Salmonella typhimurium

J Bacteriol, 1984 Oct, 160(1), 122 - 30
Genetic characterization and molecular cloning of the tripeptide permease (tpp) genes of Salmonella typhimurium; Gibson MM et al.; Of the three bacterial peptide transport systems only one, the oligopeptide permease, has been characterized in any detail . We have now isolated Salmonella typhimurium mutants deficient in a second transport system, the tripeptide permease (Tpp), using the toxic peptide alafosfalin . Alafosfalin resistance mutations map at three loci, the gene encoding peptidase A (pepA) and two transport-defective loci, tppA and tppB . Locus tppA has been mapped to 74 min on the S . typhimurium chromosome, cotransducible with aroB, and is a positive regulator of tppB . Locus tppB maps at 27 min in the cotransduction gap between purB and pyrF . We cloned tppB, the structural locus for the tripeptide permease . Two simple methods are described for mapping the location of cloned DNA fragments on the chromosome of S . typhimurium.

Infect Immun, 1984 Oct, 46(1), 231 - 6
Brucellacidal activity of human and bovine polymorphonuclear leukocyte granule extracts against smooth and rough strains of Brucella abortus; Riley LK et al.; The microbicidal activities of freeze-thaw and high-salt extracts of human and bovine polymorphonuclear leukocyte (PMN) granules were tested against a smooth intermediate strain (45/0) and a rough strain (45/20) of Brucella abortus which differ in virulence and survival within PMNs . Freeze-thaw extracts of human PMN granules were more brucellacidal than high-salt extracts when supplemented with hydrogen peroxide (H2O2) and potassium iodide (KI), whereas the opposite was found with freeze-thaw and high-salt extracts of bovine PMN granules . There was no oxygen-independent killing of either the smooth or rough strain of B . abortus by amounts of granule extracts which caused 100% killing of a deep rough mutant (Re) of Salmonella typhimurium . The oxygen-dependent brucellacidal activity of granule extracts was dependent on concentrations of myeloperoxidase (MPO) units, H2O2, and KI . Maximal brucellacidal activity was observed at pH 5.5 to 6.0 . The smooth strain, 45/0, was more resistant to oxygen-dependent killing by granule extracts than was the rough strain, 45/20 . Granule extracts were more brucellacidal than purified MPO at equivalent levels of MPO enzyme units, suggesting that at least one other reaction enhances killing by the MPO-H2O2-I- system.

Biochemistry, 1984 Sep 25, 23(20), 4767 - 73
Phosphorothioate analogues of 5-phosphoribosyl 1-diphosphate: synthesis, purification, and partial characterization; Smithers GW et al.; The 1-phosphorothioate analogues of 5-phosphoribosyl 1-diphosphate (P-Rib-PP) have been prepared enzymatically, in reactions catalyzed by P-Rib-PP synthetase from Salmonella typhimurium . 5-Phosphoribosyl 1-O-(2-thiodiphosphate) (P-Rib-PP beta S) was synthesized from ribose 5-phosphate (Rib-5-P) and the Mg2+ complex of adenosine 5'-O-(3-thiotriphosphate) . The SP and RP diastereomers of 5-phosphoribosyl 1-O-(1-thiodiphosphate) (P-Rib-PP alpha S) were synthesized from Rib-5-P and the Mg2+ complex of adenosine 5'-O-(2-thiotriphosphate) (ATP beta S) (SP diastereomer, delta-configuration) and the Cd2+ complex of ATP beta S (RP diastereomer, delta-configuration), respectively . The strategy for the synthesis and stereochemical assignment of the P-Rib-PP alpha S diastereomers was based on the specificity of P-Rib-PP synthetase for the (delta)-beta, gamma-bidentate metal-nucleotide substrate and the stereochemical course of the synthetase reaction, leading to inversion of configuration at the P beta atom of the nucleotide {Li, T . M., Mildvan, A . S., & Switzer, R . L . (1978) J . Biol . Chem . 253, 3918-3923}, and the known configurations of the Mg2+ and Cd2+ beta, gamma-bidentate complexes of the ATP beta S diastereomers {Jaffe, E . K., & Cohn, M . (1979) J . Biol . Chem . 254, 10839-10845} . The P-Rib-PP analogues were purified by gradient elution from DEAE-Sephadex and characterized by chemical analysis and 31P nuclear magnetic resonance {Smithers, G . W., & O'Sullivan, W . J . (1984) Biochemistry (following paper in this issue)} . A preliminary account of their interaction with human brain hypoxanthine phosphoribosyltransferase and yeast orotate phosphoribosyltransferase (OPRTase) is described.(ABSTRACT TRUNCATED AT 250 WORDS)

J Biol Chem, 1984 Sep 10, 259(17), 10983 - 8
Oxygen taxis and proton motive force in Salmonella typhimurium; Shioi J et al.; The aerotactic response of Salmonella typhimurium SL3730 has been quantitatively correlated with a change in the proton motive force (delta p) as measured by a flow-dialysis technique . At pH 7.5, the membrane potential (delta psi) in S . typhimurium changed from -162 +/- 13 to -111 +/- 15 mV when cells grown aerobically were made anaerobic, and it returned to the original value when the cells were returned to aerobiosis . The delta pH across the membrane was zero . At pH 5.5, delta psi was -70 mV in aerobiosis and -20 mV in anaerobiosis, and delta pH was -118 and -56 mV for aerobic and anaerobic cells, respectively . A decrease in delta p resulted in increased tumbling, and an increase in delta p resulted in a smooth swimming response at either pH . Inhibition of aerotaxis at pH 7.5 by various concentrations of KCN correlated with a decreased delta p, due to a decreased delta psi in aerobiosis and little change in delta psi in anaerobiosis . At concentrations up to 100 mM, 2,4-dinitrophenol decreased delta psi, but did not inhibit aerotaxis because the difference between delta psi in aerobic and anaerobic cells remained constant . Considered as a whole, the results indicate that aerotaxis in S . typhimurium is mediated by delta p.

Carcinogenesis, 1984 Sep, 5(9), 1179 - 81
Mutagenicity of smoke condensate of bidi--an indigenous cigarette of India; Shirname LP et al.; The possible mutagenicity of bidi smoke condensate (BSC), an indigenous form of an Indian cigarette has been studied using three short-term test systems . It was seen that BSC caused frame-shift mutations in Salmonella typhimurium strains TA 98 and TA 1538 and required metabolic activation . In the mammalian test systems, BSC induced 8 azaguanine resistant mutations in V79 Chinese hamster cells in the presence of S9 mixture and induced elevated frequencies of micronucleated erythrocytes in the bone marrow of Swiss mice.

Cancer Res, 1984 Sep, 44(9), 3736 - 43
Pharmacological and preclinical toxicological studies of 1,2-diaminocyclohexane(isocitrato)platinum(II); Macquet JP et al.; The antitumor activity of a new highly water-soluble platinum derivative, (1,2-diaminocyclohexane)(isocitrato)platinum(II) (NSC 350602; PHIC), was studied in L1210 leukemia cells inoculated into mice . PHIC was found to be active for i.p . graft-i.p . treatment, i.p . graft-i.v . treatment, and i.v . graft-p.o . treatment . A significant activity was observed on early and advanced L1210 leukemia even when the treatment was delayed 6 days after the graft . A comparison between the activities of PHIC, cisplatin (NSC 119875), and (4-carboxyphthalato)(1,2-diaminocyclohexane)-platinum(II) (NSC 271674; DACCP) for i.p . graft-i.p . treatment indicated that the highest activity was observed for divided doses rather than single dose in the case of PHIC and DACCP and not for cisplatin . Under these conditions, PHIC gave larger treated versus control survival time values or a greater number of surviving animals than did cisplatin and DACCP . No cross-resistance between PHIC and cisplatin could be detected in L1210 leukemia cells resistant to cisplatin . Mutagenicity studies on Salmonella typhimurium revealed that PHIC is far less mutagenic than cisplatin on TA100 and TA98 strains . Other pharmacological parameters, such as growth inhibition rate of cultured L1210 cells, penetration, and DNA binding in L1210 cells inoculated in mice, were compared for PHIC and cisplatin together with their in vitro rates of hydrolysis and platinum:DNA adducts . No nephrotoxicity was detected with PHIC at the maximum nonlethal dose level in mice in contrast to results with cisplatin . A preclinical study was conducted in baboons at 100, 150, and 200 mg/kg . No nephrotoxicity could be detected at a dose of 100 mg/kg without prehydration for six courses at 3-week intervals . At 200 mg/kg, an increase of blood creatinine was controlled by prehydration . Gastrointestinal toxicity was mild during the three regimens . Phase I clinical trials are under way.

Sci Total Environ, 1984 Sep, 38, 275 - 81
Study of mutagenic pollution in Bombay; Shenoy CN et al.; Airborne suspended particulate matter (SPM) from seven areas in and around Bombay city were collected over glass fibre filters (0.8 micrometer porosity) . The chemicals from the SPM were extracted in dimethylsulfoxide and distilled water and were further tested for mutagenicity by Ames' test using for five mutants of Salmonella typhimurium . Of the seven areas studied, only four exhibited mutagenicity, which was confirmed by dose-response assays using the mutant strain TA 100 . The very high mutagenicity observed in central Bombay correlates with the higher incidence of respiratory tract diseases in the resident population.

J Med Chem, 1984 Sep, 27(9), 1161 - 6
Potential antitumor agents: synthesis and biological properties of aliphatic amino acid 9-hydroxyellipticinium derivatives; Auclair C et al.; Aliphatic amino acids glycine, alanine, valine, and leucine were conjugated to the antitumor drug N2-methyl-9-hydroxyellipticinium (NMHE) through a peroxidase-catalyzed oxidation reaction . NMR studies of the adducts so obtained have indicated (i) that the amino acids were linked to NMHE between the nitrogen of their primary amine and the C-10 position of the ellipticine ring and (ii) that a double bond was present between the nitrogen and the alpha-carbon of the amino acid moiety . All amino acid-NMHE adducts exhibit a higher lipophilic property than the parent compound (NMHE) directly correlated with the length of the aliphatic chain of the amino acids . The adducts interact with DNA through an intercalating process with apparent binding constant ranging from 2 X 10(5) to 5 X 10(5) M-1 at pH 7.40 . The presence of the amino acid moiety linked to NMHE results (i) in a slight decrease of the cytotoxicity on L1210 cells in vitro (ID50 ranged from 0.20 to 0.50 microM) as compared to NMHE (ID50 = 0.05 microM), (ii) in a decrease of the antitumor efficiency in vivo against L1210 leukemia for leucine-NMHE and valine-NMHE (ILS at LD0/2 = 35% and 31%, respectively), (iii) in a suppression of the antitumor activity for alanine-NMHE and glycine-NMHE (ILS less than 25%), (iv) in a strong increase in the bacteriostatic activity on the quaternary ammonium sensitive Escherichia coli BL101 strain and on Salmonella typhimurium TA98 strain . The bacteriostatic effect is directly correlated with the lipophilic property of the drugs . These findings are discussed in terms of a structure-activity relationship.

Zh Mikrobiol Epidemiol Immunobiol, 1984 Sep, (9), 43 - 9
{Isolation of Salmonella typhimurium enterotoxin in partially purified form and study of its properties}; Fluer FS; S . typhimurium enterotoxin, partially purified in accordance with our scheme (salting out with 75% ammonium sulfate, dialysis and gel filtration in a column with Sephadex G-150, followed by electrofocusing), showed enterotoxic activity in the intestinal loop of a rabbit and yielded the positive result in the cutaneous test . S . typhimurium enterotoxin proved to be protein with a molecular weight of 140000 daltons and the isoelectric point equal to 4.4 . The biological activity of S . typhimurium enterotoxin was neutralized with homologous antiserum and with antiserum to cholera enterotoxin . Heating the preparation at 75 degrees C for 30 minutes led to a considerable decrease in its enterotoxic activity.

Res Vet Sci, 1984 Sep, 37(2), 230 - 3
Growth of Salmonella typhimurium in the caecum of gnotobiotic chickens with Eimeria tenella; Fukata T et al.; Gnotobiotic chickens infected with Eimeria tenella (5 X 10(4) oocysts per bird) received an oral inoculation of 100 Salmonella typhimurium two, four, six or eight days after coccidial infection at four days old . When S typhimurium was given two or four days after E tenella infection, S typhimurium counts in the caecal contents were similar to the counts in birds infected with S typhimurium alone . When S typhimurium was given six or eight days after E tenella infection, counts of the organism were significantly greater than with S typhimurium infection alone . There were no differences in the number of chickens positive for S typhimurium in the caecal contents, bile, liver and spleen between the two groups.

J Gen Microbiol, 1984 Sep, 130 ( Pt 9), 2277 - 83
Mechanism of the protective action of anti-Salmonella IgM in experimental mouse salmonellosis; Saxen H; The kinetics of mouse salmonellosis caused by Salmonella typhimurium was studied in mice preinjected with the IgM or IgG fraction prepared from a rabbit anti-Salmonella serum . Compared on the basis of antibody units determined by an enzyme immunoassay, IgM was ten times more effective than IgG in promoting removal of the bacteria from blood after intravenous (IV) injection and their uptake in the reticuloendothelial system (RES) . The subsequent killing of the bacteria was, however, only minor, in accord with the negligible protective effect of serum antibodies in IV infection . IgM was over 1000 times more effective than IgG in promoting killing of the bacteria after intraperitoneal (IP) challenge . Neither antibody had an effect on the multiplication of the bacteria in the RES . The protective action of antibody was thus almost entirely mediated by peritoneal-cavity cells acting in the very early phase of infection . The greater effect of IgM is suggested to be a special feature of Salmonella infections, connected with the capacity of these bacteria for intracellular survival and multiplication in the RES.

Am J Vet Res, 1984 Sep, 45(9), 1858 - 61
Vaccination of calves against Salmonella dublin with aromatic-dependent Salmonella typhimurium; Smith BP et al.; Ten Holstein calves were divided into 2 groups . Five calves served as nonvaccinated controls, and 5 calves were vaccinated IM at 2 and 3 weeks of age with 10(9) aromatic-dependent (aro-) Salmonella typhimurium strain SL1479 containing O antigens 1, 4, 12 . Serious adverse reactions to vaccination were not observed in the calves . Mean maximum rectal temperature increase in the vaccinated calves was 1.5 C . One calf had diarrhea and depressed appetite for 1 day after vaccination . At 5 weeks of age, all calves were challenge exposed orally with 1.5 X 10(11) virulent S dublin strain SL1367 (O antigens 9,12) . After challenge-exposure inoculum was given, 1 of 5 vaccinated calves died and 4 of the 5 nonvaccinated calves died (P less than 0.05) . Thus, some cross serotype protection against S dublin was induced by parenteral vaccination of calves with aro- S typhimurium strain SL1479, although protection was not complete.

J UOEH, 1984 Sep 1, 6(3), 257 - 63
{Mutagenesis of amino and/or methyl analogs of acridine in Salmonella and yeast: a comparison between the spot-test and the pre-incubation methods}; Goto C et al.; The relationship between mutagenic activities and chemical structure of acridine derivatives was examined by using Salmonella typhimurium strains TA 1537 and TA 1977 and yeast Saccharomyces cerevisiae . Most analogs with amino and/or methyl group(s) caused frameshift-type mutation in Salmonella without mammalian microsomal enzyme activation . The 9-amino analogs were strong mutagens and mutagenicity was also increased when 10-position was methylated in 1-amino and 2-amino compounds . However, 9-amino derivatives did not cause mitochondrial mutation in yeast, where 3,6-diamino and/or 10-methyl groups were structural requisites for significant mutagenic activity . In comparison with the pre-incubation method, the spot-test method was shown to be less sensitive . The mutagenicity of some compounds could not be detected by the spot-test method . Mutagenic activities of these drugs were revealed and increased markedly with an increase in pre-incubation period up to 20 min, suggesting that the pre-incubation of tester bacteria with a compound prior to a mutagenicity assay is necessary for the detection of mutagenesis of these compounds.

Food Chem Toxicol, 1984 Sep, 22(9), 725 - 30
Effects of vitamin A on cyclophosphamide mutagenicity in vitro (Ames test) and in vivo (mouse micronucleus test); Busk L et al.; The effect of vitamin A on cyclophosphamide mutagenicity was measured both in vitro and in vivo . In the Ames test in Salmonella typhimurium TA1535 with mouse-liver S-9 mix, the addition of retinol, retinyl acetate or retinyl palmitate caused a dose-dependent inhibition of cyclophosphamide mutagenicity . In the micronucleus test in male NMRI mice fed low, normal or high levels of vitamin A, the induction of micronuclei in bone marrow by an ip dose of cyclophosphamide was unaffected by vitamin A status . Thus, this study provides no evidence that activation of a procarcinogen in the liver or bone marrow of mice can be modified by vitamin A . One of the possible reasons for the observed absence of inhibition by vitamin A in vivo may be a lack of correlation between the oral dose of retinoid and the resulting level of vitamin A in the bone marrow . The difference between results in vitro and in vivo may also have been due to a difference in the availability and potency of added vitamin A in vitro compared with the forms absorbed and stored in vivo.

Poult Sci, 1984 Sep, 63(9), 1732 - 7
Effect of Eimeria tenella infection in chickens fed the feed artificially contaminated with Salmonella typhimurium; Morishima H et al.; Effect of Eimeria tenella infection on Salmonella typhimurium infection of chickens was tested using feed experimentally contaminated with S . typhimurium . Four experiments were conducted . In Experiments 1 and 2, chickens received feed contaminated with 10(3) or 10(2) cfu of S . typhimurium per g for 5 days after E . tenella infection . In Experiments 3 and 4, chickens were fed feed contaminated with 10(2) or 10 cfu of S . typhimurium per g for 3 days before E . tenella infection . In all experiments, chickens were necropsied 3 to 14 days after E . tenella infection . The number of S . typhimurium in the cecal contents was counted and the presence of the organism in the liver and bile was examined . In Experiments 1 and 2, there was no significant difference in S . typhimurium infection between the group infected with S . typhimurium alone and the group infected with both E . tenella and S . typhimurium . In Experiments 3 and 4, S . typhimurium counts in the cecal contents of chickens in the concurrently infected group were significantly greater than those of chickens in the S . typhimurium alone-infected group.

Mutat Res, 1984 Sep, 141(1), 11 - 4
The direct mutagenic activity of alpha, omega-dihalogenoalkanes in Salmonella typhimurium . Strong correlation between chemical properties and mutagenic activity; Buijs W et al.; A series of 18 alpha, omega-dihalogenoalkanes (kappa(CH2)n kappa with n = 1-6 and kappa = Cl, Br, I) was tested for direct mutagenic activity in Salmonella strains TA1530, TA1535 and TA100 using spot-test procedures . The results indicate that the mutagenic behaviour of these compounds is strongly dependent upon the carbon chain length as well as the type of halogen involved . This behaviour correlates with the leaving group ability and the degree of neighbouring group participation in nucleophilic displacement reactions of the different halogen atoms.

J Bacteriol, 1984 Sep, 159(3), 900 - 4
Heterogeneity of lipid A: comparison of lipid A types from different gram-negative bacteria; Mattsby-Baltzer I et al.; Chloroform-soluble purified lipid A preparations from 10 sources, including five Escherichia coli strains (EH100, K-12, O127, O111, RCDC), two Salmonella strains (Salmonella typhimurium, Salmonella minnesota R595), Shigella sonnei II, and a hybrid of Shigella flexneri and E . coli K-12, were compared with lipid A from S . flexneri . Purified lipid A from S . flexneri was earlier found to be composed of eight fractions . The various lipid A preparations were assayed by thin-layer chromatography . Chromatograms were stained for phosphate or carbohydrate by molybdenum blue or orcinol, respectively . The number of major bands found for each lipid A preparation varied between 7 and 10, depending on the source . Comparable bands, based on Rf, were found among all of the different lipid A preparations, but the quantity of each band varied between the sources of lipid A . Four bands (designated 2, 3, 7, and 8) were abundant in every preparation . Variations of conditions used for preparing lipid A, such as changing of hydrolysis time, did not affect the appearance of lipid A on thin-layer chromatography . Change in the type of acid used for hydrolysis also did not affect the band pattern, but it did change the quantitative amounts of the various bands to some degree.

J Bacteriol, 1984 Sep, 159(3), 1090 - 2
Map locations and functions of Salmonella typhimurium men genes; Kwan HS et al.; Menaquinone (men) mutants of Salmonella typhimurium isolated on the basis of their inability to produce trimethylamine were characterized with respect to mutation site, the ability to cross-feed each other and be cross-fed by known Escherichia coli men mutants, and response to intermediates of the menaquinone biosynthetic pathway . Cross-feeding tests were based on the requirement of menaquinone for hydrogen sulfide production . Genotypes corresponding to the menA, B, C, D, and possibly E genes described in E . coli were all identified . Additional studies of deletions in the menBCD area revealed that this cluster lies between ack/pta and glpT, as in E . coli . The ack and pta mutants were also defective in the production of trimethylamine and failed to produce gas in the absence of added formate.

J Bacteriol, 1984 Sep, 159(3), 1056 - 9
Excretion of unassembled flagellin by Salmonella typhimurium mutants deficient in hook-associated proteins; Homma M et al.; Of the flagellar filamentless mutants of Salmonella typhimurium, the flaV, flaU, and flaW mutants, which are defective in hook-associated proteins, synthesized flagellin molecules, but flagella did not polymerize at the tips of the mutant hooks and were excreted into the culture medium as intact monomers.

Radiat Res, 1984 Sep, 99(3), 609 - 26
Toxic variability and radiation sensitization by Pt(II) analogs in Salmonella typhimurium cells; Richmond RC et al.; A rationale is presented for the development of toxic, i.e., cytocidal, antitumor drugs as clinical hypoxic cell radiation sensitizers . Pt(II) complex-induced hypoxic cell radiation sensitization may occur from Pt(II) complex in free solution and Pt(II) bound to DNA . Although both the free solution and the bound compartments may operate, the free solution compartment is more likely amenable to experimental and clinical control in the case of systemically active Pt drugs . Assuming equivalent cell uptake of different Pt(II) complexes, the free solution compartment of Pt(II) sensitization can be increased by utilizing less toxic analogs of the antitumor drug cis-dichlorodiammineplatinum(II) . One such less toxic Pt(II) sensitizer currently in clinical use is found to be cis-(1,1-cyclobutanedicarboxylato)diammineplatinum(II) . A new finding of both clinical and mechanistic usefulness is described: irradiation of hypoxic solutions of four cis-Pt(II) complexes, but not two trans-Pt(II) complexes, creates products that cause toxicity in excess of the unirradiated solutions.

Radiat Res, 1984 Sep, 99(3), 596 - 608
Toxic variability and radiation sensitization by dichlorodiammineplatinum(II) complexes in Salmonella typhimurium cells; Richmond RC; The oxidative coordination compound cis-dichlorodiammineplatinum(II) (cis-DDP) is again shown to be a hypoxic cell radiation sensitizer . The mechanism of cis-DDP-induced radiation sensitization is complex . Results here indicate that cis-DDP sensitization operates in part through reactive free radicals, in part through the interactions of radiation-induced reactive Pt(I) intermediates, and in part through the involvement of thermodynamic and kinetic aspects of Pt(II)-DNA binding during irradiation . For the first time, radiation sensitization by trans-DDP is compared with a sensitizing concentration of cis-DDP within the same study . Both analogs are sensitizers, but with significant differences . Further, irradiated hypoxic solutions of cis-DDP are found to be more toxic than unirradiated solutions.

J Med Chem, 1984 Sep, 27(9), 1156 - 61
Synthesis, spectral analysis, and mutagenicity of 1-, 3-, and 6-nitrobenzo{a}pyrene; Chou MW et al.; The mutagenic environmental pollutants 1-, 3-, and 6-nitrobenzo{a}pyrene were synthesized . Nitration of 7,8,9,10-tetrahydrobenzo{a}pyrene with sodium nitrate in trifluoroacetic acid and acetic anhydride at ambient temperature gave a mixture of 1-, 3-, and 6-nitro-7,8,9,10-tetrahydrobenzo{a}pyrene, which was separated by chromatography . Dehydrogenation of the isolated nitrotetrahydrobenzo{a}pyrenes with 2,3-dichloro-4,5-dicyano-1,6-benzoquinone produced 1-, 3-, and 6-nitrobenzo{a}pyrene in high yield . Comparison of the spectral data of these compounds with those obtained from direct nitration of benzo{a}pyrene confirmed that 1- and 3-nitrobenzo{a}pyrenes are indeed the minor products of the latter reaction . This confirmation also verifies that 1- and 3-nitrobenzo{a}pyrene were the minor nitrated products of benzo{a}pyrene formed in model air atmospheres . The 1-, 3-, and 6-nitrobenzo{a}pyrene were mutagenic in Salmonella typhimurium tester strains TA98 and TA100 in the presence of a mammalian microsomal (S9) activating system . Both 1- and 3-nitrobenzo{a}pyrene, but not 6-nitrobenzo{a}pyrene, were also direct-acting mutagens in these strains . However, only 6-nitrobenzo{a}pyrene exhibited weak mutagenic activity when tested in Chinese hamster ovary cells, while only 3-nitrobenzo{a}pyrene produced a concentration-dependent decrease in cellular survival.

Cell Immunol, 1984 Sep, 87(2), 528 - 37
Separate transfer of mouse protection and delayed-type hypersensitivity with Salmonella typhimurium transfer factor; Kita E et al.; Delayed-type hypersensitivity (DTH) induced with Salmonella typhimurium transfer factor (TF) contributed to an increase in mean survival days of mice challenged with homologous organisms and afforded only a low level of host protection as determined by survival rate, compared with that obtained by active immunization . TF of other enteric bacteria could transfer DTH which is cross-reactive to salmonella antigen but did not afford host protection . Although TF of Listeria monocytogenes did not transfer the cross-reactive DTH, it could confer the significant increase in mean survival days against the lethal challenge with S . typhimurium . Listerial ribosomal vaccine conferred the high level of mouse protection without inducing DTH to salmonella antigen . The resistance generated upon active immunization with listerial ribosomal vaccine could be enhanced by the injection of S . typhimurium TF to the same level as that obtained after immunization with homologous ribosomal vaccine . Among salmonella TF, there could be no cross-reactive immunity between S . typhimurium and S . choleraesuis, although the cross-reactive DTH was observed . The DTH transfer ability of TF was sensitive to Pronase which could not affect the ability to transfer host immunity, but RNase could abolish the ability to transfer host immunity without impairing DTH transfer activity . These results suggest that in mouse typhoid infection, DTH is not associated with host protection as determined by survival rate.

J Immunol, 1984 Sep, 133(3), 1190 - 6
Differences in delayed-type hypersensitivity responses in various mouse strains in the C3H lineage infected with Salmonella typhimurium, strain SL3235; Killar LM et al.; Immunization with a virulent Salmonella typhimurium, strain SL3235, has been found to provide high levels of protection against challenge with virulent Salmonella in hypersusceptible mouse strains in the C3H lineage . These mouse strains include the lipopolysaccharide-hyporesponsive C3/HeJ mouse and the closely related but lipopolysaccharide-responsive C3HeB/FeJ mouse . To assess the role of cellular immunity in the protection elicited by this attentuated organism, delayed-type hypersensitivity (DTH) was measured in these mouse strains and in inherently resistant mice . Of the mouse strains tested, only the inherently resistant CD-1 and C3H/HeNCrlBR mice developed significant DTH responses, as assessed by footpad swelling tested at various times after immunization with SL3235 . The hypersusceptible C3H/HeJ and C3HeB/FeJ mice failed to exhibit significant DTH responses despite their high levels of immunity.

Chem Biol Interact, 1984 Sep 1, 51(1), 49 - 62
Mutagenic activity of possible metabolites of 4-nitrobiphenyl ether; Miyauchi M et al.; A series of possible metabolites--4-nitrosobiphenyl ether (4-NO), 4-hydroxylaminobiphenyl ether (4-NHOH), 4-aminobiphenyl ether (4-NH2), 4-hydroxyacetylaminobiphenyl ether (4-N(OH)Ac), 4-acetoxyacetylaminobiphenyl ether (4-N(OAc)Ac)involved in the toxic effects of 4-nitrobiphenyl ether (4-NO2) was synthesized and tested for mutagenic activity toward Salmonella typhimurium TA100 strain in the presence and the absence of liver homogenates of guinea pig treated with Kaneclor-500 . 4-NO2, 4-NO and 4-NHOH showed direct-acting mutagenicity . 4-NO and 4-NHOH showed high mutagenic activity, while the mutagenic activity of 4-NO2 was very weak compared to 4-NO and 4-NHOH . 4-NO showed antimicrobial action at high concentrations . The other three compounds tested induced no mutation . Upon addition of NAD(P)H, the mutagenic activities of 4-NO and 4-NHOH were slightly enhanced, but no enhancement was observed by addition of NAD(P)+ . Metabolic activation with guinea pig liver homogenates enhanced the mutagenic activities of 4-NO2 and 4-NO, and converted 4-NH2, 4-N(OH)Ac and 4-N(OAc)Ac to the product(s) responsible for the mutagenic activity . Addition of bis(p-nitrophenyl)phosphate, a deacetylase inhibitor, inhibited the mutagenic activities of 4-N(OH)Ac and 4-N(OAc)Ac by about 70% in the presence of NADPH and about 77% in the absence of NADPH . High performance liquid chromatography (HPLC) analysis of non-enzymatic conversion-products of 4-NHOH and 4-BO with and without NADPH indicated that 4-NHOH disappeared after 30 min of incubation and was converted completely to 4-NO without NADPH, while with NADPH, 4-NHOH disappeared very slowly and was detected even after 4 h of incubation . In the case of 4-NO, no decrease of 4-NO was observed without NADPH, while with NADPH 4-NO decreased quickly and a significant amount of 4-NHOH appeared . The mechanism of the NAD(P)H-dependent increase in mutagenicity is also discussed.

J Pediatr Gastroenterol Nutr, 1984 Sep, 3(4), 585 - 92
Studies with enterotoxigenic microorganisms: effects of candidate antidiarrhoeals in experimental animals in vivo; Burke V et al.; Chlorpromazine or aspirin alone, when given to rats parenterally, reduced intestinal fluid secretion induced by cell-free preparations of enterotoxigenic organisms including Escherichia coli, Aeromonas hydrophila, Staphylococcus pyogenes, and Salmonella typhimurium . A combination of chlorpromazine-aspirin given parenterally caused much more marked reduction of fluid secretion . Indomethacin also had significant antisecretory effects against a range of bacterial enterotoxins, while loperamide was effective against heat-labile toxin (LT)-positive E . coli and A . hydrophila . Nicotinamide increased net fluid absorption in the presence of E . coli LT, A . hydrophila, and S . typhimurium . Of the adsorbents tested, aluminum hydroxide showed a positive effect only with E . coli LT and A . hydrophila, while cholestyramine affected net fluid flux only with E . coli ST (heat-stable toxin) . Charcoal was effective against all microorganisms tested but only when premixed with the perfusate before the experiments . Aspirin and chlorpromazine probably act at multiple sites to decrease intestinal secretion, and the combination of low doses of these drugs with possibly different sites of action may have advantages over a single agent used in high dosage.

Genetics, 1984 Sep, 108(1), 1 - 23
Functional interchangeability of DNA replication genes in Salmonella typhimurium and Escherichia coli demonstrated by a general complementation procedure; Maurer R et al.; Twenty-four genes from Salmonella typhimurium that affect DNA replication were isolated from a lambda-Salmonella genomic library by lysogenic complementation of temperature-sensitive mutants of Salmonella or E . coli, using a new plaque complementation assay . The complementing lambda clones, which make red plaques in this assay, and noncomplementing mutant derivatives, which make uncolored plaques, were used to further characterize the temperature-sensitive Salmonella mutants and to establish the functional similarity of E . coli and Salmonella DNA replication genes . For 17 of 18 E . coli mutants representing distinct loci, a Salmonella gene that complemented the mutant was found . This result indicates that single Salmonella replication proteins are able to function in otherwise all E . coli replication complexes and suggests that the detailed properties of Salmonella and E . coli replication proteins are very similar . The other seven Salmonella genes that were cloned were unrelated functionally to any E . coli genes examined . --As an aid to the derivation of chromosomal mutations affecting some of the cloned genes, a general method was developed for placing a transposon in the Salmonella chromosome in a segment corresponding to cloned DNA . Chromosomal mutations were derived in Salmonella affecting a gene (dnaA) that was cloned by complementation of an E . coli mutant by using the transposon-encoded drug resistance as a selectable marker in local mutagenesis.

J Infect Dis, 1984 Sep, 150(3), 425 - 35
Immunity to infection with Salmonella typhimurium: mouse-strain differences in vaccine- and serum-mediated protection; Eisenstein TK et al.; Three mouse strains in the C3H lineage--C3H/HeJ, C3HeB/FeJ, and C3H/HeNCr1BR--were tested for their ability to be protected against infection with Salmonella typhimurium by a panel of nonviable vaccines and by passive transfer of hyperimmune serum . These strains differ in their innate susceptibilities to infection with S . typhimurium, but all are histocompatible . The same vaccines showed a widely different ability to protect different mouse strains . Ability to protect was not closely related to the capacity of the mice to make either agglutinating or anti-O antibody (as shown by ELISA) in response to a particular vaccine . Passive transfer of antibody was shown to protect inherently resistant mice but not inherently susceptible strains . These observations suggest that reported discrepancies in vaccine efficacy among laboratories may be attributable to differences in the mouse strains used and raise the question as to what might be an appropriate mouse model for human infections with Salmonella species.

J Antimicrob Chemother, 1984 Sep, 14 Suppl B, 153 - 9
Severe multiresistant Salmonella typhimurium systemic infections in Central Africa--clinical features and treatment in a paediatric department; Lepage P et al.; During a 21-month period, we observed an outbreak of severe systemic infections due to multiresistant Salmonella typhimurium among 66 children in the in-patient Department of Paediatrics of Kigali, Rwanda . These infections were more likely to occur in subjects who had stayed for a long time in the hospital for severe illness and/or malnutrition . The children usually presented first with mild to moderate diarrhoea and fever . Later, sever pulmonary involvement was often noted (rales: 58%; respiratory distress: 42%) . Moreover, there were four cases of abscess, three arthritis and one meningitis . Of the 66 children, 48 were treated with cefotaxime . The fatality-rate among this group was 10.4% . The fatality-rate among the 18 other untreated patients was 77.9%, suggesting a high efficiency of cefotaxime against these strains of multiresistant Salm . typhimurium.

J Bacteriol, 1984 Sep, 159(3), 951 - 7
Regulation of Salmonella typhimurium ilvYC genes; Blazey DL et al.; The Salmonella typhimurium LT2 ilvYC genes were studied by fusion of each gene to the Escherichia coli K-12 galK gene . The expression of ilvY and ilvC could then be determined by measurement of the galK-encoded galactokinase enzyme . The promoter for ilvC, pC, was located by this technique to a 0.42-kilobase BglII-EcoRI fragment of the S . typhimurium ilvGEDAYC gene cluster . This sequence was completely sufficient for alpha-acetohydroxyacid-inducible galK expression . The ilvY gene was located within a 1.0-kilobase XhoI-SalI fragment . ilvY gene expression was constitutive with respect to ilv-specific control signals . The ilvY gene was transcribed in the same direction as the other two transcriptional units in the ilvGEDAYC gene cluster, ilvGEDA and ilvC . Transcription of the ilvC gene was completely dependent upon the activity of its own promoter, pC, and independent from transcription of the ilvY gene . The role of the intervening region between ilvY and ilvC in regulation of ilvC expression was explored.

J Bacteriol, 1984 Sep, 159(3), 1000 - 5
Analysis of promoter mutations in the histidine transport operon of Salmonella typhimurium: use of hybrid M13 bacteriophages for cloning, transformation, and sequencing; Lee GS et al.; Mutations that cause an increased level of expression of the histidine transport operon were isolated and characterized genetically . Five independently isolated promoter-up mutations were transferred to an M13 hybrid phage that carries the histidine transport operon, and their nucleotide sequences were determined . For all five mutations, the change was the same as the one previously determined for promoter-up mutation dhuA1: a C-to-T change in the Pribnow box rendered this region more homologous to the consensus sequence . Methods for enabling Salmonella typhimurium to support growth of M13 phage effectively and for easy transfer of chromosomal mutations onto the hybrid phage are presented.

