J Bacteriol, 1979 Dec, 140(3), 805 - 8 Isolation of temperature-sensitive pantothenate kinase mutants of Salmonella typhimurium and mapping of the coaA gene; Dunn SD et al.; Temperature-sensitive pantothenate kinase mutants of Salmonella typhimurium LT2 were selected by using the excretion of pantothenate at the nonpermissive temperature as a screening method . Thermolability of the pathothenate kinase activity in extracts of the mutants was demonstrated . The mutations were mapped at min 89 of the Salmonella chromosome, near rpoB, by transduction . As pantothenate kinase catalyzes the first step in the biosynthesis of coenzyme A from pantothenate, the new genetic locus has been designated coaA. Proc Natl Acad Sci U S A, 1979 Dec, 76(12), 6510 - 4 Gene for the RNA polymerase sigma subunit mapped in Salmonella typhimurium and Escherichia coli by cloning and deletion; Scaife JG et al.; The genes for the RNA polymerase sigma subunit (rpoD) and DNA primase (dnaG) of Salmonella typhimurium have been cloned into lambda vectors . Combined restriction, deletion and functional analysis of the cloned fragment allows us to map the genes precisely on the fragment, establishes the direction in which rpoD is transcribed, and reveals the existence of at least one new gene in the vicinity . A closely homologous, smaller fragment of Escherichia coli DNA, also cloned into lambda, contains rpoD and at least part of dnaG. J Bacteriol, 1979 Dec, 140(3), 798 - 804 Response to a metal ion-citrate complex in bacterial sensing; Ingolia TD et al.; Salmonella typhimurium responds chemotactically to gradients of divalent cations in the presence of citrate ions . The actual chemoeffector is the citrate-metal ion complex, which acts as an attractant . Citrate (which is also a chemoeffector for Salmonella) and the citrate-metal ion complex are recognized by different receptors . The response of Salmonells, which can transport citrate through its membrane, is quite different than that of Escherichia coli, which cannot. J Environ Pathol Toxicol, 1979 Dec, 3(1-2), 227 - 31 Mutagenicity of skin tanning lotions; Pham HN et al.; Two lotions that tan skin in the absence of sunlight and their active ingredient, dihydroxyacetone (DHA), are mutagenic in Salmonella typhimurium strain TA100 without metabolic activation . However, addition of S-9 mix that contains Aroclor 1254-induced rat hepatic microsomes enhances significantly the mutagenic activity of all three agents . Both lotions and DHA also cause primary DNA damage as determined by the rec-assay in Bacillus subtilis . The potential human health hazard of these lotions is discussed. Mutat Res, 1979 Dec, 68(4), 327 - 36 Studies on the mutagenicity of p-phenylenediamine in Salmonella typhimurium . Presence of PCB's in rat-liver microsomal fraction induced by Aroclor; Shahin MM et al.; The mutagenicity of fresh solutions of p-phenylenediamine (PPD) and Aroclor 1254 was investigated . The histidine-requiring strains of Salmonella typhimurium were used in the absence and presence of uninduced and/or Aroclor-induced rat-liver homogenate . The presence of polychlorinated biphenyls (PCBs) was also examined by chromatographic methods in Aroclor-induced rat-liver homogenate . In the absence of metabolic activation, as well as in the presence of uninduced rat-liver homogenate, PPD was not mutagenic in the strains used . In the presence of Aroclor-induced S9 a twofold increase (or less) was observed in the number of revertant colonies over those of the controls in TA1538 and TA98 . There was no increase in the number of revertant colonies over those of the controls when PPD was dissolved in NH4OH solution and the solution mixed with H2O2 before the addition of S9 mix . Aroclor 1254 was not mutagenic in TA1538 or TA98 . However, the presence of PCBs in Aroclor-induced rat-liver homogenate (induced S9) was identified by gas-liquid chromatography (GLC), high-performance liquid chromatography (HPLC) and gas--liquid chromatography/mass spectrometry (GC/MS). Mutat Res, 1979 Dec, 64(6), 379 - 89 Effects of the hepatic S9 fraction from aroclor-1254-treated rats on the mutagenicity of benzo{alpha}pyrene and 2-aminoanthracene in the Salmonella/microsome assay; Zeiger E et al.; The mutagenicity of benzo{alpha}pyrene and 2-aminoanthracene for Salmonella typhimurium TA98 in the plate-incorporation test was studied using liver S9 from untreated and aroclor-1254-treated rats . The induction of liver S9 protein, arylhydrocarbon hydroxylase (AHH), and cytochrome P448/450 was followed with time . There was no change in protein concentrations with induction; AHH and cytochrome levels were increased at 1, 3, 5 and 7 days post Aroclor treatment . Benzo{alpha}pyrene mutagenicity was enhanced with Aroclor treatment while 2-aminoanthracene mutagenicity was depressed . The benzo{alpha}pyrene mutagenicity showed a positive correlation with the levels of AHH and cytochrome on the plate; 2-aminoanthracene showed a negative correlation with activity in induced samples. Mutat Res, 1979 Dec, 64(6), 363 - 77 Mutagenicity and metabolism of dimethylnitrosamine and benzo{alpha}pyrene in tissue homogenates from inbred Syrian hamsters treated with phenobarbital, 3-methylcholanthrene or polychlorinated biphenyls; Hutton JJ et al.; There are significant differences between mice and hamsters in polycyclic hydrocarbon and nitrosamine metabolism . Homogenates of liver, lung and intestinal mucosa from 6 strains of Syrian golden hamster were compared for their ability to metabolize benzo{alpha}pyrene (BP) and dimethylnitrosamine (DMN) to mutagens . Females of strains MHA/SSLak, LSH/SlLak, CB/SsLak, PD4/Lak LHC/Lak and Lak:LVG (SYR) were either untreated or received phenobarbital (PB), 3-methylcholanthrene (MC) or polychlorinated biphenyls (AR) to induce drug-metabolizing enzymes . Salmonella typhimurium TA92 and TA98 were used as indicators of the formation of mutagans . Dimethylnitrosamine demethylase (DMND) was assayed using 1 mM DMN as substrate . Aryl hydrocarbon hydroxylase (AHH) was measured using benzo{alpha}pyrene as substrate . MC does not induced AHH activity in hamster liver, but is an excellent inducer of enzymes converting BP to mutagens . This lack of correlation between increased AHH activity and increased metabolism of BP to mutagen in liver is in marked contrast to correlations seen in mice . MC induces AHH in hamster lung and intestinal mucosa . AR induces AHH in liver, lung and intestinal mucosa . Activity of DMND in liver is not affected by treatment of hamsters with BP or AR, but is repressed approx . 30% by treatment with MC . Activity of DMND and conversion of DMN to mutagen are correlated (r = 0.59) in hamster liver . Microsomes of hamster liver are more effective than those from mouse in converting DMN to mutagen, despite similar DMND activities in livers from the two species. J Dairy Sci, 1979 Dec, 62(12), 1873 - 9 Elucidation of the inhibitory factors of yogurt against Salmonella typhimurium; Rubin HE et al.; The inhibitory nature of yogurt against contaminating microorganisms has been studied extensively . Nevertheless, the factors responsible for the death of Salmonella typhimurium in yogurt have not been elucidated . An understanding of these factors is important for the determination of yogurt's safety to consumer health . Yogurt fermented for 18 h at 42 C had a stable environment with the following conditions: pH 3.85, oxidation-reduction potential -80 mV, lactic acid concentration 158 mM, and acetic acid concentration 3.7 mM . Under these conditions, lactic acid was responsible for virtually all of yogurt's bactericidal activity against S . typhimurium at 37 C . Die-off rates were observed when these conditions were reproduced artificially in milk (artificial milk yogurt) and when lactic acid was added back to 18-h yogurt from which acids were removed by passage of the whey through a Dowex 1 (Cl-) anion exchange column (cationic yogurt) . Factors that augmented lactic acid inhibition of S . typhimurium were low pH and low oxidation-reduction potential . The die-off rate of S . typhimurium was more rapid in yogurt whey (yogurt minus the casein fraction) than in whole yogurt, indicating that the casein fraction was partially able to protect Salmonella. J Biol Chem, 1979 Nov 10, 254(21), 11000 - 9 Separation and purification of a potent bactericidal/permeability-increasing protein and a closely associated phospholipase A2 from rabbit polymorphonuclear leukocytes . Observations on their relationship; Elsbach P et al.; Two antibacterial proteins from rabbit polymorphonuclear leukocytes, a potent bactericidal cationic protein that increases the envelope permeability of susceptible gram-negative bacteria and a phospholipase A2, have been purified to near homogeneity by ion exchange, gel filtration, and hydrophobic interaction chromatography . The apparently noncatalytic bactericidal/permeability-increasing protein has an approximate molecular weight of 50,000 and is isoelectric at pH 9.5 to 10.0 . The molecular properties, including amino acid composition, and the antibacterial potency and specificity of this rabbit leukocyte protein and of the bactericidal/permeability-increasing protein from human granulocytes that we have recently purified (J . Biol . Chem . 253, 2664-2672, 1978) are closely similar . Both proteins kill several strains of Escherichia coli and Salmonella typhimurium . Rough strains are more sensitive than smooth strains . All gram-positive bacterial species tested are insensitive to high concentrations of either rabbit or human protein . The phospholipase A2, purified by hydrophobic interaction chromatography on phenyl-Sepharose, ran as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 14,000 and had a specific enzymatic activity comparable to that of purified phospholipases A2 from other sources . Separation of the phospholipase A2 from the bactericidal/permeability-increasing protein has no noticeable effect on the bactericidal and permeability-increasing activities of the purified bactericidal protein, but removes the ability of the phospholipase A2 to hydrolyze the phospholipids of intact Escherichia coli . Upon recombination of the phospholipase A2 with the bactericidal/permeability-increasing protein, the phospholipase A2 regains its activity toward the phospholipids of intact E . coli suggesting that these two antibacterial leukocyte proteins act in concert. Cancer Res, 1979 Nov, 39(11), 4752 - 5 Increased production of mutagenic metabolites of carcinogens by tissues from senescent rodents; Baird MB et al.; Activation of the procarcinogens benzo(a)pyrene and 2-fluorenamine by liver homogenates (S9) prepared from senescent male CFN rats and C57BL/6J mice resulted in an enhanced production of mutagenic metabolites when compared to young rodents, as indicated by an enhancement of the induced reversion frequency in a Salmonella typhimurium bioassay . Similar results were observed when carcinogen activation was mediated by purified hepatic microsomes, indicating that the age-related differences in carcinogen activation did not result from aging changes in carcinogen metabolism involving non-microsomal mechanisms . The metabolites of many procarcinogens are thought to be the ultimate carcinogens in mammals . Therefore, the present findings are consistent with the hypothesis that some fraction of the markedly increased of neoplasia observed in senescent mammals is a result of age-related alterations in the metabolism of chemical carcinogens. Appl Environ Microbiol, 1979 Nov, 38(5), 1015 - 7 Mutagenicity of 5,6-dimethoxysterigmatocystin, a metabolite from Aspergillus multicolor, in the Salmonella/microsome system; Wehner FC et al.; The natural sterigmatocystin derivative, 5,6-dimethoxysterigmatocystin, was found to be a mutagen for Salmonella typhimurium strains TA98 and TA100 after metabolic activation in a mammalian microsome system. Toxicology, 1979 Nov, 14(3), 255 - 62 Effect of weak-, non-, and co-carcinogenic chemicals on 2-acetylaminofluorene-induced mutation in Salmonella typhimurium; Weeks CE et al.; The effects of various weak, non-, and co-carcinogenic chemicals on 2-acetylaminofluorene-induced mutation in Salmonella typhimurium were studied . We found that a single co-mutagen could provide for either enhanced or decreased mutagenesis . A differential effect on mutagenic expression was dependent upon: (1) the type of inducer of S-9 (supernatant from liver homogenate centrifuged at 9000 x g) liver enzymes; (2) the amount of S-9 enzyme preparation employed; and (3) the combined dose of mutagen plus co-mutagen studied . No effect was observed in the absence of S-9 . Our data suggest that in S . typhimurium a primary factor in the alteration of mutagenesis by a combination of chemicals is changes in metabolism of the principal mutagen. Biull Eksp Biol Med, 1979 Nov, 88(11), 592 - 5 {Mutagenic and carcinogenic actions of some polycyclic aromatic hydrocarbons}; Linnik AB et al.; The carcinogenic and mutagenic actions of benz(a)pyrene (BP) and its derivatives 6-methyl-, 6-formyl-, 6-chloro-, 6-hydroxy-, 6-acetoxy-, 6-methoxy- and 4(5)-methoxy-BP were studied in mice and bacteria Salmonella typhimurium TA-98 and TA-100, respectively . The potent carcinogenic agents BP, 6-methyl-, 6-formyl-BP proved also mutagenic in bacteria of both strains . Weak carcinogenic compounds (6-chloro-, 6-methoxy-, 4(5)-methoxy-BP) and noncarcinogenic ones (6-acetoxy-, 6-hydroxy-BP) either turned out nonmutagenic or mutagenic in one of two bacterial strains tested . The differences in carcinogenic and mutagenic actions of the substances under study are not relative to the rate of their oxidation in the enzymatic system. J Toxicol Environ Health, 1979 Nov, 5(6), 1149 - 58 Mutagenicity of halogenated and oxygenated three-carbon