bluuebunny/crossref_metadata_2025 huggingface dataset:
THE MICROFLORA OF RAW MILK AS DETERMINED BY PLATING ON YEASTREL‐MILK AGAR INCUBATED AT 30°
Authors: THOMAS S. B. , HOBSON PHYLLIS M. , BIRD ELIZABETH R. , KING KAY P. , DRUCE R. G. , COX D. R.
Published: March 2008

The classification of the predominant types of bacteria found in 87 farm milk supplies, examined within 8–10 hr of production, was done by plating on Yeastrel‐milk agar, incubating for 72 hr at 30° and picking 24 colonies at random from each countable plate for detailed study. Although the results indicate some general trends, such as the predominance of micrococci in milk of low count (< 2 times 104 colonies/ml), the co‐dominance of streptococci, corynebacteria and micrococci in milk with colony counts between 2 times 104 and 2 times 105/ml, and the dominance of nonpigmented Gram‐negative rods and streptococci in the high count milks (2 times 105–5 times 106 colonies/ml), several milk samples, irrespective of colony count level, had a characteristic individual microflora dominated by either corynebacteria, aerobic sporeformers, coli‐aerogenes organisms, fluorescent pseudomonads or flavobacteria.
FLAGELLATION OF AZOTOBACTER SPP. AS DEMONSTRATED BY ELECTRON MICROSCOPY
Authors: BAILLIE ANN , HODGKISS W. , NORRIS J. R.
Published: March 2008

The results of an electron microscope survey of flagellation in the genus Azotobacter are presented and the implications of the findings are discussed.
THE OCCURRENCE AND GROWTH OF STAPHYLOCOCCI ON PACKED BACON, WITH SPECIAL REFERENCE TO STAPHYLOCOCCUS AUREUS
Authors: EDDY (the late) B. P. , INGRAM M.
Published: March 2008

Staphylococcus aureus occurs and survives in bacon curing brines and may be found on shop sliced and on vacuum packed bacon. Under anaerobic conditions it competes with the indigenous flora of the bacon: its growth is favoured by low numbers of other organisms and by high storage temperatures. Packs of bacon for sale should carry the instruction to keep in a cool place.
THE OXIDASE ACTIVITY OF STAPHYLOCOCCI
Authors: STEEL K. J.
Published: March 2008

SUMMARY: By the use of Kovacs'(1956) test, oxidase activity was demonstrated in 23 of 66 strains of coagulase negative staphylococci (or micrococci) but in none of 82 strains of coagulase positive staphylococci. Less sensitive methods showed fewer reactions or failed to demonstrate them at all. Oxidase activity could not be correlated with other biochemical features.
Bacterial Sulphate Reduction and the Development of Alkalinity. II. Laboratory Experiments with Soils
Authors: Abd‐el‐Malek Y. , Rizk S. G.
Published: March 2008

In waterlogged soils sulphate reduction was characterized by increases in counts of sulphate reducers, an increase in titratable alkalinity, insoluble carbonate and soluble sulphides, and a decrease in soluble Ca+++ Mg++. Presence of organic matter greatly enhanced sulphate reduction. A linear relationship between the amount of sulphate reduced and increases in titratable alkalinity and insoluble carbonate were apparent. The potential effects of sulphate reduction on soil fertility through the development of alkalinity are discussed.
The Effect of Variation in pH on the Heat Resistance of Cultures of Streptococcus faecalis
Authors: White Helen R.
Published: March 2008

Three strains of Streptococcus faecalis were exposed to heat (60°) in phosphate and citrate‐phosphate buffer solutions at various levels of pH and their resistance measured by calculation of decimal reduction time. All three strains were more susceptible to heat at low and at high pH than at pH approaching neutrality. In the range pH 6°6–7°0 there were considerable variations in resistance with maximum survival usually at pH 6°8; on both sides of this value, sensitivity was sharply increased. Preliminary experiments at other lethal temperatures gave similar results.
A Note on the Isolation of Salmonellae
Authors: Jameson J. E.
Published: March 2008

The following note was inspired by a paper by McCoy (1962) in which it was stated that no advantage resulted from ‘secondary enrichment».
A Genealogical Study of Clonal Development of Escherichia coli
Authors: Quesnel L. B.
Published: March 2008

Summary: The generation times of individual Escherichia coli cells inoculated on to a cellophane membrane surrounded by liquid synthetic medium in a continuous flow system were determined by direct observation for up to seven generations. The presence and production of nonviable cells was also recorded. A wide variety of developmental patterns was found among the developing clones; increased viability and a decrease in generation times with increasing age of the population were observed. The phenomenon of alternation of generations is described and discussed. Five factors contributory to the lag phase were distinguished, and their relative effect may be deduced from the results.
Studies on the Application of Kanamycin to the Control and Treatment of Some Bacterial Diseases of Fish
Authors: Conroy D. A.
Published: March 2008

Summary: A study has been made of the pathogenicity of Aeromonas liquefaciens, Aer. hydrophila, Aer. punctata, Pseudomonas putida and Ps. fluorescens to freshwater fish, and a description of the symptoms produced by each one of these organisms is given.