Genetics, 1984 Sep, 108(1), 25 - 38
Genetic analysis of DNA replication in bacteria: dnaB mutations that suppress dnaC mutations and dnaQ mutations that suppress dnaE mutations in Salmonella typhimurium; Maurer R et al.; We have isolated and characterized extragenic suppressors of mutations in two different target genes that affect DNA replication in Salmonella typhimurium . Both the target and the suppressor genes are functional homologues of known replication genes of E . coli that were identified in intergeneric complementation tests . Our results point to interactions in vivo involving the dnaB and dnaC proteins in one case and the dnaQ and dnaE proteins in the other case . The suppressor mutations, which were isolated as derivatives of lambda-Salmonella in vitro recombinants, were detected by an adaptation of the red plaque complementation assay . This method was applicable even when the locus of suppressor mutations was not chosen in advance.

Med J Aust, 1984 Aug 18, 141(4), 217 - 9
Salmonella food poisoning; Keogh AM et al.; During an outbreak of Salmonella typhimurium food poisoning in September 1983, in Sydney, 10 affected subjects were admitted to the same hospital . On admission to hospital, all patients were severely dehydrated; two patients developed acute tubular necrosis, while a third patient had myopericarditis . Bacteraemia was confirmed in two patients, in one of whom no organisms were isolated from stool cultures . Antibiotic agents were administered to all patients, because of the unusually severe nature of the infection . This outbreak illustrates that salmonella gastroenteritis, although usually fairly mild and self-limiting, can be a virulent disease resulting in serious complications . Appropriate management should include careful initial assessment of suspected cases, vigorous correction of fluid and electrolyte disturbances, and judicious use of antibiotic agents when bacteraemia or severe toxaemic features are present.

Mutat Res, 1984 Aug, 130(4), 267 - 72
Depletion of the reduced glutathione level in the liver and production of the mutagens in the intestine in the mice inducing hepatoma by feeding on a high level dose of sorbic acid; Tsuchiya T et al.; Mutagenicity was detected using Salmonella typhimurium TA98 in the acidic components of the intestinal contents of mice, in which a high incidence of hepatoma had been reported due to feeding on a diet containing 15% sorbic acid (Ishizawa et al., 1980) . Furthermore, the glutathione level in the liver of the 15% sorbic acid group was decreased to 40% of the amount found in controls after a 3-month feeding period, and this low level was maintained for long periods (12 months) until the end of the experiments . There was also a close correlation between the extent of depletion of the hepato-glutathione level and the concentration of sorbic acid added to the diet . Consequently, the hepatoma which developed in mice fed a 15% sorbic acid diet was considered to be induced both by the depletion of the hepato-glutathione level over the long periods, and by the gradual production of various mutagens in the intestine which were absorbed and transferred to liver to be metabolically activated.

Infect Immun, 1984 Aug, 45(2), 332 - 8
Zinc concentration and survival in rats infected with Salmonella typhimurium; Tocco-Bradley R et al.; Percent survival was measured in male rats injected intravenously with live Salmonella typhimurium when plasma and tissue zinc levels were manipulated . Alzet pumps implanted intraperitoneally infused zinc gluconate or sodium gluconate (controls) from the onset of infection to 72 h postinfection . Plasma and tissue zinc levels were manipulated by infusing (i) 180 micrograms of Zn per h to achieve supranormal plasma and tissue zinc concentrations, (ii) 120 micrograms of Zn per h to prevent the infection-induced fall and to maintain plasma zinc levels at noninfection levels while raising tissue levels above that of infected controls, and (iii) 30 micrograms of Zn per h to increase tissue zinc levels while allowing the infection-induced decrease in plasma zinc . Preventing the fall in plasma zinc while raising liver zinc to supranormal levels enhanced rather than reduced percent survival; raising plasma and liver zinc to supranormal levels returned survival to control levels . Loading the liver with an excess of zinc without changing plasma zinc (30 micrograms of Zn per h) did not increase percent survival in the infected host . Pretreatment or administration of zinc at the time of infection led to increased percent survival compared with administration of zinc 4 h after the onset of infection.

Genetika, 1984 Aug, 20(8), 1270 - 8
{Genetic activity of base analogs in Salmonella typhimurium and Escherichia coli and Saccharomyces cerevisiae}; Pavlov IuI et al.; The study of 6-N-hydroxylaminopurine (HAP) and 2-amino-6-N-hydroxylaminopurine (AHAP) activity in bacteria and the yeast was undertaken . AHAP was found to be more effective as a mutagen in bacteria and HAP--in the yeast . Mutagenic and lethal effects or analogues were independent of excision and mutagenic repair both in bacteria and the yeast . Deletion in uvrB region of Salmonella genome leads to hypersensitivity to lethal and mutagenic action of analogues . Both of the latter only cause reversions of base-substitution but not frameshift mutations . Considering the data obtained and the information from published papers, we proposed that HAP and AHAP exert their mutagenic action, like classical analogues, by means of incorporation into DNA and disturbing the regular replication laws.

Mutat Res, 1984 Aug-Sep, 137(2-3), 79 - 88
Lack of mutagenicity of diphenylhydantoin in in vitro short-term tests; Leonard A et al.; The mutagenicity of diphenylhydantoin (DPH) and its major metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin (HPPH), has been re-evaluated by the Ames test using Salmonella typhimurium and, for DPH only, by an in vitro cytogenetic test with human lymphocytes and a turbidimetric assay of tubulin polymerization . As negative results were obtained in all test systems used here, one has to conclude that DPH is devoid of mutagenic properties.

Toxicology, 1984 Aug, 32(2), 117 - 30
Metabolism, DNA binding, and cytotoxicity of aflatoxin B1 in tracheal explants from Syrian hamster; Coulombe RA Jr et al.; Metabolism, DNA binding and cytopathological effects of aflatoxin B1 (AFB1) were studied in isolated tracheal explants from Syrian golden hamsters . Explants were exposed to 0.1, 0.5 and 1.0 microM {14C}AFB1 in Dulbeccos's modified Eagle medium for 24 h, then analyzed for AFB1-DNA binding and AFB1 metabolism . Binding (pmol AFB1/mg DNA) was dose-related (16.3 +/- 1.9 to 180.8 +/- 16.1) and analysis of the culture medium revealed the metabolic conversion products aflatoxicol (AFL) and aflatoxin Q1 (AFQ1) . Ultrastructural analysis of sections of tracheal epithelium revealed degenerative changes primarily in the non-ciliated epithelial cells . Autoradiographic analysis of the same treated explants, however, showed no discernible distribution of label with respect to either cell type or cell location, with the exception of increased grain densities overlying vacuoles containing dark droplets . In addition, S9 prepared from hamster trachea was shown to activate AFB1 to mutagens detectable by Salmonella typhimurium TA 98, but was approximately 70 times less active on a per mg protein basis than was S9 prepared from hamster liver . These results demonstrate the metabolic capabilities of tracheal epithelial cells in the activation of AFB1, thus indicating that AFB1 present in respiratory particles may be activated by pulmonary mixed-function oxidases, posing a hazard to those exposed.

J Environ Sci Health B, 1984 Aug, 19(6), 565 - 77
Genotoxicity of methyl parathion in short-term bacterial test systems; Rashid KA et al.; Genotoxicity of the insecticide methyl parathion was investigated in Salmonella typhimurium and Escherichia coli bacterial test systems for the detection of back mutations and DNA-damage . Methyl parathion was mutagenic to S . typhimurium strain TA100 after activation with rat liver microsomal and cytosolic enzymes . In DNA repair tests, methyl parathion was effective in inducing damage to the S . typhimurium strain TA1538 which lack excision repair compared to the strain TA1978 which is proficient in excision repair mechanisms . Normal laboratory light conditions had no effect on the mutagenicity tests, however, exposure of methyl parathion in the petri dish containing the tester strain TA100 and rat liver microsomal and cytosolic enzymes reduced the mutagenic activity and increased the toxic effects of methyl parathion.

Zentralbl Bakteriol Mikrobiol Hyg {A}, 1984 Aug, 257(3), 414 - 25
{Protection against experimental Salmonella typhimurium infection in mice . Immunostimulating activity of heterologous Salmonella S-forms, R-mutants, lipopolysaccharides and muramyl dipeptide in vaccines combined with S . typhimurium}; Schlecht S; In vaccines consisting of acetone-killed Salmonella, 90% of the bacteria were replaced by: heterologous Salmonella S-forms, R-mutants of Salmonella or Escherichia coli, lipopolysaccharide from S . typhimurium (S-form) or from R-mutants of Salmonella or E . coli and by muramyl dipeptide . Active immunizations of NMRI mice with these vaccines were undertaken . Mice received two intraperitoneal injections of the vaccines at intervals of 14 days, and were challenged with various doses of S . typhimurium C5 10 days later . The protective capacity of the mixed vaccines was compared with that of monovaccines (S . typhimurium) and with the effectiveness of vaccines consisting of the supplementing component (relatively weak immunizing ability) alone . The LD50 served as criterion for protective capacity . The results showed that S . typhimurium S-form could be replaced by Salmonella R-mutants belonging to different chemotypes without a recognizable decrease in protective immunizing capacity of the vaccines . Effective vaccines were also attained when heterologous Salmonella S-forms, which exhibit no O-antigenic determinants in common with S . typhimurium, were used as supplements . Mixtures with E . coli R-mutants proved to be less effective . In addition, the diminished dose of S . typhimurium could be so effectively supplemented with lipopolysaccharide from S . minnesota R 595 that complete protection was achieved . In contrast, comparable doses of R lipopolysaccharides from E . coli were somewhat less effective . Vaccines of LPS-extracted bacteria exhibited a reduced protective capacity and were ineffective when used as supplements in mixed vaccines . Analogous results were obtained when R-mutants served as basic vaccines in place of the S . typhimurium S-form indicating that an immunogenic component is enhanced in these organisms too and that their immunogenic capacity is not brought about barely by general stimulation of the immune system . However, the full effectiveness of the R-monovaccines was often not attained with supplements . Immunization with mixed vaccines of S . typhimurium S-form and heterologous Salmonella S-forms or Salmonella R-mutants led to equally high agglutinin and haemagglutinin titers as those obtained with monovaccines of S . typhimurium S-form.

Sci Total Environ, 1984 Aug 1, 37(2-3), 171 - 6
Chlorination of ozonated soil fulvic acid: mutagenicity studies in Salmonella; Kowbel DJ et al.; Samples of soil fulvic acid (SFA) were ozonated and subsequently chlorinated under acidic or slightly basic conditions . The residues were tested for His+ reversion in a fluctuation assay, using Salmonella typhimurium TA100 as the tester strain . The ozonated/chlorinated samples were mutagenic, but activity was dependent on the amount of ozone utilized and the pH of the reaction medium . Although increases in cell concentrations were also induced by some mutagenic samples, this alone did not account for the mutagenicity observed . Unchlorinated samples displayed insignificant activity.

Mutat Res, 1984 Aug-Sep, 137(2-3), 89 - 93
Mutagenicity of hexachlorobutadiene, perchlorobutenoic acid and perchlorobutenoic acid chloride; Reichert D et al.; Hexachloro(1,3)butadiene (HCBD) is a well known environmental contaminant . The nephrocarcinogenic potential of HCBD has been shown in long-term studies with rats . Experiments were performed to assist in determining whether this effect is mediated by epigenetic or genotoxic mechanisms and to compare the mutagenic properties of HCBD with those of its monooxidation products, perchloro-3-butenoic acid (PCBA) and perchloro-3-butenoic acid chloride (PCBAC), which are conceivable metabolites of HCBD . All 3 compounds are mutagenic to the Salmonella typhimurium tester strain TA100 . The mutagenic effect is dose-dependent and parallels the chemical reactivity of the compounds . HCBD is only mutagenic in the presence of drug-metabolizing enzymes (S9 mix) with an increased protein content . The mutagenic response after incubation with PCBAC and PCBA is 2-3-fold that of HCBD . Additionally, both PCBAC and PCBA exert a mutagenic response in the absence of S9 mix . The experiments support the assumption of a genotoxic potential of HCBD.

Mutat Res, 1984 Aug-Sep, 137(2-3), 71 - 8
The mutagenicity on Salmonella typhimurium of nitrobenzoic acids and other wastewater components generated in the production of nitrobenzoic acids and nitrotoluenes; Sundvall A et al.; The wastewater contained mutagens which induced mutations in Salmonella typhimurium TA1535, TA1538, TA98 and TA100 . By the use of nitroreductase-proficient and -deficient tester strains, it was possible to demonstrate that the mutagens were to a great extent aromatic nitro compounds . 30-40% of the mutagenicity could be related to the 16 identified nitroaromatic compounds . Although 13 of these induced mutations, one single compound, 3,5-dinitrobenzoic acid, was responsible for more than 80% of their total mutagenicity . p-Nitrobenzoic acid was used for further studies of the enzymatic nitroreduction leading to the formation of reactive intermediates . The bacterial enzymes and the active metabolites did not seem to be oxygen-sensitive, as the mutagenicity was decreased when anaerobic incubation was applied . The addition of dicoumarol resulted in a decreased effect, indicating that bacterial DT diaphorase or an enzyme with similar properties is responsible at least in part for the activation of this compound . Under our experimental conditions rat-liver enzymes were not able to produce any detectable amounts of mutagenic metabolites of p-nitrobenzoic acid when the nitroreductase-deficient strain TA100NR was used.

Mutat Res, 1984 Aug-Sep, 137(2-3), 133 - 7
Bacterial reversion assay and micronucleus test carried out on hydrogenated glucose syrups 'Malti-Towa' (powder) and maltitol crystal; Takizawa Y et al.; Two preparations of maltitol (4-O-alpha-D-glucopyranosyl-D-sorbitol), hydrogenated glucose syrups and maltitol crystal, were examined for genotoxic potential by a battery of short-term tests . In the bacterial reversion assay, maltitol induced no detectable revertants in any of the tester strains, Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA1538, or Escherichia coli WP2/pKM101 at doses of 0.5-50 mg per plate with and without rat liver S9 mix . In the micronucleus test, no significant increase in the frequency of micronucleated erythrocytes was observed in bone marrow of mice after administration of the two preparations at 3.75-30 g per kg by gastric intubation.

J Infect Dis, 1984 Aug, 150(2), 236 - 41
The significance of hospitals as reservoirs for endemic multiresistant Salmonella typhimurium causing infection in urban Brazilian children; Riley LW et al.; To identify possible sources of multiply drug-resistant Salmonella typhimurium among children in Sao Paulo, Brazil, we reviewed records of 470 children who had visited eight outpatient clinics from March 1981 to May 1982 and of 28 children who had been admitted to one referral hospital between June and November of 1982, and we examined plasmid profiles of the Salmonella isolates by agarose-gel electrophoresis . S . typhimurium was identified in 37 of these children . Case-control studies showed that children with S . typhimurium infections were more likely to have been hospitalized before onset of diarrhea than were either age-matched children without diarrhea (P = .031) or age-matched children with nonbacterial diarrhea (P = .035) . Four distinct plasmid profiles, each of which was temporally clustered, were identified in 20 (67%) of 30 S . typhimurium strains isolated from previously hospitalized children and in two (28%) of seven strains from children not previously hospitalized . Each of three of these four profiles was associated with a different hospital, results suggesting that multiresistant-S . typhimurium infections in Sao Paulo are often nosocomially acquired.

Food Chem Toxicol, 1984 Aug, 22(8), 677 - 9
Evaluation of the genotoxicity of lac dye; Banerjee TS et al.; Red lac dye, a by-product of the shellac industry, has the potential for use in foods, drugs and cosmetics as a colouring agent . As part of a series of tests of the suitability of lac dye for this purpose an evaluation of its genotoxicity was carried out . Lac dye was non-mutagenic in Ames tests using five strains of Salmonella typhimurium with or without metabolic activation . No cytotoxicity or mutagenicity was observed in Chinese hamster lung (V79) cells exposed to lac dye in vitro . A clastogenic effect was observed in the bone-marrow cells of mice that had been treated with lac dye ip or orally.

Toxicol Appl Pharmacol, 1984 Aug, 75(1), 137 - 46
Mutagenicity testing of agent orange components and related chemicals; Mortelmans K et al.; Components of the herbicide Agent Orange--2,4-dichlorophenoxyacetic acid (2,4,-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and their esters, and the contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)--and related chemicals were tested for mutagenicity using Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 . No mutagenic activity was observed for any of the chemicals tested.

J Bacteriol, 1984 Aug, 159(2), 787 - 9
In vitro polymerization of flagellin excreted by a short-flagellum Salmonella typhimurium mutant; Ikeda T et al.; The culture medium of a short-flagellum mutant of Salmonella typhimurium contained a large amount of mutant flagellin and a small amount of strong inhibitors of flagellin polymerization . After being freed of the inhibitors, the mutant flagellin could be polymerized in vitro, although under nonphysiological conditions.

J Bacteriol, 1984 Aug, 159(2), 704 - 12
New Salmonella typhimurium mutants with altered outer membrane permeability; Sukupolvi S et al.; We describe three new classes of Salmonella typhimurium mutants with increased sensitivity to hydrophobic agents . In contrast to many previously described mutants, the phage sensitivity pattern of these mutants did not give any indication of defective lipopolysaccharide . Furthermore, they had no detectable changes in their phospholipid or outer membrane protein composition, and their growth rate and cell morphology were normal . Class B mutants were nearly as sensitive to novobiocin, fusidic acid, erythromycin, rifampin, and clindamycin as are deep rough (heptoseless) mutants; in addition they were sensitive to methicillin, penicillin (to which heptoseless mutants are resistant), gentian violet, and anionic and cationic detergents . Class A and C mutants had less sensitive, but characteristic phenotypes . None of the three classes were sensitive to serum bactericidal action . The class B mutation mapped between map positions 7 and 11 on the S . typhimurium chromosome, and the class C mutation mapped between positions 5 and 7 . The map position for the class A mutation remained undefined, but it was separate from the class B and C mutations and, like those, did not correspond to any gene loci known to participate in the synthesis of major outer membrane constituents.

J Bacteriol, 1984 Aug, 159(2), 663 - 7
Cytochrome o as a terminal oxidase and receptor for aerotaxis in Salmonella typhimurium; Laszlo DJ et al.; Cytochrome o was the only oxidase of the electron transport system that was present in exponentially growing Salmonella typhimurium ST1 . Identification of cytochrome o was made by the (CO-reduced)-minus-(reduced) difference spectra and by the photochemical action spectrum of the relief, by light, of CO-inhibited respiration . Cytochrome o also functioned as the receptor for chemotaxis to oxygen (aerotaxis) . The concentration of oxygen that elicits the maximum response for aerotaxis (0.7 microM) was similar to the Km for respiration (0.74 microM), and both aerotaxis and respiration were blocked 5 mM KCN.

Cancer Res, 1984 Aug, 44(8), 3408 - 13
Identification of trans-1,2-dihydro-1,2-dihydroxy-6-nitrochrysene as a major mutagenic metabolite of 6-nitrochrysene; El-Bayoumy K et al.; Liver 9000 X g supernatant from rats was used to study the metabolism of {6- 14C}nitrochrysene under aerobic conditions . The major ethyl acetate-soluble metabolite (1.06 nmol/mg of protein in 30 min) was identified as 1,2-dihydro-1,2-dihydroxy-6-nitrochrysene, based on its mass, UV, and proton magnetic resonance spectra . Under aerobic conditions, 6-aminochrysene was not detected as a metabolite . However, when incubations were carried out in an atmosphere of 4% O2 in N2, both 1,2-dihydro-1,2-dihydroxy-6-nitrochrysene (0.04 nmol/mg of protein) and 6-aminochrysene (0.05 nmol/mg of protein) were detected . Further metabolism of the 14C-labeled 1,2-dihydro-1,2-dihydroxy-6-nitrochrysene by rat liver 9000 X g supernatant under aerobic conditions gave a major metabolite which was identified tentatively as 1,2-dihydroxy-6-nitrochrysene . The mutagenic activities of 6-nitrochrysene, trans-1,2-dihydro-1,2-dihydroxy-6-nitrochrysene and 6-aminochrysene were assessed in Salmonella typhimurium strains TA100 and TA98 . In the absence of rat liver 9000 X g supernatant, trans-1,2-dihydro-1,2-dihydroxy-6-nitrochrysene was the more potent mutagen in TA100 but, in TA98, it was less active than was 6-nitrochrysene . In the presence of rat liver 9000 X g supernatant, both trans-1,2-dihydro-1,2-dihydroxy-6-nitrochrysene and 6-nitrochrysene were more mutagenic in TA100 than in the assays performed without an activating system, and the dihydrodiol metabolite was more mutagenic than was 6-nitrochrysene . In TA98 with activation, trans-1,2-dihydro-1,2-dihydroxy-6-nitrochrysene, 6-aminochrysene, and 6-nitrochrysene were all mutagenic . The results of this study indicate that trans-1,2-dihydro-1,2-dihydroxy-6-nitrochrysene is a major proximate mutagen of 6-nitrochrysene in S . typhimurium TA100.

J Immunol, 1984 Aug, 133(2), 988 - 92
IgA-dependent cell-mediated activity against enteropathogenic bacteria: distribution, specificity, and characterization of the effector cells; Tagliabue A et al.; Antibody-dependent cellular cytotoxicity (ADCC) against murine enteropathogenic bacteria such as Salmonella typhimurium and Salmonella tel aviv or Shigella X16 was assessed by using IgG, IgA, and secretory IgA (sIgA) in a 2-hr in vitro assay where peripheral and intestinal lymphocytes were used as effector cells . It was found that IgG could arm splenocytes (SpL) better than IgA . However, IgG did not arm lymphocytes from Peyer's patches (PPL) or from mesenteric lymph nodes (MnL), whereas IgA of plasmacytoma origin against S . tel aviv and purified intestinal sIgA against Shigella X16 induced specific antibacterial ADCC with both SpL and PPL . When sIgA were tested with intestinal lymphocytes from the epithelium and the lamina propria, i.e., cells from the gut mucosa which first interact with enteric bacteria, it was found that both these lymphoid populations were able to express sIgA-dependent ADCC against Shigella X16 . In parallel tests, cells from thymus and popliteal lymph nodes failed to express ADCC . Blocking studies with purified IgG and IgA of goat, rabbit, and mouse origin demonstrated that the Fc-alpha and Fc-gamma receptors were specifically involved in IgA- or IgG-dependent antibacterial ADCC . At least two effector populations, a macrophage and a Thy-1.2- lymphocyte, were observed to exert IgA-ADCC at the splenic level, whereas only lymphoid cells expressed this activity at the GALT level . Together, these results describe a new activity of IgA against enteropathogenic bacteria.

Mutat Res, 1984 Aug, 140(4), 169 - 74
Structure-dependent variation in the mutagenic, prophage-inducing and antibacterial activities of 5-nitro-2-furamide derivatives; Kato Y et al.; A comparative survey of the mutagenic, prophage-inducing and antibacterial activities of 3 structure-related series of 5-nitro-furan derivatives including 5-nitro-2-furohydrazide imide, 5-nitro-2-furamide oxime and 5-nitro-2-furohydrazide has been undertaken . Among the compounds assayed, the 5-nitro-2-furohydrazide imide series was found to be most active with regard to mutagenic and antibacterial activities against Salmonella typhimurium TA100 and prophage-inducing activity in Escherichia coli GY5027 . A clear correlation was observed between the chemical structure and the mutagenic and prophage-inducing activities which were approximately correlated to the antibacterial activity.

J Immunol, 1984 Aug, 133(2), 950 - 7
Monoclonal antibodies to Salmonella lipopolysaccharide: anti-O-polysaccharide antibodies protect C3H mice against challenge with virulent Salmonella typhimurium; Colwell DE et al.; The present investigation reports the production of monoclonal antibodies to antigenic determinants of the O-polysaccharide of Salmonella typhimurium lipopolysaccharide (LPS), and assesses the effectiveness of these antibodies in protecting C3H mice against the lethal effects of Salmonella infection . Hybridomas were generated by fusing spleen cells from (BALB/c X A/J)F1 (CAF1) mice hyperimmunized by i.v . injection with acetone-killed S . typhimurium SR-11 with X63-Ag8.653 murine myeloma cells . Hybridomas producing antibodies reactive with S . typhimurium SR-11 whole cells were subcloned, and seven of the resulting clones as well as one previously described clone were selected for use in the studies reported here . Monoclonal antibodies from these eight clones were of the IgG1 (1), IgG3 (6), or IgM (1) isotype and were specific for the O-polysaccharide region of Salmonella LPS, reacting with LPS from smooth S . typhimurium SR-11 and LT-2, but not with LPS from rough S . minnesota R60 (Ra), R345 (Rb), or R595 (Re) . The effectiveness of each monoclonal antibody in protecting C3H/HeN and C3H/HeJ mice against the lethal effects of Salmonella infection was evaluated by comparing the median length of survival of groups of mice given antibody by i.p . injection before i.p . challenge with virulent S . typhimurium SR-11 to that of animals that received no antibody . Three out of eight monoclonal anti-O-polysaccharide antibodies, ST-1 (IgM), 10-5-47 (IgG3), and 10-5-6 (IgG3), provided significant (p less than 0.01) protection to C3H/HeN mice challenged with approximately 10(4) LD100 of Salmonella . Only antibodies ST-1 and 10-5-6, however, extended the median length of survival of C3H/HeJ mice beyond that of infected controls . Mouse antiserum prepared against S . typhimurium SR-11 was equally protective in C3H/HeJ mice . In an attempt to understand the contribution of antibody specificity to the relative differences in the protective capacities of the monoclonal antibodies, their reactivities with several Salmonella reference strains of different classical serotypes were examined . Although some differences in reactivity against the different strains were apparent, this approach was not adequate for defining the fine specificity of these monoclonal antibodies . The results of this study provide evidence that monoclonal antibodies with specificity to the O-polysaccharide region of Salmonella LPS can protect C3H mice against challenge with the homologous bacterial strain.

Can J Microbiol, 1984 Aug, 30(8), 991 - 6
Evidence for involvement of pyrH+ of an Escherichia coli K-12 F-prime factor in inhibiting construction of hybrid merodiploids with Salmonella typhimurium; Kelln RA; Transconjugants were not recovered in matings between Salmonella typhimurium and Escherichia coli K-12 strains carrying the chromosomal region between leu and argF on an F-prime factor, even when a restriction-deficient recipient was used . A mutant F-prime factor compatible for transfer to S . typhimurium was constructed by transposon mutagenesis and characterized as being deficient in directing the synthesis of UMP kinase (encoded by pyrH) . Other compatible F-prime factors were readily constructed by employing a procedure designed to select for strains carrying F-prime factors harboring pyrH mutations.

EMBO J, 1984 Aug, 3(8), 1745 - 52
The genetic control of DNA supercoiling in Salmonella typhimurium; Richardson SM et al.; We have elucidated the genetic control of DNA supercoiling in Salmonella typhimurium . The level of superhelix density is controlled by two classes of genes . The only member of the first class is topA, the structural gene for topoisomerase I . The second class, tos, (topoisomerase one suppressor) consists of at least two genes, one of which is linked to gyrA, the structural gene for the topoisomerase subunit of DNA gyrase . Deletions of topA result in oversupercoiling of plasmid DNA . These mutations do not require the acquisition of second-site compensatory mutations to allow cell growth, in contrast to the situation in Escherichia coli . However, tos mutations, unlinked to topA, have been isolated which reduce plasmid superhelix density . We conclude that the level of DNA supercoiling in S . typhimurium is a dynamic balance between the effects of the gene products of topA (relaxation) and tos (supercoiling) which act independently of each other . Using a variety of combinations of these mutations we have constructed a series of isogenic strains, each of which has a different but precisely defined level of plasmid supercoiling; the series as a whole provides a wide range of supercoiling both above and below the wild-type level.

Pediatr Res, 1984 Aug, 18(8), 789 - 94
Neutrophil bactericidal dysfunction towards oxidant radical-sensitive microorganisms during experimental iron deficiency; Moore LL et al.; We developed a clear-cut nutritional iron deficiency anemia without concomittant malnutrition in rats given a low iron diet, and we restored normal iron and hemoglobin levels in these same animals with iron dextran injections . The neutrophil function studies performed during and after a period of iron deficiency showed the following: Phagocytosis of Staphylococcus aureus 502A, Streptococcus pneumoniae, and Salmonella typhimurium was not altered by iron deficiency or by the administration of iron; phagocytosis of Candida albicans was moderately abnormal during iron deficiency, and became normal with the restoration of iron sufficiency . Microbicidal activity towards Staphylococcus aureus 502A and Candida albicans, two catalase-positive microorganisms, was markedly decreased (to 50% of control values) and returned to normal when iron sufficiency was restored . Killing of a catalase-negative organism, Streptococcus pneumoniae was normal in iron-deficient rats . This pattern of differential bactericidal activities suggested an abnormality of the oxidant radical-generating machinery in neutrophils of iron-deficient animals . Indeed, iron deficiency caused a marked decrease of neutrophil nitroblue tetrazolium dye reduction, which disappeared after iron administration . Neutrophil myeloperoxidase activity was slightly decreased in iron deficient rats and returned to normal after iron administration . Microbicidal activity towards a gram-negative, catalase-positive organism, Salmonella typhimurium, was equal in iron deficient and iron sufficient animals . Our combined results suggest that a definite microbicidal defect is the consequence of nutritional iron deficiency, apart from any protein-calorie malnutrition . This defect affects the disposal in PMNs of two catalase-positive microorganisms (which require intracellular production of oxidant radicals for their destruction) but not of a catalase-negative bacterial species.(ABSTRACT TRUNCATED AT 250 WORDS)

J Bacteriol, 1984 Aug, 159(2), 618 - 23
Location and analysis of nucleotide sequences at one end of a putative lac transposon in the Escherichia coli chromosome; Buvinger WE et al.; A segment of Escherichia coli DNA that contained a discontinuity of homology with Salmonella typhimurium DNA was isolated . The segment, 1,430 base pairs long, was derived from one end of the lac "loop," a region of about 12 kilobase pairs of E . coli DNA, including the lac operon which has no detectable homology with S . typhimurium DNA (K . Lampel and M . Riley, Mol . Gen . Genet . 186:82-86, 1982) . The nucleotide sequence of the 1,430-base-pair segment of DNA was determined . The location of the junction of discontinuity of homology within the segment was established by hybridization experiments . Nucleotide sequences at or near the junction were determined to be similar to sequences that are involved in site-specific inversion in S . typhimurium, E . coli, phage P1, and phage Mu . Similar sequences are also present within the terminal inverted repeat sequences of transposon Tn5 and at the V-D-J joining sequences of eucaryotic immunoglobulin genes . Therefore, the lac operon, together with flanking DNA, may have been inserted into the E . coli chromosome at one time via a site-specific recombination event . Rearrangement events of this kind undoubtedly have played a significant role in the evolutionary divergence of chromosomal DNAs.

J Bacteriol, 1984 Aug, 159(2), 453 - 9
Aspartate-specific peptidases in Salmonella typhimurium: mutants deficient in peptidase E; Carter TH et al.; The only dipeptide found to serve as a leucine source for a Salmonella strain lacking peptidases N, A, B, D, P, and Q was alpha-L-aspartyl-L-leucine . A peptidase (peptidase E) that specifically hydrolyzes Asp-X peptides was identified and partially purified from cell extracts . The enzyme (molecular weight, 35,000) is inactive toward dipeptides with N-terminal asparagine or glutamic acid . Mutants (pepE) lacking this enzyme were isolated by screening extracts for loss of the activity . Genetic mapping placed the pepE locus at 91.5 map units and established the gene order metA pepE zja-861::Tn5 malB . Duplications of the pepE locus showed a gene dosage effect on levels of peptidase E, suggesting that pepE is the structural gene for this enzyme . Mutations in pepE resulted in the loss of the ability to grow on Asp-Pro as a proline source but did not affect utilization of other dipeptides with N-terminal aspartic acid . Loss of peptidase E did not cause a detectable impairment in protein degradation . Two other peptidases present in cell extracts of mutants lacking peptidases N, A, B, D, P, Q, and E also hydrolyze many Asp-X dipeptides.

J Biol Chem, 1984 Jul 25, 259(14), 8753 - 7
The sulfonylurea herbicide sulfometuron methyl is an extremely potent and selective inhibitor of acetolactate synthase in Salmonella typhimurium; LaRossa RA et al.; The sulfonylurea herbicide sulfometuron methyl inhibits the growth of several bacterial species . In the presence of L-valine, sulfometuron methyl inhibits Salmonella typhimurium, this inhibition can be reversed by L-isoleucine . Reversal of growth retardation by L-isoleucine, accumulation of guanosine 5'-diphosphate 3'-diphosphate (magic spot), and relA mutant hypersensitivity suggest sulfometuron methyl interference with branched-chain amino acid biosynthesis . Growth inhibition of S . typhimurium is mediated by sulfometuron methyl's inhibition of acetolactate synthase, the first common enzyme in the branched-chain amino acid biosynthetic pathway . Sulfometuron methyl exhibits slow-binding inhibition of acetolactate synthase isozyme II from S . typhimurium with an initial Ki of 660 +/- 60 nM and a final, steady-state Ki of 65 +/- 25 nM . Inhibition of acetolactate synthase by sulfometuron methyl is substantially more rapid (10 times) in the presence of pyruvate with a maximal first-order rate constant for conversion from initial to final steady-state inhibition of 0.25 +/- 0.07 min-1 (minimal half-time of 2.8 min) . Mutants of S . typhimurium able to grow in the presence of sulfometuron methyl were obtained . They have acetolactate synthase activity that is insensitive to sulfometuron methyl because of mutations in or near ilvG, the structural gene for acetolactate synthase isozyme II.

J Mol Biol, 1984 Jul 25, 177(1), 1 - 18
A repetitive DNA sequence, rhs, responsible for duplications within the Escherichia coli K-12 chromosome; Lin RJ et al.; A novel family of large, imperfectly repeated DNA sequences has been found in Escherichia coli . Two members of this family, rhsA and rhsB, occur as direct repeats, flanking the pit glyS xyl segment of the chromosome . Unequal sister-chromatid crossing over between rhsA and rhsB accounts for the frequent tandem duplication of the glyS locus that has been observed by various workers . This unequal recombination is recA-dependent . The rhsA locus is operationally defined as the segment between xyl and mtl that is repeated at other chromosomal locations . Using this definition, rhsA extends minimally 5500 base-pairs; 3800 base-pairs of rhsA are sufficiently homologous to rhsB to form an S1 nuclease-resistant heteroduplex with it . The rhsA sequence also exhibits internal repetition . At least one additional rhs sequence occurs in the E . coli chromosome unlinked to either rhsA or rhsB . Southern analysis of restriction digests of genomic DNA from E . coli strains C and B/5 showed that both of these strains have rhs hybridizable patterns similar to strain K-12, but the rhs sequence is absent in Salmonella typhimurium . The function of the rhs sequences has not been discovered . In the course of this work we developed a technique, termed "transductional walking", by which chromosomal DNA adjacent to a previously cloned DNA segment can be cloned through genetic procedures.

Carcinogenesis, 1984 Jul, 5(7), 853 - 6
Mutagenicity of gastric juice: the importance of controlling histidine concentration when using Salmonella tester strains; O'Connor HJ et al.; The mutagenic activity of gastric juice has been assessed using bacterial tester strains that undergo reverse mutation (Salmonella typhimurium:his(-)----his(+)) . Free histidine, a known source of inaccuracy in this mutation test system, was detected in 42 of 73 juice samples (concentration range 3.5-992.4 micrograms/ml); high histidine concentrations were significantly correlated with hypochlorhydria . The effect of histidine was controlled by using a pre-incubation modification of the Salmonella fluctuation test in which juice samples and their corresponding control cultures containing equivalent amounts of histidine were incubated with the tester bacteria prior to plating out . Significant mutagenic activity was found in a high proportion of samples (18 of 20) . The histidine content in gastric juice which can affect in vitro mutagenicity testing must be adequately controlled before positive or negative results can be equated with the presence or absence of intragastric carcinogens.