compounds; Stolzenberg SJ et al.; Four structurally related three-carbon compounds, known for their antifertility activity in the male, and the brominated derivatives of two of these compounds were tested for mutagenic activity by the Salmonella typhimurium test of Ames et al . In the presence of strain TA-100, a base-pair substituion detector strain, 1,2-dibromo-3-chloropropane (DBCP), was the most active compound tested but required enzymatic conversion by 59 microsomal preparation to an active mutagen . Three of these compounds containing an epoxide group-epichlorohydrin, epibromohydrin, and glycidol-were highly active direct mutagens, not requiring 59 for activation, alpha-Chlorohydrin was the least active compound tested; alpha-bromohydrin was 40 times more active than its chlorinated analog . Epibromohydrin was only slightly more active than epichlorohydrin, but both were highly active . With both of the halogenated epoxides, 59 preparation caused a substantial decrease in mutagenic activity at every concentration tested . All six compounds showed dose-related responsiveness for the base-pair substitution detector strains used . However, they were relatively inactive against the frameshift detector strain of S . typhimurium, TA-98 . Glycerol, propylene glycol, and n-propanol, which are also three-carbon compounds containing one or more hydroxy groups, were inactive when trested at high concentrations with strain TA-100. J Antibiot (Tokyo), 1979 Nov, 32(11), 1118 - 24 2-Amino-5-methyl-5-hexenoic acid, a methionine analog produced by Streptomyces sp . MF374-C4; Takeuchi M et al.; 2-Amino-5-methyl-5-hexenoic acid (AMHA), a new methionine analog, was isolated from a fermentation broth of Streptomyces sp . MF374-C4 based on its reversal of the effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in a test system that determines the size of growth zones of revertants (His+) of Salmonella typhimurium TA1535 . AMHA also inhibited growth of the tester strain in a synthetic medium . These AMHA activities were abolished by methionine . The incidence of spontaneous streptomycin-resistant mutations of Escherichia coli K12 was not decreased by AMHA at concentrations where cell growth was partially inhibited . AMHA inhibited protein synthesis but not DNA or RNA synthesis in S . typhimurium TA1535 and E . coli K-12 . The analog inhibited formation of methionyl-tRNA but not of valyl-tRNA in a cell-free system of E . coli, and supported ATP-PPi exchange in the cell-free system . At concentrations where it inhibited cell growth, AMHA decreased the number of foci, induced by ROUS sarcoma virus, on cultured sheets of chick-embryo fibroblasts . The effects of AMHA on focus formation and on the cell growth were overcome by methionine. Mutat Res, 1979 Nov, 63(1), 1 - 10 Mutagenicity of fluorene derivatives: a proposed mechanism; Levin DE et al.; Several derivatives of fluorene, a tricyclic, organic molecule, have been found to induce both frameshift mutations and base-pair substitutions in Salmonella typhimurium strains developed by Ames . Comparisons of the mutagenic potency of these derivatives for several strains of Salmonella suggest the importance of a carbonyl group substituted at the carbon-9 position of mutagenic derivatives, with respect to mutagenic potency . In this study, we present a feasible mechanism for the interaction of mutagenic fluorene derivatives with deoxyribonucleic acid . This mechanism requires the interaction of the mutagenic molecule with carbon-8 of guanine and a second concurrent interaction with the C-4 amino group of an adjacent cytosine residue. Mutat Res, 1979 Nov, 68(3), 211 - 6 Mutagenicity of pyrrolizidine alkaloids in the Salmonella/mammalian-microsome test; Yamanaka H et al.; The mutagenicities of 7 pyrrolizidine alkaloids to Salmonella typhimurium TA100 were demonstrated by a modified Ames's method . The pyrrolizidine alkaloids found to be mutagenic were clivorine, fukinotoxin, heliotrine, lasiocarpine, ligularidine, LX201 and senkirkine . Pre-incubation of these alkaloids with S9 mix and bacteria in a liquid medium was essential for demonstration of their mutagenicities. Mutat Res, 1979 Nov, 68(3), 195 - 9 Mutagenicity of nitrosamines formed from nitrosation of spermidine; Hotchkiss JH et al.; 5 nitrosamines formed from the nitrosation of spermidine were investigated for mutagenicity using various strains of Salmonella typhimurium in the presence and absence of S9 mix . Using the plate incorporation method, 3-butenyl-(2-propenyl)-N-nitrosamine, 3-hydroxybutyl (2-hydroxypropyl)-N-nitrosamine, 4-hyroxybutyl-(2-hydroxypropyl)-N-nitrosamine, 4 hydroxybutyl-(3-hydroxypropyl)-N-nitrosamine, and in the liquid test 3-hydroxybutyl-(3-hydroxypropyl)-N-nitrosamine were mutagenic in the absence of S9 mix. Mutat Res, 1979 Nov, 68(3), 183 - 93 Mutational studies with diquat and paraquat in vitro; Benigni R et al.; Diquat and paraquat were assayed in the following tests . (1) Ames test in Salmonella typhimurium (strains TA1535, TA1537, TA1538, TA98 and TA100) with and without rat-liver microsomal fractions . (2) Resistance to 8-azaguanine in Salmonella typhimurium (strain hisG46, TA92 and TA1535 . (3) Repair test in Salmonella typhimurium (strains TA1538 and TA1978) . (4) Gene mutations in Aspergillus nidulans: 8-AG resistance and methionine suppression (meth A1 locus) . (5) Lethal recessive damage in Aspergillus nidulans . (6) Unscheduled DNA synthesis (UDS) in human epithelial-like cells (EUE) . Diquat and paraquat were positive in S . typhimurium (in the repair test and the 8-AG resistance system), in A . nidulans (for gene mutations and lethal recessive damage induction) and in EUE cells (UDS induction). Cancer Lett, 1979 Nov, 8(1), 71 - 6 Mutagenicity of metabolites of carcinogenic aminoazo dyes; Degawa M et al.; The mutagenicity of 8 azo dyes and 6 p-phenylenediamine derivatives, which comprised the metabolites of carcinogenic 4-aminoazobenzene derivatives, was studied on Salmonella typhimurium TA98 and TA100 . 4'-Hydroxy-N-methyl-4-aminoazobenzene and its O-sulfate and O-glucuronide, and 3-hydroxy-4-aminoazobenzene were mutagenic on TA98 in the presence of S-9 mix . p-Phenylenediamine and its o-methoxyl derivative were definitely mutagenic on TA98 with the addition of S-9 mix . All metabolites tested were non-mutagenic on TA100, although the mother azo dyes were mutagenic both on TA98 and TA100 in the presence of S-9 mix . These results rule out a possibility that the mutagenicity, at least on TA100 microbes, of carcinogenic 4-aminoazobenzene derivatives may be mediated by any of the ring-hydroxyl or azo reduction metabolites and their conjugates produced from the azo dyes by incubation with S-9 mix. J Virol, 1979 Nov, 32(2), 583 - 92 Salmonella bacteriophage glycanases: endorhamnosidases of Salmonella typhimurium bacteriophages; Svenson SB et al.; Twelve bacteriphages lysing only smooth Salmonella typhimurium strains were shown to have similar morphology--an icosahedric head to which a short, noncontractile tail carrying six spikes was attached . All phages degraded their lipopolysaccharide (LPS) receptors as shown by their ability to cleave off {14C}galactosyl-containing oligosaccharides from S . typhimurium cells labeled in their LPS . The oligosaccharides inhibited the alpha-D-galactosyl-specific Bandeiraea simplicifolia lectin agglutination of human type B erythrocytes, indicating that all 12 phage glycanases were of endorhamnosidase specificity, i.e., hydrolyzed the alpha-L-rhamnopyranosyl-(1 leads to 3)-D-galactopyranosyl linkage in the S . typhimurium O-polysaccharide chain . Two of the phages, 28B and 36, were studied in more detail . Whereas the phage 28B glycanase hydrolyzed the S . typhimurium LPS into dodeca- and octasaccharides, the phage 36 glycanase in addition cleaved off tetrasaccharides . Both phage enzymes hydrolyzed the O-polysaccharide chains of LPS from Salmonella belonging to serogroups A, B, and D1, which are built up of tetrasaccharide-repeating units identical except for the nature of the 3,6-dideoxyhexopyranosyl group (R) . : FORMULA:(SEE TEXT) . The phage 28B and 36 endorhamnosidases hydrolyzed also an LPS from which the 3,6-dideoxyhexosyl substituents had previously been hydrolyzed off . However, neither of the enzymes was active on LPS preparations in which the C2-C3 bond of the L-rhamnopyranosyl ring had been opened by periodate oxidation . Glucosylation at O-6 of the D-galactopyranosyl residues in the S . typhimurium LPS was found to be incompatible with hydrolysis by both enzymes . However, in an LPS glucosylated at O-4 of the D-galactopyranosyl residues, the adjacent alpha-L-rhamnopyranosyl linkages were found to be perferentially cleaved. J Bacteriol, 1979 Nov, 140(2), 607 - 11 Pyridine nucleotide cycle of Salmonella typhimurium: in vitro demonstration of nicotinamide mononucleotide deamidase and characterization of pnuA mutants defective in nicotinamide mononucleotide transport; Kinney DM et al.; The enzyme nicotinamide mononucleotide deamidase, an integral component of the proposed four-membered pyridine nucleotide cycle (PNC IV), has been demonstrated in extracts of Salmonella typhimurium LT2 . The enzyme has an optimum pH of 8.7 and deamidates nicotinamide mononucleotide, forming nicotinic acid mononucleotide . Sigmoidal kinetic data suggest that this enzyme may be allosteric and therefore an important regulatory component of pyridine nucleotide cycle metabolism . Mutants previously designated pncC in anticipation of their lacking nicotinamide mononucleotide deamidase were examined and found to have normal levels of this enzyme . {14C}nicotinamide mononucleotide uptake studies, however, revealed a defect in the transport of this compound . Accordingly, the genetic designation for this locus was changed to pnuA to reflect its involvement in pyridine nucleotide uptake . Evidence is presented for the existence of two separate nicotinamide mononucleotide transport systems. J Bacteriol, 1979 Nov, 140(2), 567 - 73 Electron acceptor taxis and blue light effect on bacterial chemotaxis; Taylor BL et al.; Salmonella typhimurium and Escherichia coli from anaerobic cultures displayed tactic responses to gradients of nitrate, fumarate, and oxygen when the appropriate electron transport pathway was present . Such responses were named "electron acceptor taxis" because they are elicited by terminal electron acceptors . Mutant strains of S . typhimurium and E . coli were used to establish that functioning electron transport pathways to nitrate and fumarate are required for taxis to these compounds . Aerotaxis in S . typhimurium was blocked by 1.0 mM KCN, which inhibited oxygen uptake . Similarly, a functioning electron transport pathway was shown to be essential for the tumbling response of S . typhimurium and E . coli to intense light (290 to 530 nm) . Some inhibitors and uncouplers of respiration were repellents of S . typhimurium . We propose that behavioral responses to light or electron acceptors involve electron transport-mediated perturbations of the proton motive force. Cancer Lett, 1979 Nov, 8(1), 87 - 92 Mutagenicity of chamuvaritin: a benzyldihydrochalcone isolated from a medicinal plant; Uwaifo AO et al.; The mutagenic effects of chamuvaritin, dihydrobenzylchalcone isolated from Uvaria chamae, were investigated using Salmonella typhimurium tester strains TA92, TA94--98, TA100--1535, TA1537 and TA1538 . The phytochemical was mutagenic in tester strains TA98 and TA100 and required activation by the hepatic S-9 microsomal enzyme preparation. J Toxicol Sci, 1979 Nov, 4(4), 317 - 26 Differential mutagenicities of triamino benzenes against Salmonella typhimurium TA98 in the presence of S9 fractions from polychlorinated biphenyls-, phenobarbital- or 3-methylcholanthrene-pretreated rats, hamsters and mice; Yoshikawa K et al.; Mutagenicity of 6 aminobenzene derivatives against Salmonella typhimurium TA98 was studied in the presence of various S9 fractions . S9, which has been prepared form the livers of rats, hamsters and mice after pretreatment with different types of inducers; polychlorinated biphenyls, phenobarbital and 3-methylcholanthrene, was used as the methabolic activating enzyme in this mutation assay . The S9 fractions from 3-methylcholanthrene-treated rats and mice are most useful for mutation induction by the all aminobenzenes used . The mutagenic activity of the compounds was clearly correlated to 3-methylcholanthrene-induced cytochrome P-450 . However, any significant correlation between aniline hydroxylase activity and the mutagenesis was not observed. Mutat Res, 1979 Nov, 68(3), 225 - 34 Mutagenicity tests with griseofulvin; Leonard A et al.; Griseofulvin was studied for its ability to induce structural chromosomal aberrations in germ and somatic cells of the male mouse . It was also tested for its capacity to produce his+ revertants in Salmonella typhimurium . All tests yielded negative results, whereas highly significant effects were recorded in control assays with thio-TEPA. Mutat Res, 1979 Nov, 68(3), 207 - 10 Mutagenicity of nitrosodiethanolamine on Salmonella typhimurium; Hesbert A et al.; Nitrosodiethanolamine was examined in the Ames assay for bacterial mutagens . In absence of S9 activation a mutagenic effect was found. J Biol Chem, 1979 Oct 25, 254(20), 9947 - 50 In vivo methylation of prokaryotic elongation factor Tu; Ames GF et al.; In Salmonella typhimurium and Escherichia coli, elongation factor Tu (EF-Tu) is methylated as shown by its incorporation of labeled methyl residues from {methyl-3H}methionine . Analysis of the nature of the methyl-containing residues by protein hydrolysis, followed by paper chromatography and high voltage electrophoresis showed that both mono- and dimethyllysine are present . Eighty per cent of the EF-Tu molecules are methylated if