Microorganism

Mol Gen Mikrobiol Virusol, 1990 Oct, (10), 28 - 30
{Regulation of phenylalanine biosynthesis in the obligate methylotroph Methylobacillus M75}; Maksimova NP et al.; Regulation of phenylalanine biosynthesis has been studied in the bacterium Methylobacillus M75 on the level of enzymes 3-deoxy-D-arabinoheptulose-7-phosphate-synthase, chorismatmutase, prephenatdehyrataze . The DAHP-synthase is shown to be synthesized constitutively and its activity is inhibited by all aromatic aminoacids and antranilate . The synthesis of chorismatmutase and prephenatdehydratase is repressed by tyrosine, the activity of the latter enzyme, besides that, is inhibited by phenylalanine, the effect of which is decreased in the presence of tyrosine.

J Hosp Infect, 1990 Oct, 16(3), 257 - 61
Mycobacterium chelonei isolation from broncho-alveolar lavage fluid and its practical implications; Nye K et al.; Mycobacterium chelonei was isolated from the broncho-alveolar lavage fluid of seven patients on eight occasions over a 6-month period . The same bacterium was identified in the hospital water supply . Despite the use of a recommended disinfection procedure, it proved impossible to eradicate the organism until the bronchoscopes were treated with ethylene oxide and the use of tap water in rinsing was abandoned.

Gene, 1990 Sep 28, 94(1), 69 - 75
Cloning, sequence and expression in Escherichia coli of the Methylobacillus flagellatum recA gene; Gomelsky M et al.; By means of interspecific complementation of an Escherichia coli recA- mutation with phasmids containing a gene bank from an obligate methylotroph, Methylobacillus flagellatum (Mf), the recA+ gene from this bacterium was identified . When expressed in an E . coli recA- host, it can function in recombination, DNA repair, and prophage induction . The nucleotide sequence of the gene has been determined . The coding region consists of 1032 bp specifying 344 amino acids . The deduced RecA protein structure shows a striking homology with RecA from other bacteria, except for the C-terminal region and some residues which were proposed to be responsible for the coprotease ability of RecA proteins . The region preceding the recA-Mf gene start codon has no SOS box--the LexA repressor binding site . Expression of the recA-Mf gene in E . coli proved to be DNA-damage independent.

Biochem Biophys Res Commun, 1990 Sep 14, 171(2), 777 - 86
Mode of action and substrate specificity of a purified exo-1,4-beta-D-glucosidase cloned from the cellulolytic bacterium Ruminococcus albus AR67; Ware CE et al.; A gene encoding exo-1,4-beta-D-glucosidase, from Ruminococcus albus AR67, was cloned in Escherichia coli, restriction mapped, and shown to be expressed from sequences within the insert that function as a promoter in E . coli . The cloned enzyme was located predominantly in the cytoplasm (40%) and attached to insoluble cell components (48%) . After purification to homogeneity, the enzyme (Mr = 64,000, monomeric) was specific for substrates with beta-D-glucopyranosyl configuration and was inactive against alpha-glucosides, lactosides and xylosides . Km values of the enzyme decreased with increasing chain length (G2-G5) . Glucose was the major product of hydrolysis from cellodextrins . Preference for longer chain cellodextrins is consistent with exo-1,4-beta-D-glucan glucohydrolase mode of action {E.C . 3.2.1.74}.

Biochemistry, 1990 Sep 4, 29(35), 8085 - 93
The form II fructose 1,6-bisphosphatase and phosphoribulokinase genes form part of a large operon in Rhodobacter sphaeroides: primary structure and insertional mutagenesis analysis; Gibson JL et al.; Fructose 1,6-bisphosphatase (FBPase) and phosphoribulokinase (PRK) are two key enzymes of the reductive pentose phosphate pathway or Calvin cycle of photosynthetic carbon dioxide assimilation . Early studies had indicated that the properties of enzymes isolated from photosynthetic bacteria were clearly distinct from those of enzymes obtained from the chloroplasts of higher plants {for a review, see Tabita (1988)} . The eucaryotic enzymes, which are light activated by the thioredoxin/ferredoxin system (Buchanan, 1980), were each shown to contain a putative regulatory amino acid sequence (Marcus et al., 1988; Porter et al., 1988) . The enzymes from photosynthetic bacteria are not controlled by the thioredoxin/ferredoxin system but exhibit complex kinetic properties and, in the case of PRK, there is an absolute requirement of NADH for activity . In the photosynthetic bacterium Rhodobacter sphaeroides, the structural genes of the Calvin cycle, including the genes that encode FBPase (fbp) and PRK (prk), are found in two distinct clusters, and the fbp and prk genes are closely associated in each cluster . In the present investigation, we have determined the nucleotide sequence of the fbpB and prkB genes of the form II cluster and have compared the deduced amino acid sequences to previously determined sequences of light-activated enzymes from higher plants and from other eucaryotic and procaryotic sources . In the case of FBPase, there are several regions that are conserved in the R . sphaeroides enzymes, including a protease-sensitive area located in a region equivalent to residues 51-71 of mammalian FBPase.(ABSTRACT TRUNCATED AT 250 WORDS)

J Cell Physiol, 1990 Sep, 144(3), 408 - 15
Caffeine, an inhibitor of endocytosis in Dictyostelium discoideum amoebae; Gonzalez C et al.; The effect of the trimethylxanthine, caffeine, was examined on the growth and endocytosis pathways of the vegetative amoebae of the cellular slime mold Dictyostelium discoideum . Caffeine at concentrations of 1.5-3 mM was found to inhibit axenic growth, fluid-phase pinocytosis, and secretion of lysosomal enzymes . Cell viability was unaffected by incubation for 16 hours with 5 mM caffeine but decreased markedly thereafter . Phagocytosis of the bacterium Escherichia coli by Dictyostelium amoebae was also inhibited by caffeine, although at concentrations twofold to threefold higher . Caffeine rapidly entered into amoebae to reach an equilibrium between extracellular and intracellular concentrations, and it was not appreciably metabolized by Dictyostelium . Inhibition of growth and endocytosis was reversible upon removal of the drug and was partially counteracted by 10 mM adenosine . As caffeine discharged intracellular calcium stores in Dictyostelium (Abe et al., 1988), its inhibitory effect on endocytosis could result from the perturbation of calcium homeostasis . In agreement with this hypothesis, the cation La3+ (10 microM), a Ca2(+)-transport inhibitor, also strongly reduced fluid-phase pinocytosis.

FEMS Microbiol Lett, 1990 Sep 1, 59(1-2), 95 - 9
Sizing of the Leptospira genome by pulsed-field agarose gel electrophoresis; Baril C et al.; Pulsed-field gel electrophoresis allowed the determination of the size of the genome of Leptospira, a bacterium of the spirochete family . The three restriction enzymes, NotI (5'GC/GGCCGC), NheI (5'G/CTAGC), ApaI (5'-GGGCC/C) generated DNA fragments of suitable size . The results are compatible with a size of 5000 kb for the chromosome of both the pathogenic and the saprophytic species of Leptospira.

FEMS Microbiol Immunol, 1990 Sep, 2(2), 83 - 8
Induction of tumoricidal activated macrophages by a liposome-encapsulated glycolipid, trehalose 2,3,6'-trimycolate from Gordona aurantiaca; Furukawa M et al.; A mycolic acid-containing glycolipid, trehalose 2,3,6'-trimycolate, prepared from a non-pathogenic acid-fast bacterium Gordona aurantiaca, was shown to induce strong tumoricidal activity in peritoneal exudate cells by intravenous or intraperitoneal injection of liposome-encapsulated preparations . The mycolic acid derivative containing a high proportion of unsaturated fatty acids rendered macrophages cytotoxic against syngeneic mastocytoma cells in the absence of endotoxin, for over 14 days after the injection . The macrophages were ascertained to be at low intracellular levels of a lysosomal enzyme beta-galactosidase and an ectoenzyme alkaline phosphodiesterase, a specific pattern as previously described for "primed macrophages" . However the culture supernatants of the peritoneal exudate cells were not cytotoxic.

Zentralbl Bakteriol, 1990 Sep, 273(4), 431 - 54
The technique of polymerase chain reaction--a new diagnostic tool in microbiology and other scientific fields (review); Thiele D; The polymerase chain reaction, a method of so far unknown sensitivity and specificity, is about to become an important diagnostic tool in microbiology . Practically even a single bacterium, virus particle, or parasite can be detected by it . Furthermore, this technique has been used with highly promising results in other scientific fields like genetics, forensic medicine and archeology . This article reviews technical aspects and variations of this new technique.

J Med Microbiol, 1990 Sep, 33(1), 61 - 6
Ultrastructure of a spiral micro-organism from pig gastric mucosa ("Gastrospirillum suis"); Mendes EN et al.; The ultrastructural features of a helical-shaped bacterium occurring in the stomach of pigs, within the mucus on the mucosal surface of antral pits, were examined . The bacterial cell had three to eight spiral turns, flattened and truncated ends and was approximately 4.0 microns long and 0.6 microns wide . In some sections, up to six flagella, about 22 nm in diameter, were seen arising from each pole . The cytoplasm contained sparse, irregular granules, numerous ribosomes and large single-layered membrane-bound granules . In the flagella insertion area, there was a highly electron-dense component, the "polar membrane" . This micro-organism differed from similar bacteria described in cats, dogs and monkeys, and may cause inflammation in the antral mucosa of pigs similar to Helicobacter pylori infection in man . Furthermore, it was morphologically similar to the spiral micro-organism distinct from H . pylori which has been described recently in human antral mucosa from patients with gastritis and may be of potential significance as a pathogen in man . The name "Gastrospirillum suis" is proposed for this bacterium.

Respir Med, 1990 Sep, 84(5), 377 - 85
Acute bronchitis in the community: clinical features, infective factors, changes in pulmonary function and bronchial reactivity to histamine; Boldy DA et al.; A descriptive study of acute bronchitis in patients without pre-existing pulmonary disease was undertaken in the community during the winter months of 1986-87 . Forty-two episodes were investigated in 40 individuals . The cardinal symptom was the acute onset of cough (100%), usually productive (90%) . Wheezing was noted by 62% of patients, but heard on auscultation in only 31% . A potential pathogen was isolated in 29% of cases with a virus (eight cases) being identified more frequently than either Mycoplasma pneumoniae (three cases) or a bacterium (three cases) . The acute illness was associated with significant reductions in forced expired volume in 1 second (P less than 0.02) and peak expiratory flow (P less than 0.001) but not forced vital capacity compared to 6 weeks later . Ten of the 27 (37%) patients who had a histamine challenge test performed at 6 weeks had a PD20 of less than 7.8 mumol histamine . Thirty-nine episodes (93%) were treated with antibiotics by the general practitioner, the clinical course being unremarkable apart from one patient who developed a lingular pneumonia despite antibiotic therapy . Further studies are required to assess whether acute bronchitis causes an acute increase in bronchial hyperresponsiveness and whether either antibiotics or inhaled bronchodilators or anti-inflammatory therapy has a useful role in the management of this predominantly viral illness.

J Bacteriol, 1990 Sep, 172(9), 5425 - 31
Identification of genes affecting production of the adhesion organelle of Caulobacter crescentus CB2; Mitchell D et al.; Transposon (Tn5) mutagenesis was used to identify regions in the genome involved with production, regulation, or attachment to the cell surface of the adhesive holdfast of the freshwater bacterium Caulobacter crescentus CB2 . A total of 12,000 independently selected transposon insertion mutants were screened for defects in adhesion to cellulose acetate; 77 mutants were detected and examined by Southern blot hybridization mapping methods and pulsed-field gel electrophoresis . Ten unique sites of Tn5 insertion affecting holdfast function were identified that were clustered in four regions of the genome . Representative mutants of the 10 Tn5 insertion sites were examined by a variety of methods for differences in their phenotype leading to the loss of adhesiveness . Four phenotypes were identified: no holdfast production, production of a smaller or an altered holdfast, production of a holdfast that was unable to remain attached to the cell, and a fourth category in which a possible alteration of the stalk was related to impaired adhesion of the cell . With the possible exception of the last class, no pleiotropic mutants (those with multiple defects in the polar region of the cell) were detected among the adhesion-defective mutants . This was unexpected, since holdfast deficiency is often a characteristic of pleiotropic mutants obtained when selecting for loss of other polar structures . Overall, the evidence suggests that we have identified regions containing structural genes for the holdfast, genes involved with proper attachment or positioning on the caulobacter surface, and possibly regions that regulate the levels of holdfast production.

J Bacteriol, 1990 Sep, 172(9), 4877 - 87
Developmental sensory transduction in Myxococcus xanthus involves methylation and demethylation of FrzCD; McCleary WR et al.; Myxococcus xanthus is a bacterium that moves by gliding motility and exhibits multicellular development (fruiting body formation) . The frizzy (frz) mutants aggregate aberrantly and therefore fail to form fruiting bodies . Individual frz cells cannot control the frequency at which they reverse direction while gliding . Previously, FrzCD was shown to exhibit significant sequence similarity to the enteric methyl-accepting chemotaxis proteins . In this report, we show that FrzCD is modified by methylation and that frzF encodes the methyltransferase . We also identify a new gene, frzG, whose predicted product is homologous to that of the cheB (methylesterase) gene from Escherichia coli . Thus, although M . xanthus is unflagellated, it appears to have a sensory transduction system which is similar in many of its components to those found in flagellated bacteria.

Mol Gen Genet, 1990 Sep, 223(2), 205 - 10
Accumulation of carotenoids in structural and regulatory mutants of the bacterium Myxococcus xanthus; Martinez-Laborda A et al.; Accumulation of carotenoids in Myxococcus xanthus is absolutely dependent on illumination with blue light . We report the analysis of the carotenoids of dark- and light-grown cultures of the wild type and several previously characterized mutants . A carR mutant produces the same carotenoids in the dark as the wild type grown in the light . This agrees with previous evidence indicating that the carR gene codes for a general negative regulator of the system . A cis-dominant mutation in the gene carA causes constitutive expression of the light-inducible gene carB, which is linked to carA . In the dark, the carA mutant produces high levels of phytoene, the first C40 colourless carotenoid precursor; in the light, it produces the same carotenoids as the wild type . Since a mutation in carB blocks accumulation of phytoene, we propose that carB, and probably other linked genes also controlled by carA, code for enzymes involved in the synthesis of phytoene . This is virtually the only carotene accumulated by strains mutated in the gene carC, which is unlinked to the others . Thus carC codes for phytoene dehydrogenase, the enzyme that converts phytoene into coloured carotenoids . The results presented here also provide evidence for control of carotenogenesis by an endproduct that is independent of the blue light effect.

J Bacteriol, 1990 Sep, 172(9), 5299 - 306
CsgA, an extracellular protein essential for Myxococcus xanthus development; Shimkets LJ et al.; CsgA mutants of Myxococcus xanthus appear to be defective in producing an extracellular molecule essential for the developmental behaviors of this bacterium . The csgA gene encodes a 17.7-kilodalton polypeptide whose function and cellular location were investigated with immunological probes . Large quantities of the CsgA gene product were obtained from a lacZ-csgA translational gene fusion expressed in Escherichia coli . The chimeric 21-kilodalton protein was purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Affinity-purified polyclonal antibodies raised against the fusion protein were used to determine the cellular location of the native CsgA protein by colloidal gold labeling and transmission electron microscopy . Between 1,100 and 2,200 extracellular molecules of CsgA per developing M . xanthus cell were detected, most of which were associated with the extracellular matrix . The anti-CsgA antibodies inhibited wild-type development unless they were first neutralized with the fusion protein . Together these results suggest that the CsgA gene product has an essential, extracellular function during development, possibly as a pheromone.

Plasmid, 1990 Sep, 24(2), 90 - 9
Chloramphenicol acetyltransferase expression in marine Rhodobacter sp . NKPB 0021 by use of shuttle vectors containing the minimal replicon of an endogenous plasmid; Matsunaga T et al.; A vector, pUK318, was constructed to allow the expression of foreign genes in the marine photosynthetic bacterium Rhodobacter sp . NKPB 0021 . This strain has been cured of its two endogenous plasmids . pUK318 consists of a 2.3-kb PstI-BamHI restriction fragment, containing a marine Rhodobacter plasmid replication region, cloned into pUC18 . This fragment was derived from plasmid pRD31, a 3.1-kb endogenous plasmid purified from the marine strain Rhodobacter sp . NKPB 043402 . A kanamycin resistance gene from Tn903 was cloned into the PstI restriction site to provide antibiotic selection . pUK318 was transferred to Rhodobacter sp . NKPB 0021 by transformation, and efficiencies of 7.2 x 10(-5) were obtained . Furthermore, pUK318 was stably maintained when transformants were grown either heterotrophically or photosynthetically in the absence of antibiotics . pUK318 was used to express the Escherichia coli chloramphenicol acetyl transferase (CAT) gene in Rb . NKPB 0021 . Transformants expressed a maximum CAT activity of 1.12 mmol/min/g dry cells . In addition, the DNA region essential for pUK318 replication in Rb . NKPB 0021 was localized to a 1.36-kb HincII-PstI fragment . This is the first report of a plasmid vector containing a marine Rhodobacter-specific replicon that allows stable expression of foreign genes in the absence of antibiotic selection.

Hua Xi Yi Ke Da Xue Xue Bao, 1990 Sep, 21(3), 252 - 5
{Construction of the human cytomegalovirus B gene clone and its restriction site analysis by computer}; Wu J et al.; We constructed two clones of the human cytomegalovirus strain AD169, using the plasmid pBR322 and the recipient bacterium Escherichia coli strain HB101 . The human cytomegalovirus B gene was isolated from the recombinant plasmid pAT153 that contained the 20.7-kb Hind III F fragment of the human cytomegalovirus genome . The recombinant plasmid pAT153 was digested with BamHI and a 8.5-kb fragment was isolated and ligated with BamHI-digested pBR322 to form the recombinant plasmid pB1 . pB1 was further digested with BamHI-Hind III and a 5.1-kb fragment was isolated, and ligated with BamHI-Hind III digested pBR322 to form the recombinant plasmid pBH1 . The human cytomegalovirus B gene sequence was analysed by Beckman Microgenie Systems . The results indicated that the human cytomegalovirus B gene could be further digested by 13 kinds of restrict endonucleases . The size of the restrict fragments was between 22 base pairs to 2.9 kilobase pairs . The construction of the expression plasmid that contained human cytomegalovirus B gene is now in progress.

Mol Microbiol, 1990 Sep, 4(9), 1567 - 74
Mutagenesis, cloning and complementation analysis of C4-dicarboxylate transport genes from Rhodobacter capsulatus; Hamblin MJ et al.; Transposon mutagenesis was used to isolate insertion mutants of the photosynthetic bacterium Rhodobacter capsulatus which were unable to grow under aerobic conditions in the dark on malate, succinate or fumarate as sole carbon sources . Of five mutants isolated, all were deficient in C4-dicarboxylate transport . However, these mutants were still capable of photoheterotrophic growth, although at a slower rate than the wild type, on malate and succinate (but not fumarate) . The mutated locus (designated dct) was complemented in trans using a cosmid gene bank . Subcloning and complementation analysis indicated that at least three closely linked genes essential for aerobic dicarboxylate transport were contained within an 8.3 kb region of the Rhodobacter capsulatus chromosome.

J Bacteriol, 1990 Sep, 172(9), 5071 - 8
Sequence analysis and transcriptional organization of the Rhodopseudomonas viridis cytochrome c2 gene; Grisshammer R et al.; The cytochrome c2 gene (cycA) of the purple nonsulfur bacterium Rhodopseudomonas viridis was isolated from a genomic library by using two degenerate oligonucleotides containing all possible DNA sequences predicted from the published amino acid sequence of this protein (Ambler et al., Proc . Natl . Acad . Sci . USA 73:472-475, 1976) . Cloning and sequence analysis of the cytochrome c2 gene indicated the presence of a typical procaryotic 20-residue signal peptide, suggesting that this periplasmic protein in synthesized in vivo as a precursor . In addition, four amino acids were found to be different by comparing the published sequence of the mature protein with that deduced from the isolated cycA gene (Lys-14----Leu, Ser-46----Ala, Ile-84----Val, Leu-97----Ile) . Northern (RNA) blot analysis and fine mapping of the 5' and 3' ends of the cycA gene transcript from photoheterotrophically grown R . viridis cells revealed one abundant transcript of 523 to 530 nucleotides in length, with the transcription start site at position -39 relative to the coding region of cytochrome c2 . A low-abundance transcript with an extended 3' end (about 600 bases in length) is thought to be processed by exonucleases, resulting in the slightly shorter main transcript.

J Theor Biol, 1990 Aug 23, 145(4), 535 - 45
Evolutionary relationships between "Q-type" photosynthetic reaction centres: hypothesis-testing using parsimony; Beanland TJ; Hypotheses concerning the evolutionary relationships between "Q-type" photosynthetic reaction centres are tested using amino acid parsimony analysis of subunit sequences and an alignment based on dot matrix comparisons . Strong evidence is found for independent gene duplications having produced the L and M subunits of the photosynthetic purple bacterial reaction centre and D1 and D2 of Photosystem-II . Much support is also found for the L and M subunits of the green filamentous bacterium Chloroflexus aurantiacus arising from the same gene duplication as the purple bacterial subunits, suggesting there was an ancestral bacterial heterodimeric reaction centre . These conclusions caution against over-extrapolation from the purple bacterial reaction centre to Photosystem-II, and suggest that the latter is more ancient than previously supposed.

Nature, 1990 Aug 16, 346(6285), 674 - 7
Isolation and sequence of an FK506-binding protein from N . crassa which catalyses protein folding; Tropschug M et al.; Slow protein-folding reactions are accelerated by a prolyl cis/trans isomerase isolated from porcine kidney which is identical to cyclophilin, a protein that is probably the cellular receptor for the immunosuppressant cyclosporin A . Catalysis probably involves the isomerization of prolyl peptide bonds in the folding protein chains . Cyclosporin A inhibits folding catalysis by cyclophilin . Here we report the isolation, cloning, sequencing and expression of another protein with prolyl isomerase activity from Neurospora crassa which is unrelated to cyclophilin and which also catalyses slow steps in protein folding . This protein does, however, show sequence similarity to a human protein that binds to another, recently discovered immunosuppressive drug, FK506 . Moreover, it shares 39% identity with the carboxy-terminal 114 residues of a cell-surface protein from the bacterium Legionella pneumophila, the causative agent of Legionnaires' disease . Catalysis of folding by the FK506-binding protein from N . crassa is inhibited by FK506, but not by cyclosporin A . Thus, at least two different classes of conformationally active enzymes (conformases) exist that catalyse slow steps in protein folding . Both occur in a wide variety of cells and are inhibited by immunosuppressive drugs.

J Biol Chem, 1990 Aug 15, 265(23), 13741 - 9
ATP-dependent and NAD-dependent modification of glutamine synthetase from Rhodospirillum rubrum in vitro; Woehle DL et al.; Glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum is the target of both ATP- and NAD-dependent modification . Incubation of R . rubrum cell supernatant with {alpha-32P}NAD results in the labeling of glutamine synthetase and two other unidentified proteins . Dinitrogenase reductase ADP-ribosyltransferase does not appear to be responsible for the modification of glutamine synthetase or the unidentified proteins . The {alpha-32P}ATP- and {alpha-32P} NAD-dependent modifications of R . rubrum glutamine synthetase appear to be exclusive and the two forms of modified glutamine synthetase are separable on two-dimensional gels . Loss of enzymatic activity by glutamine synthetase did not correlate with {alpha-32P}NAD labeling . This is in contrast to inactivation by nonphysiological ADP-ribosylation of other glutamine synthetases by an NAD:arginine ADP-ribosyltransferase from turkey erythrocytes (Moss, J., Watkins, P.A., Stanley, S.J., Purnell, M.R., and Kidwell, W.R . (1984) J . Biol . Chem . 259, 5100-5104) . A 32P-labeled protein spot comigrates with the NAD-treated glutamine synthetase spot when glutamine synthetase purified from H3 32PO4-grown cells is analyzed on two-dimensional gels . The adenylylation site of R . rubrum glutamine synthetase has been determined to be Leu-(Asp)-Tyr-Leu-Pro-Pro-Glu-Glu-Leu-Met; the tyrosine residue is the site of modification.

Appl Environ Microbiol, 1990 Aug, 56(8), 2494 - 8
Detection of plasmid DNA from all Chlamydia trachomatis serovars with a two-step polymerase chain reaction; Welch D et al.; A polymerase chain reaction was used to amplify a 137-base-pair sequence of DNA from a Chlamydia trachomatis plasmid . Various parameters of the polymerase chain reaction were explored, and it was found that two short steps per reaction cycle were sufficient to achieve 10(12)-fold amplification in less than 1 h . By use of this procedure, 10(-18) g of a sequence of plasmid DNA, representing the amount of that sequence found in one C . trachomatis bacterium, was amplified to the point where it was clearly visible on an ethidium bromide-stained polyacrylamide gel under UV light . DNA from intact cells from each of the 15 serovars of C . trachomatis could also be amplified for visualization . With this procedure, the presence or absence of C . trachomatis DNA in a sample could be established in less than 1.5 h . The speed and extreme sensitivity of this detection procedure may make it a useful method for the detection of C . trachomatis, and similar techniques should be possible for any type of bacteria.

Proc Natl Acad Sci U S A, 1990 Aug, 87(16), 6077 - 81
Juxtaposition of expressed variable antigen genes with a conserved telomere in the bacterium Borrelia hermsii; Kitten T et al.; Borrelia hermsii, an agent of relapsing fever, survives in mammals through antigenic variation . Change in serotype-specific variable outer membrane proteins (Vmps) occurs when a Vmp gene at an expression site is replaced with a previously silent gene for another Vmp . Silent and active genes are on separate linear plasmids . The upstream site for a nonreciprocal recombination between two linear plasmids is near the 5' ends of the expressed and silent genes . In the present study we sought the downstream recombination sites in two serotypes, 7 and 21 . Restriction fragments containing plasmid telomeres were identified by susceptibility to digestion with BAL-31 and rapid reannealment following denaturation . Whereas both silent genes and a minority population of both expression-linked genes were several kilobases from the telomeres, the predominant population of both expressed genes had 3' ends near plasmid telomeres . Sequence analysis of the predominant expression plasmids revealed that the telomeric sequences were the same in serotypes 7 and 21 . Identical sequence was also downstream of silent Vmp genes . Switching of Vmp genes appears to occur by recombination that involves both upstream and downstream sites . The expression plasmid's telomere is preserved in the recombination event.

J Bacteriol, 1990 Aug, 172(8), 4497 - 504
Gene encoding the 5.7-kilodalton chlorosome protein of Chloroflexus aurantiacus: regulated message levels and a predicted carboxy-terminal protein extension; Theroux SJ et al.; The major light-harvesting pigment of the green filamentous bacterium Chloroflexus aurantiacus is bacteriochlorophyll (Bchl) c, localized in chlorosomes attached to the inner surface of the cytoplasmic membrane . Chlorosomes consist of four polypeptides and associated pigments and lipids . Previous studies of the inducible assembly of the photosynthetic apparatus had indicated that the major chlorosomal polypeptides are present as high-molecular-weight aggregates before the appearance of mature chlorosomes, and a mechanism for posttranslational processing of a polyprotein had been proposed . We have isolated the gene (csmA) encoding the 5.7-kilodalton chlorosomal polypeptide from C . aurantiacus in order to determine whether this protein is synthesized as part of a polyprotein . Analysis of the nucleotide sequence of csmA indicates that the gene is not large enough to encode more than one known chlorosome polypeptide . Transcriptional analysis indicates that csmA is transcribed as a small message whose abundance is regulated in response to oxygen, so that no csmA message is detectable in cells grown aerobically in the dark . Comparison of the sequence predicted by csmA with the peptide sequence of the Bchl c binding protein purified from chlorosomes indicates that this protein is synthesized with a carboxy-terminal extension of 27 amino acids . We discuss possible roles for this carboxy-terminal extension in the assembly of chlorosomes.

FEMS Microbiol Lett, 1990 Aug, 58(3), 263 - 8
Analysis of immune response: comparison of immunoblots after isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis using cytoplasmic protein extract from Brucella; Zygmunt MS et al.; Analysis of the immune response towards the facultative intracellular bacterium, Brucella melitensis, was studied by immunoblotting after either isoelectric focusing (IEF) or sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) . A cytoplasmic extract (CPE) of Brucella melitensis was used as antigen to analyse the response in 17 sera from naturally infected goats . CPE analysed by IEF exhibited 25 proteins within the pH range of 4.35 to 6 . Immunoblotting revealed most of the stained bands around pH 4.5-5.4 . CPE analysed by SDS-PAGE showed more than 20 silver stained proteins in the molecular range of 16-18 kDa to 70 kDa but immunoblotting revealed only 1 to 6 bands according to the sera tested . Because proteins are preserved in their native state with IEF, in contrast to SDS-PAGE treatment, this technique may be best suited for analysis of the overall response to natural infection.

J Bacteriol, 1990 Aug, 172(8), 4370 - 7
Identification, cloning, and sequencing of piv, a new gene involved in inverting the pilin genes of Moraxella lacunata; Marrs CF et al.; Moraxella lacunata is a bacterium that is a causative agent of human conjunctivitis and keratitis . We have previously cloned the Q and I pilin (formerly called beta and alpha pilin) genes of Moraxella bovis and determined that an inversion of 2 kilobases (kb) of DNA determines which pilin gene is expressed . Using an M . bovis pilin gene as a hybridization probe to screen a lambda ZAP library of M . lacunata DNA, we have isolated a clone that not only contains the entire type 4 pilin gene inversion region of M . lacunata but inverts the 2-kb region on a plasmid subclone (pMxL1) in Escherichia coli . Deletion derivatives of pMxL1 yielded some plasmids that still had the entire inversion region but were phase locked into one or the other of the two potential orientations . Similarly, insertions of a 2-kb streptomycin-resistant element (omega) within some regions outside of the inversion also resulted in phase-locked plasmids . These deletions and insertions thus localize a probable invertase necessary for the inversion event . The region was sequenced, and an open reading frame with over 98% DNA sequence homology to an open reading frame that we previously found in M . bovis and called ORF2 appeared to be a strong candidate for the invertase . This conclusion was confirmed when a plasmid containing the M . bovis ORF2 supplied, in trans, the inversion function missing from one of the M . lacunata phase-locked inversion mutants . We have named these putative invertase genes piv(ml) (pilin inversion of M . lacunata) and piv(mb) (pilin inversion of M . bovis) . Despite previously noted sequence similarities between the M . bovis sites of inversion and those of the Hin family of invertible segments and a 60-base-pair region within the inversion with 50% sequence similarity to the cin recombinational enhancer, there is no significant sequence similarity of the Piv invertases to the Hin family of invertases.

Biotechnology (N Y), 1990 Aug, 8(8), 746 - 9
Applications of imaging spectroscopy in molecular biology . II . Colony screening based on absorption spectra; Arkin AP et al.; Digital imaging spectroscopy has been used to obtain the grayscale spectrum of colored bacterial colonies directly from petri dishes . Up to 500 individual colony spectra can be simultaneously recorded and processed from a single plate . Spectra can be obtained in the visible to near infrared region (400nm-900nm) with 10nm resolution . Instrument response is normalized through run-time radiometric calibration such that each grayscale spectrum can be converted to the ground-state absorption spectrum of the colony . In this study, mutants of the photosynthetic bacterium Rhodobacter capsulatus have been differentiated by the absorption spectra of their pigment-protein complexes . This imaging technique is applicable to chromogenic systems in which colony and/or media color (e.g . indicator plates) provides a quantitative indicator of gene expression.

Biochemistry, 1990 Jul 24, 29(29), 6911 - 8
Azotobacter vinelandii flavodoxin: purification and properties of the recombinant, dephospho form expressed in Escherichia coli; Taylor MF et al.; The nifF gene coding for the flavodoxin from the nitrogen-fixing bacterium Azotobacter vinelandii (strain OP) was cloned into the plasmid vector pUC7 {Bennett, L . T., Jacobsen, M . R., & Dean, D . R . (1988) J . Biol . Chem . 263 1364-1369} and the resulting plasmid transformed and expressed in Escherichia coli strain DH5 . Recombinant Azotobacter flavodoxin is expressed at levels 5-6-fold higher in E . coli than in comparable yields of Azotobacter cultures grown under nitrogen-fixing conditions . Even higher levels were observed with flavodoxin expressed in E . coli under control of a tac promoter . Electron spin resonance spectroscopy on whole cells and in cell-free extracts showed the flavodoxin to be largely in the semiquinone form . The flavodoxin purified from E . coli exhibited the same molecular weight, isoelectric point, flavin mononucleotide (FMN) content, N-terminal sequence, and carboxyl-terminal amino acids as for the wild-type Azotobacter protein . The recombinant flavodoxin differed from native flavodoxin in that it exhibited an increased antigenicity to flavodoxin antibody and did not contain a covalently bound phosphate . Small differences are also observed in circular dichroism spectral properties in the visible and ultraviolet spectral regions . The recombinant, dephospho flavodoxin exhibits an oxidized/semiquinone potential (pH 8.0) of -224 mV and a semiquinone/hydroquinone couple (pH 8.0) of -458 mV . This latter couple is 50-60 mV higher than that exhibited by the native flavodoxin . Resolution of recombinant dephospho flavodoxin resulted in an apoflavodoxin that was much less stable than that prepared from the native protein.(ABSTRACT TRUNCATED AT 250 WORDS)

FEBS Lett, 1990 Jul 2, 267(1), 33 - 7
Electron microscopy of native and artificial methylreductase high-molecular-weight complexes in strain Gö 1 and Methanococcus voltae; Hoppert M et al.; The preparation of inside-out vesicles from methanogenic bacteria with protein cell walls was improved with regard to the preservation of structure and localization of membrane-bound proteins . Complexes similar to the methanoreductosome in the methanogenic bacterium Go 1 were also found attached to the inner aspect of the cytoplasmic membrane of Methanococcus voltae . Methanoreductosomes were purified from crude extracts of Go 1-cells by affinity chromatography . Under specific conditions at high protein concentrations methyl-CoM-methylreductase molecules isolated from Go 1-cells could be reassociated to spherical complexes of various sizes, with an appearance similar to that of methanoreductosomes isolated from strain Go 1.

Appl Environ Microbiol, 1990 Jul, 56(7), 2193 - 9
Monoclonal antibodies against the ruminal bacterium Selenomonas ruminantium; Brooker JD et al.; Monoclonal antibodies were raised against whole cells of two different strains of Selenomonas ruminantium and tested for specificity and sensitivity in immunofluorescence and enzyme-linked immunosorbent assay procedures . Species-specific and strain-specific antibodies were identified, and reactive antigens were demonstrated in solubilized cell wall extracts of S . ruminantium . A monoclonal antibody-based solid-phase immunoassay was established to quantify S . ruminantium in cultures or samples from the rumen, and this had a sensitivity of 0.01 to 0.02% from 10(7) cells . For at least one strain, the extent of antibody reaction varied depending upon the stage of bacterial growth . Antigen characterization by immunoblotting shows that monoclonal antibodies raised against two different strains of S . ruminantium reacted with the same antigen on each strain . For one strain, an additional antigen reacted with both monoclonal antibodies . In the appropriate assay, these monoclonal antibodies may have advantages over gene probes, both in speed and sensitivity, for bacterial quantification studies.

