bluuebunny/crossref_metadata_2025 huggingface dataset:
Interrelationship between Colony Type, Phage Susceptibility and Virulence in Xanthomonas oryzae
Authors: Goto M.
Published: March 2008

Summary: A colonial mutant of Xanthomonas oryzae. (tentatively designated T) had a transparent colony (associated with absence of polysaccharide), resistance to the bacteriophage Bpl and markedly attenuated virulence. Phage resistant mutants with the same colonial characteristics as the wild type (W), which is opaque because of abundant polysaccharides produced, showed various degrees of virulence. Disease symptoms were not suppressed when cells of T were mixed with W in various proportions and used to inoculate rice plants. Disease severity was dependent on the proportion of T in the inoculum and the multiplication of T in the plant was proportional to its initial number of cells in the mixture. When infected rice plants were grown in irrigation water containing phage, little or no selection of phage‐resistant mutants was detected in spite of repeated and high selection pressure. This may be explained by an insufficient supply of bacterial cells from diseased leaves into the irrigation water and by the very low propotion of phage‐resistant mutants that are virulent.
A Note on a Method for Demonstrating Yeast Catalases after Electrophoresis in Acrylamide Gels
Authors: Bruce J. , Morris E. O.
Published: March 2008

Summary: A method for demonstrating sites of catalase activity after electrophoresis of yeast cell extracts in acrylamide gel is described. The method yields permanent preparations of catalase patterns and thereby facilitates the recording of results.
Identification and Typing of Clostridia in Raw Milk in Egypt
Authors: Naguib Kh. , Shouman M. T.
Published: March 2008

Summary: Three spp. of clostridia were isolated from samples of raw cow and buffalo milk obtained near Cairo. Of 150 isolates of anaerobes, 108 were Clostridium perfringens, 30 were Cl. butyricum, and 12 were Cl. sporogenes. The Cl. perfringens isolates comprised 100 nonhaemolytic and 8 pathogenic haemolytic strains. The latter strains typed by neutralization tests, were of type A. Fifteen of the nonhaemolytic strains were also of type A; of these, 6 strains produced heat resistant spores and 9 strains produced heat susceptible spores. Feeding mice with these 15 nonhaemolytic strains caused marked reduction in intestinal passage time.
Studies on the Mechanism of the Antimicrobial Action of Oleuropein*
Authors: Juven B. , Henis Y. , Jacoby B.
Published: March 2008

Summary: Oleuropein, the bitter principle of green olives, is surface active; this and its effect on cell membranes, as demonstrated with human erythrocytes, seems to be the basis of its antimicrobial activity. Oleuropein effected a significant leakage of glutamate, potassium and inorganic phosphate from Lactobacillus plantarum. Oleuropein had no effect on the rate of glycolysis when added to resting cells of L. plantarum but it caused a decrease in the ATP content of the cells.
The Bacteria in an Antarctic Peat
Authors: Baker J. H. , Smith D. G.
Published: March 2008

Summary: Of a total of 119 strains of bacteria from 3 depths in an acid peat on Signy Island, S. Orkney, 52% belonged to the genus Brevibacterium. Twelve other genera were recorded of which numerically the most important were Arthrobacter, Cellulomonas, Kurthia and Micrococcus. 62% of the collection were psychrophilic, but only 4 strains were obligate psychrophiles. No pattern could be established for the various genera from different depths. The fine structure of an obligately psychrophilic pleomorphic rod from the peat is illustrated and discussed.
A Direct Turbidimetric Assay of Pyocine
Authors: Merrikin D. J. , Terry C. S.
Published: March 2008

Summary. An assay of pyocine based on the turbidimetric measurement of the percentage inhibition of a sensitive indicator strain of Pseudomonas aeruginosa is described. The tendency of this organism to clump is circumvented in the method which is simple, rapid in performance and has good precision and reproducibility.
The Degradative Versatility, Arylesterase Activity and Hydroxylation Reactions of Acinetobacter lwoffii NCIB 10553
Authors: Grant D. J. W.
Published: March 2008

Summary. A study of the range of organic compounds utilized as sole carbon source by Acinetobacter lwoffii NCIB 10553 indicates that the organism is Acinetobacter A2 in the classification of Baumann, Doudoroff & Stanier (1968). NCIB 10553 resembles NCIB 8250 (‘Vibrio 01′, described by Fewson, 1967a, b). NCIB 10553 adapted to utilize acetylsalicylate does not grow with the lower n‐alkanes, whereas it does utilize some sugars, although after a lag, and grows readily on a number of aromatic and aliphatic carboxylic esters, including triglycerides, natural oils and fats and other compounds of pharmaceutical interest. Cell‐free extracts readily hydrolyse fatty acid esters of the mono‐ and dihydroxybenzoates and of catechol, quinol, phenol and p‐nitrophenol. They also simultaneously hydroxylate and decarboxylate salicylate, 2,3‐, 2,4‐, 2,5‐ and 2,6‐dihydroxybenzoate but only in the presence of NADH (or NADPH) and FAD. Some other aromatic acids are slowly oxidized under these conditions.
Some Aspects of the Mode of Action of the Antibacterial Compound Bronopol (2‐bromo‐2‐nitropropan‐1,3‐diol)
Authors: Stretton R. J. , Manson T. W.
Published: March 2008

Summary. A series of nitro compounds studied inhibited Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, bronopol being the most active derivative. Bronopol causes some membrane damage. A consideration of its action on enzyme activity, reaction with cell constituents and chemical reaction with cysteine, glutathione and proteins suggests that the oxidation of thiol groups to disulphides may be its primary action.
The Effects of Rehydration and Oxygen on the Heat Resistance of High Vacuum Treated Spores
Authors: Soper C. J. , Davies D. J. G.
Published: March 2008

