bluuebunny/crossref_metadata_2025 huggingface dataset:
An Examination of the Value of Adding Peptone to Diluents Used in the Bacteriological Testing of Bacon Curing Brines
Authors: Patterson J. T. , Cassells J. A.
Published: March 2008

The organisms present in Wiltshire curing brines have been shown to die in various diluents. The addition of 0·1% of peptone aided survival, but did not completely remove the bactericidal effect. Diluents at pH 6–7 gave better survival than those at pH 5.
The Microflora of Milking Equipment Cleansed by Chemical Methods
Authors: Thomas S. B. , Hobson Phyllis M. , Elson K.
Published: March 2008

Summary: The incidence of the main types of bacteria among 2,856 isolated on Yeastrel‐milk agar incubated at 30° from 121 rinses of dairy equipment cleansed by chemical methods, showed that micrococci were dominant in low colony count (<104/ft2) rinses of equipment treated by immersion cleaning in caustic soda or cleansed in detergent‐hypochlorite solutions, whereas nonpigmented Gram‐negative rods were dominant in low count rinses of equipment cleansed with detergent‐sterilizers containing quaternary ammonium compounds. Gram‐negative rods were dominant and streptococci frequent in high count (<2·5 × 105/ft2) rinses irrespective of the chemical used. A high proportion of the streptococci and coli‐aerogenes organisms gave acid reactions in litmus milk after 72 h at 22°, many of the anaerogenic Gram‐negative rods and several of the aerobic sporeformers gave proteolytic reactions, whereas the majority of the micrococci, corynebacteria and other asporogenous Gram‐positive rods showed no change. Bacteria isolated from high count rinses were more active in producing milk spoilage reactions at 22° than those isolated from low count rinses.
The Effect of Freezing on the Radiation Sensitivity of Bacterial Spores
Authors: Matsuyama A. , Thornley Margaret J. , Ingram M.
Published: March 2008

Summary: Bacillus pumilus spores, irradiated under aerobic conditions, were inactivated exponentially at the same rate whether they were at room temperature (10–13°) in phosphate buffer or at ‐79° in phosphate buffer or in heart infusion broth.

Clostridium welchii spores were irradiated in Robertson's cooked meat medium under anaerobic conditions. With unheated spores, and those subjected to a heat shock before irradiation, the inactivation rate was the same at room temperature and ‐79°. The same applied to spores heat shocked after irradiation for doses up to 450 Krads, but above this dose level the spores irradiated frozen were more sensitive.

The effect of the heat shock, whether applied before or after irradiation, was to increase the number of survivors, and the proportionate increase appeared to vary with dose.
The Bacteriology of Trickling Filters
Authors: James A.
Published: March 2008

Summary: The nature of the bacterial flora of trickling filters has been investigated. It consisted primarily of Gram‐negative, rod shaped bacteria closely related to the flora of fresh water. These bacteria were able to grow on nutrient agar at 22° and belonged mainly to the genera Achromobacter, Alcaligenes, Flavobacterium, Pseudomonas and Zoogloea. The results failed to confirm the importance previously attributed to coli‐aerogenes organisms, aerobic sporeformers and filamentous bacteria. The influence of homogenization on these findings is discussed. Further evaluation of the ecological importance of the various groups of bacteria was carried out by metabolic studies using synthetic sewage.
The Resistance of Gallic Acid and its Alkyl Esters to Attack by Bacteria able to Degrade Aromatic Ring Structures
Authors: Beveridge E. G. , Hugo W. B.
Published: March 2008

Summary: Various bacteria capable of degrading aromatic ring structures were unable to utilize gallic acid, methyl, ethyl or propyl gallates as sole carbon sources for growth when tested in liquid and solid media. A bacterial isolate was obtained which degraded gallic acid but not methyl, ethyl or propyl gallates, although ellagic acid, a major spontaneous degradation product of the gallate esters, was utilized to a limited degree.
Serratia indica as a Bacterial Tracer for Water Movements
Authors: Ormerod J. G.
Published: March 2008

Summary: Methods are described for obtaining suitable liquid cultures of Serratia indica for transporting mature cultures in the field and for viable cell determination using membrane filters. The effect of culture medium composition on growth curves and on viability of very dilute suspensions of the organism in vitro in distilled and sea water was investigated. The results of a field investigation at a sewage outfall are described.
The Effect of Tannins on the Morphology and Hydrogenase Activity of Sulphate Reducing Bacteria
Authors: Booth G. H. , Mercer Stella J.
Published: March 2008

Two strains of Desulphovibrio desulphuricans were found to have much reduced hydrogenase activity for sulphate reduction and methylene blue reduction after repeated subculture in medium containing mimosa tannin. The loss of activity was not reversed on transfer back to a medium containing no tannin. Changes in the morphology and motility of these organisms, and of the related organism Desulphovibrio orientis, brought about by culture in media containing tannins are reported.
The Influence of Temperature on the Effect of Bacteriostatic Concentrations of Phenol Against Escherichia coli
Authors: Parkinson J. C. , Pickett J. M.
Published: March 2008