By means of in vitro and in vivo studies, it was shown that Kanamycin is an effective therapeutic agent in the control and treatment of bacterial fish diseases caused by these organisms.
A Note on the Microbiological Assay of a New Penicillin (Orbenin) in Milk
Authors: Hooke E. J. , Ball G. M.
Published: March 2008

Summary: A plate assay method for the routine determination of Orbenin (BRL 1621) and methicillin in milk is given and its sensitivity compared with the triphenyltetrazolium chloride tube assay method.
A Novel Polystyrene Dish for the Production of Anaerobiosis
Authors: Naylor P. G. D.
Published: March 2008

Summary: The design and construction of a polystyrene dish to be used with alkaline pyrogallol for the production of anaerobic conditions is described. Paper mats are used to carry the reducing system, and the use of cellulose adhesive tape to effect an airtight seal is recommended.
Residual Air in the Steam Sterilization of Textiles with Pre‐Vacuum
Authors: Henry P. S. H. , Scott E.
Published: March 2008

Summary: An account is given of difficulty in sterilizing small loads of cotton materials in an autoclave that is efficient with large loads. The effect cannot be due to original air left in the package since the amount of this would not be greater for small loads than for large. Nor would residual air in the free space of the autoclave interfere unless it entered the package with the steam. The extent to which this takes place is discussed and several ways for reducing it are proposed. ‘Boiling out’ of moisture from the cotton in the later stages of evacuation would help, but the conclusion is reached that this does not occur with many existing pre‐vacuum autoclaves when the cotton is enclosed in drums, and only to a limited extent with bare cotton‐wrapped packages. It can be induced by more effective pumping, but this is more expensive than the other remedies proposed.
The Effect of the Addition of Copper Sulphate to the Diet on the Bacterial Flora of the Alimentary Tract of the Pig
Authors: Smith H. Williams , Jones J. E. T.
Published: March 2008

Summary: The use of copper sulphate as a dietary supplement had no observable effect on the bacterial content of the alimentary tract of the pig.
Metabolic Injury in Frozen Bacteria
Authors: Postgate J. R. , Hunter J. R.
Published: March 2008

Summary: Aerobacter aerogenes populations, partly killed by freezing and thawing, usually showed more viable bacteria when plated on a rich medium than on a poor one. This ‘metabolic injury’ was not due to osmotic sensitivity or to toxic materials in the agar. Freezing and thawing was not significantly mutagenic and mutation to nutritional exigence did not account for the phenomenon. The survivors of freezing and thawing showed long lag phases in the recovery media, during which lag periods further mortality occurred.
The Influence of Ward Ventilation on Hospital Cross Infection
Authors: Steingold L. , Dunn L. , Hawksworth E. , Limb L.
Published: March 2008

Summary: A ventilation system combining fresh air intake with recirculation of ward air, through an electrostatic air filter, was introduced into a ward in which it had been shown that poor ventilation was a major factor in its high cross infection rate. A considerable reduction in bacterial air contamination and in the cross infection rate in that ward was achieved.
The Use of the Wide‐Bore Dropping‐Mercury Electrode for the Determination of Rates of Oxygen Uptake and of Oxidation of Ammonia by Micro‐Organisms
Authors: Painter H. A. , Jones K.
Published: March 2008

Summary: Convenient and reliable polarographic methods, using a wide‐bore dropping‐mercury electrode, for determining the dissolved oxygen content and the rate of respiration of sewage and activated sludge are described and verified by independent procedures. Using thiourea to inhibit Nitrosomonas spp., a technique was developed by which the uptake of oxygen by heterotrophs could be distinguished from that used in ammonia oxidation. Conditions are discussed under which accurate estimates of the rate of uptake of oxygen due to the oxidation of ammonia could be made. Typical values are given for the rates of respiration and of nitrification of activated sludge and also for the rates of respiration of a phenol‐destroying pseudomonad.
Studies on the Dose Requirement for the Radiation Sterilization of Medical Equipment. II. A Comparison between Continuous and Fractionated Doses
Authors: Burt Margaret M. , Ley F. J.
Published: March 2008

Summary: The lethal effect of gamma radiation on spores of Bacillus pumilus air dried on to a glass surface was measured by constructing dose‐survivor curves. In one set of experiments the doses used were delivered without interruption, and in another set they were fractionated in various ways with storage intervals between fractions of up to one week. The data presented confirms the view that the efficiency of sterilization by irradiation would not be affected by interruption of dose delivery as might occur in plant operation. A situation where effects might be observed is discussed.
The Effect of Freeze Drying on the Viability of Chromobacterium lividum
Authors: Fisher P. J.
Published: March 2008

Old well‐pigmented cultures of Chromobacterium lividum withstood freeze drying and subsequent storage better than young unpigmented cultures. Recovery from the dried state was greater when the recovery medium contained blood.
Disintegration and Organoleptic Deterioration of Processed Strawberries caused by the Mould Byssochlamys nivea
Authors: Put Henriëtte M. C. , Kruiswijk J. Th.
Published: March 2008

Summary: In the Netherlands the disintegration of processed strawberries, accompanied by unpleasant odour and flavour, is generally caused by the mould Byssochlamys nivea. Pectolytic enzymes produced during the growth of the mould are responsible for the disintegration. The organism is not killed by the heat treatment normally applied to strawberries.
A Study of Some Organisms of Public Health Significance from Fish and Fishery Products
Authors: Appleman M. D. , Bain Nora , Shewan J. M.
Published: March 2008

Summary: Various media selective for potential food poisoning staphylococci have been investigated to determine the most suitable ones for use with fish. These were then used with 161 samples of fish and fish products simultaneously with estimations of viable bacterial counts and of the numbers of coli‐aerogenes organisms. Attempts to isolate salmonellae from these were also made.
The Use of Sulphamezathine for Inhibiting Proteus Spp. on Baird‐Parker's Isolation Medium for Staphylococcus aureus
Authors: Smith B. A. , Baird‐Parker A. C.
Published: March 2008

