Infect Immun, 1988 Jan, 56(1), 204 - 12 Control of endotoxin activity and interleukin-1 production through regulation of lipopolysaccharide-lipoprotein binding by a macrophage factor; Warren HS et al.; Lipopolysaccharides (LPSs) extracted from gram-negative bacteria are much less active when bound to serum lipoproteins . We present evidence here that the binding of radiolabeled LPS extracted from Escherichia coli O113 and Salmonella typhimurium to lipoproteins in rabbit serum is increased 8 to 24 h after a single intravenous injection of homologous or heterologous LPS . Supernatants of activated macrophages containing interleukin-1 also stimulate increased binding . The isolated product of this binding does not induce the production of interleukin-1 by macrophages in vivo or in vitro and is unable itself to stimulate increased binding of LPS to lipoprotein . Normal rabbit sera spiked with lipoprotein fractions prepared from tolerant but not normal rabbit sera bind increased amounts of LPS . These data suggest that there may exist a self-regulated mechanism for decreasing the toxicity of LPS and the production of LPS-induced interleukin-1; this mechanism is controlled by a macrophage factor and functions through altering the binding of LPS to certain serum lipoproteins. Clin Orthop, 1988 Jan, (226), 231 - 4 Chronic osteomyelitis of the hand caused by Salmonella typhimurium . A case report; Monsivais JJ et al.; Salmonella osteomyelitis of the hand unassociated with hemoglobinopathy developed in a 39-year-old woman . After 11 debridement and curettage operations on the affected finger, she was successfully treated with excision of the diseased bone and reconstruction with a silicone prosthesis and extensor indicis transfer . This patient, examined 19 years after the onset of symptoms, illustrates that Salmonella osteomyelitis may persist for an exceedingly long period when limited curettage is the only method of treatment. Int J Immunopharmacol, 1988, 10(7), 863 - 73 Immunopotentiating activities of a low molecular weight lipopeptide, RP 56 142--studies in infectious models; Floc'h F et al.; RP 56 142, N2-{N-(N-lauroyl-L-alanyl)-gamma-D glutamyl} L,L-2,6-diaminopimelamic acid belongs to a family of immunomodulating lipopeptides . Its structure is directly derived from that of lauroyltetrapeptide RP 40 639 which is a mixture of two stereoisomers, one of which (with D,D-2,6 diaminopimelamic acid) is totally devoid of in vivo activity . RP 56 142 displayed potent protective activities against bacterial infections such as K . pneumoniae, L . monocytogenes or S . typhimurium (at doses ranging between 0.03 and 100 mg/kg s.c., i.p., i.v.) . In combined treatment protocols, suboptimal doses of RP 56 142 given preventively (day-1) or curatively (day 0 + 4h) significantly protected mice receiving antibiotics at doses which were ineffective when administered by themselves . Given s.c . 1 or 2 days before infectious challenge, RP 56 142 was able to normalize and even enhance significantly the resistance of mice previously immunocompromised by lomustine, 5-fluorouracile or hydrocortisone . These results correlated with the stimulation of the clearance of a virulent Salmonella typhimurium strain and with an important production of colony-stimulating factor in RP 56 142-treated mice. Arch Immunol Ther Exp (Warsz), 1988, 36(6), 701 - 9 Phagocytic and bactericidal properties of macrophages of mice immunized with outer membrane proteins (OMP) of Shigella; Czarny A et al.; Macrophages obtained from peritoneal exudates of mice immunized with the single doses (1 and 5 micrograms) of OMP were shown to have stronger phagocytic as well as bactericidal properties in relation to Shigella flexneri bacilli than nonactivated macrophages . Macrophages from the animals immunized with 10, 20 and 30 micrograms OMP doses showed phagocytic and bactericidal properties similar to those of nonactivated macrophages while the immunization with the dose 50 micrograms resulted in their suppression . Likewise, activity of macrophages from mice immunized twice or three times with various doses of OMP did not differ much from that obtained after immunization with single OMP doses . On the other hand, immunization of mice with a sublethal dose of live Shigella flexneri did not activate either phagocytic or bactericidal properties of macrophages . Besides, phagocytic and bactericidal activity of macrophages of mice immunized with OMP of Shigella was determined in relation to Salmonella typhimurium . The doses 1 and 5 micrograms of OMP resulted in slight activation of macrophages which manifested itself by a little increase in their phagocytic and bactericidal ability . When used in the dose 10 micrograms, OMP remained without any effect on the above activity of macrophages . Only the dose 50 micrograms, slightly suppressed their phagocytic properties. Cytobios, 1988, 55(221), 87 - 94 Regulatory effects of testosterone and 17 beta-oestradiol on the metabolism of dimethylnitrosamine by renal and hepatic microsomal enzymes from BALB/c mice; Ampy FR et al.; Previous investigations with BALB/c mice have demonstrated that no sex-related differences exist in the ability of liver microsomal fractions (S-9) to biotransform dimethylnitrosamine (DMN) to its active mutagenic metabolites as evidenced by bacterial screening assays . In contrast, kidney microsomal enzymes from adult male BALB/c mice and not from females, castrates, and immature animals, were capable of activating DMN . The present study was designed to test the effects of testosterone and oestradiol on DMN bioactivation by hepatic or renal microsomal enzymes . Mutagenic assays were performed using liver and kidney microsomal enzymes with the histidine deficient mutant Salmonella typhimurium TA100 . Results indicate that testosterone treatment of female BALB/c mice resulted in an increase in the ability of their renal microsomal enzymes to metabolize DMN to its active mutagenic intermediates . Renal microsomal enzymes from female mice treated with 17 beta-oestradiol had no effect on DMN metabolism . However, the ability of the renal microsomal enzymes treated with 17 beta-oestradiol to bioactivate DMN was significantly decreased in males. Drugs Exp Clin Res, 1988, 14(6), 375 - 8 Correlation of in vitro activities of the fluoroquinolones to their in vivo efficacies; Fernandes PB et al.; The new fluoroquinolones have activity against Gram-positive and Gram-negative bacteria . In order to differentiate between the compounds, the authors have compared their in vitro activities and correlated these results with their in vivo efficacies . Norfloxacin (N), pefloxacin (P), enoxacin (E), ofloxacin (O), difloxacin (D), ciprofloxacin (C), fleroxacin (F), A-61827 (A), temafloxacin (T) and lomefloxacin (L) were used in these studies . In vitro, C was the most active compound against Gram-negative aerobic bacteria and A was the most active compound against Gram-positive cocci and anaerobic bacteria . In mouse protection tests, C, D, A, O, T and F had similar activities against Escherichia coli and Pseudomonas aeruginosa . D, T and A were the most active quinolones against Staphylococcus aureus and Streptococcus pyogenes and Strep . pneumoniae in mouse protection tests . D was the most active agent against intracellular infection with Salmonella typhimurium, followed by O, T, A and F . The other compounds were ineffective in this test . All the quinolones were effective in treating E . coli pyelonephritis in mice . The doses required to treat P . aeruginosa pyelonephritis in mice were four times greater than those required to treat E . coli . Resistant P . aeruginosa mutants could be isolated from the kidneys after quinolone treatment . Systemic infections with E . coli, Staph . aureus and P . aeruginosa in neutropenic mice required high doses of the fluoroquinolones and F, T and A were ineffective at doses of 100 mg/kg against P . aeruginosa in this model . Differences in in vitro potencies were not reflected in in vivo efficacies.(ABSTRACT TRUNCATED AT 250 WORDS) Ann Nutr Metab, 1988, 32(3), 113 - 20 {Influence of different types of experimental obesity on resistance of the mouse to infection by Salmonella typhimurium and Klebsiella pneumoniae}; Conge GA et al.; Resistance to infections inducing two types of immune response, humoral and cell-mediated, has been measured in mice after Salmonella typhimurium and Klebsiella pneumoniae inoculation; the animals exhibited different kinds of obesity: genetic, ob/ob and db/db mutants, induced by fat diet or gold thioglucose (aurothioglucose) injection (determining obesity of central origin) . Klebsiella infection was aggravated in all types of obesity . Salmonella infection was aggravated in genetically diabetic and dietary-obese mice . The two kinds of genetically obese mice show an important functional decrease in splenic lymphocytes . In contrast, aurothioglucose-obese mice were more resistant than controls. Microbios, 1988, 53(216-217), 181 - 90 Mechanism of caffeine repression of mitomycin C induced reversion in Salmonella typhimurium strain TA94; Kim J et al.; Caffeine significantly repressed his- reversion of Salmonella typhimurium TA94 induced by mitomycin C (MMC) . The decrease in the number of revertants with increasing concentrations of caffeine was accompanied by a decrease in cell viability . Reversion rates (revertants/viable cells) in the presence of caffeine were higher than in the absence of caffeine . The results of this study indicate that the apparent antimutagenic activity of caffeine on MMC induced reversion is due to the potentiation by caffeine of MMC-induced lethality. Mol Microbiol, 1988 Jan, 2(1), 141 - 52 Role of the intercistronic region in post-transcriptional control of gene expression in the histidine transport operon of Salmonella typhimurium: involvement of REP sequences; Stern MJ et al.; The high-affinity histidine permease of Salmonella typhimurium is encoded by a four-gene operon containing a large intercistronic region located between the first gene (hisJ) and the three distal genes (hisQ, hisM, hisP) . The level of expression of hisJ is 30-fold greater than that of hisP . In order to investigate the role of the intercistronic region in intra-operonic control of gene expression, we have isolated MudII-mediated lacZ gene fusions to hisQ, hisM and hisP . We have used these fusions to isolate and analyse mutants that have altered levels of expression of the hisQ gene, the first gene downstream from the intercistronic region . The results indicate that intra-operonic regulation is due to a combination of factors including efficiency of translational initiation, mRNA degradation, and retroregulation of hisJ expression . They also suggest that the REP (Repetitive Extragenic Palindromic) sequences, which are located in the hisJ-hisQ intercistronic region, may interfere with translation of the hisQ gene and affect upstream messenger RNA stability by protecting it from 3' to 5' nuclease degradation (in agreement with data presented by Newbury et al., 1987). Jpn J Cancer Res, 1988 Jan, 79(1), 32 - 41 Mutagenicity and nitropyrene concentration of indoor air particulates exhausted from a kerosene heater; Kinouchi T et al.; The particulates in a room warmed with a radiant kerosene heater were collected, extracted and fractionated into diethyl ether-soluble neutral, acidic and basic fractions . The mutagenicity of these fractions was measured with Salmonella typhimurium strains TA98, TA98NR, TA98/1,8-DNP6 and TA100 in the presence and absence of S9 mix . Room air without the heater showed very low mutagenicity . However, a sample from a room at the beginning of the burning period showed very high mutagenicity (237 His+ revertants/plate/m3 of air in strain TA98 in the absence of S9 mix) . In contrast, emissions from the heater after it was burning stably showed low mutagenicity (9 His+ revertants/plate/m3) . The crude extract of particulates from the heater at the beginning of the burning period was analyzed by high-pressure liquid chromatography (HPLC) and showed a considerable amount of nitropyrenes (NPs); the concentrations of 1-NP and 1,6-diNP were 1.62 ng and 0.149 ng/m3 of air, respectively, and accounted for 1.2% and 17.6%, respectively, of the mutagenicity in strain TA98 in the absence of S9 mix . In addition, an HPLC-Ames histogram showed that peaks of mutagenicity corresponding to 1-NP and diNPs accounted for 75.7% (1-NP, 4.9%; 1,6-diNP, 17.1%; 1,8-diNP, 46.3%; 1,3-diNP, 7.4%) of the HPLC-recovered mutagenicity for strain TA98 without S9 mix . These results that kerosene heaters, especially immediately after ignition, create mutagenic substances such as NPs. J Cancer Res Clin Oncol, 1988, 114(2), 177 - 82 Catechin as an antimutagen: its mode of action; Nagabhushan M et al.; In the present study, we report that the betel quid ingredient catechu, its extract and pure principle catechin were nonmutagenic in Salmonella typhimurium TA 100, TA 1535, TA 98, and TA 1538 assays with or without metabolic activation . They also exhibited dose-dependent decreases in mutagenicity of benzo(a)pyrene {B(a)P} and dimethylbenz(a)anthracene (DMBA) in strain TA 98 with metabolic activation . We further report that these compounds inhibited activities of cytochrome P-450 and had no effect on glutathione-S-transferase but increased the glutathione content in rat liver tissue . Simultaneous treatment of catechin prevented the mutagenic activity of B(a)P and DMBA metabolites in strain TA 98 in the absence of metabolic activation . Pre- and post-treatment of bacteria with catechin had no effect on the mutagenicity of B(a)P and DMBA metabolites . Catechin also inhibited the in vitro binding of 3H-B(a)P metabolites to calf thymus DNA . Catechu extract and catechin inhibited the nitrosation of methylurea by nitrite at pH 3.6 and 30 degrees C . The formation of nitrosomethylurea in the reaction mixture was monitored by measuring the histidine revertants of strain TA 1535 in the absence of metabolic activation . Pre- and post-treatment of catechu extract or catechin had no effect on the mutagenicity of nitrosomethylurea in TA 1535 . The nitrosation inhibition by catechin was through scavenging of nitrite observed at pH 3.6 . The above study indicates that catechu in betel quid may act as an antimutagen and may suppress the mutagenic potential of other betel quid mutagens. Drug Metabol Drug Interact, 1988, 6(3-4), 349 - 58 DNA-binding of sulfur-containing metabolites from 35S-(pentachlorobutadienyl)-L-cysteine in bacteria and isolated renal tubular cells; Vamvakas S et al.; S-(Pentachlorobutadienyl)-L-cysteine (PCBC) is the penultimate metabolite formed from the nephrocarcinogen hexachlorobutadiene (HCBD) . It is activated by cysteine conjugate beta-lyase (beta-lyase) to yield thioacylating metabolites thought to be responsible for PCBC-induced cytotoxicity and mutagenicity . We have investigated the beta-lyase dependent DNA-binding of metabolites formed from 35S-PCBC in Salmonella typhimurium (S . typhimurium) TA100 and in rat renal proximal tubule cells . 