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| J Bacteriol, 1977 Aug, 131(2), 716 - 8 Phosphoenolpyruvate:sugar phosphotransferase system in Ancalomicrobium adetum; Saier MH Jr et al.; Ancalomicrobium adetum possesses a membrane-associated phosphoenolpyruvate:sugar phosphotransferase system, the components of which exhibited enzymatic cross-reactivity with those from Salmonella typhimurium. J Bacteriol, 1977 Aug, 131(2), 583 - 8 Characterization of an endonuclease associated with the drug resistance plasmid pKM101; Lackey D et al.; An endonuclease was detected in strains of Salmonella typhimurium containing the drug resistance plasmid pKM101 . The enzyme was not detectable in strains lacking this plasmid, but it was present in strains containing mutants of pKM101 that were no longer able to enhance host cell mutagenesis . The endonuclease had a molecular weight of roughly 75,000 and, at pH 7.0, was equally active on single-stranded and duplex deoxyribonucleic acid (DNA) . The reaction with single-stranded DNA was optimal at pH 5.5, whereas with duplex DNA the optimum was pH 6.8 . The enzyme required a divalent cation for activity, and it had no detectable exonuclease activity with single-stranded or duplex DNA . The endonuclease extensively degraded DNA with no apparent base specificity, forming 5'-phosphomonoester termini . Although characterization of the endonuclease has not revealed its function, the enzyme does not appear to be a restriction endonuclease. J Biol Chem, 1977 Jul 25, 252(14), 4904 - 12 Lipid A mutants of Salmonella typhimurium . Purification and characterization of a lipid A precursor produced by a mutant in 3-deoxy-D-mannooctulosonate-8-phosphate synthetase; Rick PD et al.; We describe here the isolation, purification, and structural characterization of a lipid A precursor synthesized under nonpermissive conditions by a mutant of Salmonella typhimurium conditionally defective in the synthesis of the 3-deoxy-D-mannoctulosonate (2-keto-3-deoxyoctonate, KDO) region of the lipopolysaccharide . The precursor was isolated free from lipopolysaccharide, murein, and phospholipids by extraction of delipidated cells with 90% phenol/CHCL3/petroleum ether . The molecule was recovered from the phenol phase after precipitation of lipopolysaccharide with H2O and subsequently purified by DEAE-cellulose chromatography . Structural analyses showed that the lipid A precursor is a phosphorylated glucosamine disaccharide containing one ester and two amide-linked residues of beta-hydroxymyristate . In contrast to lipid A, the precursor disaccharide lacks ester-linked 12:0 and 14:0 fatty acids as well as KDO . The molecule contains 2 phosphate residues both of which were identified as phosphomonoesters by 31P NMR spectroscopy . One of the phosphomonoesters is located in position 1 of the reducing terminal glucosamine residue; the location of the other phosphomonoester was not determined . The structure of the precursor provides strong support for the conclusion that KDO incorporation occurs at an early stage in lipid A biosynthesis prior to the incorporation of ester-linked saturated fatty acids. Biochim Biophys Acta, 1977 Jul 21, 498(1), 282 - 93 Stereoselectivity and stereospecificity of the alpha,beta-dihydroxyacid dehydratase from Salmonella typhimurium; Armstrong FB et al.; 1 . In addition to the known 2R,3R- and 2R, 3S-2,3-dihydroxy-3-methylpentanoic acids (DHI), the 1S,3S- and sS,DR-isomers were prepared . 2S-2,3-Dihydroxy-3-methylbutanoic acid (DHV) was also prepared in addition to the known 2R-isomer . 2 . The six dihydroxy acids were examined for their ability to promote the growth of isoleucine-valine (ilv)-requiring strains of Salmonella typhimurium and to serve as substrates for the alpha,beta-dihydroxyacid dehydratase of the same organism . 3 . Only 2R,3R-2,3-dihydroxy-3-methylpentanoic and 2R-2,3-dihydroxy-3-methylbutanoic acids supported growth of the ilv strains of S . typhimurium . 4 . alpha,beta-Dihydroxyacid dehydratase utilized the three isomers with the 2R-configuration as substrates but not those with the 2S-configuration . 5 . In an additional growth study that utilized the 3R- and 3S-isomers of 3-methyl-2-oxopentanoic acid, the alpha-keto acid analogue of isoleucine, only the 3S-isomer supported growth . 6 . It is concluded that the mechanism of action of the dehydratase is stereospecific in that the proton that is attached to C-3 of the substrate occupies the same steriochemical position as the departing hydroxyl group (Fig . 6). Mutat Res, 1977 Jul, 44(1), 9 - 19 Testing of some azo dyes and their reduction products for mutagenicity using Salmonella typhimurium TA 1538; Garner RC et al.; A series of ten azo dyes as well as various single ring aromatic amines substituted on the benzene ring were tested for bacterial mutagenicity with Salmonella typhimurium TA 1538 using a soft-agar overlay method . Two dyes, sudan 2 and chrysoidin induced mutation but only in the presence of a rat liver preparation . Chrysoidin was the more active . Testing of its reduction products, aniline and 1,2,4-triaminobenzene showed a liver metabolite of the latter compound could be responsible for the mutagenic effect, having a comparable mutagenicity with 1,2-diamino-4-nitro-benzene, one of the mutagenic constituents of hair dyes . Structure-activity studies on a series of ring-substituted anilines indicated that mutagenic activity required at least two positions to be substituted with either amino or nitro groups, or one of each . The bacteria as well as the liver enzyme preparation may partake in the activation of these chemicals . The correlation between mutagenicity and carcinogenicity for this group of compounds is discussed. J Gen Microbiol, 1977 Jul, 101(1), 143 - 9 DNA degradation in wild-type and repair-deficient strains of salmonella typhimurium exposed to ultraviolet light of photodynamic treatment; Ziebell R et al.; Five mutants of Salmonella typhimurium strain LT2 trp DI (ColEI)+, initiallly detected because they released little or no colicin when tested on solid medium, proved to be sensitive to ultraviotet light (u.v.) . Further testing indicated that one of the mutants was deficient in genetic recombination and was probably a recA-type mutant, while three of the others were deficient in DNA polymerase activity and appeared to be typical polA mutants . The fifth mutant was less sensitive than the others to methyl methanesulphonate, showed reduced proficiency in genetic recombination, and was of approximately normal u.v . mutability . This mutant may be a counterpart of the class known as uvrD in Escherichia coli . All five mutants degraded significantly more of their DNA following exposure to u.v . than did the wild-type strain . The recA-type mutant and the possible uvrD mutant also degraded significantly more of their DNA spontaneously than did the wild-type . Treatment with visible light and acridine orange (photodynamic treatment) cause no significant degradation of DNA in the wild-type strain, a highly significant increase in the extent of DNA degradation in a polA mutant, and a decrease in the extent of degradation in the recA-type mutant. Cancer Lett, 1977 Jul, 3(1-2), 1 - 8 Mutagenicity of smoke condensates from cigarettes, cigars and pipe tobacco; Sato S et al.; Smoke condensates from cigarettes, cigars and pipe tobacco were mutagenic on Salmonella typhimurium TA100 and TA98 when activated with rat liver microsomal system . Mutagenicity of a unit weight of smoke condensate was rather high in cigars, low in pipe tobacco and intermediate in cigarettes . Specific mutagenic activity was almost comparable among smoke condensates from low- to high-tar cigarettes, although some variations were observed depending upon the country producing the cigarettes . Marked mutagenicity of cigarette smoke condensate could not be explained by the benzo (a) pyrene or nitroso compounds it actually contained, suggesting the presence of other very potent mutagens in tobacco smoke condensates. Infect Immun, 1977 Jul, 17(1), 98 - 104 Role of endotoxin contamination in ribiosomal vaccines prepared from Salmonella typhimurium; Misfeldt ML et al.; Ribosomal vaccines prepared from Salmonella typhimurium SR-11 and 6707 an Re mutant bacterium of strain LT2, were effective immunogens in A/J and C3H/HeDub inbred mice . Only SR-11 ribosomes were able to induce significant protection in C3H/HeJ mice . C57BL/6J mice were not protected by either ribosomal preparation . A/J mice were protected against salmonella infection by purified SR-11 endotoxin preparations . Neither the C3H/HeDub, the C3H/HeJ, nor the C57BL/6J mice were protected by the endotoxin preparation . Passive hemagglutination studies showed that C3H/HeJ mice had no antibodies to O antigen but were significantly protected by SR-11 ribosomes . In contrast, C57BL/6J mice, which had the highest titers of O antibodies of the four inbred mouse strains, were not protected by SR-11 ribosomes . Endotoxin cannot totally account for the effectiveness fo ribosomal account for the effectiveness of ribosomal vaccines prepared from S . typhimurium. Mutat Res, 1977 Jul, 48(3-4), 319 - 25 Relation between chemical constituents of tobacco and mutagenic activity of cigarette smoke condensate; Mizusaki S et al.; Mutagenic activities of cigarette smoke condensate were assayed in the presence of S-9 Mix using Salmonella typhimurium TA 98 . The results were examined in relation to chemical data of tobacco leaves . Among the nitrogenous constituents examined, the contents of total nitrogen and protein nitrogen and the soluble nitrogenous fraction were positively and significantly related to an increase in mutagenic activity of the smoke condensate, whereas nicotine and nitrate were not important in contributing to mutagenic potency of such condensates . The age of tobacco leaves influenced the mutagenic potency of the condensate, which was lowest in leaves from the lower stalk position and increased with ascending leaf position on the stalk . Smoke condensate from tobacco with higher sugar content resulted in lower mutagenic activity . The present results, together with the previous study on the mutagenicity of the amino acid pyrolyzates, suggest that potent mutagens in cigarette smoke condensate are nitrogen-containing compounds, which may be formed from proteins and amino acids during the burning of a cigarette. Mutat Res, 1977 Jul, 48(3-4), 313 - 8 Mutagenicity of nitrovin--a nitrofuran feed additive; Joner PE et al.; Nitrovin, a nitrofuran feed additive, is shown to be directly mutagenic in Salmonella typhimurium TA 98 and TA 100 between 0.1 and 2.5 microgram per plate (0.09--2.3 micrometer) . Addition of a rat-liver homogenate reduces the mutation rates . Nitrovin inhibits growth of the same bacteria in suspension cultures at concentrations above 0.09 micrometer. Mutat Res, 1977 Jul, 48(3-4), 307 - 12 Mutagenicity tests on anthelmintics: microsomal activation of viprynium embonate to a mutagen; Macphee DG et al.; Eight anthelmintic preparations readily available in Australia were tested for mutagenicity in the Salmonella typhimurium test system . A slightly modified version of the procedure recommended by Ames et al . {2} was adopted, in that the test samples were placed in "wells" cut out of the agar of a plate previously seeded with the appropriate tester strain . Addition of a mixture of rat liver microsomal enzymes and appropriate co-factors ("S-9 mix") to one of the two wells on a single plate allowed a possible requirement for metabolic activation to be recognised . Using this procedure, viprynium embonate was found to be non-mutagenic . It was however, activated by the rat liver microsome preparation to a mutagen capable of causing both base-pair substitution (detected with strain TA100) and frameshift (detected with strain TA98) mutations . The other seven compounds tested all gave negative results in this system. Mutat Res, 1977 Jul, 48(3-4), 279 - 86 Mutagenic activity of amino acid pyrolyzates in Salmonella typhimurium TA 98; Matsumoto T et al.; Pyrolyzates of 25 amino acids and 5 indole derivatives were tested for mutagenicity in the histidine-requiring mutant Salmonella typhimurium TA 98 . Significant mutagenic activity was detected with pyrolyzates of most of the amino acids . These pyrolyzates required a liver microsomal fraction, as representative of mammalian metabolism, to be detected as mutagens . Among the pyrolyzates tested, the highest mutagenic activity was observed with that of L-tryptophan . As little as 10 microgram of the pyrolyzate of L-tryptophan had detectable mutagenic activity toward TA 98 . The optimal pyrolysis temperatures for the formation of mutagenic products were shown to be 500 degrees C for L-tryptophan and 600 degrees C for the other amino acids . The results from pyrolyses of some indole derivatives suggest that an amino group at the alpha-position to the carboxyl group of L-tryptophan plays an important role in the formation of mutagens. Mutat Res, 1977 Jul, 48(3-4), 271 - 8 Mutagenic studies with acrylonitrile; Milvy P et al.; The mutagenicity of acrylonitrile (vinyl cyanide, propenenitrile) has been demonstrated in the Ames Salmonella typhimurium/liver microsome assay system . Acrylonitrile, in the presence of a mouse liver homogenate produced mutations in the TA 1535, TA 1538 and TA 1978 strains . Exposure of the bacteria was achieved by spotting the acrylonitrile on a "lawn" of salmonella, by shaking a reaction mixture consisting of bacteria, liver homogenate and acrylonitrile, and by exposing the homogenate and bacteria to an atmosphere containing the acrylonitrile . Mutagenesis by this latter method was observed at exposures as low as 57 ppm, less than three times the TLV of 20 ppm that is designated in the United States. J Bacteriol, 1977 Jul, 131(1), 111 - 8 Regulation of L-cystine transport in Salmonella typhimurium; Baptist EW et al.; A kinetic analysis of L-cystine uptake in wild-type Salmonella typhimurium indicates the presence of at least two, and possibly three, separate transport systems . CTS-1 accounts for the majority of uptake at 20 muM L-cystine, with a Vmax of 9.5 nmol/min per mg and a Km of 2.0 muM; CTS-2 is a low-capacity, higher-affinity system with a Vmax of 0.22 nmol/min per mg and a Km of 0.05 muM; a third, nonsaturable process has been designated CTS-3 . We find that wild-type CTS-1 levels are at least 11 times higher in sulfur-limited cells than in L-cystine-grown cells . Pleiotropic cysteine auxotrophs of the types cysE (lacking serine transacetylase) and cysB- (lacking a regulatory element of positive control) have very low levels of CTS-1 even when grown under conditions of sulfur limitation, which response is analogous to that previously observed for cysteine biosynthetic enzymes (N . M . Kredich, J . Biol . Chem . 246:3474-3484, 1971) . CTS-1 is induced in cysE mutants by growth in the presence of O-acetyl-L-serine (the product of serine transacetylase), again paralleling the behavior of the cysteine biosynthetic pathway . Strain DW25, a prototrophic cysBc mutant, which is constitutive for cysteine biosynthesis, is also derepressed for CTS-1 when grown on L-cystine . Since CTS-1 is regulated by sulfur limitation, O-acetyl-L-serine, and the cysB gene product, the same three conditions controlling cysteine biosynthesis, we propose that this transport system is a part of the cysteine regulon. Cancer Lett, 1977 Jul, 3(1-2), 45 - 52 Correlation of bacterial mutagenicity and hamster cell transformation with tumorigenicity induced by 2,4-toluenediamine; Pienta RJ et al.; In the presence of rat liver microsome enzymes, 2,4-toluenediamine (TDA) was mutagenic for several tester strains of Salmonella typhimurium . TDA induced morphological transformation in an in vitro carcinogenesis system using secondary culture target cells prepared from cryopreserved primary Syrian hamster embryo cells . These results now correlate bacterial mutagenicity and in vitro morphological transformation with the reported tumorigenicity of this compound. Cancer Res, 1977 Jul, 37(7 Pt 1), 2209 - 13 Mutagenicity of cancer chemotherapeutic agents in the Salmonella/microsome test; Benedict WF et al.; Seventeen cancer chemotherapeutic agents were tested for their ability to mutate Salmonella typhimurium tester strains in the Salmonella/microsome mutagenicity test . There was a high correlation between the mutagenicity and carcinogenicity of a given agent . Carcinogens positive in the test were Adriamycin, daunomycin, 1-propanol-3,3'-iminodimethanesulfonate, cyclophosphamide, isophosphamide, hycanthone, chlornaphazin, nitrogen mustard, uracil mustard, melphalan, and thio-tepa . Two carcinogesn, actinomycin D and bleomycin, were not detected as mutagens . The presumptive noncarcinogen, methotrexate, was negative in the test . Tilorone and 6-mercaptopurine, tentatively classified as noncarcinogens, were mutagenic . The carcinogenicity of cis-dichlorodiammineplatinum(II), which was positive in the test, has not been determined. Genetics, 1977 Jul, 86(3), 513 - 26 Characterization of Salmonella typhimurium mutants with altered glutamine synthetase activity; Funanage VL et al.; A number of glutamine auxotrophs of Salmonella typhimurium were isolated and characterized genetically . Three of the mutations appear to be closely linked and are complemented by episomes carrying the glnA region of Escherichia coli . The lesions in these strains are approximately 20% linked by P1 transduction with a mutation in the rha gene, but are unlinked to ilv . Another mutation causing glutamine auxotrophy in strain JB674 is genetically distinct from the others . Strain JB674 grown in glucose medium containing ammonia as the nitrogen source has reduced levels of glutamine synthetase that is more adenylylated than in the parent strain, suggesting that the enzyme can not be deadenylylated normally . The lesion causing glutamine auxotrophy in JB674 lies in the region corresponding to the glnB and glnE genes affecting glutamine synthetase modification in Klebsiella areogenes . Four Gln+ revertants of JB674 have glutamine synthetase activities 4 to 6 fold higher than normal . One mutation causing this increased enzyme synthesis has been shown by three-factor crosses with the glnA mutations to lie near or within the glnA gene. J Biol Chem, 1977 Jun 25, 252(12), 4416 - 7 Phosphoprotein phosphatase activity associated with the cytoplasmic membrane of Salmonella typhimurium and Escherichia coli; Tuttle RC et al.; Membrane-associated phosphoprotein phosphatase activity was demonstrated in extracts of Salmonella typhimurium and Escherichia coli . The active protein could be extracted from the membrane as a large water-soluble complex (Mr greater than 150,000) . Maximal activity was observed at pH 6 to 7 in the presence of a divalent cation . The enzyme appears to be distinct from previously described phosphatases. Mol Gen Genet, 1977 Jun 8, 153(2), 205 - 10 Effect of mutant host RNA polymerase on the bifunctional activities of P22 gene c1; Tokuno S et al.; The product of phage P22 gene c1 has two functions: (1) it promotes synthesis of repressor and (2) during the first minutes of infection it retards expression of some lytic genes . We call the second, negative function "c1 retardation" . We investigated c1 retardation in a mutant host of Salmonella typhimurium that is resistant to rifampicin and carries an altered RNA polymerase . No c1 retardation of DNA synthesis was detectable in this host after infection with wild-type phages . This elimination of the normally detectable c1 function leads to the conclusion that the mutant RNA polymerase interferes with the expression of c1 gene activity . Wild-type genes form clear plaques on the mutant host . Mutants of P22 called cly were isolated by others . These mutants form turbid plaques on the altered RNA polymerase host . Infections with P22 cly in the mutant host resulted in detectable c1 retardation . The cly mutation therefore restores c1 activity in a host which wild-type c1 is not expressed . Two spontaneous mutants were isolated from the mutant host . These two strains allowed partial expression of c1 retardation, although they remained rifampicin resistant . We interpret our data to indicate that expression of the normal functions of the gene c1 product requires an interaction of that product with the host RNA polymerase. Mol Gen Genet, 1977 Jun 8, 153(2), 179 - 83 On the ability of Salmonella typhimurium cells to form deoxycytidine nucleotides; Janion C; It is known that cdd- S . typhimurium mutants selected for resistance to 5-fluorodeoxycytidine (FdCyd) possess no deoxycytidine kinase activity . The present study postulates that this method of screening selects double mutants defective in cytidine deaminase and in deoxycytidine kinase . To prove this hypothesis, the cdd mutant of S . typhimurium was constructed by P1-mediated transfer of ccd- gene into a new genetic background, and the activity of deoxycytidine kinase was assayed . Transductants exhibited no deoxycytidine kinase activity, showing that the absence of this enzyme is not limited to a specific cdd- mutant, but includes all strains of S . typhimurium . The toxicity of FdCyd for the bacterial strains possessing deoxycytidine kinase, as well as the role of nucleoside phosphorylase in nucleotide formation by S . typhimurium, is discussed. Nucleic Acids Res, 1977 Jun, 4(6), 1945 - 56 Biosynthesis of tRNA in histidine regulatory mutants of Salmonella typhimurium; Bossi L et al.; HisU mutants of Salmonella typhimurium are depressed in the histidine operon since they have lower intracellular concentration of histidyl-tRNAHis . In this paper we present evidences showing that a strain carrying a hisU mutation (hisUl206) is altered in a nucleolytic enzyme involved in tRNA maturation process . The analysis of several hisU mutants indicates that hisU region of bacterial genome may account for more than one function involved in tRNA biosynthesis. Acta Pathol Microbiol Scand {B}, 1977 Jun, 85(3), 212 - 8 The tendency of smooth and rough Salmonella typhimurium bacteria and lipopolysaccharide to hydrophobic and ionic interaction, as studied in aqueous polymer two-phase systems; Magnusson KE et al.; In aqueous two-phase system, the partition of bacteria and lipopolysaccharide from a rough (R) strain (Rd-mutant) of Salmonella typhimurium is influenced by polymers with covalently linked hydrophobic groups indicating hydrophobic structures accessible at the cell surface . Furthermore, the partition of the R bacteria is influenced by a number of inorganic positive and negative ions, presumably as a consequence of interaction with negatively charged surface structures . In contrast, smooth (S) bacteria and lipopolysaccharide from the parent strain do not seem to participate in either hydrophobic or charge interaction indicating extensive hydrophilicity without charge . Thus, the S-specific polysaccharide side chain of S . typhimurium might serve the purpose of blindfolding aspecific host defence mechanisms dependent on hydrophobicity and charge . On the contrary, the R bacteria and R lipopolysaccharide have physico-chemical properties which predispose to interaction with several types of cells, organelles and molecules. Genetics, 1977 Jun, 86(2 Pt . 1), 237 - 60 Ochre suppression in Salmonella typhimurium; Michalka J et al.; A bacterial strain was constructed which permitted positive selection for ochre suppressor mutations as well as for the loss of suppressor function . A derivative bearing an ochre suppressor mutation was selected following mutagenesis with N-methyl-N-nitroso-N'-nitroguanidine . The suppressor-bearing strain was treated with nitrous acid to eliminate suppressor function by mutation, and a strain lacking suppressor activity was selected . The selected strain which had lost suppressor function was then subjected to mutagenesis to induce a second suppressor mutation . The alternating sequence (induction of an ochre suppressor mutation leads to induction of a mutation eliminating ochre suppressor activity) was repeated 29 and one-half times in a single strain . Some of the suppressor mutations were tentatively mapped at four locations on the chromosome . The first suppressor mutation selected maps at about minute 30 on the chromosome . The second suppressor selected maps at approximately minute 60, while the third suppressor maps nearby, possibly as far as minute 72 . Among the subsequently selected suppressor mutations, all eleven which were mapped were cotransducible with the gal and nic loci near minute 36 on the chromosome and may represent more than one suppressor gene . Deletions were selected which inactivate two of the ochre suppressor alleles mapping near the gal-nic region, suggesting that one or more such genes are dispensable . Some evidence also suggests that the occurrence of either deletion mutations or transduction-mediated recombination events in the gal-nic region can cause instability of nearby suppressor alleles. Eur J Biochem, 1977 Jun 1, 76(1), 41 - 9 Isolation of mutants conditionally blocked in the biosynthesis of the 3-deoxy-D-manno-octulosonic-acid--lipid-A part of lipopolysaccharides derived from Salmonella typhimurium; Lehmann V et al.; A procedure is described for the selection of conditional 3-deoxy-D-manno-octulosonic-acid--Lipid A mutants which depends on temperature sensitivity for both synthesis of complete lipopolysaccharide and for growth . Using this procedure new types of mutants were isolated which cease growth and accumulate lipid A precursors following a shift to nonpermissive temperatures . All precursor molecules differ in their charge as judged by DEAE-cellulose chromatography . While they all contain glucosamine, phosphate and 3-hydroxymyristic acid, they lack detectable 3-deoxy-D-manno-octulosonic acid (dOclA) as well as the nonhydroxylated fatty acids of the complete lipid A structure . Three mutants proved to be conditionally defective in dOclA metabolism, whereas one seems to be blocked at a relatively early step in lipid A synthesis . The phenotypes of all these mutants appear to be due to single mutations by reversion analysis and by characterization of the temperature-resistant revertants . Studies of these mutants may shed light on the essential role of the complete dOclA--lipid A part of lipopolysaccharides in membrane function. Am J Vet Res, 1977 Jun, 38(6), 743 - 7 R factor types found in Salmonella typhimurium and Escherichia coli isolated from calves in a confined environment; Sato G et al.; Typing of R factors by genetic properties was done with Salmonella typhimurium and Escherichia coli isolated from calves on a feedlot where epizootics of clinical or subclinical calf salmonellosis had repeatedly occurred during 5 years . Forty-nine R factors from S typhimurium were fi- (no fertility inhibition) and spp- (no restriction against phage lambda vir) . Twenty-three (46.9%) of them belonged to compatibility group Ialpha and the remainder were nontypable . Fourteen R factors from E coli belonged to different genetic types: fi+ (11=78.6%) and fi- (3=21.4%); spp+ (1=7.1%) and spp- (13=92.9%); compatibility groups FII (5=35.7%), N (1=7.1%), and nontypable (8=57.2%) . In contrast to the R factors of S typhimurium, 9 (64.3%) of the 14 R factors of E coli carried resistance against aminobenzyl penicillin with or without kanamycin resistance . The compatibility groups of R factors of S typhimurium seemed to be useful as a subsidiary epizootiologic marker in this feedlot. Infect Immun, 1977 Jun, 16(3), 1005 - 12 Hepatic clearance of Salmonella typhimurium in silica-treated mice; Friedman RL et al.; Scanning electron microscopy demonstrates that crystalline silica destroys liver Kupffer cells but has no other obvious deleterious effects on the liver . Silica-treated livers still retain the ability to trap large numbers of bacteria perfused through the portal vein even though the rate of clearance is well below normal . In vivo, silica treatment decreases the rate of bacterial clearance from the blood, alters the in vivo organ distribution of cleared bacteria, and decreases the mean lethal dose of Salmonella typhimurium over 100-fold . Cumulatively, the data indicate that silica treatment enhances susceptibility to gram-negative infection, probably by destruction of macrophages. J Clin Invest, 1977 Jun, 59(6), 1188 - 95 Structural features of Salmonella typhimurium lipopolysaccharide required for activation of tissue factor in human mononuclear cells; Rickles FR et al.; Activation of mononuclear cell tissue factor was examined utilizing lipopolysaccharides obtained from wild-type and both Rc and Re mutants of Salmonella typhimurium . Wild-type (smooth) lipopolysaccharide, galactose-deficient (Rc) lipopolysaccharide, heptose-deficient (Re) lipopolysaccharide, and lipid A preparations were all active in their ability to generate tissue factor activity in human mononuclear cells grown in tissue culture . Polymyxin B has been reported to prevent some of the lethal effects of endotoxin in vivo, and the drug reportedly binds to the 2-keto-3-deoxyoctulosonate-lipid A region of the lipopolysaccharide molecule . Polymyxin B was effective in inhibiting the tissue factor generating activity of wild-type lipopolysaccharide, Re lipopolysaccharide, and lipid A in a dose-dependent fashion . Treatment of lipid A preparations with mild alkali abolished the ability of these preparations to activate tissue factor in cells . Analogous to many of the other biologic properties of lipopolysaccharide, tissue factor activation in human mononuclear cells appears to depend upon the integrity of the lipid A portion of the molecule. J Bacteriol, 1977 Jun, 130(3), 983 - 90 Regulation of enzyme synthesis by the glutamine synthetase of Salmonella typhimurium: a factor in addition to glutamine synthetase is required for activation of enzyme formation; Bloom FR et al.; In Klebsiella aerogenes but not in Salmonella typhimurium glutamine synthetase can function during nitrogen-limited growth to increase the rate of synthesis of histidase from the hut genes of S . typhimurium 15-59 (hutS . 15-59) . Formation of proline oxidase is also not increased in nitrogen-limited cultures of S . typhimurium . However, in hybrid strains of Escherichia coli or K . aerogenes, the glutamine synthetase of S . typhimurium activates synthesis of histidase from the hutS . 15-59 genes . Apparently, glutamine synthetase is necessary but not sufficient for activation of transcription of the hut genes; another factor must also be present . This factor is active in both K . aerogenes and E . coli but is missing or altered in S . typhimurium. Science, 1977 May 27, 196(4293), 1000 - 1 Mutagenic activity of nitrite-treated foods: human stomach cancer may be related to dietary factors; Marquardt H et al.; By the Salmonella typhimurium test, extracts of Japanese raw fish treated in the laboratory with nitrite showed mutagenic activity which is prevented by addition of ascorbate . Extracts from similarly treated beef and hot dogs were nonmutagenic . The data conform to a working concept that the high stomach cancer incidence in Japanese and certain other populations may be due to specific dietary factors of an alkylnitrosamide type. Biochemistry, 1977 May 17, 16(10), 2130 - 6 Sodium-dependent methyl 1-thio-beta-D-galactopyranoside transport in membrane vesicles isolated from Salmonella typhimurium; Tokuda H et al.; Membrane vesicles isolated from Salmonella typhimurium G-30 grown in the presence of melibiose catalyze methyl 1-thio-beta-D-galactopyranoside (TMG) transport in the presence of sodium or lithium, as shown initially with intact cells by Stock and Roseman (Stock, J., and Roseman, S . (1971), Biochem . Biophys . Res . Commun . 