methylation occurs at a unique lysine residue . The EF-Tu fraction which is not methylated is still able to accept methyl groups, as shown by methylation of approximately 10% of the EF-Tu after addition of chloramphenicol (D-(-)-threo-2,2-dichloro-N-{beta-hydroxy-alpha-(hydroxymethyl)-o-nitrophenethyl} acetamide) to inhibit further protein synthesis . There is no evidence of turnover of the methyl residues . We attempted to separate the methylated from the nonmethylated form of EF-Tu by isoelectric focusing on polyacrylamide gel, but were unable to do so. J Biol Chem, 1979 Oct 10, 254(19), 9695 - 702 Membrane receptors for aspartate and serine in bacterial chemotaxis; Clarke S et al.; High affinity binding sites for serine and aspartate have been characterized in membranes from Salmonella typhimurium and Escherichia coli . Greater than 80% of these sites have been identified as chemotaxis receptors . Mutants lacking binding sites for these amino acids have been shown to have corresponding defects in taxis . The substrate specificity of each of the receptors in Salmonella is very high; most analogs of serine and aspartate do not bind to these receptor sites and do not affect chemotaxis . The transport of these amino acids is apparently not related to chemotaxis . At least 2500 serine receptors and 1200 aspartate receptors with dissociation constants of about 5 microM are present in the membrane fraction of logarithmically growing cells. Mol Gen Genet, 1979 Oct 2, 176(1), 87 - 93 Altered linkage values in phage P22--mediated transduction caused by distant deletions or insertions in donor chromosomes; Krajewska-Grynkiewicz K et al.; The effects of distant deletions or insertions in the Salmonella typhimurium donor strains on P22--mediated cotransducibility of genetic markers was studied . We found that deletions of histidine operon, unit 44 of the chromosome map, changed the linkage of markers purF and aroC (unit 49) and pyrF and trpA (unit 34) . They did not change the linkage of more distant markers pyrE and cysE . The effect of three types of insertions was examined . The donor strains carried F factor, Tn10 transposon or pi-his duplication inserted close to histidine operon . These insertions caused alteration of purF-aroC linkage while pyrF-trpA cotransduction values were not affected . These data show that the effect of the chromosome rearrangements extends to at least 5% of S . typhimurium chromosome length and may reach as much as 10% of it . Our results are in agreement with the model of Chelala and Margolin (1974) concerning formation of transduction particles . They indicate that the cotransducibility changes caused by deletions or insertions extent further than it might have been expected from previous reports. Mutat Res, 1979 Oct, 62(3), 425 - 37 Mutagenic activation of 2-acetylaminofluorene by guinea-pig liver homogenates: essential involvement of cytochrome P-450 mixed-function oxidases; Takeishi K et al.; 2-Acetylaminofluorene (AAF) was highly mutagenic to Salmonella typhimurium strain TA98, when activated by a liver post-mitochondrial supernatant fraction (S9 fraction) from guinea-pigs, in spite of the resistance of this species to AAF carcinogenesis and the low capacity of the liver of this species for N-hydroxylation of AAF . The mutagenicity was comparable to or higher than that resulting from activation by mouse- or rat-liver S9 fraction, and was not enchanced by treatment with cytochrome P-450 inducers, a combination of phenobarbital and 5,6-benzoflavone . In an attempt to understand this unexpected result we examined whether a cytochrome P-450 mixed-function oxidase system participated in the mutagenic activation of AAF by guinea-pig liver, as it does in the case of mouse liver . The mutagenic activation was: (1) completely dependent on the addition of a co-factor, NADPH, to the mutation assay system, (2) completely suppressed by antiserum against NADPH--cytochrome c reductase, and (3) sensitive to a cytochrome P-450 inhibitor, 7,8-benzoflavone . These results indicate that the cytochrome P-450 enzyme system is essentially involved even in the mutagenic activation of AAF by guinea-pig-liver S9 fraction . Based on both the present and other data, the mechanism of the mutagenic activation is discussed to explain the observed high mutagenic potential of AAF in the presence of guinea-pig-liver S9 fraction. J Virol, 1979 Oct, 32(1), 98 - 101 Is the injection of DNA enough to cause bacteriophage P22-induced changes in the cellular transport process of Salmonella typhimurium? Bandyopadhyay PN, Das Gupta B, Joshi A, Chakravorty M. It was demonstrated earlier in this laboratory that phage P22 induces a transient depression in the cellular transport processes of the host Salmonella typhimurium immediately after infection and that an effective injection process is enough to cause the depression . By using defective phage particles that contain host DNA instead of phage DNA for infection, it has been demonstrated that the injection of phage-specific DNA is essential for this . The defective particles adsorbed to the host and injected their DNA, but the cellular transport processes of the host were not altered . Thus, the injection of host DNA by the phage fails to affect the transport process . Insensitivity of the phage DNA-induced depression in transport to chloramphenicol rules out the involvement of newly synthesized protein in this change and indirectly suggests the possible role of phage DNA-associated internal proteins of P22. J Virol, 1979 Oct, 32(1), 1 - 7 Regulation of late functions in Salmonella bacteriophages P22 and L studied by assaying endolysin synthesis; Bode W; The rate of endolysin synthesis in Salmonella typhimurium cells infected by bacteriophage P22 or L was taken as a measure for the activity of 23 gene product (the positive regulator for the "late" genes of P22 and L) . Endolysin in coded for by gene 19 . The amber mutations in gene 23 of P22 and L, used in this study, reduced the rate of endolysin synthesis by a factor of ca . 90 for P22 and of ca . 20 for L . In mixed infections with 19- and 23- mutants the 23 gene products of P22 and L ACT As positive regulators for the respective gene 19 in cis and in trans . Cross-specificity of the 23 gene products, i.e., turning on expression of gene 19 on a chromosome of the other species, could not be demonstrated. J Gen Microbiol, 1979 Oct, 114(2), 227 - 46 Methionine transport in Salmonella typhimurium: evidence for at least one low-affinity transport system; Ayling PD et al.; The systems which transport methionine in Salmonella typhimurium LT2 have been studied . Fourteen mutants, isolated by three different selection procedures, had similar growth characteristics and defects in the specific transport process showing a Km of 0.3 microM for L-methionine, and therefore lack the high-affinity, metP transport system . The sites of mutation in four of the mutants were shown by P1-mediated transduction to be linked (0.3 to 1.1%) with a proline marker located at unit 7 on the S . typhimurium chromosome . The high-affinity system was subject to both repression and transinhibition by methionine, and it may also be regulated by the metJ and metK genes . There appeared to be at least two additional transport systems with relatively low affinities for methionine in the metP763 mutant strain, with apparent Km values for methionine of 24 microM and approximately 1.8 mM . The latter system, with a very low affinity for methionine, was inhibited by leucine . In addition, methionine inhibited leucine transport, suggesting that one of the low-affinity methionine transport systems may actually be a leucine transport system. Mutat Res, 1979 Oct, 68(2), 101 - 6 Mutagens in coffee and tea; Nagao M et al.; Coffee prepared in the usual way for drinking contains a substance(s) that is mutagenic to Salmonella typhimurium TA100 without mammalian microsomal enzymes . One cup of coffee (200 ml) contains mutagen(s) inducing 1.4-4.6 X 10(5) revertants under standard conditions . Instant coffee too is mutagenic to TA100 and one cup of instant coffee prepared from 1 g of coffee powder and 200 ml of water induced 5.6-5.8 X 10(4) revertants of TA100 . Caffeine-free instant coffee also has similar mutagenicity . Addition of microsomal enzymes abolished the mutagenicity . Black tea, green tea and Japanese roasted tea were also mutagenic to TA100 without S9 mix and one cup of these teas prepared in the ordinary way produced 1.7-3.8 X 10(4) revertants of TA100 . Black tea and green tea were also mutagenic to TA98 in the presence of S9 mix after treatment with a glycosidase from Aspergillus niger, hesperidinase . This type of mutagen in one cup of black tea induced 2.4 X 10(5) revertants of TA98. Cancer Lett, 1979 Oct, 7(6), 307 - 12 Mutagenic activity of gastric juice; Montes G et al.; Gastric juice samples from patients of a rural area of the Colombian Andes at high risk to gastric cancer were tested for mutagenesis with Salmonella typhimurium strains TA100 and TA1538 . Direct mutagenic effect was found in samples with detectable amounts of nitrite . This effect was not accountable by nitrite alone . Nitrite-negative samples from the same area and samples from the low-risk area of Cali were negative using the same mutagenesis assay. Proc Natl Acad Sci U S A, 1979 Oct, 76(10), 5244 - 8 Nucleotide sequences of trpA of Salmonella typhimurium and Escherichia coli: an evolutionary comparison; Nichols BP et al.; The complete nucleotide sequences of trpA of Salmonella typhimurium and Escherichia coli were determined . The nucleotide sequences are 24.8% divergent, compared with amino acid sequence divergence of 14.9% . Over half of the codons of each gene contain synonymous nucleotide changes . The pattern of synonymous nucleotide changes is consistent with the interpretation that such changes result from random mutational events . We do not find any evidence indicating that codon selection or RNA structure is of major selective value . We conclude that polypeptide function is the primary basis of selection in trpA and that most synonymous codon changes are selectively neutral. Proc Natl Acad Sci U S A, 1979 Oct, 76(10), 4941 - 5 leu operon of Salmonella typhimurium is controlled by an attenuation mechanism; Gemmill RM et al.; The nucleotide sequence of the control region of the leu operon of Salmonella typhimurium was determined . A prominent feature of this region is a signal for termination of transcription . In vitro, transcription does terminate at this site, yielding a leader RNA of about 160 nucleotides as a major product . This leader RNA is potentially translatable into a peptide containing 28 amino acids, 4 of which are adjacent leucine residues . Several regions of base complementarity exist within the leader, positioned such that pairing of one region precludes pairing of another . The position of the four leucine codons relative to two regions of base complementarity suggest a model for the regulation of the leu operon similar to that proposed by Yanofsky and coworkers for the trp operon . In addition, a third region of base complementarity was identified which, when incorporated into the model, explains why premature termination is the usual outcome when transcription is initiated in vitro by purified RNA polymerase. J Bacteriol, 1979 Oct, 140(1), 297 - 300 Chemotaxis of Salmonella typhimurium toward citrate; Kihara M et al.; Salmonella, but not Escherichia coli, was attracted to citrate, a distinction that is understandable in view of the inability of E . coli to transport tricarboxylic acids . The Salmonella response to citrate and to two previously described attractants, aspartate and malate, was mutually noncompetitive . Citrate taxis different from citrate uptake in that it did not require Na+, was constitutive, and was not repressible by glucose. J Bacteriol, 1979 Oct, 140(1), 267 - 75 Role of gene flaFV on flagellar hook formation in Salmonella typhimurium; Kutsukake K et al.; Nine temperature-sensitive nonflagellate mutants defective in flaFV were isolated from a strain of Salmonella typhimurium . Among them three mutants were found to produce flagella with abnormally shaped (either straight or irregularly curved) hooks at the permissive temperature . Two mutations that rendered hooks straight were located in one of the eight segments of flaFV defined by deletion mapping . The mutation that rendered hooks irregularly curved was located in a different segment . An flaR mutation was introduced into the latter mutant . At the permissive temperature, the resulting double mutant produced polyhooks whose wavelength and amplitude were both exceedingly reduced . These polyhook structures were more thermolabile than those of the flaFV+ strain . Hook protein of the former strain was shown to have a slightly positive electric charge compared with that of the latter . From these results and other available information, it is inferred that flaFV is the structural gene for the hook protein in Salmonella. J Bacteriol, 1979 Oct, 140(1), 261 - 6 Immuno-electron microscopic localization of lipopolysaccharide antigens on ultrathin sections of Salmonella typhimurium; Takamiya H et al.; Lipopolysaccharide antigens were demonstrated on ultrathin sections of styrene-embedded Salmonella typhimurium by direct postembedding staining with ferritin-labeled antibodies . The antigenicity, partially masked in the embedding process, could be satisfactorily recovered by treatment of ultrathin sections with nonspecific protease . As judged from the reaction site of the ferritin-labeled antibodies, the lipopolysaccharides were localized in two zones . The broader zone of densely distributed ferritin molecules was superimposed over the whole outer cellwall, and a smaller zone revealing antigenicity was found