichia coli uridine diphosphate glucose hydrolase, and demonstration of an inhibitor, in salmonella typhimurium cytoplasm. | 1975 | 1093908 | |
| selection for a large genetic duplication in salmonella typhimurium. | salmonella typhimurium strains containing a duplication of nearly a third of the genome have been isolated by a simple procedure involving selection for improved utilization of l-malate as sole carbon source. the duplication occurs at a very high spontaneous frequency. strains containing the duplication can be isolated selectively on malate medium, or by a non-selective procedure involving hfr conjugation. when strains containing the duplication are maintained on non-selective medium, the duplic ... | 1975 | 1093939 |
| mutations in salmonella typhimurium conferring resistance to felix o phage without loss of smooth character. | several mutants obtained from smooth salmonella typhimurium strains by selection for resistance to felix o (fo) phage [whose receptor site includes the n-acetylglucosamine branch of the lipopolysaccharide (lps) core] were smooth in cultural properties, antigenic character and phage sensitivity pattern (except for their fo resistance). however, the affected genes of several such 'for' (fo-resistant) mutants were shown by transduction of map in the short cyse-pyre segment, which includes nearly al ... | 1975 | 1094090 |
| reversible inactivation of the isocitrate dehydrogenase of escherichia coli ml308 during growth on acetate. | during aerobic growth of escherichia coli ml308 on acetate as sole carbon source, the apparent synthesis of isocitrate dehydrogenase was repressed relative to cultures on other carbon sources, such as glucose, which do not employ the glyoxylate bypass as an anaplerotic sequence. when cells were removed from an acetate medium, or when compounds were added which made the operation of the glyoxylate bypass unnecessary, the activity of isocitrate dehydrogenase rapidly increased 3- to 4-fold but fell ... | 1975 | 1094097 |
| transport in bacteriophage p22-infected salmonella typhimurium. | there was rapid efflux of l-leucine, l-phenylalanine, and alpha-methyl-d-glucoside after infection of salmonella typhimurium with the clear plaque mutant c1 of phage p22. the efflux was similar to that observed with cyanide or arsenate treatment except that there was partial recovery in the case of phage infection and almost complete recovery under the condition of lysogeny. there was no efflux after infection with the temperature-sensitive mutant ts16c1 at nonpermissive temperature. superinfect ... | 1975 | 1094132 |
| tissue-mediated mutagenicity of vinylidene chloride and 2-chlorobutadiene in salmonella typhimurium. | 1975 | 1094302 | |
| interaction between phosphoribosyltransferase and purified histidine trna from wild type salmonella typhimurium and a derepressed hist mutant strain. | we have examined the interaction between phosphoribosyltransferase and purified trna-his from the wild type strain of salmonella typhimurium, lt-2, and the histidine regulatory mutant histl504. histidyl-trna from the mutant strain functions normally in protein synthesis but is defective in its role in the repression mechanism of the histidine operon. phosphoribosyltransferase has been suggested as a possible aporegulator for this operon and as such might be expected to interact abnormally with t ... | 1975 | 1094423 |
| the persistence of salmonella typhi murium in various types of manure with and without admixture of silage effluent. | 1975 | 1094814 | |
| purification and properties of thymidine phosphorylase from salmonella typhimurium. | 1975 | 1094953 | |
| outer membrane of salmonella typhimurium: reconstitution of sucrose-permeable membrane vesicles. | 1975 | 1095017 | |
| effect of excision repair system on antibacterial and mutagenic activity of daunomycin and other intercalating agents in salmonella typhimurium. | daunomycin and adriamycin, are more mutagenic and antibacterial for a strain of salmonella typhimurium defective for the uvrb gene than for its uvr+ counterpart. other intercalating agents, as some acridine dyes, affect equally the two bacterial strains. | 1975 | 1095395 |
