Salmonella typhimurium

Mutat Res, 1985 May, 149(3), 311 - 9
Genetic and quantum chemical basis of the mutagenicity of nitroarenes for adenine-thymine base pairs; McCoy EC et al.; The mutagenicity of nitroarenes for Salmonella typhimurium strains with adenine-thymine base pairs at the mutational site is dependent upon enzymic reduction of the nitro function . Although the electrophilic metabolites of nitroarenes are capable of mutating adenine-thymine base pairs, they show a marked preference for guanine-cytosine pairs when given a choice . Quantum chemical calculations indicate the reactivity order for nucleophilic sites in an AT run of base pairs to be the N-7 of adenine (N7(A)) first, followed by an approximately equal reactivity for C-8 of adenine (C8(A)) and O4 of thymine (O4(T)) . Given the low probability of reaction of electrophilic metabolites of nitroarenes with adenine-thymine base pairs, the mutagenic potency of nitroarenes for strains with adenine-thymine base pairs at the mutational site is remarkable.

J Bacteriol, 1985 May, 162(2), 738 - 45
High-molecular-weight components in lipopolysaccharides of Salmonella typhimurium, Salmonella minnesota, and Escherichia coli; Peterson AA et al.; Lipopolysaccharide from smooth strains of Salmonella typhimurium, Salmonella minnesota, and Escherichia coli O111:B4, O55:B5, and O127:B8 was fractionated by gel filtration chromatography . All lipopolysaccharide samples separated into three major populations . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the fractions from S . typhimurium and S . minnesota indicated that the three peaks were made up of molecules with average O-antigen lengths of (i) 70 or more repeat units, (ii) 30 and 20 repeats units in the samples from S . typhimurium and S . minnesota, respectively, and (iii) 1 repeat unit . In contrast to the Salmonella samples, peak 1 from the E . coli samples was not detected on polyacrylamide gels and lacked detectable phosphate . This high-molecular-weight material had a sugar composition similar to that of O-antigen and was tentatively identified as capsular polysaccharide . Peaks 2 and 3 of the E . coli samples were analogous to those of the Salmonella isolates, containing lipopolysaccharide molecules with averages of 18 and 1 O-antigen repeat units, respectively . These lipopolysaccharide molecules did not completely dissociate during electrophoresis, and multimers were detected as distinct, anomalous, slow-migrating bands . Increasing the concentration of sodium dodecyl sulfate in the gels resulted in the dissociation of these multimers.

Carcinogenesis, 1985 May, 6(5), 727 - 32
Nitroreductase-dependent mutagenicity of p-nitrophenylhydroxylamine and its N-acetyl and N-formyl hydroxamic acids; Corbett MD et al.; p-Nitrophenylhydroxylamine (NPH) and two hydroxamic acids derived from it were synthesized and subjected to mutagenicity testing in Salmonella typhimurium strains TA98, TA98NR, TA1538 and TA1538NR . In addition, p-dinitrobenzene (DNB), p-nitroaniline (NA) and p-nitroacetanilide (AcNA) were simultaneously examined for mutagenic action against these four tester strains . NPH, its N-acetyl (AcNPH) and N-formyl (FoNPH) derivatives, and also DNB displayed strong mutagenic action to the nitroreductase-containing strains, TA98 and TA1538 . NPH was the most potent chemical in this series against both of these strains, while the two hydroxamic acids AcNPH and FoNPH, and also DNB displayed approximately the same degree of mutagenicity . In the nitroreductase-deficient strains, TA98NR and TA1538NR, the mutagenicity of these four compounds was markedly reduced . The necessity for nitroreduction in order to activate these promutagens is fairly certain; however, the lack of mutagenicity of NA and AcNA towards all four tester strains made the interpretation of these data somewhat more complicated . Several possible bioactivation pathways were presented, with one mechanism in particular being proposed . This mechanism requires only that the strong electron-withdrawing nitro group be converted to an electron-donating group by bacterial nitroreductase . Such a mechanism is unique for the bioactivation of nitro aromatics by nitroreductase, since the enzymatic reduction need not produce the intermediary hydroxylamine metabolite.

J Bacteriol, 1985 May, 162(2), 810 - 6
Allosteric regulation of glycerol kinase by enzyme IIIglc of the phosphotransferase system in Escherichia coli and Salmonella typhimurium; Novotny MJ et al.; The mechanism by which enzyme IIIglc of the bacterial phosphotransferase system regulates the activity of crystalline glycerol kinase from Escherichia coli has been studied, and the inhibitory effects have been compared with those produced by fructose-1,6-diphosphate . It was shown that the free, but not the phosphorylated, form of enzyme IIIglc inhibits the kinase . Mutants of Salmonella typhimurium were isolated which were resistant to inhibition by either enzyme IIIglc (glpKr mutants) or fructose-1,6-diphosphate (glpKi mutants), and each mutant type was shown to retain full sensitivity to inhibition by the other regulatory agent . Other mutants were fully or partially resistant to regulation by both agents . The two regulatory sites on the kinase are evidently distinct but must overlap or interact functionally . Kinetic analyses have revealed several mechanistic features of the regulatory interactions . (i) Inhibition by both allosteric regulatory agents is strongly pH dependent, with maximal inhibition occurring at ca . pH 6.5 under the assay conditions employed . (ii) Binding of enzyme IIIglc to glycerol kinase is also pH dependent, the Ki being near 4 microM at pH 6.0 but near 10 microM at pH 7.0 . (iii) Whereas fructose-1,6-diphosphate inhibition apparently requires that the enzyme exist in a tetrameric state, both the dimer and the tetramer appear to be fully sensitive to enzyme IIIglc inhibition . (iv) Inhibition by enzyme IIIglc (like that by fructose-1,6-diphosphate) is noncompetitive with respect to both substrates . (v) The inhibitory responses of glycerol kinase to fructose-1, 6-diphosphate and enzyme IIIglc show features characteristic of positive cooperativity at low inhibitor concentration . (vi) Neither agent inhibits completely at high inhibitor concentration . (vii) Apparent negative cooperativity with respect to ATP binding is observed with purified E . coli glycerol kinase, with glycerol kinase in crude extracts of wild-type S . typhimurium cells, and with glpKr and glpKi mutant forms of glycerol kinase from S . typhimurium . These results serve to characterize the regulatory interactions which control the activity of glycerol kinase by fructose-1,6-diphosphate and by enzyme IIIglc of the phosphotransferase system.

J Bacteriol, 1985 May, 162(2), 722 - 7
Ion selectivity of gram-negative bacterial porins; Benz R et al.; Twelve different porins from the gram-negative bacteria Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, and Yersinia pestis were reconstituted into lipid bilayer membranes . Most of the porins, except outer membrane protein P, formed large, water-filled, ion-permeable channels with a single-channel conductance between 1.5 and 6 nS in 1 M KCl . The ions used for probing the pore structure had the same relative mobilities while moving through the porin pore as they did while moving in free solution . Thus the single-channel conductances of the individual porins could be used to estimate the effective channel diameters of these porins, yielding values ranging from 1.0 to 2.0 nm . Zero-current potential measurements in the presence of salt gradients across lipid bilayer membranes containing individual porins gave results that were consistent with the conclusions drawn from the single-channel experiments . For all porins except protein P, the channels exhibited a greater cation selectivity for less mobile anions and a greater anion selectivity for less mobile cations, which again indicated that the ions were moving inside the pores in a fashion similar to their movement in the aqueous phase . Three porins, PhoE and NmpC of E . coli and protein P of P . aeruginosa, formed anion-selective pores . PhoE and NmpC were only weakly anion selective, and their selectivity was dependent on the mobility of the ions . In contrast, cations were unable to enter the selectivity filter of the protein P channel . This resulted in a high anion selectivity for all salts tested in this study . The other porins examined, including all of the known constitutive porins of the four gram-negative bacteria studied, were cation selective with a 3- to 40-fold preference for K+ ions over Cl- ions.

Infect Immun, 1985 May, 48(2), 597 - 600
Binding activity of a murine anti-lipid A monoclonal antibody; Elkins K et al.; In this report we briefly describe an immunoglobulin G3 monoclonal antibody, 2G6/1H11, which binds purified lipid A from Salmonella minnesota and a lipid A precursor molecule derived from Salmonella typhimurium . 2G6/1H11 does not bind well to purified whole S . typhimurium lipopolysaccharide (LPS), S . minnesota LPS, LPS preparations from a series of S . minnesota rough mutants, or intact S . typhimurium bacteria . Thus, there are antigenic determinants in purified lipid A which are not exposed when lipid A is presented as part of the whole LPS molecule or intact bacteria.

J Immunol, 1985 May, 134(5), 2872 - 8
Control of B cell proliferation: inhibition of responses to B cell mitogens induced by plasma cell tumors; Berman JE et al.; A multitude of factors has been described that positively and negatively regulate B cell proliferation . A model system for the study of negative control of B cell function is provided by mice bearing plasmacytomas (PC-mice) . In PC-mice, the primary immune response, as measured by development of antibody-forming cells (AFC), is severely suppressed . The present report specifically identifies a block in B cell proliferation as the apparent cause of this reduction in AFC production . Thus, the proliferative response of B cells from the spleens of PC-mice (PC-spleens) was significantly impaired when stimulated with four different B cell mitogens (lipopolysaccharide, Salmonella typhimurium mitogen, anti-mu conjugated to Sepharose, and 8-mercaptoguanosine) . Nevertheless, the mitogen-responsiveness of these B cells was recovered when they were segregated by various methods from macrophages . These data suggest that the proliferative ability of the B cells in PC-spleens is inherently normal . In concordance with this conclusion, it was shown that suppressor cells from PC-spleens can block the proliferation of normal B cells derived from nontumor-bearing mice . This inhibition does not require direct cell contact and is mediated via soluble factors . The relevance of these results to previous studies of PC-induced immunosuppression and to the control of normal B cell proliferation is discussed.

Ann Inst Pasteur Microbiol, 1985 May-Jun, 136A(3), 289 - 301
Salmonella typhimurium strains carrying haemolysin plasmids and cloned haemolysin genes from Escherichia coli; Hacker J et al.; Like all other Salmonella typhimurium strains examined, the smooth variants SF1397 (LT2) and 1366 and also their semi-rough and rough derivatives are non-haemolytic . Nevertheless, two haemolysin (Hly) plasmids of E . coli belonging to the inc groups incFIII,IV (pSU316) and incI2 (pHly152) were able to be introduced into these strains by conjugation and stably maintained . A considerable percentage of the Hly+ transconjugants obtained had lost parts of their O-side chains, a result of selection for the better recipient capability of "semi-rough" variants rather than the direct influence of the Hly+ plasmids themselves . In contrast to the incFIII,IV plasmid pSU316, which exhibited higher conjugation rates with rough recipients, the incI2 plasmid pHly152 was accepted best by smooth strains . Transformation with cloned E . coli haemolysin (hly) determinant was inefficient (less than 10(-6)) for smooth strains, but 10(2) - 10(3) times higher for rough recipients, and was increased by the use of Salmonella-modified DNA . The transformants and transconjugants were relatively stable and showed the same haemolytic activity as the E . coli donor strains . The virulence of the Hly+ smooth, semi-rough and rough S . typhimurium strains was tested in two mouse models, and neither the mortality rate nor the ability to multiply within the mouse spleen was influenced by the hly determinants.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1985 May, 180(5-6), 540 - 7
Determination of mutagenic activities in different fractions of automobile exhaust condensate by the Salmonella/oxygenase mutagenicity test system; Norpoth K et al.; Automobile exhaust condensate of a passenger car (gasoline engine) was separated into fractions of 2-3 rings containing -, 4-7 rings containing polycyclic aromatic hydrocarbons (PAHs) and PAH-free fractions . All fractions were tested for mutagenicity by the Ames system . The highest dose-dependent increase in revertant colonies was found for the 4-7 ring PAH-fraction when tested with Salmonella typhimurium TA 98 and TA 100 . These results are compatible with data obtained in in-vivo tests by previous investigations . The mutagenicity of these fractions in the absence of the oxygenase was negligible.

J Biol Chem, 1985 Apr 25, 260(8), 4724 - 8
A single amino acid substitution in the enzyme 5-enolpyruvylshikimate-3-phosphate synthase confers resistance to the herbicide glyphosate; Stalker DM et al.; The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EC 2.5.1.19), encoded by the aroA locus, is a target site of glyphosate inhibition in bacteria . A glyphosate-resistant aroA allele has been cloned in Escherichia coli from a mutagenized strain of Salmonella typhimurium . Subcloning of this mutant aroA allele shows the gene to reside on a 1.3-kilobase segment of S . typhimurium DNA . Nucleotide sequence analysis of this mutant gene indicates a protein-coding region 427 amino acids in length . Comparison of the mutant and wild type aroA gene sequences reveals a single base pair change resulting in a Pro to Ser amino acid substitution at the 101st codon of the protein . A hybrid gene fusion between mutant and wild type aroA gene sequences was constructed . 5-Enolpyruvylshikimate-3-phosphate synthase was prepared from E . coli cells harboring this construct . The glyphosate-resistant phenotype is shown to be associated with the single amino acid substitution described above.

J Mol Biol, 1985 Apr 20, 182(4), 579 - 87
Two type I restriction enzymes from Salmonella species . Purification and DNA recognition sequences; Nagaraja V et al.; We have purified the type I restriction enzymes SB and SP from Salmonella typhimurium and S . potsdam, respectively, and determined the DNA sequences that they recognize . These sequences resemble those previously determined for the type I enzymes, EcoB, EcoK and EcoA, in that the specific part of the sequence is divided into two domains by a spacer of non-specific sequence that has a fixed length for each enzyme . Two main differences from the previously determined sequences are seen . Both of the new sequences are degenerate and one of them, SB, has one trinucleotide and one pentanucleotide-specific domain rather than the trinucleotide and tetranucleotide domains seen for all of the other enzymes . The only conserved features of the recognition sequences are the adenosyl residues that are methylated in the modification reaction . For all of the enzymes these are situated ten or 11 base-pairs apart, one on each strand of the DNA . This suggests that the enzymes bind to DNA along one face of the double helix making protein-DNA interaction in two successive major grooves with most of the non-specific spacer sequence in the intervening minor groove.

JAMA, 1985 Apr 12, 253(14), 2058 - 60
An outbreak of multiple-drug-resistant Salmonella enteritis from raw milk; Tacket CO et al.; In early 1983, an outbreak of illness caused by raw milk contaminated with multiple-antimicrobial-resistant Salmonella typhimurium occurred in Arizona . One of the cases involved a 72-year-old woman who died with Salmonella enteritis and sepsis that had not responded to treatment with chloramphenicol . The S typhimurium isolates from this patient, from other ill persons, and from raw milk were resistant to ampicillin, chloramphenicol, kanamycin sulfate, streptomycin, sulfonamide, and tetracycline . These resistances were mediated by a 105-megadalton R plasmid . During the epidemic period, 43% of the S typhimurium isolates submitted to the Arizona Department of Health Services were resistant to chloramphenicol, and 80% of these possessed the same plasmid resistance . Although there was evidence of spread of the S typhimurium in the community, there was no evidence of spread of this Salmonella R plasmid to the normal flora of patients or their family members a median of 14 weeks after the infection . This outbreak demonstrates the ability of drug-resistant Salmonella to spread from the animal to the human reservoir and, in a suitable host, produce a fatal infection.

Am Ind Hyg Assoc J, 1985 Apr, 46(4), 187 - 91
Destruction of aromatic amines in laboratory wastes through oxidation with potassium permanganate/sulfuric acid into non-mutagenic derivatives; Castegnaro M et al.; Nine aromatic amines, i.e., benzidine; o-tolidine; o-dianisidine; 3,3'-dichlorobenzidine; 4-aminobiphenyl; 1- and 2-naphthylamine; 4,4'-methylene bis(2-chloroaniline) and m-toluenediamine, were oxidized with potassium permanganate/sulfuric acid . Experimental conditions for complete degradation of these aromatic amines are described . The disappearance of the parent compound through oxidation was measured using HPLC coupled with UV spectrophotometry . The corresponding degradation products were found to be non-mutagenic to Salmonella typhimurium strains TA100, TA98 and TA97, both in the presence and absence of a rat liver S9 activation system . A collaborative study, involving 11 laboratories, has shown the applicability and the reproducibility of this degradation method.

Cancer Lett, 1985 Apr, 26(3), 343 - 7
Mutagenicity and tumor initiating activity of methylated benzo{k} fluoranthenes; Amin S et al.; The mutagenic activities toward Salmonella typhimurium TA100 and tumor initiating activities on mouse skin of the polynuclear aromatic hydrocarbons benzo{k}fluoranthene (BkF),2-methylBkF,8-methylBkF,9-methyl-BkF and 7,12-dimethylBkF were compared . BkF and 2-methylBkF were the most mutagenic of the compounds tested and had comparable activity; they were more active than 7,12-dimethylBkF . 8-MethylBkF and 9-methylBkF were not mutagenic . BkF and the methylated BkFs had similar tumor initiating activities on mouse skin . The results suggest that 8,9-dihydro-8,9-epoxy-BkF might be involved in the metabolic activation of BkF to a mutagen, but do not indicate which metabolite may be involved in BkF tumorigenesis.

Infect Immun, 1985 Apr, 48(1), 244 - 7
Immunomodulation of the antibody response to lipopolysaccharide in C3H/HeJ mice by complexing with heterologous ribosomes; Phillips M et al.; We show that formaldehyde fixation of Salmonella typhimurium lipopolysaccharide (LPS) to ribosomes purified from Brucella abortus induced a primary immunoglobulin M (IgM) response to LPS in C3H/HeJ mice and upon revaccination resulted in elevated titers of IgM and induction of IgG antibody to the O antigens of LPS, as measured by an enzyme-linked immunosorbent assay . A similar LPS-Aspergillus fumigatus ribosomal complex yielded IgM and IgG antibody to LPS only after secondary stimulation . These results demonstrate that the hyporesponsiveness of C3H/HeJ mice with respect to antibody formation to LPS can be overcome by complexing this molecule to ribosomal particles and provide a theoretical mechanism for the action of some "ribosomal" vaccines . The results are compatible with the hypothesis that LPS in complex with the ribosomes is converted to a T-dependent form of the antigen to which the C3H/HeJ mice can respond.

Mutat Res, 1985 Apr-May, 156(1-2), 93 - 102
Differential mutagenic activity of IQ (2-amino-3-methylimidazo{4,5-f}quinoline) in Salmonella typhimurium strains in vitro and in vivo, in Drosophila, and in mice; Wild D et al.; IQ, a heterocyclic aromatic amine which is formed during the frying of meat, was prepared by chemical synthesis . Its genotoxic potential was studied in bacteria, Drosophila and in mice . A mutagenic effect of IQ (frameshift induction) was detected in Salmonella typhimurium in experiments without metabolic activation; this effect was several orders of magnitude lower than that observed in the presence of an activation system . Ames tests with liver-homogenate S9 fraction from PCB-induced mice and rats confirmed the high mutagenic potency of IQ metabolites (Kasai et al., 1980a) . Comparative studies on diagnostic Salmonella strains revealed that the high frameshift-inducing activity is independent of the plasmid pkM101; it is, however, greatly reduced by an intact excision-repair system for DNA lesions . The mutagenic activity of the metabolite(s) formed in vitro by S9 mix has a half-life of ca . 14 min . In the fruit fly, Drosophila melanogaster, IQ induced when used at sublethal concentrations, X-chromosomal recessive lethal mutations in male germ cells in a dose-dependent manner . In mice, tests were performed to detect somatic mutations: chromosomal anomalies (micronuclei) in bone marrow, and gene mutations (affecting coat pigmentation) in mice exposed to IQ in utero . No genotoxic effects were observed in these assays . However, the formation of mutagenic metabolites in the liver of IQ-treated mice was unequivocally demonstrated in host-mediated assays using Salmonella as mutagen probes in mice . The data demonstrate genotoxic activity of IQ in prokaryotic and eukaryotic organisms . The possible reasons for the different response of mammalian systems in vivo and the Salmonella system are discussed.

Aust J Exp Biol Med Sci, 1985 Apr, 63 ( Pt 2), 177 - 82
The correlation between serum IgA antibody levels and resistance to infection with Salmonella typhimurium after oral immunization with various salmonellae; Srisart P et al.; Subsequent to oral feeding of various Salmonella strains to mice, the IgA antibodies directed against the O-somatic antigens of the immunising strain were measured in both serum and intestinal juice, using the ELISA technique . 21 days after oral immunization the IgA antibody levels were relatively high only in those mice which were resistant to challenge with a virulent strain of Salmonella typhimurium . Because there was no correlation between protection and the specificity of the 'O' somatic antigens of the immunising and challenge strains, the IgA antibodies measured were not responsible for protection . Nevertheless, the level of these antibodies affords a good index of the resistance of mice or immune status of mice to Salmonella infection.

Eur J Clin Microbiol, 1985 Apr, 4(2), 129 - 31
Enterotoxigenicity among Salmonella typhimurium strains isolated in France; Baloda SB et al.; Twenty strains of Salmonella typhimurium isolated in France from patients with diarrhea were tested for enterotoxins and cytotoxic factors by conventional bioassays . Eighteen of the strains produced enterotoxins to varying degrees and did not react with antisera to Escherichia coli heat-labile enterotoxin . Cytotoxic factors were present in two strains . These findings suggest that efforts to elucidate the virulence mechanisms of Salmonella spp . isolated in different parts of the world should be renewed.

Appl Environ Microbiol, 1985 Apr, 49(4), 822 - 7
Effects of dissolved organic carbon and second substrates on the biodegradation of organic compounds at low concentrations; Schmidt SK et al.; Pseudomonas acidovorans and Pseudomonas sp . strain ANL but not Salmonella typhimurium grew in an inorganic salts solution . The growth of P . acidovorans in this solution was not enhanced by the addition of 2.0 micrograms of phenol per liter, but the phenol was mineralized . Mineralization of 2.0 micrograms of phenol per liter by P . acidovorans was delayed 16 h by 70 micrograms of acetate per liter, and the delay was lengthened by increasing acetate concentrations, whereas phenol and acetate were utilized simultaneously at concentrations of 2.0 and 13 micrograms/liter, respectively . Growth of Pseudomonas sp . in the inorganic salts solution was not affected by the addition of 3.0 micrograms each of glucose and aniline per liter, nor was mineralization of the two compounds detected during the initial period of growth . However, mineralization of both substrates by this organism occurred simultaneously during the latter phases of growth and after growth had ended at the expense of the uncharacterized dissolved organic compounds in the salts solution . In contrast, when Pseudomonas sp . was grown in the salts solution supplemented with 300 micrograms each of glucose and aniline, the sugar was mineralized first, and aniline was mineralized only after much of the glucose carbon was converted to CO2 . S . typhimurium failed to multiply in the salts solution with 1.0 micrograms of glucose per liter . It grew slightly but mineralized little of the sugar at 5.0 micrograms/liter, but its population density rose at 10 micrograms of glucose per liter or higher . The hexose could be mineralized at 0.5 micrograms/liter, however, if the solution contained 5.0 mg of arabinose per liter.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutat Res, 1985 Apr-May, 156(1-2), 61 - 7
Mutagenicity of polycyclic aromatic hydrocarbons and quinones on Salmonella typhimurium TA97; Sakai M et al.; 18 polycyclic aromatic hydrocarbons (PAHs) and 7 quinones were tested for mutagenicity using Salmonella typhimurium TA97, TA98 and TA100 with or without metabolic activation . In the presence of metabolic activation, TA97 was more susceptible to mutation than either TA98 or TA100 by many of PAHs tested . PAHs such as 1-methylphenanthrene, fluoranthene, pyrene, benzo{a}pyrene, benzo{e}pyrene and perylene had high mutagenic effects on TA97 in the presence of metabolic activation . 1,6- and 1,8-pyrenequinones were also highly mutagenic on TA97 in the presence or absence of metabolic activation . It appears that pyrene is mutagenic through its metabolic conversion to pyrenequinones.

Mutat Res, 1985 Apr-May, 156(1-2), 53 - 9
Mutagenicity of some derivatives of dipyrido{1,2-a:3',2'-d}imidazoles in Salmonella typhimurium with metabolic activation by rat liver and small intestine subcellular fractions; N'Goy K et al.; The mutagenic effect of 2-amino-dipyrido{1,2-a:3',2'-d}imidazole (Glu-P-2) was compared with that of the 3-amino, 3-nitro, or 3-N-hydroxylated derivatives of the same base ring with methyl groups at positions 4 and 6 of the molecule . The compounds were tested in Salmonella typhimurium strain TA98 without metabolic activation and in the presence of different concentrations of subcellular fractions from livers or small intestines of rats pretreated with different P448/P450 inducers . The 4,6-dimethyl compounds are always more mutagenic than Glu-P-2 . Pretreatment with Aroclor 1254 (ARO) is the most effective inducer in the activation of the 2- and 3-amino compounds by liver S9, whereas the same fraction decreases the mutagenicity of the 3-nitro derivative . S9 from small intestine increased the mutagenic effect of the 3-nitro and 3-N-hydroxylated compounds, but it was unable to activate the amino compounds.

Mutat Res, 1985 Apr-May, 156(1-2), 39 - 52
Mutagenicity studies on coffee . The influence of different factors on the mutagenic activity in the Salmonella/mammalian microsome assay; Friederich U et al.; Recently, mutagenic activity on several strains of Salmonella typhimurium has been found in many heat-processed foodstuffs . The previously reported direct-acting mutagenic activity of coffee in Salmonella typhimurium TA100 (Ames assay) was confirmed in our study . In addition to TA100, a mutagenic effect of coffee was also found by using the newly developed strain TA102 . The mutagenic activity was abolished by the addition of rat-liver homogenate . 10% S9 mix completely eliminated the mutagenic activity of 30 mg of coffee per plate . The addition of reduced glutathione to active S9 further decreased the mutagenic activity and also reduced the mutagenicity together with inactivated S9 . The compound or compounds responsible for this inactivation are heat-labile and seem to be located in the cytosol fraction of the S9 . Part of the mutagenicity of coffee was also lost spontaneously upon incubation at temperatures between 0 degrees and 50 degrees C . The loss of activity was dependent on temperature, being more pronounced at 50 degrees C compared to 0 degrees C (at 50 degrees C approximately 50% of the mutagenic activity was lost after 6 h) . As anaerobic conditions prevented this loss of mutagenicity almost totally, oxidative processes are probably responsible for the inactivation . The stability of the mutagen was not influenced by incubation at low pH values (pH 1-3), with or without the addition of pepsinogen . The mutagenic properties of methylglyoxal, which to some extent could be responsible for the mutagenic activity of coffee, were compared with those of coffee . Methylglyoxal was strongly mutagenic towards Salmonella typhimurium TA100 and TA102 . Its mutagenic activity was partially inactivated by the addition of 10% S9 . Glyoxalase I and II together with reduced glutathione abolished the mutagenic activity of methylglyoxal but reduced the mutagenicity of coffee by only 80% . Since these enzymes occur in mammalian cells, the mutagenic compound(s) of coffee could also be degraded in vivo . This conclusion is supported by the fact that a long-term carcinogenicity study with rats was negative . These results clearly demonstrate that the effects observed in vitro do not necessarily also occur in vivo, but that in vitro experiments may contribute to the understanding of fundamental mechanisms of chemical carcinogenesis.

J Environ Sci Health B, 1985 Apr, 20(2), 153 - 65
Mutagenicity tests with gallic and tannic acid in the Salmonella/mammalian microsome assay; Rashid KA et al.; Gallic acid, tannic acid mixture and a purified fraction of tannic acid were evaluated for possible mutagenic activity in three strains of Salmonella typhimurium, TA98, TA100, and TA1535 . These chemicals were not mutagenic either before or after activation with rat and woodchuck microsomal and cytosolic enzymes . However, tannic acid mixture and tannic acid fraction both gave a significantly (p = 0.05) dose-related reduction in the number of the revertant colonies, compared to the normal spontaneous revertants with no apparent toxic effects in the background lawn . With an agar diffusion assay, the chemicals exhibited toxic effects at 5000 micrograms/disc.

Proc Natl Acad Sci U S A, 1985 Apr, 82(8), 2478 - 82
Metabolically activated steviol, the aglycone of stevioside, is mutagenic; Pezzuto JM et al.; Stevioside, a constituent of Stevia rebaudiana, is commonly used as a noncaloric sugar substitute in Japan . Consistent with reports in the literature, we have found that stevioside is not mutagenic as judged by utilization of Salmonella typhimurium strain TM677, either in the presence or in the absence of a metabolic activating system . Similar negative results were obtained with several structurally related sweet-tasting glycosides . However, steviol, the aglycone of stevioside, was found to be highly mutagenic when evaluated in the presence of a 9000 X g supernatant fraction derived from the livers of Aroclor 1254-pretreated rats . Expression of mutagenic activity was dependent on both pretreatment of the rats with Aroclor 1254 and addition of NADPH; unmetabolized steviol was not active . The structurally related species, isosteviol, was not active regardless of metabolic activation . Similarly, chemical reduction of the unsaturated bond linking the carbon-16 and -17 positions of steviol resulted in the generation of two isomeric products, dihydrosteviol A and B, that were not mutagenic . In addition, ent-kaurenoic acid was found to be inactive . It is therefore clear that a metabolite of an integral component of stevioside is mutagenic; structural features of requisite importance for the expression of mutagenic activity include a hydroxy group at position 13 and an unsaturated bond joining the carbon atoms at positions 16 and 17 . A potential metabolite of steviol, steviol-16 alpha,17-epoxide, was synthesized chemically and found to be ineffective as a direct-acting mutagen . Thus, although stevioside itself appears innocuous, it would seem prudent to expeditiously and unequivocally establish the human metabolic disposition of this substance.

Fundam Appl Toxicol, 1985 Apr, 5(2), 382 - 90
Lack of concordance of the Salmonella/microsome assay with the mouse dermal carcinogenesis bioassay for complex petroleum hydrocarbon mixtures; Cragg ST et al.; Typical petroleum hydrocarbon mixtures were tested directly, without extraction, in the Salmonella/microsome mutagenesis assay in order to determine if the assay would be useful to predict their carcinogenic activity . The carcinogenic activity of each sample had been previously characterized in the in vivo mouse dermal carcinogenesis bioassay . The series of samples evaluated offered several advantages . They spanned a wide boiling point range, were well characterized chemically, had been tested for carcinogenic activity in a single laboratory, and varied in potency in vivo from inactive to highly active . Mutagenicity testing was performed in several well-established contract laboratories that routinely perform the assay . These laboratories were the main contracting laboratories for these assays at the time and had previously tested petroleum samples for clients . Initially, the first laboratory tested 13 samples in five strains of Salmonella typhimurium with and without rat liver S-9 (Arochlor 1254 induced), utilizing both plate and suspension techniques . None of the 13 samples exhibited a mutagenic response, even though 9 of the 13 were slightly to highly dermally carcinogenic in mice . Because of the unexpected results, it was decided to repeat the mutagenicity assays in two other laboratories . Six of the thirteen samples were selected, ranging in carcinogenic potency from negative to highly active . Again, none were mutagenic in the second contract laboratory . In a third facility, only one sample of the six exhibited a definite mutagenic response . However, the response was observed with a sample having only weak carcinogenic activity and, unusual for petroleum hydrocarbons, occurred without activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutat Res, 1985 Apr, 149(2), 265 - 9
Activation of N-acetoxy- and N-hydroxy-2-acetylaminofluorene to mutagenic and cytotoxic metabolites by V79 Chinese hamster cells; Glatt H et al.; N-Acetoxy-2-acetylaminofluorene (AAAF) and N-hydroxy-2-acetylaminofluorene (OH-AAF) are mutagenic to V79 cells, causing the induction of 6-thioguanine-resistant clones, and are cytotoxic . The presence of the deacetylase inhibitor, paraoxon, drastically reduces both the mutagenic and cytotoxic effects . This strongly suggests that deacetylated metabolites are the major active species . Furthermore, when Salmonella typhimurium TA98 is used as target organism, addition of homogenate of V79 cells strongly potentiates the mutagenicity of OH-AAF . To our knowledge, this is the first report demonstrating a significant biological effect due to the metabolism of a mutagen by V79 cells.

Mutat Res, 1985 Apr, 142(4), 187 - 92
Activity of bromochlorodifluoromethane (BCF) in three mutation tests; Styles JA et al.; The halocarbon BCF was tested in 3 assays to assess its mutagenicity and clastogenicity . It produced a positive response in Salmonella typhimurium strain TA1535 but was negative in TA1537, TA1538, TA98 and TA100 . In an L5178Y mouse lymphoma microwell assay (TK locus), BCF was negative . BCF was administered at 5000 and 50 000 ppm in air for 6 h to groups of C57B1/6J mice of both sexes . Animals were killed at 24, 48 and 72 h after cessation of exposure and the incidence of bone marrow micronuclei per 1000 PCEs determined . There was no significant difference in the incidences of micronuclei between untreated animals and those exposed to either concentration of BCF at any of the sampling times . These results suggest that BCF is mutagenic in vitro in only one strain of Salmonella; in mammalian cells the compound induced no gene mutation in vitro nor clastogenic activity in vivo at doses that also produced clear evidence of toxicity.

Mutat Res, 1985 Apr, 142(4), 153 - 8
Inhibitory effect of organic solvents on the mutagenicity of N-nitrosodialkylamines in Salmonella; Mori Y et al.; The influence of organic solvents on the mutagenicity of 11 N-nitrosamines was examined in Salmonella typhimurium TA100 using the Ames's liquid incubation assay in the presence of rat-liver S9 . The mutagenic activities of N-nitrosodimethylamine, N-nitrosodiethylamine, 6 oxidative derivatives of N-nitrosopropylamine and N-nitroso-2,6-dimethylmorpholine were considerably decreased by addition of dimethyl sulfoxide, dimethyl formamide, acetone, 95% ethanol or acetonitrile, which are recommended for use as solvents in the assay by Ames's group, to the incubation mixture . The mutagenic activities of N-nitrosodipropylamine and N-nitrosodibutylamine, which are barely soluble in water, were also suppressed by increasing concentrations of dimethyl sulfoxide . These organic solvents did not appear to exert their influence by desmutagenic and antimutagenic actions . In contrast, the recoveries of unmetabolized carcinogens from preincubation mixtures and from agar plates were significantly higher in the presence of organic solvents than in their absence . The results indicate that the inhibitory effect is a result of interference with the process of metabolic activation by liver S9.

Mutat Res, 1985 Apr, 142(4), 149 - 52
Mutagenicity of pyrene in Salmonella; Matijasevic Z et al.; Pyrene was tested for mutagenicity in Salmonella typhimurium strains TA97, TA98, TA100 and TA1537 . Mutagenicity was seen in all strains when S9 was present.

J Med Microbiol, 1985 Apr, 19(2), 159 - 67
Effect of a lysolecithin analogue on nonspecific resistance to infection of mice; Vassilev TL et al.; The effect of racemic 1-octadecyl-2-methoxy-sn-glycero-3 phosphorylcholine (ET-18-OCH3) on the nonspecific resistance of mice to infection with Salmonella typhimurium was investigated . Two S . typhimurium strains with different virulence were studied and no effect was observed in either case at concentrations of ET-18-OCH3 up to 100 micrograms/mouse . However, a concentration of 500 micrograms/mouse caused decreased resistance to S . typhimurium, correlating with a depression of carbon clearance . Treatment of macrophages with ET-18-OCH3 in vitro inhibited phagosome-lysosome fusion, but had no effect on zymosan-induced luminol-dependent chemiluminescence . The relationship between the adjuvant and nonspecific anti-infectious activity of ET-18-OCH3 and other compounds is discussed.

J Bacteriol, 1985 Apr, 162(1), 183 - 9
Locations of hook-associated proteins in flagellar structures of Salmonella typhimurium; Homma M et al.; Hooks of the flagella of Salmonella typhimurium were purified from an flaL mutant . Hook-associated proteins, namely HAP1, HAP2, and HAP3, were separated from them, and the antibody against each HAP was prepared . By immunoelectron microscopic observation, these three kinds of antiHAP antibodies were found to bind on the distal ends of hooks of filamentless mutants consistently with their composition of HAPs . The antiHAP2 antibody bound to the very tops of the claw-shaped ends of the hooks which contain all three HAPS . The antibodies against HAP1 and HAP3 bound to the basal areas and the middle areas, respectively, of the claw-shaped ends . The order of disassembly of the component proteins by heat treatment of the hook structure from the filamentless mutants was (HAP2, HAP3) greater than HAP1 greater than hook protein . These observations were consistent with our layered structure model: HAP1, HAP3, and HAP2 are assembled at the distal end of the hook in this sequence . All three HAPs were detected in the hook-filament complexes prepared from a flagellate strain . When the hook-filament structure was treated with antibody against HAP1 and with the anti-rabbit immunoglobulin G antibody, the antibody aggregate was observed in the region corresponding to the boundary between filament and hook . This observation strongly suggests that HAP1 is the protein connecting filament with hook . The locations of HAP2 and HAP3 in the hook-filament structure were not clarified with the same procedure.