over the cell membrane, which strongly supports the concept that the latter is the site of synthesis of lipopolysaccharides . The well-defined labeled areas between these two antigenic zones may be the routes whereby the synthesized polysaccharide molecules reach the cell wall. J Bacteriol, 1979 Oct, 140(1), 141 - 6 Regulation of O-acetylserine sulfhydrylase B by L-cysteine in Salmonella typhimurium; Hulanicka MD et al.; A technique based on resistance to azaserine was used to isolate mutants lacking O-acetylserine sulfhydrylase B, one of two enzymes in Salmonella typhimurium capable of synthesizing L-cysteine from O-acetyl-L-serine and sulfide . The mutant locus responsible for this defect has been designated cysM, and genetic mapping suggests that cysM is very close to and perhaps contiguous with cysA . Strains lacking either O-acetylserine sulfhydrylase B or the second sulfhydrylase, O-acetylserine sulfhydrylase A (coded for by cysK), are cysteine prototrophs, but cysK cysM double mutants were found to require cysteine for growth . O-Acetylserine sulfhydrylase B was depressed by growth on a poor sulfur source, and depression was dependent upon both a functional cysB regulatory gene product and the internal inducer of the cysteine biosynthetic pathway, O-acetyl-L-serine . Furthermore, a cysBc strain, in which other cysteine biosynthetic enzymes cannot be fully repressed by growth on L-cystine, was found to be constitutive for O-acetylserine sulfhydrylase B as well . Thus O-acetylserine sulfhydrylase B is regulated by the same factors that control the expression of O-acetylserine sulfhydrylase A and other activities of the cysteine regulon . It is not clear why S . typhimurium has two enzymes whose physiological function appears to be to catalyze the same step of L-cysteine biosynthesis. J Natl Cancer Inst, 1979 Oct, 63(4), 977 - 82 Assay for mutagenicity of bile in Sprague-Dawley rats treated subcutaneously with intestinal carcinogens; Moriya M et al.; To investigate the mode of action of sc injected intestinal carcinogens, the mutagenicity assay of bile collected from noninbred Sprague-Dawley rats treated sc with carcinogens was conducted in the presence and absence of beta-glucuronidase . The bile samples from rats inoculated with 4-aminobiphenyl were mutagenic for Salmonella typhimurium TA100 only in the presence of beta-glucuronidase, whereas those from the 3,2'-dimethyl-4-aminobiphenyl-treated rats did not require the enzyme for mutagenicity toward strain TA100 . On the contrary, the assays with S . typhimurium G46 and TA100 of bile from rats inoculated with 1,2-dimethylhydrazine, azoxymethane, or methylazoxymethanol acetate failed to reveal mutagenicity whether beta-glucuronidase was added or not, though these carcinogens were highly mutagenic for strain G46 in the Salmonella-microsome mutagenicity test and/or in the host-mediated assay. J Natl Cancer Inst, 1979 Oct, 63(4), 903 - 7 Concentration-dependent mutation by alkylating agents in human lymphoblasts and Salmonella typhimurium: N-methyl-N-nitrosourethane and beta-propiolactone; Penman BW et al.; The toxic and mutagenic effects of the alkylating agents N-methyl-N-nitrosourethane (MNUT) and beta-propiolactone (BPL) were quantitatively measured in human lymphoblasts and Salmonella typhimurium . Forward mutation to 6-thioguanine resistance was measured in the human lymphoblasts, and forward mutation to 8-azaguanine resistance was measured in the bacterial cells after equigenerational (1.5 doubling times) exposures . In both systems, the induced mutant fraction rose linearly as a function of concentration for BPL and was biphasic for MNUT . The responses of the two assay systems to eight alkylating agents were compared . The exposure of the cells to each alkylating agent was calculated as exposure concentration multiplied by the time of exposure, and allowance was made for the decomposition of the alkylating agents during exposure (integral exposure) . Human cells were 2.5--13 times more sensitive than was S . typhimurium to the alkylating agents methyl methanesulfonate, ethyl methanesulfonate, propyl methanesulfonate, N-methyl-N'-nitro-N-nitrosoguanidine, methylnitrosourea, and MNUT . S . typhimurium cells were three times more sensitive to butyl methanesulfonate and 25 times more sensitive to BPL than were human cells. J Natl Cancer Inst, 1979 Oct, 63(4), 1093 - 6 Inhibition of 2-fluorenamine-induced mutagenesis in Salmonella typhimurium by vitamin A; Baird MB et al.; Vitamin A alcohol (retinol) completely inhibited the mutagenicity of the carcinogen 2-fluorenamine (2-FA) in Salmonella typhimurium TA98 when the mutagen was activated by liver microsomes from CFN rats . The mutagenicity of 2-FA activated by 9,000Xg rat liver supernatant S9 was inhibited by retinol to a lesser degree . The decline in the number of his+ revertants was not an artifact due to bacterial killing, inasmuch as retinol was not toxic to the bacteria at levels that totally inhibited mutagenesis by 2-FA . Mutagenesis induced by adriamycin, an antibiotic that does not require metabolic activation for mutagenic potential, was unaffected by vitamin A . These results indicate that retinoids inhibit the metabolic activation of some chemical carcinogens to forms that can interact with DNA . Our findings are consistent with the hypothesis that retinoids may exert anticancer activity by inhibiting carcinogen activation, thereby inhibiting tumor induction . In addition to the more widely accepted role of retinoids in modulating the proliferation of epithelially derived neoplasms. Cancer Lett, 1979 Oct, 7(6), 325 - 30 Inhibitors for the mutagenicities of colon carcinogens, 1,2-dimethylhydrazine and azoxymethane, in the host-mediated assay; Moriya M et al.; Inhibitory effects of several chemicals on the mutagenicities of 1,2-dimethylhydrazine (DMH) and azoxymethane (AOM) for Salmonella typhimurium G46 in the host-mediated assay were investigated . They were carbon disulfide (CS2), tetraethylthiuram disulfide (disulfiram, DSF), sodium diethyldithiocarbamate (SDDC), ethylene-bis(dithiocarbamato) manganese (Maneb), pyrazole (PZ), aminoacetonitrile hydrogen sulfate (AAN), and sodium selenite (SE) . All the compounds, except for SE, inhibited the mutagenicities of DMH and AOM. Acta Med Okayama, 1979 Oct, 33(5), 405 - 7 Tumor induction in Swiss mice by filtrable agent and Salmonella typhimurium; Hamazaki Y et al.; Combined inoculation of a cell-free extract of leukotic tissue of D103 mice and Salmonella typhimurium into adult Swiss mice induced leukosis and solid tumors . The induced solid tumors were histologically multifarious, and were transplantable in Swiss mice, but not in other strains of mice. Gann, 1979 Oct, 70(5), 663 - 70 Mutagenic and DNA-damaging effects of N-alkyl-N-(alpha-acetoxyalkyl)nitrosamines, models for metabolically activated N,N-dialkylnitrosamines; Mochizuki M et al.; Mutagenic and DNA-damaging effects of a series of N,N-dialkylnitrosamines monosubstituted at the alpha-carbon with an acetoxyl group were tested in Salmonella typhimurium, Escherichia coli, and Bacilus subtilis in the absence of metabolic activation system . The compounds comprised 8 N-alkyl-N-(acetoxymethyl)nitrosamines (alkyl=methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, or tert-butyl) and N-butyl-N-(1-acetoxybutyl)nitrosamine . All the compounds, except one with a tert-butyl group, gave positive results in these mutagenicity and repair tests . Presumed release of alkyl cations from the corresponding alpha-acetoxy derivatives by hydrolysis and heterolysis caused mutagenic and DNA-damaging effects in the bacteria . Structure-activity correlation of the compounds was noted in these tests and discussed in regard to the mutagenicity with metabolic activation and carcinogenicity of N,N-dialkylnitrosamines . The results support the hypothesis that alpha-carbon hydroxylation is one probable mechanism involved in the metabolic activation of N,N-dialkylnitrosamines. Zentralbl Bakteriol {Orig A}, 1979 Oct, 245(1-2), 71 - 88 {Protective role of Salmonella R mutants in Salmonella infection in mice (author's transl)}; Schlecht S et al.; NMRI mice were immunized with acetone-killed bacteria of 6 salmonella R mutants, 5 homologous and 6 heterologous Salmonella S forms and 3 E . coli R mutants . The animals were then challenged with graded amounts of live S . typhimurium . The results show that the protection obtained was dependent on the number of immunizing injections and on the time interval between them . Thus in the case of Salmonella R-mutants two immunizations increased the LD50 of challenge by an index of two (log 10) compaired to one immunization . A third immunization led to only a small further increase, the protection however, was longer lasting . A 3 fold immunization with two Salmonella typhimurium mutants, one SR- and one Ra form, led to a protection comparable to that obtained with S form bacteria . In contrast to the R-mutants, with Salmonella typhimurium S form a high degree of long-lasting protection was achieved already after a single immunization, and was not increased significantly by repeated injections . In animals immunized with Salmonella typhimurium S form the difference between non-lethal and 100% lethal challenge dose varied by a factor of 10 (one injection dose) . In contrast, in animals immunized with Salmonella R mutants the above differences were more gradual extending over 3, 4 or more infection doses . This was also true for animals immunized with lower doses of S . typhimurium S form and for the non-immunized control animals . For comparison the protective effect of heterologous Salmonella S forms and of E . coli R-mutants was studied . These were found to be less effective in affording protection to Salmonella typhimurium than the above Salmonella R forms . The various strains used for immunization may be placed in the following sequence in order of decreasing protection: Salmonella typhimurium S form, Salmonella R-mutants, heterologous Salmonella S forms, E . coli R mutants . In a parallel investigation the antibody inducing properties of Salmonella R mutants and heterologous Salmonella S forms were studied . In all cases homologous hemaglutinating antibodies to all the strains used for immunization were detectable . In immunization with Salmonella R mutants in addition to homologous titres, agglutinating antibodies to Salmonella typhimurium S form were also produced in significant amounts . There was, however, no correlation between the time of appearance of protection and that of appearance of antibodies nor between the hight of antibody titres and degree of protection . The detection of agglutinins to the infecting microorganisms represents therefore no valid criterium for the effectiveness of R mutants and heterologous Salmonella S forms as protective vaccines . From the present results it is concluded that in addition to the O antigen one or more further cell components exist which are involved in rendering animals immune to Salmonella typhimurium and probably also to other Salmonella S form bacteria. Biochemistry, 1979 Sep 18, 18(19), 4159 - 65 A single amino acid substitution in a histidine-transport protein drastically alters its mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis; Noel D et al.; Mutation hisJ5625 has altered the histidine-binding protein J of Salmonella typhimurium such that histidine transport is impaired, even though binding of histidine by the J protein is unimpaired {Kustu, S.G., & Ames, G.F . (1974) J . Biol . Chem . 249, 6976--6983} . We have determined by protein analytical methods that the only effect of this mutation has been the substitution of a cysteine residue for an arginine at a site in the interior of the polypeptide chain . This arginine residue is therefore potentially essential for the transport function of the protein . The mutant protein migrates in sodium dodecyl sulfate-polyacrylamide gel electrophoresis more slowly than the wild type protein, as if its molecular weight were greater by as much as 2000 . Since this behavior is apparently due to a single amino acid replacement, a molecular weight difference even between two closely related proteins should not be inferred solely on the basis of sodium dodecyl sulfate gel electrophoresis. J Microw Power, 1979 Sep, 14(3), 275 - 80 Lack of microbial genetic response to 2.45-GHz CW and 8.5- to 9.6-GHz pulsed microwaves; Dutta SK et al.; Strain D4 of the yeast Saccharomyces cerevisiae, and strains TA-1535, TA-100 and TA-98 of the bacterium Salmonella typhimurium, were exposed to 2.45-GHz continuous wave or 8.5- to 9.6-GHz pulsed electromagnetic radiation (EMR) at various power densities from 1 to 45 mW/cm2 . The temperature during radiation was maintained at 30 degrees C for yeast cultures and at 37 degrees C for bacterial cultures . The studies revealed no increase in mutations or of mitotic gene conversions when cells were radiated for two hours or less . Decreased viability of cells was noted in all cultures tested after radiation at power densities of 30 mW/cm2 or more; however, no reliable changes in genetic events occurred. Aust Vet J, 1979 Sep, 55(9), 413 - 7 Effect of environmental temperature on susceptibility of young chickens to Salmonella typhimurium; Soerjadi AS et al.; Day-old chickens kept in a cold environment (18 degrees to 22 degrees C) were more susceptible to a low and moderate challenge of Salmonella typhimurium than chickens similarly challenged and kept in a warm environment (32 degrees to 36 degrees C) . Cold stress at 10 degrees C for 24 h when applied to 12-day-old chickens effectively increased the number of birds shedding organisms . However a similar cold stress on 20-day-old chickens resulted in a less dramatic increase in the number of birds shedding organisms . Of the 60 birds previously challenged with S . typhimurium and then subjected to cold stress, 16 birds recommenced shedding and 7 birds with no previous history of shedding began to shed organisms. Ann Immunol (Paris), 1979 Sep-Oct, 130C(5), 743 - 8 {Inflammation and host resistance against bacteria . I.