Appl Environ Microbiol, 1990 Jul, 56(7), 2025 - 8
Viable endospores of Thermoactinomyces vulgaris in lake sediments as indicators of agricultural history; Nilsson M et al.; Bacteria of the genus Thermoactinomyces form endospores with an extreme longevity in natural habitats . We isolated Thermoactinomyces sacchari from 9,000-year-old varved (annually laminated) sediment; thus, T . sacchari is probably one of the oldest known living organisms . More importantly, we tested and verified the hypothesis that there is a relationship between concentrations of dormant, viable endospores of T . vulgaris in lake sediments and the extent of agriculture in the catchments of the lakes . In surface sediments, low concentrations were recorded in forest lakes and the concentrations increased with increasing areas of cultivated land around the lakes . In varved sediment cores from three lakes, we found a temporal relationship between records of T . vulgaris endospores and the pollen of plants indicating agriculture . Endospores were very rare in sediments deposited before agriculture, ca . 1100 A.D . From then to between 1300 and 1700 A.D., a period with restricted cultivation, low but more regular rates of accumulation of endospores were recorded . High endospore accumulation rates were found with the subsequent agricultural expansion . This investigation confirms suggestions that this bacterium could be used as a paleoindicator for agricultural activity and be complementary to pollen analyses . Viable bacteria in continuous records of lake sediments are also potential material for evolutionary studies.

J Cell Biol, 1990 Jul, 111(1), 87 - 94
Development of a cell-free system to study the membrane assembly of photosynthetic proteins of Rhodobacter capsulatus; Troschel D et al.; A cell-free translation system from the facultatively photoheterotrophic bacterium Rhodobacter capsulatus is described . Synthesis of two proteins of the bacterium's photosynthetic apparatus (light-harvesting complex B870 alpha and beta) was performed by SP6 polymerase transcription of the subcloned genes, isolation of the mRNA and translation in vitro using a cell-free extract of R . capsulatus cells . The integration of these proteins in vitro into added intracytoplasmic membrane vesicles (ICM) is demonstrated . Without addition of ICM approximately 70% of the synthesized B870 proteins were soluble . If, however, ICM were present during synthesis, the majority of the soluble protein was found to associate with the membranes . The membrane-associated polypeptides could be solubilized only by detergent treatment but could not be extracted by treatment at alkaline pH (Na2CO3), suggesting that the proteins had been firmly inserted into the lipid bilayer . Moreover, the B870 alpha and beta proteins that integrated in vitro into ICM were also found to associate with pigment ligands and to assemble into a native reaction center/B870 complex . The native conformation of this complex isolated from ICM by Triton fractionation was demonstrated by microspectral analysis of the bound pigments.

Mol Microbiol, 1990 Jul, 4(7), 1199 - 205
Protein transfer into the recipient cell during bacterial conjugation: studies with F and RP4; Rees CE et al.; Transfer of donor cell proteins to the recipient bacterium was examined in F- and RP4-mediated conjugation . Transfer of a 120 kD polypeptide, identified as the larger product of the plasmid DNA primase gene, was readily detected during RP4-promoted conjugation . The protein was transmitted to the cytoplasm of the recipient, presumably complexed to the transferred ssDNA . F DNA was transferred without detectable association with any cytoplasmic tra protein or with the ssDNA-binding protein encoded by the plasmid . However, a 92 kD protein, possibly F TraD product, was transmitted to the membrane fraction of the recipient cell.

Infect Immun, 1990 Jul, 58(7), 2076 - 84
The 56-kilodalton major protein antigen of Rickettsia tsutsugamushi: molecular cloning and sequence analysis of the sta56 gene and precise identification of a strain-specific epitope; Stover CK et al.; Lasting immunity against Rickettsia tsutsugamushi, the causative agent of scrub typhus fever, has been demonstrated to be strain specific . Two protein antigens of 110 and 56 kilodaltons (kDa) have been shown to exhibit strain-specific epitopes . The 56-kDa scrub typhus antigen (Sta56) is an abundant outer membrane protein of R . tsutsugamushi and is an antigen often recognized by humans infected with this obligate intracellular bacterium . In this study the complete gene encoding Sta56 (strain Karp) was cloned into pBR322 on a 2.3-kilobase genomic HindIII DNA fragment and the complete 56-kDa polypeptide was expressed in Escherichia coli . DNA sequence analysis of the 2.3-kilobase HindIII fragment revealed an open reading frame large enough to encode a 56-kDa polypeptide . A putative signal sequence was identified at the deduced amino terminus of the Sta56 polypeptide, and pulse-chase analysis of maxicells labeled with {35S}methionine demonstrated that a higher-molecular-weight precursor matures into the 56-kDa polypeptide . Epitope scanning analysis with synthetic peptides derived from the deduced amino acid sequence identified an octapeptide (located from amino acid residues 117 to 124) that was reactive with a Karp strain-specific monoclonal antibody (K13F88A) . Other epitopes recognized by different monoclonal antibodies, including another Karp strain-specific monoclone (K1E106), were localized to different regions of the protein based on their reactivities with lambda gt11 recombinants expressing various portions of the sta56 gene.

Biochemistry, 1990 Jun 26, 29(25), 5968 - 74
Direct observation of the phase behavior of the lipid bilayers of phage PM2 and the intact host cells by 1H-31P cross-polarization NMR; Odahara T et al.; A method for obtaining the 31P NMR spectrum of a particular supramolecular structure in an intact biological system was developed by applying the 1H-31P cross-polarization technique to a lipid-containing bacteriophage, PM2, and its host bacterium, Alteromonas espejiana . It was shown that 31P NMR spectra of nucleic acids and lipid bilayers can be obtained separately with short and long thermal contact times, respectively . The temperature dependence of the chemical shift anisotropy (delta sigma = sigma parallel - sigma perpendicular) was examined for the separately obtained membrane spectra . Referring to the results of thermal analysis and 31P NMR spectra of bilayers of the extracted phospholipids, the phase transition of the biomembrane was identified for the PM2 phage and the host cell . The dynamic state of the biomembrane of the intact bacterium was directly monitored in detail . The phase behavior of the PM2 lipid bilayer showed good agreement with the earlier report (Akutsu et al., 1980) . It turned out that the phase behavior of the intact biomembrane is different from that of the bilayer of the extracted lipids for both PM2 and the host cell . Namely, the terminal temperatures of the phase transition of the host cell and PM2 membranes were lower and higher than those of the extracted phospholipids, respectively.

J Mol Biol, 1990 Jun 5, 213(3), 411 - 4
Preliminary X-ray crystallographic analysis of holotoxin from Bordetella pertussis; Raghavan M et al.; Pertussis (whooping cough) is a serious infectious disease caused by the bacterium Bordetella pertussis . One of the major virulence factors is a protein known as pertussis toxin, which is composed of six subunits, with a total molecular weight of 106,000 . Enzymatic transfer of ADP-ribose from NAD to a family of GTP-binding proteins is effected by the largest subunit (S1 or the A monomer), while binding of host cells and entry of S1 to the interior is a function of the other subunits (the B oligomer) . The holotoxin crystallizes in the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions a = 98.4 A, b = 164.2 A and c = 195.2 A . The crystals are suitable for high-resolution X-ray diffraction analysis.

J Exp Med, 1990 Jun 1, 171(6), 1931 - 42
Definition of a specific interaction between the early T lymphocyte activation 1 (Eta-1) protein and murine macrophages in vitro and its effect upon macrophages in vivo; Singh RP et al.; The Eta-1 gene specifies a secreted product of activated T cells and is associated with genetic resistance to infection by an obligate intracellular bacterium . Previous studies have suggested that eta-1 might affect the ability of macrophages to migrate to the site of bacterial infection and/or to inhibit intracellular bacterial growth . We therefore examined the interaction of eta-1 with macrophages in vitro and in vivo . We find that macrophages express approximately 10(4) eta-1 receptors/cell and each receptor has a Kd of approximately 5 x 10(-10) M . The subsequence of eta-1 containing an RGD motif is required for binding because a synthetic peptide containing the eta-1 RGD domain inhibited protein attachment to macrophages . We also found that subcutaneous inoculation of mice with eta-1 resulted in a cellular infiltrate comprised primarily of macrophages . We propose that the interaction between eta-1 and its receptor on macrophages results in a change in macrophage physiology resulting in accumulation of these cells at extravascular sites.

J Bacteriol, 1990 Jun, 172(6), 3379 - 87
Surface proteins of the gliding bacterium Cytophaga sp . strain U67 and its mutants defective in adhesion and motility; Burchard RP et al.; Surface proteins of the gliding bacterium Cytophaga sp . strain U67 that make contact with glass substrata were radioiodinated, using a substratum-immobilized catalyst (Iodo-Gen) . At least 15 polypeptides were iodinated, fewer than the number labeled by surface biotinylation of whole cells; these polypeptides define the set of possible candidates for the surface protein(s) that mediates gliding-associated substratum adhesion . The labeling of three adhesion-defective mutants exhibited two characteristic patterns of surface iodination which involved addition, loss, or alteration of several polypeptides of high molecular weight . An adhesion-competent revertant of mutant Adh3 and one of Adh2 exhibited the wild-type labeling pattern . Two other Adh2 revertants resembled their adhesion-defective parent . The labeling pattern of surface polypeptides of a nongliding but adhesive cell strain was similar to that of the wild type.

J Bacteriol, 1990 Jun, 172(6), 3117 - 24
Use of nonmotile mutants to identify a set of membrane proteins related to gliding motility in Cytophaga johnsonae; Pate JL et al.; Nonmotile mutants of the gliding bacterium Cytophaga johnsonae were examined to identify proteins that might be involved in gliding motility . Wild-type and mutant cell proteins were solubilized and fractionated by using Triton X-114, and the proteins that partitioned into the aqueous phase or the detergent phase were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for proteins that differed between wild-type and mutant cells . Seventeen proteins, ranging in size from 16 to 150 kilodaltons, were implicated by this technique as having some relationship to gliding and were designated Gld-1 through Gld-17 . All Gld proteins behaved as integral membrane proteins, partitioning into the detergent phase . All 56 mutants examined exhibited changes in 1 or more of the Gld proteins, with the number of proteins altered in any mutant varying from 1 to 11 . Several lines of evidence suggested that proteins Gld-12 through Gld-15 are glycoproteins . Analysis of banding patterns of detergent-fraction proteins of motile revertants supported the idea that the Gld proteins have a role in gliding motility.

J Bacteriol, 1990 Jun, 172(6), 3051 - 9
Expression of the Caulobacter heat shock gene dnaK is developmentally controlled during growth at normal temperatures; Gomes SL et al.; Caulobacter crescentus has a single dnaK gene that is highly homologous to the hsp70 family of heat shock genes . Analysis of the cloned and sequenced dnaK gene has shown that the deduced amino acid sequence could encode a protein of 67.6 kilodaltons that is 68% identical to the DnaK protein of Escherichia coli and 49% identical to the Drosophila and human hsp70 protein family . A partial open reading frame 165 base pairs 3' to the end of dnaK encodes a peptide of 190 amino acids that is 59% identical to DnaJ of E . coli . Northern blot analysis revealed a single 4.0-kilobase mRNA homologous to the cloned fragment . Since the dnaK coding region is 1.89 kilobases, dnaK and dnaJ may be transcribed as a polycistronic message . S1 mapping and primer extension experiments showed that transcription initiated at two sites 5' to the dnaK coding sequence . A single start site of transcription was identified during heat shock at 42 degrees C, and the predicted promoter sequence conformed to the consensus heat shock promoters of E . coli . At normal growth temperature (30 degrees C), a different start site was identified 3' to the heat shock start site that conformed to the E . coli sigma 70 promoter consensus sequence . S1 protection assays and analysis of expression of the dnaK gene fused to the lux transcription reporter gene showed that expression of dnaK is temporally controlled under normal physiological conditions and that transcription occurs just before the initiation of DNA replication . Thus, in both human cells (I . K . L . Milarski and R . I . Morimoto, Proc . Natl . Acad . Sci . USA 83:9517-9521, 1986) and in a simple bacterium, the transcription of a hsp70 gene is temporally controlled as a function of the cell cycle under normal growth conditions.

Proc Natl Acad Sci U S A, 1990 Jun, 87(12), 4504 - 8
Proofreading in vivo: editing of homocysteine by methionyl-tRNA synthetase in Escherichia coli; Jakubowski H; Previous in vitro studies have established a pre-transfer proofreading mechanism for editing of homocysteine by bacterial methionyl-, isoleucyl-, and valyl-tRNA synthetases . The unusual feature of the editing is the formation of a distinct compound, homocysteine thiolactone . Now, two-dimensional TLC analysis of 35S-labeled amino acids extracted from cultures of the bacterium Escherichia coli reveals that the thiolactone is also synthesized in vivo . In E . coli, the thiolactone is made from homocysteine in a reaction catalyzed by methionyl-tRNA synthetase . One molecule of homocysteine is edited as thiolactone per 109 molecules of methionine incorporated into protein in vivo . These results not only directly demonstrate that the adenylate proofreading pathway for rejection of misactivated homocysteine operates in vivo in E . coli but, in general, establish the importance of error-editing mechanisms in living cells.

Mol Microbiol, 1990 Jun, 4(6), 977 - 89
Localized transposon Tn5 mutagenesis of the photosynthetic gene cluster of Rhodobacter sphaeroides; Coomber SA et al.; Four genes essential for bacteriochlorophyll biosynthesis were known to be encoded within a 45 kb region of the Rhodobacter sphaeroides genome, the boundaries of which are defined by puh and puf genes for reaction-centre and light-harvesting LH1 complexes . The cluster is represented by eight overlapping inserts cloned in the mobilizable vector pSUP202 . We have used localized transposon Tn5 mutagenesis to characterize this cluster further; a total of 87 independent insertions were generated which identify nine genes for bacteriochlorophyll biosynthesis, six for carotenoid biosynthesis, and puhA encoding the reaction-centre H subunit . This work provides an essential framework for a detailed study of the structure and expression of genes for photosynthesis in this bacterium.

J Gen Microbiol, 1990 Jun, 136 ( Pt 6), 1161 - 6
DNA restriction fingerprint analysis of the soil bacterium Azospirillum; Giovannetti L et al.; Total DNAs of 18 strains of Azospirillum from different sources and geographical areas were compared by restriction endonuclease pattern analysis . Fragments obtained with HindIII or BglII were separated by PAGE and stained with silver nitrate . Each strain possessed a unique and reproducible fingerprint with each enzyme, thereby facilitating strain recognition . UPGMA analysis recovered clusters of band patterns that were compared to the distribution of species within the genus Azospirillum.

Biochemistry, 1990 May 22, 29(20), 4886 - 92
Coordination and redox properties of a novel triheme cytochrome from Desulfovibrio vulgaris (Hildenborough); Tan JA et al.; A high molecular weight multiheme c-type cytochrome from the sulfate-reducing bacterium Desulfovibrio vulgaris (Hildenborough) has been spectroscopically characterized and compared with the tetraheme cytochrome c3 . The protein contains a pentacoordinate high-spin heme (gz 6.0) and two hexacoordinate low-spin hemes (gz 2.95, gy 2.27, gx 1.48) . From analysis of the g values for the low-spin hemes by the procedure of Blumberg and Peisach (Palmer, 1983) and comparison with with the optical spectra from a variety of c-type cytochromes, it is likely that these low-spin hemes are bound by two histidine residues . The NO derivative displayed typical rhombic EPR features (gx 2.07, gz 2.02, gy 1.99) . Addition of azide does not lead to coupling between heme chromophores, but the ligand is accessible to the high-spin heme . The use of a glassy-carbon electrode to perform direct (no promoter) electrochemistry on the cytochrome is illustrated . Differential pulse polarography of the native protein gave two waves with reduction potentials of -59 (5) and -400 (8) mV (versus NHE) . The cyanide adduct gave two waves with reduction potentials of -263 (8) and -401 (8) mV . The cytochrome was found to catalyze the reduction of nitrite and hydroxylamine.

J Biol Chem, 1990 May 15, 265(14), 8329 - 38
Genetic and biochemical characterization of carotenoid biosynthesis mutants of Rhodobacter capsulatus; Armstrong GA et al.; We have used genetic and biochemical techniques to study carotenoid biosynthesis (crt) mutants of Rhodobacter capsulatus, a purple non-sulfur photosynthetic bacterium . All nine identified crt genes are located within the 46-kilobase pair photosynthesis gene cluster, and eight of the crt genes form a subcluster . We have studied the operon structure of the crt gene cluster using transposon Tn5.7 mutants . The Tn5.7 insertion sites in 10 mutants have been mapped to high resolution (25-267 base pairs) by Southern hybridization . Two insertions each map within the coding regions of the crtA, crtC, crtE, and crtF genes, and one insertion lies within the crtI gene . The insertion in crtI is not polar on the downstream crtB gene, suggesting that crtI and crtB may form two separate operons . Another insertion located in the 5' noncoding region between the divergent crtA and crtI genes has no effect on wild-type pigmentation and apparently lies between the promoters for these operons . A Tn5.7 mutation in the 3' region of crtA yields a bacteriochlorophyll-minus phenotype, while a 5' insertion affects only carotenoid biosynthesis . Regulatory signals for transcription of a downstream operon required for bacteriochlorophyll biosynthesis may thus overlap the coding region of crtA . We also present the first evidence for the functions of the crtB, crtE, and crtJ gene products using a new in vitro assay for the incorporation of {14C}isopentenyl pyrophosphate into carotenoid precursors and phytoene in cell-free extracts . Extracts from a crtE mutant accumulate {14C}prephytoene pyrophosphate, while those from crtB and crtJ mutants accumulate {14C}geranylgeranyl pyrophosphate . We therefore propose that CrtE is the phytoene synthetase and that CrtB, and possibly CrtJ, are components of the prephytoene pyrophosphate synthetase.

Am J Med, 1990 May 14, 88(5A), 41S - 45S
Studies of the outer membrane proteins of Branhamella catarrhalis; Murphy TF; PURPOSE: Branhamella catarrhalis has emerged as an important human pathogen in the past several years . Therefore, studies of the outer membrane have been undertaken in order to identify virulence factors and begin to understand the immune response to infection . MATERIALS AND METHODS: The outer membrane of B . catarrhalis has been purified by sucrose density centrifugation . The outer membrane proteins (OMPs) of 50 strains from diverse sources were isolated by simpler methods and studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Experiments were designed to identify OMPs that express determinants on the surface of the intact bacterium . RESULTS: Eight major OMPs have been identified (OMPs A through H) . The OMP patterns from diverse strains were strikingly similar . OMP E (approximately 56,000 daltons) and OMP G (approximately 28,000 daltons) have determinants that are surface-exposed and these determinants are shared among a majority of strains of B . catarrhalis . CONCLUSION: These observations have important implications with regard to the immune response to infection and future vaccine development.

Mol Microbiol, 1990 May, 4(5), 811 - 20
Cloning and sequence analysis of linear plasmid telomeres of the bacterium Borrelia burgdorferi; Hinnebusch J et al.; Borrelia burgdorferi, the Lyme disease agent, has double-stranded linear plasmids with covalently closed ends . DNA at the ends, or telomeres, of two linear plasmids of B . burgdorferi strain B31 was examined . Telomeric sequences from both ends of a 16 kb linear plasmid and from one end of a 49 kb linear plasmid were cloned and sequenced . An 18 bp AT-rich inverted repeat was found at each end of the 16 kb linear plasmid . The sequences of the two ends of this plasmid were different beyond these short inverted terminal repeats . The cloned end of the 49 kb linear plasmid had sequence identity with one end of the 16 kb linear plasmid . The end sequence common to both plasmids contained a series of phased, short direct repeats and a 52 bp palindrome adjacent to a highly AT-rich region . These findings indicate that Borrelia linear plasmid telomeres have structural features different from those of other known replicons.

Biophys J, 1990 May, 57(5), 1009 - 23
Mathematical analysis of cell-target encounter rates in three dimensions . Effect of chemotaxis; Charnick SB et al.; Efficient and rapid immune response upon challenge by an infectious agent is vital to host defense . The encounter of leukocytes (white blood cells of the immune system) with their targets is the first step in this response . Analysis of the kinetics of this process is essential not only to understanding dynamic behavior of the immune response, but also to elucidating the consequences of many leukocyte functional abnormalities . The motion of leukocytes in the presence of targets typically involves a directed, or chemotactic component . These immune cells orient the direction of their motion in the presence of gradients in chemical attractants generated by pathogens . Fisher and Lauffenburger (1987 . Biophys . J . 51:705-716) developed a model for macrophage/bacterium encounter in two dimensions which includes chemotaxis, and applied it to the particular system of alveolar macrophages (phagocytic leukocytes on the lung surface) . Their model showed that macrophage/target encounter is likely the rate-limiting step in clearance of bacteria from the lung surface (Fisher, E . S., D . A . Lauffenburger, and R . P . Daniele . 1988 . Am . Rev . Resp . Dis . 137:1129-1134) . We have extended this model to analyze the effects of cell motility properties and geometric parameters on cell-target encounter in three dimensions . The differential equation governing encounter time in three dimensions is essentially the same as that in two dimensions, except for changed probability values . Our results show that more highly directed motion is necessary in three dimensions to achieve substantially decreased encounter times than in two dimensions, because of the increased search dimensionality . These general results were applied to the particular system of neutrophils operating in three dimensions in response to a bacterial challenge in connective tissue . Our results provide a plausible rationalization for both the chemotactic and chemokinetic behavior observed in neutrophils . That is, these cells exhibit in vitro a greater chemotactic bias and a more dramatic variation of speed with attractant concentration than alveolar macrophages, and our results indicate that these behaviors can have a greater influence in three-dimensional connective tissue infection situations than in two-dimensional lung surface infection cases . In addition, we show that encounter apparently is not generally the rate-limiting step in this neutrophil response . These findings have important implications for correlating in vitro measured defects in cell motility and chemotaxis properties with in vivo functions of host defense against infection.

Infect Immun, 1990 May, 58(5), 1195 - 200
Synthesis and secretion of Bordetella pertussis adenylate cyclase as a 200-kilodalton protein; Bellalou J et al.; Bordetella pertussis, the etiological agent of whooping cough, synthesizes a calmodulin-sensitive adenylate cyclase that is suspected to play a major role in the virulence of this bacterium . We show that adenylate cyclase synthesized as a 200-kilodalton protein is the product of the cyaA gene and that various virulent Bordetella species secrete this high-molecular-weight polypeptide without apparent proteolytic processing . When submitted to trypsin digestion, the 200-kilodalton protein was converted to a stable 45- to 50-kilodalton species . This corresponds to the size of the enzyme previously purified from a culture supernatant . The molecular heterogeneity reported for the various identified forms of adenylate cyclase could therefore result in part from proteolytic degradation or molecular aggregation of the major 200-kilodalton form of the enzyme.

Izv Akad Nauk SSSR Biol, 1990 May-Jun, (3), 415 - 9
{The marine bacterium Alteromonas piscicida--a producer of enzymes with thrombolytic action}; Demina NS et al.; The ability of marine bacteria A . piscicida to produce exoproteases that were able to lyse human blood clots has been studied . Optimal conditions for biosynthesis of these enzymes have been found . The enzyme has been partially purified . In concentration of 1 mg/ml it has activity corresponding to that of 500 micrograms/l plasmine and 100 micrograms/ml trypsine . The enzyme activity was completely inhibited after incubation in human blood plasma.

Z Naturforsch {C}, 1990 May, 45(5), 459 - 62
Sequence analysis of four atrazine-resistant mutants from Rhodopseudomonas viridis; Ewald G et al.; Four atrazine-resistant mutants from the purple bacterium Rhodopseudomonas viridis were isolated . Sequence analysis revealed three different mutant strains carrying mutations in the herbicide-binding pocket: i) MAV 2: L212-Glu----Lys, ii) MAV 3: L216-Phe----Ser and iii) MAV 4 = MAV 5: L217-Arg----His, L220-Val----Leu . Except MAV 3 all Rps . viridis mutants are different from those selected by their resistance towards the closely related triazine terbutryn.

Postgrad Med, 1990 May 1, 87(6), 159 - 61, 164
Treatment of Lyme disease . Best use of antibiotics; Rahn DW; Lyme disease is a tick-borne illness caused by the spirochetal bacterium Borrelia burgdorferi . Recognition of the clinical manifestations and geographic range of this illness has expanded rapidly in recent years . Although much remains to be explained about this infection, most patients can be treated effectively on the basis of the clinical experience gathered to date . Antibiotics are the mainstay of therapy for all stages of illness . Development of a vaccine and improvement in laboratory diagnostic techniques glimmer on the horizon but will not replace careful clinical observation and follow-up as the foundations of management.

Plasmid, 1990 May, 23(3), 226 - 36
Plasmid from photosynthetic bacterium Ectothiorhodospira Sp . carries a transposable streptomycin resistance gene; Deragon JM et al.; Centrifugation through a cesium chloride density gradient and agarose gel electrophoresis of the DNA from the purple non-sulfur photosynthetic bacterium Ectothiorhodospira sp . resolved a single extrachromosomal element, plasmid pDG1 . Its size was estimated to be 13.2 kilobases by restriction endonuclease mapping . Plasmid pDG1 and two restriction fragments thereof were cloned in Escherichia coli C600 with plasmid pBR327 as a vector to form mixed plasmids pDGBR1, pDGBR2, and pDGBR3 . The resistance to streptomycin and mercury found in Ectothiorhodospira sp . was transferred to E . coli C600 after transformation with pDGBR1 but not with pDGBR2 and pDGBR3 . The replication origin of pDG1 was estimated to be within a 2-kilobase restriction fragment of pDG1 by monitoring its replication in E . coli HB101, using a kanamycin resistance reporter gene . High stringency molecular hybridization with 32P-labeled pDG1 identified specific fragments of genomic DNA, suggesting the integration of some plasmid sequences . In accordance with the hypothesis that this integration is due to a transposon, we tested the transfer of streptomycin resistance from pDG1 into plasmid pVK100 used as a target . For this test, we regrouped in the same cells of E . coli HB101, pDGBR1 and mobilizable plasmid pVK100 (tetr,kmr) . We used the conjugation capacity of the pVK100/pRK2013 system to rescue the target plasmid pVK100 into nalidixic acid-resistant E . coli DH1 . The transfer frequency of streptomycin resistance into pVK100 was 10(-5), compatible with a transposition event . In line with the existence of a transposon on pDG1, heteroduplex mapping indicated the presence of inverted repeats approximately 7.5 kb from one another.

Pathol Biol (Paris), 1990 May, 38(5), 441 - 5
{Mathematical study of the sensitivity curves of Escherichia coli exposed to polymyxins}; Peyret M et al.; The time killing curves of five strains of Escherichia coli (ATCC 25922, ATCC 29194, CIP 54125, CIP 54127, CIP 54117 (K 12)) exposed to five concentrations of polymyxin B are similar: latency phasis, two decreasing phasis and for the low polymyxin B concentrations growth phasis . In our experimental conditions, the Mg(+)+ and Ca(+)+ concentrations of the medium (Mueller-Hinton; medium A: Ca(+)+ = 9 mg/l, Mg(+)+ = 0.5 mg/l; medium B: Ca(+)+ = 35 mg/l, Mg(+)+ = 15.5 mg/l; medium C: Ca(+)+ = 60 mg/l, Mg(+)+ = 20 mg/l) have no time effect upon the killing curves . A decreasing biexponential model can be fitted to the data . Such a model is compatible with interaction between antibiotic and bacterium and can be formalized accorrding to the equation: T + ATB K1 in equilibrium of K2 T* - ATB K3----ATB + dead with ATB: Polymyxine B in excess, T: target bacterium and T*: modification target bacterium.

J Bacteriol, 1990 May, 172(5), 2765 - 8
FtsZ regulates frequency of cell division in Escherichia coli; Bi E et al.; Cell division is regulated so that it occurs only once per cell cycle . In Escherichia coli, a rod-shaped bacterium, division normally takes place at the center of the long axis of the cell; however, in the minicell mutant, division can also take place at the cell pole . Such divisions take place at the expense of normal divisions, resulting in an overall increase in nucleated cell length . We report here that increasing the level of FtsZ can completely suppress the cell length of the minicell mutant by increasing the frequency at which cell division events take place . This result suggests that the level of FtsZ controls the frequency of cell division in E . coli.

Gene, 1990 Apr 30, 89(1), 129 - 32
Expression of cloned restriction and modification genes, hjaIRM from Hyphomonas jannaschiana in Escherichia coli; Danaher RJ et al.; A type-II RM system, HjaI, was identified in the marine bacterium, Hyphomonas jannaschiana . The ENase recognizes GATATC, and DNA fragments generated after cleavage with this enzyme contain blunt ends . A DNA fragment encoding these enzymes was cloned and expressed in Escherichia coli, although the level of expression of the cloned genes was low . DNA methylated by M.HjaI was not restricted by the Mcr or Mrr restriction systems of E . coli . Although H . jannaschiana is a marine bacterium isolated near the thermal vents on the floor of the Pacific Ocean, the biochemical properties of the ENase were similar to those of EcoRV, an isoschizomer isolated from E . coli.

J Biol Chem, 1990 Apr 25, 265(12), 6817 - 26
The role of methylation in chemotaxis . An explanation of outstanding anomalies; Weis RM et al.; The role of methylation in chemotaxis is understood generally, but several anomalies exist which bring into question the timing of methylation relative to sensing . A double mutant bacterium, deficient in both methyltransferase and methylesterase (Tr-Es-) is capable of chemotaxis even though the respective single mutants (Tr- and Es-) are not . This Tr-Es- mutant will accumulate in capillaries containing aspartic acid but not in capillaries containing serine despite the fact that both the aspartate and serine receptors are part of the methylation-dependent pathway . To understand these anomalies, a combination of theoretical analyses and experimental studies was performed . A mathematical analysis of the gradients of aspartate and serine in the capillary assay shows that outside the capillary the gradients are shallow, but just inside the mouth of the capillary they are very steep . Also, when the number of bacteria accumulated in the capillary is at a maximum, the range of attractant concentrations in the steep gradient just inside the mouth of the capillary is optimal for response and partial adaptation by the Tr-Es- mutant . We postulate that random motion brings the Tr-Es- mutant into the capillary, where it is able to move up the steep gradient . The difference in timing of the responses to serine and aspartate explains why the Tr-Es- mutant accumulates in aspartate- but not in serine-containing capillaries . A simple diffusion-capture model incorporating these concepts can account for experimental values of the number of Tr-Es- bacteria accumulating in the capillary . These studies provide a rational explanation for all of the apparent anomalies and lead to the conclusion that methylation/demethylation plays a crucial role in sensing as well as setting the zero point of the receptor.

FEBS Lett, 1990 Apr 9, 263(1), 10 - 4
Receptor-active glycolipids of epithelial cells of the small intestine of young and adult pigs in relation to susceptibility to infection with Escherichia coli K99; Teneberg S et al.; Glycolipids from mucosa scrapings of small intestine of neonatal and adult pigs were tested by the thin-layer chromatogram overlay assay for the binding of Escherichia coli K99 . There was practically no binding to acid or non-acid glycolipids of adult pig, known to be resistant to infection with this bacterium . However, piglets, which are susceptible to infection, showed a clear binding to a doublet band in the acid glycolipid fraction . The receptor-active glycolipid was isolated and shown by mass spectrometry, NMR spectroscopy and degradation methods to be NeuGc alpha-3Gal beta 4Glc beta Cer (NeuGc-GM3), the two bands being due to heterogeneity of the ceramide . When tested against various reference glycolipids, NeuAc-GM3 was shown to be inactive . This ganglioside was dominating in adult pig . The apparent developmental disappearance of N-glycolyl groups in glycolipids of intestinal mucosa may have a correspondence in protein-linked sequences as well as thus explain the resistance of adult pigs to infection with E . coli K99.

Am J Gastroenterol, 1990 Apr, 85(4), 399 - 403
14C-urea breath test for the detection of Helicobacter pylori; Veldhuyzen van Zanten SJ et al.; The high urease activity of Helicobacter pylori can be used to detect this bacterium by noninvasive breath tests . We have developed a 14C-urea breath test which uses 5 microCi 14C with 50 mg nonradioactive urea . Breath samples are collected at baseline and every 30 min for 2 h . Our study compared the outcome of the breath test to the results of histology and culture of endoscopically obtained gastric biopsies in 84 patients . The breath test discriminated well between the 50 positive patients and the 34 patients negative for Helicobacter pylori: the calculated sensitivity was 100%, specificity 88%, positive predictive value 93%, and negative predictive value 100% . Treatment with bismuth subsalicylate and/or ampicillin resulted in lower counts of exhaled 14CO2 which correlated with histological improvement in gastritis . The 14C-urea breath test is a better "gold standard" for the detection of Helicobacter pylori than histology and/or culture.

J Bacteriol, 1990 Apr, 172(4), 2113 - 23
A Caulobacter gene involved in polar morphogenesis; Driks A et al.; At specific times in the cell cycle, the bacterium Caulobacter crescentus assembles two major polar organelles, the flagellum and the stalk . Previous studies have shown that flbT mutants overproduce flagellins and are unable to form chemotaxis swarm rings . In this paper, we report alterations in both the stalk and the flagellar structure that result from a mutation in the flagellar gene flbT . Mutant strains produce some stalks that have a flagellum, produce some stalks that have an extra lobe protruding from their sides, have filaments lacking the 29-kilodalton flagellin, and produce several unusual cell types, including filamentous cells as well as predivisional cells with two stalks and predivisional cells with no stalk at all . We propose that flagellated stalks arise as a consequence of a failure to eject the flagellum at the correct time in the cell cycle and that the extra stalk lobe is due to a second site for the initiation of stalk biogenesis . Thus, a step in the pathway that establishes the characteristic asymmetry of the C . crescentus cell appears to be disrupted in flbT mutants . We have also identified a new structural feature at the flagellated pole and the tip of the stalk: the 10-nm polar particle . The polar particles appear as a cluster of approximately 1 to 10 stain-excluding rings, visible in electron micrographs of negatively stained wild-type cells . This structure is absent at the flagellar pole but not in the stalks of flbT mutant predivisional cells.

J Clin Microbiol, 1990 Apr, 28(4), 814 - 6
Isolation of a previously undescribed rickettsia from an aborted bovine fetus; Dilbeck PM et al.; A previously undescribed obligate intracellular bacterium was isolated from an aborted bovine fetus . The organism was resistant to penicillin, replicated within cytoplasmic vacuoles, exhibited structural characteristics compatible with the rickettsias, and shared antigenic determinants with Cowdria ruminantium.

Proc Natl Acad Sci U S A, 1990 Apr, 87(8), 3235 - 9
Atomic-resolution structure of the cellulose synthase regulator cyclic diguanylic acid; Egli M et al.; Cyclic diguanylic acid acts as a regulator for cellulose synthase activity in the bacterium Acetobacter xylinum . We report the x-ray crystal structure of the regulator at atomic resolution . The structure contains two independent molecules that adopt almost identical conformations . The two molecules form self-intercalated units that are stacked on each other . Two different G.G base-pairing modes occur between the stacks . The more stable one has two or possibly three hydrogen bonds between two guanines and is related to the type of hydrogen bonding that is believed to exist between G-rich strands at the ends of chromosomes.