Summary. Damage induced in bacterial spores by exposure to reduced pressures of the order of 10‐8 torr, has been assessed in terms of the differences in the heat resistance of the dried spores. The response of the spores has been assessed as a function of (a), the drying temperature from 0‐65°; (b) the duration and level of rehydration; (c) the presence or absence of oxygen during heating. Comparison has also been made between spores dried to a given water level and spores rehydrated to the same water level after prolonged drying. Log survivors/heating time curves for treated spore samples have been constructed and have been shown to exhibit a shoulder at high survival levels and a linear portion below a surviving fraction of 0·1. These curves have been explained on the basis of the shoulder representing the time during which necessary structural changes occur in the spore, before the lethal mechanism responsible for the linear portion of the curve becomes operative. The heat response has been shown to be a function of the temperature of drying, and of the presence of oxygen during heating, the structural change itself being reversible by water.
Ecological Studies on the Lactobacillus Flora Associated with the Crop Epithelium of the Fowl
Authors: Fuller R.
Published: March 2008

Summary. The lactobacillus flora lining the crop of the chicken became established soon after hatching and adhered to the crop epithelium throughout the life of the bird: adhesion was unaffected by drastic changes in diet and was of widespread occurrence. Adhering lactobacilli were isolated from birds but not from mammals. Only these avion lactobacilli adhered to chicken crop epithelial cells. It is suggested that these lactobacilli have formed a symbiotic relationship with the chicken and help to regulate the composition of its intestinal microflora.
The Use of Enrichment Serology for Salmonella Detection in Human Foods and Animal Feeds
Authors: Boothroyd Margery , Baird‐Parker A. C.
Published: March 2008

Summary. Samples (2208) of food raw materials and products were examined for the presence of salmonellae by use of conventional salmonella detection procedures and the enrichment serology (ES) techniques described by Sperber & Deibel (1969); 348 samples were positive for salmonellae by the conventional procedures. Using the ES technique with a 24 h elective enrichment step, 93–98% of samples positive by the conventional procedures were also positive by the ES technique. Selective enrichment of food samples using tetrathionate broth containing novobiocin, incubated at 41°, led to the best recovery of salmonellae by both the conventional and ES techniques.
Interaction of Glutaraldehyde with Spheroplasts of Escherichia coli
Authors: Munton T. J. , Russell A. D.
Published: March 2008

Glutaraldehyde, in the presence or absence of sodium bicarbonate, caused an increase in the optical density of spheroplasts of Escherichia coli. The aldehyde, particularly at alkaline pH, prevented lysis of spheroplasts when these were suddenly exposed to a hypotonic environment. It is proposed that the stabilization which occurs results from the crosslinking activity of glutaraldehyde on the cell envelope of E. coli.
Production of Lipase by Staphylococcus aureus under Various Growth Conditions
Authors: Mates A. , Sudakevitz D.
Published: March 2008

Staphylococcus aureus produces an extracellular lipase in a synthetic medium. The composition of the medium affected the amount of enzyme produced: medium containing 2% of peptone was optimal for enzyme production. Tweens added to the media decreased the amount of lipase synthesized depending on the concentration used and the nature of the fatty acid bound to the molecule of polyoxyethylene sorbitan. Carbohydrates that the bacteria could metabolize inhibited lipase production. Bile salts and NaCl decreased the amount of enzyme produced. Optimum lipase production was at pH 7·5 and 37°. The conditions for synthesis of staphylococcal lipase are similar to those described for other bacterial lipases and different from those described for fungi.
A Rapid Technique for Obtaining One‐step or Multi‐step Antibiotic Resistant Mutants Employing Mutator Strains of Escherichia coli K12
Authors: Mount D. W. , Moody E. E. M. , Lew N. , Walker A.
Published: March 2008

A rapid technique is described for obtaining one‐ or multi‐step antibiotic resistant mutants from mutator strains of Escherichia coli K12. The method may be used to test the ability of E. coli to mutate to resistance to increasing concentrations of antibiotics which have not been tested previously. The method has been used to obtain multi‐step mutants which are resistant to high concentrations of polymyxin B.
Studies on the Affinity of Methanol‐ and Methane‐utilizing Bacteria for their Carbon Substrates
Authors: Harrison D. E. F.
Published: March 2008

Methanol‐ and methane‐utilizing organisms were grown in chemostat culture and the response of respiration rate to different concentrations of substrate was measured. Cells of Pseudomonas extorquens NCIB 9399 grown on methanol demonstrated a high affinity for methanol (Km=20·4 μM). The affinities for formaldehyde and formate were 104 μM and 228 μM, respectively. The maximum respiration rate was similar for all 3 substrates. Methanol concentrations of < 1·1 M did not inhibit respiration. The concentrations of formaldehyde that inhibited respiration were > 100 times the Km for formaldehyde so that inhibition by formaldehyde formed as an intermediate in methanol oxidation would be very unlikely. The Km for methane of a culture of a pseudomonad grown on methane was very low, 26 μM; that of the same organism for methanol was 50 μM. The maximum respiration on methanol was c. twice that on methane so that no methanol accumulation would be expected in a methane limited chemostat culture of this organism.
The Bacterial Flora of the Atlantic Salmon (Salmo salar L.) in Relation to its Environment
Authors: Horsley R. W.
Published: March 2008