| [mutagenicity testing of irradiated laboratory animal feed in the 'host-mediated' assay with salmonella typhimurium g 46]. | food irradiated with 10 mev-electrons (dose: 4-5 mrad) was tested for mutagenic effects, using the host-mediated assay. irradiated 'altomin' (a pelleted laboratory diet) was fed to mice for 9 to 44 days. after the 30th day of feeding, the animals additionally received irradiated glucose-solution instead of drinking water. results did not indicate any mutagenic activity of the irradiated diet on the histidine-auxotroph strain of salmonella typhimurium used in the assay. | 1975 | 1095506 |
| conservation of salmonella typhimurium deoxyribonucleic acid by chromosomal insertion in a partially diploid escherichia coli hybrid. | a partially diploid escherichia coli hybrid recovered from mating with a salmonella typhimurium donor was converted to an hfr strain, designated wr2080, as a means to examine the manner in which the added salmonella genetic material was conserved in it. the salmonella argh-+, metb-+, and rha-+ alleles contained as supernumerary genes in wr2080 were transferred together to e. coli recipients in interrupted mating experiments approximately 25 min after initial parental contact; transfer of the all ... | 1975 | 1095545 |
| properties of the imidazolylacetolphosphate aminotransferase produced in a mutant demonstrating no apparent genetic involvement of the structural gene. | genetic studies with strain hisbh22 of salmonella typhimurium indicate it contains a deletion within the histidine operon involving part of the hish gene and all of the hisb gene, but not extending into the adjacent hisc gene which is adjacent to hisb. however, the specific activity of the hisc product, imidazolylacetolphosphate aminotransferase (ec 2.6.1.9), in this strain is only 10 to 15% of that found in extracts from other mutants with a normal hisc gene. we have examined the rate of aminot ... | 1975 | 1095553 |
| mutagenicity testing with salmonella typhimurium strains. i. unusual phenotypes of the tester strains. | some of the salmonella typhimurium strains in mutagenesis testing are atypical. unlike the wild s. typhimurium these do not produce h-2-s, are not agglutinated by s. typhimurium typing sera and on fermentation of carbohydrates they do not produce gas. thus these tester strains cannot readily be identified as s. typhimurium by standard laboratory procedures. this may cause a problem in the differentiation of tester strains from bacterial contaminants. the possibility exits that these phenotypic t ... | 1975 | 1095918 |
| [a histologic study of ceratophyllus consimilis wagn. fleas infected by the agent of murine typhus (salmonella typhimurium)]. | histological studies of c. consimilis infected with s. typhimurium have shown that the microbes are preserves along the whole extent of the alimentary canal, expecially in the midgut and pyloric portion. bacteria are concentrated in the gastral cavity; in addition, they were found to penetrate the alimentary epithelium cells and pyloric valve tissue. the number of microbes and their distribution in the intestine undergo great variations that depends largely on the insects feeding rhythm. during ... | 1975 | 1096029 |
| [characteristics of the multiresistant strains of salmonella typhimurium causing cross infections in pediatric hospitals]. | 1975 | 1096262 | |
| [phage typing and biotyping of salmonella typhi-murium (author's transl)]. | 1998 strains of salmonella typhi-murium from two different regions of west-germany were investigated according to their biotype and phagetype. 132 strains were isolated from sewage, 320 strains from animals and the others from human beings. 60 different phagetypes were found. the phagetype 49 occurred most often (11,9% resp. 10,3%). a correlation between biotype and phagetype could not be observed. nearly every phagetype could be divided into several biotypes. however, only few biotypes prevaled ... | 1975 | 1096503 |
| enzootic occurrence of chloramphenicol-resistant salmonella typhimurium var copenhagen in calf population. | chloramphenicol (cp)-resistant salmonella typhimurium var copenhagen was frequently isolated (44.1 to 76.7%) from dead, diseased, and healthy calves on 3 farms in 1973 in northern japan. on 2 of the farms, cp-resistant salmonella appeared suddenly during an epizootic of salmonella infection, and persisted. of 87 cp-resistant to tetracycline (tc), streptomycin (sm), and sulfonamides (sa), and the remaining 13 isolates from dead calves on a farm were resistant to tc, sm, sa, and kanamycin (km). re ... | 1975 | 1096689 |