Infect Immun, 1985 Apr, 48(1), 169 - 74
Effect of streptomycin administration on colonization resistance to Salmonella typhimurium in mice; Que JU et al.; The addition of 5 mg of streptomycin sulfate per ml to the drinking water of Swiss white mice resulted in a 100,000-fold reduction in the 50% implantation dose of streptomycin-resistant Salmonella typhimurium for the animals . When streptomycin-treated and untreated mice were challenged orogastrically with 10(3) viable S . typhimurium organisms, 100% of the treated and none of the untreated mice excreted the pathogen in their feces . Similarly, translocation of S . typhimurium from the intestinal tract to the liver, spleen, and mesentery occurred in 10 of 10 treated mice but in none of the untreated mice 7 days after challenge with 10(3) CFU . Studies of colonization dynamics showed that S . typhimurium was present at high population levels in the intestines of streptomycin-treated mice and in detectable levels in the liver, spleen, and mesentery within 72 h after challenge with 10(3), 10(5), or 10(8) organisms . In untreated mice challenged with either 10(3) or 10(5) S . typhimurium organisms, the organisms were isolated from ileal and cecal tissues but not from ileal or cecal contents or from extraintestinal tissue 72 h after challenge . When untreated mice were challenged with 10(8) organisms, however, S . typhimurium was present in all organs and in intestinal contents . Streptomycin treatment, therefore, facilitated colonization and development of streptomycin-resistant S . typhimurium populations in intestines of mice and the subsequent translocation of the organisms from the intestinal tract to other tissues.

Am Rev Respir Dis, 1985 Apr, 131(4), 662 - 5
A case of invasive penicilliosis in Hong Kong with immunologic evaluation; So SY et al.; A 53-yr-old Chinese sailor developed prolonged pyrexia with unresolved lobar pneumonia, cervical lymphadenopathy, generalized subcutaneous abscesses, and pericardial effusion . Penicillium marneffei was isolated from pericardial fluid and subcutaneous pus and was demonstrated on histologic sections of lymph nodes and lung tissue . The penicilliosis was treated successfully with amphotericin B, ketoconazole, and 5-fluorocytosine . Subsequently, he also developed other T-lymphocyte-related opportunistic infections such as disseminated cutaneous herpes zoster and chronic osteomyelitis of sternum caused by Salmonella typhimurium . He was also a chronic carrier of cytomegalovirus . Further investigations showed that he had persistent depression of T-lymphocyte function and enhancement of B-lymphocyte activity, the cause of which was undetermined.

Infect Immun, 1985 Apr, 48(1), 40 - 3
Adoptive transfer of murine host protection to salmonellosis with T-cell growth factor-dependent, Salmonella-specific T-cell lines; Paul C et al.; A spent medium antigen was prepared from the avirulent RIA strain of Salmonella typhimurium . Lymph node cells isolated from female BALB/c mice injected subcutaneously with the spent medium antigen exhibited antigen-specific proliferation . By using these cells and T-cell growth factor, continuous spent medium antigen-specific, Thy 1.2-sensitive lines were generated . These cells exhibited antigen-specific proliferation in vitro and were effective in inducing significant (P less than 0.01) host protection when adoptively transferred to naive syngeneic mice.

Mutat Res, 1985 Apr-May, 156(1-2), 77 - 82
Mutagenicity and chemical reactivity of epoxidic intermediates of the isoprene metabolism and other structurally related compounds; Gervasi PG et al.; The mutagenic activities of the epoxidic intermediates of the isoprene biotransformation were investigated using Salmonella typhimurium and compared with those of other structurally related epoxides . The compound 2-methyl-1,2,3,4-diepoxybutane, chemically analogous to the well known carcinogenic 1,2,3,4-diepoxybutane, was found to be as mutagenic as the latter . Moreover, the mutagenic activities of oxiranes were correlated to their alkylating powers towards nicotinamide and to their half-lives for spontaneous hydrolysis . The relationship between alkylating power and mutagenicity was found to hold for the stable epoxides that react mainly by an SN2 substitution mechanism.

Proc Natl Acad Sci U S A, 1985 Apr, 82(7), 2077 - 81
Mechanisms determining aerobic or anaerobic growth in the facultative anaerobe Salmonella typhimurium; Yamamoto N et al.; We isolated mutant strains of the facultative anaerobe Salmonella typhimurium that grow either aerobically or anaerobically . Strict anaerobic mutants contained a defective DNA topoisomerase I gene (topI), while strict aerobic mutants contained a defective DNA gyrase subunit A gene (gyrA, also nalA) . Topoisomerase I activity was detected in cell-free extracts of strict aerobic mutants but not of strict anaerobic mutant strains, whereas gyrase activity was detected in extracts of strict anaerobic mutants but not of strict aerobic mutants . Furthermore, extracts of wild-type cells, cultured under vigorous aerobic condition, contain topoisomerase I activity but no significant gyrase activity . In contrast, the extracts of anaerobically cultured wild-type cells contain gyrase activity but no significant topoisomerase I activity . Sucrose gradient centrifugation with ethidium bromide showed that chromosomal DNA in strict aerobic mutants and aerobically grown wild-type cells was relaxed, while the chromosomal DNA of strict anaerobic mutants and anaerobically grown wild-type cells was more supercoiled . Aerobic cultures of wild type and strict aerobic mutants produced both superoxide dismutase and catalase, whereas anaerobic cultures of wild type and strict anaerobic mutants did not . These results lead us to conclude that activity of topoisomerase I, associated with relaxation of chromosomal DNA, is necessary for expression of genes required for aerobic growth, whereas activity of gyrase, associated with supercoiling of chromosomal DNA, is necessary for expression of genes required for anaerobic growth.

J Bacteriol, 1985 Apr, 162(1), 307 - 16
Composite IS1 elements encoding hydroxamate-mediated iron uptake in FIme plasmids from epidemic Salmonella spp; Colonna B et al.; Eleven FIme plasmids representative of those identified in epidemic strains of Salmonella wien and Salmonella typhimurium isolated in North Africa, Europe, and the Middle East have been examined for the presence of determinants of toxigenicity, adherence, and iron-sequestering mechanisms . Chemical and genetic data indicated that all plasmids code for a hydroxamate-mediated iron assimilation system . Detailed analysis of derivative plasmids and cloned fragments of FIme plasmid pZM61 demonstrated that the general genetic and structural organization of the DNA region containing the genes for hydroxamate biosynthesis and cloacin DF13 receptor was virtually identical to that described for the aerobactin-mediated iron uptake system of pColV-K30 . This DNA region is part of a composite element that is 16.7 kilobases long and carries its IS1 modules as inverted repeats . A very similar element is present in either orientation in all nine FIme plasmids analyzed.

Acta Pathol Microbiol Immunol Scand {B}, 1985 Apr, 93(2), 125 - 31
Mannose-specific and hydrophobic interaction between Escherichia coli and polymorphonuclear leukocytes--influence of bacterial culture period; Ohman L et al.; The influence of culture period on mannose-specific and hydrophobic properties of the bacterial surface and on bacteria/polymorphonuclear leukocyte (PMNL) interaction was studied . Four E . coli strains, PN7 (01:K1), ABU2 (ON:K14), CU9 (06:K14) and CU13 (08:KN) and two Salmonella typhimurium strains 395 MR10 and 395 MS, well characterized according to physicochemical surface properties, presence of type 1 fimbriae and interaction with PMNL, were used in the study . The results show that with prolonged culture period, the liability to hydrophobic interaction increases, the agglutination-strength of mannose-specific maltobionamide liposomes increases, while the agglutination-titer with guinea-pig erythrocytes remains constant . Furthermore, the mannose-specific association with and metabolic activation of PMNL is augmented, while the ingestion is unchanged . In addition, our results demonstrate differences in sensitivity between the methods used to detect exposure of mannose-specific structures on the surface of bacteria, and that the culture condition is important for bacterial surface properties . It thus appears that the culture conditions have a great influence on the surface properties of E . coli bacteria and the interaction with phagocytic cells.

J Biol Chem, 1985 Mar 25, 260(6), 3716 - 8
Crystallization and preliminary X-ray crystallographic data of the tryptophan synthase alpha 2 beta 2 complex from Salmonella typhimurium; Ahmed SA et al.; The tryptophan synthase alpha 2 beta 2 complex from Salmonella typhimurium can be crystallized by the method of vapor diffusion from solutions of polyethylene glycol 8000 and various salts . Thin needles are obtained in the presence of a monovalent cation (Na+), thicker crystals are obtained in the presence of divalent cations (Mg2+, Mn2+, Fe2+, Ca2+, Zn2+), and square-faced crystals are obtained in the presence of spermine . Although the spermine and Mg2+ crystals differ in morphology, they are both monoclinic and in space group C2 with a = 184.5 A, b = 62.4 A, c = 67.7 A, beta = 94 degrees 40', and one alpha beta pair of Mr = 71,700/asymmetric unit . The crystals appear reasonably resistant to radiation damage and should be suitable for a complete structure investigation . The separated S . typhimurium alpha, holo-beta 2, and apo-beta 2 subunits do not crystallize under these conditions nor do the alpha 2 beta 2 complex or the alpha- or holo-beta 2 subunits from Escherichia coli or from an interspecies hybrid.

Nature, 1985 Mar 21-27, 314(6008), 257 - 60
Sulphate sequestered in the sulphate-binding protein of Salmonella typhimurium is bound solely by hydrogen bonds; Pflugrath JW et al.; An important question in understanding substrate binding by proteins is how charged groups are stabilized in the absence of their solvation shell . We have addressed this question here by solving the structure of the sulphate-binding protein of Salmonella typhimurium with bound substrate at 2.0 A resolution . The results are remarkable in that the charged oxygen atoms of the sulphate molecule, which is buried and completely inaccessible to the solvent, are not stabilized by the formation of salt-bridges but by hydrogen bonds donated by specific residues of the protein . These hydrogen bonds are in turn coupled via peptide units to several resonating hydrogen bonding systems . These findings may be of general significance for the role of electrostatic interactions in protein structure and function.

Experientia, 1985 Mar 15, 41(3), 396 - 7
Lack of mutagenicity of irradiated glucose in Salmonella typhimurium using host-mediated assay; Varma MB et al.; Experiments were conducted to study the ability of irradiated glucose to induce reverse mutations in S . typhimurium by host-mediated assay . The results revealed no significant increase in the frequency of reverse mutations compared to controls.

Biomaterials, 1985 Mar, 6(2), 129 - 32
Mutagenicity of endodontic sealers; Orstavik D et al.; Four endodontic sealer materials and some of their chemical constituents were subjected to Ames' test for mutagenicity with the Salmonella/microsome assay . Extracts of two zinc oxide-eugenol based materials and of one gutta-percha-zinc oxide-chloroform based sealer were negative in the test . Extracts of a synthetic polymer material, based on epoxy-bis-phenol A, induced mutations in Salmonella typhimurium TA 100 as did extracts of the epoxy-bis-phenol A resin alone . Formaldehyde, an active ingredient from one of the ZnO-based materials, induced mutations in both Salmonella typhimurium TA 98 and TA 100 . The mutagenic activity of formaldehyde as well as of the epoxy material was reduced in the presence of rat liver microsomes.

J Pharmacobiodyn, 1985 Mar, 8(3), 199 - 205
Effect of liver S9 from 3,4,5,3',4'-pentachlorobiphenyl-pretreated rats on the mutagenic activity of the various carcinogens toward Salmonella typhimurium TA 98; Ozawa N et al.; Effects of liver 9000 X g supernatant fraction from 3,4,5,3',4'-pentachlorobiphenyl- and 2,4,5,2',4',5'-hexachlorobiphenyl-pretreated rats (PenCB-S9 and HexCB-S9, respectively) on the mutagenic activities of well-known carcinogens, benzo-{a}pyrene (BP), Glu-P-1 (2-amino-6-methyldipyrido {1,2-a:3',2'-d}imidazole), Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido{4,3-b}indole), and aflatoxin B1 (AFB), toward Salmonella typhimurium TA 98 have been described . Although the mutagenic activities of all of these carcinogens were enhanced by these S9, PenCB-S9 especially highly activated BP, Glu-P-1, and Trp-P-1 . The ability of PenCB-S9 to activate the carcinogens was much higher than that of liver 9000 X g supernatant fraction from 3-methylcholanthrene-pretreated rats (MC-S9) . PenCB-S9 enhanced the mutagenic activity of BP 8 times higher than MC-S9, while Glu-P-1 and Trp-P-1 were activated by PenCB-S9 twice as much as by MC-S9 . Effect of HexCB-S9 on the mutagenic activities of the above-mentioned three carcinogens was much less than those of PenCB- and MC-S9 and a little higher than that of 9000 X g supernatant fraction from rats pretreated with phenobarbital . As for AFB, phenobarbital was the most potent inducer, and HexCB and PenCB were next to this . Data suggest that PenCB is a strong inducer of P-448 species which activate environmental toxicants.

Jpn J Cancer Res, 1985 Mar, 76(3), 184 - 91
Alpha-hydroxylation and mutagenicity of unsymmetrical N-nitrosodialkylamines with a butyl group; Suzuki E et al.; In order to compare the extents of metabolic alpha-hydroxylation of the two alkyl groups in unsymmetrical N-nitrosodialkylamines, N-nitroso-N-alkylbutylamines (alkyl = methyl, ethyl, propyl, butyl, and amyl) were incubated with liver microsomes prepared from phenobarbital- or polychlorinated biphenyl (PCB)-treated and untreated rats, and aldehydes produced by the alpha-hydroxylation were determined quantitatively . Although an increased production of aldehydes was observed with the induced microsomes compared with the non-induced microsomes, no marked differences were noted between the two alkyl groups of these unsymmetric nitrosodialkylamines in regard to the extent of alpha-hydroxylation with the exception of N-nitroso-N-methylbutylamine (NMBA) . The amount of aldehydes produced from these nitrosamines increased with elongation of the alkyl chain, amounting to 10-30% of the compounds incubated, and the recovery in the incubation (total aldehyde + nitrosamine recovered) was found to be more than 90%, indicating that alpha-hydroxylation is the principal oxidative metabolic pathway of the nitrosamines in vitro . The microsomal alpha-hydroxylation was inhibited by dimethyl sulfoxide and the extent of the hydroxylation was shown to be positively correlated with the mutagenic potency of the nitrosamines . Based on the mutagenic behavior of NMBA tested on Salmonella typhimurium TA1535 and Escherichia coli WP2 hcr- and the extent of the formation of formaldehyde and butyraldehyde from NMBA in the presence of the induced microsomes and S9 mix, it was concluded that NMBA acts as both a methylating and a butylating agent.

Mutat Res, 1985 Mar, 142(3), 121 - 5
Weak mutagenicity to Salmonella of the formaldehyde-releasing anti-tumour agent hexamethylmelamine; Ashby J et al.; Hexamethylmelamine (HEMLA) is a metabolism-dependent formaldehyde-releasing agent related in structure to hexamethylphosphoramide (HMPA) . Both compounds are known to be mutagenic to Drosophila . HMPA, in common with the other formaldehyde-releasing agents studied, is non-mutagenic to Salmonella . The present paper describes the mutagenicity of HEMLA to strain TA100 of Salmonella typhimurium . Activity is dependent upon both the use of a pre-incubation assay protocol and on high concentrations of Aroclor-induced rat liver in the S9 mix . HMPA was inactive under similar conditions of test.

Mutat Res, 1985 Mar, 142(3), 103 - 7
The effect of quercetin on the mutagenicity of 2-acetylaminofluorene and benzo{alpha}pyrene in Salmonella typhimurium strains; Ogawa S et al.; The comutagenic and desmutagenic effect of quercetin on the mutagenicity of typical mutagens e.g . 2-acetylaminofluorene (AAF), 4-nitroquinoline-1-oxide (4NQO) and benzo{alpha}pyrene (B{a}P), in Salmonella typhimurium TA98, TA100 and TA98/1,8 DNP6 were examined . In the mixed application of AAF with quercetin in the presence of mammalian metabolic activation system (S9 mix), the numbers of revertants in TA98 increased by as much 2.2-5.0-fold compared with the sum of those in the separate applications of AAF and quercetin . A 1.4-2.7-fold increase was observed in TA100 . Quercetin did not affect the mutagenicity of 4NQO, and depressed that of B{a}P . Dose-response curves for mutagenicity of quercetin with or without AAF (5 micrograms/plate) were examined . The results suggest that quercetin, present in a molarity of up to 1.5 times that of AAF, is apparently effective in enhancing the mutagenicity of AAF, because a linear dose-response curve was observed in the range of 0-5 micrograms/plate quercetin with AAF although quercetin alone was not mutagenic in the same range . Dose-response curves for mutagenicity of quercetin with or without 5 micrograms/plate B{a}P did not increase compared with that for quercetin alone . The mutagenicity of the mixed application of B{a}P with quercetin was reduced to about 60% of the sum of separate application at doses ranging from 25 to 100 micrograms/plate of quercetin . Since enhancement and depression of mutagenicity by quercetin were observed for indirect mutagens, AAF and B{a}P, respectively, in the presence of S9 mix, quercetin may affect the metabolic pathway of these mutagens.

Biochimie, 1985 Mar-Apr, 67(3-4), 327 - 34
Use of a new DNA intercalating fluorescing probe for studies on the mechanism of frameshift mutagenesis in Salmonella typhimurium; Rene B et al.; As a general rule, ellipticine derivatives are mutagenic and intercalate into double-stranded nucleic acids . We have tested a new fluorescent ellipticine compound, 10{(1-carboxy-2-methylpropylidene)-amino}-9-hydroxy-2-methylell ipticinium (val-NMHE), for establishing the relationship between the amount of drug bound to nucleic acids in situ in Salmonella typhimurium and its biological effects: decrease of growth rate and mutagenesis . Val-NMHE is mutagenic only on Ames'strain TA 1977 which carries a + 1 frameshift mutation . On a per cell basis, the number of revertants is not linearly correlated to the amount of drug bound to nucleic acids: this number is relatively higher for increasing amounts of drug . This effect is not related to the mere probability of interaction between the drug molecule and its target, a GGGG/CCCC sequence . It might be explained by other hypotheses briefly discussed herein.

Appl Environ Microbiol, 1985 Mar, 49(3), 505 - 8
Effect of pH, temperature, and potassium sorbate on amino acid uptake in Salmonella typhimurium 7136; Tuncan EU et al.; The effect of sorbate on L-serine and L-histidine uptake in Salmonella typhimurium was studied at various pH levels, temperatures, and amino acid and sorbate concentrations . Low pH had an apparent synergistic effect on amino acid uptake inhibition caused by sorbate . The relationship between sorbate concentration and the amount of amino acid uptake inhibition was not linear . Compared with L-histidine, L-serine uptake was more sensitive to changes in pH, temperature, and sorbate concentration . Various degrees of amino acid uptake inhibition by sorbate may be related to differences between amino acid transport systems . The results of this study suggest that sorbate acts as a noncompetitive inhibitor of amino acid uptake in S . typhimurium.

J Appl Bacteriol, 1985 Mar, 58(3), 251 - 5
Protective effect of casein toward Salmonella typhimurium in acid-milk; Rubin HE; Lactic acid is the inhibitory agent in yoghurt responsible for the inhibition of Salmonella typhimurium . Casein, however, may exert a protective effect toward the survival of the salmonella in acid-milk products . Salmonella typhimurium was found to die-off 21.2% more rapidly in 18-h yoghurt-whey than in 18-h yoghurt at 37 degrees C with a pH of 3.85 and 1.42% lactic acid . When casein was added to yoghurt-whey, the die-off rate of the salmonellas was reduced to that found in yoghurt . The rate remained unchanged when 4.8% sodium caseinate was added to the whey . When 0 to 14% casein was added to the acid-whey the die-off rate changed from 9.7 to 24.0 min/log reduction of cells, respectively . There was a direct correlation between the increase in casein concentration and length of survival of the salmonellas . At a pH of 3.85, 4.2 or 4.5, the die-off rate was 6.5, 13.0 or 40 min/log reduction of cells in milk containing 1.42% lactic acid, and was 4.0, 10.0 or 33.3 min/log reduction, respectively, in whey with 1.42% lactic acid . Thus, the protective effect of casein toward Salm . typhimurium increased as the pH increased . This indicated that casein exerts a protective effect on Salm . typhimurium in acid dairy products and the degree of protection depends on the casein concentration, the form of the casein molecule and the pH.

Carcinogenesis, 1985 Mar, 6(3), 441 - 4
Genotoxicity of the food mutagen 2-amino-3-methylimidazo-{4,5-f}quinoline (IQ) and analogs; Barnes WS et al.; The food mutagen 2-amino-3-methylimidazo{4,5-f}quinoline (IQ) is an analogue of quinoline, a hepatocarcinogen . 2-Aminofluorene, benzidine and 3,2'-dimethyl-4-aminobiphenyl (DMAB) are potent inducers of unscheduled DNA repair in primary culture rat liver hepatocytes, as was IQ (151 grains/nucleus at 1 X 10(-6) M) . Quinoline, on the other hand, is only weakly positive in this assay (15 grains/nucleus at 1 X 10(-3) M) . IQ, quinoline and DMAB were applied topically to shaved skin of Sencar mice with promotion by 12-O-tetradecanoylphorbol 13-acetate (TPA) for 20 weeks, when 14 of 20 mice in the quinoline group had 25 tumors, but only one of 30 animals in the IQ group and five of 30 in the DMAB group were tumor-bearing . Analogs of IQ synthesized by substitution at the 2- or 3-position with amino or methyl groups were assayed with the Ames Salmonella typhimurium tester strains TA98 and TA100 . Mutagenicity for TA98 is reduced in the absence of the 3-methyl group and is completely abolished with removal of the 2-amino moiety . None of these analogs are strong mutagens for TA100 . Exocyclic N-oxidation is a likely obligatory step in the activation of IQ to a mutagen.

Arch Dermatol, 1985 Mar, 121(3), 348 - 9
The mutagenicity of dinitrochlorobenzene; Black HS et al.; A sample of dinitrochlorobenzene, determined by gas-liquid chromatography and mass spectrometry to be greater than 98% pure, was tested in the Salmonella typhimurium plate assay . The chemical evoked a marked mutagenic response at all concentrations tested (3 to 150 micrograms per plate) . These results confute the suitability of this agent for the treatment of benign skin disorders.

Mutat Res, 1985 Mar, 149(1), 9 - 15
Relationship between mutagenic potency in Salmonella typhimurium and chemical structure of amino- and nitro-substituted biphenyls; Nohara M et al.; All positional isomers of mononitro- and monoaminobiphenyls and those of dinitro-, diamino- and aminonitrobiphenyls, which have one substituent on each benzene ring, were assayed for mutagenicity in Salmonella typhimurium by the Ames method . The results suggest that the structural requirements favoring mutagenic activity are the presence of substituents at the 4-position and their absence at the 2'-position . The introduction of an amino group to the 3'- or 4'-position of 4-nitrobiphenyl or a nitro group to 3'- or 4'-position of 4-aminobiphenyl enhanced the mutagenicity . Among the mutagenic compounds, 4-nitro analogues were mutagenic in strains TA98 and TA100 in the absence of a microsomal metabolic activation system . Strain TA98NR was not reverted by the direct-acting mutagens, whereas strain TA98/1,8-DNP6 was as revertible as strain TA98; these results suggest that the direct-acting mutagenicity involves the reduction of the nitro group by bacterial nitroreductase but does not involve specific esterification enzymes.

Mutat Res, 1985 Mar, 149(1), 25 - 32
1-Nitrosopyrene: an intermediate in the metabolic activation of 1-nitropyrene to a mutagen in Salmonella typhimurium TA1538; Heflich RH et al.; Incubation of Salmonella typhimurium TA1538, in suspension culture, with 1.5 or 23 microM 1-nitropyrene resulted in a time-dependent increase in reversions for up to 7 h . In contrast, when the bacteria were exposed to 1.5 microM 1-nitrosopyrene, a reduction product of 1-nitropyrene, maximum reversion induction occurred after 1 h and a much higher mutation frequency was detected . Examination of DNA isolated from Salmonella typhimurium incubated with 4.1 microM {4,5,9,10-3H}1-nitrosopyrene indicated the presence of one major adduct, N-(deoxyguanosin-8-yl)-1-aminopyrene, the same adduct observed previously when the bacteria were exposed to 1-nitropyrene . When calf thymus DNA was treated with 1-nitrosopyrene in the presence of ascorbic acid, 1-aminopyrene was formed concomitant with the production of N-(deoxyguanosin-8-yl)-1-aminopyrene . In the absence of ascorbic acid, a 20-fold reduction in DNA binding was observed and 1-aminopyrene was not detected . The observations that 1-nitrosopyrene forms the same DNA adduct and is more mutagenic than 1-nitropyrene, suggest that 1-nitrosopyrene is an intermediate in the mutagenic activation of 1-nitropyrene in Salmonella typhimurium TA1538 . Since reduction of 1-nitrosopyrene was necessary to get appreciable DNA binding in vitro, further reduction of 1-nitrosopyrene to N-hydroxy-1-aminopyrene is probably required in the activation pathway.

Mutat Res, 1985 Mar, 142(3), 99 - 102
Induction of umuC gene expression by nitrogen dioxide in Salmonella typhimurium; Kosaka H et al.; Gaseous nitrogen dioxide (NO2) was found to induce umuC gene expression in Salmonella typhimurium carrying the umuC-lacZ fusion plasmid . The induction level of the umu operon responsible for inducible mutagenesis was measured by the level of beta-galactosidase in the cell, encoded by the fusion gene . NO2 gas was bubbled into bacterial suspensions at 10, 30 and 90 microliters/l for 30 min at a flow rate of 100 ml/min . Expression of the umuC gene varied with the concentration, flow rate and bubbling time of the NO2 gas . Although NO2 gas induces SOS functions, mutagenesis due to it was not detectable in Salmonella typhimurium TA100 and TA102 . Nitric oxide gas (NO) did not induce any umuC gene expression.

Mutat Res, 1985 Mar, 142(3), 87 - 91
Induction of the SOS response by ICR191 does not influence frameshift mutagenesis at the hisC3076 marker of Salmonella typhimurium; Podger DM et al.; Reversion of the Salmonella typhimurium frameshift marker hisC3076 by ICR191 and 9-aminoacridine in rec+ and recA1 backgrounds was examined using the standard plate-reversion assay . For both compounds, the level of reversion observed in the recA strain is significantly greater than in the rec+ strain . Thus reversion of hisC3076 is not recA-dependent, but is recA-modulated . The ability of a mutagen (or mutagenic treatment) to induce the recA lexA-dependent SOS response does not therefore imply that mutagenic effects will also be recA-dependent.

Mutat Res, 1985 Mar, 142(3), 109 - 13
Effects of pH on weak and positive control mutagens in the Ames Salmonella plate assay; Popkin DJ et al.; The effects of pH on the mutagenic activity of several chemicals were evaluated in the standard Ames Salmonella typhimurium plate-incorporation assay . The pH of the base agar was varied between 6.0 and 8.0 . The positive control compounds routinely used in this laboratory, 2-aminoanthracene, 4-nitro-o-phenylenediamine, sodium azide and nitrofurantoin, showed increasing mutagenic activity as the pH was decreased to 6.0 . However, the activity of two weakly mutagenic cosmetic ingredients, 2,2',4,4'-tetrahydroxybenzophenone and trans-4-phenyl-3-buten-2-one, was completely eliminated at pH levels near 6.0 . It is concluded that plates poured with agar with pH levels below 7.0 can result in strong responses for the positive control chemicals but give negative results for some mutagens.

J Bacteriol, 1985 Mar, 161(3), 1017 - 22
Identification of the phosphocarrier protein enzyme IIIgut: essential component of the glucitol phosphotransferase system in Salmonella typhimurium; Grenier FC et al.; The phosphoenolpyruvate-dependent phosphorylation of glucitol has been shown to require four distinct proteins in Salmonella typhimurium: two general energy-coupling proteins, enzyme I and HPr, and two glucitol-specific proteins, enzyme IIgut and enzyme IIIgut . The enzyme IIgut was solubilized from the membrane and purified about 100-fold, free of the other protein constituents of the phosphotransferase system . Enzyme IIIgut was found in both the soluble and the membrane fractions . The soluble enzyme IIIgut was purified to near homogeneity by gel filtration, hydroxylapatite chromatography, and hydrophobic chromatography on butylagarose . It was sensitive to parital inactivation by trypsin and N-ethylmaleimide, but was stable at 80 degrees C . The protein had an approximate molecular weight of 15,000 . It was phosphorylated in the presence of phosphoenolpyruvate, enzyme I, and HPr, and this phosphoprotein was dephosphorylated in the presence of enzyme IIgut and glucitol . Antibodies were raised against enzyme IIIgut . Enzyme IIIglc and enzyme IIIgut exhibited no enzymatic or immunological cross-reactivity . Enzyme IIgut, enzyme IIIgut, and glucitol phosphate dehydrogenase activities were specifically induced by growth in the presence of glucitol . These results serve to characterize the glucitol-specific proteins of the phosphotransferase system in S . typhimurium.

Infect Immun, 1985 Mar, 47(3), 605 - 12
Immunity to Salmonella typhimurium infection in C3H/HeJ and C3H/HeNCrlBR mice: studies with an aromatic-dependent live S . typhimurium strain as a vaccine; Killar LM et al.; Immunization with avirulent Salmonella typhimurium strain SL3235, a smooth, aroA- derivative, was shown to induce high levels of resistance to challenge with virulent S . typhimurium in innately hypersusceptible C3H/HeJ mice and inherently resistant C3H/HeNCrlBR mice . Strain SL3235 is one of a class of avirulent aroA- derivatives made from various strains and species of Salmonella that are being considered as vaccine candidates for cattle and humans . This paper supports their efficacy and potential utility in this regard . In C3H/HeJ mice, immunity against over 1,000 50% lethal doses of virulent S . typhimurium was evident as early as 3 days after immunization and persisted for at least 7 months . Further, the vaccine was effective over a broad spectrum of doses, ranging from 10(4) to 10(6) organisms . Infection with SL3235 led to marked splenomegaly in both mouse strains . The relationship of splenomegaly to the growth kinetics and colonization by SL3235 in the spleens of infected C3H/HeJ and C3H/HeNCrlBR mice was followed . SL3235 initially multiplied slowly in the spleens of both mouse strains and then was rapidly cleared . Less multiplication was seen in the resistant C3H/HeNCrlBR mice than in C3H/HeJ mice . Maximum splenomegaly occurred after clearance of the organism had begun . Protection against virulent S . typhimurium persisted after virtually all of the SL3235 vaccine strain had been cleared from the spleen . Cross-protection against Listeria monocytogenes was evident, but had a later onset, waned by 21 days, and was not detectable by 1 month after vaccination . Demonstration of this cross-protection is consistent with the interpretation that SL3235 induces cellular immunity . One-week immune spleen cells adoptively transferred anti-S . typhimurium and anti-L . monocytogenes immunity . T cell-enriched fractions were ineffective in adoptive transfer, as were spleen cells taken 2 weeks or later after immunization . Protective capacity was in the adherent cell fraction and seemed to be associated with macrophages . Evidence for induction of a population of sensitized T cells was obtained by using a peritoneal exudate T-lymphocyte proliferation assay on peritoneal T lymphocytes collected 1 to 3 months after SL3235 infection.

Cell Immunol, 1985 Mar, 91(1), 75 - 91
Macrophage-mediated mitogenic suppression induced in mice of the C3H lineage by a vaccine strain of Salmonella typhimurium; Lee JC et al.; Salmonella typhimurium, strain SL3235, an avirulent organism, has been used as a live vaccine in mice of the C3H lineage and has been found to confer high levels of protection . In the present study, it was found that intraperitoneal injection of approximately 5 X 10(5) live SL3235 induced potent suppression of spleen cell mitogenic responses to a panel of B- and T-cell mitogens in the Salmonella-hypersusceptible C3H/HeJ and C3HeB/FeJ, and the inherently resistant C3H/HeNCrlBR mice . Maximal suppression (greater than 99%) was seen at 1 week, and was still significant but waning (50%) at 3 weeks postimmunization . In contrast, cells of mice receiving acetone-killed cells were not suppressed . Removal of macrophages, but not T or B cells, restored responsiveness, indicating that suppression was macrophage mediated . Prostaglandins were not the major mediator of suppression, as in vitro administration of indomethacin failed to abrogate suppression . As mitogenic suppression occurred in mice with high levels of Salmonella immunity, the suppression is interpreted as a marker of a powerful immunomodulatory process induced by live cells, rather than as an indication of poor immune status of the host.

J Bacteriol, 1985 Mar, 161(3), 836 - 49
Purification and characterization of the flagellar hook-basal body complex of Salmonella typhimurium; Aizawa SI et al.; The hook-basal body complex of Salmonella typhimurium, a major component of its flagellar apparatus, was subjected to detailed analysis by electron microscopy and gel electrophoresis . The study was facilitated by the development of an improved protocol for isolation of the complexes in high yield and purity . Nine proteins were identified with the structure . These proteins had apparent molecular weights of 65,000 (65K), 60K, 42K, 38K, 32K, 30K, 27K, 16K, and 14K . Small but reproducible shifts in the apparent molecular weights of specific proteins from conditionally nonflagellate mutants indicated the following gene-polypeptide correspondences: flaFV, 42K; flaFVI, 32K; flaFVII, 30K; flaFIX, 38K; flaAII.1, 65K . Several new morphological features of hook-basal body complexes were recognized, including a clawlike structure on the cytoplasm-proximal M ring and additional material at the cytoplasmic face of the M ring . Based on this study and the work of others, we suggest that the morphological features of the hook-basal body complex correspond to the following proteins: hook-filament junction, 60K; hook, 42K; rod, 30K and 32K; L ring and outer cylinder wall, 27K; P ring, 38K; S ring, unknown; M ring 65K.

Ann Trop Paediatr, 1985 Mar, 5(1), 3 - 6
Use of non-carbonated soft drinks to provide safe drinking water; Gracey M et al.; Non-carbonated, low-calorie soft drink concentrates (cordials), when diluted according to manufacturers' instructions, had significant antibacterial effects in vitro . Bacteria affected include Vibrio cholerae, Aeromonas hydrophila, Shigella sonnei, Salmonella typhimurium and Escherichia coli . With vibrios, bacterial counts were reduced from 10(6)/ml to undetectable numbers in less than 10 min . Escherichia coli in an initial concentration of 10(6)/ml became undetectable after incubation for 1 h with one brand of cordial . Naturally contaminated water can be rendered potable by incubation with cordials at room temperature for 1 h . This may be a way to reduce the risk of water-borne diarrhoea, particularly where the cleanliness of drinking waters cannot be otherwise assured, for example when making up oral rehydration fluids and for travellers in high-risk areas.

Nucleic Acids Res, 1985 Feb 11, 13(3), 673 - 85
Nucleotide sequence and biochemical characterization of the metJ gene from Salmonella typhimurium LT2; Urbanowski ML et al.; The nucleotide sequence of the Salmonella typhimurium metJ gene is presented along with the sequence of the promoter region for the closely linked metB gene . The two genes are transcribed in opposite directions, with transcription initiating from a single promoter for metB, and from two apparent promoters for metJ . RNA polymerase binding sites for metJ and metB, determined by in vitro protection studies, lie adjacent to each other and may overlap . The two metJ promoters, PJ1 and PJ2, are separated by approximately 65 base pairs . Binding of RNA polymerase in vitro could only be observed for PJ1, even though transcripts are initiated from both promoters in vivo . The metJ gene codes for a polypeptide of 105 amino acids with a calculated Mr of 12,110 . The translation start site was determined by N-terminal amino acid sequence analysis of a metJ-lacZ fusion protein.