Xenobiotica, 1984 Jul, 14(7), 545 - 8
Glutathione transferase-mediated and non-enzymatic activation and detoxication of the N-hydroxy derivative of Trp-P-2, a potent pyrolysate promutagen; Saito K et al.; Glutathione (GSH) transferase-mediated and non-enzymatic activation and detoxication of 3-hydroxyamino-1-methyl-5H-pyrido{4,3-b}indole (N-OH-Trp-P-2) were studied in vitro . N-OH-Trp-P-2 is an active metabolite of 3-amino-1-methyl-5H-pyrido{4,3-b}indole (Trp-P-2), a mutagenic and carcinogenic heterocyclic amine . The enzymatic GSH conjugation with N-OH-Trp-P-2 was catalysed by rat-liver GSH transferase and a rat-liver cytosol fraction to form three conjugates (CH-1, CH-2 and CH-3) . The mutagenicities of the GSH conjugates were studied by using Salmonella typhimurium TA98 as the tester strain . The GSH conjugates except for CH-3 were completely detoxicated products, but CH-3 was found to be a more potent mutagen than N-OH-Trp-P-2 . The mutagenicity of CH-3 seemed to be due to the direct action of the conjugate, but not to N-OH-Trp-P-2 formed from it.

Rev Infect Dis, 1984 Jul-Aug, 6(4), 439 - 43
Separation and characterization of toxic and nontoxic forms of lipid A; Takayama K et al.; Highly purified and well-characterized samples of precursors and derivatives of bacterial lipopolysaccharides (LPS) were used to study the relationship between the chemical structure of lipid A and its toxicity . These samples included lipids X and Y (monosaccharide precursors of lipid A) from Escherchia coli MN7; incomplete lipid A (a disaccharide precursor of lipid A) from Salmonella typhimurium i50; and monophosphoryl lipid A, TLC-3 (a derivative of LPS), from S . typhimurium G30/C21 . In addition, a diphosphoryl lipid A, TLC-3, was prepared from LPS of S . typhimurium G30/C21 and characterized by positive fast atom bombardment mass spectrometry . The diphosphoryl lipid A, TLC-3 fraction, was determined to be very toxic by the chick embryo lethal-dose test (CELD50 = 0.0064 microgram) . Lipids X and Y, incomplete lipid A, and monophosphoryl lipid A (TLC-3), were all nontoxic (CELD50 greater than 10 micrograms) . These results suggest a multiple structural requirement for toxicity of lipid A . Toxic lipid A must contain all of the following components: a glucosamine disaccharide, a sugar-1-phosphate, and normal fatty acid(s).

Mutat Res, 1984 Jul, 137(1), 17 - 28
Genotoxicity of apomorphine and various catecholamines in the Salmonella mutagenicity test (Ames test) and in tests for primary DNA damage using DNA repair-deficient B . subtilis strains (rec assay); Suter W et al.; Apomorphine, N-nor-N-propyl-apomorphine, dopamine, L-DOPA, 6-hydroxydopamine and adrenaline were evaluated for genotoxicity using the Ames test and DNA repair-deficient and DNA repair-proficient Bacillus subtilis strains (rec assay, H17/M45; HLL3g/HJ-15) . In the absence of an S9 liver homogenate, apomorphine induced frame-shift mutations in Salmonella typhimurium, mainly in strain TA1537; no indication of DNA-damaging effects in B . subtilis was observed . N-Nor-N-propyl-apomorphine was tested using strain TA1537 only and found to be mutagenic . Dopamine, L-DOPA, 6-hydroxydopamine and adrenaline were non-mutagenic when tested without S9, whereas they were all more toxic for DNA repair-deficient than for DNA repair-proficient B . subtilis strains, indicating a DNA-damaging potential . In a second set of experiments the mode of action of apomorphine and the relevance of the positive Ames test data were investigated . Glutathione in physiological concentrations reduced the mutagenic effect of apomorphine in a dose-dependent way, both in the presence and the absence of S9 . S9 also reduced the mutagenicity of apomorphine . By comparing the effects of a complete S9 mix with those of a preparation without glucose-6-phosphate and NADP, it became clear that S9 also had an activating effect, overshadowed under standard conditions by its deactivating activity . Apomorphine was not mutagenic under anaerobic conditions . Superoxide dismutase and catalase reduced the mutagenic effect of apomorphine . All test conditions which reduced the mutagenic effect also inhibited the dark discoloration of the tester plates, indicating a retardation of apomorphine oxidation . It can, therefore, be concluded that oxidation of apomorphine leads to mutagenic products which induce frame-shift mutations in Salmonella typhimurium . This oxidation was prevented both by glutathione in concentrations well below physiological levels and/or by catalase and superoxide dismutase . Under these conditions, apomorphine was non-mutagenic in therapeutic concentrations as well as at higher dose levels . The possibility of genotoxic side effects occurring in patients treated with apomorphine as an emetic drug is therefore considered to be very unlikely.

Mutat Res, 1984 Jul, 127(2), 113 - 8
Effect of Japanese seaweed (Laminaria angustata) extracts on the mutagenicity of 7,12-dimethylbenz{a}anthracene, a breast carcinogen, and of 3,2'-dimethyl-4-aminobiphenyl, a colon and breast carcinogen; Reddy BS et al.; Animal model studies suggest that diets containing Laminaria angustata, a brown seaweed commonly eaten in Japan, inhibit breast carcinogenesis . In order to identify the compound(s) in the seaweed responsible for tumor-inhibiting activity, we used Ames/mammalian microsome assay system to determine the antimutagenic (or anticarcinogenic) effect of various solvents and water extracts of Laminaria angustata . The antimutagenic effects of acetone, ether, chloroform, chloroform + methanol, hot water and cold water extracts on the mutagenicity induced by 7,12-dimethylbenz{a}anthracene (DMBA), a breast carcinogen, and 3,2'-dimethyl-4-aminobiphenyl (DMAB), a colon and breast carcinogen, was studied using the Salmonella typhimurium strains TA98 and TA100 . All extracts were nonmutagenic in both bacterial tester strains . The addition of 10-100 mg solvent extracts of seaweed/plate greatly inhibited DMAB-induced mutagenicity in both tester strains (80-96% inhibition) and DMBA-induced mutagenicity in TA100 (about 82%), whereas hot and cold water extracts produced a moderate inhibition in a dose-related manner in both strains.

Food Chem Toxicol, 1984 Jul, 22(7), 535 - 9
Inactivation of quercetin mutagenicity; Friedman M et al.; Combinations of oxygen and alkaline pH were found to inactivate irreversibly the mutagenicity of quercetin towards Salmonella typhimurium strain TA98 . Exposure time, quercetin concentration and polyphenol oxidase were also important variables determining the extent of quercetin inactivation . Temperature had a relatively weak influence on the extent of inactivation . The metal salts, ferrous, ferric and copper sulphates also brought about inactivation but this effect was partially reversed when the pH of the incubation medium was reduced from 7 to 2 . Ferric sulphate had a much smaller effect than did the ferrous salt except in the presence of tyrosinase and oxygen at pH 7 . Zinc sulphate impaired quercetin mutagenicity only very slightly in the presence of tyrosinase and oxygen . When an oxygen-saturated solution of quercetin was exposed to tyrosinase at various pH values, the ultraviolet absorption maximum of quercetin near 370 nm decreased to an extent that correlated with the mutagenicity of quercetin under those conditions.

Can J Microbiol, 1984 Jul, 30(7), 916 - 21
Tricarboxylate transport in a Cit+ Escherichia coli: evidence for the role of an outer membrane protein; Tomas JM et al.; A strain of Escherichia coli of bovine origin able to use tricarboxylates as single carbon source is described . Tricarboxylate utilization (Cit+) and fluorocitrate sensitivity (FCs) could be transferred conjugatively to E . coli K12 and were not plasmid borne . No evidence was found for tct gene products of Salmonella typhimurium . A citrate-inducible outer membrane protein of 21-22 kilodaltons (kd) was found only in Cit+ strains . A protein (21-22kd) protein was also found in wild-type E . coli K12 and in fluorocitrate-resistant mutants of Cit+ strains, but it was present in a cryptic form no longer inducible by citrate . Fluorocitrate-resistant mutants of Cit+ strains were still able to transport citrate by a fluorocitrate-insensitive system . High levels of the 22-kd protein correlated with reduced growth induction times on citrate and with the ability to effectively transport citrate.

Rev Infect Dis, 1984 Jul-Aug, 6(4), 567 - 72
Lipid A and immunotherapy; Ribi E et al.; Endotoxin isolated from Re mutants of Salmonella typhimurium or Salmonella minnesota and consisting only of 3-deoxy-D-mannooctulosonic acid (KDO) and lipid A synergistically enhances the ability of mycobacterial cell wall skeleton (CWS) to regress transplantable, line-10 tumor (hepatocellular carcinoma) in syngeneic guinea pigs . Tumor regression is rapid, and systemic tumor immunity concomitantly develops when as little as 50 micrograms of each of these two components is combined and injected intralesionally . Selective removal of KDO from endotoxin yields diphosphoryl lipid A, which retains its toxic properties . Subsequent selective removal of the phosphate moiety at the reducing end of the diphosphoryl lipid A molecule yields nontoxic, monophosphoryl lipid A (determined by lethality for chick embryos) . Like the parent endotoxin or toxic diphosphoryl lipid A, monophosphoryl lipid A retains the ability to synergistically enhance the antitumor activity of mycobacterial CWS adjuvant . Both di- and monophosphoryl lipid A contain mixtures of a series of structural analogs . They can be separated chromatographically into single components that differ in number, type, and position of ester-linked fatty acids . Comparison of chromatographic fractions reveals that components of toxic and nontoxic lipid A can be paired according to structure . Each component of the pair has the same molecular structure, with the exception of an additional phosphate group in the toxic component . The toxicity of "lipid A's" liberated from endotoxin by acid hydrolysis appears to be determined by the proportion of di- and monophosphoryl lipid A in the hydrolysis mixture . Structural analogs of monophosphoryl lipid A, which differ in degree of O-acylation and type and distribution of fatty acids, have comparable antitumor activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Rev Infect Dis, 1984 Jul-Aug, 6(4), 535 - 41
Stimulation of spleen cells and macrophages of C3H/HeJ mice by a lipid A precursor derived from Salmonella typhimurium; Vogel SN et al.; Lipid A is that portion of the lipopolysaccharide (LPS) molecule believed to mediate most of the biologic activities associated with protein-free endotoxic preparations . C3H/HeJ mice possess a mutation at the Lps gene locus (Lpsd) that results in a state of profound hyporesponsiveness to the biologic effects of LPS (and more specifically, lipid A) in vivo . The relative unresponsiveness in vivo to LPS exhibited by these mice is reflected at a cellular level, as evidenced by a failure of many different cell types derived from the C3H/HeJ strain to respond to LPS or lipid A in vitro; this lack of response contrasts with that of cell cultures prepared from endotoxin responsive (Lpsn) mouse strains . Evidence is presented which demonstrates that a lipid A precursor molecule, produced by a mutant of Salmonella typhimurium conditionally defective in the synthesis of 3-deoxy-D-mannooctulosonic acid, stimulates mitogenesis in C3H/HeJ splenic cultures and induces cultures of C3H/HeJ macrophages to produce significant levels of the monokine interleukin-1 (IL-1; previously referred to as lymphocyte activating factor or LAF) and prostaglandins of the E series . These findings suggest the possibility that the failure of C3H/HeJ cells to respond to intact LPS or lipid A may be related to a defect in the processing of lipid A or LPS to a suitably stimulatory form, rather than to a defect in the recognition of the lipid A region.

Rev Infect Dis, 1984 Jul-Aug, 6(4), 455 - 62
Effect of altered lipid A synthesis on the synthesis of major proteins of the Salmonella typhimurium outer membrane; Rick PD et al.; The effect of altered lipid A synthesis on the synthesis of major outer membrane proteins was investigated in mutants of Salmonella typhimurium conditionally defective in the synthesis of 3-deoxy-D-mannooctulosonic acid (KDO) . The defect is due to a mutation in the structural gene for KDO-8-phosphate synthetase (designated kdsA), and expression of this lesion results in the accumulation of a precursor of lipid A that not only lacks KDO but is also deficient in ester-linked fatty acyl residues . During the initial 20-30 min following a shift of mutants to nonpermissive conditions, the rate of synthesis of the OmpA protein increased approximately 2.5-fold and then decreased . In contrast, the rates of synthesis of total cell-envelope proteins, as well as that of the porin proteins, were unaffected . The mechanism responsible for the initial increase in the rate of OmpA synthesis remains to be established . However, it appears that the subsequent decrease in the rate of OmpA synthesis may be related to a decrease in the stability of OmpA messenger RNA . The effect of nonpermissive conditions on the rate of OmpA synthesis was specifically related to expression of the kdsA lesion, and it was not found to be strain-specific or uniquely related to a single kdsA mutant allele.

Atherosclerosis, 1984 Jul, 52(1), 123 - 6
Effect of bacterial lipopolysaccharide on serum high density lipoprotein cholesterol in rabbits; Kerttula Y et al.; The effect of bacterial lipopolysaccharide (LPS) on serum lipids was examined in rabbits . LPS was prepared from the smooth Salmonella typhimurium LT2 strain and given intravenously at a dose of 100 ng/kg b.wt . There were no significant changes in serum triglyceride or cholesterol levels in 1-3 days after the administration of LPS . There was, however, a decrease in serum high density lipoprotein (HDL) cholesterol, which was greatest after 2 days (P less than 0.001) . Simultaneously, the HDL/total cholesterol ratio decreased (P less than 0.005).

Toxicol Lett, 1984 Jul, 22(1), 15 - 20
Evaluation of the mutagenic potential of endod (Phytolacca dodecandra), a molluscicide of potential value for the control of schistosomiasis; Pezzuto JM et al.; Extracts of the fruit of Phytolacca dodecandra (endod) demonstrate molluscicidal and other biological activities . Since this plant is indigenous to some countries where schistosomiasis is a common problem, it has been proposed that it may be socioeconomically feasible to employ endod as an aid in the control of this disease through its use to control the snail vector . As an initial step in the safety assessment of this substance, its mutagenic potential was determined utilizing Salmonella typhimurium strain TM677 . The seeds and fruit of Phytolacca americana, also molluscicidal, were additionally evaluated for mutagenic potential . Using a variety of conditions, no mutagenic activity could be demonstrated for any of the extracts tested . Thus, subject to the results of future safety assessment, endod remains a viable candidate as a useful molluscicide.

Mutat Res, 1984 Jul, 137(1), 7 - 15
Lack of mutagenicity of synthetic pyrethroids in Salmonella typhimurium strains and in V79 Chinese hamster cells; Pluijmen M et al.; Seven pyrethroids, i.e., cypermethrin, permethrin, deltamethrin, bioresmethrin, resmethrin, cismethrin and fenvalerate, were not found to be mutagenic in (a) Salmonella typhimurium strains TA100 or TA98 in the presence or absence of a rat liver activation system using the plate incorporation assay and fluctuation tests, or (b) V79 Chinese hamster cells in the presence or absence of hepatocytes.

Mutat Res, 1984 Jul, 137(1), 39 - 45
The effect of acetyl-CoA supplementation on the mutagenicity of benzidines in the Ames assay; Kennelly JC et al.; The conventional Ames assay metabolising system was confirmed to be deficient in its ability to N-acetylate . This may render the test less sensitive to compounds which normally have an acetylation step during their in vivo activation to carcinogens . The addition of acetyl-coenzyme A to the S9 mix in the Ames assay increased the mutagenicity of benzidine in Salmonella typhimurium strains TA98 and TA1538 4-5-fold . This was consistent with the observation that benzidine is N-acetylated prior to DNA binding in vivo in rat liver . Two 3,3'-disubstituted benzidines, o-tolidine and o-dianisidine, were also tested . A smaller increase in o-tolidine mutagenicity, compared to that observed with benzidine, occurred with the addition of acetyl-coenzyme A . However, the production of acetylated metabolites from o-tolidine was only 37% of that from benzidine . The mutagenicity of o-dianisidine was unaffected by acetyl-coenzyme A . Acetylation of o-dianisidine was only 16% of that observed with benzidine, and the N-acetyl derivatives of o-dianisidine showed lower mutagenicity than the parent amine . The differing responses of benzidine, o-tolidine and o-dianisidine to addition of acetyl-coenzyme A suggests it may not be possible to simply infer the metabolism of 3,3'-disubstituted benzidines to DNA binding species from data on benzidine itself.

Mutat Res, 1984 Jul, 137(1), 29 - 32
Mutagenicity of some synthetic quinolines and quinoxalines related to IQ, MeIQ or MeIQx in Ames test; Grivas S et al.; 3-Methyl- and 3,4-dimethyl-3H-imidazo{4,5-f}quinoline, 3,8-dimethyl-3H-imidazo{4,5-f}quinoxaline, N6-methyl- and N6,7-dimethylquinoline-5,6-diamine, as well as N6,3-dimethylquinoxaline-5,6-diamine, have been synthesized . Only the first-mentioned compound was active in Ames test; the response was equal for Salmonella typhimurium TA98 and TA100, regardless of enzymatic activation (S9) . However, its mutagenicity to TA98 + S9 was 300-1300 times smaller than the values reported for the related compounds, 3-methyl- and 3,4-dimethyl-3H-imidazo{4,5-f}quinolin-2-amine ('IQ' and 'MeIQ'), and for 3,8-dimethyl-3H-imidazo{4,5-f}quinoxalin-2-amine ('MeIQx') . Hence, the presence of the imidazole ring and the 2-amino group in the molecule seems to be important for the high mutagenicity of the latter compounds.

Br J Cancer, 1984 Jul, 50(1), 91 - 6
Mutagenic and cytotoxic activity of doxorubicin and daunorubicin derivatives on prokaryotic and eukaryotic cells; Babudri N et al.; The mutagenic and cytotoxic activity of two newly synthesized doxorubicin derivatives and of one daunorubicin derivative were studied in V79 Chinese hamster cells and bacteria (Salmonella typhimurium and Escherichia coli) . The results showed that all the compounds tested were cytotoxic and mutagenic for both prokaryotic and eukaryotic cells . However, in both systems, the two 4-desmethoxy- and the 4'-desoxy-derivatives were more active than the parent compounds, indicating that modifications in the aglycone or in the sugar moiety can produce appreciable changes in the biological properties of the anthracycline antibiotics . The in vitro activities observed in this study correlated with the in vivo antitumour potency.

J Bacteriol, 1984 Jul, 159(1), 206 - 13
Salmonella typhimurium synthesizes cobalamin (vitamin B12) de novo under anaerobic growth conditions; Jeter RM et al.; In this paper, we report that the enteric bacterium Salmonella typhimurium synthesized cobalamin de novo under anaerobic culture conditions . Aerobically, metE mutants of S . typhimurium need either methionine or cobalamin as a nutritional supplement for growth . The growth response to cobalamin depends upon a cobalamin-requiring enzyme, encoded by the gene metH, that catalyzes the same reaction as the metE enzyme . Anaerobically, metE mutants grew without any nutritional supplements; the metH enzyme functioned under these conditions due to the endogenous biosynthesis of cobalamin . This conclusion was confirmed by using a radiochemical assay to measure cobalamin production . Insertion mutants defective in cobalamin biosynthesis (designated cob) were isolated in the three major branches of the cobalamin biosynthetic pathway . Type I mutations blocked the synthesis of cobinamide, type II mutations blocked the synthesis of 5,6-dimethylbenzimidazole, and type III mutations blocked the synthesis of cobalamin from cobinamide and 5,6-dimethylbanzimidazole . Mutants that did not synthesize siroheme (cysG) were blocked in cobalamin synthesis . Genetic mapping experiments showed that the cob mutations are clustered in the region of the S . typhimurium chromosome between supD (40 map units) and his (42 map units) . The discovery that S . typhimurium synthesizes cobalamin de novo only under anaerobic conditions raises the possibility that anaerobically grown cells possess a variety of enzymes which are dependent upon cobalamin as a cofactor.

Infect Immun, 1984 Jul, 45(1), 62 - 6
Mouse fibroblast interferon modifies Salmonella typhimurium infection in infant mice; Bukholm G et al.; The effect of mouse fibroblast interferon on Salmonella typhimurium infection in infant mice was examined . The lethality to mice that had been given S . typhimurium intragastrically was significantly reduced in a dose-dependent manner when the mice were pretreated with fibroblast interferon . Lower doses of interferon delayed the development of disease . Interferon neutralized with anti-interferon globulin did not influence the lethality of S . typhimurium to mice . In mice treated with interferon there was also a reduced invasiveness of S . typhimurium in intestinal epithelial cells in vivo . It was further demonstrated in an in vitro system that interferon pretreatment of mouse L-929 cells inhibited the invasiveness of the bacteria in a dose-dependent manner . The in vitro inhibition was neutralized with anti-interferon globulin . The results indicate that interferon inhibits Salmonella bacteria from invading cells and establishing an intracellular state of infection . This may represent an important factor in the pathogenesis of disease.

Infect Immun, 1984 Jul, 45(1), 29 - 35
Cationic antimicrobial proteins isolated from human neutrophil granulocytes in the presence of diisopropyl fluorophosphate; Shafer WM et al.; Acid (0.2 M sodium acetate, pH 4.0) extracts of granules recovered from disrupted human polymorphonuclear granulocytes (PMNs) exhibited in vitro antimicrobial activity against Salmonella typhimurium . To minimize proteolytic destruction or modification of antimicrobial proteins derived from these granules, we pretreated the PMNs with the serine protease inhibitor diisopropyl fluorophosphate . Fractionation of such extracts by carboxymethyl Sephadex and Sephadex G-75 chromatography resulted in the recovery of at least two antimicrobial, cationic proteins . These proteins differed substantially in antimicrobial activity, amino acid composition, and molecular weight (Mr, 37,000 and 57,000) . As we have shown before (Shafer et al., Infect . Immun . 43:834-858), with unfractionated proteins, these two proteins exhibited diminished activity against a polymyxin B-resistant (PBr) mutant of S . typhimurium compared with their activity against the isogenic parental polymyxin B-sensitive (PBs) strain . Expression of the relevant mutation (prmA) in the PBr mutant decreases the electronegativity of lipid A, owing to increased 4-amino-4-deoxy-L-arabinosylation at the 4' phosphate residue (Vaara et al., FEBS Lett . 129:145-149) . The data suggest that at least two different cationic proteins account for the antimicrobial capacity of extracts from human PMN granules . Moreover, the availability of anionic charges in the outer membrane of S . typhimurium due to free lipid A phosphates apparently dictates phenotypic levels of resistance to both of the cationic proteins extracted from human PMN granules.

Cancer Res, 1984 Jul, 44(7), 2848 - 54
Molecular requirements for the mutagenicity of malondialdehyde and related acroleins; Basu AK et al.; Malondialdehyde, a product of lipid peroxidation and prostaglandin biosynthesis, is mutagenic in Salmonella . To determine the molecular requirements for its mutagenicity, we tested a series of beta-substituted acroleins in Salmonella typhimurium hisD3052 . Mutagenicity is dependent on the steric bulk of the substituent (revertants/mumol) at the beta position: beta- methoxyacrolein , 220; beta- ethoxyacrolein , 110; and beta- isobutoxyacrolein , 40 . A good leaving group at the beta position substantially increases the mutagenic activity (revertants/mumol): beta-(p-nitrophenoxy)acrolein, 620; beta- benzoyloxyacrolein , 320; beta- chloroacrolein , 890; and di-gamma- oxopropenyl ether, 870 . These data suggest that nucleophilic attack on the beta-carbon followed by elimination of the beta substituent is important for mutagenicity . Substitution of a methyl group at the alpha-carbon abolishes mutagenicity of these compounds . This effect can be explained by the lack of chemical reactivity of the alpha-methyl analogues toward oxygen or nitrogen nucleophiles . Propynal , which can add nucleophiles to generate a substituted acrolein, exhibits the highest mutagenicity (1370 revertants/mumol) in this series . The importance of the aldehyde functionality is suggested by the nonmutagenicity of propiolonitrile , ethyl propiolate , 4-benzoyloxy-3- buten -2-one, and 4-methoxy-3- buten -2-one . Aldehyde addition subsequent to the formation of the Michael adduct is, therefore, important for mutagenesis . An investigation of the toxicity of the present series indicates that toxicity and mutagenicity are independent events based on different chemical reactions.

J Bacteriol, 1984 Jul, 159(1), 130 - 7
Conditionally transposition-defective derivative of Mu d1(Amp Lac); Hughes KT et al.; A Mu d1 derivative is described which is useful for genetic manipulation of Mu-lac fusion insertions . A double mutant of the specialized transducing phage Mu d1(Amp Lac c62ts) was isolated which is conditionally defective in transposition ability . The Mu d1 derivative, designated Mu d1-8(Tpn{Am} Amp Lac c62ts), carries mutations which virtually eliminate transposition in strains lacking an amber suppressor . In such strains, the Mu d1-8 prophage behaves like a standard transposon . It can be moved from one strain of Salmonella typhimurium to another by the general transducing phage P22 with almost 100% inheritance of the donor insertion mutation . When introduced into a recipient carrying supD, supE, or supF, 89 to 94% of the Ampr transductants were transpositions of the donor Mu d1-8, from the transduced fragment into new sites . The stability of Mu d1-8 in a wild-type, suppressor-free background was sufficient to permit use of the fusion to select constitutive mutations without prior isolation of deletions to stabilize the fusion . Fusion strains could be grown at elevated temperature without induction of the Mu d prophage . The transposition defect of Mu d1-8 was corrected by a plasmid carrying the Mu A and B genes.

Acta Pathol Microbiol Immunol Scand {A}, 1984 Jul, 92(4), 195 - 204
The effect of exercise and fasting on the myocardial protein and lipid metabolism in experimental bacterial myocarditis; Ilback NG et al.; A generally nonlethal Salmonella typhimurium infection in weanling rats produced bacterial myocarditis and myocardial hyperplasia . Myocardial lesions were characterized by focal infiltrates of inflammatory cells (predominantly mononuclear), segmental myocyte necrosis, and incipient fibrosis . Although bacterial infections are infrequently associated with myocarditis, the S . typhimurium infection in young rats produced a new experimental model of diffuse myocardial inflammatory foci . Biochemical changes in the myocardium included great increases in total myocardial contents of protein (23%), RNA (39%) and DNA (43%) and several lipid fractions (35-55%) as well as in tissue activities of acid hydrolases, such as cathepsin D (124%) and beta-glucuronidase (135%), all of which contrasted with the relatively limited areas of histologic involvement (1.5%) . To study the effects of additional stress in this model infection, some rats were exercised by forced running in wheels for 2 hours and others were fasted for 24 hours before samples were obtained . The short period of forced exercise in this infection caused an additional increase of myocardial protein content (47%) but with no additional change in histology . The expected fasting-induced degradation of protein as well as an infection-associated increase in myocardial lipids were each prevented when rats were fasted during ongoing acute infection . Protein degradation, as reflected by heightened acid hydrolase activities, seemed to occur at a similar rate regardless of other stresses, whereas the rate of myocardial protein synthesis appeared to be alterable.

EMBO J, 1984 Jul, 3(7), 1587 - 93
Molecular cloning, sequencing, and expression of the crr gene: the structural gene for IIIGlc of the bacterial PEP:glucose phosphotransferase system; Nelson SO et al.; The phosphoenolpyruvate:glucose phosphotransferase system (PTS) of Salmonella typhimurium is involved both in glucose transport and in the regulation and synthesis of adenylate cyclase and several transport systems . The crr gene has been implicated in this regulating mechanism . A 9.6-kb segment of the S . typhimurium chromosome containing the crr gene was cloned in pAT153 . The cloned fragment also complemented cysA mutations but did not contain a functional pts operon which is closely linked to the crr gene and codes for two enzymes of the PTS . Although cysA and crr have been reported to be located on opposite sides of ptsHI, our results suggest that the correct gene order is cysK-ptsHI-crr-cysA . Expression of crr plasmids in a maxicell system yielded two proteins which reacted with specific anti-serum against IIIGlc . The apparent mol . wts . in SDS-polyacrylamide gels were 20 000 and 21 000, the former corresponding to the major band of purified IIIGlc . Both forms were also observed in bacterial extracts and purified IIIGlc . The crr gene was localized on a 1-kb EcoRI-EcoRV fragment of the 9.6-kb insert and sequenced . It codes for a single protein (18 556 D) containing 169 amino acid residues and identified as IIIGlc.

J Biol Chem, 1984 Jun 25, 259(12), 7719 - 25
Sites of methyl esterification and deamination on the aspartate receptor involved in chemotaxis; Terwilliger TC et al.; The receptors involved in bacterial chemotaxis are post-translationally modified by specific enzymes which catalyze the deamination of glutaminyl residues and the methyl esterification and demethylation of glutamyl residues . In this work we identify the sites of these covalent modifications on the aspartate receptor from Salmonella typhimurium . These were identified using the properties of the Staphylococcus aureus V8 protease which cleaves peptide bonds following glutamyl but not glutaminyl residues . We show here that bonds following methyl-esterified glutamyl residues are also resistant to the protease . A comparison of the fragments obtained after V8 protease cleavage of methyl-esterified (or deaminated) peptides with the fragments from the corresponding unmodified peptides immediately yields the sites of modification . Three of the four methyl-esterified glutamyl residues are located near the middle of the receptor amino acid sequence; one of these is synthesized as a glutaminyl residue and is deaminated by the esterase to form a glutamyl residue . The fourth site of methyl esterification is located near the carboxyl terminus . All four sites occupy analogous positions in a well-conserved arrangement of residues which may form a binding site for the esterase and the methyltransferase.

Eur J Biochem, 1984 Jun 15, 141(3), 579 - 83
The hemolytic effect of Salmonella typhi Ty 2 porins; Calderon I et al.; Two outer membrane proteins of Salmonella typhi Ty 2 were extensively co-purified . According to their migration in dodecylsulfate/polyacrylamide gel electrophoresis and solubility characteristics, these proteins are homologous to the 35-kDa and 36-kDa porins found in Salmonella typhimurium . A porin homologous to the 34-kDa one has not been found in S . typhi Ty 2 . A critical step in the purification of porins is heating at 100 degrees C in 2% sodium dodecyl sulfate before Sephadex gel filtration . The absence of detergent in aqueous suspensions enhances porin aggregation, these aggregations inducing human red cell lysis . Porins obtained by an alternative procedure consisting of heating at 60 degrees C instead of 100 degrees C were also hemolytic . Using nanomolar concentration of porins a strong influence of temperature on the hemolytic effect was observed . Porin-induced hemolysis was inhibited with anti-porin serum, as well as by a treatment with phenylglyoxal, which reacts with the arginine residues of proteins . The membrane-disrupting ability of porins aggregates might explain some pathogenic characteristics of gram-negative bacterial infections.

Microbiol Sci, 1984 Jun, 1(3), 69 - 72
Phylogeny of strains of Salmonella typhimurium; Old DC; The combined use of biotyping and phage typing has been used to identify major clones of Salmonella typhimurium . Recombination studies among isolates of different clones indicate their genetic relatedness and allow construction of a phylogenetic tree showing relationships among major biotypes . Possible lines of their descent from a common archetypal ancestor are discussed.

Appl Environ Microbiol, 1984 Jun, 47(6), 1355 - 7
Mutagenicity of tetramic mycotoxin cyclopiazonic acid; Sorenson WG et al.; Cyclopiazonic acid was shown to be mutagenic to Salmonella typhimurium TA98 and TA100 in the presence of metabolic activation . The activity of cyclopiazonic acid in the presence of aflatoxin B1 was studied in complete factorial experiments with strain TA98 . Both mycotoxins produced significant mutagenic activity and in combination . The activity in combination appeared to be additive rather than synergistic . The specific activity of cyclopiazonic acid was estimated to be approximately 140 revertants per mu mol in strain TA98.

Mutat Res, 1984 Jun, 136(3), 159 - 68
Mutations in Salmonella typhimurium and inactivation of Bacillus subtilis transforming DNA induced by phenylhydroxylamine derivatives; Nohmi T et al.; Phenylhydroxylamine (PHA) and its derivatives such as monomethyl (2-Me, 3-Me, 4-Me) and dimethyl (2,3-diMe, 2,4-diMe, 2,5-diMe, 2,6-diMe, 3,4-diMe, 3,5-diMe) were tested for their mutagenicity and for their inducing ability to inactivate transforming DNA . All these compounds except PHA and 3,5-diMePHA were found to be mutagenic in Salmonella typhimurium TA100 even in the absence of S9 mix, and their mutagenic potency was in the order: 2,6-diMe- greater than 2,4-diMe- = 3,4-diMe- greater than 4-Me- greater than 2,3-diMe- = 2,5-diMe- greater than 2-Me- = 3-MePHA . Besides mutagenicities, all the PHA derivatives except 2,6-diMePHA caused severe reductions in the activity of Bacillus subtilis transforming DNA . To establish the structure-activity relationship, we examined the correlation between these activities and the stabilities of the PHA derivatives, and the results indicated that the more chemically unstable the PHA derivatives were, the more active they were with respect to the mutations and to the inactivation of the transforming DNA . The mutagenic activity of 2,6-diMePHA was the sole exception, because it was most stable, but its induced mutation frequency was highest . From these results, we suggest that all the PHA derivatives, except 2,6-diMePHA, cause DNA damage through the generation of active molecular species, such as nitrenium ions, without any enzymatic activation, while 2,6-diMePHA requires further metabolic activation by bacterial enzymes to stimulate mutagenesis.

J Bacteriol, 1984 Jun, 158(3), 972 - 7
Anaerobiosis, formate, nitrate, and pyrA are involved in the regulation of formate hydrogenlyase in Salmonella typhimurium; Barrett EL et al.; Three groups of mutants defective in the fermentative production of gas were isolated from Salmonella typhimurium LT2 subjected to transposition mutagenesis with Mu d(Apr lac) . One group consisted of strains which lacked hydrogenase . The mutation site for this group was located in the vicinity of the known hyd gene . A second group consisted of mutants which lacked the formate dehyrogenase associated with hydrogenase . The mutation site was located in four of them . It was not in the vicinity of the previously described fhlD gene but was instead located at 93 min on the Salmonella map . The third mutant group, which consisted of strains that produced gas in triple sugar iron agar but not in nutrient agar supplemented with glucose, appeared to be pyrA mutants . The insertion site was located in the vicinity of pyrA , and they required arginine and pyrimidines for growth . Expression of the lac operon in the hyd mutants was induced by anaerobiosis . It was only slightly increased by the addition of formate under anaerobic conditions and slightly decreased by the addition of nitrate . Nitrate had no effect in an hyd ::Mu d strain that also carried a chlC::Tn10 insertion . Full expression of the lac operon in the fhl mutants required both formate and anaerobic conditions . The presence of nitrate in addition to formate resulted in activities about half those obtained in its absence, even in the fhl ::Mu d chlC::Tn10 double mutant . In the absence of formate, nitrate reduced expression only in the fhl ::Mu d single mutants . Expression of the lac operon among the pyrA mutants was repressed by arginine and cytosine and also by anaerobiosis . An explanation for the involvement of pyrA in aerobic and anaerobic energy metabolism is proposed.

Jpn J Exp Med, 1984 Jun, 54(3), 91 - 6
Depression of resistance against Salmonella infection in sarcoma 180-bearing mice and its restoration by Salmonella mini-cells; Kurashige S et al.; The reduction of resistance against Salmonella infection was resulted from the reduction of macrophage activities in Sarcoma 180-bearing mice . Mean survival day of S180-bearing mice was markedly reduced to 1.4 +/- 0.5 days after the challenge with 1 X 10(8) of Salmonella typhimurium LT2 cells in contrast with 6.8 +/- 1.9 days of normal mice . Eighty percent of S180-bearing mice died within 14 days after the challenge with 1 X 10(6) of LT2 cells, whereas all of normal mice survived more than 30 days after the challenge with 3 X 10(6) or less of LT2 cells . Chemotactic and O2- producing activities of macrophages collected from S180-bearing mice which were treated with Salmonella mini-cells restored to normal level . Bactericidal activity of macrophages was also restored by the mini-cell treatment . The restoration of the resistance to Salmonella was accompanied with increases of macrophage activities.

