Salmonella typhimurium

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 hamsters . Analysis of the results on 23 of the chemicals tested in 3 of the participating laboratories showed that 8 were negative when tested in all laboratories and 13 were positive . Two chemicals gave positive results in 2 laboratories; the same 2 chemicals were negative when tested in the third laboratory.

Proc Natl Acad Sci U S A, 1979 Jul, 76(7), 3097 - 101
Isolation and mapping of plasmids containing the Salmonella typhimurium origin of DNA replication; Zyskind JW et al.; A purified EcoRI restriction endonuclease fragment that determines resistance to kanamycin and is incapable of self-replication was used to select autonomously replicating fragments from an EcoRI digest of a Salmonella typhimurium F' plasmid containing the chromosomal region believed to include the S . typhimurium origin of DNA replication . Both the F factor and S . typhimurium chromosome replication origins were cloned by this procedure . The EcoRI fragmentment containing the S . typhimurium origin of replication is 19.4 kilobase pairs long and includes functional asp+ and uncB+ genes . Restriction endonuclease analysis of deletions obtained from the S . typhimurium origin plasmid indicated that the replication origin (ori region) is contained within a 3.3-kilobase pair region . Comparison with Escherichia coli origin plasmids shows colinearity of gene arrangement on the chromosomes in this region and suggests that some, but not all, regions of the nucleotide sequence in the origin region may be conserved (identical) in these two bacterial species.

Clin Exp Immunol, 1979 Jul, 37(1), 1 - 6
Locating salmonella resistance gene on mouse chromosome 1; Plant J et al.; The inherited resistance of inbred mouse strains to Salmonella typhimurium injected subcutaneously has been reported to be controlled primarily by a single gene designated Ity . Resistant mice have the dominant allele Ityr and sensitive mice are homozygous for the recessive allele Itys . This paper describes studies undertaken to locate the gene using readily distinguishable phenotypes as chromosome markers . Appropriate F1 backcross and F2 generations of hybrids between resistant and susceptible inbred strains of mice, with or without the particular phenotypic markers, were tested both for susceptibility to salmonella sci and presence of the marker . Independent segregation of the characteristics eliminated all chromosomes except Chromosome 1 . C57L mice resistant to S . typhimurium, Ityr Ityr and leaden, ln ln, located on Chromosome 1, were crossed with BALB/c mice sensitive to S . typhimurium and non-leaden . In the F2 generation mice, ln always segregated with Ityr . The presence of only one leaden mouse sensitive to S . typhimurium out of sixty leaden F2 mice tested linked Ityr closely with ln on Chromosome 1 . This result will be of use in further experiments with hybrid populations by enabling us to predetermine resistance or sensitivity to S . typhimurium without infecting the mice, so permitting experiments on the nature of the inheritance in unsensitized mice.

Can J Comp Med, 1979 Jul, 43(3), 247 - 54
Studies on experimental enteric salmonellosis in ponies; Owen R et al.; Clinical, bacteriological, serological and haematological observations were made on 13 adult ponies orally inoculated with Salmonella typhimurium . The results were compared to two control ponies and four others infected by accidental transmission . The clinical responses in inoculated ponies included pyrexia lasting four days and neutropaenia during the first five days after inoculation followed by a neutrophilia . Pyrexia and neutropaenia was associated with maximal shedding of organisms in the rectal faeces . Changes in the character of the faeces occurred between one and two days after inoculation and appeared to be associated with the serological response . Serological responses occurred in all the infected ponies except one . At necropsy, of the 14 ponies with positive cultures in the colon, seven had negative cultures in the rectal faeces . Serological studies performed on 43 clinically normal horses indicated a correlation between age and salmonella agglutination titre.

Mutat Res, 1979 Jul, 67(3), 209 - 14
Platinum(II) complexes generate frame-shift mutations in test strains of Salmonella typhimurium; Andersen KS; cis-Diamminodichloroplatinum(II) (cis-PDD) and diaquoethylenediamineplatinum(II) induce histidine revertants in Salmonella typhimurium strains TA98 (frame-shift mutation) and TA100 (base-pair substitution mutation) . A linear dose--response relationship is found with cis-PDD acting on TA98 and TA100 . Salmonella typhimurium strains TA1535, TA1537 and TA1538 are not sensitive to the mutagenic action of cis-PDD . All 5 strains are sensitive to the toxic effect of cis-PDD . Platinum(II) complexes induce mutations (frame-shift or base-pair substitution) only in strains carrying the R-factor plasmid.

Mutat Res, 1979 Jul, 61(2), 387 - 92
Reversal of sodium-azide mutagenicity by liver preparations and by gastric juice; de Flora S et al.; Sodium azide was found to be mutagenic for Salmonella typhimurium by inducing base-pair substitutions that were not enhanced by pKM101 plasmid (R factor) . However, the mutagenicity of sodium azide was decreased by enzyme proteins contained in rat-liver post-mitochondrial fractions, depending on the NADPH-generating system . Pre-incubation with human gastric juice also decreased azide mutagenicity . These metabolic effects might explain the conflicting nature of the mutagenicity and carcinogenicity tests reported in the literature . Laboratory reagents containing 0.1% sodium azide as a preservative showed the expected patterns of mutagenicity and of metabolic deactivation, and no aspecific interaction could be detected between azide and the various components, including proteins, of the reagents tested.

Mutat Res, 1979 Jul, 61(2), 181 - 9
DNA--benzo{a}pyrene adducts formed in a Salmonella typhimurium mutagenesis assay system; Santella RM et al.; The DNA adducts formed in Salmonella typhimurium when bacteria are incubated with radioactive benzo{a}pyrene and liver microsomal enzymes from several sources has been investigated . When enzyme preparations from Aroclor I254 or 3-methylcholanthrene induced C57BL/6N (B6) mice were used to mediate activation, the predominant product was an adduct between the 10 position of 7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha epoxy-7,8,9,10-tetrahydrobenzo{a}pyrene and the N-2 position of deoxyguanosine . Similar results were obtained with human liver and with Aroclor-induced rat-liver enzyme preparations . This adduct is also the major DNA product previously found when human tissues or certain rodent cells were incubated with benzo{a}pyrene . On the other hand, when activation of benzo{a}pyrene was mediated by a phenobarbital-induced B6 mouse-liver enzyme preparation, the extent of binding was quite low and the profile of DNA adducts in S . typhimurium DNA was quite different . Thus, under appropriate conditions, the activation and DNA binding of benzo{a}pyrene inthe microsome mediated S . typhimurium mutagenesis assay generally resembles that seen in intact mammalian cells . Caution must be exercised, however, in the choice of microsome-activation systems.

Biull Eksp Biol Med, 1979 Jul, 88(7), 62 - 5
{Cytophilic immunoglobulins on the surface of neutrophilic granulocytes in mice perorally immunized with a live vaccine made from the supressor revertant S . typhimurium Rev 8}; Aleshkin VA et al.; The reaction of the spleen cell migration inhibition in the presence of monospecific antisera against mouse G, A and M immunoglobulins was used to detect cytophilic antibodies on the surface of mouse granulocytes . The oral administration of ACR live vaccine from suppressor revertant Salmonella typhimurium Rev . 8 protected the mice against infection induced by virulent species of mouse . Salmonella typhimurium . The immunized mice showed an increase in cytophilic IgG on the surface of neutrophile granulocytes.

Antibiotiki, 1979 Jul, 24(7), 498 - 502
{Change in the biological properties of salmonellae in acquiring resistance to chloramphenicol}; Nemchenko VV et al.; Mutants of Salmonella typhimurium and Salmonella abony resistant to 40 microgram/ml of chloramphenicol were obtained during selection according to the method of Szybalski on Hottinger broth with increasing concentrations of the antibiotic . By the colony morphology the mutants were divided into 4 groups . The study of the mutant biological properties revealed changes in the growth rate characterized by elongation of the lag-phase and exponential phase, changes in the biochemical activity evident from lower fermentation rate of some carbohydrates and production of hydrogen sulphide and changes in some amino acid dependence . Increased cross resistance to tetracycline and benzylpenicillin and decreased resistance to kanamycin were noted . The LD50 of most mutants was increased as compared to that of the initial strains . Combination of several types of the changes was observed in some mutants . It is supposed that resistance to chloramphenicol in the mutants is due to mutations in several genes . Some of such genes had pleuotropic effect because of the changes in the structure of the ribosome 50S subunits.

J Bacteriol, 1979 Jul, 139(1), 107 - 14
Functional homology of chemotaxis genes in Escherichia coli and Salmonella typhimurium; DeFranco AL et al.; Generally nonchemotactic mutants of Escherichia coli and Salmonella typhimurium were analyzed by interspecies complementation tests to determine the functional correspondence between the che genes of these two organisms . The E . coli che region was introduced into Salmonella recipients by means of a series of F-prime elements . Wild-type che genes of E . coli F'420 complemented all che mutants of Salmonella except cheS, cheV, and a subclass of cheU . A series of tester episomes carrying E . coli che mutations were then used to determine which E . coli che function was responsible for the complementation of each Salmonella che defect . By this method, the following correspondences were determined: cheAE and chePS,cheWE, and cheWS, cheXE and cheRS, cheYE and cheQS, cheCE and cheUS, cheBE and cheXS, and cheZE and cheTS . (The subscripts E and S refer to E . coli and S . typhimurium genes, respectively.) In some tests, especially those involving the last two pairs of genes, poor complementation was observed between noncorresponding genes . A model explaining these observations in terms of subunit interactions is proposed.

Cancer Res, 1979 Jul, 39(7 Pt 1), 2660 - 4
Carcinogenicity of 2-hydroxybenzo(a)pyrene and 6-hydroxybenzo(a)pyrene in newborn mice; Chang RL et al.; Benzo(a)pyrene (BP), 2-hydroxybenzo(a)pyrene (2-HOBP), and 6-hydroxybenzo(a)pyrene (6-HOBP) were tested for tumorigenicity by i.p . injection into newborn mice . The mice were treated sequentially with 200, 400, and 800 nmol of compound on the first, eighth and fifteenth day of life, and the animals were killed at 24 weeks of age . Treatment with 2-HOBP caused about 4-fold more pulmonary tumors than BP, while 6-HOBP had little or no tumorigenic activity . Newborn mice treated with 2-HOBP, BP, and 6-HOBP had a 98, 81, and 11% incidence of pulmonary adenomas with an average of 24, 6.4, and 0.11 adenomas per mouse, respectively . In the control group, 7.5% of the animals had pulmonary adenomas with an average of 0.08 adenoma per mouse . When 25, 50, or 100 nmol of BP or 2-HOBP was applied to mouse skin once every 2 weeks for 60 weeks, both compounds had about the same carcinogenic activity . These results demonstrate the importance of evaluating the carcinogenic potential of chemicals in more than one tumor system . BP and 2-HOBP were tested for mutagenicity towards two strains of Salmonella typhimurium and towards Chinese hamster V79 cells in the presence of hepatic microsomes from rats pretreated with Aroclor 1254 . The products formed during the metabolism of 2-HOBP or BP by liver microsomes had significant mutagenic activity.

Mutat Res, 1979 Jul, 61(2), 129 - 51
Nitrous acid mutagenesis of duplex DNA as a three-component system; Thomas HF et al.; Purified native Hemophilus influenzae DNA is relatively insusceptible to nitrous acid (NA) mutagenesis in vitro, but is readily mutated following denaturation . NA mutagenicity for duplex DNA is significantly increased in the presence of various alcohols, glycols, phenols or primary amines . Phenol-extracted DNA contains dissociable contaminants of low molecular weight that enhance NA mutagenesis . Enhancement of NA mutagenesis by phenol and by spermine is due to the formation of unstable molecular species . We propose that reactive organic nitroso compounds are formed which then serve as delivery vehicles to promote mutagenicity of native DNA, perhaps via transnitrosation reactions . Similar reactions probably occur in vivo to promote NA-induced base substitution (but not frameshift) mutations in Salmonella typhimurium and in Escherichia coli . The possible significance of these observations to carcinogenesis is discussed.

J Bacteriol, 1979 Jul, 139(1), 80 - 7
Arylsulfatase in Salmonella typhimurium: detection and influence of carbon source and tyramine on its synthesis; Henderson MJ et al.; Arylsulfatase synthesis was shown to occur in Salmonella typhimurium LT2 . The enzyme had a molecular weight of approximately 50,000 and was separated into five forms by isoelectrofocusing . The optimal pH for substrate hydrolysis was pH 6.7, with Michaelis constants for nitrocatechol sulfate and nitrophenyl sulfate being 4.1 and 7.9 mM, respectively . Enzyme synthesis was strongly influenced by the presence of tyramine in the growth medium . The uptake of {14C}tyramine and arylsulfatase synthesis were initiated during the second phase of a diauxie growth response, when the organism was cultured with different carbon sources . Adenosine 3',5'-cyclic monophosphoric acid enhanced the uptake of tyramine and the levels of arylsulfatase synthesized . However, the addition of glucose and glycerol to organisms actively transporting tyramine and synthesizing enzyme caused a rapid inhibition of both of these processes . This inhibition was not reversed by adding adenosine 3',5'-cyclic monophosphoric acid . The results suggest that the effect of the carbon source on tyramine transport and arylsulfatase synthesis may be explained in terms of inducer exclusion.

J Bacteriol, 1979 Jul, 139(1), 71 - 9
Genetics and regulation of D-xylose utilization in Salmonella typhimurium LT2; Shamanna DK et al.; Twenty-one Xyl- mutants of Salmonella typhimurium were selected: all had lost one or more of the activities for D-xylose isomerase, C-xylulokinase, or D-xylose transport . The mutants were classified into five functional groups: xylR, pleiotropic negative (12 mutants); xylA, D-xylose isomerase defective (3 mutants); xylB, D-xylulokinase defective (2 mutants); xylT, D-xylose transport defective (1 mutant); and 3 mutants with defective D-xylose isomerase and D-xylulokinase . Some nonsense mutations were identified among the xylR mutants . Two F'xyl plasmids were isolated by selection for early transfer of xyl+ by an Hfr which transfers xyl as a terminal gene; a plasmid with a mutation in the xyl genes, F'xylR1, was also isolated . Complementation tests using F'xyl plasmids indicate that expression of the xylA, xylB, and xylT genes is under the positive control of the xylR regulatory gene . Conjugation crosses and P22-mediated transduction data indicate that all the xyl mutations tested are in a cluster of genes at 78 units on the linkage map, and that the gene order is xylT--xylR--xylB--xylA--glyS--mtlA,D.

J Bacteriol, 1979 Jul, 139(1), 64 - 70
Uptake and catabolism of D-xylose in Salmonella typhimurium LT2; Shamanna DK et al.; Salmonella typhimurium LT2 grows on D-xylose as sole carbon source with a generation time of 105 to 110 min . The following activities are induced at the indicated time after the addition of the inducer, D-xylose: D-xylulokinase (5 min), D-xylose isomerase (7 to 8 min), and D-xylose transport (10 min) . All other pentoses and pentitols tested failed to induce isomerase or kinase . Synthesis of D-xylose isomerase was subject to catabolite repression, which was reversed by the addition of cyclic adenosine monophosphate . Most of the radioactive counts from D-{14C}xylose were initially accumulated in the cell in the form of D-xylose or D-xylulose . D-Xylose uptake in a mutant which was deficient in D-xylose isomerase was equal to that of the wild type . The apparent Km for D-xylose uptake was 0.41 mM . Some L-arabinose was accumulated in D-xylose-induced cells, and some D-xylose was accumulated in L-arabinose-induced cells . D-Xylitol and L-arabinose competed against C-xylose uptake, but D-arabinose, D-lyxose, and L-lyxose did not . Osmotic shock reduced the uptake of D-xylose by about 50%; by equilibrium dialysis, a D-xylose-binding protein was detected in the supernatant fluid after spheroplasts were formed from D-xylose-induced cells.

Appl Environ Microbiol, 1979 Jul, 38(1), 1 - 6
Method for Salmonella concentration from water at pH 3.5, using micro-fiber glass filters; Block JC et al.; A method is described for the concentration of Salmonella from water . As is done with enterovirus, Salmonella bacteria were concentrated from water in two steps: by pH 3.5 adsorption on and pH 9.5 elution from 8-micron porosity micro-fiber glass filter tubes . This method worked in less than 30 min, and Salmonella typhimurium was inactivated only slightly in spite of rapid pH variations (pH 3.5 to 9.5) . It was demonstrated that the retention by the filters stems from two phenomena: a low retention in the micro-fiber glass labyrinth for small filtered volumes, and a high retention by adsorption at pH 3.5 for any filtered volume (experiments done with 15- and 80-liter samples) . Addition in tap water of trivalent ions like Al3+ did not increase Salmonella adsorption . In most of the trials, Salmonella recovery varied from 42 to 93% . Preliminary field investigations indicate that enterovirus and Salmonella may both be concentrated from the same water sample by this procedure.

Experientia, 1979 Jun 15, 35(6), 801 - 2
Depression of spontaneous and ionophore-induced neurotransmitter release by Salmonella; Person RJ; Exposure of frog neuromuscular junctions to heat-killed, lyophilized Salmonella typhimurium (SR 11) produces an early increase in spontaneous transmitter release followed by depression of release and blockade of the obligatory release usually induced by ionophore X537A.

Asian J Infect Dis, 1979 Jun, 3(2), 89 - 91
In vitro drug resistance of salmonellae in Singapore; Lam S et al.; Strains of Salmonella typhi isolated in Singapore were susceptible to chloramphenicol (except from two imported cases) and most of them also generally susceptible to ampicillin and septrin . Drug-resistant strains of Salmonella typhimurium appeared in 1971 and caused out-breaks among young children . However, decreasing drug-resistance of S . typhimurium was recorded in recent years following a drop in the number of cases . Other Salmonella serovers were found relatively susceptible to the antibiotics tested.

Appl Environ Microbiol, 1979 Jun, 37(6), 1118 - 21
Mutagenic activity of Fusarium moniliforme isolates in the Salmonella typhimurium assay; Bjeldanes LF et al.; A total of 33 isolates of Fusarium moniliforme from several food or feed crops were grown on sterile cracked corn, and chloroform-isopropanol extracts were assayed for mutagenic activity in the Salmonella typhimurium-microsome system by using tester strain TA98 or TA100 or both . Extracts of 21 (64%) of the isolates assayed against TA100 were mutagenic . Activities of seven of these extracts were increased markedly with incorporation of the liver homogenate (S-9) into the assay . Seven (33%) of the isolates assayed against TA98 were weakly active, with the liver homogenate having little effect on reversion rates.

J Gen Microbiol, 1979 Jun, 112(2), 251 - 9
Transduction of fimbriation demonstrating common ancestry in FIRN strains of Salmonella typhimurium; Old DC et al.; The production of fimbriate (Fim+) recombinants was observed in transductional crosses between different pairs of wild-type strains of different biotypes of Salmonella typhimurium . Fim+ recombinants were readily produced in transductions from Fim+ donor strains to Fim- recipient strains and, less frequently, between some pairs of Fim- strains, for example, between almost any strain of the firn biogroup (Fim- Inl- Rha- Bxyl-) and many strains of the non-FIRN Fim- biogroup . None of numerous crosses between different pairs of FIRN strains gave Fim+ recombinants, suggesting that the fim mutation was present at the same intragenic site in all FIRN strains . FIRN strains are thought to have descended from a single ancestral FIRN bacterium which originated by a series of mutations from a strain of the common biotype 1a (Fim+ Inl+ Rha+ Bxyl+) . Two FIRN-like (Fim- Inl+ Rha- Bxyl-) strains that did not yield Fim+ recombinants in crosses with FIRN strains were probably wild-type Inl+ mutants from FIRN strains.