J Immunol, 1990 Apr 1, 144(7), 2738 - 44
The HL-60 model for the interaction of human macrophages with the Legionnaires' disease bacterium; Marra A et al.; The facultative intracellular pathogen, Legionella pneumophila, multiplies within and kills human monocytes and alveolar macrophages . We show that L . pneumophila strain Philadelphia-1 infects, multiplies within and kills the promyelocyte HL-60 cell line after its differentiation into macrophage-like cells . The characteristics of the interaction between L . pneumophila and differentiated HL-60 cells closely resemble those between L . pneumophila and human peripheral blood monocytes . With both cell types, C receptors and serum C mediate attachment of L . pneumophila, which are taken up by coiling phagocytosis . The replicative phagosome is lined with ribosomes; intracellular multiplication is iron-dependent; and replicating bacteria ultimately destroy the host cell . As in human monocytes, an avirulent mutant derivative of L . pneumophila Philadelphia-1, 25D, does not replicate in and is not cytopathic for differentiated HL-60 cells . Differentiated HL-60 cells therefore provide a convenient and faithful model for the study of L . pneumophila-mononuclear phagocyte interaction.

J Immunol, 1990 Apr 1, 144(7), 2771 - 80
Phagocytosis of Mycobacterium tuberculosis is mediated by human monocyte complement receptors and complement component C3; Schlesinger LS et al.; We have examined the receptor-ligand interactions and the method of phagocytosis of virulent Mycobacterium tuberculosis by human monocytes . mAb against complement receptors (CR) inhibit adherence and phagocytosis of M . tuberculosis in fresh nonimmune serum . A mAb against the type 1 CR (CR1) inhibits adherence of M . tuberculosis by 40 +/- 5%, and three different mAb against the type 3 CR (CR3) each inhibit adherence by 39 +/- 5% to 47 +/- 4% . A mAb against CR1 used in combination with one of the three mAb against CR3 inhibits adherence by up to 64 +/- 7% . Most strikingly, two mAb used in combination against CR3 inhibit adherence by up to 81 +/- 2% . mAb against other monocyte surface Ag do not significantly influence adherence . In like fashion, mAb against CR but not other monocyte surface Ag inhibit adherence of preopsonized M . tuberculosis in the presence of heat-inactivated serum . By electron microscopy, monocytes ingest all M . tuberculosis that adhere in the presence of nonimmune serum; mAb against CR3 markedly inhibit ingestion . In contrast to CR, the FcR and the beta-glucan-inhibitable receptor for zymosan play little or no role in mediating M . tuberculosis adherence or ingestion . Adherence of M . tuberculosis is serum-dependent, requiring greater than or equal to 2.5% serum for optimal adherence . Heat inactivation of serum markedly reduces adherence of M . tuberculosis (75.5 +/- 7%) and preopsonization of bacteria enhances adherence by 2.9 +/- 0.4-fold . Adherence is also markedly reduced in C3- or factor B-depleted serum; repletion with C3 or factor B increases adherence by 2.1 +/- 0.4-fold and 1.86 +/- 0.05-fold, respectively . Fab anti-C3 IgG markedly inhibits monocyte adherence of preopsonized M . tuberculosis (71 +/- 1%) . C component C3 is fixed to M . tuberculosis by the alternative C pathway as determined by a whole bacterial cell ELISA . Human monocytes ingest M . tuberculosis by conventional phagocytosis as viewed by electron microscopy . This study demonstrates that human monocyte CR1 and CR3 mediate phagocytosis of M . tuberculosis and C component C3 in serum is acting as the major bacterium-bound ligand.

Oral Microbiol Immunol, 1990 Apr, 5(2), 49 - 56
Probe-specific DNA fingerprinting applied to the epidemiology of localized juvenile periodontitis; DiRienzo JM et al.; Although Actinobacillus actinomycetemcomitans has been recognized as a primary etiological agent in localized juvenile periodontitis, questions remain concerning the source of infection, mode of transmission, and relative virulence of strains . DNA fingerprinting analysis, using a randomly cloned chromosomal DNA fragment as a probe, revealed that previously characterized strains of A . actinomycetemcomitans displayed significant restriction site heterogeneity which could be applied to the typing of clinical isolates of this bacterium such that individual strains or variants could be traced within subjects from localized juvenile periodontitis families . Hybridization data derived from an analysis of bacterial isolates obtained from families participating in an ongoing longitudinal study of the disease showed that a single individual could be infected with more than one strain or variant of A . actinomycetemcomitans and that various members of the same family could harbor different strains or variants of the bacterium . In several cases the clinical isolates were matched to characterized laboratory strains by comparing hybridization patterns generated by digestion of the DNA with several restriction enzymes in independent reactions . Thus, probe-specific DNA fingerprinting of A . actinomycetemcomitans will permit us to determine if particular strains or variants are frequently associated with sites of periodontal destruction . Attention could then be focused on determining the virulence properties of those strains or variants that have in vivo significance.

Infect Immun, 1990 Apr, 58(4), 868 - 73
Role of the putative "link" glycopeptide of intestinal mucin in binding of piliated Escherichia coli serotype O157:H7 strain CL-49; Sajjan SU et al.; Purified rat intestinal mucin was used to identify mucin-binding sites for type 1-piliated Escherichia coli O157:H7 strain CL-49 isolated from a patient with hemorrhagic colitis and hemolytic uremic syndrome . Optimum binding of bacteria in a microtiter binding assay occurred with a mucin coating concentration of 15 micrograms (protein)/150 microliters . In hapten inhibition studies, several nonmucin glycoproteins bearing exposed mannosyl residues in N-linked oligosaccharides were effective inhibitors, as was rat mucin . The same glycoproteins caused bacterial aggregation . High-molecular-mass glycoproteins of the mucin were separated from its 118-kilodalton "link" glycopeptide fraction, and the latter was shown to be the mucin-binding component for E . coli CL-49 and its purified type 1 pili . This was confirmed in hemagglutination inhibition studies . Treatment of the link glycopeptide with jack bean alpha-mannosidase or endo-beta-N-acetylglucosaminidase H destroyed bacterial binding activity . Chemical or enzymatic modifications of intact rat mucin were undertaken to evaluate the normal accessibility of the link glycopeptide receptors to E . coli CL-49 . Deglycosylation with trifluoromethane-sulfonic acid abolished binding, whereas pronase digestion had no effect . Reduction and alkylation as well as lipid extraction enhanced bacterial binding by the mucin, presumably by causing greater exposure of receptor sites . In summary, our binding studies revealed, for the first time, that intestinal mucin bears oligomannosyl receptors for type 1 pili and that these receptors are located on N-linked oligosaccharides of the 118-kilodalton link glycopeptide region of the mucin . Our experiments suggest the receptors are normally partly "covered" by noncovalently bound lipid . In addition, release of the link component from the rest of the mucin by disulfide bond reduction causes greater exposure of specific bacterium-binding sites.

Appl Environ Microbiol, 1990 Apr, 56(4), 949 - 55
Identification of Francisella species and discrimination of type A and type B strains of F . tularensis by 16S rRNA analysis; Forsman M et al.; Tularemia is a zoonotic disease, occurring throughout the Northern Hemisphere . The causative agent, the bacterium Francisella tularensis, is represented by two main types . Type A is found in North America, whereas type B is mainly found in Asia and Europe and to a minor extent in North America . No routine technique for rapid diagnosis of tularemia has been generally applied . We have partially sequenced 16S rRNAs of two F . tularensis strains, as well as the closely related Francisella novicida . Of 550 nucleotides analyzed, only one difference in 16S rRNA primary sequence was found . This 16S rRNA analysis enabled the construction of oligonucleotides to be used as genus- and type-specific probes . Such probes were utilized for the establishment of a method for rapid and selective detection of the organism . This method allowed identification of Francisella spp . at the level of genus and also discrimination of type A and type B strains of F . tularensis . The analysis also permitted the detection of F . tularensis in spleen tissue from mice infected with the bacterium . The results presented will enable studies on the epizootiology and epidemiology of Francisella spp.

FEBS Lett, 1990 Mar 26, 262(2), 189 - 93
A repeated decapeptide motif in the C-terminal domain of the ribosomal RNA methyltransferase from the erythromycin producer Saccharopolyspora erythraea; Dhillon N et al.; Re-analysis of the primary structure of the ribosomal RNA N-methyltransferase that confers self-resistance on the erythromycin-producing bacterium Saccharopolyspora erythraea has confirmed the presence of a C-terminal domain containing extensive repeat sequences . Nine tandem repeats can be discerned, with a decapeptide consensus sequence GGRx(H/R)GDRRT, although no single residue is wholly invariant . This highly polar, potentially flexible domain, which is predicted to adopt either a random coil or a structure with beta turns, has a counterpart in the erythromycin methyltransferase of an erythromycin-producing species of Arthrobacter . It also significantly resembles a portion of the C-terminal region of the eukaryotic protein nucleolin, which is unusually rich in dimethylarginine and glycine, and which is also predicted to behave as a random coil in solution . This resemblance, despite the very different roles of these proteins in ribosome biogenesis, strengthens the idea that in both rRNA methyltransferases and nucleolin these C-terminal sequences might contribute to rRNA binding.

J Biol Chem, 1990 Mar 15, 265(8), 4364 - 8
Heme-copper and heme-heme interactions in the cytochrome bo-containing quinol oxidase of Escherichia coli; Salerno JC et al.; The cytochrome bo quinol oxidase of Escherichia coli is one of two respiratory O2 reductases which the bacterium synthesizes . The enzyme complex contains copper and 2 mol of b-type heme . Electron paramagnetic resonance (epr) spectroscopy of membranes from a strain having amplified levels of this enzyme complex reveals signals from low- and high-spin b-type hemes, but the copper, now established as a component of the oxidase, is not directly detectable by epr . The high-spin signal from the cytochrome bo complex, which we attribute to cytochrome o, when titrated potentiometrically, gives a bell-shaped curve . The low potential side of this curve is biphasic (Em7 approximately 180 and 280 mV) and corresponds to the reduction/oxidation of the cytochrome(s) . The high potential side of the bell-shaped curve is monophasic (Em7 approximately 370 mV) and is proposed to be due to reduction/oxidation of a copper center which, when in the Cu(II) form, is tightly spin-coupled to a heme, probably cytochrome o, resulting in a net even spin system and loss of the epr spectrum . The low-spin cytochrome b titrates biphasically with Em7 values of approximately 180 and 280 mV, similar to the high-spin component but without the loss of signal at high potentials.

Chem Pharm Bull (Tokyo), 1990 Mar, 38(3), 794 - 6
Enzymatic sulfation of quercetin by arylsulfotransferase from a human intestinal bacterium; Koizumi M et al.; A novel type of arylsulfotransferase was partially purified from human intestinal bacteria and its enzymatic properties were examined . Polyphenols such as chalcone, xanthone and flavonoid were found to be sulfated by the bacterial arylsulfotransferase though the sulfation activity varied depending upon the positions of the hydroxyl groups . Quercetin, as an example of a flavonol, was rapidly sulfated when p-nitrophenyl sulfate (PNS) was taken as a donor substrate . At a ten-fold molar excess of PNS over quercetin, two products, the 3,3'-disulfate and 3,3',7-trisulfate derivatives, were formed, but the 4'- and 5-hydroxyl groups were not sulfated . In the case of equimolar or two-fold molar excess of PNS to quercetin, only the 3,3'-disulfate was produced and no monosulfate was formed . The enzymatic procedure is useful as a specific and convenient method for the preparation of polyphenol sulfate esters.

Appl Environ Microbiol, 1990 Mar, 56(3), 782 - 7
High diversity in DNA of soil bacteria; Torsvik V et al.; Soil bacterium DNA was isolated by minor modifications of previously described methods . After purification on hydroxyapatite and precipitation with cetylpyridinium bromide, the DNA was sheared in a French press to give fragments with an average molecular mass of 420,000 daltons . After repeated hydroxyapatite purification and precipitation with cetylpyridinium bromide, high-pressure liquid chromatography analysis showed the presence of 2.1% RNA or less, whereas 5-methylcytosine made up 2.9% of the total deoxycytidine content . No other unusual bases could be detected . The hyperchromicity was 31 to 36%, and the melting curve in 1 X SSC (0.15 M NaCl plus 0.015 M sodium citrate) corresponded to 58.3 mol% G+C . High-pressure liquid chromatography analysis of two DNA samples gave 58.6 and 60.8 mol% G+C . The heterogeneity of the DNA was determined by reassociation of single-stranded DNA, measured spectrophotometrically . Owing to the high complexity of the DNA, the reassociation had to be carried out in 6 X SSC with 30% dimethyl sulfoxide added . Cuvettes with a 1-mm light path were used, and the A275 was read . DNA concentrations as high as 950 micrograms ml-1 could be used, and the reassociation rate of Escherichia coli DNA was increased about 4.3-fold compared with standard conditions . C0t1/2 values were determined relative to that for E . coli DNA, whereas calf thymus DNA was reassociated for comparison . Our results show that the major part of DNA isolated from the bacterial fraction of soil is very heterogeneous, with a C0t1/2 about 4,600, corresponding to about 4,000 completely different genomes of standard soil bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

J Bacteriol, 1990 Mar, 172(3), 1250 - 5
Outer membrane polysaccharide deficiency in two nongliding mutants of Cytophaga johnsonae; Godchaux W 3rd et al.; Phenol-extractable polysaccharides firmly associated with the outer membrane of the gliding bacterium Cytophaga johnsonae could be resolved by gel filtration in sodium dodecyl sulfate (SDS) or by SDS-polyacrylamide gel electrophoresis into a high-molecular-weight (H) fraction (excluded by Sephadex G-200) and a low-molecular-weight (L) fraction . Fraction L was rich in components typical of lipid A and the core region of lipopolysaccharide (P, 3-hydroxy fatty acids, and 2-keto-3-deoxyoctonate) and evidently was a lipopolysaccharide with a limited number of distal, repeating polysaccharide units, as judged by SDS-polyacrylamide gel electrophoresis . In relation to total carbohydrate, the H fraction was rich in amino sugar but poor in (possibly devoid of) the lipid A and core components . Two nongliding mutants were highly deficient in the H fraction; one of these was deficient in sulfonolipid but could be cured by provision of a specific sulfonolipid precursor, a process that also resulted in the return of both the H fraction and gliding, as well as the ability to move polystyrene latex spheres over the cell surface . Hence, the polysaccharide may be the component that is directly involved in motility, and the presence of sulfonolipids in the outer membrane is necessary for the synthesis or accumulation of the polysaccharide . This conclusion was reinforced by the fact that the second nongliding, polysaccharide-deficient mutant had a normal sulfonolipid content.

Indian J Med Res, 1990 Mar, 91, 98 - 105
Cultivation of a nocardioform acid-fast chemoautotrophic bacterium from armadillo tissues infected with Mycobacterium leprae; Dastidar SG et al.; A nocardioform bacterium was isolated from the spleen tissue of an armadillo infected with M . leprae and easily propagated in pure culture in mineral salt medium supplemented with only simple C and N sources (e.g., liquid paraffin, tetradecane, ammonium salts, urea, asparagine, gelatin, xanthin, hypoxanthin etc.) . Complex organic substances, e.g., tyrosin, casein, peptone, meat extract, egg proteins, serum, blood, yeast extract as well as medium 199, did not support the growth of this organism . Microscopically, the organism consisted of acid-fast, long, slender rods which originated from long, fragmented hyphae, or sporulating mycelial tufts; it was acid-fast (at less than 4.0% H2SO4) which was pyridine-susceptible . It produced DOPA-oxidase and Catalase and was lysozyme resistant; this grew best under reduced O2 tension, at pH 7.0 to 8.0 and 28 degrees C . Serologically, it appeared to be only weakly related to the prototype human multibacillary leprosy-derived (reference) nocardioform strain, Nocardia brasiliensis and N . caviae, but was variably related to several mycobacteria strains.

J Biol Chem, 1990 Feb 5, 265(4), 1958 - 63
Direct voltammetry of the Chromatium vinosum enzyme, sulfide:cytochrome c oxidoreductase (flavocytochrome c552); Guo LH et al.; The electrochemistry of the enzyme, sulfide:cytochrome c oxidoreductase, also known as flavocytochrome c552 from the purple sulfur bacterium, Chromatium vinosum, has been studied using several modified electrodes . Direct electron transfer between the heme of the flavocytochrome and an electrode is observed in the presence of a redox-inactive cationic species which promotes the voltammetry of the enzyme . Quasi-reversible electron transfer was achieved using the aminoglycoside, neomycin, as a promoter at either a modified gold or polished edge-plane graphite electrode . Further evidence for direct electron transfer is provided by the catalytic response of the enzyme at the electrode in the presence of substrate . Also reported is the direct spectroelectrochemistry of flavocytochrome c552 at an optically transparent thin layer gold electrode modified with Cys-Glu-Cys in the presence of neomycin.

Proc Natl Acad Sci U S A, 1990 Feb, 87(4), 1506 - 10
Protein N-myristoylation in Escherichia coli: reconstitution of a eukaryotic protein modification in bacteria; Duronio RJ et al.; Protein N-myristoylation refers to the covalent attachment of a myristoyl group (C14:0), via amide linkage, to the NH2-terminal glycine residue of certain cellular and viral proteins . Myristoyl-CoA:protein N-myristoyltransferase (NMT) catalyzes this cotranslational modification . We have developed a system for studying the substrate requirements and biological effects of protein N-myristoylation as well as NMT structure-activity relationships . Expression of the yeast NMT1 gene in Escherichia coli, a bacterium that has no endogenous NMT activity, results in production of the intact 53-kDa NMT polypeptide as well as a truncated polypeptide derived from proteolytic removal of its NH2-terminal 39 amino acids . Each E . coli-synthesized NMT species has fatty acid and peptide substrate specificities that are indistinguishable from those of NMT recovered from Saccharomyces cerevisiae, suggesting that the NH2-terminal domain of this enzyme is not required for its catalytic activity . By using a dual plasmid system, N-myristoylation of a mammalian protein was reconstituted in E . coli by simultaneous expression of the yeast NMT1 gene and a murine cDNA encoding the catalytic (C) subunit of cAMP-dependent protein kinase (PK-A) . The fatty acid specificity of N-myristoylation was preserved in this system: {9,10(n)-3H}myristate but not {9,10(n)3H}palmitate was efficiently linked to Gly-1 of the C subunit . {13,14(n)-3H}10-Propoxydecanoic acid, a heteroatom-containing analog of myristic acid with reduced hydrophobicity but similar chain length, was an effective alternative substrate for NMT that also could be incorporated into the C subunit of PK-A . Such analogs have recently been shown to inhibit replication of certain retroviruses that depend upon linkage of a myristoyl group to their gag polyprotein precursors (e.g., the Pr55gag of human immunodeficiency virus type 1) . A major advantage of the bacterial system over eukaryotic systems is the absence of endogenous NMT and substrates, providing a more straightforward way of preparing myristoylated, analog-substituted, and nonmyristoylated forms of a given protein for comparison of their structural and functional properties . The system should facilitate screening of enzyme inhibitors as well as alternative NMT fatty acid substrates for their ability to be incorporated into a specific target protein . Our experimental system may prove useful for recapitulating other eukaryotic protein modifications in E . coli so that structure-activity relationships of modifying enzymes and their substrates can be more readily assessed.

Mol Gen Mikrobiol Virusol, 1990 Feb, (2), 29 - 32
{Transposon mutagenesis, elimination and mobilization of plasmids in nitrogen-fixating bacterium Azospirillum brasilense Sp245}; Katsy EI et al.; The expressed difference in the plasmid profile of A . brasilense Sp245 is registered as a result of Tn5-Mob-mutability . Integration of the vector pSUP5011 into one of the A . brasilense Sp245 plasmid and using of the Tn5-Mob transposon to mobilize the 85Md cryptic plasmid are reported . The properties of A . brasilense Sp245 with the mutant plasmids composition (surface structure, acetylene and nitrate reduction, ability to a number of carbohydrates utilization, formation of melanin, antibiotics resistance specter) have been analyzed . The transposon Tn5-Mob insertion into the 85Md plasmid resulted in isolation of a mutant excreting a melanin-like pigment into the medium . The results suppose 85Md plasmid participation in melaninogenesis.

Oral Microbiol Immunol, 1990 Feb, 5(1), 8 - 11
Actinobacillus actinomycetemcomitans mitogenicity for B cells can be attributed to lipopolysaccharide; Eastcott JW et al.; The purpose of this investigation was to determine the component(s) of whole Actinobacillus actinomycetemcomitans bacteria responsible for B cell mitogenic activity . Congenitally athymic "nude" rats were used as a source of B cells devoid of T lymphocyte activity . Spleen cells were cultured with, or without, whole formalin-killed A . actinomycetemcomitans bacteria or with purified LPS from A . actinomycetemcomitans . Dose-response curves to A . actinomycetemcomitans cells or to A . actinomycetemcomitans-LPS showed that responses were dose dependent . If optimal quantities of both A . actinomycetemcomitans and A . actinomycetemcomitans-LPS were added in combination, the proliferative responses were the same as if either was added alone, i.e., the responses were not additive . Polymyxin B at 2 micrograms/well completely abrogated the proliferative response of athymic rat splenocytes to 10(7) A . actinomycetemcomitans cells or to 1.25 micrograms A . actinomycetemcomitans-LPS/well . Therefore, the in vitro early proliferative response of B cells to A . actinomycetemcomitans can be attributed to the presence of LPS on A . actinomycetemcomitans cells . A considerable portion of the in situ lymphocytic gingival response to A . actinomycetemcomitans infection seen in periodontal disease patients may be a B cell mitogenic response to the LPS of this bacterium.

Appl Microbiol Biotechnol, 1990 Feb, 32(5), 544 - 9
Oriented immobilization of bacterial photosynthetic membrane; Hara M et al.; We have examined a method for oriented immobilization of photosynthetic membrane fragments on a solid surface by specific avidin-biotin interaction . Photosynthetic membrane fragments from the purple non-sulphur photosynthetic bacterium Rhodopseudomonas viridis, of which the H-subunit of the photosynthetic reaction centre was biotinylated, was immobilized on an avidin-adsorbed plate . Orientation of the immobilized membrane on the plastic plate was checked by an antisera binding assay that could react to the respective sides of the membrane: the H-subunit side was selectively adsorbed on the plate . Light-induced potential and current responses could be measured when the membrane immobilized on the SnO2-coated glass plate was dried and sandwiched with a counter electrode of Hg . The electrical response in the immobilized membrane was much improved in comparison with the control (membranes were simply adsorbed on the plate), supporting the idea that the membranes have an orientation on solid surfaces.

Toxicon, 1990, 28(6), 707 - 14
Production of paralytic shellfish toxins by a bacterium Moraxella sp . isolated from Protogonyaulax tamarensis; Kodama M et al.; A bacterium Moraxella sp . isolated from Protogonyaulax tamarensis was cultured in various conditions . Changes of toxicity and toxin components of the cells during culture were analyzed by bioassay and HPLC-fluorometric analysis . Toxin productivity of Moraxella sp . increased when it was cultured in nutrition-deficient environments . The main toxins produced by Moraxella sp . in these conditions were gonyautoxins (GTXs), mainly GTX 1 and 4 which are major toxins of P . tamarensis.

Soc Sci Med, 1990, 30(6), 675 - 91
Cow dung, rock salt, and medical innovation in the Hindu Kush of Pakistan: the cultural transformation of neonatal tetanus and iodine deficiency; Mull DS et al.; In mountain villages of Chitral District in northwestern Pakistan, dried cow dung is used as Westerners would use talcum powder when babies are swaddled and rock salt is consumed in tea and other foods . Both substances are esteemed as conveying beneficial 'heat' and 'strength' . Unfortunately, however, cow dung sometimes contains a bacterium that causes neonatal tetanus, and the resulting toxin may enter through the baby's unhealed umbilical cord and cause death . Further, rock salt contains no iodine, and Chitral's soil is so iodine-deficient that goiter is very common . Thus local health workers advocate use of talcum powder rather than cow dung, immunization against tetanus, and replacement of rock salt by powdered iodized salt . The present report documents widespread community acceptance of these innovations despite the fact that the biomedical model of tetanus and goiter was not well understood and indigenous concepts of the causes of the diseases remained virtually undisturbed . Most of the villagers were Ismaili Muslim followers of the Aga Khan; their receptivity to such health messages was influenced by the high value that their religion places on advancement through 'education' and was correlated with their proximity to Ismaili health workers whom they trusted . A major implication of this research for primary health care programs is that when one is attempting to change existing health practices, explication of biomedical models should not be the only focus of concern . Attentiveness to the context in which behavior changes are introduced and interpreted is at least equally important . Further, the fact that new knowledge was added to the old without replacing it illustrates the complexity of human cognition and points to limitations in the KAP (knowledge-attitude-practice) model of health belief and behavior . This report adds to a small but important body of literature documenting the dynamic nature of medical pluralism in the developing world.

Digestion, 1990, 47(1), 29 - 34
Presence of Helicobacter pylori in patients with non-ulcer dyspepsia revealing normal antral histological characteristics; Loffeld RJ et al.; Two hundred consecutive patients suffering from non-ulcer dyspepsia were studied for the presence of Helicobacter pylori in antral gastritis and normal antral mucosa, using the combination of culture, modified Giemsa stain and a sensitive immunoperoxidase stain as means of detection . H . pylori gastritis was present in 56% of the cases . The bacterium was present in 75% of cases of normal antral mucosa, however, in low numbers . It is concluded that 87% of patients with non-ulcer dyspepsia are H . polory-positive implying a larger role for the micro-organism as initially thought.

J Fr Ophtalmol, 1990, 13(6-7), 333 - 8
{Torpid endophthalmitis in pseudophakia: diagnostic and therapeutic difficulties . Apropos of 4 cases}; Salvanet-Bouccara A et al.; The authors report four cases of chronic endophthalmitis following extracapsular cataract extraction with intraocular lens implantation in the posterior chamber . The first attack of intraocular inflammation occurred in the form of recurrent iridocyclitis two to six months after surgery . The first attack usually responded well to local corticosteroids . After many relapses of inflammation, increasingly resistant to medical treatment, a severe attack occurred leading to the decision to treat such endophthalmitis surgically: endocular fluid aspiration, vitrectomy, intraocular injection of antibiotics combined with systemic antibiotics and corticosteroids . It may be very difficult to prove the infectious origin of torpid endophthalmitis . Growing bacteria from endocular fluid aspirates is much more difficult than in acute endophthalmitis . No organisms were found in this series by this method, despite the fact that fluid aspiration was often performed many times in these 4 cases . A bacterium was identified in 3 cases, twice on the implant itself and once after culture of an iridectomy specimen . Intraocular antibiotic injections resulted in the complete recovery of one patient . Following failure of standard treatment, intraocular lens explantation resulted in the disappearance of infectious inflammatory signs in 3 cases . The treatment of chronic endophthalmitis is governed by the same rules as acute endophthalmitis but is not always as successful . Intraocular lens removal is often the only solution and confirms the pathogenic hypothesis that slime production by organisms, their adherence to the intraocular lens and their quiescent state make them less vulnerable to antibiotics and host defences.

Bull Mem Acad R Med Belg, 1990, 145(3-4), 184 - 8; discussion 189-92
{Lyme disease: clinical and sero-epidemiological study of Borrelia burgdorferi infections in Belgium}; Bigaignon G; Lyme disease is a multi-systemic infection caused by the spirochaete Borrelia burgdorferi: this bacterium, discovered in 1982 in the United States, is mainly transmitted by a tick bite, Ixodes ricinus in Europe . In Belgium, a first seroepidemiological study of 3 years has revealed 190 patients and the whole spectrum of clinical pictures was observed, including the early stage of this infection in the skin (erythema chronicum migrans), neurological involvement and arthritis . The Lyme borreliosis is endemic in our country: the incidence ranges from low near the coast to high in the south-eastern part of Belgium.

Reprod Nutr Dev, 1990, Suppl 2, 203s - 204s
{O-demethylation and metabolism of the methoxyl group of vanillic acid, monomer model of lignin, by the rumen bacterium Syntrophococcus sucromutans}; Dore J et al.; The O-demethylation of a lignin monomer by washed cells of the rumen bacterium S sucromutans was studied using chemically synthesized O-{methyl-14C}vanillate . During cometabolism of pyruvate and vanillate, the label from the methoxyl group was incorporated into acetate, the sole product, which was singly labeled in the methyl group.

J Bacteriol, 1990 Jan, 172(1), 419 - 23
Energy-dependent uptake of 4-chlorobenzoate in the coryneform bacterium NTB-1; Groenewegen PE et al.; The uptake of 4-chlorobenzoate (4-CBA) in intact cells of the coryneform bacterium NTB-1 was investigated . Uptake and metabolism of 4-CBA were observed in cells grown in 4-CBA but not in glucose-grown cells . Under aerobic conditions, uptake of 4-CBA occurred with a high apparent affinity (apparent Kt, 1.7 microM) and a maximal velocity (Vmax) of 5.1 nmol min-1 mg of protein-1 . At pH values below 7, the rate of 4-CBA uptake was greatly reduced by nigericin, an ionophore which dissipates the pH gradient across the membrane (delta pH) . At higher pH values, inhibition was observed only with valinomycin, an ionophore which collapses the electrical potential across the membrane (delta psi) . Under anaerobic conditions, no uptake of 4-CBA was observed unless an alternative electron acceptor was present . With nitrate as the terminal electron acceptor, 4-CBA was rapidly accumulated by the cells to a steady-state level, at which uptake of 4-CBA was balanced by excretion of 4-hydroxybenzoate . The mechanism of energy coupling to 4-CBA transport under anaerobic conditions was further examined by the imposition of an artificial delta psi, delta pH, or both . Uptake of 4-CBA was shown to be coupled to the proton motive force, suggesting a proton symport mechanism . Competition studies with various substrate analogs revealed a very narrow specificity of the 4-CBA uptake system . This is the first report of carrier-mediated transport of halogenated aromatic compounds in bacteria.

Proteins, 1990, 8(4), 352 - 64
The structure of rubredoxin from Desulfovibrio desulfuricans strain 27774 at 1.5 A resolution; Stenkamp RE et al.; The structure of a small rubredoxin from the bacterium Desulfovibrio desulfuricans has been determined and refined at 1.5 A resolution . The hairpin loop containing seven residues in other rubredoxins is missing in this 45 residue molecule, and once that fact was determined by amino acid sequencing studies, refinement progressed smoothly to an R value of 0.093 for all reflections from 5 to 1.5 A resolution . Nearly all of the water molecules in the well-ordered triclinic unit cell have been added to the crystallographic model . As in the other refined rubredoxin models, the Fe-S4 complex is slightly distorted from ideal tetrahedral coordination.

Enzyme Microb Technol, 1990 Jan, 12(1), 28 - 32
NADH production from NAD+ with a formate dehydrogenase system involving immobilized cells of a methylotrophic Arthrobacter strain; Nath PK et al.; A convenient and economical method of NADH production from NAD+ has been established using a formate dehydrogenase system involving immobilized cells of a methanol-utilizing bacterium . Arthrobacter sp, KM62 . Four kinds of cell entrapment were studied . An immobilized cell preparation showing a high NADH production activity was obtained by entrapment in a kappa-carrageenan gel lattice . The NADH-producing activity of the immobilized cells was investigated under various conditions . The NADH-producing activity was evoked on the addition of Triton X-100 to the reaction mixture . The conditions for the continuous production of NADH with an immobilized cell column were also investigated . When a reaction mixture containing 10 mumol (6.63 mg) ml-1 NAD+ was passed through the column (1.2 x 20 cm) containing 1.62 g (as dry weight) of immobilized cells, at a space velocity of 0.125 at 35 degrees C, complete conversion was attained.

Biochemistry, 1989 Dec 26, 28(26), 9898 - 904
Isolation of a photoactive photosynthetic reaction center-core antenna complex from Heliobacillus mobilis; Trost JT et al.; A photoactive reaction center-core antenna complex was isolated from the photosynthetic bacterium Heliobacillus mobilis by extraction of membranes with Deriphat 160c followed by differential centrifugation and sucrose density gradient ultracentrifugation . The purified complex contained a Mr 47,000 polypeptide(s) that bound both the primary donor (P800) and approximately 24 antenna bacteriochlorophylls g . Time-resolved fluorescence emission spectroscopy indicated that the antenna bacteriochlorophylls g are active in energy transfer to P800, exhibiting a decay time of 25 ps . The complex contained 1.4 menaquinones, 9 Fe, and 3 labile S2- per P800 . The complex was photoactive with an exponential decay time of 14 ms for P800+ yet showed no EPR-detectable Fe-S center signal in the g less than or equal to 2.0 region, either by chemical reduction to -600 mV or by illumination of reduced samples . The complex is similar to photosystem I of oxygen-evolving photosynthetic systems in that both the primary donor and a core antenna are bound to the same pigment-protein complex.

Gene, 1989 Dec 21, 85(1), 115 - 24
Type 1 fimbriae of Escherichia coli as carriers of heterologous antigenic sequences; Hedegaard L et al.; A strategy has been designed for the construction of recombinant bacterial strains which eventually may become useful as live vaccines and which may also be relevant for the preparation of conventional vaccines . The approach used is the fusion of small antigenic peptide sequences into specific segments of a protein whose location on the bacterial surface ensures that the recombinant organism is able to present the inserted antigen to the host (animal or human) infected by the bacterium . The chosen surface protein is a naturally occurring polymer of Escherichia coli, viz., type 1 fimbriae . The results obtained show that fusion of such foreign sequences into selected points of the structural protein of the fimbriae results in the production of functionally normal type 1 fimbriae . Furthermore, hybrid fimbriae carrying such small epitope sequences can be recognized by antibodies directed against the foreign parent protein . This observation is an important prerequisite for the eventual design of useful vaccines . The analysis of the fimbrial protein and its potential as a carrier of foreign peptides from hepatitis B surface antigen, foot-and-mouth disease virus and poliovirus indicated that there may be several positions in the protein which may turn out to be relevant for this purpose and be important fusion sites.

EMBO J, 1989 Dec 20, 8(13), 3951 - 61
Mutations conferring resistance to quinol oxidation (Qz) inhibitors of the cyt bc1 complex of Rhodobacter capsulatus; Daldal F et al.; Several spontaneous mutants of the photosynthetic bacterium Rhodobacter capsulatus resistant to myxothiazol, stigmatellin and mucidin--inhibitors of the ubiquinol: cytochrome c oxidoreductase (cyt bc1 complex)--were isolated . They were grouped into eight different classes based on their genetic location, growth properties and inhibitor cross-resistance . The petABC (fbcFBC) cluster that encodes the structural genes for the Rieske FeS protein, cyt b and cyt c1 subunits of the cyt bc1 complex was cloned out of the representative isolates and the molecular basis of inhibitor-resistance was determined by DNA sequencing . These data indicated that while one group of mutations was located outside the petABC(fbcFBC) cluster, the remainder were single base pair changes in codons corresponding to phylogenetically conserved amino acid residues of cyt b . Of these substitutions, F144S conferred resistance to myxothiazol, T163A and V333A to stigmatellin, L106P and G152S to myxothiazol + mucidin and M140I and F144L to myxothiazol + stigmatellin . In addition, a mutation (aer126) which specifically impairs the quinol oxidase (Qz) activity of the cyt bc1 complex of a non-photosynthetic mutant (R126) was identified to be a glycine to an aspartic acid replacement at position 158 of cyt b . Six of these mutations were found between amino acid residues 140 and 163, in a region linking the putative third and fourth transmembrane helices of cyt b . The non-random clustering of several inhibitor-resistance mutations around the non-functional aer126 mutation suggests that this region may be involved in the formation of the Qz inhibitor binding/quinol oxidation domain(s) of the cyt bc1 complex . Of the two remaining mutations, the V333A replacement conferred resistance to stigmatellin exclusively and was located in another region toward the C terminus of cyt b . The L106P substitution, on the other hand, was situated in the transmembrane helix II that carries two conserved histidine residues (positions 97 and 111 in R . capsulatus) considered to be the axial ligands for the heme groups of cyt b . The structural and functional roles of the amino acid residues involved in the acquisition of Qz inhibitor resistance are discussed in terms of the primary structure of cyt b and in relation to the natural inhibitor-resistance of various phylogenetically related cyt bc/bf complexes.

