bluuebunny/crossref_metadata_2025 huggingface dataset:
Levamisole and bovine immunity: in vitro and in vivo effects on immune responses to herpesvirus immunization
Authors: Babiuk L. A. , Misra V.
Published: May 2010

Levamisole was shown to enhance in vitro blastogenic responses of bovine lymphocytes to nonspecific mitogens (phytohemagglutinin and pokeweed mitogen) as well as to infectious bovine rhinotracheitis virus and purified protein derivative. Greatest enhancement was observed at suboptimal concentrations of viral antigen. In addition to enhancing lymphocyte reactivity levamisole also affected macrophage activity as determined by increased Fc receptor activity and [3H]glucosamine incorporation. Levamisole (5–50 μg/mL) enhanced type II immune (or γ) interferon production by macrophage–lymphocyte cultures. Administration of levamisole and attenuated infectious bovine rhinotracheitis vaccine virus in vivo did not elevate cellular or humoral responses.
Factors affecting recovery of latent herpes simplex virus from human trigeminal ganglia
Authors: Lewis M. E. , Warren K. G. , Jeffrey V. M. , Shnitka T. K.
Published: May 2010

The rate of recovery of herpes simplex virus (HSV) from human trigeminal ganglia explant monolayers is affected by two factors: (1) time elapsed from the death of an individual to the establishment of in vitro culture of ganglia and (2) surface area onto which ganglia are explanted. Spontaneous reactivation of HSV from human trigeminal ganglia can be maximized when ganglia are obtained within 12 h of death and explanted onto a surface area of 250 cm2. Viruses isolated by explantation of human trigeminal ganglia were found to be uniformly HSV type 1 by restriction enzyme analysis.
Physiological controls of bacterial spinae production in complex medium and their value as indicators of spina function
Authors: Easterbrook K. B. , Sperker S.
Published: May 2010

Complex medium is rendered alkaline by the growth of marine pseudomonad D71, and in such a medium spinae are produced towards the end of log phase when the pH has increased over 7.5. Spinae production is unaffected by changes in oxygen tension and illumination but controlled by interactions of pH, salt concentration, and temperature. Under optimal laboratory conditions for growth a culture is partially spined but it becomes increasingly spined as growth temperature or pH is increased or ionic concentration decreased. By contrast, flagella are produced at low temperatures and pH, suggesting that spinae function in an opposite sense to flagella accommodating the bacterium to its environment. The conditions controlling spinae production are discussed in the context of possible spina function.
Restriction fragment analysis for differentiation of indistinguishable temperate coliphages
Authors: Dhillon T. S. , Dhillon Elvera K. S. , Linn Stuart
Published: May 2010

DNA of lambda and seven related phages was digested with restriction endonuclease, EcoRI. Seven different fragment patterns were observed, only two of the eight phages showing identical profiles. Restriction enzyme fragment analysis is thus shown to be a sensitive tool for the differentiation of biologically indistinguishable phages.
Competition for nodulation of Pisum sativum cv. Afghanistan requires live rhibozia and a plant component
Authors: Broughton W. J. , Samrey Ursula , Bohlool B. Ben
Published: May 2010

Nodulation of Pisum sativum cv. Afghanistan by Rhizobium leguminosarum strain Tom can be blocked by R. leguminosarum strain PF2 (isolated from P. sativum cv. Rondo) which does not form nodules of Afghanistan peas. We tested PF2 for its ability to produce bacteriocins and other compounds inhibitory to the growth of Tom. Neither strain was antagonistic toward the other. Similarly, there was no evidence for the production of inhibitors as the rhizobia grew in the plant rhizosphere. Apart from an already noted (Broughton et al. 1980. Can. J. Microbiol. 26: 562–565) ability of PF2 to accumulate on the root surfaces two to three times faster than Tom, we could not find a reason to explain the complete blocking of nodulation. In other experiments using PF2 (and Tom) killed by exposure to massive doses of gamma irradiation, dead cells still bound to the roots but they were incapable of blocking nodulation by living Tom. Finally, when both rhizobia were used to inoculate P. sativum cv. Rondo (they both form nodules on this plant), roughly one third of the nodules contained Tom, one third contained PF2, and one third contained both strains (i.e.,there was no evidence for competition). We conclude, therefore, that competition in this system is dependent upon live bacteria and requires cooperation from the plant.
The effect of growth media upon the ultrastructure of Blastomyces dermatitidis
Authors: Zahraee Mina H. , Wilson Thomas E. , Scheer Eleanor R.
Published: May 2010

The ultrastructure of yeast, intermediate transitional forms, and mycelia of Blastomyces dermatitidis cultured in brain heart infusion (BHI) was compared with that of like forms grown in leucine–glucose (LG) medium. Blastomyces dermatitidis yeasts were also grown in yeast extract – peptone (YP) medium and in glucose – yeast extract – peptone (GYP) medium, and their ultrastructures were compared with BHI-grown yeasts. Yeast, intermediate, and mycelial cells cultured in LG had more granular cytoplasm and better defined membranes than analogous BHI-grown cells. Yeasts grown in LG contained more glycogen and fewer lipid bodies and had no visible intracytoplasmic membrane systems. Some yeasts from LG cultures had bizarre shapes and structure. Intermediate and mycelial forms from LG cultures contained more glycogen and lipid bodies than analogous cells from BHI. Yeasts grown in YP had a more highly defined internal structure than BHI-grown yeasts. Some cells were doubly budded, and some were elongated. Similar elongated yeasts were found growing in GYP. Yeasts grown in GYP lacked a well-defined internal structure and had less glycogen than BHI-grown yeasts. They had no visible lipid bodies, but large vacuoles were present. Intrayeast hyphae were observed only in BHI-grown intermediate cells.
Role of exotoxin A and proteases of Pseudomonas aeruginosa in respiratory tract infections
Authors: Baker Neil R.
Published: May 2010