Summary. During early exponential growth of Escherichia coli in the absence of phenol there is a natural death rate at 20, 30, and 44° but at the optimum temperature around 37° there is little if any significant death. The influence of a rise in temperature from 20 to 44° is to decrease the generation time and at 44° the lower generation time compensates for a reduced generation index. The main effect of sub‐bacteriostatic concentrations of phenol is to increase the generation time but at 30, 37 and 44° there is a significant reduction in the generation index at the higher concentrations resulting in a dynamic bacteriostasis. At 20° bacteriostasis is due mainly to a large generation time but there is a little growth and so bacteriostasis is essentially dynamic. There is also evidence to suggest that the effect of a particular concentration of phenol on the generation index is not merely influenced by the temperature but by the generation time under the particular set of conditions. If phenol is added to rapidly growing cultures of E. coli the effect of a rise in temperature is to reduce the concentration required for bacteriostasis but if it is added during the lag phase there is a maximum in the bacteriostatic concentration between 20 and 37°.
Psychrotrophic Clostridia
Authors: Beerens H. , Sugama S. , Tahon‐Castel M.
Published: March 2008

Of 287 strains of clostridia of 23 different species 96 grew well at 6°, 77 of which were Clostridium carnofoetidum var. amylolyticum and 16 were Cl. perfringens.

The water of polluted wells seems to be the normal habitat of Cl. carnofoetidum var. amylolyticum. This species is both proteolytic and saccharolytic and is not pathogenic for mice or guinea pigs. Spores survive at 80° for 40 min. Mg is essential to obtain sporulation of the strains in artificial environments.

Growth temperatures vary between 6 and 37° with an optimum at 30°. At 6° strains untrained to grow at this temperature grow in about 5 days in Rosenow medium. Trained stains have a lag phase of 24 h. Growth curves show a longer logarithmic phase at 6° than at 30°. At the end of this phase the bacterial count is the same at both temperatures. Cl. carnofoetidum var. amylolyticum is, therefore, a true psychrotrophic species.

Glucose and pyruvate breakdown studied by Warburg's method confirms the slowing down of metabolism at 6°. A study of amino acid degradation indicates that serine is the substance most rapidly attacked at 37°, but at 6° the activity against serine disappears completely.

In Rosenow medium at the first inoculation 8 strains of Cl. perfringens out of 24 failed to grow at 6° after 30 days. They were all enterotoxic types. Among the other 16 strains none survived beyond the tenth transfer at 6° and it was not possible to train any strain to grow at this temperature. An examination of the growth curves shows that they are not truly psychrotrophic.
A New Alginate Adjuvant
Authors: Scherr George H. , Markowitz Abraham S. , Skelton L. Z.
Published: March 2008

Studies with a new, low polymer sodium alginate adjuvant are described using soluble, as well as particulate, antigens. Comparative data in experimental animals for the titres elaborated using the sodium alginate as an adjuvant were, in most cases, as good as, or superior to, antibody titres procured with Freund's adjuvant. The alginate adjuvant is miscible with water and can be used as a liquid sodium salt prior to injection, after which it forms an insoluble gel as the calcium alginate which is gradually absorbed from the site of the inoculation.
Bacterial Growth on and Penetration of the Shell Membranes of the Hen's Egg
Authors: Board R. G.
Published: March 2008

Commonly occurring contaminants of rotten eggs multiplied in a buffered solution of mineral salts containing intact shell membranes. Aeromonas liquefaciens, a nonpigmented pseudomonad, and sometimes a proteolytic strain of a Cloaca sp. caused the membranes to lose their pink colour. This was associated with a marked increase in the turbidity of the suspending medium and with the appearance of substances which reacted with Nessler's reagent and ninhydrin. These changes were not seen after growth of Proteus vulgaris, Alcaligenes faecalis, Pseudomonas fluorescens or non‐proteolytic strains of Cloaca spp. No differences were noted in the rate of penetration of the shell and shell membranes by these two groups.
The Morphology of some Bacteriophages Specific to Serratia marcescens
Authors: Bradley D. E.
Published: March 2008

A number of bacteriophage isolates specific to Serratia marcescens was obtained from sewage, and examined in the electron microscope. Six different morphological types were found, some of them identical with various coliphages. The only new morphological type possesses a massive octahedral head and contractile tail; it is believed to be the largest phage so far isolated. Electron micrographs of the isolates revealed the molecular structure of the virions, which was comparable with that of similar coliphages. The similarity between coliphages and some Serratia spp. phages indicates a close relationship between the host organisms.
A Cooling Modification to an Apparatus for Phage Typing of Staphylococcus aureus
Authors: Dunn L. J. , Steingold L.
Published: March 2008

Difficulty is experienced through overheating of the Tarr apparatus for phage typing. The provision of a cooling coil which overcomes this difficulty is described.
The Identification, Epidemiology and Pathogenicity of the Salmonellae of Subgenus II
Authors: Rohde R.
Published: March 2008

A short description of the biochemical criteria used in the differentiation of the salmonellae of subgenera I, II and Arizona is given. Important antigenic differences have been found between the subgenera I and II. The pathogenicity and epidemiology of subgenus II are discussed. In 1960 Kauffmann proposed dividing the salmonellae on the basis of certain fementative differences into two biochemically defined subgenera. This subdivision is useful and is already carried out in a number of laboratories.
The Decomposition of Uric Acid in Built Up Poultry Litter
Authors: Schefferle Henrietta E.
Published: March 2008