Can J Genet Cytol, 1979 Jun, 21(2), 255 - 9
Tryptophan-requiring parental strains yield Salmonella typhimurium x Escherichia coli hybrid recombinants with functional tryptophan operons; Stetter DW et al.; Crosses between an Escherichia coli Hfr trp strain and three Salmonella typhimurium F- trp strains produced some trp+ hybrids in which the tryptophan operon is composed of genes from both parental species.

Can J Biochem, 1979 Jun, 57(6), 710 - 5
Purification and properties of a citrate-binding transport component, the C protein of Salmonella typhimurium; Sweet GD et al.; Salmonella typhimurium was shown to contain a citrate-binding protein (C protein) which was purified to homogeneity from the periplasmic fraction released by cold osmotic shock . The protein is dimeric, has an apparent molecular weight of 28 000 and an isoelectric point of 6.1 . Sodium ions were required for optimum substrate binding, however, the divalent cations Zn2+, Mg2+, and Co2+ were inhibitory . The C protein was relatively stable but sensitive to various detergents and chaotropic agents . Approximately one citrate molecule was bound per molecule of protein and citrate binding (Kd = 1-2.6 microM) was strongly competitively inhibited by DL-isocitrate and DL-fluorocitrate but not by other carboxylates . Neither succinate, glutamate, nor acetate were bound to the C protein . No apparent enzyme activity was associated with this protein . A concomitant reduction in the level of binding protein and in citrate transport activity occurred in osmotically shocked cells as well as with L-malate- or succinate-grown cells . Fluorocitrate-resistant mutants were simultaneously defective in citrate transport, citrate binding, and production of cross-reacting material . One transport-defective mutant did produce citrate binding protein.

Mutat Res, 1979 Jun, 67(2), 113 - 21
Diethylstilbestrol and 11 derivatives: a mutagenicity study with Salmonella typhimurium; Glatt HR et al.; Diethylstilbestrol was tested for mutagenicity with his- S . typhimurium strains under 10 different matabolic situations (no exogenous metabolizing system; S9 mix from liver homogenate of rats induced with Aroclor 1254, with or without inhibition of epoxide hydratase; liver and/or kidney S9 mix from control or hamsters treated with Aroclor 1254; horse-radish peroxidase + H2O2) . Under none of these conditions did diethylstilbestrol give any indication of a mutagenic effect . Furthermore, 11 metabolites and other derivatives of diethylstilbestrol, 2 of them potent inducers of sister-chromatid exchange in cultured fibroblasts, were not mutagenic with any of the 4 tester strains (S . typhimurium TA100, TA98, TA1537, TA1535) in the presence or absence of S9 mix from liver homogenate of rats induced with Aroclor 1254 . Thus, one of the few known human carcinogens is very resistant to detection by the mammalian enzyme-mediated Salmonella typhimurium mutagenicity test (Ames test) . This is especially remarkable since the metabolizing systems used included: (1) some of very high metabolic activity (S9 mix from liver homogenate of rats and hamsters induced with Aroclor 1254); (2) metabolizing systems from organs susceptible to the carcinogenic activity of diethylstilbestrol (hamster kidney); as well as (3) a mixture of (1) and (2) in case both activities are required for the carcinogenic effect in the whole animal.

Mutat Res, 1979 Jun, 67(2), 101 - 12
Mutagenic activity of propylene oxide in bacterial and mammalian systems; Bootman J et al.; Propylene oxide is used extensively in the chemical and food manufacturing industries, but relatively little is known of its ability to interact with genetic material . Studies were undertaken to investigate its ability to induce gene mutations and primary DNA damage in bacteria and chromosomal damage in mammalian cells . The induction of base-substitution mutations was demonstrated in spot tests with strains of Salmonella typhimurium and Escherichia coli at 700 micrograms/plate of propylene oxide; inclusion of a preparation of rat-liver microsomes and cofactors (S9 mix) was without significant effect on this response . A linear dose--response relationship was recorded in plate tests with S . typhimurium strains TA100 and TA1535 over the range 100--750 micrograms/plate . After addition to dividing lymphocytes in cultures established from human peripheral blood, propylene oxide caused dose-related chromosomal damage, detected at 1.85 and 9.25 micrograms/ml . Oral administration of propylene oxide at 2 x 100, 2 x 250 or 2 x 500 mg/kg to male mice produced no detectable increases in the incidence of micronucleated, polychromatic erythrocytes in bone marrow . A male mouse dominant lethal test employing oral doses of 50 or 250 mg/kg/day for 14 days gave no evidence of mutagenic action on sperm . Intraperitoneal injections of propylene oxide at 2 x 300 mg/kg induced increased numbers of micronucleated erythrocytes in mice, but lower doses given by this route had no such effect . Possible reasons for the contrasting findings in vitro and in vivo are discussed.

Mutat Res, 1979 Jun, 64(3), 183 - 94
Evaluation of three metabolic activation systems by a forward mutation assay in Salmonella; Pueyo C et al.; The strain SV3 of Salmonella typhimurium was used as the indicator bacterium in the intrasanguineous host-mediated mutagenicity assay . Bacterial distribution and spontaneous mutation frequency were determined after intravenous injection of SV3 into CD1 male mice . Bacteria were cleared at an exponential rate from the blood stream and recovered mainly from the liver and in smaller quantities from the lungs and kidneys . No bactericidal effect was observed during incubation within the animal, and bacterial division occurred in the liver and probably in the kidneys . The significance of an increased mutation frequency of bacteria recovered from untreated animals is discussed . Mutation induction was measured in bacteria recovered from liver, lungs and kidneys of CD1 mice and CD rats treated with dimethylnitrosamine (DMN) . The sensitivity of the intrasanguineous host-mediated technique was compared with the sensitivity of the assay in vitro with microsomal preparations from each tissue and host . Activation by isolated perfused liver and lungs from CD rats was included for comparison with the results from experiments in vivo and in vitro.

J Antibiot (Tokyo), 1979 Jun, 32(6), 607 - 9
Evaluation of the mutagenicity of aminoglycoside antibiotics in Salmonella typhimurium and Saccharomyces cerevisiae; Koeda T et al.; The mutagenicity of aminoglycoside antibiotics (KM, AKM, DKB, RSM, AMK, GM, TOB) has been studied in cells of the bacteria Salmonella typhimurium and in the yeast Saccharomyces cerevisiae . The bacterial strains (Ames') monitor reverse mutation (point mutation) and the yeast strain D5 monitors mitotic crossing-over, mitotic gene conversion and point mutation . None of these antibiotics demonstrated any mutagenic activities in either the bacteria or the yeast.

Infect Immun, 1979 Jun, 24(3), 817 - 20
Immunotherapy of guinea pig line 10 hepatoma with nonliving BCG cells in aqueous medium; Bekierkunst A et al.; Killed BCG cells suspended in 1.5% carboxymethylcellulose cured guinea pigs with established line 10 tumors in a high percentage of cases . The bacterial preparation of BCG in carboxymethylcellulose displayed a stronger tumor regressive activity and the process of healing was accelerated when endotoxin from a rough (Re) strain of Salmonella typhimurium was added to the BCG bacilli.

Infect Immun, 1979 Jun, 24(3), 808 - 16
Identification of protective cell surface proteins in ribosomal fractions from Salmonella typhimurium; Misfeldt ML et al.; Cell surface antigen preparations from Salmonella typhimurium SR-11 prepared by either trichloroacetic acid extraction or boiling in sodium dodecyl sulfate were able to protect C3H/HeJ, C3H/HeDub, and A/J mice . Some of the proteins found in these preparations were shown to exist in the protective ribosomal fraction isolated from S . typhimurium SR-11 . Passage of ribosomes isolated from S . typhimurium SR-11 and 6707 through a Sepharose 2B column removed the protective immunogen from 6707 ribosomes but did not completely remove it from SR-11 ribosomes . Immunity to salmonella infection in C3H/HeJ mice induced by ribosomal vaccines may be dependent on the presence of cell surface proteins in the ribosomal fraction.

Immunology, 1979 Jun, 37(2), 329 - 32
The natural resistance of radiation chimeras to S . typhimurium C5; Hormaeche CE; Differences in the in vivo net growth rate of Salmonella typhimurium C5 during the first week of infection in different mouse strains are controlled by a single autosomal gene . In lethally irradiated mice repopulated with semi-allogeneic bone marrow, the early net growth rate shows the phenotype of the donor of the bone marrow cell and not the phenotype of the irradiated recipient . Thus, genetically controlled differences in in vivo bacterial net growth rate are a consequence of mechanisms operating in cells which have originated from bone marrow precursors . Natural resistance to S . typhimurium C5 requires, in addition to slow net growth rate, other mechanisms which come into operation at the end of the first week of the infection . These later acting processes are more complex and can not be transferred to susceptible mice using bone marrow cells alone.

Immunology, 1979 Jun, 37(2), 319 - 27
Genetics of natural resistance to salmonellae in mice; Hormaeche CE; The genetics of natural resistance to salmonellae were studied in F1 hybrid and backcross mice . Overall resistance to Salmonella typhimurium C5 is complex, but one parameter, the early net growth rate of the organism in vivo, is controlled by a single autosomal gene or cluster of genes . 'Slow' net growth rate is necessary but insufficient, for resistance to S . typhimurium C5 . Resistance requires the participation of other mechanisms, detectable by the end of the first week, which presumably involve an immune response . F1 hybrids bred from parents of low, intermediate and high natural resistance showed either high or low resistance . Most of the F1 hybrids were of a similar high resistance, and were bred from pairs in which at least one parent showed slow net growth rate . Hybrids of low resistance were only obtained when neither parent showed slow net growth rate . No hybrid was less resistant than the parents, many were more resistant . Backcross analysis on two hybrids challenged with S . typhimurium C5 supports the hypothesis of complex genetic control of overall resistance but with single gene control of the early net growth rate of the organism . Similar experiments were performed using a much more virulent organism, S . enteritidis 5694 . All mouse strains were very susceptible (LD 50 less than ten organisms) to this strain given either i.v . or s.c . This organism produced an overwhelming infection which did not allow the cell-mediated immune response time to develop . This, however, did not interfere with the mechanism controlling early net growth rate, and genetic analysis using this organism gave similar results to those obtained with S . typhimurium C5 . These results suggest that the mechanism regulating early net growth rate does not operate via the cell-mediated immune response, which develops later in the course of the infection.

Immunology, 1979 Jun, 37(2), 311 - 8
Natural resistance to Salmonella typhimurium in different inbred mouse strains; Hormaeche CE; The mechanisms of natural resistance to intravenous challenge with Salmonella typhimurium C5 are complex . LD50 determinations showed inbred mouse strains of low, intermediate and high natural resistance, with BALB/c and B10 strains the most susceptible, A/J the most resistant . Delayed (footpad) hypersensitivity was not by itself a measure of natural resistance . Resistant mouse strains sensitized either s.c . or i.v . with an attenuated salmonella strain showed positive 48 h footpad reactions when tested 8 days later with a salmonella extract, but three very susceptible strains also showed positive reactions . Determinations of the in vivo net growth rate of salmonellae in the liver and spleen during the first phase of the infection (up to day 4) arrange the different mouse strains into two categories of fast and slow net growth rate . All fast net growth rate strains are susceptible, but not all slow net growth rate strains are resistant . Besides slow net growth rate, resistance requires the participation of other factors appearing in the second phase of the infection (towards the end of the first week) probably involving the cellular immune response, which halts further bacterial growth . Not all slow net growth rate strains are equally capable of suppressing bacterial growth in this second phase . The host mechanism determining slow net growth rate is inherited as a dominant trait, and appears to be operating before the main cellular immune response . The influence of this mechanism on net growth rate is reflected in the time to death following a given dose of salmonellae . The present results suggest that overall resistance to salmonellae is polygenic, but that the mechanism responsible for the differences in early net growth rate is less complex.

Chem Biol Interact, 1979 Jun, 26(1), 11 - 25
Mechanisms of action of carcinogenic aromatic amines: an investigation using mutagenesis in bacteria; Scribner JD et al.; The mutagenicities of groups of N-acetoxy-N-arylacetamides, nitroarenes, arylamides and arylamines were determined in the Salmonella typhimurium tester stains TA98, TA1538, TA100, TA1535 and TA1537 . Three broad classes of mutagenic activity were found, interpreted as follows: class A, including 2-naphthylamine, produced essentially only base-pair substitution without induction of error-prone repair; class B, including 4-aminobiphenyl, caused consideration induction of error-prone repair, accompanied by a lower level of frame shifting; class C, including N-acetoxy-2-acetamidofluorene, produced high levels of frame shifting, with some induction of error-prone repair . Correlation of these results with known reactions of certain aromatic amine derivatives with nucleosides and nucleic acids, and with molecular orbital calculations, suggests that the effect of class A is produced by small aromatic groups attached to extranuclear heteroatoms in DNA bases, the effect of class B is caused by large aromatic groups attached to extranuclear heteroatoms or by arylamines attached to C-8 of guanine, while the effect of class C is caused by arylamides attached to C-8 of guanine, probably rotating into the helix, as proposed by others . The data also suggest that the N-acetoxy-N-arylacetamides are generally useful models for ultimate metabolites derived in vivo, even if the in vivo metabolites do not carry an acetyl group . Finally, there is a rough correlation between the sum of reversions induced in TA98 and TA100 by the N-acetoxy-N-arylacetamides and their previously determined local carcinogenicities . There is a poor correlation between mutagenicity in any one tester strain and carcinogenicity.

J Bacteriol, 1979 Jun, 138(3), 731 - 8
Apparent involvement of purines in the control of expression of Salmonella typhimurium pyr genes: analysis of a leaky guaB mutant resistant to pyrimidine analogs; Jensen KF; A leaky guaB mutant of Salmonella typhimurium LT-2 was obtained during a selection for mutants resistant to a combination of the two pyrimidine analogs, 5-fluorouracil and 5-fluorouridine . In the absence of exogenous guanine compounds, the growth rate of this mutant is limited by the endogenous supply of guanine nucleotides due to a defective inosine 5'-monophosphate dehydrogenase . Under these conditions the guanosine 5'-triphosphate pool is about 20% of normal, the cytidine 5'-triphosphate pool is reduced to below 60%, and the uridine 5'-triphosphate pool is slightly elevated . Simultaneously, levels of the pyrimidine biosynthetic enzymes are abnormal: aspartate transcarbamylase, orotate phosphoribosyltransferase, and orotidylic acid decarboxylase levels are increased 4-, 11-, and 3-fold, respectively . Levels of dihydroorotase and dihydroorotate dehydrogenase are decreased to 10 and 20%, respectively . The pyrimidine metabolism of the guaB mutant is restored completely by addition of guanine (or xanthine) to the growth medium . The data indicate purine nucleotide involvement in the regulation of expression of the pyr genes of S . typhimurium.

J Hyg (Lond), 1979 Jun, 82(3), 481 - 8
A survey of trimethoprim resistance in the enteric bacterial flora of farm animals; West B et al.; For 29 months the Veterinary Investigation Centres, covering the whole of Great Britain, forwarded trimethoprim-resistant gram negative enteric bacteria to the Wellcome Research Laboratories . These were examined for degree of resistance, presence and type of R factors . Trimethoprim resistance was found in 0.6% of the total number of strains examined by the Veterinary Investigation Centres . Trimethoprim R factors were demonstrated in one quarter of the resistant strains, and R factors were found in two strains of Salmonella typhimurium . It was concluded that while the incidence of trimethoprim resistance revealed by the survey gave no cause for alarm, the detection of resistant strains, and particularly R factors, indicated that the drug should continue to be used only for specific therapeutic purposes.

Environ Health Perspect, 1979 Jun, 30, 191 - 203
Use of Ames test in evaluation of shale oil fractions; Pelroy RA et al.; Conditions that affect the sensitivity of the Ames assay of complex hydrocarbon mixtures derived from shale oil were studied . Two fractions, one enriched in polynuclear aromatic compounds (PNA fraction), and a second fraction enriched in aromatic and heterocyclic amines (basic fraction), were selected for most of this work because of their comparatively high mutagenicity (i.e., compared with raw shale oil) . The crude shale oil, as well as the basic, PNA, and tar fractions were mutagenic against the Salmonella typhimurium test strains, TA98 and TA100 . Mutation was dependent on metabolic activation by microsomal (S9) enzymes . Both test strains responded equally well to the crude product and to the basic fraction; however, strain TA100 was more effective than TA198 in demonstrating the mutagenicity of the PNA fraction . The mutagenicity of the tar fraction could be most easily detected after metabolic activation in a liquid medium, as opposed to S9 activation in the top agar of the standard Ames assay . The mutagenicity of the basic fraction or 2-aminoanthracene was also demonstrated by metabolic activation in a liquid medium . In other set of experiments, the effect of chemical composition on the expression of mutagenicity in the standard Ames assay was estimated . Premutagens requiring metabolic activation were added to the basic and PNA fractions, and the numbers of revertants obtained in the presence of the fractions were compared with mutation induced by the compounds alone . The basic fraction did not interfere with the mutagenicity of 2-aminoanthracene and 7,9 dimethylbenz{c}acridine . Moreover, in certain experiments, the mutagenicity of the complex fraction plus the added compound was higher than expected on the basis of assays performed on these materials separately . Conversely, the PNA fraction prevented or strongly inhibited mutation by several polynuclear aroumatic compounds, and an acridine . However, the PNA fraction did not inhibit mutation induced by 2-aminoanthracene . The effect of the basic fraction on stability of the S9 enzymes in the standard Ames test was also determined.

Environ Health Perspect, 1979 Jun, 30, 179 - 84
Evaluation of feasibility of mutagenic testing of shale oil products and effluents; Epler JL et al.; In an effort to gather preliminary information on the potential genetic hazards of proposed or existing oil shale technologies, we have begun a correlated analytical and genetic analysis of a number of test materials . The work is divided into two phases: one deals with known compounds expected to occur in the environment through shale oil production or use; the other deals with actual samples from existing or experimental processes . A fractionation procedure has been applied to crude product and aqueous product material from an oil shale process . Mutagenicity of the various fractions was assayed by using reversion of histidine-requiring auxotrophs of Salmonella typhimurium (strain TA100, base-substitution mutant; TA98 and TA1537, frameshift mutants) . In order to incorporate metabolic activation of these fractions and compounds, we used liver homogenates (S-9) from rats induced with Aroclor 1254 in the standard plate assay . Preliminary results implicate chemical constituents of these fractions (identified or predicted) were tested individually for their mutagenic activity and correlated with the genetic monitoring.

