bluuebunny/crossref_metadata_2025 huggingface dataset:
A study of the antibacterial activity of some polyhexamethylene biguanides towards Escherichia coli ATCC 8739
Authors: Broxton P. , Woodcock P.M. , Gilbert P.
Published: March 2008

The antibacterial action of some polyhexamethylene biguanides upon Escherichia coli has been investigated. An amine ended dimer (AED) (n= 2), a polydisperse mixture sold by I.C.I. Limited as the active ingredient of Vantocil IB (PHMB, n= 5.5) and a high molecular weight (HMW) fraction (n≤ 10) of PHMB were used. PHMB and the high molecular weight fraction totally inhibited growth and motility of Esch. coli in liquid culture, whilst amine ended dimer never totally inhibited either function, irrespective of concentration. Growth inhibition and bacteriocidal activity increased with increasing levels of biocide‐polymerization. The three compounds, whilst being active over different concentration ranges, possessed similar concentration exponents and temperature coefficients. Cytoplasmic membrane damage and disruption of the cell envelope, indicated by loss from the cells of 260 nm absorbing materials, inorganic phosphate, and changes in permeability towards the dye 2‐p‐toluidinylnaphthylene‐6‐sulphonate, was observed at concentrations which were markedly bactericidal whilst bacteristatic concentrations caused only loss of potassium. Loss of cytoplasmic materials from treated cells in all instances followed first‐order kinetics. This indicated that irreversible damage was initiated and completed within a short time of contact between cells and biocide. Alteration of cytoplasmic membrane permeability towards various cations was assessed by measuring rates of lysis of sphaeroplasts in isotonic solutions of Na, Li and Cs acetate. For a given biocide concentration, the rates of lysis were inversely proportional to the hydrated ionic radii of the cation. This indicated that the damage to the cytoplasmic membrane was non‐specific and proportional to biocide concentration. Temperature coefficients (Q10) of approximately 2.0 for the loss of 260 nm absorbing material, inorganic phosphate and potassium from treated cell‐suspensions and bacteriocidal activity suggested that death of cells and cytoplasmic membrane damage are directly associated and are a direct result of biocide action, rather than mediated through the induction of autolytic enzymes.
Bacterial uptake of algal extracellular products: an experimental approach
Authors: Jones J. G. , Simon B.M. , Cunningham C.R.
Published: March 2008

Methods for partitioning planktonic algal and bacterial populations were examined. If samples were filtered under gravity through a 1 μm pore size Nuclepore polycarbonate membrane the algae were retained on the filter and most (usually > 80%) of the bacteria were found in the filtrate. The application of any vacuum or pressure during this process resulted in the appearance of chlorophyll in the filtrate. In radiotracer experiments this would lead to an overestimate of 14C incorporation into the bacteria. There was excellent agreement between measurements of partition efficiency by epifluorescence direct counts of bacteria and by uptake of trace quantities of tritiated glucose. The methods were applied to the measurement of algal excretion of dissolved organic matter and its uptake by bacteria over light‐dark cycles. An illuminated water bath was adapted to provide shortened (3–24 h) light‐dark cycles which could be used to examine interactions between individual algal and bacterial species. Estimates of bacterial heterotrophic production based on the assimilation of labelled algal extracellular products were lower than those calculated from the incorporation of SO2‐4.
Factors regulating the density of bacteria in process waters of a paper mill
Authors: Väätänen P. , Niemelä S.I.
Published: March 2008

Variations in the numbers of total colonies of Klebsiella pneumoniae, Acinetobacter spp. and pseudomonads were investigated in process waters of a paper mill in southern Finland. Variations were related to independent parameters, namely temperature, pH, redox potential and production of offset paper, by using multiple regression analysis. Temperature was the most significant regressor variable and was negatively correlated with bacterial counts. It accounted for up to about 80% of the variance in bacterial counts in various parts of the process. The significance of temperature was due to its fluctuations in a critical range, above and below the maxima for bacterial growth. The pH level was also significant for total colony count and for K. pneumoniae. Redox potential and the production of offset paper were of significance for Acinetobacter spp. Washing the paper machine with water and lye decreased the numbers of bacteria in process waters.
Phages naturally associated with the aizawai variety of insect pathogen Bacillus thuringiensis and their relevance to strain identification
Authors: Jones D.R. , Karunakaran V. , Burges H.D.
Published: March 2008

Of 36 strains of the ‘aizawai’ variety of Bacillus thuringiensis (H‐serotype 7) 16 were naturally associated with bacteriophages, 11 of which were isolated at titres of 106 plaque‐forming units/ml and above. These 11 phages had varied host ranges among Bacillus cereus and five strains of the ‘aizawai’ variety of B. thuringiensis. Host range, plaque morphology and differences in cold lability indicated dissimilarities between the phages, which could be used taxonomically to differentiate between strains of this bacillus.
Trimethylsilyl‐sugar profiles of Streptococcus milleri and Streptococcus mitis
Authors: Aluyi H.S. , Drucker D.B.
Published: March 2008