44, 132) . TMG-dependent sodium uptake is also observed, but only when a potassium diffusion potential (interior negative) is induced across the vesicle membrane . Cation-dependent TMG accumulation varies with the electrochemical gradient of protons generated as a result of D-lactate oxidation, and the vesicles catalyze D-lactate-dependent sodium efflux in a manner which is consistent with the operation of a proton-sodium exchange mechanism . Although the stoichiometry between sodium and TMG appears to be 1:1 when transport is induced by a potassium diffusion potential, evidence is presented which indicates that the relationship may exceed unity under certain conditions . The results are explained in terms of a model in which TMG-sodium (lithium) symport is driven by an electrochemical gradient of protons which functions to maintain a low intravesicular sodium or lithium concentration through proton--sodium (lithium) antiport. Eur J Biochem, 1977 May 2, 75(1), 257 - 66 Isolation, purification and properties of an intermediate in 3-deoxy-D-manno-octulosonic acid--lipid A biosynthesis; Lehmann V; Incomplete lipid A has been purified from a mutant of Salmonella typhimurium which is temperature-sensitive both in synthesis of 3-deoxy-D-manno-octulosonic acid 8-phosphate (dOclA-8-P) and in growth . Pulse-chase experiments have shown that the incomplete lipid A molecule is the intermediate in the biosynthesis of the dOclA-lipid A portion of lipopolysaccharides . The purification procedure included DEAE-cellulose chromatography and electrodialysis . A highly water-soluble precursor material was obtained, consisting of glucosamine, phosphate and 3-hydroxymyristic acid in a molar ratio of 1:1.2:2.1 . Labeling experiments as well as chemical degradation procedures revealed the precursor molecule to be composed of a diphosphorylated glucosamine-disaccharide carrying two amide-linked and two ester-linked 3-hydroxymyristic acids . In contrast to the complete dOclA-lipid A part, the intermediate lacks 3-deoxy-D-manno-octulosonic acid as well as nonhydroxylated fatty acids . On the basis of these findings a pathway for the final steps in dOclA-lipid A biosynthesis is proposed. Appl Environ Microbiol, 1977 May, 33(5), 1184 - 91 Methyl bromide as a microbicidal fumigant for tree nuts; Schade JE et al.; Methyl bromide (MeBr) has broad microbicidal activity, but its use as a disinfectant for food is limited by the resulting bromide residues . Increasing the MeBr concentration, exposure temperature, or exposure period of a treatment tended to increase both the microbicidal efficacy of MeBr and the bromide residues . Its sporicidal activity was less at high than at low relative humidity within the range of 20 to 99% . Both the efficacy and the resulting residues of a MeBr treatment varied inversely with the load of product in a fumigation chamber due to sorption of the fumigant . Fumigation tests with almond kernels inoculated with Escherichia coli or Salmonella typhimurium indicated that MeBr can be used to disinfect whole nut kernels without resulting in excessive bromide residues, although the MeBr level necessary is higher than that normally used for insect control. Infect Immun, 1977 May, 16(2), 493 - 9 Responsiveness of rabbit spleen and appendix cells to bacterial mitogens; Scheffel JW et al.; Rabbit spleen and appendix cells were used to test the mitogenic activity of a commercial lipopolysaccharide (LPS) preparation from Salmonella typhimurium (Difco), a preparation extracted from it, and cell wall preparations from smooth (45/0) and rough (45/20) strains of Brucella abortus . On the basis of {3H}thymidine incorporation ratios (E/C), that is, the incorporation rate among cells treated with the mitogen relative to that of untreated cells, the extracted LPS and both Brucella cell wall preparations, but not the commercial LPS were potent mitogens for rabbit spleen cells . By the same criterion, only the Brucella cell wall preparation produced a significant, but minimally so, response among appendix cells . The weak responsiveness of appendix cells may be more apparent than real, however, and may not imply a difference in intrinsic susceptibility to mitogens by these two populations, because unstimulated appendix cells incorporated thymidine at 10 times the rate of unstimulated spleen cells . Appendix cells, then, may not be susceptible to further stimulation, even by active mitogens . Therefore, the significance of E/C ratios may be equivocal when materials are assayed for mitogenic activity on lymphoid populations whose basal activity is relatively high. J Bacteriol, 1977 May, 130(2), 604 - 9 Influence on motility of Escherichia coli and Salmonella typhimurium by a naturally occurring conjugative plasmid; Bohlin T et al.; In a collection of 45 R-plasmids, one was found to be associated with loss of motility of its Escherichia coli K-12 and Salmonella typhimurium host bacteria when tested in conventional motility agar . Genetic experiments, as well as analyses of deoxyribonucleic acid, showed that inhibition of motility was caused by a conjugative plasmid that was separate from the R-plasmid . This second plasmid, named pUM5, was fi- and mediated the same type of sex pilus (F-like) as the accompanying R-plasmid but lacked resistance determinants . Preliminary studies indicated that bacterial cells carrying the motility inhibition plasmid pUM5 were still equipped with flagella . The mechanism by which flagellar action is disturbed by the plasmid is presently not known. J Bacteriol, 1977 May, 130(2), 577 - 82 Suppression of the DnaA phenotype by mutations in the rpoB cistron of ribonucleic acid polymerase in Salmonella typhimurium and Escherichia coli; Bagdasarian MM et al.; A class of mutations that confer resistance to rifampin in Salmonella typhimurium and Escherichia coli also suppresses the thermosensitivity of chromosome initiation in dnaA mutants . Ribonucleic acid polymerase is resistant to rifampin in vitro in these suppressive mutants, and the suppressors of dnaA cannot be separated from the rpoB mutations by transduction . It is concluded, therefore, that certain rpoB mutations may suppress the DnaA phenotype. Ann Sclavo, 1977 May-Jun, 19(3), 402 - 8 {Ulterior acquisitions regarding the salmonellosis (author's transl)}; Cipolloni AP et al.; The Authors report the results of the bacteriological researches on the incidence of the Salmonella of our zone, after a brief consideration of general aspects salmonellosis . Our observations are refered to 1005 samples of feces of which 84 cases proved positive to Salmonella . It is pointed out that morbidity, represented by Salmonella typhi, paratyphi A and B is low, while it is high for the Salmonella typhimurium and Salmonella enteritidis . The Authors conclude stating that epidemiological situation of salmonellosis still represents a problem of remarkable importance which demands the intensification and the use of efficacious measures of prophylaxis. Poult Sci, 1977 May, 56(3), 1041 - 2 Degeneration of the mucosal surface of the small intestine of the chicken in Salmonella infection; Bayer RC et al.; Day-old chicks were infected with Salmonella typhimurium . The impact on the intestinal mucosa was observed by scanning and transmission electron microscopy . Salmonella infected birds were characterized as having areas on their intestinal mucosal cells devoid of microvilli . The absence of microvilli probably interferes with absorption of the digesta. Zh Mikrobiol Epidemiol Immunobiol, 1977 May, (5), 37 - 42 {Change in the protective activity of the ribosomal fractions of Salmonella typhimurium in mutations in the rfa region and the transduction replacement of the rfb region}; Likhoded VG et al.; It was shown that mutation in the rfa region causing disturbances in the structure of the basal part of the polysaccharide of the cell wall or the absence of O-specific side chains led to the loss of protective activity of the ribosomal fractions isolated from the cells of the murine typhoid salmonella by sedimentation with dihydrostreptomycine sulphate . Ribosomal fractions isolated from the murine typhoid salmonella transductants with the replaced rfb region failed to protect the animals from the infection with the virulent . S . typhimurium, S . enteritidis cultures . The virulence of the mutants and transductants was also changed in comparison with the initial strains. Proc Natl Acad Sci U S A, 1977 May, 74(5), 1932 - 6 Use of a distant reporter group as evidence for a conformational change in a sensory receptor; Zukin RS et al.; A highly sensitive method for demonstrating ligand-induced conformational changes in protein molecules in solution is described . The method utilizes an environmentally sensitive reporter group that is known to be distant from the active site . In the present application a conformational change is demonstrated in the galactose receptor of Salmonella typhimurium, involved in bacterial sensing and transport, by means of an extrinsic fluorophore, 5-iodoacetamidofluorescein, attached at a single methionine residue, and the intrinsic tryptophan fluorophore . Binding of the ligand galactose perturbs the microenvironment of both the fluorescein and tryptophan, as shown by both spectral and potassium iodide quenching changes . The distance between the two dyes is established by fluorescence energy transfer methods to be 41 +/- 10A . Since only one molecule of galactose binds per molecule of receptor and since the galactose molecule is only about 5 A in length, changes at one of these sites reflect the result of an indirect effect . Hence, there must be a ligand-induced conformational change that is propagated a minimum of 30 A through the receptor molecule. Proc Natl Acad Sci U S A, 1977 May, 74(5), 1836 - 40 A gene from Escherichia coli affecting the sigma subunit of RNA polymerase; Harris JD et al.; The RNA polymerase sigma subunits of Escherichia coli K, E . coli C, and Salmonella typhimurium can be resolved by electrophoresis . Using this technique, we have analyzed Salmonella strains carrying F' plasmids from E . coli K in order to map the gene for the sigma factor . Partial diploid analyses show the location of the sigma gene at 62-66 min on the E . coli genetic map . This gene is cotransducible with toIC and dnaG, at 66 min. Proc Natl Acad Sci U S A, 1977 May, 74(5), 1831 - 5 Chromosomal location of a structural gene for the RNA polymerase sigma factor in Escherichia coli; Nakamura Y et al.; A set of F' strains of Escherichia coli K-12 partially diploid for various chromosomal segments has been examined for possible gene dosage effects in the synthesis of sigma factor of the DNA-dependent RNA polymerase (RNA nucleotidyltransferase; nucleoside-triphosphate:RNA nucleoti-dyltransferase, EC 2.7.7.6) . It was found that all F' strains diploid for the dnaG region synthesize sigma at rates two to three times higher than other F' or F- strains . Moreover, strains of Salmonella typhimurium harboring these F' plasmids produce E . coli sigma in addition to Salmonella sigma . This has been shown on the basis of the finding that Salmonella sigma can be precipitated with antiserum against E . coli RNA polymerase but is distinguishable from E . coli sigma in its mobility in sodium dodecyl sulfate/polyacrylamide gel electrophoresis . E . coli sigma polypeptides thus produced seem to be stable in cells of S . typhimurium . These results indicate that a structural gene for sigma (rpoD) is located at the metC-argG region, probably near the dnaG locus (66 min on the current genetic map of E . coli). Cancer Lett, 1977 May, 2(6), 335 - 9 Mutagenicities of protein pyrolysates; Nagao M et al.; Smoke condensate obtained by pyrolysis of proteins, such as lysozyme and histone, was shown to be mutagenic to Salmonella typhimurium TA100 and TA98 . In vitro metabolic activation by a mammaliam postmitochondrial enzyme preparation (S-9 Mix) was required . Smoke condensates obtained by pyrolysis of DNA, RNA, starch and vegetable oil were slightly mutagenic, whereas those from pyrolysis of L- and D-tryptophan and 5-hydroxy-D,L-tryptophan were very strongly mutagenic with metabolic activation by S-9 Mix . Because of the high correlation between mutagenicity and carcinogenicity, it is theorized that the cooking of proteinaceous foods might be an important cause of human cancers. Cancer Lett, 1977 May, 2(6), 319 - 22 Inhibitory effects of selenium of the mutagenicity of 2-acetylaminofluorene (AAF) and AAF derivatives; Jacobs MM et al.; Selenium (Se) decreased the mutagenicity of 2-acetylaminofluorene (AAF), N-hydroxy-2-acetylaminofluorene (N-OH-AAF) and N-hydroxyaminofluorene (N-OH-AF) in the Salmonella typhimurium TA 1538 bacterial tester system . Metabolism of AAF and N-OH-AFF to the active mutagen, N-OH-AF, was accomplished by rat liver extracts . Graded decreases in mutagenicity with increasing Se concentrations were observed for each of the three mutagens . Se decreased the mutagenicity of AAF, N-OH-AAF and N-OH-AF to 65, 68 and 61% of their respective controls with mutagen alone . The effective molar ratios of Se to mutagen yielding these decreases were approximately 10:1 (Se:AAF), 10:1 (Se:N-OH-AAF) and 300:1 (Se:N-OH-AF) . The largest Se effect observed was accomplished by a molar ratio of 100:1 (Se:N-OH-AAF) yielding 28% of the mutagenicity elicited by N-OH-AAF alone. Cancer Lett, 1977 May, 2(6), 305 - 10 The mutagenicity of methylbenzylnitrosamine and its alpha-acetoxy derivatives; Tannenbaum SR et al.; Biological activity of the alpha-acetoxy derivatives of methylbenzylnitrosamine was evaluated using tester strains of Salmonella typhimurium . Compound III, oxidized on the benzyl moiety, was more toxic and more mutagenic than Compound IV, oxidized on the methyl side chain . Compound IV was weakly toxic and was non-mutagenic at the concentrations tested . The presence or absence of the uvrB repair system had no effect on the toxicity of either Compound II or IV . Neither the alpha-oxidized compounds nor the parent nitrosamine reverted the frameshift mutants . As a mutagen, Compound III was approximately as active as N-nitroso compounds not requiring metabolic activation, more active than alpha-acetoxy dialkylnitrosamines and less active than the cyclic alpha-acetoxynitrosopyrrolidine. J Infect Dis, 1977 May, 135(5), 813 - 23 Protective effects of passively transferred immune T- or B-lymphocytes in mice infected with Salmonella typhimurium; Hochadel JF et al.; Purified populations of bone marrow-derived (B-) lymphocytes and thymus-derived (T-) lymphocytes were obtained from C3D2F1 hybrid mice shown to be immune to Salmonella typhimurium . These subpopulations of lymphocytes were injected into normal mice; four days later the animals were challenged with 50 50% lethal doses of S . typhimurium, and viable bacteria in livers, spleens, and blood were counted at various intervals after challenge . On day 8 after challenge, the mice supplemented with B-lymphocytes showed a significant decrease in the number of organisms recovered from all three sites, compared with that seen in recipients of T-lymphocytes and in controls . The mice given B-lymphocytes showed a better rate of survival (65%) than mice that received only T-lymphocytes (21%) or T-lymphocyte fractions contaminated 10%-30% with B-lymphocytes (49%) . These data indicate that, although the humoral response is not totally protective, it does play an important role in the suppression of the infection during its early stages. Cancer Res, 1977 May, 37(5), 1468 - 75 Comparative electrophilicity, mutagenicity, DNA repair induction activity, and carcinogenicity of some N- and O-acyl derivatives of N-hydroxy-2-aminoflourene; Bartsch H et al.; N-Myristoyloxy-N-acetyl-2-aminofluorene, N-acetoxy-N-myristoyl-2-aminofluorene, N-myristoyloxy-N-myristoyl-2-aminofluorene, and N-hydroxy-N-myristoyl-2-aminofluorene each yielded a high incidence of sarcomas in male rats within 5 to 7 months after s.c . injection of 64 micronmoles in divided doses . N-Acetoxy-N-acetyl-2-aminofluorene and N-hydroxy-2-acetylaminofluorene, although potent carcinogens at the s.c . site, were less active than the above derivatives with a myristoyl substituent . N-Sulfonoxy-N-acety--2-aminofluorene (purity larger than or equal to 70%) had little or no carcinogenic activity when administered in large amounts by s.c . injection to rats . The low incidence of tumors could have resulted from N-hydroxy-2-acetylaminofluorene or other decompostion products of the N-sulfonozy derivative . Each of the N-acetoxy and N-myristoyloxy derivatives of N-acetyl-2-aminofluorene and of N-myristoyl-2-aminofluorene showed electrophilic activity toward methionine; N-acetoxy-N-acetyl-2-aminofluorene was the most reactive and N-myristoyloxy-N-myristoyl-2-aminofluorine was the least reactive . Each of these esters also induced unscheduled tritiated thymidine incorportation in nondividing cultured human fibroblasts and thus appeared to induce lesions in DNA that lead to repair synthesis.EACH OF THE N-acetoxy derivatives was highly mutagenic for Salmonella typhimurium strains TA98 and TA1538 without tissue activation; neither N-myristoyloxy derivative was mutagenic under these conditions . While there was a qualitative correspondence between several of the above activities of these 2-aminofluorene derivatives, the quantitative differences and the lack of detectable mutagenicity of the 2N-myristoyloxy derivatives for S . typhimurium indicate the need for multiple short-term tests in the qualitative prediction of potential carcinogenic activity. Mutat Res, 1977 May, 43(2), 159 - 64 Asbestos and glass fibres in bacterial mutation tests; Chamberlain M et al.; Asbestos fibres are carcinogenic in man and experimental animals but fine glass fibres are known, at present, only to be carcinogenic in experimental animals . Asbestos and glass fibres have been studied in mutation tests using auxotrophic strains of Escherichia coli and Salmonella typhimurium . The mutagenic activities of the positive control mutagens ultraviolet light, potassium chromate, ethyl methanesulphonate and benzo(a)pyrene were detected in the experiments . However, no mutagenic activity was found to be associted with any of the asbestos and glass fibres tested over a wide range of concentrations . The implications of these findings for the mode of action of asbestos and glass fibres as carcinogens are discussed. Anesthesiology, 1977 May, 46(5), 346 - 50 Mutagenicity of halogenated ether anesthetics; Baden JM et al.; An in vitro microbial assay system employing two histidine-dependent strains of Salmonella typhimurium, TA1535 and TA100, was used to test the mutagenicities of enflurane, methoxyflurane, isoflurane and fluroxene . Enflurane, isoflurane and fluroxene in concentrations ranging from 0.01 to 30 per cent and methoxyflurane in concentrations ranging from 0.01 to 7 per cent were incubated with bacteria in the presence or absence of homogenates of liver prepared from rats pretreated with the enzyme inducer, Aroclor 1254 . Enflurane, methoxyflurane, isoflurane, and urines from patients anesthetized with these agents were not mutagenic . Fluroxene, however, was highly mutagenic, and therefore poses a possible hazard for operating room personnel and patients. J Biol Chem, 1977 Apr 25, 252(8), 2793 - 5 Identification of a gamma-glutamyl methyl ester in bacterial membrane protein involved in chemotaxis; Van Der Werf P et al.; Evidence is presented that a methyltransferase enzyme, previously shown to be necessary for chemotaxis and identified as the cheR gene product, catalyzes the formation of a gamma-glutamyl methyl ester in one or more membrane proteins of Salmonella typhimurium . The rates of release of methyl label from the methylated protein in acid, base, and hydroxylamine are consistent with a methyl ester and not with a methylated imidazole, guanidino, or amino group . A gamma-glutamyl methyl ester was isolated from a proteolytic digest of the modified protein. Biochemistry, 1977 Apr 5, 16(7), 1443 - 51 Nuclear magnetic resonance and fluorescence studies of substrate-induced conformational changes of histidine-binding protein J of Salmonella typhimurium; Robertson DE et al.; The histidine-binding protein J of Salmonella typhimurium binds L-histidine as a first step in the high-affinity active transport of this amino acid across the cytoplasmic membrane . High-resolution nuclear magnetic resonance spectroscopy has been used to monitor the conformation of histidine-binding protein J in the presence and absence of substrate . Evidence is presented to show that this binding protein undergoes a conformational change involving a substantial number of amino-acid residues (including tryptophans) in the presence of L-histidine and that this change is specific for L-histidine . In order to monitor the involvement of tryptophan residues in the substrate-induced conformational change, 5-fluorotryptophan has been incorporated biosynthetically into the histidine-binding protein J using a tryptophan autotroph of Salmonella typhimurium . There are no significant differences in the conformation and binding activity between the 5-fluorotryptophan-labeled and the normal histidine-binding protein J . Proton and fluorine-19 nuclear magnetic resonance studies of the 5-fluorotryptophan-labeled binding protein show that at least one (and possibly two) of the tryptophan residues undergo(es) a change toward a more hydrophobic environment in the presence of L-histidine . These observations are supported by fluorescence data and by differences in the reactivity of the tryptophan residues of this protein toward N-bromosuccinimide in the presence and absence of substrate . The present results are consistent with models for the action of periplasmic-binding proteins in shock-sensitive transport systems of gram-negative bacteria which require a substrate-induced conformational change prior to the energy-dependent translocation of substrates. Mutat Res, 1977 Apr, 48(2), 121 - 9 Mutagenicities of N-nitrosamines on Salmonella; Yahagi T et al.; The mutagenic activities of 11 N-nitrosamines were tested using Salmonella typhimurium TA100 and TA98 . All the carcinogenic N-nitrosamines were mutagenic on TA100 with a drug-activating system from the rat liver, whereas N,N-diphenylnitrosamine, a non-carcinogen, was not mutagenic . None of the N-nitrosamines was mutagenic on TA98, except N,N-diethylnitrosamine which was weakly mutagenic . To detect the mutagenicity of N,N-dimethylnitrosamine, the pre-incubation of bacteria and N,N-dimethylnitrosamine with S-9 Mix before if was poured onto plates was obligatorily required . Dimethyl sulfoxide inhibited the mutagenic effect of N,N-dimethylnitrosamine. Mikrobiyol Bul, 1977 Apr, 11(2), 287 - 90 {Salmonella typhimurium isolated from the spinal fluid of 2 children}; Meco O et al.; In this article isolation of S . typhimurium bacteria from cebrospinal fluid of two children is reported. Mutat Res, 1977 Apr, 48(2), 237 - 48 Detection of mutagenic activity in particulate air pollutants; Tokiwa H et al.; Ames's strains of Salmonella typhimurium were used to evaluate the mutagenic activity of airbone particulate materials collected at six different points in the industrial area of Ohmuta and the residential area Fukuoka . Tests were done in presence of rat-liver S-9 fraction isolated from rats that had been treated with Aroclor 1254 . When the number of revertant colonies per plate was plotted against the amount of methanol extract of particulate air pollutants, using strain TA98, approximately linear relationships were observed for active samples . Generally, mutagenic activity of the samples increased in proportion to the density of air pollutants . In our system, 38--349 microng of methanol extract, from 0.225--4.51 m3 of air from the factory districts in Ohmuta City gave 100 his+ revertants per plate . On the other hand, 54--2300 microng of air pollutants, from 1.29--14.1 m3 of air from the residential districts in Fukuoka City, gave a comparable activity . Every sample from each area had mutagenic activity . Chemicals in air pollutants were fractionated by alumina column chromatography and identified by gas chromatography and mass spectrometry . More than 28 compounds, including 12 unknown substances were identified as polycyclic hydrocarbons . Twelve of these compounds are already known to be carcinogens and to induce reversions to histidine independence in strain TA98 of Salmonella. Mutat Res, 1977 Apr, 48(2), 145 - 53 Mutagenicity of anti-cancer nitrobenzofuroxans; Thompson S et al.; Anti-leukaemically active benzofuroxans were tested for mutagenicity in Salmonella typhimurium . Mutagenicity was not found to be correlated to the previously established anti-leukaemic activity . One anti-leukaemically inactive compound after exposure to liver microsomal enzymes proved the most mutagenic of the derivatives for TA100, whereas after similar treatment, the mutagenicity of the most potent anti-leukaemic compound was reduced . All twelve derivatives tested were mutagenic in a base-substitution strain which was defective in excision-repair and also carried a plasmid-linked repair deficiency . Mutagenicity of five dervatives was undetectable in strains proficient for one or the other of the above repair pathways . Nine of the benzofuroxans could also be detected as mutagens in the frameshift tester strain TA98. Mutat Res, 1977 Apr, 48(2), 139 - 43 Relative efficiencies of a series of square-planar plantinum(II) compounds on Salmonella mutagenesis; Lecointe P et al.; Twelve Pt(II) compounds have been tested for mutagenicity on Salmonella typhimurium (strain TA 100) . Very high mutagenic activities were found for the cis derivatives . A correlation is suggested between these results and a formerly described model of chemical reactivity towards DNA, according to which cis derivatives from intra-strand chelates with guanine . A smaller activity was found with monodentate complexes with DNA. Mutat Res, 1977 Apr, 46(2), 53 - 6 The use of rec-bacteria for testing of carcinogenic substances; Ichinotsubo D et al.; A series of rec-Escherichia coli strains were tested for their sensitivity to four known carcinogenic compounds by examination of a zone of inhibited bacterial growth around a central well containing the test chemical . The mutants recA-, recB-, recC-, and recA- recB- recC- were all more sensitive to the mutagens than the parental strain AB1157 . The recB- recC- strain was examined with a larger series of compounds and was found to respond to many of the substances in a similar way as the Salmonella typhimurium strains of Ames but with some notable exceptions . Nitrosamines, with rat liver microsomal activation, could be detected at lower levels and a group of aromatic amino compounds failed to react with these rec-E . coli . An unusual feature of these rec-mutants is their sensitivity to mixtures of nitrosamines and 2-acetyl amino-fluorene in the absence of microsomal activation. Appl Environ Microbiol, 1977 Apr, 33(4), 947 - 54 Use of enzyme-labeled antibodies to detect Salmonella in foods; Krysinski EP et al.; An indirect enzyme-labeled antibody technique (ELAT), in which Salmonella typhimurium was used as a model, was developed as a method to detect Salmonella in food samples . A cellulose-acetate membrane filter, the matrix for detection, was placed on a membrane-filter base and overlaid with a multiwelled lucite template . Mixed broth enrichment cultures were dispensed in the template wells, and cells were spotted onto the membrane via suction . After fixation, the membranes were immersed in rabbit anti-S . typhimurium flagella antibody, washed, immersed in goat anti-rabbit antibody conjugated to peroxidase, and washed . Exposure of membranes to the substrates 3,3'-diaminobenzidine or benzidine resulted in development of brown or blue macroscopic reaction products, respectively, on spots containing S . typhimurium . ELAT results agreed with those of enrichment serology and cultural procedures on three food products containing known levels of S . typhimurium . Because of the magnification effect of the enzyme-substrate reaction, fewer cells were needed for detection than with enrichment serology, thereby reducing the total analysis time . The ability to test 14 or more samples simultaneously on a 47-mm membrane filter would facilitate screening large number of samples . Pending the development of a pure H antisera pool for the common Salmonella serotypes free from O antibodies, the ELAT demonstrated potential as a Salmonella detection methodology. Zh Mikrobiol Epidemiol Immunobiol, 1977 Apr, (4), 86 - 91 {Change in phagocytic activity toward the agent of tularemia in highly sensitive animals with mixed infections}; Dunaeva TN et al.; An increase of the ingestive and digestive capacity of neutrophils to the homologous causative agent and tularemia microbe was revealed by the opsonophagocytic test in Microtus arvalis, albino mice and guinea pigs infected with sublethal Yersinia pseudotuberculosis and Salmonella typhimurium doses . In subsequent tularemia infection some of the animals displayed a reduction of the septicemia intensity, prolongation of the disease and elevation of the susceptibility threshold . Period of manifestation of the inhibitory action on tularemia coincided with that of the increase in phagocytic activity Proc Natl Acad Sci U S A, 1977 Apr, 74(4), 1535 - 7 Inhibition of histidyl-tRNA-adenosine triphosphate phosphoribosyltransferase complex formation by histidine and by guanosine tetraphosphate; Kleeman JE et al.; Formation of the complex between the first enzyme of histidine biosynthesis from Salmonella typhimurium, ATP phosphoribosyltransferase {1-(5'-phosphoribosyl)-ATP: pyrophosphate phosphoribosyltransferase; EC 2.4.2.17}, and histidyl-tRNA is shown to be inhibited by L-histidine and by guanosine-5'-diphosphate-3'-diphosphate in the presence of histidine . Higher histodine levels make guanosine tetraphosphate a more effective inhibitor . Relatively high concentrations of guanosine-5'-triphosphate also inhibit complex formation, but this inhibition is not enhanced by histidine . The possible implications of these observations with respect to the gene regulatory activity of this enzyme are discussed. J Bacteriol, 1977 Apr, 130(1), 347 - 53 Degradation of Escherichia coli beta-galactosidase fragments in protease-deficient mutants of Salmonella typhimurium; Miller CG et al.; The degradation rates of several mutationally generated fragments of Escherichia coli beta-galactosidase were determined in wild-type strains of Salmonella typhimurium and in mutant Salmonella strains lacking several proteases and peptidases . Three termination fragments (produced by lacZ545, lacZ521, and lacZX90) and one internal reinitiation (restart) fragment {lacZpi(1)} are degraded in wild-type Salmonella strains at the same rates observed in wild-type Escherichia coli strains . Mutations that lead to loss of peptidases N, A, B, P, and Q or to loss of protease I or II do not affect the decay rates of any of these fragments . In addition, all of these peptidases and proteases are present in E coli mutants carrying deg mutations (deg mutations are known to stabilize beta-galactosidase fragments) . Apparently, none of the proteases and peptidases that are currently accessible to direct genetic analysis plays a role in the early steps of the degradation of protein fragments. J Bacteriol, 1977 Apr, 130(1), 223 - 31 Chemotactic mechanism of Salmonella typhimurium: preliminary mapping and characterization of mutants; Warrick HM et al.; Some new, generally nonchemotactic mutants of Salmonella typhimurium were isolated and they, together with previously isolated mutants and some from other investigators, were mapped . Most of the mutants were classified in nine complementation groups, which are probably individual genes . Of these, five map at the end of the flagella region and appear in the order motB-(cheWcheP)-cheX-cheQ-cheR-flaC . Two of the mutations, cheU and cheV, map in the flaQ and flaAII genes, respectively . The remaining genes, cheS and cheT, have not yet been mapped . Most of the mutants are phenotypically smoothly swimming, but some are constantly tumbling . Two of the groups show dominant behavior as recipients in genetic crosses; the rest are recessive . The mutants vary in their responses to stimuli but, since their responses to all chemoeffectors are abnormal, the central processing, rather than individual, receptors must be impaired . The two mutations that coincide with genes for flagella probably involve the locus of the final delivery of sensing signal to the flagella. J Bacteriol, 1977 Apr, 130(1), 420 - 8 Regulation of two phosphatases and a cyclic phosphodiesterase of Salmonella typhimurium; Kier LD et al.; The regulation of three Salmonella typhimurium phosphatases in reponse to different nutritional limitations has been studied . Two enzymes, an acid hexose phosphatase (EC 3.1.3.2) and a cyclic phosphodiesterase (EC 3.1.4.d), appear to be regulated by the cyclic adenosine 3' ,5'-monophosphate (AMP) catabolite repression system . Levels of these enzymes increased in cells grown on poor carbon sources but not in cells grown on poor nitrogen or phosphorus sources . Mutants lacking adenyl cyclase did not produce elevated levels of these enzymes in response to carbon limitation unless cyclic AMP was supplied . Mutants lacking the cyclic AMP receptor protein did not produce elevated levels of these enzymes in response to carbon limitation regardless of the presence of cyclic AMP . Since no specific induction of either enzyme could be demonstrated, these enzymes appear to be controlled solely by the cyclic AMP system . Nonspecific acid phsphatase activity (EC 3.1.3.2) increased in response to carbon, nitrogen, phosphorus, or sulfur limitation . The extent of the increase depended on growth rate, with slower growth rates favoring greater increases, and on the type of limitation . Limitation for either carbon or phosphorus resulted in maximum increases, whereas severe limitation of Mg2+ caused only a slight increase . The increase in nonspecific acid phosphatase during carbon limitation was apparently not mediated by the catabolite repression system since mutants lacking adenyl cyclase or the cyclic AMP receptor protein still produced elevated levels of this enzyme during carbon starvation . Nor did the increase during phosphorus limitation appear to be mediated by the alkaline phosphatase regulatory system . A strain of Salmonella bearing a chromosomal mutation, which caused constitutive production of alkaline phosphatase (introduced by an episome from Escherichia coli), did not have constitutive levels of nonspecific acid phosphatase. J Bacteriol, 1977 Apr, 130(1), 399 - 410 Resolution and purification of three periplasmic phosphatases of