--Increased resistance against Listeria monocytogenes and Salmonella typhimurium in mice, following their treatment with bradykinin, kallidin and methionyl-lysyl-bradykinin (author's transl)}; Fauve RM et al.; Mice pretreated with kinins are more resistant to a lethal challenge of Listeria monocytogenes . The multiplication of Listeria is decreased in the liver and spleen and the blood clearance of Salmonella typhi-murium is increased. Biochem J, 1979 Sep 1, 181(3), 771 - 4 The catalytically active form of histidinol dehydrogenase from Salmonella typhimurium; Burger E et al.; The active-enzyme-sedimentation procedure was used to identify the catalytically competent form of histidinol dehydrogenase (EC 1.1.1.23) isolated from Salmonella typhimurium . At pH 9.4 the active species has a sedimentation coefficient S20,W of 5.4S, indicating that the dimer with a mol.wt . of approx . 83 000 is the enzymically active form. Arch Toxicol, 1979 Sep, 42(4), 259 - 64 Detection of the carcinogenic nitrofuran derivative VR-6 as a mutagen in the Salmonella/microsome test; Baumeister M et al.; The carcinogenic nitrofuran, VR-6, was evaluated for mutagenicity in Salmonella typhimurium TA 100 using the plate assay (Ames test) . The dose-response curve indicated that S . typhimurium TA 100 is a very sensitive genetic indicator for this chemical class and that basepair substitution appears to be the molecular mechanism with VR-6 . The results reported here provide evidence, that VR-6 is a directly acting mutagen for S . typhimurium TA 100 and that the chemical is partially deactivated in the presence of rat liver homogenates . Comparison of the results obtained with this agent in the Ames test with data from a subacute animal study, showed a good agreement in predicting the carcinogenic risk. Mol Gen Genet, 1979 Sep, 175(2), 145 - 9 Constitutive mutation of cysJIH operon in a cysB deletion strain of Salmonella typhimurium; Ostrowski J et al.; In a cysB deletion strain a new mutation, denoted cys-2332 was isolated, which causes the constitutive expression of the cysJIH operon . cys-2332 is closely linked to cysJIH and presumably is located in the initiator region of this operon, rendering its expression independent of the cysB gene product and the internal inducer O-acetyl-L-serine . The presence of sulfite reductase (encoded by cysI and cysJ) activity in a cysB- cys-2332 double mutant indicates that cysG, which is not linked to cysJIH but is required for the synthesis of the sulfite reductase co-factor siroheme, is not controlled by cysB. Cancer Lett, 1979 Sep, 7(5), 259 - 64 Formation of mutagens in cooked foods . I . Beef; Spingarn NE et al.; Mutagens detectable by Salmonella typhimurium TA98, after activation by liver S-9 fraction, are formed when meat is cooked by frying, broiling and boiling . High levels of mutagenic activity are formed rapidly when frying, or more slowly during broiling . Formation of mutagens in boiled beef stock requires several days under reflux, but shows a strong concentration dependence . Time curves suggest that a period exists during which mutagens are not readily formed; however, after this period mutagen production is rapid . Hamburgers from commercial franchises were frequently mutagenically active. Proc Natl Acad Sci U S A, 1979 Sep, 76(9), 4280 - 4 Differences in mutagenicity and cytotoxicity of (+)- and (-)-benzo{a}pyrene 4,5-oxide: a synergistic interaction of enantiomers; Chang RL et al.; In order to study the biological effects of (+)- and (-)-benzo{a}pyrene 4,5-oxide, a synthesis of these molecules has been developed based on the resolution of (+/-)-cis-4,5-dihydroxy-4,5-dihydrobenzo{a}pyrene . The (-) enantiomer of benzo{a}pyrene 4,5-oxide was 1.5- to 5.5-fold more mutagenic than the (+) enantiomer in strains TA 98, TA 100, TA 1537, and TA 1538 of Salmonella typhimurium and in Chinese hamster V79 cells . In studies with V79 Cells, the (-) enantiomer of benzo{a}pyrene 4,5-oxide was also more cytotoxic than the (+) enantiomer . When mixtures of the enantiomers were studied in V79 cells, synergistic cytotoxic and mutagenic responses were observed . The greatest cytotoxic and mutagenic effects occurred with a 3:1 mixture of the (-) and (+) enantiomers of benzo{a}pyrene 4,5-oxide, respectively. Mutat Res, 1979 Sep, 62(2), 221 - 5 Azide-induced mutagenesis in gram-negative bacteria is recA-and lexA-independent; Szwacka M et al.; Azide-induced mutagenesis was investigated in Salmonella typhimurium and Escherichia coli . Azide was highly effective in inducing mutation in uvrB, uvrB recA and uvrB recB mutants of S . typhimurium . The mutagenic effect of azide was also observed in uvrA lexA mutants of E . coli K12 and E . coli B/r . These results suggest that azide-induced mutagenesis is due to mis-replication of DNA. Infect Immun, 1979 Sep, 25(3), 863 - 72 Artificial Salmonella vaccines: O-antigenic oligosaccharide-protein conjugates induce protection against infection with Salmonella typhimurium; Svenson SB et al.; Outbred mice were vaccinated with various artificial Salmonella vaccines and subsequently challenged intraperitoneally with graded doses of virulent Salmonella typhimurium . The Salmonella vaccines used were: (i) octasaccharide, obtained by hydrolysis of the O-antigenic polysaccharide chain of S . typhimurium strain SH 4809 with phage P22-associated endo-rhamnosidase and covalently linked to either diphtheria toxin or edestine; (ii) purified outer membrane proteins (porins) from S . typhimurium; and (iii) octasaccharide covalently linked to porins . All vaccines induced significant protection against experimental infection of mice with S . typhimurium . However, vaccination with the octasaccharide-porin conjugate resulted in better protection than that obtained by vaccination with octasaccharide or porin vaccines separately . Rabbit antibodies raised against the different vaccines were also passively administered intravenously to mice . Such mice were protected against challenge with virulent S . typhimurium by antibodies specific for the S . typhimurium O-antigen or for the porins . Thus, active immunization with more than one surface component of Salmonella bacteria improved the efficacy of the vaccine . The data from the passive immunization experiments also emphasized the role of humoral immunity for protection against S . typhimurium infection. Infect Immun, 1979 Sep, 25(3), 857 - 62 Immunization with major outer membrane proteins in experimental salmonellosis of mice; Kuusi N et al.; Porin (outer membrane protein) preparations extracted from a rough (Rb2) mutant of Salmonella typhimurium proved to be good immunogens in mice and rabbits . The antibody response achieved was measured by using enzyme-linked immunosorbent assay techniques . High titers of both antiporin and antilipopolysaccharide were detected in both species . The rabbit antiserum raised against the porins and the porin preparations themselves had a highly significant protective capacity against intraperitoneal Salmonella infection of mice . Absorption of the rabbit antiporin serum with lipopolysaccharide immunosorbent did not change its protective capacity in a passive immunization experiment, suggesting that the antiporin antibody preparations were the active components. Mutat Res, 1979 Sep, 68(1), 9 - 13 Mutagenic activity of thiram in Ames tester strains of Salmonella typhimurium; Zdzienicka M et al.; The mutagenic activity of thiram was investigated in 4 histidine-requiring strains of Salmonella typhimurium (TA1535, TA100, TA1538, TA98) with and without activation by liver microsomes . In strains TA1535 and TA100, thiram induces mutations without metabolic activation . The presence of rat-liver microsome fraction, cysteine or glutathione abolish its mutagenic activity in these strains . In contrast, thiram requires metabolic activation for the expression of its mutagenic activity in TA1538 and TA98 strains . The compounds containing the sulphydryl group abolish mutagenic activity of thiram in these strains, too. Mutat Res, 1979 Sep, 68(1), 51 - 8 Genetic toxicity of procarbazine in bacteria and yeast; Bronzetti G et al.; Procarbazine {N-isopropyl-alpha-(2-methylhydrazino)-p-toluamide hydrochloride} is used to treat Hodgkin's disease . This compound was tested in vitro without and with S10 fraction from mice liver (microsomal assay) using Saccharomyces cerevisiae strain D7, Salmonella typhimurium (strains TA98, TA100, TA1535) and in vivo in Swiss albino mice (host-mediated assay) using D7 . Procarbazine, without S10 fraction, is highly toxic and induced mitotic crossover, gene conversion, and reverse mutation in D7 . It had a toxic effect on all the Salmonella strains; but did not induce reverse mutations at the histidine loci . Procarbazine, with S10 fraction, was less toxic and did not induce genetic effects in yeast or Salmonella . In the host-mediated assay, no genetic effects were seen. Mutat Res, 1979 Sep, 68(1), 41 - 9 Mutagenicity evaluation of the two antimalarial agents chloroquine and mefloquine, using a bacterial fluctuation test; Schupbach ME; The two antimalarial agents chloroquine and mefloquine have been tested for mutagenicity in Salmonella typhimurium strains TA1535, TA1537 and TA1538 . Chloroquine was found to revert strain TA1537 at concentrations of 100 and 250 micrograms/ml, most likely due to intercalation . No mutagenicity was found with mefloquine at concentrations up to 2.5 micrograms/ml, neither without nor with metabolic activation by Ca2+-precipitated rat liver microsomes . Higher concentrations of mefloquine and chloroquine inactivated the bacteria. Mutat Res, 1979 Sep, 68(1), 23 - 30 Mutagenic cholesterol preparations; Smith LL et al.; Naturally air-aged commercial samples of USP or reagent-grade cholesterol contain components which are mutagenic towards Salmonella typhimurium strains TA1537, TA1538 and TA98 . These mutagenic components are associated with the polar cholesterol autoxidation products, but identity of the mutagenic components has not been achieved . Pure crystalline nonmutagenic cholestrol free from autoxidation products becomes mutagenic towards these strains upon heating at 70 degrees in air or following exposure to 60 Co gamma-radiation. Mutat Res, 1979 Sep, 68(1), 15 - 22 In vivo conversion of sodium azide to a stable mutagenic metabolite in Salmonella typhimurium; Owais WM et al.; Salmonella typhimurium TA1530 and G46 strains growing in minimal medium supplemented with sodium azide produce a stable mutagenic metabolite which is not azide . The production of this metabolite is restricted to the log phase of bacteria grown in the presence of azide . The metabolite is highly mutagenic in DNA-repair defective base-substitution strains TA1530 and TA1535, but ineffective in frameshift strains TA1538 and TA1537 . The metabolite induces mutations in resting cells of the TA1530 strain. Mutat Res, 1979 Sep, 68(1), 1 - 8 The mutagenicity of nitrosamides in Salmonella typhimurium; Lijinsky W et al.; 34 nitrosamides (10 nitrosoalkylcarbamates, 2 nitrosoalkylnitroguanidines, 12 nitrosoalkylureas, 6 substituted nitrosoalkylureas, and 4 cyclic nitrosoalkylureas) were tested for mutagenicity in Salmonella . All were direct-acting mutagens of varying potency. J Bacteriol, 1979 Sep, 139(3), 993 - 1000 Mutation spoT of Escherichia coli increases expression of the histidine operon deleted for the attenuator; Winkler ME et al.; F'-episomes carrying the Salmonella typhimurium wild-type or attenuator-deleted histidine (his) operons were introduced into Escherichia coli strains containing relA or spoT single and double mutations known to affect guanosine 3'-diphosphate 5'-diphosphate (ppGpp) and guanosine 3'-triphosphate 5'-diphosphate (pppGpp) levels . Expression of the his operon and expression of the gene for 6-phosphogluconate dehydrogenase (gnd) were measured during balanced growth in amino acid-rich and minimal media . The data were consistent with the interpretation that ppGpp is a positive effector of his operon expression, whereas pppGpp is not an essential effector . The conclusion that his operon expression is maximally stimulated at a lower than maximum intracellular ppGpp concentration was further confirmed . Neither ppGpp nor pppGpp appeared to influence gnd gene expression . The metabolic regulation of the E . coli his operon was found to be similar to the ppGpp-meidated metabolic regulation of the S . typhimurium his operon. J Bacteriol, 1979 Sep, 139(3), 899 - 910 Two mutations which affect the barrier function of the Escherichia coli K-12 outer membrane; Coleman WG Jr et al.; Two genetically distinct classes of novobiocin-supersensitive mutants were isolated from Escherichia coli K-12 . One class, given the phenotypic name NbsA, lies at 10 min on the E . coli chromosome . The order of the genes in this region, based on transductional analyses, is proC NbsA plsA purE . The second, NbsB, lies at 80 min . The order of the genes in this region, based on transduction analyses, is xyl cysE NbsB pyrE . Both classes of mutants show increased sensitivity to hydrophobic drugs but are different: NbsA cells tend to be more sensitive to cationic agents, whereas NbsB cells show the opposite tendency . The sole detectable biochemical alteration in NbsA strain is greater than 90% reduction in the phosphate content of the lipid A region of the lipopolysaccharide . The NbsB mutation results in lipopolysaccharide that contains primarily the stereoisomer D-glycero-D-mannoheptose, rather than L-glycero-D-mannoheptose, and which contains very little of the distal sugars . Since NbsA strains have apparently normal outer membrane proteins and total cellular phospholipids, changes solely in lipopolysaccharide can increase permeability to certain hydrophobic antibiotics . Complementation studies indicate that the NbsA marker is probably allelic with acrA . In addition, the NbsB marker is genetically and phenotypically similar to the rfaD locus of Salmonella typhimurium . For this reason, the phenotypic designations NbsA and NbsB have been changed to the genotypic designations acrA and rfaD, respectively. J Bacteriol, 1979 Sep, 139(3), 842 - 9 Ribosomal ribonucleic acid isolated from Salmonella typhimurium: absence of the intact 23S species; Winkler ME; Ribonucleic acid (RNA) isolated by four distinct methods and from a variety of Salmonella typhimurium strains lacked intact 23S ribosomal RNA (rRNA) . On sucrose gradients which minimize aggregation, the vast majority of S . typhimurium rRNA sedimented as a 16S peak with a 14S shoulder . RNA from this region of the gradient was resolved into three discrete bands by electrophoresis in formamide . Two very minor S . typhimurium RNA peaks were resolved at 21S and 10S on sucrose gradients, and each peak formed discrete bands in electrophoresis . It is concluded that if S . typhimurium does possess an intact 23S rRNA species, this species is extremely "labile." The absence of isolatable S . typhimurium 23S rRNA possibly reflected in vivo processing of the rRNA before isolation . Under certain conditions, S . typhimurium rRNA formed discrete aggregates which sedimented similarly to intact Escherichia coli 23S rRNA. J Bacteriol, 1979 Sep, 139(3), 1097 - 101 The ends of Tn10 are not IS3; Ross DG et al.; By heteroduplex and hybridization analysis we showed that the inverted repetition (here called IS10) at the ends of the translocatable tetracycline resistance element Tn10 is not IS3, as had previously been reported by Ptashne and Cohen (J . Bacteriol . 