Seventy strains of ‘viridans‐group’ streptococci were analysed gas chromatographically after preparation of trimethylsilyl ethers of their cellular sugars. The resulting profiles were evaluated as a possible aid to taxonomy. Glycerol, glucose, galactose, N‐acetyl‐glucosamine and N‐acetylmuramic acid were found in all strains, in varying amounts. Rhamnose was the major neutral sugar in most strains, other than representatives of Streptococcus mitis, which invariably had ribose and usually anhydroribitol but no rhamnose. One strain of Strep, mitis possessed arabitol. Some strains of Strep. mitis and ‘Strep. milleri’ were alone in containing N‐acetylgalactosamine. A combination of N‐acetylgalactosamine and rhamnose in the absence of ribose was diagnostic for strains of ‘Strep. milleri’.
Detection of chemotaxis in Azospirillum brasilense
Authors: Barak Rina , Nur I. , Okon Y.
Published: March 2008

Azospirillum brasilense strain Cd responded chemotactically to amino acids, sugars and organic acids. Chemotactic rings were observed in semisolid agar plates containing oxidizable substrates. Increasing sodium succinate concentration decreased the velocity of ring expansion. Chemotactic activity of Azospirillum was also examined by a newly developed technique using a channelled chamber. Varying the concentrations of aspartic and glutamic acids affected the chemotactic response of the bacteria. In both assays chemotaxis was obtained under conditions that prevented aerotaxis.
Uptake hydrogenase system in urd bean (Vigna mungo) Rhizobium in relation to nitrogen fixation
Authors: Pahwa Kamlesh , Dogra Romesh Chander
Published: March 2008

Twenty‐five isolates of urd bean (Vigna mungo) Rhizobium were tested for the presence of an H2‐uptake system using triphenyl tetrazolium chloride reduction as the screening procedure. The isolates which reduced the dye rapidly at early stages of growth were found to recycle H2 both in culture as well as in nodules. H2‐uptake positive, H2‐uptake negative strains and H2‐uptake negative mutants were compared on the basis of their effect on dry matter accumulation and N2‐fixation. Greenhouse experiments have shown the beneficial effect of the H2‐uptake positive system in nodules on N2‐fixation. Plants inoculated with H2‐uptake positive strains produced higher N content and dry matter over the plants inoculated with H2‐uptake negative strains.
A note on the micro‐organisms associated with the fermentation of seeds of the African oil bean tree (Pentaclethra macrophylla)
Authors: Obeta J.A.N.
Published: March 2008

Fermentation of oil bean seeds involves a mixture of bacteria in which Bacillus spp. are the predominant and most actively involved organisms. Other bacteria involved are Staphylococcus spp., Micrococcus spp. and Leuconostoc spp., but these do not appear to play any major role in the fermentation.
Hazard analysis applied to microbial growth in foods: Development of mathematical models describing the effect of water activity
Authors: Broughall J.M. , Anslow P.A. , Kilsby D.C.
Published: March 2008

Mathematical models have been developed which describe the effect of lowering the water activity on the growth kinetics of Staphylococcus aureus and Salmonella typhimurium. By treating the lag phase and exponential phase kinetics separately predictions can be made on the extent of microbial growth over successive time‐temperature cycles. Staph. aureus was far more tolerant than Salm. typhimurium to lowered water activity and under near growth limiting conditions of water activity and temperature was showing lag periods as long as ca 40 d. The maximum lag period observed for Salm. typhimurium was ca 5 d. Under these conditions the predicted generation times for Staph. aureus were 2–3 d and for Salm. typhimurium 1–4 d.
Precursors of the major end products of aerobic metabolism of Brochothrix thermosphacta
Authors: Dainty R.H. , Hibbard Christine M.
Published: March 2008

To further our understanding of off‐odour production by Brochothrix thermosphacta, the nature and origins of its end products have been compared during aerobic growth in complex and in minimal, defined medium. In complex medium glucose is the major precursor of acetoin and acetic acid but alanine may be an additional minor source. Isobutyric, isovaleric (3‐methylbutyric) and 2‐methylbutyric acids are derived exclusively from valine, leucine and isoleucine, respectively. In minimal defined medium although the same end products are produced they are all derived from glucose.
Automated statistical analysis of microbial enumeration by dilution series
Authors: Hurley Margaret A. , Roscoe M.E.
Published: March 2008

Equations are formulated for the standard error and confidence interval for the MPN estimate of microbial density from a general dilution series. A statistical test of homogeneity is presented. This tests whether a handling error in the dilution series may have occurred which would invalidate the density estimate. The analysis may be automated using a Basic computer program which contains a fast algorithm for the solution of the general MPN equation. This allows the calculation of the MPN, standard error, 95% confidence interval and test statistic for any dilution series, with any degree of replication at each dilution level, with variable sample volumes at each dilution level, with variable dilution ratio between levels, and with any number of levels.
A note on a selective medium for wine yeasts
Authors: Kish S. , Sharf R. , Margalith P.
Published: March 2008