Hamster tracheal organ culture has been used to study the role of exotoxin A and proteases of Pseudomonas aeruginosa in infections of the respiratory tract. Tracheal explants infected with a toxin producing, protease producing strain or a toxin deficient, protease producing strain displayed evidence of exfoliation and disorganization of the tracheal epithelium 12 h after initiation of infection. A toxin producing protease deficient strain caused some desquamation of cells and cellular swelling, but exfoliation was not evident. Each of the toxin producing and (or) protease producing strains inhibited protein synthesis of the explants. Purified exotoxin inhibited protein synthesis and caused some pathological changes similar to those observed with the toxin producing strain. Purified elastase from P. aeruginosa only inhibited protein synthesis at 10 μg/mL but caused exfoliation at 0.01 μg/mL. Alkaline protease had no detectable effect on the explants. The effects of active infection could be prevented by treatment with gentamycin. All the strains tested caused an inhibition of ciliary activity, but no correlation could be made with any of the extracellular products. Exotoxin A and elastase may be responsible for much of the destruction of respiratory tract tissue in Pseudomonas infections although other bacterial factors and host factors are of importance.
Characteristics of the cellulase produced by Myceliophthora thermophila D-14
Authors: Sen Sribir , Abraham T. K. , Chakrabarty S. L.
Published: May 2010

A thermophilic fungus, isolated from the city wastes and identified as Myceliophthora thermophila D-14, produces cellulase and β-glucosidase. The optimum pH, temperature, and incubation period for extracellular enzymes acting on different types of cellulosic substrates were determined. The apparent Km values of these enzymes were ascertained by using culture filtrates. Partial purification of the enzymes was carried out by (NH4)2SO4 precipitation and gel filtration. Electrophoresis of the fractions obtained from gel filtration revealed at least eight components in the enzymes. The involvement of all the components for degradation of native cellulosic wastes, especially cotton, was determined and synergestic effects were indicated.
The differential susceptibility of gonococcal opacity variants to sex hormones
Authors: Salit Irving E.
Published: May 2010

Neisseria gonorrhoeae exist in transparent (Tr) and opaque (Op) colony forms. Op forms are recovered from patients early in the menstrual cycle; Tr colonies predominate late in the cycle. The mechanism for this colonial variation was examined by determining the influence of gonodal hormones on growth inhibition of Op and Tr isogenic variants of gonococci. The estrogens, estrone and estradiol, enhanced growth whereas 19-nortestosterone, testosterone, and progesterone significantly inhibited gonococcal growth. Testosterone and progesterone inhibited growth of the Op variants to a greater degree than the Tr variants. Mixtures of Tr and Op colonies grown in the presence of progesterone became predominantly Tr, as occurs in the luteal phase of the menstrual cycle. This study supports the hypothesis of hormonal influence on colonial variation but employed artificial in vitro conditions and high hormone levels.
Catabolite repression in Streptomyces venezuelae. Induction of β-galactosidase, chloramphenicol production, and intracellular cyclic adenosine 3′,5′-monophosphate concentrations
Authors: Chatterjee S. , Vining L. C.
Published: May 2010

Chloramphenicol production was studied in cultures of Streptomyces venezuelae growing in a simple buffered medium with ammonia as the nitrogen source and glucose, lactose, or a glucose–lactose mixture as the sole source of carbon. With each carbon source the antibiotic was formed during growth. In the glucose–lactose medium, the production pattern was biphasic; a marked decrease in the rate of synthesis was associated with depletion of glucose from the medium and a corresponding diauxie pause in growth. Cells of S. venezuelae contained an inducible β-galactosidase. Induction by lactose was suppressed by glucose. Measurement of the concentration of intracellular adenonsine 3′,5′-cyclic monophosphate during growth of cultures with glucose or a glucose–lactose mixture as the source of carbon showed no appreciable changes coinciding with depletion of glucose or the onset of chloramphenicol biosynthesis. It is concluded that the cyclic nucleotide does not mediate selective nutrient utilization or control antibiotic biosynthesis in this organism.
Selection of temperature-resistant mutants of Chinese hamster cells for growth on D-galactose
Authors: Thirion Jean-Paul , Aw E. J.
Published: May 2010

Somatic cell variants of Chinese hamster V79 were selected for rapid growth on D-galactose at high temperatures. Their phenotypes are stable after many generations in the absence of selection pressure. They clone in D-galactose at temperatures at which the wild type cannot, while in D-glucose, the variants and the wild type appear to have the same growth properties. The use of such variants should be very important for the study of gene regulation of carbohydrate metabolism in mammalian cells.
Factors affecting the lytic susceptibility of some marine and terrestrial bacteria
Authors: Laddaga Richard A. , MacLeod Robert A.
Published: May 2010