Summary. The aerobic flora of the skin of 56 Atlantic salmon from coastal, estuarine and river waters was analysed quantitatively; 50 skin and 33 gill samples were analysed qualitatively. The water at each sampling station was also analysed. The principal genera on the skin and gills were Moraxella, Flavobacterium, Cytophaga and Pseudomonas; members of Acinetobacter, Bacillus, Aeromonas, Vibrio, the Entrobacteriaceae, Micro‐coccaceae and some coryneforms were also present. The gill flora was similar to that of the skin, which reflected that of the environment.
Effects of Polyethylene Glycol 400 Monolaurate and Sodium Chloride Mixtures on the Antibacterial Activity of Solubilized Trichlorocarbanilide
Authors: Elkhouly A. E. , Woodroffe R. C. S.
Published: March 2008

Summary. Polyethylene glycol 400 monolaurate (PGM), a nonionic surfactant, affected the solubility of trichlorocarbanilide (TCC), the amount solubilized being directly proportional to the concentration of PGM in the system. The bacteriostatic activity of TCC against Staphylococcus aureus was affected by high but not low concentrations of PGM; proportions of PGM to the germicide of up to 10: 1 did not interfere with the minimum inhibitory concentration (MIC) of TCC (0·08 μg/ml). The bactericidal activity against Staph. aureus of systems consisting of TCC and different proportions of PGM with and without 0·5% of NaCl was much higher than that of saturated aqueous solutions of TCC alone. However, TCC solutions containing NaCl and PGM were more bactericidal than corresponding systems without NaCl; the death rates in TCC‐PGM‐NaCl systems were 2–4 times that in TCC‐PGM systems. The marked increase in the death rate was obtained with systems containing 2·5% of PGM.
Studies on the Mode of Action of Glutaraldehyde on Escherichia coli
Authors: McGucken Patricia V. , Woodside W.
Published: March 2008

Summary. Glutaraldehyde was readily taken up by Escherichia coli cells with an increase in solutions buffered to pH 7·9; it was paralleled by a corresponding increase in bactericidal activity. Attempts to desorb glutaraldehyde from the cells indicated that the drug molecules were firmly bound. Inhibition of synthesis of macromolecules was demonstrated. Cell walls of E. coli exhibited a much reduced rate of hydrolysis following treatment with glutaraldehyde.
The Observation of Micro‐organisms on Surfaces by Incident Fluorescence Microscopy
Authors: Paton A. M. , Jones S. M.
Published: March 2008

Summary. Two methods of viewing surfaces by incident fluorescence microscopy are described for application in microbiological studies associated with food manufacture, agricultural research and dermatological investigations.
Germination of Spores of Bacillus cereus in Milk and Milk Dialysates: Effect of Heat Treatment
Authors: Wilkinson Gillian , Davies F. L.
Published: March 2008

Summary. The germination of spores of Bacillus cereus was studied in milk and in media consisting of the low M.W. fraction of milk. Dialysates, centrifugates, filtrates and acid whey supported germination to an extent similar to that in the milk from which they were derived. HTST (72° for 15 sec) pasteurized milk or derived media supported appreciable germination whereas raw milk or media derived from it supported little or none. Whey produced by the action of rennet was an exception in that it was equally stimulatory for germination whether derived from raw or pasteurized milk. Heat treatments for 15 see using temperatures between 65–75° rendered the milk most suitable as a germination medium but temperatures > 80° were necessary for spore activation. Of the 2 effects, activation was the more important; at treatment temperatures > 80° germination was increased despite the less favourable medium which resulted. The extent of germination in pasteurized milk varied with different isolates and could be related to their source, those from pasteurized milk germinating the most readily. The practical implications of these findings are discussed together with the preliminary work to examine the nature of the germination factor(s) produced during HTST pasteurization.
Microbial Progression in Sliced Vacuum Packaged Bacon at Refrigeration Temperatures
Authors: Dempster J. F.
Published: March 2008

Summary. Three hundred and forty eight strains of micro‐organisms were isolated from packaged bacon which had been cured by one or other of 2 methods (A and B) and stored at 0–10° for 7 weeks. Before storage, Micrococcus sub‐group 7 (47%) and coryneform bacteria (33%) were the principal contaminants of bacon cured by method A and Micrococcus subgroup 1 (20%) and Microbacterium thermosphactum (21%), in bacon cured by method B. After 7 days at 0°, coagulase negative staphylococci accounted for 10 and 33% of the microflora in bacon A and B, respectively: other organisms were micrococci, 60% (A) and 25% (B); corynebacteria, 20% (A) and 12·5% (B), yeasts (Torulopsis candida and T. dattila) 5% (A) and 29% (B). In the following month at 10°, Micrococcus sub‐group 5 was the dominant (43–88%) contaminant of bacon B; the incidence of Streptococcus Group N ranged from 27–36% and that of unidentified lactic acid bacteria from 23–32%. Towards the end of storage, the order of dominance was Micrococcus sub‐group 3 (38–58%) and atypical streptobacteria (38%) in A; Streptococcus Group N (42%) and Gram positive rods (5–20%) in B. Staphylococci tended to die out during storage of bacons cured by the 2 methods and coagulase positive staphylococci were not isolated.
Comparison of Five Media for the Isolation of Coliform Organisms from Dehydrated and Deep Frozen Foods
Authors: Moussa R. S. , Keller Nicole , Curiat G. , De Man J. C.
Published: March 2008