The decomposition of uric acid in built up poultry litter appears to be brought about almost exclusively by the action of aerobic bacteria. Organisms decomposing uric acid usually comprised about one quarter of the bacterial population. They were strains of Corynebacterium and less frequently strains of Nocardia, Streptomyces, Pseudomonas, Alcaligenes and Achromobacter. Uric acid was converted to ammonia by some of the organisms but only to urea by the majority. Hydrolysis of urea to ammonia could be brought about by strains of Corynebacterium, Micrococcus, Alcaligenes, Achromobacter and Cytophaga which had no action on uric acid. It is suggested that the ammoniacal smell and high alkalinity of built up poultry litter result largely from the decomposition of uric acid. The identity of the bacteria concerned is discussed.
The Incidence of Clostridium botulinum Type E in Fish and Bottom Deposits in the North Sea and off the Coast of Scandinavia
Authors: Cann D. C. , Wilson Barbara B. , Hobbs G. , Shewan J. M. , Johannsen A.
Published: March 2008

A previous report concerning the high incidence of Clostridium botulinum type E in marine deposits in Swedish coastal waters has been confirmed. The organism was not found in the North Sea or in fish caught in the North Sea or the Skagerrak.
Comparative Studies on Coryneform Bacteria from Milk and Dairy Sources
Authors: Jayne‐Williams D. J. , Skerman T. M.
Published: March 2008

Summary. Physiological characteristics of 133 strains of coryneform bacteria originating from milk, milk products and dairy equipment were studied. Based on the results of a number of selected tests, the majority of these strains have been classified in four groups, the first three comprising organisms derived from aseptically drawn milk. Group I strains were lipolytic, nonhaemolytic, nonproteolytic, V‐P and urease positive, grew in the presence of 9% NaCl, and had a nutritional requirement fulfilled by Tween 80. They were identified as Corynebacterium bovis.

Group II strains were also urease and V‐P positive, but were nonlipolytic, haemolytic, salt sensitive, and they liquefied gelatin slowly at 22°. Marked changes in morphology were shown; cells from 6–8 h cultures were predominantly large coryneform rods, whereas those from 24–36 h (or older) cultures were almost uniformly coccoid. Evidence is presented in support of the identification of these strains as C. ulcerans. Group III comprised catalase and V‐P negative, lipolytic organisms which liquefied coagulated serum; they grew optimally on media containing blood in a CO2‐enriched atmosphere and were identified as C. pyogenes. The last group consisted of organisms isolated from market milk, milk products and dairy utensils; presumably for these the udder is not a suitable habitat. They were salt sensitive, V‐P negative, nonhaemolytic and nonlipolytic, and, although exhibiting variable heat resistance, closely resembled C. lacticum. Although heat labile, some of the strains which had pronounced caseolytic activity were otherwise similar to descriptions of C. liquefaciens; however it is held that there are insufficient grounds to justify their taxonomic separation from C. lacticum.

A residue of 11 isolates originating from the same sources as Group IV strains could not be satisfactorily classified and have been placed in a Miscellaneous group.
Production of Riboflavin by Arthrobacter globiformis
Authors: Veldkamp H. , Venema P. A. A. , Harder W. , Konings W. N.
Published: March 2008

Summary. The yellow pigment excreted by a strain of Arthrobacter globiformis during exponential growth was identified as riboflav in. The amount produced was approximately 5 μ/mg of cells formed (dry weight) in all media tested, rich as well as poor. This value was also found in media containing 1% of Tween So, even though the concentration of internal flavins then was nearly one‐half the normal value. Over production of riboflavin in most media was 40‐50 fold. The specific growth rate of the riboflavin producer was sevral per cent less than that of a normal strain of the same species.
An Examination of Corynebacterium spp. by Gel Electrophoresis
Authors: Robinson K.
Published: March 2008

Summary. The cell free extracts of 24 organisms of the genus Corynebacterium were examined by starch gel electrophoresis for esterase, catalase and peroxidase activity. The protein components of eleven of these extracts were also detected after electrophoresis in polyacrylamide gel. The results indicate a separation of the members of the genus into distinct subgroups comparable to those obtained by grouping strains according to habitat.
Sporulation of Clostridium perfringens (welchii) in Four Laboratory Media
Authors: Groom Rosemary A. , Strong Dorothy H.
Published: March 2008

Summary. Sporulation of 7 strains of Clostridium perfringens (welchii) was investigated in 4 laboratory media. A method to induce rapid and simultaneous sporulation was attempted which involved obtaining a purely vegetative culture to inoculate the test media. Heat resistance of spores produced in the individual media by each of 4 selected strains was investigated. The clean spores for the heating tests were obtained by a special procedure which included chilling to 6° for a minimum of 1 week immediately following the usual incubation period, then centrifuging, resuspending to volume in 0.85% NaCl solution and pasteurizing at 75° for 20 min before subjecting to the heating tests. Morphology of each strain was studied using stained microscopic preparations from the 24 h sporulating cultures.

In the Ellner medium spore counts approaching 107/ml were recorded and this medium appeared to be the most efficient when judged in terms of numbers of spores produced. In other media the counts were in the range 104‐105 spores/ml. Cooked meat medium yielded slightly higher spore counts than did either SEC broth or modified Wagenaar & Dack medium, the latter contained in a dialysis sac apparatus. A period of chilling to 6° for a minimum of 1 week following incubation enhanced maturation in all cultures except those grown in SEC broth for 24 h or 15 days and those grown 15 days in the modified Wagenaar & Dack medium.