| stimulation of enzyme synthesis by sublethal concentrations of chloramphenicol is not mediated by ribonucleotide pools. | growth of salmonella typhimurium lt-2 strain pyra81 in minimal medium containing 0.8 mug of chloramphenicol (cap) per ml resulted in a 50 to 100% increase in the steady-state nucleotide pools in the cells. when such a culture was starved for uracil, the pyrimidine nucleotide pools decayed much more slowly in cap-treated cells than in controls. an attempt was made to determine whether this effect of cap on nucleotide pools could account for enhanced enzyme derepression observed under the same con ... | 1975 | 1096806 |
| mutagenic activity of cyclophosphamide, ifosfamide, and trofosfamide in different genes of escherichia coli and salmonella typhimurium after biotransformation through extracts of rodent liver. | experiments are performed to compare the mutagenic properties of the three phosphamide esters of nitrogen mustard, cyclophosphamide (cp), ifosfamide (if), and trofosfamide (tf), in different bacterial systems. the systems include forward mutations leading to resistance against 5-methyltryptophan (mtr) and from galr-s18 to gal-+ in escherichia coli 343/113, back mutations from arg56 to arg-+ in escherichia coli 343/113 and back mutations from hisg46 to his-+ in salmonella typhimurium ta1535. cp, ... | 1975 | 1096853 |
| anthranilate synthetase-anthranilate 5-phosphoribosylpyrophosphate phosphoribosyl-transferase from salmonella typhimurium. inactivation of glutamine-dependent anthranilate synthetase by agarose-bound anthranilate. | exposure of the anthranilate synthetase-anthranilate phosphoribosyltransferase enzyme complex (chorismate pyruvate-lyase (amino-accepting) ec 4.1.3.27 and n-(5-phosphoribosyl)-anthranilate pyrophosphate phosphoribosyl-transferase, ec 2.4.2.18) from salmonella typhimurium to agarose-bound anthranilate led to the slow inactivation of glutamine-dependent anthranilate synthetase activity, an activity dependent on protein-protein interaction in the enzyme complex. region i of phosphoribosyltransferas ... | 1975 | 1096955 |
| cell surface protein of salmonella typhimurium. | lactoperoxidase-catalyzed radioiodination with na125i was performed both on intact salmonella typhimurium 1195 and on ghost membrane isolated from the same bacterial strain. ghost membrane was also prepared from radioiodinated whole bacteria. the labelled proteins from both these ghost membrane preparations were compared by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to identify the cell surface proteinmfrom the results obtained it was concluded that one major pr ... | 1975 | 1097078 |
| factors affecting metabolism and mutagenicity of dimethylnitrosamine and diethylnitrosamine. | for exploration of the factors affecting dimethylnitrosamine (dmn) mutagenicity, for gathering of information on the metabolism of dmn, a frequently used and relatively well-understood carcinogen, and for explanation of metabolic variations in dmn carcinogenicity, parallel in vitro assays of the microsomal activation of dmn to a mutagen and of dmn demethylation were performed. salmonella typhimurium g46 reversions to histidine independence increase linearly with time of incubation for 30 min. a ... | 1975 | 1097107 |
| metabolism of cigarette smoke condensates by human and rat homogenates to form mutagens detectable by salmonella typhimurium ta1538. | nineteen fractions of whole condensate of smoke from the university of kentucky reference cigarette iri were tested for mutagenicity in vitro using a bacterial indicator system. as little as 25 mug of the active fractions were mutagenic toward histidine-requiring salmonella typhimurium ta1538, if the condensates were incubated in the presence of rat or human liver homogenates of lung were relatively inactive. homogenates from livers of rats that had been treated with 3-methylcholanthrene convert ... | 1975 | 1097108 |
| glyceraldehyde phosphate at the reducing terminus of salmonella q haptens. salmonella montevideo. | the o antigen polysaccharide of salmonella montevideo was isolated from a core-defective mutant by the phenol/water procedure, and was suspected to contain phosphomonester and cyclic phosphodiester at its reducing end in anology to the o hapten from salmonella typhimurium (kent and obsborn, 1968. therefore, it was chromatographed on a deae-cellulose column. whereas one part eluted with water the other part of the polysaccharide could only be eluted with buffer. both fractions were further purifi ... | 1975 | 1097244 |