Arch Toxicol, 1985 Feb, 56(4), 267 - 71
In vitro mutagenicity of valepotriates; von der Hude W et al.; Valepotriates are epoxide-bearing triesters of the monoterpene alcohol 4,7-dimethylcyclopenta-(c)-pyrane isolated from the roots of several Valerianacae species . They are regarded as the main tranquilizing constituents of these drugs . Although the valepotriates valtrate/isovaltrate (VAL) and dihydrovaltrate (DH-VAL) showed a strong alkylating activity against the nucleophilic agent 4-(p-nitrobenzyl)-pyridine (NBP), they were not clearly mutagenic for the strains TA98, TA100, TA1535, and TA1537 of Salmonella typhimurium or for the strains WP2 and WP2 uvrA- of Escherichia coli in the absence of a metabolic activation system (S9-mix) . However, the valepotriates were mutagenic for TA100, WP2 and WP2 uvrA- at concentrations up to about 1.0 mumole/plate when S9-mix was added to the test system . With more than 1 mumole/plate the valepotriates were toxic in the presence of a metabolic activation system for all strains tested . The mutagenicity of the valepotriates was inversely related to the protein content of the S9-mix used . The mutagenicity and toxicity of the valepotriates could be inhibited when the S9-mix was preincubated with the esterase inhibitor paraoxon (1 mM) for 5 min before the test compounds and bacteria were added . Therefore, bioactivation of the valepotriates by an enzymatic hydrolysis of their ester groups is considered . This could be proven by activating the valepotriates with purified esterase.

Sci Total Environ, 1985 Feb, 41(2), 173 - 86
Mutagenicity of three agricultural soils; Brown KW et al.; A chemical and biological testing protocol was employed to evaluate the mutagenic potential of the organic compounds extracted from three agricultural soils . The analytical procedures used included bioassays with Salmonella typhimurium and Aspergillus nidulans for the detection of point mutations and a gas chromatography/mass spectrometry/computer system to identify major organic constituents . The extracts of all three soils exhibited mutagenic response in the bioassays . At a dose level of 1000 micrograms per plate, the organic extract of the Bastrop clay induced 434 net revertants; while at the same dose level the Norwood sandy clay and the Sassafrass sandy loam induced 35 and 178 net revertants, respectively, in the Salmonella assay with metabolic activation . In the Aspergillus assay, the extract of the Norwood and Bastrop soils induced a positive response without metabolic activation; this effect was reduced or eliminated in the presence of metabolic activation . Chemical analysis identified a variety of initiators, promotors, inhibitors, and cocarcinogens; however, there were no mutagenic compounds identified in any of the soil extracts . The results of this combined testing protocol indicate that the agricultural soils tested had an inherent level of mutagenic activity, which was not detected by GC/MS analysis alone, and this activity may be related to the past history of agricultural practices, including biocide applications, fertilization, and cultivation.

Mutat Res, 1985 Feb-Apr, 147(1-2), 37 - 43
Epidermal enzyme-mediated mutagenicity of the skin carcinogen, 2-aminoanthracene; Bickers DR et al.; Using four Salmonella typhimurium tester strains (TA1537, TA1538, TA98 and TA100) and the promutagen 2-aminoanthracene, an epidermal S9-mediated mutagenicity assay was developed . Using an activation mixture derived from whole skin of the rat, mutagenicity was observed in tester strain TA98 whereas an activation mixture derived from the dermis resulted in mutagenicity in tester strains TA1538, TA98 and TA100 . Activation mixtures from both the epidermis and the liver produced a positive response in all of the tester strains studied . Activation mixtures from liver were shown to have the highest specific activity followed in decreasing order of potency by epidermis, dermis and whole skin . These results indicate that the skin, a target tissue directly exposed to environmental chemicals, is capable of converting 2-aminoanthracene to mutagenic moieties . Since the skin of the rat is known to be susceptible to tumor induction by 2-aminoanthracene our findings re-emphasize that membrane-bound enzymes can influence toxic responses including mutagenicity to xenobiotics in cutaneous tissue.

Infect Immun, 1985 Feb, 47(2), 534 - 9
Modulation of in vitro natural cell-mediated activity against enteropathogenic bacteria by simple sugars; Nencioni L et al.; Lymphoid cells from mouse Peyer's patches and spleens were tested in a 2-h in vitro assay for their natural activity against the enteropathogenic bacteria Salmonella typhimurium, Salmonella enteritidis, Salmonella tel aviv, and Shigella sp . X16 . The antibacterial activity expressed by normal cells was detected against all the bacterial strains tested with the exception of Peyer's patch lymphocytes against S . tel aviv and splenocytes against Shigella sp . X16 . To determine whether the different expression of natural antibacterial activity might be due to lectin-like proteins interacting with the saccharidic moieties of the bacterial wall, 11 simple sugars were preincubated with the effector cells before the in vitro assays . We found that some of them could block the natural antibacterial activity as well as induce antibacterial activity when this was not spontaneously expressed . Interestingly, a different panel of sugars among those employed was observed to affect the antibacterial activities for each of the above-mentioned bacterial targets and each effector cell . However, the same panel of sugars was able to block or stimulate the lymphocyte activity when bacteria with the same somatic antigens as two substrains of S . typhimurium and one strain of Salmonella schottmuelleri were employed . To further investigate the interaction between effector cells and bacteria, effector cells or Shigella sp . X16 targets were treated with proteolytic, glycolytic, and lipolytic enzymes before the in vitro assays . Furthermore, EDTA was used to analyze the role of divalent cations in this experimental system . The results obtained suggest that lectin-like proteins playing a role in this interaction are present not only on lymphocytes but also on bacteria and that divalent cations are essential for the expression of in vitro antibacterial activity.

Ecotoxicol Environ Saf, 1985 Feb, 9(1), 84 - 91
Toxic impact of effluents from petrochemical industry; Nikunen E; The toxicity of effluents from a petrochemical industry center in southern Finland was tested by conducting bioassays on organisms from three different trophic levels . In fish tests, rainbow trout (Salmo gairdneri) were caged at the discharge site and simultaneously at a reference area . The only clear differences, among the measurements of 25 metabolic parameters, were observed in fish liver where activities of two detoxication enzymes were significantly increased in the exposed group . The water flea (Daphnia magna) was used both in acute (EC50) and long-term reproduction tests . No acute lethal toxicity was detected in any of the wastewater samples investigated . A combined effluent, however, caused a reduction in the reproduction rate with an EC50 of 3% . No mutagenic activity was observed with the Ames test (Salmonella typhimurium, strains TA 97, TA 98, and TA 100) in concentrated effluents, in sediment samples, or in liver samples from predator fish caught from the discharge site.

Carcinogenesis, 1985 Feb, 6(2), 237 - 42
Inhibition of the mutagenicity of bay-region diol-epoxides of polycyclic aromatic hydrocarbons by tannic acid, hydroxylated anthraquinones and hydroxylated cinnamic acid derivatives; Huang MT et al.; Tannic acid and several hydroxylated anthraquinone and cinnamic acid derivatives inhibited the mutagenic activity of (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo {a}pyrene (B{a}P 7,8-diol-9,10-epoxide-2), an ultimate mutagenic and carcinogenic metabolite of benzo {a}pyrene . The mutagenic activity of 0.05 nmol of B{a}P 7,8-diol-9,10-epoxide-2 towards strain TA 100 of Salmonella typhimurium was inhibited 50% by incubation of the bacteria and the diol-epoxide with tannic acid (0.5 nmol), anthraflavic acid (7 nmol), rufigallol (7 nmol), quinalizarin (10 nmol), alizarin (30 nmol), purpurin (60 nmol), and danthron (88 nmol) . Dose-dependent, but weaker antimutagenic activity was observed for quinizarin, and a number of hydroxylated cinamic acid derivatives . Gallic acid and m-digallic acid, major components of tannic acid, possessed less than 1% of the anti-mutagenic activity of tannic acid, although m-digallic acid was over 3 times more active than gallic acid . The anti-mutagenic activity of tannic acid was a result of its interaction with B{a}P 7,8-diol-9,10-epoxide-2 since the rate of disappearance of the diol-epoxide from cell-free solutions in 1:9dioxane:water was markedly stimulated by the polyphenol . Tannic acid was a highly potent inhibitor of the mutagenic activity of the bay-region diol-epoxides of benzo{a}pyrene, dibenzo{a,h}pyrene and dibenzo{a,i}pyrene, but higher concentrations of tannic acid were needed to inhibit the mutagenicity of the chemically less reactive benzo{a}-pyrene 4,5-oxide and the bay-region diol-epoxides of benz{a}-anthracene, chrysene and benz{c}phenanthrene.

J Bacteriol, 1985 Feb, 161(2), 673 - 80
Oxygen regulation in Salmonella typhimurium; Strauch KL et al.; Regulation by oxygen of the peptidase T (pepT) locus of Salmonella typhimurium was studied by measuring beta-galactosidase levels in strains containing a pepT::Mu d1(Apr lac) operon fusion . beta-Galactosidase was induced in anaerobic cultures and late-exponential and stationary-phase aerated cultures . Peptidase T activity also was induced under these growth conditions . pepT+ but not pepT strains will utilize as amino acid sources the tripeptides Leu-Leu-Leu and Leu-Gly-Gly only when grown anaerobically . Mutations at two loci, oxrA and oxrB (oxygen regulation) prevent induction of the pepT locus . The oxrA locus is homologous to the fnr locus of Escherichia coli . We have isolated 12 independent Mu d1 insertions (oxd::Mu d1, oxygen dependent) that show induction of beta-galactosidase in anaerobic cultures and stationary-phase aerated cultures . These insertions fall into nine classes based on map location . All of the oxd::Mu d1 insertions are regulated by oxrA and oxrB and therefore define a global regulon that responds to oxygen limitation.

Chem Biol Interact, 1985 Feb-Apr, 53(1-2), 145 - 53
Structure-mutagenicity relationships of 5-nitro-2-furylethylenes in Salmonella typhimurium TA98; Sturdik E et al.; Mutagenicity of three selected series of 2-furylethylene was determined by the Ames test . These included: nine alkylesters and eleven N-alkylamides of 5-nitro-2-furylacrylic acid (NFAA) and ten derivatives differing not only at exocyclic double bond, but also in the position 5 of the furan ring . Mutagenicity of the derivatives depends on the presence of the 5-nitro-furan centre in the molecule; side chains in the position 2 modify the degree of mutagenicity . Among the derivatives of NFAA tested as changing the substituents virtually does not affect chemical properties of the 5-nitrofuran ring . Mutagenicity of the n-alkyl congeners decreases linearly with increasing lipophilicity . Mutagenicity of the derivatives with branched alkyl substituents is lower than expected from the behaviour of the n-alkyl homologues.

Ecotoxicol Environ Saf, 1985 Feb, 9(1), 92 - 100
A comparison of the mutagenicity of soluble trivalent chromium compounds with that of potassium chromate; Langerwerf JS et al.; The mutagenic potential of water soluble complexes of trivalent chromium with five different amino acids in Salmonella typhimurium strains TA92, TA94, TA98, and TA100 was studied . All complexes were nonmutagenic at concentrations up to 50 mumol/plate in the strains used . In contrast, trivalent chromium chloride was slightly mutagenic in TA98 and a considerable increase in numbers of revertants was observed in TA94 . Hexavalent chromium was nonmutagenic in TA98 . Strong mutagenic effects were found in TA92, TA94, and TA100 . The large difference in mutagenicity between trivalent and hexavalent chromium is discussed with respect to affinity to extracellular phosphate, diffusability through membranes and reactivity with DNA . More definitive statements about the toxicological risks of the water soluble chromium complexes requires additional studies with well defined compounds in test systems specially suited to study metal complexes.

Acta Pathol Microbiol Immunol Scand {B}, 1985 Feb, 93(1), 67 - 72
Invasiveness of Salmonella typhimurium in HEp-2 cell cultures pre-infected with Mycoplasma hominis and Mycoplasma orale; Bukholm G et al.; The influence of mycoplasma infection on the in vitro invasiveness of S . typhimurium in HEp-2 cell cultures has been tested . Two strains of arginine-utilizing mycoplasma species Mycoplasma hominis and M . orale both seemed to inhibit the bacterial in vitro invasiveness . Both the ratio of infected cells and the number of intracellular bacteria per cell were reduced in the mycoplasma-infected cultures.

Eur J Biochem, 1985 Feb 1, 146(3), 597 - 603
Cloning and characterization of the pyrE gene and of PyrE::Mud1 (Ap lac) fusions from Salmonella typhimurium; Neuhard J et al.; A lambda-specialized transducing phage carrying the pyrE gene from Salmonella typhimurium LT2 was constructed and used as the source of DNA for subcloning the pyrE gene into pBR322 . The pyrE gene product was identified as a 23-kDa polypeptide using a minicell system for analysis of plasmid-encoded proteins . Studies utilizing a promoter-cloning vehicle provided evidence for the existence of two promoter regions, one located close to the start of the structural gene and the other positioned more than 300 base pairs upstream . Transcription from the more distal promotor was the only situation in which significant regulation by pyrimidines was observed . Additional studies served to localize sites involved in the regulation of pyrE expression and led to the inference that regulation does not occur at the level of initiation of transcription . A procedure was developed for the construction of plasmids through recombination in vivo, whereby pyrE::Mud1 (Ap lac) fusions were transferred to a recipient pyrE+ plasmid by bacteriophage P22-mediated transduction . This enabled the identification of the integration sites of Mud within pyrE and also verified the deduced orientation of the pyrE gene in the parental plasmid . The nucleotide sequence of the 5' end of the pyrE gene was determined, including 150 nucleotide residues encoding the first 50 N-terminal amino acids of orotate phosphoribosyltransferase, and 400 nucleotides upstream from the start of the coding region . The leader region contains sequences characteristic of a rho-independent transcriptional terminator preceded by a cluster of thymidylate residues . In addition, the leader RNA contains an open reading frame with a UGA stop codon immediately preceding the putative transcriptional terminator . The nucleotide sequence suggests that pyrE expression is regulated by modulated attenuation, as has been proposed to be the case for both pyrB and pyrE expression in Escherichia coli.

Cancer Lett, 1985 Feb, 26(1), 113 - 9
Mutagenicity of flour from the palmyrah palm (Borassus flabellifer) in Salmonella typhimurium and Escherichia coli; Andersen PH et al.; Flour from the young shoots of the palmyrah palm (Borassus flabellifer) was tested in Salmonella typhimurium, strains TA98 and TA100 (Ames test) and Escherichia coli, strains WP2, WP2uvrA, CM881 and CM891 . The flour was tested in two forms: boiled and raw . Both forms showed dose related mutagenic responses in the basepair substitution sensitive strains TA100 and Escherichia coli WP2uvrA, CM881 and CM891 . The flour from boiled palmyrah shoots exerted a somewhat stronger mutagenic effect on TA100 than flour from the raw shoots . This investigation adds mutagenicity to the wide range of biological effects of palmyrah flour already described (induction of malignant lymphomas, immunosuppression, neurotoxicity and clastogenicity).

Ann Intern Med, 1985 Feb, 102(2), 189 - 93
Recurrent Salmonella typhimurium bacteremia associated with the acquired immunodeficiency syndrome; Glaser JB et al.; Seven Haitian and one white patient with the acquired immunodeficiency syndrome and Salmonella typhimurium bacteremia were identified over a 28-month period . In three patients bacteremia developed concurrently with an opportunistic infection associated with the acquired immunodeficiency syndrome . The remaining five patients had their initial episodes of bacteremia 3 to 11 months before the diagnosis of the acquired immunodeficiency syndrome . These five patients had signs suggestive of the syndrome, plus evidence of disordered cellular immune function (lymphopenia, anergy, decreased T-helper cells, decreased proliferative responses, and a deficiency in mononuclear-cell alpha interferon production) . Salmonella typhimurium bacteremia in the appropriate clinical setting may be an opportunistic pathogen associated with the acquired immunodeficiency syndrome.

Arch Ophthalmol, 1985 Feb, 103(2), 257 - 60
Lipopolysaccharide tolerance inhibits eye inflammation . I . Reduced immune complex or lipopolysaccharide effects; Howes EL Jr et al.; The effect of endotoxin tolerance on ocular inflammation was studied in rabbits . A single intravenous (IV) injection of endotoxin (bacterial lipopolysaccharide {LPS}) produced a mild acute iridocyclitis . Repeated daily (five to seven days) IV injections of LPS (5 micrograms extracted from Salmonella typhimurium) led to a state of refractoriness or LPS "tolerance," and ocular inflammation was no longer produced . In contrast to controls, in rabbits tolerant to LPS, IV LPS failed to elevate prostaglandin E2, thromboxane B2, or chemotactic factors in the aqueous humor . Rabbits tolerant to LPS also resisted the increase in vascular permeability normally induced by an ocular reversed passive Arthus reaction . These results demonstrated that LPS tolerance can induce anti-inflammatory effects in the eye.

Anal Biochem, 1985 Feb 1, 144(2), 390 - 402
Quantitation of chemically induced DNA strand breaks in human cells via an alkaline unwinding assay; Daniel FB et al.; DNA strand breaks induced in human CCRF-CEM cells by electrophilic chemicals (carcinogens/mutagens) can be readily quantitated via a facile alkaline unwinding assay . This procedure estimates the number of chemically induced DNA strand breaks on the basis of the percentage DNA converted from double-stranded to single-stranded form during an exposure to the alkaline unwinding conditions . The assay is based on the assumption that each strand break serves as a strand unwinding point during the alkaline denaturation . The extent of strand separation can be standardized with respect to the initial level of induced strand breaks by the use of X-rays, which produce known levels of DNA strand breaks per rad in mammalian cells . Subsequent to the alkaline exposure, the single- and double-stranded DNA were separated by use of thermostated hydroxylapatite columns (60 degrees C), and the DNA was quantitated via a fluorescence assay (Hoechst 33258 compound) . A correlation was shown between mammalian DNA strand-breaking potential (as measured in this procedure) and the propensity of these chemicals to revert Salmonella typhimurium TA100.

Acta Pathol Microbiol Immunol Scand {B}, 1985 Feb, 93(1), 61 - 5
Invasiveness of Salmonella typhimurium in HEp-2 cell cultures pretreated with UV-inactivated coxsackie virus; Bukholm G et al.; The invasiveness of Salmonella typhimurium was significantly enhanced in cell cultures pretreated with UV-inactivated virus . During the first 3 hours of virus infection there was no difference between the enhancement achieved with non-inactivated and that achieved with UV-inactivated virus . After 4 and 5 hours pretreatment the effect of non-inactivated virus was more pronounced than that of UV-inactivated virus . The results indicate that during the early period of virus infection the enhancement of bacterial invasiveness by pretreatment with virus is the result of a direct interaction between the virus and the cell membrane . During the later phase of viral reproduction, viral RNA induced alteration of the cell metabolism, and these altered products might be involved in the interaction.

J Bacteriol, 1985 Feb, 161(2), 813 - 6
Salmonella typhimurium contains an anion-selective outer membrane porin induced by phosphate starvation; Bauer K et al.; A mutant of Salmonella typhimurium was selected that is constitutive for the pho regulon . It exhibited constitutive glycerol-3-phosphate transport activity and synthesized a new outer membrane porin . Upon measurement of porin activity in black lipid films, it exhibited anion selectivity . It therefore appears analogous to the Escherichia coli PhoE porin.

J Bacteriol, 1985 Feb, 161(2), 641 - 9
Regulation of a cya-lac fusion by cyclic AMP in Salmonella typhimurium; Jovanovich SB; cya-lac and crp-lac operon fusions were isolated in Salmonella typhimurium by using the phage Mu d1(lac cts Apr) . Both transduction and reversion analyses have indicated that lac expression is controlled by the appropriate promoter, e.g., either crpp or cyap . By using chromosomal mobilization techniques, we found that cya had a clockwise direction of transcription on the standard S . typhimurium map . The cya-lac fusions could be complemented by Escherichia coli F'133, which covers cya, with a resultant 17 to 38% decrease in cya expression . Cyclic AMP was found to be able to repress the expression of the cya-lac fusion ninefold when present at 25 mM . This repression was not seen in crp backgrounds, and hence is mediated by the cAMP receptor protein . Repression of cya was also found upon growth on carbon sources known to elicit high cyclic AMP levels.

J Bacteriol, 1985 Feb, 161(2), 484 - 92
Genetic analysis of Escherichia coli oligopeptide transport mutants; Andrews JC et al.; The composition of the outer membrane channels formed by the OmpF and OmpC porins is important in peptide permeation, and elimination of these proteins from the Escherichia coli outer membrane results in a cell in which the primary means for peptide permeation through this cell structure has been lost . E . coli peptide transport mutants which harbor defects in genes other than the ompF/ompC genes have been isolated on the basis of their resistance to toxic tripeptides . The genetic defects carried by these oligopeptide permease-negative (Opp-) strains were found to map in two distinct chromosomal locations . One opp locus was trp linked and mapped to the interval between att phi 80 and galU . Complementation studies with F'123 opp derivatives indicated that this peptide transport locus resembles that characterized in Salmonella typhimurium as a tetracistronic operon (B . G . Hogarth and C . F . Higgins, J . Bacteriol . 153:1548-1551, 1983) . The second opp locus, which we have designated oppE, was mapped to the interval between dnaC and hsd at 98.5 min on the E . coli chromosome . The differences in peptide utilization, sensitivity and resistance to toxic peptides, and the L-{U-14C}alanyl-L-alanyl-L-alanine transport properties observed with these Opp-E . coli strains demonstrated that the transport systems encoded by the trp-linked opp genes and by the oppE gene(s) have different substrate preferences . Mutants harboring defects in both peptide transport loci defined in this study would not grow on nutritional peptides except for tri-L-methionine, were totally resistant to toxic peptides, and would not actively transport L-{U-14C}alanyl-L-alanyl-L-alanine.

EMBO J, 1985 Feb, 4(2), 539 - 47
Nitrogen regulation in Salmonella typhimurium . Identification of an ntrC protein-binding site and definition of a consensus binding sequence; Ferro-Luzzi Ames G et al.; We have investigated the DNA-binding ability of a nitrogen regulatory protein, the product of the ntrC gene, to several nitrogen-regulated promoters in Salmonella typhimurium . The ntrC protein is able to bind to the regulatory region (dhuA) of an operon coding for genes involved in the active transport of histidine, but not to another transport-related regulatory region, argTr . It bound to two different sites within the regulatory region of glnA (glutamine synthetase) and to one site in the regulatory region for the ntrBC operon . A consensus sequence has been derived from these four binding sites . The binding sequence displays dyad symmetry, as expected for the dimeric ntrC protein . The relationship of the binding sites to regulation of transcription initiation and termination, and to published homologies within the sequences of regulatory sites for nif genes is discussed.

Infect Immun, 1985 Feb, 47(2), 434 - 40
Cloning and characterization of genes involved in production of mannose-resistant, neuraminidase-susceptible (X) fimbriae from a uropathogenic O6:K15:H31 Escherichia coli strain; Hacker J et al.; The uropathogenic Escherichia coli strain 536 (O6:K15:H31) exhibits a mannose-resistant hemagglutination phenotype (Mrh) with bovine erythrocytes and delayed Mrh with human and guinea pig erythrocytes . Neuraminidase treatment of the erythrocytes abolishes mannose resistant hemagglutination, which is typical for X fimbriae . E . coli strain 536 synthesizes two different fimbriae (Fim phenotype) protein subunits, 16.5 and 22 kilodaltons in size . In addition the strain shows mannose-sensitive hemagglutination and common type I (F1) fimbriae . The cosmid clone E . coli K-12(pANN801) and another nine independently isolated Mrh+ cosmid clones derived from a cosmid gene bank of strain 536 express the 16.5-kilodalton protein band, but not the 22-kilodalton protein, indicating an association of the Mrh+ property with the "16.5-kilodalton fimbriae." All cosmid clones were fimbriated, and they reacted with antiserum produced against Mrh+ fimbriae of the E . coli strain HB101(pANN801) and lacked mannose-sensitive hemagglutination (F1) fimbriae . From the Mrh fim cosmid DNA pANN801, several subclones coding for hemagglutination and X fimbriae were constructed . Subclones that express both hemagglutination and fimbriae and subclones that only code for the hemagglutination antigen were isolated; subclones that only produce fimbriae were not detected . By transposon Tn5 mutagenesis we demonstrated that about 6.5 kilobases of DNA is required for the Mrh+ Fim+ phenotype, and the 1.5- to 2-kilobase DNA region coding for the structural protein of the fimbriae has been mapped adjacent to the region responsible for the Mrh+ phenotype . Two different regions can thus be distinguished in the adhesion determinant, one coding for hemagglutination and the other coding for fimbria formation . Transformation of plasmid DNA from these subclones into a Mrh- Fim- mutant of E . coli 536 and into a galE (rough) strain of Salmonella typhimurium yielded transformants that expressed both hemagglutination and fimbria production.

Zh Mikrobiol Epidemiol Immunobiol, 1985 Feb, (2), 34 - 8
{Mapping of the genetic determinant controlling Salmonella K-antigen synthesis . II . Nonmotile mutants of Salmonella typhimurium}; Romanova IuM et al.; According to the preliminary data, S . typhimurium K-antigen is located in the area of minutes 40-44 on the Salmonella chromosome map . The formation of nonmotile mutants from motile Salmonella strains was induced by the action of nitrosoguanidine . Two main groups of mutants differing in their reaction of agglutination with H- and K-antisera were obtained: Mot-H-K- (motA or motB mutants) and Mot-H-K- (H1- or fla- mutants) . The transduction transfer of the sign of motility by phage P22HT to H-K- mutants and to H1- and flaE- mutants led to the restoration of agglutination ability with respect to H- and K-antisera in all Mot+ transductants under study simultaneously . The restoration of H+K+ phenotype was also observed in spontaneous motile revertants obtained from H-K- mutants . Thus, the gene controlling the synthesis of K-antigen in Salmonellae was shown to be incorporated into the Fla operon, the regulatory system of the operon controlling the expression of this gene.

J Gen Microbiol, 1985 Feb, 131 ( Pt 2), 245 - 52
Characterization of a Salmonella typhimurium mutant defective in phosphoribosylpyrophosphate synthetase; Jochimsen BU et al.; This study describes the isolation and characterization of a mutant (strain GP122) of Salmonella typhimurium with a partial deficiency of phosphoribosylpyrophosphate (PRPP) synthetase activity . This strain was isolated in a purE deoD gpt purin auxotroph by a procedure designed to select guanosine-utilizing mutants . Strain GP122 had roughly 15% of the PRPP synthetase activity and 25% of the PRPP pool of its parent strain . The mutant exhibited many of the predicted consequences of a decreased PRPP pool and a defective PRPP synthetase enzyme, including: poor growth on purine bases; decreased accumulation of 5-aminoimidazole ribonucleotide (the substrate of the blocked purE reaction) under conditions of purine starvation; excretion of anthranilic acid when grown in medium lacking tryptophan; increased resistance to inhibition by 5-fluorouracil; derepressed levels of aspartate transcarbamylase and orotate phosphoribosyltransferase, enzymes involved in the pyrimidine de novo biosynthetic pathway; growth stimulation by PRPP-sparing compounds (e.g . guanosine, histidine); poor growth in low phosphate medium; and increased heat lability of the defective enzyme . This mutant strain also had increased levels of guanosine 5'-monophosphate reductase . This genetic lesion, designated prs, was mapped by conjugation and phage P22-mediated transduction at 35 units on the Salmonella linkage map.

Biochemistry, 1985 Jan 29, 24(3), 701 - 7
Accessibility to bacterial nucleic acids of the intercalating drug aliphatic amino acid ellipticinium derivatives in Escherichia coli and Salmonella typhimurium; Banoun H et al.; The fluorescence of the aliphatic (amino acido)-N2-methyl-9-hydroxyellipticinium (AA-NMHE) derivatives {Auclair, C., Voisin, E., Banoun, H., Bernardou, J., Meunier, B., & Paoletti, C . (1984) J . Med . Chem . 27, 1161-1166}, namely, dehydroglycino-NMHE, dehydroalanino-NMHE, dehydrovalino-NMHE, and dehydroleucino-NMHE, has been characterized . The changes in the fluorescence properties of the drugs, including increase in quantum yields, increase in fluorescence lifetimes, and occurrence of energy transfer upon binding to DNA in vitro, have been further investigated . The measurement of the fluorescence increment of AA-NMHE when bound to fluorescent sites inside intact bacteria has been found to be suitable for the determination of the accessibility of the drugs to bacterial nucleic acids according to the method of Lambert and Le Pecq {Lambert, B., & Le Pecq, J.B . (1984) Biochemistry 23, 166-176} . With this methodology, the kinetics of drug uptake, the ability of the drug to reach the bacterial nucleic acids at equilibrium, and the nature of the ligand binding model have been determined in two AA-NMHE-sensitive strains, Escherichia coli BL 101 (Lambert & Le Pecq, 1984) and Salmonella typhimurium TA 98 {Ames, B.N., Lee, F.D., & Durston, W.E . (1973) Proc . Natl . Acad . Sci . U.S.A . 70, 782-786} . The main results obtained are the following: At nonsaturating concentrations, each AA-NMHE exhibits a marked difference in its ability to reach the bacterial nucleic acids . This parameter seems to be correlated with the antibacterial efficiency of the drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

J Cancer Res Clin Oncol, 1985, 109(3), 203 - 7
Experimental studies on mutagenic and carcinogenic effects of tobacco chewing; Shah AS et al.; The alcoholic extract of the chewing (Pandharpuri) variety of tobacco (Nicotiana tabacum) was subjected to mutagenicity and tumorigenicity studies . The extract was found to be mutagenic in strain TA 98 of Salmonella typhimurium in the presence of S 9 mixture . It also induced 8 AZG-resistant mutation in V 79 Chinese hamster cells . Administration of tobacco extract to male Swiss mice by gavage or mixed with diet resulted in an increased incidence of lung/liver tumors . Further, an additive effect of tobacco extract and hexachlorocyclohexane on liver tumor induction was observed.

Gene, 1985, 34(2-3), 137 - 45
High-level expression of M13 gene II protein from an inducible polycistronic messenger RNA; Johnston S et al.; Bacteriophage M13 gene II has been cloned in the plasmid expression vector pING1 and thereby placed under the control of the inducible araB promoter of Salmonella typhimurium . Upon induction with arabinose, gene II is transcribed as part of a polycistronic messenger RNA which initiates at the araB promoter . Subsequent translation of this message results in the coordinate, high-level expression of several proteins, including the gene II protein . Using this expression system, we have been able to overproduce gene II protein to a level of almost 15% of the total protein in Escherichia coli cells, thus providing an abundant source for its purification.

Environ Mutagen, 1985, 7(2), 213 - 32
Mutagenicity testing of di(2-ethylhexyl)phthalate and related chemicals in Salmonella; Zeiger E et al.; Di(2-ethylhexyl)phthalate and 33 other phthalates, ethylhexanol derivatives, and related chemicals were tested for mutagenicity in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 without metabolic activation and in the presence of rat and hamster liver S-9 metabolic activation systems . No mutagenic activity was seen with any of the chemicals tested.

Bioelectromagnetics, 1985, 6(4), 405 - 14
Biological effects of high-frequency electromagnetic fields on Salmonella typhimurium and Drosophila melanogaster; Hamnerius Y et al.; Salmonella typhimurium and Drosophila melanogaster were exposed to continuous wave (CW) 2.45-GHz electromagnetic radiation, pulsed 3.10-GHz electromagnetic radiation, CW 27.12-MHz magnetic fields, or CW 27.12-MHz electric fields (only Drosophila) . The temperatures of the treated sample and the nonexposed control sample were kept constant . The temperature difference between exposed and control samples was less than +/- 0.3 degrees C . Ames' assays were made on bacteria that had been exposed to microwaves (SAR 60-130 W/kg) or RF fields (SAR up to 20 W/kg) when growing exponentially in nutrient broth . Survival and number of induced revertants to histidine prototrophy were determined by common plating techniques on rich and minimal agar plates . The Drosophila test consisted of a sensitive somatic system where the mutagenicity was measured by means of mutations in a gene-controlling eye pigmentation . In none of these test systems did microwave or radiofrequency fields induce an elevated mutation frequency . However, a significantly higher concentration of cells was found in the bacterial cultures exposed to the 27-MHz magnetic field or 2.45-GHz CW and 3.10-GHz pulsed microwave radiation.

Microbiol Immunol, 1985, 29(7), 659 - 69
Sequential production of alpha and beta interferons and gamma interferon in the circulation of Listeria monocytogenes-infected mice after stimulation with bacterial lipopolysaccharide; Nakane A et al.; Sequential production of interferon (IFN)-alpha/beta and IFN-gamma in the circulation of mice which had been previously infected with viable Listeria monocytogenes was induced by injection of lipopolysaccharide (LPS) derived from Salmonella typhimurium . IFN-alpha/beta production occurred 2 hr after injection of LPS, thereafter IFN-gamma appeared and the maximum titer was demonstrated at 6 hr . At that time, almost all of the IFN was IFN-gamma . IFN-gamma production in response to LPS was observed from the 5th through the 11th day after infection with Listeria, but it was not demonstrated in either mice infected with lower doses of viable Listeria or mice immunized with heat-killed bacteria . IFN-alpha/beta production was not drastically affected by treatment with hydrocortisone, cyclophosphamide, carrageenan, antithymocyte serum, or anti-asialo GM1 antibody, whereas IFN-gamma production was suppressed by administration of all those agents . Noteworthily, IFN-alpha/beta, but not IFN-gamma, was produced even 6 hr after stimulation with LPS in cyclophosphamide- or antithymocyte serum-treated mice . IFN-gamma induction by LPS was markedly suppressed in mice in which IFN-alpha/beta produced by Listeria infection itself had been depleted by treatment with anti-mouse IFN-alpha/beta antibody, but it was not inhibited in mice when IFN-alpha/beta induced not by Listeria infection but by LPS had been depleted by treatment with anti-mouse IFN-alpha/beta antibody.

Arch Immunol Ther Exp (Warsz), 1985, 33(4), 515 - 21
Nonopsonic phagocytosis and intracellular killing of Salmonella typhimurium by peritoneal macrophages of mice immunized with slime-extract from Pseudomonas aeruginosa; Maresz-Babczyszyn J et al.; Treatment of mice with slime-extract (SE) from Pseudomonas aeruginosa strain 219 failed to increase the proportion of ingested cells of Salmonella typhimurium by immune macrophages (M phi) of mice . However, activated with SE peritoneal SE peritoneal M phi displayed the enhancement of their nonspecific bactericidal activity . It has been found that immune M phi, depending on the dose of SE used for vaccination, killed intracellularly 38 to 67% of bacterial cells, whereas the mean value for the bactericidal capacity of normal resident phagocytes was 7% . The dose of 100 micrograms of SE enhanced activation of M phi to higher degree than 200 or 400 micrograms . The increase of microbicidal properties of M phi was also seen when mice were pretreated with 50 or 100 micrograms of SE and 24 h later were injected with live S . typhimurium cells . However, the amount of 200 or 400 micrograms significantly reduced the killing activity of M phi against these bacteria.

Folia Microbiol (Praha), 1985, 30(3), 231 - 6
Phenol-water extracts of gram-positive Listeria monocytogenes and gram-negative Salmonella typhimurium . Comparison of biological activities; Hofman J et al.; Using phenol--water extraction, a lipopeptidopolysaccharide complex (LPPS) was isolated from Listeria monocytogenes . Some biological and immunological properties of LPPS were compared with lipopolysaccharide isolated by the same procedure from Salmonella typhimurium . LPPS possesses low pyrogenicity, but the immunological activity is comparable with LPS: slightly lower adjuvant and polyclonal stimulating effect, almost equal mitogenic effect on mouse spleen cells and higher mitogenic effect on human peripheral blood cells . The results are discussed in connection with the chemical structure of both substances.

Vox Sang, 1985, 48(5), 276 - 83
Properties of human anti-lipopolysaccharide gamma globulin: specificity and protective effects; Gaffin SL et al.; Blood donated to the Natal Blood Transfusion Service was screened by an enzyme-linked immunosorbent assay (ELISA) for anti-lipopolysaccharide (anti-LPS) antibodies . Plasma units with high concentrations (greater than 40 micrograms/ml) of anti-LPS IgG were pooled and fractionated to obtain a gamma globulin (lot LG-1) . The binding of LG-1 antibodies to LPS prepared from 14 bacterial species and strains was found to be the highest to LPS from Shigella flexneri, Salmonella abortus equi and Salmonella typhimurium and intermediate with Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enteritidis and Escherichia coli 026:B6 . Differential absorption experiments showed that LG-1 contained a mixture of specific and cross-reacting antibodies . A large proportion of antibodies binding to Sh . flexneri LPS were mainly specific, while those binding to S . typhimurium and the other Salmonella species tested were largely cross-reactive . There was little correlation between the spectrum of activity of the LG-1 antibodies and the incidence of gram-negative bacteria in blood cultures taken from hospital patients in an area covered by the Transfusion Service . Mice treated with LG-1 prior to inoculation with P . aeruginosa were significantly protected against morbidity and mortality compared to controls.