35Sulfur was found in DNA isolated from S . typhimurium (410 +/- 93 DNA-adducts per 10(6) nucleotides) and renal cells (68 or 97 DNA-adducts per 10(6) nucleotides) . Enzymatic hydrolysis of the isolated DNA to yield 3'-nucleotide phosphates and fractionation of the hydrolysate by HPLC indicated the presence of 3 distinct, 35S-containing metabolites which did not coelute with unchanged 3'-nucleotide phosphates and likely represent DNA constituents modified by 35S-PCBC metabolites . Identical retention volumes were obtained for altered bases isolated from bacteria and from renal cells . The results obtained indicate that PCBC metabolites may covalently bind to DNA and implicate genotoxic mechanisms in HCBD-induced nephrocarcinogenicity. Chir Pediatr, 1988, 29(5), 291 - 2 {Torsion of the spleen}; Mendes J et al.; The authors describe, a case of torsion of the splenic hilum complicated with a Salmonella typhimurium infection in a child aged 14 months . The existence of a defect of the spleen fixation to the parietal peritoneum, the wandering spleen, that occurs during foetal life is responsible for this situation . The etiology of this entity as well as its clinical presentation and differential diagnosis are analysed . the therapeutic indications os splenectomy and splenopexy are discussed. Boll Ist Sieroter Milan, 1988, 67(1), 57 - 61 Survival of bacteriophage 1 of the Salmonella typhimurium phage typing scheme in different liquid pharmaceutical preparations; Papaconstantinou AT et al.; The survival of bacteriophage 1 of the Salmonella typhimurium phage typing scheme was studied in seven commonly used liquid pharmaceutical preparations of different composition . Commercially available flacons of Septobore colyre, Thilodexine eye drops, Bradoral gargle solution, Novalgin drops, Garamycin injection, Anatoxal-antigen tetanic purificate and Antidiphtheric serum, were used . It was found that the phage viability in these drugs varied greatly . Thus in Septobore the page was almost completely eliminated in less than one week, while in Garamycin the number of plaque forming units (PFU) remained stable during the experiment (18 months) . The viability of the phage showed intermediate values in the other five pharmaceutical preparations . The possible reasons for these differences in viability and the significance of phage (and viruses) survival in medicins are discussed. J Hyg Epidemiol Microbiol Immunol, 1988, 32(4), 457 - 65 Local and systemic immune response in rabbits after intraintestinal immunization with a double-marker attenuated strain of Salmonella typhimurium; Denchev V et al.; Local and systemic immune response was studied in 3 groups of rabbits immunized and reimmunized 190 days later with S . typhimurium double-marker attenuated strain 1,771 and doses ranged from 20.10(9) to 0.2.10(9) cells . Another group of rabbits was immunized with extract (hydroxylammine) vaccine . It was found that the attenuated strain persisted for considerable time in the gut, and induced pronounced and continuous immune response as measured by the passive hemagglutination test . The serum antibody response had the character of a secondary one with switching on the synthesis of IgM to IgG already after basic immunisation . By the Coombs' technique it was shown that specific immunoglobulins demonstrated in feces were secretory antibodies of the class IgA (SIgA) . The immune response developed after reimmunization was still more vigorous and prolonged pointing to an immune memory existance . It was possible to obtain well manifested immunity with the lowest dose . The extract vaccine revealed only weak and transitory serum and intestinal antibody levels without SIgA appearance . The results obtained in this setup make S . typhimurium 1771 a perspective candidate for a live vaccine. Gynecol Obstet Invest, 1988, 26(2), 113 - 7 Mutagenicity testing of amniotic fluid from diabetic women, with special reference to their smoking habits; Rivrud GN et al.; Amniotic fluid from 16 diabetic and 78 healthy women at term was tested for capacity to cause mutations in Salmonella typhimurium bacterial tester strain TA98 (Ames test) . Diabetes as well as heavy smoking increased the mutagenic activity of amniotic fluid . The difference between groups of diabetics and controls was significant in both nonsmokers and women who had smoked more than 5 cigarettes the last 48 h before delivery . It seems plausible that metabolic disturbances, perhaps enhanced by a lowered oxygenation, in some instances could produce mutagenic compounds . Mutagenic activity in amniotic fluid may be one of the factors underlying the increased incidence of congenital malformations in the offspring of diabetic women . Early mutations could cause such developmental errors in the embryos, and possibly also in future generations by damage to germ cells . Heavy smoking alone also caused an increase in mutagenic activity in term amniotic fluid . Our findings reflected an enhancing effect of smoking in diabetes . A pregnant diabetic woman who smoked would thus further endanger her already jeopardized pregnancy. Arch Toxicol, 1988, 62(2-3), 103 - 9 Trenbolone growth promotant: covalent DNA binding in rat liver and in Salmonella typhimurium, and mutagenicity in the Ames test; Lutz WK et al.; DNA binding in vivo: {6,7-3H}beta-trenbolone (beta-TBOH) was administered p.o . and i.p . to rats . After 8 or 16 h, DNA was isolated from the livers and purified to constant specific radioactivity . Enzymatic digestion to deoxyribonucleotides and separation by HPLC revealed about 90% of the DNA radioactivity eluting in the form of possible TBOH-nucleotide adducts . The extent of this genotoxicity, expressed in units of the Covalent Binding Index, CBI = (mumol TBOH bound per mol nucleotide)/(mmol TBOH administered per kg body weight) spanned from 8 to 17, i.e . was in the range found with weak genotoxic carcinogens . Ames test: low doses of beta-TBOH increased the number of revertants in Salmonella strain TA100 reproducibly and in a dose-dependent manner . The mutagenic potency was 0.2 revertants per nmol after preincubation of the bacteria (20 min at 37 degrees C) with doses between 30 and 60 micrograms per plate (47 and 94 micrograms/ml preincubation mixture) . Above this dose, the number of revertants decreased to control values, accompanied by a reduction in survival . The addition of rat liver S9 inhibited the mutagenicity . DNA binding in vitro: calf thymus DNA was incubated with tritiated beta-TBOH with and without rat liver S9 . Highest DNA radioactivities were determined in the absence of the "activation" system . Addition of inactive S9 (without cofactors) reduced the DNA binding by a factor of up to 20 . Intermediate results were found with active S9 . DNA binding in Salmonella: beta-TBOH was irreversibly bound to DNA isolated from S . typhimurium TA100 after incubation of bacteria with {3H}beta-TBOH. Chem Biol Interact, 1988, 67(3-4), 215 - 23 Mutagenicities of N-acyl-N-arylhydroxylamines for Salmonella; Wang CY et al.; The N-formyl, N-acetyl and N-propionyl derivatives of N-hydroxy-trans-4-aminostilbene (N-OH-AS), N-hydroxy-4-aminobiphenyl (N-OH-ABP) and N-hydroxy-2-aminonaphthalene (N-OH-AN) were synthesized and examined for their mutagenicities in Salmonella typhimurium TA 98 . The N-formyl derivatives were direct-acting mutagens possibly due to hydrolysis, either spontaneously or by bacterial enzymes to hydroxylamines . Their mutagenicities were enhanced by rat liver microsomes and cytosol . All acetyl and propionyl derivatives required activation by either liver cytosol or microsomes . NADPH slightly decreased the microsome-mediated mutagenicities of the N-acyl derivatives of N-OH-AN . However, it greatly enhanced the cytosol-mediated mutagenicities of these hydroxamic acids, probably due to stabilization of their hydroxylamine derivatives . The mutagenicities reported here do not correlate with previously reported carcinogenicity data . Thus, data obtained in Salmonella mutagenicity studies may not necessarily directly reflect carcinogenic potential in mammalian systems due to the different mechanisms of activation. J Cancer Res Clin Oncol, 1988, 114(4), 363 - 8 Genotoxic activities of benzamidine and its N-hydroxylated metabolite benzamidoxime in Salmonella typhimurium and mammalian cells; Clement B et al.; The genotoxic potentials of benzamidine and benzamidoxime were determined to study the toxicological relevance of the metabolic N-oxygenation (N-hydroxylation) of benzamidines to benzamidoximes . Benzamidoxime induced DNA single-strand breaks (in rat hepatocytes) and DNA amplification in SV40-transformed hamster cells . In the experiments performed, benzamidine itself was only marginally positive in the hepatocyte/DNA single-strand break assay . Since these cells possess an intact metabolization apparatus, the biological activities may be attributed to toxic and genotoxic metabolites formed by biotransformation . In the Salmonella typhimurium mutagenicity test (TA 98 and TA 100) benzamidoxime alone exhibited a low mutagenicity in the TA 98 strain in the presence of rabbit liver S-9 fractions . These results permit recognition of the metabolic N-hydroxylation of benzamidines to benzamidoximes as a process to toxication . Indirect evidence for the formation of a glucuronide of benzamidoxime has been obtained from in vitro experiments, but it could not be established that this process was a decisive factor in the genotoxicity of benzamidoxime. Environ Mol Mutagen, 1988, 12(2), 253 - 9 Mutagenicity of halogenated propanes and their methylated derivatives; Ratpan F et al.; 1,2,3-Tribromopropane, 1,2,3-trichloropropane, and 1,2-dibromo-3-chloropropane are mutagenic in strains TA1535 and TA100 of Salmonella typhimurium, but only in the presence of rat liver S9 mix . This requirement for metabolic activation was unexpected for an alkyl halide and thus suggested the metabolic formation of the 2-keto derivatives (di-haloacetone) . The 2-methyl derivatives of the halopropane compounds did not induce a doubling of revertants compared to controls . It was demonstrated that none of these compounds is converted into a secondary material that could be determined as structurally different by gas chromatography . These observations suggest that lack of mutagenicity of the methylated compounds is a manifestation of a steric effect. Environ Mol Mutagen, 1988, 12(2), 243 - 52 Weak and unexpected mutagenicity to Salmonella of the rat hepatocarcinogen methapyrilene; Ashby J et al.; The rat liver carcinogen methapyrilene is shown to be a selective mutagen to strain TA1535 of Salmonella typhimurium when tested in the absence of S9 mix and using the standard plate-incorporation assay protocol . The activity observed was weak but was reproducible for a range of samples on many occasions of test and was not due to impurities . These data contrast with six earlier reports of the inactivity of this chemical in the Salmonella mutation assay. Scand J Infect Dis, 1988, 20(2), 221 - 3 Erythema nodosum and conjunctivitis triggered by enteritis due to Salmonella typhimurium; Lauhio A et al.; We describe a patient, a 59-year-old woman, who developed erythema nodosum and conjunctivitis after enteritis due to Salmonella typhimurium . The patient was HLA-B27 negative and had circulating immune complexes, as determined by the conglutinin-binding enzyme immunoassay . Immunopathogenesis of the extraintestinal findings is discussed. Environ Mol Mutagen, 1988, 12(1), 65 - 73 Mutagenicity of products generated by the reaction between several antiparasitic drugs and nitrite; Alba MA et al.; Drugs containing secondary aliphatic amines, heterocyclic nitrogen, or secondary aliphatic amido groups (chloroquine, dehydroemetine, mebendazole, and piperazine) and pyrimidine derivatives such as pyrantel pamoate were reacted in vitro with sodium nitrite at pH 3.7 and became mutagenic for Salmonella typhimurium strain TA1535 . The products derived from the nitrosation of chloroquine and dehydroemetine required metabolic activation by mammalian hepatic S9 to be mutagenic . The N-nitroso derivatives of mebendazole, piperazine, and pyrantel pamoate were mutagenic with and without S9, although more activity was noted in the presence of S9 with the nitrosated compounds formed from mebendazole and piperazine . Under identical conditions, no mutagenic products were detected from quaternary ammonium salts such as bephenium hydroxynaphthoate or drugs containing tertiary heterocyclic amino groups, such as iodochlorhydroxyquin. Antimicrob Agents Chemother, 1988 Jan, 32(1), 57 - 62 Oral ciprofloxacin treatment for Salmonella typhimurium infection of normal and immunocompromised mice; Brunner H et al.; Oral treatment of Salmonella typhimurium infection with ciprofloxacin was compared