Eighteen gram-negative marine bacteria and two terrestrial species, Escherichia coli and Pseudomonas aeruginosa, were examined for their sensitivity to lysis in distilled water after exposure either to a salt solution containing a sea water concentration of Mg2+ (0.05 M) or to 0.5 M NaCl. A spectrum of lytic susceptibility was observed among the marine bacteria ranging from those organisms which lysed in distilled water after exposure to the Mg2+-containing solution, through organisms which could be sensitized to lysis by washing with the NaCl solution, to organisms which failed to lyse in distilled water even after having been washed with a solution of 0.5 M NaCl. Pseudomonas aeruginosa and E. coli fell within this spectrum, the former being capable of being induced to lyse in distilled water by washing with 0.5 M NaCl, while the latter failed to lyse in distilled water after this treatment. It was thus concluded that no overall distinction could be made between marine and terrestrial bacteria on the basis of the sensitivity of the two groups of organisms to lysis in freshwater.Quite large decreases in optical density and increases in the release of ultraviolet-absorbing material took place when cells preexposed to the Mg2+-containing solution or to 0.5 M NaCl were subsequently suspended in distilled water even though in some cases no loss of cell numbers could be detected. In most cases two to three times as much K+ as Na+ and 1/10 to 1/100 as much Mg2+ was required to prevent these changes. For three of the marine bacteria and P. aeruginosa grown in a terrestrial type medium little difference in the requirements for Na+ and K+ to prevent the optical density changes was noted. For P. aeruginosa grown in a marine type medium, cells required more K+ than Na+ to prevent these changes.
Immunological techniques to identify Azospirillum associated with wetland rice
Authors: Ladha J. K. , Barraquio W. L. , Watanabe I.
Published: May 2010

Azospirilla associated with wetland rice were isolated and characterized by employing immunodiffusion and immunofluorescence techniques. Antisera against two strains belonging to Azospirillum lipoferum produced at least one heat-labile precipitation band with most isolates of A. lipoferum and A. brasilense. Antisera against two strains belonging to A. lipoferum and one strain belonging to A. brasilense produced one band only with strains of their respective species. Fluorescent antibody reactions with Azospirillum were species specific. Specificity of these antisera and fluorescent antibodies was further demonstrated with bacteria other than Azospirillum.
Streptonigrin toxicity in Escherichia coli: oxygen dependence and the role of the intracellular oxidation–reduction state
Authors: Harley John B. , Fetterolf Caroline J. , Bello Cesar A. , Flaks Joel G.
Published: May 2010

The bacterial physiology of streptonigrin toxicity was further investigated. An optimal oxygen concentration for toxicity was inferred from data showing that steptonigrin at 5 µg/mL was rapidly lethal to aerobic cultures of Escherichia coli K12 JF361, but was without effect on anaerobic cultures and was bacteriostatic to cultures incubated in 5 atm of oxygen plus 1 atm of air (5 atm O2 plus air) (1 atm = 101.325 kPa). Escherichia coli were protected from a potentially lethal concentration of streptonigrin during anaerobic incubation, whether previously grown anaerobically, aerobically, or in 5 atm O2 plus air. Superoxide dismutase activity increased with increasing oxygen tension in the medium, but was not significantly changed by a lethal concentration of streptonigrin. Although the superoxide dismutase activity was four times greater in E. coli grown in 5 atm O2 plus air than those grown in air alone, the aerobic survival in 5 µg/mL streptonigrin was identical, which suggested that superoxide dismutase was not rate limiting for toxicity. Escherichia coli K12 strains deficient in glutathione (KMBL54-129, AB1157-821, and AB1157-830) were protected from streptonigrin poisoning. Dithiothreotol (5.0 mM), diamide (1 mM), methyl viologen (1 mM), and cyanide (10 mM) protected aerobic E. coli from 5 µg/mL streptonigrin.These data are also consistent with a model of in vivo streptonigrin toxicity that requires a favorable intracellular oxidation–reduction state and an optimal concentration of molecular oxygen.
Sporopachydermia quercuum, a new yeast species found in exudates of Quercus rubra
Authors: Lachance Marc-André
Published: May 2010

A new species of Sporopachydermia Rodrigues de Miranda has been isolated from exudates of red oaks (Quercus rubra). Morphologically, it resembles S. cereana by producing curved cells. Physiologically, it is closer to S. lactativora. It differs from both species by its lower maximum temperature of growth. The epithet quercuum is proposed to indicate its origin.
Activity of California encephalitis group viruses in Entrelacs (province of Quebec, Canada)
Authors: Belloncik S. , Poulin L. , Maire A. , Aubin A. , Fauvel M. , Jousset F. X.
Published: May 2010

During the summer of 1979, indicator rabbits were placed in three sites in Entrelacs (Laurentian area, province of Quebec) and mosquitoes were collected in order to monitor arbovirus activity in the area. Eight seroconversions to California encephalitis (CE) group viruses were detected in rabbits during June, July, and August. Twenty-five strains identified as members of the CE group were isolated: 3 were obtained from viremic rabbit sera, 1 from adult Aedes communis reared in the laboratory from field-collected larvae, and 21 from mosquito pools. Twenty-two of these were typed as snowshoe hare (SSH) virus. No evidence of La Crosse (LAC) virus was detected but three strains belonging to the CE group showed antigenic properties different from reference SSH, LAC, or Jamestown Canyon (JC) viruses. One isolate identified as Flanders virus was obtained from Culex pipiens. Three mosquito species (A. communis, A. punctor, and A. excrucians) were involved in the transmission cycle of SSH virus in Entrelacs. This is the first report, in the province of Quebec, of SSH isolation from animal sera and the first demonstration of its transovarial transmission.
Bacteriocin production by Pseudomonas syringae PsW-1 in plant tissue
Authors: Smidt Mary L. , Vidaver Anne K.
Published: May 2010