J Interferon Res, 1985 Winter, 5(1), 45 - 53
Effect of human gamma interferon on invasiveness of Salmonella typhimurium in HEp-2 cell cultures; Bukholm G et al.; The effect of human gamma interferon (HuIFN-gamma) on the invasiveness of Salmonella typhimurium, Shigella flexneri and Yersinia enterocolitica serotype 0:3 in HEp-2 cell cultures was examined . The intracellular and extracellular bacteria were identified by a combination of Nomarski differential interference contrast microscopy and UV incident light microscopy applied on the same microscope . Pretreatment of HEp-2 cells with HuIFN-gamma reduced in a dose dependent manner the number of S . typhimurium bacteria per cell and the proportion of cells containing bacteria . Maximum inhibitory effect was observed with approximately 10 units per ml of HuIFN-gamma . The inhibitory effect of interferon as well as the antiviral effect was eliminated when the preparation was neutralized with monoclonal anti-interferon globulin and was acidified to pH 2 . Murine gamma interferon did not influence invasiveness of S . typhimurium . No effect of interferon was observed when the bacteria were incubated in cell cultures at 4 degrees C . Invasiveness of S . flexneri and Y . enterocolitica was not influenced by treatment of cells with HuIFN.

Jpn J Cancer Res, 1985 Jan, 76(1), 28 - 36
In vitro metabolism of N-nitrodialkylamines; Suzuki E et al.; The in vitro metabolism of N-nitramines was investigated in order to compare it with that of N-nitrosamines and to elucidate the mode of mutagenic action . N-Nitrodibutylamine (NO2DBA) and N-nitrodiethylamine (NO2DEA) were incubated with liver microsomes and hepatocytes prepared from rats treated with phenobarbital, and the products were analyzed by high-performance liquid chromatography and gas-liquid chromatography . The in vitro metabolic pattern of these nitramines was similar to that of the corresponding nitrosamines, except that N-nitro-N-alkylamines (produced via alpha-hydroxylation) were identified after incubation of the nitrodialkylamines . In the case of NO2DBA, besides N-nitro-N-butylamine, several nitramines produced by omega, omega-1, and omega-2 oxidations were identified as metabolites . NO2DBA and NO2DEA were mutagenic to Escherichia coli WP2 hcr- but not to Salmonella typhimurium TA1535 . They were mutagenic only in the presence of hepatic microsomes, whereas their metabolites, N-nitro-N-butylamine and N-nitro-N-ethylamine, were direct mutagens . Thus, N-nitrodialkylamines are also metabolically activated to mutagens through alpha-hydroxylation.

Mutat Res, 1985 Jan-Feb, 155(1-2), 41 - 7
Mutagenicity of methyl bromide in a series of short-term tests; Kramers PG et al.; Methyl bromide is commonly used as a soil fumigant in greenhouses . In the framework of a toxicological evaluation, it was tested for possible genotoxic properties in two bacterial test systems (the fluctuation test using Klebsiella pneumoniae and the plate test using Salmonella typhimurium TA100 and TA98), two systems using mammalian cells in vitro (forward mutations at the TK and HPRT loci in L5178Y mouse lymphoma cells and unscheduled DNA synthesis in primary rat-liver cells) and in the sex-linked recessive lethal test using Drosophila melanogaster . Methyl bromide was active in all tests except the DNA-repair assay . The results indicate a relatively low mutagenic efficiency of the compound, as expected from its alkylating properties.

Mutat Res, 1985 Jan-Feb, 148(1-2), 13 - 23
Factors affecting the mutagenic activity of quercetin for Salmonella typhimurium TA98: metal ions, antioxidants and pH; Hatcher JF et al.; The mutagenic activity of quercetin for Salmonella typhimurium TA98 was inhibited by addition of metal salts . MnCl2 was a potent inhibitor, followed by CuCl2, FeSO4, and FeCl3, the probable mechanism being facilitated catalytic oxidation of quercetin . With quercetin incorporated at a level of 100 nmoles/plate, approximate doses (nmoles/plate) to give 50% inhibition of mutagenic activity were: MnCl2 less than 10 (-S9), 18 (+S9); CuCl2 65 (-S9), greater than 100 (+S9); FeSO4 190 (-S9), greater than 300 (+S9); or FeCl3 275 (-S9), greater than 300 (+S9) . Ascorbate, superoxide dismutase, and, to a lesser extent, NADH and NADPH, all enhanced the mutagenic activity of quercetin in the absence of the mammalian-microsome (S9) system, but had no significant effect in the presence of the S9 mix . The maximum enhancement of activity by ascorbate or superoxide dismutase was approximately 87% of the increase achieved by addition of the S9 mix . Tyrosinase (catechol oxidase) substantially reduced the mutagenic activity of quercetin in the absence of the S9 mix . At lower levels of tyrosinase, activity was restored by incorporation of the S9 mix . It is proposed that the S9 mix enhances the mutagenic activity of quercetin by scavenging superoxide radicals, thus inhibiting the autoxidation of quercetin, and possibly by reducing quinone oxidation products of quercetin . The mutagenic activity of quercetin increased substantially when the pH of the media was decreased . This may be due in part to a decrease in ionization of quercetin at lower pH, thereby increasing its absorption by the tester strain, to a decrease in the rate of autoxidation of quercetin at lower pH, or to a combination of these.

J Bacteriol, 1985 Jan, 161(1), 435 - 7
Fermentation mechanism of fucose and rhamnose in Salmonella typhimurium and Klebsiella pneumoniae; Badia J et al.; An equimolar amount of 1,2-propanediol was detected in the medium when Salmonella typhimurium or Klebsiella pneumoniae fermented L-fucose or L-rhamnose . These metabolic conditions induced a propanediol oxidoreductase that converted the lactaldehyde formed in the dissimilation of either sugar into the diol . The enzyme was further identified by cross-reaction with antibodies against Escherichia coli propanediol oxidoreductase . This indicates that L-fucose and L-rhamnose fermentation takes place in these species by 1,2-propanediol production and excretion.

Princess Takamatsu Symp, 1985, 16, 77 - 86
Nitrosatable precursors of mutagens in vegetables and soy sauce; Nagao M et al.; Nitrosatable precursors of mutagens that show mutagenicity to Salmonella typhimurium TA100 without S9 mix after treatment with nitrite at pH 3 were found in various foods . From Chinese cabbage, three indole compounds, indole-3-acetonitrile, 4-methoxyindole-3-acetonitrile, and 4-methoxyindole-3-aldehyde, were identified as mutagen precursors . 1-Methylindole and 2-methylindole, which are present in cigarette smoke showed strong mutagen precursor activity . Escherichia coli WP2 uvrA/pKM101 is more sensitive than S . typhimurium TA100 to nitrosatable precursors in soy sauce after treatment with 1-3 mM nitrite . The mutagenicity of soy sauce towards E . coli WP2 uvrA/pKM101 is partly explained by 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) and tyramine reported previously . Oral administration of soy sauce and nitrite to male Fischer 344 rats for 2 years induced basal cell proliferation of the forestomach and intestinal metaplasia of the glandular stomach, but did not induce cancers in any organ . 3-Diazotyramine, a mutagenic nitrosation product of tyramine that is present at high concentrations in various foods induced squamous cell carcinomas of the oral cavity of rats when given in their drinking water . The carcinogenesis by N-benzylmethylamine, a nitrosatable precursor and nitrite was prevented by thioproline.

Acta Vitaminol Enzymol, 1985, 7 Suppl, 75 - 8
Effect of beta-carotene on mutagenic activity of some antineoplastics; Belisario A et al.; Mutagenic activity on Salmonella typhimurium strains of some cytostatic drugs in the absence and in the presence of beta-carotene was evaluated . Cyclophosphamide mutagenicity was reduced by the retinoid both in vitro and in vivo . Conversely, its metabolite 4'-hydroxy-cyclophosphamide, which does not require enzymatic transformation to exert genotoxic activity against bacteria, was not affected by the presence of beta-carotene . Moreover, the mutagenic activity of cis-Platinum, Adriamycin and 4'Epiadriamycin, which are typical direct-acting mutagens, was not affected by beta-carotene . Data obtained confirm that beta-carotene is able to prevent mutagenic activity of cyclophosphamide by interfering with its metabolic activation but failed to inhibit the interaction of genotoxic compounds with bacterial DNA.

J Basic Microbiol, 1985, 25(10), 663 - 7
{Bioassay for the detection of hydroxamate-iron-chelators (Aerobactin)}; Rabsch W et al.; Different Salmonella strains were tested for aerobactin production in a hydroxamate-bioassay with the aerobactin indicator strain E . coli LG 1522 . The majority of hospital strains of Salmonella typhimurium produce hydroxamate siderophore . On the other hand S . typhimurium strains belonging to phage type n . c . 1/72/n . c., biochemical type b from human and animal sources, were unable to produce this siderophore . Serotypes other than S . typhimurium for example the multiresistent S . wien hospital strains, which were isolated in western europe and in the GDR, can excreate hydroxamate siderophore . Plasmids pIE 528 and pIE 5 234 isolated from Salmonella hospital strains produce hydroxamate siderophore in the enterobactin negative Salmonella typhimurium-strain enb-7 . Thus, the hydroxamate bioassay may be a useful supplementary test for epidemiological strain characterization.

Nucleic Acids Symp Ser, 1985, (16), 5 - 8
Frameshift mutagenicity of dinitrobenzene derivatives on Salmonella typhimurium TA98 and Tm elevation of calf thymus DNA by dinitrobenzene derivatives; Furukawa H et al.; 1-Chloro-2,4-dinitrobenzene and m-dinitrobenzene were mutagenic on Salmonella typhimurium TA98 without S-9mix . But 1-substituted-2,4-dinitrobenzene derivatives which substituted by electron releasing groups such as OH-, NH2- or CH3- did not show mutagenicity on Salmonella typhimurium TA98 without S-9mix . Tm of calf thymus DNA was elevated by addition of m-dinitrobenzene or 1-chloro-2,4-dinitrobenzene, and falled by addition of 1-substituted-2,4-dinitrobenzenes which substituted by electron releasing substituents such as OH-, NH2- or CH3- groups . The mutagenic dinitrobenzene derivatives such as 1-chloro-2,4-dinitrobenzene showed the special changes in the difference spectra about four bases of the DNA and this compound.

J Toxicol Environ Health, 1985, 16(3-4), 355 - 77
Assay of phenacetin genotoxicity using in vitro and in vivo test systems; De Flora S et al.; Phenacetin was assayed in a battery of five short-term tests . (1) In a DNA-repair test using various Escherichia coli strains, the drug was not directly genotoxic nor did it induce nonreparable DNA damage in the presence of rat liver S9 fractions, while it was weakly active following activation with hamster liver S9 . (2) In the Ames reversion test (strains TA97, TA98, TA100, and TA102 of Salmonella typhimurium, phenacetin reverted only TA100, and only in the presence of hamster liver S9 . Mutagenicity was related to the concentration both of the drug and of the above metabolic system . There was no activation with hamster kidney S9, uninduced chicken liver S9, or with a variety of liver S9 preparations from rats treated with enzyme inducers (Aroclor 1254, phenobarbital, or 3-methylcholanthrene) and/or glutathione depletors (diethyl maleate or buthionine sulfoximine) . Hamster liver S9 compared favorably to rat and even more to chicken liver S9 fractions also in activating various promutagens {3-amino-1-methyl-SH-pyrido (4,3-b)-indole, 2-aminofluorene, aflatoxin B1, benzo{a}pyrene, and benzo{a}pyrene-trans-7,8-diol} and in decreasing the mutagenicity of direct-acting compounds (4-nitroquinoline N-oxide and sodium dichromate) . (3) Phenacetin was borderline positive in a forward mutation test (6-thioguanine resistance) in V79 cells, only in the presence of hamster liver S9, and gave negative results in the presence of rat liver S9 or without any metabolic system . (4) Following in vivo treatment, the alkaline elution assay did not reveal any DNA fragmentation in bone-marrow cells of ip-treated mice or in liver cells of rats treated by gavage . Apparent DNA damage was instead observed in the kidneys of rats receiving the drug by gavage or in the liver following ip administration . However, the effect was prevented (liver) or reduced (kidney) by preliminary perfusion of the organs, which discards (liver) or makes uncertain (kidney) the hypothesis of a true in vivo DNA damage . (5) Phenacetin ip induced in mouse bone-marrow cells a poor yet statistically significant increase in sister chromatid exchanges.

Circ Shock, 1985, 17(3), 213 - 22
Efficaciousness of immunoglobulin G prophylaxis on mortality and physiological variables in gram-negative peritonitis in rodents; Emerson TE Jr et al.; A rapidly expanding role involving the use of immunoglobulin preparations in conditions other than the classical immunodeficiency syndromes is evident in recent years . Treatment with immunoglobulin may be especially important during infection in which specific antibody to pathogens has been consumed, degraded, or not produced and in cases in which antibiotic treatment is ineffective . Recent studies in animals and humans support this concept, although further studies are needed to fully develop it . This study was completed to explore possible beneficial effects of prophylactic treatment of rodents during severe Salmonella typhimurium peritonitis with a newly developed native immunoglobulin G preparation for intravenous use (IGIV pH 4.25) . This study demonstrates that IGIV pH 4.25 increases survival time and decreases absolute mortality, prevents hypotension and acidosis, and ameliorates or prevents changes in variables indicative of organ damage during S . typhimurium bacteremia in the rat . Studies in mice indicate that protection is mediated by antibody to cell surface antigen (s) of S . typhimurium.

J Toxicol Environ Health, 1985, 16(1), 61 - 9
Mutagenicity evaluation of phthalic acid esters and metabolites in Salmonella typhimurium cultures; Agarwal DK et al.; The mutagenic potential of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEPH), as well as metabolites of DEHP--i.e., mono-2-ethylhexyl phthalate (MEHP), 2-ethylhexanol (2-EH), and phthalic acid (PA)--were tested in Salmonella typhimurium cultures using the Ames test procedure . The compounds were tested on strains TA98, TA100, TA1535, TA1537, TA1538, and TA2637 for base-pair substitution or frameshift-type mutations . Spot tests yielded negative responses for all compounds with the strains tested . Each compound was tested for a dose-effect relationship in the TA98, TA100, TA1535, and TA1538 systems . DEP and DBP exhibited a mildly positive response in both TA100 and TA1535 cultures, and DMP showed a similar response in TA1535 . Normalization of the data for cytotoxicity of DMP suggests TA100 has a mildly positive effect . The higher doses of these compounds exhibited some cytotoxic effects . The mutagenic effects were apparently abolished by the addition of S9 fraction in TA100 and TA1535 cultures, while no effect, other than cytotoxicity, was observed in the TA98 and TA1538 systems . DEHP, MEHP, 2-EH, and PA exhibited no mutagenicity in any of the strains of Salmonella typhimurium tested, with or without S9 metabolic activation . MEHP and 2-EH, however, exhibited a moderate cytotoxic effect in most cultures.

Environ Mutagen, 1985, 7 Suppl 5, 1 - 248
Reproducibility of microbial mutagenicity assays: II . Testing of carcinogens and noncarcinogens in Salmonella typhimurium and Escherichia coli; Dunkel VC et al.; A total of 63 chemicals were tested for mutagenicity in Salmonella typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538, and Escherichia coli WP2 uvrA in a four-laboratory study . Sixty of the chemicals had been tested for carcinogenicity by the National Cancer Institute or the National Toxicology Program . All chemicals were tested for mutagenicity without metabolic activation and with liver S-9 preparations from uninduced and Aroclor 1254-induced F344 rats, B6C3F1 mice, and Syrian hamsters . The intra- and interlaboratory reproducibility of the Salmonella assay with regard to the overall judgment of mutagenic or nonmutagenic was good . The results in the E coli strain, however, exhibited a high degree of variability between laboratories . With one or two exceptions, the mutagens were detected with S-9 preparations from all three species . The uninduced liver S-9 preparations did not activate any chemicals to mutagens that were not also activated by induced S-9, but some chemicals were detected as mutagens only when induced S-9 was used . A positive mutagenic response in Salmonella was predictive of carcinogenicity 69% of the time; when equivocal carcinogens and borderline mutagens were included, the predictivity increased to 83% . Conversely, 76% of the carcinogens were mutagens . When the equivocal carcinogens were included, the proportion dropped to 75% . Relatively few chemicals (18%) were mutagenic in E coli . Not all the carcinogens induced tumors in both rats and mice, and the species-specific carcinogenicity could not be predicted from the S-9-specific mutagenicity.

Environ Mutagen, 1985, 7(6), 881 - 8
Mutagenicity of chili extract and capsaicin in short-term tests; Nagabhushan M et al.; Vanillin, capsaicin and chili extracts were tested for mutagenicity in Salmonella typhimurium histidine-deficient tester strains TA 98, TA 100, TA 1535, TA 1537, and TA 1538 . Vanillin was nonmutagenic, whereas chili extract and capsaicin were mutagenic with metabolic activation . Capsaicin, an active component of chili extract, was the more potent mutagen . The positive samples were also tested in two mammalian test systems: the micronucleus test and the 8-azaguanine-resistant mutagenesis assay that used V79 Chinese hamster cells . It was observed that both were negative for the latter test at the dose level tested, whereas in the micronucleus test, only capsaicin was positive near the LD50 dose . Capsaicin also inhibited DNA synthesis in the testes of Swiss mice injected at two dose levels.

Environ Mutagen, 1985, 7(6), 839 - 55
Mutagenicity of algal metabolites of benzo(a)pyrene for Salmonella typhimurium; Schoeny R et al.; The metabolism and growth effects of benzo(a)pyrene (BaP) were studied using a freshwater green alga, Selenastrum capricornutum . Algal cultures were incubated under gold light with BaP added at concentrations of 40, 160, 400, and 1,200 micrograms/liter for the periods of 1-4 days . The metabolites and BaP were identified and quantified from ethyl acetate extracts of both algal cells and incubation medium . The ethyl acetate extracts were evaluated for genotoxicity using a micro-volume Salmonella typhimurium forward mutation assay with resistance to 8-azaguanine for selection . This assay detected the presence of small quantities of BaP and was particularly sensitive to the mutagenicity of BaP diols . Of those extracts prepared from algae and medium from cultures exposed to 400 micrograms BaP/liter (10 micrograms/25 ml culture), only algal cell extracts from one day's growth were mutagenic . In cultures exposed to 1,200 micrograms BaP/liter (30 micrograms/25 ml culture), mutagenic materials were produced or persisted in both algae and media throughout the 4-day incubation . The observed mutagenic response can be attributed in part to the presence of unmetabolized BaP or to BaP diols.

Comp Immunol Microbiol Infect Dis, 1985, 8(1), 9 - 16
Role of outer membrane proteins in immunity against murine salmonellosis--1 . Antibody response to crude outer membrane proteins of Salmonella typhimurium; Natarajan M et al.; The humoral immune response to crude outer membrane proteins (comp) of S . typhimurium in mice has been characterized . Maximal and quicker antibody response was observed when 50 micrograms of comp was injected intraperitoneally . The comp of smooth C5 strain of S . typhimurium evoked antibody response to both lipopolysaccharide (LPS) and proteins . Absorption of these sera with LPS coated erythrocytes eliminated the antibodies to LPS completely, while the antibody level to protein was left unaltered . The comp from rough mutant (lacking O-specific chain of LPS) of S . typhimurium elicited antibodies to proteins but not to LPS . These results indicate the concomitant production of antibodies to Salmonella outer membrane proteins also . The significance of such antibodies in protection and diagnosis has been discussed.

Environ Mutagen, 1985, 7(4), 535 - 46
Comparisons of mutation induction by six monocyclic aromatic amines in Salmonella typhimurium tester strains TA97, TA1537, and TA1538; Shahin MM et al.; The mutagenicity of six monocyclic aromatic amines (2,4-diaminoanisole, 2,4-diaminoethoxybenzene, 2,4-diaminopropoxybenzene, m-phenylenediamine, 2,4-diaminotoluene, and nitro-p-phenylenediamine) was investigated in Salmonella typhimurium strains TA97, TA1537, and TA1538 in the presence of two different amounts of Aroclor 1254-induced S9 preparations . Strain TA1538 was found to be the most responsive of the three strains with this group of compounds . Regarding the other strains, TA1537 responded to three of the compounds better than strain TA97, if one calculates responsiveness as the fold-increase in numbers of revertants per plate . However, if one calculates the number of revertants per nanomole or compares the number of induced revertants per plate, TA97 was more responsive than TA1537 for all six compounds . Comparisons of mutagenesis from tests involving strain TA97 are complicated by the large variations in spontaneous mutation frequencies in this strain . The amount of S9 per plate is another important variable in tests of monocyclic aromatic amines; in general, more revertants are detected when the S9 mix contains 10% S9 than when it contains 4% S9 . Nevertheless, in all our tests of 2,4-diaminoanisole, 2,4-diaminoethoxybenzene, and 2,4-diaminopropoxybenzene, the same relationship between chemical structure and mutagenic activity was observed . In all three strains, the mutagenic responses become less when the alkoxy substituent on the molecule becomes larger.

Environ Mutagen, 1985, 7(4), 429 - 37
Niridazole: Evidence for promutagenic events involving guanine-cytosine and adenine-thymine base pairs; Speck WT et al.; Niridazole, a widely used antiprotozoan agent, is mutagenic for Salmonella typhimurium strains that contain guanine-cytosine as well as adenine-thymine base pairs at their mutational sites . The mutagenic activity for both types of targets depends upon nitroreduction.

Mol Gen Genet, 1985, 200(3), 493 - 6
A mutational hot-spot in the hisM gene of the histidine transport operon in Salmonella typhimurium is due to deletion of repeated sequences and results in an altered specificity of transport; Payne GM et al.; Duplicated sequences within hisM, a gene coding for a membrane-bound component of histidine transport, result in frequent deletions which, being in frame, allow production of an altered protein with apparent changed specificity of transport . While the wild-type transport system does not transport L-histidinol but does transport L-histidine and several of its analogs, the hisM deletion mutants do not transport the latter compounds but do transport L-histidinol . These results are interpreted as supporting the hypothesis (Ames and Higgins 1983) that transport through periplasmic systems involves binding of the substrate by the cytoplasmic membrane-bound components.

Environ Mutagen, 1985, 7(5), 645 - 53
The role of DNA sequence and structure of the electrophile on the mutagenicity of nitroarenes and arylamine derivatives; Rosenkranz HS et al.; The mutagenicities of a series of nitroarenes and related electrophilic metabolites of aromatic amines were studied in Salmonella typhimurium strains TA98 and TA97, which have, respectively, (GCGC/CGCG)2 and (CCC/GGG)2 as their mutational sites . For electrophiles, primarily bicyclic species, that form adducts with nucleophilic sites other than the C8 of guanine (G), the ratios of activities in the two strains is near unity . On the other hand, for electrophiles consisting of cyclic structures with more than two rings and that are reported to react solely with the C8 of G, the ratio of activities (TA98/TA97) is in excess of 1.6 . Quantum mechanical calculations indicate that (1) in the plane of G, the N7, N3, and 06 of G are more likely nucleophilic targets than C8 and (2) adduct formation at the C8 of G requires electrophilic attack from above or below the plane of G . It is hypothesized that because of steric hindrances, nitroarenes and derivatives containing in excess of two rings cannot react with the preferred nucleophilic sites and, therefore, form adducts with the more accessible C8 . However, such an out-of-the-plane attack is influenced by the nature of the nearest neighbor, as evidenced by the difference in mutagenic responses of TA98 and TA97, alternating GCs being preferred over other combinations . Further quantum mechanical calculations indicate that the nature of the nearest neighbor does indeed affect the nucleophilicity of the C8 of G but that the expression of this effect is apparently masked by the overriding steric effects.

Environ Mutagen, 1985, 7(5), 625 - 44
Computer analysis of toxicological data bases: mutagenicity of aromatic amines in Salmonella tester strains; Klopman G et al.; There is an increasing problem in the world of toxicological evaluation in that, while test results of new compounds are appearing regularly, traditional methods of analysis of such data are cumbersome and slow . The new computer program CASE (computer automated structure evaluator) was designed to handle just such problems . It analyzes molecules and their associated biological activity on the basis of structural fragments found and identified by the program as being important for the activity based on statistical tests of significance . The program was used to examine mutagenicity in Salmonella typhimurium strains TA98 and TA100 (with S9 activation) of approximately 80-100 aromatic amines . The resulting structural features were then used in a predictive fashion to test the expected mutagenic properties of a smaller set of about 20 compounds.

Mol Gen Genet, 1985, 199(3), 512 - 7
Identification of a cis-acting regulatory region in the pncB locus of Salmonella typhimurium; Kinney DM et al.; The pncB locus of the pyridine nucleotide cycle of NAD biosynthesis in Salmonella typhimurium was examined in terms of genetic structure and regulation . The gene appears to be regulated at the level of transcription in response to the end product of the pathway, NAD . Insertions into promotor proximal regions of the gene relinquish it from regulation, while insertions into more distal regions allow retention of regulation . Regulation cannot be restored in trans to strains containing promotor proximal insertions implicating the existence of a cis acting regulatory region.

Neoplasma, 1985, 32(3), 313 - 21
Stimulatory effect of potassium ions on MNU- and MNNG-induced mutagenesis in Salmonella typhimurium TA1535 and TA100; Balansky RM et al.; The liquid suspension modification of the standard Salmonella mutagenicity assay employing Ames tester strains of Salmonella typhimurium TA1535 and T100 was used to study the influence of potassium, sodium and calcium on the mutagenic activity of MNU and MNNG . The toxic and mutagenic activities of MNU and MNNG were better expressed when potassium-containing solution was used as a solvent . Short-term pretreatment of bacteria cells with potassium-containing solutions increased the mutagenic efficiency of both chemicals . Potassium-induced increased sensibility of S . typhimurium TA1535 to MNU was completely reversible after 20 min incubation of bacteria in a nutrient broth at 37 degrees C . The mutagenic activity of MNU was reduced after a short-term pretreatment of S . typhimurium TA1535 with a 0.9% solution of CaCl2, while NaCl did not change the mutagenic response of bacteria to MNU.

Neoplasma, 1985, 32(3), 307 - 12
Monitoring of effects of cis-diamminedichloroplatinum II (Platidiam) . Part II . Tests for mutagenic activity in the indicator system of Salmonella typhimurium his- strains (Ames test); Vancurova M et al.; The mutagenic activity of the cytostatic drug Platidiam (cis-diamminedichloroplatinum II complex, cis-DDP) produced in Czechoslovakia was tested . In the used Ames test, as an indicator system, Salmonella typhimurium his- strains were employed . The tests for mutagenicity were performed in vitro using assays both without metabolic activation and therewith, as well as with metabolic activation under in vivo conditions . The analyses revealed a mutagenic effect of the cis-DDP complex in Platidiam in all of the followed tests . These effects were direct, no metabolic activation was observed . Furthermore, the mutagenic activity of the drug was influenced by the duration of interaction between Platidiam and the mammalian organism, which was apparently due to the pharmacokinetic properties of the active substance.

J Basic Microbiol, 1985, 25(2), 119 - 26
{Iron uptake of Salmonella typhimurium strains from different epidemiological sources}; Rabsch W et al.; All Salmonella typhimurium strains tested were able to use iron from transferrin . In buffered nutrient broth -- poor in iron-content -- the strains were tested in 59FeCl3 and 59Fe-transferrin uptake in different growth phases . In the early log phase the strains are able to catch the 59Fe3+ in a very great amount as it is necessary for the growth . The content of 59Fe per cell was in the late log phase reduced until to a value, which seen to be enough for growth . The acquisition of 59Fe-transferrin between the early and late log phase tested by 4 S.typhimurium strains was different.

Gene, 1985, 34(1), 129 - 34
The araBAD operon of Salmonella typhimurium LT2 . III . Nucleotide sequence of araD and its flanking regions, and primary structure of its product, L-ribulose-5-phosphate 4-epimerase; Lin HC et al.; The araD gene of Salmonella typhimurium LT2 consists of 744 nucleotides and has an ORF coding for a protein of 248 amino acid residues with a calculated Mr of 27059 . The product of araD, L-ribulose-5-phosphate 4-epimerase, was purified and the amino terminal sequence was determined . It is identical to that predicted by the ORF . A 143-bp intercistronic region was found between the araA and araD genes which can form stem-loop structures with calculated free energies of up to -76.7 kcal/mol . Three sets of sequences within this 143-bp region are comparable to a consensus sequence deduced from several known intercistronic regions . Approximately equimolar amounts of the araBAD operon products were present in L-arabinose-induced cells . Sequences similar to both rho-independent and rho-dependent transcription terminators are present after the araD gene.

Gene, 1985, 34(1), 123 - 8
The araBAD operon of Salmonella typhimurium LT2 . II . Nucleotide sequence of araA and primary structure of its product, L-arabinose isomerase; Lin HC et al.; The nucleotide sequence of gene araA of Salmonella typhimurium LT2 has been determined . The gene encodes an L-arabinose isomerase (EC 5.3.1.4) of 500 amino acid residues with a calculated Mr of 55814 . The ATG start codon of araA is 10 bp distal to the TAA termination codon of araB . A presumed ribosome-binding site (RBS) "TAAGGA" 7 bp from the ATG codon overlaps the stop codon of araB . L-Arabinose isomerase was purified and the amino acid composition is in agreement with that predicted from the DNA sequence . The NH2-terminus of the protein is modified as the sequence cannot be analyzed by the automated Edman degradation . Amino acid composition analyses of both NH2-terminal and C-terminal cyanogen bromide (CNBr) cleaved peptides and partial amino acid sequence of the C-terminal peptide are consistent with the deduced amino acid sequence.

Biochimie, 1985 Jan, 67(1), 149 - 54
Overproduction of the membrane-bound components of the histidine permease from Salmonella typhimurium: identification of the M protein; Ames GF et al.; The periplasmic histidine permease of Salmonella typhimurium is composed of a soluble histidine-binding protein and three membrane-bound components . These latter are produced in very small amounts and only two, the Q and the P protein, have been previously identified . This paper describes the construction of a plasmid carrying the hisQ, hisM, and hisP genes under the control of the lambda PL promoter, thus allowing great overproduction of those gene products . The M protein has been identified in such overproducing strains and its nature confirmed by constructing in vitro hisM deletions within the plasmid . With these results the identification of all components of the histidine permease has been completed.

Basic Life Sci, 1985, 31, 283 - 95
Induction of mutation and chromosome damage by excess bases and nucleosides; Anderson D; The studies reported in this communication were conducted to determine if naturally occurring cell constituents could themselves cause mutation . All the bases and their corresponding nucleosides have been shown in culture to produce chromosome damage in P388 mouse lymphoma and Chinese hamster ovary cells (CHO) and adenosine has produced an increased incidence of sister chromatid exchanges in CHO cells . In addition thymidine has produced an increase in V79 cells resistant to 8-azaguanine and ouabain, although no effects were seen in six strains of Salmonella typhimurium . Such damage probably arises as a result of imbalanced DNA-precursor pools . Thus mutagenic events may arise by mechanisms unrelated to direct alterations of DNA.

Can J Microbiol, 1985 Jan, 31(1), 54 - 61
Histopathological evidence for protective immunity induced by sonicated Salmonella vaccine; Hsu HS et al.; The highly susceptible inbred C3H/HeNMTV mice were vaccinated with fragments derived from sonicated Salmonella typhimurium and then infected with the pathogen . All of the vaccinated mice survived an otherwise rapidly fatal challenge of 10(5) organisms, i.e., greater than 10(3) x mean lethal dose (LD50) . The vaccine also protected two-thirds of the mice infected with 10(6) bacteria and extended the survival time of the remainder in their fatal disease . Histopathological findings showed that, like the control mice, the vaccinated and infected mice developed abscesses with infiltration of polymorphonuclear leukocytes in the organs of the reticuloendothelial system during the early stage of the infection . However, unlike the primary lesions in the control mice, the lesions of the vaccinated mice tended to be discrete and self-limiting . They began to transform into granulomas after the first week of infection . Recovery and regeneration of tissues were evident 3 weeks after the infection.

Can J Comp Med, 1985 Jan, 49(1), 43 - 9
Chemotaxis of porcine neutrophils under agarose; Smith GS et al.; The standardization of pig neutrophil chemotaxis under agarose is described . The mean chemotactic index for pig neutrophils from six pigs measured over four days was 1.29 . Comparative studies of human and pig neutrophil chemotaxis under agarose revealed a lower chemotactic index for pig neutrophils (mean of 1.18) compared to human neutrophils (mean of 2.43) . The results suggest that this is due to differences intrinsic to human and pig neutrophils . In vitro pig neutrophil chemotaxis was measured in normal pigs and in pigs following experimental Salmonella typhimurium infection . Significant alterations in chemotaxis were not evident one and seven days postinfection.

Avian Dis, 1985 Jan-Mar, 29(1), 1 - 11
The effects of treatments of cecal contents on their protective properties against Salmonella in poults; Reid CR et al.; The effect of manipulating adult turkey cecal contents was assessed . Treatment of day-old poults with cecal contents diluted up to 1/3000 protected 90% of the birds against subsequent challenge with 10(3) colony-forming units of Salmonella typhimurium . The addition of penicillin G and streptomycin to adult cecal contents reduced their protective effects by 20% and 50%, respectively . When cecal contents were heat-treated at 65 C for 15 minutes or filter-sterilized, the protective properties were lost . Anaerobic cultures of cecal contents in reinforced clostridial medium afforded protection against challenge, but protection was lost on subsequent subcultures . Thioglycollate broth culture of cecal contents did not protect.

Acta Pharmacol Toxicol (Copenh), 1985 Jan, 56(1), 20 - 9
Comparative genotoxicity and nephrotoxicity studies of the two halogenated flame retardants tris(1,3-dichloro-2-propyl)phosphate and tris(2,3-dibromopropyl)phosphate; Soderlund EJ et al.; Tris(1,3-dichloro-2-propyl)phosphate (Tris-CP) was metabolized to products which were mutagenic for Salmonella typhimurium TA100 in the presence of liver microsomes from phenobarbital (PB)-pretreated rats and NADPH . Effects of various inhibitors and inducers of cytochrome P-450 on Tris-CP mutagenicity were in accordance with PB-inducible forms of this enzyme system being responsible for the formation of mutagenic product(s) . A comparison was made between the toxic potential of the two halogenated flame retardants Tris-CP and tris(2,3-dibromopropyl)phosphate (Tris-BP) in 5 in vitro tests . Tris-CP was much less potent than Tris-BP with respect to bacterial (Salmonella/microsome or Salmonella/hepatocyte assay) and mammalian (V79 cells) mutagenicity, as well as DNA repair synthesis in hepatocytes . On the other hand, Tris-CP and Tris-BP were both equally effective in transforming Syrian hamster embryo cells in vitro . Tris-CP was not nephrotoxic to rats after a single dose of 500 mg/kg intraperitoneally, whereas Tris-BP caused extensive tubular necrosis accompanied by elevated levels of plasma urea and creatinine.

Toxicol Lett, 1985 Jan, 24(1), 111 - 6
Mutagenicity of some monoaromatic hydroxamic acids; Wei CI et al.; The mutagenicity of some monoaromatic hydroxamic acids was tested in the presence and absence of rat liver S-9 with Salmonella typhimurium tester strains TA98 and TA100 . Of the five N-(chlorophenyl)-substituted hydroxamic acids and seven N-arylformohydroxamic acids tested, 2 of the first and 4 of the latter series were mutagenic to both strains upon metabolic activation . None of the four N-acetyl-type hydroxamic acids was mutagenic to either strain, even upon activation . Because some of the N-acetyl-derived hydroxamic acids were inactive, whereas the same aromatic nucleus possessing a formyl group displayed significant activity, a consideration of the nature of the aryl group in hydroxamic acid mutagenicity is important.