Summary: The addition of 50 μg of sulphamezathine/ml to egg‐tellurite‐glycine‐pyruvate agar was effective in suppressing the growth and swarming of Proteus spp. Small numbers of Staphylococcus aureus (103/g) could be recovered quantitatively on the modified medium in the presence of up to 106/g of mixed Proteus vulgaris and Proteus mirabilis strains.
A Compact Medium‐Making Unit
Authors: Elliott E. , Hurst A.
Published: March 2008

Summary: Media making on a large laboratory scale has hitherto involved considerable manipulation and some personal risk. The report describes an apparatus which obviates these disadvantages and also saves time.
Fluorescent Studies in the Genus Clostridium. II. A rapid method for differentiating Clostridium botulinum types A, B and F, types C and D, and type E
Authors: Walker P. D. , Batty Irene
Published: March 2008

Summary: Fluorescent labelled specific antisera have been used to distinguish between types A, B and F, types C and D, and type E of Clostridium botulinum.
The Bactericidal Action of Low Molecular Weight Compounds on Mycobacterium tuberculosis
Authors: Barker Ruth M.
Published: March 2008

Summary: Lower members of the carboxylic fatty acid series, hydroxy acids, alcohols, amides, ureas, urethanes and some other low molecular weight compounds have been tested for bactericidal action on Mycobacterium tuberculosis H37 Rv and BCG. The rate of bactericidal action of acetic acid is shown to be dependent on the concentration of undissociated acid. The bactericidal activity of normal fatty acids increases with increase in the length of the carbon chain. A comparison of the times required by equimolar solutions to sterilize a culture shows that maximum activity is reached at undecylic acid (C11). The bactericidal activity of corresponding acids, hydroxy acids and alcohols is compared.
Studies on the Heat Resistance of Bacteria, with Particular Reference to the Genus Microbacterium: I. A New Technique using Solid Media
Authors: Anagnostopoulos G. D. , Seaman A. , Woodbine M.
Published: March 2008

Summary: The new technique depends upon spreading bacterial cells over the surface of an agar medium in a Petri dish. The cells are heated, cooled, grown and counted in situ. The plates are preheated on the surface of a water bath and held for the required time on the surface of a second bath at the desired temperature. They are cooled by cold water jetted on to the base. The experimental control of factors affecting the accuracy of the method are discussed and applications suggested.
The Types and Distribution of Thiobacilli in Biological Systems Treating Carbonization Effluents
Authors: Hutchinson M. , White D.
Published: March 2008

Summary: An extensive investigation of 30 strains of bacteria which oxidize inorganic sulphur compounds led to the recognition of three major groups. A study of the occurrence of these groups in biological effluent systems suggested that the organisms generally believed to be responsible for the oxidation of thiosulphate and thiocyanate, the autotrophic thiobacilli, were absent in many instances. It is suggested that in these instances heterotrophic organisms, which are found throughout all the systems, may be responsible for the destruction of the sulphur compounds. A heterotrophic organism which destroys thiocyanate, but not thiosulphate, has been isolated.
Chemical and Microbiological Changes during Storage of Vacuum Packed Sliced Bacon
Authors: Tonge R. J. , Baird‐Parker A. C. , Cavett J. J.
Published: March 2008

Summary: The micro‐ecology of block cured, sliced, vacuum packed bacon has been studied during storage at 20 and 30°; high salt (8–12% NaCl, based on the aqueous phase) and low salt (5–7% NaCl) bacon were used. The dominant flora of all samples during the first 9 days' storage comprised catalase positive cocci. They persisted in the high salt bacon but, under lower salt conditions, group D streptococci and motile lactic acid bacteria became dominant.

Of the chemical changes studied, proteolysis, lipolysis and reduction of nitrate and nitrite were due largely to coagulase negative subgroup II staphylococci. Micrococci which predominated at 20° were capable of reducing nitrate to nitrite but of only slightly increasing free amino or fatty acids.

Inoculation of low count bacon with subgroup II staphylococci confirmed that this group was responsible for putrefaction in low salt bacon stored at temperatures above 20°. Similarly micrococci which tend to delay spoilage did not contribute much to the off odours and it was thought that the heterofermentative catalase negative organisms could contribute to typical sour spoilage.
Characteristics of Pseudomonas solanacearum
Authors: Hayward A. C.
Published: March 2008

Summary: A collection of 185 isolates of Pseudomonas solanacearum has been classified into 4 biotypes according to their capacity to oxidize 3 disaccharides (lactose, maltose and cellobiose) and 3 hexose alcohols (mannitol, sorbitol and dulcitol). Biotype 2 which oxidized the disaccharides but not the hexose alcohols appears to have a restricted host range; it was obtained solely from two plant hosts, potato and tomato, whereas biotype 1, which oxidized neither group of carbohydrates, and biotype 3 which oxidized both, were obtained from a diversity of plant hosts. A bacteriophage isolated from material infected with biotype 2 showed a high degree of specificity for isolates of biotype 2. The present known distribution of the 4 biotypes is given and their relationship to host range is discussed. A neotype culture for Ps. solanacearum is proposed.
The Flagella of Pseudomonas solanacearum
Authors: Hodgkiss W.
Published: March 2008

Summary: Electron microscopic examination of 5 strains of Pseudomonas solanacearum, including the proposed neotype, NCPPB 325, showed that the cells of these organisms possess polar flagella.
The Effect of Inhibitors on Sulphate Reducing Bacteria: a Compilation
Authors: Saleh A. M. , Macpherson Rhona , Miller J. D. A.
Published: March 2008