The production and activity of syringacin W-1, a particulate bacteriocin made by Pseudomonas syringae PsW-1, was studied in plant tissue. The bacteriocin is rod shaped, approximately 20 nm wide and 75 nm long, and composed of an outer sheath and inner core. Both the producing strain, PsW-1, and a sensitive strain, 16, grew within red kidney bean stems. Strains PsW-1 and 16, or mutants derived from them, were injected into bean stems singly or in mixtures. All singly inoculated strains grew well. However, when the bacteriocin-producing strain was co-inoculated with the sensitive strain, the latter grew poorly, if at all. This was not due to competition for available nutrients, since the sensitive strain grew as well in the presence of a bacteriocin-nonproducing mutant as it did alone. Also, a bacteriocin-resistant mutant grew as well in the presence of the producing strain as it did alone. Bacteriocin activity and particles were recovered from infected plant tissue.
Do corrinoids function in the methanogenic dissimilation of methanol by Methanosarcina barkeri?
Authors: Shapiro S.
Published: May 2010

The participation of corrinoids in the biosynthesis of CH3-S-CoM and CH4 from CH3OH by extracts of heterotrophically and autotrophically grown cells of Methanosarcina barkeri was investigated. Alkyl-B12 derivatives severely inhibited the transfer of the Co-methyl moiety of CH3-B12 to HS-CoM, but hardly affected the formation of CH3-S-CoM and CH4 from CH3OH. 1-Iodoalkanes completely suppressed methanogenesis from CH3OH, but only slightly inhibited the biosynthesis of CH3-S-CoM. Additionally, [methyl-3H]methylcobalamin could not be detected in cell-free extracts following biosynthesis of [methyl-3H]CH3-S-CoM from HS-CoM and excess [methyl-3H]CH3OH. These results indicate that methylcobalamin-HS-CoM methyl-transferase is not involved in the biosynthesis of CH3-S-CoM or CH4 from CH3OH by M. barkeri.
Inhibition of uridine 5′-diphosphate-N-acetylmuramyl-L-alanine synthetase by β-chloro-L-alanine in Escherichia coli
Authors: Ishiguro Edward E.
Published: May 2010

The synthesis of the nucleotide precursors for peptidoglycan is regulated by the relA gene in Escherichia coli. Thus, nucleotide precursors labeled with [3H]diaminopimelic acid accumulated in a relA strain but not in an isogenic relA+ strain during amino acid deprivation. Furthermore, nucleotide precursor synthesis was relaxed in the amino acid deprived relA+ strain by treatment with chloramphenicol. Uridine diphosphate-N-acetylmuramyl-pentapeptide (UDP-MurNAc-pentapeptide) was the major component accumulated during the relaxed synthesis of nucleotide precursors in both relA+ and relA strains. The effect of β-chloro-L-alanine (CLA) on the relaxed synthesis of nucleotide precursors for peptidoglycan was determined. At a low concentration (0.0625 mM) CLA inhibited the synthesis of UDP-MurNAc-pentapeptide and caused the accumulation of UDP-MurNAc-tripeptide. Thus, low concentrations of CLA probably inhibited alanine racemase, as reported previously. Higher concentrations of CLA also inhibited an earlier step in nucleotide precursor synthesis. This was shown to be due to the inhibition of UDP-MurNAc-L-alanine synthetase by CLA. CLA inhibited the activity of this enzyme in cell-free extracts as well as in intact cells.
Phenotypic differentiation of some of the Veillonella species with the API ZYM system
Authors: Kelley Roger W.
Published: May 2010

The genus Veillonella comprises at least eight deoxyribonucleic acid homology groups distinct at the species level. Conventional phenotypic tests are unable to differentiate these species. Use of the API ZYM system allows differentiation of four of the eight homology groups.
Breakdown and reassociation of bacterial spinae
Authors: Easterbrook K. B. , Coombs R. W.
Published: May 2010

The tubular appendage, spina (Easterbrook and Coombs. 1976. Can. J. Microbiol. 22: 438–440), dissociates most efficiently under conditions of low ionic strength (0.01 M), high pH (10), and high temperature (95 °C). The protomer, spinin, thus produced is stable under these conditions and reassociates on cooling to give two distinct filamentous polymeric structures that differ in their stability, protein conformation, and reassociation characteristics. Under conditions of low ionic strength (0.01 M), reassociation is relatively slow and leads to a product that has significant amounts of α-helix in addition to the high β-sheet component; under conditions of high ionic strength (1 M), reassociation is rapid and the non-β-sheet component is in the random coil configuration. Since polymerization of the latter structure is "seeded" by either endogenous or exogenously supplied spina fragments, the protomers comprising it are assumed to be in the same conformation as in the spinae. High ionic strength induces folding of the protomer, multimeric association, and finally, elongation by a temperature-dependent process. Reassociation appears to be pH (6–10) independent and, apart from a possible minor calcium effect, cation nonspecific.
Inhibition of ciliary activity in organ cultures of ferret trachea in reference to genetic and biological characters of influenza virus strains
Authors: Diaz-Rodriguez P. , Boudreault A.
Published: May 2010

As reported previously, attenuated stable inhibitor-resistant influenza viruses can be screened by a 50% ciliary activity inhibition test in ferret tracheal organ cultures. This test was further applied to 5 attenuated cold-adapted influenza strains and to 11 strains with known a percentage of RNA–RNA hybridization with the parental A/PR/8/34 (H0N1) virus strain. Again, with one exception, attenuated strains could be clearly differentiated from virulent ones. It was concluded that virulence of influenza strains for man can be detected using this test regardless of the techniques used to prepare attenuated variants. A preliminary screening of attenuated candidates for live influenza vaccines can be achieved with confidence on ferret tracheal organ cultures.
In vitro and in vivo association and subcellular distribution of toxic and experimentally modified endotoxin
Authors: Tavakoli Hassan , Moon Robert J.
Published: May 2010

