摘要:

The structural polypeptides of the cholera bacteriophagehave been analysed by sodium dodecyl sulphate – polyacrylamide gel electrophoresis. Eight different polypeptides were identified. The apparent molecular weights of the polypeptides were 143 000, 96 500, 68 000, 53 000, 37 500, 29 500, 21 000, and 13 500, respectively. The percentage of total protein corresponding to each polypeptide was estimated.

ISSN:0008-4166    

DOI:10.1139/m81-011

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

A peripheral leukocyte migration inhibition test has been used to demonstrate cellular immunity to a protein component ofNeisseria gonorrhoeae. Human leukocytes served as effector cells in an agarose method to distinguish antigen-sensitive from nonsensitive individuals. Leukocytes, preincubated with antigen, were placed in wells in medium 199 agarose. After 18 h of incubation the migration index was calculated by dividing the area of migration of cells preincubated with antigen by the area of migration of the control cells.Significant migration inhibition was demonstrated for 16 of the 30 patients with uncomplicated gonorrhoea. Maximum inhibition was obtained 7–10 days following the onset of symptoms and the duration of that response varied from 14 to more than 40 days. There was a statistically significant positive correlation between the number of previous infections and migration inhibition. A control group, which included individuals withNeisseria meningitidisinfection, showed an insignificant response to this gonococcal antigen.Although these results indicate the presence of cell-mediated immunity, the significance of this response in the protection of the host or in the pathogenesis of gonococcal disease has yet to be determined.

ISSN:0008-4166    

DOI:10.1139/m81-012

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Analysis of partially purified crude extract ofEscherichia coliK12 by chromatography and gel electrophoresis has resulted in the separation of three distinct activities which catalyse the reduction of nitrofurazone (semicarbazone of 5-nitro-2-furaldehyde) in the presence of oxygen (type I nitroreductases). The major enzymatic activity (type IA), which was dependent solely on NADPH as a cofactor, was absent from nitrofurazone-resistant strains NFR 402 and NFR 502, but present in SIL 41, a strain which is only marginally resistant to the nitrofuran. The remaining nitroreductase activities (IB1and IB2) utilize either NADH or NADPH as a cofactor. These activities coelute from DEAE-cellulose at pH 7.2, but may be differentiated by their behaviour on CM-cellulose at pH 5.8. The reductase activity missing in SIL 41 was observed in extracts of strain NFR 402 but not NFR 502. This enzyme (IB1) though retained by DEAE-cellulose had no affinity for CM-cellulose. The only reductase present in extracts of NFR 502 (a nitrofuran-resistant strain selected after two mutational events) was type IB2. This activity, also detectable in SIL 41 and NFR 402, has not been mapped genetically. An interesting feature of the type IB2enzyme is its apparent inactivation by MnCl2which has been routinely used as a partial purification step in the past.

ISSN:0008-4166    

DOI:10.1139/m81-013

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

The carbonic anhydrase activity and the growth ofNeisseria sicca19 were inhibited by the sulfonamide acetazolamide (10−5 M). Such inhibition was completely overcome by the addition of exogenous bicarbonate. Some carbonic anhydrase activity associated with the membranous envelope fraction of the cell was released when cells were broken by sonic treatment but not during cell breakage by high-pressure extrusion. After the selective solubilization (4 °C) of the inner membrane of envelopes by treatment with 1% sodium lauroyl sarcosinate, all detectable carbonic anhydrase activity was found in the soluble (inner membrane) fraction. After fractionation of the cell envelope into inner and outer membranes by treatment with ethylenediaminetetraacetate (EDTA) followed by sucrose density gradient centrifugation, the total and specific activity of carbonic anhydrase paralleled that of succinate dehydrogenase, an inner membrane enzyme marker. The Coomassie blue stained protein patterns after polyacrylamide gel electrophoresis of the bands from the sucrose density gradient provided confirmation that the inner and outer membranes had indeed been separated.

ISSN:0008-4166    

DOI:10.1139/m81-014

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Experimental pyelonephritis was produced in mice by the intravenous injection ofPseudomonas aeruginosa. Immune response to infection was studied by passive hemagglutination antibody titers. Vaccination of mice with liveP.aeruginosaor culture filtrates (Pseudomonasantigen) induced antibodies and resulted in a high degree of protection against death and pyelonephritis following subsequent hematogenous challenge with the homologous strain. Transfer of immune serum protected mice against death following infection with the homologous strain and with a heterologous strain. However, immune serum failed to protect mice from kidney infection by the heterologous strain. These data indicate that immune serum seemed to protect against early, overwhelming bacteremia but did not prevent a chronic course of kidney infection by a heterologous strain.