Summary: The effects of about 200 bacteriostatic and bactericidal agents on sulphate reducing bacteria, including some hitherto unpublished results, are tabulated.
The Maintenance of Discrete Bacterial Colonies on the Surface of Objects Embedded in Agar
Authors: Kingston D.
Published: March 2008

Summary: Bacterial colonies grown on objects embedded in agar sometimes show a tendency to become confluent. Glass coverslips and polytetrafluorethylene (Teflon) discs were inoculated with Staphylococcus lactis and completely embedded in serum agar. If the surface of the agar were flooded with broth before the plates were incubated the colonies had a tendency to run together, but not if the plates were incubated after thorough drying. Drying also prevented confluence occurring when broth had been injected on to the surface of the embedded object. Drying the poured plate probably acts by removing fluid squeezed out at the interface.
The Effect of Carbonation, Benzoic Acid and pH on the Growth Rate of a Soft Drink Spoilage Yeast as determined by a Turbidostatic Continuous Culture Apparatus
Authors: Pergio J. A. , Gimbert B. L. , Bashford T. E.
Published: March 2008

Summary: A turbidostatic continuous culture apparatus is described, which has been used to determine the effect of variations in carbonation, benzoic acid and pH on the growth rate of a soft drink spoilage yeast. Results are presented and a model is derived which, it is believed, enables the spoilage potential of many carbonated soft drinks to be predicted.
The Growth of Gram‐Negative Bacteria in the Hen's Egg
Authors: Board R. G.
Published: March 2008

Summary: Bacteriological and chemical methods were used to follow the course of infection in eggs, incubated at 27°, the air cells of which had been inoculated with a suspension of washed bacteria. In the 3–4 days following inoculation, limited bacterial multiplication occurred in the inner membrane of the air cell but very few organisms entered the albumen. These populations then remained static or decreased slightly until renewed multiplication occurred 12–30 days after inoculation. This was induced by contact of the yolk and the shell membranes: it occurred on the 12–20th day in eggs in which the yolk moved towards the site of inoculation, but later when the yolk moved in the opposite direction. At this time there was a general infection of the egg contents and significant changes occurred in the pH and glucose concentration in the albumen. In eggs that had been inoculated with chromogenic and/or proteolytic bacteria, the first macroscopic changes of the contents were seen at this time. The rate and extent of the initial multiplication was influenced by the composition of the fluid used to suspend the washed bacteria and, in all instances, the fastest multiplication occurred when iron was added to the inoculum. Moreover, renewed multiplication occurred when iron was added to the albumen of eggs in which the bacteria were in the stationary phase.
Decomposition of β‐Naphthol by a Soil Pseudomonad
Authors: Walker N.
Published: March 2008

Summary: A pseudomonad resembling Pseudomonas fluorescens, which grows with β‐naphthol as sole source of carbon, was isolated from soil. It did not grow on either naphthalene, α‐naphthol, 1,2‐ or 2,3 dihydroxynaphthalene. Phenol, benzoic acid, o‐, p‐ and (to a small extent) m‐hydroxybenzoic acids supported growth of the organism. A maroon coloured substance was produced from β‐naphthol in cultures and by washed organisms. β‐Naphthol oxidation depended on an induced enzyme system. β‐Naphthol‐grown organisms oxidized β‐naphthol and 2,3‐ and 2,6‐dihydroxynaphthalene immediately and several mono‐ and di‐hydroxybenzoic acids, including salicylic acid, only after a lag. 2,3‐Dihydroxynaphthalene may be a metabolite of β‐naphthol.
Quantitative Studies on Some of the Gram‐negative Anaerobic Bacteria in the Pig Alimentary Tract
Authors: Fuller R. , Lev M.
Published: March 2008

Summary. A medium suitable for isolating some groups of Gram‐negative anaerobic bacteria from the pig alimentary tract is described. Colony counts were made of Gram‐negative anaerobes in the gut of pigs varying in age from 1 day to 6 months. The genera Bacteroides, Veillonella, Sphaerophorus and Peptostreptococcus were recognized on the basis of morphology. The Bacteroides spp. were of two morphological types: a coccobacillus, present only in pigs up to 18 days of age and a bacillus, present in all the pigs with the exception of those between the ages of 43 and 67 days. Veillonellae were absent from the gut of pigs up to 11 days of age and thereafter were usually the predominant anaerobic flora. Sphaerophorus spp. were not isolated until the pigs reached 43 days of age. Peptostreptococci were isolated only occasionally.
The Metabolism of Gallic Acid by Pseudomonas convexa X.1
Authors: Beveridge E. G. , Hugo W. B.
Published: March 2008

Summary. Some aspects of gallic acid (3,4,5‐trihydroxybenzoic acid) degradation by a bacterial isolate, Pseudomonas convexa X.1, have been investigated. The ability of suspensions of this organism, previously adapted to gallic acid, to oxidize a variety of organic substrates was studied and the results obtained, analyzed with the aid of Stanier's simultaneous adaptation theory in an attempt to identify intermediates of eallic acid metabolism. As a result, α‐ketoglutaric acid was suspected of being such an intermediate and was later isolated as its 2,4‐dinitrophenylhydrazone during gallic acid metabolism. Gallic acid adapted cells of Ps. convexa X.1 were not able to oxidize the gallate esters and attempts to induce activity were unsuccessful. The usefulness of Stanier's theory for selection of potential metabolites is discussed and a tentative degradative pathway for gallic acid metabolism is proposed.
Distribution and Properties of Serological Types of Streptococcus faecium, Streptococcus durans and Related Strains
Authors: Barnes Ella M.
Published: March 2008

Summary. The distribution of 19 serological types of Streptococcus faecium and related organisms has been studied, using 367 strains isolated mainly from faecal samples. Several types occurred in man as well as in pigs, sheep, cattle or chickens.