J Natl Cancer Inst, 1979 Jun, 62(6), 1523 - 8
Carcinogenicity test of six nitrosamides and a nitrosocyanamide administered orally to rats; Bulay O et al.; Six nitrosamides {ethylnitrosourea (ENU), 2-hydroxyethylnitrosourea (HENU), carboxymethylnitrosourea, 1-nitroso-5,6-dihydrouracil (NDHU), 1-nitrosohydantoin, and N-methyl-N-nitrosobenzamide (MNB)} and ethylnitrosocyanamide (ENC) were administered chronically in sodium citrate-buffered drinking water to MRC Wistar rats . ENU induced tumors of the reticuloendothelial system (RES) (50% incidence), mammary glands, and large intestine . NDHU in drinking water produced hepatocellular carcinomas (96% incidence), but NDHU injected ip caused mostly tumors at the injection sites (54% incidence) . HENU produced bone tumors (38% incidence) and RES tumors (28% incidence) . ENC produced nasal cavity tumors (36% incidence) . Papillomas and/or carcinomas of the forestomach, tongue, and pharynx were induced by most of the compounds, with the highest incidence in the forestomach (47% for MNB); these tumors were attributed to local action when the compounds were ingested . Carcinogenicity was not quantitatively correlated with direct mutagenicity for Salmonella typhimurium TA1535.

J Bacteriol, 1979 Jun, 138(3), 957 - 61
Pyridine nucleotide cycle of Salmonella typhimurium: regulation of nicotinic acid phosphoribosyltransferase and nicotinamide deamidase; Foster JW et al.; Nicotinic acid phosphoribosyl transferase (NAPRTase) and nicotinamide deamidase activities from Salmonella typhimurium were examined regarding their regulation by either feedback inhibition or repression mechanisms . The results indicate that neither enzyme is subject to feedback inhbition . Nicotinamide deamidase does not appear to be under repression control . NAPRTase, however, is repressed when cells are grown in minimal medium supplemented with various intermediates of the pyridine nucleotide cycle . The concentration of exogenously supplied pyridine nucleotide necessary to effect repression of NAPRTas was found to be that concentration which will result in a nadA mutant generation time of less than 60 min . Furthermore, the results presented indicate that nicotinamide adenine dinucleotide is the actual corepressor molecule . The analogs 6-aminonicotinic acid and 6-aminonicotinamide were also capable of repressing NAPRTase, but only when an intact pyridine nucleotide cycl permitted conversion to 6-aminonicotinamide adenine dinucleotide . The role of a repressible NAPRTase is discussed in relation to the overall functioning of the pyridine nucleotide cycle.

Appl Environ Microbiol, 1979 Jun, 37(6), 1152 - 6
Redox potential-dependent nitrite metabolism by Salmonella typhimurium; Page GV et al.; Salmonellae are generally resistant to the inhibitory effects of NaNO2 . Removal of the lipopolysaccharide of Salmonella typhimurium by ethylenediaminetetraacetic acid pretreatment did not result in subsequent inhibtion of growth by NaNO2, indicating that lipopolysaccharide does not function to exclude NaNO2 from the cell . NaNO2 disappeared from the medium while the cells were growing, but, after stationary phase was reached, no further losses were observed unless the pH was maintained above 7.0 . Similar losses were observed in a cell-free system if the redox potential of the medium was between -250 and -175 mV . If the disrupted cell suspension was first heated in a boiling water bath for 15 to 18 min, no NaNO2 loss was observed regardless of the redox potential . S . typhimurium is capable of metabolizing NaNO2, possibly by means of a nitrite-reducing enzyme function which is redox controlled.

Science, 1979 May 25, 204(4395), 879 - 81
Physical factors affecting the mutagenicity of fly ash from a coal-fired power plant; Fisher GL et al.; The two finest, most respirable coal fly ash fractions collected from the smokestack of a power plant were more mutagenic than two coarser fractions . Mutagenicity was evaluated in the histidine-requiring bacterial strains TA 1538, TA 98, and TA 100 of Salmonella typhimurium . Ash samples collected from the hoppers of an electrostatic precipitator in the plant were not mutagenic . The mutagens in coal fly ash were resistant to x-ray or ultraviolet irradiation, possibly as a result of stabilization by fly ash surfaces . All mutagenic activity is lost with heating to 350 degrees C.

Helv Chir Acta, 1979 May, 46(1-2), 167 - 9
{Vaccination against staphylococcal infections in animal experiments}; Geret UC et al.; Based on favour and clinical observations we have undertaken to observe the effect of vaccination against staphylococcic infection in the mouse . A standard amount of staphylococcus was used together with a metal implant . After two weeks in the control group always an infection could be observed, and germs could be cultivated . In the groups with staphypan and in the groups with vaccinated specific vaccinia a less strong infection was observed, while a vaccinia made from salmonella typhimurium and diphtheria-toxoid showed the strongest effect . The use of unspecific vaccinia deserves further attention in relation to operations which can be made after vaccination of the patient.

Toxicology, 1979 May, 13(1), 7 - 15
Liver extract mediated mutagenicity of acrylonitrile; De Meester C et al.; The mutagenic activity of acrylonitrile vapours towards Salmonella typhimurium strains strictly depends upon the presence of a liver postmitochondrial fraction . The reversion rate varies according to the animal species from which the S9 fraction is obtained as well as to the pretreatment of the animals . The comparatively weak activating effect of the microsomal fraction and the inability of both SKF525A and carbon monoxide to inhibit the S9 mediated mutagenicity of acrylonitrile (ACN) suggest that the cytochrome P-450-dependent monooxygenases do not play a major role in the metabolic activation of ACN into a mutagenic intermediate (s).

Genetics, 1979 May, 92(1), 17 - 26
A refined map of the hisG gene of Salmonella typhimurium; Hoppe I et al.; The hisG gene is the most operator-proximal structural gene of the histidine operon; it encodes the feedback-inhibitable first enzyme of the biosynthetic pathway . Previously, hisG mutants were mapped into seven intervals defined by the availble deletion mutations having endpoints in the hisG gene . The map has been refined using over 60 new deletion mutants . The new map divides the gene into 40 deletion intervals, which average approximately 30 base pairs in length . The map has been used to analyze the distribution of insertion sites for the transposable element Tn10 and has permitted conclusions on the diistribution of duplication endpoints . The map promises to be useful in analysis of his regulation and, more particularly, in the determination of the possible role of the hisG enzyme in this mechanism.

Genetics, 1979 May, 92(1), 1 - 15
Histidine mutants requiring adenine: selection of mutants with reduced hisG expression in Salmonella typhimurium; Johnston HM et al.; A method is described for the selection of Salmonella typhimurium mutants with reduced levels of hisG enzyme activity . This method is based on the fact that the hisG enzyme catalyzes the consumption of ATP in the first step of histidine biosynthesis . Normally, this reaction is closely regulated, both by feedback inhibition and by repression of the operon . However, conditions can be set up that result in the uncontrolled use of adenine in histidine biosynthesis . Cells grown under these conditions become phenotypic adenine auxotrophs . Some revertant clones that no longer require adenine contain mutations in hisG, hisE, or the his-control region . The hisG mutations are of all types (nonsense, frameshift, missense, deletion and leady types), and they map throughout the hisG gene.

Mutat Res, 1979 May, 60(3), 349 - 55
Mutagenicity of 8-ethoxycaffeine in vitro . Induction of point mutations in the Salmonella/microsome test and of sister-chromatid exchanges as well as chromosomal aberrations in Chinese hamster ovary cells (CHO line); Strobel R et al.; The caffeine derivative 8-ethoxycaffeine (EOC) was tested in 3 different test systems in vitro . Each experiment was carried out with and without S9 mix . Incubation temperatures were 20 and 37 degrees C . (1) In the Salmonella/microsome test, EOC behaved as a pro-mutagen in the Salmonella typhimurium strain TA1535 . No mutagenic activity was found in experiments without S9 mix . The influence of temperature was negligible . The mutagenic activity of EOC depended mainly on the mammals used to prepare the S9 fraction and on the agents given to them to induce liver enzymes . (2) EOC did not induce sister-chromatid exchanges in cell cultures, either at 20 or at 37 degrees C . (3) On the other hand, EOC induced chromosomal aberrations when the cells were incubated at 37 degrees C without S9 mix.

J Gen Microbiol, 1979 May, 112(1), 171 - 9
Differences between the anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferases of Salmonella typhimurium strains LT2 and LT7; Dooley M et al.; The anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferases (PRT), coded by the second structural gene (trpB) of the tryptophan (trp) operon in strains LT2 and LT7 of Salmonella typhimurium, differ from each other in a number of parameters . These include the apparent Km values for their substrates anthranilic acid and 5-phosphoribosylpyrophosphate, thermostability, sensitivity to substrate inhibition by anthranilic acid, as well as end-product inhibition by tryptophan and specific activity . The PRT of strain LT7 further differs from that of strain LT2 in that its apparent Km for 5-phosphoribosylpyrophosphate is three to seven times higher when associated with anthranilate synthase in the enzyme complex which catalyses the first two steps of tryptophan biosynthesis than in its free uncomplexed form, which the PRT of strain LT2 shows the same apparent Km for this substrate in both its free and complexed forms . These results confirm and extend the finding of Stuttard (1975) that strains LT2 and LT7 differ genetically form each other at a single site within region II of the trpB gene.

Int J Artif Organs, 1979 May, 2(3), 153 - 8
The removal of 14C labeled endotoxin by activated charcoal; Pegues AS et al.; Endotoxin shock due to Gram-negative enteric bacteria is of major medical concern with an estimated 100,000 fatalities in the United States per year . An effective therapy for endotoxin shock, particularly in combination with significant liver damage, has not been available to date . Since activated charcoal is known as a universal sorbent, the use of activated charcoal in a hemoperfusion apparatus to remove endotoxin has interesting possibilities . Current assays for endotoxin are inadequate . The Limulus Amoebocyte Lysate (LAL) assay was found to give nonreproducible results within our range of requirements for accuracy . We, therefore, grew Salmonella typhimurium in 14C-labeled glucose to obtain 14C labeled endotoxin . Radiolabeled endotoxin was used to measure the rate of adsorption on activated charcoal . The rates of removal of endotoxin from normal saline, plasma, and whole blood will be presented in graphical form for use in design calculations . This work provides a foundation for encouraging in vivo hemoperfusion experimentation now underway at the University of Oklahoma and the Veteran's Administration Hospital in Oklahoma City.

Chem Biol Interact, 1979 May, 25(2-3), 157 - 75
Metabolic and mutagenicity studies on DDT and 15 derivatives . Detection of 1,1-bis(p-chlorophenyl)-2,2-dichloroethane and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethyl acetate (kelthane acetate) as mutagens in Salmonella typhimurium and of 1,1-bis(p-chlorophenyl) ethylene oxide, a likely metabolite, as an alkylating agent; Planche G et al.; Using a novel in vitro technique, whereby microsomal enzymes were embedded in an agar layer to prolong their viability, 1,1-bis(p-chlorophenyl) ethylene(DDNU), a mammalian metabolite of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), was converted by microsomal mono-oxygenases of mouse liver into 1,1-bis(p-chlorophenyl)-1,2-ethanediol (DDNU-diol) . The putative epoxide intermediate, 1,1-bis(p-chlorophenyl)ethylene oxide (DDNU-oxide), a new compound, was synthesized; it showed weak alkylating activity with 4-(4-nitrobenzyl)pyridine but was not mutagenic in Salmonella typhimurium strains TA100 and TA98 . DDT and 13 of its metabolites or putative synthetic derivatives, including 1,1-bis(p-chlorophenyl)-2,2-dichloroethylene (DDE), 1 1,1-bis(p-chlorophenyl)-2-chloroethylene (DDMU), 1,1-bis(p-chlorophenyl)-2-chloroethane (DDMS)-DDNU, 2,2-bis(p-chlorophenyl)ethanol (DDOH), bis(p-chlorophenyl)acetic acid (DDA) and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethanol (Kethane), caused no mutagenic effects in S . typhimurium strains TA100 or TA98, either in the presence or absence of a mouse-liver microsomal fraction . 1,1-Bis(p-chlorophenyl)-2,2,2-trichloroethyl acetate (Kelthane acetate) was a direct-acting mutagen in strain TA100, whereas 1,1-bis(p-chlorophenyl)-2,2-dichloroethane (DDD) was mutagenic in TA98, only in the presence of a mouse-liver microsomal system . The results are discussed in relation to possible pathways whereby DDT is activated to mutagenic and/or carcinogenic metabolites.

Mutat Res, 1979 May, 67(1), 21 - 6
Mutagenicity of cyclic nitrosamines in Salmonella typhimurium: effect of ring size; Rao TK et al.; Mutagenicity of cyclic nitrosamines with varying carcinogenic potentials was assayed in the Salmonella histidine-reversion system . Mutagenicity in the pour-plate assay was compared with that in the liquid pre-incubation test . The smaller ring compounds (nitrosoazetidine, nitrosopyrrolidine, and nitrosopiperidine) exhibited a similar effect in both assays . The large ring compounds (nitrosohexamethyleneimine, nitrosoheptamethyleneimine, nitrosooctamethyleneimine, and nitrosododecamethyleneimine) were more effective in the liquid pre-incubation test . Our results suggest a reasonable relationship between their mutagenic and carcinogenic activities.

Mutat Res, 1979 May, 67(1), 1 - 8
Mutagenicity test of dyes used in cosmetics with the Salmonella/mammalian-microsome test; Muzzall JM et al.; 37 dyes including 3 anthraquinone, 22 azo; 5 xanthene, 5 fluorandiol, and 2 thioindigo dyes, were tested for mutagenic potential with the Salmonella/mammalian-microsome test . Two frame-shift histidine mutants (TA1537 and TA98) and two base-pair substituted histidine mutants (TA1535 and TA100) of Salmonella typhimurium were employed . Both the spot test and the plate-incorporation assay indicated that one azo dye, D&C Orange No . 17, was mutagenic with three of the bacterial test strains . The mutagenic response of D&C Orange No . 17 was depressed by the addition of the microsomal fractions from rat livers . Of the chemicals used to synthesize D&C Orange No; 17 was depressed by the addition of the microsomal fractions from rat livers . Of the chemicals used to synthesize D&C Orange No . 17, beta-naphthol was not mutagenic but 2,4-dinitroaniline was mutagenic to the same Salmonella strains as D&C Orange No . 17 . Dimethyl sulfoxide extracts of lipsticks of similar formula but without D&C Orange No . 17 were tested in the plate incorporation assay . Only those containing D&C Orange No . 17 were mutagenic and the dye was mutagenic at concentrations consumed in normal daily use.

J Med Chem, 1979 May, 22(5), 473 - 6
Ames test of 1-(X-phenyl)-3,3-dialkyltriazenes . A quantitative structure-activity study; Venger BH et al.; The mutagenicity of 1-(X-phenyl)-3,3-dialkyltriazenes was tested in the Ames test using Salmonella typhimurium TA92 . The following quantitative structure-activity relationship (QSAR) was formulated: log 1/C = 1.09 log P -1.63 sigma+ + 5.58 . In this expression, C is the molar concentration of triazene producing 30 mutations/10(8) bacteria above background . This equation is based on 17 congeners and has a correlation coefficient of 0.974 . The QSAR for mutagenicity is compared with QSAR for antileukemia action and toxicity (LD50) in mice . The mutagenicity of aflatoxin B (log 1/C = 9.5) and DTIC (log 1/C = 3.0) have also been determined.

Br J Anaesth, 1979 May, 51(5), 417 - 21
Mutagenicity of inhalation anaesthetics: trichloroethylene, divinyl ether, nitrous oxide and cyclopropane; Baden JM et al.; The mutagenic potential of trichloroethylene, divinyl ether, nitrous oxide and cyclopropane was assessed in vitro by microbial assay employing two histidine-dependent strains of Salmonella typhimurium, TA1535 and TA100 . Anaesthetic agents in various concentrations were incubated with bacteria in the presence or absence of an enzyme system prepared from enzyme-induced rat liver . Nitrous oxide and cyclopropane were not mutagenic, whereas divinyl ether gave a strongly positive response . Results for trichloroethylene were equivocal . These and previous studies with the salmonella system, together with mutagenicity studies using different test systems, indicate that modern inhalation anaesthetic agents are unlikely to be mutagenic.

J Bacteriol, 1979 May, 138(2), 297 - 304
Genetic mapping of the chromosomal replication origin of Salmonella typhimurium; Joh K et al.; Two hundred strains of Escherichia coli harboring Filv+ plasmids which carry a segment of the Salmonella typhimurium chromosome were isolated independently . Among them, two strains were found to harbor F' plasmids that are able to replicate in Hfr cells of E . coli; i.e., they carry a site designated poh (permissive on Hfr) of the S . typhimurium chromosome . The poh site is presumably identical with the replication origin (oriC) of the bacterial chromosome . These two plasmids carry the dnaA-uncA-rbs-ilv-cya-metE region of the chromosome of S . typhimurium . Other F' plasmids which only carried the ilv-cya-metE region were unable to be maintained in Hfr cells . The poh site (= oriC) of S . typhimurium thus is located in the uhp-ilv region of the chromosome . The two plasmids carrying the poh site of S . typhimurium can suppress the temperature-sensitive character of an E . coli mutant that carries the temperature-sensitive dnaA46 allele, when the plasmids exist in the mutant cells . This suggests that the dnaA chromosome in place of the dnaA gene product of E . coli itself . The ability of the plasmids carrying the poh site of S . typhimurium to replicate in Hfr cells of E . coli suggests that the replication system of E . coli can recognize the Salmonella replication origin.

Biochemistry, 1979 May 1, 18(9), 1729 - 38
Mechanistic studies with vinylglycine and beta-haloaminobutyrates as substrates for cystathionine gamma-synthetase from Salmonella typhimurium; Johnston M et al.; Cystathionine gamma-synthetase (EC 4.2.99.9), a key enzyme in bacterial methionoine biosynthesis, has been found to use L-vinylglycine (2-amino-3-butenoate) and L-beta-haloaminobutyrates (X = F, Cl) as substrates in addition to the physiological gamma-substituted substrate O-succinyl-L-homoserine (OSHS) . Vinylglycine is a substrate both for alpha-ketobutyrate formation (the normal product from gamma elimination with OSHS) and for cystathionine formation (the normal gamma-replacement product with OSHS) in the presence of cysteine . This behavior substantiates that the stabilized vinylglycine--pyridoxal phosphate (PLP) alpha carbanion is the key partitioning species in this enzyme's catalysis . The Vmax values for ketobutyrate production and cystathonine formation from vinylglycine are equivalent at approximately 45 U/mg, whereas the corresponding Vmax values from OSHS are 20 and 200 U/mg, respectively, suggesting different rate-determining steps with these two substrates . The beta-haloaminobutyrates undergo catalyzed HX elimination to yield bound aminocrotonate--PLP directly as a an initial intermediate and as a precursor of ketobutyrate . Little or no cystathionine formation is detectable when these substrates are incubated with enzyme and the normal cosubstrate cysteine, strongly indicating that the aminocrotonate--PLP intermediate is not in rapid, reversible equilibrium with the stabilized vinylglycine--PLP carbanion; in normal catalysis, the prototropic shift from alpha carbanion to aminocrotonate appears functionally unidirectional . The HX-elimination step from beta-chloroaminobutyrate is nonconcerted as demonstrated by a 3H2O in equilibrium chloroaminobutyrate exchange reaction . Further suggestion for discrete beta-halo-alpha-carbanionic intermediates derives from the observation that the haloaminobutyrates appear to a partition between ketobutyrate formation and enzyme inactivation . Since neither vinylglycine nor OSHS causes any detectable inactivation during turnover, it is likely that the inactivation species is not a common intermediate, i.e., the electrophilic aminocrotonate--PLP species (a potential Michael acceptor), but rather a species peculiar to the beta-haloaminobutyrate pathway . The beta-halo-alpha-carbanion--PLP intermediate has beta-halo-alpha-iminodihydropyridine character in the p-quinoid resonance contributor and is a good candidate for an alkylating agent by an SN2--displacement mechanism . Spectroscopic analyses of incubations with the various amino acid substrates show a number of long-wavelength absorbing species forming during turnover, tentative assignments are suggested.