Mutat Res, 1985 Jan-Feb, 142(1-2), 9 - 12
Pinacolyl methylphosphonochloridate: in vitro covalent binding to DNA and mutagenicity in the Ames test; Ivanovic V et al.; In the present study, in vitro binding of 14C-labeled pinacolyl methylphosphonochloridate (PiCl) to calf-thymus DNA has been investigated . The data reveal that, at PiCl concentrations of 0.038-0.26 mM, the binding is rapid and saturable at the extent of modification of 1 PiCl molecule per 2000 nucleotides . A similar range of PiCl concentrations was toxic, but did not produce a significant increase in mutagenicity in Salmonella typhimurium TA100 and TA98 . Our results are of relevance with regard to the in vitro assessment of Soman-like organophosphates and the mutagenic risk of these agents and related pesticides.

Mutat Res, 1985 Jan-Feb, 142(1-2), 13 - 8
The effects of S9 mix from rat oesophagus, salivary gland, and liver on the mutagenicity of the rat oesophageal carcinogen N-nitroso-N-methylaniline in the Salmonella typhimurium assay; Anderson D et al.; The present study examines the feasibility of using the Salmonella typhimurium plate-incorporation assay of Ames for detecting target-organ specificity with N-nitroso-N-methylaniline (NMA), a compound for which the target site for tumour formation in the rat is the oesophagus . Thus it was anticipated that the oesophagus would bioactivate this compound . The compound has been investigated using S9 from Aroclor- and NMA-induced rat oesophagus, salivary gland and liver in the presence and absence of the co-mutagen, norharman . No response to NMA was seen with oesophageal S9 even though benzo{a}pyrene produced a dose-related increase in revertants in strain TA98 and TA100 . No response to NMA was seen with salivary-gland S9 . However, a response was produced with Aroclor-induced rat-liver S9 in the presence of norharman and with NMA-induced rat-liver S9 in the absence of norharman.

Environ Mutagen, 1985, 7(2), 185 - 200
Increased mutagenicity of chromium compounds by nitrilotriacetic acid; Loprieno N et al.; Nitrilotriacetic acid trisodium salt (NTA), which is a substitute for polyphosphates in household laundry detergents, and N-nitrosoiminodiacetic acid (NIDA), a derivative of NTA produced by metabolism of soil microorganisms, were tested for in vitro mutagenicity in bacteria and yeasts . No gene reversions in five strains of Salmonella typhimurium (TA 1535, TA1537, TA1538, TA98, and TA100), no forward gene mutations in Schizosaccharomyces pombe P1, and no mitotic gene conversions at two loci in Saccharomyces cerevisiae D4 were induced by NTA (up to 870 micrograms/plate or 40 micrograms/ml) and NIDA (up to 2,000 micrograms/plate or 1,000 micrograms/ml), independently of the presence of rat liver metabolic activation . The influence of NTA on the mutagenic and clastogenic activity of several chromium compounds was examined in the Salmonella/microsome assay and in the sister chromatid exchange (SCE) assay in mammalian cell cultures (Chinese hamster ovary {CHO} line) . NTA does not affect the genetic inactivity of water-soluble Cr(III) (Cr2{SO4}3) and the direct mutagenicity of soluble Cr(VI) (Na2CrO4,K2Cr2O7) compounds . The very insoluble Cr(VI) compounds PbCrO4 and PbCrO4 X PbO are instead clearly mutagenic in the Salmonella/microsome assay (TA100 strain) only in the presence of NTA or NaOH . The mutagenicity of lead chromates is correlated with the amounts of Cr(VI) solubilized by NTA or alkali, as detected by the colorimetric reaction with diphenylcarbazide and atomic absorption spectrophotometry . In the SCE assay, the insoluble lead chromates are directly clastogenic owing to prolonged treatment conditions and cellular endocytosis . The chromosome-damaging activity of PbCrO4 is significantly increased by NTA but not by NaOH.

Chem Biol Interact, 1985 Jan, 52(3), 301 - 9
Studies on the mutagenicity and tumor-initiating activity of methylated fluorenes; Lavoie EJ et al.; Several methylated analogs of fluorene were evaluated as mutagens in Salmonella typhimurium TA98 and TA100 in the presence and absence of microsomal activation . Among the methylated derivatives of fluorene assayed were 9-methylfluorene, 2-fluoro- and 2,7-difluoro-9-methylfluorene, 1,9-, 2,9-, 3,9- and 4,9-dimethylfluorene, 2,3,9-trimethylfluorene and 2,7,9-trimethylfluorene . Mutagenic activity was observed for several of these fluorene derivatives in the presence of rat liver homogenate . The data support a previous observation that a single methyl substituent in the 9-position of fluorene is associated with mutagenic activity within this series of compounds . Substitution with fluorine at both the 2- and 7-positions of 9-methylfluorene was not associated with a loss of mutagenic activity as evidenced by the similar mutagenic activity of 2,7-difluoro-9-methylfluorene and 9-methylfluorene . However, 2,7,9-trimethylfluorene was not mutagenic under these assay conditions . 9-Methylfluorene, 1,9-, 2,9-, 3,9- and 4,9-dimethylfluorene and 2,3,9-trimethylfluorene were active as mutagens in the presence of rat liver homogenate, but were inactive as tumor initiators when assayed on mouse skin.

Mutat Res, 1985 Jan-Feb, 155(1-2), 75 - 81
Assessment of the genotoxic effects of methyl chloride in human lymphoblasts; Fostel J et al.; The activity of methyl chloride was measured in 4 genotoxicity assays . In an established human lymphoblast line, a 3-h treatment with 0-5% methyl chloride resulted in a dose-related increase in mutant fraction at the thymidine kinase locus and induction of sister-chromatid exchange . No increase in DNA damage, as measured by alkaline elution, was detected in the lymphoblasts at concentrations of methyl chloride shown to be mutagenic . Also, a concentration-related increase in 8-azaguanine-resistant fraction in Salmonella typhimurium was observed following a 3-h treatment with atmospheres containing 0-20% methyl chloride . Thus, methyl chloride is a weak, direct-acting mutagen for bacteria and human cells in culture.

Mutat Res, 1985 Jan-Feb, 155(1-2), 49 - 51
Study of the mutagenicity of metal derivatives with Salmonella typhimurium TA102; Marzin DR et al.; The mutagenic potential of 16 metal derivatives was studied with a new mutant of Salmonella typhimurium, the strain TA102 (Levin et al., 1983) . Some of these compounds are known as carcinogens (As, Cr VI, Cd, Ni) or suspected carcinogens in man (Pb, Hg), others are known as non-carcinogens (Cr III, Al, Cu, Mn, Fe) . Among these 16 derivatives, only the two Cr(VI) compounds are strong mutagens (K2Cr2O7 or K2CrO4).

Mutat Res, 1985 Jan-Feb, 155(1-2), 1 - 6
Mutagenic and alkylating activities of organophosphate impurities of commercial malathion; Imamura T et al.; The purpose of this study was to determine if 4 major organophosphate impurities of malathion were active as alkylators of nitrobenzylpyridine (NBP) or as mutagens in the Salmonella typhimurium bioassay . Malathion, isomalathion, O,O,O-trimethyl phosphorothioate, O,O,S-trimethyl phosphorothioate, and O,S,S-trimethyl phosphorodithioate produced alkylated NBP at varying rates . In order of increasing NBP reactivity, the compounds ranked: O,O,O-trimethyl phosphorothioate = O,O,S-trimethyl phosphorothioate less than O,S,S-trimethyl phosphorodithioate less than isomalathion = malathion . At 37 degrees C, the most reactive compounds produced an NBP alkylation rate equal to approximately 25% of the rate produced by methyl methanesulfonate, a potent Salmonella mutagen . However, none of the organophosphates were mutagenic in S . typhimurium TA97, TA98 and TA100 when tested by the standard plate-incorporation method or by the preincubation modification of the plate-incorporation method . The possible relationships between NBP reactivity and the biological activities of these organophosphates are discussed.

Mutat Res, 1985 Jan-Feb, 148(1-2), 25 - 34
Naturally occurring carbonyl compounds are mutagens in Salmonella tester strain TA104; Marnett LJ et al.; Strains of Salmonella typhimurium that carry a nonsense mutation at the site of reversion detect a variety of naturally occurring and synthetic carbonyl compounds as direct-acting mutagens . TA104 is reverted efficiently by formaldehyde, alpha, beta-unsaturated aldehydes (enals), and dicarbonyl compounds, such as diacetyl and glutaraldehyde . This strain is much more sensitive to carbonyl mutagenesis than is TA100, a strain previously reported to detect aldehydes as mutagens, or any other characterized strains of Salmonella . Long-chain enals are very toxic to TA104, but addition of a reduced glutathione chase following an incubation period decreases this toxicity, thus enabling the detection of 4-hydroxy-pentenal, a homolog of the lipid peroxidation product, 4-hydroxy-nonenal, as a mutagen . This is the first report of the mutagenicity of a hydroxy-enal, a class of enals produced by lipid peroxidation . Testing conducted with strains that carry the nonsense mutation in different repair backgrounds indicates that the presence of pKM101 and the deletion of the uvrB gene facilitate the detection of enals and dicarbonyls, but not malondialdehyde, as mutagens . Since carbonyl compounds are widely distributed in foods, are generated during cellular metabolism, and are present in body fluids, they may make a significant contribution to the risk of human cancer.

J Bacteriol, 1985 Jan, 161(1), 442 - 5
Transformation of Salmonella typhimurium with plasmid DNA: differences between rough and smooth strains; MacLachlan PR et al.; Lipopolysaccharide-defective mutants of Salmonella typhimurium were transformed by plasmid DNA with a Ca2+ treatment method . Only those mutants with an Rc or Rd2 chemotype, due to galE or rfaF mutations, respectively, gave efficiencies greater than 10(5) transformants per microgram of DNA, frequencies 8- to 630-fold higher than with smooth strains or other rough mutants.

J Bacteriol, 1985 Jan, 161(1), 353 - 60
Fine structure analysis of Salmonella typhimurium glutamate synthase genes; Madonna MJ et al.; Glutamate synthase activity is required for the growth of Salmonella typhimurium on media containing a growth-rate-limiting nitrogen source . Mutations that alter glutamate synthase activity had been identified in the gltB gene, but it was not known which of the two nonidentical subunits of the enzyme was altered . To examine the gene-protein relationship of the glt region, two nonsense mutations were identified and used to demonstrate that gltB encodes the large subunit of the enzyme . Six strains with independent Mu cts d1 (lac bla) insertions were isolated, from which a collection of deletion mutations was obtained . The deletions were transduced with the nonsense mutations and 38 other glt point mutations to construct a fine-structure genetic map . Chromosome mobilization studies, mediated by Hfr derivatives of Mu cts d1 lysogens, showed that gltB is transcribed in a clockwise direction, as shown in the S . typhimurium linkage map . Studies of the polar effects of three Mu cts d1 insertions indicated that the gene for the small subunit maps clockwise to gltB and that the two genes are cotranscribed to form a glt operon.

Environ Mutagen, 1985, 7(1), 73 - 85
In vitro enhancement of the mutagenicity of 4-nitro-o-phenylenediamine by plant S-9; Gentile JM et al.; The direct-acting mutagen 4-nitro-o-phenylenediamine (NOP) was activated in vitro by pea or tobacco S-9 into a more potent mutagen in Salmonella typhimurium strain TA98 . NOP mutagenicity was not altered by Aroclor 1254-induced rat liver S-9 . The plant S-9 activation of NOP was heat-sensitive but was not NADPH-dependent, did not involve superoxide radicals, and was not inhibited by CO . A direct relationship between plant peroxidase and NOP activation was established . Several purified peroxidases including horseradish peroxidase, chloroperoxidase, and lactoperoxidase also activated NOP . The perodoxidative process was not H2O2-dependent but was partially inhibited by a peroxidase inhibitor.

Carcinogenesis, 1985 Jan, 6(1), 59 - 64
Enhancement of DNA binding and mutagenicity of 1-nitropyrene by zinc acetate in Salmonella typhimurium TA100; Sakai K et al.; The effect of zinc acetate on the mutagenicity of 1-nitropyrene (1-NP) in Salmonella typhimurium TA100 was examined . By the pre-treatment of the cells with zinc ions (0.24 mM) the revertant colonies caused by 1.5 microM of 1-NP in the pre-incubation mixtures increased approximately 3-fold, while the survival colonies decreased to approximately 75% under the same conditions . The enhancing effect of zinc ions on the mutagenicity was not dependent on the increase of 1-NP incorporation into the cells . The addition of zinc ions to whole cell preparations had no enhancing effect on the 1-NP reductase activity . The effect of zinc acetate on the binding of {3H}1-NP to DNA in S . typhimurium TA100 was examined . The amount of {3H}1-NP bound to DNA increased by the pre-treatment of the cells with zinc ions . A good correlation was found between the extent of binding of 1-NP to DNA and the frequency of induced histidine reversions in the cells treated with zinc ions under the experimental conditions used.

Infect Immun, 1985 Jan, 47(1), 106 - 11
Effect of age on fever and acute-phase response of rats to endotoxin and Salmonella typhimurium; Tocco-Bradley R et al.; Age-related effects on endogenous pyrogen-mediated febrile and acute-phase responses to endotoxin and Salmonella typhimurium challenge were investigated in young adult and aged Fisher 344 rats . After injection of endotoxin, the febrile response over 6 h and the fall in plasma iron and zinc after 6 h were determined in 14 young adult and 14 aged rats in their thermoneutral zone (26 degrees C) and in 14 young adult and 14 aged rats maintained in a cold environment (15 degrees C) . Although at 26 degrees C aged rats showed only a slightly diminished febrile response compared with that of young adult rats, at 15 degrees C they had a markedly diminished febrile response compared with that of young adult rats . At both 26 and 15 degrees C, the injection of endotoxin led to a fall in iron and zinc concentrations in the plasma of both young adult and aged rats . The intact trace metal response diminished but febrile response suggest that aged rats are able to produce endogenous pyrogen but have a reduced capacity to respond to this substance . In 22 aged and 22 young adult rats maintained at 26 degrees C and challenged with S . typhimurium, the febrile response was significantly less in the aged rats but the survival rate was virtually identical . When 10 young adult and 10 aged rats were placed at a temperature of 15 degrees C after injection with S . typhimurium, the febrile response in the aged rats was significantly lower than that in the young adult rats at only one time point, and the survival rate did not differ between the two age groups . Survival after challenge with S . typhimurium was not influenced adversely by the diminished febrile response.

Vet Med Nauki, 1985, 22(8), 38 - 44
{Therapeutic aspects of salmonellosis in veal calves}; Groothuis DG et al.; The present investigation was undertaken to improve dosage regimens--using amoxycillin, chloramphenicol or trimethoprim/sulphadiazin--in Salmonella dublin or Salmonella typhimurium infected vealcalves . The pharmacokinetic of these drugs was studied after i/v, oral, and i/m administration (bio-availability, local irritation at the injection site, volume of distribution, and elimination half-life) . The most important conclusion was that amoxycillin, chloramphenicol, and trimethoprim were suitable for oral administration to vealcalves, although the bioavailability of chloramphenicol and trimethoprim was significantly less when administered with a milk replacer concurrently . In vitro the antibacterial activities of these drugs were compared with each other . Addition of sulphadiazin to trimethoprim lowered its MIC for S . dublin, but it reduced the killing rate compared to that of trimethoprim alone . In the efficacy studies the activities of several serum enzymes and the plasma concentrations of Fe, Zn, Cu, and bilirubine were measured . Using optimal dose regimens based on MIC values and blood levels treatment with either of the three drugs was of equal efficacy.

Drugs Exp Clin Res, 1985, 11(3), 163 - 7
Comparative in vitro activity of aztreonam and other antimicrobial agents against Salmonella species; Paradelis AG et al.; The in vitro activity of aztreonam, the first monobactam antibiotic, was compared with that of 17 other antimicrobial agents against 79 strains of Salmonella species . The microorganisms were isolated from hospitalized patients, surface waters and seafoods during the decade 1975-1984 . They included the following species: Salmonella typhi 63, Salmonella typhimurium 5, Salmonella wien 5, Salmonella heidelberg 2, Salmonella arizonae 2, Salmonella paratyphi B 1 and Salmonella enteritidis 1 . The minimum inhibitory concentration (MIC) values of the antibiotics were determined using a serial dilution method in agar . A final inoculum size of 10(5) colony-forming units (CFU) X ml-1 of the tested microorganisms was used . Aztreonam exhibited a superior antimicrobial activity to that of the other antibiotics tested . Aztreonam inhibited 90% of the strains by 0.8 micrograms X ml-1 (MIC range was 0.05 to 1.56 micrograms X ml-1) . There was no major difference between minimum bactericidal concentration and MIC values of aztreonam and the effect of inoculum size upon MIC values was observed at 10(7) CFU X ml-1.

Cancer Immunol Immunother, 1985, 19(2), 127 - 9
Synergistic anti-suppressor effect of mini cells prepared from Salmonella typhimurium and mitomycin C in EL 4-bearing mice; Kurashige S et al.; The subcutaneous growth of EL4 cells was significantly accelerated when they were injected together with spleen cells collected from mice which had received EL4 cells SC 14 days previously, and all mice died within 18 days after receiving this mixture; 80% of mice which received a mixture of EL4 and spleen cells collected immediately after EL4 graft survived over 40 days . Spleen cells collected 14 days after EL4 graft suppressed the blastogenic responses of normal spleen lymphocytes to concanavalin A, pokeweed mitogen, and lipopolysaccharide of Escherichia coli in a mixed culture system . Acceleration of tumor growth was retarded when EL4 cells were injected together with spleen cells from EL4-bearing mice treated with both Salmonella typhimurium mini-cells and mitomycin C, and 60% of mice survived over 40 days . Blastogenic responses of normal spleen lymphocytes mixed with spleen cells from EL4-bearing mice treated with both mini-cells and mitomycin C were restored almost to control levels . The results suggest that combination treatment with mini-cells and mitomycin C synergistically inhibits the induction of suppressor cells in EL4-bearing mice.

J Bacteriol, 1985 Jan, 161(1), 277 - 84
Cloning of rfaG, B, I, and J genes for glycosyltransferase enzymes for synthesis of the lipopolysaccharide core of Salmonella typhimurium; Kadam SK et al.; R-prime plasmids carrying the pyrE-rfa-cysE region of the chromosome of Salmonella typhimurium were isolated by using the vector pULB113 (RP4::mini-Mu) . One of the R-prime plasmids was used as a source of DNA to clone the rfa genes for lipopolysaccharide synthesis to pBR322 . The following three hybrid plasmids were constructed: pKZ15, with a 4.0-kilobase EcoRI fragment of S . typhimurium DNA, containing the rfaG gene; pKZ27, a 9-kilobase BglII fragment with the rfaG, rfaB, and rfaI genes; and pKZ26, a 7.7-kilobase HindIII fragment with the rfaG, rfaB, rfaI, and rfaJ genes . We propose that these cloned genes code for four glycosyltransferases used for synthesis of the lipopolysaccharide core region (rfaG for glucosyltransferase I; rfaI for galactosyltransferase I; rfaB for galactosyltransferase II; and rfaJ for glucosyltransferase II) . For all four genes, mutants which lacked the appropriate enzyme activity were complemented by the plasmids to give completed core lipopolysaccharide with O (somatic) side chains; for rfaG, rfaB, and rfaI, mutants gave restored or even amplified levels of the appropriate glycosyltransferase in in vitro assays . We show that the order of genes in the region is pyrE-rfaG-(rfaB-rfaI)-rfaJ-rfaL-rfaF -cysE.

Gene, 1985, 40(1), 67 - 78
Nucleotide sequence of the rpsU-dnaG-rpoD operon from Salmonella typhimurium and a comparison of this sequence with the homologous operon of Escherichia coli; Erickson BD et al.; In Escherichia coli the genes encoding ribosomal protein S21 (rpsU), DNA primase (dnaG), and the 70-kDal sigma subunit of RNA polymerase (rpoD) are contained in a single operon . These gene products are involved in the initiation of translation, DNA replication, and transcription, respectively . We have examined the homologous region in the closely related bacterium Salmonella typhimurium and have found that the same three genes are similarly organized . We have sequenced the DNA for this operon in S . typhimurium and have compared the (nt) nucleotide and amino acid (aa) sequences with E . coli . In the coding regions, the sequence conservation varies from extremely high for rpsU to moderate for dnaG with respect to both nt and aa sequence . In the noncoding regions, sequences thought to be important for the regulation of transcription are conserved, while other sequences are not conserved . aa differences in DNA primase and sigma are not randomly distributed and suggest regions that may be important for protein structure or function.

Gene, 1985, 39(2-3), 129 - 40
Cloning and characterization of the multifunctional his-3 gene of Neurospora crassa; Legerton TL et al.; We have cloned the his-3 gene of Neurospora crassa and determined its nucleotide sequence . The gene specifies a protein of 863 amino acids (aa) and contains a 59-bp intron which interrupts aa 800, a proline residue . The 5' end of the his-3 transcript is heterogeneous with major starts 122 and 124 bp upstream from the start codon . There are three possible polyadenylation sites, 119, 120 and 121 bp after the UAA stop codon . The protein shows two regions of homology to the yeast HIS4 gene which correspond to the hisIE and hisD genes of Escherichia coli and Salmonella typhimurium . Northern analysis shows that the level of his-3 mRNA increases severalfold in cultures subjected to histidine starvation.

Mol Gen Genet, 1985, 199(3), 486 - 94
Characterization of the 3' end of the leucine operon of Salmonella typhimurium; Friedberg D et al.; The nucleotide sequence of the leuD gene of Salmonella typhimurium and of the downstream flanking region are presented . S1 mapping experiments identified 3' endpoints of leu mRNA 140 and 285 nucleotides downstream of the UAA stop codon of leuD mRNA . Experiments employing pulse-labeled RNA suggest that these endpoints result from transcription termination rather than RNA processing . Our results indicate that the organization of the 3' non-translated region of the leu operon from S . typhimurium resembles that of the trp operon of Escherichia coli . Further, our results suggest that the leu operon of S . typhimurium does not contain structural genes other than those identified by genetic experiments, i.e . leu, A,B,C and D.

Mol Gen Genet, 1985, 199(3), 406 - 9
Refined genetic analysis of the region II che mutants in Salmonella typhimurium; Kutsukake K et al.; From a detailed complementation analysis of the region II che mutants of Salmonella typhimurium, we have located five che genes, cheA, cheW, cheR, cheB, and cheY . We have shown that corrections are required in the previous assignment of the mutations in four strains: both SL2514 and SL2515 which have been reported to be cheY mutants are cheR mutants, SL2539 is not a cheA but a cheW mutant, and ST171 which has been reported to be a cheZ mutant is a double mutant with defects in both cheA and cheB . Since ST171 is the only "cheZ mutant" so far isolated, the idea that the cheZ gene might play an essential role in chemotaxis in S . typhimurium as in Escherichia coli has lost its experimental basis . Furthermore, a number of deletion mutants in region II resulting from the excision of Tn10 have been isolated and analysed . From these experiments, we propose that the gene order in region II is flaK-flaE-motA-motB-cheA-cheW-cheR-cheB-++ +cheY-flaM-flaC, which is identical with that in E . coli.

Gene, 1985, 35(1-2), 187 - 97
Cloning and initial characterization of the metJ and metB genes from Salmonella typhimurium LT2; Urbanowski ML et al.; The metJ and metB genes of Salmonella typhimurium have been cloned into Escherichia coli K-12 on a 19-kb EcoRI fragment in the plasmid vector pACYC184 . The presence of a functional metB+ gene on this plasmid, designated pGS89, was demonstrated by its ability to complement a metB- E . coli mutant . The presence of a functional metJ+ gene on this plasmid was demonstrated by its ability to repress metC+ gene expression in a metJ- mutant transformed with this plasmid . The metJ gene product was identified in a minicell system as a polypeptide of Mr 12000 . This polypeptide was not produced when the metJ gene was inactivated by insertion of a Tn5 element . Transformation of an E . coli metB- mutant with plasmid pGS89 (metB+, metJ+) results in transformants that grow slowly on glucose-minimal medium or glucose-minimal medium supplemented with homocysteine . Methionine addition, however, restores normal growth . This phenotype requires the relA- mutation in the host strain and at least two other plasmid loci, one of which is the metJ+ gene . Transformation of an E . coli metJ- mutant with metJ- derivatives of plasmid pGS89 results in transformants that are unable to grow on either glucose-minimal medium or glucose-minimal medium supplemented with methionine . This phenotype requires the presence of a functional metB+ gene on the plasmid, and is unrelated to the status of the relA gene.

Gene, 1985, 34(1), 111 - 22
The araBAD operon of Salmonella typhimurium LT2 . I . Nucleotide sequence of araB and primary structure of its product, ribulokinase; Lin HC et al.; Hybrid plasmids containing the araBAD operon of Salmonella typhimurium LT2 were characterized by Southern blot and genetic analyses . The nucleotide sequence of araB was determined . The araB gene product, ribulokinase (EC 2.7.1.16), was purified and the results of amino acid composition analysis and partial amino acid sequence are in agreement with predictions from the DNA sequence . Ribulokinase is 569 amino acid residues long and has a calculated Mr of 61 793 . Ribulokinase shares significant homology with xylulose kinase from Escherichia coli . Codon usage in the araB gene does not favor those codons which have intermediate codon-anticodon binding energy.

Toxicon, 1985, 23(1), 157 - 72
Enterotoxin-induced fluid accumulation during experimental salmonellosis and cholera: involvement of prostaglandin synthesis by intestinal cells; Duebbert IE et al.; Challenge of rabbit intestinal loops with Salmonella typhimurium or Vibrio cholerae resulted in significant elevation of mucosal cyclic adenosine monophosphate (cAMP) and prostaglandin concentrations . This effect could be reproduced in vitro by exposing either isolated epithelial cells from normal rabbits or Chinese hamster ovary cells to purified cholera toxin or cell-free lysates of Salmonella . Indomethacin treatment of animals challenged with Salmonella resulted in less fluid accumulation, in addition to lower concentrations of intestinal cAMP and prostaglandins, compared to that of similarly changed loops in normal animals . Likewise, intestinal loop challenge of indomethacin-treated rabbits with V . cholerae or purified cholera toxin also resulted in decreased fluid secretion and diminished levels of tissue cAMP and prostaglandins . Intestinal loop tissue from normal animals challenged with V . cholerae displayed 10-fold higher levels of prostaglandins than tissue from uninfected animals . Prostaglandin levels in Salmonella-infected intestinal loops were similarly elevated, but by only 2-3 fold . Chinese hamster ovary cell monolayers were simultaneously exposed to either 10 ng of cholera toxin or 20 microliter of Salmonella lysate and varying concentrations of indomethacin ranging from 1 ng/ml to 10 micrograms/ml . Indomethacin decreased both cAMP and prostaglandin levels in Chinese hamster ovary cells . At high indomethacin concentrations, the cells lost their ability to respond to stimulation with either cholera toxin or Salmonella lysate, while retaining greater than 95% viability as determined by trypan blue exclusion . The prostaglandin and cAMP content of epithelial cells from Salmonella-challenged loops was increased in crypt epithelial cell fractions . Prostaglandin concentrations were elevated in isolated intestinal epithelial cells exposed to purified cholera toxin in vitro . These data indicate that prostaglandins synthesized by the epithelial cells are involved in the pathogenesis of both experimental cholera and salmonellosis . The data are consistent with an enterotoxin-mediated mechanism for both diarrheal diseases and argue against the role of inflammatory cells as the source of elevated cAMP and prostaglandins appearing in the intestinal mucosa during experimental salmonellosis.

Plasmid, 1985 Jan, 13(1), 75 - 7
Restriction endonuclease mapping of R27 (TP117), an incompatibility group HI subgroup 1 plasmid from Salmonella typhimurium; Taylor DE et al.; A circular map of the IncHI plasmid R27 corresponding to a genome size of 182 kb was established using the restriction endonucleases ApaI, XbaI, and PstI . The map was derived from the results obtained by hybridizing individual ApaI and XbaI fragments to blotted digests of the plasmid, as well as from complete and partial digests . Analysis of a deletion mutant derived by in vitro digestion with PstI and of transfer-defective and tetracycline-sensitive deletion mutants of R27 derived by Tn5 insertion were instrumental in determining the positions of some fragments.

Dev Biol Stand, 1985, 61, 233 - 40
Immunomodulation by Bordetella pertussis: antiviral effects; Winters AL et al.; Treatment of mice by intraperitoneal inoculation of pertussis vaccine or lipopolysaccharide extracted from B . pertussis will effect resistance to rabies virus, encephalomyocarditis virus, Semliki Forest virus, and Herpes simplex virus . Our previous observations indicated that treatment of C3H/HeN (+/nu) and BDF1 mice with pertussis vaccine injected i.p . five days prior to a mouse adenovirus lethal dose i.p . challenge elicited resistance to clinical disease and death . Susceptibility returned to a portion of the test population 35 days after pertussis vaccine treatment . The pertussis vaccine induced resistance developed in athymic (nude) mice also; however, the population succumbed to infection 35 days later . Titration of pertussis vaccine with respect to induction of resistance indicated the median effective dose (ED50) was approximately 25 micrograms dry weight . This report describes the antiviral activity of acellular components extracted from pertussis vaccine . Extraction of B . pertussis cells with 1.0M NaCl and ammonium sulfate fractionation (20-40% saturation) of the extract resulted in an acellular preparation that induced resistance to lethal dose mouse adenovirus infection . The resistance inducing activity was retained after treatment of the extract with detergent (GAF Emulphogene BC 720) to remove lipopolysaccharide and adsorption to alum gel . Comparison of endotoxin content of pertussis vaccine acellular fractions, polysaccharide fraction and purified lipopolysaccharide suggested that endotoxin probably plays a role in the induction of resistance . The endotoxin content of a Emulphogene-treated preparation that protected 80% of a test population was 39 ng . The lipopolysaccharide extracted from Escherichia coli, Vibrio cholerae, Salmonella typhimurium, and Salmonella minnesota did not induce a resistant state seven days after administration; however, lipopolysaccharide extracted from B . pertussis induced a resistant state.(ABSTRACT TRUNCATED AT 250 WORDS)

Teratog Carcinog Mutagen, 1985, 5(5), 339 - 45
Propyldazine is mutagenic in Salmonella typhimurium and Escherichia coli: distinct specificity for strains TA1537 and TA97; Glatt H et al.; The antihypertensive drug propyldazine (Atensil) was demonstrated to be mutagenic with auxotrophic mutants of Salmonella typhimurium and Escherichia coli . Addition of liver S9 mix (postmitochondrial supernatant fraction supplemented with an NADPH-generating system) had little, if any, effect on the mutagenicity . The mutagenicity showed an unusual pattern of strain specificity . Increased frequencies of reversion were observed with all strains whose auxotrophy was caused by frame-shift mutations: the number of revertant colonies per plate from S . typhimurium TA98, TA1538, TA97, and TA1537 was increased up to 5-, 9-, 43-, and 160-fold, respectively, above background . Among the strains that became auxotrophic by substitution mutations, S typhimurium TA102, E . coli WP2, and E coli WP2 uvrA yielded positive results (twofold above background) . S . typhimurium TA1535 and TA100 were not reverted by propyldazine . It should be noted that propyldazine, due to its low toxicity and good solubility, could be tested up to very high doses . Hence, although quite impressive mutagenic effects occurred, the mutagenic potency was moderate even in the most responsive strains, TA1537 and TA97 (about 0.3 and 1.0 revertants per nmole, respectively) . With the limitation that the strain specificities were different, the mutagenic potency of propyldazine was in the same order of magnitude as that of hydralazine and dihydralazine, two related antihypertensive drugs which were already known to be mutagenic . In our hands, both compounds were mutagenic in S typhimurium TA1535, TA100, TA1537, and TA98 . These results differ from data in the literature in that we found clear but weak effects even with strains for which others have reported negative results.

Teratog Carcinog Mutagen, 1985, 5(3), 195 - 203
The mutagenicity of sodium bisulfite on base-substitution strains of Salmonella typhimurium; De Giovanni-Donnelly R; The mutagenic effects of sodium bisulfite on Salmonella typhimurium LT2 strains carrying the hisG46 allele were investigated . Treating the cells with 1 M sodium bisulfite in 0.2 M acetate buffer (pH 5.2) for various time intervals at 37 degrees C resulted in an increase in the yield of mutants above the spontaneous level . The fold enhancement of the mutant yield and the fold enhancement of the mutant frequency were greatest for the parent strain hisG46 with wild type DNA repair; the derived strains with reduced repair capacity responded to a lesser degree . While sodium bisulfite was mutagenic when tested in liquid suspension assays, strain hisG46 did not respond when the standard Ames plate incorporation assay was used . The greater mutagenic response in repair-proficient strains suggests that normal repair capacities may favor the mutagenic activity of sodium bisulfite . Transduction studies demonstrated that mutations of his+ were closely linked to the hisD gene, and probably were in the structural hisG gene itself.

Boll Ist Sieroter Milan, 1985, 64(3), 247 - 8
Epidemiological value of the gamma-glutamyltransferase test in Salmonella typhimurium; Nastasi A et al.; The simple and rapid method of Giammanco et al . (1980) has been used for the detection of the gamma-glutamyltransferase (gamma-GT) by means of a chromogenic substrate in 803 endemic and epidemic strains of Salmonella typhimurium from Southern Italy . About 20% of the strains have been proved gamma-GT negative . Both in endemic and epidemic isolates, negative and positive strains were respectively belonging to different phage types . The reported data suggest that the presence or absence of the gamma-GT in S . typhimurium is an epidemiological marker quickly and easily detectable by the described chromogenic test.

Teratog Carcinog Mutagen, 1985, 5(1), 63 - 73
Mutagenic activation of 2-aminofluorene by fluorescent light; White GL et al.; To determine the effect of artificially produced light on the direct mutagenicity of 2-aminofluorene, that arylamine was irradiated with either sun, cool-white, black, blue, or yellow fluorescent light or held in the dark prior to assaying for mutagenicity using Salmonella typhimurium strain TA98 . The effectiveness of these exposures in potentiating the mutagenicity of 2-aminofluorene was sun greater than black greater than cool-white greater than blue greater than yellow approximately equal to dark . By varying the radiant flux densities produced by the lamps and using optical filters, wavelengths of light up to approximately 450 nm were found to be effective in the mutagenic potentiation . Studies using radical scavengers and oxygen modifiers indicated that the light-induced mutagenicity was dependent on oxygen and that singlet oxygen may be an effective activator of 2-aminofluorene . The mutagenicity of fluorene was not increased by exposure to light, while only sunlight potentiated the mutagenicity of 2-acetylaminofluorene . This result suggested the importance of the primary amine in the mutagenic activation of 2-aminofluorene by light . Light-activated 2-aminofluorene was less mutagenic in strains TA98NR and TA98/1,8-DNP6 than in TA98 . This observation, combined with the dependence of the photoactivation on oxygen and amino-substitution, indicated that the light-enhanced mutagenicity was at least partially due to N-oxidized photoproducts . These studies indicate that the effect of light on environmental contaminants must be considered in assessing their genotoxic potential.

Teratog Carcinog Mutagen, 1985, 5(1), 29 - 40
Effects of vitamins A, C, and E on aflatoxin B1-induced mutagenesis in Salmonella typhimurium TA-98 and TA-100; Raina V et al.; The effects of retinoids (vitamin A analogs) and vitamins C and E on the aflatoxin B1 (AFB1)-induced mutagenesis in Salmonella typhimurium TA-98 and TA-100 were investigated . The bioassay was performed under conditions that permitted the effects of vitamins on carcinogen metabolism to be assessed separately from effects on the expression of the mutated bacterial cell . Both retinoic acid and retinol inhibited (up to 50%) AFB1-induced mutagenesis in S . typhimurium TA-98, but only retinol inhibited (up to 75%) mutagenesis in TA-100 . Retinoic acid inhibition of mutagenesis in S . typhimurium TA-98 was pronounced over a wide concentration range (i.e., 2 X 10(-10) to 2 X 10(-8) M) however, at the higher concentrations (i.e., 2 X 10(-8) to 2 X 10(-6) M range) the predominant effect was the inhibition of the metabolism of AFB1 to its mutagenic metabolites . Vitamin E was more potent in inhibiting the expression of AFB1-induced mutagenesis than vitamin C . However, the major inhibitory effects of vitamin E were related to the metabolism of AFB1, whereas vitamin C was inhibitory at both metabolic and the post-metabolic levels of the AFB1 mutagenesis assay . The results of these investigations suggest that vitamins A, C, or E inhibit both AFB1 metabolism to its mutagenic metabolites as well as the expression of AFB1-induced mutated bacterial cells.