Strains of the same serological type showed a diversity of fermentation reactions, so that organisms which could be identified as Streptococcus durans shared a common type antigen with Strep. faecium strains. The evidence given here supports the proposal that Strep. durans should in future be considered as a variant of Strep. faecium.

It has also been shown that, in common with those of Streptococcus faecalis, the type antigens of the Strep. faecium types are cell wall components.
The Action of Ethylenediaminetetra‐acetic Acid on Pseudomonas aeruginosa
Authors: Gray G. W. , Wilkinson S. G.
Published: March 2008

It has been shown that ethylenediaminetetra‐acetic acid (EDTA) has a direct bactericidal action against strains of Pseudomonas aeruginosa and Alcaligenes faecalis. The action against Ps. aeruginosa is considered to take the form of competition for a metal essential to the integrity of the cells: some of the factors influencing this antibacterial action have been discussed. From a study of the release of solutes from cells of Ps. aeruginosa, it was concluded that the action of EDTA takes place at the cell wall of the organism: an effect by EDTA on the isolated walls of sensitive organisms has been demonstrated.
The Preservation of Plant Pathogenic Bacteria
Authors: Lelliott R. A.
Published: March 2008

Some 160 cultures were preserved by freeze drying, under mineral oil and in soil. After storage for 5 years all freeze dried cultures were viable; most cultures of xanthomonads were viable under oil and in soil; pseudomonads survived well in soil but only moderately well under oil; soft‐rotting Erwinia spp. survived poorly but storage under oil was better than in soil; other Erwinia spp. and most Corynebacterium spp. survived well in soil and under oil. The mean half lives in years (h) calculated for freeze dried cultures of groups of closely related bacteria were: Erwinia‘chrysanthemi group’, 0·40; Erwinia‘carotovora group’, 0·51; Pseudomonas‘syringae group’, 0·50; Xanthomonas spp., 0·84 years. Estimated half lives for Corynebacterium spp. ranged from 1·8 to 6·5 years. There was no evidence that bacteria which had been in culture for more than 3 years before being freeze dried had a longer storage life than those freeze dried within 3 years of isolation. Cultures of the Pseudomonas‘syringae group’had a longer storage life when freeze dried by Greaves’method (h= 0·73) than when freeze dried by Annear's method (h=0·50). There appeared to be no general correlation between half life in storage and either the proportion of cells surviving the freeze drying process or the viable cell count immediately after freeze drying. Most of the variation in the results could be attributed to variation in viable cell count between different ampoules of the same batch of a culture.
Bacteriological Examination of Shell Fish
Authors: Moussa Raouf S.
Published: March 2008

Aquatic edible molluscs (oysters, wedge‐shell, butter‐fish, sting‐winkle, date‐shell and sea‐urchins) caught from sea water near Alexandria were found to be grossly polluted. Most of the samples examined showed exceptionally high counts of coli‐aerogenes bacteria and enterococci; many salmonellae were also isolated. Discrimination of polluted shell fish may be accomplished by testing the sea water or more conveniently by determining the most probable number index of shell fish liquor. The coli‐aerogenes count is probably the best available standard; there is however a positive linear relationship between the coli‐aerogenes and the enterococcal counts. This conclusion, drawn from scatter diagrams, was also confirmed by the calculation of the correlation coefficient r=+ 0·9, when the logarithms of the geometric means were used. A seasonal variation in the coli‐aerogenes and the enterococcal counts of shell fish liquor was noted which could only be attributed to the temperature differences in summer and winter.
An Instrument for Continuous Viewing of Roll Tube Cultures under a Stereoscopic Microscope
Authors: Barclay G. A.
Published: March 2008

An instrument which fits on the stage of a CTS M6100 stereoscopic microscope and provides a continuous field of view for roll tube cultures is described. It has been used to facilitate the rapid counting of colonies on soil extract agar.
The Location of Bacteria in Skin
Authors: Baxby D. , Woodroffe R. C. S.
Published: March 2008

The Castroviejo Keratotome has been used in an attempt to determine the quantitative distribution of bacteria within various thicknesses of pig skin. Results of bacterial counts obtained from serial sections of pig skin indicated that even after vigorous washing, which would remove most of the “transient”surface bacteria, the majority of bacteria were found in the outer 0·3 mm, with decreasing numbers in progressively deeper sections. The results obtained from closely adjacent areas of pig skin from the same animal were comparable, but there were occasional high counts. This indicated that the distribution of bacteria along the skin surface was not constant. The possibility that these high counts were derived from areas immediately above a gland is discussed. The results of bacterial counts made on surface sections of human skin removed with the Keratotome are also presented.
The Inhibition of Spores of Bacillus subtilis by Cetrimide Retained on Washed Membrane Filters and on the Washed Spores
Authors: Chiori C. O. , Hambleton R. , Rigby G. J.
Published: March 2008

Spores of Bacillus subtilis were filtered on membrane filters and then exposed to solutions of cetrimide. The spores, and the membranes themselves, even after being washed retained inhibitory concentrations of cetrimide. This might present a problem in counting bacterial survivors of cetrimide action by a membrane technique. The inhibitory effect of the low cetrimide concentrations retained by the membranes and the spores can be eliminated by washing with a Lubrol–lecithin solution.
Relationship between Heat Activation and Percentage Colony Formation for Bacillus stearothermophilus Spores: Effects of Storage and pH of the Recovery Medium
Authors: Cook A. M. , Brown M. R. W.
Published: March 2008