| separate regulation of transport and biosynthesis of leucine, isoleucine, and valine in bacteria. | since both transport activity and the leucine biosynthetic enzymes are repressed by growth on leucine, the regulation of leucine, isoleucine, and valine biosynthetic enzymes was examined in escherichia coli k-12 strain eo312, a constitutively derepressed branched-chain amino acid transport mutant, to determine if the transport derepression affected the biosynthetic enzymes. neither the ilub gene product, acetohydroxy acid synthetase (acetolactate synthetase, ec 4.1.3.18), nor the leub gene produ ... | 1975 | 1097409 |
| intrinsic and extrinsic light responses of salmonella typhimurium and escherichia coli. | exposure to intense light in the region between 390 and 530 nm has been shown to have three effects on the motility of salmonella typhimurium and escherichia coli. short pulses of light initiate continuous tumbling. longer exposures to light induce smooth swimming, and prolonged exposures induced paralysis. the tumbling response is intimately connected with the chemical gradient-sensing apparatus of the bacterium and can be overcome by strong temporal gradients of attractant. some mutants of s. ... | 1975 | 1097417 |
| amino-terminal sequences of indoleglycerol phosphate synthetase of escherichia coli and salmonella typhimurium. | the partial sequences of the first 40 residues of indoleglycerol phosphate synthetase of escherichia coli and salmonella typhimurium were determined, and three amino acid differences were observed among the 38 residues compared. | 1975 | 1097427 |
| sex pili as immunogens. | groups of chickens were vaccinated intravenously with live cultures of escherichia coli k12 possessing transfer factors f, i, a2 or no transfer factor (tra-minus) and their immunity challenged by injecting them intravenously with an f-plus strain of salmonella heidelberg or an f-plus or i-plus strain of salmonella typhimurium. compared with the tra-minus strain, vaccination with the f-plus, but not the i-plus or a2-plus, k12 strain significantly reduced the mortality rate caused by the f-plus sa ... | 1975 | 1097591 |
| salmonella typhimurium infections in renal transplant patients. report of five cases. | five patients with salmonella typhimurium infection after a renal cadaveric graft are described. salmonella were isolated from the urine of four patients, from the stool of one patient, from the blood of two patients, from the hip joint of one patient and from the cerebrospinal fluid of one patient. infections were difficult to eradicate and necessitated prolonged antibiotic treatment. renal function only deteriorated after the infection in some patients; salmonellosis could have triggered the r ... | 1975 | 1097951 |
| [the development of drug resistance in salmonella strains isolated from animals in sweden 1955-65 and 1973-4(author's transl)]. | 134 salmonella strains, isolated from animals in 1955-65 were compared to 133 salmonella strains isolated in 1973-74, with regard to their drug resistance and the frequentcy of r-factors. no significant changes were observed during the reference period. salmonella typhi-murium in comparison with other serotypes harboured a significantly larger number of resistant strains. of the recently isolated resistant strains that were searched for r-factors, about half the number were carriers. all strains ... | 1975 | 1098012 |
| the metabolism of n4-hydroxycytidine-a mutagen for salmonella typhimurium. | salmonella typhimurium cells were grown in the presence of (14c)-n4-hydroxycytidine (n4ohcyd), a mutagenic nucleoside, and labelling in dna and rna digest was traced. the results show that this analogue is incorporated into rna at a level of 40 mug/100 mg, and into dna with a yield at least 100 times smaller. some n-minus4ohcyd was rapidly metabolized and labelling was found in all ribo- and deoxyribo-nucleosides. | 1975 | 1098023 |
| hemagglutinating properties of salmonella typhimurium strains isolated from avian sources. | a total of 565 strains of salmonella typhimurium and s. typhimurium var. copenhagen, isolated from avian species, were examined for their ability to cause hemagglutination of turkey erythrocytes. results showed that 541 (95.7%) of the strains caused varying degrees of hemagglutination. the hemagglutinating principle was maintained in cultures stored at 5 degrees c. as formalized suspensions for as long as 6 months. it was destroyed by exposure to a temperature of 80 degrees c. for 1 minute or to ... | 1975 | 1098032 |