Rev Argent Microbiol, 1979 May-Aug, 11(2), 57 - 63
{Comparative study of microbial methods for the detection of genetic toxicity}; D'Aquino M et al.; It is important to have a rapid and accurate method to detect the toxic action of drugs and chemical compounds used by man . A comparative study with two microbial systems was carried out: one using Salmonella typhimurium and the other using Bacillus subtilis . The 1-8-dihydroxyantraquinone was the tested drug and the N-methyl-N'-nitro-N-nitrosoguanidine and the 2-aminofluorene were used as control substances . These compounds were used as such or after previous transformation by a microsomal system . The results obtained showed that both systems: the S . typhimurium and the B . subtilis work in a similar way, but the latter allows a more direct action of drug on the genetic material . The effect of the solvents: ethanol and dimethylsulfoxide was analysed, because they affected the transformation and reversion processes that were carried out.

Res Vet Sci, 1979 May, 26(3), 273 - 6
The inhibitory effect of bovine rumen fluid on Salmonella typhimurium; Chambers PG et al.; The possible fate of Salmonella typhimurium in the rumen was investigated by monitoring rumen volatile fatty acids (VFA), lactate concentrations and pH over periods which included regular feeding and 48 h starvation . Preparations were made containing 50 per cent rumen fluid from the cow or VFA solutions, and then inoculated with S typhimurium . Viable counts before and after incubation for 24 h at 37 degrees C were compared . Incubation in broths with high concentrations of VFA and low pH resulted in a marked decrease in salmonella numbers, while lower VFA concentrations had little or no inhibitory effect on growth.

Biochemistry, 1979 Apr 17, 18(8), 1413 - 22
Immunochemical analysis of membrane vesicles from Escherichia coli; Owen P et al.; Membrane vesicles isolated from Escherichia coli ML 308--225 have been analyzed by crossed immunoelectrophoresis, and immunoprecipitates corresponding to the following cellular components have been identified: ATPase (EC 3.6.1,3), two or three NADH dehydrogenases (EC 1.6.99.3), D-lactate dehydrogenase (EC 1.1.1.27), glutamate dehydrogenase (EC 1.4.1.4), dihydro-orotate dehydrogenase (EC 1.3.3.1), 6-phosphogluconate dehydrogenase (EC 1.1.1.43), polynucleotide phosphorylase (EC 2.3.7.8), beta-galactosidase (EC 3.2.1.23), lipopolysaccharide, and Braun's lipoprotein . The cellular origin of many of the vesicle immunogens is determined, and Braun's lipoprotein is used as a marker to quantitate the extent of outer membrane contamination (less than 3%) . Membrane antigens are also characterized with regard to their amphiphilic or hydrophilic properties by charge-shift crossed immunoelectrophoresis . Furthermore, the following immunogens cross-react with components in membrane vesicles prepared from Salmonella typhimurium: one of the three NADH dehydrogenases, ATPase, polynucleotide phosphorylase, 6-phosphogluconate dehydrogenase, Braun's lipoprotein, and three unidentified antigens . In the accompanying paper {Owen, P., & Kaback, H . R . (1979) Biochemistry 18 (following paper in this issue)} quantitative immunoadsorption is utilized to establish the topology of the vesicles with respect to the distribution of antigens on the inner and outer faces of the membrane.

Biochemistry, 1979 Apr 3, 18(7), 1386 - 92
Electrolyte effects on the activity of mutant enzymes in vivo and in vitro; Kohno T et al.; All temperature-sensitive histidine auxotrophs of Salmonella typhimurium tested are corrected by addition of neutral salts to their growth medium . The correctability seems to result from direct electrolyte effects on mutant protein stability since several of the mutant proteins are also salt correctable in vitro.

Environ Health Perspect, 1979 Apr, 29, 63 - 69
Biological activity of tobacco smoke and tobacco smoke-related chemicals; Kouri RE et al.; Exposure to whole cigarette smoke from reference cigarettes results in the prompt (peak activity is 6 hrs), but fairly weak (similar to 2 fold), induction of murine pulmonary microsomal monooxygenase activity . This activity can be detected by using as substrates either benzo(a)pyrene or ethoxyresorufin, and can be inhibited by treatment with cycloheximide or actinomycin D . Unlike the induction of pulmonary monooxygenases following intratracheal administration of 3-methylcholanthrene, these cigarette smoke-induced increases were not unequivocally linked to the Ah locus . Whole smoke condensate and fractions derived from these condensates can; a) induce pulmonary monooxygenase activity, b) inhibit benzo(a)pyrene metabolism in vitro, c) be metabolized to forms mutagenic to Salmonella typhimurium tester strains TA153, or TA98, d) transform C3H 10T1/2 cells in vitro, and e) enhance the carcinogenicity of benzo(a)pyrene in murine pulmonary tissue . A potentially important observation is that whereas hepatic tissue is capable of activating whole cigarette smoke condensate to mutagenic forms in vitro, murine pulmonary tissue does not seem capable of such activation . Although these pulmonary-derived tissue homogenates have significant AHH activity and can metabolize Aflatoxin B1, 2-aminofluorene and 7, 8-dihydro-7,8-dihydroxybenzo(a)pyrene to mutagenic forms, these homogenates fail to activate both cigarette smoke condensate and the pro-mutagen, 6-aminochrysene . These results are discussed with reference to the concept that whole cigarette smoke may be both a potential "initiator" and "promotor" of lung cancer in mice, and that this latter property may be the most important in determining cancer risk.

Can J Microbiol, 1979 Apr, 25(4), 535 - 41
Aquarium pets as a source of antibiotic-resistant salmonellae; Trust TJ et al.; Thirteen serotypes of Salmonella isolated from imported ornamental aquarium frogs, snails, and their waters were shown to be multi-drug-resistant . Among the resistances exhibited were resistance to gentamicin, sulfamethoxazole-trimethoprim, cephalothin, and nalidixic acid . Frog isolates displayed eight different patterns and snails isolates had two different resistance patterns . The most common serotype, Salmonella typhimurium, was resistant to 18 antibacterials while other salmonellae were resistant to 9 to 16 antibacterials . Resistances in S . typhimurium and S . bovis-morbificans were conjugative and a number of R plasmids participated in the resistance . The plasmid-mediated resistance in S . typhimurium was stable and the levels of resistance conferred were markedly higher than in the other salmonellae tested . Resistance of other serotypes was non-conjugative and resistance to the beta-lactam antibiotics was unstable.

Cancer Res, 1979 Apr, 39(4), 1328 - 33
Comparison of mutagenicity, antitumor activity, and chemical properties of selected nitrosoureas and nitrosoamides; Brundrett RB et al.; A number of nitrosoureas and nitrosoamides have been compared with respect to mutagenicity for Salmonella typhimurium, in vitro cytotoxicity, in vivo toxicity and antitumor activity against murine L1210 leukemia, and chemical properties . Despite chemical similarities between the nitrosoureas and nitrosoamides, they show important differences in biological activity . Some of the nitrosoureas are very active antitumor agents, and they are less mutagenic than are the corresponding nitrosoamides, which lack antitumor activity.

Can J Comp Med, 1979 Apr, 43(2), 200 - 6
Experimental Klebsiella and Salmonella infection in neonatal swine; Wilcock BP; Twenty colostrum-fed piglets from three sows were separated from the sows 24 hours after birth and were randomly divided into five groups of four piglets each . Every piglet in each of four test groups was orally inoculated with about 10(10) colony forming units of Salmonella typhimurium, Salmonella choleraesuis var Kunzendorf or one of two isolates of Klebsiella pneumoniae . One group served as uninoculated controls . Piglets infected with K . pneumoniae developed severe diarrhea beginning about 12 hours after inoculation . They became dehydrated and weak but continued to drink . There were no morphological alterations in intestinal mucosa when piglets were killed and necropsied 48 or 72 hours after inoculation . Klebseilla pneumoniae was isolated from intestine and feces but not from liver or spleen . Piglets inoculated with S . choleraesuis became lethargic and disinterested in food by 24 hours after inoculation . Diarrhea developed by 48 hours after inoculation . Lesions at necropsy 60 or 72 hours postinoculation were subcutaneous edema, mesenteric lymphadenitis, diffuse intestinal superficial mucosal necrosis with villous atrophy, and focal deep ulceration in the ileum . Salmonella choleraesuis was isolated from all segments of intestine and from feces, liver and spleen . Piglets inoculated with S . typhimurium developed a relatively mild diarrheal disease with lesions similar to those with S . choleraesuis infection but less severe . The inoculated organism was recovered from all areas of intestine and from feces, liver and spleen . Serum from infected and control piglets had high (greater than 1:256) agglutinating titres against S . typhimurium but low titres (0 to 1:8) against S . choleraesuis . The agglutinins were assumed to originate from colostral antibodies.

Can J Microbiol, 1979 Apr, 25(4), 475 - 85
The influence of cations on the permeability of the outer membrane of Salmonella typhimurium and other gram-negative bacteria; Stan-Lotter H et al.; The high sensitivity of rough mutants of Salmonella typhimurium, S . minnesota, and Escherichia coli 08 (i.e . with defects in the carbohydrate core of the lipopolysaccharide) to several antibiotics and to the dye gentian violet could be substantially reduced by the addition of cations (Mg2+, Na+) into the growth medium . One heptoseless mutant of S . typhimurium (chemotype Re) and its isogenic smooth parent strain were studied in more detail . The uptake of gentian violet was about 20% in the smooth strain, about 60% in the Re strain grown without additional cations, but decreased to about 15% in the same strain, when cations had been present during growth . In all cases, almost 50% of the gentian violet taken up by the cells was membrane-bound . The total membranes of the Re strain grown in nutrient broth without additional Mg2+ ions were reduced in the 36K and 34K major outer membrane proteins compared with the smooth strain; when grown with added cations the Re total membranes (and even whole cells) did not revert to the protein pattern of the smooth strain.

Eur J Immunol, 1979 Apr, 9(4), 338 - 41
Induction of thymocytotoxic autoantibodies after injection of bacterial lipopolysaccharides in mice; Izui S et al.; The injection of bacterial lipopolysaccharides (Salmonella typhimurium and Escherichia coli LPS) has been shown to induce thymocytotoxic autoantibodies in various strains of mice (C57BL/6, BALB/c, DBA/2, AKR, A/J and C3HeB/FeJ) . Titers up to l:16 were observed . Such antibodies did not develop in C3H/HeJ mice which are low responders to LPS . The thymocytotoxic antibodies had the following characteristics: (a) 2-mercaptoethanol sensitivity, (b) optimal reactivity at 4 degrees C, (c) cytotoxicity for autologous and syngeneic thymocytes but not for spleen cells . The cytotoxicity decreased after absorption with thymocytes, spleen cells or brain tissue but not with kidney or liver homogenates . These LPS-induced thymocytotoxic antibodies were similar to the natural thymocytotoxic antibody occurring in NZB mice.

Mutat Res, 1979 Apr, 66(4), 373 - 80
The mutagenicity of halogenated alkanols and their phosphoric acid esters for Salmonella typhimurium; Nakamura A et al.; 9 halogenated alkanols, 9 corresponding tris (haloalkyl)phosphates, and 2 bis-(2,3-dibromopropyl)phosphate salts were evaluated for mutagenicity against Salmonella typhimurium TA98, TA100, TA1535, TA1537 and TA1538, with and without rat liver in vitro metabolic activation system (S9 mix) . Most of the test samples showed mutagenic activity in the strains TA100 and TA1535, but not in the strains TA98, TA1537 and TA1538 . In general, the mutagenic activities of the phosphates obtained with S9 mix were greater than the activities obtained without S9 mix . Among the phosphates, several structure--activity relationships were found; i.e., (i) the bromoalkyl derivatives were more mutagenic than the corresponding chloroalkyl derivatives, (ii) the beta-haloethyl derivatives were more mutagenic than the gamma-halopropyl derivatives, (iii) the phosphates having adjacent beta and gamma halogen atoms in the alkyl moiety, e.g., tris-(2,3-dibromopropyl)phosphate, were particularly potent mutagens, (iv) the branched carbon chain reduced the mutagenic activities in spite of the presence of beta-halogen atoms, e.g., tris(1-bromomethyl-2-bromoethyl)phosphate . However, such relations did not necessarily apply to the halogenated alkanols . It is concluded that the metabolic activation pathway via haloalkanols to mutagens must not be in common with all tris-BP-like phosphates.

Mutat Res, 1979 Apr, 66(4), 367 - 71
Mutagenic action of a series of epoxides; Wade MJ et al.; The mutagenicity of a series of 13 epoxide compounds was studied using a bacterial plate assay system . The histidine-dependent tester strains TA98 (for frameshift mutagens) and TA100 (for base-pair substitution mutagens) of Salmonella typhimurium were used . Mutagenicity was evaluated both with and without the additon of rat liver microsomal extract . Dieldrin, diglycidyl ether of bis phenol A and 3 of its homologues were not mutagenic . Allyl glycidyl ether, n-butyl glycidyl ether, vinly cyclohexene diepoxide, glycidol, glycidal-dehyde, diglycidyl ether, diepoxybutane and diglycidyl ether of substituted glycerine were mutagenic in the TA100 strain, causing reversion of the bacteria to histidine independence . Dose-reponse curves of the mutagenicity of the latter 4 compounds were obtained . On a molar basis, glycidaldehyde was about 20-50 times more potent in producing mutation that were the other 3 epoxides in the dose-response test . In general, the mutagenicity of the epoxides was not enhanced or diminished by the addition of microsomal extract.

Mutat Res, 1979 Apr, 66(4), 349 - 55
Antioxidants reduce the mutagenic effect of malonaldehyde and beta-propiolactone . Part IX . Antioxidants and cancer; Shamberger RJ et al.; Increasing concentrations of malonaldehyde and beta-propiolactone were increasingly mutagenic with 7 mutants of Salmonella typhimurium, 5 of which mutated bya frameshift mechanism and 2 of which mutated through base-pair substitution . The antioxidants vitamin C, vitamin E, selenium and butylated hydroxytoluene (BHT) at 3 logarithmic concentrations markedly reduced mutagenesis in those strains which mutated by frameshift mechanism.

Mutat Res, 1979 Apr, 66(4), 337 - 48
Mutagenicity of phenanthrene and phenanthrene K-region derivatives; Bucker M et al.; Phenanthrene and 9 K-region derivatives, most of them potential metabolites of phenanthrene, were tested for mutagenicity by the reversion of histidine-dependent Salmonella typhimurium TA1535, TA1537, TA1538, TA98 and TA100 and the rec assay with Bacillus subtilis H17 and M45 . The strongest mutagenic effects in the reversion assay were observed with phenanthrene 9,10-oxide, 9-hydroxyphenanthrene and N-benzyl-phenanthrene-9,10-imine . Interestingly, the mutagenic potency of the arene imine was similar to that of the corresponding arene oxide . This is the first report on the mutagenicity of arene imine . The mutagenic effects of all these phenanthrene derivatives were much weaker than that of the positive control benzo{a}pyrene 4,5-oxide . Even weaker mutagenicty was found with cis-9,10-dihydroxy-9,10-dihydrophenanthrene and with trans-9,10-dihydroxy-9-10-dihydrophenanthrene . The other derivatives were inactive in this test . However, 9-10-dihydroxyphenanthrene and 9,10-phenanthrenequinone were more toxic to the rec- B . subtilis M45 strain than to the rec+ H17 strain . This was also true for phenanthrene 9,10-oxide and 9-hydroxyphenanthrene, but not with the other test compounds that reverted (9,10-dihydroxy-9,10-dihydrophenanthrenes; N-benzyl-phenanthrene 9,10-imine; benzo{a}pyrene 4,5-oxide) or did not revert (phenanthrene, 9,10-bis-(p-chlorophenyl)-phenanthrene 9,10-oxide, 9-10-diacetoxyphenanthrene) the Salmonella tester strains . Although the K region is a main site of metabolism and although all potential K-region metabolites were mutagenic, phenanthrene did not show a mutagenic effect in the presence of mouse-liver microsomes and an NADPH-generating system under standard conditions . However, uhen epoxide hydratase was inhibited, phenanthrene was activated to a mutagen that reverted his- S . typhimurium . This shows that demonstration of the mutagenic activity of metabolites together with the knowledge that a major metabolic route proceeds via these metabolites dose not automatically imply a mutagenic hazard of the mother compound, because the metabolites in question may not accumulate in sufficient quantities and therefore the presence and relative activities of enzymes that control the mutagenically active metabolites are crucial . N-Benzyl-phenanthrene 9.10-imine was mutagenic for the episome-containing S . typhimurium TA98 and TA100 but not for the precursor strains TA1538 and TA1535 . This arene imine would therefore be useful as a positive control during routine testing to monitor in the former strains the presence of the episome which is rather easily lost.

Mutat Res, 1979 Apr, 66(4), 329 - 35
delta 1-Tetrahydrocannabinol and 1 alpha, 2 alpha-epoxyhexahydrocannabinol: mutagenicity investigation in the Ames test; Glatt H et al.; 1,2-Epoxyhexahydrocannabinol is a metabolite of delta 1-tetrahydrocannabinol . Because many epoxides are mutagens, we investigated 1,2-epoxyhexahydrocannabinol as well as delta 1-tetrahydrocannabinol for mutagenicity with Salmonella typhimurium TA1535, TA1537, TA98 and TA100 in the presence and in the absence of S9 mix from liver homogenate of rats treated with Aroclor 1254 . Additionally, an epoxide hydratase inhibitor was used in some experiments . Whereas several other epoxides and further positive controls, not requiring activation or activated under the same conditions, respectively, showed strong mutagenicity, no indications of a mutagenic hazard by 1,2-epoxyhexahydrocannabinol or by delta 1-tetrahydrocannabinol were found.