122:776--781, 1975) . Further analysis confirmed the homology between IS3 and the alpha beta sequence of F and demonstrated that IS10 was not present in the genomes of Salmonella typhimurium LT2 or Escherichia coli K-12. J Bacteriol, 1979 Sep, 139(3), 1082 - 4 his-Linked hydrogen sulfide locus of Salmonella typhimurium and its expression in Escherichia coli; Voll MJ et al.; A his-linked H2S locus of Salmonella typhimurium has been further defined by direct isolation of H2S mutants . Expression of this locus in Escherichia coli has been demonstrated. Cancer Res, 1979 Sep, 39(9), 3780 - 2 Mutagenicity of the naturally occurring carcinogen cycasin and synthetic methylazoxymethanol conjugates in Salmonella typhimurium; Matsushima T et al.; The aglycone methylazoxymethanol of the naturally occurring carcinogenic glucoside, cycasin, has previously been shown to be mutagenic, but cycasin per se has not . In this work, cycasin was demonstrated to be mutagenic using a modification of the Ames Salmonella test in which it was preincubated with beta-glucosidase and the tester strain in liquid medium . The mutagenicity of cycasin to six histine-depedent Salmonella strains varied considerably with strain HisG46 being the most susceptible . Methylazoxymethyl-beta-D-glucosiduronic acid, which also is nonmutagenic per se, similarly became mutagenic when preincubated with beta-glucuronidase . Methylazoxymethyl acetate, which is slightly mutagenic by the Ames standard pour plate method, became highly mutagenic on preincubation . The mutagenicity of free methylazoxymethanol was confirmed, and a linear dose-response relationship was observed . The common conditions required for activation of nonmutagenic methylazoxymethanol conjugates, the glucoside cycasin and methylazoxymethyl-beta-D-glucosiduronic acid, are 90-min preincubation at 30 degrees, pH 6.5, with an appropriate hydrolase and Salmonella typhimurium HisG46. Cancer Res, 1979 Sep, 39(9), 3289 - 318 Chemical characterization of 465 known or suspected carcinogens and their correlation with mutagenic activity in the Salmonella typhimurium system; Rinkus SJ et al.; Since chemicals exhibiting mutagenic activity pose a potential hazard to their users, there is increasing acceptance of mutagenicity testing as an integral part of a premarketing toxicological evaluation of chemicals . In vitro testing has gained much notoriety as quick and relatively inexpensive means to assess the mutagenic potential of chemicals . However, the innovative use of microsomes to simulate metabolism has not changed the fact that in vitro activation cannot duplicate faithfully the metabolism that occurs in vivo . This shortcoming will express itself by the production of false negatives and possibly false positives during mutagenicity screening . This assertion is also borne out by a reanalysis of the ability of known animal carcinogens to cause mutations in the generally recognized premier in vitro system, the Salmonella-S-9 system . Although previous studies have suggested that a high percentage (greater than 85%) of all carcinogens will be mutagenic in this system, with no indication that false negatives are associated with certain chemical types, these findings are of uncertain practical value due to the limited number of chemical types that were considered . An analysis of 465 compounds with known or suspected carcinogenic activity indicates that about 58% have been adequately tested in Salmonella, that the testing has concentrated on certain chemical types and has neglected others, and that some categories of carcinogens exhibit individual correlations that are unsatisfactorily low by any standard . Poorly detected categories of carcinogens include: azonaphthols; carbamyls and thiocarbamyls; phenyls; benzodioxoles; polychlorinated aromatics, cyclics, and aliphatics; steroids; antimetabolites; and symmetrical hydrazines . Nonstandard procedures are necessary to optimize the testing of chemicals that are bactericidal, that are volatile, or that cross-link DNA . False negatives appear to arise for two reasons: an inability to devise an in vitro activation system that can be reliably used in a standard way; and an inability to detect the entire spectrum of mutational events that can lead to the induction of cancer. Bol Med Hosp Infant Mex, 1979 Sep-Oct, 36(5), 833 - 7 {Subdural empyema due to Salmonella typhimurium . Analysis of a case}; Gonzalez-Mata A et al.; The case was that of an infant with congenital hydrocephalus who developed subdural empyema . The most outstanding items were, the age of the patient (18 months), the identification of Salmonella typhimurium, a germ rarely described responsible for this pathology, the absence of anacrobe germs and the possible hematogenous dissemination from the digestive tract when the port of entry usually associated is the infection of the paranasal sinuses . The most useful method for study was the computerized axial tomography. Rev Infect Dis, 1979 Sep-Oct, 1(5), 813 - 20 Effect of subminimal inhibitory concentrations of mecillinam on the synthesis of DNA, RNA, and protein of Salmonella typhimurium: a proposed mechanism of action; Amaral L; Salmonellae alter their rod-like morphology to become large ovals within 3-5 hr after being exposed to concentrations of mecillinam below the minimal inhibitory concentration . Before this overt morphologic change occurs, synthesis of DNA increases, with a concomitant decrease in total protein synthesis . Incorporation of {3H}leucine into cell wall protein is markedly inhibited by mecillinam, whereas incorporation of leucine into soluble intracellular proteins is enchanced by the drug . Electrophoretic separation of stained, soluble intracellular proteins of salmonellae exposed to mecillinam indicates that as many as 15-20 individual groups of protein occur at higher concentrations in mecillinam-exposed salmonellae than in unexposed control organisms . These results suggest that, at low concentrations, mecillinam binds selectively to cell wall components, thereby interfering with the assembly of the cell wall during growth . This interference causes a buildup of newly synthesized soluble proteins that are normally involved in cell wall assembly . The weakening of the cell wall, combined with this buildup, causes the cell to assume a three-dimensional oval structure that is the result of equal hydrostatic pressure exerted by the medium. J Am Vet Med Assoc, 1979 Aug 15, 175(4), 359 - 61 Zoonotic diseases in psittacine birds: apparent increased occurrence of chlamydiosis (psittacosis), salmonellosis, and giardiasis; Panigrahy B et al.; Between September 1977 and November 1978, chlamydiosis (psittacoisis) was diagnosed in 52 of 128 parrots, 5 of 12 cockatiels, 2 of 5 cockatoos, 3 of 6 macaws, 1 of 22 conures, 2 of 18 lovebirds, and 6 of 76 parakeets; 2 lories and 1 lorikeet were chlamydiosis negative . Two cases of human chlamydiosis were associated with two submissions of parrots subsequently found to have active infection . Twenty parrots (including 13 that were chlamydiosis positive), 2 cockatiels, 1 macaw, 1 lorie, and 1 parakeet yielded salmonella organisms, of which 16 were identified as Salmonella typhimurium, 8 as untypeable monophasic salmonellae of serogroup B, and 1 as S arizonae . Three S typhimurium from parrots that had been treated with chlortetracycline for chlamydiosis were resistant to tetracyclines, streptomycin, and sulfonamides; another isolate was found to be resistant to chloramphenicol only . Severe giardiasis was diagnosed in parakeets originating from six aviaries. Cancer Res, 1979 Aug, 39(8), 3070 - 3 Synthesis of the glucuronic acid conjugate of methylazoxymethanol; Matsumoto H et al.; The glucuronic acid conjugate of methylazoxymethanol was synthesized by oxidizing the primary alcohol of the glucose moiety of cycasin (methylazoxymethanol-beta-D-glycopyranoside) to a carboxylic acid . The oxidation was carried out by bubbling oxygen gas through a cycasin solution in the presence of a platinum-on-carbon catalyst . A band at 1715 cm-1, not present in the cycasin infrared spectrum, appeared in the spectrum of the oxidized cycasin product, establishing the presence of a carboxylic acid group . The oxidation product is methylazoxymethanol-beta-D-glucosiduronic acid because, when hydrolyzed with Escherichia coli beta-glucuronidase, it produced methylazoxymethanol and glucuronic acid and also indicated retention of the beta-linkage of cycasin . Varying quantities of the synthesized methylazoxymethanol-glucosiduronic acid, injected into Wistar rats of both sexes and of varying weights, were not acutely toxic . The compound was mutagenic to Salmonella typhimurium when preincubated with E . coli beta-glucuronidase, but not when preincubated with bovine liver glucuronidase. Genetics, 1979 Aug, 92(4), 1023 - 40 Specificity of insertion by the translocatable tetracycline-resistance element Tn10; Kleckner N et al.; Genetic analysis of 131 independent transpositions of the tetracycline-resistance element Tn10 from a single site in phage P22 into the histidine operon of Salmonella typhimurium reveals that Tn10 insertions are not randomly distributed along this chromosomal target . The insertions occur in 22 different "clusters"; insertions within each cluster are very tightly linked in recombination tests . Tn10 insertions are not evenly distributed among the identified clusters . The existence of these clusters suggests that this chromosomal target contains particular genetic signals that guide Tn10 to particular preferred positions for insertion . Insertions within each cluster occur in both orientations with roughly equal frequency.--The relationship among different insertions within each cluster has been examined . The resolution of genetic mapping places an upper limit of about 50 basepairs on the distance between different insertions within a cluster . Different insertions within a cluster usually have the same reversion frequency; however, heterogeneity in reversion frequency has been detected in at least two clusters . For most clusters, the available data are consistent with the simple possibility that all insertions within a cluster are at identical positions; however, the data do not exclude other possibilities. Appl Environ Microbiol, 1979 Aug, 38(2), 267 - 74 Toxins of molds from decaying tomato fruit; Harwig J et al.; Among 27 mold isolates from decaying tomatoes, culture filtrates or ethyl acetate extracts of 8 isolates grown in yeast extract-sucrose medium were markedly toxic (mortality, greater than 50%) to brine shrimp larvae . The toxicity of six of these isolates could be attributed to the presence of citrinin, tenuazonic acid, or T-2 toxin . Ethyl acetate extracts of five Alternaria isolates and one Fusarium isolate were mutagenic for Salmonella typhimurium strains . In ripe tomatoes inoculated with toxin-producing isolates and incubated at 25 degrees C, one Alternaria alternata isolate produced tenuazonic acid in seven of seven tomatoes at levels of up to 106 micrograms/g and alternariol methyl ether in one of the seven tomatoes at 0.8 microgram/g . Another A . alternata isolate produced tenuazonic acid or alternariol methyl ether at much lower levels in only three of seven tomatoes . Patulin and citrinin were produced by a Penicillium expansum isolate at levels of up to 8.4 and 0.76 microgram/g, respectively . In tomatoes incubated at 15 degrees C, a Fusarium sulphureum isolate produced T-2 toxin, HT-2 toxin, and neosolaniol at levels of up to 37.5, 37.8 and 5.6 micrograms/g, respectively . If these mycotoxins are thermostable, they may occur at detectable levels in tomato products whenever partially moldy tomatoes are used as raw material. CRC Crit Rev Toxicol, 1979 Aug, 6(3), 189 - 209 Mutagenic factors in cooked