Cell association and organ distribution of toxic and experimentally modified endotoxin were compared in whole animals and hepatoma tissue culture (HTC) cells. For both toxic and poly-L-α-ornithine mixed endotoxin in vivo, most of the endotoxin becomes associated with the reticuloendothelial system (RES) rich organs. Organ distribution does not change from 1 to 5 h. Significantly less detoxified endotoxin becomes associated with RES-rich organs.Association and nuclear transfer of toxic endotoxin in HTC cells are gradual and time-dependent processes. Plasma treatment increased association of endotoxin with HTC cells. Poly-L-α-ornithine (4 μg/mL) also significantly increases HTC cell association of endotoxin, and nuclear transfer of endotoxin was similar in principle to the toxic material. Association of detoxified endotoxin with HTC cells is significantly higher than toxic endotoxin and increases with time. In contrast with toxic and poly-L-α-ornithine mixed endotoxin, nuclear association of alkaline-treated detoxified endotoxin did not increase significantly during 5 h of incubation.Cumulatively, these observations indicate that while tissue culture cells could provide a more controllable experimental system by which to study the fate and pathogenic mechanism of endotoxin at the cellular and subcellular level, HTC cells under the conditions employed herein do not yield binding data which compare favorably with in vivo results. Caution must be exercised when extrapolating in vitro data to the actual in vivo action of endotoxin.
Adaptive resistance to polymyxin in Pseudomonas aeruginosa due to an outer membrane impermeability mechanism
Authors: Gilleland Jr. H. E. , Farley Linda B.
Published: May 2010

The isolated outer membrane from cells of a Pseudomonas aeruginosa strain exhibiting adaptive resistance to polymyxin was not affected by polymyxin treatment, as monitored by electron microscopy of negatively stained preparations. This was in sharp contrast with extensive disruption by polymyxin of the outer membranes of the parent polymyxin-sensitive strain and the resistant strain following reversion to greater polymyxin sensitivity. The isolated cytoplasmic membrane of the polymyxin-resistant strain, on the other hand, remained sensitive to the disruptive effects of polymyxin treatment. The permeability characteristics of the resistant strains appeared to be altered, as indicated by differences in minimal inhibitory concentrations for a variety of antibiotics between the polymyxin-sensitive and polymyxin-resistant strains. No evidence was found for a polymyxin-inactivating enzyme in osmotic shock fluid from the polymyxin-resistant strain. No evidence for a cytoplasmic membrane repair mechanism was found in the polymyxin-resistant strain. These observations suggest that the mechanism of adaptive polymyxin resistance in this model system is the alteration of the outer membrane so that it excludes polymyxin from reaching the still sensitive cytoplasmic membrane.
Characterization of bacteriocin 28 produced by Clostridium perfringens
Authors: Li A. W. , Verpoorte J. A. , Lewis R. G. , Mahony D. E.
Published: May 2010

Bacteriocin 28, produced by Clostridium perfringens, was characterized by gel filtration and sodium dodecyl sulfate – polyacrylamide gel electrophoresis as a glycoprotein with a molecular weight of approximately 100 000. Density gradient centrifugation suggested a lower weight of 84 000. The bacteriocin bound firmly to phenyl-Sepharose CL-4B gel, indicating hydrophobic properties, and elution from this gel with ethylene glycol clearly separated bacteriocin from the alpha and theta toxins of C. perfringens, the latter of which was also hydrophobic. Bacteriocin 28 was immunogenic, inducing neutralizing and precipitating antibodies, and possessed three isoelectric points: 7.37, 7.05, and 5.4. Amino acid and carbohydrate analysis of the active material showed a composition of 15 amino acids and several carbohydrates. The molecule demonstrated instability with increasing purification, and several approaches to purification are described.
The spermosphere model. I. Its use in growing, counting, and isolating N2-fixing bacteria from the rhizosphere of rice
Authors: Thomas-Bauzon Danièle , Weinhard Pierrette , Villecourt P. , Balandreau J.
Published: May 2010

The composition of the N2-fixing microflora of a rice rhizosphere was studied by a new enrichment and isolation procedure: rather than using an artificial C source, the exudates from a germinating seed ("the spermosphere model") are used. In this study, this system gave N2-fixing isolates with a frequency of 65%. Thirty-two of the many isolates obtained have been studied in detail; these were Klebsiella oxytoca, Enterobacter cloacae, Pseudomonas paucimobilis, and Azospirillum. All these bacteria were present at densities higher than 105 per gram of dry soil in the intial rice rhizosphere.
Biosynthetic ornithine and arginine decarboxylases: correlation of rates of synthesis with activities in Escherichia coli during exponential growth and following nutritional shift-up
Authors: Boyle Stephen M. , Adachi Kazuo
Published: May 2010

Whether guanosine tetraphosphate (ppGpp) has a role in the regulation of the putrescine biosynthetic enzyme, ornithine decarboxylase, in Escherichia coli is controversial. Different laboratories have reported either direct or indirect correlations between ppGpp levels and ornithine decarboxylase activity using different in vivo conditions. In this report, using conditions in vivo to modulate ppGpp levels, experiments are described which bear on the controversy. The rates of synthesis and biological activities of the biosynthetic ornithine and arginine decarboxylases (ODC and ADC) were measured in E. coli K-12 during experimental growth and during nutritional shift-up. There were good correlations between changes in their respective activities and the rates of synthesis of these enzymes during steady state or shift-up. ODC activity or rate of synthesis changed directly in concert with ppGpp levels, while ADC activity or rate of synthesis changed inversely with ppGpp levels. These observations support the contention that ppGpp does not inhibit ODC activity.
Sensitivity of methanogenic bacteria to dicyclohexylcarbodiimide
Authors: Sprott G. Dennis , Jarrell Ken F.
Published: May 2010