Mutat Res, 1985 Jan-Feb, 155(1-2), 27 - 33
Photodecomposition of 1-nitropyrene and other direct-acting mutagens extracted from diesel-exhaust particulates; Stark G et al.; The effect of irradiation with wavelengths of 320-418 nm on direct-acting mutagenicity of 1-nitropyrene (1-NP) and particulate-matter extracts of a direct-injecting diesel engine was examined . The activity of samples in the Ames test with and without addition of S9 mix in Salmonella typhimurium strain TA98, TA100 and TA1538 decreased with increasing irradiation energy . Visible light was sufficient to destroy the mutagenicity of a 0.1-mM 1-NP solution . The same was true for particulate matter crude extracts as well as the transitional and oxygenate subfractions isolated by column chromatography . UV spectroscopy, thin-layer chromatography and GC-MS analysis were performed to characterize the irradiation products of 1-NP . The mechanism of photodecomposition of 1-NP at different wavelengths and the significance of this finding for the evaluation of health risks from diesel vehicles are discussed.

Acta Microbiol Pol, 1985, 34(3-4), 287 - 92
Bioindication of mutagenic and carcinogenic pollutants in waters of the Oława River; Pawlaczyk-Szpilowa M et al.; Samples of raw waters from the Olawa River, chlorinated raw water, raw water filtered through activated charcoal and treated and chlorinated water before and after ozonization were examined with the use of the Ames test for potential carcinogenic activity . Positive results were obtained for raw water with Salmonella typhimurium strains TA 98 and TA 1535 and for chlorinated raw water with strain TA 1537.

Int Arch Allergy Appl Immunol, 1985, 78(4), 353 - 7
The effects of binding mouse IgA to dinitrophenylated Salmonella typhimurium on physicochemical properties and interaction with phagocytic cells; Edebo L et al.; The binding of mouse IgA antibody to DNP-conjugated bacteria enhanced the hydrophobic interaction when measured in dextran-poly(ethyleneglycol) two-phase systems and hydrophobic interaction chromatography . Similarly the interaction with polymorphonuclear leukocytes in vitro increased . In contrast, the rate of clearance of IgA-reacted bacteria from the blood stream of mice, after intravenous injection, was reduced under the conditions tested . Our data showed, with respect to increased hydrophobic interaction and opsonization, that binding of IgA antibody to bacteria produced less pronounced effects than those of IgG antibody binding . In contrast, secretory IgA antibody binding has been shown to reduce hydrophobic interaction and phagocytosis . Thus, serum IgA antibody has properties intermediate to IgG and SIgA with respect to hydrophobicity and opsonization.

Int Arch Allergy Appl Immunol, 1985, 78(4), 345 - 52
Enhancement of hydrophobic interaction, negative charge and phagocytosis by dinitrophenyl ligand coupling to Salmonella typhimurium 395 MS; Edebo L et al.; Dinitrophenylation of Salmonella typhimurium bacteria increased their hydrophobicity, negative charge, and interaction with PMNL in vitro, effects which are similar to the consequences of S-R mutation in S . typhimurium . The effects are ascribed to the hydrophobicity of the dinitrophenyl (DNP) ligand . Coupling of DNP-groups to the bacteria also enhanced their clearance by the reticuloendothelial system after intravenous injection into mice . Extensive DNP-coupling to the bacteria led to rapid deposition of injected bacteria outside the reticuloendothelial system . The kinetics of DNP-coupling showed saturation at 4-5 X 10(7) DNP groups per bacterium, similar for S and R bacteria, boiled and nonboiled . After 2 h of reaction with fluoro-2,4-dinitrobenzene (FDNB) more than 80% of the total DNP coupling observed after 4 h had occurred . The capacity of MOPC-315 IgA myeloma protein, which possesses anti-DNP activity, to bind to dinitrophenylated bacteria paralleled the number of DNP groups per bacterium, but smaller numbers of IgA molecules were bound . Approximately one IgA molecule bound per thousand DNP ligands . Only when bacteria were boiled prior to DNP coupling was agglutination observed after the addition of anti-DNP-IgA.

CRC Crit Rev Biochem, 1985, 19(2), 145 - 90
Porin from bacterial and mitochondrial outer membranes; Benz R; The outer membrane of gram-negative bacteria acts as a molecular filter with defined exclusion limit for hydrophilic substances . The exclusion limit is dependent on the type of bacteria and has for enteric bacteria like Escherichia coli and Salmonella typhimurium a value between 600 and 800 Daltons, whereas molecules with molecular weights up to 6000 can penetrate the outer membrane of Pseudomonas aeruginosa . The molecular sieving properties result from the presence of a class of major proteins called porins which form trimers of identical subunits in the outer membrane . The porin trimers most likely contain only one large but well-defined pore with a diameter between 1.2 and 2 nm . Mitochondria are presumably descendents of gram-negative bacteria . The outer membrane of mitochondria contains in agreement with this hypothesis large pores which are permeable for hydrophilic substances with molecular weights up to 6000 . The mitochondrial porins are processed by the cell and have molecular weights around 30,000 Daltons . There exists some evidence that the pore is controlled by electric fields and metabolic processes.

Environ Mutagen, 1985, 7(4), 489 - 500
Metabolic activation of organic extracts from diesel, coke oven, roofing tar, and cigarette smoke emissions in the Ames assay; Williams K et al.; Four environmental emissions samples were ranked by their genotoxic potency in several bioassays . Although the relative potency of a series of automotive emissions (diesel and gasoline) in the Ames assay correlated well with the relative potency in mammalian cell and mouse skin, this was not the case for the coke oven, roofing tar, and cigarette smoke condensate (CSC) emissions . This study examines the role of metabolic activation in determining the difference between a microbial and a mammalian bioassay in ranking the genotoxic potency of these environmental emissions . Uninduced and Aroclor 1254-induced S9 from both rat and hamster liver were compared as the metabolic activator in the Ames assay with Salmonella typhimurium TA98 . The diesel emissions sample was direct-acting while the other samples required activation . The standard S9 concentration (only Aroclor-induced rat, approximately 1.25 mg protein/plate) also produced the maximum mutagenic activity . Induced S9s produced higher mutagenic activity than uninduced . The hamster S9 gave significantly higher mutagenic activities than rat S9 for the coke oven and CSC . The relative potency of these four samples was not significantly different between the microbial (Ames), mammalian cell (mouse lymphoma), and tumor initiation (mouse skin) assays . These results suggest that the differences observed between the relative mutagenic activity of these emissions in the mammalian cell and microbial assays was not due to a lack of optimization of the S9 system but may be inherent in the different response of the indicator cells to different chemical classes.

Environ Mutagen, 1985, 7(4), 471 - 87
Mutagenicity of the fractionated organic emissions from diesel, cigarette smoke condensate, coke oven, and roofing tar in the Ames assay; Austin AC et al.; Mobile and stationary combustion sources emit particle-bound organics that, after extraction, are mutagenic to Salmonella typhimurium . In this study, the organic emissions from diesel, cigarette smoke condensate (CSC), coke oven, and roofing tar were fractionated and compared for mutagenicity in the Ames assay . This study demonstrated major differences in the distribution of mutagenicity among the four emission sources . Within each source, the relative mutagenicity of each fraction was significantly different in the presence and absence of an exogenous metabolic activation . In the diesel sample, over 90% of the mutagenic activity is located in the aromatic and polar neutral (PN) fractions; nitrated polynuclear aromatic hydrocarbons (NO2-PNAs) can account for a significant portion of this activity . Most of the mutagenicity of the coke oven main sample was found in the organic base (BASE) and PN fractions, which contained aromatic amines and nitrogen heterocycles . The CSC sample also had a high percentage of the mutagenic activity in the BASE fraction . Chemical analysis, however, indicates that the components in the CSC differed from those of the coke oven main sample . The roofing tar sample, which was not mutagenic in the absence of metabolic activation, contained several components that were very mutagenic after fractionation . This may be due to the separation of toxic components from the mutagenic components . The roofing tar emissions contained aromatic and polar mutagenic constituents . Although the specific mutagens in these different sources are not identical, they all cause frameshift mutations and appear to be compounds that could be classified as polycyclic organic matter.

J Biol Chem, 1984 Dec 25, 259(24), 15212 - 4
The primary structure of Salmonella typhimurium HPr, a phosphocarrier protein of the phosphoenolpyruvate:glycose phosphotransferase system . A correction; Powers DA et al.; The protein HPr is a low-molecular-weight phosphocarrier protein of the bacterial phosphoenolpyruvate:glycose phosphotransferase system . We have recently reported the complete primary amino acid sequence of HPr isolated from Salmonella typhimurium (Weigel, N., Powers, D.A., and Roseman, S . (1982) J . Biol . Chem . 257, 14499-14509) . This sequence is incorrect at certain residues; the correct primary structure of the protein is presented in this report . The corrected structure generally agrees with the primary sequence predicted for HPr from Escherichia coli (based on the nucleotide sequence of the corresponding ptsH gene) . The one apparent ambiguity is at the carboxyl terminus.

Biochem Pharmacol, 1984 Dec 15, 33(24), 4051 - 6
Regiospecific and diastereoselective inactivation of mutagenic 9,10-dihydrobenzo{a}-pyrene 7,8-oxide by hepatic cytosolic glutathione S-transferase; Watabe T et al.; Racemic, (7R,8S)-(+)-, and (7S,8R)-(-)-9,10-dihydrobenzo{a}pyrene 7,8-oxides (DBPOs) showed markedly different mutagenicity towards Salmonella typhimurium TA 98 in the order of (7R,8S)-(+)- greater than racemic greater than (7S,8R)-(-)-DBPOs . The enantiomeric epoxides were inactivated at significantly different rates by preincubating with rat liver cytosol fortified with glutathione (GSH) in the order of (7S,8R)-(-)- greater than racemic greater than (7R,8S)-(+)-DBPOs . Two non-mutagenic water-soluble metabolites were isolated from the preincubation mixture containing racemic DBPO as a substrate, separated by hplc, and identified by 13C nmr and uv absorption spectroscopy as diastereoisomers of S-(8-hydroxy-7,8,9,10-tetrahydrobenzo{a}pyren-7-yl)glutathione (conjugates I and II) . Conjugates I and II were specifically yielded from (7R,8S)-(+)- and (7S,8R)-(-)-DBPOs, respectively, at different rates by rat liver cytosol; apparent values of Km were 20.1 and 15.6 microM and of Vmax 17.2 and 26.7 nmole/mg protein/min for (7R,8S)-(+)- and (7S,8R)-(-)-DBPOs, respectively . Conjugates I and II, therefore, were reasonably assigned to have (7S,8S)- and (7R,8R)-configurations, respectively . Conjugate II was yielded preferentially to conjugate I from racemic DBPO at an early stage of the enzyme reaction.

Atherosclerosis, 1984 Dec, 53(3), 331 - 6
A search for mutagens in human aortal lipid extracts; Johnson BH et al.; In view of hypotheses suggesting mutagenesis is implicated in atherosclerosis, a total of 18 lipid extracts of human aortal tissues was examined by the standard Ames mutagenicity bioassay using Salmonella typhimurium or by a liquid modification thereof . One lipid extract of intimal-medial tissue contained detectable mutagenic activity against test strain TA98 in the liquid medium bioassay and against TA1538 in the standard plate assay following metabolic activation . Six other samples appeared to have weak activity against strains TA98, TA1538, or TA100 . The other aortal samples were nonmutagenic.

Carcinogenesis, 1984 Dec, 5(12), 1745 - 7
N-Nitroso-2-hydroxymorpholine, a mutagenic metabolite of N-nitrosodiethanolamine; Hecht SS; N-Nitroso-2-hydroxymorpholine was synthesized from N-(2-hydroxyethyl)aminoacetaldehyde diethylacetal by nitrosation and hydrolysis . It was detected as a metabolite of N-nitrosodiethanolamine in rat hepatic 9000 g supernatant . It was mutagenic toward Salmonella typhimurium TA 1535, with and without activation . The results suggest that N-nitroso-2-hydroxymorpholine, which is formed by metabolic beta-oxidation of N-nitrosodiethanolamine, could be involved in carcinogenesis by N-nitrosodiethanolamine.

Carcinogenesis, 1984 Dec, 5(12), 1709 - 15
Enhancement of the mutagenicity of carcinogenic arylamines by ethinyl estradiol; Purdy RH et al.; Ethinyl estradiol, the estrogenic component of oral contraceptives, has been shown to enhance the mutagenicity of 2-aminofluorene, 2-acetylaminofluorene, N-hydroxy-2-acetylaminofluorene, and N-acetoxy-2-acetylaminofluorene with strain TA 98 of Salmonella typhimurium and various rat liver activating systems . The magnitude of the enhancement of mutation produced by ethinyl estradiol is dependent upon: the type of mixed-function oxidase inducer of the liver activating system; the structure and concentration of the arylamine; the concentration of ethinyl estradiol; and metabolism of ethinyl estradiol to its catechol, 2-hydroxyethinyl estradiol, by the activating system . Moxestrol, a biologically potent estrogenic derivative of ethinyl estradiol which is not metabolized effectively to its catechol by the mixed-function oxidases, does not enhance the mutagenicity of the above arylamines and related compounds . Both 2-hydroxyethinyl estradiol and 2-hydroxymoxestrol enhance the mutagenicity of 2-aminofluorene and 2-acetylaminofluorene . Neither the estrogens nor their catechols are mutagenic by themselves in this system . In the presence of ethinyl estradiol, a marked inhibition of ring hydroxylation of 2-acetylaminofluorene was demonstrated . Since ring hydroxylation is a well established detoxification pathway of arylamine and arylamide metabolism, the enhancement of mutagenicity by ethinyl estradiol may be the result of a net increase in N-hydroxylation of arylamines and arylamides.

Carcinogenesis, 1984 Dec, 5(12), 1637 - 40
Comparative genotoxicity of nitrogen mustard and nor-nitrogen mustard; Hartley-Asp B et al.; Nitrogen mustard and nor-nitrogen mustard were investigated in Salmonella typhimurium and human lymphocytes for genotoxicity . Point mutations were assessed using the plate test, the conventional spot test and a method in which the substances were not in direct contact with the microorganisms . Both compounds were active, but nor-nitrogen mustard was far more potent than nitrogen mustard in all bacterial systems . Cytogenetic experiments with human lymphocytes revealed that both compounds induced a dose dependent increase in chromosomal aberrations and sister chromatid exchanges, but that nitrogen mustard was 10 times more potent than nor-nitrogen mustard . Thus, the spectrum of activity for nor-nitrogen mustard and nitrogen mustard differ . Nor-nitrogen mustard was more effective in inducing point mutation damage than nitrogen mustard and a reversal of potency was found for cytogenetic damage . These results indicate that although these two substances induce the same type of DNA lesions the amounts of the different DNA adducts vary.

Zentralbl Bakteriol Mikrobiol Hyg {A}, 1984 Dec, 258(4), 544 - 63
{Epidemiology and phage typing of Salmonella typhimurium in Austria 1980-1982}; Thiel W et al.; From 1980 to 1982 a total of 4541 strains of S . typhimurium of human origin and 745 S . typhimurium of non-human sources were received by the Salmonella Centre . During this period, the percentage of S . typhimurium rose from 33% to 51% (human origin) and from 12% to 33% (non-human origin), respectively . The incidence of infection was 20.0, the regional distribution showed a prominence of the eastern and western parts of Austria with Styria as leading country (46.2) . 60% of the isolates of S . typhimurium were associated with illness, which was 10% more than for the other salmonellae; concerning outbreaks as well as single cases, S . typhimurium dominated, whereas the proportion of carriers of S . typhimurium among foodhandlers was small (12% S . typhimurium, 31% other salmonellae) . As to the age-specific attack-rate, children younger than 5 years by far predominated with 67.2, with a falling tendency in the other age groups . As far as food is concerned, the increase of S . typhimurium in poultry is particularly striking . According to the phage-typing results, LT 10 was prominent in the years 1980 and 1981, whereas in 1982, LT 66, accounting for 62% out of 2201 tested human isolates dominated among 44 different phage-types as epidemic strain, especially in Styria and eastern Austria . In addition, LT 10 and LT 3 could be found more frequently . Starting from the important role of food in Salmonella associated enteritis, LT 66 leads to chicken as the main source of infection . Apart from LT 66, LT 1, 2, 3 and LT 140 were more frequent in non-human isolates . This infiltration of LT 66 into the Austrian chicken industry could have its origin in imported parent chickens . As mechanism the single replacement of LT 10 by LT 66 is discussed as well as the phage-conversion of LT 10 . The other possible chains of infection (other poultry, feeding-staff, man) are regarded as less probable . To prove this thesis investigations on plasmids should be done.

Aust J Exp Biol Med Sci, 1984 Dec, 62 ( Pt 6), 755 - 61
Infections with Salmonella typhimurium and Nippostrongylus brasiliensis in mice selectively reared for high or low immune responsiveness to Nematospiroides dubius; Sitepu P et al.; Mice which had been selectively reared over six generations for high (H) and low (L) immune responsiveness to N . dubius (Sitepu and Dobson, 1982) were infected with Salmonella typhimurium and N . brasiliensis to examine the specificity of the selection process for heterologous infections . H mice were marginally more susceptible than L mice to S . typhimurium, whereas H mice were more resistant to infection with N . brasiliensis than L mice . Both H and L mice were protected against N . dubius following immunization with N . brasiliensis larvae.

Zh Mikrobiol Epidemiol Immunobiol, 1984 Dec, (12), 107 - 10
{Mechanism of action of N-acetylglucosaminyl-N-acetylmuramylalanyl-D-isoglutamine on the nonspecific anti-infection resistance of mice}; Kalina NG et al.; The stimulating influence of glucose-containing muramyldipeptide (GMDP) on the nonspecific resistance of mice was shown to depend on the features of the pathogenesis of the infection . Thus, the intraperitoneal injection of GMDP increased the survival rate of mice infected with Escherichia coli, but had no stimulating effect on the resistance of the animals to Salmonella typhimurium natural infection in whose pathogenesis macrophages played an essential role . Experiments demonstrated that GMDP was capable of enhancing the ingestive function of macrophages, but did not increase their bactericidal activity with respect to this infection.

J Gen Microbiol, 1984 Dec, 130 ( Pt 12), 3339 - 42
Genetic analysis of three additional fla genes in Salmonella typhimurium; Yamaguchi S et al.; In Salmonella typhimurium, 27 fla genes responsible for formation of flagella have been identified and assigned to three regions on the genetic map, termed fla regions I to III . By genetic analysis of 1984 non-flagellate mutants obtained from a phase-1 stable strain of S . typhimurium, SJW1103, three additional fla genes were identified; one, termed flaW, was assigned to fla region I and the other two, termed flaV and flaX, to fla region III . By intergeneric complementation tests, the flaW, flaV and flaX genes were shown to be functionally homologous with flaS, flbC and flaP of Escherichia coli, respectively . Electron microscopy showed that flaW and flaV mutants carried hook-basal body structures.

J Clin Microbiol, 1984 Dec, 20(6), 1076 - 9
Outbreak of Salmonella typhimurium gastroenteritis due to an imported strain resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole in a nursery; Lamb VA et al.; An outbreak caused by a highly resistant strain of Salmonella typhimurium occurred in a nursery at a university medical center . The outbreak strain, which was resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole, was apparently imported from the Far East by a Cambodian refugee . The five patients involved had severe underlying diseases, and bacteremia and meningitis developed in one of these patients . The only reservoir identified was the gastrointestinal tracts of the infected patients, and infection was probably transmitted by the contaminated hands of hospital personnel . The outbreak was rapidly brought under control by isolating cases outside of the nursery and by instituting enteric precautions for infants who remained in the nursery . When compared by disk diffusion susceptibility tests with 353 strains of S . typhimurium tested at the Centers for Disease Control, the imported strain had a unique antibiogram . Bacteriophage typing of the strains revealed that all were untypable; this, in itself, was a good marker, because only 5 to 10% of S . typhimurium isolates in this country have this property . Agarose gel electrophoresis of isolates from the five patients revealed an identical plasmid banding pattern consisting of three large and three small plasmids . Highly resistant strains of S . typhimurium imported from the Far East may spread rapidly when introduced into a hospital nursery . Prompt institution of control measures may limit the outbreak and prevent systemic infections for which there are few effective therapeutic agents.

Mutat Res, 1984 Dec, 129(3), 299 - 310
A dual assay for the specific screening of 3-methylcholanthrene- and phenobarbital-like chemical inducers of cytochrome P-450 monooxygenases; Lesca P et al.; We present and evaluate a dual assay, the CYPIA (Cytochrome P-450 induction assay) for the detection and the simultaneous identification of chemicals belonging either to the 3-methylcholanthrene or phenobarbital classes of cytochrome P-450 monooxygenase inducers . These inducers play an important role in the mutagenic activation of chemical compounds as well as in many pharmacological and toxicological events and therefore should be screened by drug and chemical designers . After treatment of male rats or mice by chemicals, the liver preparations (S9) have been used in the Salmonella typhimurium test, to activate either ethidium bromide or cyclophosphamide into mutagenic metabolites . These transformations are specifically catalyzed by cytochrome P-450-dependent monooxygenases induced by 3-methylcholanthrene-like and phenobarbital-like chemical inducers, respectively . The mutagenicity data were strikingly correlated with other methods (production of {3H}benzo{a}pyrene bay-region metabolites, benzphetamine demethylase activity, immunological double-diffusion analysis) . Compared to the latter methods, the CYPIA, based on a single and widespread technology, introduces an interesting simplification, and improves the specificity and the sensitivity of the responses.

J Hyg (Lond), 1984 Dec, 93(3), 539 - 46
Further observations on the excretion of salmonella in the faeces of calves fed milk substitute; Hinton M et al.; Swabs of rectal faeces were obtained daily for 28 days from 90 calves reared in five batches during the summer of 1983 . The calves were purchased unweaned in markets and fed a milk-substitute diet . Salmonella typhimurium phage type DT204c was isolated from calves in four batches and Salmonella newport from one . When the data from the 90 calves were considered together the incidence of salmonellas, excretion rose to peak between 5 and 7 days after purchase before declining to low levels during the fourth week . Salmonella was isolated from 55 (61%) calves; 30 were positive on up to four occasions while 21 and 4 animals respectively were positive between 5 and 11 and 15 and 20 times . In the majority of animals infection was probably subclinical since treatment with antibacterial drugs and excretion of S . typhimurium coincided in four calves only.

Food Chem Toxicol, 1984 Dec, 22(12), 971 - 5
Ames mutagenicity tests of overheated brewed coffee; Blair CA et al.; Five kinds of coffee samples were prepared from a commercial drip-grind coffee in order to examine the mutagenicity of brewed coffee using the Ames test . The samples prepared were a thick coffee syrup, coffee solid residues, dichloromethane and ethanol extracts of solid residues, a dichloromethane extract of a distillate from normally heated brewed coffee and dichloromethane extracts of distillates from overheated (150-300 degrees C) brewed coffee . The samples were tested for mutagenicity towards Salmonella typhimurium strains TA98 and TA100 both with and without metabolic activation (S-9 mix) . Only the extracts of the distillates obtained from coffee heated to 150 degrees or 300 degrees C exhibited mutagenicity towards strain TA98 with S-9 mix.

J Bacteriol, 1984 Dec, 160(3), 1041 - 6
Role of protein synthesis in the survival of carbon-starved Escherichia coli K-12; Reeve CA et al.; In a typical Escherichia coli K-12 culture starved for glucose, 50% of the cells lose viability in ca . 6 days (Reeve et al., J . Bacteriol . 157:758-763, 1984) . Inhibition of protein synthesis by chloramphenicol resulted in a more rapid loss of viability in glucose-starved E . coli K-12 cultures . The more chloramphenicol added (i.e., the more protein synthesis was inhibited) and the earlier during starvation it was added, the greater was its effect on culture viability . Chloramphenicol was found to have the same effect on a relA strain as on an isogenic relA+ strain of E . coli . Addition of the amino acid analogs S-2-aminoethylcysteine, 7-azatryptophan, and p-fluorophenylalanine to carbon-starved cultures to induce synthesis of abnormal proteins had an effect on viability similar to that observed when 50 micrograms of chloramphenicol per ml was added at zero time for starvation . Both chloramphenicol and the amino acid analogs had delayed effects on viability, compared with their effects on synthesis of normal proteins . The need for protein synthesis did not arise from cryptic growth, since no cryptic growth of the starving cells was observed under the conditions used . From these and previous results obtained from work with peptidase-deficient mutants of E . coli K-12 and Salmonella typhimurium LT2 (Reeve et al., J . Bacteriol . 157:758-763, 1984), we concluded that a number of survival-related proteins are synthesized by E . coli K-12 cells as a response to carbon starvation . These proteins are largely synthesized during the early hours of starvation, but their continued activity is required for long-term survival.

Infect Immun, 1984 Dec, 46(3), 819 - 25
Flagella help Salmonella typhimurium survive within murine macrophages; Weinstein DL et al.; In this study, we evaluated how flagella enhance the pathogenicity of Salmonella typhimurium in strain C57BL/6J mice . When mice were infected orally with flagellated or nonflagellated S . typhimurium, equivalent numbers of bacteria colonized the gastrointestinal tracts of the animals, but the number of flagellated organisms increased faster once colonization began in the spleens and livers . To evaluate this differential rate of Salmonella growth, the rate of blood clearance, and the kinetics of net multiplication of salmonellae in splenic tissue after intravenous challenge, the two groups of mice were compared . We found that clearance of bacteria from the blood was the same for flagellated or nonflagellated strains . However, the number of flagellated bacteria in the spleen increased logarithmically until the death of the animals, whereas the number of nonflagellated salmonellae increased only slightly . In contrast, both flagellated and nonflagellated strains grew exponentially in the spleens of mice pretreated with silica, a macrophage toxic agent . In an in vitro macrophage assay, flagellated salmonellae survived longer than nonflagellated organisms . These results indicate that flagella either protect S . typhimurium from the intracellular killing mechanisms of murine macrophages or that flagella enhance the ability of S . typhimurium to multiply within murine macrophages.

Infect Immun, 1984 Dec, 46(3), 814 - 8
Flagella of Salmonella typhimurium are a virulence factor in infected C57BL/6J mice; Carsiotis M et al.; To determine whether flagella, chemotaxis, and motility of Salmonella typhimurium are virulence factors in infected C57BL/6J mice, we constructed isogenic pairs of derivatives of the nonfimbriated virulent strain SL3201 . Of each pair, one member contained a mutation in a single gene that is required for expression of normal chemotactically directed motility, whereas the other member contained the wild-type form of the gene . No additional differences between the members of a pair were evident . The phenotypic parameters examined for all derivatives included in vitro growth rate, sensitivity to P22 phage, amino acid auxotrophy, and biotype . For a flagellated and nonflagellated pair, the electron microscopic appearance of each member was examined as well as its lipopolysaccharide and outer membrane profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . The virulence of the various derivatives was then assessed in mice challenged orally, intraperitoneally, or intravenously . The results established that flagella, whether functional or nonfunctional as organelles of motility, were S . typhimurium virulence factors and that neither chemotaxis nor motility was required for virulence.

Infect Immun, 1984 Dec, 46(3), 663 - 7
In vivo analysis of impaired macrophage bactericidal capacity during experimental African trypanosomiasis; Glick DL et al.; Since innate resistance of mice to Salmonella typhimurium depends on an intact macrophage system, we have used this bacterium to investigate the effect of Trypanosoma brucei subsp . rhodesiense infection on macrophage phagocytic and cytolytic function . CBA/CaJ mice infected with T . brucei subsp . rhodesiense have decreased resistance to S . typhimurium, since doubly infected mice rapidly succumb to sublethal doses of S . typhimurium . Although trypanosomiasis is known to suppress antibody formation, such a suppression of antibody does not seem to play a role in trypanosome-induced sensitivity to S . typhimurium . A trypanosome-induced blockade of the reticuloendothelial system also does not occur, since parasitized and control mice clear S . typhimurium from the blood equally well . Early killing (0 to 48 h) of S . typhimurium in the liver and spleen is mainly macrophage mediated, and mice infected with trypanosomes kill S . typhimurium in the liver and spleen very poorly . Apparently trypanosomiasis inhibits macrophage bactericidal activity, but has no effect on phagocytosis.

Cancer Res, 1984 Dec, 44(12 Pt 1), 5599 - 604
Structure-activity relationship of anthracycline-induced genotoxicity in vitro; Westendorf J et al.; Anthracycline antitumor antibiotics, such as Adriamycin and daunomycin, are potent genotoxic agents and carcinogens . A variety of anthracycline derivatives was investigated in various in vitro short-term tests, i.e., mutagenesis in Salmonella typhimurium and V79 Chinese hamster cells and induction of unscheduled DNA synthesis in primary rat hepatocytes . Compounds containing a daunosamine sugar moiety (Adriamycin, daunomycin, 4-demethoxydaunomycin, 4-demethoxyadriamycin, and carminomycin) were highly active in both mutagenesis assays . Addition of S9 to the bacteria and cocultivation of V79 cells with rat hepatocytes, in general, decreased the mutagenicity of these compounds . In contrast, anthracyclines with N-alkylated sugar moieties (aclacinomycin A, marcellomycin, musettamycin, pyrromycin, rudolfomycin, N,N-dimethyladriamycin, N,N-dimethyldaunomycin, N-benzyldaunomycin, N,N-dibenzyldaunomycin, 3'-deamino-3'-methoxypiperidinodaunomycin, morpholinodaunomycin, cyanomorpholinodaunomycin, and cyanomorpholinoadriamycin) were weakly mutagenic or not mutagenic at all in both bacterial and mammalian cells . The two latter compounds were weakly active in the Salmonella/microsome assay only after addition of S9 . Results obtained in the DNA repair studies did not correlate to these mutagenicity data; while most compounds, including Adriamycin and daunomycin, were either weakly active or inactive at inducing unscheduled DNA synthesis in primary rat hepatocytes, morpholinodaunomycin, cyanomorpholinodaunomycin, and cyanomorpholinoadriamycin were extremely active . The results indicate that the mutagenicity of anthracyclines is related more to differences in their sugar moiety than to differences in the chemical structure of their aglycones; N-alkylation of the sugar moiety can abolish or greatly reduce their mutagenic activity . Moreover, induction of unscheduled DNA synthesis, although considered to be due to DNA damage, is not correlated to anthracycline-induced mutations but may possibly indicate covalent DNA interaction.

J Immunol, 1984 Dec, 133(6), 3313 - 8
Genetic control of natural resistance to Salmonella typhimurium in mice during the late phase of infection; O'Brien AD et al.; Previous studies have shown that C57L and DBA/2 mice are able to control the initial net growth of Salmonella typhimurium in splenic and hepatic tissues, but when infected i.p., they ultimately succumb to the typhoid-like disease caused by this Gram-negative bacterium . In this investigation, it was observed that the late-phase susceptibility of both the C57L and DBA/2 strains to murine typhoid was not only evident when mice were challenged i.p., but also when mice were challenged subcutaneously, i.v., and orally . Genetic analyses were then performed to characterize the gene or genes responsible for this susceptibility . The results of such experiments were consistent with the hypothesis that a single autosomal recessive gene is primarily responsible for the susceptibility . This gene was distinct from all other previously defined S . typhimurium response genes . The chromosomal location of the late-phase susceptibility gene could not be determined; no linkage was observed between expression of the late-phase susceptible phenotype and selected markers on chromosomes 1, 2, 4, 5, or 7.

Proc Natl Acad Sci U S A, 1984 Dec, 81(23), 7333 - 7
ATP-binding sites in the membrane components of histidine permease, a periplasmic transport system; Hobson AC et al.; Two components of the histidine permease in Salmonella typhimurium, the membrane-bound P and M proteins, react with the photoaffinity labeling reagent 8-azido-ATP in isolated membranes . The extent of labeling is decreased by the addition of ATP and somewhat less by addition of GTP, CTP, UTP, and ADP . Cyclic AMP, NAD, FAD, and S-adenosylmethionine have little effect . We propose that one or both of these proteins have a site capable of binding an adenine nucleotide and that, therefore, they may be involved in the energy-coupling step in active transport.

Infect Immun, 1984 Dec, 46(3), 677 - 81
Mouse monoclonal antibodies reactive with J5 lipopolysaccharide exhibit extensive serological cross-reactivity with a variety of gram-negative bacteria; Nelles MJ et al.; We describe two mouse monoclonal antibodies reactive with lipopolysaccharide derived from the J5 mutant of Escherichia coli O111:B4 . These antibodies react with purified lipopolysaccharide derived from rough mutants of E . coli and Salmonella typhimurium and also with lipopolysaccharide associated with both smooth- and rough-phenotype, gram-negative bacteria . Both antibodies appear to bind determinants present in the lipopolysaccharide core region, and this reactivity is inhibited in the presence of polymyxin B . Although their patterns of reactivity differ, both antibodies exhibit extensive serological cross-reactivity with a variety of gram-negative bacteria . Reagents of this type should prove useful in animal models to delineate the requisite affinity, epitope specificity, immunoglobulin class, etc., needed for the prevention and treatment of gram-negative bacteremia.

Cell, 1984 Dec, 39(3 Pt 2), 643 - 52
Conformational change in the DNA associated with an unusual promoter mutation in a tRNA operon of Salmonella; Bossi L et al.; We describe two novel types of mutations which decrease transcription of a tRNA operon in Salmonella typhimurium . One mutation consists of a 3 bp deletion at position -70 from the transcription start site . The second mutation is a single bp insertion between the -10 region and the transcription start site . The region around position -70 shows unusual physical properties . DNA fragments carrying the wild-type version of this region exhibit abnormally low electrophoretic mobility in polyacrylamide gels . This anomalous electrophoretic behavior is corrected if gels are run at high temperature or if the fragments contain the 3 bp deletion at -70 . Our results indicate the existence of an unusual DNA conformation, probably involving DNA bending, in the region preceding the tRNA operon promoter . This structure is apparently disrupted by the 3 bp deletion . The transcriptional defect of the -70 mutant suggests a role for the unusual conformation in promoter function.

J Bacteriol, 1984 Dec, 160(3), 833 - 41
Regulation of expression of the ilvB operon in Salmonella typhimurium; Weinberg RA et al.; The ilvB gene of Salmonella typhimurium encodes the valine-sensitive form of acetohydroxy acid synthase, acetohydroxy acid synthase I, which catalyzes the first step in the parallel biosynthesis of isoleucine and valine . Although nearly all of the other genes involved in this pathway are clustered at minute 83, ilvB was found to lie at minute 80.5 . Expression of ilvB was shown to be nearly completely repressed by the end products leucine and valine . Studies in which we used strains with mutations in cya (adenylate cyclase) and crp (cAMP receptor protein) demonstrated that synthesis of acetohydroxy acid synthase I is enhanced by the cAMP-cAMP receptor protein complex . Although no stimulation was achieved by growth on poor carbon sources, introduction of crp on a multicopy plasmid led to markedly increased expression . Strains of S . typhimurium lacking valine-resistant acetohydroxy acid synthase II (ilvG) are like Escherichia coli K-12 in that they are not able to grow in the presence of L-valine owing to a conditional isoleucine auxotrophy . The valine toxicity of these ilvG mutants of S . typhimurium was overcome by increasing the level of acetohydroxy acid synthase I . Enzyme activity could be elevated either by maximally derepressing expression with severe leucine limitation, by introduction of either ilvB or crp on a multicopy plasmid, or by the presence of the ilv-513 mutation . This mutation, which is closely linked to genes encoding the phosphoenol pyruvate:sugar phosphotransferase system (pts), causes highly elevated expression of ilvB that is refractory to repression by leucine and valine, as is the major ilv operon . The response of ilvB to the cAMP-cAMP receptor protein complex was not affected by this lesion . Data obtained by using this mutant led us to propose that the two modes of regulation act independently . We also present some evidence which suggests that ilvB expression may be affected by the phosphoenol pyruvate:sugar phosphotransferase system.