Aust J Exp Biol Med Sci, 1984 Jun, 62 ( Pt 3), 243 - 52
Trypanosoma lewisi: the effect of thymectomy on the production of ablastin and the termination of the parasitaemia in infected rats; Drew PA et al.; This study investigated the effect of the depletion of T lymphocytes on the production of ablastin and the termination of the parasitaemias in Porton strain rats infected with Trypanosoma lewisi . Weanling rats were thymectomised or sham-thymectomised and then X-irradiated . After allowing 96 days for recovery from these procedures the rats were infected with T . lewisi . The rats were considered to be T lymphocyte depleted if they were unable to mount an antibody response to sheep red blood cells before the infection, a delayed type hypersensitivity response to trypanosomal antigen after they had cleared the infection, and if they succumbed to subsequent challenge with an intracellular bacterial parasite, Salmonella typhimurium C5 . The T lymphocyte depleted rats were found to have no macroscopic thymus remnants visible at autopsy . The sham-thymectomised and unoperated control rats retained all the T lymphocyte functions tested for . There was no difference between the control and the T lymphocyte depleted rats in the ability to eliminate the parasite following infection with T . lewisi . Ablastin titres in the serum, measured by a sensitive in vitro assay, were found to be the same in each of the groups of rats tested, regardless of their T lymphocyte status . It is concluded that T lymphocytes are not essential for rats to eliminate a T . lewisi infection, nor for the production of ablastin.

Acta Pathol Microbiol Immunol Scand {B}, 1984 Jun, 92(3), 145 - 9
Effect of cytochalasin B and dihydrocytochalasin B on invasiveness of entero-invasive bacteria in HEp-2 cell cultures; Bukholm G; The effect of cytochalasin B (CB) and di-hydrocytochalasin B (H2CB) on the invasiveness of Salmonella typhimurium, Shigella flexneri and Yersinia enterocolotica serotype 0:3 in HEp-2 cell cultures was examined . The intra-cellular and extra-cellular bacteria were identified by a combination of Nomarski interference contrast microscopy and UV incident light microscopy applied on the same light microscope . Pre-treatment of cells with CB and H2CB inhibited the uptake of S . typhimurium and S . flexneri in the HEp-2 cell cultures . The effect was time and dose dependent . On the other hand, the drugs did not influence the invasiveness of Y . enterocolitica . The results indicate that activity of cellular actin micro-filaments is essential for invasiveness of S . typhimurium and S . flexneri.

Mutat Res, 1984 Jun-Jul, 140(2-3), 71 - 4
Lack of mutagenicity to S . typhimurium of neopentyl bromide and pentaerythrityl tetrachloride: relation to chemical structure; Ashby J et al.; Neopentyl bromide and pentaerythrityl tetrachloride were shown here to be non-mutagenic to 7 strains of Salmonella typhimurium . These inactivities are reflected in the inability of either compound to produce a colour reaction in the chemical alkylation test of Epstein (4-nitrobenzylpyridine, NBP) . It is suggested that the lack of biological reactivity of these two alkyl halides is due to steric crowding of the halogen group . These findings are significant within the context of the potent mutagenicity of mono-haloalkanes in general . The similarity between the odour of pentaerythrityl tetrachloride and camphor is discussed.

Mutat Res, 1984 Jun-Jul, 140(2-3), 55 - 9
Formation of 2-amino-3,7,8-trimethylimidazo {4,5-f}quinoxaline, a new mutagen, by heating a mixture of creatinine, glucose and glycine; Negishi C et al.; When a mixture of creatinine, glycine and glucose was heated for 2 h at 128 degrees C in diethylene glycol containing 14% water, two mutagens were formed . One of them, responsible for 90% of the mutagenicity, has already been identified as 2-amino-3,8-dimethylimidazo{4,5-f}quinoxaline (MeIQx) . The other mutagen was purified and characterized . The UV absorption, mass and NMR spectra suggested that this mutagen was 2-amino-3,7,8-trimethylimidazo{4,5-f}quinoxaline (7,8-DiMeIQx) . Comparison of the spectral properties of the compound obtained from the heated model mixture with those of synthetic material confirmed this structure . 7,8-DiMeIQx is a newly identified compound which, at a dose of 1 microgram, induced 163 000 and 9900 revertants of Salmonella typhimurium TA98 and TA100, respectively, with S9 mix.

Mutat Res, 1984 Jun-Jul, 140(2-3), 147 - 53
Metabolic activation capabilities of S9 and hepatocytes from uninduced rats to convert carcinogenic N-nitrosamines to mutagens; Rumruen K et al.; 6 carcinogenic nitrosamines were studied in Salmonella typhimurium TA1535 after activation by S9 and by hepatocytes . All nitrosamines were activated by S9 from induced rats, regardless of their organotropy . The hepatocarcinogenic nitrosamines (N-nitrosodimethylamine, NDMA; N-nitrosodiethylamine, NDEA; N-nitrosomorpholine, NM and N-nitrosodibutylamine, NDBA) were activated to mutagens by S9 and by hepatocytes both derived from noninduced rat livers, NDMA and NM inducing more his+ revertants in the presence of hepatocytes . The oesophageal carcinogenic nitrosamine N-nitrosomethylbenzylamine (NMBeA) and bladder organotrophic N-nitroso(4-hydroxybutyl)butylamine(NBBOH) were neither converted by liver preparations of uninduced rats into mutagenic intermediates nor by hepatocytes . This study indicates that isolated cells derived from untreated animals may be better suited to study liver specific activation in vitro than disrupted subcellular metabolizing systems from induced animals.

J Appl Bacteriol, 1984 Jun, 56(3), 439 - 47
A method for the enumeration of male-specific bacteriophages in sewage; Havelaar AH et al.; Male-specific bacteriophages adsorb to F-pili and thus can only infect male host strains . A method was developed for the selective enumeration of these phages, based on the observation that in sewage there are few phages capable of infecting F- -salmonellas--usually less than 10 pfu/ml . Using a male Salmonella strain, constructed by the introduction of the plasmid F'42 lac::Tn5 into Salmonella typhimurium phage type 3, plaque counts in secondary effluent were found to be in the range of 60-8200 pfu/ml . Practically all the phages detected had a host range restricted to male Salmonella or Escherichia coli strains, were resistant to chloroform and their infectivity was inhibited by RNase . Electron microscopy of lysates revealed phage particles that were morphologically identical to the male-specific single-strand RNA phages . Similar results were obtained with a strain of Salm . indiana carrying F'42 lac . A derivative of the Salm . typhimurium LT2 strain carrying an F-plasmid (F'42 lac fin P301) derepressed for fertility inhibition by the resident plasmid pSLT was equally sensitive to male-specific phages, but from sewage samples many other phages infecting F- E . coli but not F- Salmonella were isolated using this host strain.

EMBO J, 1984 Jun, 3(6), 1435 - 40
Comparison of a forward and a reverse mutation assay in Salmonella typhimurium measuring L-arabinose resistance and histidine prototrophy; Ruiz-Rubio M et al.; A forward and a reverse mutation assay designed to detect environmental mutagens have been compared in Salmonella typhimurium . The forward mutation assay scored resistance to L-arabinose and the reverse assay, reversion of histidine auxotrophy . Eighteen chemicals of different structural groups, all known to be mutagenic in the histidine reverse assay, were applied to strains carrying the genetic markers needed to perform both mutation assays . The mutagenicity of each chemical was determined by both plate and liquid tests . The plate test counted absolute numbers of surviving mutants and the liquid test separately measured survival and frequency of mutants among the survivors . All the chemicals used were found to be mutagenic in both mutation assays . The response of the L-arabinose assay was equal to or larger than the response of the histidine assay in the case of 16 chemicals . The two other compounds, 2-nitrofluorene and sodium azide, were detected more efficiently by the histidine assay . Sodium azide, a non-carcinogenic compound, is a potent mutagen in the histidine assay, but very weak in the L-arabinose assay.

Clin Exp Immunol, 1984 Jun, 56(3), 531 - 6
Genetic control of in vitro natural cell-mediated activity against Salmonella typhimurium by intestinal and splenic lymphoid cells in mice; Tagliabue A et al.; In vitro natural anti-bacterial activity against Salmonella typhimurium by lymphocytes from Peyer's patches and spleens was assessed in several mouse strains . C3H/HeN and CBA/J mice, which are resistant to S . typhimurium infections, showed a natural anti-bacterial activity significantly higher than BALB/c, C57BL/10, C57BL/6 and C3H/HeJ mice, i.e . strains susceptible to the in vivo bacterial infection . In these susceptible strains and also in A/J mice, a significantly higher natural activity was observed in females compared to males . The sex control of natural anti-bacterial activity was further stressed by the fact that orchidectomy could induce a strong activity in low responder C57BL/10 male mice . With the exception of Beige mice, a low natural killer (NK) strain also with no natural activity against S . typhimurium in both sexes, the genetic distribution of natural anti-bacterial activity was extremely different from that of the NK activity . Thus, these results further stress the difference between natural anti-bacterial activity and NK cytotoxicity . Furthermore, our data establish a possible link, although with some exceptions, between in vivo susceptibility to S . typhimurium infections and in vitro natural activity against these bacteria.

Biophys Chem, 1984 Jun, 19(4), 279 - 87
A high-resolution 1H-NMR investigation of the histidine-binding protein J of Salmonella typhimurium . Substrate-induced conformational changes; Cedel TE et al.; High-resolution 1H-NMR spectroscopy at 600 MHz has been used to investigate the conformational transitions of the histidine-binding protein J of Salmonella typhimurium in solution as a function of pH and of L-histidine concentration . The dissociation constant for the binding of L-histidine to histidine-binding protein J increases from 6.0 X 10(-8) to 5.1 X 10(-7) M in going from pH 5.57 to 8.00 . The conformation of this protein as observed by 1H-NMR also changes over this range of pH . However, when L-histidine is bound, the changes in conformation with pH are much smaller . Also, the pK for the single histidyl residue in histidine-binding protein J changes from 6.75 in the absence of L-histidine to 6.52 when L-histidine is bound . Earlier work in this laboratory resulted in the identification of several proton resonances believed to be at or near the L-histidine-binding site . Two of these resonances have been assigned to a tyrosine and the single histidyl residue in the histidine-binding protein J molecule.

Appl Environ Microbiol, 1984 Jun, 47(6), 1327 - 30
Enzyme-linked immunosorbent assay for detection of Salmonella lipopolysaccharide in poultry specimens; Rigby CE; An enzyme-linked immunosorbent assay (ELISA) for detection of salmonellae was developed and evaluated by using artificially contaminated specimens of poultry feed, feces, litter, or carcass rinsings, and naturally contaminated water samples . Specimens containing salmonellae of serogroups B or C2 inhibited the binding of polyvalent anti-O serum to microtiter plate wells coated with lipopolysaccharide of Salmonella typhimurium (serogroup B) or Salmonella albany (serogroup C2), respectively . Treatment of specimens with Rhozyme 41 (a protease) inhibited nonspecific reactions . The ELISA detected 106 of 111 culture-positive specimens contaminated with salmonellae of serogroups B or C2 . Nineteen of 20 specimens containing salmonellae of serogroup C1 and all of 36 culture-negative specimens were ELISA negative . All seven water samples that contained salmonellae of serogroups B or C2, including three that were culture positive only after delayed secondary enrichment, were ELISA positive . Seven of the nine water samples that contained salmonellae of other serogroups, and all 38 culture-negative samples, were ELISA negative . The ELISA was simple to perform, produced results in 48 h, and was more economical than culture methods.

Am J Vet Res, 1984 Jun, 45(6), 1081 - 5
Relationship of cutaneous delayed hypersensitivity to protection from challenge exposure with Salmonella typhimurium in calves; Merritt FF et al.; The purpose of this investigation was to relate cutaneous delayed hypersensitivity reactions to the degree of immunity induced in calves given a live virulent or a modified-live strain of Salmonella typhimurium . Calves were placed into 1 of 5 groups on the basis of the vaccinal strain given and route of the vaccination: (I) nonvaccinated controls, (II) vaccinated twice by IM inoculation with small doses of the live virulent strain, (III) vaccinated (IM) twice with the modified-live strain, (IV) vaccinated (orally) twice with the modified-live strains, and (V) vaccinated (IM, and then orally) twice with the modified-live strain . Skin testing was performed by intradermal injection of fragmented S typhimurium as antigen . Double skin fold thickness and visual assessments were recorded at 3, 6, 24, 48, and 72 hours after antigen was administered . Biopsy samples for histopathologic evaluation were obtained . After vaccination and skin testing were complete, calves were orally challenge exposed with 1.5 X 10(11) virulent S typhimurium . Cutaneous delayed-type hypersensitivity reactions (48 hours) were observed in all except controls (group I) and 2 of 3 calves vaccinated orally with the modified-live vaccine strain (group IV) . Significant correlations between positive skin tests and protection from challenge exposure were observed except in group V calves, in which positive skin test results were seen, but adequacy of the immunity (or survival after challenge exposure) was inconsistent.

Mutat Res, 1984 Jun, 136(3), 233 - 45
An evaluation of the genotoxic properties of herbicides following plant and animal activation; Plewa MJ et al.; Commercial and technical grades of 11 herbicides and 13 combinations of commercial grade herbicides were evaluated for their genotoxic properties with Salmonella typhimurium, Saccharomyces cerevisiae directly and following plant and animal activation, or with Zea mays . The herbicides were related by their use in commercial corn (maize) production . Commercial grade formulations of each herbicide and combination of herbicides were also evaluated in situ with the pollen waxy locus assay of Z . mays . Eradicane and bifenox were negative in all assays . Alachlor, propachlor, procyazine and SD50093 (a formulation of cyanazine plus atrazine) were positive in one assay . Cyanazine, dicamba and metolachlor were positive in 2 assays . Atrazine, simazine and butylate were tested only in situ . Atrazine and simazine were positive and butylate was negative . Of the combinations of herbicides evaluated with the 3 genetic assays, alachlor plus bifenox and procyazine plus metolachlor were positive in 1 assay and metolachlor plus atrazine was positive in 2 assays . Of the combinations of herbicides evaluated only in situ, butylate plus atrazine, eradicane plus atrazine, eradicane plus cyanazine and metolachlor plus cyanazine were positive while butylate plus cyanazine was negative.

Mutat Res, 1984 Jun, 136(3), 217 - 21
Testing of 2,4,5-T-amino acid conjugates for mutagenic activity in Salmonella typhimurium strains; Rashid KA et al.; Since amino acid conjugates are plant metabolites of the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 5 amino acid conjugates (aspartic acid, glutamic acid, leucine, methionine and tryptophan) of 2,4,5-T were tested for possible mutagenic activity utilizing 5 strains of Salmonella typhimurium (TA97, TA98, TA100, TA1535 and TA1538) with and without rat-liver microsomal and cytosolic enzymes . These compounds did not cause any significant increase in reversions when compared with controls in the presence or absence of the activating system . Further, linear regression analysis showed no significant (p less than 0.05) dose-response relationships . Thus, it was concluded that the tested amino acid conjugates of 2,4,5-T are not mutagens or promutagens in these assays.

Mutat Res, 1984 Jun, 136(3), 209 - 15
Genotoxic activity of nitroaromatic explosives and related compounds in Salmonella typhimurium; Whong WZ et al.; A number of nitroaromatic explosives and related compounds were examined for mutagenic activity with the Salmonella/mammalian microsome test . 9 of 11 nitroaromatics tested were mutagenic, including 2,4,6-trinitrotoluene, the most widely produced military explosive . All the nitroaromatics, except 2,4,6-trinitrophenol and 2,3,5-trinitroresorcinol, were at least an order of magnitude more mutagenic than 3 dinitrotoluene (DNT) isomers . The most active compound was 2,3,5-trinitronaphthalene, which was approximately 5000 times more mutagenic than DNT isomers . These compounds induced predominantly frameshift mutations . The mutagenic activity did not require S9 activation, but was largely dependent on the presence of an intact nitroreductase capability in the test bacteria . This implied that reduced metabolites, possibly hydroxylamines, are the proximal mutagenic intermediates.

Mutat Res, 1984 Jun, 136(3), 169 - 71
Absence of mutagenicity of trioxane and dioxolane in Salmonella typhimurium; Kowalski Z et al.; The mutagenic activity of trioxane and dioxolane was investigated in 5 histidine-requiring strains of S . typhimurium: TA1535, TA1537, TA1538, TA98 and TA100 with and without activation by liver microsomes . They were not mutagenic under any of these conditions with any of the his- S . typhimurium tester strains (in the presence or absence of S9 mix from liver homogenate of rats induced with Aroclor 1254).

J Hyg (Lond), 1984 Jun, 92(3), 385 - 94
Factors influencing salmonella shedding in broiler chickens; Gustafson RH et al.; Three variables were included in a study to determine their effect on the incidence of Salmonella typhimurium in broilers challenged at four days of age . Variables included the presence or absence of a feed additive, avoparcin; the use of new or used litter and the initiating dose of salmonella . Cloacal swabs were taken from approximately 600 chicks at weekly intervals for 45 days . At 10(4), 10(6) and 10(8) c.f.u./chick there was a direct association of challenge dose and the incidence of positive chicks for the first several weeks . Chicks raised on used litter showed an appreciable reduction in susceptibility to salmonella when compared to control animals on fresh litter . As the birds approached slaughter age, the influence of litter hygiene and challenge dose diminished under the conditions of this study . Avoparcin in the diet at 10 p.p.m . had no enhancing effect on salmonella shedding at any time during the 45-day sampling period . The implications of competitive exclusion are discussed.

Chem Biol Interact, 1984 Jun, 50(1), 39 - 48
The protective action of glutathione on the microbial mutagenicity of the Z- and E-isomers of 1,3-dichloropropene; Creedy CL et al.; The Z(cis)- and E(trans)-isomers of 1,3-dichloropropene (DCP), in confirmation of previous reports, caused dose-dependent increases in the numbers of reverse mutations in Salmonella typhimurium TA100 in the presence and absence of a 9000 X g supernatant fraction (S9) from the livers of Aroclor-treated rats . The relevance of these findings to mammals is uncertain, not least because of major differences in the metabolism of the DCPs in the microbial assay systems and in vivo . For example, (Z)-DCP is efficiently detoxified in mammals by the operation of a glutathione (GSH)-dependent S-alkyl transferase . It is possible that such detoxification could proceed only very slowly in the microbial assays because the concentrations of GSH could be severely rate-limiting even in those assays fortified by the addition of S9 . The results obtained in the current study demonstrate a dramatic reduction in the microbial mutagenicity of both (Z)- and (E)-DCP when the concentration of GSH in the microbial assays was adjusted to a normal physiological concentration (5 mM) . However, this protective action of GSH was at least as effective in the absence of S9 as in its presence, suggesting that it was not mediated by mammalian GSH transferase . There appears to be little or no GSH alkyl or aryl transferase in the cytosol of S . typhimurium TA100, but intracellular GSH is present at a concentration similar to that found in mammalian cells . Since the uncatalysed reaction between the DCPs and glutathione is relatively slow, the effect is not due simply to their destruction by GSH . It is possible that a physiological concentration of extracellular GSH maintains the intracellular GSH in a reduced form in which its nucleophilic thiol group competes effectively with the nucleophilic centres in the bacterial DNA for the haloalkenes . The current results highlight the efficiency of GSH-linked systems in affording protection against the genotoxic action of the DCPs . It may be presumed that their operation would exert a major limiting effect on the genotoxicity of (Z)- and (E)-DCP in mammals.

Am J Epidemiol, 1984 Jun, 119(6), 907 - 12
An outbreak of salmonellosis associated with a fatality in a healthy child: a large dose and severe illness; Taylor DN et al.; In June 1982, an outbreak of Salmonella gastroenteritis occurred on a farm in Wyoming . All eight affected persons became severely ill 8-18 hours after they had eaten homemade ice cream . A previously healthy 13-year-old boy died 37 hours after exposure; his mother and four younger siblings were transferred to intensive care units in hospitals in adjoining states, and the remaining two adult males were hospitalized locally . Salmonella typhimurium was isolated from all eight ill persons, from the remaining ice cream, and from the family's hens whose eggs were used in the preparation of the ice cream . All Salmonella contained identical plasmids (60-, 5.6-, and 3.3-megadalton); the ice cream contained 10(6) salmonellae/g and, according to food histories, individuals consumed an estimated dose of between 10(8) and 10(9) organisms . The fatal illness occurred in the boy who had eaten the largest amount of ice cream (10(9) organisms) . This report demonstrates that Salmonella can cause fatal illness in previously healthy individuals and that the incubation period and the severity of the illness may be related to the dose.

Mutat Res, 1984 Jun, 127(1), 31 - 7
Production of frameshift mutations in Salmonella by phenanthridinium derivatives: enzymatic activation and photoaffinity labeling; Fukunaga M et al.; The effect of metabolic activation on the mutagenic potential of some phenanthridinium compounds was examined in Salmonella typhimurium strains TA1538 and TA1978 . All of the compounds tested were mutagenic in TA1538, a DNA excision-repair-deficient strain, when metabolizing enzymes were included in the assay . Reversions were not detected when these compounds were examined under the same conditions in TA1978 , the isogenic strain of TA1538 proficient in DNA repair . The mutagenic activity of an azido analog of propidium iodide was also examined using photoactivation and enzymatic activation, and with both conditions, reversions were observed in TA1538 but not in TA1978 . Furthermore, the ranking of mutagenic activity of propidium azide relative to ethidium azide analogs was comparable for both types of activation . The evidence from several studies suggests that the structural requirements for mutagenic activity for this series of phenanthridinium compounds appear to be the same whether mutagenesis is induced via photoactivation or metabolic activation . The interaction with DNA resulting in covalent alteration of the DNA is implicated as the mutagenic mechanism whether the active species is generated by metabolic- or photo-activation.

J Immunol, 1984 Jun, 132(6), 3109 - 15
The role of lipopolysaccharides in the action of the bactericidal/permeability-increasing neutrophil protein on the bacterial envelope; Weiss J et al.; The killing of gram-negative bacteria by the bactericidal/permeability-increasing protein ( BPI ) of neutrophils requires surface binding, and is accompanied by a discrete increase in outer membrane permeability to small hydrophobic substances . This outer membrane alteration appears to be related to perturbation of outer membrane lipopolysaccharides (LPS) . BPI causes extracellular release of LPS, but only at supra-saturating doses . Nevertheless, because the organization of LPS in the outer membrane is altered by pretreatment of bacteria with saturating doses of BPI (producing maximal bactericidal and permeability-increasing effects), the amount of LPS released during Tris-EDTA treatment is reduced by 80% . BPI markedly (approximately 50%) and selectively stimulates biosynthesis of LPS, suggesting an attempt by BPI -killed bacteria to repair outer membrane damage . The removal of surface-bound BPI by 40 mM Mg2+ initiates time- and temperature-dependent repair of the outer membrane permeability barrier and a further increase (approximately 170% of control) in LPS synthesis, even though the bacteria are no longer viable . Mg2+-induced repair is blocked when: 1) a temperature-sensitive mutant (Salmonella typhimurium HD50 ) with a conditional defect in LPS synthesis is incubated at the nonpermissive temperature (42 degrees C); and 2) LPS synthesis is selectively inhibited by a diazaborine derivative (Sandoz drug No . 84474) . In contrast, repair is normal by the mutant at permissive temperatures (30 degrees C) and by the parent strain (S . typhimurium AG701 ) at both 30 degrees C and 42 degrees C . Inhibition (greater than 85%) of protein synthesis by chloramphenicol has little or no effect on repair . These findings indicate that the repair of the permeability barrier after the removal of BPI from the surface requires newly made LPS, but apparently no biosynthesis of other outer membrane constituents, which strongly suggests that the effects of BPI on LPS are mainly responsible for the break-down of the outer membrane permeability barrier.

J Bacteriol, 1984 Jun, 158(3), 1208 - 10
Minimal requirements for rotation of bacterial flagella; Ravid S et al.; An in vitro system of cell envelopes from Salmonella typhimurium with functional flagella was used to determine the minimal requirements for flagellar rotation . Rotation in the absence of cytoplasmic constituents could be driven either by respiration or by an artificially imposed chemical gradient of protons . No specific ionic requirements other than protons (or hydroxyls) were found for the motor function.

J Bacteriol, 1984 Jun, 158(3), 1122 - 7
Enzymatic proof for the identity of the S-sulfocysteine synthase and cysteine synthase B of Salmonella typhimurium; Nakamura T et al.; S-Sulfocysteine synthase was isolated from Salmonella typhimurium LT-2 to homogeneous form with polyacrylamide gel electrophoresis . The molecular weight of this enzyme was determined to be ca . 55,000 . The enzyme consisted of two identically sized subunits, and it contained one pyridoxal phosphate per subunit . The enzyme catalyzed the biosynthesis of cysteine or S-methylcysteine from sulfide or methanethiol and O-acetylserine, respectively, in addition to the formation of S-sulfocysteine from thiosulfate and O-acetylserine . The enzyme is identical to cysteine synthase B . The intracellular level of this enzyme was regulated by lesser extents of the same factors as those effective for cysteine synthase A.

Carcinogenesis, 1984 Jun, 5(6), 809 - 14
Formaldehyde as a possible mutagenic metabolite of N-nitrodimethylamine and of other agents which are suggested to yield non-alkylating species in vitro; Pool BL et al.; N-Nitramines are biologically active compounds of environmental significance . In this study the suggested bioactivation of N- nitrodimethylamine via oxidation at the methyl-group was confirmed, as was indicated by formaldehyde liberation . N- Nitrodimethylamine and formaldehyde as well as the suggested metabolites, N- nitrohydroxymethylmethylamine and N- nitromethylamine were tested for mutagenicity in histidine auxotrophic Salmonella typhimurium strains in a variety of conditions . N- Nitrodimethylamine was mutagenic only in S . typhimurium TA 100 after pre-incubation with bacteria and a complete metabolizing mixture containing 9000 g liver supernatant and NADPH-regenerating cofactors . N- Nitrohydroxymethylmethylamine and formaldehyde were approximately equally mutagenic without the metabolizing mixture in TA 100 and TA 98, but not in TA 1535 . The addition of the 9000 g supernatant of homogenized liver increased the yield of his+ revertants induced by the two compounds . N- Nitromethylamine was not mutagenic with or without the metabolic activation system . The results suggest that formaldehyde is possibly the mutagenically active intermediate formed during in vitro metabolism of N- nitrodimethylamine . Furthermore the participation of formaldehyde as the mutagenic intermediate of other non-alkylating N-nitro and N-nitroso compounds is demonstrated.

Cancer Res, 1984 Jun, 44(6), 2320 - 4
Mutagenicity of the enantiomers of the diastereomeric bay-region benzo(c)phenanthrene 3,4-diol-1,2-epoxides in bacterial and mammalian cells; Wood AW et al.; The mutagenic activities of the enantiomers of the pair of diastereomeric bay-region benzo(c)phenanthrene 3,4-diol-1,2-epoxides were evaluated in histidine-dependent strains of Salmonella typhimurium and in an 8-azaguanine-sensitive Chinese hamster cell line . In strains TA 98 and TA 100 of S . typhimurium, the range in mutagenic activity observed for the four optically active isomers was less than 4- and 2-fold, respectively . The diol-epoxide with (1S,2R,3R,4S) absolute configuration and the benzylic hydroxyl group trans to the epoxide oxygen {(+)-diol epoxide-2} was the most active isomer in both strains . The enantiomeric (-)-diol-epoxide-2 isomer, with (1R,2S,3S,4R) absolute configuration identical to that of the exceptionally tumorigenic (+)-diol-epoxide-2 isomers of benzo(a)pyrene, benz(a)anthracene, and chrysene, was the least active isomer in strain TA 98 (27%) and the second most active isomer in strain TA 100 (90%) . In Chinese hamster V79 cells (-)-diol-epoxide-2 was the most active of the four benzo(c)phenanthrene isomers, and a 4- to 5-fold range in mutagenic activity was observed . The differences in mutagenic activity between the four bay-region diol-epoxide isomers of benzo(c)phenanthrene in the three test systems are relatively small when compared with results from similar studies with optically active bay-region diol-epoxide isomers of three other polycyclic aromatic hydrocarbons, and may be explicable, in part, by a tendency of the hydroxyl groups of benzo(c)phenanthrene diol-epoxides to adopt comparable pseudodiequatorial conformations.

Mutat Res, 1984 Jun, 130(3), 153 - 8
The presence of the mutagenic polycyclic aromatic hydrocarbons benzo{a}pyrene and benz{a}anthracene in creosote P1; Bos RP et al.; Several fractions of creosote P1 separated by TLC showed mutagenicity towards Salmonella typhimurium TA98 . Thus mutagenicity is probably caused by the presence of mutagenic aromatic hydrocarbons . The mutagenic polycyclic aromatic hydrocarbons, benzo{a}pyrene and benz{a}anthracene, were detected in concentrations of 0.18 and 1.1% respectively . Because these compounds are probably not essential for the wood-preserving properties of creosote , a more selective composition of the product should be considered.

Mutat Res, 1984 Jun, 127(1), 9 - 14
Selenium modified mutagenicity and metabolism of benzo{a}pyrene in an S9-dependent system; Teel RW et al.; Selenium added to the incubation mix containing rat-liver S9 modified both the metabolism and mutagenicity of benzo{a}pyrene (BaP) and several of its metabolites . Selenium (Na2SeO3) inhibited the S9-dependent mutagenic effects of BaP on Salmonella typhimurium strain TA100 as indicated by the number of histidine-dependent revertants counted . This inhibition was concentration-dependent over a range of 12.5 to 100 ppm . When used as the substrate the BaP metabolites 7,8-dihydrodiol, 9,10-dihydrodiol and 3-hydroxy also produced significantly fewer revertants in TA100 when selenium was included in the incubation mix . High-performance liquid chromatographic analysis of metabolites from S9-dependent metabolism of BaP indicated that selenium inhibited the formation of 3-hydroxy-BaP, 9,10-dihydrodiol, 7,8-dihydrodiol, 1,3- and 3,6-quinone . Eluting samples on an alumina column to isolate the conjugated metabolites showed that selenium caused 12% less binding to glucuronides, no significant differences in binding to sulfate esters or glutathione but the amount of unmetabolized BaP and unconjugated metabolites was increased by 48% . These results suggest that selenium inhibits S9-dependent BaP metabolism therefore reducing the mutagenic effects of this compound.

J Bacteriol, 1984 Jun, 158(3), 948 - 53
Promoter mutation causing catabolite repression of the Salmonella typhimurium leucine operon; Gemmill RM et al.; Two mutations that affect expression of the Salmonella typhimurium leu operon were investigated . leu operon DNA from these mutant strains was cloned, and nucleotide sequences of the leu control regions were determined . leu-500, which eliminates expression of all four leu genes simultaneously, is a point mutation in the -10 region of the leu promoter . leu-2012 is a point mutation within the -35 region of the leu promoter . leu-2012 suppressed leucine auxotrophy caused by leu-500 only when the medium contained a carbon source that does not cause catabolite repression . A cya mutation (adenylate cyclase deficiency) introduced into the leu-500 leu-2012 strain caused leu enzymes to be made only if cAMP was supplied exogenously . A leu-500 leu-2012 strain containing a crp mutation (cAMP receptor protein deficiency), on the other hand, could not make leu enzymes even in the presence of cAMP . In vitro transcription experiments demonstrated that the leu-2012 mutation created a new transcription initiation site . RNA polymerase utilized this site in vitro in the absence of added cAMP receptor protein and cAMP.

J Bacteriol, 1984 Jun, 158(3), 928 - 33
Cloning and characterization of the Salmonella typhimurium metE gene; Schulte LL et al.; The metE gene of Salmonella typhimurium was cloned into plasmid pACYC184 by using a lambda gt7 -metE transducing phage as a source of metE DNA . The recombinant plasmid, designated pGS41 , carries a 12.8-kilobase-pair EcoRI insert fragment . The metE gene was subcloned from pGS41 into plasmid pBR322 on a 4.2-kilobase-pair EcoRI-HindIII fragment (plasmid pGS47 ) and a 4.5-kilobase-pair PstI fragment (plasmid pGS69 ) . The location of metE in these plasmids was determined by transposon Tn5 insertional inactivation experiments . A metE-encoded polypeptide of 92,500 Mr was detected in a minicell system by using metE+ plasmids as templates . Truncated polypeptides replaced the 92,500-Mr polypeptide when plasmid derivatives containing Tn5 insertions that inactivate metE were used in the system . A comparison of the site of each Tn5 insertion and the size of the polypeptide made in the minicell system allowed us to determine the direction of transcription and translation . The location of the metE promoter was determined by using an in vitro transcription system and by RNA polymerase protection of restriction endonuclease sites.

Mutat Res, 1984 Jun, 136(3), 185 - 99
Relationships between structures and mutagenic potencies of 16 heterocyclic nitrogen mustards (ICR compounds) in Salmonella typhimurium; DeMarini DM et al.; 16 heterocyclic nitrogen mustards (ICR compounds), which were synthesized for use as possible antitumor agents by Creech and coworkers, were tested for mutagenicity in Salmonella typhimurium strains TA1535, TA1536, TA1537, TA1538, TA98 and TA100 . The compounds were incorporated into the top agar at 5 doses: 0.5, 1, 2.5, 5 and 10 micrograms/plate . All of the compounds were negative in TA1535 except ICR 449, which was positive in all 6 strains . The other 15 compounds were positive in the remaining strains with the following exceptions: ICR 371 and 355 were negative in TA100; ICR 445 was negative in TA98 and TA100; and ICR 360 was negative in TA1537, TA1538, TA98 and TA100 . Good qualitative agreement was observed between the mutagenic and antitumor activities of the 16 compounds, and between the mutagenic and carcinogenic activities of the 5 compounds that have been tested for carcinogenicity by Peck and coworkers . However, no significant correlation was found between mutagenic potency in Salmonella and antitumor potency in mice for the 16 compounds . Also, for the 5 compounds that have been tested for carcinogenicity, no significant correlation was found between their mutagenic potency in Salmonella and their carcinogenic potency in mice . In Salmonella, the secondary (2 degrees) amines generally were more mutagenic than their tertiary (3 degrees) amine homologs, although the opposite result has been reported in certain eukaryotes . Relationships between structures and potencies for the different nuclei of the 16 ICR compounds are discussed, as are similarities and differences in strain sensitivities . We conclude that the Salmonella his reversion test is not a good predictor of the antitumor and carcinogenic potencies of these ICR compounds.

Infect Immun, 1984 Jun, 44(3), 633 - 6
Isotype of protective anti-Salmonella antibodies in experimental mouse salmonellosis; Saxen H et al.; Mice and a rabbit were immunized with heat-killed Salmonella typhimurium bacteria or with an O-4,12 antigen-specific octasaccharide-protein conjugate . Immunoglobulin isotypes of the antisera were tested for their capacity to protect mice against experimental salmonellosis . Antibodies of immunoglobulin M + A isotypes were more protective than the immunoglobulin G antibodies in each of the two pools of mouse sera . The same protective pattern was also seen with a rabbit antiserum elicited by the artificial octasaccharide-protein conjugate, i.e., with antibodies with the exclusive specificity for the O-4,12 antigen determinants of S . typhimurium.

Biochem Biophys Res Commun, 1984 May 16, 120(3), 865 - 72
Inactivation of glucosamine-6-phosphate synthetase from Salmonella typhimurium LT 2 SL 1027 by N beta-fumarylcarboxyamido-L-2,3-diamino-propionic acid; Chmara H et al.; N beta- fumarylcarboxyamido -L-2,3-diaminopropionic acid ( FCDP ), a novel glutamine analog, inhibits the reaction of glucosamine-6-phosphate synthetase (EC 5.3.1.19) from Salmonella typhimurium LT 2 by irreversible inactivation of the enzyme . The kinetic data on enzyme inhibition and inactivation are presented . It is suggested that the enzyme inactivation occurs according to a sequential mechanism.

Biochem Pharmacol, 1984 May 15, 33(10), 1601 - 3
Metabolic activation and deactivation of fusarin C, a mutagen produced by Fusarium moniliforme; Gelderblom WC et al.; The metabolic activation and deactivation of fusarin C, a mutagen produced by Fusarium moniliforme strain MRC 826, was studied by the Salmonella typhimurium mutagenicity assay using tester strain TA 100 . A microsomal monooxygenase, preferably induced by phenobarbitone (PB) activities the mutagen to its active mutagenic form . Deactivation of the mutagenic metabolite seems to occur through chemical binding to thiol groups and by enzymatic conjugation mediated by a cytosolic glutathione -S-transferase.