Salmonella typhimurium; Kier LD et al.; A survey of Salmonella typhimurium enzymes possessing phosphatase or phosphodiesterase activity was made using several different growth conditions . These studies revealed the presence of three major enzymes, all of which were subsequently purified: a cyclic 2' ,3'-nucleotide phosphodiesterase (EC 3.1.4.d), an acid hexose phosphatase (EC 3.1.3.2), and a nonspecific acid phosphatase (EC 3.1.3.2) . A fourth enzyme hydrolyzed bis-(p-nitrophenyl)phosphate but none of the other substrates tested . No evidence was found for the existence of an alkaline phosphatase (EC 3.1.3.1) or a specific 5'-nucleotidase (EC 3.1.3.5) in S . typhimurium LT2 . All three phosphatases could be measured efficiently in intact cells, which suggested a periplasmic location; however, they were not readily released by osmotic shock procedures . The nonspecific acid phosphatase, which was purified to apparent homogeneity, yielded a single polypeptide band on both sodium dodecyl sulfate and acidic urea gel electrophoretic systems. J Bacteriol, 1977 Apr, 130(1), 192 - 9 Transcription of the hut operons of Salmonella typhimurium; Cooper TG et al.; We have measured, by ribonucleic acid-deoxyribonucleic acid hybrid formation, the amounts of hut-specific ribonucleic acid contained in extracts of various mutant strains of Salmonella typhimurium . Our data are consistent with a model in which regulation of Hut enzyme production occurs at the level of transcription and support earlier genetic evidence indicating that all of the hut genes are transcribed in the clockwise direction on the S . typhimurium chromosome . These results also suggest that promoter sites of the two hut operons may differ in their ability to initiate transcription. Cancer Res, 1977 Apr, 37(4), 1112 - 4 Light-induced mutagenicity of neutral red (3-amino-7-dimethylamino-2-methylphenazine hydrochloride); Gutter B et al.; Illumination of Salmonella typhimurium in the presence of neutral red (3-amino-7-dimethylamino-2-methylphenazine hydrochloride) results in mutations of the base substitution type. Mutat Res, 1977 Apr, 48(2), 225 - 36 Nitrosation in vitro and in vivo by sodium nitrite, and mutagenicity of nitrogenous pesticides; Seiler JP; 37 nitrogenous pesticides, belonging to the chemical groups of amides, carbamates and ureas, were nitrosated with sodium nitrite in vitro . The nitrosated compounds were tested for mutagenic activity in the bacterial spot test with Salmonella typhimurium his G 46 . Those pesticides reacting positively in this test after nitrosation were then fed to mice in combination with sodium nitrite in order to assess the formation and mutagenicity of these nitroso compounds in vivo . With the already known exception of ethylenethiourea (ETU), no pesticide produced enhanced numbers of micronuclei in mouse bone-marrow erythrocytes when fed together with nitrite . Dose-response experiments with intraperitoneal injection of N-nitroso-ETU revealed an apparent no-effect level of about 15--18 mg/kg . The findings are correlated with the pesticide residues actually present in the environment. Mutat Res, 1977 Apr, 48(2), 131 - 8 Mutagenicity of 22 N-nitrosamides and related compounds for Salmonella typhimurium TA1535; Lee K et al.; Twenty-two N-nitrosamides and related compounds, including 14 nitrosoureas, 5 nitrosocarbamates, and one nitrosocyanamide, were tested at various concentrations for mutagenic activity towards Salmonella typhimurium TA1535 without the use of microsomes . The ether-water partition coefficient, solubility in water, and half-life in aqueous solution were also measured . Twenty compounds were mutagenic, with "standard mutagenic concentrations" (i.e . those producing 100 mutants/dish) of 0.0024--6500 micron . Standard mutagenic concentration was negatively correlated with the partition coefficient . Three compounds (ethyl 2-acetoxyethylnitrosocarbamate, nitrosocarbaryl, and methylnitrosobenzamide) were more active than the classic mutagen methylnitrosonitroguanidine . Nitrosocarbamates were at least 50 times more mutagenic than the corresponding nitrosoureas . Nitrosodihydrouracil and propylene-nitrosourea were more active than related compounds . Ethylnitrosocyanamide was 730 times more mutagenic than ethylnitrosourea . Fifteen of the test compounds (of which 14 were mutagenic) had previously been assayed in rats for carcinogenicity, all with positive results. Proc Natl Acad Sci U S A, 1977 Apr, 74(4), 1662 - 6 The product of a newly identified gene, gInF, is required for synthesis of glutamine synthetase in Salmonella; Garcia E et al.; The product of a newly identified gene, glnF, which is distinct from the glutamine synthetase structural gene (glnA), is required for synthesis of glutamine synthetase {L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2{ in Salmonella typhimurium and probably in Escherichia coli . Salmonella strains with ICR (2-chloro-6-methoxy-9-{3-(2-chloroethyl)aminopropylamino}acridine dihyodrochloride)-induced (frameshift) mutations in glnF are glutamine auxotrophs; they have less than 10% oof wild-type glutamine synthetase activity or antigen and are unable to derepress the synthesis of the enzyme . The mutant allele is recessive to the wild-type allele, indicating that the glnF gene encodes a diffusible product . Mutant glnF strains have normal activities of all proteins involved in covalent modification of glutamine synthetase: adenylyltransferase (EC 2.7.7.42), PII, uridylyltransferase, and uridylyl removing enzyme . In addition, they have glutamate synthase (EC 1.4.1.13) and glutamate dehydrogenase (EC 1.4.1.4) activities . Thus, glnF does not encode the structure of any of these proteins . The above evidence suggests that the product of the glnF gene is (or produces) a positive regulatory factor that is required for synthesis of glutamine synthetase; it indicates that auto-regulation cannot account for control of the synthesis of glutamine synthetase in Salmonella. J Bacteriol, 1977 Apr, 130(1), 411 - 9 Properties of two phosphatases and a cyclic phosphodiesterase of Salmonella typhimurium; Weppelman R et al.; The properties of three phosphatases from Salmonella typhimurium have been examined . A cyclic 2',3'-nucleotide phosphodiesterase (EC 3.1.4.d) hydrolyzes cyclic 2',3'-purine and -pyrimidine nucleotides, as well as 3'-mononucleotides, and has a pH optimum of about 7.5 . It requires divalent cations for activity and has a molecular weight of 67,000 . Acid hexose phosphatase (EC 3.1.2.2) possesses activity towards hexose phosphates as well as other sugar phosphates . The enzyme is apparently a dimer of 37,000-dalton subunits . Nonspecific acid phosphatase (EC 3.1.3.2) hydrolyzes a variety of phosphate esters, including nucleotides and sugar phosphates . The enzyme also hydrolyzes the phosphoric anhydride bonds of pyrophosphate and nucleotides . Michaelis constants of the nonspecific acid phosphatase for several of its substrates are in the 1 to 2 mM range . Nonspecific acid phosphatase is a dimer of 27,000-dalton subunits. Biochim Biophys Acta, 1977 Mar 29, 497(1), 323 - 8 The origin of the sulfur atom in thiamine; Bellion E et al.; The mode of biosynthesis of the thiazole moiety of thiamine, 4-methyl-5beta-hydroxyethyl thiazole (MHET) was studied using Salmonella typhimurium as test organism . It was shown by isotope incorporation experiments, that the sulfur atom, but not carbon-3, of cysteine is incorporated into MHET, indicating a separation of the sulfur atom of cysteine from the carbon chain during incorporation . Isotope competition experiments revealed that the incorporation of {35S}cysteine is not significantly diluted by the presence of methionine, homocysteine, and glutathione . No incorporation of label from {14C}glutamate and {14C}formate was observed, leaving the origin of the five-carbon unit still in doubt. Biochim Biophys Acta, 1977 Mar 18, 475(2), 267 - 75 Partial derepression of the isoleucine-valine enzymes during methionine starvation is Salmonella typhimurium; Rizzino A et al.; Methionine starvation of methionine auxotrophs in the presence of excess branched-chain amino acids results in a partial derepression of the isoleucine and valine enzymes . Reversed-phase chromatography indicated that isoleucine, valine and leucine tRNA were altered during methionine starvation . In addition, the total tRNA isolated from cells under these conditions were undermethylated . The observed derepression may be caused by the inability of methyl-deficient tRNA's to participate adequately in normal regulatory functions. Mol Gen Genet, 1977 Mar 7, 151(2), 121 - 6 Detection of messenger RNA from the isoleucine--valine operons of Salmonella typhimurium by heterologous DNA-RNA hybridization: involvement of transfer RNA in transcriptional repression; Childs G et al.; A hybridization assay using Escherichia coli K-12 DNA isolated from the specialized transducing bacteriophage gammaCI857St68h80 dilv was used to examine the rate of synthesis of the messenger RNA's (mRNA) derived from the isoleucine-valine (ilv) gene cluster of Salmonella typhimurium . In all cases examined, changes in ilv enzyme levels could be correlated with changes in the rate of synthesis of ilv mRNA . Several well characterized regulatory mutants of S . typhimurium had rates of synthesis of ilv mRNA 3 to 8-fold higher than the repressed wild-type strain . The increased rates of ilv mRNA synthesis found in a hisT strain as well as in isoleucyl-and leucyl-tRNA SYNTHETASE MUTANTS, STRONGLY SUGGESTS A ROLE FOR BRANCHED-CHAIN AMINOACYL-TRNA's in transcriptional control. Infect Immun, 1977 Mar, 15(3), 842 - 5 Mitogenic activity of cell wall components from smooth and rough strains of Brucella abortus; Kreutzer DL et al.; On the basis of {3H}thymidine incorporation by normal mouse spleen cell cultures, cell wall preparations from a smooth (45/0) strain and a rough (45/20) strain of Brucella abortus were strongly mitogenic . On the other hand, none of several subcomponents extracted from the cell wall preparations, including aqueous and phenolic lipopolysaccharides, was active . These results contrast with the marked mitogenic activity of lipopolysaccharides isolated from other gram-negative bacteria such as Salmonella typhimurium. Tubercle, 1977 Mar, 58(1), 13 - 8 Fatal generalized BCG histiocytosis; Doleckova V et al.; An infant was vaccinated at the age of 3 days with BCG vaccine . At the age of 3 years 10 months he developed an infection by Salmonella typhimurium . The infection persisted with recurrent episodes of fever, peri-nephritic abscess, abscesses of lymph nodes, hepatomegaly, splenomegaly and paravertebral and retro-peritoneal abscesses, from which Salmonella were isolated . At the age of 6 years and 2 months later . At post-mortem examination there were widespread histiocytic nodules in many organs, from which Mycobacterium bovis BCG were cultured . One previous case has been reported from Czechoslovakia . The mother of that child was the sister of the father of the child reported here . It was not possible to investigate the possibility of abnormalities of humoral or cellular immunity in the family. Mutat Res, 1977 Mar, 42(3), 335 - 42 Mutagenicities of quinoline and its derivatives; Nagao M et al.; Quinoline, recently reported to be carcinogenic in rats {12}, was mutagenic to Salmonella typhimurium tester strains TA100 and TA98 in the presence of the metabolic activation system S-9 mix . 2-Chloroquinoline, a non-carcinogen {12}, was non-mutagenic with or without S-9 mix . 8-Hydroxyquinoline, which is t known to be carcinogenic, was mutagenic with S-9 mix to both bacterial strains . The mutagenicities of 17 other quinoline derivatives that are not known to be carcinogenic were tested, and 12 of these compounds were mutagenic. Infect Immun, 1977 Mar, 15(3), 950 - 7 Role of zinc in the abatement of hepatocellular damage and mortality incidence in endotoxemic rats; Sobocinski PZ et al.; Intraperitoneal administration of zinc (ZnIP) as zinc chloride prior to or simultaneously with a lethal quantity of intraperitoneally administered Salmonella typhimurium endotoxin significantly protected rats against toxin-induced mortality and hepatocellular damage . Pretreatment with amounts of zinc chloride ranging from 0.4 to 2.0 mg/100 g of body weight resulted in 80 to 100% survival compared with 10% survival in untreated control rats at 24 h after endotoxin treatment . Zinc chloride treatment in excess of 2.0 mg/100 g of body weight appeared to be toxic and provided diminished protection . In contrast with the protection obtained with ZnIP, intravenously administered zinc did not provide protection . The effectiveness of ZnIP to enhance survival if it was given after endotoxin was greatly diminished as a function of time after endotoxin . The extent of hepatocellular damage was assessed at various times after endotoxin administration in ZnIP-treated and untreated rats by measurement of plasma ornithine carbamoyltransferase activity and histological examination of liver sections . Endotoxin absorption from the peritoneal cavity and hepatic uptake were studied by using 51Cr-labeled endotoxin . ZnIP pretreatment significantly reduced 51Cr-labeled endotoxin content of blood and liver when compared to untreated controls, and effectively prevented endotoxin-induced elevations in plasma ornithine carbamoyltransferase activity and hepatic tissue necrosis . These data indicate that protection afforded by ZnIP treatment results as a consequence of the ability of zinc to diminish absorption of the toxin from the peritoneal cavity and subsequent hepatic uptake. J Virol, 1977 Mar, 21(3), 956 - 64 Regulation of Bacteriophage P22 DNA synthesis and repressor levels in P22cly infections; Tokuno SI et al.; A rifampin-resistant mutant of Salmonella typhimurium carries an altered RNA polymerase . Wild-type (c+) phage P22 displays clear plaques and a reduced lysogenization frequency on this mutant host . The cly mutants of P22 were isolated on the basis of their ability to lysogenize such mutant hosts . Two classes of regulatory events, both of which are dependent on P22 gene c1 activity, are necessary for the establishment of lysogeny in P22 . The positive events culminate in repressor synthesis; the negative events cause a retardation in phage DNA synthesis . Neither the positive nor the negative events are observed in P22c+ infections of the mutant host . Both effects are found in P22cly infections of the mutant host . Observable results of both the negative and the positive events are exaggerated in P22cly infections of wild-type hosts as compared to P22c+ infections . The cly mutation apparently increases the positive and negative regulatory events so that they are detectable in the mutant host and exaggerated in wild-type hosts . Possible mechanisms that result in the high frequency of lysogenization that characterizes the cly mutation and the nature of the cly mutation are discussed. J Bacteriol, 1977 Mar, 129(3), 1601 - 6 Physical characterization of a plasmid cointegrate containing an F'his gnd element and the Salmonella typhimurium LT2 cryptic plasmid; Manis JJ et al.; A recombinant plasmid (pAS19) isolated from a derivative of Salmonella typhimurium LT2, containing the strain LT2 cryptic plasmid and an F'his gnd element, has been physically characterized . The pAS19 plasmid contour length equals the sum of the contour lengths of the cryptic plasmid and F'his gnd element . Deoxyribonucleic acid (DNA)-DNA hybridization experiments demonstrated that whereas the pAS19 plasmid exhibits extensive DNA homology with both the cryptic plasmid and the F'his gnd element, there is little DNA homology between these latter two plasmids . The DNA fragmentation pattern of the pAS19 plasmid produced by the restriction endonuclease R-EcoRI is consistent with that expected for a composite plasmid cointegrate containing most, if not all, of the DNA sequences present in its two component plasmids. J Bacteriol, 1977 Mar, 129(3), 1289 - 97 Fine-structure map of the histidine transport genes in Salmonella typhimurium; Ames GF et al.; Afine-structure genetic map of the histidine transport region of the Salmonella typhimurium chromosome was constructed . Twenty-five deletion mutants were isolated and used for dividing the hisJ and hisP genes into 8 and 13 regions respectively . A total of 308 mutations, spontaneous and mutagen induced, have been placed in these regions by deletion mapping . The histidine transport operon is presumed to be constituted of genes dhuA, hisJ, and hisP, and the regulation of the hosP and hisJ genes by dhuA is discussed . The orientation of this operon relative to purF has been established by three-point crosses as being: purF duhA hisJ hisP. Infect Immun, 1977 Mar, 15(3), 997 - 8 Effectiveness of parenteral and oral typhoid vaccination in mice challenged with a Salmonella typhi-Salmonella typhimurium hybrid; Diena BB et al.; Live Salmonella typhi administered intraperitoneally, acetone-killed S . typhi administered intraperitoneally, and live S . typhi given orally, with their effectiveness decreasing in that order, protected Swiss white mice against death from challenge with a virulent Salmonella typhimurium hybrid expressing S . typhi antigens. Infect Immun, 1977 Mar, 15(3), 988 - 92 Neutralization of Salmonella toxin-induced elongation of Chinese hamster ovary cells by cholera antitoxin; Sandefur PD et al.; A partially purified preparation of the delayed skin permeability factor from Salmonella typhimurium caused Chinese hamster ovary cells to elongate . The elongation effect and the skin test activity were blocked by monospecific rabbit antisera against cholera toxin and against the B fragment of cholera toxin, Cancer Lett, 1977 Mar, 2(4-5), 221 - 6 Mutagenicities of smoke condensates and the charred surface of fish and meat; Nagao M et al.; Smoke condensates obtained from broiling fish showed mutagenic activity for Salmonella typhimurium TA100 and TA98 . Metabolic activation was required to induce mutagenic activity of smoke condensates of some species of fish . The smoke condensate obtained during charcoal broiling of beefsteak was far less mutagenic than that of fish, with or without metabolic activation . Extracts of the charred surface of broiled fish and meat also contained mutagenic substances . These extracts needed metabolic activation to exhibit mutagenicities on TA98 . The mutagenic activity of the smoke condensate obtained from one sardine weighing 100 g was equivalent to that of 132 micrograms benzo(a)pyrene and that of the charred surface of the sardine was equivalent to 358 micrograms benzo(a)pyrene . One piece of beefsteak weighing 190 g, contained mutagenic activity equivalent to that of 855 micrograns benzo(a)pyrene. J Bacteriol, 1977 Mar, 129(3), 1387 - 96 Ornithine transcarbamylase from Salmonella typhimurium: purification, subunit composition, kinetic analysis, and immunological cross-reactivity; Abdelal AT et al.; Ornithine transcarbamylase (OTCase) was purified to hemogeneity from a derepressed strain of Salmonella typhimurium . The optimal pH for enzyme activity is 8.0 . The molecular weight of the enzyme was calculated to be 116,000, based on measurements of the sedimentation coefficient by sucrose gradient ultracentrifugation and the Stokes radius by gel filtration . Polyacrylamide gel electrophoresis of cross-linked OTCase in the presence of sodium dodecyl sulfate showed that the enzyme is composed of three identical subunits . The molecular weight of the monomer was determined to be 39,000 . Steady-state kinetics indicate that the reaction mechanism is sequential . The limiting Michealis constants for carbamylphosphate and ornithine were determined to be 0.06 and 0.2 mM, respectively . The dissociation constant for carbamylphosphate was 0.02 mM . Product and dead-end inhibition patterns are consistent with an ordered Bi Bi mechanism, in which carbamylphosphate is the first substrate added and phosphate is the last product released . OTCase activity was inhibited by arginine, but relatively high concentrations were required for significant inhibition . The inhibition by arginine might be physiologically significant in the regulation of carbamlphosphate utilization; a single carbamylphosphate synthetase is responsible for the synthesis of carbamylphosphate for both arginine and pyrimidines in S . typhimurium and the inhibition by argine might serve to divert carbamlphosphate to the synthesis of pyrimidines when arginine is present at high concentrations . The crossreaction of OTCases from different microorganisms with purified antibodies raised against the homogeneous OTCase from S . typhimurium was investigated . The results of immunotitration and immunodiffusion experiments revealed a high degree of identity between the enzymes form S . typhimurium and Esherichia coli B and W . In these three cases, a single gen (argl) encodes OTCase . Wild-type E . coli K-12 and strain 3000 X 111, which carry two OTCase genes (argI, argF), also revealed similar cross-reactivity, supporting the hypothesis that argF is the product of a relatively recent duplication . The activity of OTCase from Bacillus subtilis was partially inhibited by antibodies against the enzyme from S . typhimurium, indicating unusual conservation of primary structure among widely different taxonomic groups . OTCase from Saccharomyces cerevisiae, whose molecular weight and primary structure are similar to those of the enzyme from S . typhimurium, was without detectable cross-reactivity. Eur J Biochem, 1977 Mar 1, 73(2), 521 - 7 Proton movements coupled to sugar transport via the galactose transport system in Salmonella typhimurium; Thienen GM et al.; We have studied proton movements associated with substrate transport via the galactose transport system in Salmonella typhimurium . The addition of galactose to lightly buffered suspensions of anaerobic, non-metabolizing cells of Salmonella typhimurium, specifically induced for the galactose transport system, causes an increase in extracellularpH as galactose and protons enter the cell together . Other substrates for this transport system, D-fucose, 2-deoxygalactose, glucose and 2-deoxyglucose similarly cause an influx of protons when transported . In contrast, transport via the other major transport system for galactose, the methylgalactoside transport system, is not coupled to H+ influx . Comparison of kinetic data obtained from pH measurements with data obtained from measurement of active transport of galactose via the galactose transport system suggests that the apparent Km of the galactose transport system for this sugar differs under energized and non-energized conditions . At pH 7.2 the permeant anion SCN- increases both the rate and extent of galactose-induced proton influx; at pH 6 the rate, but not the extent is increased by SCN-. Biochim Biophys Acta, 1977 Feb 14, 465(1), 152 - 64 Outer membrane of Salmonella typhimurium . Electron spin resonance studies; Nikaido H et al.; The supramolecular structure of the outer membrane of Salmonella typhimurium that produces an Rc-type lipopolysaccharide was studied by adding spin-labeled fatty acid probes to membranes as well as model bilayers . Lipopolysaccharide of this organism apparently formed a bilayer structure in 0.2 M NaCl/0.01 M MgCl2, and the electron spin resonance spectra suggested that the motion of the segments of hydrocarbon chains near the carboxyl end was quite restricted even at high temperature; this is presumably due to the anchoring of more than a dozen fatty acid residues to a single backbone structure . In the presence of Mg2+, we could produce lipoplysaccharide-phospholipid mixed bilayers contining up to 50% (by weight) lipoplysaccharide . Their spectra showed no sign of major heterogeneity, and the maximum hyperfine splitting values were considerably larger than in phospholipid-only liposomes; these results suggest that the two components are finely interspersed and that the mobility of phospholipid hydrocarbons is severely restricted by the hydrocarbon chains of lipopolysaccharide . In spite of the presence of lipoplysaccharide in an amount equal to or exceeding that of phospholipids, the outer membrane produced spectra remarkably similar to those of the inner membrane, which does not contain lipoplysaccharide, and there was little sign of immobilization by lipopolysaccharides . Signals corresponding to the pure lipoplysaccharide phase were not detected, either . These results suggest that the phospholipids and lipopolysaccharides are segregated into separate domains in the outer membrane, and the fatty acid probes enter almost exclusively into the phospholipid domains . This conclusion was fully corroborated by determining, through the exchange broadening of line width, the total area of the domains that accommodated the spin label probes. Biochemistry, 1977 Feb 8, 16(3), 381 - 6 Properties of the galactose binding protein of Salmonella typhimurium and Escherichia coli; Zukin RS et al.; The galactose binding protein implicated in transport and in chemotaxis has been purified to homogeneity from the shock fluids of Salmonella typhimurium and Escherichia coli . Both proteins are monomers of molecular weight 33 000 and exhibit cross-reactivity with antibody . The Salmonella galactose receptor showed binding of 1 mol of {14C}galactose or 1 mol of {14C}glucose at saturation . The dissociation constants were 0.38 and 0.17 muM, respectively . In light of the previously published report that the E . coli protein contains two binding sites with two different affinities, the binding characteristics of this protein were reexamined . Using highly purified radiolabeled substrate and homogeneous protein, a single binding site and single binding affinity were seen galactose (KD = 0.48 muM) or for glucose (KD = 0.21 muM) . The competition between glucose and galactose for the same site is intriguing in view of the competition between ribose and galactose at the receptor level. Biochim Biophys Acta, 1977 Feb 4, 464(3), 589 - 601 Outer membrane of Salmonella typhimurium . Identification of proteins exposed on cell surface; Kamio Y et al.; Proteins exposed on the outer surface of the outer membrane of Salmonella typhimurium were identified by reacting intact cells with a covalent labeling reagent . Since the outer membrane permitted the free diffusion of small hydrophilic molecules, we used a macromolecular reagent, CNBr-activated dextran, as the non-penetrating labeling agent . We also used a mutant producing a lipopolysaccharide with a very short (i.e . hexasaccharide) carbohydrate chain, in order to avoid steric hindrance by the carbohydrates on membrane surface . Results showed that out of the four "major" proteins of molecular weight around 35 000, three were exposed, and that at least six other proteins were also exposed on cell surface . Only two or three outer membrane proteins consistently did not react with the reagent in intact cells. Aust Vet J, 1977 Feb, 53(2), 82 - 7 Prevention of Salmonella typhimurium infection inpoultry by pretreatment of chickens and poults with intestinal extracts; Lloyd AB et al.; Day-old chickens or turkey poults when pretreated with an oral dose of intestinal fluid froma healthy adult bird, were considerably more resistant to the subsequent establishment of Salmonella typhimurium in their intestinal tract than were non-treated chickens or turkey poults . Caecal fluid was more effective as a pretreatment than were washings taken from other parts of the gastro-intestinal tract of a healthy adult bird . This increased resistance of pretreated chickens or poults is thought to result from the rapid establishment of a conventional indigenous microflora which inhabits establishment and growth by the invading enteric pathogen. Appl Environ Microbiol, 1977 Feb, 33(2), 434 - 44 Generalized indicator plate for genetic, metabolic, and taxonomic studies with microorganisms; Bochner BR et al.; We have developed an indicator plate that works well for diverse types of substrates and microorganisms . The plates are inexpensive and easy to prepare . The essential components are agar, buffer, growth-supporting nutrients, a test substrate, and 2,3,5-triphenyl tetrazolium chloride (TTC) . Using various strains of Salmonella typhimurium and Escherichia coli, we have studied and defined the contribution of each component to the satisfactory function of the plate . Colonies capable of catabolizing the test substrate reduce TTC and produce a deep red formazan, whereas colonies failing to catabolize the substrate remain uncoloured . Those with intermediate rates of catabolism differ in rate and/or extent of color formation . In all cases the color is stable because TTC reduction is essentially irreversible . Since the mode of action of these plates is fairly well understood, alternative formulations can be devised to meet specific needs . The general applicability of this TTC indicator system makes it an extremely useful tool in microbial genetics, metabolism, and taxonomy. Proc Natl Acad Sci U S A, 1977 Feb, 74(2), 533 - 7 Identification of a protein methyltransferase as the cheR gene product in the bacterial sensing system; Springer WR et al.; Methylation of membrane-bound proteins with apparent molecular weights around 65,000 does not occur in mutants of the generally nonchemotactic cheR class of Salmonella typhimurium . This was shown to be due to the lack of a protein methyltransferase in these mutants by means of an in vitro assay using soluble proteins, membranes, and S-adenosylmethionine as the methyl donor . The methylase from the wild type was purified, characterized, and shown to be of molecular weight 38,000 . It is specific for proteins in S . typhimurium and Escherichia coli membranes . The methylase is not required for tumbling but appears to be essential for maintaining the appropriate rate constants and levels of the regulator of the chemotactic response. Infect Immun, 1977 Feb, 15(2), 491 - 9 Comparison of the virulence of O:9,12 and O:4,5,12 Salmonella typhimurium his+ transductants for mice; Lyman MB et al.; The purpose of these experiments was to determine whether qualitative differences in the O repeat unit of the lipopolysaccharide of pathogenic Salmonella species affected virulence for mice . O:4,5,12 and O:9,12 sister his+ transductants were derived from a virulent Salmonella typhimurium . Fermentation markers were introduced by transduction to differentiate these strains, and the strains were used as mixed challenge to CF1 and C57B1/6J mice . Liver and spleen cultures of the mice of various intervals after challenge indicated that the O:4,5,12 member of the nearly isogenic pair regularly multiplied to a greater extent than the O:9,12 after intraperitoneal challenge for both strains of mice . After oral challenge, there was little difference in the amount of multiplication of the O:4,5,12 and O:9,12 strains in CF1 mice, but the O:4,5,12 was the predominant strain recovered in 8 of 10 instances in the C57B1/6J mice. Zentralbl Bakteriol {Orig A}, 1977 Feb, 237(1), 54 - 64 {Epidemiologic relationship of infections with Salmonella typhimurium in Switzerland studied by phage typing (author's transl)}; Pagon S et al.; In the area, controlled by the Institute of Microbiology of St . Gall, 262 S . typhi murium strains could be isolated during 1973 . By means of phage typing, according to GUINEE, 20 different phage types as well as 6 additional atypically reacting strains, with characteristic atypical pattern, were recognized . The phage type 650 was most frequently encountered (37.0%) folowed by types 61 (20.2%) and 505 (10.3%) . An intensive change in phage types was noted among 114 cases, observed over 7 months, in the region of Wil SG . In the beginning, 5 different phage types were determined, but in the following 2 months, they were replaced by the type 650, and, finally, by the type 61 . Phage typing enabled the understanding of epidemiologic relationship of two outbreaks occurring in Kirchberg (type 650) and Butschwil (type 61) by consumption of infected slaughtered beef . Also, an outbreak of the infection in Wil, transmitted by an infected butcher, could be cleared . Testing of the resistance against tetracycline, chloramphenicol, ampicillin and trimethoprim-sulphamethoxazol showed that 80.1% of the strains were sensitive and 18.3% were resistent against tetracycline; some phage types were sensitive (2, 3, 4, 61 etc.), predominantly sensitive (650) or resistent (330, 450, 504, 505 ARS-12) . Four strains were resistent against one or more chemotherapeutic agents used. Zentralbl Bakteriol {Orig A}, 1977 Feb, 237(1), 44 - 53 {Drug resistance of phage types of Salmonella typhimurium (author's transl)}; Balzer K; Antimicrobial susceptibility testing (disk diffusion test) and phage typing (method according to Anderson, performed by Prof . Brandis, Bonn) of 703 strains of Salmonella typhimurium from humans, isolated in Essen and surrounding during 1972 to 1975, was performed to dertermine whether characteristic patterns of drug resistance were associated with a single phage type or not . The most frequently isolated phage types are phage type 17 (12.2%), 12 (10.1%), 49 (8.1%), 15a (5.7%), 2 (3,3%) and the untypable phage type (46.7%) . Resistance to tetracycline (45%) was most common, followed