Considerable heat resistance, expressed as percentage spore survival, was recorded for spores of 4 strains when heated at 80°, and heat resistance generally increased with lengthening of incubation time for the culture. Survival of spores heated at 100° for 10 min was usually less than 0.01% but spores in SEC broth after 15 days showed a somewhat greater heat resistance than the others. In no instance did total destruction of spores occur at 100°.
Chemical Disinfection of Hospital Woollen Blankets in Laundering
Authors: Dickinson J. C. , Wagg R. E.
Published: March 2008

Summary. Three laundry disinfecting processes for woollen blankets were tested in a hospital laundry against total bacteria. Results were somewhat indefinite owing to a low general level of infection and the incidence of slight recontamination during drying. Before drying, disinfection was demonstrated. Laboratory simulated launderings on pieces of blanket infected with Pseudomonas pyocyanea showed significant differences between the processes.
Some Morphological and Physiological Characteristics of Gram Negative Anaerobic Bacteria isolated from the Alimentary Tract of the Pig
Authors: Fuller R.
Published: March 2008

Summary. A collection of 100 strains of Gram negative anaerobic bacteria isolated from the alimentary tract of the pig has been divided into four groups on morphological and physiological grounds. The four groups resemble the genera Bacteroides, Sphaerophorus, Veillonella and Peptostreptococcus as described in Bergey's Manual (Breed, Murray & Smith, 1957).
Analysis of the Crystal Antigens of Bacillus thuringiensis by Gel Diffusion
Authors: Pendleton I. R. , Morrison R. B.
Published: March 2008

Summary. The antigenic patterns of the crystal protein inclusions of Bacillus thuringiensis were determined. No specific antigenic patterns associated with previously described subgroups of this species were found. A larger number of categories of crystal antigen than of flagellar antigen or esterase type were found. In some cases isolates indistinguishable in classifications based on flagellar antigens or esterase types could be subdivided by their crystal antigenic pattern. The use of crystal antigens in classification is discussed.
Some Observations on the Taxonomy of the Genus Microbacterium. II. Cell Wall Analysis, Gel Electrophoresis and Serology
Authors: Robinson K.
Published: March 2008

Summary. The chemical composition of the cell wall mucopeptide, the esterases and catalases of the cell free extracts, and the serology of the 25 species of microbacteria whose morphological and cultural characteristics had been investigated previously, were examined. Suggestions are made about the relationships of the species within the genus Microbacterium and with other genera.
Use of Ferritin Labelled Antibodies in the Location of Spore and Vegetative Antigens of Bacillus subtilis
Authors: Walker P. D. , Thomson R. O. , Baillie Ann
Published: March 2008

The ferritin labelled antibody technique has been used to locate vegetative antigens in the spores of Bacillus subtilis. The results confirm those previously described for B. cereus.
Occurrence of Micrococci and Staphylococci in the Intestines of Piglets and Pigs
Authors: Wilssens A. T. E. , Vandé Casteele J. C.
Published: March 2008

Over 300 Gram positive, catalase positive cocci isolated from the intestinal contents of piglets and pigs were examined and classified by the methods of Baird‐Parker (1963). Most of the subgroups of the Micrococcaceae were represented in the samples, but Staphylococcus subgroups I, III, and VI were present only in the piglets. Subgroup VI could be clearly subdivided further into VI (the original subgroup of Baird‐Parker) and VIa, according to the response in the acetoin test. The organisms belonging to subgroup VIa were quite frequently isolated. In adult pigs Micrococcus subgroups 2, 3, 4, 5, 6 and 7 were found, but in piglets only subgroups 3, 5 and 7 occurred. A high proportion of the strains isolated belonged to Micrococcus subgroups 5 and 7.
Enumeration of Coagulase Positive Staphylococci in Cheese
Authors: Rammell C. G. , Howick Jocelyn M.
Published: March 2008

A method is described for the enumeration of coagulase positive staphylococci in cheese. Samples are emulsified in 1% sodium citrate solution and suitable dilutions plated out on the surface of bovine blood agar. After incubation at 37° for 18–20 h, the number of haemolytic staphylococcal colonies is counted. Less than 3% of such staphylococci were coagulase negative.
A Note on the Continuous Flow culture of Mixed Populations of Lactobacilli and Streptococci
Authors: Lewis Patricia M.
Published: March 2008

Pure cultures of thermophilic yogurt starter strains of Lactobacillus and of Streptococcus, and 2‐member cultures of these strains, were established in chemostat continuous cultures and maintained for periods of up to 6 and 9 days, and one month respectively. Cultures were maintained at 45° in a 100 ml chemostat vessel at flow rates varying from 0.2‐1.4 culture volumes/h, giving a yield, at the highest flow rate, equivalent to 33 batches a day. The population values obtained in 2‐member cultures were similar to those occurring in pure cultures, indicating different growth limiting factors for the two organisms. Some oscillation in population densities occurred but the system was thought to be fundamentally suitable for production of mixed starter cultures.
A New Method for Evaluating Surface Contamination of Raw Meat
Authors: Williams M. L. B.
Published: March 2008

A method is described by which all surface organisms are washed off into a sampling diluent.
Physiology of an Obligately Psychrophilic Marine Pseudomonas Species
Authors: Harder W. , Veldkamp H.
Published: March 2008