Anal Biochem, 1984 May 15, 139(1), 1 - 16
Isoelectrophoretic separation and the detection of soluble proteins containing acid-labile phosphate: use of the phosphoenolpyruvate:sugar phosphotransferase system as a model system for N1-P-histidine- and N3-P-histidine-containing proteins; Mattoo RL et al.; Procedures have been developed for the detection of acid-labile phosphorylations of proteins . The phosphoproteins were separated by native isoelectric focusing while maintaining the gel at about 0 degree C, and denaturing urea-Nonidet isoelectric focusing gels were adapted to run at -10 degrees C . The proteins of the bacterial phosphoenolpyruvate:sugar phosphotransferase system (PTS), HPr, which contains 1-P-histidine, and factor IIIglc and enzyme I, which contain 3-P-histidine when they are phosphorylated, were used to develop the conditions . Autoradiography of {32P}-labeled phosphoproteins was carried out on frozen gels which had not been acid fixed in order to avoid hydrolysis of the phosphohistidines . The frozen gels were subsequently fixed and stained, and reautoradiography revealed whether the phosphoproteins were acid stable or labile . In addition to the known proteins of the PTS, at least one other protein whose phosphorylation was dependent on enzyme I and HPr was found in Salmonella typhimurium and Escherichia coli {E.B . Waygood , and R.L . Mattoo (1983) Canad . J . Biochem . Cell Biol . 61, 150-153} . Initial experiments with rat tissues have demonstrated acid-labile phosphorylations in proteins which were either {gamma-32P}ATP or {32P}phosphoenolpyruvate dependent . The interconversion of phosphoenolpyruvate and ATP in crude extracts of bacterial cells was examined, and appropriate controls were found . Protein phosphorylation dependent upon phosphoenolpyruvate was much greater in S . typhimurium and E . coli than the corresponding ATP-dependent phosphorylation, while the opposite was found for rat tissues.

J Biol Chem, 1984 May 10, 259(9), 5851 - 6
Characterization of an R-plasmid dihydrofolate reductase with a monomeric structure; Joyner SS et al.; A plasmid-encoded dihydrofolate reductase that originated in a clinical isolate of Salmonella typhimurium (phage type 179) moderately resistant to trimethoprim has been isolated and characterized . The dihydrofolate reductase (called type III) was purified to homogeneity using a combination of gel filtration, hydrophobic chromatography, and methotrexate affinity chromatography . Polyacrylamide gel electrophoresis under denaturing and nondenaturing conditions indicated that the enzyme is a 16,900 molecular weight monomeric protein . Kinetic analyses showed that trimethoprim is a relatively tight binding inhibitor (Ki = 19 nM) competitive with dihydrofolate . The enzyme is also extremely sensitive to methotrexate inhibition (Ki = 9 pM) and has a high affinity for dihydrofolate (Km = 0.4 microM) . The sequence of the first 20 NH2-terminal residues of the protein shows 50% homology with the trimethoprim-sensitive chromosomal Escherichia coli dihydrofolate reductase and suggests that the two enzymes may be closely related . This is the first example of a plasmid encoding for a monomeric dihydrofolate reductase only moderately resistant to trimethoprim, and a resistance mechanism, dependent in part on the high dihydrofolate affinity of the type III enzyme, is proposed.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1984 May, 179(2), 162 - 9
{Significance of antibiotic-forming microorganisms in biological waste water clarification}; Schomburg I et al.; Streptomyces spec . producing antibiotics were detected very seldom in the wastewater pretreatment plant of Braunschweig . However, Bacillus spec . producing antibiotics are common . There are about one permille of the total population of bacteria in wastewater (Fig . 1) . Reflecting the total number of bacteria, the psychrophilic microorganisms growing at 20 degrees C increase more during the oxidation step of wastewater treatment than the mesophilic bacteria growing at 30 or 37 degrees C . But reflecting the bacilli the strains producing antibiotics growing at 30 or 37 degrees C propagate stronger than the psychrophilic group (Fig . 2) . About 90% or more of a total of 194 isolated Bacillus strains producing antibiotics showed antibiotic activity against the tested grampositive bacteria Listeria monocytogenes and Staphylococcus aureus . Only few strains were active against Candida albicans, E . coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella typhimurium (Fig . 3, 4, and Table 1) . During the summer (July) the percentage of strains producing antibiotics against grampositive bacteria was higher than in the winter (January) (Fig . 4) . Also the deep freezing of samples increased the percentage of antibiotic producers (Fig . 2) . Some species were isolated even only from freezed and again thawed samples (Table 1).

Mutat Res, 1984 May, 140(1), 7 - 11
Metabolism of acridine by rat-liver enzymes; McMurtrey KD et al.; Metabolism of acridine by S10 fractions from control adult male Sprague-Dawley rats produces mainly 9- acridone , apparently catalyzed by aldehyde oxidase ( ED1 .2.3.1) . In contrast, the predominant metabolic product produced by the corresponding S10 fraction of PCB-induced liver enzymes is a dihydrodiol (either the 2,3- or 3,4-isomer) presumably derived from an epoxide . Several minor metabolites of unknown structure are also formed . During in vitro reactions aldehyde oxidase requires neither atmospheric oxygen nor NADPH . Acridine has been reported to be mutagenic to Salmonella typhimurium, but only in the absence of PCB-induced activating enzymes . It also has been reported to produce chromosomal aberrations in cultured Chinese hamster cells both with and without enzymatic activation . While a connection between aldehyde oxidase catalysis and mutagenic action of acridine has not been established, the extensive metabolic potential of this compound implies that complete description of mutagenicity will be difficult.

J Natl Cancer Inst, 1984 May, 72(5), 1113 - 6
Mutagenic impurities in 1,3-dichloropropene preparations; Talcott RE et al.; A widely used pesticide, 1,3-dichloropropene {(DCP) CAS: 542-75-6}, has been reported to be mutagenic to Salmonella typhimurium TA100, but large variations in specific mutagenic activity have been observed among different preparations . The purposes of this investigation were to determine the probable cause of the interpreparational variation and to provide new information on the nature of the mutagenic activity . Four preparations were assayed for mutagenic activity before and after silicic acid chromatography . None of the preparations retained mutagenic activity after chromatography, but each contained direct-acting mutagenic polar impurities . The specific mutagenic activities of the unpurified DCP samples appeared to be determined by the mutagenic activities of their polar impurities . A mixture of mutagenic polar impurities could be regenerated by refluxing a purified DCP preparation for 6 hours . The fraction of polar impurities from one of the preparations was analyzed by gas chromatography-mass spectroscopy . Although its composition was too complex to characterize completely, two known mutagens, epichlorhydrin (CAS: 106-89-8; 1-chloro-2,3-epoxypropane) and 1,3-dichloro-2-propanol (CAS: 96-23-1), were tentatively identified . In view of these results, future studies are required to establish whether DCP itself is a chemical carcinogen or whether its previously observed carcinogenicity resulted from the presence of mutagenic impurities.

Jpn J Antibiot, 1984 May, 37(5), 918 - 26
{The mutagenicity evaluation of MT-141, a new cephamycin}; Hirano F et al.; Mutagenicity of MT-141, a new cephamycin, was evaluated by in vitro and in vivo assays . MT-141 did not induce mutations of the test strains, Escherichia coli WP2 (uvr A) and Salmonella typhimurium TA1535, TA1537, TA1538, TA100 and TA98, with and without metabolic activation in vitro . In bone marrow micronucleus assay with male mice, MT-141 showed no induction of micronucleated polychromatic erythrocyte at 6 hours and 30 hours after administration . In addition MT-141 was found not to cause any dominant lethal effects on male mice for 8 weeks after administration.

Food Chem Toxicol, 1984 May, 22(5), 355 - 60
The effects of butylated hydroxytoluene on the in vitro metabolism, DNA-binding and mutagenicity of aflatoxin B1 in the rat; Fukayama MY et al.; Butylated hydroxytoluene pretreatment in the rat enhanced the total in vitro metabolism of aflatoxin B1 by the hepatic postmitochondrial fraction (S-9) and increased the formation of aflatoxin M1, aflatoxin Q1 and a metabolite tentatively identified as the aflatoxin-glutathione conjugate, the latter being the major metabolite produced . Addition of diethyl maleate, a glutathione depletor, to the incubation mix, reduced formation of the conjugate . No significant difference between treated and control animals was observed in the S-9-mediated binding of aflatoxin B1 to calf thymus DNA . However, the mutagenicity of aflatoxin B1 in Salmonella typhimurium TA98 was significantly lower in the presence of S-9 from BHT-treated rats than with S-9 from controls.

Cancer Res, 1984 May, 44(5), 1831 - 9
Comparative aflatoxin B1 mutagenesis of Salmonella typhimurium TA 100 in metabolic and photoactivation systems; Israel-Kalinsky H et al.; Salmonella typhimurium TA 100 was mutagenized with photoactivated aflatoxin B1 (AFB1) and AFB2 . Levels of mutagenesis induced by AFB1 correlated with levels of in vitro covalent binding of {3H}AFB1 to calf thymus DNA . The same phenomenon was observed with AFB2 . Photoactivated AFB1 induced lethality in the mutagenized cultures, and AFB2 failed to do so . Extraction of nucleic acids from cultures mutagenized by photoactivated or metabolically activated {3H}AFB1 revealed that: (a) in situ levels of {3H}AFB1 binding to DNA were proportional to induction of mutational and lethal events in both cases; (b) mammalian metabolism and photoactivation produced AFB1:DNA lesions possessing comparable lethality and mutagenicity; and (c) {3H}AFB1 binding levels to bacterial RNA did not correlate with mutagenesis and lethality.

Bull Soc Pathol Exot Filiales, 1984 May-Jun, 77(3), 284 - 7
{Biotypes of Salmonella typhimurium in Iraq}; Allos G et al.; 207 Salmonella typhimurium strains isolated from childrens below three years (190 strains), adult patients (8 strains), health carriers (7 strains) or animals (2 strains) were studied with the biotyping scheme of Cordano, Richard and Vieu (1971) . Five biovars were found and 76.8% of the strains were TTR+, Ino+, Tre+, d . Tar- (biovar d) . In Irak the epidemiology of the Salmonella typhimurium human infections is associated with an high frequency of strains of Salmonella typhimurium 0:5- (var . Copenhagen), biovar d.

Behring Inst Mitt, 1984 May, (74), 174 - 82
Chronic bacterial infection models for BRM screening; Dickneite G et al.; Models of chronic infections have been established to test the therapeutic and prophylactic potency of biological response modifiers (BRM) . As an example for a BRM the immunostimulating drug Bestatin was tested . It is of dipeptide nature and was purified from culture supernatants of Streptomyces olivoreticuli . In two chronic bacterial infection models, induced by the inoculation of NRMI mice with Salmonella typhimurium or with a nephropathogenic strain of Escherichia coli, Bestatin acted prophylactically as well as therapeutically . This could be seen from the reduction of bacterial organ colonization and the inhibition of organ lesion formation . Bestatin could be shown to stimulate macrophage activity and to potentiate delayed type hypersensitivity, but not be effective on the humoral immune response.

Ann Microbiol (Paris), 1984 May-Jun, 135A(3), 467 - 71
{Vaccination using Salmonella typhimurium Rc in protein-deprived BALB/c mice}; Binder P et al.; Four-week old BALB/c mice were fed a 4% protein diet for 6 weeks . At the 3rd week of undernourishment, they were orally vaccinated with a live vaccine, Salmonella typhimurium Rc . the mice were challenged 3 weeks after vaccination, and malnutrition was discontinued at that time . Results suggested that the live vaccine may be pathogenic when associated with a protein-deficient diet.

Cancer Lett, 1984 May, 23(1), 97 - 101
Mutagenicity of the two main components of commercially available carcinogenic aristolochic acid in Salmonella typhimurium; Schmeiser HH et al.; One of the 2 main components of the commercially available carcinogenic aristolochic acid (AA) was isolated, the other was enriched . Three different aristolochic acid samples (AAI 99% pure; AAI 65% + AAII 35%; AAI 32% + AAII 68%) were assayed for mutagenic activity in Salmonella typhimurium TA1537, TA100 and TA100 NR with and without the addition of a metabolizing mixture . The two main components (AAI and AAII) were direct mutagens in Salmonella strains TA1537 and TA100 with almost equal mutagenic potency . In TA100 NR the aristolochic acid samples showed no or only a very low level of biological activity, indicating the necessity of nitroreduction for the bioactivation of the samples . These findings suggest that both AAI as well as AAII can be used in further studies to elucidate the metabolism of aristolochic acid.

Zh Mikrobiol Epidemiol Immunobiol, 1984 May, (5), 55 - 8
{Capacity of triterpene glycosides from holothurians to stimulate antibacterial resistance in a model of experimental murine salmonellosis}; Sedov AM et al.; When injected intraperitoneally into mice in doses of 40.0-0.4 microgram, Cucumarioside, the preparation of triterpene glycosides obtained from sea cucumbers (Cusumaria japonica), enhanced the resistance of the animals to the subsequent challenge with Salmonella typhimurium . The study of the duration of the persistence of salmonellae in mice receiving the preparation in a dose of 0.001 microgram revealed a decrease in the contamination of their organs . The same dose of the preparation stimulated the phagocytic activity of peritoneal exudate cells with salmonellae showing decreased cytopathogenic action . This suggests that Cucumarioside enhances nonspecific protective factors, activates the macrophagal system and facilitates the development of complete phagocytosis.

J Bacteriol, 1984 May, 158(2), 571 - 4
Gratuitous repression of avtA in Escherichia coli and Salmonella typhimurium; Whalen WA et al.; avtA , which encodes transaminase C (alanine-valine transaminase), is repressed by excess-L-alanine or L-leucine, and also by limitation for any of a number of amino acids in Escherichia coli and Salmonella typhimurium . Amino acid limitation causes repression by promoting the accumulation of L-alanine or L-leucine or both . avtA is also repressed by L-alpha-aminobutyric acid and other nonprotein amino acids which are structurally similar to L-alanine . We hypothesize that L-alanine and L-alpha-aminobutyric acid, whose syntheses are catalyzed by transaminase C, are the true corepressors of avtA . Repression by structural analogs of the true corepressors is termed gratuitous repression.

Food Chem Toxicol, 1984 May, 22(5), 399 - 401
Ames mutagenicity tests on purified 3-nitropropionic acid; Hansen TJ; 3- Nitropropionic acid is a toxic compound produced by several moulds involved in food fermentation or spoilage . An impure commercial sample of this compound was previously reported as being mutagenic to Salmonella typhimurium strains TA1535 and TA100 . In the present study, a sample from the same lot of 3- nitropropionic acid was mutagenic in strain TA100 without metabolic activation, but this activity was diminished after recrystallization . This sample was not mutagenic in strain TA98, before or after recrystallization . A new, purer commercial sample was non-mutagenic in strains TA98, TA100 and TA1538, with or without metabolic activation . Therefore the mutagenicity reported to be due to 3- nitropropionic acid was considered to be due to the impurity(ies).

Carcinogenesis, 1984 May, 5(5), 635 - 9
Mutagenic properties of N-cyclopropyl and N-allyl-N-nitroso compounds . Studies on the nature of alkylating species; Wiessler M et al.; A series of directly acting N-nitroso compounds, N-nitroso-N-allyl urea 6, N-nitroso-N-cyclopropyl urea 7, N-nitroso-acetoxymethyl-allylamine 8, N-nitroso-acetoxymethyl- cyclopropylamine 9, N-nitroso(1- acetoxyethyl )allylamine 10 and N-nitroso(1- acetoxyethyl ) cyclopropylamine 11, which may hydrolize to liberate either cyclopropylating or allylating electrophiles, were synthesized and comparatively investigated for mutagenicity in Salmonella typhimurium TA 1535 . Hydrolysis rates in aqueous buffered solution do not differ significantly in the allyl- and cyclopropyl series . Analysis of the hydrolysate of all compounds revealed only the presence of allylalcohol and not cyclopropanol . In contrast to the expected equal potencies, due to chemical rearrangement of the alkylating species from cyclopropylcation to allylcation , the results showed that the cyclopropylating analogs were much more effective mutagens than were the allylating compounds . We conclude that for the cyclopropylating compounds the diazonium ion intermediate - and not the free cation - is the alkylating species, during mutagenesis.

Chem Biol Interact, 1984 May, 49(3), 351 - 68
Metabolism of 1,8-dinitropyrene by Salmonella typhimurium; Bryant DW et al.; Earlier work has shown that many nitroaromatic and nitroheterocyclic compounds are directly 'activated' to their ultimate mutagenic forms through the action of bacterial nitroreductase enzymes . However, in the case of 1,8-dinitropyrene (DNP) and certain other nitroarenes the pathway of activation is more complex and neither the identity of the ultimate mutagens nor the nature of the DNA adducts formed are known . We now show that Salmonella typhimurium strains TA98 and TA1538, which are sensitive to DNP and have wild type nitroreductase complements, do metabolize DNP to 1-amino-8-nitropyrene (ANP) and 1,8- diaminopyrene (DAP) but that these compounds are much weaker mutagens than DNP . These two strains (TA98 and TA1538) contain two separable components of nitroreductase activity as determined using nitrofurazone as the substrate . The major component, at least, is capable of reducing both 1-nitropyrene (NP) and DNP although the rates are much lower than with nitrofurazone . TA98NR , a mutant of TA98 that is resistant to nitrofurazone and NP but not to DNP, lacked the major nitroreductase but retained two minor components . In contrast, a mutant ( DNP6 ) which is resistant to DNP (but not to NP) contained a full complement of nitroreductases . When the metabolism of {3H}DNP by crude extracts of TA98 was re-examined, previously undetected metabolites were found . These were more polar than DAP and ANP and were also seen when TA98NR was used as the source of enzyme . These metabolites were not formed when enzymes from TA98DNP6 or TA98NR / DNP6 were used . This work supports the notion that some enzymic activity other than (or in addition to) nitroreductase is required for the activation of DNP and that the new polar metabolites may be related to this process.

Chem Biol Interact, 1984 May, 49(3), 329 - 40
Enzyme inhibition as a possible mechanism of the mutagenicity of dithiocarbamic acid derivatives in Salmonella typhimurium; Rannug A et al.; In recent years data have accumulated regarding genotoxic properties of dithiocarbamic acid derivatives . The results from the present work indicate that the mutagenicity of these compounds depends on an indirect effect via oxygen radicals . Mutagenicity of tetramethylthiuram disulfide ( TMTD ), that was used as a model substance, was established with both frameshift and base substitution sensitive strains of Salmonella typhimurium . Addition of copper ions resulted in a decreased survival at low dithiocarbamate doses . The dose response curves seem to correlate with the formation of two types of metal dithiocarbamate complexes . At low doses charged complexes are formed, while the formation of uncharged complexes is favoured at higher dosages . The data suggest that this formation of uncharged metal complexes implies a decreased toxicity but at the same time an increased mutagenicity . The mutagenicity of both TMTD and its ethyl analogue TETD was enhanced by oxygen . Furthermore, TMTD potentiates the mutagenic action of menadione, a substance that produces O(2) and H2O2 by redox cycling with molecular oxygen . Interaction of uncharged metal dithiocarbamate complexes with both production and detoxification of reactive forms of oxygen is suggested to be responsible for the direct mutagenic effects via oxidative damage to DNA . A further enhancement of the oxygen radical content of the cells by adding microsomes that produce oxygen radicals via autoxidation of cytochrome P-450 is proposed as the mechanism for the 'metabolic activation of TMTD '.

Cell, 1984 May, 37(1), 225 - 32
AppppA and related adenylylated nucleotides are synthesized as a consequence of oxidation stress; Bochner BR et al.; AppppA , ApppGpp , AppppG , ApppG , and ApppA rapidly accumulate to high levels in Salmonella typhimurium following exposure to a variety of oxidizing agents, but not to a variety of other stresses . Among the agents inducing these adenylylated nucleotides are 1-chloro-2,4-dinitrobenzene, diamide, hydrogen peroxide, t-butyl hydroperoxide, N-ethyl maleimide, iodoacetamide, cadmium chloride, and a variety of quinones . Some of these oxidizing agents cause preferential synthesis of specific adenylylated nucleotides, e.g., N-ethyl maleimide induces ApppA and menadione induces ApppGpp . Our data, as well as other evidence in the literature, strongly suggest that oxidation stress is coupled to adenylylated nucleotide synthesis by aminoacyl-tRNA synthetases . Although adenylylated nucleotides are made by tRNA synthetases in vitro, their synthesis in vivo is not a simple consequence of inhibition of synthetase activity . Compounds that inhibit normal charging by aminoacyl-tRNA synthetases do not result in the synthesis of adenylylated nucleotides, nor do mutations in tRNA synthetase structural genes or tRNA structural, modifying, or processing genes . We propose that the family of adenylylated nucleotides are alarmones signaling the onset of oxidation stress, and that particular ones may be alarmones for specific oxidative stresses, e.g., ApppGpp for oxidative damage to amino acid biosynthesis.

Cancer Res, 1984 May, 44(5), 2023 - 32
Phagocytosis and solubilization of fixed cells by metastatic hamster embryo fibroblasts, Nil2C2; Sakiyama H et al.; When Nil2C2, a metastatic clone derived from hamster embryo fibroblasts (Nil), was inoculated over {3H}leucine-labeled fixed cells, Nil2C2 cells solubilized and phagocytosed fixed cells, and the radioactivity was released into the culture medium as trichloroacetic acid-soluble fragments . The solubilization of fixed cells was dependent on both the time of incubation of living cells with fixed cells and the number of living cells inoculated . Nil2C2 cells were shown by autoradiographic and electron microscopic studies to peel off fixed cells and ingest them as large fragments . The solubilization of fixed cells was significantly decreased when plasminogen was depleted from the culture medium . Protease inhibitors such as leupeptin, epsilon-aminocaproic acid, and soybean trypsin inhibitor partially inhibited the proteolysis and phagocytosis of Nil2C2 cells . Mouse peritoneal macrophages activated by Salmonella typhimurium solubilized fixed cells after the addition of 12-O-tetradecanoylphorbol-13-acetate . However, they did not phagocytose fixed cells as large fragments.

J Bacteriol, 1984 May, 158(2), 603 - 8
Positive control of the L-rhamnose genetic system in Salmonella typhimurium LT2; Al-Zarban S et al.; A total of 28 L-rhamnose-negative mutants in Salmonella typhimurium LT2 were all linked by P22 transduction and were classified into five groups on the basis of genetic and biochemical experiments . Deletion mapping showed that the gene order was rhaD rhaA rhaB rhaC rhaT . rhaA mutants lacked an inducible L-rhamnose isomerase, rhaB mutants lacked an inducible L- rhamnulokinase , and rhaD mutants were probably defective in L- rhamnulose -1-phosphate aldolase . Mutants that were unable to accumulate L-{14C}rhamnose but could grow on 1% L-rhamnose were designated rhaT to indicate a defect in L-rhamnose transport . Genetic evidence supports the hypothesis that the rhaC gene is a positive regulator of rha gene expression . (i) Pleiotropically negative mutants in the rhaC gene were isolated at a high frequency . (ii) Mutants containing an insertion or deletion within the rhaC gene had a pleiotropically negative phenotype . (iii) Complementation tests indicated that rhaC + was dominant to rhaC - . (iv) Rha+ revertants of deletion and Tn10 insertion mutations in the rhaC gene were isolated.

Zh Mikrobiol Epidemiol Immunobiol, 1984 May, (5), 48 - 50
{Ultrastructural study of the surface formations of Salmonella typhimurium H-3048 grown on a medium with sodium arachidonate added}; Pak SG et al.; Ultrastructural changes in the surface formations of S . typhimurium grown in a culture medium with sodium arachidonate added at different concentrations have been studied by means of electron microscopy.

Infect Immun, 1984 May, 44(2), 274 - 81
Mechanism of interaction of Salmonella and Schistosoma species; Melhem RF et al.; In endemic areas where Salmonella and Schistosoma species co-occur, several lines of evidence suggest a synergistic bacteria-parasite interaction that results in a protracted course for the salmonella infection that has proven difficult to diagnose and therapeutically remedy . In an in vitro system using a pilus-negative and a pilus-producing transductant strain of Salmonella typhimurium we show that pili are the ligands for bacterial adherence to the schistosome surface tegument . Antipili antibodies produced in rabbits against purified pili, purified and digested to monovalent (Fab) fragments, blocked the association of Salmonella sp . to the surface tegument of Schistosoma sp., further demonstrating that pili are the appendages necessary for bacteria-parasite surface interaction . The use of carbohydrates, lectins, and enzymes demonstrated that the bacteria-parasite surface interaction was specific, mediated by pili that specifically recognize and bind to mannose-like receptors, probably glycolipids, on the surface of the worms . We suggest that prolonged salmonellosis in schistosome-infected patients is due to an association of Salmonella sp . with the schistosome worms themselves and further that the schistosome worms provide a multiplication focus for these bacteria in the portal mesenteric system, with a persisting bacteremia following.

J Biol Chem, 1984 Apr 25, 259(8), 4846 - 51
The biosynthesis of gram-negative endotoxin . Identification and function of UDP-2,3-diacylglucosamine in Escherichia coli; Bulawa CE et al.; Escherichia coli mutants defective in the pgsB gene are phosphatidylglycerol-deficient in certain genetic settings and accumulate novel, glucosamine-derived phospholipids (Nishijima, M., and Raetz, C . R . H . (1979) J . Biol . Chem . 254, 7837-7844) . The simplest of these compounds is 2,3-diacylglucosamine 1-phosphate (2,3-diacyl-GlcN-1-P) ("lipid X" of E . coli), in which beta-hydroxymyristoyl moieties are the sole fatty acid substituents (Takayama, K., Qureshi, N., Mascagni, P., Nashed, M . A., Anderson, L., and Raetz, C . R . H . (1983) J . Biol . Chem . 258, 7379-7385) . We now report a sensitive radiochemical method for detection of 2,3-diacyl-GlcN-1-P in wild type E . coli and demonstrate that there are about 4000 molecules/cell (0.02% of the total CHCl3-soluble phosphorus) . In mutants bearing the pgsB1 lesion, the levels are 100- to 300-fold higher . In addition, we have discovered a novel liponucleotide, UDP-2,3-diacyl-GlcN, that also accumulates in conjunction with the pgsb1 mutation . This material represents 0.005% of the wild type phospholipid and accumulates 50- to 100-fold in the mutant . The identification of UDP-2,3-diacyl-GlcN in E . coli is based on: 1) migration of a minor 32P-labeled lipid from wild type and mutant cells with a UDP-2,3-diacyl-GlCn standard during two-dimensional thin layer chromatography; 2) susceptibility of this 32P-labeled material to cleavage by a liponucleotide-specific pyrophosphatase; and 3) chromatographic identification of {32P}UMP and {32P}2,3-diacyl-GlcN-1-P (lipid X) as the sole products of the enzymatic degradation . As shown in the accompanying article, this novel nucleotide is crucial for biosynthesis of lipid A disaccharides in extracts of E . coli and Salmonella typhimurium.

Experientia, 1984 Apr 15, 40(4), 370 - 1
Effect of the rat liver S9 fraction on the mutagenicity of azathioprine in the Salmonella/mammalian microsome assay; Nepomnaschy I et al.; Azathioprine is a direct acting mutagen in Salmonella typhimurium TA100 and TA1535 . Addition of rat liver S9 fraction with or without co-factors, or glutathione, causes a decrease in the mutagenicity of azathioprine in TA100 and an increase in TA1535, indicating the effect of SH groups.

Mutat Res, 1984 Apr, 126(2), 139 - 44
Relationship between polarographic reduction potential and mutagenicity of nitroarenes; Klopman G et al.; A series of nitropyrenes and other nitroarenes were reduced electrochemically with a dropping mercury electrode . The half-wave potentials (E1/2) corresponding to the reduction of the various nitro functions mutagenicities exhibited by these chemicals in Salmonella typhimurium strains TA98 and TA1538 was demonstrated . A linear relationship between E1/2 and the calculated energies of the Lowest Unoccupied Molecular Orbital (LUMO) was also established . This indicates that the mutagenicities of nitroarenes can be predicted from calculated LUMO energies.

Cancer Lett, 1984 Apr, 22(3), 305 - 14
Antimutagenic effect of rat small intestine in vitro on 1,1,2,3-tetrachloropropene and 1,1,2,3,3-pentachloropropene; Santodonato J et al.; The direct mutagenic activity of 1,1,2,3- tetrachloropropene and 1,1,2,3,3- pentachloropropene in Salmonella typhimurium was measured before and after incubation in the presence of intact segments of rat small intestine in vitro . The number of revertants in tester strain TA100 was reduced by about 95% when these chloropropenes were exposed to rat small intestine for 10-30 min immediately prior to determination of mutagenicity . The existence of an intestine-mediated detoxication reaction was postulated, and was supported by observations that incubation with the chloropropenes for 30 min caused a 48-68% depletion of intestinal glutathione in vitro . Although addition of glutathione to the chloropropenes reduced mutagenicity, the amount of tissue glutathione consumed during incubation of mutagen with intestinal segments is probably insufficient to account for the detoxication . Additional metabolic reactions and/or non-specific protein binding may occur in the intact intestine which contribute to the antimutagenic effect . These initial results support the existence of an effective detoxication mechanism by the small intestine which is likely to reduce the absorption of direct-acting mutagens and other electrophiles.

Cancer Lett, 1984 Apr, 22(3), 255 - 62
Mutagenicity of 1-nitropyrene metabolites from lung S9; King LC et al.; The mutagenicity of 1-nitropyrene metabolites from rabbit lung S9 incubates was evaluated using the Salmonella typhimurium plate incorporation assay with strain TA98, with and without Aroclor-induced rat liver S9 . The following metabolites were isolated, identified and quantitated by HPLC: 1-nitropyrene -4,5- or -9,10-dihydrodiol (K-DHD), N-acetyl-1-aminopyrene ( NAAP ), 1-aminopyrene (1-AMP), 10-hydroxy-1-nitropyrene, 4-, 5-, 6-, 8- or 9-monohydroxy-1-nitropyrene (phenols) and 3-hydroxy-1-nitropyrene . The predominant metabolites formed by lung S9 incubates were K-DHD, 3-OH-1-nitropyrene and phenols . All of the metabolites were mutagenic in the absence of the exogenous rat liver S9 metabolic activation system, and several, including two unidentified metabolites were more potent than the parent 1-nitropyrene . The mutagenicity of 3 of the metabolites ( NAAP , 10-OH-1-nitropyrene and phenols) were enhanced by S9 while most of the other metabolites were less mutagenic in the presence of S9 . These results indicate that lung tissue is capable of both oxidative and reductive metabolism which produced mutagenic metabolites, several of which were more potent than the parent compound, 1-NP.

J Natl Cancer Inst, 1984 Apr, 72(4), 863 - 9
N-nitrosophenacetin: its synthesis, characterization, mutagenicity, and teratogenicity; Lin JK et al.; Reaction of phenacetin (CAS: 62-44-2; p-acetophenetidide) with nitrous fumes (N2O3) in glacial acetic acid at 0-5 degrees C yields N-nitrosophenacetin (NP), 2-nitrophenacetin, N-nitroso-2-nitrophenacetin (NNP), and other compounds . Both NP and NNP are fairly stable at low temperature (-30 degrees C) but extremely labile at ambient temperature . NP (median lethal dose to Sprague-Dawley rat: 21 mg/kg body wt) is 80 times more toxic than its parent compound phenacetin and is directly mutagenic to bacterial cells including Salmonella typhimurium and Sarcina lutea . The mutagenicity of NP is comparable to that of N-methyl-N'-nitro-N-nitrosoguanidine {(MNNG) CAS: 70-25-7; 1-methyl-3-nitro-1-nitrosoguanidine} and requires no microsomal metabolic activation . The teratogenic potential of NP was studied in White Leghorn chick embryos given a single dose of 5-15 micrograms/egg on day 6 of incubation . A low incidence of exencephaly and eyelid defect and a high incidence of feather and claw malformations were found in the treated group; no such malformed embryos were found in the control group . The teratogenicity of NP was found to be weaker than that of MNNG, but stronger than that of N-methyl-N-nitrosourea (CAS: 684-93-5), dimethylnitrosamine (CAS: 62-75-9; N-nitrosodimethylamine), and diethylnitrosamine (CAS: 15-18-5; N-nitrosodiethylamine).

Mikrobiyol Bul, 1984 Apr, 18(2), 99 - 106
{Salmonella tester strain TA104 for the detection of mutagenic and carcinogenic chemicals in our environment}; Menevse S et al.; We used the Salmonella mutagenicity test for detecting chemical carcinogens as mutagens in the Salmonella typhimurium tester strain TA104 . The mutagenicity of several compounds was assessed by induction of histidine revertants in the TA104 . In each experiment we routinely included positive mutagenesis controls using three different concentrations of known mutagens . The mutagenic chemicals such as sodium azide, hydrogen peroxide and hydroxylamine were found to be mutagenic to TA104 at very low concentration (10(-4) mg/ml) . Their mutagenic activity decreased while their concentrations were increased . The effect of acridine orange, 2, 4, 6-trinitrobenzene sulphonic acid, 2- phenylnaphthalene and 20- methylcholanthrene were also found to be mutagenic to TA104 at the concentration of 10(-2) mg/ml . The mutagenicity of other materials such as hair dyes, meat- broth preparations+ and cigarette smoke condensates were also tested, and all of them were found to be mutagenic to TA104 . The highest mutagenic activities were observed at the concentration of 10 mg/ml for two different hair dyes and of 1 mg/ml for cigarette smoke condensates.

J Appl Toxicol, 1984 Apr, 4(2), 97 - 100
Mutagen formation in browning model systems; Shibamoto T; A browning model system, consisting of diacetyl and ammonia, produced frameshift and base-pair substitution mutagens when the system was heated over 20 min and 120 min, respectively . The major product was 2,4,5- trimethylimidazole , which showed no mutagenicity toward Salmonella typhimurium strains TA98 and TA100 with or without metabolic activation . When furfural was reacted with nitrate under mild conditions (for 30 min to 3 h at 0-25 degrees C and pH 2-7), it did not produce mutagenic nitrofuran derivatives . However, the ethyl ether extract obtained from the reaction mixture of furfural and nitrate with hydrochloric acid exhibited strong mutagenic activities toward S . typhimurium strains TA98 and TA100 in the presence of metabolic activation . The major product of this reaction mixture, 4- nitrofurfural , exhibited no mutagenicity toward tester strains TA98 and TA100 with or without metabolic activation . Pure active mutagen(s) was (were) not, however, identified in either system.

Acta Pathol Microbiol Immunol Scand {B}, 1984 Apr, 92(2), 107 - 13
Activation of polymorphonuclear leukocytes by salmonella; Huixiu J et al.; The interaction of polymorphonuclear leukocytes (PMN) with salmonella, as studied by chemiluminescence and phagocytosis, was very different for a number of clinical isolates . Particularly bacteria in the serogroups C1 and E4 deviated from other Salmonella . The differences were observed in the rate of activation, peak value, duration of the chemiluminescence, and in the extent of association and ingestion as studied microscopically . Old laboratory S-strains such as Salmonella typhimurium 395 MS and S . minnesota S99 , which did not associate with the PMN, showed little activation of the PMN, whereas their phagocytosis-sensitive R-mutants induced rapid activation, high peak values, and short duration of the chemiluminescence . Certain isolates belonging to the C1/E4 group induced intermediate types of reactions . The kinetics of the activation was related to the physicochemical surface properties of the bacteria . Heating the bacteria at 70 degrees C for 45 min enhanced the activation of PMN by the S-type strains conspicuously but in different ways, whereas that of R-mutants was delayed . Different clinical isolates of salmonella have shown different physico-chemical surfaces, liability to phagocytosis by PMNs and different degrees of eliciting inflammatory mediators from PMNs in vitro . The results indicate that the C1/E4 group of Salmonella has pathogenicity mechanisms different from most salmonellae.

J Appl Bacteriol, 1984 Apr, 56(2), 269 - 74
L-Rhamnose utilisation in Salmonella typhimurium; Akhy MT et al.; L-Rhamnose is degraded by strains of Salmonella typhimurium by isomerisation to L- rhamnulose , phosphorylation to L- rhamnulose -1-phosphate and cleavage to lactaldehyde and dihydroxyacetone phosphate . The enzymes involved are, respectively, rhamnose isomerase ( RhaI ), rhamnulokinase ( RhuK ) and an aldolase (Ald) . Strains able to grow rapidly on L-rhamnose contained a high-affinity uptake system for 3H-L-rhamnose that was induced by L-rhamnose and repressed by D-glucose . The synthesis of RhaI and RhuK was also induced by L-rhamnose but was not repressed by D-glucose . The synthesis of Ald was constitutive . Data are presented on some strains which grow very slowly on L-rhamnose and on others which do not utilise it.