Arch Int Physiol Biochim, 1984 Dec, 92(5), 333 - 7
Biochemical and phenotypical correction of an envelope mutant of Salmonella typhimurium; Pizarro RA et al.; Salmonella typhimurium DA 361 bears an env D1 mutation with the following abnormal phenotypical and biochemical characteristics: a) it autolyses at stationary phase in nutrient broth; b) it grows in chains of short rods; c) it is a poor maltose fermenter and d) it has a diphosphatidylglycerol (DPG) content twice as high than its isogenic non-lytic pair DA 362 (env D+) and LT2, of which both are derivatives . Growth of DA 361 in the presence of 400 mM ethanol leads on a 50% decrease of DPG level, thereby equalling its PG/DPG ratio with those of the control strain . Consequently, a correction on the other phenotypical and biochemical anomalies are induced since the DA 361 strain decreases its autolytic activity, ferments normally maltose and appear as rods undifferentiated from DA 362.

Schweiz Med Wochenschr, 1984 Nov 17, 114(46), 1645 - 50
{Acquired immunodeficiency syndrome, chronic coccidiosis and Salmonella typhimurium septicemia in a couple from Zaire . Immunological functions and attempt at immunostimulation by thymopentin}; Martin-Du Pan RC et al.; A clinical review of a young couple from Zaire with acquired immunodeficiency syndrome (AIDS) is reported . Both had opportunistic infections such as Salmonella typhimurium septicemia, genital herpes and digestive candidiasis . The husband was hospitalized for diarrhea from Isospora belli infection and for hemoptysis from an aspergilloma . His wife was admitted for a thoracic herpes zoster infection and left hemiplegia preceding subacute encephalitis . In both patients the biological immune functions were compatible with AIDS: presence of antibody against lymphadenopathy virus, decreased in OKT4+/OKT8+ ratio, and lack of lymphocyte response to mitogens which was partially restored in vitro after addition of interleukin 2 and thymopentin (TP-5) in the husband . In vitro monocyte cultures showed increased production of prostaglandins E2 (PGE2) and a slight decrease in interleukin 1 production . The symptomatic treatments and an attempt at immunostimulation with TP-5 in the husband are described.

J Mol Biol, 1984 Nov 15, 179(4), 729 - 43
Fluorine-19 nuclear magnetic resonance study of 5-fluorotryptophan-labeled histidine-binding protein J of Salmonella typhimurium; Post JF et al.; Fluorine-19 nuclear magnetic resonance has been used to investigate the histidine-binding protein J from Salmonella typhimurium . The protein has been labeled with fluorine-19 by growing the bacterial cells of a tryptophan auxotroph in the presence of 5-fluorotryptophan . Incorporation of up to 70% was achieved . The binding of L-histidine to the 19F-labeled protein is not affected by the isotopic labeling . The protein contains one tryptophan residue, giving rise to a single 19F resonance . Upon binding L-histidine to 19F-labeled histidine-binding protein J, the observed 19F resonance is shifted downfield by about 0.6 parts per million, indicating a conformational change of the protein molecule and a more hydrophobic environment for the 19F nucleus . Additional fluorescence experiments confirm that the tryptophan residue is located inside the hydrophobic core of the protein . 19F spin-lattice relaxation times of the 19F-labeled protein as a function of temperature show no difference between the free protein and the protein-histidine complex . However, the linewidth for the free protein is much larger than that of the protein-substrate complex . This can be explained by slow fluctuations between different conformations of the free protein molecule having slightly different 19F chemical shifts . Both with and without the substrate, the tryptophan residue is immobile inside the protein molecule as shown by the total disappearance of the 19F signal upon broadband irradiation at the 1H frequency . Also, the 19F spin-lattice relaxation times indicate that the protein is a rather rigid structure, in which rapid motions of the tryptophan residue on the time scale of 10(-8) second are not prominent.

J Environ Sci Health B, 1984 Nov-Dec, 19(8-9), 689 - 701
Potential of 2,4-dichlorophenoxyacetic acid conjugates as promutagens in the Salmonella/microsome mutagenicity test; Rashid KA et al.; Hepatic S9 preparations from Aroclor 1254 induced rats and 3-methylcholanthrene induced woodchucks were used to investigate, in vitro, the mutagenic potential of five amino acid conjugates of 2,4-Dichlorophenoxyacetic acid (alanine, aspartic acid, leucine, methionine and tryptophan) . Five strains of Salmonella typhimurium (TA97, TA98, TA100, TA1535, TA1538) were utilized for this purpose . Dose-response effects producing a two-fold increase of revertants over spontaneous levels were not observed with either S9 preparation indicating that the amino acid conjugates are not promutagens in these assays.

Gann, 1984 Nov, 75(11), 966 - 75
Species difference between rats and mice in activities of enzymes activating aromatic amines: effect of dietary 3-methoxy-4-aminoazobenzene; Degawa M et al.; Male Donryu rats and B6C3F1 mice were treated with dietary 3-methoxy-4-aminoazobenzene (3-MeO-AAB) (0.06% or 0.09%), and subcellular fractions of the liver were examined for ability to mutagenically activate 3-MeO-AAB and 2 amino acid pyrolysate components using Salmonella typhimurium TA 98 as a tester strain . The treatment resulted in striking induction of enzyme(s) for the mutagenic activation of these aromatic amines in rats, but the effect was smaller in mice . The enzyme(s) involved in the reaction was characterized as an isotype of microsomal cytochrome P-448.

Cancer Res, 1984 Nov, 44(11), 5073 - 8
Characterization of mutagenic glucuronide formation from benzo(a)pyrene in the nonrecirculating perfused rat liver; Kari FW et al.; Excretion of mutagenic metabolites of benzo(a)pyrene into bile from livers of corn oil- or 3-methylcholanthrene-treated Sprague-Dawley rats perfused with a nonrecirculating perfusion system was quantitated . Mutagenic benzo(a)pyrene metabolites were detected using Salmonella typhimurium (strain TA 98) grown in the presence of limiting amounts of histidine . Microsomes were not included in the bacterial assay since metabolic activation was carried out by the perfused liver . Mutagenic activity was detected only if beta-glucuronidase was added to the assay mixture or if bile was treated with acid to hydrolyze glucuronides prior to assay . When livers were perfused with 20 microM benzo(a)pyrene, stable, mutagenic glucuronides were exported from corn oil-treated livers at maximal rates of 149 +/- 24 (S.E.) revertants/g/hr and at rates of 225 +/- 22 revertants/g/hr in livers from 3-methylcholanthrene-treated rats . Chromatography of bile by high-performance liquid chromatography demonstrated that two peak areas contained phenolic glucuronides which were hydrolyzed by beta-glucuronidase . These two peaks, one which cochromatographed with authentic 3-benzo(a)pyrenyl-beta-D-glucuronide, accounted for all of the mutagenic activity in bile from livers perfused with benzo(a)pyrene . A good correlation (r = 0.86) between rates of mutagen production and rates of formation of phenolic glucuronides was observed under a variety of experimental conditions . The mutagenic activity observed with pure 3-benzo(a)pyrenyl-beta-D-glucuronide exposed to beta-glucuronidase was 4 revertants/nmol . When the rate of mutagen production was divided by the rate of production of 3-benzo(a)pyrenyl-beta-D-glucuronide by the perfused liver, a value of 4 revertants/nmol was also obtained . Therefore, it is concluded that mutagens exported in bile from livers perfused with benzo(a)pyrene can be accounted for predominantly by hydrolysis products of phenolic glucuronides.

Food Chem Toxicol, 1984 Nov, 22(11), 897 - 900
Examination of some fragrance substances for mutagenic activity; Williams J et al.; We tested 64 perfumes and aftershaves for mutagenicity in Salmonella typhimurium strains TA98 and TA100; most were tested both with and without metabolic activation . None of the test compounds gave a positive mutagenic response . The available amounts of some test samples were very small, however, and the possibility that larger samples might have produced positive results cannot be altogether discounted . Some tests indicated the presence of cytotoxic substances which require chemical analysis.

Gene, 1984 Nov, 31(1-3), 279 - 83
Molecular cloning of the phosphoenolpyruvate carboxylase gene, ppc, of Escherichia coli; Sabe H et al.; The ColE1 hybrid plasmid, pLC20-10, carrying the ppc gene and the argECBH gene cluster of Escherichia coli K-12, was characterized . The ppc gene coding for phosphoenolpyruvate carboxylase (EC 4.1.1.31), was subcloned into the plasmid pBR322 to give the plasmids pS2 and pS3 . These plasmids carried a 4.4-kb SalI segment containing the ppc gene, in both orientations . The specific activity of the enzyme was increased approx . 20-fold by these plasmids . Experiments with maxicells harboring pS2 showed that the 90-kDal enzyme subunit was encoded by the plasmid . The location of the ppc gene in pS2 and the direction of transcription of the gene were determined . In DNA-DNA hybridization experiments using pS2 as a probe, significant hybridizations were observed with DNAs from E . coli strains K-12 and W, and from Salmonella typhimurium, but not with those from Chlorella regularis, Anacystis nidulans, Rhodospirillum rubrum, and Pseudomonas AM-1.

Zh Mikrobiol Epidemiol Immunobiol, 1984 Nov, (11), 40 - 4
{Effect of the transfer of the R plasmids of resistant Salmonella typhimurium strains of different origins on the phage sensitivity of Salmonella typhimurium}; Iakovleva ON et al.; It has been shown that after the transfer of R-plasmids from S . typhimurium strains of different origin to S typhimurium strains sensitive to antibiotics these latter strains, as a rule, cannot be typed according to the scheme of Felix and Kellow These strains retain sensitivity to phages from I . G . Chiarkadze's collection, but the spectrum of their phage sensitivity is narrower . In one case the recipient was noted to change its phagovar to that of the donor . S . typhimurium donor strains, differing in the degree of their influence on the virulence of recipients, do not differ in their capacity for changing their sensitivity to the phages from the international collection of Felix and Kellow and from I . G . Chirakadze's collection.

Anticancer Res, 1984 Nov-Dec, 4(6), 399 - 402
Mutagenicity of selected functionalized benz(c)acridines and a benz(a)phenazine in the Salmonella typhimurium/microsome assay; Walker BA et al.; Five functionalized benz(c)acridines - 5,6-dimethylbenz(c)acridine; 5,6,7-trimethylbenz(c)acridine; 7-chloro-5,6-dimethylbenz(c)acridine; 7-amino-5,6-dimethylbenz(c)acridine; 7-oxo-5,6-dimethylbenz(c)-acridine and 5,6-dimethylbenz(a)phenazine - were tested for mutagenic activity in the Ames Salmonella typhimurium assay . Compounds were initially screened by spot tests with 5 tester strains and both plate incorporation and pre-incubation assays were performed when the results of the tests were positive or weakly positive . All assays were done with and without S9 activation . 7-Amino-5, 6-dimethylbenz(c)acridine and 7-chloro-5, 6-dimethylbenz(c)acridine were found to be moderately mutagenic with the 3 frameshift strains TA1537, TA98, and TA97.

Mutat Res, 1984 Nov-Dec, 141(3-4), 153 - 9
Mutagenesis by N-nitroso compounds in Salmonella typhimurium TA102 and TA104: evidence for premutagenic adenine or thymine DNA adducts; Guttenplan JB et al.; Mutagenesis induced by the N-nitroso compounds: N-nitrosomethylurea, N-nitrosoethylurea, N-nitrosodi-n-propylamine and N-nitrosopyrrolidine was measured in Salmonella typhimurium TA100, TA102 and TA104 . TA100 detects damage mainly at G-C base pairs while TA102 and TA104 can detect damage at A-T base pairs . In general all strains were similarly sensitive, except that TA104 was much less sensitive to high doses of N-nitroso-N-methylurea . In TA104 a significant percentage of the revertants induced by all agents except NMU resulted from point mutations at A-T base pairs, indicating that adenine or thymine DNA adducts are important premutagenic adducts formed by certain N-nitroso compounds.

Mutat Res, 1984 Nov-Dec, 141(3-4), 145 - 7
Protection from toxic and mutagenic effects of H2O2 by catalase induction in Salmonella typhimurium; Winquist L et al.; Demple and Halbrook (1983) have reported that pretreatment of E . coli with H2O2 induces protection against the toxic effects of subsequent treatment with H2O2, which cannot be attributable to catalase induction, but rather to inducible repair of oxidative DNA damage . Here we report that pretreatment of Salmonella typhimurium with small doses of H2O2 also renders them resistant to subsequent higher doses of H2O2 . However, this induced protection against H2O2, both concerning survival and mutations, is proportional to the amount of induced catalase activity of the bacteria, which accelerates the breakdown of H2O2 in the medium, thus lowering the effective dose.

Radiat Res, 1984 Nov, 100(2), 396 - 411
Radiation-induced mutagenicity and lethality in ames tester strains of salmonella; Isildar M et al.; Mutation and killing induced by X radiation and 60CO gamma radiation were studied in six different histidine-requiring auxotrophs of Salmonella typhimurium . Strain TA100, which is sensitive to base-pair substitutions, and strains TA2637 and TA98, which are sensitive to frameshifts, carry the pKM101 plasmid and exhibit significantly higher radiation-induced mutations compared to their plasmidless parent strains TA1535, TA1537, and TA1538, respectively . Among the plasmid-containing strains, TA98 and TA2637 are much more sensitive to the mutagenic action of radiation than is TA100 based on a comparison with their respective spontaneous mutation rates; however, no uniformity was observed in the responses of the strains to the lethal action of ionizing radiation . The pKM101 plasmid provides partial protection against lethality in TA100 and TA2637, whereas the same plasmid enhances the lethal action of ionizing radiation in TA98 . The following conclusions are consistent with these observations: (1) the standard Ames Salmonella assay correctly identifies ionizing radiation as a mutagenic agent; (2) frameshift-sensitive parent strains are more sensitive to the mutagenic effects of ionizing radiation than is the only strain studied that is sensitive to base-pair substitutions; and (3) enhancement of mutagenesis and survival is related to plasmid-mediated repair of DNA damage induced by ionizing radiation and does not involve damage induced by Cerenkov-generated uv radiation which is negligible for our irradiation conditions.

Cancer Res, 1984 Nov, 44(11), 4993 - 5003
Mutagenicity of cyclopenta-fused isomers of benz(a)anthracene in bacterial and rodent cells and identification of the major rat liver microsomal metabolites; Nesnow S et al.; The microsomal metabolites and mutagenic activity of four cyclopenta-fused benz(a)anthracenes, benz(j)aceanthrylene {B(j)A}, benz(e)aceanthrylene {B(e)A}, benz(l)aceanthrylene {B(l)A}, and benz(k)acephenanthrylene {B(k)A}, have been studied . Aroclor 1254-induced rat liver microsomes metabolized B(j)A to B(j)A-1,2-dihydrodiol, B(j)A-9,10-dihydrodiol, B(j)A-11,12-dihydrodiol, and 10-hydroxy-B(j)A; B(e)A-1,2-dihydrodiol, B(e)A-3,4-dihydrodiol, and B(e)A-5,6-dihydrodiol; B(l)A to B(l)A-1,2-dihydrodiol, B(l)A-4,5-dihydrodiol, and B(l)A-7,8-dihydrodiol; and B(k)A to B(k)A-4,5-dihydrodiol and B(k)A-8,9-dihydrodiol . With each polycyclic aromatic hydrocarbon, metabolism occurred on the cyclopenta ring . All four isomers were active as gene mutagens in Salmonella typhimurium and in Chinese hamster V79 cells . In the S . typhimurium mutation studies, using Aroclor 1254-induced rat liver S9, B(j)A, B(e)A, and B(l)A required significantly less microsomal protein for maximal mutation response than B(k)A and B(a)P, suggesting a one-step activation mechanism, presumably on the cyclopenta-fused ring . B(j)A, B(e)A, and B(l)A were significantly more mutagenic than B(k)A and B(a)P in S . typhimurium . In the Aroclor 1254-induced rat liver S9-mediated V79 mutagenesis system, all four isomers were active, with B(l)A the most active . When Syrian hamster embryo cells were used as the metabolic activation component for V79 cells, only B(l)A produced a significant response and was equivalent in activity to B(a)P . A helical configuration for B(l)A is inferred from the identification of two trans-B(l)A-1,2-dihydrodiols, syn and anti, which have been synthesized, separated, and characterized . The metabolically formed dihydrodiol is anti-trans-B(l)A-1,2-dihydrodiol, and experimental evidence suggests that the metabolically formed B(l)A-1,2-oxide is the anti-isomer . Synthetic B(l)A-1,2-oxide was found to be a direct-acting mutagen in S . typhimurium and Chinese hamster V79 cells and is estimated to account for up to 40% of the mutagenic activity of the parent hydrocarbon . Therefore, certain cyclopenta-ring fusions on benz(a)anthracene appear to markedly increase its genotoxic and carcinogenic activities.

J Pharmacobiodyn, 1984 Nov, 7(11), 798 - 803
Interaction between quercetin and superoxide radicals . Reduction of the quercetin mutagenicity; Ueno I et al.; Interaction between quercetin and superoxide radicals was investigated using xanthine-xanthine oxidase system and potassium superoxide as superoxide radical generators . Superoxide radical scavenging action of quercetin was demonstrated by measurement of the electron spin resonance spectrum of the 5-hydroperoxy-2,2-dimethyl-1-pyrrolidinyloxyl adduct . Degradation of quercetin by the radicals was demonstrated spectrophotometrically . Reduction of the quercetin mutagenicity by the radicals was demonstrated in the Salmonella typhimurium strain TA 98 by the Ames test.

Plasmid, 1984 Nov, 12(3), 149 - 60
A specialized host-vector system for the in vivo cloning of the trp operon of wild-type and mutant strains of Salmonella typhimurium by generalized transduction; Patterson T et al.; Using in vitro methods, a 14.2-kb EcoRI fragment of the Salmonella typhimurium chromosome containing the trp operon plus associated flanking sequences from deletion mutant delta trpDCB763 was cloned into the EcoRI site of plasmid pBR322 in a S . typhimurium host . An in vivo cloning vector was constructed from the recombinant plasmid by the in vitro excision of a SalI fragment that contains the entire trp operon . The derived plasmid (pSTP21) carries a hybrid insert made up of the 5.4-kb EcoRI-SalI upstream flanking sequence and the 3.2-kb SalI-EcoRI downstream flanking sequence . Plasmid pSTP21 has been used as a receptor plasmid to clone a variety of mutant and wild-type trp operons by RecA-dependent in vivo recombination between the insert DNA of the plasmid and the homologous trp flanking sequences of transducing DNA fragments transferred into the cell by bacteriophage P22 . The host-vector system developed for the in vivo cloning permits the differentiation of plasmid transductants from chromosomal transductants on the primary selective medium . Expression of the cloned trp operons is regulated normally by tryptophan . A substantial amplification of trp enzymes is attainable upon derepression . The recombinant plasmids are stably inherited in RecA+ and RecA- S . typhimurium hosts . However, conditions of high expression of the trp operon lead to a rapid loss of cellular viability and of plasmid stability.

J Gen Microbiol, 1984 Nov, 130 ( Pt 11), 2873 - 81
NAD metabolism in Salmonella typhimurium: isolation of pyridine analogue supersensitive (pas) and pas suppressor mutants; Foster JW et al.; Mutants of Salmonella typhimurium supersensitive to the nicotinic acid analogue 6-amino-nicotinic acid (6ANA) were isolated as unable to grow on what are normally subinhibitory concentrations of the analogue . The mutations were classified on the basis of their map positions as pasA (89-92 units), pasB (66-69 units), pasC (18-22 units), pasD (18 units) and pasE (55 units) . The mutants exhibited a wide range of minimal inhibitory concentrations towards 6ANA, and several were affected in terms of growth . The data suggest that most of the mutations probably reside in genes whose products utilize nicotinamide adenine dinucleotide (NAD) as a cofactor, the altered gene products being more sensitive to internal 6-amino NAD concentrations . Secondary mutations which suppress the Pas- phenotype were found to reside in the following NAD-related loci; pncB, nadB and nadD . Two of the pncB mutants appear to be affected in the expression of NAPRTase while several of the nadB mutants are apparently insensitive to feedback inhibition by internal NAD concentrations.

J Bacteriol, 1984 Nov, 160(2), 826 - 30
Cyclic AMP phosphodiesterase in Salmonella typhimurium: characteristics and physiological function; Botsford JL; The physiological function of cyclic AMP (cAMP) phosphodiesterase in Salmonella typhimurium was investigated with strains which were isogenic except for the cpd locus . In crude broken-cell extracts the properties of the enzyme were found to be similar to those reported for Escherichia coli . The specific activity in the mutant was less than 1% that in the wild type . Rates of cAMP production in the mutant were as much as twice those observed in the wild type . The amount of cAMP accumulated when cells grew overnight with limiting glucose was 4.5-fold greater in the mutant than in the wild type . The intracellular concentration of cAMP in the two strains was measured directly, using four different techniques to wash the cells to remove extracellular cAMP . The cAMP level in the cpd strain was only 25% greater than in the wild type . The functional concentration of the cAMP receptor protein-cAMP complex was estimated indirectly from the specific activity of beta-galactosidase in the two strains after introducing F'lac . When cells were grown with carbon sources permitting synthesis of different levels of cAMP, the specific activity of the enzyme was at most 25% greater in the cpd strain . The cpd strain was more sensitive to the effects of exogenous cAMP . Exogenous cAMP relieved both permanent and transient catabolite repression of the lac operon at lower concentrations in the cpd strain than in the wild type . When cells grew with glucose, glycerol, or ribose, exogenous cAMP inhibited growth of the mutant strain more than the wild type.

J Bacteriol, 1984 Nov, 160(2), 682 - 6
Mapping and spacer identification of rRNA operons of Salmonella typhimurium; Lehner AF et al.; The rRNA operons of Salmonella typhimurium have been characterized with respect to their map position, orientation, and type of tRNA spacer . One of the seven rrn operons was found to be linked to pheA and another was found to be linked to aroE . This information, together with published information about the other five rrn operons, shows that S . typhimurium and Escherichia coli are essentially identical in terms of the number, the map position, and the orientation of all seven operons . S . typhimurium and E . coli were also similar in that four of the rrn spacer regions code for tRNAGlu2 and three code for tRNAAla1B . However, the two species differed in that rrnD coded for tRNAGlu2 and rrnB coded for tRNAAla1B in S . typhimurium . This is the opposite of the arrangement in E . coli . We have tabulated the coordinates of the BamHI and PstI sites flanking six of the S . typhimurium rrn genes and present revisions for the coordinates of some of the E . coli sites.

Infect Immun, 1984 Nov, 46(2), 559 - 63
Activation of complement system by porins extracted from Salmonella typhimurium; Galdiero F et al.; The effect of porins purified from Salmonella typhimurium on the complement system was investigated both in vitro and in vivo . Incubation of porins with either human or guinea pig serum resulted in the consumption of the total complement activity when an amount of porins ranging from 8 to 10 micrograms per 100 microliters of serum was used . The activation of the complement system was temperature dependent, suggesting an active process rather than passive adsorption of the complement components by porins . In addition, the activation had a fast kinetic and proceeded mainly through the classical pathway . This conclusion is supported by the consumption of C1s and C4 in normal human serum treated with porins and also by the depletion of C3 activity in the C1s-deficient serum which was marked only when purified C1s was added to the serum before incubation with porins . Injection of 100 micrograms of porins into guinea pigs induced profound complement consumption at 6 h postinjection that persisted up to 12 h . We conclude from this study that porins can effectively contribute to complement activation and to subsequent biological events induced by gram-negative bacteria.

Zh Mikrobiol Epidemiol Immunobiol, 1984 Nov, (11), 101 - 5
{Systemic immunological memory in enteral immunization with the O antigen from S . sonnei}; Liubinskaia MM et al.; Mice received S . sonnei O-antigen at various concentrations (0.01-20,000 micrograms/ml) in drinking water . Systemic immunological memory, induced by feeding with O-antigen, was manifested by secondary immune response to parenteral boosting with homologous O-antigen or ribosomal vaccine . A pronounced priming effect was also produced by O-antigen at concentrations as low as 0.01 micrograms/ml after courses of feeding as short as 1-3 days . Even high doses of the antigen had no tolerogenic activity . The state of immunological memory was formed at least 12 days after the first feeding and lasted for a long period (at least 4 months after the last feeding) . The specificity of immunological memory was proved in experiments with heterologous O-antigen (Salmonella typhimurium): the insignificant stimulating action of this antigen was revealed only when high concentrations of the antigen (1000 micrograms/ml) were used for feeding.

Biochemistry, 1984 Oct 23, 23(22), 5188 - 94
Inactivation of the dadB Salmonella typhimurium alanine racemase by D and L isomers of beta-substituted alanines: kinetics, stoichiometry, active site peptide sequencing, and reaction mechanism; Badet B et al.; The pyridoxal phosphate dependent Salmonella typhimurium dadB alanine racemase was inactivated with D- and L-beta-fluoroalanine, D- and L-beta-chloroalanine, and O-acetyl-D-serine . Enzyme inactivation with each isomer of beta-chloro{14C}alanine followed by NaBH4 reduction and trypsin digestion afforded a single radiolabeled peptide . In the same manner, NaB3H4-reduced native enzyme gave a single labeled peptide after trypsin digestion . Purification and sequencing of these three radioactive peptides revealed them to be a common, unique hexadecapeptide which contained labeled lysine at position 6 in each case . Enzyme which had been inactivated, but not reductively stabilized with NaBH4, released a labile pyridoxal phosphate-inactivator adduct on denaturation . The structure of this adduct suggests that the enzyme was inactivated by trapping the coenzyme in a ternary adduct with inactivator and the active site lysine . Under denaturing conditions, facile alpha,beta-elimination occurred, releasing the aldol adduct of pyruvate and pyridoxal phosphate . Reduction of the ternary enzyme adduct blocked this elimination pathway . The overall mechanism of racemase inactivation is discussed in light of these results.

Biochemistry, 1984 Oct 23, 23(22), 5182 - 7
Catabolic alanine racemase from Salmonella typhimurium: DNA sequence, enzyme purification, and characterization; Wasserman SA et al.; The alanine racemase encoded by the Salmonella typhimurium dadB gene was purified to 90% homogeneity from an overproducing strain . At 37 degrees C the enzyme has a specific activity of 1400 units/mg (V max, L- to D-alanine) . Active enzyme molecules are monomers of Mr 39 000 with one molecule of pyridoxal 5'-phosphate bound per subunit . The Km's for L- and D-alanine are 8.2 and 2.1 mM, respectively . Measurement of turnover numbers yielded the expected Keq value of 1.0 . Determination of 22 of the 25 N-terminal amino acid residues of the purified polypeptide allowed localization of cloned DNA encoding the structural gene . Sequencing of subcloned DNA revealed that the dadB gene encodes a polypeptide of 356 amino acids whose calculated molecular weight (apoenzyme) was 39 044.

J Biol Chem, 1984 Oct 10, 259(19), 11679 - 81
Subunit association of enzyme I of the Salmonella typhimurium phosphoenolpyruvate: glycose phosphotransferase system . Temperature dependence and thermodynamic properties; Kukuruzinska MA et al.; The bacterial phosphoenolpyruvate:glycose phosphotransferase system plays an essential role in diverse physiological phenomena . To perform these functions, the system is stringently regulated, although the underlying molecular regulatory mechanisms have not been established . A potential target for this type of regulation is the first protein in the phosphotransfer sequence, Enzyme I, which catalyzes the following reaction: P-enolpyruvate + Enzyme I Mg2+ in equilibrium phospho-I + pyruvate . We reported previously that Enzyme I from Salmonella typhimurium consists of identical subunits which associate in a temperature-dependent manner; the mode of association was found to be either monomer-dimer or isodesmic . The association reaction has now been investigated by analytical gel chromatography at 8, 11, and 23 degrees C . At each temperature, the mode of association was strictly monomer-dimer . The apparent association equilibrium constant, K'a, increased dramatically with temperature, with an enthalpy of 54.8 +/- 6.3 kcal/mol . At 23 degrees C, K'a decreased slightly when the enzyme solution contained either Mg2+ or phosphoenolpyruvate . However, when both ligands were present, i.e . under conditions where Enzyme I is phosphorylated, K'a decreased significantly (25-fold at 11 degrees C and 50-fold at 23 degrees C) . These results are in accord with a model for the action of Enzyme I which involves a cycle of association and dissociation . This model has potentially important implications for regulating Enzyme I and the bacterial phosphoenolpyruvate:glycose phosphotransferase system.

Carcinogenesis, 1984 Oct, 5(10), 1219 - 24
4-Chloro-6-methoxyindole is the precursor of a potent mutagen (4-chloro-6-methoxy-2-hydroxy-1-nitroso-indolin-3-one oxime) that forms during nitrosation of the fava bean (Vicia faba); Yang D et al.; Fava beans (Vicia faba) upon treatment with nitrite under simulated gastric conditions, form a direct-acting bacterial mutagen, comparable in specific activity to the most potent known mutagens for several strains of Salmonella typhimurium . The precursor of the mutagen was isolated and identified as 4-chloro-6-methoxyindole by u.v., i.r., m.s . and n.m.r . The precursor was dechlorinated with NaBH4 and PdCl2 as the catalyst and the product obtained from this reaction was identified as 6-methoxyindole . Since synthetic 4-chloro-6-methoxyindole was not available, structure activity studies were conducted on substituted indoles . Nitrosation of 4-chloroindole closely follows the results for nitrosation of 4-chloro-6-methoxyindole . The major product of nitrosation of 4-chloroindole is 4-chloro-2-hydroxy-N1-nitroso-indolin-3-one oxime . Thus, it appears that the major nitrosation product of 4-chloroindole and of 4-chloro-6-methoxyindole is a stable alpha-hydroxy N-nitroso compound . This is the first reported case of stable alpha-hydroxy N-nitroso compounds . In the presence of N-(1-naphthyl)ethylenediamine dihydrochloride (NEDD), the alpha-hydroxy N-nitroso compound rearranges to an aromatic diazonium ion which couples with the diamine to form an azo dye . Studies on nitrosation kinetics indicate that the nitrosation of indoles are relatively fast reactions . Both the structural and rate studies give strong support to the hypothesis that intragastric nitrosation of fava beans yield the putative gastric carcinogen in the high-risk area in Colombia.

Avian Dis, 1984 Oct-Dec, 28(4), 1071 - 8
Practical aspects of competitive exclusion for the control of Salmonella in turkeys; Anderson WR et al.; In laboratory trials, a fourth-passage culture of adult chicken cecal contents was protective against challenge with Salmonella typhimurium in turkey poults raised on wood-shavings poultry litter . The culture was not protective against pre-treatment exposure to hatchery-introduced S . bredeney and was inhibited in poults that had received an antibiotic injection at the hatchery . The inhibitory effect of the hatchery antibiotic could be avoided if the cecal-culture treatment was delayed by 3 to 4 days after antibiotic injection . Under field conditions, there was a significant reduction in the salmonella contamination of turkeys and their environment when cecal culture was given to poults raised on wood-shavings litter sprayed with a quaternary ammonium compound . When used alone, both the cecal culture and the litter disinfectant were ineffective in preventing the establishment of S . heidelberg infection . Further studies are required to confirm the possibility of a synergistic effect between the two treatments . For the control of salmonella in turkeys, use of cecal cultures may be limited by the interference of antibiotics and by their failure to protect against pretreatment exposure to salmonella.

Carcinogenesis, 1984 Oct, 5(10), 1367 - 70
The induction of liver cancer by dietary deficiency of choline and methionine without added carcinogens; Ghoshal AK et al.; Fischer 344 male rats fed a choline-methionine deficient diet for from 13 to 24 months developed a 100% incidence of putative preneoplastic hepatocyte nodules and a 51% incidence of hepatocellular carcinoma . The addition of 0.8% choline chloride completely prevented the development of both the nodules and the cancer . The diet contained no added known carcinogen . Analysis of the deficient and supplemented diets revealed no detectable volatile nitrosamines or nitrosamides, nitrite, nitrate or malonaldehyde, less than 0.9 p.p.b . aflatoxin B1 and barely detectable levels of Ames positive material with one strain of Salmonella typhimurium . These findings indicate that a dietary deficiency of choline and methionine can be a major rate limiting factor in the development of liver cancer.

J Bacteriol, 1984 Oct, 160(1), 131 - 6
Anaerobic and leucine-dependent expression of a peptide transport gene in Salmonella typhimurium; Jamieson DJ et al.; Using Mu d1-mediated lac operon fusions, we studied the transcriptional regulation of the genes encoding two peptide transport systems, the oligopeptide permease and the tripeptide permease . The four opp genes were found to be constitutively expressed, whereas the genes encoding the tripeptide permease are under a complex set of regulatory controls . Two loci, tppA and tppB, are required for tripeptide permease function . Locus tppA is shown to be a positive regulator of tppB expression . In addition, tppB expression is specifically induced by exogeneous leucine or by anaerobiosis . Anaerobic induction of tppB is independent of the fnr gene product which is required for the anaerobic expression of several respiratory enzymes . Thus, there must be at least two distinct pathways for the anaerobic regulation of gene expression.

Sci Total Environ, 1984 Oct, 39(1-2), 161 - 75
Mutagenicity of photochemical reaction products of polycyclic aromatic hydrocarbons with nitrite; Ohe T; Six kinds of polycyclic aromatic hydrocarbons (PAHs) were subjected to ultraviolet light irradiation with nitrite for 1, 4, 8 and 24 h, and the irradiated samples were tested for mutagenicity towards Salmonella typhimurium TA 98, TA 100 and TA 1538 . Irradiated samples of pyrene, fluoranthene and benzo{a}pyrene showed marked mutagen responses towards TA 98 and TA 1538, especially in the absence of S9 mix . The direct-acting mutagenic activity of these samples, showing high activities at 1-8 h, decreased greatly with the development of irradiation . Further, these direct-acting mutagens were mostly present in the neutral fraction . On the other hand, the mutagenicity of the irradiated sample of 5,6-benzoquinoline was high both with and without S9 mix, and was mostly present in the basic fraction because of its authentic characteristic . There was no correlation between the yield of 1-nitropyrene and the mutagenic activity of the photochemical reaction product of pyrene with nitrite . Further studies by TLC separation suggested that a considerable number of direct-acting mutagens formed in this experiment were more polar than nitrated PAH such as 1-nitropyrene.

Zh Mikrobiol Epidemiol Immunobiol, 1984 Oct, (10), 96 - 9
{Protective properties of plasma from burned and irradiated rats in relation to the in vivo lethal effects of endotoxins}; Budagov RS et al.; The intraperitoneal injection of Salmonella typhimurium and Escherichia coli endotoxins into previously irradiated rats killed 80% of the animals within 24 hours . After the combined injection of these endotoxins with the heterologous plasma of intact rats mortality rate decreased to 12% and 19%, respectively . A deep burn of the skin, acute radiation sickness and combined radiation and thermal lesion did not abolish this phenomenon of humoral detoxication; at different periods after the action of heat, radiation or both the plasma of the test rats exerted its protective effect practically to the same extent as in the controls.

Zh Mikrobiol Epidemiol Immunobiol, 1984 Oct, (10), 49 - 52
{Effect of plasmids for multiple antibiotic resistance on the change in Salmonella typhimurium phagovar}; Kaftyreva LA et al.; The data on the influence of acquired plasmid resistance to antibiotics on S . typhimurium phagovar . Plasmid R was transferred from S . typhimurium strain, isolated from the focus of hospital salmonellosis and resistant to the lytic action of phages, to Escherichia coli K12 and then to antibiotic-sensitive S . typhimurium strains of different phagovars, isolated from patients with alimentary toxicoinfections . The influence of plasmid R on the phagovar of recipient strains, most pronounced in strains of phagovar I, was revealed . The transconjugates of this phagovar considerably changed sensitivity to phages and in some cases acquired resistance to the lytic action of typing phages, thus becoming identical in this feature to the donor of the plasmid.

Arch Microbiol, 1984 Oct, 139(2-3), 265 - 71
Filamentous growth of Escherichia coli K12 elicited by dimeric, mixed-valence complexes of ruthenium; Gibson JF et al.; Dimeric, mixed-valence {(Ru(II),Ru(III)} compounds of ruthenium caused filament formation in growing cultures of Escherichia coli K12 . Three compounds with the general formula Ru2(NH3)6X5 X H2O (where X is a halide) were tested; in order of decreasing effectiveness (and with the concentration giving maximum effect), these were the bromo (10(-5) M), chloro (10(-4) to 10(-5) M), and iodo (10(-3) to 10(-4) M) analogues . Filamentation elicited by the bromo and chloro compounds was spontaneously reversible after 3-4 h, and tentatively attributed to oxidation of the active mixed-valence form to inactive Ru(III) complexes . Several compounds known to accelerate division of filaments formed under other conditions were ineffective in reversing the filamentation, but the presence of 0.43 M-dimethylsulphoxide totally inhibited filamentation caused by the bromo or chloro compounds and by cis-Pt(NH3)2Cl2 (cisplatin), an established filamenting and antitumour agent . The ruthenium complexes bound to mammalian DNA, but were without effect on the UV spectrum or cellular content of DNA in E . coli, despite showing marked mutagenic activity in reverse mutation tests with Salmonella typhimurium . Cells remained sensitive to inhibition of division by the ruthenium complexes until immediately prior to the division event . Possibilities for the (probably complex) mode of action and the potential of related compounds for therapeutic use are discussed.