Nucleic Acids Res, 1989 Dec 11, 17(23), 9531 - 41
Strong structural effect of the position of a single acetylaminofluorene adduct within a mutation hot spot; Koehl P et al.; The NarI restriction enzyme recognition site, G1G2CG3CC, has been identified as a hotspot for -2 frameshift mutations induced by N-2-acetylaminofluorene (AAF) on the basis of a forward mutation assay in plasmid pBR322 in the bacterium Escherichia coli . AAF binds primarily to the C-8 position of guanine residues, and the three guanines of the NarI site are similarly reactive . Despite this similar chemical reactivity, only binding of AAF to the G3 residue causes the -2 frameshift mutations . To study the mechanisms underlying the specificity of the mutagenic processing further, we monitored the structural changes induced by a single AAF adduct within the NarI site by means of CD spectroscopy and thermal denaturation . The NarI sequence was studied as part of the 12-mer ACCGGCGCCACA . The purification and characterization of the three isomers having a single AAF adduct covalently bound to one of the three guanines of this 12 mer are described . The analysis of the melting profiles of the duplexes formed when these three isomers are annealed with the oligonucleotide of complementary sequence shows the same destabilizing effect of the AAF adduct on the three DNA helices . It is also shown, from the CD spectra, that modification of guanine G1 or G2 by AAF does not induce major changes in the helical structure of DNA . On the other hand, modification of guanine G3 induces a change in the CD signal that suggests the formation of a local left handed structure within the 12-mer duplex . These results show the polymorphic nature of the DNA structure in the vicinity of an AAF adduct.

Eur J Biochem, 1989 Dec 8, 186(1-2), 175 - 80
ATP synthesis coupled to methane formation from methyl-CoM and H2 catalyzed by vesicles of the methanogenic bacterial strain Gö1; Peinemann S et al.; Methanogenesis from methyl-CoM and H2, as catalyzed by inside-out vesicle preparations of the methanogenenic bacterium strain Go1, was associated with ATP synthesis . That this ATP synthesis proceeded via an uncoupler-sensitive transmembrane proton gradient was concluded from the following results: 1 . Various inhibitors that affected methane formation (e.g . 2-bromomethanesulfonate) also prevented ATP synthesis . 2 . The protonophore 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile, in combination with the K+ ionophore valinomycin, inhibited ATP synthesis completely without affecting methanogenesis . 3 . The ATP synthase inhibitor diethylstilbestrol inhibited ATP synthesis . 4 . Addition of the detergent sulfobetaine inhibited both methane formation and ATP synthesis; the former but not the latter could be restored by adding titanium(III) citrate as electron donor . In addition it was shown that ATP synthesis could also be driven by transmembrane proton gradients artificially imposed on the vesicles . Furthermore net methanogenesis-dependent ATP formation was shown by measuring {32P}phosphate incorporation.

Eur J Biochem, 1989 Dec 8, 186(1-2), 317 - 23
Dependence on membrane components of methanogenesis from methyl-CoM with formaldehyde or molecular hydrogen as electron donors; Deppenmeier U et al.; Methane formation from 2-(methylthio)-ethanesulfonate (methyl-CoM) and H2 by the soluble fraction from the methanogenic bacterium strain Go1 was stimulated up to tenfold by the addition of the membrane fraction . This stimulation was observed with membranes from various methanogenic species belonging to different phylogenetic families, but not with membranes from Escherichia coli or Acetobacterium woodii . Treatment of the membranes with strong oxidants, i.e . O2 and K3{Fe(CN)6}, or with SH reagents, i.e . Ag+, p-chloromercuribenzoate or iodoacetamide, caused an irreversible decrease or loss in stimulatory activity, as did heat treatment at temperatures above 78 degrees C . Methanogenesis from methyl-CoM with formaldehyde instead of H2 as electron donor depended similarly on the membrane fraction . With membranes, 1 mol HCHO was oxidized to 1 mol CO2 and allowed the formation of 2 mol CH4 from 2 mol CH3-CoM . Without membranes, per mol of HCHO oxidized 1 mol H2 was formed and 1 mol CH4 was produced from CH3-CoM; the rate was 10-20% of that in the presence of membranes . When methyl-CoM was replaced by an artificial electron acceptor system consisting of methylviologen and metronidazole, the formaldehyde-oxidizing activity was no longer stimulated by the membrane fraction . These results demonstrate for the first time an essential function of membrane components in methanogenic electron transfer.

Behav Neurosci, 1989 Dec, 103(6), 1348 - 55
Random-walk chemotaxis: trial and error as a control process; Marken RS et al.; The biased random-walk chemotaxis of the bacterium Escherichia coli is a remarkably effective method of navigation based on random trial-and-error responding rather than steering . Humans restricted to the same mode of responding are able to navigate to target locations, just like the bacterium . This mode of navigation can be modeled as an input control process that selectively retains favorable and rejects unfavorable consequences of the random responses . The selection process is determined by the internal organization of the system rather than the external influence of the environment (as in natural selection or reinforcement).

Biomed Environ Sci, 1989 Dec, 2(4), 366 - 75
Effect of tributyltin on Escherichia coli: role of modifying factors; Singh K; The effects of inorganic and organic tin compounds and various factors affecting the toxicity of the latter to Escherichia coli were studied . In comparison to stannous chloride, tributyltin chloride (TBTC) was more inhibitory to the growth of the test organism; this may be due to its greater liposolubility and ready absorption through the bacterial membrane . The toxicity of TBTC to E . coli was modulated by various factors, such as pH, sulfate and chloride ions, and the presence of glucose, succinate, and reducing agents like cysteine and dithiothreitol (DTT) . TBTC was more toxic to cells in minimal than in complex media . Similarly, this compound was more inhibitory to the growth of E . coli at acid pH than at basic pH . Succinate in contrast to glucose, when used as a carbon source, made the bacterium more sensitive to TBTC . Cysteine and DTT (both at a final concentration of 0.5 mM) partially protected the cells against the inhibitory effect of this agent.

Radiat Res, 1989 Dec, 120(3), 537 - 44
Evidence for the cloning of Deinococcus radiodurans DNA fragments that render Escherichia coli radiation resistant; Barrows LR; DNA from the radiation-resistant bacterium Deinococcus radiodurans was isolated and used to generate a cosmid library . This cosmid library was grown in Escherichia coli and radiation-resistant E . coli were isolated . Following exposure to 1000 Gy the radiation-resistant transformants exhibited a survival of approximately 10(-1) instead of the 10(-11) exhibited by the nontransformed E . coli . Smaller fragments of DNA were subcloned from the radiation-resistant E . coli; these fragments bestow similar levels of radiation resistance (ratio of slopes = 6.8) to native E . coli upon transfection.

Hua Xi Yi Ke Da Xue Xue Bao, 1989 Dec, 20(4), 441 - 4
{A serological survey of Legionnaires' disease in domestic fowls and animals in Chengdu area}; Liu HC et al.; A serological survey of antibodies against Legionella pneumophila (Lp) serotypes in Chengdu area by microagglutination test showed that there were high levels of antibodies against serotypes Lp1 and Lp6 in healthy domestic fowls and animals (rabbits, pigs, chickens, ducks and geese) . In rabbits, antibodies against serotypes Lp1-Lp6 were determined, showing positive rates (titer greater than or equal to 1:16) ranging 6.3-23.8% . Among them only the serotype Lp3 did not show any positive one . The highest positive rate was observed in pigs' anti-Lp6 (89.8%), significantly higher than those reported in America, Denmark and Nanjing, China . The results suggested that recessive infections of Legionnaires' Disease Bacterium might occur in domestic fowls and animals . So the epidemiological surveillance of Legionnaires' disease in animals, as well as in environment (water and soil) is of importance for the prevention in man.

Semin Respir Infect, 1989 Dec, 4(4), 284 - 92
Prevention of pertussis; Anderson EL; Pertussis (whooping cough) is an acute respiratory disease caused by Bordetella pertussis . It occurs worldwide and is an important cause of morbidity and mortality in areas where immunization rates are low, particularly among children less than 1 year of age . The characteristic presentation of pertussis is paroxysmal coughing followed by a long inspiratory effort that produces the classic whoop . Lymphocytosis is frequently present . Complications include pneumonia and seizures secondary to hypoxia . The paroxysmal and convalescent stages of the illness can each last several weeks . Transmission occurs readily by respiratory droplets, and atypical or mild cases in older children and adults can be important in spread of the infection . Isolation, early erythromycin therapy, and erythromycin prophylaxis can reduce transmission, but vaccination is the primary means of control . An inactivated whole cell suspension of the bacterium has been an effective vaccine for protecting against pertussis since the 1950s, but whole cell vaccine may allow mild infections to occur and has been associated with local and systemic reactions that have eroded public acceptance . Component or acellular pertussis vaccines that are less reactogenic have been in use in Japan since 1981 and appear to be effective there . Development of an acellular preparation that is equally or more efficacious than whole cell vaccine may be possible, but clinical trials for measurement of protection against pertussis are difficult and trials with new pertussis vaccines will have to be carefully performed to avoid the controversies generated by earlier trials.

FEBS Lett, 1989 Nov 20, 258(1), 175 - 6
Crystallization and preliminary X-ray crystallographic study of the quinoprotein methanol dehydrogenase from bacterium W3A1; Xia ZX et al.; Methanol dehydrogenase from bacterium W3A1 has been crystallized by the macroseeding method to give single crystals suitable for three-dimensional structural study at resolution greater than 3 A . The crystals belong to the group P2(1), and have unit cell dimensions a = 124.13 A, b = 62.87 A, c = 84.71 A, and beta = 92.89 degrees . There is one dimeric molecule of 114,600 Da per asymmetric unit.

Arch Biochem Biophys, 1989 Nov 15, 275(1), 244 - 51
The action of free radicals on Deinococcus radiodurans carotenoids; Carbonneau MA et al.; The possible role of carotenoids as free radical scavengers has not been completely elucidated . To gain further insight into the quenching of OH radicals by carotenoids, we used a feasible bacterial model, Deinococcus radiodurans, a red pigmented bacterium . We compared the action of H2O2 which produces in vivo OH radicals by a Fenton-type reaction on the parental and two mutant strains, i.e., a red pigmented and a colorless one . While the red pigmented bacteria were resistant to H2O2 action, the colorless strain was significantly more sensitive and its sensitivity was dose-dependent . In the red pigmented strains, H2O2 induced a significant decrease in one carotenoid (X5), which could be responsible for the antioxidant activity.

Mol Cell Biol, 1989 Nov, 9(11), 4767 - 76
Interactions between yeast photolyase and nucleotide excision repair proteins in Saccharomyces cerevisiae and Escherichia coli; Sancar GB et al.; The PHR1 gene of Saccharomyces cerevisiae encodes a DNA photolyase that catalyzes the light-dependent repair of pyrimidine dimers . In the absence of photoreactivating light, this enzyme binds to pyrimidine dimers but is unable to repair them . We have assessed the effect of bound photolyase on the dark survival of yeast cells carrying mutations in genes that eliminate either nucleotide excision repair (RAD2) or mutagenic repair (RAD18) . We found that a functional PHR1 gene enhanced dark survival in a rad18 background but failed to do so in a rad2 or rad2 rad18 background and therefore conclude that photolyase stimulates specifically nucleotide excision repair of dimers in S . cerevisiae . This effect is similar to the effect of Escherichia coli photolyase on excision repair in the bacterium . However, despite the functional and structural similarities between yeast photolyase and the E . coli enzyme and complementation of the photoreactivation deficiency of E . coli phr mutants by PHR1, yeast photolyase failed to enhance excision repair in the bacterium . Instead, Phr1 was found to be a potent inhibitor of dark repair in recA strains but had no effect in uvrA strains . The results of in vitro experiments indicate that inhibition of nucleotide excision repair results from competition between yeast photolyase and ABC excision nuclease for binding at pyrimidine dimers . In addition, the A and B subunits of the excision nuclease, when allowed to bind to dimers before photolyase, suppressed photoreactivation by Phr1 . We propose that enhancement of nucleotide excision repair by photolyases is a general phenomenon and that photolyase should be considered an accessory protein in this pathway.

Appl Environ Microbiol, 1989 Nov, 55(11), 2819 - 26
Degradation of chlorinated aliphatic hydrocarbons by Methylosinus trichosporium OB3b expressing soluble methane monooxygenase; Oldenhuis R et al.; Degradation of trichloroethylene (TCE) by the methanotrophic bacterium Methylosinus trichosporium OB3b was studied by using cells grown in continuous culture . TCE degradation was a strictly cometabolic process, requiring the presence of a cosubstrate, preferably formate, and oxygen . M . trichosporium OB3b cells degraded TCE only when grown under copper limitation and when the soluble methane monooxygenase was derepressed . During TCE degradation, nearly total dechlorination occurred, as indicated by the production of inorganic chloride, and only traces of 2,2,2-trichloroethanol and trichloroacetaldehyde were produced . TCE degradation proceeded according to first-order kinetics from 0.1 to 0.0002 mM TCE with a rate constant of 2.14 ml min-1 mg of cells-1 . TCE concentrations above 0.2 mM inhibited degradation in cell suspensions of 0.42 mg of cells ml-1 . Other chlorinated aliphatics were also degraded by M . trichosporium OB3b . Dichloromethane, chloroform, 1,1-dichloroethane, and 1,2-dichloroethane were completely degraded, with the release of stoichiometric amounts of chloride . trans-1,2-Dichloroethylene, cis-1,2-dichloroethylene, and 1,2-dichloropropane were completely converted, but not all the chloride was released because of the formation of chlorinated intermediates, e.g., trans-2,3-dichlorooxirane, cis-2,3-dichlorooxirane, and 2,3-dichloropropanol, respectively . 1,1,1-Trichloroethane, 1,1-dichloroethylene, and 1,3-dichloropropylene were incompletely converted, and the first compound yielded 2,2,2-trichloroethanol as a chlorinated intermediate . The two perchlorinated compounds tested, carbon tetrachloride and tetrachloroethylene, were not converted.

Infect Immun, 1989 Nov, 57(11), 3364 - 71
Adhesion and ultrastructural properties of human enterotoxigenic Escherichia coli producing colonization factor antigens III and IV; Knutton S et al.; Human enterotoxigenic Escherichia coli (ETEC) producing colonization factor antigen III (CFA/III) and coli surface antigens 4, 5, and 6 (CS4, CS5, and CS6) of CFA/IV were examined ultrastructurally and for ability to adhere to human small intestinal enterocytes and to cultured human intestinal mucosa . Strains of serotypes O25:H-, O25:H42, and O167:H5 producing CFA/III plus CS6, CS4 plus CS6, and CS5 plus CS6, respectively, showed good adhesion to human enterocytes (1.8 to 4.2 bacteria per brush border) and cultured human intestinal mucosa, whereas variants lacking these antigens or producing only CS6 were nonadherent (0 to 0.03 bacterium per brush border) . By electron microscopy, CFA/III, CS4, and CS5 appeared as morphologically distinct rodlike fimbriae: CFA/III was 7 to 8 nm in diameter, CS4 was 6 to 7 nm in diameter, and CS5 was 5 to 6 nm in diameter . CS5 was unusual in that it appeared to be composed of two fine fibrils arranged in a double-helical structure . CS6 was difficult to characterize morphologically but possibly has a very fine fibrillar structure . By specific fimbrial staining and immunoelectron microscopy . CS4 and CS5 were shown to promote mucosal adhesion of ETEC; a similar adhesion role for the CS6 antigen could not be confirmed . ETEC strains of serotypes O27:H7, O27:H20, O148:H28, and O159:H20 which produced CS6 showed good adhesion to human enterocytes (1.6 to 3.0 bacteria per brush border), whereas variants which lacked CS6 were nonadherent (0 to 0.01 bacterium per brush border) . These strains, however, also produced fimbrial or fibrillar surface antigens, in addition to CS6, which probably represent additional coli surface antigens responsible for the observed adhesive properties of these ETEC serotypes.

Mol Gen Genet, 1989 Nov, 219(3), 445 - 52
Cloning and sequencing of the fbcF, B and C genes encoding the cytochrome b/c1 complex from Rhodopseudomonas viridis; Verbist J et al.; The complete nucleotide sequence of the genes encoding the Rieske FeS, the cytochrome b and the cytochrome c1 subunits of the ubiquinol-cytochrome c2 oxidoreductase from the photosynthetic purple bacterium Rhodopseudomonas viridis, and the derived amino acid sequences are presented . These three genes, fbcF, fbcB and fbcC, are located at contiguous sites of the genome . The DNA-deduced amino acid sequences are compared with known primary structures of corresponding proteins from other purple photosynthetic bacteria, as well as mitochondria, cyanobacteria and chloroplasts.

AIDS, 1989 Nov, 3(11), 751 - 3
Disseminated cat-scratch disease in a patient with AIDS; van der Wouw PA et al.; A patient with AIDS developed subcutaneous nodules and associated osteolytic lesions with negative stains and cultures for bacteria, fungi and parasites . Flucloxacillin was not effective but treatment with vancomycin was associated with improvement . Six months later the patient became severely ill, with fever, malaise and multiple skin and laryngeal papules . Cat-scratch disease was diagnosed from the typical epithelioid angiomatosis seen in skin biopsies with bacterium-like structures in the Warthin-Starry stain . Retrospectively these typical structures were also seen in earlier biopsies . All lesions improved after therapy with erythromycin had been instituted.

Orv Hetil, 1989 Oct 8, 130(41), 2195 - 7
{Mass screening of neonates for histidinemia}; Havass Z et al.; The authors report on newborn mass-screening for histidinemia by Guthrie bacterium inhibition assay . 51,618 newborns were screened and 805 cases with more than 5 mg% histidine blood level were found . A second test, urocanic acid thin-layer chromatography was done from these samples . According to these tests no histidinemic patient was detected . It is worth mentioning that blood histidine level exceeded 20 mg% in 55 cases from 805 newborns . Considering our screening results, the low incidence and the relatively good prognosis of the disease, a mass-screening in Hungary is not necessary.

Appl Environ Microbiol, 1989 Oct, 55(10), 2601 - 6
Growth and luminescence of the bacterium Xenorhabdus luminescens from a human wound; Colepicolo P et al.; Xenorhabdus luminescens, a newly isolated luminous bacterium collected from a human wound, was characterized . The effects of ionic strength, temperature, oxygen, and iron on growth and development of the bioluminescent system were studied . The bacteria grew and emitted light best at 33 degrees C in a medium with low salt, and the medium after growth of cells to a high density was found to have antibiotic activity . The emission spectrum peaked at 482 nm in vivo and at 490 nm in vitro . Both growth and the development of luminescence in X . luminescens required oxygen and iron . The isolated luciferase itself exhibited a temperature optimum at about 40 degrees C; after purification by affinity chromatography, it showed two bands (52 and 41 kilodaltons) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicative of an alpha and beta subunit structure . Reduced flavin mononucleotide (Km of 1.4 microM) and tetradecanal (Km of 2.1 microM) were the best substrates for the luciferase, and the first-order decay constant under these conditions at 37 degrees C was 0.79 s-1.

J Clin Microbiol, 1989 Oct, 27(10), 2388 - 90
Establishment of 2-docosanol as a cellular marker compound in the identification of Mycobacterium xenopi; Larsson L et al.; Sixteen strains of Mycobacterium xenopi were studied by gas chromatography and thin-layer chromatography . Data on the cellular fatty acids, fatty alcohols, mycolic acids, and glycolipids indicated that this bacterium possesses a specific lipid composition . 2-Docosanol, detected in all studied strains, was found to constitute a useful chemical marker in the identification of M . xenopi.

J Gen Microbiol, 1989 Oct, 135 ( Pt 10), 2735 - 41
Characterization of soluble fibronectin binding to Bacille Calmette-Guérin; Aslanzadeh J et al.; Fibronectin (FN), a 420 kDa glycoprotein, consists of two similar subunits linked by a disulphide bond near the C-terminal end . FN is present in soluble and matrix forms in various body fluids and tissues and has been shown to bind to variety of organisms . We characterized the conditions required for 125I-FN binding to Bacille Calmette-Guerin (BCG) . The binding was dose-dependent, reached saturation within 3 min, and was essentially irreversible for at least 24 h under optimal binding conditions at pH 6.0 . In contrast, the binding was reversible (greater than 90% in 24 h) when the pH was increased to 10.0 . Scatchard analysis of the dose-response experiments produced a straight line, suggesting the presence of a single class of FN receptor on BCG . 125I-FN binding was trypsin-sensitive, suggesting that the BCG-binding molecule is a protein . The number of FN receptors was determined to be 8000-15,000 per bacterium . 125I-FN binding was pH dependent, with maximal binding at acidic pH . 125I-FN binding was sensitive to the presence of NaCl, with 0.08 M-NaCl inhibiting binding by 85% . These data demonstrate that soluble FN binds to a trypsin-sensitive cell-surface component of BCG in an essentially irreversible manner.

J Bacteriol, 1989 Oct, 171(10), 5473 - 8
Sodium dependence of acetate formation by the acetogenic bacterium Acetobacterium woodii; Heise R et al.; Growth of Acetobacterium woodii on fructose was stimulated by Na+; this stimulation was paralleled by a shift of the acetate-fructose ratio from 2.1 to 2.7 . Growth on H2-CO2 or on methanol plus CO2 was strictly dependent on the presence of sodium ions in the medium . Acetate formation from formaldehyde plus H2-CO by resting cells required Na+, but from methanol plus H2-CO did not . This is analogous to H2-CO2 reduction to methane by Methanosarcina barkeri, which involves a sodium pump (V . Muller, C . Winner, and G . Gottschalk, Eur . J . Biochem . 178:519-525, 1988) . This suggests that the reduction of methylenetetrahydrofolate to methyltetrahydrofolate is the Na+-requiring reaction . A sodium gradient (Na+ out/Na+ in = 32, delta pNa = -91 mV) was built up when resting cells of A . woodii were incubated under H2-CO2 . Acetogenesis was inhibited when the delta pNa was dissipated by monensin.

Mikrobiyol Bul, 1989 Oct, 23(4), 348 - 55
{In vitro reaction between methylene blue and the chromosomal DNA of E . coli}; Izbirak A; In the present work, the chromosomal DNA isolated from the bacterium E . coli was treated with methylene blue . Formation of a heat-stable complex with methylene blue and E . coli chromosomal DNA, has changed the hyperchromic characteristics of E . coli DNA to some extent . It seemed possible that in vivo binding of the dye with DNA may inhibit the separation of DNA chains thus preventing the DNA replication.

Infect Immun, 1989 Oct, 57(10), 2938 - 41
Surface-exposed and antigenically conserved determinants of outer membrane proteins of Branhamella catarrhalis; Murphy TF et al.; The outer membrane proteins (OMPs) of Branhamella catarrhalis were studied in an effort to identify surface-exposed determinants that are conserved among strains of the bacterium . Aliquots of polyclonal antiserum were absorbed individually by strains of B . catarrhalis . The absorbed antisera were tested in comparison with unabsorbed antiserum in an immunoblot assay against OMPs of the homologous strain . The absence of a band recognized by antibodies in the absorbed antiserum compared with the unabsorbed antiserum indicated that surface-exposed determinants of the absorbing strain cross-reacted with determinants on the homologous strain . Two antisera were absorbed individually by 20 strains of B . catarrhalis, and the absorbed sera were studied in this way in immunoblot assays . OMP E (molecular weight, ca . 56,000) expresses surface-exposed determinants that are shared among 17 of the 20 strains studied . Antibodies to OMP G (molecular weight, 28,000) were absorbed from both antisera by 14 of the 20 strains . These studies demonstrate that OMP E and OMP G express determinants that are exposed on the surface of the intact bacterium . Furthermore, these determinants are antigenically conserved among a majority of strains of B . catarrhalis . On the basis of these observations, OMPs E and G should be considered when bacterial antigens are evaluated as potential vaccine candidates.

Eur J Biochem, 1989 Sep 1, 184(1), 15 - 9
Purification and properties of a polyol dehydrogenase from the phototrophic bacterium Rhodobacter sphaeroides; Schneider KH et al.; A polyol dehydrogenase was detected in cell extracts of the facultative phototrophic bacterium Rhodobacter sphaeroides strain Si 4 grown on D-glucitol (sorbitol) as the sole carbon source . The enzyme was purified 150-fold to apparent homogeneity by steps involving fractionated (NH4)2SO4 precipitation, chromatography on Q-Sepharose and phenyl-Sepharose, and FPLC on Superose 12 . The relative molecular mass (Mr) of the native polyol dehydrogenase was 47,200 as calculated from its Stokes' radius (rs = 2.76 nm) and sedimentation coefficient (s20, w = 4.15 S) . SDS/PAGE resulted in one single band representing a polypeptide with a Mr of 52,200, indicating that the native protein is a monomer . The isoelectric point of the polyol dehydrogenase was determined to be pH 4.3 . The enzyme was specific for NAD+ and oxidized both D-glucitol and D-mannitol to D-fructose, as well as D-arabinitol to D-ribulose . The pH optimum of substrate oxidation was pH 9.0 in 0.1 M Tris/HCl and that of substrate reduction was pH 6.5 in 0.1 M potassium phosphate . The reactions exhibited normal Michaelis-Menten kinetics allowing the estimation of KM values for NAD+ (0.18 mM) in the presence of D-glucitol, and for D-glucitol (31.8 mM), D-mannitol (0.29 mM) and D-arabinitol (1.8 mM), respectively . The KM value for D-fructose was 16.3 mM and that for NADH 0.02 mM . The equilibrium constants determined for the conversion of D-mannitol, D-glucitol and D-arabinitol were 4.5 nM, 0.58 nM and 80 pM, respectively . Based on the catalytic preference of the polyol dehydrogenase for D-mannitol, an enzymatic assay for D-mannitol was elaborated.

Infect Immun, 1989 Sep, 57(9), 2705 - 11
Chlamydia trachomatis-induced production of interleukin-1 by human monocytes; Rothermel CD et al.; Human diseases caused by the intracellular bacterium Chlamydia trachomatis include genital tract infections and blinding trachoma . Chlamydial infections are characterized by chronic inflammation and scarring, and development of such complications is thought to be immunologically mediated . In this study, we show that coculture of C . trachomatis (serovar L2) with human blood monocytes induced the production of interleukin-1 (IL-1), an important mediator of inflammation, tissue remodeling, and scarring . IL-1 was produced in response to UV-inactivated elementary bodies containing from 0.1 to 50 micrograms of protein per ml, with a maximal response at 5 to 10 micrograms/ml . IL-1 activity was detected by 6 h of incubation and was maximal by 24 h . Peak levels were maintained throughout 96 h of incubation . Rabbit antibody to human IL-1(alpha + beta) effectively neutralized the thymocyte-stimulating activity of the supernatants . The apparent molecular weight of chlamydia-induced IL-1 was 16,000, as determined by gel filtration on a Bio-Gel P-60 column . Isoelectric focusing yielded two peaks of activity, with pIs of 5.5 and 6.9 . Neutralization studies with antisera against human IL-1 alpha and IL-1 beta showed that the acidic and neutral peaks corresponded to IL-1 alpha and IL-1 beta, respectively, with IL-1 beta predominating . Heat-killed chlamydiae, which are not internalized by monocytes, were effective IL-1 inducers, indicating that phagocytosis was not required for IL-1 induction . Purified C . trachomatis lipopolysaccharide was also an effective IL-1 inducer, suggesting that the response to intact organisms may be largely a response to chlamydial lipopolysaccharide . Finally, purified chlamydial major outer membrane protein induced low but detectable IL-1 activity.

J Bacteriol, 1989 Sep, 171(9), 5039 - 47
Topology and acylation of spiralin; Wroblewski H et al.; Of the 51 polypeptides detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the plasma membrane of the helical mollicute Spiroplasma melliferum, 21 are acylated, predominantly with myristic (14:0) and palmitic (16:0) chains . This is notably the case for spiralin, the major membrane protein of this bacterium, which contains an average of 0.7 acyl chains per polypeptide, attached very probably by ester bonds to alcohol amino acids . The amphiphilicity of spiralin was demonstrated by the behavior of the protein in charge-shift electrophoresis, its incorporation into liposomes, and its ability to form in the absence of lipids and detergents, globular protein micelles (diameter, approximately 15 nm) . The presence of epitopes on the two faces of the cell membrane, as probed by antibody adsorption and crossed immunoelectrophoresis, and the strong interaction between spiralin and the intracytoplasmic fibrils show that spiralin is a transmembrane protein . The mean hydropathy of the amino acid composition of spiralin (-0.30) is on the hydrophilic side of the scale . Surprisingly, the water-insoluble core of spiralin micelles, which is the putative membrane anchor, has a still more hydrophilic amino acid composition (mean hydropathy, -0.70) and is enriched in glycine and serine residues . Taking into account all these properties, we propose a topological model for spiralin featuring a transbilayer localization with hydrophilic domains protruding on the two faces of the membrane and connected by a small domain embedded within the apolar region of the lipid bilayer . In this model, the membrane anchoring of the protein is strengthened by a covalently bound acyl chain.

J Bacteriol, 1989 Sep, 171(9), 4836 - 43
Induction of anaerobic gene expression in Rhodobacter capsulatus is not accompanied by a local change in chromosomal supercoiling as measured by a novel assay; Cook DN et al.; In the photosynthetic bacterium Rhodobacter capsulatus, the enzyme DNA gyrase has been implicated in the expression of genes for anaerobic metabolic processes such as nitrogen fixation and photosynthesis . To assess the involvement of supercoiling in anaerobic gene expression, we have developed an assay to detect in vivo changes in superhelicity of small regions of the bacterial chromosome . Our method is based on the preferential intercalaction of psoralen into supercoiled versus relaxed DNA, and we have demonstrated the sensitivity of the assay in vivo on chromosomal regions from 2 to 10 kilobases in size . In experiments with inhibitors of gyrase, the reactivity of individual chromosomal fragments to psoralen decreases by a factor of 1.8 compared with DNA from control cultures . We used our assay to determine whether there is a change in superhelicity near the genes coding for essential proteins for photosynthesis upon a shift from respiratory to anaerobic photosynthetic growth . For comparison, we also examined a restriction fragment containing the fbc operon, which codes for the subunits of cytochrome bc1, a membrane-bound electron transport complex utilized during both aerobic and anaerobic photosynthetic growth . During this shift in growth conditions, the puf and puh mRNAs, coding for structural polypeptides of the photosynthetic apparatus, underwent a six- to eightfold induction, while the amount of mRNA from the fbc locus remained constant . However, we detected no change in the superhelicity of either the genes for photosynthesis or those for the bc1 complex during this metabolic transition . Our data thus do not support a model in which stable changes in chromosomal superhelicity regulate anaerobic gene expression . We suggest instead that the requirement for DNA gyrase in the transcription of photosynthesis genes results from the requirement for a swivel near heavily transcribed regions of the chromosome.

J Gen Microbiol, 1989 Sep, 135 ( Pt 9), 2357 - 64
Polymerase chain reaction for the detection of Mycobacterium leprae; Hartskeerl RA et al.; A polymerase chain reaction (PCR) using heat-stable Taq polymerase is described for the specific detection of Mycobacterium leprae, the causative agent of leprosy . A set of primers was selected on the basis of the nucleotide sequence of a gene encoding the 36 kDa antigen of M . leprae . With this set of primers in the PCR, M . leprae could be detected specifically with a detection limit approximating one bacterium . This PCR appears to meet the criteria of specificity and sensitivity required for a useful tool in epidemiology and eventually for the control of leprosy.

J Clin Microbiol, 1989 Sep, 27(9), 1961 - 4
Plaque assay for virulent Legionella pneumophila; Fernandez RC et al.; Methods of assessing virulence of Legionella pneumophila, the etiologic agent of Legionnaires disease, include the infection of guinea pigs, fertile chicken eggs, and mammalian and protozoan cell cultures . Guinea pig assays, in particular, are expensive, laborious, or unsuitable for routine screening of Legionella isolates . We have developed a virulence assay that requires the enumeration of viruslike plaques which are the result of virulent L . pneumophila infecting mouse L929 cells . Each plaque is the consequence of the initial infection of an L cell with a single bacterium . A nonvirulent mutant derived from the serial passage of virulent L . pneumophila on Mueller-Hinton agar fails to survive within L cells and consequently fails to produce plaques.

Am J Vet Res, 1989 Sep, 50(9), 1437 - 41
Infectious bovine keratoconjunctivitis epizootic associated with area-wide emergence of a new Moraxella bovis pilus type; Vandergaast N et al.; Pilus-mediated adherence is a virulence attribute of Moraxella bovis . Several pilus types have been shown to exist among strains of this bacterium, but correlation between pilus type and specific field cases of the disease has not been done . During the summer of 1987, an epizootic of infectious bovine keratoconjunctivitis was reported in 7 Iowa counties . Eight isolates of M bovis were secured from 12 episodes studied . All 8 of the isolates were nearly homogeneous in biochemical properties and had the same plasmid biotype . Pilus typing performed by immunofluorescence and immunogold electron microscopy identified a single new pilus type among 5 of the 8 isolates . This pilus type was identified in field cases that developed within a narrow time frame and over large distances . The implication of these findings is that infectious bovine keratoconjunctivitis epizootics may be associated with emergence of a novel pilus type, and that rapid dissemination over wide distances can occur, presumably by transportation of carrier cattle.

J Biol Chem, 1989 Aug 25, 264(24), 14233 - 9
Properties of a novel D-stereospecific aminopeptidase from Ochrobactrum anthropi; Asano Y et al.; A novel aminopeptidase active toward D-amino acid-containing peptides, D-amino acid amides, and D-amino acid esters has been purified 2,800-fold to homogeneity from a bacterium Ochrobactrum anthropi SCRC C1-38, which had been isolated from soil . The enzyme has a molecular weight of about 122,000 and is composed of two identical subunits (Mr = 59,000) . The optimal pH for activity was 8.0 . It showed strict D-stereospecificity toward substrates including low molecular weight D-amino acid amides such as D-alanine amide, D-alpha-aminobutyric acid amides, and D-serine amide; D-alanine N-alkylamides such as D-alanine-p-nitroanilide, D-alanine benzylamide, and D-alanine n-butylamide; and peptides with a D-alanine at the NH2 terminus such as D-alanylglycine, D-alanylglycylglycine, D-alanyl-L-alanyl-L-alanine, and D-alanine oligomers . Generally, the enzyme did not act on substrates composed of L-amino acid at the NH2 terminus, although it showed low stereospecificity only toward substrates such as the methyl esters of L-alanine, L-serine, and L-alanine-p-nitroanilide . Comparing the Km and Vmax values for the major substrates, it is clear that the enzyme prefers peptides to amino acid arylamides or amino acid amides . The enzyme was tentatively named as "D-aminopeptidase." EDTA and divalent cations have no effect on the enzyme activity . The enzyme appears to be a thiol peptidase.