The numerical assessment of wine yeast in the presence of excessive numbers of apiculate yeasts has been attempted by the use of a differential medium. Medium ESY containing 150 mg/l bisulphite and 12% by volume of ethanol (pH 5·5) was found suitable for the enumeration of wine yeasts when present even at low concentrations in the natural microflora during the early stages of a grape juice fermentation. Apiculate yeasts seem to persist longer at low fermentation temperatures.
The effect of yoghurt on some components of the gut microflora and on the metabolism of lactose in the rat
Authors: Garvie Ellen I. , Cole C.B. , Fuller R. , Hewitt D.
Published: March 2008

Garvie, E.I. Cole, C.B., Fuller, R. & Hewitt, D. 1984. The effect of yoghurt on some components of the gut microflora and on the metabolism of lactose in the rat. Journal of Applied Bacteriology56, 237–245

Feeding yoghurt or base milk (from which the yoghurt was prepared by fermentation) to rats increased the counts of coliforms in the gut whereas the counts of lactobacilli were reduced by yoghurt but not by the base milk. Lactobacillus bulgaricus survived in the guts of gnotobiotic and conventional rats when yoghurt was fed continuously. Streptococcus thermophilus also survived in gnotobiotic rats but its ability to survive in conventional rats could not be examined. Both organisms failed to colonise the gut when a small inoculum of yoghurt was administered orally to germfree rats maintained on the stock diet. Streptococcus thermophilus but not Lact. bulgaricus grew in the rat diet when tested in vitro. Two enzyme systems (β‐galactosidase and lactase) were studied using, respectively, o‐nitrophenyl‐β‐D‐galactopyranoside (ONPG) and lactose as the test substrates. Enzyme levels estimated with both substrates. increased in the gut contents when rats were fed yoghurt but an increase was only found with ONPG in the intestinal mucosa fraction. The bacterial origin of all this increased activity is discussed. The other lactose‐containing diets did not affect enzyme activity to the same degree. Feeding yoghurt changed the lactobacillus flora from one which was predominantly hetero‐fermentative (Lact. reuteri) to one which was predominantly homofermentative (Lact. salivarius).
Microbial growth at reduced water activities: some physicochemical properties of compatible solutes
Authors: Chirife J. , Favetto G. , Fontán C. Ferro
Published: March 2008

Chirife, J., Favetto, G. & Ferro Fontán, c. 1984. Microbial growth at reduced water activities: some physicochemical properties of compatible solutes. Journal of Applied Bacteriology56, 259–268.

The water activities (aw) of solutions of D‐arabitol (a major compatible solute in yeasts grown at reduced aw) and also of related polyols (L‐arabitol, xylitol and ribitol) were determined at 25d̀C. The aw of saturated solutions of L‐proline and monopotassium L‐glutamate (solutes which accumulate in bacterial cells at reduced aw) were also determined. The viscosities of L‐proline, monopotassium L‐glutamate and D‐arabitol solutions were measured at 25, 30, 35 and 40d̀C for various concentrations up to high molalities. The relative viscosity curves were described using a theoretical model for the concentration dependence of viscosity. No relationship of viscosity of the electrolytes to effectiveness as ‘compatible solutes’ were evident, neither were the compatible solutes particularly effective ‘structure makers’ or ‘structure breakers.’
The uptake and utilization of Entodinium caudatum, bacteria, free amino acids and glucose by the rumen ciliate Entodinium bursa
Authors: Coleman G.S. , Hall F.J.
Published: March 2008

Coleman, G.S. & Hall, F.J. 1984. The uptake and utilization of Entodinium caudatum, bacteria, free amino acids and glucose by the rumen ciliate Entodinium bursa. Journal of Applied Bacteriology56, 283–294.

Washed suspensions of Entodinium bursa were incubated anaerobically with Entodinium caudatum, ten species of bacteria and a yeast. The rate of uptake and digestion of these micro‐organisms was investigated. Protozoa grown in vivo did not engulf Proteus mirabilis or Klebsiella aerogenes but rapidly took up Bacillus mega‐terium, Selenomonas ruminantium, Torulopsis glabrata and Streptococcus bouis, although only the last was digested with release of soluble material into the medium. Protozoa grown in vitro engulfed each of the bacteria tested, taking up Megasphaera elsdenii and i>Proteus mirabilis most rapidly. Individual bacterial species and mixed rumen bacteria were engulfed more rapidly (up to 20 times) by protozoa grown in vivo than those grown in vitro, although the latter digested over 80% of theB. megaterium, Escherichia coli and P. mirabilis taken up. Labelled Ent. caudatum was extensively digested after engulfment by Ent. bursa. Some of the digestion products were released into the medium but individual amino acids were transferred as such from Ent. caudatum protein to Ent. bursa protein. Engulfed bacteria and polysaccharide granules were transferred intact from one protozoon to the other. Free amino acids were also taken up intact from the medium into protozoal protein but there was little biosynthesis of amino acids from glucose. When available for engulfment Ent. caudatum was quantitatively a much more valuable source of amino acids for protein synthesis by Ent. bursa than free amino acids or bacteria.
Applications of fluorescent antibody for detecting capsular substances in Staphylococcus epidermidis
Authors: Ichiman Y.
Published: March 2008

Ichiman, Y. 1984. Applications of fluorescent antibody for detecting capsular substances in Staphylococcus epidermidis, Journal of Applied Bacteriology56, 311–316.