Methanospirillum hungatei strains GP1 and JF1 when exposed to the adenosinetriphosphatase inhibitor N,N′-dicyclohexylcarbodiimide experienced a marked decline in growth rates, methane synthesis activities, and intracellular ATP concentrations. Although growth was inhibited, the intracellular ATP concentrations of all other methanogens tested were little affected by high concentrations of dicyclohexylcarbodiimide (500 μM). Thus, for studies of ATP synthesis, or for ATP depletion in whole cell suspensions of methanogens, the use of dicyclohexylcarbodiimide appears limited to M. hungatei.
Characterization of indicator bacteria in municipal raw water, drinking water, and new main water samples
Authors: Clark J. A. , Burger C. A. , Sabatinos L. E.
Published: May 2010

Municipal water samples were analyzed by membrane filter (MF) and presence–absence (P-A) tests for pollution indicator bacteria. In four years, 11 514 bacterial cultures were isolated from either raw water, drinking water, or new main water samples submitted to three environmental laboratories. The bacterial species occurring most often in all types of water samples were Escherichia coli (11.6–39.7%), Enterobacter aerogenes (18.1–26.3%), Aeromonas hydrophila (8.8–17.0%), Klebsiella pneumoniae (7.7–10.3%), and Citrobacter freundii (5.09–22.7%). A lactose – lauryl tryptose – tryptone broth was examined as an alternative medium to modified MacConkey broth in the presumptive portion of the P-A test. The intensity of acid and gas production in presumptive positive P-A bottles was compared with the types and frequencies of indicator bacteria shown by confirmatory tests. The results of detecting indicator bacteria following the analysis of 53 130 samples over a 2-year period were arranged by water source (well, lake, river, mixed) and water type (raw or drinking) to determine the influence of these parameters on the recovery of indicator bacteria. A further subdivision of the sample types into raw surface, raw ground, in-plant, plant discharge, reservoir, and distribution samples demonstrated the effect of water treatment practices.
Response of Clostridium perfringens and its L form to bacteriocins of C. perfringens
Authors: Mahony D. E.
Published: May 2010

Clostridium perfringens strain No. 28 and its penicillin-induced stable L form were treated with 10 different bacteriocins of C. perfringens. Viable count and labelled amino acid incorporation experiments revealed that the L form was sensitive to two and possibly three bacteriocins to which the bacillus was not, while both forms were commonly sensitive to two other bacteriocins and resistant to five others. Adsorption of bacteriocin, immunity factors, or perhaps uptake of bacteriocin might be proposed to explain the responses of these organisms to bacteriocins.
Wine yeast isozymes. I. Genetic differences in 18 stock cultures
Authors: Subden R. E. , Irwin D. , Cunningham J. D. , Meiering A. G.
Published: May 2010

Electrophoretic analysis of three dehydrogenase and two reductase isozymes was performed on 18 commonly used yeast strains. Gene polymorphism was noted for all five isozyme activities. Based on the homology of banding patterns, two main groups of yeast strains were identified. No two yeast strains had identical banding patterns.
Serological types of Pasteurella multocida isolated from turkeys and chickens in Canada
Authors: Bhasin J. L.
Published: May 2010

Outbreaks of fowl cholera continue to plague the Canadian poultry industry despite widespread immunization against the causative agent, Pasteurella multocida. Fowl cholera bacterins currently employed by domestic poultry growers contain three serological types, namely, serotypes 1, 3, and 4. In this study a total of 84 strains of P. multocida were isolated in Canada from outbreaks of fowl cholera in turkeys and chickens. Serotyping was accomplished using the gel diffusion precipitin test. Based on the gel diffusion precipitation patterns, 27 serotypes containing one to six antigenic determinants were recognized. The most prevalent serotype both in turkeys and chickens appeared to be type 3. Significantly, greater than 20% of P. multocida isolates failed to react with antisera raised against serotypes 1, 3, and 4.
Differentiation in roller tube cultures of wild-type and two cyclic AMP mutant strains of the cellular slime mould Polysphondylium pallidum
Authors: Paterno Gary D. , O'Day Danton H.
Published: May 2010

Submerged cultures of wild-type Polysphondylium pallidum (WS320) undergo a developmental sequence in which cells agglutinate and form tight aggregates within which extensive stalk and some spore differentiation occurs. Development of submerged cultures of P. pallidum bears many similarities to fruiting body cultures except that differentiation occurs in the absence of morphogenesis. Here we extend the results of an earlier study of submerged cultures of P. pallidum WS320 (Paterno and O'Day. 1981. Can. J. Microbiol. 27: 924–936) by showing that these cultures respond to several exogenous agents (cyclic AMP, lithium chloride, ammonium chloride, colchicine, and concanavalin A) in the same way as slime mould fruiting body cultures. However, two mutants abnormal in cyclic AMP production which complement to form fruiting bodies on agar plates could not form normal submerged culture aggregates when mixed together. Complementation tests with mutant and wild-type cells also failed. The inability of the mutants (PN507 and PN518) to complement in submerged cultures suggests that their fruiting complementarity may be based on a morphogenetic event. A low molecular weight fraction from wild-type cells could enhance development and stalk cell differentiation in WS320 and one mutant, PN507, but not in PN518. Together these data reveal that submerged cultures can be utilized to test the effects of extracellular factors on development and used as a source for the isolation of factors that regulate cellular differentiation.
Incidence of plasmid DNA in Salmonella strains isolated from clinical sources in Ontario, Canada, during 1979 and 1980
Authors: Taylor Diane E. , Levine Jessie G. , Kouvelos Kallie L.
Published: May 2010