Biochim Biophys Acta, 1989 Aug 17, 976(1), 70 - 6
The Rhodospirillum rubrum cytochrome bc1 complex: peptide composition, prosthetic group content and quinone binding; Kriauciunas A et al.; A cytochrome bc1 complex, essentially free of bacteriochlorophyll, has been purified from the photosynthetic purple non-sulfur bacterium Rhodospirillum rubrum . The complex catalyzes electron flow from quinol to cytochrome c (turnover number = 75 s-1) that is inhibited by low concentrations of antimycin A and myxothiazol . The complex contains only three peptide subunits: cytochrome b (Mr = 35,000); cytochrome c1 (Mr = 31,000) and the Rieske iron-sulfur protein (Mr = 22,400) . Em values (pH 7.4) were measured for cytochrome c1 (+320 mV) and the two hemes of cytochrome b (-33 and -90 mV) . Electron flow from quinol to cytochrome c is inhibited when the complex is pre-illuminated in the presence of a ubiquinone photoaffinity analog (azido-Q) . During illumination, the azido-Q becomes covalently attached to the cytochrome b peptide and, to a lesser extent, to cytochrome c1.

Arch Biochem Biophys, 1989 Aug 15, 273(1), 206 - 14
Electron spin resonance measurements of the effect of ionophores on the transmembrane pH gradient of an acidophilic bacterium; McLaggan D et al.; The delta pH in ionophore-treated cells of an acidophile has been determined by electron spin resonance spectroscopy . The values obtained were comparable to those obtained using the more conventional techniques involving radiolabeled probes . No binding of the spin-labeled probe was observed as determined by two independent control experiments and by the characteristics of the probe signal . These results led us to conclude that the delta pH measured in protonophore/ionophore-treated cells is a result of a Donnan potential, which may be a physical property of all intact bacterial cells at low pH values.

J Biol Chem, 1989 Aug 5, 264(22), 13109 - 13
Carotenoid biosynthesis in photosynthetic bacteria . Genetic characterization of the Rhodobacter capsulatus CrtI protein; Bartley GE et al.; Carotenoids are photoprotective pigments present in many photosynthetic and nonphotosynthetic organisms . The desaturation of phytoene into phytofluene is an early step in the biosynthetic pathway that in the photosynthetic bacterium Rhodobacter capsulatus is mediated by the product of the crtI gene . Here we report the sequence of this gene and the identification of CrtI as a membrane protein of approximate Mr 60,000 . Mutant strains with 5-fold lower or 10-fold higher levels of CrtI with respect to wild type have only small differences in their carotenoid content, indicating that the cellular concentration of CrtI is not a limiting factor in carotenoid biosynthesis . However, a correlation was found between the levels of CrtI and the formation of a photosynthetic antenna system.

Biosci Rep, 1989 Aug, 9(4), 383 - 419
The photosynthetic reaction centre from the purple bacterium Rhodopseudomonas viridis; Deisenhofer J et al.; We first describe the history and methods of membrane protein crystallization, and show how the structure of the photosynthetic reaction centre from the purple bacterium Rhodopseudomonas viridis was solved . The structure of this membrane protein complex is correlated with its function as a light-driven electron pump across the photosynthetic membrane . Finally we draw conclusions on the structure of the photosystem II reaction centre from plants and discuss the aspects of membrane protein structure.

EMBO J, 1989 Aug, 8(8), 2149 - 70
Nobel lecture . The photosynthetic reaction centre from the purple bacterium Rhodopseudomonas viridis; Deisenhofer J et al.; In our lectures we first describe the history and methods of membrane protein crystallization, before we show how the structure of the photosynthetic reaction centre from the purple bacterium Rhodopseudomonas viridis was solved . Then the structure of this membrane protein complex is correlated with its function as a light-driven electron pump across the photosynthetic membrane . Finally we draw conclusions on the structure of the photosystem II reaction centre from plants and discuss the aspects of membrane protein structure . Sections 1 (crystallization), 4 (conclusions on the structure of photosystem II reaction centre and evolutionary aspects) and 5 (aspects of membrane protein structure) were presented and written by H.M., Sections 2 (determination of the structure) and 3 (structure and function) by J.D . We have arranged the paper in this way in order to facilitate continuous reading.

J Gen Microbiol, 1989 Aug, 135 ( Pt 8), 2299 - 305
Genetic mapping in Streptomyces clavuligerus by protoplast fusion; Illing GT et al.; The development of a protoplast manipulation protocol for the industrially important bacterium Streptomyces clavuligerus, which produces the beta-lactamase inhibitor clavulanic acid, made possible a preliminary genetic mapping study based on protoplast fusion crosses . A preliminary position for 11 markers on the S . clavuligerus genetic map is proposed . Fusion progeny were characterized by random spore analysis because the markers present in the strains were not amenable to the conventional four-on-four selection procedure . Whilst the resulting map is similar to that derived by conjugation for S . clavuligerus and S . coelicolor, further analysis of the markers is required to confirm these observations.

Sci China B, 1989 Aug, 32(8), 960 - 9
Allosteric regulation of the state of adenylylation of glutamine synthetase in permeabilized cell preparations of Rhodopseudomonas sphaeroides; Wang X et al.; Following a freeze-thaw cycle, and the treatment of Rhodopseudomonas sphaeroides with the nonionic detergent Lubrol PX, the permeabilized cell suspensions can be assayed directly both for the intracellular levels of glutamine synthetase and the state of adenylylation (i.e . the average number n of adenylylated subunits/dodecameric molecules) . It seems that all components of the bicycle system are retained if cells grown with low concentrations of ammonia as the sole nitrogen source are used . The value of n was dependent upon the concentration of substrates (ATP, Pi) and allosteric effectors (ATP, glutamine and alpha-ketoglutarate) of adenylytransferase . The value of n affected by UTP, the specific substrate of the uridylyltransferase shows first the evidence that the bicycle cascade control system studied in Escherichia coli may exist in this phototrophic bacterium.

Kansenshogaku Zasshi, 1989 Aug, 63(8), 801 - 10
{Legionella dumoffii and Legionella pneumophila serogroup 5 isolated from 2 cases of fulminant pneumonia}; Fujita I et al.; We encountered two cases of legionella pneumonia which ran a dramatic course and isolated Legionella dumoffii from one patient and Legionella pneumophila serogroup 5 from the other patient . The patient from whom L . dumoffii was isolated was a 59-year-old male with no basic disease . He presented chill, fever, coughing and other symptoms, starting on July 3, 1986, his disease was diagnosed as pneumonia at the clinic of his company . The patient was then introduced and admitted to our hospital . On admission chest radiography disclosed zonal pneumonia with an unclear border in the right superior lobe of the lung; a beta-lactam preparation was administered, but no effect was obtained and the lung lesion showed a rapid advance . From this condition, we suspected legionella pneumonia and changed the therapy to treatment with erythromycin and rifampicillin . Despite this, no improvement occurred and the patient died on the 26th hospital day . Colonies like Legionella colonies were separated from a total of seven specimens of biopsy aspirated matter from the airway and autopsy collected lung abscess and tracheal secretions, and the bacterium was identified L . dumoffii based on the biochemical and serological properties . In addition, the patient's serum was found to have an increased antibody titer against L . dumoffii . Based on these findings, the patient's disease was diagnosed as pneumonia as caused by L . dumoffii, a relatively rare bacterium as a member of the genus Legionella . The patient from whom Legionella pneumophila serogroup 5 was isolated was an 81-year-old man with basic diseases such as heart failure, anemia and hypothyroidism . He presented fever, general fatigue, anorexia and other symptoms, starting around June 2, 1987; pneumonia was suspected and the patient was urgently admitted to our hospital . The patient died of pneumonia of unknown cause on the second hospital day . To clarify the cause, autopsy was conducted; a large number of colonies like Legionella colonies were noted in the lung tissue . Identification test was then conducted and the bacterium was identified as L . pneumophila; we concluded that the patient's pneumonia had been caused by the identified bacterium L . pneumophila . The isolate was further subjected to slide agglutination test and identified as L . pneumophila serogroup 5.

Mol Gen Genet, 1989 Aug, 218(2), 340 - 7
Genes coding for the reversible ADP-ribosylation system of dinitrogenase reductase from Rhodospirillum rubrum; Fitzmaurice WP et al.; Nitrogen fixation activity in the photosynthetic bacterium Rhodospirillum rubrum is controlled by the reversible ADP-ribosylation of the dinitrogenase reductase component of the nitrogenase enzyme complex . This report describes the cloning and characterization of the genes encoding the ADP-ribosyltransferase (draT) and the ADP-ribosylglycohydrolase (draG) involved in this regulation . These genes are shown to be contiguous on the R . rubrum chromosome and highly linked to the nifHDK genes . Sequence analysis revealed the use of TTG as the initiation codon of the draT gene as well as a potential open reading frame immediately downstream of draG . The mono-ADP-ribosylation system in R . rubrum is the first in which both the target protein and modifying enzymes as well as their structural genes have been isolated, making it the model system of choice for analysis of this post-translational regulatory mechanism.

Nature, 1989 Jul 20, 340(6230), 205 - 9
Bacterial conjugative plasmids mobilize DNA transfer between bacteria and yeast; Heinemann JA et al.; Conjugative plasmids of Escherichia coli can mobilize DNA transmission from this bacterium to the yeast Saccharomyces cerevisiae . The process shares some of the features of conjugation between bacteria and could be evolutionarily significant in promoting trans-kingdom genetic exchange.

J Exp Med, 1989 Jul 1, 170(1), 145 - 61
Structural and functional studies of the early T lymphocyte activation 1 (Eta-1) gene . Definition of a novel T cell-dependent response associated with genetic resistance to bacterial infection; Patarca R et al.; We describe a murine cDNA, designated Early T lymphocyte activation 1 (ETA-1) which is abundantly expressed after activation of T cells . Eta-1 encodes a highly acidic secreted product having structural features of proteins that bind to cellular adhesion receptors . The Eta-1 gene maps to a locus on murine chromosome 5 termed Ric that confers resistance to infection by Rickettsia tsutsugamushi (RT), an obligate intracellular bacterium that is the etiological agent for human scrub typhus . With one exception, inbred mouse strains that expressed the Eta-1a allele were resistant to RT infection (RicR), and inbred strains expressing the Eta-1b allele were susceptible (RicS) . These findings suggest that Eta-1 is the gene inferred from previous studies of the Ric locus (5) . Genetic resistance to RT infection is associated with a strong Eta-1 response in vivo and inhibition of early bacterial replication . Eta-1 gene expression appears to be part of a surprisingly rapid T cell-dependent response to bacterial infection that may precede classical forms of T cell-dependent immunity.

Appl Environ Microbiol, 1989 Jul, 55(7), 1796 - 800
Phenotypic and genomic studies of "Cytophaga psychrophila" isolated from diseased rainbow trout (Oncorhynchus mykiss) in France; Bernardet JF et al.; Five strains of gliding bacteria were isolated in France from farmed diseased rainbow trouts reared at low water temperature . The resemblance of these bacteria to the known fish pathogen "Cytophaga psychrophila" led to their comparative study with reference strain NCMB 1947 and with an American isolate . Morphological, physiological, and biochemical characteristics of the seven strains proved to be similar . Comparison of their DNA by the S1 nuclease DNA-DNA hybridization method showed that the seven strains formed a tight genomic species with DNA relatedness above 90% . This is the first identification of this fish pathogen in a European country . The main phenotypic characteristics differentiating this bacterium from other nonpathogenic gliding bacteria of fish origin include a poor gliding movement, yellow compact or weakly rhizoid colonies on solid media, and the presence of flexirubin-type pigments . The inability to metabolize any carbohydrates, the strong proteolytic activity, the absence of growth in more than 0.5% NaCl, and the tolerance to a maximum temperature of 25 degrees C are also useful characteristics of this group of bacteria.

Bioorg Khim, 1989 Jul, 15(7), 927 - 39
{Photosystem II of rye . Nucleotide sequence of psbB and psbH genes, coding 47-kDa of chlorophyll(a)-binding and 10-kDa phosphorylated subunits}; Bukharov AA et al.; Chloroplast DNA was isolated from rye seedlings by the non-aqueous method . The region of rye ctDNA which comprises two genes psbB and psbH encoding polypeptide subunits of photosystem II (47 kappa l) Chl alpha -binding protein (CP alpha -1) and 10 kD phosphoprotein, respectively) and two ORFs in the opposite strands in the psbB--psbH spacer region encoding hydrophobic peptides with strongly charged C-terminal segments was sequenced . The deduced amino acid sequences of polypeptide products of the genes were compared with those of different plant species (in case of the psbB product also with sequence of a cyano-bacterium Synechocystis) and revealed some highly conservative amino acid residues and regions of polypeptide chains, which apparently play essential role in the interaction with other PS II subunits and in the binding of chlorophyll molecules . Some speculations are made on the possible function of the peptides encoded by the two ORFs.

Zentralbl Bakteriol, 1989 Jul, 271(2), 197 - 204
Factors affecting infectivity of Tyzzer's organism in cultured mouse hepatocytes; Kawamura S et al.; Factors affecting the infectivity of Tyzzer's organism, an obligate intracellular bacterium, were examined in cultured mouse hepatocytes . The organisms were subjected to physical and chemical impairments and the infectivity was estimated by immunofluorescence that discriminated adhesion and entry of the organisms to host cells and by the plaque assay . Pretreatment of the organisms with either mild heat or formalin abolished adhesion . UV irradiation completely removed the plaque forming ability, while adhering and entering capacity were more resistant in this order . Entry of the organism into host cells was suppressed in the presence of erythromycin, gentamicin or oxytetracycline, while it was relatively little susceptible to ampicillin, kanamycin or rifampicin . Plaquing efficiencies were increased by centrifugation during the infection . These results suggest that not only a structural but also a functional integrity of the organisms was requisite for establishment of the infection at the initial stage.

Arch Biochem Biophys, 1989 Jul, 272(1), 254 - 61
In vitro kinetics of reduction of cytochrome c554 isolated from the reaction center of the green phototrophic bacterium, Chloroflexus aurantiacus; Meyer TE et al.; The photochemical reaction center in the green bacterium Chloroflexus aurantiacus is similar to that found in purple phototrophic bacteria and interacts with a multiheme membrane-bound cytochrome . We have examined the kinetics of reduction of the pure solubilized reaction center cytochrome by laser flash photolysis of solutions containing lumiflavin or FMN . Reduction by lumiflavin semiquinone followed single exponential kinetics and the observed rate constant (kobs) was linearly dependent on protein concentration (k = 1.8 X 10(7) M-1s-1 heme-1) . This result suggests either that the four hemes have similar reduction rate constants which cannot be resolved or that there are large differences in rate constant and only the most reactive heme (or hemes) was observed under these conditions . To determine the relative reactivities of the four hemes, we varied the extent of heme reduction at a single total protein concentration . As the hemes were progressively reduced by steady-state illumination prior to laser flash photolysis, kobs for the reaction with fully reduced lumiflavin decreased nonlinearly . Second-order rate constants for the four hemes were assigned by nonlinear least-squares analysis of kobs vs oxidized heme concentration data . The second-order rate constants obtained in this way for the highest and lowest potential hemes differed by a factor of about 20, which is larger than expected for c-type cytochromes based on redox potential alone (a factor of about 3 would be expected) . This is interpreted as being due to differences in steric accessibility . Relative to the highest potential heme, which is as reactive as a typical c-type cytochrome, we estimated a steric effect of approximately twofold for heme 2, and steric effects of approximately fivefold for hemes 3 and 4 . Using fully reduced FMN as reductant of oxidized cytochrome, ionic strength effects indicate a minus-minus interaction, with approximately a -2 charge near the site of reduction of the highest potential heme.

Biochemistry, 1989 Jun 27, 28(13), 5544 - 53
Characterization of four herbicide-resistant mutants of Rhodopseudomonas viridis by genetic analysis, electron paramagnetic resonance, and optical spectroscopy; Sinning I et al.; Herbicides of the triazine class block electron transfer in the photosynthetic reaction centers of purple bacteria and PSII of higher plants . They are thought to act by competing with one of the electron acceptors, the secondary quinone, QB, for its binding site . Several mutants of the purple bacterium Rhodopseudomonas viridis resistant to terbutryn {2-(methylthio)-4-(ethylamino)-6-(tert-butylamino)-s-triazine} have been isolated by their ability to grow photosynthetically in the presence of the herbicide . Sequence analysis of the genes coding for the L and M subunits of the reaction center showed that four different mutants were obtained, two of them being double mutated: T1 (SerL223----Ala and ArgL217----His), T3 (PheL216----Ser and ValM263----Phe), T4 (TyrL222----Phe), and T6 (PheL216----Ser) . The residues L223 and L216 are involved in binding of QB, whereas L217 and L222 are not . M263 is part of the binding pocket of the primary quinone, QA . The affinity of the reaction centers for terbutryn and the electron transfer inhibitor o-phenanthroline, determined via the biphasic charge recombination after one flash, is decreased for all mutants . The affinity for ubiquinone 9 is also decreased, except in T1 . Characterization by EPR spectroscopy showed that the QB.-Fe2+ signal of T4, having a g = 1.93 peak, is different from the signals obtained with the wild type and the other mutants but very similar to those of Rhodospirillum rubrum and PSII . The results obtained by the combination of these different techniques are discussed with respect to the three-dimensional structure of the wild type and the mode of binding of ubiquinone, terbutryn, and o-phenanthroline as determined by X-ray structure analysis.

Eur J Biochem, 1989 Jun 15, 182(2), 363 - 6
Spectroscopic characterization of the nickel and iron-sulphur clusters of hydrogenase from the purple photosynthetic bacterium Thiocapsa roseopersicina . 2 . Electron spin-echo spectroscopy; Cammack R et al.; Pulsed electron-spin-resonance techniques were applied to the hydrogenase of the purple photosynthetic bacterium Thiocapsa roseopersicina, an enzyme which contains nickel and iron-sulphur clusters but no flavin . The linear electric field effect profile of the spectrum in the region of g = 2.01 indicated that the strong ESR signal in the oxidized protein is due to a {3Fe-4S} cluster . The electron spin-echo envelope of this spectrum was modulated by hyperfine interactions with 1H and 14N nuclei, probably from the polypeptide chain . The ESR spectrum of this species shows a complex pattern arising from spin-spin interaction with another paramagnet . When the protein was partially reduced by ascorbate plus phenazine methosulphate, the complexity of the spectrum was abolished but the form of the electron spin-echo envelope modulation (ESEEM) pattern was unchanged . This indicates that the reversible disappearance of the spin-spin interaction pattern on partial reduction is not due to cluster interconversion to a {4Fe-4S} cluster . In the ESR spectrum of nickel(III), weak hyperfine interactions with 1H and 14N were also observed by ESEEM . The nature of the interacting nuclei is discussed.

Eur J Biochem, 1989 Jun 15, 182(2), 357 - 62
Spectroscopic characterization of the nickel and iron-sulphur clusters of hydrogenase from the purple photosynthetic bacterium Thiocapsa roseopersicina . 1 . Electron spin resonance spectroscopy; Cammack R et al.; The thermostable hydrogenase from Thiocapsa roseopersicina was examined by low-temperature ESR spectroscopy . Two types of signals were detected, from an oxidized iron-sulphur cluster and a nickel centre (Ni-A) . In the oxidized protein additional signals were observed due to spin-spin interaction between the two paramagnetic centres . This interaction could be reversibly abolished by reduction to a redox potential below 105 mV . This implies that an additional redox centre is involved in the interaction, for which an Fe3+ ion is suggested . Reduction with hydrogen induced a second type of nickel ESR signal (Ni-C), corresponding to an intermediate redox state seen in other nickel hydrogenases . The Ni-C species was light-sensitive at cryogenic temperatures . At temperatures near to 4.2 K the Ni-C signal showed evidence of interaction with another paramagnetic centre, presumably a second iron-sulphur cluster . On reoxidation a signal due to a third Ni(III) species, Ni-B, increased in amplitude . These results establish that metal centres in the hydrogenase from T . roseopersicina are closely similar to those of the well-studied hydrogenase from Chromatium vinosum.

Biochemistry, 1989 Jun 13, 28(12), 5261 - 8
1H NMR characterization of Chromatium gracile high-potential iron protein and its ruthenium-modified derivatives . Modulation of the reduction potentials in low- and high-potential {Fe4S4} ferredoxins; Sola M et al.; The NMR spectra of the high-potential iron protein from the photosynthetic bacterium Chromatium gracile and its ruthenium-labeled (His-42 and His-20) derivatives are reported . The isotropically shifted resonances in both the oxidized and reduced forms show a complex pH dependence due to the presence of three ionizable residues (Glu-44, His-20, and His-42) . Assignments have been made to specific residues and the spectral features compared to those of other bacterial HiPIP's . The decrease in the reduction potential with increasing pH for this class of proteins is attributed to stabilization of the oxidized state of the cluster by delocalization of electron density onto the neighboring Tyr-19 residue.

Helv Chir Acta, 1989 Jun, 56(1-2), 249 - 52
{Therapeutic concepts in infected hip prosthesis}; Babst R et al.; In the period from January 1980 to December 1987, 62 patients with infected hip joint arthroplasties were treated . The duration of observation was on average 37 months (minimum 12 months, maximum 91 months) . The choice of treatment modality depended on the type of infection, the state of anchorage of the endoprosthesis, the general condition of the patient, the type of bacterium and the state of the tissue surrounding the implant . 42 arthroplasties (67%) healed primarily . The remaining 20 were subject to 46 further operations (2.3 relapse operations/patient) . 14 subsequently healed (23%) and six cases remained definitively infected.

Biol Chem Hoppe Seyler, 1989 Jun, 370(6), 591 - 9
Terminal phenylalanine and tyrosine biosynthesis of Microtetraspora glauca; Speth AR et al.; The enzymes of the terminal steps of the phenylalanine and tyrosine biosynthesis were partially purified and characterized in Microtetraspora glauca, a spore-forming member of the order Actinomycetales . This bacterium relies exclusively on the phenylpyruvate route for phenylalanine synthesis, no arogenate dehydratase activity being found . Prephenate dehydratase is subject to feedback inhibition by phenylalanine, tyrosine and tryptophan, each acting as competitive inhibitor by increasing the Km of 72 microM for prephenate . Based on the results of gel chromatography on Sephadex G-200, the molecular mass of about 110,000 Da is not altered by any of the effectors . The enzyme is quite sensitive to inhibition by 4-hydroxymercuribenzoate . Microtetraspora glauca can utilize arogenate and 4-hydroxyphenylpyruvate as intermediates in tyrosine biosynthesis . Prephenate and arogenate dehydrogenase activities copurifying from ion exchange columns with coincident profiles were detected . From gel-filtration columns the two activities eluted at an identical molecular-mass position of about 68,000 Da . The existence of a single protein exhibiting substrate ambiguity is consistent with the findings, that both dehydrogenases have similar chromatographic properties, exhibit cofactor requirement for NAD and are inhibited to the same extent by tyrosine and 4-hydroxymercuribenzoate.

Eur J Cell Biol, 1989 Jun, 49(1), 24 - 32
Cytoplasmic membrane systems involved in bacterium release into soybean nodule cells as studied with two Bradyrhizobium japonicum mutant strains; Roth LE et al.; Two Bradyrhizobium japonicum, Tn5-induced, mutant strains, ML126 and ML150, were studied . Both induce host cell division to form normal-sized nodules that do not fix nitrogen and whose cells have very few bacteroids (Bar-) . Early-infection (15 days post infection) cells have much endoplasmic reticulum (ER), numerous Golgi bodies, and large vacuoles that are probably secondary lysosomes . Later the cytoplasm of the host cells of both are dominated by hundreds of vesicles containing only finely fibrous material and that appear to originate by the degradation of the cell walls of the infection threads; they have been named "infection-thread wall degradation vesicles" (IWDV) . Phosphotungstic acid-chromic acid (PACA) staining of thin sections shows that IWDV membranes and the plasma membranes of both the cells and infection threads usually stain quite intensely, while the membranes of other cell organelles do not . The membranes of the few symbiosomes present in the mutants also stain with PACA . This evidence suggests that largely the host-cell plasma membrane gives rise to both the vesicle and symbiosome membranes in these mutants . In cells induced by both mutants, ER appears to be deficient, a finding suggesting that an ER-synthesis signal is involved in the normal release process, that ER synthesis is prerequisite to a normal volume of release, and that insufficient ER can impair symbiosome formation . In the mutant-induced infections, normal lysosomes develop and engulf both symbiosomes and cytoplasmic vesicles, but the retardation of this activity is the probable cause of the cytoplasm becoming overloaded with vesicles.

Eur J Cell Biol, 1989 Jun, 49(1), 13 - 23
Bacterium release into host cells of nitrogen-fixing soybean nodules: the symbiosome membrane comes from three sources; Roth LE et al.; The release process of bacteria into the cytoplasm of soybean nodule cells has been studied, and three functional zones of the infection thread are delineated . Zone 1 is found over the greatest length of very long infection threads . Zone 2 is a short region where membrane mobilization by exocytosis of endoplasmic reticulum (ER) into the infection-thread membrane takes place; the result is that much new membrane and wall degradation enzymes can be provided . In addition, de novo membrane formation takes place inside the infection thread in apposition to the bacterial outer membrane . Zone 3 is the endocytic region where both bacteria and infection-thread wall degradation vesicles are released into the host cytoplasm and constitute a second product of endocytosis at the infection thread tip . Evidence is presented indicating that the symbiosome membrane, even at its time of origin, is composed of membrane from three sources: the host infection-thread membrane, ER, and de novo synthesis; the membrane formation that is so large for these purposes is probably carried out both from the ER directly and also through the Golgi-apparatus synthesis . Evidence is also given that the bacteria have lost their exopolysaccharide coatings before release into symbiosomes.

J Bacteriol, 1989 Jun, 171(6), 3205 - 10
Purification and properties of L-alanine dehydrogenase of the phototrophic bacterium Rhodobacter capsulatus E1F1; Caballero FJ et al.; In the phototrophic nonsulfur bacterium Rhodobacter capsulatus E1F1, L-alanine dehydrogenase aminating activity functions as an alternative route for ammonia assimilation when glutamine synthetase is inactivated . L-Alanine dehydrogenase deaminating activity participates in the supply of organic carbon to cells growing on L-alanine as the sole carbon source . L-Alanine dehydrogenase is induced in cells growing on pyruvate plus nitrate, pyruvate plus ammonia, or L-alanine under both light-anaerobic and dark-heterotrophic conditions . The enzyme has been purified to electrophoretic and immunological homogeneity by using affinity chromatography with Red-120 agarose . The native enzyme was an oligomeric protein of 246 kilodaltons (kDa) which consisted of six identical subunits of 42 kDa each, had a Stokes' radius of 5.8 nm, an s20.w of 10.1 S, a D20,w of 4.25 x 10(-11) m2 s-1, and a frictional quotient of 1.35 . The aminating activity was absolutely specific for NADPH, whereas deaminating activity was strictly NAD dependent, with apparent Kms of 0.25 (NADPH), 0.15 (NAD+), 1.25 (L-alanine), 0.13 (pyruvate), and 16 (ammonium) mM . The enzyme was inhibited in vitro by pyruvate or L-alanine and had two sulfhydryl groups per subunit which were essential for both aminating and deaminating activities.

J Bacteriol, 1989 Jun, 171(6), 3162 - 7
Construction and characterization of an Azotobacter vinelandii strain with mutations in the genes encoding flavodoxin and ferredoxin I; Martin AE et al.; Flavodoxin and ferredoxin I have both been implicated as components of the electron transport chain to nitrogenase in the aerobic bacterium Azotobacter vinelandii . Recently, the genes encoding flavodoxin (nifF) and ferredoxin I (fdxA) were cloned and sequenced and mutants were constructed which are unable to synthesize either flavodoxin (DJ130) or ferredoxin I (LM100) . Both single mutants grow at wild-type rates under N2-fixing conditions . Here we report the construction of a double mutant (DJ138) which does not synthesize either flavodoxin or ferredoxin I . When plated on ammonium-containing medium, this mutant had a very small colony size when compared with the wild type, and in liquid culture with ammonium, this double mutant grew three times slower than the wild type or single mutant strains . This demonstrated that there is an important metabolic function unrelated to nitrogen fixation that is normally carried out by either flavodoxin or ferredoxin . If either one of these proteins is missing, the other can substitute for it . The double mutant phenotype can now be used to screen site-directed mutant versions of ferredoxin I for functionality in vivo even though the specific function of ferredoxin I is still unknown . The double mutant grew at the same slow rate under N2-fixing conditions . Thus, A . vinelandii continues to fix N2 even when both flavodoxin and ferredoxin I are missing, which suggests that a third as yet unidentified protein also serves as an electron donor to nitrogenase.

Proc Natl Acad Sci U S A, 1989 Jun, 86(12), 4435 - 9
Mutations in the maize mitochondrial T-urf13 gene eliminate sensitivity to a fungal pathotoxin; Braun CJ et al.; URF13, the product of the mitochondrial T-urf13 gene, confers on Texas cytoplasmic male-steril maize (Zea mays L.) a unique susceptibility to a fungal pathogen (Bipolaris maydis race T) and sensitivity to its pathotoxin . Expression of URF13 in Escherichia coli imparts pathotoxin sensitivity to the bacterium . We show by ion uptake studies in E . coli that a pathotoxin-URF13 interaction causes membrane permeability . Similarly, mitochondrial dysfunction caused by membrane permeabilization probably accounts for increased colonization of maize carrying the Texas cytoplasm by toxin-producing pathogens . Site-directed mutagenesis studies show that approximately one-quarter of the amino acids at the carboxyl end of URF13 can be eliminated without affecting toxin sensitivity . We have identified two dicyclohexylcarbodiimide (DCCD) binding sites in the URF13 protein and show that one of the sites is involved in conferring DCCD protection against the pathotoxin . Substitutional mutations at this DCCD binding site also eliminate toxin sensitivity.

Nippon Shishubyo Gakkai Kaishi, 1989 Jun, 31(2), 521 - 34
{Role of heparitinase in the initial stage of gingival inflammation}; Murakami J; For the purpose of elucidating the effect of heparitinase in gingival tissue, paper strips were inserted in the gingival sulcus of a dog and were treated with heparitinase (experimental group), an enzyme-free solution (control group) or inactivated enzyme (control group) for 20 minutes once a day in order to determine the pathohistological changes in the periodontium after 3, 10 and 14 days . No marked difference was noted between the 3-day enzyme-treated group and the control groups, but for the 10-day and 14-day enzyme-treated groups, enlargement of the intercellular epithelium, neutrophil infiltration and inflammatory cellular infiltration, mainly of neutrophils, in the subepithelial connective tissue were observed . Examination of the effect of a tracer, 3H-Dextran, on the permeability of the epithelium to heparitinase revealed incorporation of 3H-Dextran by the enzyme-treated group at about 2 times as much as that by the control group, and there were more silver particles indicative of 3H-Dextran according to autoradiographic findings . Determination of the intratissue location of bacterium-derived heparitinase by the fluorescent antibody technique revealed fluorescence positivity on the gingival sulcus epithelial side but not on the oral epithelial side, and that it was more frequent in the region of the enlarged intercellular area of the upper layer of the gingival sulcus epithelium . These results suggest that bacterium-derived heparitinase present in the epithelium of the gingival sulcus of a dog lowered the defense competence peculiar to the epithelium and elevated of the permeability epithelium to bacterium-produced substances, leading to its involvement in the onset of gingival inflammation by decomposing heparan sulfate, an inter-cellular epithelial matrix.

Arch Biochem Biophys, 1989 Jun, 271(2), 502 - 7
Expression of a cytochrome c2 isozyme restores photosynthetic growth of Rhodobacter sphaeroides mutants lacking the wild-type cytochrome c2 gene; Fitch J et al.; Deletion of the cytochrome c2 gene in the purple bacterium Rhodobacter sphaeroides renders it incapable of phototrophic growth (strain cycA65) . However, suppressor mutants which restore the ability to grow phototrophically are obtained at relatively high frequency (1-10 in 10(7)) . We examined two such suppressors (strains cycA65R5 and cycA65R7) and found the expected complement of electron transfer proteins minus cytochrome c2: SHP, c', c551.5, and c554 . Instead of cytochrome c2 which elutes from DEAE-cellulose between SHP and cytochrome c', at about 50 mM ionic strength in wild-type extracts, we found a new high redox potential cytochrome c in the mutants which elutes with cytochrome c551.5 at about 150 mM ionic strength . The new cytochrome is more acidic than cytochrome c2, but is about the same size or slightly smaller (13,500 Da) . The redox potential of the new cytochrome from strain cycA65R7 (294 mV) is about 70 mV lower than that of cytochrome c2 . The 280 nm absorbance of the new cytochrome is smaller than that of cytochrome c2, which suggests that there is less tryptophan (the latter has two residues) . In vitro kinetics of reduction by lumiflavin and FMN semiquinones show that the reactivity of the new cytochrome is similar to that of cytochrome c2, and that there is a relatively large positive charge (+2.6) at the site of reduction, despite the overall negative charge of the protein . This behavior is characteristic of cytochromes c2 and unlike the majority of bacterial cytochromes examined . Fourteen out of twenty-four of the N-terminal amino acids of the new cytochrome are identical to the sequence of cytochrome c2 . The N-termini of the cycA65R5 and cycA65R7 cytochromes were the same . The kinetics and sequence data indicate that the new protein may be a cytochrome c2 isozyme, which is not detectable in wild-type cells under photosynthetic growth conditions . We propose the name iso-2 cytochrome c2 for the new cytochrome produced in the suppressor strains.

Arch Biochem Biophys, 1989 Jun, 271(2), 433 - 40
Effect of aerobic growth conditions on the soluble cytochrome content of the purple phototrophic bacterium Rhodobacter sphaeroides: induction of cytochrome c554; Bartsch RG et al.; When grown anaerobically in the light, Rhodobacter sphaeroides contains appreciable quantities of cytochromes c2 and c', but smaller amounts of other soluble cytochromes such as cytochrome c551.5, cytochrome c554, and an oxygen-binding heme protein . When R . sphaeroides is mass cultured aerobically in the dark to stationary phase, the content of cytochrome c2 does not change appreciably, whereas cytochrome c554 is approximately 8-fold more abundant, cytochrome c' is at least 10-fold less abundant, and cytochrome c551.5 is fivefold lower than in the phototrophically grown cells . These observations confirm previous literature reports that in this organism a cytochrome c553 (or c554 in our experience) is more abundant when cells are grown aerobically . Furthermore, the aerobic cytochrome c554 is positively identified with the previously characterized minor cytochrome c554 component of anaerobic photosynthetic cells . Preliminary sequence results show that cytochrome c554 is a member of the cytochrome c' structural family, but differs from normal cytochromes c' in having a methionine sixth ligand to the heme . The levels of electron carrier proteins of low redox potential had previously been reported to be less in aerobic than in photoheterotrophic cells and we have verified that observation for the specific examples of cytochromes c' and c551.5 . The oxygen binding heme protein, SHP, is not induced by aerobic growth.