Ten obligately psychrophilic bacteria were isolated from North Sea water using conventional enrichment culture techniques at low temperatures. Whereas Arrhenius plots of the growth rate of obligate psychrophiles were linear down to the freezing point of the 0.25% lactate‐artificial sea water medium used, Arrhenius plots of facultative strains showed a deviation from linearity at temperatures a few degrees above 0°. It thus appears that the growth rate of obligate psychrophiles is higher at low temperatures, indicating that in competitive processes in cold natural environments, these organisms are at an advantage. The optimum temperature for growth of one of the isolates, a Pseudomonas sp., was 14.5°; the maximum temperature was between 19 and 20°. Respiration was optimal at 23°, and no inactivation of respiratory activity was found within 5 h at 25°. Cells incubated at supermaximal temperatures showed a release of UV absorbing material. RNA synthesis could not be detected at these temperatures. This is considered to be one of the major factors defining the maximum growth temperature of this organism.
A Note on Penicillinase Production and Penicillin Sensitivity of Staphylococci in the Disc Test
Authors: Holt R. J.
Published: March 2008

The sensitivities were determined of 306 isolates of Staphylococcus aurcus and of a smaller number of Staph, albus to various penicillin derivatives, as estimated by a conventional disc method, and their production of penicillinase (β‐lactamase). Many strains of Staphylococci which gave restricted but clear zones of inhibition round discs were shown to produce β‐lactamase.

It is suggested that all strains of staphylococci showing such restricted inhibition zones round discs of β‐lactamase‐sensitive penicillins should be reported as relatively resistant to these derivatives.
Growth of Moulds on a Fraction of n‐Alkanes Predominant in Tridecane
Authors: Ratledge C.
Published: March 2008

Species of Helicostylum, Rhizopus, Aspergillus, Penicillium and Fusarium can use as carbon source a fraction of n‐alkanes containing mainly dodecane, tridecane and tetradecane. Yields of mycelium after 21 days were usually <2g/l but the addition of Brussels sprout blanching liquor increased the growth of the Aspergillus, Penicillium and Fusarium spp. 4‐ to 9‐fold. When Penicillium funiculosum and P. soppi were grown on the hydrocarbon fraction, 50% (w/w) of their total fatty acids had carbon chain lengths of < 16. When grown on sucrose the proportion was c. 2% (w/w). A culture of P. soppi grown on sucrose failed to produce short chain fatty acids when the n‐alkanes were substituted as carbon source.
Role of Colon Liquor in the Cultivation of Cellulolytic Bacteria from the Large Intestine of the Horse
Authors: Davies M. Elizabeth
Published: March 2008

A study has been made of the growth promoting properties of colon liquor in the culture of cellulolytic organisms from the large intestine of the horse. Several substances were investigated as replacements for it in culture media.
Bacterial Degradation of Plasticized PVC
Authors: Booth G. H. , Cooper A. W. , Robb J. A.
Published: March 2008

Sixtytwo bacterial cultures isolated from a range of deteriorated plastic materials were tested for their ability to degrade a particular PVC mix plasticized with di‐iso‐octyl sebacate. Twentythree of them, mainly members of the genera Pseudomonas and Brevibacterium, gave weight losses of up to 20% in 2 weeks in laboratory conditions. The degradation, which was accompanied by a loss of flexibility of the material, was greatly increased in vigorously aerated cultures.
Shigella spp., Salmonella choleraesuis and Arizona in Rappaport's medium
Authors: Vassiliadis P.
Published: March 2008

None of 111 Shigella strains, including all Sh. flexneri types, 2 Sh. boydii types and Sh. sonnei II strains, multiplied in Rappaport's enrichment medium even after a quite heavy inoculation. Moreover the medium proved to be inadequate for the survival of these germs. Of 2 Salm. choleraesuis and 3 Salm. choleraesuis var. kunzendorf strains suspended in saline and inoculated in Rappaport's medium, only 2 of the var. kunzendorf strains multiplied after 48 h. When these strains were suspended in a faecal‐saline dilution the 3 Salm. choleraesuis var. kunzendorf strains grew vigorously in 24 h and 1 Salm. choleraesuis strain grew after 48 h. Only 3 Arizona strains of the 11 tried multiplied vigorously in Rappaport's medium.
A Magnetically Driven Tissue Homogenizer
Authors: Cameron J. , Godfrey E. I.
Published: March 2008

The construction of a magnetically driven tissue homogenizer operating in a 10 ml volume at 2000 rev/min and capable of homogenizing a guinea‐pig spleen in 10–20 sec is described.
Towards the Isolation of Respiratory Syncytial Virus from the Environment
Authors: Kingston D.
Published: March 2008

Respiratory syncytial virus in 1 μl drops of tissue culture homogenate on polythene gave c. 10% survival on drying and c. 1% survival over 24 h, depending on the vehicle and humidity, but showed no significant loss in liquid suspension over 3 h, or if 100 ft3 of air were blown through the suspension. When drops were deposited on nutrient agar plates there was no significant loss over a period of 3 h, even if 10 ft3 of air were passed over the surface. However, only c. 10% of the virus deposited in this way could be recovered, though 90% of bacteria could be recovered by wiping the agar firmly in the presence of liquid.