Can J Microbiol, 1984 Oct, 30(10), 1264 - 70
Inefficient in vitro killing of virulent or nonvirulent Salmonella typhimurium by murine polymorphonuclear neutrophils; Baron EJ et al.; The bactericidal capability of murine peritoneal polymorphonuclear neutrophils against virulent and nonvirulent Salmonella typhimurium was examined in an in vitro system . Although preincubation of the bacteria in specific murine antiserum elicited greater chemiluminescence from phagocytizing neutrophils than did incubation in normal murine serum, antiserum did not enhance ingestion, as less than 5% of the challenge was taken up by neutrophils under any of the conditions studied . Nonvirulent salmonellae showed a transient decrease in viable numbers early during in vitro incubation with or without intact neutrophils . Virulent salmonellae, however, were able to multiply without a lag period except when these bacteria were pretreated with antiserum and incubated in association with intact murine neutrophils . Results of these in vitro studies suggest that the murine polymorphonuclear neutrophil and antisalmonella antibody must act together to effect neutrophil-associated bactericidal activity against virulent salmonellae, and thus, that the neutrophil alone does not play a major role in the protection of unvaccinated, sensitive mice from disease caused by S . typhimurium.

J Appl Bacteriol, 1984 Oct, 57(2), 355 - 9
The influence of scald water pH on the death rates of Salmonella typhimurium and other bacteria attached to chicken skin; Humphrey TJ et al.; Factory trials where scald tank water was maintained at pH 9.0 +/- 0.2 showed that compared with the usual system of scalding when the water is at pH 6.0 for much of the working day the bacterial counts on carcases post scalding and plucking were significantly lower . In laboratory experiments, attached Salmonella typhimurium and the naturally occurring skin flora were found to be killed significantly more quickly in water at pH 9.0 +/- 0.2.

J Appl Bacteriol, 1984 Oct, 57(2), 299 - 308
Conductance measurements of the lag phase of injured Salmonella typhimurium; Mackey BM et al.; The duration of the lag phase of Salmonella typhimurium injured by heating, freezing, acidification or drying was measured using the 'Malthus' conductance meter . Results confirmed those previously obtained by viable counting and additionally, revealed the very wide variation in lag between and within populations and the extreme length of lag that can occur in some severely injured cells . In an extreme example, the measured lag times of low numbers of bacteria taken from the same heat-injured population ranged from 16 h to 70 h . The implications for the detection of injured micro-organisms in food are discussed.

Cancer Lett, 1984 Oct, 24(3), 281 - 9
A comparison of the effect of selenium on the mutagenicity and metabolism of benzo{a}pyrene in rat and hamster liver S9 activation systems; Teel RW; When selenium (Na2SeO3) was included in the incubation mix containing rat or hamster liver S9 preparations both the metabolism and mutagenicity of benzo{a}pyrene (BaP) and several of its metabolites were altered . At non-toxic concentrations selenium inhibited the S9 dependent mutagenicity of BaP and a number of its metabolites on Salmonella typhimurium strain TA100 as indicated by the number of histidine independent revertants observed . High performance liquid chromatographic analysis of S9 generated metabolites of BaP from rat and hamster liver indicated that selenium caused quantitative differences in the amounts of the metabolic products . In hamster liver S9 differences were reflected in decreased amounts of strongly mutagenic BaP-7,8-dihydrodiol and increased amounts of 4,5- and 9,10-dihydrodiols that were weakly mutagenic to TA100 in that system . In rat liver S9 selenium caused quantitatively similar decreases in BaP-7,8- and 9,10-dihydrodiol and 3-hydroxy-BaP . When used as substrate 3-hydroxy-BaP was the most mutagenic to TA100 in the rat activation system whereas BaP-7,8-dihydrodiol was most mutagenic in the hamster S9 system . Assays that measured the formation of water-soluble conjugates of BaP indicated that selenium did not significantly alter the formation of sulfate ester or glutathione conjugates although a 12-17% reduction of labeled metabolites bound to the glucuronide fraction was observed . Results described in this report suggest that selenium modified the metabolism and hence the mutagenicity of BaP to TA100 by affecting mixed-function oxidase and/or epoxide hydratase activity in both the rat and hamster liver S9 activation systems.

Mutat Res, 1984 Oct, 141(2), 83 - 8
Frameshift mutagenesis by acridines in wild-type, uvrB and polA strains of Salmonella typhimurium with and without plasmid pKM101; Ferguson LR et al.; A large range of acridines, including several anilinoacridines which are active as antitumour agents, have been studied for their ability to revert derivatives of Salmonella typhimurium strains carrying the frameshift marker hisC3076 . The strains used all carried deep-rough (rfa) mutations, and were either wild-type with respect to DNA-repair capacity or carried uvrB, polA1 or polA3 (amber) mutations . Derivatives with and without the mutation-enhancing N group plasmid pKM101 were also used . 9-Aminoacridine and other acridines appeared similar to the anilinoacridines for the most part, in that frameshift mutagenesis and toxicity appeared to be unaffected by the uvrB mutation or by the presence of plasmid pKM101 . Exceptions were ICR191, 3-NO2-acridine and 1- or 3-NO2-anilinoacridine derivatives in which mutagenesis was increased in uvrB strains and also when pKM101 was present . These compounds were slightly more toxic in the uvrB background, but less toxic when pKM101 was present in either the uvrB or wild-type backgrounds . Mutagenesis by most compounds was reduced by the polA1 mutation and virtually eliminated (except in the case of ICR191) by the polA3 mutation . Plasmid pKM101 occasionally enhanced mutagenesis in the polA1 strain, whereas in the polA3 it appeared to have no effect whatsoever . Again, there were no obvious differences in toxicity between Pol+ and Pol- strains.

Mutat Res, 1984 Oct, 138(1), 9 - 16
Mutagenicity of cadmium in Salmonella typhimurium and its synergism with two nitrosamines; Mandel R et al.; Cadmium chloride (CdCl2) at concentrations of 0.5 mM was significantly mutagenic in Salmonella typhimurium tester strains and reverted histidine auxotrophy due either to missense (TA1975 and TA1535) or to frameshift (TA1537) mutations . It also induced forward mutations to 8-azaguanine resistance in each strain, but failed to increase mutation frequencies in strain TA100 . More importantly, CdCl2 increased the mutagenicity of two common nitrosamines in synergistic fashion, at a level up to 30-fold greater than expected from simple additivity . The mutation frequency induced by N-methyl-N'-nitro-N-nitrosoguanidine was increased about 10-fold in the presence of 0.5 mM CdCl2 . This synergism was seen both in the induction of 8-azaguanine resistance and the reversion of histidine auxotrophy and was observed in the repair-proficient strain TA1975 as well as its repair-defective (uvrB-) derived strain TA1535 . The synergism was dependent upon Cd concentration and was much reduced at 0.25 mM CdCl2 . The strongest synergism was observed in the reversion of histidine auxotrophy in TA1975 by 180 microM methylnitrosourea and 0.5 mM CdCl2 . In contrast to mutagenicity, there was no evidence for synergism in the toxicity of CdCl2 . These data suggest that cadmium might interfere with the repair of both spontaneous and nitrosamine-induced mutations . They also raise the possibility that cadmium and nitrosamines may have synergistic effects as environmental carcinogens.

Mutat Res, 1984 Oct, 138(1), 21 - 32
Genotoxicity studies with paracetamol; Dybing E et al.; Paracetamol and its major ultimate reactive metabolite, N-acetyl-p-benzoquinone imine (NAPQI) were studied for their genotoxic potential . Neither paracetamol nor NAPQI were found to cause mutations in Salmonella typhimurium, whereas NAPQI was severely cytotoxic to the bacteria . Radiolabelled paracetamol was found to bind covalently to DNA added to mouse-liver microsomal incubations at a rate of 2.6 pmoles/mg DNA/min . Paracetamol also bound covalently to hepatic DNA at a level of 15 pmoles/mg DNA after a hepatotoxic dose of paracetamol to mice . NAPQI caused extensive DNA single-strand breaks as evidenced by alkaline elution of DNA from treated Reuber hepatoma cells . This effect occurred at concentrations which later resulted in cytotoxicity . Paracetamol was shown to induce increased DNA-repair synthesis in isolated mouse-liver cells in monolayer culture, at concentrations where also cytotoxicity was evident . Increased DNA-repair synthesis occurred at lower paracetamol concentrations in cells isolated from mice pretreated with phenobarbital . Taken together, these data show that paracetamol can cause DNA interaction leading to damage at levels which are cytotoxic.

Mutat Res, 1984 Oct, 130(5), 315 - 20
A new strain of Salmonella typhimurium reverted by mitomycin C and N-methyl-N'-nitro-N-nitrosoguanidine--a possible universal tester for mutagenic compounds; Balbinder E et al.; A strain of Salmonella typhimurium, SO1007, which carries the amber mutation trpD28 plus the plasmid pKM101 was reverted very efficiently by two mutagens with different mutagenic specificities and modes of action: mitomycin C (MC) and N-methyl-N'-nitro-N-nitrosoguanidine (NG) . By selecting revertants on minimal agar supplemented with anthranilic acid (AA), two distinct phenotypic classes of TrpD28 revertants can be recovered: prototrophs (MM+) and anthranilate utilizers (AA+) . Since each phenotypic class is known to be caused by a variety of mutational events, reversion of trpD28 on minimal-anthranilate medium may be useful for detecting mutagenic agents regardless of the types of mutations they may cause . Thus, strains like SO1007 may be useful as 'universal' detectors of mutagenic compounds . In the course of these experiments we also observed that pKM101 does not protect but, on the contrary, sensitizes the host bacteria slightly to the toxic effects of MC.

Mutat Res, 1984 Oct, 129(1), 47 - 55
Mutagenic activities of cyclophosphamide (NSC-26271) and its main metabolites in Salmonella typhimurium, human peripheral lymphocytes and Chinese hamster ovary cells; Winckler K et al.; Cyclophosphamide (CPA) and its main metabolites were analyzed with respect to their mutagenic activities in Salmonella, human peripheral lymphocytes (PL), and Chinese hamster ovary (CHO) cells . In Salmonella, the compounds were activated with S9 mix from rat livers, which were unstimulated or stimulated with Aroclor 1254 or phenobarbital . For the enzyme inducers the following order of efficiency was found for all test compounds except carboxyphosphamide: phenobarbital greater than Aroclor 1254 greater than non-induced . The most potent mutagens in all 3 test systems were 4-OH-CPA, PAM and nor-HN2 . S9 mix transforms 4-OH-CPA to strong mutagenic compounds in the Salmonella assay . All metabolites tested in the Salmonella assay were activated by S9 mix to higher mutagenic potential.

Mutat Res, 1984 Oct, 129(1), 39 - 46
Dissociation of malondialdehyde mutagenicity in Salmonella typhimurium from its ability to induce interstrand DNA cross-links; Basu AK et al.; Malondialdehyde (MDA), an in vivo metabolite of lipid peroxidation and prostaglandin biosynthesis, is mutagenic in Salmonella typhimurium . It is a reactive electrophile that can form interstrand cross-links in DNA . To explore the possibility that MDA-induced interstrand cross-links are the pre-mutagenic lesion, we have quantitated the ability of highly purified preparations of MDA to form interstrand cross-links when reacted with linear plasmid DNA . At physiological temperature and pH, MDA did not form DNA cross-links as determined by DNA denaturation followed by agarose gel electrophoresis . DNA cross-links were formed, however, when incubations with MDA were carried out at either pH 4.2 or temperatures exceeding 60 degrees . alpha-Methylmalondialdehyde (CH3MDA) was found to cross-link DNA more efficiently than MDA, but was not mutagenic in any tester strain of Salmonella . MDA polymers, formed by acid incubation of MDA, also were capable of inducing cross-links . However, an inverse relationship was observed between mutagenicity and extent of polymerization . The pattern of mutagenic response for MDA in different strains of Salmonella was compared with mitomycin C, an established mutagenic cross-linking agent . Error-prone repair and a UvrB+ phenotype, which are needed for the induction of mutations by mitomycin C, were not required for MDA mutagenesis . These findings, taken together, dissociate the mutagenicity of MDA from its ability to form interstrand cross-links with DNA.

Mutat Res, 1984 Oct, 129(1), 33 - 8
Desmutagenic substance in water extract of grass-wrack pondweed (Potamogeton oxyphylus Miquel); Sato T et al.; It was found that the water extract of grass-wrack pondweed (Potamogeton oxyphylus Miquel) had inhibitory activity for reverse mutations induced by benzo{a}pyrene, 2-aminoanthracene and 2-nitrofluorene with Salmonella typhimurium TA100 and TA98 . The active substance was heat-resistant, and the molecular weight was above 300 000 . The substance acted as a desmutagen rather than an antimutagen or inhibitor of metabolic activation.

Mutat Res, 1984 Oct, 129(1), 19 - 24
Superoxide dismutase acts as an enhancing factor for quercetin mutagenesis in rat-liver cytosol by preventing its decomposition; Ochiai M et al.; The mutagenicity of quercetin towards Salmonella typhimurium TA98 was enhanced by rat-liver cytosol . The enhancing factors in the cytosol were separated into 4 fractions by gel filtration, and one of them was identified as superoxide dismutase (SOD) . It is suggested that SOD increases the mutagenicity of quercetin by protecting it from degradation.

Mutat Res, 1984 Oct, 129(1), 13 - 8
Mutagenicity of benzidine and 4-aminobiphenyl after metabolic activation with isolated hepatocytes and liver 9000 X g supernatant from rat, hamster and guinea pig; Neis JM et al.; The mutagenicity of benzidine and 4-aminobiphenyl towards Salmonella typhimurium strain TA1538 was measured in the presence of isolated hepatocytes from rat, hamster and guinea pig . The mutagenic potency of these compounds was also assayed with S9 (9000 X g supernatant) prepared from disrupted hepatocytes . The influence of acetyl coenzyme A, the cofactor for the acetylation reaction, on the mutagenicity of these aryl amines was investigated . For all 3 animal species it was found that the mutagenicity of benzidine is higher with intact hepatocytes than with S9 prepared from disrupted hepatocytes . Addition of acetyl coenzyme A to the S9 fraction increased the mutagenicity of benzidine . In contrast to benzidine, the mutagenicity of 4-aminobiphenyl appeared to be lower with hepatocytes than with S9 . Addition of acetyl coenzyme A to the S9 fraction decreased the mutagenicity of 4-aminobiphenyl . The mutagenic potency of 4-aminobiphenyl was almost equal in the presence of the liver preparations from the 3 different species, whereas obvious species differences were seen with benzidine.

Food Chem Toxicol, 1984 Oct, 22(10), 797 - 801
Mutagenicity studies on N-nitrosated products of the Maillard browning reaction: N-nitroso-fructose-amino acids; Pool BL et al.; The N-nitroso derivatives of D-fructose-L-glycine, D-fructose-L-alanine, D-fructose-L-phenylalanine, D-fructose-L-serine, Dfructose-L-aspartic acid and D-fructose-L-tryptophan (a mixture of alpha-N-nitroso-D-fructose-L-tryptophan and 'indolyl-nitrosamine'-D-fructose-L-tryptophan) were tested for mutagenicity in five auxotrophic strains of Salmonella typhimurium with and without metabolic activation (S-9 mix) . The alanine, phenylalanine and aspartic acid compounds were not mutagenic . The glycine and serine compounds showed a very low but reproducible increase in the numbers of his+ revertants in strain TA1535 without S-9 mix . The mixture containing both nitrosated D-fructose-L-tryptophan compounds was mutagenic in all five strains, with or without metabolic activation . The alpha-N-nitroso-D-fructose-L-tryptophan component of the mixture, which is nitrosated at the amino group, was isolated and tested without S-9 mix . It was mutagenic in three strains . Unnitrosated D-fructose-L-amino acids, D-fructose, and the individual L-amino acids were non-mutagenic when tested under those conditions for which a positive response had been obtained with the corresponding nitrosated compounds . These results indicate the potential value of developing analytical methods to identify alpha-N-nitroso-D-fructose-L-tryptophan in food or food extracts that are to be screened for mutagenic components.

Carcinogenesis, 1984 Oct, 5(10), 1263 - 6
Possible involvement of a vicinal, non-bay-region dihydrodiol-epoxide in the activation of dibenzo{a,e}fluoranthene into bacterial mutagens; Malaveille C et al.; Dibenzo{a,e}fluoranthene, its 7-hydroxy, 3,4- and 12,13-dihydrodiol metabolic derivatives as well as three synthetic, structurally related hydrocarbons, were tested for mutagenicity towards Salmonella typhimurium TA100 strain in the presence of 3-methylcholanthrene-treated rat and mouse liver post-mitochondrial supernatants . Of these compounds, the 12,13-dihydrodiol showed the highest activity, being 6-10 times more mutagenic than the parent compound . Our data, in conjunction with those of previous studies on the liver microsomal metabolism and DNA binding of dibenzo{a,e}fluoranthene and its dihydrodiols, indicate that activation of dibenzo{a,e}fluoranthene to bacterial mutagens may occur predominantly through a vicinal, non-bay-region 12,13-dihydrodiol epoxide.

Invest Ophthalmol Vis Sci, 1984 Oct, 25(10), 1184 - 91
Characterization of endotoxin-induced C5-derived chemotactic activity in aqueous humor; Rosenbaum JT et al.; Although a cellular exudate characterizes acute anterior uveitis, few studies have sought to identify the chemoattractant(s) contributing to this phenomenon . As a model of acute ocular inflammation, the authors have injected rabbits intravenously with endotoxin (Salmonella typhimurium LPS, 2.5 micrograms/kg) . In a Boyden chamber assay, aqueous humor drawn 3 hr after LPS (post-LPS aqueous) exhibited chemotactic activity for purified rabbit granulocytes (PMN) . "Checkerboard" analysis indicated that chemotaxis, rather than protein-induced chemokinesis, primarily accounted for PMN migration . Aqueous from normal rabbits demonstrated no chemotactic activity . Chemotactic activity was maximal at 3 hr post-LPS (versus 1 or 5 hr) . PMN migration exhibited a direct correlation with the concentration of aqueous tested (0.5-5%) . Several observations indicated that this chemotactic activity is complement (C5)-derived . It is inhibited by antibodies to C5 but not affected by antibodies to C3 . Similar to rabbit C5a, chemotactic activity in post-LPS aqueous was heat stable at 56 degrees C X 30 min, attracted both human and rabbit PMN at similar concentrations and induced release of beta glucuronidase from PMN . In addition, prior incubation of rabbit PMN with partially purified C5a (densensitization) specifically inhibited chemotactic responses to both C5a and post-LPS aqueous without inhibiting responses to another chemoattractant, n-formyl-methionyl-leucyl-phenylalanine . Finally, chemotactic activity from post-LPS aqueous could be recovered from a Sephadex G75 column and eluted similarly to chemotactic activity in zymosan activated rabbit serum or 13,700 D molecular weight marker . The presence of complement-derived chemotactic activity in this model should not be construed as evidence that this activity contributes to the pathogenesis of endotoxin-induced inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

Infect Immun, 1984 Oct, 46(1), 55 - 63
Small virulence plasmid of Shigella dysenteriae 1 strain W30864 encodes a 41,000-dalton protein involved in formation of specific lipopolysaccharide side chains of serotype 1 isolates; Watanabe H et al.; A 6-megadalton plasmid, pHW400, of Shigella dysenteriae 1 strain W30864 was previously found to specify one or more functions for O-antigen production and bacterial virulence (H . Watanabe and K . N . Timmis, Infect . Immun . 43:391-396, 1984) . The region of pHW401, a Tn801-tagged derivative of pHW400, responsible for O-antigen production has been localized by gene cloning and Tn5 transposon mutagenesis . Analysis of lipopolysaccharide isolated from S . dysenteriae 1 bacteria carrying mutant plasmids revealed that the determinant for O-antigen synthesis, designated rfp, codes for a function involved in the formation of the O-polysaccharide side chain structure of lipopolysaccharide . Analysis of radioactively labeled proteins synthesized in minicells of Escherichia coli carrying mutant plasmids identified the product of the rfp gene as a 41,000-dalton protein . Southern hybridization with a DNA fragment carrying the rfp gene demonstrated that this determinant is present on 6-megadalton plasmids in other isolates of S . dysenteriae 1 but is not present at all in a variety of other Shigella, E . coli, and Salmonella typhimurium strains that were tested.

Eur J Biochem, 1984 Oct 1, 144(1), 113 - 9
Phosphoenolpyruvate-dependent phosphorylation site in enzyme IIIglc of the Escherichia coli phosphotransferase system; Dorschug M et al.; Enzyme-IIIglc is part of the glucose phosphotransferase system of Escherichia coli and Salmonella typhimurium and is phosphorylated by phosphoenolpyruvate in a reaction requiring enzyme I (phosphoenolpyruvate-protein phosphotransferase), and the histidine-containing phospho-carrier protein HPr . In this paper we report the isolation of IIIglc from E . coli and the characterization of the active center . Alkaline hydrolysis of {32P}P-IIIglc and chromatography of the hydrolysate suggested that the phosphoryl group is bound to a histidyl residue in P-IIIglc of S . typhimurium . Here we present 1H-NMR measurements of IIIglc and P-IIIglc from E . coli which further substantiate that the phosphoryl group in P-IIIglc is linked to the N-3 position of a histidyl residue . After phosphorylation of IIIglc with {32P}Phosphoenolpyruvate, enzyme I and HPr, the phosphorylated protein was cleaved with either alkaline protease from Streptomyces griseus or subtilisin from Bacillus subtilis . According to amino acid analysis both proteases produced the same peptide carrying the phosphoryl group . The amino acid sequence of this peptide was found to be Val-His-Phe-Gly-Ile-Asp . The lower electrophoretic mobility of P-IIIglc on dodecylsulfate/polyacrylamide gels and its stronger binding to the hydrophobic matrix of a reversed-phase column compared to unphosphorylated protein may indicate a structural change following phosphoenolpyruvate-dependent phosphorylation.

Clin Exp Immunol, 1984 Oct, 58(1), 167 - 73
Relationship between immune system and gram negative bacteria . I . Spontaneous binding of smooth and rough Salmonella to human peripheral blood lymphocytes; Jirillo E et al.; Over the past years many reports have emphasized that either Gram positive or Gram negative bacteria possess the ability to bind spontaneously to human peripheral blood lymphocytes (PBL) . Here, bacterial binding to human PBL has been studied by using a smooth (S) Salmonella typhimurium LT-2 and two rough (R) mutants of Salmonella minnesota R 345 (Rb) and R 595 (Re), which possess specific deletions in their lipopolysaccharide (LPS) molecule . Our results provide evidence that all three bacterial strains spontaneously bind to PBL, even though Re and mostly Rb cells display the highest degree of adherence . The three major regions of LPS (O-polysaccharide chain, R core and lipid A) seem to be involved in the binding since adherence is specifically inhibited by pretreating PBL with S- or R-LPS extracted from homologous bacteria . Furthermore, using a panel of monoclonal antibodies to lymphocyte surface antigens, S- and R-Salmonella bacteria bind to T lymphocytes (preferentially T8+ cells), while few B cells are coated by bacteria . Additionally, bacterial binding is significantly reduced by trypsin pretreatment of PBL, this suggesting that proteins (or glycoproteins) of the PBL membrane are involved in the binding.

Cancer Res, 1984 Oct, 44(10), 4308 - 11
Mutagenic activity of tumor-associated macrophages in Salmonella typhimurium strains TA98 and TA 100; Fulton AM et al.; Suspensions of cells from a series of strain BALB/cfC3H mouse mammary tumors, and adherent and nonadherent cells from the tumors, were tested for their ability to increase the mutation rate of Salmonella typhimurium tester strains TA98 and TA100 . Significant increases were seen with cells from three of four tumor lines tested on the TA98 strain and with one of four tested on the TA100 strain . The mutagenic activity was due primarily to cells in the adherent fractions which were greatly enriched for macrophages.

Eur J Clin Microbiol, 1984 Oct, 3(5), 406 - 10
Relationship between growth temperature and shedding of lipopolysaccharides by gram-negative bacilli; Mackowiak PA; To explore the possibility that physiologically elevated temperatures might reduce the shedding of lipopolysaccharides (LPS) by gram-negative bacteria, the in vitro rates of growth and LPS release by Escherichia coli 055 and Salmonella typhimurium were compared at 33 degrees C, 37 degrees C and 41 degrees C . Rates of LPS accumulation in liquid culture supernatants were measured by radioimmunoassay for O-antigen . Escherichia coli 055 cells, adapted to 35 degrees C and then grown at different temperatures, showed increased growth and LPS release rates parallel with rising incubation temperatures . The growth of a clinical isolate of Salmonella typhimurium (not a laboratory strain) was suppressed slightly at 33 degrees C, but LPS shedding was unaffected by temperature changes . Adaptation of Escherichia coli 055 to 40 degrees C was associated with a smooth-rough transition and a reduced release rate of O-antigen, but no difference in growth rate when compared with a 35 degrees C-adapted strain . Thus, the release rate of LPS by gram-negative bacteria does not necessarily parallel their growth rate . This mechanism does not seem to explain the apparently beneficial effect of fever on the outcome of gram-negative infections in higher animals.

J Immunol, 1984 Oct, 133(4), 2255 - 60
Monoclonal antibodies demonstrate multiple epitopes on the O antigens of Salmonella typhimurium LPS; Elkins K et al.; To investigate the complexity of the antigenic determinants presented on the surface of Salmonella typhimurium, a panel of murine monoclonal antibodies was generated and characterized . Hybridomas specific for S . typhimurium (strain TML, O antigens 1, 4, 12) were produced by immunization with acetone-killed and dried bacteria and standard fusion procedures . In this report, 15 such monoclonal antibodies, all of which bind lipopolysaccharide (LPS) extracted from S . typhimurium, are described . The fine specificity of these antibodies was assessed by examining the differential binding of each antibody to a panel of Salmonella strains, which selectively express different O antigenic determinants . This analysis defined several distinct categories of monoclonal antibodies of varying isotypes . Four anti-O:4-specific antibodies were identified . Two were specific for O:1 . One antibody appears to react with the core polysaccharide of S . typhimurium LPS . Several of the monoclonal antibodies recognized LPS determinants that are presumably created by a combination of O antigens . For instance, one bound only to Salmonella strains that expressed both O:1 and O:12, whereas another bound only to those strains which expressed both O:4 and O:12 . A group of three antibodies bound to any strain that simultaneously expressed O:1, O:4, and O:12 . A distinct group of three monoclonal antibodies also bound strains that expressed O:1, O:4, and O:12, but only when the O:5 antigenic determinant was not present . The latter are, in that respect, S . typhimurium strain TML LPS-specific . The results of this analysis suggest that the epitopes of the S . typhimurium LPS molecule that are recognized by the host are considerably more complex than has been previously indicated by classical serology.

Microbiologica, 1984 Oct, 7(4), 353 - 66
Immune response in mice and effects on cells by outer membrane porins from Salmonella typhimurium; Tufano MA et al.; In this study, we describe the role of porins extracted from the outer membrane of S . typhimurium on the interaction with the host organism . The tests were performed on CD-1 mice immunized both with whole S . typhimurium cells and with purified porins . The antibody titres obtained in mice treated with purified porins and in those treated with whole Salmonella are 1/320 and 1/80 respectively . Cell-mediated response was found to be stimulated in both mice groups: our results show that T lymphocytes determine an increase in H3-thymidine incorporation and MIF production . An increase in lymphocytes with membrane immunoglobulins was observed in the lymphocyte population from the spleens of the treated mice . Purified porins added to macrophages cultures exerted a toxic effect at concentrations between 10 and 20 micrograms/ml . Subinhibiting concentrations (5 micrograms/ml) led to modifications in the surface tension of macrophages layers adhering to the slides . Moreover, subinhibiting porins concentrations were found to modify macrophage functionality as shown by evaluation of the phagocytic index and of intracellular killing, both of which were found to have diminished with respect to controls . When purified porins were added in vitro to populations enriched with T and B lymphocytes, at concentrations between 1 and 5 micrograms/ml they were found to be mitogenic with respect to B lymphocytes . The results we obtained showed that lymphocytes with IgM increase in porins tests . Eventually, purified porins added to Hela and Hep-2 cells were shown to exert a toxic effect which became detectable in the final concentration of 5 micrograms/ml and 1 micrograms/ml for Hela and Hep-2 cells respectively.

Proc Natl Acad Sci U S A, 1984 Oct, 81(19), 6105 - 9
Suppressor sufJ: a novel type of tRNA mutant that induces translational frameshifting; Bossi L et al.; We describe the DNA sequence change responsible for the creation of a frameshift-suppressor gene in Salmonella typhimurium . The suppressor, sufJ, results from a base-pair insertion in the gene coding for a threonine transfer RNA (tRNA3Thr) . Unlike previously studied frameshift suppressor mutations, the sufJ insertion does not fall within the sequence corresponding to the tRNA anticodon . The insertion (a G.C base pair) occurs within a run of three G.C base pairs in that region of the gene coding for one strand of the anticodon stem . In the secondary structure of the mature tRNA, the net result is that an extra, unpaired cytidine residue is pushed into the anticodon loop, thus increasing the size of the loop to eight nucleotides . These findings are discussed in connection with the peculiar "three-out-of-four" method of reading by the sufJ suppressor . A unifying model is presented accounting for the contrasting decoding behaviors of tRNAs with eight-nucleotide-long anticodon loops.

Proc Natl Acad Sci U S A, 1984 Oct, 81(19), 6095 - 9
Genetic recombination can generate altered restriction specificity; Fuller-Pace FV et al.; A recombinant strain, isolated following the transduction of an Escherichia coli recipient carrying the Salmonella typhimurium (SB) specificity genes with DNA from a donor having the Salmonella potsdam (SP) specificity, was shown {Bullas, L.R., Colson, C . & Van Pel, A . (1976) J . Gen . Microbiol . 95, 166-172} to have neither SB nor SP specificity but to encode a novel restriction specificity, SQ . The heteroduplex analysis of the hsdS (specificity) genes of the SB and SP restriction and modification systems described here identifies a conserved sequence of around 100 base pairs flanked by two nonhomologous regions each of approximately 500 base pairs . This organization parallels that previously deduced from the DNA sequences of the hsdS genes of the related E . coli K-12, B, and D restriction systems . The present heteroduplex analyses further show that the hsdS gene conferring the SQ specificity derives one nonhomologous region from the SB gene and the other from the SP gene, as predicted from genetic exchange within the conserved sequence . This finding supports the idea that two domains of an hsdS polypeptide, which are different for each specificity, may correlate with two regions of the DNA sequence recognized . It has been shown that the recognition sequences for E . coli K-12 and B each consist of two short oligonucleotide sequences interrupted by a nonspecific sequence . A similar organization is suggested for the Salmonella specificity systems, providing the potential for evolutionary diversification of restriction specificities as a result of recombination within the conserved sequence of the hsdS gene.

Proc Natl Acad Sci U S A, 1984 Oct, 81(19), 6080 - 4
Extension of bacteriophage lambda host range: selection, cloning, and characterization of a constitutive lambda receptor gene; de Vries GE et al.; A set of plasmids has been constructed that carry a constitutive lamB gene (LamBc phenotype) from Escherichia coli and that confer functional phage lambda receptors to bacteria other than E . coli . This E . coli LamBc strain has been selected to escape both maltose-inducible and glucose-repressible control . Constitutivity results from an IS-3 insertion, carrying a mobile promoter, proximal to lamB . The LamBc DNA has been cloned into both broad and narrow host-range plasmids, and the resulting pTROY plasmids have been transferred to diverse bacteria . Both Salmonella typhimurium/pTROY and Klebsiella pneumoniae/pTROY strains efficiently adsorb phage lambda; Pseudomonas aeruginosa/pTROY strains do not . Introduction of a functional E . coli LamB protein into foreign bacterial will allow these bacteria carrying pTROY plasmids to be infected by phage lambda recombinant DNA libraries, phage lambda::Tn insertion mutagenesis vectors, and in vivo lambda-packaged cosmids.

J Bacteriol, 1984 Oct, 160(1), 391 - 4
ilvB-encoded acetolactate synthase is resistant to the herbicide sulfometuron methyl; LaRossa RA et al.; The herbicide sulfometuron methyl is a potent inhibitor of the branched-chain amino acid biosynthetic enzyme acetolactate synthase (ALS) isolated from bacteria, fungi, and plants . However, it did not prevent growth of wild-type Salmonella typhimurium LT2 or Escherichia coli K-12 . These species each contain two acetolactate synthase isozymes . Growth of S . typhimurium and E . coli mutants lacking ALS I was prevented by the herbicide, suggesting that activity of the remaining ALS isoenzyme (II or III, respectively) was stopped by sulfometuron methyl . Synthesis of ALS I requires either an relA function or an elevated cyclic AMP level . A relA mutant of S . typhimurium was inhibited by sulfometuron methyl on rich carbon sources that display a basal cyclic AMP level but not on poor carbon sources where the cyclic AMP concentration is elevated . When L-valine, which allosterically inhibits ALS I activity, was added, growth retardation of the relA- strain by sulfometuron methyl was observed on both poor and rich carbon sources . Enzymological analyses indicated that ALS I activities derived from both species were resistant to the herbicide . In contrast, activities of S . typhimurium ALS II and E . coli ALS III were abolished by sulfometuron methyl.

J Bacteriol, 1984 Oct, 160(1), 22 - 7
Proline uptake through the major transport system of Salmonella typhimurium is coupled to sodium ions; Cairney J et al.; Strains of Salmonella typhimurium deficient in one or more of the proline transport systems have been constructed and used to study the mechanism of energy coupling to transport . Proline uptake through the major proline permease (PP-I, putP) is shown to be absolutely coupled to Na+ ions and not to H+ ions as has previously been assumed . Transport through the minor proline permease (PP-II, proP), however, is unaffected by the presence or absence of Na+ . The effect of Na+ on the kinetics of proline uptake shows that external Na+ increases the Vmax for transport . It seems probable that proline transport through PP-I is also coupled to Na+ ions in Escherichia coli.

What Is Cell Biology?, What Is Yeast?, What Is Bioengineering?, What Is Genome?, What Is Biofilm?, o, Microbes, n, Bacterium, n, Microbiology, n, Bacteriology, r, Microbe, e, Microbial, a, Pseudomonas aeruginosa, i, Erythromycin, c, Bacillus subtilis, s, Campylobacter, e, Streptococci, r, Staphylococcus, c, Bacillus subtilis, a, Clostridia, c, Microbial, a, Pasteurella, a, Klebsiella, i, Streptomycin, r, Salmonella typhimurium, c, Antimicrobial, s, Yeasts, r, Antibiotics, i, Haemophilus, a, Staphylococcus aureus, s, Antimicrobial, s, Lactobacillus

Scientific Publications - Work Done by Microbiology Reader Bioscreen C
Agricultural Microbiology Anaerobic Microbiology Antimicrobial Susceptibility Artificial Atmosphere Bioassay of Antibiotics Biofilm Microbiology Bioreactor Technology Biotechnology Cell Biology Clinical Microbiology Environmental Microbiology Experiments with Yeast	Fermentation Food Microbiology Functional Genomics Gene Technology Growth Media Development Growth Rate and Lag Time Industrial Microbiology Medical/Pharmaceutical Field Microbiological Assay Microbiological Research Microbiology of Cosmetics go to a specific theme...	Military Microbiology Molecular Microbiology Mutagenicity and Genotoxicity Oral Microbiology Patents Postantibiotic Studies Soil Microbiology Spore Microbiology Veterinary Microbiology Waste/Wastewater Treatment Water Microbiology Wine Microbiology

� 2005 Transgalactic Ltd (manufacturer of Bioscreen C software) | Privacy Statement | P.O. Box 1393, 00101 Helsinki, Finland, phone: +358 9 85172920, fax: +358 9 8749481, e-mail: microbiology@bionewsonline.com

Last modified: May 25, 2005