A fluorescent antibody technique was developed for the determination of the type of capsule of strains of Staphylococcus epidermidis. Many mouse virulent and avirulent strain populations were investigated. Of 300 fresh isolates of Staph. epidermidis, 27 were mouse virulent strains and of these 74.1% and 25.9% were mono‐ and polyvalent, respectively. The frequency of capsular type antigens I, II and III, produced by the 27 virulent strains was found to be 18.5%, 88.9% and 18.5%, the majority being capsular type II. In the mouse avirulent strains, capsular type antigen production was demonstrated in 263 out of 273 strains examined and mono‐ and polyvalent capsular types comprised 52.3% and 44.0%, respectively. Capsular type I, II, III strains and non‐typable strains occurred at frequencies of 15.0%, 95.2%, 34.9% and 3.7% respectively, the majority of mouse avirulent strains also being capsular type II. These results indicate that a majority of ordinary Staph. epidermidis produce capsular type antigens although the capability is quantitatively different according to strain.
A comparison of contact plate and calcium alginaie swab techniques for quantitative assessment of bacteriological contamination of environmental surfaces
Authors: Scott Elizabeth , Bloomfield Sally F. , Barlow C.G.
Published: March 2008

Scott, E. Bloomfield, S.F. & Barlow, C.G. 1984. A comparison of contact plate and calcium alginate swab techniques for quantitative assessment of bacteriological contamination of environmental surfaces. Journal of Applied Bacteriology56, 317–320.

A contact plate method for enumeration of bacteriological contamination at 9 environmental sites in 64 homes was compared with swab sampling techniques. Contamination levels of 100 or more organisms/21–25 cm2 were demonstrated more frequently using swab methods, but for some sites where low numbers of organisms were present, higher recovery rates were obtained using contact plates. When contamination levels from contact plate and swab techniques were compared according to rank order a good correlation was obtained. Results of this investigation indicate that the contact plate method is satisfactory for differentiation of ‘hygiene levels’ at environmental sites whilst facilitating handling of large numbers of samples in a field survey.
A new selective and differential agar medium for Escherichia coli and coliform organisms
Authors: Wright R.C.
Published: March 2008

Wright, R.C. 1984. A new selective and differential agar medium for Escherichia coli and coliform organisms. Journal of Applied Bacteriology56, 381–388.

An enriched lauryl sulphate‐aniline blue agar medium which is selective for Escherichia coli and coliform organisms is described. From faecal samples, the medium gave higher counts of colonies producing acid from lactose than media containing bile salts. From contaminated water and food samples, the medium gave comparable or higher counts of colonies identified as E. coli than standard media. Colonies of E. coli were more readily differentiated from those of other coliform organisms.
Infectivity of Rhizobium meliloti as affected by extracellular polysaccharides
Authors: Olivares J. , Bedmar E.J. , Martinez‐Molina E.
Published: March 2008

Olivares, J., Bedmar, E.J. & Martinez‐Molina, E. 1984. Infectivity of Rhizobium meliloti as affected by extracellular polysaccharides. Journal of Applied Bacteriology56, 389–393.

The addition of crude extracellular polysaccharide (EPS) preparations from highly infective Rhizobium meliloti increased the infectivity of a poorly infective strain. The addition of crude EPS preparations from another species did not promote nodu‐lation, suggesting the specificity of such an effect. Acid treatment of the crude EPS preparations resulted in total inhibition of nodulation.
A note on an improved molybdate agar for the selective isolation of yeasts from tropical fruits
Authors: Rale V.B. , Vakil J.R.
Published: March 2008

Rale, V.B. & Vakil, J.R. 1984. A note on an improved molybdate agar for the selective isolation of yeasts from tropical fruits. Journal of Applied Bacteriology56, 409–413.

Molybdate agar was fortified with 0.125% calcium propionate and used for routine isolation and differentiation of a variety of yeasts from mixed floras including large numbers of fungi and actinomycetes inhabiting tropical fruits. The results suggest that this technique could be usefully incorporated in yeast isolation and identification procedures.
Interactions between Azotobacter chroococcum and vesicular‐arbuscular mycorrhiza and their effects on plant growth
Authors: Brown Margaret E. , Carr G. R.
Published: March 2008

Brown, M. E. & Garr, G. R. 1984 Interactions between Azotobacter chroo‐coccum and vesicular‐arbuscular mycorrhiza and their effects on plant growth. Journal of Applied Bacteriology56, 429–437.