Air and surface samples were taken in 13 isolation cubicles in which there was an infant suffering from acute bronchiolitis without recovery of the virus, though virus had been isolated from the throats of 8 of the infants, 5 at the time of sampling. The total volume of air sampled was 226 ft3 with liquid impingers and 1146 ft3 on agar. Hartmannellid amoebae were isolated on 2 occasions, one from the air samples and one from surface samples, and an adenovirus type 10 was isolated from the swab of a chair.
Serological Identification Scheme for the Genus Saccharomyces
Authors: Campbell I.
Published: March 2008

In a survey of 17 species of the genus Saccharomyces, 4 serological groups were detected by slide agglutination tests. Group A contained S. cerevisiae, S. rouxii, S. acidifaciens and certain strains of S. carlsbergensis; these species may subsequently be identified by agglutination tests with specific sera. S. cerevisiae also occurred in group B, with S. fragilis and S. marxianus. Group C included S. ellipsoidens, a second group of strains of S. carlsbergensis and 8 other Saccharomyces spp. It was not possible to identify all members of this group as antigenically distinct species; only S. chevalieri, S. inusitatus and S. veronae could be identified by specific sera. The fourth group, D, contained the species S. acidifaciens, S. delbrueckii and S. fermentati. The primary classifications into groups A, B, C and D is equally applicable to fluorescence microscopy, cells of one group in a culture of another group being detectable even at low levels of contamination.
Influence of Amino Acids, Carboxylic Acids and Sugars on the Growth of Methylococcus capsulatus on Methane
Authors: Eroshin V. K. , Harwood J. H. , Pirt S. J.
Published: March 2008

The influence of 3 types of compounds (L‐amino acids, carboxylic acids and sugars) on the growth of Methylococcus capsulatus in Petri dishes was investigated. Increase in colony diameter was used as the growth parameter. L‐amino acids and carboxylic acids which are normal metabolic intermediates prevented growth in low concentrations. Threonine, leucine, histidine and glycine were especially inhibitory; c. 0.01% was sufficient to suppress growth completely. Glutamic acid at 0.1 % concentration completely suppressed growth but at 0.005% markedly stimulated growth; similar effects were shown by lysine, methionine, glutamic acid, tryptophane, tyrosine, proline and citric acid. Among the sugars, glucose was the most potent growth inhibitor; maltose and sucrose had practically no effect.
Studies on the Mineral Nutrition of the Bulbiformin Producing Strain of Bacillus subtilis
Authors: Mahmood M.
Published: March 2008

The elements S, P and K were shown to be essential for both growth and bulbiformin production by Bacillus subtilis. The optimum requirements for these elements were 40, 50, 710 p/m, respectively, for both growth and antibiotic activity. The requirement of K for maximum growth was higher than for antibiotic activity. Calcium sulphate and calcium phosphate as S and P sources were particularly favourable for growth. Calcium or potassium sulphate and Na2S were suitable sources of S, and Ca3(PO4)2, NaH2PO4, K2HPO4 and MgHPO4 suitable sources of P for bulbiformin production.
Medium Volume and the Survival of Serratia marcescens
Authors: Domey R. G. , Saurino V. R. , Simon G. T.
Published: March 2008

Experiments were designed to test the null hypothesis that volume of agar medium in 100 mm Petri dishes has no influence on the colony count of the facultative organism, Serratia marcescens. With a constant inoculum in 9, 12, 15 and 18 ml volume of medium the surface counts were statistically equivalent, but the subsurface counts increased as a direct function of volume variation. Over the range studied, at the P= 0.95 level, the null hypothesis was accepted for surface colony counts but was rejected for subsurface colony counts.
A Soil Perfusion Apparatus
Authors: Cripps R. E. , Norris J. R.
Published: March 2008

A soil perfusion apparatus is described which features an enclosed system of small size. It has been successfully used to isolate micro‐organisms capable of utilizing various aromatic compounds as sole sources of carbon and energy.
The Metabolic Availability of Phenol Analogues to Bacterium NCIB 8250
Authors: Beveridge E. G. , Tall D.
Published: March 2008

Of the monosubstituted phenols examined only 3 could be utilized by bacterium NCIB 8250 as sole carbon sources for growth. Only 3‐ and 4‐fluorophenols, and 4‐chlorophenol, in addition to phenol and catechol, were oxidized by the phenol metabolizing pathway. Fluoride ions were liberated during the metabolism of 3‐ and 4‐fluorophenols and accumulation of toxic intermediates was indicated at the higher substrate levels of the fluorophenols and 4‐chlorophenol. Phenol analogues inhibited phenol metabolism to varying degrees and some may have exerted an uncoupling effect on phenol metabolism. Only the fluorophenols and phenol induced phenol metabolizing activity in growing cells. Growth in the presence of certain other analogues resulted in cells whose inductive lag phase towards phenol was reduced.
Salmonellae in Meat and Poultry, Poultry Plant Cooling Waters and Effluents, and Animal Feedingstuffs
Authors: Patterson J. T.
Published: March 2008

Although a low incidence of salmonellae had been found in 735 broiler chicks in 1961, none were found in 803 carcasses from 4 processing plants in 1966. Small numbers, mainly S. typhimurium, were found in the drains of 2 of these plants when swabs were left for several days. No isolations were made from the waters used to cool broilers or turkeys, or from 84 turkey carcasses. However, 39 of 444 (9%) of duck carcasses harboured S. typhimurium, and 9 of 22 (41%) of duck cooling waters were positive. Two isolations of S. typhimurium were made from 38 samples of pork sausages, and one of S. dublin from 125 samples of frozen boned‐out beef. Three of 29 samples of cooked poultry meat were positive for S. typhimurium. In animal feedingstuffs 8 of 112 (7%) of samples of meat and bone meal had 7 different serotypes present, and salmonellae were also found in feather meal, blood meal and pig compound meal. S. typhimurium phage type 23 has been isolated from ducks, poultry meat, pork sausages and meat and bone meal, suggesting a chain of infection. The significance of the isolations of salmonellae from the various sources is discussed, and some methods of control suggested.
Media Selective for Listeria monocytogenes
Authors: Kramer Pamela A. , Jones Dorothy
Published: March 2008