J Bacteriol, 1989 Jun, 171(6), 3560 - 3
Rapid bacterial swimming measured in swarming cells of Thiovulum majus; Garcia-Pichel F; Swarming cells of the sulfide-oxidizing bacterium Thiovulum majus form bands and show bioconvective patterns of swimming when placed in vessels containing H2S/O2 interfaces . Measurements of swimming velocities with video microscopic recordings under such conditions showed mean cell speeds as high as 615 microns s-1, unprecedented in bacteria.

J Bacteriol, 1989 Jun, 171(6), 3168 - 75
Ammonium inhibition of nitrogenase activity in Herbaspirillum seropedicae; Fu H et al.; The effect of oxygen, ammonium ion, and amino acids on nitrogenase activity in the root-associated N2-fixing bacterium Herbaspirillum seropedicae was investigated in comparison with Azospirillum spp . and Rhodospirillum rubrum . H . seropedicae is microaerophilic, and its optimal dissolved oxygen level is from 0.04 to 0.2 kPa for dinitrogen fixation but higher when it is supplied with fixed nitrogen . No nitrogenase activity was detected when the dissolved O2 level corresponded to 4.0 kPa . Ammonium, a product of the nitrogenase reaction, reversibly inhibited nitrogenase activity when added to derepressed cell cultures . However, the inhibition of nitrogenase activity was only partial even with concentrations of ammonium chloride as high as 20 mM . Amides such as glutamine and asparagine partially inhibited nitrogenase activity, but glutamate did not . Nitrogenase in crude extracts prepared from ammonium-inhibited cells showed activity as high as in extracts from N2-fixing cells . The pattern of the dinitrogenase and the dinitrogenase reductase revealed by the immunoblotting technique did not change upon ammonium chloride treatment of cells in vivo . No homologous sequences were detected with the draT-draG probe from Azospirillum lipoferum . There is no clear evidence that ADP-ribosylation of the dinitrogenase reductase is involved in the ammonium inhibition of H . seropedicae . The uncoupler carbonyl cyanide m-chlorophenylhydrazone decreased the intracellular ATP concentration and inhibited the nitrogenase activity of whole cells . The ATP pool was not significantly disturbed when cultures were treated with ammonium in vivo . Possible mechanisms for inhibition by ammonium of whole-cell nitrogenase activity in H . seropedicae are discussed.

J Bacteriol, 1989 Jun, 171(6), 3102 - 7
Regulation of carbon monoxide dehydrogenase and hydrogenase in Rhodospirillum rubrum: effects of CO and oxygen on synthesis and activity; Bonam D et al.; Exposure of the photosynthetic bacterium Rhodospirillum rubrum to carbon monoxide led to increased carbon monoxide dehydrogenase and hydrogenase activities due to de novo protein synthesis of both enzymes . Two-dimensional gels of {35S}methionine-pulse-labeled cells showed that induction of CO dehydrogenase synthesis was rapidly initiated (less than 5 min upon exposure to CO) and was inhibited by oxygen . Both CO dehydrogenase and the CO-induced hydrogenase were inactivated by oxygen in vivo and in vitro . In contrast to CO dehydrogenase, the CO-induced hydrogenase was 95% inactivated by heating at 70 degrees C for 5 min . Unlike other hydrogenases, this CO-induced hydrogenase was inhibited only 60% by a 100% CO gas phase.

J Dent Res, 1989 Jun, 68(6), 1094 - 7
Resolution of ion translocating proteolipid subclasses active in bacterial calcification; Swain LD et al.; Formation of calcium hydroxyapatite occurs on membrane surfaces via interaction of calcium, inorganic phosphate, phospholipids, calcifiable proteolipids, and ion flux to and from the nucleating site . Recently, this laboratory reported that proteolipids from the calcifying bacterium, Bacterionema matruchotti, act as an ionophore when reconstituted into bacteriorhodopsin-proteoliposomes . This ionophoric activity is blocked by {14C}dicyclohexylcarbodiimide ({14C}DCCD) . SDS-PAGE shows that {14C}DCCD binds to a single band of Mr 8500 . To determine whether proteins other than the {14C}DCCD-binding protein are involved, we examined the function of proteolipid species extracted by solvents of differing polarity . Proteolipids were isolated independently from chloroform:methanol (2:1) and chloroform:methanol:HCl (200:100:1) extracts of the bacteria by Sephadex LH-20 chromatography and were electrophoresed on 12.5% acrylamide gels . The chloroform:methanol extract contained a major hand at Mr 10,000 that was not present in gels of proteolipid isolated by acidified solvent . Proteolipids extracted in chloroform:methanol:HCl included a broad band at Mr 8500, which co-migrated with the {14C} DCCD-binding protein . The rate and extent of proton translocation were not altered when either proteolipid extract was added individually to bacteriorhodopsin proteoliposomes . However, when proteolipids isolated from the chloroform:methanol and chloroform:methanol:HCl extracts were combined, the rate and extent of translocation were increased . These data demonstrate that at least two proteolipid proteins are necessary for ionophoric activity, the Mr 10,000 protein isolated by chloroform:methanol 2:1 and the {14C}DCCD-binding protein requiring acidified solvent for extraction.

Eur J Biochem, 1989 May 15, 181(3), 689 - 94
Isolation and partial characterization of a cytochrome-o complex from chromatophores of the photosynthetic bacterium Rhodospirillum rubrum FR1; Schrattenholz AS et al.; A cytochrome-o complex was isolated from chromatophores of photoheterotrophically grown Rhodospirillum rubrum FR1 . The enzyme was extracted with the non-denaturating detergent taurodeoxycholate and subsequently purified by sucrose-density-gradient centrifugation and gel-permeation HPLC . The complex contains two types of cytochromes, one of them cytochrome o, and two copper atoms . It catalyzes the reduction of molecular oxygen, when N,N,N',N'-tetramethyl-p-phenylenediamine or ubiquinol 10 are offered as electron donors . The oxidase activity is inhibited by cyanide, carbon monoxide and 2-heptyl-2-hydroxyquinoline N-oxide . The molecular mass of the protein is 136 +/- 15 kDa . The subunit analysis, by SDS continuous and gradient gels, revealed four subunits with molecular mass 66 kDa (subunit I), 36 kDa (subunit II), 20 kDa (subunit III) and 11 kDa (subunit IV).

Trends Biochem Sci, 1989 May, 14(5), 183 - 6
Nitrogenases without molybdenum; Pau RN; For 50 years molybdenum had been considered to have an indispensable catalytic function for nitrogen fixation . Two nitrogenases recently isolated from the bacterium Azotobacter have changed this view . One is a vanadium-containing enzyme and the other lacks both molybdenum and vanadium . Similar nitrogenases may occur in other nitrogen-fixing organisms.

Rev Infect Dis, 1989 May-Jun, 11(3), 440 - 51
Nature of protective immunity to Francisella tularensis; Tarnvik A; Tularemia is caused by the facultative intracellular bacterium Francisella tularensis . Attenuated live vaccines, such as F . tularensis LVS (live vaccine strain), afford good--although not complete--protection; how to judge the degree of this protection has long been a problem . Both natural infection and vaccination result in immunospecific and long-lasting humoral and cell-mediated immunity . The latter is the crucial protective mechanism, whereas the humoral response protects only against strains of reduced virulence, such as those used in the vaccines . Immune serum has been used to screen for structures of F . tularensis with the ability to induce a protective immune response . This immune serum is, however, primarily directed toward antigens different from those involved in cell-mediated immunity . Serum antibodies from primed individuals recognize carbohydrate capsule antigens of F . tularensis, whereas T lymphocytes recognize membrane polypeptides of the organism . The preparation of membrane polypeptides from F . tularensis is now facilitated by the availability of a capsule-deficient mutant of F . tularensis LVS . In vitro, several membrane polypeptides of the mutant stimulate T lymphocytes from vaccinees and from naturally infected individuals . Further studies of the mechanisms of induction of protective immunity should focus on these membrane polypeptides.

J Med Microbiol, 1989 May, 29(1), 13 - 7
Bovine platelet aggregation by Fusobacterium necrophorum; Kanoe M et al.; Fusobacterium necrophorum aggregated bovine platelets . The aggregation was paralleled by the haemagglutinating ability of the organism . Treatment of the bacterial cells with antiserum to the homologous purified haemagglutinin reduced the degree of platelet aggregation . Scanning electronmicroscopy revealed that little lysis of the affected platelets occurred during the 1-h incubation period . Purified haemagglutinin became bound to the surfaces of the platelet cells as shown by immunofluorescence microscopy . These observations suggest that platelet aggregation is mediated by the haemagglutinin and may be related to the pathogenicity of the bacterium.

Gene Anal Tech, 1989 May-Jun, 6(3), 57 - 61
A synthetic translation-terminator gene . A tool for dissecting the translation direction of a gene; Maruyama IN et al.; A 41-nucleotide-long duplex DNA, which contains the translation termination codon TAA in six reading frames and lactose operator sequence of Escherichia coli, has been synthesized . This fragment may be useful not only for producing a truncated protein encoded in a plasmid, but also for the identification of the precise coding region and translation direction of a bacterial gene in the cloned chromosomal segment . The synthetic fragment was inserted into beta-lactamase structural gene in pBR322 in order to test the in vivo activity . The plasmid produced mutant beta-lactamase reduced in size, as expected from the insertion site, and rendered the host bacterium constitutive for beta-galactosidase . Thus, termination codons and lactose operator in synthetic nucleotide appear to be functional in vivo.

J Bacteriol, 1989 May, 171(5), 2827 - 34
Microaerophilic growth and induction of the photosynthetic reaction center in Rhodopseudomonas viridis; Lang FS et al.; Rhodopseudomonas viridis was grown in liquid culture at 30 degrees C anaerobically in light (generation time, 13 h) and under microaerophilic growth conditions in the dark (generation time, 24 h) . The bacterium could be cloned at the same temperature anaerobically in light (1 week) and aerobically in the dark (3 to 4 weeks) if oxygen was limited to 0.1% . Oxygen could not be replaced by dimethyl sulfoxide, potassium nitrate, or sodium nitrite as a terminal electron acceptor . No growth was observed anaerobically in darkness or in the light when air was present . A variety of additional carbon sources were used to supplement the standard succinate medium, but enhanced stationary-phase cell density was observed only with glucose . Conditions for induction of the photosynthetic reaction center upon the change from microaerophilic to phototrophic growth conditions were investigated and optimized for a mutant functionally defective in phototrophic growth . R . viridis consumed about 20-fold its cell volume of oxygen per hour during respiration . The MICs of ampicillin, kanamycin, streptomycin, tetracycline, 1-methyl-3-nitro-1-nitrosoguanidine, and terbutryn were determined.

Int J Parasitol, 1989 May, 19(3), 235 - 40
Studies on the surface coat (glycocalyx) of the dauer larva of Anguina agrostis; Bird AF et al.; Imprints of the surface coat (glycocalyx) from the cuticles of living second stage dauer larvae (DL2) of Anguina agrostis (syn . A . funesta) have been examined using incident light fluorescence microscopy and scanning electron microscopy . These surface coats contain residues of N-acetyl-D-glucosamine which were detected by treatment with wheat germ agglutinin labelled with either fluorescein or rhodamine . They also contain protein which was demonstrated by treatment with either pepsin or trypsin . These enzymes inhibited the attachment of the coryneform bacterium Clavibacter sp . to the surface coat, indicating that proteins play a crucial role in the adhesion of these bacteria to the nematode . This inhibition of attachment was reversed within 18 h after removal of the DL2 from the enzymes, indicating that the nematode was capable of renewing its surface proteins.

Dent Cadmos, 1989 Apr 30, 57(7), 87 - 8
{Bacterial enzymatic activity in the oral cavity}; Calvarano G et al.; The research is intended to get knowledge of some enzymatic activity of Actinomyces Israeli bacteria isolated from the mouth of several subjects and it shows how such bacterium can give rise to erosive phenomena of the enamel of the teeth and also to infections of the periodontal through a process causing the formation of a cloudy halo in the cultures.

Biochem Biophys Res Commun, 1989 Apr 28, 160(2), 839 - 43
Cytochrome oxidase of an acidophilic iron-oxidizing bacterium, Thiobacillus ferrooxidans, functions at pH 3.5; Kai M et al.; Cytochrome oxidase of Thiobacillus ferrooxidans was partially purified . The oxidase preparation had haems a and c, and oxidized ferrocytochrome c-552 of the bacterium . The optimal pH of the reaction was 3.5 . The enzyme also oxidized the reduced form of rusticyanin, a copper protein of the bacterium . Our results indicate that the reduction of molecular oxygen by this enzyme may occur in the periplasm.

Biochim Biophys Acta, 1989 Apr 17, 974(1), 114 - 8
Absence of a bicarbonate-depletion effect in electron transfer between quinones in chromatophores and reaction centers of Rhodobacter sphaeroides; Shopes RJ et al.; Higher plants, algae, and cyanobacteria are known to require bicarbonate ions for electron flow from the first stable electron acceptor quinone QA to the second electron acceptor quinone QB, and to the intersystem quinone pool . It has been suggested that in Photosystem II of oxygenic photosynthesis, bicarbonate ion functions to maintain the reaction center in a proper conformation and, perhaps, to provide the protons needed to stabilize the semiquinone (QB-) . In this paper, we show that bicarbonate ions do not influence the electron flow, from the quinone QA to QB and beyond, in the photosynthetic bacterium Rhodobacter sphaeroides . No measurable effect of bicarbonate depletion, obtained by competition with formate, was observed on cytochrome b-561 reduction in chromatophores; on the flash-dependent oscillation of semiquinone formation in reaction centers; on electron transfer from QA- to QB; or on either the fast or slow recovery of the oxidized primary donor (P+) which reflects the P+QA- ----PQA or the P+QB- ----PQB reaction . The lack of an observed effect in Rhodobacter sphaeroides in contrast to the effect seen in Photosystem II is suggested to be due to the amino-acid sequence differences between the reaction centers of the two systems.

Biochem J, 1989 Apr 15, 259(2), 369 - 76
Postsecretory modifications of streptavidin; Bayer EA et al.; Streptavidin, an extracellular biotin-binding protein from Streptomyces avidinii, exhibits a multiplicity in its electrophoretic mobility pattern which depends both upon the conditions for growth of the bacterium and upon the protocol used in the purification of the protein . The observed structural heterogeneity appears to reflect the action of two types of postsecretory molecular events: proteolytic digestion of the intact Mr-18,000 subunit to a minimal molecular size (approx . Mr 14,000), and aggregation of the native tetramer into higher-order oligomeric forms . The extent of subunit degradation and/or tetrameric aggregation affects the capacity of a given streptavidin preparation to interact with biotin-conjugated proteins in different assay systems.

Am Rev Respir Dis, 1989 Apr, 139(4), 988 - 95
Long-term pulmonary sequelae after Legionella pneumophila infection in the hamster; Parenti CM et al.; It has been reported that infections with Legionella pneumophila can lead to chronic inflammatory and fibrotic reactions in the human lung . To better characterize the nature of the residual abnormalities caused by this bacterium, we inoculated Syrian hamsters intratracheally with 10(8) serotype 1 L . pneumophila organisms and assessed histologic, functional, and biochemical changes at intervals up to 180 days . Acutely, L . pneumophila caused an intense alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) response within the lower air spaces, air-filled lungs were noncompliant, and there was an associated 25 to 50% increase in the lung content of collagen and elastin after 10 days . An inflammatory response, consisting principally of AM and centered around the terminal bronchioles, was still prominent in some infected lungs after 90 and 180 days, and the severity of the inflammation was correlated with a persistent restrictive defect in the elastic behavior of the lung . However, by histologic examination, fibrosis was not prominent, and the more representative abnormality was one of mild, diffuse air-space enlargement . Frank emphysematous changes were present focally in some lungs . In addition, an irregularly distributed lymphocytic infiltrate and goblet cell metaplasia were present in the larger bronchi of infected animals . We conclude that a single infection with L . pneumophila is capable of causing long-term inflammatory reactions in the lung, with morphologic features of both fibrosis and emphysema.

Infect Immun, 1989 Apr, 57(4), 1263 - 70
DNA sequence of mip, a Legionella pneumophila gene associated with macrophage infectivity; Engleberg NC et al.; In a previous study, a 24-kilodalton (kDa) protein surface antigen of Legionella pneumophila was cloned into Escherichia coli and found to be expressed on the host cell surface . Subsequently, a site-directed mutation in this gene (designated mip) in L . pneumophila was found to impair the capacity of this bacterium to initiate intracellular infection in human macrophages . The work presented here indicates that the antigenic gene product is distinct from the 24- to 29-kDa major outer membrane protein of L . pneumophila . In addition, the antigen was identified as a highly basic protein on two-dimensional nonequilibrium polyacrylamide gels and on two-dimensional monoclonal antibody immunoblots . When the DNA fragment encoding this protein was sequenced, a long open reading frame of 699 base pairs was identified within a region to which antigen expression was previously mapped . mip mRNA isolated from both L . pneumophila and transformed E . coli had the same 5' end, as determined by primer extension analysis, indicating that the same promoter sequences are used in both species . A likely factor-independent transcriptional terminator was found 20 residues downstream of the stop codon, suggesting that mip is encoded on a monocistronic message . The inferred polypeptide began with a possible 20- to 24-residue signal sequence, and, as predicted by two-dimensional electrophoresis, had a molecular weight of 24,868 and was a potent polycation with an estimated pI of 9.8.

Infect Immun, 1989 Apr, 57(4), 1290 - 8
Actin accumulation at sites of bacterial adhesion to tissue culture cells: basis of a new diagnostic test for enteropathogenic and enterohemorrhagic Escherichia coli; Knutton S et al.; Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E . coli (EHEC) adhere to the intestinal mucosa and produce an attaching and effacing (AE) lesion in the brush border microvillous membrane; the AE lesion is characterized by localized destruction of microvilli and intimate attachment of bacteria to the apical enterocyte membrane . A similar lesion is seen when bacteria adhere in vitro to a variety of human tissue culture cell lines . In both cases, dense concentrations of microfilaments are present in the apical cytoplasm beneath attached bacteria . Using a fluorescein-labeled phallotoxin, we have shown that these microfilaments are composed of actin . Cells infected with EPEC and EHEC strains known from electron microscopic studies to produce the AE lesion all exhibited intense spots of fluorescence which corresponded in size and position with each adherent bacterium; cells infected with adherent E . coli strains known not to produce the AE lesion did not produce this striking pattern of fluorescence and were indistinguishable from uninfected control cells . These results indicate that such site-specific concentrations of cytoskeletal actin are characteristic of the AE membrane lesion and can form the basis of a simple, highly sensitive diagnostic test for EPEC and EHEC.

J Bacteriol, 1989 Apr, 171(4), 2235 - 7
Effects of inhibition of the B subunit of DNA gyrase on conjugation in Escherichia coli; Hooper DC et al.; Antagonism of the DNA gyrase B subunit in the donor bacterium by coumermycin or thermal inactivation inhibited transfer of plasmid R64drd-11 . Coumermycin also inhibited Hfr transfer, with kinetics after drug removal suggesting that transfer resumed from the point of inhibition, in contrast to inhibition with nalidixic acid, after which transfer reinitiated from the origin of transfer.

Eur J Biochem, 1989 Mar 15, 180(2), 393 - 8
Biochemical characterization of phi X174-protein-E-mediated lysis of Escherichia coli; Witte A et al.; Energetic and permeability properties of Escherichia coli cells were determined prior to and during lysis caused by expression of the cloned gene E of bacteriophage phi X174 . Before onset of cell lysis the transmembrane gradients for K+, Na+ or Mg2+/ions, the level of ATP and the membrane potential, were unaffected . All these parameters changed simultaneously at the time of lysis onset, as monitored by measurements of culture turbidity as well as by determining the various specifications over a period of 1 min . During cell lysis chromosomal DNA was fragmented whereas plasmid DNA was liberated in its intact supercoiled form . Cytoplasmic constituents were released almost entirely, as indicated by the activity of beta-galactosidase in the supernatant fraction of protein-E-lysed cells . Periplasmic enzymes were only found in limited amounts in the cell supernatant and most remained associated with the cell ghosts . Such ghosts exhibited no gross cell damage or morphological alterations when compared with intact E . coli by light microscopy . All parameters investigated indicated that protein-E-mediated lysis of E . coli is caused by the formation of a transmembrane tunnel structure through the envelope complex of the bacterium.

Nippon Saikingaku Zasshi, 1989 Mar, 44(2), 533 - 9
{An immune adjuvant activity of mycolic acid-containing glycolipid, trehalose-2,3,6'-trimycolate, derived from Gordona aurantiaca}; Ohtsubo Y et al.; A mycolic acid-containing glycolipid, trehalose-2,3,6'-trimycolate (GaGM), derived from Gordona aurantiaca, an acid-fast bacterium closely related taxonomically to Mycobacterium, was investigated for its immune adjuvant activity on cell-mediated responses in the mouse . I.V . injection of liposomes containing GaGM enhanced the generation of cytotoxic T-lymphocyte (CTL) against syngeneic and allogeneic tumor cells . In addition, the injection of GaGM augmented the natural killer (NK) activity and the antibody-dependent cellular cytotoxicity (ADCC) . These results suggest that the injection of GaGM induces the production of interleukin-2 (IL-2), since such effector cells as CTL, NK and K cells have been shown to require IL-2 for their development.

FEBS Lett, 1989 Feb 27, 244(2), 447 - 50
The crystal structure of the three-iron ferredoxin II from Desulfovibrio gigas; Kissinger CR et al.; The crystal structure of oxidized ferredoxin II from the sulfate-reducing bacterium Desulfovibrio gigas has been determined and refined at 1.7 A resolution . The folding of the polypeptide chain is similar to that of the 2{4Fe-4S} ferredoxin in Peptococcus aerogenes, except for an extended helical segment near the C-terminus . The single {3Fe-4S} cluster in D . gigas is similar to a {4Fe-4S} cluster, but lacks one Fe atom and is coordinated to Cys-8, -14 and -50 . The side chain of Cys-11 is not bound to the cluster, but is rotated toward the solvent and modified by some, as yet undetermined, chemical group . Cys-18 and Cys-42 form a disulfide bridge . A previously undetected extra amino acid is found after residue 55.

Gene, 1989 Feb 20, 75(2), 235 - 41
Identification of a gene required for the terminal step in erythromycin A biosynthesis in Saccharopolyspora erythraea (Streptomyces erythreus); Weber JM et al.; We have identified a transcription unit in the ermE region of the chromosome of the erythromycin (Er)-producing bacterium Saccharopolyspora erythraea (Streptomyces erythreus) that is briefly switched on at about the time that macrolide production commences . Disruption of the transcription unit, herein designated eryG, by insertion of an integrational plasmid vector, caused a block at the terminal step in the biosynthesis of erythromycin, the conversion of erythromycin C to A by O-methylation.

Biochem J, 1989 Feb 15, 258(1), 255 - 9
High-level expression of fully active yeast flavocytochrome b2 in Escherichia coli; Black MT et al.; Wild-type flavocytochrome b2 (L-lactate dehydrogenase) from the yeast Saccharomyces cerevisiae and three singly substituted mutant forms (F254, R349 and K376) have been expressed in the bacterium Escherichia coli . The enzyme expressed in E . coli contains the protohaem IX and flavin mononucleotide (FMN) prosthetic groups found in the enzyme isolated from yeast, has an electronic absorption spectrum identical with that of the yeast protein and an identical Mr value of 57,500 estimated by SDS/polyacrylamide-gel electrophoresis . N-Terminal amino-acid-sequence data indicate that the flavocytochrome b2 isolated from E . coli begins at position 6 (methionine) when compared with mature flavocytochrome b2 from yeast . The absence of the first five amino acid residues appears to have no effect on the enzyme-catalysed oxidation of L-lactate, since Km values for the yeast- and E . coli-expressed wild-type enzymes were identical within experimental error . The F254 mutant enzyme expressed in E . coli also showed kinetic parameters essentially the same as those found for the enzyme from yeast . The R349 and K376 mutant enzymes had no activity when expressed in either yeast or E . coli . The yield of flavocytochrome b2 from E . coli is estimated to be between 500- and 1000-fold more than from a similar wet weight of yeast (this high level of expression results in E . coli cells which are pink in colour) . The increased yield has allowed us to verify the presence of FMN in the R349 mutant enzyme . The advantages of E . coli as an expression system for flavocytochrome b2 are discussed.

J Biol Chem, 1989 Feb 15, 264(5), 2678 - 82
EPR studies with 77Se-enriched (NiFeSe) hydrogenase of Desulfovibrio baculatus . Evidence for a selenium ligand to the active site nickel; He SH et al.; The periplasmic hydrogenase containing equivalent amounts of nickel and selenium plus non-heme iron {NiFeSe) hydrogenase) has been purified from cells of the sulfate reducing bacterium Desulfovibrio baculatus (DSM 1748) grown on a lactate/sulfate medium containing natural Se isotopes and the nuclear isotope, 77Se . Both the 77Se-enriched and unenriched hydrogenases were shown to be free of other hydrogenases and characterized with regard to their Se contents . EPR studies of the reduced nickel signal generated by redox titrations of the enriched and unenriched (NiFeSe) hydrogenases demonstrated that the gx = 2.23 and gy = 2.17 resonances are appreciably broadened by the spin of the 77Se nucleus (I = 1/2) . This observation demonstrates unambiguously that the unpaired electron is shared by the Ni and Se atoms and that Se serves as a ligand to the nickel redox center of the (NiFeSe) hydrogenase.

J Mol Biol, 1989 Feb 5, 205(3), 511 - 8
Image reconstruction of the flagellar basal body of Caulobacter crescentus; Stallmeyer MJ et al.; The bacterium Caulobacter crescentus has a single polar flagellum, which is present for only a portion of its cell cycle . The flagellum is ejected from the swarmer cell and then synthesized de novo later in the cell cycle . The flagellum is composed of a transmembrane basal body, a hook and a filament . Single-particle averaging and image reconstruction methods were applied to the electron micrographs of negatively stained basal bodies from C . crescentus . These basal bodies have five rings threaded on a rod . The L and P rings are connected by a bridge of material at their outer radii . The E ring is a thin, flat disk . The S ring has a triangular cross section, the sides of the triangle abutting the E ring, the rod and the M ring . The M ring, which is at the inner membrane of the cell, has a different structure depending on the method of preparation . With one method, the M ring makes a snug contact with the S ring and is often capped by an axial button, a new component apparently distinct from the M ring . With the other method, the M ring is similar to that of S . typhimurium; that is, it contacts the S ring only at an outer radius and lacks the button . Averages of the rod-hook-filament subassembly ejected by swarmer cells reveal that the rod consists of two parts with the E ring marking the approximate position of the break . The structures of basal bodies from two mutants defective in the hook assembly were found to be indistinguishable from wild-type basal bodies, suggesting that the assembly of the basal body is independent of the hook or filament assembly.

Biochim Biophys Acta, 1989 Feb 2, 994(2), 138 - 41
Purification and partial characterization of glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum; Soliman A et al.; Glutamine synthetase (L-glutamate: ammonia ligase (ADP-forming), EC 6.3.1.2) from the photosynthetic bacterium Rhodospirillum rubrum grown under nitrogen fixing conditions has been purified to homogeneity . The purification procedure involves affinity chromatography on ADP-agarose type 2 as the major purification step . The recovery in the purification is 70% . The specific activity of the purified enzyme is about 10-times higher in the gamma-glutamyl transferase assay than in the coupled biosynthetic assay . The molecular weight was determined to 530,000 by native gradient polyacrylamide gel electrophoresis and to 500,000 by gel filtration . The subunits have an apparent molecular weight of 52,000 . Glutamine synthetase isolated from Rsp . rubrum which had been exposed to ammonium ions ('switch-off') before harvest had about 20% of the transferase activity compared with the enzyme purified from nitrogen-starved cells . The low-activity form showed two bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Scand J Dent Res, 1989 Feb, 97(1), 33 - 42
Outer membranous vesicles and leukotoxic activity of Actinobacillus actinomycetemcomitans from subjects with different periodontal status; Tervahartiala B et al.; Strains of A . actinomycetemcomitans (A.a) from juvenile periodontitis patients (JP), adult periodontitis patients (AP), and 14-yr-old healthy children were tested for the correlation between leukotoxin activity and the number of outer membranous vesicles measured in electron micrographs . To determine the potential for connective tissue destruction following the interaction of polymorphonuclear leukocytes (PMN) with the bacteria, the lysosomal release of neutrophil elastase was assessed . The highest potential to kill leukocytes and to release lysosomal elastase from them was observed in the strains isolated from JP patients . No correlation existed between leukotoxic activity and the number of outer membranous vesicles per bacterium when the data from A.a . strains from all sources were combined . Furthermore, no significant differences were found between the numbers of outer membranous vesicles in the three groups tested . The only significant correlation between the number of vesicles and leukotoxicity was found in the A.a . strains derived from the mouths of healthy children.

Electrophoresis, 1989 Feb, 10(2), 116 - 22
Genomically linked cellular protein databases derived from two-dimensional polyacrylamide gel electrophoresis; Neidhardt FC et al.; In its most useful form a cellular protein database should be genomically based, because it is the genome which determines both the total number of proteins a cell can make and the particular ones that will be made under any given condition . Such a database should trace each protein back to its structural gene, and should account for every structural gene of a cell . Recent advances in molecular biology greatly facilitate the construction of such gene-protein databases . The mapping of genes of unidentified proteins resolved from total cell extracts on two-dimensional gels can now be accomplished by largely biochemical methods, without the necessity of isolating mutants or performing genetic crosses . Other techniques permit one to search gels for the product of any newly discovered gene (or open reading frame) suspected of encoding a protein . Consequently, gene-protein indices can be built independently and simultaneously from either direction--deducing the genetic map from the protein pattern, or finding the protein pattern from information encoded in the genome . A database of this sort is being constructed for the bacterium, Escherichia coli . Given the current pace of DNA nucleotide sequencing, the development of total gene-protein indices for a variety of cells can be anticipated in the near future.

Aktuelle Traumatol, 1989 Feb, 19(1), 28 - 34
{Observations on post-traumatic osteitis}; Stuhldreier G et al.; The following study reports the frequency, the promoting factors, the therapy and her results of the 32 patients with posttraumatic osteitis we treated between 1984 and 1986 in the Surgical University Clinic Tubingen . Most of the primary injuries were caused by traffic-accidents; especially dangerous were those with motor-bikes, which led frequently via open fractures of the shank to osteitis . We saw the highest infection-rates after plate-osteosyntheses . The infects became obvious in most cases either about one month after the accident or a year later coinciding with the increased use of the limb . The most frequent bacterium was Staph . aureus both in the mono-infections and in the mixed-infections forming a third of the group . We always performed an operative therapy with the intention to stabilize the bone and to clean the infection-site . The strict performance of this management led to infect-suppression in all cases with the need of only one amputation.

Appl Environ Microbiol, 1989 Feb, 55(2), 340 - 7
Occurrence of two different forms of protocatechuate 3,4-dioxygenase in a Moraxella sp; Sterjiades R et al.; Two alternative forms of protocatechuate 3,4-dioxygenase (PCase) have been purified from Moraxella sp . strain GU2, a bacterium that is able to grow on guaiacol or various other phenolic compounds as the sole source of carbon and energy . One of these forms (PCase-P) was induced by protocatechuate and had an apparent molecular weight of 220,000 . The second form (PCase-G) was induced by guaiacol or other phenolic compounds, such as 2-ethoxyphenol or 4-hydroxybenzoate . It appeared to be smaller (Mr 158,000), and its turnover number was about double that of the former enzyme . Both dioxygenases had similar properties and were built from the association of equal amounts of nonidentical subunits, alpha and beta, which were estimated to have molecular weights of 29,500 and 25,500, respectively . The (alpha beta)3 and (alpha beta)4 structures were suggested for PCases G and P, respectively . On the basis of two-dimensional gel electrophoresis, the alpha and beta polypeptides of PCase-G differed from those of PCase-P . Amino acid analysis supported this conclusion . Both PCases, however, had several other properties in common . It is proposed that both isoenzymes were generated from different sets of alpha and beta subunits, and the significance of these data is discussed.

Int J Biol Macromol, 1989 Feb, 11(1), 49 - 55
Ability of the phototrophic bacterium Rhodospirillum rubrum to produce various poly (beta-hydroxyalkanoates): potential sources for biodegradable polyesters; Brandl H et al.; Studies have been carried out in order to optimize growth and culture conditions for the intracellular formation of poly(beta-hydroxyalkanoates) (PHA) in the phototrophic, purple, non-sulphur bacterium Rhodospirilum rubrum . Its potential to produce novel copolymers was investigated . Recently, it has become of industrial interest to evaluate these polyesters as potentially biodegradable plastics for a wide range of possible applications . On an industrial scale, the use of photosynthetic bacteria could harness sunlight as an energy source for the production of these materials . R . rubrum was grown anaerobically in the light on different linear and branched beta-hydroxycarboxylic acids and various n-alkanoic acids . Under nitrogen-limiting conditions a PHA content of up to 45% of cellular dry weight was detected . When R . rubrum was grown on different concentrations of various n-alkanoic acids, intracellular PHA production was detected on all acids used . In most of the cases, the storage polymer contained beta-hydroxybutyrate (HB) and beta-hydroxyvalerate (HV) monomer units . Grown on n-alkanoic acids with a chain length of four carbon atoms and more, R . rubrum produced a copolymer containing the beta-hydroxyhexanoate (HC) repeating unit in addition to the HB and HV monomer . Using beta-hydroxyheptanoic acid as the carbon source, a polyester which contained HB, HV, HC, and beta-hydroxyheptanoate was formed . These copolyesters represent a novel class of biodegradable thermoplastics . The results demonstrate the metabolic flexibility of R . rubrum to form many different types of polyesters which might substitute plastics synthesized from petrochemicals.

FEMS Microbiol Lett, 1989 Feb, 48(3), 279 - 82
Degradation of quinoline-4-carboxylic acid by Microbacterium sp; Roger P et al.; From soil enrichment culture of quinoline-4-carboxylic acid-degrading bacterium was isolated . The organism was identified as Microbacterium sp . Mutants were induced with N-methyl-N'-nitro-N-nitrosoguanidine . One mutant accumulated successively two metabolites which were identified as 2-oxo-1,2-dihydro-quinoline-4-carboxylic acid and 8-hydroxy-2-oxo-2H-1-benzopyran-4-carboxylic acid.

Presse Med, 1989 Jan 7-14, 18(1), 17 - 20
{Maternal-child transmission of Chlamydia trachomatis . A prospective inquiry in 168 pregnant women}; Francois P et al.; A prospective study was performed in 168 pregnant women in order to evaluate the frequency of perinatal transmission of Chlamydia trachomatis and to measure its effects on the child's health during his first 3 months of life . The micro-organism was detected by an immunoenzymatic method specific to Chlamydia antigens, and microimmunofluorescence was used for serological testing . Cervical smears taken at the end of pregnancy were positive in 3 women (1.7 per cent), while the sera of 37 women were positive for Chlamydia trachomatis . Altogether, 26.8 per cent of the women explored had had a contact with the micro-organism . Conjunctival smears taken from 1 month old infants were all negative, but 4 infants (out of 126) had positive nasal smears . The mothers of 2 of these had been exposed to the bacterium, but all 4 mothers had negative cervical smears . Antibody titres in 3-month old infants were 1.2 dilution on average below those found in the mothers . Women exposed to Chlamydia trachomatis are frequently unmarried; their pregnancies tend to shorter than normally, and their infants have more frequent episodes of rhinitis . These peculiarities are insufficiently pronounced to single out a population at risk that might benefit from detection of the bacterium.