Gel electrophoresis of DNA from 70 clinical strains of Salmonella revealed a heterogeneous plasmid population. Plasmid DNA, ranging in molecular weight from 1.4 × 106 to 145 × 106, was demonstrated in 26 of 32 antibiotic-resistant strains. Several resistant strains carried up to six plasmids; however, of these, five strains which were multiply resistant contained a single plasmid of molecular weight 54 × 106 to 145 × 106. Only one incompatibility group H2 (IncH2) plasmid (pDT28) was detected in a strain of S. heidelberg; thus, this represents a reduction in the prevalence of these plasmids in Ontario Salmonella strains since 1974. The pDT28 plasmid resembled other IncH2 plasmids by its high molecular weight (145 × 106) and by virtue of its temperature-sensitive mode of transfer, resistance to tellurium, and inhibition of coliphage development. Of the 38 antibiotic-susceptible Salmonella strains, approximately half contained plasmids, ranging in molecular weight from 1.4 × 106 to 60 × 106. The plasmid-containing antibiotic-susceptible strains carried either a group of two to four small plasmids, with molecular weights less than 4.5 × 106, or a single large plasmid of molecular weight 23 × 106 or 60 × 106.
Genetic mapping of catabolite-resistant mutants of Bacillus subtilis
Authors: Sun Dongxu , Takahashi I.
Published: May 2010

Using mutants of Bacillus subtilis that are able to sporulate in the presence of relatively high concentrations of various carbon sources, catabolite resistance mutations were mapped by PBS1 transduction and transformation. Catabolite resistance mutations were localized at six different loci on the chromosome of B. subtilis. The map positions of our mutants suggest that they are distinct from sacUh, catA, and scoC reported by other investigators. Relations between our findings and initiation of sporulation have been discussed.
Phenotypic changes in colonial morphology of Neisseria gonorrhoeae
Authors: Norrod E. Pinina , Williams Robert P.
Published: May 2010

Phenotypic changes in the colonial morphology of four opacity variants of Neisseria gonorrhoeae strain F62 occurred upon growth in the presence of 14 mM pyruvate. Each of the naturally occurring opacity variants, a transparent, an opaque, and two deeply opaque, became more opaque; in addition, colonies of the opaque variants became rougher. Pyruvate did not appear to have a direct function in these colonial changes. Its effects were due to the ability of pyruvate to retard the oxidation of cysteine that was added to the medium in a defined supplement. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) of outer membranes showed that the opacity-associated proteins of the naturally occurring variants were not affected by growth in the presence of pyruvate; therefore, the induced opacity changes appear to have another basis. However, other proteins were affected. SDS–PAGE of the outer membranes, as well as of cell fractions composed predominantly of cytosol and of cytoplasmic membranes, revealed quantitative differences in the protein profiles after growth in the presence of pyruvate of each variant.
Autolysis of Penicillium oxalicum with special reference to its cell walls
Authors: Perez-Leblic M. I. , Reyes Fuensanta , Lahoz R. , Archer S. A.
Published: May 2010

Cultures of Penicillium oxalicum growing on a denned medium supplemented with yeast extract reached the onset of autolysis after 3 days at 25 °C. Thenceforth, autolysis was progressive and eventual reductions in dry weight of 96% were recorded by day 47. The pH of the medium fluctuated between 4.0 during the exponential phase of growth and 9.0 during autolysis. Electron microscopy of autolyzing cultures revealed a progressive loss of cytoplasmic ultrastructure. Digestion of the cell walls, with a rapid hydrolysis of the three external layers and a low hydrolysis of the two inner layers, was accompanied by deep pitting and by loss of the distinct five-layered structure. A lytic enzyme complex was obtained from the filtrates of extensively autolyzed cultures. It was rich in (1 → 3)-β-glucanase and other enzymes active against a range of fungal cell wall and storage polysaccharides. This enzyme complex degraded extensively isolated cell walls of P. oxalicum and three other Ascomycetes but had less effect on walls isolated from Mucor mucedo or Schizophyllum commune. In the case of P. oxalicum, cell walls harvested from young cultures were more readily digested than were the walls from older cultures.
The primary alkylsulfatase of Pseudomonas aeruginosa: inducer specificity and induction kinetics
Authors: Fitzgerald John W. , Franklin Bobbie L.
Published: May 2010

The ability of primary alkylsulfate esters and alkanesulfonates to induce alkylsulfatase formation in Pseudomonas aeruginosa was compared on the basis of maximum enzyme levels, induction rate, and levels of induction as a function of inducer concentration. Apparent Kinducer values for these effectors were calculated from linear relationships between reciprocals of induction rate and inducer concentration. Maximum enzyme levels estimated from linear progress relationships for each effector indicated that little major distinction could be made between effectors. Excepting carbon chain lengths of C8 which induced about the same level of enzyme, sulfate esters were generally better inducers than sulfonates with little or no apparent induction occurring with effectors of chain length ≤ C6. These observations also held true when rates were compared, except that the rate for the C8 ester was approximately ninefold greater than that for the analogous sulfonate. Apparent Kinducer constants decreased with increasing alkyl chain length for the esters (C6–C12) and the sulfonates (C8–C14). Values for the esters were approximately sixfold greater than those for sulfonates of equivalent chain length. Plots of log apparent Kinducer values against carbon chain length for each series of esters and sulfonates yielded straight-line relationships characteristic of an homologous series in each instance.
Characterization of intracellular polysaccharides of Streptomyces
Authors: Braña Alfredo F. , Manzanal Manuel B. , Hardisson Carlos
Published: May 2010