Colony counts of unheated spores were higher in a medium at pH 5·9 than in media of higher pH. The pattern was reversed as the spores were heated. Slide germination studies showed that about 8% or less of unheated spores germinated in slide culture. Optimal heat activation resulted in about 50% germination. The colony counts of heat activated spores dropped significantly upon storage for 9 months, but those of unheated spores did not.
Further Evaluation of a Rapid Immunofluorescence Technique for Detecting Salmonellae in Meat and Poultry
Authors: Georgala D. L. , Boothroyd Margery , Hayes P. R.
Published: March 2008

A rapid 18–24 h immunofluorescence technique detected 14 of 15 positive samples in tests on 706 routine samples, which included 656 home produced raw beef samples. The rapid technique also recorded 49 false positive results, i.e. samples which proved negative in subsequent cultural tests. The immunofluorescence technique could be used as a presumptive screening test aimed at the rapid detection of negative samples. In this way salmonella free raw materials should usually be cleared for production within 1 day of sampling.
The Growth and Toxin Production of Clostridium botulinum Type E in Certain Vacuum Packed Fish
Authors: Cann D. C. , Wilson Barbara B. , Hobbs G. , Shewan J. M.
Published: March 2008

The growth and toxin production of Clostridium botulinum type E in various types of vacuum packed fish products was tested, with particular reference to the time/temperature relationship of storage. Toxin production was most rapid in herring although smoking retarded its development. With as small an inoculum as 102 spores/pack, fresh herring became toxic after storage for 15 days at 5°. Irradiation of three species of fish after inoculation with Cl. botulinum type E showed that spores surviving radiation germinated and produced toxin more rapidly than an equivalent concentration of spores in nonirradiated fish.
A Study of the Breakdown of Organic Phosphates by Micro‐organisms from the Root Region of Certain Pasture Grasses
Authors: Greaves M. P. , Webley D. M.
Published: March 2008

A survey of micro‐organisms isolated from the root surface, rhizosphere soil and nonrhizosphere soil of pasture grasses (Ryegrass, S23; Timothy, S50; Cocksfoot, S143) was made to determine their ability to attack phenolphthalein diphosphate, sodium glycerophosphate, sodium phytate, lecithin, ribonucleic and deoxyribonucleic acids. The total numbers of organisms capable of decomposing these compounds were higher on the root surface and in the rhizosphere soil of the grasses when compared with the numbers in nonrhizosphere soil. Occasionally, preferential stimulation of organisms hydrolysing some of the compounds was observed in the root regions. The addition of deoxyribonucleic acid to medium inhibited the numbers of colonies developing in dilution plate counts. This inhibition was generally more pronounced on root surface organisms than on those from nonrhizosphere soil.
Studies on Heat Resistance with reference to Coryneform Bacteria: An Improved Technique using a Multiplate Holder
Authors: Anagnostopoulos G. D.
Published: March 2008

Summary. An improved technique for determining heat resistance is described. It is based on the method described previously (Anagnostopoulos, Seaman & Woodbine, 1964a) and it involves the use of a rotatory multiplate holder which renders the method more efficient.
A Medium for the Isolation of Staphylococci from Foodstuffs
Authors: Giolitti G. , Cantoni C.
Published: March 2008

Summary. A liquid medium for the isolation of staphylococci from foodstuffs, containing lithium chloride, potassium tellurite and glycine as inhibitors of contaminants other than cocci, is described. Micrococci are inhibited in the cultures by anaerobic conditions produced by agar seals. With this medium staphylococci are easily isolated even when their numbers in foodstuffs are low.
Production of Freeze‐dried Brucella abortus Strain 19 Vaccine using Cells produced by Continuous Culture†
Authors: Boyce K. J. , Edgar A. W.
Published: March 2008

Summary. A method of producing freeze dried Brucella abortus Strain 19 vaccine using continuous flow culture is described, and details of the equipment and technique used are given.
The Microflora of Hand Washed Milk Bottles
Authors: Thomas S. B. , King Kay P. , Davies Angela
Published: March 2008

Summary. The examination of a series of 713 milk bottles cleansed by hand washing at producer‐retailer farm dairies showed that though nearly 60% attained satisfactory bacteriological standards, about 30% gave high colony counts (>600/bottle), while coli‐aerogenes organisms were found in 17% and milk spoilage organisms in 25% of them. The microflora of efficiently cleansed bottles, with colony counts of <200/bottle, was dominated by micrococci and aerobic sporeforming rods. Only 3.7% of the 259 cultures from these bottles gave acid reactions in litmus milk in 72 h at 22°. Inefficiently cleansed bottles, with colony counts of >600/bottle, had quite a different type of microflora which was usually dominated by Gram negative rods (achromobacteria, nonfluorescent pseudomonads and flavobacteria). A much higher proportion (19%) of the 393 cultures from these bottles gave acid reactions in litmus milk.
Effect of Some Environmental Factors on Psychrophilic Microbacteria
Authors: Brownlie L. E.
Published: March 2008

Summary. The growth of three psychrophilic strains of Microbacterium isolated from meat was studied at 10 temperatures between 0° and 35° and at 6 water activity (aw) levels between 0.99 and 0.94. The temperature and water relations of the three strains were similar. For all strains the rate of growth was fastest at 25° and aw 0.99, and growth did not occur at 35°.