Food Chem Toxicol, 1984 Apr, 22(4), 253 - 9
Mutagenicity of 2-hydroxyalkyl-N-nitrosothiazolidines; Umano K et al.; The mutagenicity of 2-hydroxyalkyl-N- nitrosothiazolidines was tested using Salmonella typhimurium strains TA98 and TA100 . The N- nitrosothiazolidines tested were unsubstituted N- nitrosothiazolidine (NT), N- nitrosothiazolidine -4-carboxylic acid ( NTC ), 2-hydroxymethyl-N- nitrosothiazolidine ( HMNT ), 2-(1,2,3,4- tetrahydroxybutyl )-N- nitrosothiazolidine , 2-(1,2,3,4- tetrahydroxypentyl )-N- nitrosothiazolidine , 2-(1,2,3,4,5- pentahydroxypentyl )-N- nitrosothiazolidine ( PHPNT ) and 2-(1,2,3,4,5- pentahydroxypentyl )-N- nitrosothiazolidine -4-car boxylic acid . Among the N- nitrosothiazolidines tested, only HMNT and PHPNT exhibited clear dose-response mutagenicity toward strain TA100 with or without metabolic activation . None of the 2-hydroxyalkyl-N- nitrosothiazolidines were mutagenic to strain TA98 . NT exhibited much stronger mutagenicity than either HMNT or PHPNT . Mutagenic activities of NT and PHPNT were eliminated by carboxyl substitution in the position alpha to the N-nitroso group.

Mutat Res, 1984 Apr, 136(1), 49 - 54
Frameshift mutagenicity in Salmonella typhimurium of furocoumarins in the dark; Quinto I et al.; The dark mutagenicity of 4,5',8-trimethylpsoralen (4,5',8-TMP), 5-methoxypsoralen (5-MOP), 8-methoxypsoralen (8-MOP), 3-carbethoxypsoralen (3-CPs) and two new pyridopsoralens (PyPs and MePyPs) was tested using the Ames Salmonella plating assay in the absence of metabolic activation . 4,5',8-TMP, 8-MOP and the two pyridopsoralens were found to be weak frameshift mutagens in strain TA1537 whereas 5-MOP and 3-CPs did not demonstrate any significant mutagenic activity . These findings support the notion that the genetic risks of these psoralens in the dark may be considered to be negligible.

Mutat Res, 1984 Apr, 136(1), 23 - 31
Mutagenicity of several derivatives of dipyrido{1,2-a:2',3'-d}imidazoles; N'Goy K et al.; Different derivatives of dipyrido{1,2-a:2',3'-d}imidazoles have been investigated, as mutagens for Salmonella typhimurium . The nature of different substitution groups and their positions on the base ring influenced markedly the mutagenicity of these compounds . From this structure/effect relationship study, it was demonstrated that the 2 and 3 positions were of special interest . The 3-N-hydroxylated compound was the most active mutagen tested . We also observed that the frequently found frameshift mutagens were responsible for base-pair substitution . Metabolic activation by liver S9 mix increased the reversion rates of the strains tested . The SCE assays correlated poorly with the Salmonella/microsome mutagenicity test.

J Bacteriol, 1984 Apr, 158(1), 344 - 6
Genetic characterization of Salmonella typhimurium LT2 ara mutations; Lee JH et al.; Seventeen independently isolated L-arabinose utilization-deficient mutants of Salmonella typhimurium LT2 were characterized . Four complementation groups (araA, araB, araC, and araD) were identified and were equivalent to the same genes in the ara system in Escherichia coli . The order of the four genes was determined to be araD-araA-araB-araC-leu . Two transcription units were found: the araBAD operon was transcribed counterclockwise, and the araC gene was transcribed clockwise.

J Bacteriol, 1984 Apr, 158(1), 222 - 30
Direction of flagellar rotation in bacterial cell envelopes; Ravid S et al.; Cell envelopes with functional flagella, isolated from wild-type strains of Escherichia coli and Salmonella typhimurium by formation of spheroplasts with penicillin and subsequent osmotic lysis, demonstrate counterclockwise (CCW)-biased rotation when energized with an electron donor for respiration, DL-lactate . Since the direction of flagellar rotation in bacteria is central to the expression of chemotaxis, we studied the cause of this bias . Our main observations were: (i) spheroplasts acquired a clockwise (CW) bias if instead of being lysed they were further incubated with penicillin; (ii) repellents temporarily caused CW rotation of tethered bacteria and spheroplasts but not of their derived cell envelopes; (iii) deenergizing CW-rotating cheV bacteria by KCN or arsenate treatment caused CCW bias; (iv) cell envelopes isolated from CW-rotating cheC and cheV mutants retained the CW bias, unlike envelopes isolated from cheB and cheZ mutants, which upon cytoplasmic release lost this bias and acquired CCW bias; and (v) an inwardly directed, artificially induced proton current rotated tethered envelopes in CCW direction, but an outwardly directed current was unable to rotate the envelopes . It is concluded that (i) a cytoplasmic constituent is required for the expression of CW rotation (or repression of CCW rotation) in strains which are not defective in the switch; (ii) in the absence of this cytoplasmic constituent, the motor is not reversible in such strains, and it probably is mechanically constricted so as to permit CCW sense of rotation only; (iii) the requirement of CW rotation for ATP is not at the level of the motor or the switch but at one of the preceding functional steps of the chemotaxis machinery; (iv) the cheC and cheV gene products are associated with the cytoplasmic membrane; and (v) direct interaction between the switch-motor system and the repellent sensors is improbable.

Proc Soc Exp Biol Med, 1984 Apr, 175(4), 518 - 21
Exercise enhances survival rate in mice infected with Salmonella typhimurium; Cannon JG et al.; Mice voluntarily trained on exercise wheels for 16-18 days and were then infected with an approximate LD50 dose of Salmonella typhimurium . These trained mice exhibited a small, but statistically significant (P = 0.037) increase in survival rate (34/77) compared to sedentary control mice (23/79) after 7 days.

J Hyg (Lond), 1984 Apr, 92(2), 177 - 82
The distribution of specific phage types of Salmonella typhimurium in chickens in Australia; Coloe PJ et al.; The distribution of specific phage types of Salmonella typhimurium within the Australian chicken industry has been studied and documented on an Australia-wide and state-by-state basis . A total of 1799 strains of S . typhimurium were obtained from Australia-wide sources and phage typing categorized 1498 of these isolates into 30 distinct phage types, with the remaining 301 strains untypable . Five phage types, 6, 26, 31, 135 and 179, accounted for 76% of the total strains typed, with the remaining 24% of strains being distributed among 25 phage types . Of the major phage types, type 31 was restricted to Victoria and Western Australia, but the other types were distributed throughout Australia . In addition, the antibiotic resistance pattern of the various phage types was determined and only five of the 30 phage types showed appreciable levels of resistance.

Infect Immun, 1984 Apr, 44(1), 168 - 74
Stimulation of cell-mediated immunity by bestatin correlates with reduction of bacterial persistence in experimental chronic Salmonella typhimurium infection; Dickneite G et al.; The effect of bestatin, a low-molecular-weight immunomodulating drug isolated from Streptomyces olivoreticuli, on Salmonella typhimurium infection was elaborated . Bestatin enhanced the delayed-type hypersensitivity reaction against S . typhimurium in a dose- and time-dependent manner . Parallel to the activation of delayed-type hypersensitivity reaction, bestatin reduced the amount of persistent bacteria in livers and spleens as well as the amount of necrotic foci found in these organs . This was shown when bestatin was given either prophylactically or therapeutically . The therapeutic effect of bestatin was even seen when the drug was given in the chronic phase of the infection, i.e., 6 days after inoculation of the animals with the infectious agent . No influence of bestatin, however, could be observed on the initial multiplication rate of S . typhimurium and concomitantly on the initial mortality rate of the infected mice . As bestatin has no direct antibiotic effect on S . typhimurium, it must be concluded that the therapeutic effects of the drug on chronic infection must be solely contributed to elevation of the host's own defense mechanisms.

Immunology, 1984 Apr, 51(4), 697 - 702
Biological activity of Pityrosporum . I . Enhancement of resistance in mice stimulated by Pityrosporum against Salmonella typhimurium; Takahashi M et al.; The effect of administration with Pityrosporum (P . orbiculare, P . ovale, P . pachydermatis and Pityrosporum sp.) on susceptibility of mice to Salmonella typhimurium infection was studied . Pretreatment of mice with 50 mg (wet weight) of killed Pityrosporum 4 days prior to the intraperitoneal (i.p.) challenge of 4 X 10(5) (10 LD50) S . typhimurium elicited resistance comparable to that induced by 500 micrograms (dry weight) of killed Propionibacterium acnes and over 30% of the infected mice survived . Among the species tested, P . pachydermatis was slightly less effective . The challenged organisms were not detected from the blood of mice treated with Pityrosporum but were present in the liver and spleen in approximately level amounts (10(4)-10(5)/organ) during the course of testing . These results suggest that the increased resistance in mice is the result of stimulation of the reticuloendothelial system by Pityrosporum.

Carcinogenesis, 1984 Apr, 5(4), 467 - 72
Factors influencing the mutagenic activity of the colon carcinogen 1,2-dimethylhydrazine in Salmonella typhimurium strain TA 1535 in vitro; Kerklaan PR et al.; The colon carcinogen 1,2-dimethylhydrazine (SMDH), a non-mutagen in the standard Ames assay, has been shown in previous experiments to become weakly mutagenic in Salmonella TA 1535 in vitro, when specific test conditions were used . The present studies were performed to determine more precisely the nature of metabolic factors and experimental conditions for optimal mutagenesis of SDMH in the same strain of Salmonella . First, it was confirmed that both the presence of rat liver S9 fractions (25 microliters/ml incubation mixture) and prolonged pre-incubation periods in liquid medium of at least 120 min were necessary to elicit SDMH mutagenesis . In contrast to results obtained with dimethylnitrosamine, which served as a model compound for the activation through oxidative, cytochrome P-450- and NADPH-dependent enzymatic processes, the activation of SDMH to mutagenic factors was not dependent on the presence of NADPH: in fact, NADPH strongly reduced the SDMH-induced mutation yields . It was also observed that growth of the indicator bacteria is an important prerequisite for mutation induction by SDMH . Aminoacetonitrile and disulfiram, two inhibitors of SDMH metabolism and carcinogenicity in mammals, also strongly inhibited SDMH mutagenesis in the present in vitro assay . It can, therefore, be concluded that (i) the right test protocol is of crucial importance for the detection of SDMH as a bacterial mutagen, and (ii) that activation pathways in vitro are (partially) different from presumed in vivo metabolism and activation.

J Immunol, 1984 Apr, 132(4), 1702 - 11
Murine immune responses to Salmonella lipopolysaccharide: oral administration of whole bacteria to C3H/HeJ mice induces secondary anti-LPS responses, especially of the IgA isotype; Jirillo E et al.; Because our past studies have shown that oral administration of thymic-dependent antigens induces higher IgA responses in lipopolysaccharide (LPS) nonresponsive C3H/HeJ mice than in syngeneic, LPS-responsive C3H/HeN animals, it was of interest to compare anti-LPS responses in these mouse strains after oral administration of particulate antigens containing LPS . C3H/HeJ and C3H/HeN mice were given smooth Salmonella typhimurium LT-2 or rough S . minnesota Rb (R345) or Re (R595) organisms by gastric intubation for 3 consecutive days/wk for 2 wk and were boosted by the i.v . route with either the same bacterial immunogen or with purified homologous LPS . Four days later, splenic anti-LPS plaque-forming cell (PFC) responses were assessed with a panel of indicator sheep erythrocytes (SRBC) coated with LPS derived from either smooth (S-LPS-SRBC) or rough (Rb-LPS-SRBC or Re-LPS-SRBC) Salmonella . In separate studies, both serum and salivary antibodies of the IgM, IgG, and IgA isotypes were determined by ELISA, with whole Salmonella cells used as the coating antigen . Oral immunization with LT-2 resulted in good IgM, IgG1 and IgA splenic anti-LPS PFC responses in C3H/HeJ mice, with the major isotype being IgA . Mice boosted i.v . with purified LPS gave five- to sixfold higher anti-S-LPS PFC responses than did mice given whole bacteria by the i.v . route . Low anti-Rb-LPS and anti-Re-LPS PFC responses were seen in both mouse strains . Enhanced immune responses in orally primed C3H/HeJ mice was not due to LPS-induced polyclonal responses, because splenic cultures from these mice gave poor mitogenic responses to LPS . A similar pattern of response was obtained when C3H/HeJ or C3H/HeN mice were given RB (R345) or Re (R595) bacteria orally and boosted i.v . with purified homologous LPS or whole cells . C3H/HeJ mice again showed higher immune responses in all isotypes than did C3H/HeN animals . Mice given Rb (R345) immunogen gave maximum responses to Rb-LPS, lower responses to Re-LPS, and no responses to S-LPS, whereas C3H/HeJ mice immunized with Re (R595) immunogen gave maximum PFC responses to Re-LPS and lower responses to Rb-LPS . Serum and salivary antibody titers closely paralleled the splenic PFC responses, and IgA antibodies were the predominant isotype observed, with higher IgA responses occurring in orally immunized C3H/HeJ mice than in C3H/HeN animals . These results clearly indicate that C3H/HeJ mice given whole Salmonella by gastric intubation elicit higher PFC and antibody responses to the three major LPS regions than do identically treated LPS-responsive C3H/HeN mice.

Avian Dis, 1984 Apr-Jun, 28(2), 416 - 25
Influence of Mycoplasma gallisepticum, infectious bronchitis, and cyclophosphamide on chickens protected by native intestinal microflora against Salmonella typhimurium or Escherichia coli; Weinack OM et al.; Chickens that have considerable resistance to Salmonella typhimurium or Escherichia coli infection by early development of a native intestinal microflora shed these bacteria following aerosol exposure to Mycoplasma gallisepticum and/or infectious bronchitis virus . Administration of cyclophosphamide to similarly treated chickens induced slight shedding of these bacteria, and the combination of cyclophosphamide and respiratory agents magnified the shedding rate . These agents also influenced the isolation rate of E . coli and S . typhimurium from the trachea and air sacs.

Res Commun Chem Pathol Pharmacol, 1984 Apr, 44(1), 131 - 9
A comparison of avian and rodent S-9 liver homogenates in the Ames test; Rosanoff KA et al.; Avian S-9 liver homogenates were obtained from phenobarbital, 3-methylcholanthrene (3-MC), polychlorinated biphenyl (Aroclor 1254) induced and control chickens . These homogenates were tested for their capacity to metabolically activate benzo{a}pyrene (B{a}P) and cyclo-phosphamide in the Salmonella typhimurium assay . Liver homogenates from 3-MC, Aroclor 1254 and phenobarbital induced chickens were more active in converting B{a}P to its ultimate mutagenic form than was S-9 obtained from Aroclor 1254 induced rats . However, Aroclor 1254 induced rat S-9 was superior to Aroclor 1254 induced avian S-9 in metabolically activating cyclophosphamide.

J Bacteriol, 1984 Apr, 158(1), 351 - 3
Interaction between IIIGlc of the phosphoenolpyruvate:sugar phosphotransferase system and glycerol kinase of Salmonella typhimurium; Postma PW et al.; Purified IIIGlc of the phosphoenolpyruvate:sugar phosphotransferase system of Salmonella typhimurium inhibits glycerol kinase . Phosphorylation of IIIGlc via phosphoenolpyruvate, enzyme I, and HPr abolishes this inhibition . The glycerol facilitator is not inhibited by IIIGlc . It is proposed that regulation of glycerol metabolism by the phosphoenolpyruvate:sugar phosphotransferase system is at the level of glycerol kinase.

J Bacteriol, 1984 Apr, 158(1), 354 - 6
Facile and gentle method for quantitative lysis of Escherichia coli and Salmonella typhimurium; Crabtree S et al.; Garrett et al . (Mol . Gen . Genet . 182:326-331, 1981) constructed strains of Escherichia coli harboring derivatives of plasmid pBR322 that carry the lysis genes (S, R, and Rz) of phage lambda . The plasmid construction placed the genes under control of the lactose operon operator-promotor (and thus of lac repressor) . Induction of E . coli strains carrying these plasmids resulted in rapid lysis of the culture unless the S gene was defective, in which case the cells grew normally . A freeze-thaw treatment of induced cells carrying an S- plasmid gave quantitative lysis of either E . coli or Salmonella typhimurium cells under exceptionally gentle conditions . The method was equally effective on exponential phase cells and stationary phase cells and was readily extended to a large number of independent cultures.

J Bacteriol, 1984 Apr, 158(1), 163 - 8
Effect of growth temperature on the acquisition of iron by Salmonella typhimurium and Escherichia coli; Worsham PL et al.; We have examined the effect of growth temperature on three systems normally induced under conditions of iron limitation: synthesis of the siderophore enterochelin (enterobactin), transport of ferric enterochelin, and production of the outer membrane protein which serves as the colicin I receptor . We found that although Salmonella typhimurium produces less enterochelin when grown at 42 degrees C, synthesis of this siderophore was not diminished in Escherichia coli grown under the same conditions . Growth at 42 degrees C under a condition of iron stress led to a reduction in the ability of cells to transport ferric enterochelin in both organisms . A two- to threefold decrease in the number of colicin I receptors was observed in cells of E . coli or S . typhimurium grown at 42 degrees C as compared with the number of receptors observed in cells grown at 37 degrees C . The colicin I receptor was shown not to be inherently unstable at 42 degrees C . By using a cir-lacZ operon fusion, it was shown that at least part of the decrease in receptor levels found in cells grown at high temperature was the result of decreased transcription of cir, the receptor structural gene . The effect of growth temperature on these systems was shown to be independent of fur, a regulatory element which mediates their enhanced production in response to iron stress . We suggest that a second regulatory element common to gene products involved in iron sequestration may be responsible for temperature regulation of these systems.

J Mol Biol, 1984 Mar 15, 173(4), 463 - 76
Polymorphic transition of the flagellar polyhook from Escherichia coli and Salmonella typhimurium; Kato S et al.; Bacterial flagellar polyhook fibers were reversibly transformed into a set of helical forms depending on pH, ionic strength and temperature . Electron microscopy with formalin fixation and freeze-drying was useful for observing three-dimensional shapes of various polyhook helices and determining their helical handedness . A Cartesian plot of curvature against twist for these polyhook helices gave a sinusoidal curve as in the case of the polymorphic forms of flagellar filament . In the study on the polymorphism of flagellar filaments . Calladine (1976, 1978) and Kamiya et al . (1979) pointed out that such a relation in the polymorphic forms could be derived from the assumption that the subunits on the near-longitudinal (11-start) helical lines should work as elastic fibers (protofilaments) having two distinct states of conformation . In contrast, the observed twist for the polyhook helices is too large to be explained by the same assumption . Instead, we must assume that subunits on the strongly twisted, 16-start helical line should work as the co-operative protofilament.

J Biol Chem, 1984 Mar 10, 259(5), 3064 - 9
Regulation of membrane glycosyltransferases by the sfrB and rfaH genes of Escherichia coli and Salmonella typhimurium; Creeger ES et al.; The role of sfrB and rfaH genes in the regulation of expression of membrane glycosyltransferases was studied in Escherichia coli and Salmonella typhimurium . The transferase enzymes form part of a multienzyme system involved in biosynthesis of the polysaccharide core of Gram-negative bacterial lipopolysaccharides . Several sfrB mutants of E . coli showed reductions of 90-98% in the activities of two of the glycosyltransferases (UDP-galactose:(glucosyl)lipopolysaccharide 1,6-galactosyltransferase and UDP-glucose: (glucosyl)lipopolysaccharide 1,3-glucosyltransferase) . Introduction of a recombinant ColE1 plasmid restored the transferase levels to normal and simultaneously corrected the F-factor defects that also characterize sfrB mutants; recombinant plasmids containing other regions of the E . coli chromosome were ineffective . An amber mutation of the S . typhimurium rfaH gene (thought to be the homologue of the E . coli sfrB gene) resulted in 97% loss of activity of the Salmonella UDP-galactose:(glucosyl)lipopolysaccharide galactosyltransferase . Antibody precipitation studies showed that the loss of enzyme activity in the amber mutant was associated with a corresponding decrease in amount, but not in size, of the transferase protein, indicating that the gene is not the structural gene for the S . typhimurium galactosyltransferase . Taken together, the results indicate that the sfrB(rfaH) gene acts as a positive regulatory element in expression of multiple glycosyltransferases in E . coli and S . typhimurium.

Infect Immun, 1984 Mar, 43(3), 1033 - 40
Expression of the natural resistance gene Lsh in resident liver macrophages; Crocker PR et al.; Innate resistance and susceptibility to Leishmania donovani infection in mice is controlled by a single gene (Lsh) thought to be identical to the genes Ity and Bcg which control the early response to Salmonella typhimurium and Mycobacterium bovis infections, respectively . In the present study, three new aspects of Lsh gene activity were demonstrated . First, it was shown that liver macrophages continue to express Lsh gene activity in vitro after their extraction from mice infected in vivo, although 2 days of infection were required before the resistant phenotype was expressed . Second, detailed examination of early growth of the parasite and tritiated thymidine labeling of the parasites indicated that this delay in expression of the resistant phenotype also occurred in vivo . Third, the expression of resistance was unaltered by the effects of lethal irradiation but could be selectively enhanced by prior treatment with suitable doses of S . typhimurium lipopolysaccharide or L . donovani membranes . These results suggest that the resistance mechanism may be expressed by resident liver macrophages after their interaction with parasite-derived material . The relevance of these findings to the other intramacrophage pathogens is discussed.

J Gen Microbiol, 1984 Mar, 130 ( Pt 3), 673 - 85
Location on the Escherichia coli genome of a gene specifying O-acetylserine (thiol)-lyase; Boronat A et al.; The plasmid pAB65, derived from a specialized transducing phage carrying DNA from about 52 min on the Escherichia coli genome, coded for two polypeptides of Mr approx . 34 000 . The expression of one was regulated by cyst(e)ine and the cysB gene product and the other by the cysB gene product only . One of these polypeptides was a subunit of O-acetylserine (thiol)-lyase (EC 4.2.99.8); the other, associated with the E . coli membrane, was the N-terminus of the product of the lambda ben gene . The pattern of peptide synthesis directed by plasmids carrying smaller DNA fragments indicated that the gene for O-acetylserine (thiol)-lyase was transcribed clockwise . The spectrum, amino acid composition and subunit number of the enzyme were determined . The enzyme appears homologous with the Salmonella typhimurium cysK gene product . This provides further evidence for the inversion of this region of the genome.

Gann, 1984 Mar, 75(3), 203 - 6
Activation of promutagenic N-nitrosomorpholine and other N-nitrosoalkylamines by near-ultraviolet irradiation in the presence of phosphates; Hayatsu H et al.; When a neutral solution of N-nitrosomorpholine, N-nitrosopyrrolidine, or N-nitrosopiperidine was irradiated with near-ultraviolet light, the solution became mutagenic to Salmonella typhimurium TA100 in the absence of metabolic activation . The formation of the active compounds required the presence of phosphate or its esters such as adenosine 5'-triphosphate during the irradiation.

Poult Sci, 1984 Mar, 63(3), 478 - 84
Effects of infection of Eimeria tenella, E . acervulina, and E . maxima upon Salmonella typhimurium infection in chickens; Takimoto H et al.; Three experiments were conducted to examine whether Salmonella typhimurium infection is enhanced by concurrent infection with Eimeria tenella, E . acervulina, or E . maxima . There were two groups in each experiment: birds infected with a daily oral dose of approximately 1 X 10(4) cfu of S . typhimurium for 5 days after coccidial infection and birds infected with S . typhimurium alone with the similar exposure schedule . Chickens were necropsied 7, 10, and 14 days after coccidial infection . The numbers of S . typhimurium in the contents of ceca and small intestine were counted, and numbers of chickens positive for S . typhimurium in the liver and bile were examined . In E . tenella infection, the S . typhimurium counts in the ceca and small intestine of concurrently infected chickens were significantly greater than those of birds infected with S . typhimurium alone . In E . acervulina infection, the S . typhimurium counts in the ceca of chickens killed 14 days after E . acervulina infection and the numbers of birds positive for S . typhimurium in the ceca of chickens killed 10 and 14 days after E . acervulina infection were significantly greater than those of chickens infected with S . typhimurium alone . In E . maxima infection, the numbers of birds positive for S . typhimurium in the ceca and liver of chickens killed 7 days after E . maxima infection were significantly greater than those of birds infected with S . typhimurium alone . Results of this study indicate that infection with E . acervulina or E . maxima is able to enhance S . typhimurium infection in chickens.

Mutat Res, 1984 Mar-Apr, 131(3-4), 89 - 95
Comparative mutagenesis by aminofluorene derivatives . A possible effect of DNA configuration; Heller EP et al.; The mutagenicity of N-acetoxy-N-2-acetylaminofluorene (N-acetoxy- 2AAF ) for Salmonella typhimuricum TA98 is greatly reduced when compared to that of N-hydroxy-2-aminofluorene . This decrease in mutagenic response is accompanied by the formation of a deoxyguanosine-2-acetylaminofluorene adduct . The deoxyguanosine-2-aminofluorene adduct, characteristic of cells exposed to N - hydroxy-2-aminofluorene, was not detected in N-acetoxy- 2AAF -treated cells . Enzymic deacetylation of N - acetoxy- 2AAF results in restoration of potent mutagenicity . N-Acetoxy-2-acetylamino-7- iodofluorene is also more mutagenic than N-acetoxy- 2AAF . Because the acetylated and unacetylated guanine adducts induce greatly different configurational changes, the results may be indicative that the introduction of the syn configuration and a possible shift to the Z-conformation at the mutational hot spot of Salmonella typhimurium TA98 {(dG-dC)8} results in reduced mutagenic potency.

Mutat Res, 1984 Mar, 135(3), 139 - 48
Mutagenicity of pyridine- and quinoline-carbohydroxamic acid derivatives; Lipczynska-Kochany E et al.; 11 pyridine- and 6 quinoline-carbohydroxamic acids were tested for mutagenicity on Salmonella typhimurium TA100 and TA98 . The results are compared with those obtained for benzohydroxamic acid and 4 naphthohydroxamic acids . Most of them were mutagenic on both these tester strains . Of the pyridine derivatives, pyridine-2-carbohydroxamic acid was the most potent mutagen . Quaternarization of the pyridine-ring nitrogen prevented the induction of mutation to a marked extent . Among the quinoline derivatives, quinoline-6-carbohydroxamic acid showed potent mutagenicity similar to that of 2-naphthohydroxamic acid . The present study supports the proposal made previously that the mechanism for mutagenicity of hydroxamic acids involves Lossen rearrangement of the acid conjugates produced by enzymic acylation (or perhaps phosphorylation or sulfation) of the hydroxamic acids, followed by carbamoylation of the target molecule in the cell by the resultant isocyanate . The multiplicity of factors determining the mutagenic potency of hydroxamic acids is discussed.

Arch Biochem Biophys, 1984 Mar, 229(2), 448 - 54
Comparison of denaturation of tryptophan synthase alpha-subunits from Escherichia coli, Salmonella typhimurium, and an interspecies hybrid; Yutani K et al.; Guanidine hydrochloride-induced denaturation and thermal denaturation of three kinds of tryptophan synthase alpha subunit have been compared by circular dichroism measurements . The three alpha subunits are from Escherichia coli, Salmonella typhimurium, and an interspecies hybrid in which the C-terminal domain comes from E . coli (alpha-2 domain) and the N-terminal domain comes from S . typhimurium (alpha-1 domain) . Analysis of denaturation by guanidine hydrochloride at 25 degrees C showed that the alpha-2 domain of S . typhimurium was more stable than the alpha-2 domain of E . coli, but the alpha-1 domain of S . typhimurium was less stable than the alpha-1 domain of the E . coli protein; overall, the hybrid protein was slightly less stable than the two original proteins . It is concluded that the stability to guanidine hydrochloride denaturation of each of the domains of the interspecies hybrid is similar to the stability of the domain of the species from which it originated . The E . coli protein was more stable to thermal denaturation than the other proteins near the denaturation temperature, but the order of their thermal stability was reversed at 25 degrees C and coincided with that obtained from guanidine hydrochloride-induced denaturation.

J Bacteriol, 1984 Mar, 157(3), 953 - 5
Genetic evidence for glucitol-specific enzyme III, an essential phosphocarrier protein of the Salmonella typhimurium glucitol phosphotransferase system; Sarno MV et al.; Positive selection procedures were developed for the isolation of mutants defective in components of the glucitol-specific catabolic enzyme system in Salmonella typhimurium . gutA (enzyme IIgut-negative), gutB (enzyme IIIgut-negative), and gutC (constitutive for the glucitol operon) mutants were isolated and characterized biochemically and genetically . The gene order was shown to be gutCAB.

J Bacteriol, 1984 Mar, 157(3), 758 - 63
Role of protein degradation in the survival of carbon-starved Escherichia coli and Salmonella typhimurium; Reeve CA et al.; When an Escherichia coli K-12 culture was starved for glucose, 50% of the cells lost viability in about 6 days . When a K-12 mutant lacking five distinct peptidase activities, CM89, was starved in the same manner, viability was lost much more rapidly; 50% of the cells lost viability in about 2 days, whereas a parent strain lacking only one peptidase activity lost 50% viability in about 4 days . Compared with the wild-type strain and with its parent strain CM17, CM89 was defective in both protein degradation and protein synthesis during carbon starvation . Similar results were obtained with glucose-starved Salmonella typhimurium LT2 and LT2-derived mutants lacking various peptidase activities . An S . typhimurium mutant lacking four peptidases, TN852, which was deficient in both protein degradation and synthesis during carbon starvation (Yen et al., J . Mol . Biol . 143:21-33, 1980), was roughly one-third as stable as the isogenic wild type . Isogenic S . typhimurium strains that lacked various combinations of three of four peptidases and that displayed protein degradation and synthesis rates intermediate between those of LT2 and TN852 (Yen et al., J . Mol . Biol . 143:21-33, 1980) displayed corresponding stabilities during carbon starvation . These results point to a role for protein degradation in the survival of bacteria during starvation for carbon.

J Bacteriol, 1984 Mar, 157(3), 764 - 71
Histidine operon control region of Klebsiella pneumoniae: analysis with an Escherichia coli promoter-probe plasmid vector; Rodriguez RL et al.; The control region for the histidine operon of Klebsiella pneumoniae was cloned and analyzed with the Escherichia coli promoter-probe plasmid pPV33 . A restriction fragment which contained the his control region was identified by its ability to activate the tetracycline resistance (Tcr) gene on this vector . Expression of Tcr by bacteria containing the his promoter-active plasmid was found to be under the attenuation control of the his promoter . DNA sequence analysis of the his control region revealed a base sequence homology of approximately 86% of the analogous DNA sequences of E . coli and Salmonella typhimurium . Most of the base alterations in the K . pneumoniae DNA sequence were found to reside in regions flanking the transcriptional and translational regulatory sites.

J Bacteriol, 1984 Mar, 157(3), 697 - 702
Isolation of F' plasmids carrying a portion of the Salmonella typhimurium histidine transport operon; Lawton KG et al.; The transposable drug resistance element Tn10 was employed as a region of homology to direct the insertion of Tn10-containing derivatives of F'ts114 lac into the chromosome of a Salmonella typhimurium strain that carries a Tn10 insertion in the histidine transport operon . Based on the direction of transfer of the resulting Hfr strains, the chromosomal Tn10 insertion was determined to be in orientation "A." New F' plasmids were selectively generated from one of the Hfr strains . The F' factors carry an intact dhuA hisJ portion of the histidine transport operon . A Southern hybridization revealed that one of the F' plasmids was formed by a type II excision event.

Infect Immun, 1984 Mar, 43(3), 834 - 8
Lipid A and resistance of Salmonella typhimurium to antimicrobial granule proteins of human neutrophil granulocytes; Shafer WM et al.; Granule extracts from human polymorphonuclear leukocytes were prepared and fractionated by chromatography on Sephadex G75-SF . One fraction exhibited potent antimicrobial activity against an Rd1 lipopolysaccharide (LPS) mutant of Salmonella typhimurium . Susceptibility of the mutant to antimicrobial activity appeared to be due to binding of granule proteins to lipid A because isolated native LPS succeeded in blocking the antimicrobial activity of granule extracts whereas base-hydrolyzed LPS failed to do so . Centrifugation of control and base-hydrolyzed LPS-protein mixtures in cesium chloride gradients suggested that only control LPS formed complexes with antimicrobial proteins . Further evidence that bactericidal proteins from polymorphonuclear leukocyte granules interact with lipid A was that sublethal concentrations of polymyxin B (an antibiotic known to bind to lipid A) rendered target bacteria phenotypically resistant to granule proteins . Moreover, a mutant of S . typhimurium which synthesized a lipid A with decreased electronegativity due to increased 4-amino-4-deoxy-L-arabinosylation at the 4'-phosphate exhibited increased resistance to both polymyxin B and granule proteins . These results suggest that polymyxin B and antimicrobial proteins derived from polymorphonuclear leukocyte granules interact with lipid A in an analogous manner.

Biochemistry, 1984 Feb 28, 23(5), 988 - 93
Comparison of F1's of oxidative phosphorylation from Escherichia coli and Salmonella typhimurium and demonstration of interchangeability of their subunits; Hsu SY et al.; The peripheral membrane portion (SF1) of proton-translocating ATPase of Salmonella typhimurium and its alpha, beta, and gamma subunits were purified and compared with the same portion (EF1) from Escherichia coli . The alpha, beta, and gamma subunits of these F1's were found to be mutually interchangeable, and all possible combinations of the three subunits from EF1 and SF1 showed ATPase activity . Both F1's could bind functionally to the integral membrane part (F0) of either bacterium, suggesting that F0 and F1 are interchangeable in these two bacteria and thus that the two F1's are closely similar at the level of subunit structure . However, SF1 differed from EF1 in some enzymological properties such as its specific activity and susceptibilities to sodium dodecyl sulfate and methanol . The specific ATPase activity of EF1 was more than twice that of SF1, and hybrid enzymes containing the beta subunit of EF1 had higher activity than other hybrids . Amino acid analysis suggested that the primary structures of the alpha subunits of the two F1's are less homologous than those of the beta subunits . Thus, the primary structure of the alpha subunit may be more species specific than that of the beta subunit.

J Mol Biol, 1984 Feb 15, 173(1), 125 - 30
Caulobacter crescentus flagellar filament has a right-handed helical form; Koyasu S et al.; Caulobacter crescentus flagellar filaments were examined for their shape and handedness . Contour length, wavelength and height of the helical filaments were 1.34 +/- 0.14 micron, 1.08 +/- 0.05 micron and 0.27 +/- 0.04 micron, respectively . Together with the value of the filament diameter, 14 +/- 1.5 nm, the parameters of the curvature (alpha) and twist (phi) were calculated as 3.9(%) for alpha and 0.026 (rad) for phi, which are similar to those of the curly I filament of Salmonella typhimurium . Dark-field light microscopic analysis revealed that the C . crescentus wild-type filament possesses a right-handed helical form . Given the result that C . crescentus cells normally swim forward, in the opposite direction to a polar flagellum, it is likely that C . crescentus swims by rotation of a right-handed curly shaped flagellum in a clockwise sense, whereas S . typhimurium and Escherichia coli swim by rotation of left-handed normal type flagella in a counterclockwise sense.

Eur J Biochem, 1984 Feb 15, 139(1), 29 - 34
Interactions in vivo between IIIGlc of the phosphoenolpyruvate:sugar phosphotransferase system and the glycerol and maltose uptake systems of Salmonella typhimurium; Nelson SO et al.; Our previous studies indicated that the ability of phosphoenolpyruvate:sugar phosphotransferase system (PTS) substrates to inhibit the uptake of glycerol or maltose in Salmonella typhimurium is dependent on the relative cellular content of the PTS-sensitive uptake system and of the PTS protein IIIGlc . Our present study confirms and extends those observations . The maltose and glycerol uptake systems are rendered (wholly or partially) insensitive to PTS inhibition by the presence of a second PTS-sensitive uptake system (respectively that for glycerol or maltose) and its substrate . Both the second PTS-sensitive uptake system and its substrate were needed for this protective effect . Galactose and the galactose permease (a PTS-insensitive transport system) did not have any effect on PTS-mediated inhibition of the maltose uptake system . The protective effect of the second PTS-sensitive uptake system and its substrate is counteracted by increasing the cellular levels of IIIGlc . Overproduction of IIIGlc in crr-plasmid-containing strains renders the glycerol and maltose uptake systems hypersensitive to inhibition by PTS substrates . We interpret our results on the basis of a stoichiometric interaction between IIIGlc and a PTS-sensitive uptake system, in which the IIIGlc--transport-system complex is inactive . Competition between two PTS-sensitive transport systems for formation of inactive complex with IIIGlc lowers the free intracellular concentration of IIIGlc resulting in a mutual protective effect against inhibition by IIIGlc.