with conventional chemotherapy with ampicillin or chloramphenicol in normal (CFW1) and immunocompromised (C57BL/6) mice . Administration of the antibiotics for 12 days reduced the number of bacteria in livers and the mortality of C57BL/6 mice significantly . Ciprofloxacin was considerably more effective than ampicillin in prolongation of the mean survival time of these mice . Similar to conventional chemotherapeutic agents, ciprofloxacin did not prevent fatal disease in most C57BL/6 mice when the treatment lasted 12 days only . On the other hand, ciprofloxacin cured lethal S . typhimurium illness in immunocompromised mice after long-term oral chemotherapy for 26 days at a dosage of 100 mg/kg twice a day . This was not achieved by either ampicillin or chloramphenicol . In normal mice, 12 days of therapy with ciprofloxacin was sufficient for a significant decrease in both the number of viable bacteria in livers and the mortality of lethally infected mice . The results provide a basis for an alternative antibiotic treatment by the oral route in immunocompromised hosts with systemic infections. Teratog Carcinog Mutagen, 1988, 8(4), 215 - 24 Comparative antimutagenicity of chlorophyllin and five other agents against aflatoxin B1-induced reversion in Salmonella typhimurium strain TA98; Whong WZ et al.; Chlorophyllin was studied for its antimutagenic activity against aflatoxin B1 in Salmonella typhimurium strain TA98 using the plate-incorporation test in the presence of S9 activation . Comparative antimutagenicity between chlorophyllin and certain commonly studied antimutagens (i.e., vitamins A, C, and E, retinoic acid, and beta-carotene) was also examined . A dose-related inhibition of aflatoxin B1 mutagenicity by chlorophyllin was observed, with the mutagenicity being abolished by 860 nmole chlorophyllin per plate . The inhibitory activity of chlorophyllin occurred only when cells were treated concurrently with chlorophyllin and aflatoxin B1 . The antimutagenic potency of chlorophyllin was comparable to that of vitamin A and higher than that of retinoic acid and beta-carotene . Vitamins C and E had no effect on aflatoxin B1 mutagenicity under the conditions used . The results of toxicity tests and a reconstruction experiment showed that inhibition of the mutagenicity of aflatoxin B1 by chlorophyllin and the other active agents was due to antimutagenicity. Microbiol Immunol, 1988, 32(5), 447 - 59 Cell-surface properties of enterotoxigenic and cytotoxic Salmonella enteritidis and Salmonella typhimurium: studies on hemagglutination, cell-surface hydrophobicity, attachment to human intestinal cells and fibronectin-binding; Baloda SB et al.; Thirteen Salmonella enteritidis and S . typhimurium strains with smooth or rough colony morphology were investigated for their surface properties based on hemagglutination (HA), hydrophobicity, and fibronectin-binding profiles . The strains showed 5 different patterns of HA which was mannose-sensitive . The rough strains possessed comparatively greater number of fimbriae than the corresponding smooth strains and also attached to human intestinal cells in greater numbers . The Salmonella strains used in this study interacted with fibronectin and its 29-kDa N-terminal fragment to varied extents . These properties may be helpful in broadening the prospective interaction capabilities of Salmonella organisms with the host surfaces. Comp Immunol Microbiol Infect Dis, 1988, 11(3-4), 153 - 61 Effect of cyclosporin A on murine experimental salmonellosis; Muthukkumar S et al.; Investigations were undertaken to evaluate the effect of cyclosporin A (CyA) on primary infection of mice with Salmonella typhimurium . Further, its effect on delayed-type hypersensitivity (DTH) and antibody response to porin, an outer membrane protein of S . typhimurium, has been characterized under different CyA regimen . When mice were infected i.p . with 5 x 10(4) live medium virulent organisms, the bacterial growth increased by about 2 log10 in CyA treated mice . CyA administered daily for 2 weeks following immunization with porin caused profound suppression of DTH and both IgM and IgG antibody responses . Given a single dose of CyA 24 h before DTH elicitation, the drug had a marked suppressive effect on DTH, but not on the antibody response to porin . Treatment on days 0-5 following immunization had no effect on the manifestation of the DTH response nor on the anti-porin IgM response whereas an enhanced level of IgG was observed in this group. Chem Biol Interact, 1988, 65(3), 261 - 73 Neutrophil-derived oxidants as mediators of chemical activation in bone marrow; Twerdok LE et al.; Neutrophil-derived oxidants have been implicated in both damage to biomolecules and the metabolic activation of xenobiotics . Since the bone marrow is a relatively neutrophil-rich tissue which is subject to xenobiotic toxicity, we have characterized the oxidant generating capability of neutrophilic cells isolated from femurs of male C57BL/6J mice . Addition of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) to neutrophil preparations (70 +/- 5% ring neutrophils and metamyelocytes) elicited superoxide anion generation, as indicated by superoxide dismutase (SOD)-inhibitable acetylated cytochrome c reduction, and oxidant-dependent chemiluminescence (CL) from luminol or lucigenin . The interaction of benzo{a}pyrene-7,8-dihydrodiol (BP-diol), a proximate carcinogenic metabolite of benzo{a}pyrene (BP), with TPA-stimulated bone marrow neutrophils resulted in azide-inhibitable CL (90%) indicative of its myeloperoxidase-dependent oxidation to an excited-state intermediate . Covalent binding of {3H}BP-diol to exogenous DNA was similarly increased 3-fold in the presence of TPA-stimulated bone marrow neutrophils . Recently, our laboratory has shown that in addition to CL, TPA-stimulated human polymorphonuclear leukocytes can activate BP-diol to an intermediate which covalently binds to DNA and elicits mutagenicity in Salmonella typhimurium TA100 . These observations combined with our current results suggest a possible role for neutrophil-derived oxidants in the mechanisms of chemically-induced bone marrow toxicity. Mol Gen Mikrobiol Virusol, 1988 Jan, (1), 36 - 40 {Metabolic regulation of the histidine operon in Escherichia coli and Salmonella typhimurium}; Perel'man BV et al.; Expression of the histidine operon in Escherichia coli cells in contrast to the one in Salmonella typhimurium is changed proportionally to cells growth rate on the different carbon sources . The specific activity of histidinol-dehydrogenase is repressed by addition of 19 amino acids both in Escherichia coli and Salmonella typhimurium independent of the growth medium used . Using of Escherichia coli and Salmonella typhimurium strains containing the heterologous histidine operons made possible to demonstrate the dependence of the histidine operon metabolic regulation to be determined by the operon itself but not by the specificity of the recipient cells . ppGpp was shown to be a positive regulator of the histidine operon expression in Escherichia coli. Mol Gen Genet, 1988 Jan, 211(1), 183 - 5 ack::Mu d1-8 (Apr lac) operon fusions of Salmonella typhimurium LT2; Kwan HS et al.; Several ack::Mu d1-8 insertions were isolated from Salmonella typhimurium on MacConkey-glucose-trimethylamine oxide medium . They could not produce gas from glucose in the absence of exogenous formate . Two of the mutants expressed beta-galactosidase activity and were shown to be ack::Mu d1-8 fusions by genetic analysis . These insertions were characterized and located on the genetic map at the ack locus by co-transduction with zei::Tn10 . The gene order zei::Tn10-ack-pta was established . The direction of transcription of ack was clockwise on the genetic map . Expression of the lac operon in ack::Mu d1-8 was increased twofold by anaerobiosis . Addition of formate, pyruvate, and acetate did not affect the anaerobic expression of the lac operon in ack::Mu d1-8. J Bacteriol, 1988 Jan, 170(1), 365 - 71 Growth-rate-dependent expression and cloning of gnd alleles from natural isolates of Escherichia coli; Barcak GJ et al.; 6-Phosphogluconate dehydrogenase (6PGD), encoded by gnd, is highly polymorphic among isolates of Escherichia coli form natural populations . As a means of characterizing the growth-rate-dependent regulation of the level of 6PGD, five gnd alleles, including the E . coli B/r allele, were crossed into E . coli K-12 with bacteriophage P1 . In each of the isogenic strains, the level of 6PGD was two- to threefold higher in cells grown on glucose than in cells grown on acetate . The level of enzyme activity in the acetate-grown cells varied about sixfold within the set of isogenic strains . The physiological importance of these differences in enzyme level is discussed . The gnd gene was cloned from five E . coli strains and Salmonella typhimurium LT-2 and mapped with twelve restriction endonucleases . gnd was located and oriented on the chromosomal DNAs . The restriction maps of the genes were aligned at conserved restriction sites, and the relative divergence of the genes was estimated from restriction site polymorphisms . The E . coli gnd genes differed from the S . typhimurium gene by about 11% . Most of the E . coli genes differed from one another by less than 5%, but one allele differed from the others by about 10% . Only the gnd gene from E . coli K-12 had an IS5 element located nearby. Antibiot Khimioter, 1988 Jan, 33(1), 43 - 6 {Determination of the O antigen of Shigella sonnei by a competitive immunoenzyme method}; Voronov AV et al.; A technique for immunoenzymatic diagnosis of dysentery by Shigella sonnei O-antigen was developed . For induction of antibodies to O-antigen rabbits were immunized by intravenous administration of a commercial antidysentery vaccine . Specific antibodies to O-antigen belonging to class G immunoglobulins and not binding to O-antigens of Sh . flexneri and Salmonella typhimurium were obtained . beta-Lactamase of Bacillus licheniformis 749/c was used as a marker enzyme in the immunoenzymatic assay . To increase the sensitivity, beta-lactamase molecules were preliminarily linked with glutaric aldehyde into oligomers . Conjugates of Sh . sonnei O-antigen with the oligomers of B . licheniformis 749/c beta-lactamase were prepared with the periodate method by oxidizing O-antigen . The conjugate was used in competing solid phase immunoenzymatic assay for determination of Sh . sonnei O-antigen in blood serum of patients with dysentery . The sensitivity of the assay is 0.5-1 ng per 1 ml of O-antigen. J Bacteriol, 1988 Jan, 170(1), 98 - 102 Complete physical map of the rfb gene cluster encoding biosynthetic enzymes for the O antigen of Salmonella typhimurium LT2; Brahmbhatt HN et al.; Biosynthesis of the Salmonella typhimurium LT2 O antigen is encoded by genes which map in the rfb cluster . The cloning and restriction enzyme analysis of part of this cluster have been described previously (H . N . Brahmbhatt, N . B . Quigley, and P . R . Reeves, Mol . Gen . Genet . 203:172-176, 1986) . The entire rfb gene cluster has now been cloned, and a detailed restriction enzyme map has been constructed which has enabled us to map the approximate positions of individual rfb genes. J Biol Chem, 1987 Dec 25, 262(36), 17350 - 5 gamma-N-methylasparagine in phycobiliproteins . Occurrence, location, and biosynthesis; Klotz AV et al.; The novel post-translationally modified residue gamma-N-methylasparagine, previously detected in the beta subunit of allophycocyanin (Klotz, A . V., Leary, J . A., and Glazer, A . N . (1986) J . Biol . Chem . 261, 15891-15894), has been found in the beta subunits of a variety of other phycobiliproteins . Representatives of C- and R-phycocyanins and B-, C-, and R-phycoerythrins all contain 1 eq of gamma-N-methylasparagine on their beta subunits as judged by the presence of methylamine in acid hydrolysates . Radiotracer experiments show that the methyl group is derived from the S-methyl of methionine, implicating S-adenosylmethionine as an intermediate methyl transfer agent . Isolation of peptides from C-phycocyanins, prepared from cells labeled by L-{methyl-14C}methionine, showed that the gamma-N-methylasparagine residue is at position beta-72, within a highly conserved region in phycobiliproteins . This location corresponds to that reported earlier for the position of gamma-N-methylasparagine in allophycocyanin and R-phycoerythrin . Phycobiliprotein alpha subunits contain insignificant amounts of the adduct . Methylamine is absent from the hydrolysates of the beta subunits or alpha beta monomers of phycobiliproteins from certain organisms . These latter data indicate that the gamma-N-methylasparagine residue is dispensable in some circumstances . The function of this modification remains to be established . gamma-N-methylasparagine was also absent from several other proteins including bovine histones, porcine myelin basic peptide, and the Salmonella typhimurium aspartate chemoreceptor, all known to undergo post-translational methylations. Biochemistry, 1987 Dec 15, 26(25), 8475 - 80 Specific proteolysis of native alanine racemases from Salmonella typhimurium: identification of the cleavage site and characterization of the clipped two-domain proteins; Galakatos NG et al.; Native DadB and Alr alanine racemases (Mr 39,000) from Salmonella typhimurium are proteolyzed at homologous positions by alpha-chymotrypsin, trypsin, and subtilisin to generate in all cases two nonoverlapping polypeptides of Mr 28,000 and 11,000 . Under nondenaturing conditions, chymotryptic digest results in an associated form of the two fragments which possesses 3% of the original catalytic activity, incorporates 0.76 equiv of the mechanism-based inactivator beta-chloro-{14C}-D-alanine {Badet, B., Roise, D., & Walsh, C . T . (1984) Biochemistry 23, 5188}, and exhibits a UV circular dichroism profile identical with that of native enzyme . Protein