by resistance to sulfanilamide (19%), ampicillin (9%), and chloramphenicol (7%) . Resistance to other antimicrobial agents (trimethoprim/sulfamethoxazol, gentamicin, colistin) was quite rare . Antibiograms of different phage types were found to be different, not only as far as the ratio of sensitive to resistant strains is concerned, but also for the ratio single-resistant to multiple-resistant strains . These differences were found to be statistically significant (chi-square-test, table 2) . Comparison of antimicrobial resistance to tetracycline showed, that the portion of resistant strains was about 70% for the untypable phage types, 40% for phage type 17 and 7% for phage type 12 . Among isolates of the phage type 49 multiple resistance was most common . The combination of resistance determinants is specified in figure 3 . A possible interrelation between resistance pattern and the presence of R-plasmids in isolated strains is discussed. Z Orthop Ihre Grenzgeb, 1977 Feb, 115(1), 116 - 8 {Spondylitis caused by Salmonella typhimurium (author's transl)}; Winkelmann W et al.; Described is a case of spondylitis caused by Salmonella typhimurium . According to literature osteomyelitis and spondylitis are rare as local manifestation of a salmonella infection . Spondylitis caused by Salmonella typhimurium, the most common species, is almost unknown . The problems in diagnosis and therapy are discussed. Mutat Res, 1977 Feb 1, 46(1), 11 - 8 Comparative mutagenicity of ICR-191 to S . typhimurium and diploid human lymphoblasts; Deluca JG et al.; Concentration-dependent mutagenicity of ICR-191 has been measured in Salmonella typhimurium strain TA98 and in a diploid human cell line . In both cell systems, approximately equigenerational exposure produced mutation linearly related to concentration in the lower range of ICR-191 concentrations tested . Saturation behavior was observed in the human cell assay but not in the bacterial assay . However, a 25-fold greater concentration of ICR-191 was required to induce a significant rise in the mutant fraction in the S . typhimurium assay than in the human cell assay . These differences may be linked to the differences in the biochemical events required for mutation or in the time of exposure to ICR-191. J Bacteriol, 1977 Feb, 129(2), 740 - 9 Influence of methionine biosynthesis on serine transhydroxymethylase regulation in Salmonella typhimurium LT2; Stauffer GV et al.; The enzyme serine transhydroxymethylase (EC 2.1.2.1; L-serine:tetrahydrofolate-5,10-hydroxymethyltransferase) is responsible both for the synthesis of glycine from serine and production of the 5,10-methylenetetrahydrofolate necessary as a methyl donor for methionine synthesis . Two mutants selected for alteration in serine transhydroxymethylase regulation also have phenotypes characteristic of metK (methionine regulatory) mutants, including ethionine, norleucine, and alpha-methylmethionine resistance and reduced levels of S-adenosylmethionine synthetase (EC 2.5.1.6; adenosine 5'-triphosphate:L-methionine S-adenosyltransferase) activity . Because this suggested the existence of a common regulatory component, the regulation of serine transhydroxymethylase was examined in other methionine regulatory mutants (metK and metJ mutants) . Normally, serine transhydroxymethylase levels are repressed three- to sixfold in cells grown in the presence of serine, glycine, methionine, adenine, guanine, and thymine . This does not occur in metK and metJ mutants; thus, these mutations do affect the regulation of both serine transhydroxymethylase and the methionine biosynthetic enzymes . Lesions in the metK gene have been reported to reduce S-adenosylmethionine synthetase levels . To determine whether the metK gene actually encodes for S-adenosylmethionine synthetase, a mutant was characterized in which this enzyme has a 26-fold increased apparent Km for methionine . This mutation causes a phenotype associated with metK mutants and is cotransducible with the serA locus at the same frequency as metK lesions . Thus, the affect of metK mutations on the regulation of glycine and methionine synthesis in Salmonella typhimurium appears to be due to either an altered S-adenosylmethionine synthetase or altered S-adenosylmethionine pools. J Bacteriol, 1977 Feb, 129(2), 589 - 98 Repression and inhibition of transport systems for branched-chain amino acids in Salmonella typhimurium; Kiritani K et al.; Kinetics of the transport systems common for entry of L-isoleucine, L-leucine, and L-valine in Salmonella typhimurium LT2 have been analyzed as a function of substrateconcentration in the range of 0.5 to 45 muM . The systems of transport mutants, KA203 (ilvT3) and KA204 (ilvT4), are composed of two components; apparent Km values for uptake of isoleucine, leucine, and valine by the low Km component are 2 muM, 2 to 3 muM, and 1 muM, respectively, and by the high Km component 30 muM, 20 to 40 muM, and 0.1 mM, respectively . The transport system(s) of the wild type has not been separated into components but rather displays single Km values of 9 muM for isoleucine, 10 muM for leucine, and 30 muM for valine . The transport activity of the wild type was repressed by L-leucine, alpha ketoisocaproate, glycyl-L-isoleucine, glycyl-L-leucine, and glycyl-L-methionine . That for the transport mutants was repressed by L-alanine, L-isoleucine, L-methionine, L-valine, alpha-ketoisovalerate, alpha-keto-beta-methylvalerate, glycyl-L-alanine, glycyl-L-threonine, and glycyl-L-valine, in addition to the compounds described above . Repression of the mutant transport systems resulted in disappearance of the low Km component for valine uptake, together with a decrease in Vmax of the high Km component; the kinetic analysis with isoleucine and leucine as substrates was not possible because of poor uptake . The maximum reduction of the transport activity for isoleucine was obtained after growing cells for two to three generations in a medium supplemented with repressor, and for the depression, protein synthesis was essential after removal of the repressor . The transport activity for labeled isoleucine in the transport mutant and wild-type strains was inhibited by unlabeled L-alanine, L-cysteine, L-isoleucine, L-leucine, L-methionine, L-threonine, and L-valine . D-Amino acids neither repressed nor inhibited the transport activity of cells for entry of isoleucine. J Virol, 1977 Feb, 21(2), 825 - 8 Patterns of transcription in bacteriophage P22-infected Salmonella typhimurium; Pipas JM et al.; Two peaks of RNA synthesis (early and late) are directed by bacteriophage P22 in lytic infections of Salmonella typhimurium . Late RNA synthesis is not seen in P22 23- infections; neither early nor late RNA synthesis occurs in P22 24- infections . Genes 23 and 24 of P22 appear to be analogous to genes Q and N of lambda, respectively. J Natl Cancer Inst, 1977 Feb, 58(2), 449 - 51 Airborne mutagens bioassayed in Salmonella typhimurium; Talcott R et al.; Particulate airborne pollutants, collected in Buffalo, New York, and Berkeley, California, were asayed for mutagenic activity in the Ames Salmonella typhimurium test system . Mutagens requiring liver enzymes for activation, as well as direct acting mutagens, were readily detected in the Buffalo sample . By contrast, only direct acting mutagens were detected in the Berkeley sample. J Natl Cancer Inst, 1977 Feb, 58(2), 393 - 4 Mutagenicity of five cyclic N-nitrosamines: assay with Salmonella typhimurium; Stoltz DR et al.; The mutagenicity of five cyclic N-nitrosamines was studied with the use of Salmonella typhimurium TA1535 in vitro with and without microsomal activation . The carcinogens nitrosopiperidine and nitrosopyrrolidine required metabolic activation before manifesting mutagenic activity . Nitrosoproline and nitrosohydroxyproline, noncarcinogens, were not mutagenic . Nitroso-3-pyrrolidinol was mutagenic in the absence of microsomes, thereby suggesting a role of hydroxylation in the metabolic activation of nitrosopyrrolidine to an ultimate carcinogenic species. J Gen Microbiol, 1977 Feb, 98(2), 379 - 85 Expression of Klebsiella nif and his genes in Salmonella typhimurium; Postgate JR et al.; Derivatives of Salmonella typhimurium carrying F prime or P prime plasmids with Klebsiella nif and his genes had specific nitrogenase activities similar to Klebsiella in selective conditions, even to showing "hyperinduction" under argon . No evidence was obtained for catabolite repression of normal nif expression but dibutyl cyclic AMP often augmented "hyperinduction" . In non-selective conditions the Klebsiella his nif determinants were rapidly lost from the plasmids; the low levels of nif expression and temperature-sensitive his expression previously reported were probably due to ready loss of his nif in the test conditions used. J Bacteriol, 1977 Feb, 129(2), 630 - 9 Galactose transport in Salmonella typhimurium; Postma PW; We have studied the various systems by which galactose can be transported in Salmonella typhimurium, in particular the specific galactose permease (GP) . Mutants that contain GP as the sole galactose transport system have been isolated, and starting from these mutants we have been able to select point mutants that lack GP . The galP mutation maps close to another mutation, which results in the constitutive synthesis of GP, but is not linked to galR . Growth of wild-type strains on glaactose induces GP but not the beta-methylgalactoside permease (MGP) . Strains lacking GP are able to grow slowly on galactose, and MGP is induced; however, D-fucose is a much better inducer of MGP . Induction of GP or MGP is not prevented by a pts mutation, although this mutation changes the apparent Km of MGP for galactose . pts mutations have no effect on GP . GP has a rather broad specificity: galactose, glucose, mannose, fucose, 2-deoxygalactose, and 2-deoxyglucose are substrates, but only galactose and fucose can induce this transport system. J Gen Microbiol, 1977 Feb, 98(2), 369 - 77 Lack of a regulatory function for glutamine synthetase protein in the synthesis of glutamate dehydrogenase and nitrite reductase in Escherichia coli K12; Newman BM et al.; Synthesis of glutamine synthetase (GS) in anaerobic batch cultures of Escherichia coli was repressed when excess NH4+ was available, but derepressed during growth with a poor nitrogen source . In wild-type bacteria there was only a weak inverse correlation between the activities of GS and glutamate dehydrogenase (GDH) during growth in various media . No positive correlations were found between the activities of GS and nitrite reductase, or between GS and cytochrome c552: both of these proteins were synthesized normally by mutants that contained no active GS . Although activities of GS and GDH were low in two mutants that are unable to synthesize cytochrome c552 or reduce nitrite because of defects in the nirA gene, the nirA defect was separated from the GS and GDH defects by transduction with bacteriophage P1 . Attempts to show that catabolite repression of proline oxidase synthesis could be relieved during NH4+ starvation also failed . It is, therefore, unlikely that nitrite reduction or proline oxidation by E . coli are under positive control by GS protein . The regulation of the synthesis of enzymes for the utilization of secondary nitrogen sources in E . coli, therefore, different from that in Klebsiella aerogenes, but is similar to that in Salmonella typhimurium. J Gen Virol, 1977 Feb, 34(2), 207 - 21 Adsorption of phage P22 to Salmonella typhimurium; Eriksson U et al.; Adsorption of phage P22 to its receptor in the lipopolysaccharide (LPS) of the envelope of Salmonella typhimurium is accompanied by a hydrolytic cleavage of the O polysaccharide chain . The enzyme, and endorhamnosidase, is found in the phage tail . Propagation of a mutant of phage P22, containing two amber mutations, under restrictive conditions permitted isolation of phage tail parts with endorhamnosidase activity . The tail parts, purified by ion exchange chromatography, were shown to be homogenous by polyacrylamide gradient gel electrophoresis, isoelectric focusing in polyacrylamide gel electrophoresis and crossed immunoelectrophoresis . The mol . wt . was estimated to 240000 . The optimal pH range for glycosidase activity was 5 to 7 and optimal temperature 37 degrees C . Hydrolysis of the O polysaccharide chain, when estimated with whole bacteria as the substrate, did not seem to be influenced by the cation concentration . Eclipse of P22 phage particles to whole bacteria was likewise uninfluenced by the cation concentration in the reaction mixture, but eclipse by isolated receptor containing LPS required cations . The optimal concentration for divalent cations was 2 X 10(-3) M, for trivalent cations 1 X 10(-3) M. J Bacteriol, 1977 Feb, 129(2), 1168 - 70 Repression of the tyrosine, lysine, and methionine biosynthetic pathways in a hisT mutant of Salmonella typhimurium; Brown BA et al.; A comparison was made of the repressibility of certain enzymes in the tyrosine, methionine, and lysine biosynthetic pathways in wild-type Salmonella typhimurium and a hisT mutant . The results show that (i) tyrosine represses the synthesis of the tyrosine-sensitive 3-deoxy-D-arabino-heptulsonic acid 7-phosphate synthetase and the tyrosine aminotransferase to the same extent in a hisT mutant as in wild type and (ii) there is no detectable alteration in the extent to which methionine represses O-succinylhomoserine synthetase or in the extent to which lysine represses the lysine-sensitive beta-aspartokinase as a result of the hisT mutation. Mol Gen Genet, 1977 Jan 18, 150(2), 205 - 9 Isolation and characterization of catalase deficient mutants of Salmonella typhimurium; Levine SA; Catalase deficient mutants (kat) of Salmonella typhimurium have been isolated . The mutantions katA1, katC6 and katD9 appear to map at about minute 10 on the Salmonella chromosome . The katC6 and katD9 lesions are complemented by the E . coli F'128 (lac + pro +) episome but the katA1 lesion is not . KatB2 maps at about minute 100 . None of the mutants are oxygen sensitive; they grow as well as wild bacteria, even when aerated. Science, 1977 Jan 7, 195(4273), 76 - 8 Tris(2,3-dibromopropyl) phosphate: mutagenicity of a widely used flame retardant; Prival MJ et al.; Tris(2,3-dibromopropyl) phosphate, a widely used flame-retardant additive for textiles, is mutagenic to histidine-requiring strains of Salmonella typhimurium . Extracts of fabrics treated with this compound are also capable of inducing mutations in these bacterial strains. Eur J Biochem, 1977 Jan 3, 72(1), 149 - 55 Formate hydrogenlyase system in Salmonella typhimurium LT2; Chippaux M et al.; Isolation from Salmonella typhimurium of mutants unable to reduce benzyl viologen under anaerobic conditions has allowed the study of the factors involved in the multienzymic formate hydrogenylase system . 1 . Depending on the affected activities, different classes of mutants were found: FHL-A mutants have lost formate dehydrogenase 1 and formate dehydrogenase 2 activities; mutations in fdhA (117 min) or fdhB (33 min) lead to such a phenotype . FHL-B and FHL-C mutants have lost formate dehydrogenase 2 activity and part or all of hydrogenase activity, respectively; both types correspond to mutations in the hyd gene (approximately 90 min) . FHL-D mutants have lost only formate dehydrogenase 2 activity; fhlD gene maps at 120 min . 2 . In some cases, mixtures of extracts from two mutants display formate dehydrogenase 2 and formate hydrogenylase activities . Restoration studies suggest the existence of one factor sensitive to growth conditions and inactivated by oxygen or heating . This factor which is present and active in FHL-C mutants, is probably the one missing in FHL-D mutants . 3 . A new scheme for the formate hydrogenylase system is proposed, in which hydrogenase transfers electrons directly to benzyl viologen. Vet Pathol, 1977 Jan, 14(1), 43 - 55 The pathogenesis rectal stricture . II . Experimental salmonellosis and ischemic proctitis; Wilcock BP et al.; 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 rectum in normal pigs, but in pigs with either rectal stricture or salmonella proctitis the dye halted at the cranial margin of the transverse mucosal defect . The predilection of rectal stricture and its proposed precursor, salmonella ulcerative proctitis, for the middle third of the rectum was attributed to a normally precarious arterial supply which renders the rectum unusually susceptible to ischemic injury and decreases its reparative capacity. Vet Pathol, 1977 Jan, 14(1), 36 - 42 The pathogenesis of porcine rectal stricture . I . The naturally occurring disease and its association with salmonellosis; Wilcock BP et al.; 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 groups of pigs examined . Ulcerative proctitis, a possible precursor of rectal stricture, was frequently in pigs with enterocolitis caused by S . typhimurium. Vet Med Nauki, 1977, 14(6), 84 - 90 {Structure of the Salmonella from animals, birds and the environment through the period of 1970-1975}; Slavkov I et al.; Studied were biochemically and serologically the species of a total of 8738 Salmonella cultures . Most of the investigated strains belonged to subgenus I--95 species; to subgenus II belonged one species (Salmonella sofia); to subgenus III belonged 4 species: Salmonella arizonae 11:b:1, 7; Salmonella arizonae 35:r:z35; Salmonella arizonae 35:z52:1, 5, 7; Salmonella arizonae 58:rz53:z57 of three serologic groups . The attention was focused on more than 20 (new to this country) Salmonellae among which a Salmonella bulgaria species new to the Salmonella genus . Data are given for the origin of the strains, the biochemical and serologic behaviour, the sensitivity to phage O1 and the phage types of Salmonella typhimurium and Salmonella enteritidis. J Bacteriol, 1977 Jan, 129(1), 246 - 53 Biosynthesis of bacterial glycogen: genetic and allosteric regulation of glycogen biosynthesis in Salmonella typhimurium LT-2; Steiner KE et al.; Structural gene mutants of the glycogen biosynthetic enzymes adenosine diphosphate glucose pyrophosphorylase (glgC) and glycogen synthase (glgA) were isolated and partially characterized . The cotransduction frequencies of these genes with the aspartic semialdehyde dehydrogenase (asd) and glycerol-3-phosphate dehydrogenase (glpD) genes suggested the unambiguous gene order of glpD glgA glgC asd . The results of the three-factor cross glpD- glgA- glgC+ X glpD+ glgA+ glgC- were consistent with the proposed order . A simultaneous and approximately equivalent derepression of the glgC, glgA, and glgB (branching enzyme) gene products was observed in the late logarithmic-early stationary phase of growth on enriched media . These results are consistent with the coordinately regulated synthesis of the three glycogen biosynthetic enzymes in Salmonella typhimurium. Microbios, 1977, 20(79), 47 - 62 Investigations on the outer membrane proteins of Salmonella typhimurium; Kabir S; The number, nature and organization of the outer membrane proteins of Salmonella typhimurium have not yet been resolved . Therefore these proteins were isolated using a concentrated solution of guanidine hydrochloride and studied using different analytical techniques . Upon chromatography on Sephadex G-200 four fractions were obtained . Only the fraction containing a protein of molecular weight 13,000 produced immunoprecipitation reactions with the antisera raised against the whole bacteria . On polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate, 7 major proteins were found, with molecular weights between 13,000 and 43,000 . Isoelectric focusing on 4.6% polyacrylamide gels resolved the outer membrane proteins into 10 bands with apparent isoelectric points between 5.0 and 8.4 . Finally these proteins could be further resolved into as many as 50 spots where a two-dimensional electrophoresis was carried out with isoelectric focusing in the first dimension, and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate in the second dimension . These results demonstrated that the outer membrane proteins of S . typhimurium are extremely heterogeneous . To investigate the mode of organization of lipopolysaccharides in the outer membrane, the membrane proteins were separated by the liquid isoelectric focusing technique . Lipopolysaccharides were primarily found to be associated with a protein of isoelectric point 7.8. Genetika, 1977, 13(12), 2189 - 94 {Intergeneric conjugational crossing of Escherichia coli with Salmonella typhimurium . II . Transfer of a polA1 mutation from Escherichia coli to Salmonella typhimurium and its phenotypic expression in the salmonella genome}; Stepanova NF et al.; The Escherichia coli structural gene for DNA polymerase I was inserted into Salmonella typhimurium chromosome by conjugal transfer . The genetic analysis of P1-mediated transduction of obtained hybrid showed that polA gene is located in it between metE and rha loci and is cotransduced with metE (about 50%) and rha (12%) . The phenotypic properties of polA1 hybrid E . coliXS . typhimurium concerning UV-MMS-NG and gamma-ray sensitivity are similar to the polA1 mutants of E . coli. Genetika, 1977, 13(11), 2017 - 22 {Intergeneric conjugational hybridization of Escherichia coli and Salmonella typhimurium . 1 . Obtaining a salmonella hybrid possessing greater recipient activity in crosses with Escherichia coli}; Stepanova NF et al.; Intergeneric hybrids were selected from mating HfrH Escherichia coli with F- Salmonella typhimurium . The hybrid obtained from E . coli leu+ and pro+ genes possessed the increased recipient ability in the mating with E . coli HfrR1 (O--ilv--metE--ara) . This hybrid lacked the ability to restrict the phage P1 DNA propagated on E . coli K-12 . The replacement of mutated uvrA gene of Salmonella for uvrA+ gene of E . coli restore uvr+ phenotype of Salmonella mutant. G Batteriol Virol Immunol, 1977 Jan-Jun, 70(1-6), 28 - 33 {Exerimental study of enterotoxic activity in some strains of Salmonella typhimurium: observations on the model of ADP-induced platelet aggregation}; Fumarola D et al.; In a previous report it has been shown that enterotoxin preparations (cholera and E . Coli) able to activate adenylatecyclase system, abrogated platelet aggregation induced by ADP . In the present study the same experimental model has been applied to some purified filtrates from Salmonella typhimurium strains . Preparations from 986 and TLM (invasive strains causing also fluid secretion) interfere with platelet aggregation, while 1027 strain (invasive but not evoking fluid secretion) didn't show such effect . It has been argued, as Sandefur and Peterson have demonstrated with different experimental models, that the system of platelet aggregation induced by ADP is valid for some strains of Salmonella typhimurium, which act with a mechanism partially involving adenylatecyclase system (i.g . cholera-like). Genetika, 1977, 13(10), 1865 - 7 {Reparation of the damages induced by UV light in salmonellae}; Brukhanskii GV et al.; The survival of Salmonella typhimurium wild type strains after UV-irradiation is studied . It is demonstrated that many of these are more sensitive to UV-irradiation than Escherichia coli of the wild type . Alkaline sucrose density gradient centrifugation has demonstrated a deficiency of these strains in normal excision repair of UV-damaged DNA . This deficiency is not a feature of Salmonella genus, because a strain is found of the same resistance and reparation ability as E . coli wild type strain. Genetika, 1977, 13(1), 132 - 7 {Specific mutagenic effectiveness of 1,4-bis-diazoacetylbutane in relation to individual genes}; Vasil'eva SV et al.; A selective effect of 1,4-bis-diazoacetylbutane (DAB) with respect to individual genes is observed when studying its mutagenic action on bacterial strains . Escherichia coli and Salmonella typhimurium . The frequency of mutations to thr+ exceeded in three orders the background of spontaneous variability for this marker . No induced mutations to trp+ and his+ leu+, which might be the result of transition, transversions, suppressor mutations and frame shift mutations, were detected . Mutagenic effect of DAB is due to the functioning of the gene uvr+ . Several hypotheses are proposed on possible mechanism of the specific effect of DAB with respect to individual genes. Acta Biochim Pol, 1977, 24(4), 329 - 34 Sulphate permease of Escherichia coli K12; Karbonowska H et al.; Some properties of the sulphate transport system and the isolation of sulphate permease mutants in E . coli K12 are described . The gene coding for sulphate permease is located in the same region as the cysA gene in Salmonella typhimurium. Genetika, 1977, 13(8), 1492 - 4 {Salmonella typhimurium--test system for detecting the mutagenic activity of environmental pollutants . II . Mutagenic effect of heavy metal salts in an in vitro system with metabolic activation}; Polukhina GN et al.; Mutagenic effect of zinc chloride on Salmonella typhimurium strain was detected using in vitro metabolic activation system . Cadmium chloride showed no significant mutagenic activity in the same system . It is recommended to use both in vitro and in vivo metabolic activation systems in mutagenicity testing of chemicals. Genetika, 1977, 13(6), 1089 - 92 {Salmonella typhimurium as a test system for detecting the mutagenic activity of environmental pollutants . I . The mutagenic action of heavy metal salts in in vivo and in vitro systems without metabolic activation}; Kalinina LM et al.; The work presents the data on mutagenic effects of heavy metal salts (Zn and Cd) on Salmonella typhimurium test strains using mutagenicity test in vitro without metabolic activation and host-mediated assay . The techniques used enabled to determine also the types of mutations arising from the exposure to ZnCl2 and CdCl2. Psychosom Med, 1977 Jan-Feb, 39(1), 19 - 24 Effects of crowding of mice on humoral antibody formation and protection to lethal antigenic challenge; Edwards EA et al.; The effects of grouping (crowding) on humoral antibody response to typhoid paratyphoid vaccine and subsequent protection from a minimal lethal challenge dose of Salmonella typhimurium were studied in white Swiss-Webster mice . The data show a trend between the degree of crowding and antibody response . Geometric mean titers of high density grouped mice were significantly lower than the geometric mean titers of the less crowded mice . Also, there were significantly less antibody responders in the high density grouped mice than in the less crowded mice . However, challenged with a minimal LD50 dose of Salmonella thphimurium, no deaths occurred in the immunized study group, regardless of measurable antibody level . In the nonimmunized controls, which were under the same stressor conditions, there was a significant difference between the level of crowding and death to challenge . The data show that nonimmunized mice in this study exhibited a marked increase in susceptibility to an infectious agent when under the stressor effect of crowding. Immunology, 1977 Jan, 32(1), 11 - 8 Physiochemical consequences of opsonization of Salmonella typhimurium with hyperimmune IgG and complement; Stendahl O et al.; Partition in an aqueous, two-polymer phase system containing dextran and polyethylene glycol was employed to investigate the physico-chemical changes inflicted upon the cell surface of a smooth strain of Salmonella typhimurium by the binding of antibody IgG and complement . The minimum antibody concentration for increased phagocytosis in vitro was approximately the same as that for a significant change in two-phase partition, ca 8000 mol/bacterium, whereas a lower concentration, less than 4000 mol/bacterium, was sufficient to increase clearance in vivo . After pepsin digestion of IgG, larger quantities, ca 35,000 mol/bacterium, was required for opsonization and to influence two-phase partition . Addition of normal rabbit or guinea-pig serum to bacteria sensitized with a low concentration of antibody IgG conspicuously enhanced phagocytosis and affinity for the dextran-rich phase . The results show that binding of 8000 IgG antibody molecules or more to smooth S . typhimurium generates physicochemical changes of the bacterial surface which from studies on S leads to R mutations are known to correlate with hydrophobicity, negative charge and phagocytosis . Such results support the view that one important function of IgG antibody and complement is to decrease the hydrophilic properties of the bacteria which is thought to be a prerequisite for phagocytosis. Mutat Res, 1977, 48(1), 29 - 36 Factors affecting mutagenic activity of cigarette smoke condensate in Salmonella typhimurium TA 1538; Mizusaki S et al.; Smoke condensates from Burley tobacco, bright-type tobacco and various brands of commercial cigarettes were tested for mutagenicity by using a microsomal test system with Salmonella typhimurium TA 1538 . Smoke condensate from Burley tobacco had much higher mutagenic activity than that from bright-type tobacco . Increased mutagenic activity was observed with smoke condensates from Burley tobacco grown with increasing amounts of nitrogen fertilizer, and from commercial cigarettes blended with Burley tobacco . There was a significant correlation between nitrate content of cigarette and mutagenic activity of the resulting smoke condensate . The results suggest that nitrate in cigarettes may influence the formation of potential mutagens during the burning of a cigarette. Mutat Res, 1977, 48(1), 17 - 27 Studies on mutagenicity of irradiated sugar solutions in Salmonella typhimurium; Aiyar AS et al.; Irradiated sugar solutions are mutagenic towards Salmonella typhimurium, the effect being dose-dependent up to 2.0 Mrad . At all doses, ribose solution exhibited greater mutagenicity than did sucrose solution . The mutagenic effect was observed only in dividing cells and appears to be directly related to the growth rate . A larger proportion of revertants was observed after incubation with irradiated sugar solution for a period of 4 h than for 24 h . Irradiation of the sugar solutions in the frozen conditions was effective in completely preventing the development of mutagenic potential . Post-irradiation storage of the sugar solutions for a prolonged period (25 weeks) also minimized their mutagenic effect . The irradiated sugar solutions gave rise to both missense and frame-shift (additon as well as deletion) types of mutation; ribose was more effective in inducing the latter type . The irradiated sugar solutions failed to show a mutagenic response in the host-mediated assay with mice as the mammalian host. Infect Immun, 1977 Jan, 15(1), 26 - 33 Mitogenic stimulation of murine spleen cells: relation to susceptibility to Salmonella infection; von Jeney N et al.; The screening of several inbred strains of mice suggested that the capacity of their spleen cells to respond to the mitogenic effect of lipopolysaccharide (LPS) of gram-negative bacteria was correlated with their resistance to intraperitoneal infection with Salmonella typhimurium . An infection of LPS into mice caused changes in the in vitro responsiveness of their spleen cells to the mitogenic effects of LPS and phytohemagglutinin . Pretreatment of mice with whole ultraviolet (UV)-killed bacteria led to a marked rise in the in vitro response of the spleen cells to UV-killed bacteria, but not to LPS or or phytohemagglutinin . This enhanced response to UV-killed bacteria was not specific for the O antigens of the bacteria. Can J Comp Med, 1977 Jan, 41(1), 107 - 11 Antimicrobial susceptibility of Salmonella isolates from the broiler chicken industry in Ontario; McGarr C et al.; Antibacterial drug resistance among 219 salmonella isolates recovered during 1974 from poultry and poultry environments at the various production stages of broiler chickens in three integrated Ontario companies are recorded . All isolates were susceptible to ampicillin, trimethroprim-sulfamethoxazole complex, furazolidone, cephaloridine and amoxicillin . A relative increase in resistance to tetracycline and streptomycin with an accompanying decrease in resistance to triple sulfa compound was recorded when compared to a previous investigation of avian salmonella isolates in Ontario . The percentage and patterns of antimicrobial resistance were comparable at the various stages of production . Resistance to tetracycline and streptomycin was the most common pattern found among both Salmonella typhimurium and other serotypes . A notably high prevalence of resistance was found among Salmonella enteritidis isolates including some isolates with R factors for chloramphenicol resistance . This latter finding is of particular concern because of the high prevalence of this serotype in poultry and in human salmonellosis. J Bacteriol, 1977 Jan, 129(1), 388 - 94 Mitomycin C-induced expression of trpA of Salmonella typhimurium inserted into the plasmid ColE1; Selker E et al.; EcoRI endonuclease digestion of the deoxyribonucleic acid of a phi80 transducing phage carrying the entire tryptophan (trp) operon of Salmonella typhimurium (phi80 S.t.trpE-A) yielded a 4.3 X 10(6)-dalton fragment containing intact trpE, trpD, and trpC and a 3.35 X 10(6)-dalton fragment containing intact trpA . The trpA fragment inserted into EcoRI-cleaved plasmids ColE1 and CR1 was expressed regardless of its orientation of insertion . Mitomycin C, a compound that induces colicin E1 production in ColE1-containing bacteria, stimulated tryptophan synthetase alpha production in cells containing ColE1-TRPA plasmids with the trpA fragment inserted in one orientation but not the other . We conclude that in the inducible plasmids trpA can be expressed from the colicin E1 promoter. J Bacteriol, 1977 Jan, 129(1), 305 - 16 Thymidine-requiring mutants of Salmonella typhimurium that are defective in deoxyuridine 5'-phosphate synthesis; Beck CF et al.; In a Salmonella typhimurium strain made diploid for the thy region by introduction of the Escherichia coli episome, F'15, mutants resistant to trimethoprim in the presence of thymidine were selected . One was shown to be defective in deoxyuridine 5'-phosphate (dUMP) synthesis; it requires deoxyuridine or thymidine for growth and is sensitive to trimethoprim in the presence of deoxyuridine . Genetic studies showed that the mutant is mutated in two genes, dcd and dum, located at 70 and 18 min, respectively, on the Salmonella linkage map . The dcd gene cotransduces 95% with udk, the structural gene for uridine kinase . Both mutations are necessary to create a deoxyuridine requirement, providing evidence for the existence of two independent pathways for dUMP synthesis . Pool studies showed that a dum mutation by itself causes a small decrease in the deoxythymidine 5'-triphosphate (dTTP) pool of the cells, whereas a dcd mutation results in a much more marked decrease . The double mutant dcd dum, when incubated in the absence of deoxyuridine, contains barely detectable levels of dTTP . Enzyme analysis revealed that dcd encodes deoxycytidine 5'-triphosphate deaminase . The gene product of the dum gene has not yet been identified; it does not encode either subunit of ribonucleoside diphosphate reductase or deoxyuridine 5'-triphosphate pyrophosphatase . Mutants deleted for the dcd-udk region of the S . typhimurium chromosome were isolated. Mutat Res, 1977 Jan, 42(1), 19 - 31 Development and applications of Bacillus subtilis test systems for mutagens, involving DNA-repair deficiency and suppressible auxotrophic mutations; Tanooka H; A mutagen-tester of Bacillus subtilis was constructed and tested with known carcinogens . The parental strain HA101 of Okubo and Yanagida carrying suppressible nonsense mutations in his and met genes was transformed to carry an excision-repair deficiency mutation . The constructed strain TKJ5211 showed a 20--30-fold higher sensitivity for His+ reversion than the parental strain when treated with UV and UV-mimetic chemicals but unchanged mutation frequency with X-rays and methyl methanesulfonate . The tester strain was used in a spot test of 30 selected chemicals and also for testing with liver homogenate activation . The results showed an almost equivalent but somewhat broader detection spectrum than the Salmonella typhimurium TA100 system . Another test method used a pair of B . subtilis strains differing in their DNA-repair capacity, i.e . the most UV-sensitive mutant HJ-15 and a wild-type strain, to detect repair-dependent DNA damage produced by chemicals . Spores could be used in either test. C R Seances Soc Biol Fil, 1977, 171(5), 1041 - 8 {Mutagenicity of the metabolites of the epoxide-diol pathway of safrole and its analogs . Study on Salmonella typhimurium}; Dorange JL et al.; Mutagenicity of the metabolites of the expoxide-diol pathway of safrole and analogues was studied on Ames' strains with Ames' method . Safrole, eugenol, eugenolmethylether, estragol, allylbenzene and 1'-hydroxysafrole, are not mutagen on TA 1535, TA 100 (point mutation) and TA 1537, TA 1538, TA 98 (frameshift mutations) without activation system . The corresponding epoxides that we have synthetized, are mutagens and inducers of point mutation in TA 1535 and TA 100 . Dose-effect curves show differences between the mutagen efficiencies of these epoxides probably in relation with their electrophilic properties . On the other hand the 2', 3'-dihydro-2',3'-dihydroxisafrole was not mutagen in Ames' test . These results confirm the promutagen character of safrole and analogues and the role of the epoxides as proximate carcinogens. C R Seances Soc Biol Fil, 1977, 171(2), 380 - 5 {Evolution of mouse intestinal and blood immunoglobulins after oral route vaccination}; Ivanoff B et al.; The authors have studied the mice immunoglobulins level after vaccination by oral route with a killed-pathogenic strain of Salmonella typhimurium and an avirulent mutant of the same bacteria . The obtained results show an increase of the intestinal IgA and IgG1 levels and a slighter one of sera IgG between the 10 th and 30 th day following immunization . No correlation was observed concerning the IgM, IgG and IgA levels and the mice protection against a challenge of pathogenic bacteria. Mutat Res, 1977, 48(1), 37 - 42 Mutation induction by the antischistosomal drug F30066 in various test systems; Ong TM et al.; The genetic activity of furapromidium (F30066), an antischistosomal drug, was studied in Salmonella typhimurium, Saccharomyces cerevisiae, Neurospora crassa and cultured Chinese hamster cells . The results show that F30066 induces gene mutations in S . typhimurium, N . crassa and Chinese hamster cells . This compound also causes gene conversions in S . cerevisiae. Proc Natl Acad Sci U S A, 1977 Jan, 74(1), 286 - 90 Structure and properties of a hybrid tryptophan synthetase of alpha chain produced by genetic exchange between Escherichia coli and Salmonella typhimurium; Yanofsky C et al.; Genetic exchange between the structural genes for the alpha chain of tryptophan synthetase {tryptophan synthase; L-serine hydro-lyase (adding indoleglycerol-phosphate), EC 4.2.1.20} of E . coli and S . typhimurium yielded recombinant genes that specified functional hybrid polypeptides . The alpha chains produced by three recombinants appeared to be identical but differed from those of E . coli and S . typhimurium by at least 27 and 8 amino acid residues, respectively . In vivo and in vitro tests of enzyme function suggest that the hybrid alpha chains are near-equivalent to their fully active parental proteins. J Supramol Struct, 1977, 6(3), 389 - 98 Energetics of galactose, proline, and glutamine transport in a cytochrome-deficient mutant of Salmonella typhimurium; Singh AP et al.; The effect of inhibitors and uncouplers on the osmotic shock-sensitive transport systems for glutamine and galactose (by the beta-methyl galactoside permease) was compared to their effect on the osmotic shock-resistant proline and galactose permease systems in cytochrome-deficient cells of Salmonella typhimurium SASY28 . Both osmotic shock-sensitive and -resistant systems were sensitive to uncouplers and to inhibitors of the membrane-bound Ca2+, Mg2+-activated adenosine triphosphatase . This suggests that uptake by both types of systems is energized in these cells by an electrochemical gradient of protons formed by ATP hydrolysis through the ATPase. Acta Biochim Pol, 1977, 24(3), 197 - 205 The N4-hydroxycytidine reduction system in toluenized cells of Salmonella typhimurium; Popowska E et al.; 1 . Enzymatic reduction of N4-hydroxycytidine to cytidine in Salmonella typhimurium is highly specific . The reaction occurs only at the nucleoside level . Free base or its 1-methyl analogue is not reduced . 2 . The pH optimum shows a broad plateau with a maximum at pH 7.0 . The apparent Km value, estimated in the toluene-treated cells, is 4.8 mM and Vmax 1.4 nmoles/min/mg of wet bacterial weight . The reaction is NADH-dependent, although in toluenized bacterial cells it can occure without addition of any exogenous factor. Mutat Res, 1977 Jan, 42(1), 3 - 17 The influence of pH on the effects of 2,4-D (2,4-dichlorophenoxyacetic acid, Na salt) on Saccharomyces cerevisiae and Salmonella typhimurium; Zetterberg G et al.; The genetic effects of 2,4-D (2,4-dichlorophenoxyacetic acid, Na salt) have been investigated in cells of the yeast Saccharomyces cerevisiae and of the bacterium Salmonella typhimurium in experiments in vitro and in vivo . Experiments in vitro showed that the killing of both yeast and bacteria is dependent on the pH in the treatment solution of 2,4-D . A dose-dependent increase of the frequency of mitotic gene conversion and mitotic recombination in yeast was observed at pH 4.50 and 4.30 . In experiments in vitro with two strains of Salmonella no significant increase of the number of revertants to prototrophy was obtained . The positive correlation between survival of cells and dissociation of 2,4-D in the pH region 2.8-5.0 indicates that the cells are unable to take up dissociated 2,4-D . Therefore the survival is high at a high pH when most 2,4-D is in dissociated form, and the survival is low at a relatively low pH when more of the 2,4-D is in its undissociated form . No genetic effects were induced by oral administration of tolerable doses of 2,4-D in host-mediated assays using mice as hosts and yeast or Salmonella as indicator cells. Mol Gen Genet, 1976 Dec 31, 142(4), 289 - 98 The role of cAMP in flagellation of Salmonella typhimurium; Komeda Y et al.; A mutational alteration either in adenylate cyclase (cya-) or in cyclic-3'5'-AMP (cAMP) receptor protein (crp-) rendered Salmonella typhimurium incapable of producing flagella . The amount of mRNA specific for flagellin in these mutants was almost negligible when assayed in an in vitro protein synthesizing system . A secondary mutation cfs, partially suppressing the cya- mutation, was identified among the revertants of cya- . A mutation in the same cistron as cfs resulted in a non-flagellate phenotype either by itself or in combination with cfs . The cistron, which was given the gene symbol flaT, was located between flaE and flaL . It was suggested that cAMP receptor protein together with cAMP modulates the gene flaT, which in turn acts as a positive effector on the synthesis of active mRNA specific for flagellin. Ciba Found Symp, 1976 Dec 7-9, (51), 107 - 24 Siderophores: diverse roles in microbial and human physiology; Neilands JB; Siderophores, defined as high affinity iron(III) ion transport agents, and their cognate membrane-bound receptor complexes, occur in the enteric bacteria Escherichia coli and Salmonella typhimurium . The total system is tightly regulated by iron repression . The transport properties of the specific siderophores enterobactin and ferrichrome (which is not made by these particular enteric bacteria) have been examined in detail . In E . coli the outer membrane receptor for ferrichrome is programmed by the tonA gene; the receptor also serves as the binding site for T1, T5, phi80, albomycin and colicin M . Similarly, in S . typhimurium phage ES18, ferrichrome and albomycin compete for the genetic equivalent of the tonA locus . The ability of ascorbic acid to protect against atherosclerosis as well as rhinovirus infection in humans may be related to the role of the vitamin in iron metabolism . Deferrisiderophores are clinically useful in the treatment of acute and chronic iron poisoning but, on the other hand, they could constitute a natural hazard by transporting actinides, such as 239Pu, through the food chain. J Cell Physiol, 1976 Dec, 89(4), 839 - 52 The function and activity of certain membrane enzymes when localized on- and off- the membrane; Hochstadt J et al.; 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 between the base moieties of adenine and AMP without requiring P-ribose-PP as an intermediate; the enzyme in aqueous solution requires P-ribose-PP, indicating a different reaction mechanism in the two environments . Like the adenine PRT of E . coli, the hypoxanthine PRT of Salmonella typhimurium (Jackman and Hochstadt, '76) also carried out an exchange reaction on the membrane only and also is more sensitive to a number of inhibitors in aqueous solution relative to the sensitivity when embedded in the membrane . In addition, however, the hypoxanthine PRT, while restricted to hypoxanthine as a substrate in the membrane, also accepts guanine as substrate in its soluble form . The membrane capacities reas determined in a guanine PRT deletion strain (Jackman and Hochstadt, '76) . Finally, in mammalian cell lines purine nucleoside phosphorylase, which translocates the ribose moiety of inosine across the plasma membrane of mouse fibroblasts undergoes a 30-fold increase in substrate turnover number upon liberation from the membrane . These data raise two important caveats with respect to study of membrane enzymes and transport . Firstly, an enzyme once solubilized and found to differ kinetically from substrate transport in situ cannot be excluded from participating in translocations in the membrane on the basis of its activity in aqueous solution . Secondly, an enzyme which "appears" largely soluble upon cell rupture cannot be assumed to be a cycloplasmic enzyme because of majority of the solubilized activity may represent only a small fraction of the enzyme molecules highly activated concomitant to their solubilization . In this latter case the ability to activate enzyme still residing on the membrane (e.g., with detergents) would be necessary in order to estimate total membrane associated activity after cell rupture. Mutat Res, 1976 Dec, 41(2-3), 233 - 40 Effect of excision repair on azide-induced mutagenesis; Kleinhofs A et al.; Azide mutagenesis was investigated in Salmonella typhimurium and Escherichia coli . Azide was highly effective in inducing his+ revertants in excision-repair deficient (uvrB) derivatives of S . typhimurium hisG46 and in inducing high frequencies of 5-fluorouracil resistant mutants in excision-repair deficient (uvrA) derivatives of E . coli B/r WP2 . In excision-repair plus strains, azide was only a marginal or ineffective mutagen, demonstrating that the bacterial excision-repair system could repair nearly all azide-induced damage . This observation suggests that the initial azide-induced lesion causes a major DNA helix distortion recognizable by the excision-repair endonucleases . The presence of recombination deficient (recB or recC) genes in combination with uvrA increased E . coli sensitivity to azide killing, but depressed azide mutagenicity . These results are similar to those reported for UV-induced mutagenesis with the E . coli strains and suggest that post-replication repair might be the error-prone step in the repair process . Azide mutagenesis specificity is, however, unique and different from UV, as demonstrated by inability of azide to revert the ochre try locus in E . coli WP2s . These results show that the initial azide-induced DNA damage is highly specific but different from UV-induced DNA damage . Metabolic inhibitors, similar in action to azide, did not induce mutations in S . typhimurium strain TA1530, a strain highly susceptible to azide mutagenesis, thus ruling out the possibility that azide mutagenesis was due to peroxide accumulation . A mechanism based on in vivo activation of azide to the actual mutagen is proposed. J Am Vet Med Assoc, 1976 Dec 1, 169(11), 1229 - 30 Survey for Salmonellae in porcine bile and cecums and on equipment surfaces in an Ohio abattoir; Hartwig NR et al.; Porcine bile samples and cecal swabbings and environmental swabbings collected from an abattoir in Columbus, Oh, were examined for salmonellae . Of 40 cecal swabbings, 6 were culture-positive for Salmonella choleraesuis and 2 of 25 swabbings of surfaces that were in contact with edible products were culture-positive for Salmonella typhimurium . All of 500 bile samples were Salmonella-free. Cancer Res, 1976 Dec, 36(12), 4525 - 9 Evaluation of the mutagenicity of compounds of known carcinogenicity, belonging to the benz{a}anthracene, chrysene, and cyclopenta{a}phenanthrene series, using Ames's test; Coombs MM et al.; Fifty-four polycyclic compounds, 29 of the cyclopenta{a}phenanthrene series, 11 chrysenes, and 14 benz{a}anthracenes, have been tested for mutagenicity by Ames's method, using Salmonella typhimurium TA100 . Without exception all 37 carcinogens and a known initiator were mutagens . Of the 16 noncarcinogens 7 were mutagenic, but none of these has yet been tested for initiating, as opposed to carcinogenic, activity . There appeared to be little quantitative correspondence between carcinogenic and mutagenic potency, however, and possible reasons for this are discussed . The aryl hydrocarbon hydroxylase inhibitor 7,8-benzoflavone strongly inhibited the mutagenicity of certain compounds when it was added to the incubations. J Bacteriol, 1976 Dec, 128(3), 794 - 800 3-Deoxy-3-fluoro-D-glucose-resistant Salmonella typhimurium mutants defective in the phosphoenolpyruvate:glycose phosphotransferase system; Melton T et al.; Three classes of phosphotransferase system mutants in Salmonella typhimurium were selected through their resistance to 3-deoxy-3-fluoro-D-glucose (DFG) . Strains with mutations in the ptsH (HPr) and/or pts I (enzyme I) genes were selected on medium containing lactate plus DFG . Strains with mutations in ptsH but not pstI were selected on medium containing fructose plus DFG . Clones isolated from fructose plus DFG semisolid plates and selected for ability to swarm were mutant in either ptsH or ptsG . Mutants of the latter class were defective in enzyme IIB', a membrane component of the glucose transport system . Some pleiotropic properties of one representative ptsG mutant are described. J Bacteriol, 1976 Dec, 128(3), 754 - 65 Salmonella typhimurium mutants generally defective in chemotaxis; Collins AL et al.; The mutations of eight chemotaxis-deficient strains of Salmonella typhimurium, including five new mutants in strain LT2, were mapped by P22 transduction in relation to various fla mot deletions in S . abortus-equi . Seven recessive che mutations mapped between motB and flaC: three, all nontumbling, the che region I, adjacent to motB, and four, including one ever-tumbling, in che region II, adjacent to flaC . Mutant che-107, never-tumbling and dominant to wild type, mapped at flaAII, other mutations of which cause either absence of flagella or lack of locomotor function . We surmise that gene flaAII specifies a protein that polymerizes to form an essential component of the basal apparatus (so that absence of gene product prevents formation of flagela); that a component built up from certain mutationally altered proteins cannot transmit (or generate) active rotation of the hook and flagellum, and so causes the Mot (paralysis) phenyotype; and that a component built up from protein with the che-107 alteration permits only counterclockwise rotation, so that the tumble, normally produced by transient clockwise rotation, cannot be effected. J Bacteriol, 1976 Dec, 128(3), 785 - 93 Fosfomycin resistance: selection method for internal and extended deletions of the phosphoenolpyruvate:sugar phosphotransferase genes of Salmonella typhimurium; Cordaro JC et al.; Selection for resistance to the antibiotic fosfomycin (FOS; L-cis 1,2-epoxypropylphosphonic acid, a structural analogue of phosphoenolpyruvate) was used to isolate mutants carrying internal and extended deletions of varying lengths within the ptsHI operon of Salmonella typhimurium . Strains carrying "tight" ptsI point mutations and all mutants in which some or all of the ptsI gene was deleted were FOS resistant . In contrast, strains carrying ptsH point mutations were sensitive to FOS . Resistance to FOS appeared to result indirectly from catabolite repression of an FOS transport system, probably the sn-glycerol-3-phosphate transport system . Resistant ptsI mutants became sensitive to FOS when grown on D-glucose-6-phosphate, which induces an alternate transport system for FOS, or when grown in the presence of cyclic adenosine 3',5'-monophosphate . A detailed fine-structure map of the pts gene region is presented. Mutat Res, 1976 Dec, 41(2-3), 209 - 16 Association of Salmonella mutants with germ-free rats: characterization of the reverse mutational response to 2-nitrofluorene; Carter JH et al.; Salmonella typhimurium strain TA1538 described by Ames, in association with otherwise germ-free rats, colonizes the gastrointestinal tract . The revertants enumerated in the feces of each of these rats varies in a coordinated manner in relation to the day on which the measurement is made . In response to the oral ingestion of a single dose of 2-nitrofluorene, the concentration of revertants in the feces increases and then returns essentially to control values within 6 days . When these rats are challenged repeatedly with a similar oral dose of 2-nitrofluorene the revertent concentration in the feces remains elevated for a progressively longer time . A change in phenotype of strain TA1538 during prolonged association rather than a change in the biology of the rat seems to explain this phenomenon . Firstly, germ-free rats exposed repeatedly to 2-nitrofluorene and then associated with strain TA1538 do not have the prolonged response characteristic of multiple challenges with 2-nitrofluorene . Secondly, strain TA1538 reisolated after several weeks of association with the otherwise germ-free rat shows other alterations such as decreased sensitivity to 2-nitrofluorene in the pour plate assay and a decreased sensitivity to crystal violet . In spite of limitations imposed by these alterations in strain TA1538, it is possible to demonstrate a dose-response relationship between the amount of 2-nitrofluorene ingested and the concentration of revertants in the feces of exposed rats. J Bacteriol, 1976 Dec, 128(3), 766 - 75 Unique aspects of the regulation of the aspartate transcarbamylase of Serratia marcescens; Wild JR et al.; Aspartate trancarbamylase (ATC ase; EC 2.1.3.2) from Serratia marcescens HY has been purified 134-fold . Its properties are unique . Unlike the ATCase from Escherichia coli and Salmonella typhimurium, the S . marcescens HY enzyme activity is not feedback inhibited by any purine or pyrimidine nucleotide effectors; instead, the enzyme is activated by both cytidine 5'-triphosphate and adenosine 5'-triphosphate . Like the ATCase from E . coli and S . typhimurium, adenosine 5'-triphosphate alters the {S}0.5 of the enzyme and, in contrast, cytidine 5'-triphosphate does not alter the {S}0.5 but, instead, alters the Vmax . As has been shown for both E . coli and S . typhimurium, effector sensitivity may be selectively dissociated form catalytic activity by treatment with heat, parachloromercuribenzoate, or neohydrin . This dissociated enzyme possesses threefold higher specific activity than the native enzyme . The sedimentation coefficient of the native enzyme is approximately 11.4S, whereas the dissociated enzyme has a value of 6.0S . Whereas it has been possible to reconstitute the E . coli and the S . marcescens ATCase enzymes from their own homologous subunits, it has not been possible to make hybrid enzymes of catalytic and regulatory heterologous subunits from each other . It was not possible to detect repression of ATCase formation after growth of prototrophic strains of S . marcescens HY supplemented with 200 mug of uracil per ml, but eightfold derepression was observed after uracil withdrawal in pyrimidine auxotrophs. J Biol Chem, 1976 Nov 10, 251(21), 6598 - 605 Sugar transport . The crr mutation: its effect on repression of enzyme synthesis; Saier MH Jr et al.; The accompanying report describes phosphotransferase system-mediated repression in mutants of Salmonella typhimurium and Escherichia coli defective in Enzyme I and histidine-containing phosphate carrier protein (HPr), the general proteins of the phosphotransferase system (PTS) . Such repression prevented the cells from synthesizing the catabolic systems required for utilization of the non-PTS compounds glycerol, maltose, melibiose, mannose 6-phosphate, and alpha-glycerol phosphate . This defect can be overcome by introducing a single mutation, designated crr, into the pts mutants . The pts crr double mutants can be induced to synthesize the non-PTS catabolic systems and can therefore grow on the non-PTS sugars . The crr gene is closely linked to but not part of the pts operon, and may be a regulatory gene for the operon . Assay of the PTS proteins in crr mutants showed that the only component detectably affected was a sugar-specific protein of the PTS, Factor IIIG1c, involved in the phsophorylation of glucose (and methyl alpha-glucoside) . In some crr mutants Factor IIIG1c was not detected, whereas in others it was present at reduced levels . Thus the crr gene appears to code for or regulate the synthesis of this protein . In addition to the general crr mutants, several classes of sugar-specific crr mutants were isolated . For example, maltose-, melibiose-, and glycerol-specific crr mutants were isolated, each being inducible for the corresponding catabolic enzyme system but not for the others . Unlike the general crr gene, the sugar-specific crr genes do not map near the pts operon. Res Commun Chem Pathol Pharmacol, 1976 Nov, 15(3), 563 - 70 The in vitro metabolism, macromolecular binding and bacterial mutagenicity of 4-chloribiphenyl, a model PCB substrate; Wyndham C et al.; 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 (sensitive to frameshift mutagens) whereas higher chlorinated PCB were only weakly mutagenic. J Gen Microbiol, 1976 Nov, 97(1), 91 - 103 Basic characterization of W-pili; Bradley DE et al.; 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- segregant strains which had lost their plasmids showed a simultaneous loss of both pili and drug-resistance characteristics . W-pili are pointed flexible filaments 10 to 12 nm thick, with an average length of 450 nm . The best host found was Salmonella typhimurium. Ann Sclavo, 1976 Nov-Dec, 18(6), 825 - 30 {Researches on antibiotic-resistance in "Shigella sonnei" and "flexneri" and in "Salmonella typhimurium" (author's transl)}; Rizzo G et al.; Ampicillin (A), streptomycin (S), aminosidin (K), chloramphenical (C) and tetracycline (T) resistance was investigated in 130 S . typhi murium, 18 Shigella flexneri and 13 Shigella sonnei strains, recovered from enteritis cases in 1970-1973 . All Salmonella and 70% Shigella strains (without any appreciable differences between Sh . sonnei and flexneri) were found resistant and most multiresistant . A-S-K-C-T resistance was frequently found: in 48% of the Salmonella and 12% of the Shigella strains . As for resistance transfer by conjugation, it was obtained in more than 90% of the resistant strains . The Authors, after some remarks about transferable resistance factors diffusion, give some advices on antibiogram making technique. Res Vet Sci, 1976 Nov, 21(3), 335 - 40 Experimental infections of sheep with Salmonella typhimurium; Brown DD et al.; Twenty-two-six-to nine-month-old lambs were infected orally with Salmonella typhimurium at levels varying from 2 x 10(13) to 1 x 10(9) and serially slaughtered to determine the pathogenesis of infection and to evaluate the efficacy of diagnostic procedures . Infection resulted in a severe fatal or potentially fatal clinical disease in lambs receiving 2 x 10(13) organisms . Observations were made on the clinical pathology, bacteriology and serology during the course of infection and extensive bacteriological examinations were undertaken at autopsy. Res Vet Sci, 1976 Nov, 21(3), 271 - 9 A comparison of the role of kinins and serotonin in endotoxin induced fever and Trypanosoma vivax infections in the goat; Veenendaal GH et al.; Goats were infected with Trypanosoma vivax or inoculated with a low pyrogenic dose of lipopolysaccharide (LPS) obtained from Escherichia coli or Salmonella typhimurium in order to obtain evidence about the role of kinins and serotonin in the pathogenesis of trypanosomiasis and in endotoxin induced ruminal stasis . The following conclusions were made: (1) whole blood serotonin and bradykinin-like activity levels and clinical symptoms during fever, induced by LPS E coli or T vivax infection are not comparable . (2) There is no good correlation between the changes in heart rate and the temperature rise during fever, evoked by LPS E Coli or T vivax infection . (3) No change of whole blood serotonin level was found during LPS induced fever and only a small increase in the whole blood bradykinin-like activity could be detected . These data suggest that the inhibition of the extrinsic ruminal contractions and the bradycardia followed by a biphasic increase in heart rate during LPS induced fever are not mediated by these substances . (4) The peaks of parasitaemia during the acute phase of T vivax infection are associated with increases in whole blood bradykinin level . However, the high blood bradykinin-like activity did not cause an inhibition of the extrinsic ruminal contractions . (5) The slightly raised bradykinin-like activity during the chronic phase of T vivax infection suggests that bradykinin is not a major factor in the pathogenesis of chronic T vivax infection . (6) The fluctuations of the blood serotonin level during temperature peaks, associated with peaks of parasitaemia and the presence of many platelet thrombi in goats dying during overwhelming parasitaemia suggests a correlation between T vivax, platelet aggregation and blood serotonin decrease. Poult Sci, 1976 Nov, 55(6), 2176 - 89 Effects of different levels of chlortetracycline in the diet of turkey poults artifically-infected with Salmonella typhimurium; Nivas SC et al.; Two separate experiments were conducted to assess the shed rate and duration of shed of S . typhimurium organisms from turkey poults orally infected with chlortetracycline-sensitive S . typhimurium in relation to chloretetracycline (CTC) given in the feed at 0, growth promotant, subtherapeutic and therapeutic levels; the emergence of resistant S . typhimurium organisms in reference to the diet given; in vitro transfer of drug resistance from thses resistant S . typhimurium donor cultures to multiply-sensitive E . coli recipients; and phage type changes, is any, of these S . typhimurium isolates . The results showed that increasing CTC in the diet from 0 to the three levels of antibiotic supplementation, appeared to (a) reduce shed and duration of shed corresponding to each level used; (b) cause a minimal development of drug resistance and its transfer (usually at sub-therapeutic levels of CTC supplementation) for the duration of the experiment; and (c) induce phage type changes in some of the S . typhimurium isolates . These phage type changes question the validity of using phage typing as a tool in epidemiological investigations. Zentralbl Bakteriol {Orig A}, 1976 Nov, 236(2-3), 262 - 8 Nosocomial infection of nurselings caused by multiple drug resistant strain of Salmonella typhimurium--utilization of a new typing method based on lysogeny of strains; Borecka J et al.; During a period of 18 months diarrheal diseases appeared among nurselings in one region of Slovakia . Salmonella typhimurium strains were isolated from 265 cases . The diseased nurselings were kept in a nurseling-home and/or were hospitalized in two city hospitals . The isolated Salmonella typhimurium strains were resistant to ampicillin, carbenicillin, tetracyclin, chloramphenicol, neomycin, kanamycin and sulphonamides, and, carried R-plasmids . The tested strains proved identical by phage typing according to the systems of Felix-Callow and Scholtens . The were lysogenic and reacted in an identical way with indicator strains . The results of tests indicate that the nosocomial infection of nurselings was caused by long-term persistance and spread of a single polyresistant strain of Salmonella typhimurium. Mutat Res, 1976 Nov 1, 41(1 spel . no), 51 - 60 The utilization of in vitro mutagenesis techniques to explain strain, age and sex related differences in dimethylnitrosamine tumor susceptibilities in mice; Brusick D et al.; The carcinogen dimethylnitrosamine (DMNA) is known to exhibit a high degree of strain, organ, age, and sex related tumor specificity in mice . Using microbial mutagenesis assay coupled with mouse tissue microsomal enzyme activation systems, evidence has been obtained that demonstrated a close relationship between the level of in vitro DMNA activation to a mutagen and in vivo tumor susceptibility . DMNA activation by liver, lung, and kidney microsomes from several mouse strains was compared by measuring the rate of mutagenic metabolites formed during incubation of the carcinogen in mutation assays using Salmonella typhimurium G-46 as the indicator microorganism. Mutat Res, 1976 Nov, 40(4), 309 - 15 Mutagenicity of the food colour brown FK and constituents in Salmonella typhimurium; Venitt S et al.; The food colour Brown FK (EEC Serial No . 