Mutat Res, 1979 Apr, 66(4), 307 - 28
Mutagenicity of 43 structurally related heterocyclic compounds and its relationship to their carcinogenicity; Glatt HR et al.; 43 heteropolycyclic compounds belonging to a homologous series were investigated for mutagenicity . The results are compared with carcinogenicity data obtained with the same batches of compounds under conditions identical for all of them . Mutagenicity was tested in the Ames test with Salmonella typhimurium strains TA1535, TA1537 and TA100 in the presence and absence of liver 10 000 g supernatant from rats treated with Aroclor 1254 . Carcinogenicity was tested by injection of the compounds into subcutaneous tissue of XVIInc/Z mice . 18 test compounds showed carcinogenic activity, some strongly, others only weakly . Of these, 17 were detected as mutagens: one weak carcinogen did not revert the Salmonella strains . No quantitative correlation was observed between the extents of the mutagenic and the carcinogenic effects . Of the 25 substances that did not produce tumours, 13 showed mutagenicity (12 in the presence, 2 in the absence, of the liver homogenate) . The mutagenic effects of these compounds were quantitatively similar to those of the compounds that produced tumours . The most sensitive strain of Salmonella typhimurium was TA100 . It detected all 30 mutagens . TA98 was mutated by 25 compounds, TA1537 by 16 compounds . No mutagenic effects were seen with TA1535 . Possible reasons for the high percentage of apparently "false positives" in the Ames test and the lack of a quantitative correlation between the potency of the mutagenic and carcinogenic effects are discussed . It is suggested that the complexity of the metabolism of these heterocyclic compounds may lead to critical differences in metabolism in mouse subcutaneous tissue in vivo and in liver homogenates from rats treated with Aroclor . Therefore the present study will be extended to life-long oral and intrahepatic carcinogenicity tests leading to a higher proportion of metabolism in the liver.

Mutat Res, 1979 Apr, 60(2), 155 - 61
Reduction in mutagenicity of cigarette smoke condensate by added sugars; Sato S et al.; The effects of adding sugars to high- and low-tar cigarettes on the mutagenicity of their smoke condensates were studied using Salmonella typhimurium TA100 and TA98 with and without metabolic activation . The sugars tested were glucose, fructose, galactose, sorbitol, sucrose and lactose . The lowest mutagenicities observed with these sugars per mg of smoke condensate assayed on TA98 with metabolic activation were 37% (high-tar cigarettes) and 22% (low-tar cigaretts) of that of smoke condensate from untreated cigarettes . Addition of sugars increased the total amounts of smoke condensates, but the mutagenicities of the total condensates were also decreased by all the sugars, the lowest values being 35% (high-tar cigarettes) and 36% (low-tar cigarettes) of that of smoke condensates from cigarettes without added sugar . On assay with TA100 with metabolic activation, decreases in both specific and total mutangenicities of condensates of high-tar cigarettes were observed with all the sugars tested except galactose and sucrose . Treatment with glucose, fructose or sorbitol decreased the specific mutagenicity of condensates of low-tar cigarettes and glucose and fructose reduced also their total mutagenicity . The effects of added sugars were more marked when assayed on TA98 than on TA100 and of the sugars tested fructose and sorbitol had the greatest effects . Addition of sugars had no effect of the mutagenicity of cigarette-smoke condensate without metabolic activation.

Mutat Res, 1979 Apr, 60(2), 143 - 53
The mutagenicities of safrole, estragole, eugenol, trans-anethole, and some of their known or possible metabolites for Salmonella typhimurium mutants; Swanson AB et al.; Safrole, estragole, anethole, and eugenol and some of their known or possible metabolites were tested for mutagenic activity for S . typhimurium TA1535, TA100, and TA98 . Highly purified 1'-hydroxyestragole and 1'-hydroxysafrole were mutagenic (approximately 15 and 10 revertants/micromole, respectively) for strain TA100 in the absence of fortified liver microsomes; trans-anethole and estragole appeared to have very weak activity . 3'-Hydroxyanethole was too toxic for an adequate test . Supplementation with NADPH-fortified rat-liver microsomes and cytosol converted 3'-hydroxyanethole to a mutagen(s) and increased the mutagenic activities for strain TA100 of 1'-hydroxyestragole, 1'-hydroxysafrole, estragole, and anethole . No mutagenicity was detected for safrole or eugenol with or without added NADPH-fortified liver preparations . The electrophilic 2',3'-oxides of safrole, 1'-hydroxysafrole, 1'-acetoxysafrole, 1'-oxosafrole, estragole, 1'-hydroxyestragole, and eugenol showed dose-dependent mutagenic activities for strain TA1535 in the absence of fortified liver microsomes . These mutagenic activities ranged from about 330 revertants/micromole for 1'-oxosafrole-2',3'-oxide to about 7000 revertants/micromole for safrole-2',3'-oxide . The arylalkenes, their hydroxylated derivatives, or their epoxides did not show mutagenic activity for strain TA98, except for 1'-oxosafrole-2',3'-oxide, which had weak activity . Since the arylalkenes are hydroxylated and/or epoxidized by hepatic microsomes, hydroxy and epoxide derivatives appear to be proximate and ultimate mutagenic metabolites, respectively, of the arylalkenes.

Mutat Res, 1979 Apr, 60(2), 135 - 42
The effects of the ultraviolet-protecting plasmids pKM101 and R205 on DNA polymerase I activity in Escherichia coli K-12; Kronish JW et al.; The mutagenesis- and repair-enhancing plasmids pKM101 and R205 were introduced into a series of Esherichia coli K-12 polA mutants including two temperature-sensitive mutants . Polymerase levels in extracts of these strains were assayed using an activated DNA template . In none of the cases did the presence of the plasmid in the strains change either the initial rate of incorporation of {3H}thymidine triphosphate into acid-soluble material or the subsequent degradation of the template at longer reaction times . Neither did the presence of the plasmids affect the proportion of N-ethylmaleimide-sensitive polymerase activity detected . Previous studies have reported increased polymerase I-like activity of polA mutants of Salmonella typhimurium and Pseudomonas aeruginosa upon introduction of mutagenesis- and repair-enhancing plasmids . Our experiments indicate that, at least, such an increase in polymerase-I-like activity is not an obligatory phenotype associated with these plasmids.

Infect Immun, 1979 Apr, 24(1), 90 - 3
Mouse protective capabilities of Escherichia coli hybrids expressing Salmonella typhi antigens; Diena BB et al.; An Escherichia coli hybrid, F1061, expressing Salmonella typhi somatic antigens 9 and 12, and a derivative of this hybrid, E . coli hybrid WR3078, expressing the S . typhi Vi antigen in addition to somatic antigens 9 and 12, were compared with S . typhi Ty2 in experiments to test their ability, as live vaccines, to protect Swiss white mice against death from challenge with a mouse-virulent Salmonella typhimurium hybrid expressing the S . typhi antigens 9, 12, Vi, and d . When the live, vaccinating organisms were administered intraperitoneally, 87.5% of the mice immunized with S . typhi Ty2 survived challenge, as compared with 62.5% of those immunized with E . coli hybrid F1061 and 55% of those inoculated with E . coli hybrid WR3078 . When live organisms were administered orally at a dose of 10(9), 67.5% of the mice immunized with S . typhi Ty2 survived challenge as compared with 47.5% of those immunized with E . coli hybrid F1061 and 40% of those administered E . coli hybrid WR3078 . Thus, the protection conferred by E . coli hybrid F1061 expressing only the S . typhi somatic antigens, although significant in this system, was inferior to that conferred by S . typhi Ty2 and the addition of the S . typhi Vi antigen to this hybrid (creating E . coli hybrid WR3078) did not enhance that protection.

Proc Natl Acad Sci U S A, 1979 Apr, 76(4), 1589 - 92
Amino acid sequence of ATP phosphoribosyltransferase of Salmonella typhimurium; Piszkiewicz D et al.; The amino acid sequence of ATP phosphoribosyltransferase {1-(5'-phosphoribosyl)-ATP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.17} of Salmonella typhimurium has been determined . The amino acid sequence analysis was carried out with a combination of manual and automated methods . It was complemented by DNA sequence analysis (done in another laboratory) of the hisG gene, which codes for it . The subunit polypeptide chain contains 299 amino acid residues and has a molecular weight of 33,216 . The amino-terminal segment of the protein is relatively basic in character and has limited sequence homologies with the lac repressor and histidinol dehydrogenase . In addition, the protein contains a 40-residue segment that has 13 residues identical with the sequence surrounding the active-site cysteine of glyceraldehyde-3-phosphate dehydrogenase.

Eur J Biochem, 1979 Apr, 95(3), 441 - 8
Characterization of porins from the outer membrane of Salmonella typhimurium . 2 . Physical properties of the functional oligomeric aggregates; Tokunaga M et al.; We have purified to homogeneity, from mutant strains of Salmonella typhimurium, the small oligomers of porin that confer permeability channels to artificial vesicle membranes reconstituted from phospholipids and lipopolysaccharide . The molecular weights of the porin oligomers from the strains SH5551 and SH6017 appeared to be 130000 and 125000, respectively, and those of the monomers were 41000 and 37500, respectively, when determined by sedimentation equilibrium in the presence of dodecylsulfate . It was thus concluded that the functional porin oligomers consisted of three identical subunits . The Stokes' radius of the trimer . dodecylsulfate complex was around 5 nm . The trimer bound less dodecylsulfate than the monomer . The trimer . dodecylsulfate complex retained at room temperature the native conformation of porin, which is rich in beta-structure . When the trimers were dissociated further by various treatments, only the porin monomers were recovered in significant amounts, and the permeability-conferring activity was lost simultaneously . We propose, therefore, that the trimer is the minimal functional unit of porin that is capable of forming permeability channels in the outer membrane of Salmonella typhimurium.

Eur J Biochem, 1979 Apr, 95(3), 433 - 9
Characterization of porins from the outer membrane of Salmonella typhimurium . 1 . Chemical analysis; Tokunaga H et al.; The three species of channel-forming outer membrane proteins, porins, have been purified to homogeneity from mutant strains of Salmonella typhimurium which produce single species of porin . Purification was by stepwise solubilization with dodecylsulfate or guanidine thiocyanate, gel filtration, and preparative gel electrophoresis . Amino acid compositions and tryptic peptide maps of the three species of porins showed close resemblance, but at the same time clear differences among them . The number of amino acid residues in the porins purified from the strains SH5551, SH6377 and SH6017 were 361, 354 and 345, and their calculated molecular weights 39800, 39300 and 38000, respectively . Amino-terminal and carboxyl-terminal amino acids in all three species of porins appeared to be alanine and phenylalanine, respectively . Neither half-cystine nor hexosamine was found in these preparation of porins . The isoelectric points of porins from the strains SH5551, SH6377 and SH6017, determined by isoelectric focusing, showed slight differences from each other . These results, and the genetic experiments from another laboratory, suggest that the three species of porins in Salmonella typhimurium are distinct polypeptides, probably coded for by distinct structural genes, which might have been derived from the same ancestral gene.

J Bacteriol, 1979 Apr, 138(1), 261 - 3
Rapid methods for generalized transduction of Salmonella typhimurium mutants; Rosenfeld SA et al.; A procedure has been developed that allows the propagation of generalized transducing phage directly on cells growing on solid media . After the donor cells are killed with chloroform, the phage can be transferred directly to recipient cells and transductants can be selected.

J Bacteriol, 1979 Apr, 138(1), 155 - 61
Regulation of nonspecific acid phosphatase in Salmonella: phoN and phoP genes; Kier LD et al.; Mutations in Salmonella typhimurium strains lacking nonspecific acid phosphatase mapped in two unlinked loci . One of these, phoP, was cotransducible by phage P22 with purB, whereas the second, phoN, was cotransducible by phage P1 with purA . Mutants with temperature-sensitive nonspecific acid phosphatase activity (measured in whole cells) were also isolated . A phoN mutant with thermolabile whole-cell activity was isolated directly from wild-type LT-2 . Several other mutants with temperature-sensitive enzyme activity were also isolated as revertants of phoN mutants . These data suggest that phoN might be a structural locus for nonspecific acid phosphatase . The observation that a mutation resulting in high level of nonspecific acid phosphatase mapped in phoP suggests a possible regulatory role for this locus.

J Natl Cancer Inst, 1979 Apr, 62(4), 911 - 8
Mutagenic activity of chemical carcinogens and related compounds in the intraperitoneal host-mediated assay; Simmon VF et al.; The mutagenic activities of 79 carcinogens, noncarcinogens, and structurally related compounds toward Salmonella typhimurium strains TA1530, TA1535, and TA1538 and toward Saccharomyces cerevisiae D3 were investigated in the intraperitoneal host-mediated assay . Fewer than half of the carcinogens were mutagenic toward the Salmonella strains . The insensitivity of the system was most marked with the aromatic amine and polycyclic hydrocarbon procarcinogens . Under the test conditions, fewer than 10% of the carcinogens showed clear mutagenic activity toward S . cerevisiae D3 . However, none of the noncarcinogens was significantly mutagenic toward either S . typhimurium or S . cerevisiae D3 . Overall, the intraperitoneal host-mediated assay does not seem suitable for routine preliminary screening of large numbers of potential carcinogens . The median lethal doses to mice of 46 compounds were determined.

J Natl Cancer Inst, 1979 Apr, 62(4), 893 - 9
In vitro mutagenicity assays of chemical carcinogens and related compounds with Salmonella typhimurium; Simmon VF; The mutagenic activity of 101 chemicals was studied with the use of the Salmonella typhimurium-microsome system described by Ames . The tester strains were TA1535, TA1536, TA1537, TA1538, TA98, and TA100 . Assays were conducted in the presence and absence of a metabolic activation system prepared from the livers of randomly bred Sprague-Dawley rats that had been pretreated with Aroclor 1254 . The test chemicals were incorporated into the agar with bacteria and the metabolic activation system . Mutagens were defined as chemicals that induced a reproducible dose-related increase in the number of histidine-independent revertants . With the use of these procedures, 65% of the organic carcinogens and 25% of the noncarcinogens were found to be mutagenic.

J Natl Cancer Inst, 1979 Apr, 62(4), 873 - 92
Evaluation of the mutagenicity and DNA-modifying activity of carcinogens and noncarcinogens in microbial systems; Rosenkranz HS et al.; The mutagenicity of 99 chemicals was determined in a standard Salmonella typhimurium assay with the use of strains TA1535 and TA1538; the DNA-modifying capacity was determined with normal and DNA polymerase-deficient Escherichia coli strains . The following categories of chemicals were studied: alkylating agents (15); nitrosamines, hydrazines, and related substances (8); heterocyclics (10); aromatic amines (36); polycyclic aromatic hydrocarbons (11); amides, ureas, and acylating agents (7); antimetabolites (5); inorganics (4); and promoters (3) . Of the substances studied, 21 were known noncarcinogens, 21 were ultimate carcinogens, and 45 were procarcinogens . Of the noncarcinogens, 35, 30, and 25% were positive in the Salmonella, E . coli, and both systems, respectively . All of the ultimate carcinogens were detectable as mutagens of DNA-modifying agents; 79, 100, and 79% gave positive tests in the Salmonella, E . coli, and both systems, respectively . Of the procarcinogens 72% were identifiable by these procedures: 52, 67, and 48% in the Salmonella, E . coli, and both assays, respectively . A tabulation of the combined data for ultimate carcinogens and procarcinogens indicates that 77% of the carcinogens gave positive results: 61, 74, and 59% in the Salmonella, E . coli, and both assays, respectively . We suggest that, for prescreening procedures with microbial assays, S . typhimurium strains TA98 and TA100 be included and the standard E . coli DNA polymerase-deficient assay be run in tandem with the Salmonella mutagenicity assay . When the standard E . coli DNA polymerase-deficient assay does not give interpretable results because of the lack of zones of growth inhibition, a modified assay with the use of liquid suspension should be performed.

Res Commun Chem Pathol Pharmacol, 1979 Apr, 24(1), 49 - 56
Effects of cyclic AMP altering drugs on endotoxin-induced termination of pregnancy; Shaw R Jr et al.; The effects of dibutyryl-cyclic AMP (DBcAMP), propranolol, and theophylline on endotoxin (LPS) challenged pregnant mice was determined by comparing the patterns of termination and times of fetal expulsion . Endotoxin isolated from wild type (WT) and Re chemotype mutant cells of Salmonella typhimurium was used . Wild type LPS caused the expulsion of the fetuses, while Re LPS primarily caused the resorption of the fetuses . The major change in pattern occurred in the propranolol treated Re LPS challenged group with a trend toward more expulsions and a decrease in uterine cyclic AMP (cAMP) levels to that approaching the group challenged with wild type LPS . The time of expulsion was also affected in the wild type LPS treated group, with propranolol hastening and DBcAMP and theophylline delaying the expulsion . These results support the hypothesis that uterine cAMP is involved in the expulsion of the fetuses.

Infect Immun, 1979 Apr, 24(1), 174 - 80
Enterochelin (enterobactin): virulence factor for Salmonella typhimurium; Yancey RJ et al.; The ability of Salmonella typhimurium to synthesize enterochelin (enterobactin; ENT) affects its capacity to grow both in vivo and in vitro . An ENT mutant (96-1), blocked in the conversion of chorismate to 2,3-dihydroxybenzoate, was derived from SR-11, a strain of high mouse virulence . This mutant was unchanged in the other characteristics tested: colonial, biochemical, antigenic, and cellular . In contrast to SR-11, growth of this mutant in complement-inactivated human serum was strongly inhibited . However, addition of 5 muM ENT to the cultures relieved their inhibition . Viable counts of bacteria injected into the mouse peritoneal cavity showed that without ENT, growth of 96-1 was inhibited markedly; with ENT, the apparent growth rate of 96-1 exceeded that of SR-11 . The 50% lethal dose (LD50) of 96-1 was 2 to 3 log units higher than that of SR-11 . When ENT was injected, the ENT- mutant exhibited an ENT-dose-related decrease in its LD50 . A single injection of 300 micrograms of ENT per mouse with the inoculum reduced the LD50 of 96-1 to that of the wild-type strain . These findings support the contention that ENT is a virulence factor for S . typhimurium.

J Bacteriol, 1979 Apr, 138(1), 235 - 40
Isolation and characterization of bacterial flagellar hook proteins from salmonellae and Escherichia coli; Kagawa H et al.; Flagellar hook proteins from Salmonella and Escherichia coli were dissociated in acid and purified by diethylamino-ethyl-cellulose column chromatography . These two proteins had the same electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels . However, analytical electrofocusing patterns showed that these proteins had different isoelectric points (4.7 for Salmonella typhimurium and 4.4 for E . coli) . Immunodiffusion and immuno-electron microscopy carried out with antisera prepared against purified hook proteins from S . typhimurium and E . coli showed that these antisera reacted with both hooks . Affinity chromatography allowed separation of antibodies specific for hook proteins from each bacterial species . These results indicate that the hook proteins share common antigenic determinants as well as specific antigens, although the specificity is not quantitatively resolved . From comparisons of the amino acid composition of the hook proteins and flagellins, it was concluded that the differences between flagellins from S . typhimurium and E . coli were larger than those between hook proteins from these species.