Further experiments on one strain showed that under aerobic conditions the range of water activities permitting growth was independent of temperature, but under anaerobic conditions the minimum water activity increased from about 0.94—0.96 as the temperature was reduced from 25° to 0°. Growth was inhibited by low concentrations of undissociated nitrous acid, and inhibition was greater at 0° than at 10° or 25°.
The Resistances of Spores of the Genus Bacillus to Phenol, Heat and Radiation
Authors: Briggs A.
Published: March 2008

Summary. The resistance of the spores of 6 species of Bacillus to 5% (w/v) of phenol at 37°, heat and gamma radiation has been determined. Two, and with heat treatment three, different shapes of log survivor time curves were observed with each lethal agent. In relation to the conditions employed in accepted sterilization procedures, all of the strains were highly resistant to phenol. Bacillus stearothermophilus, B. licheniformis and B. subtilis were resistant to gamma radiation, all three having a D value of 0.22 Mrad. Only B. stearothermophilus was heat resistant having a D value of 22.6 min at 115°. When the relative order of resistance to each agent was considered, with the exception of B. stearothermophilus, the spores showed little evidence of any relationship between their resistances to phenol, heat and gamma radiation.
Role of Disulphide Bonds in the Resistance of Bacillus cereus Spores to Gamma Irradiation and Heat
Authors: Hitchins A. D. , King W. L. , Gould G. W.
Published: March 2008

Summary. Spores of Bacillus cereus were treated with thioglycollic acid which ruptures at least 10–30% of the spore disulphide bonds by reducing them to thiol groups. The treated spores were still viable and were sensitive to lysozyme but remained as resistant to γ‐irradiation and to heat as untreated spores. Neither treated nor untreated spores were sensitized to irradiation by reagents which block thiol groups. The results did not indicate that the high content of disulphide bonds in spore coat protein protects spores against inactivation by irradiation or heat.
A High Resolution System for Chromatographic Analysis of End Products of Bacterial Fermentations
Authors: Drucker D. B. , Melville T. H.
Published: March 2008

Summary. A thin layer chromatographic technique is described which permits the rapid identification of many of the common end products of bacterial fermentations. The system resolves glycerol, butylene glycol, diacetyl and the monocarboxylic acids and affords particularly clear separation of acetic, formic and lactic acids which are otherwise difficult to distinguish.
Early Appearance of Colonies of Brucella Spp. on Solid Media containing Erythritol
Authors: Keppie J. , Witt K. A. , Smith H.
Published: March 2008

Summary. The incorporation of erythritol (1 μM/ml) in Morris medium caused the earlier appearance of colonies of virulent strains of Brucella abortus and B. melitensis. On Albimi agar erythritol accelerated the growth of B. melitensis but not that of B. abortus. There was no acceleration of the growth of a virulent strain of B. suis on either medium.
Some Observations on the Taxonomy of the Genus Microbacterium. I. Cultural and Physiological Reactions and Heat Resistance
Authors: Robinson K.
Published: March 2008

Summary. The cultural and physiological reactions and the heat resistance of 25 organisms of the genus Microbacterium were examined. They could be differentiated into 3 groups corresponding with the previously described species, Microbacterium flavum, M. lacticum and M. liquefaciens.
Pad Culture Studies on Skin Surfaces
Authors: Holt R. J.
Published: March 2008

Summary. A method is described for obtaining replicate velvet pad cultures of skin and other surfaces using malleable pads. This enables the bacterial flora of very irregular surfaces to be charted, and multiple replications on a range of selective media to be made. The application of the method to a number of clinical problems is reported.
Chlorine Dioxide Disinfection Temperature Effects
Authors: Benarde M. A. , Snow W. B. , Olivieri V. P.
Published: March 2008

Summary. Washed suspensions of Escherichia coli were exposed to different concentrations of chlorine dioxide at various temperatures. Platings of the mixtures to evaluate the numbers of surviving cells were made after 5–300 sec of contact. Survival data were best fitted by a reaction model that is first order with respect to cell concentration and to exposure time. Bactericidal rates were found to increase markedly with both increased disinfectant concentrations and increased temperatures. Activation energies at each concentration of chlorine dioxide are reported.
Identity of Gram Negative, Yellow Pigmented, Fermentative Bacteria isolated from Plants and Animals
Authors: Graham D. C. , Hodgkiss W.
Published: March 2008

Summary. Morphological, cultural and biochemical properties of 35 isolates of rod shaped Gram negative, yellow pigmented anaerogenic, fermentative bacteria were compared. The isolates comprised named cultures of Bacterium herbicola, Erwinia lathyri, E. ananas, E. milletiae, E. uredovora and B. typhi flavum, as well as organisms isolated from deer and man which were considered to be related to E. milletiae. The results showed that the organisms were indistinguishable from one another on the basis of the tests employed, and it is concluded that B. herbicola, B. typhi flavum, E. lathyri and E. ananas should be classified as Erwinia herbicola (Düggeli) Dye. Since there was insufficient information regarding the plant pathogenicity of E. milletiae and E. uredovora, it is suggested that they should remain separate species at present. The relationship of this group of organisms to certain coliforms and to flavobacteria is briefly discussed.
Investigations on the Glycerol Metabolism of Lactobacilli
Authors: Cantoni C. , Molnar Maria R.
Published: March 2008

Summary. The glycerol metabolism of homofermentative and heterofermentative strains of Lactobacillus obtained either from Culture Collections or isolated from sausages has been investigated.