sequence analysis of the denatured chymotryptic fragments indicates the presence of a tetrapeptide interdomain hinge (DadB, residues 254-257; Alr, residues 256-259) that is attacked at both ends during proteolysis . Under the previously employed digest conditions, NaB3H4-reduced DadB holoenzyme is resistant to alpha-chymotrypsin and trypsin and is labile only toward subtilisin . These data suggest that the hinge structure is essential for a catalytically efficient enzyme species and is sensitive to active site geometry . The sequence at the hinge region is also conserved in alanine racemases from Gram-positive bacteria. JAMA, 1987 Dec 11, 258(22), 3269 - 74 Massive outbreak of antimicrobial-resistant salmonellosis traced to pasteurized milk; Ryan CA et al.; Two waves of antimicrobial-resistant Salmonella typhimurium infections in Illinois totaling over 16 000 culture-confirmed cases were traced to two brands of pasteurized 2% milk produced by a single dairy plant . Salmonellosis was associated with taking antimicrobials before onset of illness . Two surveys to determine the number of persons who were actually affected yielded estimates of 168 791 and 197 581 persons, making this the largest outbreak of salmonellosis ever identified in the United States . The epidemic strain was easily identified because it had a rare antimicrobial resistance pattern and a highly unusual plasmid profile; study of stored isolates showed it had caused clusters of salmonellosis during the previous ten months that may have been related to the same plant, suggesting that the strain had persisted in the plant and repeatedly contaminated milk after pasteurization. Toxicol Lett, 1987 Dec, 39(2-3), 189 - 98 The pathologic and immunologic effects of inhaled acrolein in rats; Leach CL et al.; Four groups of 40 male Sprague-Dawley rats each were exposed by inhalation to target concentrations of 0, 0.1, 1.0, and 3.0 ppm of acrolein 6 h/day, 5 days/week for 3 weeks . Subsequent changes in local pulmonary immunity were determined by examining the number of antibody plaque-forming cells in the lung-associated lymph nodes following intratracheal immunization with sheep red blood cells . Separate groups of rats were evaluated for blastogenic responsiveness to phytohemagglutinin-P and Salmonella typhimurium antigen using spleen- and lung-associated lymph node cells . In vivo resistance was evaluated utilizing acrolein-exposed rats subsequently challenged with intravenous Listeria monocytogenes . Local pulmonary antibody responsiveness was not affected by acrolein exposure . Lymphocyte blastogenesis and resistance to Listeria challenge were not altered . Body weights and spleen weights were decreased in the 3 ppm-exposed group only . Microscopic examination of the nasal turbinates revealed acrolein-induced exfoliation, erosion, and necrosis of the respiratory epithelium as well as squamous metaplasia, however, lung histology was not affected . Thus at environmental concentrations, acrolein toxicity appeared to be confined to local nasal pathologic changes with no alterations in lung histology or immune function. Toxicol Lett, 1987 Dec, 39(2-3), 177 - 84 T-2 toxin effects on the serum amyloid P-component (SAP) response of Listeria monocytogenes- and Salmonella typhimurium-infected mice; Ziprin RL et al.; T-2 mycotoxin, given to mice 4 days prior to an intraperitoneal inoculation with Listeria monocytogenes EGD, increases the acute phase response as determined by measurements of serum amyloid protein-P (SAP), and decreases the severity of the infection . Conversely, when T-2 toxin is given simultaneously with L . monocytogenes the mice become more susceptible to the infection, and the SAP levels attained are diminished relative to the non-toxin-treated Listeria-infected controls . T-2 toxin given 4 days prior to intraperitoneal inoculation with Salmonella typhimurium had no effect on either the resultant infection or SAP levels . These results indicate that T-2 toxin modulates the acute phase response to infection, and are consistent with an in vivo role for SAP as a nonspecific host resistance factor. J Med Chem, 1987 Dec, 30(12), 2309 - 13 Design and synthesis of peptide derivatives of a 3-deoxy-D-manno-2-octulosonic acid (KDO) analogue as novel antibacterial agents acting upon lipopolysaccharide biosynthesis; Claesson A et al.; On the basis of the knowledge that the amino acid 3 (8-amino-2,6-anhydro-3,8-dideoxy-D-glycero-D-talo-octonic acid) is a potent inhibitor of 3-deoxy-manno-octulosonate cytidylyltransferase, attempts were made to design derivatives that would act as antibacterials against Gram-negative bacteria by inhibiting lipopolysaccharide biosynthesis . Compound 3 and the derivatives 15 and 16 containing an additional amino acid were not lethal to bacteria . However, compounds 17-22, which contain a N-terminally linked dipeptide, exhibited good antibacterial activity in vitro on testing against strains of the Gram-negative bacteria Escherichia coli and Salmonella typhimurium . They have no activity against Gram-positive bacteria such as Staphylococcus aureus. Infect Immun, 1987 Dec, 55(12), 2956 - 61 Bacterial-lipopolysaccharide-induced release of lactoferrin from human polymorphonuclear leukocytes: role of monocyte-derived tumor necrosis factor alpha; Koivuranta-Vaara P et al.; We have examined the role played by human peripheral blood monocytes in mediating responses of human polymorphonuclear leukocytes (PMN) to bacterial lipopolysaccharide (LPS) in vitro . When incubated with Salmonella typhimurium LPS at 37 degrees C, human PMN suspended in serum-free buffer released the specific granule constituent lactoferrin into the surrounding medium . Release of lactoferrin from PMN varied with the concentration of LPS (1 to 1,000 ng/ml) as well as with the duration of incubation (2 to 60 min) and was not accompanied by significant release of the cytoplasmic enzyme lactate dehydrogenase . LPS-induced release of lactoferrin from PMN was augmented significantly when cell suspensions were supplemented with additional monocytes and lymphocytes . Only monocytes, however, secreted significant amounts of lactoferrin-releasing activity (in a time- and concentration-dependent manner) when incubated separately with LPS . Lactoferrin-releasing activity was heat (80 degrees C for 15 min) labile, eluted after chromatography on Sephadex G-100 with an apparent molecular weight of approximately 60,000, and was inhibited by antibodies to tumor necrosis factor alpha . Thus, LPS-induced noncytotoxic release of lactoferrin from human PMN suspended in serum-free buffer is mediated, at least in part, by tumor necrosis factor alpha derived from contaminating monocytes. Carcinogenesis, 1987 Dec, 8(12), 1913 - 8 Species, sex and organ differences in induction of a cytochrome P-450 isozyme responsible for carcinogen activation: effects of dietary hepatocarcinogenic tryptophan pyrolysate components in mice and rats; Degawa M et al.; Both sexes of BALB/c X DBA/2 F1 mice and F344 rats were treated for 1 week with a diet containing 0.02% of hepatocarcinogenic tryptophan pyrolysate component (Trp P-1 or Trp P-2), and changes in the carcinogen activation enzyme activity in various organs were examined comparatively using a mutation test with Salmonella typhimurium TA98 as a tester bacterium . Hepatic enzymes from untreated mice and rats showed a definite catalytic activity for mutagenic activations of Trp P-1 and Trp P-2, whereas the activities of other organs--such as lung, kidney, small intestine and colon--were undetectable or very low . In both mice and rats either the Trp P-1 or Trp P-2 feeding resulted in induction of cytochrome P-450 isozyme(s), which could mediate in the liver but not in other organs the mutagenic activation of the carcinogen itself . As to the sex difference, the induction of the activation enzyme(s) was greater in the female animals than in the males . Species difference in the activity of hepatic enzymes catalyzing the Trp P-1 and Trp P-2 mutageneses was also observed in animals treated with the basal diet; the activity was higher in mice than in the sex-matched rats (Trp P-1, approximately 1.5-fold; Trp P-2, approximately 7-fold) . When diet containing Trp P-1 or Trp P-2 was fed for 1 week, the activity of the rat liver for Trp P-1 mutagenesis was of a level similar to that of the sex-matched mice, but for Trp P-2 mutagenesis it was less than half that in the mice . The induced hepatic enzymes in mice and rats were suggested to be 3-methylcholanthrene-inducible cytochrome P-448 isozymes as determined by mutation tests with Trp P-1, Trp P-2 and two other substrates and by immunochemical analyses of rat hepatic cytochrome P-450 using monoclonal antibodies against rat cytochrome P-448 isozymes . These results indicate that a form of cytochrome P-450 responsible for activation of Trp P-1 and Trp P-2 is inducible by dietary treatment of mice or rats with these carcinogens and that the amount of the cytochrome P-450, including resident and induced forms, is related to the species, sex and organ differences in their carcinogenic susceptibility to these chemicals. Zh Mikrobiol Epidemiol Immunobiol, 1987 Dec, (12), 71 - 4 {Prevention of the formation of the infectious process with biologically active thymic factors in the Salmonella typhimurium challenge of mice coincident with macrophage activation}; Grinevich IuA et al.; A single injection of thymostimulin into mice in a dose of 45 micrograms/kg b.w . enhances the functional activity of macrophages, reaching it maximum on day 10, which prevents the formation of an infectious process in mice challenged with S . typhimurium (LD50) . The irradiation of the animals in a sublethal dose leads to the complete abolition of the stimulating effect of thymostimulin on macrophages . The presence of an inducer mechanism of the activation of macrophages by thymostimulin, realized in the production of lymphokines, is suggested. Res Commun Chem Pathol Pharmacol, 1987 Dec, 58(3), 397 - 400 Failure of diterpenes from Jatropha curcas to induce mutation in Salmonella typhimurium TA98 and TA100; Rojanapo W et al.; No mutagenicity of five diterpenes isolated from the roots of Jatropha curcas was detected by Ame's test using both TA98 and TA100 tester strains with or without S-9 fraction from livers of rats treated with polychlorinated biphenyl. J Environ Sci Health B, 1987 Dec, 22(6), 721 - 9 Mutagenicity of chloroaniline/lignin metabolites in the Salmonella/microsome assay; Rashid KA et al.; Chloroanilines are constituents of many agrochemicals and have been found to be metabolized to succinic acid conjugates, e.g., succinamides and succinimides . The mutagenic potential of five chloroanilines and their succinamides and succinimide derivatives have been tested with two strains of Salmonella typhimurium (TA98 and TA100) with and without rat hepatic microsomal fraction . None of the compounds produced a dose response effect with a two-fold increase in revertants indicating that these compounds are not mutagens or promutagens in these assays. J Appl Toxicol, 1987 Dec, 7(6), 403 - 10 Preliminary evaluation of treatment and selection conditions which affect expression of anthracycline mutagenicity in Salmonella typhimurium and a diploid human lymphoblast cell line; Thomas HF; Mutagenic potency in the Ames Salmonella test is an important endpoint that can be influenced by biological and technical factors . The ranking of mutagenic activity of a series of anthracyclines was measured using different conditions of exposure and mutation selection . A 20 min preincubation treatment version of the Ames test using a 0.2-2.0 microgram/ml (0.36-3.60 nM/ml) dose range of each of the anthracyclines Adriamycin, Daunomycin, Carminomycin, 4'-O-methyldoxorubicin and 4-demethoxydoxorubicin confirmed the order of mutagenic potency seen with the same compounds under direct plating conditions . Preincubation results also confirm direct-plating results by showing the greater sensitivity of selection to His+ reversion over 8-azaguanine resistance to anthracycline mutagenicity . However, the order of mutagenic potency was changed by lengthening the preincubation treatment time to 2 h or reducing the population density of the treated cell inoculum by ten fold . These results suggest that certain treatment conditions enable the treated cells to diminish the phenotypic expression of anthracycline mutagenicity . For comparative purposes, daunomycin and Adriamycin mutagenicity in response to 0.1-0.2 nM/ml and 0.1-0.3 nM/ml dose ranges, respectively, were assessed in a human cell culture system with 6-thioguanine and 5-trifluorothymidine forward mutation selection . A daunomycin dose of 0.1 nM/ml generated approximately 25-fold and 20-fold increases in mutant fraction with 6-thioguanine and 5-trifluorothymidine selections, respectively . Equivalent dosing with Adriamycin generated approximately a 4-fold increase in mutant fraction with 6-thioguanine selection and little or no increase with 5-trifluothymidine selection.