Nucleic Acids Res, 1984 Feb 10, 12(3), 1559 - 62
Nucleotide sequences of three proline tRNAs from Salmonella typhimurium; Kuchino Y et al.; The nucleotide sequences of three proline tRNAs from Salmonella typhimurium were determined by post-labeling procedures . The three proline tRNAs had almost identical sequences in the D-arm and T psi C-arm, and all contained 1-methylguanosine next to the 3'-end of the anticodon . The anticodon sequences of tRNAPro1, tRNAPro2 and tRNAPro3 were 5'-CGG-3', 5'-GGG-3', and 5'-VGG-3', respectively . The nucleotide sequence homologies of tRNAPro2 to tRNAPro1 and tRNAPro3 were 68% and 78%, respectively.

J Biol Chem, 1984 Feb 10, 259(3), 1586 - 92
Tricarboxylate-binding proteins of Salmonella typhimurium . Purification, crystallization, and physical properties; Sweet GD et al.; Citrate transport in Salmonella typhimurium involves inducible periplasmic components . Two forms of a tricarboxylate-binding protein, C1 and C2, were isolated, in high yield, from the periplasm of a cyclic AMP phosphodiesterase mutant . These immunologically cross-reactive Mr = 29,000 proteins were crystallized using ammonium sulfate . CD measurements indicated considerable secondary structure: 24% a helix, and 12% beta structure . The amino acid compositions of C1 and C2 were identical . The NH2-terminal sequence of C1 was determined; C2 was found to have a blocked NH2 terminus (pyroglutamate) . C1 and C2 are products of the same gene (Somers, J . M., and Kay, W . W . (1983) Mol . Gen . Genet . 190, 20-26) . C1 and C2 bound a variety of citrate analogues and organic acids, with a predominant specificity for tricarboxylates (citrate KD 1.4 X 10(-7) M), and both required a deprotonated central carboxyl group for binding . Citrate was not bound to C protein as either a salt or metal ion complex.

Cancer Res, 1984 Feb, 44(2), 562 - 70
Stereoselectivity of rat liver microsomal enzymes in the metabolism of 7-fluorobenz(a)anthracene and mutagenicity of metabolites; Chiu PL et al.; 7-Fluorobenz(a)anthracene (7-FBA) was metabolized by rat liver microsomes predominantly to 4-hydroxy-7-FBA and 7-FBA trans-3,4-, 5,6-, 8,9-, and 10,11-dihydrodiols . Proton nuclear magnetic resonance spectral analyses indicated that the fluoro substituent causes 7-FBA trans-5,6- and 8,9-dihydrodiols to adopt preferentially quasidiaxial conformations (Chiu, P.-L., Fu, P . P., and Yang, S . K . Biochem . Biophys . Res . Commun., 106: 1405-1411, 1982) . The major enantiomers of the quasidiaxial trans-5,6- and trans-8,9-dihydrodiols have been determined by the exciton chirality method to have R,R absolute stereochemistries . By comparing with the circular dichroism spectra of BA 3R,4R- and 10R,11R-dihydrodiols, the major enantiomers of the quasidiequatorial 7-FBA trans-3,4- and trans-10,11-dihydrodiols were also found to have R,R absolute configurations . All four 7-FBA trans-dihydrodiol metabolites obtained from incubations of 7-FBA with liver microsomes prepared from untreated and 3-methylcholanthrene-, phenobarbital-, and polychlorinated biphenyl-treated male Sprague-Dawley rats were enriched in R,R enantiomers, differing only in optical purities . Pretreatment of rats with phenobarbital, 3-methylcholanthrene, and polychlorinated biphenyls changed the rate of 7-FBA metabolism by 0.47-, 1.14-, and 1.70-fold, respectively . Pretreatment of rats with enzyme inducers also altered the quantitative distribution of metabolites formed . The relative mutagenic activities of metabolites toward Salmonella typhimurium TA 100 were: 7-FBA trans-3,4-dihydrodiol greater than 7-FBA trans-10,11-dihydrodiol greater than 7-methyl-BA approximately equal to 7-FBA greater than 7-FBA trans-8,9-dihydrodiol approximately equal to 7-methyl-BA trans-10,11-dihydrodiol greater than 7-FBA trans-5,6-dihydrodiol approximately equal to 4-hydroxy-7-FBA . The relatively high mutagenic activities of 7-FBA trans-3,4- and trans-10,11-dihydrodiols suggest that both 7-FBA trans-3,4-dihydrodiol 1,2-epoxide(s) and 7-FBA trans-10,11-dihydrodiol 8,9-epoxide(s) may be the major metabolites which contribute to the carcinogenic properties of 7-FBA.

Chem Biol Interact, 1984 Feb, 48(2), 207 - 20
Dietary administration of 2(3)-t-butyl-4-hydroxyanisole elevates mouse liver microsome-mediated DNA binding and mutagenicity of aflatoxin B1; Rahimtula AD et al.; Administration of the phenolic antioxidant 2(3)-t-butyl-4-hydroxyanisole (BHA) to mice resulted in a 2-3-fold increase in the liver microsome catalyzed irreversible binding of aflatoxin B1 (AFB1) to calf thymus DNA and up to a 5-fold increase in the ability to induce mutations in Salmonella typhimurium TA98 . Maximum induction of AFB1 binding to DNA occurred after 2 days of BHA administration whereas cytosolic glutathione S-transferase was maximally induced (6-fold) only after 10 days of BHA feeding . The induction of a new cytochrome P-450 species was indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and an enhanced sensitivity to inhibition by metyrapone and alpha-naphthoflavone . Addition of control cytosol (containing glutathione S-transferase) + glutathione to control microsomes decreased AFB1 binding to DNA by 26% . However, replacement of control cytosol by BHA cytosol which contained 6 times more glutathione S-transferase only marginally enhanced the inhibition to 38% . These data suggest that BHA may exert its effect in the liver primarily through an alteration of the cytochrome P-450 dependent activation process although an increase in the conjugation of reactive metabolite may play a contributory role.

Mutat Res, 1984 Feb, 130(1), 11 - 25
Sources of variability in Ames Salmonella typhimurium tester strains: analysis of the International Collaborative Study on 'genetic drift'; Margolin BH et al.; Data from 38 laboratories using 5 strains of Salmonella typhimurium (TA98, TA100, TA1535, TA1537, and TA1538) were analyzed to determine sources and magnitudes of test data variability . Each laboratory tested the mutagenicity of 4-nitroquinoline-N-oxide by the same protocol, using both its in-house cultures and a set of reference cultures provided to all laboratories . It was found that neither plate-to-plate nor day-to-day variability within a laboratory differed substantially between the in-house and reference cultures for any strain; this indicated no difference in the laboratories' handling of the two cultures . Not surprisingly, on average, plate-to-plate variability was substantially smaller than day-to-day variability within a laboratory, which, in turn, was substantially smaller than inter-laboratory variability . The solvent DMSO was found to have a small (6-7%) but statistically significant depressive effect on the spontaneous mutant frequency for the two plasmid-containing strains, TA98 and TA100, but not for the other three strains . When the mean value and variance of all laboratories for the in-house culture were compared with the corresponding reference culture values for each dose and strain, no major differences were seen . Any increase in mean or variance in the distribution of laboratory means in one of the two cultures could be ascribed largely to a small number of laboratories . Laboratories that reported 'high' or 'low' levels of spontaneous or induced revertants per plate tended to deviate in the same direction for most strains and for both in-house and reference cultures . If 'genetic drift' contributed to the inter-laboratory variability in this collaborative study, it was a minor component that went undetected in our analyses.

Mutat Res, 1984 Feb, 130(1), 1 - 10
An international collaborative study of 'genetic drift' in Salmonella typhimurium strains used in the Ames test; Anderson D et al.; An international collaborative study of the response of 5 Salmonella typhimurium strains (TA1535, TA1537, TA1538, TA98 and TA100) to 4-nitroquinoline-N-oxide was performed . A laboratory's 'in-house' stock of these strains was compared with a set of reference strains, using a standardized protocol . The prime objective of this study was to investigate whether the ability of these strains to produce spontaneous or induced mutants had changed during their prolonged cultivation in different laboratories, i.e . to investigate their 'genetic drift' . Any observed change in mutability might contribute to the variations between laboratories in the results of the Ames test . A second objective was to obtain information on the extent of intra- and inter-laboratory variation when a standardized protocol was used . 38 laboratories participated in this study . The data were analysed statistically by 3 groups using different models and the same conclusion was reached: genetic drift is found in some strains in some laboratories, but does not contribute significantly to inter-laboratory variation in the Ames test . When the inter-laboratory variation was analysed there was considerable correlation between results for the 'in-house' and the reference strain, and between results for different strains in the same laboratory (Margolin et al., accompanying paper).

Chemioterapia, 1984 Feb, 3(1), 60 - 2
Non-mutagenicity of KBT-1585, a novel ester of ampicillin; Yamabe S et al.; The Ames test indicated that ampicillin (ABPC) and its novel ester KBT-1585 were non-mutagenic for any of the tester strains of Salmonella typhimurium TA 98, TA 100, TA 1535 and TA 1538, both in the presence and in the absence of rat liver microsomal activation mixtures . Diacetyl, the first metabolite of KBT-1585 by the in vitro hydrolysis proved to be non-mutagenic for a new tester strain TA 102 which is exquisitely sensitive to ketones and aldehydes.

J Gen Microbiol, 1984 Feb, 130 ( Pt 2), 255 - 65
Genetic analysis of H2, the structural gene for phase-2 flagellin in Salmonella; Yamaguchi S et al.; Non-flagellate H2 mutants were isolated from a phase-2 stable strain, SJW806 H1-gt- H2-enxon vh2-, a derivative of Salmonella typhimurium . By transductional crosses a deletion map and a recombination map of the H2 gene were made . There are three regions especially rich in nonflagellate mutational sites . By the use of the deletion map, mutational sites of 21 flagellar shape mutants were also determined . Most of them were located at two regions which coincide with two of the three regions rich in non-flagellate mutational sites . A gene, vh2, is closely linked to the promoter side of the H2 gene . Three-factor transductional crosses showed that the vh2 gene was on the left of the H2 gene in the present map . The H2 gene forms part of an operon with the distal gene rh1 which specifies the H1 repressor . Thus, a polarity effect of the H2 mutations on the expression of the rh1 gene was examined by observing whether a wild-type H1 allele introduced into the H2 mutants was expressed or not . Many of the H2 mutations were polar, and most of the strongly polar mutations were located in the left (promoter-proximal) half of the H2 gene, while most of the mutations in the right half of the gene were weakly polar or non-polar.

J Environ Sci Health B, 1984 Feb, 19(1), 95 - 110
Evaluation of chlordimeform and degradation products for mutagenic and DNA-damaging activity in Salmonella typhimurium and Escherichia coli; Rashid KA et al.; The mutagenic activity of chlordimeform and two of its breakdown products, 4-chloro-o-toludine and 4-chloro-N-formyl-o-toluidine were determined with five histidine dependent strains of Salmonella typhimurium (TA1535, TA1537, TA1538, TA98, TA100) and five tryptophan dependent strains of E . coli WP2 (WP2, WP2uvrA, WP67, CM611, CM571) with and without rat liver microsomal enzymes . 4-chloro-o-toluidine increased the number of the reversions of the S . typhimurium strain TA1535 more than two fold over spontaneous at the concentration of 400 micrograms/plate . The results of the DNA repair tests in the Salmonella TA1538/TA1978 and E . coli multirepair deficient systems showed that both breakdown products were active in inducing damage not repaired in at least one repair deficient strain while chlordimeform itself was inactive.

Am J Vet Res, 1984 Feb, 45(2), 326 - 32
Elimination of plasmidic resistance to ampicillin and of enterotoxinogenicity in certain enteric gram-negative bacteria after incubation with high concentrations of amprolium; Ozanne G et al.; We have observed that treatment with high concentrations of a thiamine analog (amprolium) can lead to the elimination of the plasmidic resistance to ampicillin and the production of enterotoxin in wild Escherichia coli strains and in E coli and Salmonella typhimurium strains which had received the pKM101 plasmid through bacterial conjugation . By computer analysis, we also have determined that there is a highly significant (P less than 0.01) synergism between ampicillin and amprolium which reduces considerably the growth of certain enteric bacterial strains which have a plasmidic resistance to ampicillin and which were not markedly affected by amprolium alone, in our experimental conditions . Our data indicate that the rate of loss of the plasmid pKM101 after treatment of R+ bacterial strains with amprolium can be increased.

Mutat Res, 1984 Feb, 125(2), 145 - 51
Antimutagenic effects of germanium oxide on Trp-P-2-induced frameshift mutations in Salmonella typhimurium TA98 and TA1538; Kada T et al.; A germanium compound, germanium oxide (GeO2) behaved as a potent antimutagen on frameshift-type reverse mutations induced by 3-amino-1-methyl-5H-pyrido{4,3-b}indole (Trp-P-2) in strains of Salmonella typhimurium TA98 and TA1538 with and without a plasmid pKM101, respectively . This metal antimutagen seems to work independently of the plasmid, a promotive factor in chemically induced mutagenesis through error-prone DNA repair.

Mutat Res, 1984 Feb, 125(2), 135 - 44
Microsomal transformation of emodin into a direct mutagen; Masuda T et al.; The activation mechanism of emodin, a fungal anthraquinone and constituent of rhubarb, into a direct mutagen to Salmonella typhimurium TA1537 was investigated by using the S9 and microsomes of rat livers . Upon incubating emodin with the hepatic S9 derived from PCB-pretreated rats, this anthraquinone exhibited mutagenicity in the presence of NADPH or NADH, and this enzymatic activation, maximal at pH 7.0 and occurring in the microsomes, was induced by the pretreatment of rats with PCB, 3-methyl-cholanthrene or phenobarbital and was inhibited by alpha-naphthoflavone, SKF 525A and carbon monoxide . Thin-layer chromatographic analysis revealed that emodin was biotransformed by the microsomal enzymes into at least 5 quinonoid metabolites, among which one pigment, identified as 2-hydroxyemodin (1,2,3,8-tetrahydroxy-6-methyl-anthraquinone), was proved to be a direct mutagen to the test strain, and the remaining 4 quinoniod metabolites were negative or far less active than this active principle.

J Clin Microbiol, 1984 Feb, 19(2), 100 - 4
Comparison of plasmid profile analysis, phage typing, and antimicrobial susceptibility testing in characterizing Salmonella typhimurium isolates from outbreaks; Holmberg SD et al.; We compared the phage types, antimicrobial resistance patterns, and plasmid profiles of 20 groups of isolates received at the Centers for Disease Control from Salmonella typhimurium outbreaks between 1975 and 1982 to determine the most useful laboratory method for identifying epidemiologically related isolates of S . typhimurium . In 18 (90%) of the 20 outbreaks, epidemiologically related isolates were identified as being the same by each of the three methods . In a subgroup of nine outbreaks in which isolates unrelated to the outbreak were submitted for comparison, outbreak isolates were differentiated from such control isolates six times (67%) by phage typing alone, four times (44%) by antimicrobial susceptibility testing alone, and eight times (89%) by plasmid profile analysis alone . Epidemic isolates were multiply susceptible, nontypable, or without plasmids in 14 (70%), 1 (5%), and 3 (15%), respectively, of the 20 outbreaks . Plasmid analysis appeared to be at least as specific as phage typing in identifying epidemiologically related isolates of S . typhimurium as being the same or in differentiating them from control specimens; both techniques appeared to be superior to antimicrobial susceptibility testing.

Food Chem Toxicol, 1984 Feb, 22(2), 119 - 22
Ames mutagenicity tests of products from a heated potato-starch system; Shibamoto T; A charred sample was prepared from potato starch heated with ammonium carbonate at 600 degrees C in a flask under a nitrogen stream . The water produced was collected and extracted with methylene chloride . The basic fraction obtained from the extract exhibited strong mutagenicity in Ames assays using Salmonella typhimurium strains TA98 or TA100 with metabolic activation (rat-liver S-9 mix) . The basic fraction was further fractionated by silica gel column chromatography and subsequently by Sephadex column chromatography . Some of the resulting fractions exhibited strong mutagenic activities in S . typhimurium strain TA98 with S-9 mix.

Carcinogenesis, 1984 Feb, 5(2), 155 - 9
Mutagenesis and O6-ethylguanine levels in DNA from N-nitroso-N-ethylurea-treated Salmonella typhimurium: evidence for a high mutational efficiency of O6-ethylguanine; Guttenplan JB; The dose-responses for N-nitroso-N-ethylurea (NEU)-induced mutagenesis in the hisG46 mutant, Salmonella typhimurium TA1535, and for the formation of O6-ethylguanine (O6-EtGua) and 7-ethylguanine in the DNA isolated from these cells were measured . Mutagenesis and O6-EtGua formation exhibited threshold-like behavior, whereas the formation of 7-ethylguanine was linear with dose . These results are consistent with a dependence of mutagenesis on O6-EtGua . There was no threshold in the production of O6-EtGua in isolated DNA treated with NEU . The failure of O6-EtGua to appreciably accumulate in the cellular DNA at low doses of NEU was attributed to a saturable, constitutive repair activity in the bacteria . Based on (i) the ratio of O6-EtGua in DNA to revertant fraction, (ii) published values for the size of the Salmonella genome and (iii) the target size and target bases (guanine-cytosine base pairs) for reversion of the hisG46 (missense) mutation, it was calculated that about 1/3 of the O6-EtGua's in the DNA led to mutations . Using the same calculations and data from previous experiments, a mutational efficiency for O6-methylguanine of 2/3 was obtained . Threshold-type responses in NEU-induced mutagenesis were observed in the other hisG46 mutants, TA100 and TA1975, but not in the frameshift mutant, TA98 where the dose response was linear . As TA98 contains the same DNA repair systems as TA100, frameshift mutations induced by NEU may result from DNA adducts produced linearly with dose.

Mutat Res, 1984 Feb, 135(2), 97 - 103
Mutagenic activity of methyl-substituted tri- and tetracyclic aromatic sulfur heterocycles; McFall T et al.; A number of polycyclic aromatic sulfur heterocycles have been identified in coal-derived products and in shale oils . The mutagenic activity of some of these compounds, including dibenzothiophene, benzo{b}naphtho{1,2-d}thiophene, benzo{b}naphtho{2,1-d}thiophene and benzo{b}naphtho{2,3-d}thiophene have been determined using the Salmonella/microsome mutagenicity test . These compounds demonstrated either very weak or no mutagenic activity . The methyl derivatives of each of these four compounds were assayed for mutagenic activity . Salmonella typhimurium TA98 was used as the tester strain . All assays required a rat-liver homogenate metabolic activator . Five of the methylated derivatives, 1-methylbenzo{b}naphtho{1,2-d}thiophene, 3-methylbenzo{b}naphtho{1,2-d}thiophene, 1-methylbenzo{b}-naphtho{2,1-d}thiophene, 6-methylbenzo{b}naphtho{2,1-d}thiophene and 4-methylbenzo{b}naphtho{2,3-d}thiophene demonstrated mutagenic activity . However, activity was observed only at high concentrations of the metabolic activator.

Mutat Res, 1984 Feb, 135(2), 77 - 86
Mutagenicity of flavones, chromones and acetophenones in Salmonella typhimurium . New structure-activity relationships; Elliger CA et al.; 28 flavones and 11 structurally-related flavonoids, chromones, and acetophenones, were tested for mutagenicity in the Salmonella typhimurium his reversion assay . 7 flavones, all of which were hydroxy- or methoxy-substituted at position 8, were moderate to strong mutagens in strain TA100 in the presence of rat liver S9 mix . In each case, the response of strain TA98 was either not significant or was very much weaker than that observed in strain TA100 . The activation by S9 is not mediated by the microsomal cytochrome P450 system, since activation was not diminished when microsomes were removed by centrifugation at 100 000 X g . The observed strain specificity and structural requirements for activity indicate a mutagenic mechanism different from that associated with previously reported mutagenic flavonols (3-hydroxy-flavones) which are most active in strain TA98 . The most mutagenic flavone investigated, 5,7,8-trihydroxy-flavone (norwogonin), had a potency of 17 revertants/nmole . Simplification of the chemical structures to hydroxy-substituted chromone and acetophenone systems revealed similar strain specificity, hydroxylation requirements, and S9 dependence within these structural classes, suggesting a similar activation pathway and mutagenic mechanism . The greatest mutagenic potency was observed within the flavone series, but significant potency was retained by similarly hydroxylated chromones and acetophenones . No mutagenic activity was observed in the absence of the aryl ketone moiety.

Mutat Res, 1984 Feb, 135(2), 105 - 8
Mutagenicity of amine drugs and their products of nitrosation; Andrews AW et al.; 8 drugs that are amines or amides and that interact with nitrous acid to form potentially carcinogenic and mutagenic N-nitroso derivatives were tested for mutagenicity to Salmonella typhimurium . None of the compounds was mutagenic alone, with or without liver S9 activation . After reaction with nitrite in acetic acid solution, the products of 4 of the compounds were mutagenic . Diphenhydramine and hydrochlorothiazide gave products mutagenic with or without activation, but only to strain TA98 . Methaphenilene gave products mutagenic to TA1538, TA98 and TA100 without microsomal activation . Dimethyldodecylamine-N-oxide after nitrosation was mutagenic with S9 activation to TA1535 indicating a response to the nitrosomethyldodecylamine formed . Allantoin, pyrilamine, chlorothen, methafurylene and thenyldiamine were not mutagenic alone or after nitrosation.

Mutat Res, 1984 Feb, 130(1), 45 - 51
Development of an in situ microbial mutagenicity test system for airborne workplace mutagens: laboratory evaluation; Whong WZ et al.; A simple on-site Salmonella mutagenicity test system for the detection of airborne mutagens in the workplace is being developed . The system permits entrapment of mutagenic airborne particles and vapors by impinging unfiltered ambient air into trapping medium containing bacterial tester cells . The trapping device consists mainly of a pump, an impinger and a cyclone . The impinging air flow generated by the pump is approximately 3 1/min . New Salmonella typhimurium testers which are resistant to streptomycin (Str) and 8-azaguanine (AG) were derived from the Ames testers TA98 and TA100 and the arabinose-resistant tester SV50, and were used as mutation indicators . Microbial contamination was sufficiently controlled by addition of ampicillin, Str, AG, and cycloheximide to the trapping and plating media . New tester strains retained a high mutagenic sensitivity from their parent strains . Laboratory studies with volatile mutagens (methyl methanesulfonate, ethyl methanesulfonate, and dimethylnitrosamine) showed that the vapor trapping of this system is promising . The study with suspended silica particles coated with a known mutagen (2,4,7-trinitro-9-fluorenone) indicated that the particle trapping of the system is satisfactory . Incorporation of metabolic activation into the trapping medium by confining S9 mix and tester cells in dialysis tubing enabled this system to detect promutagens . This in situ system may be useful for mutagenic monitoring in the workplace.

J Bacteriol, 1984 Feb, 157(2), 649 - 54
Bacteriophage chi sensitivity and motility of Escherichia coli K-12 and Salmonella typhimurium Fla- mutants possessing the hook structure; Kagawa H et al.; The production of hook protein and flagellin in 29 Fla- mutants of Escherichia coli K-12 was determined by the complement fixation assay . Six mutants produced hook protein, and four of them also produced flagellin . A flaE mutation was introduced into these fla mutants carrying the hook structure . All of these mutants made polyhooks and were used as hosts for a newly isolated host-range mutant of chi phage that has a high affinity for the hook structure . All except one mutant produced significant amounts of progeny phages . A flaD flaE double mutant was that exception which did not yield significant amounts of progeny by the phage propagation method . All of the flaE double mutants produced comparable amounts of polyhooks, and no qualitative difference was detected between chi-sensitive and chi-insensitive mutants by the complement fixation assay . Accordingly, it was thought that the polyhook of the flaD flaE mutant had a mechanical defect for chi phage infection . This assumption was confirmed by tethered-cell experiments; the flaD flaE mutant did not rotate . These results are well explained by a proposed regulation pathway of flagellar genes . flaE mutants can express other genes which govern the final step of the flagellar morphogenesis, whereas flaD mutants cannot rotate, possibly because the mocha operon is not expressed . The results obtained in E . coli were also found to be applicable to Salmonella typhimurium.

J Bacteriol, 1984 Feb, 157(2), 391 - 7
Change in the surface hydrophobicity of substrate cells during bdelloplast formation by Bdellovibrio bacteriovorus 109J; Cover WH et al.; During intraperiplasmic growth of Bdellovibrio bacteriovorus 109J, the substrate cell surface becomes more hydrophobic . This was shown (i) by comparing the sensitivity to hydrophobic antibiotics of wild-type and lipopolysaccharide mutant strains of Salmonella typhimurium to that of the bdellovibrio growing on these strains and (ii) by measuring the binding efficiency of these strains, Escherichia coli, and their derived bdelloplasts to octyl Sepharose . The kinetics of increase in surface hydrophobicity was similar to the kinetics of the conversion of the substrate cell peptidoglycan to a lysozyme-resistant form (M . Thomashow and S . Rittenberg, J . Bacteriol . 135:1008-1014, 1978), and hydrophobicity reached a maximum at about 60 min in a synchronous culture . The change in hydrophobicity was inhibited by chloramphenicol, suggesting that bdellovibrio protein synthesis was required . Control experiments revealed that the free-swimming bdellovibrio had a more hydrophobic surface than the deep rough mutants of S . typhimurium.

Infect Immun, 1984 Feb, 43(2), 543 - 8
Effect of iron on antibacterial immunity in vaccinated mice; Kochan I et al.; The effect of iron on resistance to Salmonella typhimurium was investigated in mice inoculated with vaccines prepared from live and avirulent (SL3770) or killed and virulent (SR11 or LT2) bacteria . It has been found that mice vaccinated with SL3770 vaccine develop an immunity which can be neutralized with iron . Iron promoted the development of lethal infections by serving as a growth-essential nutrilite for infecting bacteria and by neutralizing the acquired immunity . The titration of this dual effect of iron showed that more iron was needed to neutralize the immunity in vaccinated animals than to promote bacterial growth in normal animals . In the presence of a sufficient amount of exogenous iron, as few as 10 bacteria caused lethal infections in normal and immune mice with the same effectiveness . This iron-sensitive immunity could be changed to iron-resistant immunity by the immunological stimulation of SL3770-vaccinated mice with a sonicated vaccine prepared from heat-killed SR11 or LT2 bacteria . In distinction to iron-sensitive immunity, iron-resistant immunity could be transferred from SR11- or LT2-stimulated to normal mice with serum . Although effective in the transfer of antibacterial immunity, sera of SR11- or LT2-stimulated mice supported the growth of virulent bacteria as well as did sera of normal mice . The absorption of immune serum with either SR11 or LT2 bacteria removed its protective quality, but the sensitized bacteria remained as infectious as untreated bacteria for iron-treated normal mice . Only in SL3770-vaccinated mice were the immune serum-sensitized bacteria not able to cause the infection in spite of daily treatment with iron . These results suggest that iron-resistant immunity is due to the synergistic action of specific antibody and phagocytes of immunologically stimulated animals.

Acta Pathol Microbiol Immunol Scand {B}, 1984 Feb, 92(1), 45 - 51
Invasiveness of Salmonella typhimurium in HEp-2 cell cultures preinfected with Coxsackie B 1 virus; Bukholm G et al.; The influence of infection of HEp-2 cells with Coxsackie B 1 virus on the invasiveness of Salmonella typhimurium has been studied . The bacterial invasiveness was significantly increased in the cell cultures incubated with virus before bacterial inoculation . This effect was a function of time after introduction of virus into the cell cultures and the concentration of virus . The increase in bacterial invasiveness was observed before production of infectious virus particles and before development of cytopathogenic effect was evident . Two strains of non-invasive Escherichia coli did not show invasiveness after the virus treatment of the cells . The results indicate a specific mechanism for the interaction.

South Med J, 1984 Feb, 77(2), 234 - 6
Empyema due to Salmonella typhimurium with underlying alveolar cell carcinoma; Kate P et al.; We have described an elderly woman with empyema due to Salmonella typhimurium group B, which was resistant to conventional antibiotic treatment . Drainage revealed an underlying mass, which at necropsy was shown to be an alveolar cell carcinoma.

J Bacteriol, 1984 Feb, 157(2), 655 - 7
Physical map of Salmonella typhimurium LT2 DNA in the vicinity of the proA gene; Riley M et al.; More than 55 kilobases of chromosomal DNA of Salmonella typhimurium LT2, including the gpt, proA, ataA, and newD genes, were cloned in plasmid vector pULB113 . The locations of the genes and selected restriction endonuclease cleavage sites were established, and some of the restriction enzyme fragments were subcloned in plasmid vector pBR322.

Arch Biochem Biophys, 1984 Feb 1, 228(2), 512 - 8
Isolation and crystallization of unadenylylated glutamine synthetase from Salmonella typhimurium; Janson CA et al.; The enzyme glutamine synthetase (GS) has been isolated from a mutant strain of Salmonella typhimurium, constructed by Kustu, which lacks the enzymatic activity for adenylylation of glutamine synthetase . Thus the purified GS is uniformly unadenylylated, as confirmed by gel electrophoresis and enzyme assays . It crystallizes readily in many morphologies, at least six of which are distinct polymorphs . The most favorable crystal form for structural studies belongs to space group C2, with unit cell dimensions a = 235.5 A, b = 134.5 A, c = 200.1 A, beta = 102.8 degrees, and with one GS molecule per asymmetric unit . The crystals diffract to about 2.8 A resolution in rotation X-ray photographs and thus appear suitable for structural studies at moderate resolution . These crystals are isomorphous with crystalline GS from Escherichia coli in both adenylylated and unadenylylated states, suggesting that the enzymes from the two bacteria are similar molecules, and that adenylylation does not greatly affect the conformation of the molecule.

Int Arch Occup Environ Health, 1984, 54(1), 83 - 90
Non-mutagenicity of some wood-related compounds in the bacterial/microsome plate incorporation and microsuspension assays; Mohtashamipur E et al.; Seven commercially available wood-related compounds have been tested for mutagenicity by the use of the Ames and fluctuation test-systems . All compounds were found to be non-mutagenic . Among these compounds, 2,6-dimethoxy-p-benzoquinone showed a very weak and questionable mutagenic activity against Salmonella typhimurium TA 100 . In this connection, probable causes of nasal adenocarcinoma of woodworkers are briefly discussed.

J Cancer Res Clin Oncol, 1984, 107(1), 61 - 3
Mutagenic activity in stones from a patient with a congenital choledochal cyst; Bull P et al.; A 12-year-old boy presenting a congenital choledochal cyst complicated with stones and chronic recurrent cholangitis was subjected to surgery for cyst resection with a Roux-Y hepatojejunostomy . Potential carcinogenic factors were looked for in the cyststones using the Salmonella typhimurium plate test of Ames . High mutagenic activity was found in the stone extract incubated with the TA 98 tester strain, but not with the TA 100 strain . The test was negative with stone extracts obtained from seven patients operated on for chronic gallbladder disease . This study demonstrates the presence of a mutagenic chemical in the biliary tree of a patient with a clinical condition commonly associated with biliary tract cancer.

Carcinogenesis, 1984 Jan, 5(1), 11 - 4
Frequency of sister chromatid exchanges in human lymphocytes cultivated with a human hepatoma cell line as an indicator of the carcinogenic potency of two cyclopenta{a}phenanthrenes; Lindahl-Kiessling K et al.; We demonstrate here that the carcinogen 15,16-dihydro-11-methylcyclopenta{a}phenanthren-17-one can cause sister chromatid exchange in human lymphocytes as well as it can cause mutation in bacterial cells and in V79 hamster cells . The non-methylated parent compound which has no tumorigenic action and yet significantly mutates both Salmonella typhimurium TA 100 and hamster V79 cells, has no effect on the frequency of sister chromatid exchange . These results support the idea that sister chromatid exchanges are a valuable additional indicator of tumorigenic potential.

IARC Sci Publ, 1984, (57), 387 - 98
Destruction of carcinogenic and mutagenic N-nitrosamides in laboratory wastes; Lunn G et al.; The chemical degradation of five N-nitrosamides used widely for the experimental induction of cancer has been studied with the goal of identifying, and experimentally validating, reliable methods that can be recommended for the destruction of carcinogenic N-nitrosoureas and related compounds in laboratory wastes . Although data are not yet complete, preliminary evidence indicates that none of the five methods studied thus far is ideal for hazard-control purposes . Decomposition with 1 mol/L potassium hydroxide solution destroyed the N-nitrosamides, but generated diazoalkanes, which are carcinogenic, toxic and potentially explosive . Treatment with strong acid in the presence of sulfamic acid or iron filings completely decomposed all N-nitrosamides without forming diazoalkanes, but failed in the presence of solvents which were immiscible with water . Cleavage with hydrogen bromide in glacial acetic acid proceeded to a point of maximum degradation, following which gradual reformation of the N-nitrosamide was observed; this resynthesis could be avoided by carefully bubbling nitrogen through the reaction mixture, but degradation was slow or failed completely in the presence of hydroxylic solvents . Permanganate oxidation was effective in sulfuric acid solution, but was incomplete when an alcohol or dimethyl sulfoxide was present . Salmonella typhimurium tester strains TA1535, TA1530 and TA100, which detect base-pair substitutions in DNA, detected mutagenic degradation products in each of the destruction methods, with the exception of the hydrobromic acid/acetic acid procedure.

Rev Epidemiol Sante Publique, 1984, 32(6), 360 - 5
{Human salmonellosis in Ille-et-Vilaine in 1983}; Avril JL et al.; 224 salmonella strains from human beings, collected by the public and private laboratories of Ille-et-Vilaine during 1983, were serotyped and tested for their susceptibility to antibiotics . Salmonella typhimurium infections were the most frequent, while the other serotypes constituted a small number of strains, generally susceptible to antibiotics . No outbreak due to a multi-resistant serotype was observed . S . typhi and S . paratyphi B represent 6,25% of the strains isolated in this area during the year . Only 22% of the 224 strains collected were resistant to one or more antibiotics.

Proc Natl Sci Counc Repub China B, 1984 Jan, 8(1), 46 - 9
Vaginal contents show in vitro mutagenic activity; Wei RD et al.; In Millipore filtrate of some vaginal douching, mutagens were readily detected by means of the Ames Salmonella test . Among 521 subjects, the samples of 76 cases (14.6%) were mutagenic in Salmonella typhimurium TA98 or/and TA100 in the presence or absence of S9 mixture . Dichloromethane and chloroform were found to extract the mutagens satisfactorily.

Proc Natl Sci Counc Repub China B, 1984 Jan, 8(1), 4 - 10
The mutagenicity of nitrite-treated aqueous extract of Piper betle L; Chen HC et al.; Betel quid is chewed as a masticatory material by people in certain areas of Asia . The quid chewing has been related to oral cancer by epidemiological study . The mutagenic components in the aqueous extracts of betel quid ingredients were studied . Only nitrite-treated aqueous extract of Piper betle L fruits, leaves or rhizoma were demonstrated to exhibit a mutagenic response, using Salmonella typhimurium strains TA100 and TA1535 in the Ames test . When the aqueous extract of the fruit was nitrosated, the greatest number of mutagenic substances were formed at pH 3 . The formation of mutagens was enhanced by increasing the temperature from 5 to 95 degrees C . Maximum production of the mutagens occurred within 15 min when nitrosation was conducted at 35 degrees C . The mutagenic components in nitrite-treated aqueous extract of Piper betle L fruit were found to be N-nitrosopiperidine, N-nitrosopyrrolidine, N-nitrosomorpholine, and other compounds, as determined by gas chromatography-thermal energy analyzer.