Of a number of substances tested for inclusion in media selective for Listeria monocytogenes, thallous acetate and nalidixic acid gave encouraging results at 30° and pH 7.0. Using these selective media, L. monocytogenes was recovered from artificially infected manure, soil, silage and grass.
Serological Response Produced in Chickens by Three Strains of Mycoplasma gallisepticum
Authors: Roberts D. H.
Published: March 2008

Three strains of Mycoplasma gallisepticum, S6, F and WS7, were used to infect 3 groups of broiler chickens. Serum antibody response was investigated using the stained antigen plate agglutination (SA) test and the haemagglutination inhibition (HI) test. The HI test was more strain specific and was associated with low molecular weight (IgG) antibodies. Chickens infected with one strain did not always give an HI reaction with the heterotypic antigen. The SA test was associated with high molecular weight (IgM) antibodies. Chickens infected with the three strains always reacted serologically with the homotypic and heterotypic SA antigens. In chickens infected with the S6 and WS7 strains, the IgM and IgG antibody titres remained consistently high during the period of the experiment; in chickens infected with the F strain, the IgG antibodies had disappeared by 7 weeks after infection although the IgM antibodies persisted.
Interactions in the Recovery of Salmonella typhimurium Damaged by Heat or Gamma Radiation
Authors: Corry Janet E. L. , Kitchell A. G. , Roberts T. A.
Published: March 2008

Growth of two strains of Salmonella typhimurium in nutrient broth, selenite and tetrathionate broths, at 37 and 43°, after damage by heat or γ radiation, was compared with that of undamaged cells. Counts at 37° were made on 6 media initially and after enrichment for 24, 48 and 72 h. Analyses of variance showed complex interactions of cell damage, enrichment medium, temperature and duration of enrichment, and plating medium.

The most generally satisfactory combination of factors involving use of selective inhibitors appears to be enrichment in tetrathionate broth at 37° followed by plating at 48 h on brilliant green, Wilson & Blair, or brilliant green‐phenol red agar. After attaining maximum numbers in 18 h in selenite broth, salmonellae died off rapidly or, if heat damaged, may fail to grow at all in this enrichment medium. Incubation at 43° in either selenite or tetrathionate medium, except after pre‐enrichment, is not recommended for heat damaged salmonellae.
Aniline Utilization by a Soil Pseudomonad
Authors: Walker N. , Harris D.
Published: March 2008

A Pseudomonas sp., isolated from soil, grew with aniline as its sole carbon source. Washed cells oxidized aniline by an induced enzyme system and liberated ammonia. Washed, aniline‐grown organisms oxidized without lag aniline, catechol, p‐aminophenol and o‐ and m‐toluidine.
The Location of Chemical Components on Ultrathin Sections of Bacillus cereus Embedded in Glycol Methacrylate
Authors: Walker P. D.
Published: March 2008

The structure of Bacillus cereus during sporulation and germination is described after aldehyde fixation and embedding in a water soluble resin. The resistance of ribosomes to digestion with ribonuclease has been investigated during the various phases of growth. Increasing resistance to digestion was observed at a stage just prior to the development of the spore coat. The location of polysaccharides on similar sections corresponded with their location previously found in osmic acid fixed material.
Combined Effect of Salt Concentration and Redox Potential of the Medium on the Initiation of Vegetative Growth by Clostridium welchii
Authors: Mead G. C.
Published: March 2008

Four strains of Clostridium welchii grew in a medium containing 6% (w/v) of NaCl within 14 days at 37°. In one instance growth was obtained with 7% of NaCl from a large, but not a small, inoculum. Three of the strains grew from a large inoculum in the presence of 0.5 % of NaCl at Eh values of + 194 to + 238 mv. In a medium containing 5% of NaCl no growth occurred unless the Eh level was considerably reduced. The fourth strain was less affected until the NaCl concentration was increased to 6%.
(Symposium on Myxobacteria and Flavobacteria: Paper IX). Observations on the Taxonomy of Chromogenic Bacteria Isolated from Cannery Environments
Authors: Bean P. G. , Everton J. R.
Published: March 2008

The yellow‐orange chromogenic bacteria, commonplace in cannery environments, are capable of producing spoilage in a variety of presterilized milk‐based canned products. A wide range of cultures of these arbitrarily defined flavobacteria, including the particular food spoilage types, were subjected to taxonomic studies. A possible scheme permitting the grouping of spoilage from nonspoilage types is presented.
Thermally Induced Changes in the Physical Properties of Staphylococcus aureus
Authors: Allwood M. C. , Russell A. D.
Published: March 2008

When suspensions of Staphylococcus aureus were stored at different temperatures in water or m sucrose, an increase or decrease (depending on the temperature of storage and the nature of the environment) in o.d. and light scattering properties occurred. Such changes were related to changes in cell size, leakage of intracellular constituents from the cells and precipitation of cytoplasmic material. Electron micrographs of ultrathin sections of cells illustrated some of these changes. The results demonstrated that caution was necessary in the interpretation of changes in o.d. and light scattering properties of this organism.
Growth and Metabolic Activities of Heat Treated Staphylococcus aureus
Authors: Allwood M. C. , Russell A. D.
Published: March 2008