(ABSTRACT TRUNCATED AT 250 WORDS) Proc Natl Acad Sci U S A, 1987 Dec, 84(24), 8917 - 21 Spontaneous mutagenesis and oxidative damage to DNA in Salmonella typhimurium; Storz G et al.; Salmonella typhimurium strains containing deletions of oxyR, a positive regulator of defenses against oxidative stress, show 10- to 55-fold higher frequencies of spontaneous mutagenesis compared to otherwise isogenic oxyR+ control strains . The high spontaneous-mutation frequency in oxyR deletion strains is decreased by a factor of 3 when the strains are grown anaerobically . oxyR deletion strains show an increase in small deletion mutations and at least three of the six possible base-substitution mutations (T.A to A.T, C.G to T.A, and C.G to A.T) . However, the largest increase in mutation frequency is observed for T.A to A.T transversions (40- to 146-fold), the base-substitution mutation most frequently caused by chemical oxidants . The introduction into oxyR deletion strains of multicopy plasmids carrying the oxyR-regulated genes for catalase (katG) or alkyl hydroperoxide reductase (ahp) results in overexpression of the respective enzyme activities and decreases the number of spontaneous mutants to wild-type levels . The introduction into oxyR deletions of a plasmid carrying the gene for superoxide dismutase (sodA) decreases the mutation frequency by a factor of 5 in some strain backgrounds . Strains that contain a dominant oxyR mutation and overexpress proteins regulated by oxyR show lower spontaneous-mutation frequencies by a factor of 2 . These results indicate that oxyR and oxyR-regulated genes play a significant role in defense against spontaneous oxidative DNA damage . The role of oxidative damage to DNA in "spontaneous" mutagenesis is discussed. Proc Natl Acad Sci U S A, 1987 Dec, 84(23), 8540 - 3 Substitution of tyrosine for either cysteine in beta-lactamase prevents release from the membrane during secretion; Fitts R et al.; Six independent secretion-defective mutations were found that result in failure to release protein from the membrane into the periplasmic space of Salmonella typhimurium after removal of the signal peptide . The mutant protein is found in a membrane-bound form accessible to trypsin added to intact spheroplasts . The phenotype of these mutations supports the existence in general of an intermediate in bacterial secretion . All six mutations changed one or the other of the two cysteine residues in the mature protein to tyrosine, suggesting that these residues are involved in the release of protein into the periplasmic space, most likely by affecting protein folding. Mutat Res, 1987 Dec, 192(4), 239 - 46 SOS-inducing activity of chemical carcinogens and mutagens in Salmonella typhimurium TA1535/pSK1002: examination with 151 chemicals; Nakamura SI et al.; The umu test system is a newly developed method to evaluate genotoxic activities of a wide variety of environmental carcinogens and mutagens (Oda et al., 1985) . In the present study, we further examined the abilities of 151 chemicals to induce umu gene expression in Salmonella typhimurium TA1535/pSK1002 . Among the chemicals examined, 72 compounds induced umu gene expression, which could be defined on a basis of increased beta-galactosidase activity by 2-fold over the background level . The potent genotoxic compounds without metabolic activation were adriamycin, bleomycin, daunorubicin, 1,3-dinitropyrene, 1,6-dinitropyrene, 1,8-dinitropyrene, N-ethyl-N'-nitro-N-nitrosoguanidine, furylfuramide, methyl methanesulfonate, N-methyl-N'-nitro-N-nitrosoguanidine, mitomycin C, 1-nitropyrene and 4-nitroquino-line-1-oxide . In the presence of S9, aflatoxin B1, 2-aminoanthracene, Glu-P-1, IQ, MeIQ, MeIQx, Trp-P-1 and Trp-P-2 also induced umu gene expression markedly . Several chemicals such as 2-acetylaminofluorene, 9-aminoacridine, azobenzene, benzanthracene, benzidine, diethyl nitrosamine, 1-nitronaphthalene, paraquat, potassium dichromate and sodium nitrite were weakly genotoxic and the induction by these compounds could be detected only when the incubation time was prolonged from 2 h to 5 h . Data are also presented that some of the chemicals such as dimethyl sulfoxide, m-dioxan, 5-fluorouracil and paraquat, which have been reported to be non-mutagenic in Ames/Salmonella assay, were found to be active in inducing umu gene expression, while the known mutagenic compounds including acrylonitrile, 4,4'-dinitrobiphenyl, furfural, methylene chloride, 1-naphthylamine, sodium azide, o-tolidine and o-toluidine were non-genotoxic in the present assay system. Infect Immun, 1987 Dec, 55(12), 3035 - 43 Salmonella typhimurium deletion mutants lacking adenylate cyclase and cyclic AMP receptor protein are avirulent and immunogenic; Curtiss R 3rd et al.; Salmonella typhimurium SR-11 mutants with cya::Tn10 or crp::Tn10 mutations were found to be avirulent and immunogenic for BALB/c mice . Fusaric acid-resistant derivatives with deletions of the Tn10 and adjacent DNA sequences were constructed in S . typhimurium SR-11 strains with or without the virulence plasmid pStSR100 . These delta cya delta crp strains grew more slowly than wild-type strains . They possessed wild-type ability to attach to, invade, and persist in gut-associated lymphoid tissue for up to a week but exhibited a diminished ability to reach mesenteric lymph nodes and the spleen . Mice 4 to 8 weeks old were resistant to oral infection with 10(9) cells of several different delta cya and delta cya delta crp strains (the equivalent to 10(4) 50% lethal doses of wild-type S . typhimurium SR-11) and 30 days after immunization became resistant to oral challenge with 10(3) to 10(4) 50% lethal doses of wild-type S . typhimurium SR-11. Infect Immun, 1987 Dec, 55(12), 2891 - 901 Plasmid-associated virulence of Salmonella typhimurium; Gulig PA et al.; We investigated the role of the 100-kilobase (kb) plasmid of Salmonella typhimurium in the virulence of this organism for mice . Three strains, LT2-Z, SR-11, and SL1344, which possessed 100-kb plasmids with identical restriction enzyme digestion profiles, were cured of their respective 100-kb plasmids after Tnmini-tet was used to label plasmids . Curing wild-type virulent strains SR-11 and SL1344 raised peroral 50% lethal doses from 3 x 10(5) and 6 x 10(4) CFU, respectively, to greater than 10(8) CFU . Both wild-type strains had intraperitoneal 50% lethal doses of less than 50 CFU, whereas the intraperitoneal 50% lethal doses for cured SR-11 and SL1344 were less than 50 and 400 CFU, respectively . Reintroduction of the Tnmini-tet-labeled, 100-kb plasmid restored wild-type virulence . Invasion from Peyer's patches to mesenteric lymph nodes and spleens after peroral inoculation was the stage of pathogenesis most affected by curing S . typhimurium of the 100-kb plasmid . Wild-type S . typhimurium replicated in spleens of mice inoculated intravenously to a greater extent than did plasmid-cured derivatives . Wild-type and cured strains equally adhered to and invaded Henle-407, HEp-2, and CHO cells; furthermore, the presence of the 100-kb plasmid was not necessary for replication of S . typhimurium within CHO cells . The 100-kb plasmid had no effect on phagocytosis and killing of S . typhimurium by murine peritoneal macrophages in vitro and in vivo . Similarly, wild-type and plasmid-cured strains were resistant to killing by 90% normal human, rabbit, and guinea pig sera . All wild-type and plasmid-cured S . typhimurium strains possessed complete lipopolysaccharide, as determined by silver staining solubilized cells in sodium dodecyl sulfate-polyacrylamide gels . We have confirmed the role of the 100-kb plasmid of S . typhimurium in virulence, primarily in invasion to mesenteric lymph nodes and spleens after peroral inoculation of mice . Involvement of the 100-kb plasmid in infection of mesenteric lymph nodes and spleens suggests a role for the plasmid in the complex interaction of S . typhimurium with cells of the reticuloendothelial system. Carcinogenesis, 1987 Dec, 8(12), 1775 - 9 A monoclonal antibody against cytochrome P-450 enhances mutagen activation of N-nitrosodimethylamine by mouse liver S9: studies on the mode of action; Malaveille C et al.; The effect of the monoclonal antibody MAb 2-66-3, directed against the major rat liver phenobarbital (PB)-induced cytochrome P-450 (P-450), on the S9-mediated mutagenicity of N-nitrosodimethylamine (DMN) in Salmonella typhimurium strain TA1530 was studied using liver S9 from PB-treated mice . This MAb enhanced approximately 2-fold S9-mediated mutagenicity of DMN but inhibited both its N-demethylation and N-denitrosation by 50% . Thus MAb-mediated enhancement of DMN mutagenesis does not result from altered activation/inactivation pathways, both known to involve P-450 isozymes . DMSO, a hydroxyl radical (HO.) scavenger and desferrioxamine, an inhibitor of HO.-dependent reactions, quenched the MAb-mediated enhancement of DMN mutagenesis, implicating the HO.-dependent activation of DMN to mutagenic species . As a mechanism, we propose that the binding of this MAb to P-450 isozyme implicated in DMN metabolism decreases the functional coupling between the reductase and the P-450 complex, leading to an increased electron flow from the reductase towards molecular oxygen to form reduced oxygen species (HO.) at the expense of the monooxygenase functions. Mutat Res, 1987 Dec, 181(2), 243 - 56 Relationships between structure and mutagenic activity of environmental chemicals; Shahin MM; This review analyzes relationships between chemical structure and biological activity for several series of compounds . Its focus is on mutagenicity and carcinogenicity and the predictability of these properties on the basis of the chemical structure . Examples are selected from monocyclic aromatic amines, benzidine derivatives, aminoazobenzene derivatives, nitrofurans, aflatoxins, and sterigmatocystins . Results from mutagenicity tests in Salmonella typhimurium are summarized, and their correlation with carcinogenicity is discussed . The review is concluded with generalizations on the usefulness of studies on relationships between chemical structure and mutagenic activity. J Bacteriol, 1987 Dec, 169(12), 5841 - 4 Regulation of the metR gene of Salmonella typhimurium; Urbanowski ML et al.; Regulation of the Salmonella typhimurium metR gene was studied by measuring beta-galactosidase levels in Escherichia coli strains lysogenic for a lambda bacteriophage carrying a metR-lacZ fusion . The results indicate that the metR gene is negatively regulated by its own gene product and that this autoregulation involves homocysteine as a corepressor . In addition, the results indicate that the metR gene is negatively regulated by the metJ gene product over a 70- to 80-fold range. Acta Physiol Scand, 1987 Dec, 131(4), 609 - 17 Enteric nerves mediate the fluid secretory response due to Salmonella typhimurium R5 infection in the rat small intestine; Brunsson I; Eighteen hours after intragastric inoculation Salmonella typhimurium elicited a net fluid secretion in the jejunum and ileum of rats . The mechanisms behind the secretory response were analysed in vivo . Extrinsic denervation of the experimental intestinal segments had no effect . The nerve-blocking agents hexamethonium (i.v.) and lidocaine (serosally applied) blocked the secretion but atropine had no effect . It was demonstrated that the bacteria were invasive by culturing from the intestinal wall . The presence of inflammatory reactions was supported by the facts that i.v . indomethacin blocked the secretory response and that there was an increased capillary leakage of albumin-bound Evans Blue into the interstitium of the intestinal mucosa . There was also a secretory response upon inoculation of the jejunal and ileal segments by cell-free supernatants of broth where bacteria had been cultured for 24 h and thereafter lysed . This response was, however, blocked by i.v . atropine, which had no effect on the secretion elicited by living bacteria . We could show no presence of E . coli LT, ST or cholera toxin in the cell-free supernatant by means of ELISA-tests . We therefore conclude that (1) S . typhimurium R5 invaded the rat jejunal and ileal mucosa, thereby creating an inflammatory response which in turn activated a nerve reflex(es) within the ENS leading to a net fluid secretion; (2) the presence of prostaglandins was needed for activating the reflex(es); (3) the reflex(es) contained a nicotinergic transmission; (4) enterotoxin was of no importance for the secretory response in the model used. J Bacteriol, 1987 Dec, 169(12), 5831 - 4 Nucleotide sequences of the genes encoding type 1 fimbrial subunits of Klebsiella pneumoniae and Salmonella typhimurium; Purcell BK et al.; The nucleotide sequences of the genes encoding the subunits of Klebsiella pneumoniae and Salmonella typhimurium type 1 fimbriae were determined . Comparison of the predicted amino acid sequences of the two subunits revealed domains in which the sequences were highly conserved . Both gene products possessed signal peptides, a fact consistent with the transport of the fimbrial subunit across the membrane, but these regions showed no amino acid homology between the two proteins . The predicted N-terminal amino acid sequences of the processed fimbrial subunits were in good agreement with those obtained by purification of the fimbrial subunits. Infect Immun, 1987 Dec, 55(12), 3044 - 50 Adherence of Salmonella typhimurium to small-intestinal enterocytes of the rat; Lindquist BL et al.; The adherence of radiolabeled Salmonella typhimurium to freshly isolated enterocytes of rats was studied . The results established that type 1 fimbriated strains adhered in significantly higher numbers than did related nonfimbriated strains . Adherence was inhibited by D-mannose and methyl alpha-D-mannoside . Results of kinetic studies indicated that adherence was biphasic; the number of bacteria that adhered per enterocyte remained constant for approximately 20 min and then increased rapidly under the assay conditions . The second phase was associated with structural damage to the enterocytes . The addition of chloramphenicol did not prevent the initial attachment of bacteria to enterocytes but did prevent the second phase . Viable and nonviable bacterial cells adhered to enterocytes, but only viable bacteria were destructive . Freshly isolated enterocytes (trypan blue impermeable) and enterocytes stored overnight (trypan blue permeable) were infected by viable S . typhimurium in a similar manner, suggesting that metabolic activity of the host cell was of less consequence than metabolic activity of the bacterial cells . A model for the role of mannose-sensitive fimbriae as a virulence factor is proposed. Mutat Res, 1987 Dec, 192(4), 233 - 7 Frameshift mutagenesis by chloroquine in Escherichia coli and Salmonella typhimurium; Thomas