foods; Sugimura T et al.; The charred surface of fish and beef showed strong mutagenic activity in Salmonella typhimurium test strains when activated by S-9 mix of rat liver . The pyrolysis products of proteins and amino acids were also highly mutagenic . Among the pyrolysis products of amino acids, those of tryptophan, serine, and glutamic acid were most active . The new gamma-carboline derivatives, 3-amino-1,4-dimethyl-5H-pyrido{4,3-b}indole and 3-amino-1-methyl-5H-pyrido{4,3-b}indole, were purified from the pyrolysis products of tryptophan . These new compounds were stronger mutagens than aflatoxin B1 towards S . typhimurium TA98, a frameshift type mutant, and they also transformed cryopreserved Syrian hamster embryo cells in vitro . Tryptophan pyrolysate also contained the beta-carboline derivatives, norharman and harman, which are not mutagenic alone, but act as comutagens . A mixture of norharman or harman and nonmutagenic aniline or o-toluidine was strongly mutagenic . The mutagenicities of charred products of other foods, such as seaweed and garlic, are reviewed in this article . Flavonoids, such as kaempferol and quercetin, and glycosides of these flavonoles were mutagenic . The mutagenicity of cooked vegetables depends partly on these flavonoid derivatives . The already-known existence of benzol{a}pyrene and nitroso compounds in cooked food is also reviewed. Cancer Lett, 1979 Aug, 7(4), 221 - 5 The reduced mutagenicity of aflatoxin B1 due to hydroxylation: observations on five Salmonella typhimurium tester strains; Uwaifo AO et al.; The mutagenicity of aflatoxin M1 relative to that of aflatoxin B1, the parent compound, was studied in 5 Ames' tester strains of Salmonella typhimurium (TA 98, TA 100, TA 1535, TA 1537, TA 1538) . Aflatoxins B1 and M1 are both highly mutagenic in microsome-mediated system in TA 100 . The prediction of the relative carcinogenicity of aflatoxin M1 to aflatoxin B1 posed by the mutation of TA 100 is probably more authentic than by TA 98. Proc Natl Acad Sci U S A, 1979 Aug, 76(8), 3693 - 7 Permeabilization of cells for studies on the biochemistry of bacterial chemotaxis; Paoni NF et al.; The cell membranes of Salmonella typhimurium and Escherichia coli have been made permeable in order to introduce S-adenosylmethionine into the cell for study of the course of methylation . A series of protein bands in the Mr 60,000 region were methylated, the specific bands and the extent of methylation depending on the attractant used . The change in levels of methylation was essentially the same as the in vivo responses, indicating that the permeabilization procedure maintains the relative relationships of the cellular proteins . A shift in intensity of the methylated bands occurred over time, indicating that a sequential process is involved in the methylation of these proteins . The permeabilization technique appears to offer major advantages in tracing the biochemical processes of the behavioral system. Mutat Res, 1979 Aug, 62(1), 19 - 26 Mutagenic effects of benzo{a}pyrene after metabolic activation by hepatic 9000 g supernatants or intact hepatocytes; Brouns RE et al.; The activating capacities of isolated rat hepatocytes and 9000 g supernatant from these cells with respect to the mutagenic effect of benzo{a}pyrene on Salmonella typhimurium TA100 were investigated . No mutagenicity of benzo{a}pyrene was found with the cell-mediated assay, unless the hepatocytes were disrupted after pre-incubation with benzo{a}pyrene or the intracellular glutathione content was reduced . It is suggested that a retention of active metabolites and an effective detoxication may account for the absence of mutagenic response. Infect Immun, 1979 Aug, 25(2), 597 - 602 Bactericidal activity of fractionated granule contents from human polymorphonuclear leukocytes: antagonism of granule cationic proteins by lipopolysaccharide; Modrzakowski MC et al.; Granule extracts from human polymorphonuclear leukocytes (PMN) were prepared with 0.2 M (pH 4.0) acetate . A fraction (valley AB) with distinctive bactericidal activity against cell wall mutants of Salmonella typhimurium LT-2 was obtained after fractionation of the granule extracts by Sephadex G-100 column chromatography . The smooth parent LT-2 strain was less sensitive to the bactericidal action . Susceptibility of the rough mutants to bactericidal action increased as sugar residues decreased in the lipopolysaccharide (LPS) (Re greater than Rd2 greater than Rd1 greater than Rc greater than Ra) . Cationic protein(s) responsible for bactericidal activity could be selectively removed from the fraction by absorption with whole LT-2 cells or purified LPS . Loss of cationic protein species was confirmed by cationic polyacrylamide gel electrophoresis . Purified LPS from LT-2 or the deep rough mutant TA2168 inhibited the antimicrobial activity of the killing fraction in in vitro assays . A minor protein species (vAB1) from the valley AB fraction had an apparent molecular weight of 36,000 to 37,000 and represented a major bactericidal activity of the fraction . Small amounts of the isolated vAB1 protein were bactericidal for the smooth parent LT-2 strain. Mutat Res, 1979 Aug, 67(4), 301 - 8 Derivatives of side-chain hydroxylated nitrosamines direct acting mutagens in Salmonella typhimurium; Michejda CJ et al.; Methyl-(beta-tosyloxyethyl)nitrosamine and 3-methyl-4,5-dihydro-1,2,3-oxadiazolium tosylate are potent direct acting mutagens in the Ames assay, as is N-nitrosoprolinyl tosylate . These compounds are derived from beta-hydroxylated nitrosamines . The closely related methyl-(gamma-tosyloxypropyl)nitrosamine is not mutagenic without activation . These data are consistent with the chemical behavior of these substances, which suggest that suitable derivatives of beta-hydroxylated nitrosamines, such as O-sulfates, may be direct-acting biological alkylating agents. Mutat Res, 1979 Aug, 64(4), 249 - 58 The L-arabinose-resistance test with Salmonella typhimurium strain SV3 selects forward mutations at several ara genes; Pueyo C et al.; A new assay has been described for mutagenicity testing using an L-arabinose-sensitive strain of Salmonella typhimurium . The test strain SV3 and several L-arabinose-resistant mutants selected therefrom are characterized in the present study by 3 different criteria: inhibition of growth by L-arabinose, accumulation of keto-sugars, and activities of the enzymes involved in L-arabinose catabolism . Strain SV3 (ara-531) shows high levels of inducible L-arabinose isomerase (EC 5.3.1.4) and L-ribulokinase (EC 2.7.1.16) activities, but is deficient in L-ribulose-5-phosphate 4-epimerase (EC 5.1.3.4), the enzyme encoded in Escherichia coli by gene D in the araBAD operon . Addition of L-arabinose to SV3 growing in glycerol or casamino acids stops growth . D-Glucose only partially reverses this inhibition . Reversion of the ara-531 mutation restores different levels of epimerase activity and resistance to L-arabinose . However, the great majority of the L-arabinose-resistant mutants do not utilize L-arabinose . The physiological and enzymatic properties of these L-arabinose non-utilizing mutants suggest that L-arabinose resistance is due to forward mutations in at least 3 other genes, araA, araB and araC, blocking steps prior to L-ribulose 5-phosphate accumulation. J Med Microbiol, 1979 Aug, 12(3), 265 - 76 Biotyping and colicine typing of Salmonella typhimurium strains of phage type 141 isolated in Scotland; Barker R et al.; Cultures of Salmonella typhimurium (551 strains) of phage type 141 isolated in Scotland from 1965 to 1977 were examined for biotype and colicine type . Three main biotype clones were recognised: If (30 strains), 9f (507 strains) and 31bd (11 strains) with subtype variants 9bf (1 strain), 9cf (1 strain) and 31b (1 strain) . The contribution made by each biotype clone to outbreaks in Scotland was analysed . The findings confirmed the distinctness of the three biotype clones within the single phage type and indicated possible origins of strains of biotypes of 9f and 31bd. J Natl Cancer Inst, 1979 Aug, 63(2), 309 - 12 Mutation of human cells by kerosene soot; Skopek TR et al.; The polycyclic aromatic hydrocarbon fraction of a kerosene soot induced forward mutation in human diploid lymphoblasts when coincubated with Sprague-Dawley rat liver postmitochondrial supernatant . Two components of the kerosene soot extract, benzo{a}pyrene (BP) and cyclopenta{cd}pyrene (CP), were also tested . TP was not mutagenic at the concentration found in the soot extract, although it was active at higher concentrations . The amount of CP present could account for approximately 8% of the total mutation observed with the soot . The results were compared to data obtained previously in a similar mutation assay in Salmonella typhimurium . The protocol described permits the facile assay of mutation at the hgprt locus in human lymphoblasts; such mutation is induced by compounds of complex mixtures requiring mixed-function oxygenase activity for metabolism to genetically active derivatives. J Bacteriol, 1979 Aug, 139(2), 646 - 51 Ultrastructure of the outer membrane of Salmonella typhimurium bacteriocin-resistant mutants deficient in the 33K protein; Lounatmaa K; Outer membrane mutants of Salmonella typhimurium deficient in one, two, or three of the 33,000-dalton (33K), 34K, and 36K outer membrane proteins (7) were studied by using thin sectioning and freeze-fracturing electron microscopy techniques . The outer concave fracture face of all mutants deficient in the 33K protein had numerous particleless patches . In contrast to all previously examined 34K to 36K-deficient mutants, the 33K-deficient mutants showed marked heterogeneity in the size and distribution of such "empty" patches between cells of a culture . One mutant was deficient in both the 33K and the 34K to 36K "porin" protein complex; its outer membrane had very large particleless smooth areas . It is concluded that the 33K protein on one hand and the porin on the other are both able to form intramembraneous particles. J Bacteriol, 1979 Aug, 139(2), 573 - 82 Suppression of a deletion mutation in the glutamine amidotransferase region of the Salmonella typhimurium trpD gene by mutations in pheA and tyrA; Tanemura S et al.; Prototrophic revertants of a trpD deletion mutant that lacks the glutamine amidotransferase domain of the bifunctional component II subunit of the anthranilate synthetase-phosphoribosyltransferase complex have been found to arise by the occurrence of sublethal missense mutations in either the pheA or tyrA loci . Such suppressor mutations were obtained directly by mutation of the wild-type pheA gene as well as indirectly by partial reversion of a variety of nonleaky pheA and tyrA mutations . The suppressor strains have only a portion of the normal level of the pheA or tyrA enzyme activity and thus experience a partial limitation in the synthesis of phenylalanine or tyrosine . This limitation leads to a relaxation of end-product regulation of the phenylalanine- or tyrosine-specific enzymes of the common aromatic pathway and to the overproduction of the branch point intermediate, chorismic acid, which is one of the substrates of the anthranilate synthetase reaction . It is proposed that the high intracellular level of chorismic acid acts to elevate the non-physiological NH3-dependent anthranilate synthetase activity of the component I subunit, thereby eliminating the need for the glutamine amidotransferase activity of the component II subunit . Consistent with this is the finding that phenylalanine and tyrosine are specific inhibitors of growth of the pheA and tyrA suppressor strains, respectively, causing a shutdown of the overproduction of chorismic acid by reestablishing normal end-product control of the common pathway. J Bacteriol, 1979 Aug, 139(2), 468 - 77 Chromosomal location and expression of the structural gene for major outer membrane protein Ia of Escherichia coli K-12 and of the homologous gene of Salmonella typhimurium; Sato T et al.; The gene determining the structure of a major outer membrane protein of Escherichia coli, protein Ia, has been located between serC and pyrD, at the min 21 region of the linkage map . This is based on the isolation and characterization of E . coli-Salmonella typhimurium intergeneric hybrids as well as analyses of a mutation (ompF2) affecting the formation of protein Ia . When the serC region of the S . typhimurium chromosome was transduced by phage P1 into E . coli, two classes of transductants were obtained; one produced protein Ia like the parental strain of E . coli, whereas the other produced not protein Ia but a pair of outer membrane proteins structurally related to 35K protein, one of the major outer membrane proteins of S . typhimurium . Furthermore, a strain of S . typhimurium harboring an F' plasmid which carries the ompF region of the E . coli chromosome was found to produce a protein indistinguishable from protein Ia, beside the outer membrane proteins characteristic to the parental Salmonella strain . These results suggest that the structural genes for protein Ia (E . coli) and for 35K protein (S . typhimurium) are homologous to each other and are located at the ompF region of the respective chromosome . The bearing of these findings on the genetic control of protein Ia formation is discussed. J Bacteriol, 1979 Aug, 139(2), 442 - 7 Specific inactivator of flagellar reversal in Salmonella typhimurium; Spudich JL et al.; Specific inhibition of flagellar rotation reversal was observed after exposure of chemotactic Salmonella typhimurium to citrate autoclaved at neutral pH . The presence of a rotation reversal inactivator was established in autoclaved citrate-containing media and nutrient broth . Since modulation of flagellar rotation by attractants and