Summary. A significantly higher number of coliform and faecal coliform organisms were isolated using lactose‐glutamic acid medium than by using lauryl sulphate‐tryptone, lactose, brilliant green‐bile or EE broths. With brilliant green‐bile and lauryl sulphate‐tryptone broth, coliforms/Enterobacteriaceae were isolated less often than with the others. For the detection of faecal coliforms, EE broth proved less good than all other media. All 5 media showed more coliforms/Enterobacteriaceae after 48 h than after 24 h at 30°. Few false positive results were obtained using any of these media.
Physicochemical Effects of Long Chain Fatty Acids on Bacterial Cells and their Protoplasts
Authors: Galbraith H. , Miller T. B.
Published: March 2008

Summary. Fatty acids of chain length > C10 induced lysis of protoplasts at pH 7·4 when the concentration was nearly bactericidal. At pH 6, lauric and linoleic acids produced lysis above bactericidal concentrations but, at pH 8, lysis was produced by the same acids below bactericidal concentrations. The lysis was immediate at pH 8, but at pH 6 the effect was preceded by contraction of protoplasts. At pH 7·4 the order of lytic activity between individual fatty acids was similar to that of bactericidal activity and the response of protoplasts of Bacillus megaterium relative to those of Micrococcus lysodeikticus reflected differences in bactericidal sensitivity though whole cells were much less sensitive to fatty acid‐induced leakage effects than protoplasts. Reversal agents antagonized the lysis of protoplasts by fatty acids. A physicochemical basis for the action of fatty acids and reversal agents on protoplasts and whole cells is discussed.
Delineation of the Site of Action of an Antistaphylococcal α‐Globulin
Authors: Lentino J. R. , Yotis W. W.
Published: March 2008

Summary. The isolation of an antibacterial α‐globulin from the sera of humans as well as selected animal species has been reported. While antibacterial agent (ABA) reduced the respiration of intact cells by 55%, the anti‐respiratory effect was increased to 67% and 85% for spheroplasts and L‐forms, respectively. Studies indicated that neither cell wall nor peptidoglycan could absorb ABA quickly enough to inhibit its membrane damaging effects. Although the ribitol teichoic acid‐free mutant Staphylococcus aureus H52A5 was not susceptible to ABA, the lack of ribitol teichoic acid may have altered structurally the cell wall so that ABA access to the cell membrane was precluded. The activity of ABA was neutralized by prior exposure of staphylococci to exogenous coagulase, presumably by masking unknown receptor sites for ABA on the cell surface. In our studies with cell wall deficient organisms, we could not demonstrate coagulase reversal of ABA activity.
Comparison of an Improved Rose Bengal‐Chlortetracycline Agar with Other Media for the Selective Isolation and Enumeration of Moulds and Yeasts in Foods
Authors: Jarvis B.
Published: March 2008

Summary. A modification of the medium (RBC) of Overcast & Weakley (1969) containing 50 p/m of rose bengal and 10 p/m of chlortetracycline was compared with the oxytetracycline‐glucose‐yeast extract medium (OGY) of Mossel, Visser & Mengerink (1962) and with acidified (pH 4·5) malt extract agar for the selective isolation and enumeration of moulds and yeasts in foods. The results obtained from several foods confirm earlier observations that media containing antibacterial agents are superior to acidified ones for isolating moulds from foods. Little difference in counts was observed for yeasts on the 3 media and there was no significant difference in the counts of moulds or the incidence of recovery of moulds on the RBC or OGY. Both media suppressed growth of bacteria but the RBC medium restricted the diameter of mould colonies thereby aiding counting and preventing overgrowth of slowly growing strains by more luxuriant species such as occurs on OGY.
A Membrane Filtration Technique for the Enumeration of Escherichia coli in Seawater
Authors: Halls Sheila , Ayres P. A.
Published: March 2008

Summary. Membrane filtration has become an accepted method for enumerating Escherichia coli in water, but little published evidence could be found to judge the specificity of the method to assess faecal contamination in either fresh or saline waters. The method is used in our laboratory to monitor the extent and degree of sewage pollution in coastal areas, but there is need for information on what proportion of lactose‐fermenting colonies from seawater, developing at 44° on a 4% enriched Teepol medium, are E. coli type I. A total of 1352 colonies from seawater was tested for production of indole and for gas from lactose at 44°. In addition, 46% of the colonies were screened by the IMVEC series of tests. The proportion of colonies tested ranged from 10–100%, depending on the number of colonies on the membrane. Many of the colonies (81.9%) to which IMVEC tests were applied were E. coli type I; a further 10.9% were Irregular type I. The practical implications of these findings are discussed.
The Effect of the Phenolic Antibacterial Agent Fentichlor on Energy Coupling in Staphylococcus aureus
Authors: Bloomfield Sally F.
Published: March 2008

Summary. Experimental evidence indicates that inhibition of active transport is responsible for the bacteriostatic action of Fentichlor against Staphylococcus aureus. Fentichlor inhibits active transport and assimilation of glutamic acid, and assimilation of glucose under aerobic and anaerobic conditions, but inhibition of assimilation results mainly from inhibition of accumulation rather than direct action on the assimilation process. In the absence of glucose, Fentichlor dissipates the membrane proton gradient and ATP pool but, with glucose present, ATP synthesis is unaffected and although some acceleration of proton translocation occurs, only partial dissipation of the gradient results. Results indicate that Fentichlor‐mediated proton translocation prevents coupling of membrane proton movements to active transport as postulated by the chemiosmotic hypothesis. Fentichlor partially inhibits glycolysis and anaerobic ATP synthesis which may contribute to bacteriostasis under anaerobic conditions.
A Method for Demonstrating Bacterial Proteolytic Isoactivities after Electrophoresis in Acrylamide Gels
Authors: Foissy H.
Published: March 2008