SM et al.; Chloroquine can be detected as a direct-acting mutagen in plate-incorporation assays using the excision-deficient Salmonella typhimurium strain TA97, but very much more effectively using the repair-proficient Escherichia coli strain DG1669 which carries the lacZ19124 marker . When tested at concentrations of 200-1000 micrograms/plate with strain DG1669, the mutagenicity of chloroquine is enhanced by the addition of Aroclor-induced rat-liver S9 . Further experiments indicated that chloroquine-induced reversion frequencies were essentially identical in wild-type, recA, umuC and uvrC derivatives of DG1669, as well as in strains carrying the mutation enhancing plasmid pKM101, over a wide range of doses (0-1200 micrograms/plate) . These results suggest that neither excision repair nor SOS-type repair are important in chloroquine-induced frameshift mutagenesis. Vet Rec, 1987 Nov 28, 121(22), 514 - 6 Differentiation of Salmonella typhimurium DT204c by plasmid profile and biotyping; Wray C et al.; Seventy per cent of the United Kingdom isolates of Salmonella typhimurium from calves are phage type 204c and the study of the epidemiology of this organism requires additional methods of strain characterisation . This paper describes the applications of biotyping and plasmid-profile analysis for this purpose . One hundred and eleven isolates from 73 outbreaks of disease were examined . All belonged to the same primary biotype, although strains from 39 of the outbreaks differed in secondary tests in failing to ferment m-inositol at 25 degrees C . Four different antibiotic resistance patterns were detected among the isolates, which possessed seven distinct plasmid profiles . The spread of a distinct type through the calf marketing chain was investigated by using these techniques. J Biol Chem, 1987 Nov 25, 262(33), 16261 - 6 Sugar transport by the bacterial phosphotransferase system . Reconstitution of inducer exclusion in Salmonella typhimurium membrane vesicles; Misko TP et al.; The accompanying articles (Saffen, D.W., Presper, K.A., Doering, T.L., and Roseman, S . (1987) J . Biol . Chem . 262, 16241-16253; Mitchell, W.J., Saffen, D . W., and Roseman, S . (1987) J . Biol . Chem . 262, 16254-16260) show that "inducer exclusion" in intact cells of Escherichia coli is regulated by IIIGlc, a protein encoded by the crr gene of the phosphoenolpyruvate:glycose phosphotransferase system (PTS) . The present studies attempt to show a direct effect of IIIGlc on non-PTS transport systems . Inner membrane vesicles prepared from a wild type strain of Salmonella typhimurium (pts+), carrying the E . coli lactose operon on an episome, showed respiration-dependent accumulation of methyl-beta-D-thiogalactopyranoside (TMG) via the lactose permease . In the presence of methyl-alpha-D-glucopyranoside or other PTS sugars, TMG uptake was reduced by an amount which was dependent on the relative concentrations of IIIGlc and lactose permease in the vesicles . The endogenous IIIGlc concentration in these vesicles was in the range 5-10 microM, similar to that found in whole cells . Methyl-alpha-glucoside had no effect on lactose permease activity in vesicles prepared from a deletion mutant strain lacking the soluble PTS proteins Enzyme I, HPr, and IIIGlc . One or more of the pure proteins could be inserted into the mutant vesicles; when one of the two electrophoretically distinguishable forms of the phosphocarrier protein, IIIGlc Slow, was inserted, both the initial rate and steady state level of TMG accumulation were reduced by up to 40% . The second electrophoretic form, IIIGlc Fast, had much less effect . A direct relationship was observed between the intravesicular concentration of IIIGlc Slow and the extent of inhibition of the lactose permease . No inhibition was observed when IIIGlc Slow was added to the outside of the vesicles, indicating that the site of interaction with the lactose permease is accessible only from the inner face of the membrane . In addition to the lactose permease, IIIGlc Slow was found to inhibit both the galactose and the melibiose permeases . Uptake of proline, on the other hand, was unaffected . The results are therefore consistent with an hypothesis that dephosphorylated IIIGlc Slow is an inhibitor of certain non-PTS permeases. J Biol Chem, 1987 Nov 25, 262(33), 16254 - 60 Sugar transport by the bacterial phosphotransferase system . In vivo regulation of lactose transport in Escherichia coli by IIIGlc, a protein of the phosphoenolpyruvate:glycose phosphotransferase system; Mitchell WJ et al.; Escherichia coli and Salmonella typhimurium preferentially utilize sugar substrates of the phosphoenol-pyruvate:glycose phosphotransferase system (PTS) when the growth medium also contains other sugars . This phenomenon, diauxic growth, is regulated by the crr gene, which encodes the PTS protein IIIGlc (Saffen, D.W., Presper, K.A., Doering, T.L., and Roseman, S . (1987) J . Biol . Chem . 16241-16253) . We have proposed that non-PTS permeases are regulated by their interaction with IIIGlc, and in vitro studies from other laboratories have provided support for this model, but the in vivo effects of excess IIIGlc are not known . In the present studies, transformed cells that overproduced IIIGlc 2- and 10-fold, respectively, were constructed from a pts+ strain of E . coli and plasmids containing the crr gene . In the 2-fold overproducer, fermentation of, and growth on the non-PTS carbohydrates glycerol, lactose, maltose, and melibiose was generally more sensitive to the glucose analogue methyl-alpha-D-glucopyranoside than in a control strain containing normal levels of IIIGlc . In addition, inhibition of lactose permease activity by methyl-alpha-glucoside (inducer exclusion) was more effective in the 2-fold overproducer than in the control strain, particularly when the permease activity was high . The 10-fold IIIGlc overproducing strain had a requirement for the amino acids methionine, isoleucine, leucine, and valine that may or may not be related to the increased concentration of IIIGlc . Fermentation of non-PTS carbohydrates was also poor in the latter strain . Finally, lactose permease activity was 50% of that in control cells containing the same levels of beta-galactosidase, and the lactose permease activity in the IIIGlc overproducer was reduced to an extremely low level in the presence of methyl alpha-glucoside . Thus there is an inverse relationship between the cellular concentration of IIIGlc and the ability to metabolize non-PTS substrates . The results are consistent with the model where inducer exclusion is affected by a direct interaction between IIIGlc and a non-PTS transport system. Biochem Biophys Res Commun, 1987 Nov 13, 148(3), 947 - 53 Induction of cytochrome P-448 isozyme(s) in primary cultured rat hepatocytes by drugs which induce different isozymes in vivo; Hishinuma T et al.; Effect of 2-methoxy-4-aminoazobenzene (2-MeO-AAB) and 3-methylcholanthrene (MC) on the induction of microsomal cytochrome P-448 isozymes in primary cultured rat hepatocytes was examined by means of immunochemical methods such as protein A-enzyme-linked immonosorbent assay and immuno-blots using anti-rat cytochrome P-448 monoclonal antibodies and by means of bacterial mutation tests . Although 2-MeO-AAB selectively induced cytochrome P-448H and MC induced both cytochrome P-448H and a low spin form of cytochrome P-448 (P-448L) in the liver of rats, addition of these chemicals to primary cultured rat hepatocytes resulted in selective induction of cytochrome P-448L, as determined by the immunological methods . This was substantiated by the bacterial mutation test using Salmonella typhimurium TA 98 bacteria and two aromatic amine substrates with different specificities to the cytochrome P-448 isozymes . These results suggest that the responses of rat hepatocytes to cytochrome P-450 inducers are different in in vivo and in vitro. Mutat Res, 1987 Nov, 181(1), 73 - 9 Interaction of the mutagenic metabolite of sodium azide, synthesized in vitro, with DNA of barley embryos; Veleminsky J et al.; The in vitro synthesized sodium azide mutagenic metabolite (azidoalanine) produced single-strand breaks and proteinase K-sensitive sites in isolated, germinating barley embryos . In contrast with sodium azide, the efficiency of DNA damage induction was lower, and both types of DNA lesions were totally or partially repaired in the course of subsequent 24 h incubation of the embryos . The mutagenic azide metabolite did not inhibit DNA replication, while azide did so even at doses which are not highly mutagenic . The metabolite labelled with 14C at the amino acid residue was taken up with a similar efficiency both into barley embryos germinating for 2 days and into cells of Salmonella typhimurium TA100 . The majority of the radioactivity was incorporated into proteins, less into RNA and a negligible amount into DNA. J Bacteriol, 1987 Nov, 169(11), 4893 - 900 Phosphoenolpyruvate:glycose phosphotransferase system in species of Vibrio, a widely distributed marine bacterial genus; Meadow ND et al.; The genus Vibrio is one of the most common and widely distributed groups of marine bacteria . Studies on the physiology of marine Vibrio species were initiated by examining 15 species for the bacterial phosphoenolpyruvate:glycose phosphotransferase system (PTS) . All species tested contained a PTS analogous to the glucose-specific (IIGlc) system in enteric bacteria . Crude extracts of the cells showed immunological cross-reactivity with antibodies to enzyme I, HPr, and IIIGlc from Salmonella typhimurium when assayed by the rocket-line method . Toluene-permeabilized cells of 11 species were tested and were active in phosphorylating methyl alpha-D-glucoside with phosphoenolpyruvate but not ATP as the phosphoryl donor . Membranes from 10 species were assayed, and they phosphorylated methyl alpha-D-glucoside when supplemented with a phospho-IIIGlc-generating system composed of homogeneous proteins from enteric bacteria . Toluene-permeabilized cells and membranes of seven species were assayed, as were phosphorylated fructose and 2-deoxyglucose . IIIGlc was isolated from Vibrio fluvialis and was active in phosphorylating methyl alpha-D-glucoside when supplemented with a phospho-HPr-generating system composed of homogeneous proteins from Escherichia coli and membranes from either E . coli or V . fluvialis . These results show that the bacterial PTS is widely distributed in the marine environment and that it is likely to have a significant role in marine bacterial physiology and in the marine ecosystem. Carcinogenesis, 1987 Nov, 8(11), 1589 - 93 Heterocyclic aromatic amine-DNA-adducts in bacteria and mammalian cells detected by 32P-postlabeling analysis; Asan E et al.; The formation of DNA adducts by the fried meat mutagen and carcinogen 2-amino-3-methylimidazo{4,5-f}quinoline (IQ) was studied by means of 32P-postlabeling of DNA digests and four-directional t.l.c . Three major and five minor adducts were detected in assays of DNA digests obtained from Salmonella typhimurium TA98 cells after treatment with IQ and rat liver postmitochondrial supernatant (S9) . A qualitatively identical adduct pattern was obtained with nitro-IQ (3-methyl-2-nitroimidazo{4,5-f}quinoline), a new analogue of IQ with a nitro instead of the amino group . These two compounds, therefore, form the same ultimate metabolite . The same adduct pattern was also found after TA98/1,8-DNP6 (acetyltransferase-deficient) cells were treated with nitro-IQ; this is probably due to a residual acetyltransferase activity in this strain . Upon treatment of TA98 cells with 1 mM IQ for 3 h one adduct was detected in 4.7 x 10(5) total bases; a considerably higher adduct frequency, one in 4.2 x 10(3), was induced by nitro-IQ (70 microM, 30 min) . The IQ isomer 2-amino-1-methylimidazo{4,5-f}quinoline (isoIQ) and its nitro-analogue nitro-isoIQ (1-methyl-2-nitroimidazo{4,5-f}quinoline) also produced identical adducts . Their common adduct pattern was very similar to the IQ adduct pattern but was located in a position different from that of the IQ adduct pattern . DNA from Syrian hamster embryo (SHE) cells treated with IQ and S9 exhibited adducts apparently identical with those of Salmonella DNA. Parasite Immunol, 1987 Nov, 9(6), 705 - 19 Variable expression of the murine natural resistance gene Lsh in different macrophage populations infected in vitro with Leishmania donovani; Crocker PR et al.; Various macrophage populations isolated from mice (including congenic C57BL/10ScSn and B10.LLshr) bearing resistant or susceptible alleles for the natural resistance gene (Lsh) were infected with Leishmania donovani amastigotes in vitro and examined (a) for their ability to support growth of the amastigote population over 7 days of culture in vitro, and (b) for their ability to express Lsh gene controlled resistance and susceptibility in vitro . Resident macrophages from liver (Kupffer cells), spleen and lung, as well as 7-day bone marrow-derived macrophages and bone marrow macrophages obtained after 6 weeks of continuous culture in vitro, all supported growth of the amastigote population . Of these, significant differences in amastigote numbers in macrophages from Lshs and Lshr mice were observed after 48 h of infection in vitro for liver, lung and 7-day bone marrow macrophage populations only . Resident peritoneal macrophages grown in adherent or suspension cultures neither supported growth of the amastigote population nor showed any evidence of Lsh gene expression in vitro . Hence, multiplication of the parasite appeared to be a necessary but not sufficient condition for observation of Lsh gene activity against L . donovani in vitro . Use of tritiated thymidine incorporation and autoradiography to label dividing amastigotes showed equivalent multiplication of the parasite in liver macrophages from Lshs and Lshr mice between 24 h and 48 h after infection in vitro, with a dramatic difference observed thereafter . This was consistent with earlier observations of a 2-3 day delay in expression of Lsh gene controlled resistance in vivo . Comparison with studies using Salmonella typhimurium and Mycobacterium bovis suggests that the gene may be restricted in its action to a particular point in the parasite cell cycle, perhaps at the level of regulating DNA replication. J Gen Microbiol, 1987 Nov, 133 ( Pt 11), 3071 - 80 Isolation and genetic analysis of operator-constitutive mutants of the H1 operon in Salmonella typhimurium; Fujita H et al.; In phase-2 cells of diphasic Salmonella strains, expression of H1 is repressor, coded for by the rh1 gene . A procedure for the isolation of operator-constitutive (H1-Oc) mutants of the H1 operon is described . Using three-factor crosses between an H1-Oc H1 strain and H1-O+ H1 strains, where motility recovery via H1-phase (or phase 1) flagellation was used as the selected marker and the H1-O character was the unselected marker, the relative position of the H1-Oc site to the H1 gene was determined . A diphasic H1-Oc strain produced, in phase 2, copolymer filaments composed of H1 and H2 flagellin. Mutagenesis, 1987 Nov, 2(6), 431 - 2 Sequential and differing nitroreductive pathways for mutagenic nitropyrenes in Salmonella typhimurium; Howard PC et al.; The nitro group of nitropyrenes is required for mutagenicity in Salmonella typhimurium . 