124) is a mixture of p-sulphophenylazo derivatives of m-toluylenediamine and m-phenylenediamine and is used in the UK for colouring kippers . Brown FK and its constituents were assayed for mutagenicity in Salmonella typhimurium TA 1535, TA 1537 and TA 1538 . Samples of Brown FK from three manufacturers were mutagenic in TA 1538 (framshift mutant) when activated by a rat-liver supernatant fraction . Mutagenicity was linearly dose-dependent in the range of 0--3 mg/plate with activities ranging from 22 to 50 times the spontaneous mutation frequency . One sample of Brown FK was mutagenic in the absence of metabolic activation producing a 16-fold increase in mutation at 4 mg/plate . Two major constituents of Brown FK, 2,4-diamino-5-(p-sulphophenylazo)-toluene (I) and 1,3-diamino-4-(p-sulphophenylazo)benzend (II), each present at about 18% in the complete colour, were mutagenic in TA 1538 . Mutagenicity was linearly dose-related in the range 0--1 mumol/plate, with slopes of 0.35 mutants/nmol for compound I and 1.5 mutants/nmol for compound II . This activity was dependent on metabolic activation . Four other major constituents, (di- and tri-substituted diamines) were inactive, as was sulphanilic acid, the major excretion product of Brown FK . The mutagenicity of Brown FK could be largely accounted for by the combined effects of compounds I and II . Earlier studies showed that compounds I and II were responsible for the acute myotoxic effects seen when Brown FK was given per os to rats and pigs . Azoreductive fission of I and II to reactive triamines by gut microflora was thought to be the main metabolic pathway by which Brown FK produced its myotoxic effects, and it is proposed that the mutagenic effects of Brown FK are probably mediated by a similar mechanism. Mutat Res, 1976 Nov, 40(4), 305 - 7 Mutagenic effect of nialamide on Salmonella typhimurium; Stoltz DR et al.; The mutagenicity of an antidepressant drug, nialamide, was studied with Salmonella typhimurium TA1535-8 . Nialamied was mutagenic for strain TA1535 in the absence of rat liver extracts. Mutat Res, 1976 Nov, 40(4), 289 - 304 Mutagenic evaluation of ronidazole; Hite M et al.; Ronidazole was evaluated for mutagenic potential using in vitro microbial tests and in vivo studies in mice . The microbial test used the histidine requiring mutants of Salmonella typhimurium with and without a rat liver microsomal activation system (Ames test) . The studies in mice included the dominant lethal test, micronucleus test and cytogenetic assays . Ronidazole was given orally in doses of 50, 100 and 200 mg/kg/day in the in vivo studies . In the dominant lethal test, groups of male mice were treated for five consecutive days before being mated with untreated females . In the micronucleus test, the mice were administered the compound for 2 or 5 consecutive days; they were killed 6 h after the last dose and bone marrow was examined for the presence of micronuclei in developing erythrocytes . In the cytogenetic assays, bone marrow cells in metaphase were examined for chromosome aberrations, 6, 24 and 48 h after mice were treated acutely with the test compound . In addition, similar examinations of chromosomes were made on mice given five consecutive dosages of ronidazole and killed 6 h after the last dose . The results of the various in vivo studies did not suggest that ronidazole would be mutagenic for the mammal . Ronidazole at concentrations of 10 and 50 mug/plate was found to increase the number of back mutations of missense mutants in the in vitro bacterial test . This finding confirms the results of Voogd et al . {19} . Incorporation of the microsomal activation system had no effect on the mutagenic capability of the test compound . In conclusion, although ronidazole was shown to be mutagenic in in vitro bacterial systems, the in vivo systems did not suggest that the compound would be mutagenic for the mammal. Eur J Biochem, 1976 Nov 1, 70(1), 171 - 7 The cell-wall lipopolysaccharide of Escherichia coli K-12 . Structure and acceptor site for O-antigen and other substituents; Prehm P et al.; The lipopolysaccharides of two wild-type Escherichia coli K-12 strains, two core-deficient mutants and one SR recombinant with Salmonella typhimurium specificity were analyzed . The respective oligosaccharides were dephosphorylated and methylated . Chemical analysis of the oligosaccharides and mass spectrometric analysis of their methylated derivatives indicated the presence of core structures with different degrees of completion . In different strains of E . coli K-12 the complete core is substituted at the non-reducing end with N-acetylglucosamine or with another substituent . There are indications that the latter may be N-acetylmannosaminuronic acid . In the SR recombinant the complete (N-acetylglucosamine-free) K-12 core is substituted with one S-specific oligosaccharide of S . typhimurium . The attachment site for all these substituents is the 6-position of the non-reducing core-terminal glucose . The heterogeneity of the K-12 core preparations and mode and nature of their substitution are discussed. Z Immunitatsforsch Immunobiol, 1976 Nov, 152(3), 244 - 59 {Secretory immunoglobulins and serum antibodies after oral infection of the white mouse with Salmonella typhimurium (author's transl)}; Sziegoleit A; White Mice were infected via the gastrointestinal tract with S . typhimurium . The immunoglobulin class of specific antibodies appearing in serum and intestinal secretions was determined . Specific antibodies were detected as early as 7 days after infection in the intestinal secretions, and reached maximum titers on day 21 . These antibodies belonged exclusively to the IgA class . After day 21, at a time when serum antibodies had reached high titers, antibodies of the IgG class were also detectable in the gut in low levels . Specific antibodies of the IgM class could never be demonstrated in intestinal secretions . Antibody titers remained at almost constant levels over the entire test period of 92 days in those animals with Salmonella in their intestine . In animals, where Salmonella were no longer demonstrable in the gut, antibody titers decreased . Serum antibodies could first be detected 12 days after infection . They reached maximum titers between day 21 and 36 . Until day 21 equal levels of IgG and IgM antibodies were found . Later on, antibodies of the IgG class predominated . In Salmonella carriers antibody titers remained on high levels over the entire test period . In animals negative for S . typhimurium in liver and spleen, antibody titers declined until the end of the test period . A new and simple method for raising a class-specific anti-mouse IgA Antiserum by immunization of rabbits with IgA from washings of the small intestine is described. Mutat Res, 1976 Nov, 37(2-3), 187 - 91 Mutagenicity of K-region epoxides of polycyclic aromatic compounds: structure-activity relationship; Miyata N et al.; The mutagenicity of several K-region arene oxides was tested in histidine-dependent mutants of Salmonella typhimurium . Benzo(a)pyrene-4,5-oxide and pyrene-4,5-oxide as well as some substituted phenanthrene oxides were mutagenic in strains TA 1538 and TA 98 which detect frame-shift mutagens . Structure-activity relationships are discussed from the standpoint of chemical reactivity . The absence of direct correlation between electrophilic reactivity and mutagenicity may suggest that primilarily physical properties, such as relative position of the epoxide group and molecular shape of arene oxides, are important for the emergence of mutagenicity of arene oxides. Mutat Res, 1976 Nov, 37(2-3), 149 - 62 Comparative mutagenicity of N-nitrosamines in a semi-solid and in a liquid incubation system in the presence of rat or human tissue fractions; Bartsch H et al.; The rat liver microsome-mediated mutagenicities of a series of N-nitrosodialkylamines and heterocyclic N-nitrosamines were determined in a liquid incubation system using Salmonella typhimurium TA1530 . The influence on mutation frequency of the concentration of co-factors for mixed-function oxidase and composition and molarity of the buffer was investigated, using N-nitrosomorpholine as substrate . The mutagenicity of the N-nitroso compounds in the liquid incubation system under optimal reaction conditions at equimolar concentration was compared quantitatively with that obtained in a soft-agar incorporation assay . N-Nitrosodi-n-pentylamine and N-nitrosodi-n-butylamine showed no enzyme-mediated mutagenicity in the liquid incubation system, and metabolically activated N-nitroso-dimethylamine and N-nitroso-diethylamine showed negligible mutagenic activity in the soft-agar assays . In contrast with these results with the N-nitrosodialkylamines, the mutagenic effects of heterocyclic N-nitrosamines were similar in the liquid incubation system and in soft-agar incorporation assays . The heterocyclic N-nitrosamines showed rat-liver microsome-mediated mutagenicity in the following descending order: N-nitrosomorpholine greater than N-nitrosopyrrolidine greater than N-nitrosopiperidine greater than N-nitroso-N'-methylpiperazine . Seven human liver specimens converted all heterocyclic N-nitrosamines into mutagens; this activity was similar to that of rat liver, except that for N-nitroso-N'-methylpiperazine, fractions from three human liver biopsies were three to 30 times more active than those from untreated rats . The specific reversion of S . typhimurium TA1530 to histidine prototrophy provides experimental evidence that all the N-nitrosamines studied were converted by liver microsomal enzymes into monofunctional alkylating agents. J Gen Microbiol, 1976 Nov, 97(1), 19 - 27 Effects of inhibitors of protein, RNA and DNA synthesis on heat-injured Salmonella typhimurium LT2; Gomez RF et al.; The role of protein, RNA and DNA synthesis in the repair of thermal injury in Salmonella typhrimurium was investigated . Thermal injury was assessed by the 'minimal medium recovery' system: after heat treatment, higher viable counts are obtained on minimal-medium agar than on complex-medium agar, and the ability of heated bacteria to form colonies on complex-medium agar is recovered when they are incubated in liquid minimal medium . This recovery is inhibited by rifampin and chloramphenicol, but not by nalidixic acid . In addition, rifampin causes a loss in viability . Alkaline sedimentation analyses of radioactively labelled DNA showed that hydroxyurea and rifampin, unlike chloramphenicol and nalidixic acid, cause DNA breaks in heated bacteria . The results indicate that rifampin is lethal to heated bacteria and that chloramphenicol, though not lethal, prevents repair of thermal damage. J Bacteriol, 1976 Nov, 128(2), 661 - 4 Repression of alkaline phosphatase in Salmonella typhimurium carrying a phoA+ phoR- episome from Escherichia coli; Yagil E et al.; Salmonella typhimurium does not produce alkaline phosphatase (nor beta-galactosidase) . Nevertheless, it has the function of the phoR+ regulatory gene but lacks the function of the lacI+ regulatory gene . Several periplasmic proteins are derepressed when cells of S . typhimurium are starved for inorganic phosphate . The role of phoR is discussed. Infect Immun, 1976 Nov, 14(5), 1125 - 9 Nonspecific resistance against infection with Salmonella typhi and Salmonella typhimurium induced in mice by cord factor (trehalose-6,6'-dimycolate) and its analogues; Yarkoni E et al.; Mice pretreated intraperitoneally with trehalose-6,6'-dimycolate (cord factor) were protected against an intraperitoneal challenge with Salmonella typhi strain Ty2 or Salmonella typhimurium strain SR 11 . The nonspecific resistance to S . typhi and S . typhimurium was still detectable 7 and 14 days, respectively, after administration of cord factor . The effect of cord factor was local . Synthetic analogues of cord factor--trehalose-6,6'-dipalmitate and trehalose monopalmitate--also induced nonspecific resistance to the above virulent bacteria . The results are discussed. J Bacteriol, 1976 Nov, 128(2), 665 - 7 Effect of polymyxin on the outer membrane of Salmonella typhimurium: freeze-fracture studies; Lounatmaa K et al.; Polymyxin-caused projections on the cell surface of Salmonella typhimurium were seen as depressions in the outer concave fracture face and as protrusions in the outer convex fracture face, indicating participation of both leaflets of the outer membrane in these projections. J Bacteriol, 1976 Nov, 128(2), 528 - 35 Isolation and partial characterization of an argR mutant of Salmonella typhimurium; Kelln RA et al.; An arginine regulatory mutant (i.e., mutated in the argR gene) has been isolated from a strain of Salmonella typhimurium LT2 . The argR mutant was found to excrete arginine into the growth medium with glycerol but not glucose as carbon source . Constitutive synthesis of arginine biosynthetic enzymes was observed . Whereas previous results (A . T . Abd-E1-A1 and J . L . Ingraham, Abstr . Annu . Meet . Am . Soc . Microbiol . 1975, K169, p . 175) have shown constitutive synthesis of carbamyl phosphate synthetase in the argR mutant, the regulation of the synthesis of the last five enzymes of the pyrimidine pathway was unaffected . However, in pyrH mutants, known to exhibit derepressed synthesis of the pyrimidine enzymes, a 10-fold derepression of ornithine transcarbamylase was observed. Mutat Res, 1976 Nov, 40(4), 281 - 8 Mutagenicity of streptozotocin and several other nitrosourea compounds in Salmonella typhimurium; Zimmer DM et al.; The following nitrosourea compounds were compared for their ability to induce mutation (to histidine independence) in the histidine-requiring auxotroph Salmonella typhimurium his G46: MNU, streptozotocin (SZ, streptozocin) and its analogs SZA1 and SZA2, and the antitumor drugs BCNU, CCNU and DCNU . At equitoxic doses SZ, SZA1, SZA2 and MNU were almost equally mutagenic causing 150, 42, 140 and 170 mutants/106 survivors at 20% lethal dose (ID20) ALTHOUGH, ON A WIEGHT BASIS, SZ was the most mutagenic of all the compounds tested . At ID20 BCNU, CCNU and DCNU gave about 0.5 mutants/106 survivors . Our results show that these nitrosoureas, in common with many other drugs (such as cyclophosphamide, daunomycin, etc.) used in cancer chemotherapy, are highly mutagenic . The implication of our results in the screening of drugs for their mutagenicity to man is discussed. Mutat Res, 1976 Nov, 37(2-3), 179 - 86 Formation of mutagenic N-nitroso compounds from the pesticides prometryne, dodine and carbaryl in the presence of nitrite at pH 1; Egert G et al.; Environmental chemicals including pesticides carrying secondary and tertiary amino groups are suggested to be a health hazard to man since potentially carcinogenic nitroso compounds may be formed in the presence of nitrite at low pH values resembling conditions in the human stomach . Nitrosation of the isopropylamino-triazine Prometryne, the n-dodecyl guanidine Dodine and the N-methylcarbamate carbaryl was investigated in the presence of HCl and acetic acid at pH 1 and excess sodium nitrite for 4 h at 37 degrees C . The reaction products were extracted with CCl4 and were analyzed qualitatively and quantitatively by infrared spectroscopy, nuclear-resonance spectrometry, GC/mass spectrometry and by spectrophotometry . All compounds investigated formed N-nitroso derivatives in the following yields: carbaryl 67%, Dodine 12% and Prometryne 14% . The N-nitroso derivatives per se were not or only slightly mutagenic to Escherichia coli K12 or Salmonella typhimurium TA 1538 . However, significantly increased mutation frequencies were seen after metabolic activation by mouse-liver microsomes . These results add to the observations that among environmental chemicals not only those containing methyl- or ethyl-substituted amino groups form potentially carcinogenic nitroso derivatives but also those with iso-propylamino groups as well as alkyl-substituted guanidine derivatives. Mol Gen Genet, 1976 Oct 18, 148(1), 43 - 7 Isolation and genetic mapping of Escherichia coli aminopeptidase mutants; Latil M et al.; Many mutant strains devoid of aminopeptidase activity have been isolated in Escherichia coli . All of them produce cross-reacting material when tested against specific antiaminopeptidase antibody . The map position of the locus specifying this enzyme has been determined by three conjugations and two P1 mediated transduction experiments . By analogy with Salmonella typhimurium this locus has been called pepN (Miller, 1975) . Mutations in pepN are jointly transduced with fabA and pyrD at high frequency . These data and conjugation results suggest a location between 20.5 and 22.5 minutes on E . coli genetic map. Mol Gen Genet, 1976 Oct 18, 148(2), 143 - 8 A mutation affecting expression of the gene coding for serine transacetylase in Salmonella typhimurium; Hulanicka MD et al.; A 1,2,4-triazole resistant mutant of S . typhimurium has been isolated, in which serine transacetylase activity is seven times higher than in wild type . Partially purified serine transacetylase from a strain carrying the trz-312 mutation has kinetic properties which are virtually identical to those of the wild type enzyme and binds to O-acetylserine sulfhydrylase A to form a cysteine synthetase complex which is also indistinguishable from that found in wild type . Thus the increased activity of serine transacetylase associated with trz-312 appears to result from increased quantities of a kinetically normal, enzyme protein . Resistance to 1,2,4-triazole is probably due to the ability of trz-312 strains to synthesize O-acetyl-L-serine at a rapid enough rate to compensate for that utilized by the O-acetylserine triazolylase reaction . Genetic mapping experiments, using P1-mediated transduction, show that trz-312 is 91-99% linked to cysE, the structural gene for serine transacetylase . The results of three point crosses indicate that this mutation is located at one extreme end of the cysE locus, as would be expected for a promotor mutation. Int J Cancer, 1976 Oct 15, 18(4), 448 - 52 Prevention of benzo(a)pyrene-induced mutagenicity by homogeneous epoxide hydratase; Oesch F et al.; Benzo(a)pyrene and benz(a) anthrancene which, in contrast to the K-region epoxides benzo(a)pyrene 4,5-oxide and benz(a)anthracene 5,6-oxide, are not mutagenic to Salmonella typhimurium TA 1537 in the absence of mammalian enzyme preparations, were activated by liver microsomes from C3H mice, which had not received any pretreatment, to mutagens reverting this tester strain to histidine prototrophy . Addition of epoxide hydratase inhibitors greatly increased this mutagenicity and addition of pure epoxide hydratase reduced it by more than 95% down to the range of spontaneous mutations as observed in absence of any added mutagen . This demonstrates than the metabolic pathway responsible for the mutagenicity of both polycyclic hydrocarbons observed in this system proceeds entirely via an epoxidation pathway and that the responsible metabolites are epoxides or species arising from them . Moreover, further metabolism by epoxide hydratase does not lead to produce contributing to the mutagenicity observed with the tester strain used . Finally, the epoxides relevant for the observed mutagenicity are substrates for epoxide hydratase; indeed, modest amounts of the pure enzyme can prevent the mutagenic effect. Arch Microbiol, 1976 Oct 11, 110(1), 49 - 54 Pyrimidine ribonucleoside monophosphokinase and the mode of RNA turnover in Bacillus subtilis; Waleh NS et al.; A protein catalyzing the phosphorylation of CMP to CDP was purified and characterized . Kinase activity for UMP copurified during ammonium sulfate fractionation, DEAE-cellulose and hydroxylapatite chromatography, and gel filtration on Sephadex G-75, the ratios of activities for the two substrates remaining constant . The purified product, possessing both activities was homogeneous as judged by the single band following polyacrylamide gel electrophoresis . The protein showed no kinase activity against purine nucleoside monophosphates or the other pyrimidine nucleoside monophosphates: dCMP, dUMP, and dTMP . Thus unlike the enteric bacteria, Escherichia coli and Salmonella typhimurium which have distinct enzymes which phosphorylate UMP and CMP, Bacillus subtilis produces a single pyrimidine ribonucleoside monophosphokinase . The Km values of this enzyme from B.subtilis are 0.04 and 0.25 mM for CMP and UMP, respectively, and 0.04 and 0.4 mM for ATP at saturating concentrations of CMP and UMP, respectively . The properties of this enzyme and the differences between enteric bacteria and B.subtilis with respect to the enzymes which phosphorylate CMP are consistent with the measurements which indicate that turnover of messenger RNA is largely hydrolytic in E.coli but largely phosphorolytic in B.subtilis. Avian Dis, 1976 Oct-Dec, 20(4), 728 - 34 Comparison of six methods of detecting Salmonella typhimurium infection of chickens; Williams JE et al.; 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 method was inadequate. Infect Immun, 1976 Oct, 14(4), 851 - 7 Association of viable and inactivated Salmonella typhimurium 395 MS and MR 10 with HeLa cells; Kihlstrom E et al.; The mouse-virulent Salmonella typhimurium 395 MS, containing a complete lipopolysaccharide (LPS) structure with S-specific repeating units, and the nonvirulent, LPS-defective mutant 395 MR 10 (chemotype Rd), derived from it, were studied for their tendency to interact with HeLa cells . In the definition of interaction no distinction has been made between intracellular and cell membrane-attached bacteria . R10 bacteria were found to have a greater tendency to interact than MS bacteria . This difference was seen as early as 1 h after the start of incubation, but it became more pronounced beyond 3 h . Heat-killed and ultraviolet-killed R10 bacteria interacted with HeLa cells less than living ones . Killed MS bacteria interacted to an extent similar to that of living ones . These results are discussed in relation to the susceptibility of the bacteria to phagocytosis by professional phagocytic cells and to the physiochemical properties of the bacteria as measured by their distribution in a two-polymer, aqueous-phase system. Am J Vet Res, 1976 Oct, 37(10), 1211 - 3 In vivo spread of infectious drug resistance in turkeys; Nivas SC et al.; Multiresistant Salmonella typhimurium donor and multisensitive Escherichia coli recipient spread from the infected group of turkey poults to the control group . Contact poults given only the S typhimurium donor and placed in the same cage with infected poults given both the donor and the E coli recipient exhibited in vivo patterns of antibiotic drug resistance transfer similar to the patterns obtained in the infected poults . This in vivo spread of antibiotic drug resistance in turkeys was established for the first time . Results indicated that the potential in vivo spread of infectious drug resistance could occur in nature. J Virol, 1976 Oct, 20(1), 334 - 8 Bacteriophage-specific DNA-binding proteins in P22-lysogenic and in P22-infected Salmonella typhimurium; Schumann W et al.; Crude extracts of Salmonella typhimurium lysogenic for phages P22 or L contain proteins that specifically retain phage DNA on nitrocellulose filters . Three DNA-binding activities were found after infection with P22 . One is P22 specific, accounts for the largest proportion of DNA-binding proteins, and corresponds most likely to the c2 repressor . An early transient binding activity measured with both P22 and L DNA was found to be directly related to the expression of genes c1 and c3 . A third, late binding activity for P22 and L DNA is related to phage production. J Infect Dis, 1976 Oct, 134(4), 354 - 61 Resistance to chloramphenicol and ampicillin of Salmonella typhimurium in Ontario, Canada; Grant RB et al.; Combined resistance to chloramphenicol and ampicillin in Salmonella typhimurium is appearing in Canada . Five cases of this type of infection have been noted . The isolates are resistant to streptomycin, sulfonamides, and tetracycline, in addition to ampicillin and and chloramphenicol; four isolates are also resistant to kanamycin . In each isolate the determinant for chloramphenicol resistance is linked to a conjugative plasmid . Four of the chloramphenicol plasmids appear to be related in resistance pattern, level of antibiotic resistance mediated, and temperature sensitivity of mating ability . The same four plasmids are associated in the primary isolates of Salmonella with three different kinds of genetic units mediating resistance to ampicillin . In only one of the five strains are the genes for chloramphenicol and ampicillin resistance linked in the same plasmid. J Bacteriol, 1976 Oct, 128(1), 290 - 301 Regulation of purine utilization in bacteria . VII . Involvement of membrane-associated nucleoside phosphorylase in the uptake and the base-mediated loss of the ribose moiety of nucleosides by Salmonella typhimurium membrane vesicles; Rader RL et al.; Although uridine and adenosine are converted by membrane-associated nucleoside phosphorylases to ribose-1-phosphate (ribose-1-P) and the corresponding bases (uracil and adenine), only ribose -1-P is accumulated within Salmonella typhimurium LT2 membrane vesicles . In accordance with these observations, no uptake is observed when the vesicles are incubated with the bases or nucleosides labeled in their base moieties . The vesicles lack a transport system for ribos-1-P, since excess ribose-1-P does not inhibit the uptake of the ribose moiety of uridine . In addition, there is no exchange with preaccumulatedribose-1-P . Thus, uridine, rather than ribose-1-P, must serve as the initially transported substrate . The uptake of the ribose portion of uridine is coupled to electron transport, and the levels to which ribose-1-P are accumulated may be reduced by adding various bases to the reaction mixtures . The bases appear to inhibit the uridine phosphorylase reaction and/or cause an efflux of ribose-1-P from the vesicles . This loss of ribose-1-P reflects the accumulation of nucleosides in the external medium after being synthesized within the membranes . Synthesis of the nucleosides from intravesicular ribose-1-P and exogenous base proceeds even though the bases are not accumulated by the vesicles . Furthermore, ribose-1-P cannot significantly inhibit uridine phosphorylase activity unless the membranes are disrupted . These observations indicate that the membrane-associated nucleoside phosphorylases may have a transmembranal orientation with their base and ribose-1-P binding sites on opposite sides of the membranes . Such an asymmetric arrangement of these enzymes may facilitate the uptake of the ribosyl moiety of nucleosides by a group translocation mechanism . Thus, nucleosides may be cleaved during the membrane transport process, with the resultant bases delivered to the external environment while ribose-1-P is shunted to the intravesicular space. J Bacteriol, 1976 Oct, 128(1), 271 - 82 Ultraviolet light protection, enhancement of ultraviolet light mutagenesis, and mutator effect of plasmid R46 in Salmonella typhimurium; Mortelmans KE et al.; Plasmid R46 partially protected Salmonella typhimurium, wild type or uvrB or polA, against the lethal effect of ultraviolet (UV) irradiation, but did not protect recA mutants . The plasmid also increased frequency of UV-induced reversion to His+ in all tested his point mutants (wild type for UV sensitivity), including amber, ochre, UGA, missense, and frame-shift mutants . Plasmid R46 also increased UV-induced reversion to His+ in uvrB and polA strains, but no UV mutagenic effect was detected in R- or R46-carrying recA derivatives of a his (amber) mutant . The spontaneous reversion frequency of his nonsense mutants of all classes, and of some his missense mutants, was increased about 10-fold when the strains carried R46, but the plasmid had no effect on the spontaneous reversion frequency of some other his missense mutations or of reversion rate of his frame-shift mutants (except for two uvrB derivatives of one single-base insertion mutant) . The plasmid increased the ability of wild-type, polA, and uvrB hosts to support plaque production by UV-irradiated phage, and made strain LT2 hisG46 less sensitive to methyl methane sulfonate and to X rays and more responsive to the mutagenic effect of visible-light irradiation . R46 increased spontaneous reversion frequency of a his (amber) rec+ strain, but had no such effect in its recA sublines . Since the plasmid in the absence of host recA function fails to produce its mutator effect, or to confer UV protection or to enhance UV mutagenesis, these three effects may be produced via some mechanism involved in recA-dependent deoxyribonucleic acid repair, perhaps by an increase in activity of the "error prone" component of the inducible repair pathway. Can J Microbiol, 1976 Oct, 22(10), 1540 - 8 Influence of temperature on growth of lipopolysaccharide-deficient (rough) mutants of Salmonella typhimurium and Salmonella minnesota; Chatterjee AK et al.; Smooth strains of Salmonella typhimurium and S . minnesota, and chemotypes Ra, Rb, and Rc, which are deficient in lipopolysaccharide components of the somatic side chains and outer core region, grow normally on nutrient agar and nutrient broth up to 45 degrees C . However, most mutants with defects in the heptose region of the LPS (chemotypes Rd2 and Re) do not grow on this medium at 42 degrees C or above; a few grow at 42 degrees C but not at 45 degrees C . In liquid medium (nutrient broth, or phosphate minimal medium), growth, measured as turbidity or as colony-forming units, stops 60 to 90 min after shift from 30 to 42 degrees C; DNA and protein synthesis cease at the same time . Growth does not reoccur at 42 degrees C; protein synthesis and growth reinitiate upon shift to 30 or 37 degrees C . Growth cessation does not alter cell morphology in the phase-contrast microscope . Growth of heptose-deficient strains at 42 degrees C in nutrient broth is restored by MgCl2 (0.5 mM), NaCl (50 mM), or sucrose (100 mM) . Sensitivity to smooth-specific and rough-specific phages, and analysis of LPS composition, indicate that heptose-deficient mutants grown at temperatures from 30 to 45 degrees C, and in the presence or absence of high salt, do not contain heptose or O-specific sugars in their LPS. Am J Physiol, 1976 Oct, 231(4), 1285 - 9 Response of mouse liver glycogen cycle enzymes to endotoxin treatment; Giger O et al.; The present study was undertaken to characterize endotoxin-induced changes in carbohydrate metabolism and more specifically, to determine the contribution of glycogenolysis to the loss of liver glycogen . Female ICR mice, fasted overnight, were injected with a median lethal dose (LD50, 9 mg/kg) of endotoxin extracted from Salmonella typhimurium strain SR-11 . Glycogen synthase and glycogen phosphorylase activities were measured at 0.5 and 6 h after treatment . Endotoxin treatment did not alter total glycogen synthase activity, but the amount of enzyme present in the active form was significantly lower in endotoxic mice . There was no significant increase in glycogen phosphorylase activity in endotoxin-treated mice . Glycogen phosphorylase was activated to the same extent in control and endotoxic mice by decapitation or intravenous epinephrine (25 or 1 mug/kg) . The results of this study indicate no significant increase in glycogen phosphorylase activity in endotoxic mice, contraindicating enhanced glycogenolysis as a mechanism for depletion of carbohydrate following endotoxin injection . Altered activation of glycogen synthase, however, may contribute to the loss of glycogen during endotoxemia. J Bacteriol, 1976 Oct, 128(1), 105 - 13 Arginine-sensitive phenotype of mutations in pyrA of Salmonella typhimurium: role of ornithine carbamyltransferase in the assembly of mutant carbamylphosphate synthetase; Abdelal AT et al.; The phenotype of certain mutations in pyrA, the gene encoding carbamylphosphate synthetase (CPSase), is expressed only in the presence od exogenous arginine . In unsupplemented media, synthesis of carbamylphosphate and growth was almost normal; in arginine-containing media, synthesis of carbamylphosphate stopped, as did growth, as a consequence of starvation for pyrimidine . Genetic and biochemical evidence suggests that arginine exerts this inhibition by repressing the synthesis of ornithine carbamyltransferase (OTCase), the intracellular presence of which is required for assembly of the unequal subunits and proper functioning of the mutant CPSase . After the addition of arginine to a culture of the mutant, CPSase activity (glutamine dependent) characteristic of the intact holoenzyme progressively decreased, whereas activity (ammonia dependent) characteristic of the free large (alpha) subunit increased . Extracts of mutant cells contain free small (beta) subunits, as demonstrated directly by in vitro complementation using purified alpha subunits from wild type . The mutant enzyme from cultures grown in the presence of arginine had a markedly decreased affinity for adenosine 5'-triphosphate . Mutations in argR that cause depressed synthesis of OTCase suppressed the phenotype, and a certain mutation in argI, the gene encoding OTCase, enhanced it . In vitro experiments using purified enzyme confirm the stimulatory effect of OTCase on the activity of mutant CPSase. Can J Microbiol, 1976 Oct, 22(10), 1549 - 60 Leakage of periplasmic enzymes from lipopolysaccharide-defective mutants of Salmonella typhimurium; Chatterjee AK et al.; Mutants of Salmonella typhimurium with defects in the heptose region of the lipopolysaccharide (LPS) molecule (heptose-deficient, chemotype Re) leak periplasmic enzymes (acid phosphatase (EC 3.1.3.2), cyclic phosphodiesterase, ribonuclease I (EC 3.1.4.22), and phosphoglucose isomerase (EC 5.3.1.9) (PGI is at least partially periplasmic in E . coli and S . typhimurium; see below)) and do not leak an internal enzyme (glucose-6-phosphate dehydrogenase) into the growth medium . The extent of this leakage is markedly increased at higher temperature (42 degrees C) . Leakage of periplasmic enzymes from the strains lacking units distal to heptose I in the LPS molecule (chemotype Rd2) occurs only at 42 degrees C, and not at 30 or 37 degrees C . The extent of leakage of these enzymes from smooth strain and mutants of other LPS chemotypes (Rc, Rd1) is not significant, and is not influenced by growth temperatures . The kinetics of leakage of periplasmic enzymes after shift to 42 degrees C in nutrient broth reveal an accelerated release into the medium from heptose-deficient strains of cyclic phosphodiesterase and ribonuclease I after 30 min at 42 degrees C, and phosphoglucose isomerase after 60 min at 42 degrees C; at 30 degrees C the rate of release of cyclic phosphodiesterase and ribonuclease I is relatively slower . After 60 min at 42 degrees C in nutrient broth, growth of these strains has either slowed down or stopped . In L-broth, which permits the growth of the heptose-deficient strain (SA1377) at 42 degrees C, leakage of cyclic phosphodiesterase and phosphoglucose isomerase occurs, whereas there is no detectable leakage of these enzymes from the isogenic smooth strain (SA1355) . Thus, leakage of the periplasmic enzymes from the heptose-deficient strain occurs with or without growth . Mg2+ (0.75 mM), sodium chloride (50 mM), and sucrose (100 mM) in nutrient broth at 42 degrees C prevent the leakage of these enzymes . The shedding of LPS from the heptose-deficient as well as the smooth strains is enhanced by high temperature (42 degrees C), whereas considerable leakage of protein occurs only in the heptose-deficient strain at 42 degrees C and not in the smooth strain . The smooth and heptose-deficient strains are equally sensitive to osmotic shock although a significant proportion of acid phosphatase and cyclic phosphodiesterase activities from the heptose-deficient cells grown at 42 degrees C comes off in the Tris-NaCl wash step suggesting a rather loose attachment of these enzymes onto the cell surface. J Bacteriol, 1976 Oct, 128(1), 86 - 98 Mutant strains (nit) of Salmonella typhimurium with a pleiotropic defect in nitrogen metabolism; Broach J et al.; We have isolated mutant strains (nit) of Salmonella typhimurium that are defective in nitrogen metabolism . They have a reduced ability to use a variety of compounds including glutamate, proline, arginine, N-acetyl-glucosamine, alanine, and adenosine as sole nitrogen source . In addition, although they grow normally on high concentrations of ammonium chloride (greater than 1 mM) as nitrogen source, they grow substantially more slowly than wild type at low concentrations (less than 1 mM) . We postulated that the inability of these strains to utilize low concentrations of ammonium chloride accounts for their poor growth on other nitrogen sources . The specific biochemical lesion in strains with a nit mutation is not known; however, mutant strains have no detectable alteration in the activities of glutamine synthetase, glutamate synthetase, or glutamate dehydrogenase, the enzymes known to be involved in assimilation of ammonia . A nit mutation is suppressed by second-site mutations in the structural gene for glutamine synthetase (glnA) that decrease glutamine synthetase activity. Biochim Biophys Acta, 1976 Sep 14, 445(2), 475 - 85 Metal ion requirement and tryptophan inhibition of normal and variant anthranilate synthase-anthranilate 5-phosphoribosylpyrophosphate phosphoribosyltransferase complexes from Salmonella tyrhimrium; Robison PD et al.; 1 . Both Mn2+ and Co2+ can replace Mg2+ as the required divalent cation for all activities of the enzyme complex between anthranilate synthase (chorismate pyruvate-lyase (amino-accepting), EC 4.1.3.27) and anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferase (N(5'-phosphoribosyl)-anthranilate:pyrophosphate phosphoribosytransferase, EC 2.4.2.18) from Salmonella typhimurium . They have much lower apparent Km values than Mg2+, both for glutamine-dependent anthranilate synthase (Mn2+ = 1.1 muM, Co2+ - 2.6 muM, Mg2+ = 83 muM) and for phosphoribosyltransferase (Mn2+ = 16 muM, Co2+ = 14.6 muM, Mg2+ = 133 muM) . The ratio of total Mg2+ to total Mn2+ found in a cell extract of S . typhimurium trpE2 , the source of normal enzyme complex, was found to be 350, suggesting that Mg2+ is probably utilized by the enzyme complex in vivo under our growth conditions . 