The effects of simultaneous inoculation of roots of lettuce seedlings with vesicular‐arbuscular endophytes and Azotobacter chroococcum are described. Endophytes alone increased yields of lettuce grown in partially sterilized P‐deficient soil, but not in the same unsterile soil. Dual inoculation with endophytes and Azotobacter in both soils produced larger plants than either inoculum alone. In another poorly structured unsterile soil with adequate P for plant growth, endophytes depressed yields of lettuce. There was no association between endophytes and Azotobacter. In none of the experiments did Azotobacter influence the level of endophyte infection in the roots; but numbers of Azotobacter on the root systems were decreased in the presence of the endophytes. Azotobacter alone always increased growth of young plants before the effects of the endophytes were observed.
Radioactive labels for Protein A: evaluation in the indirect immunoradiometric assay (IRMA) for Bacillus anthracis spores
Authors: Phillips A. P. , Martin K.L.
Published: March 2008

Phillips, A.P. & Martin, K.L. 1984. Radioactive labels for Protein A: evaluation in the indirect immunoradiometric assay (IRMA) for Bacillus anthracis spores. Journal of Applied Bacteriology56, 449–456.

Staphylococcus aureus Protein A (SpA) labelled with [125I] by the Bolton & Hunter (1973) method performed about as well as labelled sheep anti‐rabbit globulin (SAR) in an indirect immunoradiometric assay (IRMA) for Bacillus anthracis spores immobilized on multispot microscope slides. SpA labelled with [3H] by propi‐onylation also performed well but would be expensive to use. SpA labelled with [3H] fluorodinitrobenzene, or labelled with [125I] by the chloramine T reaction gave erratic assay results, high noise values and low signal‐to‐noise ratios, indicating substantial direct binding of labelled SpA to the slide surface and to the bacterial preparation. The uptake of radioactively labelled SpA in the IRMA was compared with the fluorescence intensity of individual spores in a micro‐fluorometric immunofluorescence (IF) test involving dual labelled fluorescein‐[125I]‐SpA. The maximum number of SAR molecules bound to the mixture of spores and cell‐free antigens in the B. anthracis IRMA was about twice the maximum number of radioactively labelled SpA molecules bound. The SAR : SpA saturation binding ratio on the surface of the spores, however, was approximately the inverse of this. It is concluded that radioactively‐labelled SpA is not recommended in preference to anti‐species antibody reagents in bacterial IRMA tests but fiuorescein‐conjugated SpA deserves further consideration for use in microscope‐based IF tests for bacterial antigens.
A new rapid and sensitive bioluminescence assay for antibiotics that inhibit protein synthesis
Authors: Naveh A. , Potasman I. , Bassan H. , Ulitzur S.
Published: March 2008

Naveh, A., Potasman, I., Bassan, H. & Ulitzur, S. 1984. A new rapid and sensitive bioluminescence assay for antibiotics that inhibit protein synthesis.Journal of Applied Bacteriology56, 457–463.

A new sensitive, rapid and simple bioluminescence assay for antibiotics inhibiting protein synthesis is described. In this assay the ability of the tested antibiotic to inhibit the de novo synthesis of the enzymes participating in the bacterial luminescence system is determined by means of a dark variant of a luminous bacterium that undergoes prompt induction of the luminescence system with certain DNA‐intercalating agents. Upon induction, the in vivo luminescence of the dark variant is increased more than 50‐fold within 30 min. Antibiotics that block the de novo synthesis of protein limit the development of luminescence at a level that was found to be a function of the antibiotic concentration. The minimum detectable concentration of antibiotics in the bioluminescence test, after 45–60 min of incubation, was 0.1 μg ml for streptomycin, gentamicin, kanamycin, lincomycin and chlorampheni‐col and 0.3 μg/ml for neomycin, clindamycin and spectinomycin. The new bioluminescence test has been used to assay these antibiotics in serum.
A note on Pseudomonas syringae pv. berberidis infections of Berberis: aetiology of a leaf spot and leaf fall disease in England
Authors: Roberts S.J. , Preece T. F.
Published: March 2008

Roberts, S.J. & Preece, T.F. 1984. A note on Pseudomonas syringae pv. berberidis infections of Berberis: aetiology of a leaf spot and leaf fall disease in England. Journal of Applied Bacteriology56, 507–513.

A leaf spot and leaf fall disease is currently causing problems among certain Berberis spp. in England. Evergreens affected include B. julianae, B. gagnepainii, B. candidula, B. hookeri, and deciduous spp. include B. x ottawensis and B. thunbergii. The pathogen, Pseudomonas syringae pv. berberidis, which was confirmed as a distinct pathover by biochemical and host tests, was isolated from less than half of leaves showing typical symptoms. Isolates of Ps. syringae pv. berberidis from England, New Zealand and USA differed in cultural characteristics and in patho‐genicity to certain Berberis spp.
A note on the pectinolytic enzyme of Streptococcus bovis
Authors: Wojciechowicz Maria , Ziolecki A.
Published: March 2008

Wojciechowicz, M. & Ziolecki, A. 1984. A note on the pectinolytic enzyme of Streptococcus bovis. Journal of Applied Bacteriology56, 515–518.