| [transferable resistance is cultures of salmonella typhimurium isolated in recife]. | 1975 | 1098123 | |
| alkylated cytosine nucleosides: substrate and inhibitor properties in enzymatic deamination. | cytosine nucleoside deaminase (ec 3.5.4.5) from salmonella typhimurium lt2 catalyses the deamination of ribo-, deoxyribo- and arabinosyl nucleosides of cytosine alkylated at the c-5, but not at the n3 or exocyclic n4, of the pyrimidine ring. the enzyme was inert towards analogues etherified at the 3'-oh and 5'-oh of the sugar ring; it was active against the 2'-o-methyl derivative of cytidine, but not arabinosycytosine. the n4-and 5'-o-alkyl non-substrate analogues competitively inhibited deamina ... | 1975 | 1098340 |
| bactericidal and opsonic activities of normal sheep serum against gram-negative bacteria. | the bactericidal and opsonic activities of normal sheep serum against 9 smooth and 4 rough strains of gram-negative bacteria were measured. three smooth strains-escherichia coli 3662, salmonella typhimurium, and salmonella gallinarum-were resistant to the bactericidal action of normal sheep serum with or without complement. six smooth strains-e coli o78:k80(b), salmonella arizonae, proteus inconstans, klebsiella pneumoniae, salmonella stanley, and salmonella abortus-equi-were moderately sensitiv ... | 1975 | 1098532 |
| influence of rofenaid-40 feed medication on an experimental salmonella infection in chickens. | rofenaid-40 administered at 0.02% in feed to chickens experimentally infected with salmonella typhimurium resulted in less colonization and shedding of s. typhimurium than in unmedicated chickens. the antibacterial sensitivity pattern of s. typhimurium isolated from infected birds had not changed after exposure to rofenaid for 56 days. | 1975 | 1098638 |
| in situ separation of bacterial trapping and killing functions of the perfused liver. | cf-1 mice cleared and killed 80% of a 1.2 x 10(9) intravenous dose of salmonella typhimurium after 30 min. the perfused mouse liver trapped 70% of a similar dose of s. typhimurium in a single pass, but in the perfusion model no significant killing of the trapped organisms was observed. the perfused rat liver also avidly trapped bacteria. because of its larger size, we have been able to devise techniques to experimentally distinguish between the bacterial trapping and killing functions of this or ... | 1975 | 1099006 |
| deletions fusing the hisg and hisd genes in salmonella typhimurium. | frameshift mutation hisd497 occurs in the operator-proximal portion of the salmonella typhimurium gene coding for the dimeric protein, l-histidinol dehydrogenase (hdh). rare revertants of hisd497 are deletions fusing the hisd gene to the adjacent preceding structural gene, hisg (adenosine 5'-triphosphate-pr transferase). hdh purified from one revertant, hisgd4908, contains subunits of approximately normal molecular weight but with no clearly demonstrable unique amino-terminal sequence. we propos ... | 1975 | 1099075 |
| isolation of a hybrid f' factor-carrying escherichia coli lactose region and salmonella typhimurium histidine region, f42-400 (f' ts114 lac+, his+): its partial characterization and behavior in salmonella typhimurium. | episome f' ts114 lac+ (f42-114) was transferred into salmonella typhimurium carrying an f'his+ (fs400) episome, and fused episome f' ts114 lac+, his+ (f42-400) was obtained. episome f42-400 could be transferred to s. typhimurium, escherichia coli and klebsiella pneumoniae. identification of the episome was based on: (i) temperature sensitivity of the lac+ and his+ phenotypes; (ii) the fact that f- segregants, obtained after temperature curing or acridine orange curing, were simultaneously lac- a ... | 1975 | 1099076 |
| behavior of a hybrid f' ts114 lac+, his+ factor (f42-400) in klebsiella pneumoniae m5a1. | episome f' ts114 lac+, his+ (f42-400) was transferred from salmonella typhimurium to klebsiella pneumoniae. from the progeny, a strain of k. pneumoniae able to retransfer the episome was obtained. the his+ phenotype in this strain is temperature sensitive. escherichia coli female-specific phages phiii, w31, and t3 were shown to plate on k. pneumoniae. from phiii we obtained two derivatives; phiiik, which plates only on k. pneumoniae, and phiiie, which plates only on e. coli. growth of phages t3 ... | 1975 | 1099077 |