1-Nitropyrene and 1,3-dinitropyrene are reduced by the 'classical' nitroreductase, which involves a single electron transfer, while the reduction of the first nitro group of 1,6- and 1,8-dinitropyrene proceeds by a two-electron transfer mechanism and involves a different enzyme . However, reduction of the second nitro group, which is not necessary for the mutagenicity of nitropyrenes but is required for the mutagenicity of aminonitropyrenes, is catalyzed by the 'classical' nitroreductase. Mutagenesis, 1987 Nov, 2(6), 419 - 23 Assay of ptaquiloside, the carcinogenic principle of bracken, Pteridium aquilinum, by mutagenicity testing in Salmonella typhimurium; Matoba M et al.; The mutagenicity of ptaquiloside, the carcinogenic principle of Pteridium aquilinum, was tested in Salmonella typhimurium TA100 and TA98 . Under weakly basic conditions (pH 8.5), ptaquiloside decomposed into a conjugated dienone (considered to be the ultimate form), which was mutagenic in both strains . A novel bioassay, using the pre-incubation method at pH 8.5 with S . typhimurium tester strains was developed for the assay of ptaquiloside extracted from plants . By this bioassay the ptaquiloside content of ferns collected at different localities during various seasons, and in various parts of the plant was determined . The ubiquitous presence of ptaquiloside in fresh plant materials was confirmed . Bracken processed in alkali was found not to contain the carcinogen. Mutagenesis, 1987 Nov, 2(6), 415 - 8 The effect of biotransformation of 2,4-dinitrotoluene on its mutagenic potential; Couch DB et al.; Because both oxidative and reductive metabolism of the hepatocarcinogen 2,4-dinitrotoluene (2,4-DNT) can occur in vivo, we have examined the mutagenicity of compounds which can be formed from 2,4-DNT in an attempt to establish which metabolic pathways contribute to the formation of genotoxic products . A quantitative reversion assay using Salmonella typhimurium TA98 was used to evaluate the mutagenicity of these compounds . 2,4-Dinitrobenzyl alcohol, 2-amino-4-nitrotoluene and 2-nitroso-4-nitrotoluene were found to be more mutagenic to S . typhimurium than is 2,4-DNT and did not require metabolic activation by post-mitochondrial supernatants of Aroclor-induced rat liver homogenates (S9) for their effect . 2-Amino-4-nitrobenzoic acid was also mutagenic to S . typhimurium TA98 in the absence of S9, but its mutagenicity was enhanced when S9 was included in the incubation mixture . 2,4-Diaminotoluene required S9 for demonstration of mutagenicity and was approximately as effective, on a molar basis, as 2,4-DNT in inducing reversion to histidine prototrophy . These results suggest that both oxidative and reductive metabolism may be involved in production of mutagenic metabolites of 2,4-DNT. Mol Gen Genet, 1987 Nov, 210(1), 178 - 80 Amino acid alterations in a hydrophobic region of the TraT protein of R6-5 increase the outer membrane permeability of enteric bacteria; Sukupolvi S et al.; Two insertion mutations, each introducing a new negatively charged amino acid residue into a hydrophobic region of the TraT protein coded by the F-like plasmid R6-5 caused significant alterations in outer membrane permeability of Escherichia coli and Salmonella typhimurium, so that strains carrying plasmids with either of these mutations became sensitive to hydrophobic antibiotics. Pathol Biol (Paris), 1987 Nov, 35(9), 1239 - 42 {Comparative efficacy of ampicillin, chloramphenicol, cefotaxime, ceftriaxone and pefloxacin in experimental Salmonella typhimurium infection}; Nauciel C et al.; The efficacies of various antibiotics were compared in Salmonella typhimurium infection in mice . Treatment began 24 h after challenge . Antibiotics were given subcutaneously every 12 or 24 h in the following daily doses: 200 mg/kg for ampicillin, 100 mg/kg for chloramphenicol, cefotaxime and ceftriaxone, 50 mg/kg for pefloxacin . The number of bacteria in the spleens was determined after 3 and 7 days of treatment . In animals treated with ceftriaxone or pefloxacin the mean number of bacteria per spleen was from one to two log10 lower than in animals treated with other antibiotics . Similar results were obtained in genetically susceptible or resistant mice . The MIC being similar for cefotaxime, ceftriaxone and pefloxacin, the better in vivo activity of the two latter drugs appears to be related to their pharmacokinetic properties. Genetics, 1987 Nov, 117(3), 367 - 80 A novel P22 prophage in Salmonella typhimurium; Downs DM et al.; Under several sets of conditions, all of which seem to perturb purine metabolism, Salmonella typhimurium releases a variety of phages which were not known to be present in the strain . These cryptic phages are not induced by UV irradiation . Furthermore, the induction process does not require a functional recA gene product . While phages of several phenotypic classes have been recovered, including both turbid and clear plaque formers, all appear to be variants of P22 because all show DNA restriction patterns indistinguishable from that of P22 . The variety of types suggests that the cryptic prophage is mutagenized as a consequence of the induction process . All the temperature phages tested are capable of transducing a variety of chromosomal markers with high efficiency . The phages induced in this novel way are capable of forming plaques on the strains that gave rise to them . Since the strains releasing phage are not immune to P22, the parental lysogens must not express immunity and the phage must be held in a cryptic state by a novel mechanism . The released phage possess an intact P22 immunity system because many can form standard immune lysogens after reinfection of Salmonella . These results raise the possibility that Salmonella typhimurium harbors cryptic phages that are subject to a novel system of global control related to purine metabolism . Preliminary evidence suggests that the regulation system may involve DNA modification. J Trauma, 1987 Nov, 27(11), 1261 - 6 Effects of purified fibronectin alone and combined with immunoglobulin G or antithrombin-III on survival during gram-negative peritonitis or endotoxemia in rats; Emerson TE Jr; The present study was performed to determine the effects of pretreatment with purified human plasma fibronectin (FN) on survival in rats challenged with Salmonella typhimurium peritonitis or E . coli endotoxemia . The effects on survival of combining FN with immunoglobulin G (IgG) or antithrombin-III (AT-III) were also determined during S . typhimurium peritonitis and E . coli endotoxemia . Permanent survival was increased 15% in the peritonitis group (p less than 0.05) and 15% in the endotoxemic group (p greater than 0.05) . There was no enhancement in survival by combining FN with a subprotective dose of IgG preparation . AT-III alone increased survival by 50% over survival in the control group . Combining FN with AT-III increased survival 10% greater than with AT-III alone, which is suggestive of an additive effect . Results from this study suggest that FN provides modest protection during Gram-negative peritonitis or endotoxemia in the rat . Combining FN with AT-III may augment in an additive manner the marked increase in survival observed with AT-III alone in this and previous studies. Proc Natl Acad Sci U S A, 1987 Nov, 84(21), 7483 - 7 Identification of the M-ring protein of the flagellar motor of Salmonella typhimurium; Homma M et al.; The M ring is a substructure of the flagellar basal body of bacteria, which lies in the cytoplasmic membrane and is therefore close to the site where the energy of the transmembrane proton potential is converted into mechanical work of rotation of the motor . The protein from which this ring is constructed has not been identified . Flagellar hook-basal body complexes from Salmonella typhimurium were used as the immunogen for the preparation of monoclonal antibodies . An antibody obtained was directed against a major basal-body component, a 65-kDa protein that from mutant studies has been assigned as the product of the flaAII.1 gene . By immunoelectron microscopy, the antibody was observed to bind the innermost feature of the basal body: the cytoplasmic-facing surface of the M ring . We conclude that the 65-kDa protein is a component--probably the main component--of this important substructure of the flagellar motor. Mutat Res, 1987 Nov, 189(3), 223 - 61 Mutagenic activity of 27 dyes and related chemicals in the salmonella/microsome and mouse lymphoma TK+/- assays; Cameron TP et al.; A total of 27 dyes and related chemicals were tested for mutagenicity in both the Salmonella typhimurium plate-incorporation and FMN-modified assays as well as the mouse lymphoma TK+/- assay . Half of the compounds tested were monoazo dyes (14); the remainder consisted of disazo (3), aminotriphenylmethane derivatives (4), and other miscellaneous (6) color compounds . The results obtained in this study are compared with data from dyes of the same batch tested in other laboratories in the Salmonella plate-incorporation assay and in both in vitro and in vivo/in vitro UDS assays . Agreement of results from the various assays that could be compared (excluding results that were equivocal or indeterminate) ranged from 80 to 91% . Sufficient data were available to provide an overall index of in vitro activity for 15 chemicals; of these, 14 compounds could be compared to and agreed with reports of their carcinogenic potential in the literature. Mutat Res, 1987 Nov, 189(3), 189 - 204 Mutagenicity of aryl propylene and butylene oxides with salmonella; Rosman LB et al.; 10 aryl propylene oxides and 6 aryl butylene oxides were synthesized . Dose-mutagenicity relationships were studied for these compounds and for 1,2-epoxybutane, using both the preincubation and plate incorporation Ames tests with Salmonella typhimurium strains TA100 and TA1535 . Structure-mutagenicity relationships were further examined by concurrent testing at single doses with the plate incorporation assay in strain TA100 . In both series of compounds, mutagenicity showed very correlation to chemical reactivity, molar volume and partition values . However, all compounds were mutagenic in at least one system with the propylene oxides being more mutagenic than the corresponding butylene oxide derivatives . The naphthyl derivatives in each series were the most mutagenic. Infect Immun, 1987 Nov, 55(11), 2645 - 52 Plasmid-associated resistance of Salmonella typhimurium to complement activated by the classical pathway; Vandenbosch JL et al.; The association of the virulence plasmid of Salmonella typhimurium with resistance to the bactericidal activity of human serum was studied in chromosomally isogenic pairs of strains differing in their virulence plasmid status . The presence of the plasmid correlated in three pairs of strains with resistance to serum . The absence of the plasmid correlated with increased sensitivity to serum, whereas the reintroduction of the plasmid to the cell resulted in the restoration of resistance to serum . Complement was activated by the classical and alternative pathways equally well by both strains of a pair, but the differential bactericidal action of serum was apparent only after the activation of complement by the classical pathway . No differences in the chemical compositions or in the molecular weight ranges of the lipopolysaccharides were apparent between paired strains . This work confirms the presence of a virulence plasmid-associated mechanism of resistance to serum and distinguishes it from lipopolysaccharide-mediated resistance. Carcinogenesis, 1987 Nov, 8(11), 1621 - 7 Metabolic activation to a mutagen of 3-hydroxy-trans-7,8-dihydroxy-7,8-dihydrobenzo{a}pyrene, a secondary metabolite of benzo{a}pyrene; Glatt H et al.; 3-Hydroxy-trans-7,8-dihydroxy-7,8-dihydrobenzo{a}pyrene (3-OH-BP-7,8-diol) was isolated from arylsulfatase/beta-glucuronidase-treated bile of rats to which 3-hydroxybenzo{a}pyrene (3-OH-BP) has been administered . This triol was investigated for mutagenicity in Salmonella typhimurium (reversion to histidine prototrophy of strains TA 97, TA 98, TA 100 and TA 1537) and in V79 Chinese hamster cells (acquisition of resistance to 6-thioguanine) . When no exogenous metabolizing system was added the triol was inactive, while 3-OH-BP showed weak mutagenic effects with all four bacterial strains . In the presence of NADPH-fortified postmitochondrial supernatant fraction (S9 mix) of liver homogenate from Aroclor 1254-treated rats, the mutagenicity of 3-OH-BP was potentiated, and