- Volume 10, Issue 3, 1954

SUMMARY: Glucose utilization by a strain of Streptomyces griseus was studied. Under highly aerobic conditions, glucose was converted mainly to structural material and CO2, but under restricted aeration, lactic acid was formed. Pyruvic acid was also formed during the stages of most rapid growth. The metabolism of glucose was dependent upon the presence of phosphate, and the optimal hydrogenion concentration for both glucose oxidation and the rate of disappearance of inorganic phosphate was about pH 7. Phosphate esters, tentatively identified as glucose-1-phosphate and glucose-6-phosphate, were obtained in fluoride-inhibited systems. Glucose oxidation was depressed by 10−3 m-sodium iodoacetate and 10−2 m-sodium arsenite but was stimulated by 10−2 m-sodium arsenate; 10−3 m-2: 4-dinitro-phenol and 10−3 m-sodium azide had no effect. Streptomycin production was decreased by 3 x10−3 m-sodium arsenate but not by 10−2 m-sodium fluoride or 10−2 m-sodium iodoacetate. S. griseus metabolized members of the tricarboxylic acid cycle, although citrate and a-ketoglutarate gave much lower values of Q O2 at pH 7·3 than pyruvate, acetate, succinate, fumarate or malate. Ketoacids were produced in presence of arsenite from fumarate, malate, glucose, lactate, acetate, succinate, glutamate and citrate in descending order of yield. Except from fumarate, which yielded some material behaving like a-ketoglutarate, the product was chiefly pyruvate.

SUMMARY: The vitamin requirements of thirty-four strains of lactic acid bacteria, representing ten species and isolated from brewery materials, were studied. Individual strains required from one to four vitamins for normal growth on the basal medium used. Pantothenic acid was required by all the organisms. In a number of cases growth failed when groups of vitamins, individually non-essential, were omitted.

SUMMARY: Experiments were made to determine whether the infectivity of virus suspensions was influenced by exposure to daylight of normal laboratory intensity or by exposure to artificial light. The infectivity of dilutions of virus suspensions held in bottles or cells was determined after exposure to light under a variety of conditions; the influence of exposure was indicated by comparison with the infectivity of control suspensions kept in darkness. The infectivity titres indicated by serial dilutions, in phosphate saline, of unfiltered fresh suspensions of egg strains of the viruses of vesicular stomatitis, influenza, Newcastle disease and fowl-plague following exposure to daylight for 4 hr. were 3–5 logarithmic units lower than those indicated by the dark controls. Changes of this magnitude suggest that with these virus strains significant errors might arise in infectivity titrations if suspensions were exposed to light for much shorter periods. Inactivation due to exposure to daylight was demonstrated in similar experiments with an egg strain of vaccinia virus, a mouse neurotropic strain of influenza virus and with guinea-pig strains and mouse neurotropic strains of the virus of vesicular stomatitis. Results of experiments with the virus of vesicular stomatitis indicated that inactivation by exposure to light may be eliminated almost completely by the inclusion of 10% rabbit serum in the suspending medium. Losses of infectivity increased with the intensity of illumination and with the duration of exposure. Filtration or storage of certain initial materials also increased the susceptibility to inactivation of virus suspensions derived from them. The infectivity of suspensions of the virus of foot-and-mouth disease, even after filtration, was relatively stable during exposure to light.

SUMMARY: The inoculation of killed Salmonella pullorum into the developing avian embryo on or after the 17th day of incubation or of live Sal. pullorum into young chicks evoked no immediate antibody response. Approximately 20–40 days after hatching, however, agglutinins and non-agglutinating antibodies were sometimes detected in the sera of these chicks. Maximum antibody production did not occur until the chicks were approximately 100 days old.

The intravenous inoculation of killed Sal. pullorum into developing embryos on or before the 15th day of incubation stimulated the production of practically no demonstrable antibody by the chicks during approximately the first 80 or 100 days after hatching. These chicks, however, showed a marked decrease in capacity to produce demonstrable antibodies in their sera after subsequent oral infection with Sal. pullorum.

These experimental results are discussed in relation to various theories of antibody production. It is suggested that they are evidence in support of Burnet’s adaptive enzyme theory. The results are explained on the hypothesis that the introduction of antigenic material into the embryo under suitable experimental conditions enables the host cells to become adapted to the antigen, resulting in a diminished antibody response by the host, during post-embryonic life, to a subsequent challenge with similar antigenic material.

SUMMARY: Strains of Streptococcus pyogenes belonging to Types 2 and 4 elaborated an amylolytic enzyme which was not usually a product of other serological Types though it was occasionally produced by members of Types 1, 9, 22 and Types related to 4, 5 and 25. Sixty-six % of amylolytic strains were untypable by M precipitin tests.

