摘要:

The virus of herpes simplex was propagated in chick embryo tissue cultures. The rates of inactivation by gamma radiation of the infectivity and of the specific antigenicity of the infected fluid were determined. It was found that it was possible to destroy the infectivity of the bulk fluid and still retain specific complement-fixing activity. A diagnostic antigen of excellent potency and specificity can then be prepared by concentrating the irradiated fluid about 40-fold by ultrafiltration. After the addition of peptone to a concentration of 2% or arginine monohydrochloride to a concentration of 5%, the antigen can be lyophilized for stable storage. This diagnostic antigen can be produced more readily in quantity and with less exposure of personnel to infectious material than that prepared from infected chorioallantoic membranes.

ISSN:0008-4166    

DOI:10.1139/m70-010

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Quantitative recoveries of bacteria added to a number of soils were obtained using fluorescein isothiocyanate (FITC) as a stain. Enzyme fluorescence, using fluorescein diacetate or dibutyrate, could not be adapted for the routine counting of metabolizing organisms in soil. Staining with rose bengal gave recoveries of 60–80%.Soil-extract dilution plates revealed 4 × 107bacteria/g in the 0–10 cm layer in April and 27 × 107in October. One-third of this number was observed in the 20–30 cm layer. Actinomycete colonies added another 20% to the counts at the 0–30 cm depth but constituted 70% of the total colonies from the 90–120 cm depth. Microscopic counts indicated 2.2–4.6 × 109organisms/g of surface soil. The number of bacteria decreased in a linear fashion with depth but no relation was found between the numbers obtained by direct microscopy and those by plate counting. However, each of the methods showed a high relationship between the size of the bacterial population present at each depth on the different sampling dates.The observed bacteria, actinomycete spores, and hyphal segments averaged 0.6 × 1 μ. On this basis, the biomass in the top 30 cm, as determined by direct microscopy, ranged from 30 to 76 g/m2(dry weight basis). This implies, considering the amount of available energy, that the individual cells have enough energy to divide only a few times each year. Direct microscopic counting yields a quantitative picture of the organisms present but cannot separate between inactive cells, spores, and metabolizing organisms. Data from plate counts probably give a truer indication of metabolically active cells.

ISSN:0008-4166    

DOI:10.1139/m70-011

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

We have found that several inhibitors of the aggregation of human platelets also inhibit guinea pig haemolytic complement (C′). Hydroxyphenylbutazone and sulfinpyrazone were the most potent complement inhibitors among the chemicals studied in this investigation. They inhibited the haemolysis of EAC′142 by EDTA-C′. Chloroquine and hydroxychloroquine also inhibited complement. It is suggested that drugs which could inhibit both platelets and complement might prove beneficial in the treatment of thrombo-immuno-inflammatory conditions.

ISSN:0008-4166    

DOI:10.1139/m70-012

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Pectate lyase, produced byHypomyces(Fusarium)solanif. sp.cucurbitae, is considered a normal extracellular enzyme in that most of the enzyme was found in the culture medium during early stages of enzyme production and before extensive lysis. This enzyme was produced during active growth in the presence of citrus pectate but not citrus pectin. Enzyme yield was highest when the initial pH of the medium was between 5.5 and 7.5 and the temperature was between 25 and 29 C. Production of the enzyme was reduced when individual amino acids or inorganic N-sources were substituted for casein hydrolyzates. Glucose repressed enzyme formation when it exceeded 0.025%, while arabinose and xylose had little effect or stimulated greater production at 0.1%. Pectate lyase yield varied considerably, depending on fungus strain and inoculum level used. A delay in enzyme formation was reduced substantially when small amounts of agar were present in the liquid medium or the medium was solidified with agar.

ISSN:0008-4166    

DOI:10.1139/m70-013

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Cells of a marine pseudomonad were prevented from lysing when suspended in a 0.15 Msucrose solution even after treatment of the sucrose with an ion exchange resin to remove contaminating trace elements. Isolated cell envelopes of the organism in concentrations of sucrose able to prevent lysis of the cells released non-dialyzable hexosamine-containing material into the suspending medium. This did not occur when the envelopes were suspended in concentrations of NaCl able to prevent cell lysis. Glycerol was found to occupy almost all the available fluid space in a packed cell preparation of the organism. Sucrose occupied less space than glycerol, and inulin the least. When the sucrose concentration was increased from 3 mMto 0.2 M, both the sucrose and inulin spaces increased. The results have been interpreted as indicating that sucrose prevents lysis by balancing the internal osmotic pressure of the cells, that the various layers of the cell envelope of the organism differ in their permeability to various solutes, and that the whole cell shrinks in solutions of high osmotic pressure.