2 . An enzyme complex has been isolated from a mutant strain of S . typhimurium (SO-515) that has a variation in the anthranilate synthase subunit which is thought to be a single amino acid substitution . This variation causes glutamine-dependent anthranilate synthase to be hypersensitive to feedback inhibition by tryptophan (Ki = 0.4 muM compared to Ki = 20 muM for normal enzyme complex) . The phosphoribosyltransferase in the variant enzyme complex is also hypersensitive to tryptophan but the kinetics are complex and involve activation by tryptophan in the presence of low amounts of 5-phosphoribosyl 1-pyrophosphate . 3 . In the variant enzyme complex the apparent Km for Mg2+ is elevated to 360 muM for glutamine-linked anthranilate synthase but reduced to 75 muM for phosphoribosyltransferase . 4 . These results suggest that the variant enzyme complex has altered tertiary and quaternary structures and that regulation of both activities is effected by tryptophan binding to only anthranilate synthase. Biochim Biophys Acta, 1976 Sep 14, 445(2), 464 - 74 Anthranilate synthase-anthranilate 5-phosphoribosylpyrophosphate phosphoribosyltransferases from Salmonella typhimurium . Purification of the enzyme complex and analysis of multiple forms; Grove TH et al.; 1 . The anthranilate synthase-anthranilate 5-phosphoribosylpyrophosphate phosphoribosyltransferase enzyme complex (chorismate pyruvatelyase (amino-accepting), EC 4.1.3.27) - (N-(5'-phosphoribosyl)-anthranilate: pyrophosphate phosphoribosyltransferase, EC 2.4.2.18), from Salmonella typhimurium has been purified with high yields to homogeneity . Sodium dodecyl sulfate gel electrophoresis of the purified enzyme complex revealed one major band containing 96% of the protein . The final yield of enzyme complex activity ranged from 30 to 60% . The absorbance spectrum of enzyme complex showed a peak at 280 nm and fine structure with peaks at 253, 259, 266 and 269 nm . These latter wavelengths correspond closely with the known absorbance maxima of phenylalanine . 2 . When purified enzyme complex was subjected to standard gel electrophoresis, a four band pattern of protein peaks was consistently observed . The major enzyme complex band was apparently the native tetramer, having a molecular weight 280 000 and containing ammonia- and glutamine-dependent anthranilate synthase activity . The other three bands were molecular weight isomers of the major enzyme complex band . Two forms of molecular weight isomers were present: dimers and an aggregate of the native enzyme complex . The molecular weight isomers of the enzyme complex may represent forms generated by aggregation and denaturation of the native enzyme complex . 3 . A new and highly sensitive spectrophotometric assay for phosphoribosyl-transferase is described . The method is based upon the difference in extinction coefficients between anthranilate and N-(5'-phosphoribosyl)anthranilate. J Biol Chem, 1976 Sep 10, 251(17), 5300 - 9 Oligopeptide transport in proline peptidase mutants of Salmonella typhimurium; Jackson MB et al.; Investigations of peptide transport in Salmonella typhimurium are presented . A strain designated proB25, a proline auxotroph, grew on a variety of di, tri-, and tetrapeptides containing proline . In contrast (Pro)6, peptides acylated on the NH2 terminus and Ala-Pro-D-Ala did not satisfy the nutritional requirement of proB25 for proline because they were not transported . A derivative of proB25, strain TN87, deficient in a proline aminopeptidase and an X-Pro dipeptidase, was able to utilize only four of 25 proline-containing peptides investigated . The inability of TN87 to grow on most of these peptides was due to the lack of the requisite peptidase activity . Evidence for a functional dipeptide transport system in this strain is indicated by growth on Pro-Leu and Pro-Ala, and by growth inhibition by certain X-Pro dipeptides . Leu-Pro, Val-Pro, Met-Pro, and Arg-Pro cause temporary growth inhibition of strain TN87 whereas Gly-Pro, Ala-Pro, and Pro-Pro have no effect on growth . Evidence for a functional oligopeptide transport system is indicated by growth on Pro-Val-Gly and Pro-Gly-Gly and by uptake of label from L-methionyl-L-methionyl-L-{14C}methionine and L-alanyl-L-prolyl-{14C}glycine . The presence of multiple oligopeptide transport systems for certain proline-containing peptides was demonstrated using triornithine-resistant mutants (oligopeptide permease deficient) and competition experiments . Finally L-Ala-L-Pro-{14C}Gly is shown to be transported intact into strain TN87. Biochim Biophys Acta, 1976 Sep 6, 442(3), 405 - 19 Vinyl chloride mutagenicity via the metabolites chlorooxirane and chloroacetaldehyde monomer hydrate; Elmore JD et al.; 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 Salmonella typhimurium strains sensitive to base-pair mutation . A recombination repair deficient strain of Bacillus subtilis was inhibited in growth by these compounds, whereas excision repair deficient and wild type strains of Bacillus subtilis were relatively unaffected . On the basis of these assays a working hypothesis for the vinyl chloride carcinogenesis mechanism is proposed which involves chlorooxirane and chloroacetaldehyde monomer hydrate as the ultimate carcinogenic metabolites of vinyl chloride. Biochem J, 1976 Sep 1, 157(3), 573 - 6 An apparent lack of stereospecificity in the reaction catalysed by deoxyribose 5-phosphate aldolase due to methyl-group rotation and enolization before product release; Corina DL et al.; In the reaction catalysed by deoxyribose 5-phosphate aldolase (2-deoxy-D-ribose 5-phosphate acetaldehyde-lyase, EC 4.1.2.4) from Salmonella typhimurium, almost complete equilibration of the methyl-group protons of the product, acetaldehyde, occurs before its release from the enzyme surface . This phenomenon does not allow the stereo-chemical course of the reaction to be determined by using hydrogen-isotope labelling of the methyl group to generate a chiral centre. J Gen Microbiol, 1976 Sep, 96(1), 109 - 16 The formation of a dissociable plasmid cointegrate from the Flac factor and the resident plasmid of Salmonella typhimurium LT2; Rodriguez Lemoine V et al.; The Flac factor showed unstable maintenance in Salmonella typhimurium dnaC MP10LT2 . The properties of a more stable lac+ derivate (SD-1) are described . SD-1 was ts and carried the fi+ property and the ability to transfer the lac+ character . It contained a large plasmid of molecular weight about 129 X 10(6) DALTONS . The properties of SD-1 and its derivatives suggested that the large plasmid was a cointegate of Flac and the MP10lt2 plasmid . Lac+ transfer was efficient from SD-1 to M799 MP10LT2 and one lac+ exconjugant contained the intact cointegrate . The cointegrate was not successfully transferred to strains lacking MP10LT2 . It dissociated into apparently unaltered Flac and MP10LT2 plasmids, but the deletion of small parts of one or both plasmids during cointegrate formation could not be ruled out . Cointegrate dissociation was more marked in M799 than in SD-1 especially during growth in glucose-Casamino acids minimal medium . In the presence of R1drd19, the cointegrate (like the MP10LT2 plasmid) was stable maintained in the dnaC strain; maintenance of Flac was, however, unstable . It seems likely that replication of the cointegrate was controlled by the MP10LT2 plasmid constitutent. Cancer Res, 1976 Sep, 36(9 pt.1), 3358 - 66 Mutagenicity and cytotoxicity of benzo(a)pyrene benzo-ring epoxides; Wood AW et al.; Four benzo-ring epoxides of the environmental carcinogen benzo(a)pyrene (BP) were tested for mutagenic and cytotoxic activity in 3 strains of Salmonella typhimurium (TA1538, TA98, and TA100) and in Chinese hamster V79 cells . Although very unstable in aqueous solution, 7beta,8alpha-dihydroxy-0beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (diol epoxide 1), with the 7-hydroxyl group on the same face of the molecule as the epoxide oxygen, was 1.5 to 4 times as mutagenic in the bacterial strains as was its more stable stereoisomer 7beta,8alpha-dihydroxy-9alpha,10beta-epoxy-7,8,9.10-tetrahydrobenzo(a)pyrene (diol epoxide 2) . In V79 cells, diol epoxide 1 had one-third the mutagenic activity of diol epoxide 2 but was at least 10 times more labile than diol epoxide 2 in the tissue culture medium . The half-life of diol epoxide 1 in tissue culture medium was about 30 sec, whereas the half-life of diol epoxide 2 was between 6 and 12 min . 9,10-Epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, which is saturated in the benzo ring, is also very unstable and has mutagenic activity equal to or greater than diol epoxide 1 in the bacterial and mammalian cells . 7,8-Epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene was more stable in aqueous solution than any of the 9,10-epoxides of BP but was much less mutagenic in both the bacterial and mammalian cells . In v79 cells, diol epoxides 1 and 2 and 9,10-opoxy-7,8,9,10-tetrahydrobenzo(a)pyrene were more than 40 times more cytotoxic than 7,8-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene . The mutagenicity of the 2 tetrahydro epoxides toward strain TA98 of S . typhimurium was readily abolished by purified epoxide hydrase, whereas the mutagenic activity of the 2 diol epoxides was relatively unaffected by coincubation with the enzyme. Cancer Res, 1976 Sep, 36(9 pt.1), 3350 - 7 Mutagenicity and cytotoxicity of benzo(a)pyrene arene oxides, phenols, quinones, and dihydrodiols in bacterial and mammalian cells; Wislocki PG et al.; Twenty-nine benzo(a)pyrene derivatives were tested for mutagenic acitivity without metabolic activation in Salmonella typhimurium strains TA98, TA100, and TA1538 and in Chinese hamster V79 cells . The compounds studied included 4 arene oxides, all 12 isomeric phenols, 5 quinones, and 8 dihydrodiols . Benzo(a)pyrene 4,5-oxide was the most mutagenic of the compounds tested in both the bacterial and mammalian systems . The other arene oxides {benzo(a)pyrene 7,8-, 9,10-, and 11,12-oxides} were only weakly mutagenic in the S . typhimurium strains . However, in Chinese hamster V79 cells benzo(a)pyrene 11,12-oxide . Among the phenols, 6-hydroxybenzo(a)pyrene and 12-hydroxybenzo(a)pyrene were moderately mutagenic in strain TA98 of S . typhimurium, and 6-hydroxybenzo(a)pyrene was moderately mutagenic in V79 cells . The other 10 phenols, 5 quinones {benzo(a)pyrene 1,6-, 3,6-, 4,5-, 6, 12-, and 11,12-quinones} and 8 dihydrodiols {benzo(a)pyrene cis-4,5,trans-4,5-, cis-7,8-, trans-7,8-, cis-9,10-, trans-9,10-, cis-11,12-, and trans-11, 12-dihydrodiols} were eitherinactive or only weekly mutagenic . 1-Hydroxybenzo(a)pyrene and 3-hydroxybenzo(a)pyrene were weakly mutagenic in strain TA98 of S . typhimurium, and benzo(a)pyrene 7,8-dihydrodiol was weakly mutagenic in V79 cells . Benzo(a)pyrene 11,12-quinone was extremely cytotoxic to the V79 cells but had no observable toxicity in the bacterial strains. Infect Immun, 1976 Sep, 14(3), 671 - 9 Isolation of skin permeability factors from culture filtrates of Salmonella typhimurium; Sandefur PD et al.; Engerotoxins isolated from Vibrio cholerae and toxigenic Escherichia coli cause permeability alterations in rabbit skin . Firm induration and erythema are observed within 18 to 24 h, and visualization of the reaction may be enhanced by intravenous injection of Pontamine sky blue dye . Two skin permeability factors (PF) have been found in culture filtrates of Salmonella typhimurium . A rapid acting factor, produced optimally in brain heart infusion broth at 37 degrees C by numerous Salmonella species, has a critical bluing time of 1 h after completion of skin testing . This rapid PF is heat stable at 100 degrees C for at least 4 h and has no associated induration . The delayed factor is heat labile, being completly destroyed within 30 min at 75 degrees C and causes marked duration of the rabbit skin within 18 h that is indistinguishable from the permeability reactions of V . cholerae and E . coli enterotoxins . Induration produced by the delayed PF is observed only after chromatography of the culture filtrate on a Sephadex G-100 column . Thus, the effects of the delayed PF appear to be masked or blocked by an inhibitor-like substance present in crude culture filtrates . Both early and delayed factors are estimated to have a molecular weight of at least 90,000 . It is postulated that one or both of these factors may participate in the pathogenesis of Salmonella infections. Infect Immun, 1976 Sep, 14(3), 652 - 9 Variability of protection in inbred mice induced by a ribosomal vaccine prepared from Salmonella typhimurium; Misfeldt ML et al.; Ribosomal vaccines prepared from Salmonella typhimurium were effective immunogens in A/J inbred mice and C3H/HeTex, inbred mice . However, ribosomal vaccines were not protective in C57BL/6J inbred mice . A/J mice were protected against lethal challenge by attenuated S . typhimurium live-cell, ribosomal, phenol, and heat-killed vaccines . C3H/HeTex mice were protected by live-cell, ribosomal, and phenol vaccines but not the heat-killed vaccine . Only the live-cell vaccine gave significant protection in the C57BL/6J inbred mice . A comparison of the kinetics of infection in sham-immunized mice and mice immunized with ribosomes showed that ribosome preparations elicited protection against Salmonella infection in mice inherently sensitive and resistant to Salmonella. Mutat Res, 1976 Sep, 36(3), 283 - 90 A recombination-dependent replicating instability in Salmonella typhimurium; Murray GE et al.; The aromatic amino acid-requiring mutant of Salmonella typhimurium aroD321 has a stable requirement for phenylalanine and tyrosine but is highly unstable in its requirement for tryptophan . Tryptophan requiring cells derived from this strain are themselves unstable and revert back to a requirement for only phenylalanine and tyrosine . This instability is cotransducible with the aroD region and is totally dependent on the presence of a rec+ gene in the cell . These observations are interpreted in terms of a gene duplicating and excising mechanism which is itself dependent upon the normal (rec+) recombinational ability of the cell. J Bacteriol, 1976 Sep, 127(3), 1414 - 26 Interference with propagation of typing bacteriophages by extrachromosomal elements in Salmonella typhimurium: bacteriophage type 505; van Embden JD et al.; Samonella typhimurium bacteriophage type 505 is the most frequently encountered phage type in the Netherlands and its neighboring countries . Phage type 505 was analyzed with regard o the interference with propagation of the typing phages by the prophages and plasmids, present in the type strain S . typhimurium 505... J Bacteriol, 1976 Sep, 127(3), 1292 - 7 Temperature-sensitive ribonucleic acid polymerase mutant of Salmonella typhimurium with a defect in the beta' subunit; Young BS et al.; Localized mutagenes of Salmonella typhimurium followed by a {3H}uridine enrichment procedure yielded a temperature-sensitive strain with a mutation in the rpo region of the chromosome . Ribonucleic acid (RNA) polymerase (EC 2.7.7.6; nucleoside triphosphate: RNA nucleotidyltransferase) purified from this mutant was considerably less active at the nonpermissive temperature than wild-type enzyme . Furthermore, the enzyme from this mutant, unlike RNA polymerase of previously isolated temperature-sensitive mutants, was as thermostable as wild-type enzyme when preincubated at 50 degrees C . Subunit reconstitution experiments have shown that the temperature sensitivity is caused by an alteration in the beta' subunit of the enzyme. J Biol Chem, 1976 Aug 25, 251(16), 4882 - 90 Metabolism of benzo(a)pyrene and benzo (a)pyrene derivatives to mutagenic products by highly purified hepatic microsomal enzymes; Wood AW et al.; 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, and cytochrome P-448 and is partially dependent on phosphatidylcholine . Mutation frequency in both strains is linearly related to amount of cytochrome P-448 and to time of incubation . Highly purified cytochrome P-450 from phenobarbital-treated rats is relatively poor in catalyzing the formation of mutagenic metabolites from benzo (a)pyrene . Addition of 7.5 to 75 units of highly purified epoxide hydrase to the cytochrome P-448-dependent monooxygenase system decreases the number of mutations by approximately 50% and30% in strains TA 1538 and TA 98, respectively . Additional amounts of epoxide hydrase (300 units) fail to further suppress mutations, indicating that at least some, but probably not all, of the mutagenic metabolites of benzo (a)pyrene are arene oxides . In the absence of a monooxygenase system, mutations induced by benzo (a)pyrene 4,5-oxide are readily quenched by epoxide hydrase, whereas mutations induced by a diol epoxide metabolite of benzo (a)pyrene {(+/-)-7 beta, 8alpha-dihydroxy-9beta, 10beta-epoxy-7,8,9,10-tetrahydrobenzo (a)pyrene} are not . Several known and potential phenolic and dihydrodiol metabolites of benzo (a)pyrene are metabolized to products mutagenic in the Salmonella . The number of mutations induced per nmol of hemoprotein is approximately 3- to 4-fold higher when trans-7,8-dihydroxy-7,8-dihydrobenzo (a)pyrene replaces benzo (a)pyrene as a substrate for the cytochrome P-448-dependent monooxygenase system . Little or no mutagenic activity is observed with trans-dihydrodiols at positions 4,5, 9,10, or 11,12 of the hydrocarbon, either in the absence or presence of the active monooxygenase system . Of the 12 possible isomeric monophenols of benzo (a)-pyrene, only 6- and 12-hydroxybenzo (a)pyrene are moderately active bacterial mutagens; 1-, 2-, 3-, 6-, 9-, and 12-hydroxybenzo (a)pyrene are premutagens (i.e . metabolized to mutagenic products); and 4-, 5-, 7-, 8-, 10-, and 11-hydroxybenzo (a)pyrene have little or no mutagenic activity with or without further oxidative metabolism . Benzo (a)pyrene 7,8-oxide, a carcinogen on mouse skin, is weakly mutagenic but can be further metabolized to a highly active bacterial mutagen(s), presumably diol epoxide(s), by a combination of epoxide hydrase and the cytochrome P-448 monooxygenase system . This is the first example of a direct role of epoxide hydrase in the metabolic activation of a chemical to a toxic product. Biochim Biophys Acta, 1976 Aug 24, 444(1), 321 - 5 Simultaneous selection of mutants in gluconeogenesis and nucleoside catabolism in Salmonella typhimurium; Jargiello P; Penicillin selection in minimal thymidine medium, used to select mutants in deoxynucleoside catabolism, also yields a high percentage (37%) of mutants in fructose diphosphatase . The expression of the deo regulon is retarded in the mutants defective in the glyconeogenic pathway. Mol Gen Genet, 1976 Aug 19, 147(2), 195 - 202 Growth of coliphage BF23 on rough strains of Salmonella typhimurium: the bfe locus; Mojica-a T et al.; Coliphage BF23 develops in Salmonella typhimurium rough strains . The phage is neither restricted nor modified by S . typhimurium . The growth patterns of the phage were slightly different in S . typhimurium than in Escherichia coli, although phage propagated on S . typhimurium is identical to the phage propagated in E . coli by several criteria used . Mutants of S . typhimurium resistant to BF23 were isolated and found to map (by P22- and Pl-mediated transduction) in the same position as bfe mutants of E . coli . The order of genes was: metB - argC - bfe - rif - purD - metA . Phage BF23 does not form plaques on smooth S . typhimurium strains, since the phage fails to adsorb irreversibly to smooth cells . Nevertheless, on solid agar, the phage prevents growth of many (but not all) smooth strains . Moreover, UV- and alkali-inactivated phage BF23, although unable to form plaques on sensitive hosts, retains the ability to prevent growth of the host on solid medium . This ability is sensitive to protease and resistant to DNAse and RNase . Heat treatment of the phage causes rapid loss of the cell-growth-preventing-ability whereas the ability to form plaques is lost much more slowly . These results lead to a proposal that phage BF23 virions carry a colicin-like factor that kills sensitive cells. J Biol Chem, 1976 Aug 10, 251(15), 4570 - 8 A heterologous system for detecting eukaryotic enzymes which synthesize pseudouridine in transfer ribonucleic acids; Mullenbach GT et al.; tRNA pseudouridylation activities have been detected in embryonic mouse cell fractions and in extracts from HeLa, mouse L-cell and baby hamster kidney (BHK) cell lines . These activities were identified by the use of heterologous reaction systems, with tRNA from hisT strains of Salmonella typhimurium as substrate . hisT mutants are defective for an enzyme that forms psi residues in the anticodon region of many tRNAs and accumulate undermodified species of tRNA . The pseudouridylation activity from BHK cells has been examined in detail and quantitated by a modified tritium release assay (Cortese, R., Kammen, H.O., Spengler, S.J., and Ames, B.N . (1974) J . Biol . Chem . 249, 1103-1108) . Maximal rates of tritium release required a suitable cationic environment (optimally, a combination of Mg2+ and NH4+) and a thiol reductant . The activity was totally inhibited in the presence of thiol-reactive reagents, such as 5,5'-dithiobis(2-nitrobenzoic acid) and p-chloromercuribenzoate . A major portion of this 3H release activity was associated with psi modification reactions . This conclusion stems from the following observations: (a) BHK extracts preferentially catalyzed a release of 3H from hisT {5-3H}tRNA, rather than from similarly labeled wild type tRNA; (b) this activity was specific for protons attached to C5 of the pyrimidine rings; no release of 3H was obtained with hisT or wild type {6-3H}tRNA as substrate; (c) the reaction products of hisT tRNA with BHK enzyme were examined by reverse phase column chromatography of tRNAPhe isoacceptors on RPC-5 columns . The enzyme modified both of the principal isoacceptors of hisT tRNAPhe to an equal extent, yielding products indistinguishable from wild type tRNAPhe . Significant levels of 3H release were obtained by the action of enzyme on wild type {5-3H}tRNA, even after gel filtration of the enzyme . This suggests that the enzyme may be able to hypermodify certain species of wild type S . typhimurium tRNA . The activities for wild type tRNA and hisT tRNA appeared to be associated with the same enzyme. J Hyg (Lond), 1976 Aug, 77(1), 51 - 4 Salmonellosis in wild mammals; Jones PW et al.; 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 present appear to constitute a reservior for infection of domestic animals. Infect Immun, 1976 Aug, 14(2), 439 - 48 Enzymatic activities leading to pyrimidine nucleotide biosynthesis from cell-free extracts of Rickettsia typhi; Williams JC et al.; 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), were not detected in R . typhi extracts with the phosphate donors effective for control enzymes . The following enzyme activities were demonstrated in R . typhi: uridine-5'-monophosphate kinase (UMPK, EC 2.7.4.4), deoxythymidine-5'-monophosphate kinase (dTMPK, EC 2.7.4.9), and nucleosidediphosphate kinase (NDPK, EC 2.7.4.6) . Physicochemical and enzymatic analyses demonstrated that the pyrimidine nucleotide kinases of R . typhi were not of host origin and that the source (yolk sac and mouse L cells) did not influence the relative enzymatic activities . The specific activities of UMPK and dTMPK were higher when the rickettsiae were harvested before embryo death, whereas NDPK levels were slightly decreased . The specific activities of UMPK, dTMPK, and NDPK were comparable to those of S . typhimurium, and consequently the rickettsiae have potential for the anabolism of monophosphates, as do the host-independent bacteria . These results suggest that R . typhi cannot utilize host uridine or thymidine pools directly but must rely on themonophosphorylated molecules of the host cell or must synthesize the monophosphates de novo. Aust N Z J Med, 1976 Aug, 6(4), 345 - 7 Salmonella typhimurium colitis; Green PH et al.; A patient in whom Salmonella typhimurium infection caused a localised colitis is described . Colitis has been demonstrated in experimental animals infected with S . typhimurium and noted at post mortem in patients dying from S . typhimurium infection . However colitis is an infrequently recognised feature of this infection in man, the usual diagnosis being one of gastroenteritis . There have been four other cases reported with radiological evidence of colonic involvement due to salmonella infection . Colitis probably occurs more frequently than is usually recognised in this condition and must be distinguished from ulcerative colitis. Genetics, 1976 Aug, 83(4), 619 - 32 Thialysine-resistant mutant of Salmonella typhimurium with a lesion in the thrA gene; Jegede VA et al.; A mutant of Salmonella typhimurium was selected for its spontaneous resistance to the lysine analog, thialysine (S-2-aminoethyl cysteine) . This strain, JB585, exhibits a number of pleiotropic properties including a partial growth requirement for threonine, resistance to thiaisoleucine and azaleucine, excretion of lysine and valine, and inhibition of growth by methionine . Genetic studies show that these properties are caused by a single mutation in the thrA gene which encodes the threonine-controlled aspartokinase-homoserine dehydrogenase activities . Enzyme assays demonstrated that the aspartokinase activity is unstable and the threonine-controlled homoserine dehydrogenase activity absent in extracts prepared from the mutant . These results explain the growth inhibition by methionine because the remaining homoserine dehydrogenase isoenzyme would be repressed by methionine, causing a limitation for threonine . The partial growth requirement for threonine during growth in glucose minimal medium may also, by producing an isoleucine limitation, cause derepression of the isoleucine-valine enzymes and provide an explanation for both the valine excretion, and azaleucine and thiaisoleucine resistance . The overproduction of lysine may confer the thialysine resistance. J Virol, 1976 Aug, 19(2), 313 - 7 Genetic characterization of a phi80 transducing bacteriophage carrying the histidine operon of Salmonella typhimurium; Isaki LS et al.; A phi 80 transducing phage, phi 80imm lambdadhis, carrying the Salmonella his-gnd region, was characterized by immunity studies, tonB deletion analysis, and marker rescue analysis . Phi 80imm lambdadhis retains the phage immunity region of the phi 80-lambda hybrid phage from which it was derived . Bacterial genes replace most late phage genes . Deletion analysis shows the prophage gene order to be immlambda-his-gnd and indicates the orientation of the his operon to be hisOGDCBHAFIE-gnd . The structure of phi 80imm lambdadhis is remarkably similar to two independently isolated phi 80 phages that carry the his-gnd region of Escherichia coli and that, like phi80imm lambdahis, were derived by directed gene transposition to the tonB locus . A derivative of phi 80imm lambdadhis that is phi 80 immune is also reported. J Bacteriol, 1976 Aug, 127(2), 941 - 55 Bacteriophage-resistant mutants of Salmonella typhimurium deficient in two major outer membrane proteins; Nurminen M et al.; Mutants resistant to bacteriophages (P221 and PH105 or PH51) were isolated from a rfa strain of Salmonella typhimurium . They were found deficient in separate 33,000- to 36,000-dalton band proteins (major band proteins) . Double mutants derived from both types of mutants were deficient in both of the bands . The growth behavior of all the mutants was normal . The outer membrane of the mutants appeared to be more wrinkled than normal and formed vesicles in many of the mutants . In freeze-fractured cells, changes were seen in the outer membrane (particleless patches in the concave fracture face, the particles themselves being smaller than normal) . These changes were more marked in the double mutants. Mutat Res, 1976 Aug, 38(4), 259 - 70 Enhancement of base pair substitution induced by alkylating mutagens in simulated hyperbaric diving environments; Wild JR; The effect of simulated saturated diving environments on mutagenicity was investigated using two histidine auxotrophs (hisG46 and hisTA1950 derived by Ames from Salmonella typhimurium LT2) exposed to several chemical mutagens . In agar diffusion tests with impregnated paper discs, 68 atm of normoxic supporting gases (containing 0.2 atm O2) reduced the number of histidine revertants of auxotrophs exposed to N-methyl-N'-nitro-N-nitrosoguanidine (NTG) and two other alkylating agents . The effect was induced in increasing order by helium, a mixture of neon and helium, nitrogen and argon . The effect of the gases on the growth of the two strains was small and did not explain the reduction of revertant recovery . On the other hand, it was shown that NTG in concentrations of 0.6 to 250 mug/ml was significantly more lethal for the hisG46 strain under 68 and 136 atm than at 1 atm . Revertant recovery was similarly related in both conditions . The maximal number of revertants, approx . 