FEBS Lett, 1989 Jan 2, 242(2), 405 - 8
Crystallization and preliminary X-ray analysis of porin from Rhodobacter capsulatus; Nestel U et al.; Porin monomers of the phototrophic bacterium Rhodobacter capsulatus were purified . Crystals were obtained from a solution of porin solubilized with the detergent octyltetraoxyethylene within 5 days using the vapor phase equilibration technique . The crystals were rhombohedral with an edge length of 0.4 mm . The space group was trigonal R3 with unit cell constants of a = b = 95 A, c = 147 A . Reflexions were observed to 3.2 A.

J Bacteriol, 1989 Jan, 171(1), 1 - 7
Involvement of coenzyme A thioesters in anaerobic metabolism of 4-hydroxybenzoate by Rhodopseudomonas palustris; Merkel SM et al.; The initial steps of anaerobic 4-hydroxybenzoate degradation were studied in whole cells and cell extracts of the photosynthetic bacterium Rhodopseudomonas palustris . Illuminated suspensions of cells that had been grown anaerobically on 4-hydroxybenzoate and were assayed under anaerobic conditions took up {U-14C}4-hydroxybenzoate at a rate of 0.6 nmol min-1 mg of protein-1 . Uptake occurred with high affinity (apparent Km = 0.3 microM), was energy dependent, and was insensitive to external pH in the range of 6.5 to 8.2 Very little free 4-hydroxybenzoate was found associated with cells, but a range of intracellular products was formed after 20-s incubations of whole cells with labeled substrate . When anaerobic pulse-chase experiments were carried out with cells incubated on ice or in darkness, 4-hydroxybenzoyl coenzyme A (4-hydroxybenzoyl-CoA) was formed early and disappeared immediately after addition of excess unlabeled substrate, as would be expected of an early intermediate in 4-hydroxybenzoate metabolism . A 4-hydroxybenzoate-CoA ligase activity with an average specific activity of 0.7 nmol min-1 mg of protein-1 was measured in the soluble protein fraction of cells grown anaerobically on 4-hydroxybenzoate . 4-Hydroxybenzoyl-CoA was the sole product formed from labeled 4-hydroxybenzoate in the ligase reaction mixture . 4-Hydroxybenzoate uptake and ligase activities were present in cells grown anaerobically with benzoate, 4-hydroxybenzoate, and 4-aminobenzoate and were not detected in succinate-grown cells . These results indicate that the high-affinity uptake of 4-hydroxybenzoate by R . palustris is due to rapid conversion of the free acid to its CoA derivative by a CoA ligase and that this is also the initial step of anaerobic 4-hydroxybenzoate degradation.

Carcinogenesis, 1989 Jan, 10(1), 39 - 41
Unsaturated lipids and intestinal bacteria as sources of endogenous production of ethene and ethylene oxide; Tornqvist M et al.; Studies of adducts to hemoglobin (Hb) have revealed levels of hydroxyethylations of i.a . N-terminus (valines) in knowingly unexposed animals and persons (non-smokers) . This paper describes some exploratory experiments with mice, carried out with the aim of tracing the origin of these background levels . It is shown that the hydroxyethylvaline content in Hb is higher in animals fed unsaturated lipids and lower in bacterium-free as compared to control animals . Lipid peroxidation and metabolism of intestinal bacteria, giving rise to ethene, precursor of ethylene oxide, are thus indicated to be sources of observed background hydroxyethylations.

Int J Immunopharmacol, 1989, 11(1), 1 - 7
Lymphocyte activation with release of soluble mediators induced by Thermoactinomyces vulgaris in vitro; Jagerroos HJ et al.; Murine spleen lymphocytes stimulated in vitro with a hypersensitivity pneumonitis-associated bacterium, Thermoactinomyces vulgaris, were found to secrete interleukin-2 up to 7 days after mitomycin C blockade . They exerted helper effect in secondary mitogen or antigen-induced lymphocyte proliferation . Cyclosporin A, an inhibitor of interleukin-2 synthesis, caused a complete abrogation of the helper effect, suggesting that the effect was mainly due to interleukin-2 . Indomethacin, an inhibitor of prostaglandin synthesis, enhanced the helper effect in some inbred strains of mice, indicating prostaglandin-dependent downregulation . The strain variation in the prostaglandin-induced downregulation was not H-2 linked.

Can J Microbiol, 1989 Jan, 35(1), 182 - 8
Expression and regulation of Halobacterium halobium phage phi H genes; Gropp F et al.; In this paper we describe five distinct modes of phi H gene expression: (i) transcription of phage phi H during lytic growth on the sensitive host bacterium (Halobacterium halobium strain R1); (ii) transcription of the circularized prophage phi H1 in strain R(1)24; (iii) transcription of the L region of phi H present as 12-kilobase-plasmid in the immune strain R1L; (iv) transcription during the lytic growth of phage mutants containing an ISH23/50 in the immune strain R1L; (v) transcription during lytic growth of ISH23/50-insertion mutants in the sensitive host bacterium R1 showing enhancement of early transcripts . The sequential expression of the phage genome is described together with a detailed analysis of the transcription of early lytic, constitutive, and immune genes that map in the L region . The putative promoter sequences determined for several phage genes were compared with the upstream sequences of the H . halobium DNA-dependent RNA polymerase large subunit genes and with the gene for the ribosomal protein S12 homolog of H . halobium . The similarity of these putative promoter elements revealed conserved motifs that are discussed in relation to the TATA-box motif recognized by the eukaryotic DNA-dependent RNA polymerase II.

Biorheology, 1989, 26(2), 359 - 75
Microrheological aspects of adhesion of Escherichia coli on glass; Xia Z et al.; The adhesion of both live and fixed bacteria (Escherichia coli) on glass has been studied under well-defined hydrodynamic conditions, created in an impinging jet apparatus . With this technique one can accurately measure the initial deposition rate jo on the surface, the average lifetime of a bacterium on the surface, tau esc, and the surface area blocked per deposited bacterium, normalized by its projected area, gamma . The experimental results are compared to theoretical results for equivalent spheres . It is found that near the stagnation point the deposition rate jo is mainly controlled by convective diffusive transport which, for rod-shaped Eschericia coli, with an axis ratio of about 2, is found to be equal to that for spheres . No differences in jo and tau esc were found between live and fixed bacteria at low flow rates . At high flow rates fixed bacteria adhered to the surface at a slower rate . In both systems jo was found to decrease suddenly at a distance of about 150 microns from the stagnation point, in contrast to systems of spherical particles for which jo is uniform over the surface . Most likely this is due to the rotation of the rod-shaped particles, which vary their distance to the surface periodically with time . The main difference between live and fixed bacteria, besides different deposition rates in strong flows, is that gamma is about 30% larger for fixed bacteria than for live ones, resulting in a much lower final coverage for fixed bacteria . These results imply a larger repulsion between fixed bacteria than between living ones . From detachment experiments we can conclude that not all bacteria stick to the surface with the same bond strength . The variation in the bond strength is due to the aging of the bonds between the bacteria and the surface . The average bond strength corresponds to an energy of about 13-15 kT.

Ann Biol Clin (Paris), 1989, 47(7), 428 - 37
{Lyme disease and Borrelia burgdorferi infections in Europe}; Monteil H et al.; Lyme disease is endemic in Europe . The strains of the causative agent, Borrelia burgdorferi, seem to be antigenically more heterogeneous than the North American isolates . The only documented vector for this bacterium in Europe is ixodes ricinus, but other vectors might be involved as observed in the United States . The tick hosts are not yet well documented in Europe . Human infection occurs principally during summer months . The clinical aspect of the disease has particular features in Europe: at the early stage of the disease, a single and large erythema chronicum migrans is observed on the skin; complications often include meningoradiculonevritis (Bannwarth's syndrome) and later, acrodermatitis chronica atrophians; arthritis is less frequent in Europe than in the USA . The culture of B . burgdorferi from the lesions is difficult . The diagnosis of the disease is performed on the basis of serological tests: immunofluorescence assay where the important thing is to define a cutoff titer; ELISA tests using either whole cells or supernatant of sonicated cells or flagellar antigen; passive haemagglutination for IgG; IgM solid phase haemadsorption; Western blot (immunoblot) seems interesting to perform on a research basis to determine to which protein antigens patients are responding with antibody . Once antibody production begins, it is usually in the form of IgM antibody to flagellin protein (41 kD), with time, both IgM and IgG antibodies to a variety of other antigens appear . Prophylaxis is based on health services and public education because a prompt removal of the tick diminishes risk of infection with B . burgdorferi (4 p . cent of cases after tick bite) . The treatment includes aminopenicillins or tetracyclines at the early stage . The second and third stages of borreliosis are treated by high doses aminopenicillins or cetriaxone.

Microbiol Immunol, 1989, 33(12), 1053 - 7
Isolation of the saprophytic strain of MC-3 and participation of the cell surface structure in predation; Takubo Y et al.; From a predatory bacterium, MC-3, a mutant strain which lost predation ability was isolated by chance selection . Biological properties of the mutant were the same as the parent except only saprophytic property . Properties of the parent and the mutant strains of MC-3, such as bacteriolytic activity of the culture supernatant, digestion of peptidoglycan of the host bacteria, and growth by utilizing the host cells or their cytoplasmic substances, suggested that cell surface structure of the host cell plays an important role in predation and host specificity.

Arch Oral Biol, 1989, 34(8), 649 - 56
Antigens of Actinobacillus actinomycetemcomitans identified by immunoblotting with sera from patients with localized human juvenile periodontitis and generalized severe periodontitis; Watanabe H et al.; Sonicated whole cell extracts and outer membrane proteins from this bacterium were analysed using sera from 31 young patients with localized juvenile periodontitis, 55 young adults with generalized severe periodontitis and from 31 healthy control subjects . The sonicate contained 13 major bands (14-78 kDa); a greater proportion of sera from patients with generalized periodontitis reacted with 40 and 70 kDa antigens when compared with sera from localized juvenile periodontitis and controls . In contrast, a lower proportion of sera from localized juvenile periodontitis reacted with the 29 kDa antigen when compared with severe periodontitis and controls . The outer membrane proteins contained four main antigens of 19, 24, 35 and 67 kDa, which reacted with sera from all three groups . Although, so far, the findings do not allow discrimination between the two diseases, antibody responses to the 29, 40 and 70 kDa antigens of A . actinomycetemcomitans may help in the assessment of severity of the disease in patients with periodontitis.

Arch Oral Biol, 1989, 34(6), 459 - 63
Activation of human natural killer cells by lipopolysaccharide from Actinobacillus actinomycetemcomitans; Lindemann RA et al.; Lipopolysaccharide (LPS) from the Y4 strain of this bacterium, which is implicated in the pathogenesis of juvenile periodontitis, was incubated with human peripheral blood lymphocytes (PBL) and its action compared to that of LPS from Escherichia coli . Both LPS augmented cytotoxicity measured against natural killer (NK) cell-resistant tumour targets within 24 h of incubation . Cytotoxicity was exclusively found in NK-enriched low-density large granular lymphocyte fractions, as separated by Percoll gradient . LPS activated NK cells without stimulating high levels of proliferation . The minimum concentration of A . actinomycetemcomitans LPS required to activate NK cells was 1 microgram/ml; higher concentrations did not significantly increase this activation . LPS had no synergistic effect on the induction of PBL cytotoxicity by interleukin-2 . In contrast, LPS pre-activated monocytes inhibited the induction of lymphocyte cytotoxicity by either interleukin-2 or LPS.

Comp Immunol Microbiol Infect Dis, 1989, 12(3), 63 - 70
Immunomodulatory properties of a strain of Mycobacterium chelonae . I . Mouse lymphocyte responses in vitro; Neway T et al.; Immunomodulatory properties of a strain of live Mycobacterium chelonae (Mch) was investigated in an in vitro lymphocyte transformation system . Murine splenocyte activation by this bacterium was characterized by polyclonal lymphoproliferative responses in a dose dependent fashion . Optimal doses ranging from 20 to 80 micrograms of Mch (wet weight) per ml of cell suspension induced a very significant mitogenic effect . Higher doses (100 micrograms) of Mch manifested a decreased rate of tritiated thymidine ({3H} TdR) uptake whereas responsiveness of splenic lymphocytes to lower doses (0.156 microgram) was not modified . Contrary to the splenocyte responses activation of murine thymocytes by this mycobacterium is characterised by a decreased proliferation as compared to the background count of unstimulated cells . Simultaneous addition of Mch with optimal doses of Concanavalin A (Con A) and Phytohemaglutinin (PHA) potentiated polyclonal mitogenic responses of murine splenocytes to these two lectins . However, proliferation of these lymphocytes to Lypopolysaccharide (LPS) induction was not modified . BALB/C and DBA/2 spenocytes were found to be more responsive to stimulation by this Mycobacterium as compared to those of C3H/Ou and to a lesser degree to those of C57BL/6 mice.

IMA J Math Appl Med Biol, 1989, 6(4), 243 - 55
Drawbacks of selection methods for synchronous cell growth: simulation techniques; Chadha-Boreham HK et al.; Investigations of Koch & Schaecter's (1962) model for the fission of a bacterium were carried out to resolve some conflict in the findings due to Takahasi et al . (1968) and Marr et al . (1969) . A computer simulation procedure was used to reexamine the work of Takahasi et al . Our results confirm their findings that a simple formulation of Koch & Schaecter's model predicts a synchronous growth curve which fits the data reasonably well . This contrasts with the predictions of a poor fit given by the complex formulations of Marr et al . However, there is a disagreement between our results and those obtained by Takahasi et al . It involves a relationship between independence of the life length of daughter and mother cells and the degree of synchrony in growth . The practical implications of the simulation results are that selection methods are unlikely to give perfect synchrony.

J Bacteriol, 1989 Jan, 171(1), 456 - 64
Isolation of mutants and genes involved in cytochromes c biosynthesis in Rhodobacter capsulatus; Kranz RG; Mutants of the photosynthetic bacterium Rhodobacter capsulatus that have combined deficiencies in the cytochrome b/c1 complex and other c-type cytochromes have been isolated . These mutants were unable to grow anaerobically in the light or dark but could grow aerobically . Cosmids with R . capsulatus wild-type DNA that complement the mutants have been used to construct genetic and physical maps of the affected genes . Complementation profiles with Tn5 and mini-Mu insertions in these cosmids and subcloned fragments from them indicated that at least three genes (called helA, helB, and helC) are involved in the defects in cytochromes c biosynthesis . The genes are clustered, and helC is transcribed away from helA and helB . Stable insertion mutants in each gene were constructed . It is postulated that helA, helB, and helC are involved in posttranslational processing during cytochromes c synthesis.

Acta Leprol, 1989, 7 Suppl 1, 175 - 6
Bacterial antigen processing in macrophages infected with the obligate intracellular bacterium, Mycobacterium avium; de Chastellier C et al.; The intracellular pathway followed by Mycobacterium avium antigens was studied by immunofluorescence and immunoelectron microscopy after infection in bone marrow-derived macrophages with live or gamma ray-killed bacteria . Rabbit antiserum raised against whole sonicated bacteria was used to localise antigens . The acidity of the phagosomal compartment was also investigated by immunoelectron microscopy . Preliminary results seem to indicate the phagosomal compartment is less acidified than lysosomes and that M . avium antigens are very slowly processed.

Acta Biochim Biophys Hung, 1989, 24(4), 361 - 75
Purification and properties of high potential iron-sulphur protein from Thiocapsa roseopersicina; Ciszewska H et al.; High potential iron-sulphur protein (HiPIP) has been purified to electrophoretic homogeneity from the photosynthetic bacterium Thiocapsa roseopersicina . The protein has a single polypeptide chain (molecular mass 10 kDa) containing one 4Fe-4S cluster . The midpoint redox potential (E = 0.35 V), isoelectric points and pH profile, as well as the absorption, circular dichroism and Mossbauer spectroscopic properties in the reduced and oxidized states have been determined . The protein is in the reduced state as isolated; upon oxidation by ferricyanide there are characteristic changes in its visible absorption and circular dichroism spectra . HiPIP contains no alpha helix, about half of the polypeptide chain assumes beta sheet conformation . Pronounced structural differences between the oxidized and reduced states have been observed in the aromatic amino acid and Fe-S cluster spectral regions . Mossbauer spectra of the HiPIP in the two redox states reveal further differences . The possible contribution of aromatic amino acid residues, to the redox transition is discussed.

Gene, 1988 Dec 15, 73(1), 121 - 30
Functional expression of the yeast Mn-superoxide dismutase gene in Escherichia coli requires deletion of the signal peptide sequence; Schrank IS et al.; Oligodeoxyribonucleotide-directed mutagenesis has been used to delete the leader sequence-coding region from the yeast gene specifying Mn-superoxide dismutase and thus enable its expression in Escherichia coli . The deletion of this leader was demonstrated to be an absolute requirement for the synthesis of an active yeast enzyme in the bacterium . Complementation analysis in E . coli has confirmed that the product of the truncated yeast gene is active in vivo as well as in vitro.

FEBS Lett, 1988 Dec 5, 241(1-2), 60 - 4
A methyl-CoM methylreductase system from methanogenic bacterium strain Gö 1 not requiring ATP for activity; Deppenmeier U et al.; Crude inside-out vesicles from the methanogenic strain Go1 were prepared via protoplasts . These vesicles catalyzed methane formation from methyl-CoM and H2 at a maximal rate of 35 nmol/min.mg protein . Methane formation by the vesicles did not depend on the addition of ATP . This was in contrast to conventionally prepared crude extracts from the same organism or from Methanosarcina barkeri which exhibited strict ATP dependence of methanogenesis . ATP analogues inhibited methanogenesis by extracts to a much higher extent than that by vesicles . Both, particulate and soluble components prepared from the crude vesicles by ultracentrifugation were necessary for ATP-independent methane formation from methyl-CoM and H2 . Hydrogenase activity was mainly associated with the particulate fraction whereas methyl-CoM methylreductase could be assigned to the soluble fraction . The detergent sulfobetaine inhibited methane formation from methyl-CoM without affecting hydrogenase or titanium citrate-dependent methylreductase activities, indicating that an additional membraneous component is involved in methanogenesis for methyl-CoM and H2.

J Microsc, 1988 Dec, 152 ( Pt 3), 795 - 802
Scanning tunnelling microscopy of biomacromolecules; Guckenberger R et al.; When imaging biomacromolecules with a STM, coating of specimens with a conductive layer is a convenient preparation method which provides a good rate of success . Utilizing evaporated platinum/carbon as a coating film we have investigated two biomacromolecules of very different appearance . The first of these is the HPI-layer, a natural two-dimensional protein crystal with a period of 18 nm, which is found on the surface of the bacterium Deinococcus radiodurans . The second specimen is type IV collagen which forms long triple-helical strands approx . 1.5 nm in diameter . The resulting STM pictures compare very well with electron microscopical images.

Biochem J, 1988 Dec 1, 256(2), 657 - 9
Microcoulometric analysis of trimethylamine dehydrogenase; Barber MJ et al.; Trimethylamine dehydrogenase, which contains one covalently bound 6-S-cysteinyl-FMN and one Fe4S4 cluster per subunit of molecular mass 83,000 Da, was purified to homogeneity from the methylotrophic bacterium W3A1 . Microcoulometry at pH 7 in 50 mM-Mops buffer containing 0.1 mM-EDTA and 0.1 M-KCl revealed that the native enzyme required the addition of 3 reducing equivalents per subunit for complete reduction . In contrast, under identical conditions the phenylhydrazine-inhibited enzyme required the addition of 0.9 reducing equivalent per subunit with a midpoint potential of +110 mV . Least-squares analysis of the microcoulometric data obtained for the native enzyme, assuming uptake of 1 electron by Fe4S4 and 2 electrons by FMN, indicated midpoint potentials of +44 mV and +36 mV for the FMN/FMN.- and FMN.-/FMNH2 couples respectively and +102 mV for reduction of the Fe4S4 cluster.

Appl Environ Microbiol, 1988 Dec, 54(12), 3057 - 63
Characterization of an extracellular lignin peroxidase of the lignocellulolytic actinomycete Streptomyces viridosporus; Ramachandra M et al.; Previously we reported production of an extracellular lignin-inducible peroxidase by Streptomyces viridosporus (M . Ramachandra, D.L . Crawford, and A.L . Pometto III, Appl . Environ . Microbiol . 53:2754-2760, 1987) . This peroxidase was shown to oxidize 3,4-dihydroxyphenylalanine, 2,4-dichlorophenol, homoprotocatechuic acid, caffeic acid, and N,N,N',N'-tetramethylphenylenediamine and was found in higher than normal levels in strains enhanced for lignocellulose degradation . In the present study, we used a pure extracellular enzyme preparation with high peroxidase isoform P3 activity to oxidize lignin substructure model compounds of both the 1,2-diaryl propane and arylglycerol-beta-aryl ether types and containing C alpha-carbonyl and C alpha-hydroxyl groups . The reactions were monitored by gas chromatography-mass spectrometry and high-pressure liquid chromatography techniques . In the presence, but not the absence, of hydrogen peroxide, the enzyme preparation catalyzed C alpha-C beta bond cleavage in the side chains of the diaryl ethers 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (I) and 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propan-1-one (II) and the diaryl ethane 1-(4-methoxyphenyl)-2-(phenyl)ethan-1-one (III) . Rapid hydrogen peroxide consumption was observed when the enzyme preparation was added to either milled corn lignin or lignocellulose . Additional characterizations showed that this enzyme is a heme protein (Soret band, 408 nm) and a major component of the ligninolytic system of S . viridosporus T7A . This is the first report of a lignin peroxidase in a bacterium . We have designated this new lignin peroxidase as ALiP-P3.

Am Rev Respir Dis, 1988 Dec, 138(6 Pt 2), S49 - 53
The effect of bacterial products on ciliary function; Wilson R et al.; Mucociliary clearance protects the respiratory epithelium against inhaled particles . There is in vitro evidence that some bacteria produce factors that cause ciliary slowing, dyskinesia, and stasis . These changes may predominantly affect ciliary function alone or be associated with epithelial disruption and cell death . Some factors act immediately, while others can take up to a number of days to achieve effect . It is postulated that rapidly acting factors may be involved during bacterial colonization, allowing the bacterium time (by slowing clearance) to penetrate the mucociliary barrier and reach putative receptors on the epithelial surface . The compounds might similarly facilitate contiguous spread through the bronchial tree and augment the tissue damage caused by the host inflammatory response during chronic bronchial sepsis . Future work should define more clearly the in vivo significance of the largely in vitro observations made to date.

J Bacteriol, 1988 Dec, 170(12), 5698 - 704
Dichloromethane dehalogenase with improved catalytic activity isolated from a fast-growing dichloromethane-utilizing bacterium; Scholtz R et al.; A methylotrophic bacterium, denoted strain DM11, was isolated from groundwater and shown to utilize dichloromethane or dibromomethane as the sole carbon and energy source . The new isolate grew at the high rate of 0.22 h-1 compared with 11 previously characterized dichloromethane-utilizing bacteria (micromax, 0.08 h-1) . The dichloromethane dehalogenase from strain DM11 (group B enzyme) was purified by anion-exchange chromatography . It was shown to be substantially different from the set of dichloromethane dehalogenases from the 11 slow-growing strains (group A enzymes) that had previously been demonstrated to be identical . The Vmax for the group B enzyme was 97 mkat/kg of protein, some 5.6-fold higher than that of the group A enzymes . The group A dehalogenases showed hyperbolic saturation with the cosubstrate glutathione, whereas the group B enzyme showed positive cooperativity in glutathione binding . Only 1 of 15 amino acids occupied common positions at the N termini, and amino acid contents were substantially different in group A and group B dehalogenases . Immunological assays demonstrated weak cross-reactivity between the two enzymes . Despite the observed structural and kinetic differences, there is potentially evolutionary relatedness between group A and group B enzymes, as indicated by (i) hybridization of DM11 DNA with a gene probe of the group A enzyme, (ii) a common requirement for glutathione in catalysis, and (iii) similar subunit molecular weights of about 34,000.

Proc Natl Acad Sci U S A, 1988 Dec, 85(23), 9012 - 6
Structure of the reaction center from Rhodobacter sphaeroides R-26 and 2.4.1: symmetry relations and sequence comparisons between different species; Komiya H et al.; Photosynthetic reaction centers from purple bacteria exhibit an approximate twofold symmetry axis, which relates both the cofactors and the L and M subunits . For the reaction center from Rhodobacter sphaeroides, deviations from this twofold symmetry axis have been quantitated by superposing, by a 180 degrees rotation, the cofactors of the B branch onto the A branch and the M subunit onto the L subunit . An alignment of the sequences of the L and M subunits from four purple bacteria, one green bacterium, and the D1 and D2 subunits of a photosystem II-containing green alga is presented . The residues that are conserved in all six species are shown in relation to the structure of Rb . sphaeroides and their possible role in the function of the reaction center is discussed . A method is presented for characterizing the exposure of alpha-helices to the membrane based on the periodicity of conserved residues . This method may prove useful for modeling the three-dimensional structures of membrane proteins.

Microbiologia, 1988 Dec, 4(3), 149 - 60
Partial purification and characterization of ADP sulfurylase from the purple sulfur bacterium Thiocapsa roseopersicina; Alguero M et al.; High activities of ADP and ATP sulfurylase were found in the soluble protein fraction of Thiocapsa roseopersicina strain 6311 (DSM 219) . ADP sulfurylase was partially purified and characterized . It was a very labile soluble enzyme with a molecular weight of 250,000 . The optimum pH was 7.5 and the optimal temperature 35 degrees C . Under test conditions the apparent Km values were determined to be 0.33 mM for adenylylsulfate and 13 mM for phosphate.

Arch Biochem Biophys, 1988 Nov 15, 267(1), 334 - 41
Purification and characterization of an extracellular endoglucanase from the marine shipworm bacterium; Greene RV et al.; Bacterial cultures isolated from the gland of Deshayes of marine shipworm (Psiloteredo healdi) produced extracellular endoglucanase activity when cultured with 1% cellulose . An endoglucanase of subunit relative molecular mass 58,000, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was purified to homogeneity from cell-free culture medium . Similarly, the relative molecular mass of the native enzyme was 60,100 as determined by gel permeation chromatography . No carbohydrate appeared to be associated with the purified protein . The action of the purified enzyme on various cellodextrins was also studied . Only interior glucosyl linkages of cellodextrin chains larger than cellotriose were cleaved by the enzyme and the centermost bond of cellohexaose was preferentially cleaved . The Km values of the purified endoglucanase were 0.12 mM for cellotetraose, 0.05 mM for cellopentaose, and 0.11 mM for cellohexaose . Glucose, cellobiose, and cellotriose did not inhibit enzymatic activity.

Arch Biochem Biophys, 1988 Nov 15, 267(1), 69 - 74
Selective inhibition of chlorophyll biosynthesis by nicotinamide; Shioi Y et al.; Rhodobacter sphaeroides grown in the presence of nicotinamide excreted bacteriochlorophyll precursors, 2,4-divinyl protochlorophyllide (DV-Pchlide) and a small amount of 2-monovinyl protochlorophyllide (MV-Pchlide) . Accumulation of these pigments indicates that nicotinamide inhibited the bacteriochlorophyll biosynthetic pathway site-specifically between DV-Pchlide and MV-Pchlide . This phenomenon is also observed in an aerobic photosynthetic bacterium, Erythrobacter sp . OCh 114 . Among 12 nicotinamide derivatives and isomers tested, only nicotinamide was effective, indicating that in addition to the completeness of the pyridine ring skeleton at positions 1 to 3, the carboxylic acid amide group is essential for this inhibition . The technique described in this report permits the simple preparation of large quantities of DV-Pchlide.

Allergy, 1988 Nov, 43(8), 586 - 92
Immunomodulating properties of lymphocytes activated by farmer's lung associated bacterium Thermoactinomyces vulgaris in vitro; Jagerroos HJ; Thermoactinomyces vulgaris, one of the aetiological agents of farmer's lung, was analysed for its ability to activate non-immune spleen lymphocytes from 10- to 14- week-old mice . The lymphocytes were found to exert both enhancing and suppressing signals after activation, depending on the secondary stimulation used . The enhancing effect is due to interleukin-2 secreted mainly by L3T4+ lymphocytes . The suppressive action is associated with Lyt2+ lymphocytes, which are probably activated by prostaglandins or histamine; but the suppression inducer action of L3T4+ lymphocytes may also be important . Genetic regulation, independent of H-2K and D, was also detected between different inbred strains of mice in response to T . vulgaris . The genetic regulation appeared associated with the different responsiveness of Lyt-2 positive lymphocytes between different strains . These results emphasize the importance of nonspecific activation in hypersensitivity disorders induced by microbiol antigens.

Am Ind Hyg Assoc J, 1988 Nov, 49(11), 584 - 90
Legionnaires' disease in the work environment: implications for environmental health; Muraca PW et al.; Legionnaires' disease is a severe pneumonia caused by the bacterium Legionella pneumophila . Outbreaks of Legionnaire's disease have occurred in hotels, hospitals, and homes but had not been reported yet in the work environment . The authors report the occurrence of Legionnaires' disease in three employees of two industrial plants . The potable water in the two plants contained high numbers of Legionella pneumophila . Monoclonal antibody subtyping of environmental and patient isolates of L . pneumophila implicated one of the plants as the source for the disease . L . pneumophila was eradicated from this plant using acidic and caustic scale removers, calcium hypochlorite, and a biocide . A systematic approach to Legionnaires' disease in the work environment, a problem which can be expected to be recognized with increasing frequency, is presented.

Mol Gen Genet, 1988 Nov, 214(3), 592 - 4
Functional expression of Aquaspirillum magnetotacticum genes in Escherichia coli K12; Waleh NS; Gene libraries from the magnetotactic bacterium, Aquaspirillum magnetotacticum were constructed in Escherichia coli with cosmids pLAFR3 and c2RB as vectors . Recombinant cosmids able to complement the thr-1, leuB, and proA mutations of the host were identified . The Pro+ recombinant cosmid restored wild-type phenotype in proA and proB but not in the proC mutants of E . coli . The results of restriction endonuclease digestion and Southern hybridization analysis indicate that the relevent leu and pro biosynthetic genes of A . magnetotacticum are not closely linked on the chromosome.

Appl Environ Microbiol, 1988 Nov, 54(11), 2737 - 41
Carbon allocation in wild-type and Glc+ Rhodobacter sphaeroides under photoheterotrophic conditions; Macler BA et al.; The photosynthetic bacterium Rhodobacter sphaeroides is capable of producing H2 via nitrogenase when grown photoheterotrophically in the absence of N2 . By using 14C-labeled malate, it was found that greater than 95% of this substrate was catabolized completely to CO2 during H2 production . About 60% of this catabolism was associated with H2 biosynthesis, while almost 40% provided reductant for other cellular purposes . Thus, only a small fraction of malate provided carbon skeletons . The addition of ammonium, which inhibited nitrogenase activity, increased substrate conversion into carbon skeletons threefold . Catabolism of malate occurred primarily via the tricarboxylic acid cycle, but gluconeogenesis was also observed . The wild-type organism grew poorly on glucose, accumulated gluconate and 2-keto-3-deoxygluconate, and did not produce H2 . More than 50% of metabolized glucose appeared in carbon skeletons or in storage compounds . A glucose-utilizing mutant was five times more effective in utilizing this substrate . This mutant produced H2 from glucose, using 74% of metabolized substrate for this purpose . Glucose converted to storage products or to other carbon skeletons was reduced to 8% . Fixation of CO2 competed directly with H2 production for reducing equivalents and ATP . Refixation of CO2 released from these substrates under H2-producing conditions was, at most, 10 to 12% . Addition of ammonium increased refixation of respired CO2 to 83% . Patterns of carbon flow of fixation products were associated with the particular strains and culture conditions.

Dent J Malays, 1988 Nov, 10(2), 31 - 5
Prevention of bacterial endocarditis in localised juvenile periodontitis and Papillon-Lefevre syndrome patients; Yusof ZA; The bacterium Actinobacillus actinomycetemcomitans is found in large numbers in subgingival plaque and gingival tissues of patients with LJP and PLS . This bacterium too has been found to cause infective bacterial endocarditis in patients at risk . Antibiotic prophylaxis is necessary for at risk patients with LJP and PLS because significant bacteraemia is produced during extensive periodontal instrumentation, extractions and surgery which are required in managing these cases . The current antibiotic regimens recommended by the American Heart Association/Council on Dental Therapeutics are not effective against this bacterium . A two-stage prophylactic approach is advocated, first with tetracycline for two weeks to eliminate the Actinobacillus actinomycetemcomitans, followed by the regimens recommended by the American Heart Association on the day of the dental procedure itself . Tetracycline should not be used concurrently or as a substitute for the recommended regimens by the American Heart Association/Council on Dental Therapeutics.

J Gen Microbiol, 1988 Nov, 134 ( Pt 11), 2889 - 95
Utilization of IncP-1 plasmids as vectors for transposon mutagenesis in myxobacteria; Saulnier P et al.; No free plasmid has ever been found in the myxobacterium Myxococcus xanthus, but IncP-1 plasmids are able to integrate into the chromosome of this bacterium . The frequency of integration depends greatly upon the structure of the IncP-1 plasmid used . This property has been used to devise new delivery systems for transposon mutagenesis in this species . Plasmids with low integration efficiencies have proved to be efficient donors of Tn5, while plasmids with very high frequencies of integration could be used directly to generate mutations . These vectors have also proved efficient for Tn5 transfer into other species of myxobacteria, which have not so far been susceptible to genetic analysis.

J Biochem Biophys Methods, 1988 Oct, 17(2), 119 - 25
A spectrophotometric assay for the degradation of the siderophore deferrioxamine B; Castignetti D et al.; A spectrophotometric assay using ferric perchlorate in a perchloric acid solution has been developed to monitor the degradation of the trihydroxamate siderophore deferrioxamine B to monohydroxamates . Using the ferric perchlorate solution and employing various concentrations of acetohydroxamic acid (as the model monohydroxamic acid) while maintaining a constant amount of deferrioxamine B resulted in the shifting of the absorption maximum from that of ferrioxamine B to longer wavelengths and toward that of a pure ferri-acetomonohydroxamic acid solution . A similar result was noted when a cell-free extract, from a bacterium capable of using deferrioxamine B as its sole carbon source, was given the siderophore in a phosphate buffer and aliquots of the enzyme-deferrioxamine B solution were removed for analysis . The assay may thus be used to monitor the formation of the monohydroxamic acid degradation products of the siderophore by the enzyme(s) in the cell-free extract.

J Antibiot (Tokyo), 1988 Oct, 41(10), 1331 - 7
Glidobactins A, B and C, new antitumor antibiotics . I . Production, isolation, chemical properties and biological activity; Oka M et al.; New antitumor antibiotic glidobactins A, B and C were isolated from the cultured broth of a gliding bacterium, Polyangium brachysporum sp . nov . No . K481-B101 . They are novel molecules carrying the common cyclic tripeptide nucleus substituted with different alpha, beta, gamma, delta-unsaturated fatty acids . Glidobactins exhibit broad inhibitory activity against fungi and yeasts, and prolong the life span of mice inoculated with P388 leukemia cells.