ISSN:0008-4166    

DOI:10.1139/m70-014

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Selective inhibition of lactose-fermenting coliforms in the presence ofSalmonella typhimuriumwas obtained by growing the mixed culture in media containing certain synthetic β-D-galactosides. The inhibition resulted from autocytotoxicity affecting the coliforms but notS.typhimurium, and occurred with phenyl-(PG), phenethyl-(PEG), and 4-chloro-2-cyclopentylphenyl-(CPPG) β-D-galactosides. Strains of coliforms which were capable of undergoing autocytotoxicity yielded cell-free extracts that hydrolyzed PEG and CPPG, and these extracts also hydrolyzed the galactosidase assay compound,o-nitrophenyl β-D-galactoside (ONPG).They did not, however, hydrolyzeo-nitrophenyl β-D-galactoside-6-phosphate (ONPG-6-PO4).A few strains ofEnterobacter aerogenesandKlebsiella pneumoniae, although they fermented lactose, were not subject to autocytotoxicity. Cell-free extracts of these strains did not hydrolyze PEG, CPPG, or ONPG. They did, however, hydrolyze ONPG-6-PO4. In this respect, their galactosidase system resembles that ofStaphylococcus aureus: extracts ofS.aureushydrolyze ONPG-6-PO4, but not ONPG.

ISSN:0008-4166    

DOI:10.1139/m70-015

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Large numbers of chromogenic variants were isolated from cultures of a parent strain ofStaphylococcus aureusgrowing in the dialysate but not in the residue of brain heart infusion (Difco). Gas–liquid chromatographic analysis of the dialysate detected 18 amino acids in this medium. Large numbers of chromogenic variants also were isolated from 13 of 18 synthetic media deficient in a single amino acid but not in the complete synthetic medium containing all 18 amino acids. Gas–liquid chromatographic analysis detected marked quantitative differences in the amino acid metabolites present in a complete synthetic medium and the synthetic medium deficient in arginine after growth for 12 days. The data suggest that differences in the amino acid metabolism of the parent and chromogenic variants could account for the population changes observed in brain heart infusion.

ISSN:0008-4166    

DOI:10.1139/m70-016

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A two-stage principal component (P.C.) procedure was applied in a comparison of the nature and properties of 19 named cultures ofArthrobacterand 77 arthrobacter–coryneform soil isolates: cultures ofBrevibacterium linens,Nocardia cellulans,Corynebacterium michiganense, andJensenia canicruriawere also studied. These cultures were characterized in terms of their reaction to a set of 98 tests. Deoxyribonucleic acid (DNA) was isolated from 55 of the cultures and the moles % guanine + cytosine (% GC) content determined by thermal denaturation and ultracentrifugation methods. The P.C. analysis resulted in the recognition of 13 groups of cultures. Twelve of theArthrobactercultures (representing nine species) were contained in two groups, one of which contained onlyArthrobactercultures.Arthrobacter citreus,A.duodecadis,A.flavescens, andA.terregenswere contained in another group with 13 soil isolates.Arthrobacter simplexandA.tumescenswere located in separate groups which also includedB.linensandN.cellulansrespectively; otherwise these groups contained soil isolates.C.michiganensewas located in a group of four soil isolates which was spatially related to the two groups ofArthrobactercultures. Twenty-five characteristics were considered important for differentiating the groups of cultures and they were concerned with nutritional requirements, use of carbon compounds, catalase production, nitrate reduction, antibiotic sensitivity, and the Gram reaction. Most of the namedArthrobactercultures were located in groups which were separated from the groups of the soil isolates. The DNA of the 55 cultures examined contained from 40 to 74% GC: for 32 of these cultures the GC content of DNA was between 59 and 66% and for 19 cultures the GC content was between 66 and 74%. With few exceptions cultures grouped together by the numerical method had similar GC contents.

ISSN:0008-4166    

DOI:10.1139/m70-017

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A dichotomous key for determination of serological groups amongStreptomycesis described. This key is limited in that only seven specific antisera are used for testing. The utility and reliability of the application of this key were tested and compared to the results of previous taxonomic studies reported on the basis of biochemical and morphological characteristics of these organisms. Results indicate the desirability of using a combination of methods including serological characteristics on the one hand, and biochemical–morphological characteristics on the other, to increase the reliability of taxonomic studies.

ISSN:0008-4166    

DOI:10.1139/m70-018

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Yeasts were isolated from bumblebee honey collected in the Pincher Creek region of southwestern Alberta and the Melfort and Saskatoon regions of central Saskatchewan. The predominant species isolated wereTorulopsis bombicolan. sp., which produces hydroxy fatty acid sophorosides, aCandidaspecies which resembles it in its assimilatory reactions but which does not produce sophorosides, andSaccharomyces rouxii. A few cultures ofDebaryomyces phaffiiandCandida reukaufiiwere isolated. The mannans or galactomannans formed by representatives of each group were extracted and their proton magnetic resonance spectra determined and used as an aid in identification of the different species.

ISSN:0008-4166    

DOI:10.1139/m70-019

出版商:NRC Research Press    

年代:1970

数据来源: NRC