Summary. A method for detecting bacterial proteinases in gel slabs after electrophoresis is described. It consists in placing the slabs on a layer of gelatin‐agar buffer, allowing hydrolysis of the gelatin to occur and then developing the areas of hydrolysis with acid mercuric chloride. To illustrate this method we chose extracellular preparations of strains of Brevibacterium linens and Micrococcus spp.
The Egg Yolk Reaction Produced by Several Species of Bacteria
Authors: Owens J. J.
Published: March 2008

Summary. A study of the egg yolk reaction produced by various species of bacteria has shown that it is caused by the hydrolysis of phosphatidylcholine. Staphylococcus aureus and Serratia marcescens degrade phosphatidylcholine by a series of hydrolytic reactions which are initiated by phosphatidylcholine: cholesterol o‐acyltransferase. The degradation of phosphatidylcholine results in the formation of a sub‐surface, opaque homogeneous zone around colonies growing on egg yolk agar and a collar of lipid material floating on the surface of egg yolk broth. This reaction may not be shown by all species growing in egg yolk media but it can be demonstrated if enzyme extracts are used.
The Effects of Antimicrobial Substances on Rhizobium spp. and their Use in Selective Media
Authors: Pattison A. C. , Skinner F. A.
Published: March 2008

Summary. Fortyseven strains of rhizobia were tested for sensitivity to 6 antibiotics (chloramphenicol, erythromycin, penicillin, streptomycin, sulphafurazole and tetra‐cycline) using Oxoid Multodisks on yeast extract‐mannitol agar (YMA); penicillin was the least inhibitory. Growth of selected strains on YMA was also compared with that on YMA containing one or more antimicrobial substances. Penicillin (1 i.u./ml of YMA) only slightly inhibited growth of some strains that were sensitive to it by the Multodisk test but higher concentrations were too inhibitory to be used in a selective medium. YMA containing pentachloronitrobenzene (5 p/m, suspended in a 5 p/m solution of Triton X‐100), brilliant green (0.5 p/m) and sodium azide (0.5 p/m) did not inhibit 15 of 18 strains of rhizobia but was more inhibitory to the general microflora of 4 soils than was YMA. This medium (ABPA) was very inhibitory to several Rhizobium strains when supplemented with 1 i.u./ml of penicillin.
The Effect of Oxygen on the Germination and Outgrowth of Clostridium butyricum Spores and Changes in the Oxidation‐Reduction Potential of Cultures
Authors: Douglas F. , Rigby G. J.
Published: March 2008

Summary. The Eh fall observed during incubation of Clostridium butyricum spores occurred during germination and emergence, not during the log phase; it is attributed to the H2 tension resulting from metabolism. When the O2 tension in the medium was increased, the Eh fell only after a few spores outgrew and replicated; germination of remaining spores then followed. It is suggested that the few cells able initially to metabolize can (a) elaborate NADH etc. which reduce the O2 tension to a level non‐inhibitory for the remaining spores, and (b) produce the H2 tension recorded by the Pt electrode.
Repeated Examinations, Using the Laparotomy Sampling Technique, of the Gastro‐intestinal Microflora of Baboons Fed a Natural or a Synthetic Diet
Authors: Uphill Patricia F. , Wilde J. K. H. , Berger J.
Published: March 2008

Summary. Semi‐quantitative studies on serial gastro‐intestinal aspirates taken at laparotomy showed an increase in both numbers and types of organisms on passing down the baboon intestine from stomach to colon. In baboons fed a natural diet of fresh fruit and vegetables, the stomach, duodenum, and jejenum were sparsely populated, the flora consisting mainly of yeasts and lactobacilli, together with small numbers of faecal streptococci, micrococci and staphylococci. The mid‐ileum was more heavily populated, yeasts, lactobacilli and faecal streptococci being present in most samples, while lactose‐fermenting enterobacteria were isolated from half the aspirates, and in some, small numbers of micrococci, staphylococci and Clostridium welchii were present. The caecum and colon aspirates were heavily populated with all the organisms mentioned above. Differences between the intestinal flora of baboons fed the natural diet and baboons fed a synthetic diet were similar to the difference noted previously (Uphill, 1973) for the faecal flora. The suitability of laparotomy technique as a means of examining the flora of the various regions of the baboon gut is discussed.
The Flora of the Perivaginal Area: The Normal Flora and the Effect of a Deodorant Spray
Authors: Crowley Susan , Murphy Catherine T. , White Pamela M. , Noble W. C. , Rowell Elizabeth R. M. , Bluett D.
Published: March 2008

Summary. The microbial flora of the thigh adjacent to the vaginal labia and of the mucosal surface of the labia has been examined quantitatively and qualitatively in students from Colleges of Education and a University, and in persons attending a Consultant Gynaecologist for non‐suppurative conditions. In the 2 student populations, members of the Micrococcaceae and diphtheroids were the most common organisms but all populations yielded many organisms of gut origin. Differences between the populations may relate to social and hygienic conditions and should make us wary of direct comparisons with other, different populations. The effect of intimate hygiene deodorants containing 0.01% or 0.02% of chlorhexidine was compared with a base spray containing no antibacterial agent. No significant effect of these sprays on the microbial flora could be demonstrated.
A Method for the Detection of Starch Hydrolysis by Bacteria
Authors: Iverson W. G. , Millis Nancy F.
Published: March 2008