Microbiol Immunol, 1984, 28(11), 1181 - 90
Hepatic drug-metabolizing enzyme system and endotoxin tolerance: structural requirement of LPS in induction of an early tolerance; Egawa K et al.; The alteration of hepatic drug-metabolizing enzyme activities in mice given Salmonella endotoxin by single or multiple intraperitoneal injections was investigated . An essentially the same biphasic, early and late phase, endotoxin tolerance was observed in the animals receiving a single injection of endotoxin or repetitive daily injections . The results of reciprocal cross tolerance tests using lipopolysaccharide and free lipid A preparations derived from Salmonella minnesota, Salmonella typhimurium, E . coli, Pseudomonas aeruginosa, and Chromobacterium violaceum suggested that lipid A moiety plays an important role in the induction of early endotoxin tolerance to endotoxin response.

Environ Mutagen, 1984, 6(4), 517 - 27
Cytotoxicity and mutagenicity of coal oils in the CHO/HGPRT assay; DeMarini DM et al.; We used the Chinese hamster ovary cell/hypoxanthine-guanine phosphoribosyl-transferase (CHO/HGPRT) assay to determine the cytotoxicity and mutagenicity of a crude coal oil, the neutral fraction of this crude, and the following three subfractions of the neutral fraction: aliphatic, neutral polar, and a subfraction composed of polycyclic aromatic hydrocarbons plus neutral nitrogen heterocyclics . We also studied the cytotoxicity and mutagenicity of a blend of light and heavy coal-derived fuel oils before and after hydrogenation . All seven mixtures were highly cytotoxic to CHO cells, but the addition of S9 reduced the cytotoxicity . Also, hydrogenation reduced the cytotoxicity of the blend of coal-derived fuel oils . Although highly cytotoxic, none of the seven mixtures induced a clear mutagenic response in the CHO/HGPRT assay . However, previous work has shown that all of the mixtures except the aliphatic subfraction and the blend after hydrogenation are mutagenic in the histidine-reversion assay in Salmonella typhimurium . Based on chemical analyses of the mixtures, the differential sensitivity of Salmonella and CHO cells to nonmutagenic cytotoxins, and studies of the neutral fraction to which additional benzo{a}pyrene had been added, we conclude that the disparity between the results in Salmonella and those obtained in the CHO/HGPRT assay is probably due to the much greater sensitivity of CHO cells (relative to Salmonella) to the cytotoxins in these coal oils . This sensitivity, coupled with the low concentrations of mutagens relative to nonmutagenic cytotoxins in the coal oils, prevents exposure of the cells to concentrations of the mutagens in the mixtures that are high enough to be quantified in the CHO/HGPRT assay.

Clin Invest Med, 1984, 7(4), 303 - 9
Enhancement of passive antilisterial immunity and change of Lyt phenotype following in vitro stimulation of murine lymphoid cells from immune donors; Barry RA et al.; To enhance the functional activity of the immune lymphoid cells required for passive antilisterial immunity, we cultured spleen cells from Listeria-immune mice in vitro with specific mitogens or listerial antigens and then transferred these cells into normal syngeneic mice . We assayed the level of passive immunity in these recipients either by their resistance to challenge with viable Listeria monocytogenes or by their delayed-type hypersensitivity (DTH) response to listerial antigens . In vitro stimulation with the T cell mitogens concanavalin A (ConA) and phytohemagglutinin (PHA) effectively enhanced passive immunity to viable Listeria . ConA stimulation of immune cells typically enhanced adoptive immunization 100- to 1000-fold . These ConA-stimulated immune lymphoid cells maintained their antigen specificity, since they provided no significant protection against Salmonella typhimurium . Although in vitro ConA stimulation resulted in markedly enhanced passive immunity to viable Listeria, the passive delayed-type hypersensitivity response to listerial antigens was not concurrently enhanced . Stimulation with certain preparations of listerial antigens also resulted in transfer of enhanced levels of adoptive immunity against viable Listeria . In cytotoxic assays utilizing monoclonal antibodies against the Lyt differentiation antigens, the ConA-stimulated immune T cells exhibited a different Lyt phenotype relative to nonstimulated immune T lymphocytes . Our results indicate that in vitro stimulation of Listeria-immune lymphoid cells leads to the differentiation as well as proliferation of antigen-specific T cells, suggesting that the in vivo development of immunity to Listeria monocytogenes is dependent not only on increased numbers of immune T lymphocytes, but also on the differentiation of these antigen specific T cells.

J Immunopharmacol, 1984, 6(4), 339 - 58
Dissociative effects of a novel immunomodulating agent (CP-20, 961) on host defenses of mice; Wing EJ et al.; The antimicrobial and antitumor effects of CP-20,961, a synthetic lipoid amine with immunomodulating properties, were investigated . Mice given CP-20,961 ip seven or three days before challenge with ip Listeria monocytogenes had a lower mortality than control mice . By contrast, CP-20,961 did not protect against lethal challenges of either Salmonella typhimurium or Toxoplasma gondii . In parallel with the in vivo studies, peritoneal macrophages from CP-20,961-injected mice inhibited multiplication of L . monocytogenes but not T . gondii . Further studies demonstrated that CP-20,961 protected mice against an ip challenge of P815 tumor cells as measured by survival time . This correlated with the ability of stimulated peritoneal macrophages to inhibit (3H-TdR uptake inhibition) and kill (Cr51 release) P815 cells in vitro . These data indicate that CP-20,961 affords protection against an ascitic mastocytoma tumor line and at least one, but not all, intracellular pathogens . The dissociation of the immunomodulating effect, which was reflected in peritoneal macrophage function, may be characteristic of this new class of immunomodulators.

Aust J Biol Sci, 1984, 37(3), 123 - 9
Synthesis and degradation of aflatoxins by Aspergillus parasiticus . II . Comparative toxicity and mutagenicity of aflatoxin B1 and its autolytic breakdown products; Huynh VL et al.; A crude mycelial protein extract from a 16-day-old culture of A . parasiticus, on purification, lost 50% of its ability to degrade aflatoxin B1 . The addition of hydrogen peroxide increased this activity to 97% of that of the crude extract . Ducklings dosed orally with aflatoxin extracts from 14- and 20-day-old cultures containing 46 micrograms or more of aflatoxin B1 developed enlarged livers, haemorrhaged and died in less than 10 days, giving and LD50 of 17.5 and 17.1 micrograms aflatoxin B1 per 50 g body weight respectively for each extract . When pure aflatoxin B1 was mixed with either the crude or purified mycelial protein extract the aflatoxin B1 level was decreased by 29% as was the toxicity of the mixture . The main breakdown product of aflatoxin B1 was isolated and was shown to have an RF value of 0.34, was non-fluorescent, and was non-toxic for ducklings at oral doses as high as 400 micrograms per 50 g body weight . The mutagenic effect of aflatoxin B1 on Salmonella typhimurium was relative to its concentration . The main breakdown product of aflatoxin B1 was non-mutagenic.

Microbiol Immunol, 1984, 28(7), 807 - 20
Immunogenic dialyzable factor derived from a ribosomal fraction of Salmonella typhimurium III . Analysis of resistance induced by dialyzable factors; Kita E et al.; Dialyzable factors (DF) were prepared from ribosomal fractions of several organisms including rough mutants of Salmonella typhimurium LT2, salmonella species of different serogroups, other enteric bacteria and gram-positive organisms, and tested for their immunogenicity against S . typhimurium infection in mice . All of them conferred local resistance on mice challenged intramuscularly with S . typhimurium LT2 in the early stage of immunization before the establishment of delayed-type hypersensitivity (DTH) to salmonella antigens . Although DFs of enteric bacteria including rough mutants of S . typhimurium induced DTH to salmonella antigens, only DF of a two-heptose mutant of S . typhimurium LT2 afforded significant mouse protection but others only prolonged the mean time to death . DF of Listeria monocytogenes induced the cross-reacting immunity which afforded the low level of mouse protection as well as an increase in mean time to death without inducing DTH . Passive transfer of anti-O antibody did not enhance the mouse protection provided by each DF . Resistance conferred by DF of S . typhimurium LT2 consisted of two phases: (i) nonspecific macrophage activation resulting in reduction of organisms at the infected site, which became active in the early stage of immunization and (ii) salmonella-specific immunity capable of preventing systemic infection, which became active in the late stage of immunization.

Microbiol Immunol, 1984, 28(6), 691 - 702
Biological and biochemical characterization of macrophage activating factor (MAF) in murine lymphocytes: physiocochemical similarity of MAF to gamma interferon (IFN-gamma); Fukazawa Y et al.; During the course of an investigation designed to separate macrophage activating factor (MAF) activity from interferon (IFN) antiviral activity in the lymphokine-rich fraction (LKF) produced by stimulation of murine splenic cells with concanavalin A (Con A), we found molecular evidence for the similarity of the two activities . MAF activity was expressed as the rate of inhibition of intracellular growth of Salmonella typhimurium in macrophages based on the linear correlation between relative MAF activity and LKF concentration . The antiviral substance in LKF was identified as IFN-gamma based on the observation that its activity was inactivated at pH 2 and neutralized with anti-mouse IFN-gamma serum but not with anti-mouse IFN-alpha/beta serum . MAF and IFN antiviral activities displayed identical sensitivity to pH 2 and temperature . Further, neither activity was affected by beta-mercaptoethanol, but both were inactivated by guanidine hydrochloride and by sodium dodecyl sulfate, suggesting that the structures related to conformation of the protein of the two molecules may be similar . In affinity chromatography of the LKF on a Con A-Sepharose column, MAF and IFN activities were found in both the nonadsorbing (F I) and adsorbing (F II) fractions . However, the rates of F II of MAF and IFN activities increased proportionally when the sample was applied on a column of higher capacity, suggesting that the molecular structure of the mannose-containing glycosyl moiety of the two molecules may also be similar . Moreover, the intact or modified form of MAF and IFN activities of different LKF preparations showed a strong correlation, indicating that the production and denaturation of MAF activity were proportional to those of IFN antiviral activity . The results of this study provide strong evidence that MAF and IFN antiviral activities may reside in virtually the same molecular species.

Mol Gen Genet, 1984, 196(1), 152 - 7
Molecular cloning of genes involved in purine biosynthetic and salvage pathways of Salmonella typhimurium; O'Reilly C et al.; Genes have been cloned from Salmonella typhimurium which when present on the multicopy plasmid pBR322 in the E . coli strain NT31 confer a Gua+ phenotype on this strain . NT31 is a purE gpt double mutant and it was expected that a Gua+ phenotype could be conferred on it by the cloning of either gpt or purE . It was, however found that in addition to these two loci the molecular cloning of another gene, which has been identified as hpt, in pBR322 confers a Gua+ phenotype on NT31 . This result is explained by the overproduction of the hpt gene product, hypoxanthine phosphoribosyl transferase, which compensates for the lack of the gpt product guanine-xanthine phosphoribosyl transferase . Restriction analysis of the three loci, gpt, hpt and purE is also presented.

J Cell Biochem, 1984, 25(3), 139 - 59
Phosphoproteins and the phosphoenolpyruvate: sugar phosphotransferase system in Salmonella typhimurium and Escherichia coli: evidence for IIImannose, IIIfructose, IIIglucitol, and the phosphorylation of enzyme IImannitol and enzyme IIN-acetylglucosamine; Waygood EB et al.; Phosphoproteins produced by the incubation of crude extracts of Salmonella typhimurium and Escherichia coli with either {32P}phosphoenolpyruvate or {gamma 32P}ATP have been resolved and detected using sodium dodecyl sulphate polyacrylamide gel electrophoresis and autoradiography . Simple techniques were found such that distinctions could be made between phosphoproteins containing acid-labile or stable phosphoamino acids and between N1-P-histidine and N3-P-histidine . Phosphoproteins were found to be primarily formed from phosphoenolpyruvate, but because of an efficient phosphoexchange, ATP also led to the formation of the major phosphoenolpyruvate-dependent phosphoproteins . These proteins had the following apparent subunit molecular weights: 65,000, 65,000, 62,000, 48,000, 40,000, 33,000, 25,000, 20,000, 14,000, 13,000, 9,000, 8,000 . Major ATP-dependent phosphoproteins were detected with apparent subunit molecular weights of 75,000, 46,000, 30,000, and 15,000 . Other minor phosphoproteins were detected . The phosphorylation of the 48,000- and 25,000-MW proteins by phosphoenolpyruvate was independent of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) . The PTS phosphoproteins were identified as enzyme I (soluble; MW = 65,000); enzyme IIN-acetylglucosamine (membrane bound; MW = 65,000); enzyme IImannitol (membrane bound; MW = 62,000); IIIfructose (soluble; MW = 40,000); IIImannose (partially membrane associated; MW = 33,000); IIIglucose (soluble; MW = 20,000); IIIglucitol (soluble; MW = 13-14,000); HPr (soluble; MW = 9,000); FPr (fructose induced HPr-like protein (soluble; MW = 8,000) . HPr and FPr are phosphorylated on the N-1 position of a histidyl residue while all the others appear to be phosphorylated on an N-3 position of a histidyl residue . These studies identify some previously unknown proteins of the PTS and show the phosphorylation of others, which although previously known, had not been shown to be phosphoproteins.

Microbiol Immunol, 1984, 28(2), 169 - 79
Rapid purification of extracted bacterial lipopolysaccharides by continuous free-flow electrophoresis; Kuwae T et al.; The use of continuous free-flow electrophoresis for the purification of extracted lipopolysaccharides ( LPSs ) was investigated . Commercial (nucleic acid contaminated) LPS preparations, isolated by the hot phenol-water method of Westphal from Salmonella typhimurium and Escherichia coli 0111: B4, were analyzed . Continuous free-flow electrophoresis for purification of crude LPSs proved to be a rapid and useful means for the continuous purification of large amounts of LPS (more than 45 mg crude LPS per hr) and it showed good reproducibility and pure LPS . The electrophoretic profile of both crude LPSs obtained by continuous free-flow electrophoresis showed two distinct, sharp peaks; one representing the nucleic acid fraction and the other the LPS fraction . Under the continuous free-flow electrophoresis conditions employed, nucleic acid in the crude LPSs possessed low electrophoretic mobility, whereas LPS migration was negligible . Thus for both preparations pure LPS (no detectable nucleic acid) was obtained . Electrophoretic profiles of these purified LPSs on sodium dodecylsulfate-polyacrylamide gel electrophoresis were similar in both cases to those of crude LPS and of LPS purified by repeated ultracentrifugation . By immunological analysis using double immunodiffusion and immunoelectrophoresis, it was found that two components of crude E . coli 0111: B4 LPS were eliminated by continuous free-flow electrophoresis, but each component of purified E . coli 0111: B4 LPS was immunologically identical to the corresponding component in its crude LPS . In S . typhimurium LPS, none of its components were influenced by continuous free-flow electrophoresis but not by ultracentrifugation . In spite of these results, both purified LPSs possessed stronger mitogenic activity than each crude LPS . These results indicated that continuous free-flow electrophoresis is a useful means of purifying extracted crude LPS.

Carcinogenesis, 1984 Jan, 5(1), 125 - 8
Gamma interferon induction depresses murine hepatic promutagen/procarcinogen activation; Reiners JJ Jr et al.; In vivo induction of gamma interferon (IFN-gamma) by sensitization of mice with Mycobacterium bovis strain BCG and subsequent challenge with tuberculin depressed the ability of liver homogenates from treated animals to metabolically activate promutagens . The Ames Salmonella typhimurium revertant assay was used for analyses of metabolic conversion of promutagens by liver homogenates . Relative to the mutant frequencies determined with control liver homogenates, induction of IFN-gamma depressed the abilities of homogenates from treated animals to activate N-acetylaminofluorene (AAF), aflatoxin B1 (AFB1), and benzo{a}pyrene (BP) by 55%, 44% and 95%, respectively . Within 18-24 h of Aroclor 1254 treatment, liver P-450 content had increased 43%, and the relative mutant yields per unit protein for all three promutagens had approximately doubled . In vivo induction of IFN-gamma suppressed the Aroclor 1254-dependent increases in mutagenesis by AAF (63%), AFB1 (90%), and BP (reduced to a level 23% below non-Aroclor 1254 treatment) . In all cases, the levels of depression of promutagen activation qualitatively correlated with cytochrome P-450 content and the induction of IFN-gamma.

IARC Sci Publ, 1984, (57), 851 - 7
Epidemiological and experimental studies on tobacco-related oral cancer in India; Bhide SV et al.; Both population-based incidence rates and relative frequencies of oral and pharyngeal cancer seen in six major cancer hospitals in India indicate that these forms of cancer occur frequently . Case-control studies reveal that these cancers are associated with tobacco chewing and bidi smoking . Experimental studies on a variety of chewing tobacco used commonly in western India revealed that it contains N-nitrosonornicotine and 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone in microgram quantities per gram of tobacco . A crude alcoholic extract of tobacco containing these nitrosamines was mutagenic in histidine-deficient Salmonella typhimurium strain TA98 in the presence of a 9000 X g supernatant fraction . Gavage feeding of this extract for 7, 15 and 30 days induced activity of mixed-function oxygenases . Feeding of the tobacco extract by gavage or in diets induced lung and liver tumours in Swiss mice.

IARC Sci Publ, 1984, (57), 715 - 9
Mutagenicity of alpha-hydroxy N-nitrosamines in V79 Chinese hamster cells; Mochizuki M et al.; N-Nitrosodialkylamines are activated metabolically by alpha-hydroxylation . Chemical properties and bacterial mutagenicity of alpha-hydroxy N-nitrosamines have been reported previously . This paper describes potent and direct mutagenicity of four N-nitroso-N-(hydroxymethyl)alkylamines in V79 Chinese hamster cells, using ouabain resistance as an indicator . The mutagenic potency depended on the alkyl group, decreasing in the following order: methyl greater than ethyl greater than propyl, butyl . A similar order was observed for cytotoxicity . Mutagenic and cytotoxic potencies of these alpha-hydroxy N-nitrosamines in V79 cells were well correlated not only with those of model compounds (alpha-acetoxy and alpha-hydroperoxy N-nitrosamines), but also with their alkylating ability, measured by alkylation of thiophenol . The mutagenic activity of the alpha-hydroxy N-nitrosamines in V79 cells was shown to be parallel to that in Salmonella typhimurium TA1535 and to that of N-nitrosodialkylamines in V79 cells, after metabolic activation by rat hepatocytes . The results obtained here further support the conclusion that the alpha-hydroxy N-nitrosamine is the active species in the metabolic activation of carcinogenic and mutagenic N-nitrosodialkylamines.

IARC Sci Publ, 1984, (57), 491 - 7
Biochemical and biological properties of prospective N-nitrodialkylamine metabolites and their derivatives; Frei E et al.; The metabolic conversion of N-nitrodimethylamine and of N-nitrosodimethylamine was compared in vitro . The biochemical properties of the two compounds were nearly identical; however, the biological activities (carcinogenicity, mutagenicity and toxicity) of the nitramine are many times less potent . N-Nitrodimethylamine was found to be mutagenic to Salmonella typhimurium TA100 when applied at above 200 mumol/plate with metabolic activation . Its suggested metabolite, N-nitromethylamine, was not mutagenic, N-Nitromethylhydroxymethylamine, N-nitromethylacetoxymethylamine and formaldehyde were mutagenic only to S . typhimurium TA100 at low concentrations and toxic above 2 mumol/ plate . The evidence suggests that formaldehyde is the intermediate responsible for the mutagenicity of the nitramine derivatives and of the parent compound, N-nitrodimethylamine.

IARC Sci Publ, 1984, (57), 17 - 24
Presence of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acids and tyramine as precursors of mutagens in soya sauce after nitrite treatment; Wakabayashi K et al.; Soya sauce showed marked direct-acting mutagenicity toward Salmonella typhimurium TA 100 after nitrite treatment . Three precursors showing mutagenicity after nitrite treatment were isolated from soya sauce . Their structures were determined to be (-)-(1S,3S)-1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid {(-)-(1S,3S)-MTCA}, its stereoisomer (-)-(1R,3S)-MTCA and tyramine . The numbers of revertants of TA 100 induced by 1 mg each of (-)-(1S,3S)-MTCA, (-)-(1R,3S)-MTCA and tyramine, after nitrite treatment, were 17 400, 13 000 and 3 900, respectively, without S9 mix . The amounts of MTCA isomers and tyramine in various Japanese soya sauces showing mutagenicity after nitrite treatment were 82-678 and 17-2 250 micrograms/mL, respectively . Most soya sauces produced in the USA showed weaker mutagenicity than those produced in Japan and contained lower, if not undetectable, amounts of the three precursors of mutagens . The mutagenicity of MTCA isomers and tyramine accounted for 16-61 and 1-35%, respectively, of the mutagenicity of the soya sauces after nitrite treatment . The mutagen(s) produced from (-)-(1S,3S)-MTCA with nitrite was a minor product(s), the major product being the non-mutagen, (-)-(1S,3S)-1-methyl-2-nitroso-1,2,3,4-tetrahydro-beta-carboline-3-carbo xylic acid {(-)-(1S,3S)-MNTCA}, but the mutagen 4-(2-aminoethyl)-6-diazo-2,4-cyclohexadienone, produced from tyramine with nitrite, was one of the major products.

Arch Toxicol Suppl, 1984, 7, 243 - 8
Metabolic activation of 2-aminofluorene in the Salmonella mutagenicity assay by different S-9 preparations; Cantelli Forti G et al.; Before exerting a carcinogenic or mutagenic effect, many chemicals must undergo metabolic activation . The most widely used activation system is the 9,000 g supernatant fraction (S-9) of rat liver homogenate, prepared from male rats pretreated with Aroclor 1254 (AC) . The present study compares the capabilities to induce metabolic activation of 2-aminofluorene (2-AF), using different sources of S-9 preparations as a test-promutagen, both in the Ames test and in the minimal saline liquid medium (MSLM) . In particular, S-9 preparations of liver and kidney fractions from male rats and guinea pigs, with or without AC or phenobarbital (PB) pretreatment, were used . The 2-AF was tested in Salmonella typhimurium TA 1538 strain (frame-shift mutation) at different level of concentrations . In the Ames test the enzymatic activation of liver fractions, induced by PB, shows a large increase of mutagenicity of 2-AF in both animal species studied . The AC pretreatment in rats significantly reduced the mutagenic activity of 2-AF, when compared with controls . With rat renal microsomes no differences were observed in mutagenicity as compared with controls . A significant increase was seen in the microsomes of guinea pigs pretreated with AC . The experiments carried out with MSLM confirmed the results in full.

J Cancer Res Clin Oncol, 1984, 108(3), 308 - 11
Carcinogenic activity in mice of diftalone, an anti-inflammatory agent; Della Porta G et al.; The anti-inflammatory agent diftalone was administered in the diet to male and female BALB/c mice at 300-, 600-, and 1200-ppm dose levels for 80 weeks, starting at 8 weeks of age . The animals were kept under observation until 126-128 weeks of age, when the experiment was terminated . Diftalone treatment at the highest dose was hepatotoxic and induced hepatocellular tumors in females, angiomas of the liver in males, and angiosarcomas of the liver in male and female mice . The 300- and 600-ppm dose levels were not carcinogenic . The compound was not mutagenic for Salmonella typhimurium.

Cancer Immunol Immunother, 1984, 18(2), 107 - 12
Phase-I study of intravenous modified lipid A; Vosika GJ et al.; Endotoxin and the lipid-A portion of the molecule have a variety of biological effects, including the induction of necrosis and regression of malignancy . To date extensive clinical trials of endotoxin as a potential therapeutic agent have been shunned due to the toxicity of the material . Several lipid-A analogues have been described which have reduced toxicity and retain antitumor activity . We have investigated in a phase-I trial the clinical toxicity and immunological effects of monophosphoryl lipid A prepared from Salmonella typhimurium and Salmonella minnesota . Patients entered on the study received IV monophosphoryl lipid A twice weekly for a total of 4 weeks . At least three patients were entered sequentially at each of the dose levels of 10, 25, 50, 100, and 250 micrograms/m2 body surface area . One patient was treated at the dose level of 500 micrograms/m2 . The major clinical toxicity was fever, chills, and rigor, which occurred in over 50% of the treatments at doses of 250 micrograms/m2 . Two instances of bronchospasm occurred in one patient who received 250 micrograms/m2 . One patient received 500 micrograms/m2 and became hypotensive . Sequential clinical data showed no evidence of renal or hepatic toxicity . A transient decrease in the WBC and platelets occurred during the first 24 h after therapy . Immune function testing measured T cells, monocyte cytostasis, monocyte suppressor cell activity, and NK activity . These data suggested a shift in monocyte populations with activated cells moving into the tissue . Direct objective antitumor activity or necrosis was not observed in this group of patients . We conclude that monophosphoryl lipid A can be given to patients in a dose of up to 100 micrograms/m2 with acceptable toxicity . Its clinical activity as a single agent in combination with other immunomodulators remains to be demonstrated.

Mol Gen Genet, 1984, 196(3), 526 - 9
The hisD-hisC gene border of the Salmonella typhimurium histidine operon; Riggs D et al.; We have sequenced the hisD-hisC gene border of the Salmonella typhimurium histidine operon . The translation termination codon of the hisD gene overlaps with the translation initiation codon of the hisC gene in the manner AUGA . The Shine-Dalgarno sequence of the hisC gene is contained entirely within hisD and there is no intercistronic space since all of the bases are utilized in coding . Two mutations that alter the hisD-hisC gene border are analyzed . Both mutations simultaneously abolish the termination codon of hisD and modify the initiation codon of hisC . One of the mutations changes the hisC initiation codon from AUG to AUU . The AUU codon is 10 to 20% as efficient as AUG for initiation of translation of the hisC gene . The mutant hisC ribosome binding site is compared to the ribosome binding site of the Escherichia coli infC gene which has been reported to contain an AUU initiation codon . The role of overlapping termination/initiation codons in regulating translation of polycistronic mRNAs in bacterial operons is discussed.

Environ Mutagen, 1984, 6(6), 825 - 34
Evaluation of the genotoxicity of process stream extracts from a coal gasification system; Shimizu RW et al.; Extracts of three complex organic environmental mixtures, two from an experimental coal gasifier (a raw gas and a clean gas sample) and one from a coke oven main, were examined for genotoxicity . Three short-term genotoxicity assay systems were used: Ames Salmonella typhimurium reverse mutation assay, Chinese hamster ovary cell/hypoxanthine-guanine phosphoribosyl transferase (CHO/HGPRT) gene locus mutation assay, and the Chinese hamster lung primary culture/sister chromatid exchange (CHL/SCE) assay . Aroclor-1254-induced rat liver homogenate fraction (S-9) was required to observe genotoxicity in both gene locus mutation assays (CHO/HGPRT and Ames) . The relative survival of CHO cells exposed to extracts was highest in cells exposed to clean gas samples, with the raw gas sample being the most cytotoxic either with or without the addition of S-9 . All three complex mixtures induced sister chromatid exchanges in primary lung cell cultures without the addition of S-9 . The relative genotoxicity ranking of the samples varied between the mammalian and prokaryotic assay systems . Coke oven main extract produced fewer revertants in bacteria than the raw gas sample . However, the coke oven main extract was more genotoxic in the two eukaryotic systems (CHL/SCE and CHO/HGPRT) than was the raw gas sample . The results of all three assays indicate that the cleanup process used in the experimental gasifier was effective in decreasing the genotoxic materials in the process stream . These data also reemphasize the necessity of evaluating genotoxicity of complex mixtures in a variety of short-term systems.

Environ Mutagen, 1984, 6(6), 797 - 811
Structural features of nitroaromatics that determine mutagenic activity in Salmonella typhimurium; Vance WA et al.; Seventeen structurally homologous nitroaromatics were tested for direct-acting mutagenic potency in nine strains of Salmonella typhimurium . The following four structural features were determined to have a strong influence on mutagenic activity: physical dimensions of the aromatic rings, isomeric position of the nitro group, conformation of the nitro group with respect to the plane of the aromatic rings, and ability to resonance-stabilize the ultimate electrophile . Progressive addition of five- and six-membered rings to a nitrobenzene nucleus demonstrated that mutagenic activity was a direct function of size . Fluoranthene was of optimal size (four rings) for mutagenicity; an additional benzene ring, giving benzo{k}fluoranthene, reduced mutagenic activity . Nitroaromatics with a nitro group oriented along the long axis of symmetry of the molecule were more potent mutagens than those with the nitro group oriented along the short axis . These results are discussed in light of the insertion-denaturation model for intercalation of certain DNA adducts . Nitroaromatics with nitro groups sterically forced out of the plane of the aromatic rings were weakly mutagenic or nonmutagenic . Nitro groups located between two peri hydrogens or in a bay-region are examples of this conformation . Finally, structural features that contribute to resonance stabilization of the reactive nitrenium ion enhance mutagenic potency . Thus, 6-nitroindene was at least tenfold more mutagenic than 5-nitroindene . These positional isomers are structurally identical with the exception of the position of an olefinic bond in the adjacent five-membered ring which can contribute to resonance stabilization of a carbonium ion formed after bioactivation of 6-nitroindene but not of 5-nitroindene . The predictive value of these structure-activity relationships should permit a first approximation in the assessment of mutagenic potency of nitroaromatics.

Eksp Onkol, 1984, 6(4), 23 - 5
{Correlation of the mutagenic and carcinogenic activity of various aromatic amines}; Pogodina ON et al.; Six aromatic amines were studied for their mutagenic activity using Salmonella typhimurium TA 100 and TA 98 . 3,3'-dichlorobenzidine, ortho-tolidine, benzidine, 2-naphthylamine proved to be mutagenic, while aminotobias acid and 2,2',4,4'-tetraaminodiphenyl did not show mutagenic activity . Chronic experiments on mice and rats using these compounds revealed a close correlation between carcinogenicity and mutagenicity.

Nauchnye Doki Vyss Shkoly Biol Nauki, 1984, (9), 95 - 9
{Effect of nitrosourea in small doses on the frequency of mutation in Salmonella typhimurium}; Shigaeva MKh et al.; The effect of N-nitroso-N-methylurea (NMU), N-nitroso-N,N'-dimethylurea (NDMU) and N-nitroso-N-ethylurea (NEU) at doses less than 100 mkg/ml on mutability of Salmonella typhimurium strains of Ames' system (G-46, TA-1950, TA-1535, TA-100, TA-1538) has been studied . NMU and NEU at doses of 5-10 mkg/ml have been found to increase the survival and decrease the number of reversions from auxotrophity in histidine to prototrophity . The effect of given doses of NMU and NEU on bacteria repair activity has been shown . The role of pk M101 plasmide in this process is being discussed . NDMU in contrast to NMU and NEU induces read frome shift mutations and exhibits high mutagenous activity at all doses examined.

Mol Gen Genet, 1984, 195(1-2), 351 - 5
Regulation of the trimethylamine N-oxide (TMAO) reductase in Escherichia coli: analysis of tor::Mud1 operon fusion; Pascal MC et al.; Mud1 insertion mutants of Escherichia coli were obtained in which the lac structural genes were fused to the promoter of torA, a gene encoding the trimethylamine N-oxide (TMAO) reductase . Expression of the fusion is induced by TMAO and repressed by oxygen . However, in contrast to the nar operon which codes for the nitrate reductase structural genes, the tor::Mud1 fusion was found to be independent of the positive control exerted by the nirR gene product and not repressed by the molybdenum cofactor . The torA gene which is strongly linked to pyrF (28.3U) is different from any tor gene already described in E . coli or in Salmonella typhimurium.

Environ Mutagen, 1984, 6(5), 705 - 17
Mutagenicity of azo dyes following metabolism by different reductive/oxidative systems; Reid TM et al.; The mutagenic activity of a group of diazo dyes based on benzidine and its congeners was compared following metabolic activation of the dyes through sequential reduction and oxidation . The dyes were reduced by incubating them with either a suspension of rat cecal flora or a hamster S9 mix supplemented with flavin mononucleotide . The products of dye reduction were then subjected to oxidative metabolism by either Aroclor-induced rat liver S9 or by hamster liver S9; the resultant mutagenic activity was assayed with Salmonella typhimurium TA1538 . Fifteen of the 17 compounds tested were mutagenic, and the degree of mutagenicity was affected by the activity of both the reduction and oxidation systems used . Purified dyes required a reductive step to become mutagenic, but several of the crude dyes did not . All the positive compounds, however, were more mutagenic when the reduction step was included . The mutagenicity of the purified dyes was equal to or greater than that of an equimolar amount of benzidine or appropriate benzidine congener . For the crude dyes, there were no consistent quantitative relationships between the mutagenicity of the dye and that expected from the benzidine moiety.

Environ Mutagen, 1984, 6(5), 669 - 81
Mutagenic 1-nitropyrene in wastewater from oil-water separating tanks of gasoline stations and in used crankcase oil; Manabe Y et al.; Wastewater collected from oil-water separating tanks of ten gasoline stations for a year was fractionated into diethyl ether-soluble neutral, acidic, and basic fractions . Mutagenicity of these fractions was measured with Salmonella typhimurium strains TA98 and TA100 in the presence or absence of S9 mix . The neutral fractions showed high mutagenicity in the absence of S9 mix . Each neutral fraction was subjected to high-performance liquid chromatography (HPLC) and fractionated . A 1-nitropyrene(1-NP)-corresponding fraction was collected and analyzed by gas chromatography-mass spectrometry (GC-MS) and HPLC to prove that wastewater contains 1-NP and to quantitate 1-NP in wastewater . GC-MS patterns showed the following molecular and fragment ion peaks of 1-NP: 247, 217, 201, and 189 . The amount of 1-NP in 36 samples of wastewater was 4.2-25,600 ng per liter of wastewater, and 1-NP accounted for 0.3-58.5% of the total mutagenicity of the neutral fractions . The other 19 samples of wastewater did not contain any detectable 1-NP . The mutagenicity of wastewater may be due to water from car washing and contamination by used crankcase oil . A Soxhlet extract of crankcase oil used in a gasoline was fractionated into three fractions as above . Mutagenicity was measured with strains TA98, TA100, TA98NR, and TA98/1,8-DNP6 in the absence or presence of S9 mix . The neutral fraction showed the highest mutagenicity with strain TA98 in the absence of S9 mix, and its mutagenicity was decreased in strains TA98NR and TA98/1,8-DNP6 . The latter result indicates that the used engine-oil contained 1-NP and dinitropyrenes . Actually, the amounts of 1-NP and 1,6-diNP in used crankcase oil were 138 and 2.0 ng per ml of oil, respectively, and these concentrations accounted for 0.45 and 2.7%, respectively, of the total mutagenicity of the neutral fraction with strain TA98 in the absence of S9 mix . Moreover, the concentrations of 1-NP and 1,6-diNP in used crankcase oil of a diesel engine were 349 and 31 ng per ml of oil, respectively, accounting for 0.9 and 12%, respectively, of the total mutagenicity of the neutral fraction in the same assay system.

Environ Mutagen, 1984, 6(5), 633 - 50
Spontaneous mutation frequencies in Salmonella: enhancement of G/C to A/T transitions and depression of deletion and frameshift mutation frequencies afforded by anoxic incubation; Hartman Z et al.; Incubation of Salmonella typhimurium under anoxic conditions (0.1% oxygen or less) results in a substantial decrease in small (3-and 6-basepair) deletions in an A/T-rich region of the hisG gene in the hisG428 ochre mutant and also decreases the frequency of minus frameshift mutations in G/C-rich sequences in the his-D3052 and hisC3076 mutants . In contrast, the frequency of G/C-----A/T transition mutations increases substantially during anoxic growth of hisG46 . Growth of revertants of strains carrying accessory deletions in the uvrB region of the Salmonella chromosome is drastically impaired on glucose minimal medium when oxygen partial pressures are below 0.1% oxygen.

Environ Mutagen, 1984, 6(4), 585 - 92
Correlative genotoxicity studies of airborne particles in Salmonella typhimurium and cultured human lymphocytes; Krishna G et al.; The acetone extracts of ambient air particulates collected locally were tested for their capacity to induce sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs) in human lymphocytes, and to induce gene mutations (GMs) in Salmonella typhimurium . The extracts caused dose-related clastogenic/mutagenic responses in all three assay systems . With the same concentration, it seems that the Ames Salmonella/microsomal assay with TA98 gave the highest, and the chromosomal aberration assay with human lymphocytes the lowest, mutagenic/clastogenic responses, respectively . Because high frequencies of SCEs were induced by solvent extracts of airborne particles, this study further indicated the usefulness of SCE assay in human lymphocytes for genotoxicity studies of airborne particles.

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