The results show that the homofermentative lactobacilli (Thermobacterium and Streptobacterium) produce mannose phosphate which is then metabolized to lactic acid and other byproducts.
Effects of Ethylene Oxide on the Tissue and Flora of Fresh and Freeze Dried Cod Fillets
Authors: Herbert R. A. , Haight R. D.
Published: March 2008

Summary. Attempts to sterilize fresh cod fillets with ethylene oxide resulted in protein denaturation with the commensurate exudation of soluble tissue materials. The bacterial colony forming units were reduced to a level of between zero and 100/g of tissue, but sterilization was never achieved. Freeze dried cod fillet sections treated with ethylene oxide and reconstituted with sterile Ringer's solution gave a sterile product which when inoculated with a natural bacterial flora produced normal spoilage odours.
Antigens of Bacillus cereus: A Comparison of a Parent Strain, an Asporogenic Variant and Cell Fractions
Authors: Baillie Ann
Published: March 2008

Summary. The antigenic structure of a stable asporogenic variant of the M8 strain of Bacillus cereus has been compared with that of the parent strain. Ultrasonic extracts of cells of both parent strain and variant harvested at different ages have been analysed by immunoelectrophoresis against antisera prepared by injecting such extracts into rabbits.

Disintegrates of cells of the asporogenic variant were antigenically identical with disintegrates of vegetative cells of the parent strain. Disintegrates of cells in later stages of sporulation and of mature spores of the parent strain contained thermostable antigens which were never detected in the variant. Antigens of isolated cell walls, protoplasts and flagella were also studied.

Examination of esterase and catalase content of the two strains showed that although the variant had the same enzymes as the young vegetative cells of the parent strain it never developed the thermostable catalase found in disintegrated spores. Protein components of the two strains at different stages of growth and of the isolated cell fractions were studied by electrophoresis in polyacrylamide gels.
Efficacies of Vaccines containing Alginate Adjuvant
Authors: Shapiro A. , Modai Y. , Kohn A.
Published: March 2008

The efficacies of bacterial, viral and toxoid vaccines containing alginate adjuvant were compared with those of the same vaccines made with Freund's adjuvant or saline. Salmonella typhi vaccine containing alginate was more effective in producing protecting antibodies in mice than were other typhoid vaccines. Alginate slightly improved the myxovirus vaccines, influenza, NDV and EMC, but was not as effective as Freund's adjuvant. Alginate adjuvant did not improve the immunogenic properties of diphtheria toxoid.
Increase in Growth Rate of Leptospirae by Zinc Nitrate
Authors: Burger G. , Fuchs G. H. P.
Published: March 2008

Zinc nitrate at 2 × 10‐7 g/ml of medium increases the rate of cell division of leptospirae in the log phase but does not alter the final cell density of liquid cultures.
Growth and Survival of Rhizobium spp. in Peat Culture
Authors: Roughley R. J. , Vincent J. M.
Published: March 2008

The growth and survival in peat culture of 3 strains of Rhizobium representing 3 inoculation groups, were affected by the source of the peat, pH and method of pH adjustment, method of sterilization, drying temperature and moisture content. The choice of a peat for culture production can be made only on actual tests of its suitability as a medium for rhizobial growth and survival. Sterilization always permitted more rapid growth of the rhizobia and favoured their viability during storage. For the cowpea strain sterilization was essential. Sterilization by γ radiation was generally superior to autoclaving: temperatures > 100° at the time of drying adversely affected survival and multiplication. Heat of wetting, which kills many of the added rhizobia, and the production of inhibitory substances, which prevents subsequent multiplication and accelerates death during storage, are important factors. Temperatures of 80–100° were safe and sufficient to dry peat spread in a thin layer. A moisture content of 40–50% (on a wet weight basis in the finished culture) was optimal.
Effect of Magnesium Ions and Ethylenediamine Tetra‐acetic Acid on the Activity of Vancomycin against Escherichia coli and Staphylococcus aureus
Authors: Russell A. D.
Published: March 2008

When added to logarithmically dividing Encherichia coli, vancomycin caused lysis only when the nutrient medium was deficient in magnesium ions. They did not prevent vancomycin from exerting an inhibitory effect on Staphylococcus aureus growing in the log phase. Ethylenediamine tetra‐acetic acid (EDTA) was less inhibitory to E. coli than to Staph. aureus, but in sub‐bacteriostatic concentrations it potentiated the activity of sub‐inhibitory doses of vancomycin against E. coli. EDTA probably removes some cations in the cell wall, thus facilitating the entry of vancomycin; it does not potentiate the activity of sub‐bacteriostatic doses of vancomycin against Staph. aureus.
Occurrence of Bacillus subtilis with High Heat Resistance
Authors: Put Henrieutte M. C. , Aalbebsberg W. IJ.
Published: March 2008

The heat resistance of spores of Bacillus subtilis strain Bac 1–11, isolated from processed fried rice, and strain Bac 1–12, isolated from processed evaporated milk, has been determined. The calculated D112.5 of spores of Bac 1–11, in M/40 phosphate buffer (pH 6.8) and in fried rice (pH 6.4) was 4.2 min and 4.5 min (z= 18 and 20 resp.), respectively. The calculated D112.5 of spores of Bac 1–12, in M/40 phosphate buffer (pH 6.8) and in evaporated milk (pH 6.4) was 5.0 min and 6.7 min (z= 18 and 23 resp.), respectively. The extrapolated D121 values were 0.57, 0.76, 0.71 and 1.45 min, respectively.
Fine Structure of Clostridia with Special Reference to the Location of Antigens and Enzymes
Authors: Walker P. D. , Thomson R. O. , Baillie Ann
Published: March 2008

The fine structure of Clostridium sporogenes and Cl. bifermentans using ultrathin sectioning is described. The location of esterases during various stages of sporulation is related to the fine structure, together with the location of surface antigens using the ferritin labelled antibody technique.