repellents is the basis of chemotactic behavior, a specific inhibitor of rotation reversal, which is essential for tumble generation, provides a useful probe into the molecular mechanism of bacterial chemotaxis . The inactivator inhibits clockwise rotation without affecting counterclockwise rotation, speed of rotation, or the capacity of the cells to grow and divide . Inactivation of clockwise rotation is gradual and irreversible, differing from the transient inhibition of clockwise rotation by attractants, which is characterized by an immediate suppression followed by a return to normal rotation patterns . The rotation reversal inactivator is stable to acidification, rotary evaporation, lyophilization, and rehydration. J Bacteriol, 1979 Aug, 139(2), 376 - 83 Mutants defective in the 33K outer membrane protein of Salmonella typhimurium; Stocker BA et al.; Salmonella typhimurium LT2 lines, if phenotypically rough, are fully sensitive to bacteriocin 4-59, produced by Salmonella canastel strain SL1712 . Bacteriocin-resistant mutants fell into three classes . Those resistant to phage ES18 and to albomycin proved to be mutants of class chr (equivalent to tonB of Escherichia coli); these mutants still adsorb the bacteriocin and so are classified as tolerant . Another class of (incompletely) tolerant mutants was resistant to phage PH51; their envelope fractions lacked the band corresponding to outer membrane protein 34K, known to serve for adsorption of phage PH51 . A third class of mutants, which did not adsorb the bacteriocin, was unaltered in sensitivity to phages . Their envelopes lacked the 33K band, indicating absence of the outer membrane protein 33K, considered to correspond to outer membrane protein II* of E . coli, which in that species is determined at locus ompA (formerly tolG or con) . Phage P22 HT105/1 cotransduced the 33K S . typhimurium gene (to be called ompA, to accord with E . coli usage) with pyrD+ at about 30% frequency when the donor allele was ompA+ or one ompA, but at only 3 to 11% when the donor allele was another ompA . When the donor carried either of two long deletions of the put (proline utilization) operon, phage P22 HT105/1 cotransduced put (and ompA+) with pyrD+ at low frequency . The cotransduction data indicate that ompA of S . typhimurium is located between pyrD and put, nearer the former . This corresponds to the map position of ompA in E . coli K-12. J Natl Cancer Inst, 1979 Aug, 63(2), 473 - 7 Inhibition of promutagen activation by the antioxidants butylated hydroxyanisole and butylated hydroxytoluene; McKee RH et al.; Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) exhibited antimutagenic activity in the Salmonella typhimurium reversion test . Both BHA and BHT reduced reversion induced by chemicals requiring metabolic activation for effectiveness . However, they did not affect reversion induced by direct-acting mutagens . These results suggested that BHA and BHT may inhibit the metabolic activation processes and demonstrated that the S . typhimurium reversion test may be used to identify inhibitors of the neoplastic process. Infect Immun, 1979 Aug, 25(2), 513 - 20 Effect of silica on the innate resistance of inbred mice to Salmonella typhimurium infection; O'Brien AD et al.; The role of macrophages in the innate immunity of (CBA/N female X DBA/2N male)F1 female mice to Salmonella typhimurium was assessed with silica, an agent which has been reported to selectively inactivate macrophages . Silica, administered intravenously to mice, markedly decreased the phagocytic capacity of splenic macrophages but had no effect on splenic responsiveness to the B-cell mitogen lipopolysaccharidide or the T-cell mitogen phytohemagglutinin, nor did it affect the frequency of surface immunoglobulin-positive cells (B cells) . Silica given to mice 1 day before intraperitoneal challenge decreased the 50% lethal dose of S . typhimurium 100-fold . The incidence of survival of mice given silica up to 14 days before infection with a sublethal dose of organisms was also decreased . This susceptibility could also be demonstrated when silica was given 10 days, but not 20 days, after S . typhimurium infection . Poly-2-vinylpyridine-N-oxide, a lysosomal stabilizing agent, abrogated the silica effect . Deaths among silica-treated mice followed uncontrolled multiplication of the organism in the spleen . These results provide direct evidence that macrophages play an essential role in natural immunity to murine typhoid and demonstrate the efficacy of silica as a tool to analyze macrophage function. J Bacteriol, 1979 Aug, 139(2), 664 - 7 Decreased binding of polymyxin by polymyxin-resistant mutants of Salmonella typhimurium; Vaara M et al.; Polymyxin-resistant pmrA strains were shown to absorb only about 25% of the amount of polymyxin absorbed by the corresponding polymyxin-sensitive parent strains . The lipopolysaccharide from the pmrA strains bound less polymyxin than the lipopolysaccharide from the parent strains. Immunology, 1979 Aug, 37(4), 849 - 56 Differences in the genetic control of primary and secondary antibody responses; Sant'anna OA et al.; Primary and secondary antibody responses to f and s antigens of Salmonella typhimurium have been studied in H and L lines of mice genetically selected for primary reponse to sheep erythrocytes (SE) (Selection I) . The range of interline separation obtained (non-specific effect of Selection I) was as large as for the selection antigen in the primary response to f antigen and slightly smaller in the primary response to s antigen . For these two antigens the interline difference was reduced after booster . The kinetics of responses were compared with those obtained in H and L lines of Selections III and IV carried out for secondary responses to f and s antigens of S . typhimurium respectively (specific effect of Selection III and IV) . The genetic analysis was made in Selection I from the variances of individual agglutinin titres obtained in large groups of interline hybrids immunized with S . typhimurium . These calculations gave a reliable estimate of the effective number of independent loci regulating primary and secondary responses . The results demonstrated a major difference in the genetic control: a single locus regulated the secondary response to f antigen while six loci were involved in the control of the primary response . A similar difference was evident for s antigen . The primary response was likely to be under polygenic regulation although the effective number of loci could not be calculated, while the secondary response was under monogenic control. Acta Pharmacol Toxicol (Copenh), 1979 Aug, 45(2), 112 - 21 Mutagenic activation of tris(2,3-dibromopropyl)phosphate: the role of microsomal oxidative metabolism; Soderlund EJ et al.; The flame retardant tris(2,3-dibromopropyl)phosphate (Tris-BP) is converted to products which are mutagenic for Salmonella typhimurium TA 100 in the presence of rat liver microsomes, NADPH and oxygen . Other bromopropyl-compounds were also mutagenic; 2,3-dibromopropene and 2,3-dibromopropionic acid were directly mutagenic, whereas 2,3-dibromopropanol and tris(2-bromopropyl)phosphate were weakly mutagenic after addition of liver microsomes and cofactors . Typical in vivo and in vitro inhibitors of cytochrome P-450 inhibited Tris-BP mutagenicity . The effects of inducers of cytochrome P-450 on Tris-BP mutagenicity was dependent on the concentration of mutagen and microsomal protein in the assay, indicating complexity in the kinetics involved when dealing with possible multiple pathways that lead to mutagenicity . Addition of glutathione strongly inhibited Tris-BP mutagenicity . It is suggested that Tris-BP is oxidized to a reactive electrophile, possibly the 2-keto derivative, which could react with nucleophilic groups in DNA and thus lead to mutagenic events. Arch Toxicol, 1979 Jul 11, 42(3), 179 - 84 Mutagenic activity of cytostatic methyl hydrazones with different strains of Salmonella typhimurium; Gericke D et al.; Experiments are performed to ascertain the mutagenic properties of four new cytostatic methyl-hydrazones in the Ames test using different strains of Salmonella typhimurium . As could be demonstrated all four hydrazones are mutagenic per se without a metabolic activation through rat liver microsomes (S-9 fraction) . Whereas the beta-chloroethyl hydrazones B1 and B2 cause a base-pair substitution with the strains TA100 and TA1535 the methyl-hydrazones EB4 and CyB4 both cause base-pair substitution with TA100 and frameshift mutation with TA98 . At both strains the mutagenic activity of Cy84 ist powerful . Furthermore, no relation could be detected between the mutagenic properties of the methyl-hydrazones and their alkylating behaviour on 4-(4-nitrobenzyl)-pyridine. Arq Inst Biol (Sao Paulo), 1979 Jul-Dec, 46(3-4), 103 - 6 {Isolation of Salmonella from marine shellfish}; Lopes CA et al.; The present paper reports the isolation of Salmonella from oysters and clams encountered in the marine waters of Santos and destined to the human consumption . The results obtained showed the characterization of 41 (59,43%) strains of Salmonella arizonae and 28 (40,57%) of Salmonella typhimurium, by its cultural biochemical and serological properties . The drug resistance of Salmonella to several antibiotics was also investigated by determining the minimal inhibitory concentration in serial agar plate dilutions of the therapeutic agents. Cancer Lett, 1979 Jul, 7(2-3), 135 - 9 Mutagenicity of N-nitroso pyridinol carbamate with the Salmonella/mammalian microsome test; Borzonyi B et al.; Pyridinol carbamate was nitrosated to the N,N1-dinitroso derivative and the structure was proved by spectroscopic methods, including chemical ionization mass spectroscopy . By the Ames test, the dinitroso derivative showed a significant dose-dependent mutagenic response with Salmonella typhimurium strains TA 1535 and TA 100; the response became more pronounced in the presence of microsomes . As the dosage of N-nitroso pyridinol carbamate increased, the number of revertant colonies also increased . Pyridinol carbamate was not mutagenic. Cancer Lett, 1979 Jul, 7(2-3), 109 - 14 Synergistic effect of diethylstilbestrol on the mutagenicity of 2-acetylaminofluorene and N-hydroxy-acetylaminofluorene in the Salmonella assay system; Allaben WT et al.; Salmonella typhimurium, TA-1538, was used to investigate the mutagenic potential of N-2-acetylaminofluorene (2-AAF), N-hydroxy-N-2-acetylaminofluorene (N-OH-2-AAF) and diethylstilbestrol (DES) individual and in combination . In the presence of an induced or uninduced rat liver metabolizing system (S-9), the histidine requiring strain of bacteria was reverted to prototrophy by the aromatic amines but not by the synthetic estrogen . However, when DES was combined with 2-AAF or N-OH-I-AAF in the presence of the induced S-9 fraction, the number of revertant colonies was increased 2- to 4-fold above the levels obtained with the aromatic amines alone . The synergistic effect of DES, a non-mutagen, on the mutagenicity of these aromatic amines was observed only when a 3-methylcholanthrene induced rat liver S-9 fraction was used as the source of mammalian enzymes . When uninduced mouse or rat liver S-9 fractions were used in this test system, an inhibitory effect rather than an enhancing effect was observed. Mikrobiyol Bul, 1979 Jul, 13(3), 308 - 9 {A Salmonella typhimurium epidemic in premature and newborn infants (author's transl)}; Atun IH; Salmonella typhimurium was isolated from a fatal epidemic among premature and newborn infants in the Children's Hospital of Hacettepe University . The epidemic showed gastroenteritis, sepsis and meningitis . Salmonella typhimurium were isolated from 17 of 65 infants . No salmonellae were isolated from the personnel of the unit and from the personnel of the related kitchen . The mothers could not be examined . Examinations are being continued with the collaboration of the said unit and a more detailed report is being prepared. J Gen Microbiol, 1979 Jul, 113(1), 45 - 55 Interference of azide with cysteine biosynthesis in Salmonella typhimurium; Filutowicz M et al.; The growth inhibition of Salmonella typhimurium aziA mutants by sodium azide is reversed by cystine and related compounds . NADPH-sulphite reductase (hydrogen-sulphide:NADP+ oxidoreductase; EC 1.8.1.2), an enzyme of cysteine biosynthesis, is inhibited in cell extracts by sodium azide . AziB mutants which are able to grow in the presence of the inhibitor without cystine were isolated . About half of them were mapped in the cysK gene and have only residual activity of its product, O-acetylserine sulphydrylase A {O-acetyl-L-serine acetate-lyase (adding hydrogen-sulphide); EC 4.2.99.8} . Sensitivity of wild type and aziA mutants to azide was also reversed by a constitutive mutation in cysB, the regulatory gene of cysteine biosynthesis . CysK and cysB mutants showed cross-resistance to azide and 1,2,4-triazole . It is suggested that the resistance of these mutants to azide is due to an increased activity of NADPH-sulphite reductase. J Assoc Off Anal Chem, 1979 Jul, 62(4), 874 - 82 Collaborative studies on the Salmonella/microsome mutagenicity assay; Dunkel VC; Although the Salmonella/plate test has been used extensively, a collaborative study was undertaken to determine the interlaboratory reproducibility of this microbial mutagenicity assay . Four laboratories participating in the study have completed testing, under code, of 61 carcinogens and noncarcinogens . All chemicals were tested both with and without metabolic activation in Salmonella typhimurium strains TA1535, 1537, 1538, 98, and 100 . The metabolic activation systems used were derived from the livers of both uninduced and Aroclor 1254-induced Fischer rats, B6C3F1 mice, and Syrian hamst