the triol was activated to a mutagen(s) . In the presence of S9 mix, the triol was 5-18 times more mutagenic than 3-OH-BP in strains TA 97, TA 100 and TA 1537, but both compounds showed similar mutagenic potencies with strain TA 98 . These strain differences strongly suggest that the mutagenicity of 3-OH-BP in the S9 mix-mediated test was not exclusively due to metabolites of 3-OH-BP-7,8-diol . Trans-7,8-dihydroxy-7,8-dihydrobenzo{a}pyrene (BP-7,8-diol), like the triol, showed mutagenic effects only in the presence of S9 mix . Strain TA 1537 was reverted by the triol but not by the diol . In the other bacterial strains the diol was more mutagenic than the triol, the difference in potency being largest in strain TA 100 (2.5- to 10-fold, depending on the experimental conditions) . In V79 cells, the diol was a potent mutagen, while the triol showed only very weak mutagenic effects . However the triol was more cytotoxic than the diol . High cytotoxicity of the triol was observed even in the absence of S9 mix . The results of the present study demonstrate that metabolites of 3-OH-BP-7,8-diol are biologically-active derivatives of benzo{a}pyrene . Comparison of the mutagenic effectiveness in different bacterial strains also reveals that metabolites of 3-OH-BP-7,8-diol and of BP-7,8-diol substantially differ in the kind of genetic alterations they evoke. Carcinogenesis, 1987 Nov, 8(11), 1651 - 6 Inhibition of aflatoxin B1 mutagenesis in Salmonella typhimurium and DNA damage in cultured rat and human tracheobronchial tissues by ellagic acid; Mandal S et al.; Ellagic acid (EA), a plant phenol found in various fruits and nuts, was examined for its ability to inhibit aflatoxin B1 (AFB1) mutagenesis in strain TA 100 of Salmonella typhimurium . In the presence of rat liver S-9 microsomal preparation, EA (1.5 microgram/plate) inhibited the number of mutations induced by AFB1 (0.5 microgram/plate) by 50% . EA at a dose of 1000 micrograms/plate inhibited the mutation frequency by greater than 90% . EA was also tested for its ability to inhibit the DNA binding and adduct formation of AFB1 in cultured explants of rat trachea and human tracheobronchus . Explants were incubated in medium containing EA at concentrations of 10, 50 and 100 microM for 16 h followed by the addition of 1 microM {3H}AFB1 and EA for 24 h . DNA was isolated by phenol extraction and hydroxylapatite chromatography . EA caused a dose-dependent inhibition in the covalent binding of AFB1 to the DNA of both the rat trachea (9-57% inhibition) and human tracheobronchus (24-79% inhibition) . After acid hydrolysis of the isolated DNA, the AFB1-DNA adducts were separated by h.p.l.c . In tissues from both species, the major AFB1- DNA adducts were AFB1-N7-Gua {8,9-dihydro-8-(N7-guanyl)-9-hydroxyAFB1} and AFB1-N7-FaPyr (major) {8,9-dihydro-8- (2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl formamido)-9-hydroxyAFB1}, and the formation of these adducts was reduced by 28-76% in the presence of EA . These data indicate that EA has the potential to act as a naturally occurring inhibitor of AFB1-related respiratory damage in rats and in humans. Mutat Res, 1987 Nov, 189(3), 217 - 22 Mutagenicity of products formed by ozonation of naphthoresorcinol in aqueous solutions; Sayato Y et al.; The mutagenicity of products formed by ozonation of naphthoresorcinol in aqueous solution was assayed with Salmonella typhimurium strains TA97, TA98, TA100, TA102 and TA104 in the presence and absence of S9 mix from phenobarbital- and 5,6-benzoflavone-induced rat liver . Ozonated naphthoresorcinol was mutagenic in TA97, TA98, TA100 and TA104 without S9 mix . By the addition of S9 mix, the mutagenic activity of ozonated naphthoresorcinol was markedly suppressed in TA98 and TA100, but became positive in TA102 . High-performance liquid chromatography (HPLC) after derivatization to 2,4-dinitrophenylhydrazones demonstrated the formation of glyoxal as an ozonation product of naphthoresorcinol . Ion chromatographic technique also demonstrated the formation of o-phthalic acid, muconic acid, maleic acid, mesoxalic acid, glyoxylic acid and oxalic acid as ozonation products . The mutagenicity assays of these identified products with five Salmonella showed that glyoxal and glyoxylic acid were directly mutagenic; the former in TA100, TA102 and TA104, the latter in TA97, TA100 and TA104 . In the presence of S9 mix, glyoxylic acid gave a positive response of mutagenicity for TA102 . The experimental evidence supported that glyoxal and glyoxylic acid may contribute to the mutagenicity of ozonated naphthoresorcinol. J Hosp Infect, 1987 Nov, 10(3), 248 - 54 An outbreak of Salmonella typhimurium gastroenteritis in a psychiatric hospital; Galloway A et al.; An outbreak of Salmonella typhimurium (phage type 12) infection involving 11 patients and 12 members of staff occurred in a psychiatric hospital in Merseyside during a 3-week period in September and October 1984 . Bacteraemia did not occur in any patients, those affected having a mild self-limiting diarrhoea . The source of the organism remained unknown but the most probable means of transmission was by person to person contact . The outbreak was controlled by transferring affected patients to an isolation ward . Staff were encouraged to report gastrointestinal symptoms and remain off work until symptom free or until the results of cultures were known . The problems of managing the outbreak are discussed. J Exp Med, 1987 Nov 1, 166(5), 1300 - 9 Bacterial lipopolysaccharide (endotoxin) enhances expression and secretion of beta 2 interferon by human fibroblasts; Helfgott DC et al.; The human beta 2 interferon (IFN-beta 2) gene, a gene that also codes for B cell differentiation factor 2 (BSF-2), plasmacytoma/hybridoma growth factor (HGF), and hepatocyte-stimulating factor (HSF), is expressed in a variety of lymphoid and nonlymphoid tissues . Endotoxin, or bacterial lipopolysaccharide (LPS) preparations derived from the outer membrane of Escherichia coli or Salmonella typhimurium rapidly elevate IFN-beta 2 mRNA level in human skin fibroblasts (FS-4 strain) . E . coli-derived LPS enhances IFN-beta 2 mRNA expression in FS-4 fibroblasts at a concentration as low as 0.3 ng/ml; this response is near-maximal in the range of 0.1-1 microgram/ml LPS . The increase in IFN-beta 2 mRNA level caused by LPS in FS-4 cells is detected within 30 min after addition of LPS, is sustained for at least 20 h thereafter, appears to involve the protein kinase C signal transduction pathway, does not require new protein synthesis, and is inhibited by dexamethasone in a dose-dependent fashion (in the range 10(-6)-10(-8) M) . Cultures of LPS-treated FS-4 cells exhibit an antiviral state against vesicular stomatitis virus, which can be prevented by anti-IFN-beta antiserum . Medium obtained from LPS-treated FS-4 cell cultures enhances the number of immunoglobulin-secreting cells in cultures of human B-lymphoblastoid (CESS) cells . Thus, LPS may trigger a number of host defense mechanisms in the course of infection due to Gram-negative bacteria by enhancing IFN-beta 2 production by the ubiquitous fibroblast. J Bacteriol, 1987 Nov, 169(11), 5095 - 100 Cloning and expression of the Salmonella enterotoxin gene; Chopra AK et al.; This report examines the genetic basis for Salmonella typhimurium Q1 enterotoxin production . A 918-base-pair XbaI-HincII fragment of plasmid pJM17, composed of cholera toxin (CT) coding sequences (ctxAB), was used as a gene probe . With this probe, the S . typhimurium enterotoxin was identified on a 6.3-kilobase EcoRI-PstI fragment of chromosomal DNA from plasmidless strain Q1 . We cloned this 6.3-kilobase fragment into Escherichia coli RR1 . The genetic map of the cloned Salmonella enterotoxin (stx) gene was similar but not identical to the CT and E . coli heat-labile enterotoxin genes . By using synthetic oligonucleotides derived from the sequences of CT subunits A (ctxA) and B (ctxB), it was revealed that there were some conserved regions of DNA encoding the enterotoxins of strain Q1 and Vibrio cholerae . Expression of the cloned stx gene in minicells and subsequent Western blot (immunoblot) analysis with CT antitoxin demonstrated that the Salmonella enterotoxin had two or more subunits with molecular sizes of 45, 26, and 12 kilodaltons . Crude cell lysates of E . coli RR1(pCHP4), containing the cloned Salmonella enterotoxin gene, elicited fluid secretion in ligated rabbit intestinal loops and firm induration in rabbit skin . Both of these enterotoxic responses were neutralized by antisera specific for CT . Mucosal tissue from positive intestinal loops contained elevated levels of cyclic AMP . These data suggest some evolutionary relatedness between the enterotoxin genes of S . typhimurium and V . cholerae. J Bacteriol, 1987 Nov, 169(11), 5060 - 5 Isolation of Salmonella typhimurium strains that utilize exogenous 3-deoxy-D-manno-octulosonate for synthesis of lipopolysaccharide; Goldman RC et al.; Spontaneous mutants of Salmonella typhimurium LT2 were selected for the ability to accumulate exogenous 3-deoxy-D-manno-octulosonate (KDO) . Bacteria containing a gene (kdsA) which codes for a temperature-sensitive KDO-8-phosphate synthetase were plated at the restrictive temperature of 42 degrees C on medium containing 5 mM KDO . Since bacteria containing the kdsA lesion are unable to grow at 42 degrees C due to inhibition of lipopolysaccharide (LPS) synthesis and accumulation of lipid A precursor, this method allowed direct, positive selection of mutants capable of utilizing exogenous KDO for LPS synthesis . Spontaneous mutants, selected at a frequency of about 10(-6), required exogenous KDO for growth at 42 degrees C . The growth rate at 42 degrees C was nearly normal in the presence of 20 mM KDO and was directly proportional to KDO concentrations below 20 mM . Exogenous KDO also suppressed accumulation of lipid A precursor . The apparent Km for KDO accumulation was 23 mM, and the maximum rate of transport was calculated to be 505 pmol of KDO per min per 10(8) cells . Bacteria incorporated exogenous {3H}KDO exclusively into LPS, with less than 10% dilution in specific activity due to residual endogenous KDO synthesis . The mutation giving rise to the ability to accumulate exogenous KDO was extremely useful in the direct screening for new mutations in the kdsA gene after localized mutagenesis . Five mutations in kdsA were isolated, four of which were new alleles as determined by on fine-structure analysis . The ability to introduce labeled (3H, 13C, and 14C) KDO in vivo should simplify and extend the analysis of this critical metabolic pathway in gram-negative bacteria. J Infect Dis, 1987 Nov, 156(5), 751 - 7 Loss of OmpC porin in a strain of Salmonella typhimurium causes increased resistance to cephalosporins during therapy; Medeiros AA et al.; Minimal inhibitory concentrations of cephalosporins for a strain of Salmonella typhimurium from one patient increased severalfold after starting therapy with cephalexin . The first isolate with increased resistance (S20323) and an earlier, less resistant isolate (S17069) each had a TEM-1 beta-lactamase with similar Vmax and Km values . Intact cells of S20323 grown in a high osmolality medium hydrolyzed cephalosporin substrates much more slowly than did intact cells of S17069 at low substrate concentrations, a result indicating slower diffusion of cephalosporins into S20323 . In low osmolality media, S17069 produced both OmpF and OmpC porins; S20323 produced only OmpF porin . In high osmolality media with osmotic activity similar to that in the patient's tissues, synthesis of the OmpF porin was repressed in both strains and left S20323 with undetectably low levels of any porin . The increased beta-lactam resistance in S20323 is apparently a consequence of the loss of the OmpC porin. J Mol Biol, 1987 Oct 20, 197(4), 611 - 5 Mutant forms of tufA and tufB independently suppress nonsense mutations; Hughes D; The level of nonsense suppression in Salmonella typhimurium carrying error-enhancing mutations in either or both of the genes coding for the elongation factor EF-Tu has been measured . Suppression of both UGA and UAG is observed . There is no significant suppression of any of six UAA sites tested . Nonsense suppression does not require that both genes for EF-Tu be mutant . Strains carrying one mutant and one wild-type tuf gene suppress nonsense mutations . The level of suppression increases approximately additively when both tuf genes are mutant . It is suggested that these mutant forms of EF-Tu act independently of each other to suppress nonsense mutations . Suppression is not observed at all UGA and UAG sites, but instead shows a strong site specificity. Life Sci, 1987 Oct 12, 41(15), 1795 - 803 Stereochemical effect in the mutagenicity of the aflatoxicols toward Salmonella typhimurium; Yourtee DM et al.; The mutagenicities of {1R} and {1S} aflatoxicol were measured using the Salmonella microsome test . In strain TA100 the {1R} form (unnatural aflatoxicol, aflatoxicol B) had a mutagenic potency approximately four times that of the {1S} epimer (natural aflatoxicol, aflatoxicol A, Ro) in the presence of S-9 liver microsomal fraction . The order in mutagenic potency compared to some other toxicologically important aflatoxins was as follows: B1 greater than {1R} approximately equal to G1 much greater than {1S} much much greater than B2 . Thus, the trans relationship between the vinyl ether and hydroxyl groups leads to greater mutagenicity than the cis relationship . This may be important in the elucidation of stereochemical structure-activity relationships for the aflatoxins. J Biol Chem, 1987 Oct 5, 262(28), 13429 - 33 Tryptophan synthase alpha subunit glutamic acid 49 is essential for activity . Studies with 19 mutants at position 49; Yutani K et al.; We have obtained a complete set of 20 variants of the alpha subunit of tryptophan synthase of Escherichia coli at position 49 in