ISSN:0008-4166    

DOI:10.1139/m81-015

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Phenetic (numerical analysis) and genetic (DNA–DNA hybridization) studies were carried out on strains belonging or related to the speciesEscherichia coli. They have shown the diversity of its phenotypes, by the presence of plasmidic characters (citrate+, urease+, H2S+, tetrathionate reductase+, raffinose+, and saccharose+). New strains related phenetically toE.coliare also individualized. They showed less than 30% DNA relatedness withE.coli. A new definition ofE.coliis presented.

ISSN:0008-4166    

DOI:10.1139/m81-016

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Cell suspensions of methane-utilizing bacteria oxidizedn-alkanes (propane, butane, pentane, and hexane) to their corresponding alcohols and methyl ketones. The product alcohols and methyl ketones accumulated extracellularly. Methanol-grown cells of methane-utilizing bacteria did not oxidizen-alkanes. The product primary alcohol was detected in a cell-free system but only in a trace amount in the whole cell system due to further oxidation. The optimum conditions for in vivo formation of secondary alcohol and methyl ketone fromn-alkanes were compared between two distinct types of C1-utilizing microbes:Methylococcus capsulatusM1 (type I membrane) andMethylosinus trichosporiumOB3b (type II membrane). The production of acetone or 2-butanone fromn-alkanes ceased after 3 h of incubation for strain OB3b and 5 h for strain M1. The amount of these methyl ketones did not decline during 30 h of incubation. The optimum pH for the in vivo production of methyl ketones fromn-alkanes by both strains was around 7.0. However, secondary alcohols were accumulated at higher amounts around pH 6.0. The optimum temperature for the in vivo production of methyl ketones fromn-alkanes was around 40 °C for strain M1 and around 30–35 °C for strain OB3b. Higher accumulation of secondary alcohol was detected at 30–40 °C for strain M1 and 25 °C for strain OB3b.The alkane hydroxylation enzyme was located in the cell-free particulate fraction precipitated between 10 000 and 40 000 × gcentrifugation. The yield of primary and secondary alcohols fromn-alkane in the cell-free system was about equal. Evidence obtained indicates that the hydroxylation ofn-alkanes (both terminal and subterminal oxidations) is also catalyzed by the methane hydroxylation – alkene epoxidation enzyme system.

ISSN:0008-4166    

DOI:10.1139/m81-017

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

A virus was found in the ovarial calyx tissue ofMesoleius tenthredinis, an ichneumonid parasitoid; the "infection" was present inallfemales thus far examined. Virions were morphologically similar to typical baculoviruses. Apparent uncoating of viral nucleocapsids at nuclear pores was observed, indicating that reinfection of the calyx epithelium may occur. Electron microscopy of DNA extracted from calyx tissue suggests that the viral genome may be circular, and of high molecular weight.

ISSN:0008-4166    

DOI:10.1139/m81-018

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Viruses are described from several genera of ichneumonid parasitoids. New morphologic categories have been observed, one of which is similar to typical baculoviruses. Calyx particles from several species were found to contain polydisperse DNA's. An electrophoretic method for screening individual field-collected wasps for the presence of such DNA's is reported. DNA profiles obtained by this procedure were sufficiently consistent, within any particular affected species, to suggest that they could provide useful taxonomic information.

ISSN:0008-4166    

DOI:10.1139/m81-019

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Stationary phase yeast cells of the dimorphic fungusalbicanscan reinitiate growth under appropriate conditions either as yeasts through bud formation or as hyphae through germ tube formation and elongation. Stationary phase yeast cells resuspended in fresh medium at 37 °C form germ tubes and those resuspended at 25 °C form buds. Temperature shift experiments have been used to observe when cells become committed to germ tube formation and yeast budding growth under conditions favorable to each form. The two commitment processes appear to be independent and, once initiated, occur at characteristic rates with commitment to germ tube formation preceding commitment to yeast bud formation. The rate of commitment to germ tube formation was consistent with a random process or first-order kinetics. A relationship between cell volume and commitment to yeast growth and bud emergence was consistent with observations of cell volume distribution both in stationary phase cultures and between budded and unbudded cells during resumption of growth at 25 °C.

ISSN:0008-4166    

DOI:10.1139/m81-020

出版商:NRC Research Press    

年代:1981

数据来源: NRC