Staphylococcus aureus cells which had been heated at 50 or 60° were transferred to various growth media and intracellular ribonucleic acid (RNA), deoxyribonucleic acid (DNA) and amino acids were measured during the lag phase of growth. The duration of the lag phase depended on the temperature to which the cultures had been subjected, and was longest following storage at 60°. RNA synthesis occurred almost immediately on placing treated cells in a growth medium, but at a slower rate than with unheated cells. Variation in the composition of the metabolic pool of heated cells occurred during the early lag phase and may be as a result of damage to the cytoplasmic membrane with resulting loss of permeability control.
Viability of Clostridial Spores and the Requirements of Damaged Organisms
Authors: Futter B. V. , Richardson G.
Published: March 2008

A method for counting viable anaerobic spores by roll tubes incubated in an atmosphere of hydrogen compared favourably with other techniques. Reproduction of environmental conditions in individual anaerobic jars did not significantly contribute to the overall error (Coefficient of Variation of viable count, 6·7%). Colony counts did not show a Poissonian distribution, and the significance of this is discussed. Optima for some conditions for counting 4 species of Clostridium and for suspensions of spores of Cl. welchii damaged by heat, γ‐rays or ethylene oxide have been established. Damaged spores were more exacting in their cultural requirements than were control organisms, and considerable variation in incubation temperature optima was found according to the sublethal treatment employed.
Ultrasound and Vortex Stirring as Bacteriological Sampling Methods for Foods
Authors: Sharpe A. N. , Kilsby D. C.
Published: March 2008

The efficiencies of an ultrasonic cleaning tank (insonation) and a vortex stirrer for bacteriological sampling of foods were compared with a standard homogenization method. Insonation gave good recovery of micro‐organisms in a limited range of foods, and its main advantage was the very low debris content of the resultant suspension. Vortex stirring was a much more useful method for routine work, combining convenience and rapidity of sample preparation with low running costs, low noise level and easily pipettable suspensions. The high concentration of organisms obtained by vortex stirring may aid detection of low levels of contamination.
A Simplified Method for Quantitative Microbiological Examination of Deep Frozen Seafoods
Authors: Mitchell N. J.
Published: March 2008

Quantitative microbiological examination of exuded tissue juice from deep frozen seafoods is a simple, quick and reasonably accurate method and produces results not significantly different from those yielded by the examination of homogenates of seafoods.
The Assessment of Aerosol Concentration by Means of the Andersen Sampler
Authors: Peto S. , Powell E. O.
Published: March 2008

The statistical problem presented by the Andersen aerosol sampler is discussed. A Table is provided for estimating from the sampler reading the presumptive particle concentration in the aerosol, with its confidence limits.
Observations on the Sporicidal Action of Vegetable Oils Used in Fish Canning
Authors: Dallyn H. , Everton J. R.
Published: March 2008

The putrefactive anaerobe PA3679 was used to investigate possible factors present in vegetable oil which might influence the heat resistance of bacterial spores present in processed tuna fish. A water soluble component of some olive and groundnut oils significantly reduced the heat resistance of spores of this organism. Autoxidation factors in vegetable oils are suggested as the sporicidal or sporistatic agents. Attempts to identify the factor with malonaldehyde were not successful but there was some evidence that a similar carbonyl or its peroxide precursor might be involved.
A Study of the Effect of Carbon Dioxide on the Germination and Outgrowth of Spores of Clostridium butyricum using a Slide Culture Technique
Authors: Hambleton R. , Rigby G. J.
Published: March 2008

A slide culture technique for the study of germination of clostridial spores on solid media is described in which the gaseous environment can rapidly be altered. Two spore suspensions of Clostridium butyricum NCTC 7423 prepared on different media germinated slowly and at different rates in oxygen‐free nitrogen (OFN) in the absence of CO2 when incubated on the same solid germination medium. The admission of 5% of CO2 to spores germinating in OFN caused a sharp increase in germination to almost 100% within 10 min. The results show that the sporulation medium plays a part in determining the carbon dioxide requirement for germination of these spores. A surface spread colony counting technique is also described, and the results using this technique stress the importance of the medium used.
Trace Elements and Reproduction of Leptospirae
Authors: Burger G. , Fuchs G. H. P.
Published: March 2008

Low concentrations of Zn and Co salts in the medium stimulated growth of several strains of 2 species of Leptospira, but high concentrations inhibited growth. Low concentrations of Cu increased the growth rate of saprophytic leptospirae but did not affect parasitic strains; high concentrations inhibited all strains. In a Zn‐containing medium, the addition of increasing amounts of Cd was increasingly inhibitory to both species. The addition of 0·2 × 10−6 g of Zn(NO3)2. 6H2O and 10−9g of CoSO4.7H2O/ml of Korthof's medium is recommended. Saprophytic leptospirae grow better with 10−6g of CuSO4.5H2O/ml of medium.
Microbiological Assay of the β‐Exotoxin of Bacillus thuringiensis
Authors: Rosenberg G. , Carlberg G. , Gyllenberg H. G.
Published: March 2008

The β‐exotoxin of Bacillus thuringiensis var. thuringiensis suppressed the growth of Sarcina flava and certain other bacteria. The antibacterial effect on S. flava was correlated with the amount of exotoxin as determined by absorption at 260 nm as well as to the toxic response in bioassays using the larvae of the housefly. Growth inhibition of S. flava could be shown in cup plate assay of the cellfree supernatant of B. thuringiensis var. thuringiensis cultures, prepurified and purified β‐exotoxin. The results showed that it was possible to use S. flava in a quantative assay of the β‐exotoxin activity of B. thuringiensis.