The intracytoplasmic accumulation of polysaccharides has been demonstrated in four species of Streptomyces. After extraction and purification, the structural properties of these polysaccharides were investigated by chemical, spectrophotometric, and enzymatic methods. The results clearly indicated that the streptomycete polysaccharides have a degree of branching and a macromolecular structure similar to that of the glycogens isolated from other bacteria and animal sources.
An examination of fluorescence and pigment production by Rhizopus species on coconut agar medium
Authors: Thompson D. P. , Eribo Broderick E.
Published: May 2010

On coconut agar medium, all species of Rhizopus examined produced an orange–yellow pigment when observed under incandescent light and a blue–green fluorescence under longwave ultraviolet light. However, results obtained from thin-layer chromatography suggested that the characteristics were due to the presence of secondary metabolites other than aflatoxin.
Further studies on the restriction of rubella virus replication in rat glial cells in culture
Authors: Pope David D. , Alstyne Diane Van
Published: May 2010

We have shown previously that normal rat glial cells in tissue culture are nonpermissive for rubella virus (RV) replication for up to 2 weeks postinfection and that during that time, only five of the seven intracellular polypeptides associated with a normal productive infection could be observed following autoradiography. In this note we report three changes observed to occur simultaneously upon continuous subculture of these infected glia. Cell morphology and growth characteristics were significantly altered, infectious viral particles could be detected in tissue culture media, and analysis of intracellular viral polypeptides revealed the synthesis of all seven polypeptides associated with a productive RV infection. These data indicate that under the appropriate conditions normal rubella virions may be reexpressed in a manner characteristic of many persistent viral infections. In addition, immunofluorescence techniques have been employed which show that during a nonproductive infection RV antigens are expressed in some glia which bear a striking morphological resemblance to oligodendrocytes.
Hysteretic activation of methanol-coenzyme M methyltransferase by ATP
Authors: Shapiro S.
Published: May 2010

The methanol-HS-CoM methyltransferase system in extracts of autotrophically cultivated Methanosarcina barkeri undergoes a time-dependent (hysteretic) activation by ATP. Cell-free extracts incubated with Mg-ATP, and then exhaustively dialysed, exhibit substantial methyltransferase activity in the absence of added ATP, which is inhibited by the addition of Mg2+ to the reaction mixture.
Establishment of cell cultures persistently infected with spotted fever group rickettsiae
Authors: Todd W. J. , Burgdorfer W. , Mavros A. J.
Published: May 2010

A cell line was established from the tunica vaginalis of meadow voles, Microtus pennsylvanicus, which could be persistently infected with the spotted fever group rickettsiae, Rickettsia rickettsii, R. rhipicephali, and R. slovaca. As determined by light and electron microscopy, all cells in the cultures became infected and remained so even after 20 serial passages over a period of months. The rickettsiae-infected vole cell line is an excellent experimental model to study the noncytolytic host–cell interactions required for persistence of spotted fever group rickettsiae in nature.
Cytochalasin A and respiratory inhibition in the water mold Achlya ambisexualis
Authors: Manavathu Elias K. , Thomas D. des S.
Published: May 2010

Cytochalasin A, a potent thiol-blocking fungal metabolite, inhibited respiration of the freshwater fungus Achlya ambisexualis rapidly and irreversibly. Spores, germlings, and mycelia of the fungus were susceptible; the order of susceptibility was mycelia > germlings > spores. Although cytochalasin A inhibited glucose uptake in Achlya germlings. the respiratory inhibition was not due to inhibition of substrate transport. Other cytochalasins tested (cytochalasins B, D, and E) had little or no effect on respiration. Among several other thiol blockers that suppressed respiration in Achlya, only mercuric chloride was more effective than cytochalasin A in inhibiting mycelial respiration. Maleimide derivatives, including N-ethyimaleimide, were one-fifth as effective as cytochalasin A. In isolated Achlya mitochondria, cytochalasin A inhibited oxidation of pyruvate but not of α-ketoglutarate or succinate. Inhibition of pyruvate oxidation was reversible and was not attributable to inhibition of mitochondrial uptake of pyruvate. Thiol blockers effective in the intact system also inhibited respiration of mitochondria. With the exception of reversibility, cytochalasin A inhibition of mitochondria and intact mycelium was similar in the parameters examined.
Microcycle conidiation in pycnidial cirrhii of Phomopsis viticola Sacc. Induced by elemental sulfur
Authors: Pezet R. , Pont V. , Girardet F.
Published: May 2010

On a synthetic medium containing elemental sulfur (SMGS), the growth of Phomopsis viticola Sacc. decreased considerably but pycnidia formation was highly stimulated. Secondary pycnidia, developed from spores in the cirrhii themselves, were observed. Formation of pycnidia directly from spores can be described as a microcycle stage. The role of endogenous elemental sulfur in P. viticola as a differentiation inducer in the biological cycle of the fungus is discussed on the basis of the action of elemental sulfur on cellular respiration and oxidative phosphorylation.