Summary. A starch agar medium for the detection of starch hydrolysis is described. The development of a cloudy zone round the colony indicates starch hydrolysis without the use of iodine or 95% (v/v) ethanol.
Populations of Aerobic Bacteria Associated with the Roots of Apple and Cherry Plants
Authors: Barclay G. A. , Crosse J. E.
Published: March 2008

Summary. The incidence of bacteria on the surface of apple and cherry roots was compared over a period of 20 months with those in rhizosphere and root‐free soils. Seasonal variation in total and in Gram negative bacterial populations in soils and on roots was essentially similar. The highest numbers occurred between November and March and the lowest in September. Little general stimulation of bacteria near roots was detected and, on occasion, negative values were recorded for rhizosphere effect. The results indicated that edaphic factors rather than root activity had the major influence on population levels. Fluorescent pseudomonads were low in number and this suggests either that fruit tree roots were unable to support large numbers of these bacteria or that colonization from the soil populations was irregular. However, in contrast to other bacteria, there was a marked stimulatory effect on fluorescent pseudomonads, particularly in apple rhizo‐spheres where a maximum rhizosphere/soil ratio of 131 was recorded.
The Effect of Incubation Temperature on the Recovery of Spores of Bacillus subtilis 8057
Authors: Prentice G. A. , Clegg L. F. L.
Published: March 2008

Summary. The recovery of Bacillus subtilis spores was studied after different heat treatments at 95° and incubation at different temperatures in roll tubes in a gradient temperature incubator. Plate count agar and brain–heart infusion agar were used in the roll tubes. Unheated spores showed similar recoveries at 16–48° whereas heated spores had an optimum recovery temperature of c. 30.9. The rate of germination of untreated spores was greatest at c. 41° and ceased at 50°. Heated spores germinated at 52°5°, suggesting that recovery of heat‐treated spores is not limited by their ability to germinate. Outgrowth of spores at different incubation temperatures was similar for germinated and ungerminated spores. Accordingly it is outgrowth rather than germination which is sensitive to temperature.
Lipase Production and Activity as a Function of Incubation Time, pH and Temperature of Four Lipolytic Micro‐organisms
Authors: Jonsson U. , Snygg B. G.
Published: March 2008

Summary. The lipolytic activity in supernatant fractions of cultures of Saccharomycopsis lipolytica, Micrococcus caseolyticus, Bacillus licheniformis, and a Staphylococcus sp. was studied. Nutrient broth with and without emulsified olive oil was used as substrate. Optimal pH values and temperatures for the lipase produced by the 4 different micro‐organisms were determined. The lipolytic activity generally reached a maximum after incubation for 2–6 days. The subsequent decrease in the lipolytic activity was associated with a high proteolytic activity only for Micrococcus caseolyticus. The lipolytic activity was decreased by the presence of olive oil in the medium. Determination of the lipolytic activity after a certain time of incubation, the maximal lipolytic activity and a time‐integrated lipolytic activity are compared as estimators for the potential hydrolytic capacity of micro‐organisms.
Resistance of Bacillus Spores to Combined Sporicidal Treatments
Authors: Briggs A. , Yazdany S.
Published: March 2008

Summary. Moist heat at 82° (100° for Bacillus stearothermophilus) and solutions of 0.2% w/v chlorocresol or 0.01% w/v benzalkonium chloride at 24° separately showed no sporicidal activity against B. pumilis, B. stearothermophilus, B. subtilis and B. subtilis var. niger. Spores of the last organism were the most sensitive to γ radiation, the D value being 0.16 Mrad. Prior irradiation with a dose of 0.16 Mrad brought about only a slight increase in the sensitivity of the spores to moist heat. The presence of bactericide during irradiation did not affect radiation resistance. Inactivation rates were greater when the spores were heated in the presence of a bactericide than in aqueous suspension and benzalkonium chloride was more active than chlorocresol. Chlorocresol enhanced the heat activation of B. stearothermophilus at 100°. Irradiation in the presence of 0.2% w/v chlorocresol or 0.01% w/v benzalkonium chloride had no effect on the subsequent resistance of the spores when heated in the presence of these bactericides. It is concluded that it is unlikely that combinations of moist heat, radiation and bactericides, each less severe than when used in an accepted sterilization process, will lead to an alternative process which, while less damaging to the materials being sterilized, would still maintain the accepted standards of freedom from contamination.
The Effect of Temperature on the Growth of the Fireblight Pathogen, Erwinia amylovora
Authors: Billing Eve
Published: March 2008

Summary. Growth rates of Erwinia amylovora in yeast extract–peptone broth were assessed, by colony counts and turbidity measurements, at c. 3° intervals over the range 6.5–36.0°. An Arrhenius plot showed a linear relationship between doubling rate and temperatures between 9 and 18°. The slope of this line was comparable to that obtained for Escherichia coli by Ingraham (1958) between c. 12 and 30°. At 18° there was a sharp change in growth rate; between 18 and 28° the doubling time decreased only from 2.1 to 1.3 h (Q10= 1.8) but between 8 and 18° it increased from 2.1 to 14.0 h (Q10= 6.7). This apparently critical temperature is of special interest because maximum air temperatures > 18° appear necessary for epidemic blossom blight in North America.
Preliminary Microbiological Studies on the Preservation of Palm Wine
Authors: OKAFOR N.
Published: March 2008