The enzyme was produced by variants. Amylolytic organisms were generated by matt and large opaque colonies of the parent strains; small and glossy variants generated relatively fewer enzyme-positive cocci, and had often lost the amylolytic property. When studied as a single character in serial subcultures on starch agar, the property was transmissible, in some instances to 80 % of the progeny for many generations (forty or more subcultures). Other strains readily lost the property in subculture on starch agar but recovered amylolytic power during passage on plasma agar in the absence of substrate. Certain amylolytic strains contained a trypsin-resistant, serologically active substance which precipitated in anti-M, anti-T and anti-proteinase precursor serum. A similar substance diffused into the medium when strains were grown on agar containing the substrate. While serologically related to the cell antigen, the free substance was trypsin-sensitive.

Staphylococci produce coagulase in two forms. One is bound to the cell wall and is responsible for the slide test. The other is liberated as free coagulase in the medium and is responsible for the tube test. Bound coagulase acts directly on the fibrinogen of certain animals which then causes clumping of the staphylococcal cells, while free coagulase acts on the prothrombin of certain animals to give a thrombin-like product. Bound coagulase is antigenically distinct from free coagulase. It is released during autolysis and it can be used to produce specific antibodies in rabbits.

Free staphylococcal coagulase is formed early in the lag phase and is released continuously, mainly at the first division in heavily seeded cultures. With most strains the presence of serum albumin in the medium greatly enhances the production of both free and bound coagulase (Duthie, 1954). The albumin factor is relatively heat stable, but is easily destroyed by crystalline trypsin.

Salmonella, shigella, alkalescens-dispar, proteus, paracolon and coli-form strains were tested for the presence of a coagulase enzyme as manifested by the ability to clot plasma. The shigella and proteus strains examined gave negative results; a high percentage of the remaining strains clotted citrated plasma but this reaction was due to metabolism of citrate and subsequent liberation of calcium ions and not to a coagulase enzyme. Results depended on the bacterial strain and on the kind and dilution of plasma used. Utilization of citrate in citrated plasma was compared with the ability of the tested strains to attack citrate in Koser’s ammonium citrate medium and in sodium citrate peptone medium. The Shigella and Proteus species examined failed to utilize citrate in any of the media under the conditions of the tests, Salmonella species gave fairly uniform results in the three media, while paracolon, coliform and alkalescens-dispar strains differed in their activity, the highest percentage of positive reactions being obtained in plasma-containing media.

In sunlight dark-ground microscopy the flagella of a packet of motile sarcina appear as a smooth tail. The tails often stiffen into helices of two different wavelengths, one being twice as long as the other. The short and the long wavelengths are identical in Sarcina ureea and S. agilis. This phenomenon of two wavelengths, one twice as long as the other, was also found, though less frequently, in certain other bacteria. Otherwise the wavelengths of the flagella of these bacteria appeared specific.

SUMMARY: Particle counts of influenza virus preparations were made by two independent techniques; there was good agreement in the counts found by the two methods. Counts made on four strains of influenza virus and one strain of ‘incomplete’ virus showed that at the agglutination end-point there was about one virus particle per red cell. Parallel infectivity measurements of these strains made under optimal conditions showed that about ten virus particles corresponded to one ID 50.

SUMMARY: Attention is drawn to certain requirements of the current International Botanical and Bacteriological Codes of Nomenclature, with special reference to the denoting of categories, the proposal of new species, and the changing of names; three procedures commonly encountered by authors and editors. The requirements for the proposal of new specific names of fungi and bacteria are:

General requirements. The name chosen must be in Latin binomial form and should be coined according to the practices set out in the Codes (Bact. Code, Rules, 6, 27, 28, Appendix A; Bot. Code, Art. 33, 82, Rec. 83A).

The name must be effectively published. (It is desirable that scientific journals in which new taxa are proposed should indicate the exact date of publication of the parts.)

The name must be validated by a concise description (the diagnosis) of the diagnostic features of the new taxon. (The diagnostic features should not have to be deduced from an exhaustive account of the organism possibly spread over several pages.)

The description should, whenever possible, be accompanied by illustrations of which the scale and the specimen(s) on which they are based should be stated.

All measurements should be in the metric system.

The date of collection or isolation of the type material should be given together with the precise locality and the substrate or host (the last being designated by its scientific name).

The location of the type should be stated.

The etymology of the name should be explained.

Special requirements for fungi. The diagnosis must be in Latin (Bot. Code, Art. 44).

The type specimen should be deposited, if possible, in a national herbarium, and if the type is a collection and portions are deposited in several herbaria then one of these isotypes should be designated as the holotype.

Special requirements for bacteria. No Latin diagnosis is required but ‘in works written in a language unfamiliar to the majority of workers in bacteriology, it is recommended that the authors publish simultaneously the diagnosis in a more familiar language’ (Bact. Code, Rec. 12a).

Subcultures of the type strains should be deposited at one or more of the national culture collections.

SUMMARY: The growth of three yeast species was inhibited by δ-hexachlorocyclo-hexane more strongly than by the γ-isomer; the degree of inhibition was related to the inositol requirement of the given yeast. The fermentation of glucose was inhibited only by the δ-isomer and the effect was not reversed by inositol. In one species oxygen uptake was inhibited more strongly by the δ-isomer than by the γ-isomer; only the inhibition caused by the γ-isomer was affected by inositol.