J Bacteriol, 1979 Apr, 138(1), 218 - 34
Nitrogen control of Salmonella typhimurium: co-regulation of synthesis of glutamine synthetase and amino acid transport systems; Kustu SG et al.; Nitrogen control in Salmonella typhimurium is not limited to glutamine synthetase but affects, in addition, transport systems for histidine, glutamine, lysine-arginine-ornithine, and glutamate-aspartate . Synthesis of both glutamine synthetase and transport proteins is elevated by limitation of nitrogen in the growth medium or as a result of nitrogen (N)-regulatory mutations . Increases in the amounts of these proteins were demonstrated by direct measurements of their activities, by immunological techniques, and by visual inspection of cell fractions after gel electrophoresis . The N-regulatory mutations are closely linked on the chromosome to the structural gene for glutamine synthetase, glnA: we discuss the possibility that they lie in a regulatory gene, glnR, which is distinct from glnA . Increases in amino acid transport in N-regulatory mutant strains were indicated by increased activity in direct transport assays, improved growth on substrates of the transport systems, and increased sensitivity to inhibitory analogs that are trnasported by these systems . Mutations to loss of function of individual transport components (hisJ, hisP, glnH, argT) were introduced into N-regulatory mutant strains to determine the roles of these components in the phenotype and transport behavior of the strains . The structural gene for the periplasmic glutamine-binding protein, glnH, was identified, as was a gene argT that probably encodes the structure of the lysine-arginine-ornithine-binding protein . Genes encoding the structures of the histidine- and glutamine-binding proteins are not linked to glnA or to each other by P22-mediated transduction; thus, nitrogen control is exerted on several unlinked genes.

Mol Gen Genet, 1979 Mar 27, 171(3), 295 - 9
Replication and maturation of phage P22 in a mutant of Salmonella typhimurium temperature sensitive in initiation of DNA replication; Backhaus H et al.; TB37 is a dna A-mutant of Salmonella typhimurium in which the initiation of DNA replication at the origin is stopped at 42 degrees C . DNA synthesis in uninfected cells of this strain and in cells infected by phage P22 was followed by the pulse labelling technique . DNA replication ceases completely after about 50 minutes at the high temperature . After lytic infection with P22 (c2) at this time, DNA synthesis starts immediately and increases at a rate well comparable to the permissive control . Obviously the temperature sensitive function of the dnaA-product is dispensable for P22 DNA replication, especially for its initiation . This result is confirmed by the normal yield of phage particles under these conditions, provided that a late step in P22 maturation which naturally is temperature sensitive can proceed at low temperature . If TB37 is infected at 42 degrees C with P22 wild type, an unexpected high rate of phage controlled DNA synthesis is observed . Preliminary results seem to indicate that the process of integration is a prerequisite for part of this synthesis.

JAMA, 1979 Mar 9, 241(10), 1013 - 5
Salmonella typhimurium . Transmission by fiberoptic upper gastrointestinal endoscopy; Beecham HJ 3rd et al.; During a four-month period, Salmonella typhimurium developed in seven persons within five days of fiberoptic upper gastrointestinal (GI) endoscopy . A retrospective cohort study confirmed the association between S typhimurium infection and fiberoptic upper GI endoscopy . Salmonella typhimurium was cultured from the endoscopic equipment and the accessory suction equipment . The Salmonella isolated from the endoscopic and accessory suction equipment was identical to that recovered from the seven patients with salmonellosis by serotype, antimicrobial susceptibility pattern, and bacteriophage lysis pattern . Salmonella transmission was attributed to inadequate disinfection of the endoscope and accessory equipment between procedures . The original source of the contamination was not discovered.

Infect Immun, 1979 Mar, 23(3), 587 - 91
Bactericidal activity of fractionated granule contents from human polymorphonuclear leukocytes; Modrzakowski MC et al.; Proteins from human polymorphonuclear leukocyte granules were extracted with 0.2 M acetate, pH 4.0, and fractionated by Sephadex G-100 column chromatography . The fractions demonstrated selective bactericidal action against a deep rough cell wall mutant of Escherichia coli O111:B4 with rough lipopolysacharide and cell wall mutants of Salmonella typhimurium LT-2 with lipoplysacharide of Ra, Rc, Rd1, Rd2, and Re types . Smooth parent strains were most resistant to the bactericidal action . Fractions with greatest activity for the mutants were from valley regions (regions of low protein concentration) between three high protein peaks comprising myeloperoxidase, protease, and lysozyme, respectively . Susceptibility of the mutants to bactericidal action increased as sugar residues decreased in lipopolysaccharide . Gram-positive bacteria were susceptible to different fractions than were the gram-negative bacteria.

Appl Environ Microbiol, 1979 Mar, 37(3), 658 - 60
Mutagenicity of the mycotoxin emodin in the salmonella/microsome system; Wehner FC et al.; The mycotoxin emodin was found to be a frameshift mutagen for Salmonella typhimurium strain TA 1537 after metabolic activation in a mammalian microsome system.

Appl Environ Microbiol, 1979 Mar, 37(3), 517 - 20
Vivo clearance of enteric bacteria from the hemolymph of the hard clam and the American oyster; Hartland BJ et al.; American oysters, Crassostrea virginica, and hard clams, Mercenaria mercenaria, were experimentally contaminated with Escherichia coli, Salmonella typhimurium, and Shigella flexneri either by intracardial injection or via the natural route of ingestion . Bacterial inactivation in the hemolymph was monitored for 72 h after exposure to these enteric pathogens at 20 and 6 degrees C . At 6 degrees C, both mean bacterial uptake by ingestion and subsequent clearance was singificantly lower that at 20 degrees C . However, substantial bacterial clearance from the hemolymph occurred for both shellfish at each temperature . At 20 degrees C, viable bacteria were no longer detectable after 24 h in hemolymph of either clams or oysters after exposure to contaminated water containing 4 x 10(3) bacteria per ml.

J Infect Dis, 1979 Mar, 139(3), 362 - 5
The incidence of Salmonella in random-source cats purchased for use in research; Fox JG et al.; In research facilities, cats are routinely ignored as a potential source of salmonella infection . Over a period of 18 months, 142 cats received from commercial vendors for use in research were screened for enteric Salmonella . Salmonella was isolated from 15 animals, an incidence of 10.6% . Five (29%) of the 17 shipments contained animals that were positive for Salmonella . The serotypes isolated were Salmonella derby, Salmonella typhimurium, Salmonella anatum, Salmonella enteritidis, and Salmonella bredeney.

Proc Natl Acad Sci U S A, 1979 Mar, 76(3), 1343 - 7
Aflatoxin B1 mutagenesis, DNA binding, and adduct formation in Salmonella typhimurium; Stark AA et al.; Salmonella typhimurium strain TM677 was mutagenized with aflatoxin B1 (AFB1) in liquid suspension culture in the presence of a rat liver postmitochondrial supernatant . Forward mutation to 8-azaguanine resistance was measured in the treated cultures and was found to increase linearly with AFB1 concentration . DNA purified from mutagenized cells was analyzed for AFB1 adduct formation by high-pressure liquid chromatography after adduct liberation . AFB1 exposures at 0.16 and 0.32 micrometer for 35 min produced 15 and 22 AFB1--DNA adducts per genome, respectively, and induced 8-azaguanine-resistant fractions of 4.9 X 10(-4) and 9.6 X 10(-4) . Approximately 70% of the AFB1 bound to DNA was chromatographically identical to 2,3-dihydro-2-(N7-guanyl)-3-hydroxyaflatoxin B1 at the two AFB1 levels used.

Mutat Res, 1979 Mar, 66(3), 253 - 9
Comparison of the induction by cigarette smoke condensates of sister-chromatid exchanges in Chinese hamster cells and of mutations in Salmonella typhimurium; de Raat WK; Three cigarette smoke condensates were tested for the induction of sister-chromatid exchanges in ovary cells of the Chinese hamster and for mutations in Salmonella typhimurium . In the sister-chromatid exchange test an effect was obtained that was not enhanced by the inclusion of a system for metabolic activation . In the Salmonella test, an effect was only obtained by including rat-liver homogenates derived from rats treated with inducers of the enzyme systems necessary for metabolic activation . It appears that the SCE test and the Salmonella test are sensitive to different components of cigarette smoke condensates.

Mutat Res, 1979 Mar, 66(3), 247 - 52
Hydrazines as mutagens in a histidine-requiring auxotroph of Salmonella typhimurium; Tosk J et al.; Hydrazines have been found naturally in tobacco and mushrooms . Other hydrazines are used in industry, medicine, and agriculture . Although about 38 hydrazines are carcinogenic, few, if any, have been tested successfully in rapid bacterial mutagenesis assays . We have utilized a tester strain of Salmonella typhimurium (TA1530) in order to determine the mutagenic activity of a number of hydrazines and related compounds . This strain is thus shown to be effective as a tester organism for the facile detection of hydrazines as mutagens.

Mutat Res, 1979 Mar, 66(3), 207 - 21
The mutagenic action of nitroimidazoles . IV . A comparison of the mutagenic action of several nitroimidazoles and some imidazoles; Voogd CE et al.; The mutagenic action of 51 imidazoles was investigated . The fluctuation test of Luria and Delbruck was used, with Klebsiella pneumoniae as test organism . 8 compounds, including 5 with a weak mutagenic action in the fluctuation test, were also investigated by the Ames test in which Salmonella typhimurium TA100 was used . Of the 51 imidazoles examined, 33 were nitroimidazoles . 31 of the latter appeared to be mutagenic, whereas out of the 18 other imidazoles without a nitro group only 2 were mutagenic . Several of the substances tested for mutagenicity showed an antimicrobial activity . No direct relationship between antimicrobial action, growth inhibition and mutagenicity was established . With methyl-nitroimidazoles a relationship was found between the chemical structure and mutagenic action . However, when the nitroimidazoles had a more complex chemical structure, a relationship between this structure and mutagenicity could not be established.

J Bacteriol, 1979 Mar, 137(3), 1253 - 62
Salmonella typhimurium newD and Escherichia coli leuC genes code for a functional isopropylmalate isomerase in Salmonella typhimurium-Escherichia coli hybrids; Fultz PN et al.; The supQ newD gene substitution system in Salmonella typhimurium restores leucine prototrophy to leuD mutants by providing the newD gene product which is capable of replacing the missing leuD polypeptide in the isopropylmalate isomerase, a complex of the leuC and leuD gene product . Mutations in the supQ gene are required to make the newD protein available . An Escherichia coli F' factor was constructed which carried supQ- newD+ from S . typhimurium on a P22-specialized transducing genome . This F' pro lac (P22dsupQ394newD) episome was transferred into S . typhimurium strains containing th leuD798-ara deletion; the resulting merodiploid strains had a Leu+ phenotype, indicating that supQ- newD+ is dominant over supQ+ newD+, and eliminating the possibility that the supQ gene codes for a repressor of the newD gene . Furthermore, transfer of the F' pro lac (P22dsupQ39newD) into E . coli leuD deletion strains restored leucine prototrophy, showing that the S . typhimurium newD gene can complment the E . coli leuC gene . Growth rates of the S . typhimurium-E coli hybrid strains indicated that the mutant isopropylmalate isomerase in these strains does not induce a leucine limitation, as it does in S . typhimurium leuD supQ mutants . In vitro activity of the mutant isopropylmalate isomerase was demonstrated; the Km values for alpha-isopropylmalate of both the S . typhimurium leuC-newD isomerase and the S . typhimurium-E . coli hybrid isomerase were as much as 100 times higher than the Km values for alpha-isopropylmalate of the wild-type enzyme, which was 3 x 10(-4) M . Mutagenesis of E . coli leuD deletion strains failed to restore leucine prototrophy, indicating that E . coli does not have genes analogous to the S . typhimurium supQ newD genes, of that, if present, activation of a newD is a rare event or is lethal to the cell.

Immunology, 1979 Mar, 36(3), 439 - 47
Reduction of phagocytosis, surface hydrophobicity and charge of Salmonella typhimurium 395 MR10 by reaction with secretory IgA (SIgA); Magnusson KE et al.; Binding of human colostral secretory IgA (SIgA) to Salmonella typhimurium 395 MR10 decreased the liability to hydrophobic interaction of the bacteria, as analysed by hydrophobic interaction chromatography on Octyl-Sepharose and partition in an aqueous polymer two-phase system consisting of dextran, poly(ethyleneglycol) (PEG) and poly-(ethyleneglycol)-palmitate (P--PEG) . SIgA also reduced the negative charge of the bacteria . Treatment of the bacteria with centrifuged but not further fractionated colostrum added positive charge to the bacteria which was removed by treatment with pepsin . Colostral SIgA reduced the in vitro phagocytosis of S . typhimurium MR10 by polymorphonuclear leucocytes . The adhesion of the bacteria to cellulose membrane filters in the absence of phagocytes was also reduced after the interaction with SIgA . It is proposed that the binding of SIgA to bacterial surfaces has hydrophilic and anti-adhesive effects, which may serve to exclude antigen from mucosal surfaces.

Mutat Res, 1979 Mar, 60(1), 25 - 32
Aryl-monoalkyl and cyclic triazenes: direct-acting mutagens; Thomas HF et al.; An aryl-monoalkyl triazene, methyl-p-tolyl triazene (MTT) and a cyclic triazene (delta2-triazoline) are direct-acting mutagens for Salmonella typhimurium bacteria and for cell-free Hemophilus influenzae DNA . MTT causes reversion of the hisG46 base-substitution mutation, but no reversion of the hisD3052 frameshift mutation . Induced mutation frequency is not strongly influenced by modifications in the genetic background of the S . typhimurium Ames tester strains, but is mildly enhanced by the addition of a pool of amino acids to the plating medium and is strongly enhanced by liquid preincubation before plating.

Chem Biol Interact, 1979 Mar, 24(3), 265 - 85
The mutagenic effect of 1,2-dichloroethane on Salmonella typhimurium . II . Activation by the isolated perfused rat liver; Rannug U et al.; In this investigation Salmonella typhimurium strain TA 1530 and TA 1535 were combined with isolated perfused rat liver . Samples of perfusate and bile produced were tested for mutagenicity after treatment with 1,2-dichloroethane (DCE), 1,2-dibromoethane (DBE) or 2-chloroethanol . The results are in good agreement with our previous experiments which indicate that both DEC and DBE are activated through conjugation with glutathione (GSH) . Most GSH conjugates are normally excreted in bile . Following liver perfusion the bile was highly mutagenic after DCE and DBE treatments, while 2-chloroethanol did not have this effect . The highest mutagenic effect was seen 15--30 min after the addition of DCE or DBE . The production of mutagenic bile also occurred in mice treated in vivo with DCE . One possible metabolic endproduct of a GSH conjugate is the corresponding mercapturic acid . Thus synthetic N-acetyl-S-(2-chloroethyl)-L-cysteine was tested on TA 1535 and found to be as mutagenic as S-(2-chloroethyl)-L-cysteine in the concentration range 0.2--0.6 mumol/plate . Differences and similarities in the metabolism of DCE and vinyl chloride are discussed on the basis of these results.

Cancer Res, 1979 Mar, 39(3), 682 - 93
Assay of 855 test chemicals in ten tester strains using a new modification of the Ames test for bacterial mutagens; McMahon RE et al.; Determination of mutagenic activity in bacterial systems has become accepted as an initial step in the evaluation of the carcinogenic potential of new chemicals . In this paper, a bacterial mutagen screening technique is described in which chemicals can be tested in 10 tester strains over a 10,000-fold concentration gradient both with and without metabolic activation . Using this assay, 855 chemicals were tested, and 182 were found to be mutagenic in one or more of the tester strains . Included were 299 chemicals used in chemical manufacturing or laboratory synthesis . Of these, 20% gave a positive response in one or more strains . The high rate of positives undoubtedly reflects the high chemical reactivity of compounds in this group . In contrast, when 261 organic chemicals which were synthesized for evaluation as potential pharmaceutical or agricultural products were tested, only 8% were identified as mutagenic . The Salmonella typhimurium tester strains TA98 and TA1538 proved to be very reliable and efficient in detecting and identifying frame-shift mutagens . TA100 was the most sensitive tester strain, detecting 142 of the 182 mutagens encountered in the study . However, since TA100 detected both base substitution mutagens and frame-shift mutagens, this tester strain was not suitable for the specific identification of base substitution mutagens . Base substitution mutagens were more reliably detected by Escherichia coli tester strains WP2 and WP2 uvrA- than they were by S . typhimurium strains G46 and TA1535 . The data obtained when mutagens are tested by the concentration gradient procedures can include (a) the activity spectrum in tester strains, (b) identification as either frame-shift or base substitution mutagens, (c) the minimal concentration at which auxotroph growth is inhibited, and (d) mutagenic potency in terms of minimal concentration at which mutagenicity is observed . The data obtained have been found to be of immediate use . For example, with manufacturing intermediates the data have been combined with other toxicity data and used as a basis for setting safety standards for handling such compounds in the workplace . In addition, positive bacterial mutagenicity data on selected members of new series of organic compounds can serve to alert the chemist early to the possibility that the compounds may possess undesirable toxic properties, particularly carcinogenicity . Also, this type of data should be of great value both in the planning and in the interpretation of other in vitro tests designed to evaluate the potential carcinogenicity in mammals of chemicals found to be positive in bacterial tests.

J Infect Dis, 1979 Mar, 139(3), 261 - 6
Migration of epithelial cells in the small intestine of mice perorally infected with coxsackievirus B5; Shadoff N et al.; The rate of cell migration in the small intestine during enteric viral infections has not been assessed previously . CD-1 mice (33 days old) were infected perorally with 1.0 X 10(8) plague-forming units of coxsackievirus B5 and 12 hr later were injected intraperitoneally with 2 micron Ci of {3H}thymidine/g of body weight . After 2, 12, 24, 48, 60, and 72 hr, mice were killed, and the small intestine was removed . Specimens obtained at each interval were examined by radioautography; similar specimens were titrated for virus by plaque assay in HeLa cells . In mice perorally infected with coxsackievirus B5, epithelial cells migrated from crypt to villus tip in 60 hr, as compared with 48 hr in uninfected control mice and 24 hr previously reported for mice perorally infected with enteric bacteria (e.g., Salmonella typhimurium) . Virus was recovered from intestinal tissue, but no inflammatory response in the limina propria was apparent . These observations are consistent with previous report that substrate absorption rates may be altered during viral and bacterial enteric infection.

J Bacteriol, 1979 Mar, 137(3), 1165 - 75
Pyridine nucleotide cycle of Salmonella typhimurium: isolation and characterization of pncA, pncB, and pncC mutants and utilization of exogenous nicotinamide adenine dinucleotide; Foster JW et al.; Mutants of Salmonella typhimurium LT-2 deficient in nicotinamidase activity (pncA) or nicotinic acid phosphoribosyltransferase activity (pncB) were isolated as resistant to analogs of nicotinic acid and nicotinamide . Information obtained from interrupted mating experiments placed the pncA gene at 27 units and the pncB gene at 25 units on the S . typhimurium LT-2 linkage map . A major difference in the location of the pncA gene was found between the S . typhimurium and Escherichia coli linkage maps . The pncA gene is located in a region in which there is a major inversion of the gene order in S . typhimurium as compared to that in E . coli . Growth experiments using double mutants blocked in the de novo pathway to nicotinamide adenine dinucleotide (NAD) (nad) and in the pyridine nucleotide cycle (pnc) at either the pncA or pncB locus, or both, have provided evidence for the existence of an alternate recycling pathway in this organism . Mutants lacking this alternate cycle, pncC, have been isolated and mapped via cotransduction at 0 units . Utilization of exogenous NAD was examined through the use of {14C}carbonyl-labeled NAD and {14C}adenine-labeled NAD . The results of these experiments suggest that NAD is degraded to nicotinamide mononucleotide at the cell surface . A portion of this extracellular nicotinamide mononucleotide is then transported across the cell membrane by nicotinamide mononucleotide glycohydrolase and degraded to nicotinamide in the process . The remaining nicotinamide mononucleotide accumulates extracellularly and will support the growth of nadA pncB mutants which cannot utilize the nicotinamide resulting from the major pathway of NAD degradation . A model is presented for the utilization of exogenous NAD by S . typhimurium LT-2.