| membrane-associated nucleotide sugar reactions: influence of mutations affecting lipopolysaccharide on the first enzyme of o-antigen synthesis. | both the synthesis of lipopolysaccharide o-antigen and the synthesis of peptidoglycan in salmonella typhimurium proceed via membrane-bound glycosylated lipid intermediates. the first enzyme of each pathway transfers a sugar phosphate from a nucleotide sugar to the glycosyl carrier lipid (p-gcl). each enzyme catalyzes an exchange reaction between the reaction product urine monophosphate, and the nucleotide sugar substrate. several strains of s. typhimurium defective in lipopolysaccharide synthesi ... | 1975 | 1099085 |
| compatibility studies with the plasmid of salmonella typhimurium lt2. | 1975 | 1099633 | |
| an outbreak of salmonellosis propagated by person-to-person transmission on an indian reservation. | between december 21, 1969, and april 14, 1970, 44 symptomatic cases of salmonella typhimurium gastroenteritis occurred among the approximately 2500 sioux indians of the lake traverse reservation in south dakota. twenty-five cases were confirmed by positive stool culture. all 19 cases not confirmed by culture had diarrhea and were epidemiologically associated with the culture-proven cases. fourteen of these were discovered during the course of the investigation and had not been cultured previousl ... | 1975 | 1099900 |
| histidyl-trna synthetase from salmonella typhimurium: specificity in the binding of histidine analogues. | the topography of the active site of histidyl-trna synthetase has been investigated by determining ki values for a variety of structural analogues of histidine, using the atp-ppi exchange and trna aminoacylation reactions. using these kinetic constants it has been possible to have a measure of the relative binding affinity of the enzyme for the histidine analogues. the following conclusions have been drawn: (a) the enzyme is stereospecific in the formation of aminoacyl-trna complexes, since the ... | 1975 | 1100392 |
| retention of salmonella typhimurium by certain species of fish and shrimp. | marine fish (mugil cephalus, fundulus heteroclitus, trachinotus carolinus), lake shrimp (penaeus setiferus), and channel catfish (ictalurus lacustris punctatus) were exposed to salmonella typhimurium and cultured after 2 hours and at daily intervals for 30 days. salmonella typhimurium was recovered from all exposed animals after 2 hours and for 30 days in all animals except p setifurus. the organisms could not be recovered from those shrimp after the initial sampling period. apparent salmonellos ... | 1975 | 1100577 |
| growth rate of enterobacteriaceae at elevated temperatures: limitation by methionine. | the effect of elevated temperatures on growth rate was studied in five strains of enterobacteriaceae. in all the strains tested a shift to the elevated temperature resulted in an immediate decrease in growth rate which was due to limitation in the availability of endogenous methionine. the first biosynthetic enzyme of the methionine pathway-homoserine transsuccinylase-was studied in extracts of aerobacter aerogenes, salmonella typhimurium, and escherichia coli and was shown to be temperature sen ... | 1975 | 1100601 |
| studies on the mechanism of inhibition of salmonella typhimurium by 1,2,4-triazole. | the inhibition of salmonella typhimurium by 1,2,4-triazole appears to be mediated through an effect on l-cysteine biosynthesis. o-acetylserine sulfhydrylase a, the final enzyme in the l-cysteine biosynthetic pathway, was found to catalyze a reaction (triazolylase) between o-acetyl-l-serine and 1,2,4-triazole, giving 1,2,4-triazole-1-alanine as a product. in wild type s. typhimurium grown on 4 mm 1,2,4-triazole, 97% of the total o-acetyl-l-serine synthesized in vivo is incorporated into 1,2,4-tri ... | 1975 | 1100624 |
| outer membrane as a diffusion barrier in salmonella typhimurium. penetration of oligo- and polysaccharides into isolated outer membrane vesicles and cells with degraded peptidoglycan layer. | in escherichia coli and salmonella typhimurium, the cell wall that contains both the outer membrane layer and the peptidoglycan layer acts as a barrier of the molecular sieve type for the penetration of uncharged saccharides (g. decad, t. nakae, and h. nikaido (1974) fed. proc. 33, 1240). here we examined which of the layers of the cell wall limited the size of the penetrating molecules, by studying the penetration of saccharides into (a) cells whose peptidoglycan layer had been destroyed by lys ... | 1975 | 1100625 |