SUMMARY: A strain of Staphylococcus aureus was isolated from the duodenum of a case of idiopathic steatorrhoea with polyneuritis and evidence of thiamine deficiency. This organism in washed cell suspension in glucose and thiamine at 37° was found to remove 75 % of the thiamine present within 1 ½ hr. This process was much retarded by reduction of the temperature to 4° and in the absence of glucose. The thiamine which was removed was not destroyed, and death of the organisms resulted in liberation of the thiamine from the organisms into the suspending fluid. The process may be due to an active transference across cell membranes and concentration of thiamine inside the organism. It is suggested that in the presence of an abnormal intestinal flora such a mechanism may play a part in producing clinical thiamine deficiency states.

SUMMARY: N-tolyl-α-naphthylamine-8-sulphonic acid forms conjugates with protein which fluoresce when excited by ultraviolet light. When washed cell suspensions of Pseudomonas aeruginosa are treated with N-tolyl-α-naphthylamine-8-sulphonic acid no fluorescence develops, but when polymyxin is also added, fluorescence develops, thus demonstrating that the dye can penetrate to proteincontaining portions of the cells. This technique has been used to study the competition between polymyxin and certain cations for sites on the cells. From a comparison of the affinities of these cations for the polymyxin-combining groups of the cells with their ability to reverse the charge on certain colloids it is suggested that the polymyxin-combining loci of the cells may be polyphosphates.

SUMMARY: The multiplication of fowl-plague virus was studied in cultures prepared with suspensions of isolated cells of chick embryo tissues. Under favourable conditions, virus infectivity increased exponentially for 20 hr., after a latent period lasting 4–6 hr. Virus haemagglutinin production varied linearly with the number of cells added to the cultures, the regression line of this relationship showing a slope of approximately 1 when the cell concentration was kept constant and a slope higher than 1 when the number of cells was varied together with the cell concentration. Haemagglutinin production was decreased by increasing the size of the virus inoculum. A similar decrease was observed in cultures in which the depth of the fluid layer was increased. Cultures incubated at 32° for 2 days showed no haemagglutinin titres. The titres reached in cultures incubated at 35, 37 and 39° did not differ significantly. Cultures kept at 37° maintained their capacity to support virus multiplication at an approximately constant level for at least 3 days. At 22° and at 4° this capacity decreased progressively with time of storage, the decrease being more pronounced at the lower temperature. Virus multiplication was inhibited by horse serum.

SUMMARY: Colloidal copper sulphide is inhibitory to staphylococci and a number of other Gram-positive organisms, but has little effect on Gram-negative organisms. Its formation when cystine and peptides containing cystine are autoclaved with copper is thought to be responsible for the anti-staphylococcal activity of heat-sterilized copper-containing peptone solutions. Colloidal sulphur is active against the cocci but the inhibition differs in some respects from that of copper sulphide, notably in the ease with which it can be reversed by cystine, cysteine and mercapto-acetic (thioglycollic) acid. Iron and manganese sulphides also inhibit bacterial growth and the possible significance of this inhibition on the production of anaerobic toxins is discussed.

SUMMARY: When sprayed on the leaves of tobacco plants inoculated with tobacco mosaic virus 8-azaguanine caused a delay in the production of virus, and a delay in the development of systemic infection. From alkaline hydrolysates of the nucleic acid prepared from virus isolated from 8-azaguanine-treated plants, a compound was isolated which had the expected properties of 8-azaguanylic acid. This evidence together with analytical data showed that in tobacco mosaic virus from 14-day-old infections in 8-azaguanine-treated plants, about 3–4% of the guanine in the virus nucleic acid was replaced by 8-azaguanine. This incorporation of 8-azaguanine appeared to reduce the infectivity of the virus. Several other purine analogues were ineffective against tobacco mosaic virus. A serological-chromatographic method is described for the estimation of small amounts of tobacco mosaic virus in crude plant extracts.

SUMMARY: The content of ribonucleic acid (RNA), excess organic phosphate (XSP) in the RNA fraction, deoxyribonucleic acid (DNA), acid-soluble inorganic phosphate (AI) and organic phosphate (AO), and the lipid phosphate (LP) and lipid weight (L) have been determined in some ten Gram-positive and ten Gram-negative organisms, grown in the same media and harvested at the same phase of growth. A statistical analysis of the results shows that the RNA and DNA contents of the Gram-positive and Gram-negative groups do not differ significantly; the percentage of lipid phosphorus is only half as great in the Gram-positive as in the Gram-negative group; and XSP is present in all the Gram-positive organisms, but absent from all the Gram-negative ones. We suggest that a lipid-polyglycerophosphate-protein component may be a common structural feature of the cell envelopes of all Gram-positive organisms. The mechanism of the Gram reaction is considered in the light of our observations.