J Environ Pathol Toxicol, 1979 Mar-Apr, 2(4), 1099 - 107
Comparative mutagenicity of palmotoxin Bo and aflatoxins B1 and M1; Uwaifo AO et al.; The mutagenicity of palmotoxin Bo and of aflatoxin M1 relative to that of aflatoxin B1, the potent mutagen, was studied in five 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 a 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 TA-87 . The mutagenic potency of palmotoxin Bo is less than that of either aflatoxin B1 or M1.

J Biol Chem, 1979 Feb 10, 254(3), 811 - 5
Cloning of genes for bacterial glycosyltransferases . II . Selection of a hybrid plasmid carrying the rfah gene; Creeger ES et al.; A hybrid ColE1 plasmid containing DNA from Escherichia coli K12 were identified which was capable of correcting the defect in UDP-galactose:lipopolysaccharide alpha1,3-galactosyltransferase in an rfaH mutant of Salmonella typhimurium . Expression of the gene for this enzyme was also demonstrated in several strains of E . coli by direct assay . The E . coli and S . typhimurium enzymes are similar in catalytic properties and immunologic specificity . The finding of the galactosyltransferase activity in E . coli extracts is surprising since the alpha1,3-galactosylglucose disaccharide which is the product of the enzyme-catalyzed reaction does not appear to be present in the E . coli lipopolysaccharide.

J Biol Chem, 1979 Feb 10, 254(3), 804 - 10
Cloning of genes for bacterial glycosyltransferases . I . Selection of hybrid plasmids carrying genes for two glucosyltransferases; Creeger ES et al.; A method of identifying plasmids containing genes responsible for synthesis of nucleotide sugar:lipopolysaccharide glycosyltransferases is described . Hybrid ColE1 plasmids containing random fragments of the chromosome of Escherichia coli K12 were introduced into an indicator strain of Salmonella typhimurium which lacks UDP-glucose:lipopolysaccharide glucosyltransferase I due to an rfaG mutation . Plasmids capable of correcting the transferase defect were identified by their ability to convert the bacteriophage sensitivity pattern of the recipient strain from Ffm-sensitive to Ffm-resistant . Analysis of the lipopolysaccharide of the S . typhimurium/ColE1 hybrid strains and assay of cell extracts defined the new enzyme activities . Two plasmids were identified which carried the rfaG+ gene; one of these plasmids also contained genetic information for a second glucosyltransferase, the E . coli glucosyltransferase II, which normally is not present in S . typhimurium.

J Gen Microbiol, 1979 Feb, 110(2), 305 - 14
The nature of arginine auxotrophy in cutaneous populations of staphylococci; Emmett M et al.; L-Arginine was required for growth by a high percentage of strains of Staphylococcus species that were niche-specific and/or host-specific, but was usually not required for growth by species showing a wide host range . Growth stimulation patterns with arginine intermediates indicated that most of the auxotrophic strains had blocks in an early step(s) in arginine biosynthesis . These strains were designated phenotypically as Arg(CHG) according to the Salmonella typhimurium classification scheme . Staphylococcus simulans strains appeared to be either ArgA or Arg I . The ArgI strains of S . simulans and S . capitis had moderate to high ornithine carbamoyltransferase (EC 2.1.3.3) activities and therefore could not be designated as argI mutants . ArgI strains in other species had no or very low ornithine carbamoyltransferase activities . All of the natural Staphylococcus auxotrophs tested grew in the presence of L-citrulline and had moderate to high argininosuccinase (EC 4.3.2.1) activities . Arginine auxotrophs of species with a wide host range were often capable of reverting to arginine-independent or complete prototrophic growth, whereas auxotrophs of species that tended to be niche-specific and/or host-specific were incapable of reversion to arginine-independence, even in the presence of various mutagens . A relationship between the nature of arginine auxotrophy and habitat is suggested.

Gene, 1979 Feb, 5(2), 127 - 39
Construction of an M13 histidine-transducing phage: a single-stranded cloning vehicle with one EcoRI site; Barnes WM; In order to create a ready source of single-stranded DNA for DNA sequence determination by the dideoxy chain-termination method, the promoter-proximal part of the histidine operon, the hisOGD region of Salmonella typhimurium, was cloned onto the single-stranded phage M13 . Both orientations of the his DNA were cloned to supply DNA template for sequencing of each strand . Insertion was achieved at an HaeIII site in the intergenic region (IR) of M13, and a single EcoRI site was purposely regenerated at one boundary of the his DNA insert . Infected colonies, not plaques, were selected using the hisD gene as a selective marker . The single RI site and the hisD marker for auxotrophic selection represent improvements on the wild type M13 as a single-stranded vector for cloning other DNA.

J Gen Microbiol, 1979 Feb, 110(2), 409 - 19
Division and death rates of Salmonella typhimurium inside macrophages: use of penicillin as a probe; Lowrie DB et al.; In mouse peritoneal macrophages infected in vitro with Salmonella typhimurium the number of viable bacteria and the number of stainable bacteria detected by light microscopy both increased at similar rates with a doubling time of more than 1 h . Antibiotics were not present; instead extracellular bacteria were removed by frequently rinsing the cells . The bacterial doubling time in the same medium in the absence of macrophages was about 20 min . Penicillin added to macrophage monolayers rapidly entered the macrophages, reaching a diffusion equilibrium . The penicillin-induced bacterial death rate appeared to depend on the bacterial division rate as well as on the penicillin concentration . These properties of penicillin were used to monitor intracellular bacterial division and death rates . The results indicated that intracellular killing, with the disappearance of stainable bacteria, did not contribute to the extended doubling time in macrophages . It was concluded that the intracellular environment of the bacteria was probably growth inhibitory but not bactericidal.

Cancer Lett, 1979 Feb, 6(2), 67 - 72
Mutagenicity of some N- and O-acyl derivatives of N-hydroxy-2-aminofluorene in V79 Chinese hamster cells; Kuroki T et al.; Mutagenicity of 4 N- and O-acyl derivatives of N-hydroxy-2-aminofluorene (acyl: acetyl or myristoyl residue) was examined in V79 Chinese hamster cells in the absence of a metabolic activation system . N-Myristoyloxy-N-acetyl-2-aminofluorene (N-MyO-AAF) was toxic and weakly mutagenic, inducing 8-azaguanine-resistant (AZAr) mutants in V79 Chinese hamster cells in a concentration-dependent fashion; while N-acetoxy-N-myristoyl-2-aminofluorene (N-AcO-MyAF) and N-myristoyloxy-N-myristoyl-2-aminofluorene (N-MyO-MyAF) were neither cytotoxic nor mutagenic . Under the same conditions, N-acetoxy-N-acetyl-2-aminofluorene (N-AcO-AAF) was highly toxic and mutagenic . Neither of the 2 N-myristoyloxy derivatives was mutagenic in Salmonella typhimurium . These esters have been reported to produce local tumours at the site of their injection in rats, bo be electrophilic towards methionine, and to induce unscheduled DNA synthesis in cultured human fibroblasts . In view of the fact that some of the esters were mutagenic in neither S . typhimurium nor V79 Chinese hamster cells, our findings emphasize the need for multiple short-term tests in predicting potential carcinogenic activity of chemicals.

Mutat Res, 1979 Feb, 66(2), 113 - 27
Actions of an antispermatogenic, but non-mutagenic, indenopyridine derivative in mice and Salmonella typhimurium; Matter BE et al.; This paper describes a new antispermatogenic agent . Following single oral administration to mice, the indenopyridine derivative (4aRS,5SR,9bRS)-2-ethyl-1,3,4,4a,5,9b-hexahydro-7-methyl-5-p-tolyl-2H-indeno(1,2-c)pyridine hydrochloride, code No . 20-438, produced long-lasting inhibition of the spermatogenic process at dose levels of 10 mg/kg (1/40 of the lowest lethal dose) and higher . Testes weights were significantly reduced from days 2--217 after treatment, and no clear-cut evidence of a recovery was found during this time . The fertility of treated males was normal during the initial 2 weeks after treatment, followed by partial or total sterility in weeks 3--6, and incomplete recovery in weeks 7--29 after treatment . The antifertility effects were caused by maturation depletion of the germ cells, leading to oligospermia . The following rank of decreasing "susceptibility" of the germ cells was observed: Spermatocytes greater than early spermatids, intermediate spermatogonia greater than stem cells . Sperm and late spermatids were not affected . Despite the characteristic specific germ-cell pattern of antifertility effects, 20-438 showed neither indications of pre- and post-implantational dominant lethality, nor mutagenic potentiality as measured by cytogenetic analysis of spermatocytes or spermatogonia, the sperm abnormality assay, the micronucleus test, and the Salmonella assay . These data suggest that the action of 20-438, leading to oligospermia, does not involve genetic toxic effects.

J Bacteriol, 1979 Feb, 137(2), 758 - 63
Control of the receptor for galactose taxis in Salmonella typhimurium; Fahnestock M et al.; The chemotactic response to galactose in wild-type Salmonella typhimurium is not inducible by galactose, but is inducible by fucose, a non-metabolizable analog . In a galactokinase mutant, however, the galactose receptor is inducible by galactose . These data indicate that the concentration of free galactose in the cell controls the levels of the galactose receptor . The intensities of the chemotactic responses were found to vary in proportion to the concentration of galactose receptors . In bacteria with higher levels of galactose receptors, the ribose response is inhibited by galactose . This supports the model in which the ribose and galactose receptors compete for a common component of the signaling system.

J Bacteriol, 1979 Feb, 137(2), 1040 - 2
Regulation of N-acetylglutamate synthesis in Salmonella typhimurium; Abdelal AT et al.; N-Acetylglutamate synthase was purified to homogeneity from Salmonella typhimurium . The enzyme is subject to repression and feedback inhibition by arginine . Inhibition studies indicated that arginine exerts its effect primarily by reducing the affinity of the enzyme for glutamate.

J Gen Microbiol, 1979 Feb, 110(2), 421 - 9
Phagolysosome formation, cyclic adenosine 3':5'-monophosphate and the fate of Salmonella typhimurium within mouse peritoneal macrophages; Carrol ME et al.; Salmonella typhimurium did not inhibit fusion of lysosomes with the phagocytic vacuoles in infected macrophages and caused no increase in cyclic adenosine 3':5'-monophosphate . Glutaraldehyde-killed bacteria showed rapid ultrastructural degeneration within the phagolysosomes . In contrast, untreated bacteria were resistant to digestion by lysosomal enzymes . Intracellular survival of this species appears to depend on resistance to, and not evasion of, lysosomal enzymes.

J Infect Dis, 1979 Feb, 139(2), 178 - 90
The value of plasmid studies in the epidemiology of infections due to drug-resistant Salmonella wien; McConnell MM et al.; Since 1969 strains of Salmonella wien that are resistant to multiple antibacterial drugs have caused widespread epidemics of enteritis in Europe and North Africa . Of 113 British strains examined between January 1970 and January 1977, 67 were multi-resistant . These strains and 22 strains from six other countries were examined to determine their plasmid content . Two plasmids were found in the vast majority of strains: an FIme factor, conferring resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, spectinomycin, sulfonamides, and tetracyclines (ACKSSpSuT), and a nonautotransferring plasmid of resistance type ASSu . The FIme plasmids have dual incompatibility: they are incompatible with group FI factors and with the MP10 plasmid of Salmonella typhimurium, which belongs to a separate group . Other plasmids found in S . wien included principally a ColIa factor and an autotransferring plasmid that codes for ampicillin resistance and belongs to compatibility group I2 . The similarity in plasmid content of strains isolated in widely separated areas suggests that they have a clonal origin.

Appl Environ Microbiol, 1979 Feb, 37(2), 222 - 6
Conversion of 2,4,6-trinitrophenol to a mutagen by Pseudomonas aeruginosa; Wyman JF et al.; A strain of Pseudomonas aeruginosa reduced 2,4,6-trinitrophenol (picric acid) to 2-amino-4,6-dinitrophenol (picramic acid) under anaerobic conditions . Mutagenic assays of picric acid and picramic acid were carried out with histidine-requiring strains of Salmonella typhimurium . Picric acid (10 micrograms per plate) demonstrated mutagenicity (both frame shift and base substitution-gype mutations) only after activation with a rat liver homogenate preparation . Picramic acid (1 microgram per plate) induced both base pair substitution and frame shift-tupe mutations without activation by the rat liver preparation.

Cancer Lett, 1979 Feb, 6(2), 83 - 7
Mutagenicity of the non-carcinogenic dibenzylnitrosamine and an alpha-acetoxy derivative; Jacobson MK et al.; The mutagenicity of a non-carcinogenic nitrosamine, N,N-dibenzylnitrosamine (I), and a chemically synthesized alpha-acetoxy derivative, N-(alpha-acetoxy-benzyl)-N-benzylnitrosamine (II), has been examined in Salmonella typhimurium TA100 and TA1535 . Compound (I) was non-mutagenic when tested directly or in the presence of a metabolic activation system while (II) was highly mutagenic when tested directly . This is the first report on the conversion of a non-mutagenic N-nitrosamine to a mutagen by the formation of an alpha-acetoxy derivative.

Mol Gen Genet, 1979 Jan 5, 168(1), 87 - 95
Inhibition of growth by imidazol(on)e propionic acid: evidence in vivo for coordination of histidine catabolism with the catabolism of other amino acids; Bochner BR et al.; Imidazole propionic acid (ipa), a gratuitous inducer of the histidine-utilization (hut) system in Salmonella typhimurium, inhibits the organism's growth on succinate minimal medium . Induction of the hut system is necessary, but not sufficient, to cause inhibition . A study of the ability of single amino acids to relieve ipa-restricted growth suggests that insufficient glutamate is the cause of slow growth . The inhibition of growth by imidazolone propionic acid (iopa), an intermediate in the catabolism of histidine to glutamate, is similar to that by ipa . Studies using 2, 3, 5-triphenyl tetrazolium chloride plates to examine amino acid catabolism suggest that accumulation of ipa or iopa leads to inactivation of aspartate amino-transferase (AAT) . This interpretation is supported by studies of an Escherichia coli mutant lacking AAT . The mutant grows poorly on succinate minimal medium, and the poor growth is relieved by the same amino acids that relieve ipa- and iopa-restricted growth . These and other findings are discussed in terms of coordination of the histidine-utilization system with enzymatic activities involved in the catabolism of other amino acids.

J Med Chem, 1979 Jan, 22(1), 36 - 9
5-Iminodaunorubicin . Reduced cardiotoxic properties in an antitumor anthracycline; Tong GL et al.; Treatment of daunorubicin with methanolic ammonia affords 5-iminodaunorubicin, the first quinone-modified analogue of either daunorubicin or adriamycin . This product retains antileukemic activity in mice, is less cardiotoxic by electrocardiographic measurements in rats, and is nonmutagenic in Salmonella typhimurium (Ames test).

Mikrobiyol Bul, 1979 Jan, 13(1), 85 - 7
{Salmonella typhimurium isolated from a burn wound}; Atun IH et al.; Salmonella typhimurium isolated from a burn wound, in Burn Unit of Hacattepe University Hospital, General Surgery Department.

Environ Mutagen, 1979, 1(4), 383 - 9
Mutagenic evaluation of nitroparaffins in the Salmonella typhimurium/mammalian-microsome test and the micronucleus test; Hite M et al.; Three nitroparaffins (nitroethane, 1-nitropropane, and 2-nitropropane) were studied in the Salmonella typhimurium/mammalian microsome (Ames) test, with and without microsomal activation systems . Nitroethane and 2-nitropropane also were studied in an in vivo mutagenic (micronucleus) test . These studies were undertaken because these solvents are widely used in the chemical and pharmaceutical industries and 2-nitropropane was reported to cause liver cancer in rats exposed by the inhalation route . Neither nitroethane nor 1-nitropropane was active in the Ames test with Salmonella tester-strains TA1537, TA92, TA98, or TA100 . However, 2-nitropropane produced a significant increase in revertants in all of these tester strains, particularly strain TA100, where 3 microliter/plate doubled the number of revertants in the presence of microsomal enzymes . Negative results were obtained with both nitroethane and 2-nitropropane in micronucleus tests . These studies have shown that 2-nitropropane has the potential for causing point mutations in a microbial test system . However, this compound probably will not cause a chromosome mutation of the clastogenic type.

Environ Mutagen, 1979, 1(3), 277 - 82
Mutagenicity detection of in vivo nitrosation of dimethylamine by nitrite; Whong WZ et al.; In vivo nitrosation of dimethylamine by nitrite was measured with an intrahepatic host-mediated mutagenicity assay using Salmonella typhimurium as the detecting organism . It was possible to detect the product, N-nitrosodimethylamine, at much lower doses with this system than with previously reported in vivo systems . This and other improvements made it possible to detect the formation of nitrosodimethylamine from relatively low levels of gavaged precursors.

Environ Mutagen, 1979, 1(3), 269 - 76
Bile as a source of mutagenic metabolites produced in vivo and detected by Salmonella typhimurium; Connor TH et al.; The in vivo metabolic activation of several mutagenic compounds was assayed in the bile of rats, with Salmonella typhimurium as the indicator organism . It was determined that for some compounds, particularly the aromatic amines, a substantial percentage of the compound was excreted into the bile as either a nonmutagenic glucuronide conjugate or a mutagenic metabolite of the compound . Relatively low doses of the chemical were detected, and it was possible to follow the excretion pattern of the compounds over the collection period.

Environ Mutagen, 1979, 1(2), 105 - 12
Effect of the co-carcinogen benzo{e}pyrene on microsome-mediated chemical mutagenesis in Salmonella typhimurium; Rao TK et al.; Chemical agents that possess the ability to alter tumorigenicity of carcinogens (administered at subthreshold dose) constitute a major health hazard . We have employed the Ames Salmonella assay to examine the effect of co-carcinogenic benzo{e}pyrene (B{e}P) on microsome-mediated chemical mutagenesis . B{e}P enhanced the mutagenic activity induced by 2-acetylaminofluorene (2-AAF) and benzo{a}pyrene (B{a}P) in strains TA1538 and TA98 . Enhancement was also noted with N-hydroxy-2-AAF (the proximal metabolite of 2-AAF) but not with an ultimate carcinogenic form (N-acetoxy-2-AAF) . These results suggest the use of this approach to detect chemical agents that possess the ability to alter the activity of mutagenic or carcinogenic chemicals.