Biull Eksp Biol Med, 1988 Oct, 106(10), 417 - 9
{Parasympathetic component of the regulation of the kallikrein-kinin system in experimental pneumonia}; Perevozchikov PN et al.; Experimental vagus-bacterium pneumonia was modeled on 53 rabbits . Influence of nervous vagus on kallikrein-kinin system (KKS) was studied on 23 rats . It is obvious that disturbance of parasympathetic regulation may be an additional factor of KKS activation . Lowering of kinase II under experimental pneumonia was discovered both in the blood and in the lung . Activation of kinase II in the blood was after vagotomy . So parasympathetic regulation of kinase activity is of no significance in experimental pneumonia, and lowering of kinase activity is connected with bacterial factors.

J Chromatogr, 1988 Sep 9, 430(2), 329 - 39
Purification of ascitic fluid-derived murine monoclonal antibodies by anion-exchange and size-exclusion high-performance liquid chromatography; Hwang HH et al.; Ascitic fluid-derived murine monoclonal antibodies (MoAbs) of immunoglobulin (Ig) M and IgG isotypes (IgG1 and IgG2a subisotypes) were previously prepared against an isolate of Actinobacillus sp (CAs8C) for the purpose of identifying and characterizing outer membrane antigens on this bacterium . An attempt was made to purify these MoAbs by anion-exchange and size exclusion high-performance liquid chromatography (HPLC) . Hybridomas producing the IgG1 and IgG2a MoAbs posed unique difficulties in that they also secreted irrelevant IgG2b MoAbs that were present in the ascitic fluids . Anion-exchange chromatography (Protein-Pak DEAE-5PW column), with a simultaneous change in gradients of pH and ionic strength, was used to purify IgG and as a first step in the purification of IgM . There was good separation of IgG2b from IgG2a, but not from IgG1 . Size-exclusion chromatography (Protein-Pak 300 SW column) was required to complete the purification of IgM . The presence of MoAbs in the HPLC fractions was confirmed by discontinuous gradient polyacrylamide gel electrophoresis (denatured and either reduced or non-reduced conditions) and the enzyme-linked immunosorbent assay . HPLC-purified MoAbs were free from transferrin and albumin and retained their specificity for As8C.

Gene, 1988 Sep 7, 68(2), 173 - 80
The use of a chromosome integration vector to map erythromycin resistance and production genes in Saccharopolyspora erythraea (Streptomyces erythraeus); Weber JM et al.; The thiostrepton-resistance-conferring plasmid pIJ702 was integrated into the ermE region of the chromosome of erythromycin (Er)-producing bacterium Saccharopolyspora erythraea (Streptomyces erythraeus) by single, reciprocal (Campbell) recombination between DNA cloned in the vector and homologous nucleotide sequences in the chromosome . Genetic mapping experiments by conjugational transfer were used to establish that the ErR gene, ermE, was located close to the Er-production loci eryA34 and eryB25.

Biochimie, 1988 Sep, 70(9), 1291 - 6
Pore-forming colicins: synthesis, extracellular release, mode of action, immunity; Lazdunski CJ; Colicins are bacterial toxins encoded by plasmids which also confer immunity to producing cells . In a first stage, colicins are synthesized in the cytoplasm of colicinogenic cells . Subsequently they are released into the extracellular medium following the action of a small protein synthesized coordinately with the colicins . This protein is a lipoprotein and causes a non-specific increase in the envelope permeability, in particular, through the activation of an outer membrane phospholipase . After release into the medium, colicins kill sensitive cells in 3 defined steps: adsorption onto a specific receptor at the surface of the bacterium, translocation across the outer membrane and action . A specific domain of the colicin molecule is responsible for each of these steps . The most common colicins are those which kill by depolarizing the cytoplasmic membrane with the formation of voltage-dependent ionic channels . Immunity is conferred to producing cells by a membrane protein which interacts with the colicin and prevents formation or functioning of these ionic channels formed by its C-terminal domain.

J Bacteriol, 1988 Sep, 170(9), 4091 - 6
Pseudoauxotrophy of Methanococcus voltae for acetate, leucine, and isoleucine; Shieh J et al.; Methanococcus voltae is a methanogenic bacterium which requires leucine, isoleucine, and acetate for growth . However, it also can synthesize these amino acids, and it is capable of low levels of autotrophic acetyl coenzyme A (acetyl-CoA) biosynthesis . When cells were grown in the presence of 14CO2, as well as in the presence of compounds required for growth, the alanine found in the cellular protein was radiolabeled . The percentages of radiolabel in the C-1, C-2, and C-3 positions of alanine were 64, 24, and 16%, respectively . The incorporation of radiolabel into the C-2 and C-3 positions of alanine demonstrated the autotrophic acetyl-CoA biosynthetic pathway in this bacterium . Additional evidence was obtained in cell extracts in which autotrophically synthesized acetyl-CoA was trapped into lactate . In these extracts, both CO and CH2O stimulated acetyl-CoA synthesis . 14CH2O was specifically incorporated into the C-3 of lactate . Cell extracts of M . voltae also contained low levels of CO dehydrogenase, 13 nmol min-1 mg of protein-1 . These results further confirmed the presence of the autotrophic acetyl-CoA biosynthetic pathway in M . voltae . Likewise, 14CO2 and {U-14C}acetate were also incorporated into leucine and isoleucine during growth . During growth with {U-14C}leucine or {U-14C}isoleucine, the specific radioactivity of these amino acids in the culture medium declined, and the specific radioactivities of these amino acids recovered from the cellular protein were 32 to 40% lower than the initial specific radioactivities in the medium.Cell extracts of M . voltae also contained levels of isopropyl malate synthase, an enzyme that is specific to the leucine biosynthetic pathway, of 0.8 nmol min-1 mg of protein-1 . Thus, M . voltae is capable of autotrophic CO2 fixation and leucine and isoleucine biosynthesis.

Infect Immun, 1988 Aug, 56(8), 1831 - 6
Changes in infectivity and plasmid profile of the Lyme disease spirochete, Borrelia burgdorferi, as a result of in vitro cultivation; Schwan TG et al.; In vitro cultivation of Borrelia burgdorferi, the etiologic agent of Lyme spirochetosis, allows for the isolation and growth of this bacterium from infected tissues . However, continuous cultivation in modified Kelly medium causes a reduction in the number of detectable plasmids and the loss of infectivity in the white-footed mouse, Peromyscus leucopus . In an unpassaged culture of B . burgdorferi, nine plasmids were present, including seven linear plasmids ranging in size from 49 to 16 kilobases (kb) and two circular plasmids of 27 and 7.6 kb . The 7.6-kb circular and 22-kb linear plasmids were no longer detectable in spirochetes noninfective in white-footed mice, suggesting that a gene(s) encoding for factors responsible for infection may be present on one or more of these extrachromosomal elements . Furthermore, changes in spirochetal proteins and lipopolysaccharide-like material were observed also during early cultivation and may be related to loss of infectivity.

J Periodontol, 1988 Aug, 59(8), 493 - 503
Ultrastructural observations on bacterial invasion in cementum and radicular dentin of periodontally diseased human teeth; Adriaens PA et al.; In this study the bacterial invasion in root cementum and radicular dentin of periodontally diseased, caries-free human teeth was examined . In addition, structural changes in these tissues, which could be related to the bacterial invasion, were reported . Twenty-one caries-free human teeth with extensive periodontal attachment loss were studied by light and scanning electron microscopy . At the base of the gingival pocket, bacteria were found in the spaces between remnants of Sharpey's fibers and their point of insertion in the cementum . In teeth that had been scaled and root planed, most of the root cementum had been removed . Bacterial invasion was found in the remaining root cementum . The invasion seemed to start as a localized process, often involving only one bacterium . In other areas bacteria were present in lacunar defects in the cementum . These lacunae extended into the radicular dentin . In 11 teeth bacteria had invaded the dentinal tubules . Most bacteria were located in the outer 300 microns of the dentinal tubules, although occasionally they were found in deeper parts . In two of the nontreated teeth, bacteria were detected on the pulpal wall . No correlation was found between the presence of bacterial invasion and the absence of radicular cementum . No bacteria were found in the portion of the root located apically to the epithelial attachment . These data are in agreement with our results from cultural studies of the bacterial flora in these structures . It was also demonstrated that in spite of meticulous scaling and root planning and personal oral hygiene, bacterial plaque remained present on radicular surfaces . Both the invaded dentinal tubules and the lacunae could act as bacterial reservoirs from which recolonization of treated root surfaces occurs . From these reservoirs bacteria could also induce pulpal pathoses . Since these bacterial reservoirs are not eliminated by conventional mechanical periodontal treatment, it seems appropriate to combine mechanical periodontal therapy with the use of chemotherapeutic agents.

Am J Trop Med Hyg, 1988 Aug, 39(2), 173 - 8
Analysis and preparation of Bartonella bacilliformis antigens; Knobloch J; Twenty-four antigens of Bartonella bacilliformis, a bacterium which causes bartonellosis in residents of high altitude valleys of the Andes, were identified by immunoblot and immunoprecipitation using rabbit anti-Bartonella sera as well as sera of patients . The antigens were designated according to their relative molecular mass which ranged from 16 to 160 kDa . Twelve antigens were detected by antibodies in sera of bartonellosis patients using immunoblot, of which six antigens were detected by immunoprecipitation . Antigens 25, 46, 65, 75, 99, and 160 were identified as probable cell wall antigens . Antigens 50, 65, and 75 detected long-persisting antibodies . Crude Bartonella antigen applied to ELISA reacted with anti-Chlamydia psittaci antibody as well as with antibody of unknown identity in human sera, whereas immunoblot and immunoprecipitation with Triton soluble antigens revealed Bartonella-specific results . Seven Bartonella antigens were prepared by high performance liquid chromatography of which one antigen (48 kDa) reacted Bartonella-specific when applied to ELISA . It was concluded that specificity of antibody determination with crude Bartonella antigen should be confirmed by either immunoblot or immunoprecipitation.

Dis Colon Rectum, 1988 Aug, 31(8), 658 - 64
Lester R . Dragstedt 1893-1975 . Chronic ulcerative colitis . A summary of evidence implicating Bacterium necrophorum as an etiologic agent; Absence of a characteristic cell wall lipopolysaccharide in the phototrophic bacterium Chloroflexus aurantiacus; Institut fur Biologie II, Albert-Ludwigs-Universitat, Freiburg im Breisgau, Federal Republic of GermanyTwo strains of the gliding phototrophic bacterium Chloroflexus aurantiacus were investigated for the presence of lipopolysaccharide (LPS) . With both strains, all fractions of hot phenol-water extracts and the extracted cell residues from whole cells or cell homogenates were found to be free from characteristic LPS constituents, such as 3-hydroxy fatty acids, 2-keto-3-deoxyoctonate, heptoses, or O-chain sugars . Phenolchloroform-petroleum ether extracts were also free from precipitable LPS . A lipid A fraction could not be obtained, and there was no hint for glucosamine as a possible lipid A backbone amino sugar . Absence of LPS was confirmed by sodium deoxycholate gel electrophoresis.

Zentralbl Bakteriol Mikrobiol Hyg {A}, 1988 Jul, 269(1), 1 - 6
A new species of fish-pathogenic bacterium antigenically related to classical Brucellae; Gelev I et al.; A bacterial epizootic in trout (Salmo gairneri, Richardson) characterized by haemorrhagic diathesis is described in its acute and subacute form . The disease could be reproduced with the isolated new bacterial species . Two basic features characterize this bacterium: I . growth at 41 degrees C (water bath) on cultivation in solid and liquid media and 2 . antigenic relationship to the classical brucellae . Immunoelectrophoretic analysis revealed a common antigenic determinant in the LPS of the isolated fish-pathogenic bacterium and that of classical brucellae (S form).

Rev Infect Dis, 1988 Jul-Aug, 10 Suppl 2, S403 - 7
Identification, cloning, and purification of protein antigens of Treponema pallidum; Stamm LV et al.; Difficulties in culturing the bacterium Treponema pallidum have greatly hindered syphilis research . In recent years, several laboratories have begun applying recombinant DNA technology to the study of this organism . Recent work is summarized concerning the expression of T . pallidum DNA in Escherichia coli . A number of E . coli clones expressing treponemal protein antigens have been identified . In one instance, a recombinant protein was purified to homogeneity and shown to be identical to a highly immunogenic, native T . pallidum membrane protein of molecular weight 39,000, which was designated the basic membrane protein (BMP) of this organism . In addition, recent experiments are described that were designed to identify cell-surface proteins that would serve as the primary focus of our cloning efforts . Results obtained with use of several different approaches strongly suggest that the outer membrane of T . pallidum is an antigenically inert structure largely devoid of protein . However, a class of low-molecular-weight protein antigens have been identified that are actively secreted into the extracellular medium . Attempts currently are being made to clone these secreted proteins and investigate their roles in the pathogenesis and immunobiology of syphilis.

Rev Infect Dis, 1988 Jul-Aug, 10 Suppl 2, S282 - 6
The K1 capsular polysaccharide of Escherichia coli; Silver RP et al.; Epidemiologic, immunologic, and genetic evidence indicate that the K1 capsular polysaccharide confers invasiveness to Escherichia coli . The capsule, an alpha-2----8-linked homopolymer of sialic acid (NeuNAc), provides the bacterium with a physical antiphagocytic barrier . Structural similarities between K1 and human tissue components suggest that immune tolerance may also be a factor in pathogenesis of K1 disease . The molecular and genetic events involved in the synthesis and export of the K1 polysaccharide were examined . The cloned K1 genes encode at least 12 proteins involved in capsule biosynthesis . These genes appear to be coordinately regulated and functionally clustered . One cluster is associated with the synthesis and activation of NeuNAc and includes the gene encoding CMP-NeuNAc synthetase . This enzyme catalyzes the activation of NeuNAc to CMP-NeuNAc . A second region, encoding five proteins, is associated with translocation of polysaccharide to the bacterial surface . The K1 polysaccharide is a poor immunogen in humans, and an understanding of the key reactions involved in K1 synthesis may help in providing an alternative to anticapsular immunity.

Can J Vet Res, 1988 Jul, 52(3), 331 - 7
Characteristics of verotoxigenic Escherichia coli from pigs; Gannon VP et al.; Porcine verotoxigenic Escherichia coli were characterized with respect to frequency of occurrence, serogroup, and association with disease, weaning, and selected properties of the bacterium . Of 668 strains of E . coli from southern Ontario pigs with enteric disease, 32 (4.8%) produced verotoxin at 10(3)-10(7) cytotoxic doses per mL of culture supernatant . Of 22 isolates which belonged to O serogroups 138, 139 and 141, 15 produced verotoxin . Among other enterotoxigenic types of E . coli, two of 57 isolates of O157:K"V17" and two of 96 isolates of O149:K91 were verotoxigenic . The remaining 13 verotoxigenic E . coli belonged to O groups 2, 107, 120, 121 and 130 . An additional 21 verotoxigenic E . coli belonging to O groups 138, 139 and 141 and three to O157:K"V17" were identified in a collection of 47 E . coli recovered from weaned pigs with enteric disease . Verotoxigenic E . coli were associated with postweaning diarrhea, bloody stools, sudden death and edema disease . They were isolated at similar frequencies (14%) from healthy weaned pigs, and from weaned pigs with enteric disease . Isolation rates from neonates were low and significantly different from rates in weaned pigs . Neutralizing antibody to verotoxin was not detected in the sera of 45 pigs, which included pigs from herds with a history of edema disease . Verotoxin was not associated with production of colicin, hemolysin, or enterotoxins or with any of 23 biochemical properties of the organisms . The serological data indicate that porcine verotoxigenic E . coli are not a common source of verotoxigenic E . coli for humans . Porcine verotoxin may play a role in postweaning diarrhea and absence of detectable neutralizing antibody in serum may be an important aspect of pathogenesis.

FASEB J, 1988 Jul, 2(10), 2591 - 5
Modulation of the hydrophobicity of glutamine synthetase by mixed-function oxidation; Cervera J et al.; Oxidative modification of Escherichia coli glutamine synthetase renders the enzyme susceptible to proteolytic degradation by a specific protease purified from the bacterium; native enzyme is not a substrate for the protease . A model oxidizing system consisting of ascorbate, iron, and oxygen was used to generate a series of glutamine synthetases of increasing oxidative modification . We assessed the effect of oxidative modification on the surface hydrophobicity of the glutamine synthetases, utilizing hydrophobic chromatography on a phenyl matrix . Initial exposure to the oxidizing system caused inactivation of the enzyme and generated a protein that was more hydrophilic than the native form; it was not a substrate for the protease . Continued exposure to the oxidizing system yielded a protein with additional oxidative modification . This form was distinctly more hydrophobic than the native form and it was very susceptible to proteolytic attack by the purified protease . Thus, oxidative modification modulates the surface hydrophobicity of glutamine synthetase, and this modulation can control susceptibility to proteolysis.

Biochim Biophys Acta, 1988 Jun 15, 960(3), 261 - 7
Regulation of the human leukocyte 5-lipoxygenase: stimulation by micromolar Ca2+ levels and phosphatidylcholine vesicles; Puustinen T et al.; Human leukocyte 5-lipoxygenase (EC 1.13.11.12) is unique among the human lipoxygenase not only in its requirement for free ionized calcium, but also in its regulation by a membrane-associated stimulatory factor, the 100,000 x g pellet . In the present study, phosphatidylcholine (PC) vesicles, in the absence of 100,000 x g pellet, exhibited a dose-dependent stimulatory activity on the 5-lipoxygenase, which was at least as effective as the 100,000 x g pellet . Furthermore, the enzyme was activated by isolated human neutrophil plasma membranes and to a lesser degree by endoplasmic reticulum . The chemoattractant peptide fMet-Leu-Phe (0.1 microM), GTP (10 microM), toxin from bacterium Bordetella pertussis (islet activating protein, 5 micrograms/ml) and their various combinations were unable to modulate the enzymatic activity of the 5-lipoxygenase . Stimulation of the 5-lipoxygenase by relatively low levels of free ionized calcium was observed both in the presence of the pellet and PC vesicles: maximal stimulation was seen at about 10 microM Ca2+ . The human leukocyte leukotriene A4 synthase activity also exhibited a similar requirement for free calcium ions . The present study indicates that the membrane-associated stimulatory factor of the human leukocyte 5-lipoxygenase may be replaced by PC vesicles . Moreover, the 5-lipoxygenase and leukotriene A4 synthase activities require significantly lower Ca2+ levels for maximal activation than has been reported previously.

Appl Environ Microbiol, 1988 Jun, 54(6), 1602 - 5
Identification of an anthraquinone pigment and a hydroxystilbene antibiotic from Xenorhabdus luminescens; Richardson WH et al.; The entomopathogenic bacterium Xenorhabdus luminescens produces a red pigment and an antibiotic in insect carcasses in which it grows and in axenic cultures . The pigment was purified and identified as the anthraquinone derivative 1,6-dihydroxy-4-methoxy-9,10-anthraquinone, which exhibits a pH-sensitive color change, i.e., it is yellow below pH 9 and red above pH 9 . The antibiotic was also purified and identified as the hydroxystilbene derivative 3,5-dihydroxy-4-isopropylstilbene.

J Biochem (Tokyo), 1988 Jun, 103(6), 1011 - 5
Trimethylamine N-oxide respiration by aerobic photosynthetic bacterium, Erythrobacter sp . OCh 114; Arata H et al.; Erythrobacter sp . OCh 114, an aerobic photosynthetic bacterium, had trimethylamine N-oxide (TMAO) reductase activity, which increased when the culture medium contained TMAO . The reductase was located in the periplasm . The bacteria grew anaerobically in the presence of TMAO . These results suggested that Erythrobacter OCh 114 has the ability to reduce TMAO through the respiratory chain . The TMAO respiration system of this organism was different from those of facultative purple photosynthetic bacteria in two respects: (a) TMAO reductase did not have activity to reduce dimethyl sulfoxide and (b) soluble c-type cytochrome, cytochrome c551, and cytochrome b-c1 complex appeared to be involved . The photochemical activity, which is usually inoperative in the anaerobic cell suspension, was restored by TMAO, suggesting that the photosynthesis and the TMAO respiration share a common electron transfer chain.

Biochimie, 1988 Jun, 70(6), 803 - 9
Contribution of normal and error-prone ribosomes to translational error formation in vivo; Ringstrom K et al.; Introduction of tRNA missense suppressors, and/or a protease deficiency into Escherichia coli strains has no significant effect on misreading of non-sense codons . An increased cellular level of faulty proteins therefore does not seem to have much secondary effect on translational accuracy . A genetic test system with two UGA non-sense mutations in the same fused lacIlacZ gene does not demonstrate any enrichment of error-prone ribosomes after read-through of the first non-sense codon in such strains . In contrast, the addition of sublethal amounts of streptomycin to a wild type strain appears to enrich error-prone ribosomes at the second non-sense codon, indicating the existence of a subpopulation of streptomycin-binding ribosomes . Ribosomes in a ribosomal ambiguity mutant strain (rpsD) with or without tRNA missense suppressors appear to be functionally homogeneous with respect to error production, as judged by read-through of the double UGA codons . The results that the major contribution to translational error formation in vivo originates from normal ribosomes and not from error-prone defective particles . An increased translational error in a bacterium results in very little, if any, increased functional heterogeneity of the ribosomal population with respect to error production . This suggests that an autocatalytic formation of translational errors is unlikely to occur in a growing bacterium.

Eur J Clin Microbiol Infect Dis, 1988 Jun, 7(3), 406 - 7
Neonatal meningitis due to Gardnerella vaginalis; Berardi-Grassias L et al.; A case of meningitis due to Gardnerella vaginalis occurred in a five-day-old newborn who had clinical signs of fever, polypnea and a grey complexion . After treatment with ampicillin, cefotaxime and netilmicin, the patient's condition improved, and no sequelae were observed . The bacterium isolated from a pure culture of the cerebrospinal fluid was identified by biochemical characteristics to be Gardnerella vaginalis, but it was not possible to define the source and mode of contamination.

Eur J Biochem, 1988 May 16, 174(1), 177 - 82
The NADPH-linked acetoacetyl-CoA reductase from Zoogloea ramigera . Characterization and mechanistic studies of the cloned enzyme over-produced in Escherichia coli; Ploux O et al.; The NADPH-linked acetoacetyl-CoA reductase, (R)-3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.36), from the bacterium Zoogloea ramigera, involved in the formation of D-3-hydroxybutyryl-CoA for poly(D-3-hydroxybutyrate) biosynthesis, has been purified from an over-producing Escherichia coli strain . The purification was achieved in two steps, yielding an electrophoretically homogeneous enzyme of high specific activity (608 U/mg) . The enzyme is an alpha 4 homotetramer of four 25-kDa subunits . It has a Km of 2 microM and a kcat/Km of 1.8 X 10(8) M-1 s-1 for acetoacetyl-CoA; it is inhibited by acetoacetyl-CoA above 10 microM . K is 10(-10) M for the dehydrogenation . Kinetic studies of the back reaction revealed a sequential mechanism involving a ternary complex . The stereospecificity of the hydride-equivalent transfer was demonstrated using NMR techniques to be 4S (B side) . Using the fingerprint method proposed by Wierenga et al . {(1986) J . Mol . Biol . 187, 101-107}, we identified a 28-residue stretch (residues 3-31) as a possible NADPH fold . Finally the specificity of the reductase was examined using 3-oxo-acyl-CoA analogs and analogs lacking the adenosine 3',5'-bisphosphate moiety of CoA . Only the straight-chain C5 analog (3-oxo-propionyl-CoA) was found to be an alternative substrate (40%) for the reductase.

Cell, 1988 May 6, 53(3), 433 - 40
Transcription generates positively and negatively supercoiled domains in the template; Wu HY et al.; We show that transcription of a DNA molecule inside a bacterium is accompanied by local and temporal supercoiling of the DNA template: as transcription proceeds, DNA in front of the transcription ensemble becomes positively supercoiled, and DNA behind the ensemble becomes negatively supercoiled . Because bacterial gyrase and topoisomerase I act differently on positively and negatively supercoiled DNA, the formation of twin supercoiled domains during transcription is manifested by a large increase or decrease in the linking number of an intracellular plasmid when bacterial DNA gyrase or topoisomerase I, respectively, is inhibited . Such changes in linking number are strongly dependent on transcription of the plasmid in cis and on the relative orientations of transcription units on the plasmid . These results indicate that the state of supercoiling of bacterial DNA is strongly modulated by transcription, and that DNA topoisomerases are normally involved in the elongation step of transcription.

Eur J Biochem, 1988 May 2, 173(3), 483 - 9
Transcriptional regulation of genes for plant-type ribulose-1,5-bisphosphate carboxylase/oxygenase in the photosynthetic bacterium, Chromatium vinosum; Valle E et al.; The content of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the photosynthetic purple sulfur bacterium, Chromatium vinosum, grown either heterotrophically or autotrophically, was highly correlated with the level of 2.0-kb mRNA encoding genes for both large (rbcL) and small (rbcS) subunits . This result indicates the transcriptional regulation of Rubisco biosynthesis in Chromatium cells . In the analysis of transcripts for rbcL and rbcS in Escherichia coli transformed by a plasmid bearing both genes downstream of E . coli tac promoter (pCKS1), the mRNAs were found to be the same sizes as those from Chromatium . However, we were unable to detect mRNA for Rubisco in E . coli harboring a plasmid containing the genes for Rubisco and its own promoter without any E . coli promoters (pCUB1) . In the in vitro transcription experiment of pCKS1 and pCUB1 by E . coli RNA polymerase, it was observed that the enzyme could not recognize the Rubisco promoter . Therefore, we have purified RNA polymerase from Chromatium cells and developed a homologous in vitro transcription system . We have detected factor(s) for transcriptional regulation from either heterotrophically or autotrophically grown cells of Chromatium using the homologous in vitro transcription system.

Res Vet Sci, 1988 May, 44(3), 400 - 1
Experimental vaccination of rats with Dermatophilus congolensis zoospores; Davis D; The number of zoospores recoverable from the skin of rats five days after challenge with Dermatophilus congolensis, was reduced if the rats had been injected intradermally with zoospores of this bacterium two weeks previously . The difference between zoospore recovery in vaccinated and control rats was increased when the challenge was applied to scarified skin . Assays involving a 24-hour delay between scarification and challenge gave the greatest difference in zoospore recovery . In rats which had been vaccinated 12 weeks before challenge protection was reduced.

Mol Gen Genet, 1988 May, 212(2), 364 - 9
Evolutionary dynamics of tryptophan tRNAs in Mycoplasma capricolum; Yamao F et al.; Mycoplasma capricolum uses two tryptophan codons, the "universal" nonsense codon UGA and the universal codon UGG . The bacterium contains two tryptophan tRNAs, one with anticodon UCA, (U: 2'-O-methyl U derivative), and the other with CCA (5'-C: partially 2'-O-methylated) . tRNAUCA would translate codons UGA and probably UGG by wobbling . tRNACCA is much less charged by tryptophan in the cells than tRNAUCA, and the intracellular amount of tRNACCA is 5-10 times lower than that of tRNAUCA . The genes for these two tRNAs are separated by a terminator-like structure in a single operon . In vitro transcription experiments suggest that the predominance of tRNAUCA over tRNACCA results from the attenuation of transcription by this terminator-like structure.

Can J Microbiol, 1988 May, 34(5), 688 - 9
Bacterial tolerance of 100% dimethyl sulfoxide; Fedorka-Cray PJ et al.; Viable bacteria were found in six bottles of dimethyl sulfoxide (DMSO) at a concentration of approximately one bacterium per 4.4 mL . The 18 bacterial isolates appeared to be tolerating the DMSO rather than metabolizing it . No fungi were detected . DMSO must be assumed to be nonsterile unless it has been previously sterilized.

J Gen Microbiol, 1988 May, 134 ( Pt 5), 1339 - 53
New bacteriophages active on strains of Hyphomicrobium; Gliesche CG et al.; Fifty-five lytic bacteriophages isolated from water and soil samples were active on many strains of the genus Hyphomicrobium . The optimal isolation procedure was an adsorption method in which samples from a habitat similar to that of the respective host bacterium were used as the phage inoculum . According to the morphology and nucleic acid type these bacteriophages belonged to different families: Myoviridae (type A1: five phages); Styloviridae (type B1: 33 phages; type B2: eight phages) and Podoviridae (type C1: nine phages) . The Styloviridae (type B1) appeared in two morphological variants (tails flexible or rigid) . All phages investigated were specific for the genus Hyphomicrobium and were unable to lyse members of other genera of hyphal, budding bacteria (e.g . Hyphomonas, Pedomicrobium, genus D, genus T) . The host specificity of 42 phages was tested with 156 Hyphomicrobium strains: 122 strains were lysed by at least one of these phages, but 34 Hyphomicrobium strains were not susceptible . Morphotype B1 phages with identical morphology could be distinguished according to their host-range properties on prophage-containing Hyphomicrobium strains . With regard to differences in morphology and host range, 25 phages were selected for more detailed investigations . From these phages DNA was isolated; the melting transition midpoints (Tm) ranged from 67 to 93 degrees C . The upper and higher values suggested the presence of DNA modifications . Six different adsorption patterns could be distinguished among the Hyphomicrobium phages . Preferred attachment sites were the proximal pole of the mother cell, the hyphal tip, the distal pole of the bud, and the distal pole of the swarmer cell.

J Bacteriol, 1988 May, 170(5), 2406 - 8
Thioredoxin from Rhodospirillum rubrum: primary structure and relation to thioredoxins from other photosynthetic bacteria; Johnson TC et al.; Thioredoxin was isolated from a photosynthetic purple nonsulfur bacterium, Rhodospirillum rubrum, and its primary structure was determined by high-performance tandem mass spectrometry . The sequence identity of R . rubrum thioredoxin to Escherichia coli thioredoxin was intermediate to those of the Chlorobium thiosulfatophilum and Chromatium vinosum proteins . The results indicate that R . rubrum has an NADP-thioredoxin system similar to that of other photosynthetic purple bacteria.

J Bacteriol, 1988 May, 170(5), 2254 - 62
The moxFG region encodes four polypeptides in the methanol-oxidizing bacterium Methylobacterium sp . strain AM1; Anderson DJ et al.; The polypeptides encoded by a putative methanol oxidation (mox) operon of Methylobacterium sp . strain AM1 were expressed in Escherichia coli, using a coupled in vivo T7 RNA polymerase/promoter gene expression system . Two mox genes had been previously mapped to this region: moxF, the gene encoding the methanol dehydrogenase (MeDH) polypeptide; and moxG, a gene believed to encode a soluble type c cytochrome, cytochrome cL . In this study, four polypeptides of Mr 60,000, 30,000, 20,000, and 12,000 were found to be encoded by the moxFG region and were tentatively designated moxF, -J, -G, and -I, respectively . The arrangement of the genes (5' to 3') was found to be moxFJGI . The identities of three of the four polypeptides were determined by protein immunoblot analysis . The product of moxF, the Mr-60,000 polypeptide, was confirmed to be the MeDH polypeptide . The product of moxG, the Mr-20,000 polypeptide, was identified as mature cytochrome cL, and the product of moxI, the Mr-12,000 polypeptide, was identified as a MeDH-associated polypeptide that copurifies with the holoenzyme . The identity of the Mr-30,000 polypeptide (the moxJ gene product) could not be determined . The function of the Mr-12,000 MeDH-associated polypeptide is not yet clear . However, it is not present in mutants that lack the Mr-60,000 MeDH subunit, and it appears that the stability of the MeDH-associated polypeptide is dependent on the presence of the Mr-60,000 MeDH polypeptide . Our data suggest that both the Mr-30,000 and -12,000 polypeptides are involved in methanol oxidation, which would bring to 12 the number of mox genes in Methylobacterium sp . strain AM1.

Mol Microbiol, 1988 May, 2(3), 427 - 32
Covalent modification of ribulose 1,5-bisphosphate carboxylase/oxygenase in Rhodomicrobium vannielii; Mann NH et al.; The most abundant phosphorus-containing polypeptide in the purple non-sulphur bacterium Rhodomic-robium vannielii has been identified by a combination of immunoprecipitation and sucrose density gradient centrifugation as the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase . The covalent modification of the large subunit involves the phosphorylation of one or more tyrosine residues and appears to occur prior to assembly of the large subunit into the mature enzyme . In addition, the phosphorylated form of the large subunit was found to exist in at least two distinct protein complexes of Mr 410,000 and 440,000.

J Biochem (Tokyo), 1988 May, 103(5), 755 - 8
Enzymatic properties of ubiquinol:cytochrome c2 oxidoreductase in situ in Rhodopseudomonas palustris membranes; Takamiya K; The presence of ubiquinol:cytochrome c2 oxidoreductase was shown in the membranes from a photosynthetic bacterium, Rhodopseudomonas palustris . Some properties of the enzyme in situ were investigated . The optimal pH of this enzyme activity was 7.0 in the intact membranes . The activity was inhibited by both antimycin and myxothiazol . Maximal activity (Vmax) was 3-4 mol cytochrome c (c2) reduced/mol cytochrome c1.s . Apparent activity of the enzyme with horse heart cytochrome c as the electron acceptor decreased as the concentration of salts in the reaction mixture increased, whereas when R . palustris cytochrome c2 was used as the electron acceptor, the activity increased as the concentration of salts increased . Moreover, the activity of the enzyme did not depend on the species or concentration of anions but on both the concentration and valency of the cations of the salts . These salt effects were thought to be due to the change of effective concentration of cytochrome molecules caused by cations near the membrane surface, which was net negatively charged . Apparent Km for ubiquinol-1 was about 80 microM irrespective of the species of cytochrome and the presence of salts.

J Bacteriol, 1988 May, 170(5), 2126 - 35
Duplication insertion of drug resistance determinants in the radioresistant bacterium Deinococcus radiodurans; Smith MD et al.; Escherichia coli drug resistance plasmids were introduced into Deinococcus radiodurans by cloning D . radiodurans DNA into the plasmids prior to transformation . The plasmids were integrated into the chromosome of the transformants and flanked by a direct repeat of the cloned D . radiodurans segment . The plasmid and one copy of the flanking chromosomal segment constituted a unit ("amplification unit") which was found repeated in tandem at the site of chromosomal integration . Up to 50 copies of the amplification unit were present per chromosome, accounting for approximately 10% of the genomic DNA . Circular forms of the amplification unit were also present in D . radiodurans transformants . These circles were introduced into E . coli, where they replicated as plasmids . The drug resistance determinants which have been introduced into D . radiodurans in this fashion are cat (from Tn9) and aphA (from Tn903) . Transformation of D . radiodurans to drug resistance was efficient when the donor DNA was from D . radiodurans or E . coli, but was greatly reduced when the donor DNA was linearized with restriction enzymes prior to transformation . In the course of the study, a plasmid, pS16, was discovered in D . radiodurans R1, establishing that all Deinococcus strains so far examined contain plasmids.

Biochim Biophys Acta, 1988 Apr 14, 953(3), 226 - 31
Spectroscopic and ligand-binding properties of an oxygen-binding heme protein from Chromatium vinosum; Gaul DF et al.; Magnetic circular dichroism spectra were obtained for the oxidized and reduced forms of cyanide, azide and carbon monoxide complexes of an O2-binding hemeprotein isolated from the photosynthetic purple sulfur bacterium, Chronatium vinosum . Cyanide binding to the protein, which results in formation of a low-spin complex, was highly pH dependent with little complex formation observed at pH values near or below 7.

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