Palm wine is essentially a heavy suspension of yeasts and bacteria in fermenting palm sap. The water extract of a local preservative, from the bark of Sacoglottis gabonensis, failed to inhibit several yeasts and bacteria from palm wine. Sodium metabisulphite, diethylpyrocarbonate (DEPC) and sorbic acid inhibited to varying extents micro‐organisms in palm wine. Sorbic acid was thought to be the most suitable preservative tested since DEPC left a residual pungent smell and sodium metabisulphite was not suitable because it is unacceptable to man above 0.35 mg/kg of body weight (Mossel, 1971). Pasteurization at 70° for 30 min was more effective than any of the chemical methods in reducing the microbial load of the wine. It is suggested that pasteurization at 70° for 30 min combined with subsequent treatment with sorbic acid may prove useful as a means of preserving palm wine.
Variation in Colony Characteristics and Symbiotic Effectiveness of Rhizobium
Authors: HERRIDGE D. F. , ROUGHLEY R. J.
Published: March 2008

Seventeen cultures of Rhizobium CB756 varied in symbiotic effectiveness and contained a number of different colony types. An examination of single colony isolates from one culture of CB756 indicated that colony characteristics of most isolates were unstable and did not breed true. There was a relationship between symbiotic effectiveness and colony type of the original isolate. The 3 most ineffective sub‐strains were all isolated from large, gummy colonies whereas the most effective were isolated from pinpoint, dry colonies.
Observations on the Structure of Spores
Authors: WYATT P. J.
Published: March 2008

The differential light scattering characteristics of single spores of Bacillus sphaericus and Clostridium filamentosum were measured and recorded for several hundred different spores using an argon‐ion laser source (λ=514.5 nm) and a single‐particle light‐scattering photometer. Typical recorded light‐scattering patterns were interpreted analytically by adjusting the parameters of a spherically symmetrical model to the data using a least squares fitting procedure. The size fluctuations of the cores were very small which suggests that their structure may well be identical for different spores of the same species. The greater variability of the spore surface thickness seems to indicate that these components are loosely defined during sporulation and will certainly vary with growth conditions. Based on the observed lack of free water within the cores, a hypothesis is presented that dipicolinic acid (DPA) acts as a filler material in the core to prevent free water penetration.
A Study of 5920 Strains of Psychrotrophic Bacteria Isolated from Chickens
Authors: LAHELLEC CECILE , MEURIER C. , BENNEJEAN G. , CATSARAS M.
Published: March 2008

The psychrotrotrophic flora of chicken carcases in 3 different industrial processing plants has been studied. The micro‐organisms, 5920 strains, were placed in 4 categories (arranged in decreasing order of the number of isolates): (1), Pseudomonas and Achromobacter (Acineto‐bacter); (2) Flavobacterium, Corynebacterium and yeasts; (3), Aeromonas and Entero‐bacteriaceae; (4), lactic acid bacteria, Micrococcaceae and Bacillus. Different types of strains belonging to these groups are described and the importance of each is discussed with reference to the observations of other authors. The proteolytic action of 1717 of the 5920 isolates was studied.
Use of a Chemical Sanitizer for Cleaning Fish Boxes
Authors: BHADRA R. , BOSE A. N.
Published: March 2008

A number of organic, inorganic and surfactant substances were tested for their cleaning efficiency, ability to reduce bacterial load and deodorize fish boxes. A 0.1% iodine solution had good bactericidal and deodorizing properties, whilst a number of surfactants, especially the quaternary compound Quat‐LTM, had good cleaning and bactericidal properties. None of the substances used possessed all three desirable properties sought for in this study.
The Preservation of Bacteria and Fungi on anhydrous Silica Gel: an Assessment of Survival over Four years
Authors: TROLLOPE D. R.
Published: March 2008

The preservation method of Perkins (1962) using suspensions in skim‐milk was used to preserve 33 bacteria and 22 fungi on anhydrous silica gel. During storage at room temperature, 64% of the bacteria and 77% of the fungi survived 1 year or more. Storage at 4° often increased the survival period c. 2‐ to 3‐fold: 73% of the bacteria and all 12 of the fungi tested at 4° survived > 1 year. At the last testing, 60% of the bacteria and 36% of the fungi were still viable after storage at 4° for periods between 3 and 4 years. The Gram positive bacilli tended to survive the silica gel preservation process better than most Gram negative bacilli. Some factors influencing survival after preservation on silica gel are discussed; the results support the use of a closed storage tube.
The Differing Effects of Cetyltrimethylammonium Bromide and Cetrimide B.P. upon Growing Cultures of Escherichia coli NCIB 8277
Authors: SMITH A. R. W. , LAMBERT P. A. , HAMMOND S. M. , JESSUP CAROL
Published: March 2008

Growing cultures of Escherichia coli NCIB 8277, when treated with low concentrations of Cetrimide B.P., decrease in turbidity more markedly than when equivalent concentrations of cetyltrimethylammonium bromide (CTAB) are applied. Treatment with higher concentrations of CTAB but not of cetrimide evokes a prompt, extensive rise in turbidity. It is suggested that in growing cultures CTAB tends to cause cell aggregation whereas cetrimide tends to cause cell lysis, and that the lytic effect is related to the presence of impurities in cetrimide. The possibility that other antimicrobial surfactants promote lysis is considered.
The Ecology of the Acetic Acid Bacteria with Particular Reference to Cider Manufacture
Authors: PASSMORE SUSAN M. , CARR J. G.
Published: March 2008