Antonie Van Leeuwenhoek, 1979, 45(4), 531 - 46
Colonization by Salmonella typhimurium and Shigella flexneri III of the gastrointestinal tract of mice treated with beta-2-thienylalanine and streptomycin; Brown KJ et al.; Mice fed beta-2-thienylalanine (beta-2-T) by oesophageal tube were no more susceptible to gastrointestinal tract colonization by Salmonella typhimurium or Shigella flexneri III than control mice fed water . In both beta-2-T-fed and water-fed groups, the increasing dosage of S . typhimurium, in logarithmic increments to groups of mice, resulted in increasing numbers of these bacteria detectable on dilution plates from organ homogenates . Colonization by S . flexneri III only occurred at a dosage of 10(8) bacteria for both groups . Pretreatment with 50 mg streptomycin allowed 10(3) Salmonella or 10(4) Shigella to colonize both beta-2-T and water-fed groups . Coliforms, inhibited by beta-2-T under certain conditions in vitro, were found in equal numbers in both groups . No obvious differences were noted in either types of other bacteria detected or numbers recovered from the two groups . No gross behavioural changes were noted in mice fed beta-2-T and not challenged with pathogenic bacteria, and no pathological changes were noted in hepatic or splenic tissues . With increasing Salmonella dosage, collections of polymorphonuclear leucocytes, which were almost focal, and increased numbers of giant cells were noted in splenic red pulp areas, in both groups.

Acta Biol Med Ger, 1979, 38(9), 1239 - 42
Reduction of mutagenic activity of aflatoxins after UV-irradiation; Kleinwachter V et al.; Solutions of aflatoxins B1, B2, G1 and G2 and solid films of aflatoxin B1 were irradiated with UV light of wavelength corresponding to the absorption band of aflatoxins at approximately 365 nm (approximately 27 500 cm-1) . The reaction was followed spectrophotometrically . Simultaneously the mutagenicity of samples of aflatoxins was determined using Salmonella typhimurium/mammalian microsome test . UV-irradiation caused a modification in all aflatoxins studied (in aqueous and nonaqueous solutions as well as in a solid film); the final photoproducts lost completely the mutagenic activity.

Ciba Found Symp, 1979, (72), 87 - 99
Synthesis of L-cysteine in Salmonella typhimurium; Kredich NM et al.; In Salmonella typhimurium and Escherichia coli the biosynthesis of L-cysteine from L-serine and inorganic sulphate proceeds along a branched convergent pathway along one arm of which sulphate is reduced to sulphide, while on the other L-serine is acetylated to O-acetyl-L-serine . This system is subject to positive genetic control in which growth on a poor sulphur source, O-acetyl-L-serine and the product of the cysB regulatory gene are all required for derepression . The final step consists of the formation of L-cysteine from O-acetyl-L-serine and sulphide . We find that in S . typhimurium this reaction is catalysed by two different enzymes, O-acetylserine sulphydrylase A and O-acetylserine sulphydrylase B, coded for by cysK and cysM respectively . Both enzymes are under the control of the cysteine regulon, and either alone is sufficient for cysteine prototrophy during aerobic growth . Although the advantage to the bacterium of having two separate enzymes to carry out the same reaction is unclear, preliminary data suggest that O-acetylserine sulphydrylase B is preferentially utilized for cysteine biosynthesis during anaerobic growth . We speculate that one enzyme may prefer free sulphide as a substrate while the other may use a bound form of sulphide.

Infection, 1979, 7(6), 273 - 4
Combined effect of intercalating agents and antibiotics on R-factor carrying bacteria in broth culture; Lebek G et al.; Growth of Salmonella typhimurium LT2 and Escherichia coli K12 bearing any of four R-factors of the fi+ and fi- group in repressed and derepressed form was not inhibited by a combination of ethidium bromide with ampicillin and kanamycin.

Z Allg Mikrobiol, 1979, 19(8), 563 - 70
Factors influencing the copy number of F-like plasmids in Escherichia coli and Salmonella typhimurium; Pritchard JJ et al.; The copy numbers of Flac, four F-like plasmids and pLT2 were estimated in two strains of Salmonella typhimurium and (for all except pLT2) one strain of Escherichia coli . For organisms grown in casamino acids minimal medium, the plasmids spanned a 7--8 fold range of copy number with ColB-K98 having the highest copy number in each strain and R124 the lowest . The copy number of ColB-K98 was substantially greater than 1 in each of the strains tested . There was no clear relation between the plasmid size and copy number, although the plasmids studied spanned only a narrow size range . The copy number of individual plasmids was slightly reduced or not affected at all by the presence of a second plasmid in the same strain . Derivatives harbouring each of the plasmids were grown in three different media to ascertain how plasmid copy number responds to changes in growth rate . For each plasmid, the copy number increased with decreasing growth rate . Extracts from each of the three strains harbouring ColB-K98 contained two distinct plasmid species . One appeared to be about twice as large as the other and both were absent from Col- segregants.

Cancer Lett, 1979 Jan, 6(1), 1 - 5
Differential effect of a microsomal deacetylase inhibition on the mutagenicity in Salmonella typhimurium of 2-acetylaminofluorene by liver homogenates of guinea pigs, mice and rats; Okuno S et al.; The effect of paraoxon, a microsomal deacetylase inhibitor, on the mutant genicity of 2-acetylaminofluorene (AAF) by liver homogenates was compared between the AAF carcinogenesis-resistant guinea pigs and the susceptible mice and rats . The mutagenicity of AAF was mostly abolished by paraoxon, not only in the 3 kinds of untreated animals but also in guinea pigs treated with a combination of phenobarbital and 5,6-benzoflavone, whereas about 50% of the mutagenicity was resistant to paraoxon in treated mice and rats . We suggest that microsomal deacetylase activity is crucially involved in the mutagenic activation of AAF by guinea pig liver homogenates, while the enzyme activity other than the deacetylase activity is also important in the activation by liver homogenates from treated mice or rats.

Mol Gen Genet, 1979, 177(1), 95 - 101
Formate dehydrogenase mutants of Salmonella typhimurium: a new medium for their isolation and new mutant classes; Barrett EL et al.; We have designed a new medium for the differentiation of mutants of Salmonella typhimurium defective in the ability to reduce nitrate with formate, and have characterized 24 formate dehydrogenase (FDH) mutants isolated on this medium . The mutants were assayed for the ability to use formate to reduce benzyl viologen and phenazine methosulfate, and were mapped by means of conjugation and P22-mediated transduction . Mutants lacking the ability to reduce either dye were found to map at three distinct sites: at a site co-transducible with xyl (presumably fdhA), at a site or sites between 13U and 33U, but not co-transducible with aroA, bio, purB, pyrC, or pyrD (near, but not identical with fdhB), and at asite 10-20% co-transducible with pyrE, for which we suggest the designation fdhC . Six mutant isolates reduced benzyl viologen, but not phenazine methosulfate . They retained the ability to produce nitrite during growth with nitrate . They mapped between 83U and 89U, but no co-transduction was found with metE, glnA, metB, or argH . The combined biochemical and genetic data suggest the existence of a gene in this area which is essential for the reduction of nitrate with formate, but not for formate hydrogenlyase activity or for nitrate reductase activity.

Mol Gen Genet, 1979, 177(1), 1 - 11
Genetic organization of the Salmonella typhimurium ilv gene cluster; Blazey DL et al.; A number of Salmonella typhimurium ilv::Tn10 insertion strains were used to analyze the Salmonella ilv gene cluster . Tn10 generated ilv deletion mutants were employed in mapping experiments to conclusively define the gene order as ilvG-E-D-A-C . Examination of ilv enzyme levels confirms that the direction of transcription of ilvGEDA is from ilvG to ilvA . The major control locus, designated ilvO, is located before ilvG forming an ilvOGEDA transcriptional unit that is multivalently repressed by isoleucine, valine and leucine . Two internal promoters, one before ilvE and anonother before ilvD, are identified and are shown to provide repressed levels of the ilvE, D and A gene products . Possible regulation of transcription from these promoters in response to isoleucine limitation is discussed in terms of attenuation.

J Hyg Epidemiol Microbiol Immunol, 1979, 23(3), 318 - 25
Experimental study of vaccines against Salmonella typhimurium infection; Severtsova MK et al.; Serological and protective activities of vaccines from S . typhimurium and S . minnesota were studied . It has been demonstrated that active protection against infection in experimental salmonellosis in mice can only be obtained by immunization of the animals using vaccines from complete antigenic complexes isolated from S-strains . It has been found that expressed anti-infection immunity (unlike anti-endotoxic immunity) is induced to the same extent by either high-molecular components (2,000,000 daltons and more), showing great serological activity, or components with relatively low molecular weight (15,000--20,000 daltons) and minimum serological activity . Vaccines from Ra- and Re-strains of S . minnesota do not induce resistance to S . typhimurium infection in mice in either active protection tests or passive protection tests.

J Nutr Sci Vitaminol (Tokyo), 1979, 25(4), 317 - 32
Formation of DNA-damaging and mutagenic activity in the reaction systems containing nitrite and butylated hydroxyanisole, tryptophan, or cysteine; Natake M et al.; It was confirmed by the procedure of rec-assay that DNA-damaging activities were formed in the reaction systems containing nitrite and phenol derivatives including BHA, tryptophan or cysteine under gastric pH conditions . The mutagenic action of the nitrite-BHA, nitrite-tryptophan and nitrite-cysteine systems was also tested according to Ames' method using Salmonella typhimurium TA 1535 and TA 98 . The mutagenic activity was observed in the nitrite-tryptophan and nitrite-cysteine systems, though the nitrite-BHA system did not show the activity . The DNA-damaging products were generally labile, i.e., the activity decreased significantly after 1.5 to 2 hours of the reaction, except in the case of the nitrite-BHA system . The DNA-damaging activity in the nitrite-BHA system did not decrease even after 48 hours of the reaction . Nitrosophenol derivatives themselves showed the DNA-damaging activity at pH 1 . The active product in the nitrite-BHA system was isolated and the structure was determined to be 2-tert-butyl-quinone . This compound gave a positive rec-assay test, and showed no mutagenesis by Ames' method . The active product from the nitrite-cysteine system was infered to be nitrosocysteine, and the product showed both DNA-damaging and mutagenic activity.

Arch Exp Veterinarmed, 1979, 33(2), 281 - 98
{Epizootiology of Salmonella typhimurium infection in chickens}; Kohler B et al.; The incidence of S . typhimurium infections among fowl increased in thr region of Potsdam in general, and on various big farms in particular, 1976 and over the first half of 1977 . The outbreaks included subclinical infections and clinically manifest diseases which caused remarkable loss of broilers from the affected stocks (up to 15.92 per cent) . Parent stocks contaminated with S . typhimurium were to be the sources of infection in all cases . A total of 1,220 Salmonella strains were isolated from fowl and its environment, with 1,151 of them being S . typhimurium (2.98 per cent of all samples tested) . The following amounts of S . typhimurium strains were isolated from different types of samples which had been collected from infected broiler stocks: 8.10 per cent from dead broilers, 5.86 per cent from dead broiler parents, 2.11 per cent from pulp linings of transport cages for day-old chicks, 1.23 per cent from litter, 1.0 per cent from hatching material (eggs or dead and jammed embryos, and 0.12 per cent from swabs used in hygiene supervision) . No Salmonellae were isolated from feedstuff . The transmission of S . typhimurium, therefore, is though to have taken the route via the hatching egg and via congenitally infected chicks traded between breeders and propagation farms . The control and prophylaxis of S . typhimurium infections, therefore, should be based primarily on action in the centralised breeding stocks . Specific steps of such action are proposed . Fifty-three strains were biochemically and lysotypically analysed, with the following types being determined: ut/Ph 30 BT b, ut/Ph 30 BT c, n.c . 1/72/n.c . BT b, 2 n.c . BT a, and 1A/6 BT a . The first two types covered 84.9 per cent of all strains isolated from the fowl . All lysotype ut/Ph 30 strains isolated from fowl fell under the copenhagen variant which had rarely been isolated from man in the past . These results are likely to support the demand for a joint control programme for enteritis Salmonellae, with particular emphasis on S . typhimurium, for implementation in human and veterinary medicine.

Acta Biochim Pol, 1979, 26(1-2), 73 - 81
Integration of F factor and cryptic LT2 plasmid into a specific site of the Salmonella typhimurium chromosome; Hryniewicz M et al.; Suppression of dnaA mutation by F'lac and cryptic LT2 plasmid was used for selecting clones containing these plasmids integrated into rfa and galK genes.

Acta Biochim Pol, 1979, 26(1-2), 21 - 8
Properties of cysK mutants of Escherichia coli K12; Wiater A et al.; Triazole and azaserine resistant mutants of E . coli K12 affecting cysK gene coding for O-acetylserine sulphydrylase were isolated . The cysK gene in E . coli is located in the same region of chromosome as the cycK gene in Salmonella typhimurium . All azaserine and some triazole resistant mutants require cysteine for growth at a normal rate . The cysK mutants have reduced sulphate uptake . Stability and transfer by conjugation of triazole resistant phenotype were checked . Differences in sulphate metabolism between closely related organisms E . coli and S . typhimurium are discussed.

Acta Biochim Pol, 1979, 26(1-2), 171 - 7
On the different response of Salmonella typhimurium hisG46 and TA1530 to mutagenic action of base analogues; Janion C; Various mutagens are known to induce more his+ revertants in TA1530 than in hisG46 strain . To test whether the mutator effect shown by TA1530 is limited to the his mutation, the lysA8 marker was introduced into both the TA1530 and hisG46 strain, and its reversibility, after induction by N4-hydroxycytidine, was estimated . The ability to reverse the lys marker was tenfold higher in the TA1530/lysA8 transductants than in the hisG46/lysA8 transductants or in the donor for lys, the lysA8 strain.

Acta Biochim Pol, 1979, 26(1-2), 135 - 43
The smoB mutation suppressing cell filamentation and ability to support the multiplication of phage P22 in Salmonella typhimurium; Kozdroj H et al.; Isolation and properties of a Salmonella typhimurium mutant smoB are described . The mutation maps at unit 99 of the S . typhimurium chromosome between pyrB and deoC . It suppresses cell filamentation and temperature sensitivity of histidine-constitutive mutants, but does not restore the normal regulatory pattern to the histidine operon . Strains carrying the mutation have greatly reduced ability to support the growth of phage P22, but not of ES18 or Felix O.

Exp Pathol (Jena), 1979, 17(3), 158 - 66
A morphological study in germfree mice (Salmonella infection); Shirai Y et al.; The morphological manifestation of the intestinal infections of Salmonella typhimurium by the intestine rolled method in both conventional DKI and germfree mice have been investigated in our laboratory . In the conventional mice, the morphological manifestation of intestinal infection shows no difference from the general features of infection, while in the germfree mice, the manifestation is characterized by the so-called non-reactive necrotizing enteritis without cellular reaction . When infection in the germfree mice occurs, some state of immunological insufficiency should be taken into consideration . In infections of germfree mice it is difficult to consider the immunological or the allergic reaction which is expected in the conventional mice . In addition, the direct influences of bacteria such as endotoxin must be taken into consideration as another possibility, but the very limited localized lesions, as seen in this experiment cannot always be suggested to be due to the direct influence of bacteria or intoxication . Though there are many problems to be solved in the future, we are now able to state a kind of mechanism similar to that of Shwartzman's phenomenon cannot be ignored in the infection in newborns or in immunologically immature animals.

Microbiol Immunol, 1979, 23(2), 71 - 85
Alterations of lipid metabolism in mice injected with endotoxin; Sakaguchi O et al.; Some alterations in lipid metabolism in mice were observed by the intraperitoneal injection of endotoxin from Salmonella typhimurium . The content of serum triglyceride increased markedly in poisoned mice 16-24 hr postintoxication . The level of free fatty acid (FFA) in the serum of endotoxin-administered mice decreased in inverse proportion to an increase in the injected dose of endotoxin . The electrophoretic analysis of the serum lipoprotein on cellulose acetate membrane showed that pre beta-lipoprotein increased markedly and that FFA fraction in the poisoned mice sera disappeared 18 hr postintoxication . The activity of hormone-sensitive lipase in adipose tissue was elevated appreciably 2 hr after injection, but decreased more significantly after 18 hr than that in fasted control mice . On the other hand, the activity of lipoprotein lipase decreased in the post-heparin serum and adipose tissue 3 hr postintoxication, and decreased significantly after 16 hr . There were no significant differences between changes in the formation of active glycerol (alpha-GP) and in the activity of alpha glycerophosphate dehydrogenase (alpha-GPDH) in the mice liver with or without administration of endotoxin, and after 16 hr levels of both hepatic alpha-GP content and alpha-GPDH activity in poisoned mice showed a tendency to be slightly lower than those in fasted control mice.

Genetika, 1979, 15(5), 807 - 11
{Mutagenic effect of a tetrahydrodiazopyrene derivative on bacteria}; Abilev SK et al.; Mutagenic action of 3,7-diamino-4,9-dioxy-5,10-dioxo-4,5,9,10-tetrahydro-4,9-diazapiren (DDDTDP) was shown using indicator strains Salmonella typhimurium TA 1534, TA 1536, TA 1537, TA 1538 . The drug-induced mutations in strains TA 1534 and TA 1538, and it can be used as a positive control in testing mutagens capable of inducing frameshift mutations . No significant differences was observed between DDDTDP effects on strains TA 1534 and TA 1538 which did or did not bear rfa mutation causing defects of cell wall lypopolysacharide complex . Within the range of concentrations tested DDDTDP had mutagenic effect without causing essential killing of bacteria . The mutagenic effect was decreased in the in vitro system of metabolic activation (Ames' plate test in Salmonella microsomes).

Lab Anim, 1979 Jan, 13(1), 33 - 4
Studies on salmonellosis in the house mouse, Mus musculus; Shimi A et al.; Salmonellae were isolated from the faeces from 17 of 170 (10%) wild house mice . Salmonella typhimurium was isolated from 10, S . typhimurium, var . Copenhagen from 2, S . thompson from 1, and S . muenchen from 4 . It was concluded that house mice could be a reservoir of infection and play an important role in human and animal salmonellosis.

Ann Med Interne (Paris), 1979, 130(1), 17 - 21
{Primary mycotic aneurysm of the abdominal aorta from salmonella injection . A new case successfully operated upon (author's transl)}; Jaillard J et al.; A double aneurism, located in the abdominal aorta and left common iliac was found complicating a salmonella typhimurium infection which had been present for 7 months . A by-pass operation between the inaffected iliac arteries was followed by resection of the two aneurisms . Cultures taken from the walls of the aneurisms showed the presence of salmonella typhimurium . The authors stress the particular seriousness of the spontaneous evolution of such mycotic aneurisms.

Gene, 1979 Jan, 5(1), 59 - 76
Construction of plasmid cloning vehicles that promote gene expression from the bacteriophage lambda pL promoter; Bernard HU et al.; Two multiple-copy, ColE1-type, plasmid cloning vehicles, pHUB2 and pHUB4, have been constructed that carry four different single restriction sites down-stream from the phage lambda promoter pL . The promoting activity of pL is switched off at low temperature in the presence of a cIts gene that specifies a temperature-sensitive repressor but could be activated by heat induction . cIts was located either on the host chromosome, or on a second plasmid pRK248 that is compatible with the cloning vehicle, or on the vehicle itself . Three different restriction fragments, each carrying the gene trpA of Salmonella typhimurium or Shigella dysenteriae, have been inserted into the EcoRI, BamHI and SalI sites, respectively, of these plasmids and pL dependent expression of the inserted gene in Escherichia coli was determined by measuring the enzymatic activity of the trpA gene product . Heat induction resulted in a level of expression of trpA corresponding to 1 to 6.6% of the total soluble cell protein as trpA protein . The level of trpA protein production depended on the particular insert and the plasmid used.

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