A pectinolytic strain of Streptococcus bovis isolated from the bovine rumen produced an endopolygalacturonate lyase (EC 4.2.2.2). The principal decomposition products of pectin were unsaturated methyl tetra‐ and tri‐galacturonates.
Human and bovine group B streptococci: two distinct populations
Authors: Finch Lesley A. , Martin Diana R.
Published: March 2008

Group B streptococci (Streptococcus agalactiae) from humans and animals were compared for cultural, biochemical, serological and bacteriocin sensitivity properties. Each isolate possessed the group B carbohydrate antigen, hydrolysed hippurate, and was CAMP test positive. Most human isolates were characterized as bacitracin resistant, pigment producing, haemolytic, and salicin but not lactose utilizing. In contrast bovine isolates were usually bacitracin sensitive, non‐pigment producing, non‐haemolytic, salicin and lactose utilizing. Isolates from other animals behaved similarly to those from humans. Whereas human isolates belonged to a variety of serotypes and were uniformly sensitive to bacteriocins, bovine isolates showed varying sensitivity to bacteriocins and most belonged to serotype II or were non‐typable. We believe these results support the belief that Strep. agalactiae from humans and cattle are separate populations sharing the same group B carbohydrate antigen.
A general‐purpose system for characterizing medically important bacteria to genus level
Authors: Feltham R.K.A. , Wood Pauline A. , Sneath P.H.A.
Published: March 2008

A computer program and accompanying data matrix have been prepared for bacteria of medical interest, to assist the assignment of an unidentified bacterium to the most likely genus. The results on a set of relatively simple tests are entered. The program prints the more likely genera, followed by a list of diagnostic tables in Cowan & Steel (1974) and Buchanan & Gibbons (1974). Where available, identification matrices for further computer‐assisted study, are presented. This program may be of particular help in laboratories where a wide range of bacteria have to be identified.
The biochemical challenge of microbial pathogenicity
Authors: Smith H.
Published: March 2008

In the past decade there has been a revival of interest in microbial pathogenicity. The reasons for this revival are two‐fold. First, infectious disease is still with us despite the impact of the antibiotic era; for example, the rise of bacterial and fungal infections in compromised patients and the lack of a good general antiviral drug. Second, the subject of microbial pathogenicity is ripe for application of techniques of biochemistry, molecular biology and genetics that have developed in other areas of biology over the past twenty years; and the potential of these techniques is particularly attractive to young people, who are entering the field in increasing numbers.

In this lecture I shall survey the methods and difficulties of investigating microbial pathogenicity and what we know of the main aspects of the subject at the molecular level. I shall use bacteria as examples because more is known about them than other types of microbes. Lack of space prevents quoting original papers in such a wide‐ranging task; in most cases reference is made to authorative reviews.
The enrichment and early detection of Streptococcus pyogenes in skin lesions, using colistin, oxolinic acid, Todd Hewitt broth and latex agglutination
Authors: Petts D.N.
Published: March 2008

An improved selective broth, colistin, oxolinic acid, Todd Hewitt broth (COTHB) for the isolation of Streptococcus pyogenes and other streptococci from swabs is described. Staphylococci, coryneforms and Gram negative organisms are inhibited in COTHB inoculated with swabs from skin lesions. Streptococcus pyogenes could be detected by a fluorescent antibody method and by the Streptex and Phadebact streptococcal grouping methods after 6 and 24 h incubation. Other streptococci of groups B, C and G, were also detected. Streptex was the most sensitive and specific method for the detection of streptococci of groups A, B, C and G in this broth. The method detected 78% of these streptococci in COTHB after 6 h incubation and 93% after 24 h incubation. Of the Strep. pyogenes isolated, 82% were detected in the broth by the Streptex method.
The antimicrobial properties of magnesium monoperoxyphthalate hexahydrate
Authors: Baldry M.G.C.
Published: March 2008

The antimicrobial properties of magnesium monoperoxyphthalate hexahydrate (MMPP), which is a stable, water‐soluble solid peroxyacid, have been investigated. A 2% (w/w) solution of MMPP rapidly kills yeasts and vegetative bacteria and slowly inactivates bacterial endospores at 22°C. Biocidal activity, which is greater under mildly acidic conditions, is retained in the presence of organic contamination or hard water. Sporicidal action is greatly increased by a moderate rise in temperature or by using MMPP in combination with propan‐2‐ol. Such mixtures appear to be suitable for use as liquid chemical sterilants.
Characterization of a dextranolytic biotype ofFlavobacterium multivorumfrom soil
Authors: Hayward A.C. , Sly L.I.
Published: March 2008