2.6 X 10(4), was obtained at 136 atm when the concentration of NTG was 0.6--1.25 mug/ml and at 1 atm when the concentration of NTG was 5--10 mug/ml . A comparable hydrostatic environment did not affect revertant recovery . The most plausible interpretation of these results is that hyperbaric environments accelerate the rate of intracellular accumulation of NTG, which is manifest in greater mutagenicity at the lower concentrations and greater lethality at all concentrations. Zentralbl Bakteriol {Orig A}, 1976 Aug, 235(4), 439 - 52 Ultrastructure of lipopolysaccharides of Yersinia enterocolitica, Salmonella typhimurium and Escherichia coli; Acker G et al.; The fine structure of isolated lipopolysaccharides (LPS) from the rough and smooth form of an Yersinia enterocolitica strain (Ye 75 R/Ye 75 S) and from smooth forms of Salmonella typhimurium (S 1010) and Escherichia coli (Essen) were examined electron-microscopically by negative staining . Partial denaturation of LPS in Tris-buffer with acid and/or polymyxin B treatment revealed a common structure of strandlike LPS . Electron-microscopically, LPS-strands were found to consist of two identical sub-strands which form a double helix . High resolution electron microscopy permitted the identification of a total of four longitudinal fibrils (diameter approximately 20 A); therefore, each sub-strand consists of two longitudinal fibrils . These results were correlated with those obtained with positive staining procedure and chemical fixation technique . The development of the "double-track"-profile of the outer membrane was interpreted to result from the projection of the helical longitudinal fibrils into the image plane. Arch Microbiol, 1976 Aug, 109(1-2), 51 - 8 Action of polymyxin B on bacterial membranes . Binding capacities for polymyxin B of inner and outer membranes isolated from Salmonella typhimurium G30; Teuber M et al.; Radioactive mono-N-acetyl-14C-polymyxin B or natural polymyxin B are within 60 s absorbed by isolated inner (cytoplasmic) and outer membranes from Salmonella typhimuriumG30 . The sigmoidal binding isotherms indicate saturation of inner and outer membranes with approximately 30 and 60 nmoles polymyxin B bound per mg membrane, respectively . Based on the known content of these membranes in lipopolysaccharide, phosphatidylglycerol, cardiolipin and phosphatidylethanolamine, a calculation of the theoretical binding capacities yields almost identical values if lipopolysaccharide, phosphatidylglycerol and cardiolipin are assumed to function as the actual binding sites for the antibiotic in the isolated membranes . The excellent agreement between theoretical evaluation and experimental determination of polymyxin B-binding capacities leaves little doubt that the named anionic compounds are the chemoreceptors for the cationic antibiotic . This is further substantiated by very similar binding and killing kinetics of polymyxin B. Metabolism, 1976 Aug, 25(8), 877 - 84 The effect of bacterial infections on ketone concentrations in rat liver and blood and on free fatty acid concentrations in rat blood; Neufeld HA et al.; The concentrations of cytoplasmic lactate and pyruvate and the NAD+/NADH ratio and the concentrations of mitochondrial acetoacetate, beta-hydroxybutyrate, and the NAD+/NADH ratio were determined in normal, fed, and fasted rats, and in rats infected with Streptococcus pneumoniae, Francisella tularensis, and Salmonella typhimurium . The various infections were found to have little or no effect on the cytoplasmic parameters . In normal rats, fasting caused a marked increase in blood and hepatic ketone concentration and in serum free fatty acid content . Fasted infected rats, however, did not show the increase in ketone bodies or serum free fatty acids normally associated with fasting alone . The mitochondrial NAD+/NADH ratio increased as the infections progressed, reversing the normal trend . The introduction of an infection during the fasting state when ketone bodies and serum free fatty acids were elevated caused a marked depression in their concentration . These data have led to a postulation of decreased lipolysis in the infected host to account for the lowered hepatic and blood ketone bodies and the decreased level of serum free fatty acids. J Gen Microbiol, 1976 Aug, 96(2), 324 - 34 The regulation of glutamine transport and glutamine synthetase in Salmonella typhimurium; Betteridge PR et al.; Transport of glutamine by the high-affinity transport system is regulated by the nitrogen status of the medium . With high concentrations of ammonia, transport is repressed; whereas with Casamino acids, transport is elevated, showing behaviour similar to glutamine synthetase . A glutamine auxotroph, lacking glutamine synthetase activity, had elevated transport activity even in the presence of high concentrations of ammonia (and glutamine) . This suggests that glutamine synthetase is involved in the regulation of the transport system . A mutant with low glutamate synthase activity had low glutamine transport and glutamine synthetase activities, which could not be derepressed . A mutant in the high-affinity glutamine transport system showed normal regulation of glutamate synthase and glutamine synthetase . Possible mechanisms for this regulation are discussed. J Bacteriol, 1976 Aug, 127(2), 837 - 47 Deoxyribonucleic acid-binding studies on the hut repressor and mutant forms of the hut repressor of Salmonella typhimurium; Hagen DC et al.; In Salmonella typhimurium the genes coding for the enzymes of histidine utilization (hut) are clustered in two adjacent operons, hutMIGC and hut(P,R,Q)UH . A single repressor, the product of the C gene, regulates both operons by binding at two operator sites, one near M and one in (P,R,Q) . The deoxyribonucleic acid (DNA)-binding activity of the repressor was measured using DNA's containing separate operators . The repressor had greater activity when assayed using DNA containing the operator of the (P,R,Q)UH operon than when assayed using DNA containing the operator of the MIGC operon . The binding to either operator was absent in the presence of the inducer, urocanate . The DNA-binding activities were also determined for two super-repressors . The super-repressors had altered DNA-binding properties, although the self-regulated nature of the repressors complicated the analysis of the results . A purfication procedure for the wild-type repressor is presented . The purified repressor was somewhat unstable, and additional experiments using it were not performed. Mol Cell Biochem, 1976 Jul 30, 12(1), 15 - 22 Methionine-repressible homoserine dehydrogenase of Serratia marcescens: purification and properties; Shailaja MS et al.; Serratia marcescens Sa-3 possesses two homoserine dehydrogenases and neither has any aspartokinase activity unlike the case of Escherichia coli enzymes . The two enzymes have been separated . One of them is active with either NAD+ or NADP+ and has been purified about 180-fold to homogeneity . This enzyme is completely repressed by the presence of 1 mM methionine or homoserine in the growth medium, but its activity is unaffected by any amino acid of the aspartate family either singly or together . In many of its properties (such as pH optimum, Km for substrate and cofactors), it resembles its counterpart in E . coli K12 . Potassium ions stabilize the enzyme but are not essential for activity . Its molecular weight is around 155,000 as determined by gel filtration and approximately 76,000 by SDS-polyacrylamide gel electrophoresis . This suggests that the enzyme has two subunits (polypeptide chains) in the molecule: 8 M urea has no effect on enzyme activity . This enzyme represents approximately 30% of the total homoserine dehydrogenase activity of S . marcescens unlike in Salmonella typhimurium and E . coli K12 where it is a minor or a negligible component. J Toxicol Environ Health, 1976 Jul, 1(6), 921 - 8 Protocols for the dominant lethal test, host-mediated assay, and in vivo cytogenetic test used in the food and drug administration's review of substances in the gras (generally recognized as safe) list; Green S et al.; Protocols are described for the dominant lethal and in vivo cytogenetics test in rats and the host-mediated assay, using Salmonella typhimurium and Saccharomyces cerevisiae in mice, as used by the Food and Drug Administration in its mutagenicity review of substances from the generally recognized as safe (GRAS) list . In addition proctolols are described for in vitro mutagenicity tests with S . typhimurium and S . cerevisiae and for statistical treatment for evaluation of data from dominant lethal tests. Nord Vet Med, 1976 Jul-Aug, 28(7-8), 385 - 91 {Salmonella bacteria in double cream (author's transl)}; Fonden R et al.; In June 1974 a serious outbreak salmonellosis was reported from the southeast of Sweden . The epidemic was caused by Salmonella typhimurium and spread by infected cream, packed in one-way paper-plastic containers . Ordinary pasteurization of cream purposely infected with the strain in question at 60 degrees for 38 sec or 67 degrees C for 4,5 sec, resulted in a reduction by more than 7 decimal logs (Table I) . The decimal reduction time at 60 degrees in cream was estimated to roughly 1.3 sec . The cream, which caused the outbreak, was pasteurized at 90 degrees C for 2-3 sec, which should destroy all salmonella in raw cream . In Sweden pasteurized cream has to be stored at a temperature not higher than 8 degrees C . The isolated salmonella strain was not able to grow at + 8 degrees or at + 10 degrees C during 17 days in pasteurized or UHT-treated cream . During this storage the viable counts were reduced by 79% at 8 degrees and 54% at 10 degrees C . Minimum growth temperature of the strain was 11-12 degrees C . The mean generation time in pasteurized cream at 12 degrees was 9.4 hours and at 15 degrees C 3.4 hours (Fig . 1 and 2) . The salmonella strain was able to grow in competition with other bacteria in pasteurized cream even at low levels of infection (Table II) . An exposure to a higher temperature, followed by storage at + 8 degrees C did not cause a further growth of salmonella at the low temperature (Fig 3) . To avoid a recurrence, the possibility of reinfection of the cream with salmonella has to be further decreased and the cream has to be stored at a low temperature during all the storage period. Mutat Res, 1976 Jul, 40(3), 203 - 24 Mutagenesis by 9,10-anthraquinone derivatives and related compounds in Salmonella typhimurium; Brown JP et al.; Ninety 9,10-anthraquinone (AQ) derivatives and related anthracene derivatives were screened for mutagenicity with five Salmonella typhimurium tester strains with and without mammalian microsomal activation . About 35% of the compounds tested are considered to be mutagenic . Three patterns of mutagenesis were apparent . (1)Direct frameshift mutagenesis by certain AQ compounds bearing free hydroxyl groups . The most potent were anthragallol (1,2,3-trihydroxy-AQ), purpurin (1,2,4-trihydroxy-AQ) and anthraufin (1,5-dihydroxy-AQ) . Some hydroxy-AQ compounds exhibited activation by mammalian microsomal preparations, particularly at lower concentrations, and the majority of mutagenic hydroxy-AQs appeared to revert strain TA1537 (his 3076) specifically.(2)Frameshift mutagenesis by certain AQ compounds with primary amino and, in a few cases, with secondary amino groups . Mammalian microsomes invariably potentiated frameshift mutagenesis, and activity with strain TA100 (sensitive to base pair substitution) is seen in a few cases, e.g . 1,2-diamino-AQ . (3)AQ compounds with one or more nitro groups . These derivatives exhibit the least specificity with regard to tester strain reverted and to microsomal activation . All seven nitro-AQ's tested were mutagenic . In those compounds with mixed "mutagenic" functional groups, the type of mutagenesis observed is usually N02 greater than 0H greater than NH2 . AQs bearing halogens, sulfonate or alkyl groups were non-mutagenic, as were AQs substituted solely with secondary amines. Mutat Res, 1976 Jul, 40(3), 197 - 202 Mutagenicity and toxicity of amitrole . III . Microbial tests; Bamford D et al.; Amitrole (3-amino-1,2,4-triazole) inhibits bacterial growth both in Escherichia coli and Salmonella typhimurium at a concentration of 0.5% in minimal medium . Repression of growth already occurs at a concentration of 0.1% of amitrole in this medium . In complete medium the bacteria tolerate concentrations of amitrole as high as 1.7-2.4% before growth ceases . Mutagenicity was tested by differential growth comparisons on E . coli strains W 3110 thy pol A1, defective in DNA polymerase I, and its revertant pol A+ . Known mutagens (MMS, NTG, mitomycin C) were used as positive controls . Analogous negative results were also obtained in a revertant test when several trp mutant strains of Salmonella were used. J Gen Microbiol, 1976 Jul, 95(1), 166 - 72 DNA restriction and modification systems in Salmonella . SQ, a new system derived by recombination between the SB system of Salmonella typhimurium and the SP system of Salmonella potsdam; Bullas LR et al.; As the result of P1-mediated cotransduction with serB from Salmonella potsdam to the Escherichia coli/Salmonella typhimurium hybird 4617, one recombinant, L4004, was isolated which had a restriction-modification (R--M) system different from the SB and SP systems of its parents, and was designated SQ . The genes of SQ were allelic to those of the SB system of S . typhimurium and were shown by complementation experiments to be functionally related to those of the K system of E . coli . Evidence that the SQ system in L4004 arose as the result of a recombination event within the hsdS genes of SB and SP is discussed. Genetics, 1976 Jul, 83(3 PT.2), 459 - 75 Specialized transducing phages derived from phage P22 that carry the pro AB region of the host, Salmonella typhimurium: genetic evidence for their structure and mode of transduction; Jessop AP; Two independently isolated specialized transducing phages, P22pro-1 and P22pro-3, have been studied . Lysates of P22pro-1 contain a majority of transducing phages which can go through the lytic cycle only in mixed infection; these defective phages transduce by lysogenization in mixed infection and by substitution in single infection . A few of the transducing phages in P22pro-1 lysates appear to be non-defective, being able to form plaques and to transduce by lysogenization in single infection . Transduction by P22pro-3 lysates is effected by non-defective transducing phages, which transduce by lysogenization; these lysates also contain a majority of defective phages which do not co-operate in mixed infection . The P22pro-1 genome is thought to contain an insertion of bacterial DNA longer than the terminal repetition present in P22 wild type, so that at maturation a population of differently defective phages is produced . The exact structure of the P22pro-3 genome is open to conjecture, but it seems clear that the insertion of bacterial DNA is smaller than that in P22pro-1 . Both P22pro-1 and P22pro-3 are defective in integration at ataA under non-selective conditions, although both integrate on medium that lacks proline. Genetics, 1976 Jul, 83(3 PT.2), 433 - 58 Specialized transduction by bacteriophage P22 in Salmonella typhimurium: genetic and physical structure of the transducing genomes and the prophage attachment site; Chan RK et al.; P22pro-1 and P22pro-3 are specialized transducing derivatives of phage P22 that carry the proA and proB genes of Salmonella typhimurium . These genes lie immediately adjacent to the prophage attachment site on the bacterial chromosome . By examining DNA heteroduplexes in the electron microscope, we found that DNA molecules from P22pro-1 and P22pro-3 each contain a substitution which adds length to the composite genome making the intracellular replicated genome too long to fit into a single phage particle . In this respect, and in many of their biological properties, the proline-transducing phages resemble P22Tc-10, another specialized transducing phage with an oversize, intracellular replicated genome which carries a tetracycline-resistance determinant from an R-factor.--Unlike P22Tc-10, however, P22pro-1 and P22pro-3 fail to integrate normally during lysogenizing infections, even when provided with all known integration functions . These results suggest that the proline substitutions have created a defect in the phage attachment site and suggest that the Campbell model for the formation of specialized transducing phages is applicable to phage P22 with the additional feature that oversize genomes can be produced and propagated.--A physical and genetic map of the P22 genome near the prophage attachment site was constructed which shows that the insertion from the R-factor in P22Tc-10 is not at the attachment site: it is therefore unlikely that P22Tc-10 was formed in an abnormal prophage excision event as envisioned in the Campbell model, but was instead the result of a direct translocation from the R-plasmid to P22. Poult Sci, 1976 Jul, 55(4), 1580 - 2 Effects on body temperature produced by micro-injection of Salmonella typhimurium lipopolysaccharide into the third cerebral ventricle of the chicken; Kane E et al.; Salmonella typhimurium lipopolysaccharide was injected into the third cerebral ventricle of the hen via a surgically implanted cannula . Hens injected with 20-80 mug . Salmonella typhimurium lipopolysaccharide had higher (P less than .01) rectal temperatures (42.3 degrees C . compared to 41.3 degrees C.) than uninjected hens . Those injected with 0.9% NaCl had significantly lower (P less than .01) rectal temperatures (41.8 degrees C . compared to 42.3 degrees C.) than hens injected with this bacterial pyrogen . There is an indicated function for bacterial pyrogen acting directly in the hypothalamic area of the chicken. J Bacteriol, 1976 Jul, 127(1), 664 - 6 Partial characterization of nucleoids and nucleoid-plasmid complexes from Salmonella typhimurium; Manis JJ et al.; Nucleoids from Salmonella typhimurium strain LT2 consist of supercoiled deoxyribonucleic acid structures that are ribonuclease labile sedimenting at 1,700S . More than 90% of the covalently closed circular deoxyribonucleic acid of a cryptic plasmid harbored by this strain cosediments with the host's 1,700S nucleoids. J Bacteriol, 1976 Jul, 127(1), 51 - 8 Comparative study of R1-specific chromosomal transfer in Escherichia coli K-12 and salmonella typhimurium LT2; Heden LO et al.; High-frequency transfer of the chromosomal trp region by R1 observed in Escherichia coli (Pearce and Meynell, 1968) also occurs in Salmonella typhimurium . The reaction is recA independent in both species . The origin of transfer lies within a segment of the chromosome that is inverted in S . typhimurium relative to E . coli, and thus transfer occurs in a different direction in the two species . The character of R1 that is responsible, known as Tfa+, may be lost without affecting other properties of the R factor such as its own transfer. J Bacteriol, 1976 Jul, 127(1), 498 - 504 Genetic and physiological regulation of intrinsic proteins of the outer membrane of Salmonella typhimurium; Bennett RL et al.; Four major outer membrane polypeptides, accounting for approximately 20% of the total protein of the outer membrane of Salmonella typhimurium, were induced by growth in minimal medium . The polypeptides were tightly bound membrane components . Physiological and genetic evidence indicates that the four polypeptides fall in two separate regulation groups . Synthesis of one of these groups was coordinately regulated by the concentration of iron in the medium, and a mutant strain has been identified in which there is constitutive synthesis of this group of major outer membrane proteins. J Bacteriol, 1976 Jul, 127(1), 490 - 7 Mutants of Salmonella typhimurium deficient in an endoprotease; Miller CG et al.; Three bands of hydrolytic activity toward the chromogenic protease substrate N-acetyl-DL-phenylalanine beta-naphthyl ester (NAPNE) can be observed after gel electrophoresis of crude extracts of Salmonella typhimurium or Escherichia coli . Mutants deficient in one of these three activities have been isolated using a staining procedure that identifies colonies that show reduced ability to hydrolyze NAPNE . These mutants lack the strongest of the three bands of activity . The Salmonella mutations (designated apeA) are all co-transducible with purE, and the order (pro)-apeA-Hfr K17 origin-purE has been established . Strains carrying apeA mutations have wild-type doubling times . None of the apeA mutants isolated gains an auxotrophic requirement as a result of loss of the apeA gene product . The rates and extents of protein degradation during starvation for a carbon source or during growth after exposure to the amino acid analogue canavanine do not seem to be affected by apeA mutations . Revertants of apeA mutations (selected by screening for clones that have regained the ability to hydrolyze NAPNE) frequently contain a new enzymatic activity not found in wild-type cells. J Bacteriol, 1976 Jul, 127(1), 211 - 7 Salmonella typhimurium SA host specificity system is based on deoxyribonucleic acid-adenine methylation; Hattman S et al.; We have determined the nature of the deoxyribonucleic acid (DNA) modification governed by the SA host specificity system of Salmonella typhimurium . Two lines of evidence indicate that SA modification is based on methylation of DNA-adenine residues . (i) The SA+ locus of Salmonella was transferred into Escherichia coli B, a strain that does not contain 5-methylcytosine in its DNA; although the hybrid strain was able to confer SA modification, its DNA still did not contain 5-methylcytosine . (ii) the N6-methyladenine content of phage L DNA was measured after growth in various host strains; phage lacking SA modification contained fewer N6-methyladenine residues per DNA . We also investigated the possibility, suggested by others (32), that SA modification protects phage DNA against restriction by the RII host specificity system . Phages lambda, P3, and L were grown in various SA+ and SA- hosts and tested for their relative plating ability on strains containing or lacking RII restriction; the presence or absence of SA modification had no effect on RII restriation . In vitro studies revealed, however, that Salmonella DNA is protected against cleavage by purified RII restriction endonuclease (R-EcoRII) . This protection is not dependent on SA modification; rather, it appears to be due to methylation by a DNA-cytosine methylase which has overlapping specificity with the RII modification enzyme, but which is not involved in any other known host specificity system. J Bacteriol, 1976 Jul, 127(1), 120 - 7 Effects of crp mutations on adenosine 3',5'-monophosphate metabolism in Salmonella typhimurium; Rephaeli AW et al.; Wild-type Salmonella typhimurium could not grow with exogenous cyclic adenosine 3',5'-monophosphate (AMP) as the sole source of phosphate, but mutants capable of cyclic AMP utilization could be isolated provided the parental strain contained a functional cyclic AMP phosphodiesterase.All cyclic AMP-utilizing mutants had the growth and fermentation properties of cyclic AMP receptor protein (crp) mutants, and some lacked cyclic AMP binding activity in vitro . The genetic defect in each such mutant was due to a single point mutation, which was co-transducible with cysG . crp mutants isolated by alternative procedures also exhibited the capacity to utilize cyclic AMP . crp mutants synthesized cyclic AMP at increased rates and contained enhanced cellular cyclic AMP levels relative to the parental strains, regardless of whether or not cyclic AMP phosphodiesterase was active . Moreover, adenylate cyclase activity in vivo was less sensitive to regulation by glucose, possibly because the enzyme II complexes of the phosphotransferase system, responsible for glucose transport and phosphorylation, could not be induced to maximal levels . This possibility was strengthened by the observation that enzyme II activity (measured both in vitro by sugar phosphorylation and in vivo by sugar transport and chemotaxis) was inducible in the parental strain but not in crp mutants . The results suggest that the cyclic AMP receptor protein regulates cyclic AMP metabolism as well as catabolic enzyme synthesis. Mutat Res, 1976 Jul, 36(1), 1 - 10 Rat and mouse tissue-mediated mutagenicity of ring-substituted 3,3-dimethyl-1-phenyltriazenes in Salmonella typhimurium; Malaveille C et al.; 3,3-Dimethyl-1-phenyltriazene and a series of ring-substituted derivatives (X-phi-N=N-N-(CH3)2:X=substituent(s); phi=phenyl) were tested for their mutagenic and toxic action upon Salmonella typhimurium G-46 in a liquid incubation system containing 9000 g tissue supernatants and an NADPH-generating system . The compounds could be grouped into four classes according to their toxicity and mutagenicity after 1 h incubation at 37 degrees C at a concentration of 5 mM in the presence of liver supernatant fractions from phenobarbitone-pretreated mice . When a liver supernatant from untreated mice was compared with one from phenobarbitone-pretreated animals, the mutagenic effect of a series of triazenes (with X=H; 4-chloro; 4-chloro; 4-bromo; 2,4,6-trichloro) in vitro was enhanced twice to ten times . The toxicity of triazenes with X=4-methoxy or 4-acetamido was strongly decreased by a liver fraction from phenobarbitone-pretreated mice in the presence of an NADPH-generating system . With 3,3-dimethyl-1-phenyl-triazene, rat liver fractions caused a lower enzyme-mediated mutagenicity in S . typhimurium G-46 than those of mouse liver, whereas a 9000 g supernatant from brain, a major target organ for the carcinogenic action of certain triazenes, was unable, in either species, to generate metabolites mutagenic for S . typhimurium G-46. J Bacteriol, 1976 Jul, 127(1), 114 - 9 Regulation of histidase synthesis in intergeneric hybrids of enteric bacteria; Goldberg RB et al.; Regulation of the expression of the histidase coded by hutk of Klebsiella aerogenes in Salmonella typhimurium and in Escherichia coli and of the expression of the histidase coded by huts of S . typhimurium in E . coli was investigated . The hutk histidase was found to be sensitive to catabolite repression in K . aerogenes and in E . coli, but insensitive to catabolite repression in S . typhimurium; huts histidase has previously been shown to be catabolite sensitive in all three organisms . The expression of both hutk and huts histidase in E . coli was activated by nitrogen starvation . Apparently, the glutamine synthetase of E . coli may activate the formation of some glutamate- and ammonia-producing enzymes. J Biol Chem, 1976 Jun 25, 251(12), 3623 - 8 Biosynthesis of riboflavin . Structure of the purine precursor and origin of the ribityl side chain; Mailander B et al.; We studied the incorporation of 14C-labeled guanosine into riboflavin under conditions precluding the metabolic conversion of guanosine compounds to free guanine . For this purpose we isolated a mutant BM 2 of Salmonella typhimurium deficient in the enzymes IMP dehydrogenase, purine nucleoside phosphorylase, and purine nucleotide pyrophosphorylase . The mutant incorporated {ribose-14C}guanosine into riboflavin and GMP without dilution . The isolated compounds were exclusively labeled in the ribityl and ribosyl side chain, respectively . AMP and CMP were not labeled . {2-14C}Guanosine was incorporated into riboflavin and GMP without dilution . The isolated compounds were exclusively labeled in the isoalloxazine and guanine moiety, respectively . AMP and CMP were again unlabeled . We conclude that the ribose moiety of proffered guanosine is directly converted to the ribityl moiety of riboflavin . Thus the biosynthesis of the vitamin begins at the level of a guanosine compound . Guanine, ribose, ribitol, and the respective phosphates are not direct precursors of the vitamin. Biochim Biophys Acta, 1976 Jun 23, 437(1), 229 - 37 The biosynthesis of the thiazole moiety of thiamine in Salmonella Typhimurium; Bellion E et al.; The mechanism of biosynthesis of 4-methyl-5-beta-hydroxyethyl thiazole, the thiazole moiety of thiamine was studied in Salmonella typhimurium . Using the adenosine derepression technique the incorporation of various 14C-labeled precursors was determined . We found that;e1Me-14C}methionine, {2-14C}methionine, {U-14C}alanine, and {2-14C}glycine were not incorporated whereas {2-14C}tyrosine was incorporated . Degradation of the 4-methyl-5-beta-hydroxyethyl thiazole obtained after {2-14C}tyrosine incorporation revealed that all of the activity was located on carbon-2 . These findings are discussed and compared with previous findings concerning 4-methyl-5-beta-hydroxyethyl thiazole biosynthesis. Biochemistry, 1976 Jun 15, 15(12), 2561 - 70 Outer membrane of Salmonella typhimurium: accessibility of phospholipid head groups to phospholipase c and cyanogen bromide activated dextran in the external medium; Kamio Y et al.; 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 on the outer surface . In contrast, with strains that produce outer membranes containing less complete lipopolysaccharides (Rd or Re type) and reduced amounts of proteins, both methods clearly showed the presence of exposed phosphatidylethanolamine head groups . These data can be most easily explained by assuming that the outer membranes of S and Rc strains either contains all phospholipid molecules in its inner leaflet or has proteins that completely cover up the head groups at its outer surface . In either model, the reduction in the amount of outer membrane proteins in Rd or Re mutants would produce membranes with exposed phospholipid head groups . CNBr-activated dextran can be easily prepared, and reacts with high efficiency under near-physiological conditions . Its additional advantage as a nonpenetrating membrane-labeling reagent is that we can be quite confident on its impermeability because of its size, in contrast, with most other reagents whose presumed impermeability is dependent only on the presence of charged groups. Aust J Exp Biol Med Sci, 1976 Jun, 54(3), 221 - 36 The role of thymus-derived cells in immunity to salmonella infection; Davies R et al.; The ability of thymus-derived (T) cell depleted mice to eliminate a dose of the normally avirulent 11RX strain of Salmonella enteritidis was compared to that of normal mice by following the fate of the challenge organisms in the liver and spleen of both types of mice . Although the mice did not require normal numbers of T cells to survive infection with Salmonella enteritidis 11RX, T cell depletion reduced the ability of mice effectively to eliminate the organism from their tissues . In addition, T cell depletion abolished the ability of live Salmonella enteritidis 11RX vaccine to protect mice against a subsequent challenge with the virulent C5 strain of Salmonella typhimurium. Aust J Exp Biol Med Sci, 1976 Jun, 54(3), 207 - 19 A role for antibody in the expression of cellular immunity to Salmonella typhimurium C5; Davies R et al.; Immunisation of mice with alcohol-killed Salmonella typhimurium C5 vaccine before infection with Salmonella enteritidis 11RX enhanced the ability of these mice to control and eliminate a challenge dose of Salmonella typhimurium C5, compared to mice which only received live Salmonella enteritidis 11RX organisms . When alcohol-killed Salmonella enteritidis Se795 vaccine was used instead of the Salmonella typhimurium C5 vaccine, this effect was not observed . These observations imply that both humoral and cellular responses are important in the expression of immunity to slamonella infections . The bearing of these results on the observations of other workers is discussed. Infect Immun, 1976 Jun, 13(6), 1539 - 42 Characterization of the virulence and antigenic structure of Salmonella typhimurium strains with lipopolysaccharide core defects; Lyman MB et al.; The virulence and antigenic characters of Salmonella typhimurium strains, identical except for known lipopolysaccharide core defects, were compared . Smooth strains multiplied extensively and killed most mice . Deep rough strains containing only heptose I or heptose I and II in the rough core were completely eliminated after 6 h, whereas more superficial rough strains containing additional core sugars could be detected in low numbers (10(4) colony-forming units/g of tissue) for at least 7 days postinjection . Normal human serum exhaustively absorbed with certain rough strains was tested for ability to kill other rough strains . Two strains with the most superficial defects (rfaJ, rfaL) each had a unique serological character; strains with deeper defects showed much cross-reactivity . Similarities between the susceptibility of strains to the bactericidal effect of specifically absorbed serum correlated, in some cases, with similarities in in vivo behavior.
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