The ecology of the acetic acid bacteria has been studied at various stages of their association with cider manufacture. Of the 278 strains of bacteria isolated during the survey, 255 proved to be representative of 6 species of acetic acid bacteria. The remaining 23 strains included one example of the spoilage organism, Zymomonas anaerobia, but they were mostly ubiquitous soil bacteria which could not survive the low pH of apple juice and were only found associated with the early stages of cider making. The acetic acid bacteria were isolated in a sequential type of pattern. Those species which preferentially oxidize sugars were found at the early stages of processing when sugars abound, but these were replaced by the relatively more acid‐tolerant species, which are better equipped to oxidize alcohols, after the yeast fermentation had converted most of the sugar to ethanol.
The Antigens Associated with the Cell Walls of Members of the Genus Pseudomonas
Authors: TUNSTALL ANITA M. , GOWLAND G. , HOBBS G.
Published: March 2008

Three antigens were associated with the cell walls of pseudomonads. A highly antigenic, strain‐specific antigen of high molecular weight and protein or lipoprotein in nature, occurred as an envelope around the cells. It could be washed off the cells closely associated with carbohydrate material but its antigenicity was not dependent on the carbohydrate present. Another antigen, common to all strains tested, was situated below the first antigen. This was less antigenic than the strain‐specific antigen and was polysaccharide or lipopolysaccharide in nature. A second common antigen was the mucopeptide of the cell walls. This had an antigenicity similar to that of the second antigen and was dependent on both the carbohydrate and polypeptide components of the macromolecule. There appears to be some correlation between these findings and the structure of cell walls of pseudomonads are shown by electron microscopy.
Antibacterial Activity of 3‐(l‐Methyl‐5‐Nitro‐2‐Imidazolylmethylideneamino)‐2‐Oxazolidinone
Authors: FROST BETTINA M. , VALIANT M. E. , DULANEY E. L.
Published: March 2008

The nitroimidazole tested is structurally related to furazolidone in that it contains a 5‐nitro‐imidazole instead of 5‐nitrofuran. The nitroimidazole was much less active in vitro than furazolidone against a spectrum of pathogenic organisms. However, it is active in vivo by oral administration against bacterial infections of mice and its low acute toxicity gives better therapeutic indices than are obtained with furazolidone. Plasma concentrations rise rapidly following oral administration of the nitroimidazole. Sufficient urinary excretion occurred to give significant activity in a mouse kidney infection incited by Staphylococcus aureus in which nitrofurantoin was inactive.
Changes in the Extracellular Accumulation of Antibiotics during Growth and Sporulation of Bacillus subtilis in Liquid Culture
Authors: BARR J. G.
Published: March 2008

Ten antimicrobial metabolites, produced by Bacillus subtilis NCIB 8872, have been categorized into 3 groups on the basis of their antimicrobial spectra, chromatographic mobility and solvent solubility. The maximum concentration of the different groups occurred at different times during fermentation. The accumulation of one antibiotic group was characteristic of the logarithmic growth phase. Groups also differed in their persistence. The intracellular antibiotics contributed little to the total antibiotic activity of the culture. The onset of production and the maintenance of the extracellular accumulation of the 3 antibiotic groups were linked to sporulation and associated specific changes in the intracellular and extracellular protein complement. Production of the antibiotics was not controlled by glucose catabolite repression, since the presence or absence of glucose in the medium did not affect the pattern of antibiotic accumulation.
The Bacterial Flora of some Queensland Fish and its Ability to cause Spoilage
Authors: GILLESPIE N. C. , MACRAE I. C.
Published: March 2008

The bacterial flora were determined qualitatively and quantitatively on samples taken at various stages of handling several species of fish of commercial importance in Queensland. There was an overall increase in the number of bacteria during handling and processing; both the composition and quantity of the bacterial flora of individual samples taken at each stage of handling varied widely. Members of the genus Micrococcus formed the major proportion of the flora of freshly caught fish. Pseudomonas and Moraxella spp. were predominant amongst the bacterial flora able to grow at 2° and constituted the bulk of the population in samples with high bacterial counts. This psychrophilic population was markedly reduced at the filleting stage. A medium prepared by the action of trypsin on a fish muscle homogenate was used to test bacterial isolates for their ability to produce odours. Forty‐three per cent of the pseudomonad isolates produced sulphydryl odours at 5°. Only small proportions of the other groups produced detectable odours. Members of the genus Pseudomonas were considered the most important fish spoilage bacteria under the conditions found in Queensland.
Scanning Isoelectric Focusing and Isotachophoresis of Clostridium perfringens Type A Enterotoxin
Authors: YOTIS W. W. , CATSIMPOOLAS N.
Published: March 2008

Fractionation of highly purified Cl. perfringens type A enterotoxin by scanning isoelectric focusing (SIF) and isotachophoresis (IT) in polyacrylamide gels is described for the first time. The use of 2% ampholytes pH 3–6 allowed the separation of enterotoxin into 2 species. The major component had an isoelectric point of 4·5 and possessed antigenic as well as functional activity. The minor component of enterotoxin, at equivalent concentrations, was devoid of any demonstrable biological activity had an isoelectric point of 4·6 and appeared to represent approximately 15% of the purified enterotoxin. With ampholytes pH 3·5–10 the minor and major components were focused at different times than when ampholine pH 3–6 was employed. Electrofocusing of enterotoxin in the presence of 6 M‐urea did not alter the SIF pattern. During IT the major component of enterotoxin migrated ahead of the minor component. The 2 proteins were completely separated. Isotachophoretic separations required 0·023 M‐phosphate pH 6·0 as the leading ion, 0·079 M‐Tris as the counter‐ion, 0·2 M‐glycine (in Tris pH 8·1) as the terminating ion, 30 γ carrier ampholytes pH 3·5–10, 263 μg enterotoxin, 4% acrylamide and a current of 5 mA per gel column.