Bacteria obtained by enrichment on dextran as sole carbon source before plating, or by direct plating of soil suspensions on dextran agar, included a yellow, non‐motile, Gram negative rod with distinctive morphology and ultrastructure in negatively stained preparations under the electron microscope. The 16 isolates obtained all showed asymmetric division. In a small proportion of the population a phenomenon resembling budding resulted in the release of spherical cells. The isolates were compared withFlavobacterium breve, in which a similar morphology has been observed, but were clearly distinct on physiological grounds. The collection of strains formed a moderately uniform phenotype similar to, but generally more active biochemically, thanF. multivorum; all produced acid from dextran and grew on dextran as sole carbon source. Seven of the isolates produced pits in pectate gel at neutral and alkaline pH, but none broke down cellulose or chitin.Flavobacterium multivorumwhich was originally described from human clinical sources can be readily isolated from soil by the dextran enrichment technique.
Enumeration of two competing Erwinia carotovora populations in potato tubers by a membrane filter‐immunofluorescence procedure
Authors: Boer S.H. De
Published: March 2008

Relative increases in cell populations of specific Erwinia carotovora strains injected into potato tubers either singly or in combination of two strains were determined by depositing tissue extracts on membrane filters and staining cells of individual strains by immunofluorescence. The population increase of an Erw. carotovora subsp. atroseptica (Eca) strain was, in general, not affected by the presence of an Erw. carotovora subsp. carotovora (Ecc) strain. However, the increase of an Ecc strain was inhibited by the presence of an Eca strain, especially at incubation temperatures of 5° and 15°C but not at 26°C. One Ecc strain consistently increased in population over another Ecc strain at a greater rate when they were inoculated together at the same loci in comparison to when they were inoculated separately at different loci.
Influence of NaCl, NaNO2 and oxygen on the germination and growth of Bacillus licheniformis, a spoilage organism of chub‐packed luncheon meat
Authors: Bell R.G. , Lacy Karen M. De
Published: March 2008

The thermal resistance of Bacillus licheniformis spores was increased from a D70‐value of 590 min to one of 900 min by the addition of 4% NaCl to the heating medium [tryptone‐yeast extract‐glucose (TYG) broth, pH 6.8], but was decreased to 470 min in TYG broth acidified to pH 4.4. Sodium nitrite (0.02%) enhanced spore destruction at 80°C but not at 70°C; addition of 4% NaCl eliminated this effect. Less than half the number of spores surviving heat comparable to commercial cooking were heat‐damaged to the extent of being unable to grow aerobically in the presence of 4% NaCl. No growth occurred during anaerobic incubation even when the media contained no added NaCl. Oxygen was not required to trigger spore germination, but trace amounts were needed for the successful outgrowth of germinated spores. Spore germination was accelerated and enhanced by the presence of at least 2% NaCl. Therefore under anaerobic conditions NaCl promotes microbiological stability because the germinated spores cannot develop further and become moribund. It is concluded that the plastic casing of luncheon‐meat chubs is not sufficiently oxygen‐impermeable to allow the product a long shelf‐life other than at chill temperatures unless the chubs are stored in an oxygen‐free atmosphere.
The modification and evaluation of some cytochemical techniques for the enumeration of metabolically active heterotrophic bacteria in the aquatic environment
Authors: Quinn J.P.
Published: March 2008

Variants of the tetrazolium‐reduction, nalidixic acid‐inhibition and fluorescein diacetate‐hydrolysis techniques for enumeration of metabolically active bacteria were compared, using samples of planktonic, benthic, and epiphytic freshwater bacteria. Results obtained by these methods generally showed statistically significant differences. However, an INT reduction technique, without added substrate, and a slightly modified nalidixic acid procedure gave values which did not differ at the 5% level. The results indicated that from 10 to 40% of total bacteria in the samples examined were metabolically active. These values were up to two orders of magnitude higher than those obtained by conventional plate count techniques.
A study of the relative incidence of different Pseudomonas groups on meat using a computer‐assisted identification technique employing only carbon source tests
Authors: Shaw B.G. , Latty Josephine B.
Published: March 2008

A computer‐assisted probabilistic identification technique employing 18 carbon source utilization tests has been developed and applied to 787 Pseudomonas strains isolated from beef, pork and lamb stored under aerobic conditions. Seven hundred and twelve (89.7%) were identified using these tests alone and a further six (0.8%) with extra tests. Taxa detected were Ps. fragi cluster 2, 390 strains (49.6% of all isolates); Ps. fragi cluster 1, 191 strains (24.9%); meat cluster 3, 87 strains (11.1%); Ps. fluorescens biotype I, 31 strains (3.9%); Ps. fluorescens biotype III, 7 strains (0.9%); and Ps. putida, 1 strain (0.1%). The relative incidence of members of the various taxa was similar on beef, pork and lamb, and was unaffected by storage temperature in the range 0°–10°C. Each taxon was also detected at similar rates before and after spoilage. Meat origin (abattoir) affected the frequency of detection of meat cluster 3 and Ps. fluorescens biotype I strains but did not affect the incidence of detection of either cluster of Ps. fragi.
Regulation of amylase bio‐synthesis in growing and non‐growing cells of Bacillus stearothermophilus
Authors: Srivastava R.A.K. , Mathur S.N.
Published: March 2008

The regulation of amylase synthesis in growing and non‐growing cells of a thermophilic Bacillus stearothermophilus was studied. Starch induced its synthesis in growing cells, while glucose and maltose repressed it. Glucose, however, had no effect on amylase synthesis in non‐growing cells for the first 3 h. Cyclic‐AMP acted as a derepressor and completely reversed the glucose effect in growing cultures when added during the lag or the exponential phases. Apart from ATP, other nucleotides such as AMP, ADP, GMP, GDP and GTP, had no effect on amylase synthesis. The inorganic phosphates (K2HPO4, Na2HPO4) up to about 240 mmol affected amylase synthesis/secretion in growing and non‐growing conditions, whereas the organic phosphates (glucose‐6‐P and glucose‐1‐P) did not. The addition of RNA polymerase inhibitors such as actinomycin D (1 μg/ml), and rifampicin (1 μg/ml) stopped amylase synthesis by washed cells after 3 h whereas the protein synthesis inhibitor, chloramphenicol (20 μg/ml) stopped amylase synthesis instantaneously. This indicated that the m‐RNA for amylase synthesis was long lived and therefore synthesis continued even in the presence of RNA polymerase inhibitors. The glucose effect observed after 3 h was identical to that of the RNA polymerase inhibitors which indicated that glucose repression of amylase synthesis was probably at the transcriptional level.
A note on the effect of temperature on the sensitivity of Erwinia carotovora sub sp. atroseptica to the phytoalexin rishitin
Authors: Lyon G.D.
Published: March 2008

Erwinia carotovora sub sp. atroseptica grown at 25°C, suspended in 0.1% peptone water, and incubated with rishitin (500 μg/ml) at temperatures between 10° and 30°C, was more sensitive to the rishitin at the higher temperatures.
Studies on the microbiology of cassava retting for foo‐foo production
Authors: Okafor N. , Ijioma B. , Oyolu C.
Published: March 2008

Okafor N. Ijioma B. Oyolu, C. 1984. Studies on the microbiology of cassava retting for foo‐foo production. Journal of Applied Bacteriology56, 1–13.

Five bacteria (Bacillus, Lactobacillus, Klebsiella, Leuconostoc, and Corynebacterium) and a yeast (Candida spp.) were isolated from cassava being fermented for foo‐foo production. Retting of cassava was assessed by determining the weight required to crush cylindrical cassava pieces. A weight in excess of 2.5 kg was required to crush an unfermented peeled cassava cylinder 4 mm diameter and 4 cm long whereas a weight as small as 20 g could crush the same piece after retting. The organisms were studied for their ability to cause retting of sterile cassava pieces, alone or in various combinations. Retting did not occur unless either the Bacillus sp. or the Corynebacterium sp. was present. Only these two organisms hydrolysed starch. The lactic acid bacteria lowered the pH of the fermenting medium although they did not bring about retting. The typical aroma of foo‐foo was produced, however, only when the lactic acid bacteria were present in the mixture. Only the Corynebacterium sp., was, however, shown to produce pectinolytic enzymes and it is possible that the Bacillus sp. caused retting by disintegrating other cell components. The typical aroma of foo‐foo is disliked by some individuals and it seems possible that foo‐foo with a bland aroma, which will presumably be more acceptable to this group, can be produced by using organisms causing retting while excluding those forming lactic acid.
A numerical taxonomic study of lactic acid bacteria from vacuum‐packed beef, pork, lamb and bacon
Authors: Shaw B.G. , Harding Charmaigne D.
Published: March 2008

Shaw B. G. & Harding Charmaigne D. 1984. A numerical taxonomic study of lactic acid bacteria from vacuum packed beef, pork, lamb and bacon. Journal of Applied Bacteriology56, 25–40.

A numerical taxonomic study using 79 unit characters has been performed on 100 isolates of lactic acid bacteria from refrigerated vacuum‐packed beef, pork, lamb and bacon. Three clusters were observed at 78% S which contained all the strains apart from three unidentifiable streptobacteria, one Leuconostoc, and one strain of Pediococcus pentosaceus. One cluster (III) consisted of only one strain of Leuc. paramesenteroides and six unidentifiable Leuconostoc strains. The two largest clusters (I and II) were both composed entirely of streptobacteria. Cluster I contained 31 strains (G + C content 33–2–36–9 moles %) which were not identifiable with any described species. Cluster II contained 57 strains (G + C content 40–7–43–7 moles %) which were provisionally identified with Lactobacillus sake or Lact. bavaricus according to the lactic acid isomer produced. The division of nearly all the streptobacteria into two clearly defined clusters has resolved problems which have existed in the classification of lactic acid bacteria from vacuum‐packed meat.
Effects of microbial colonization of barley (Hovdeum vulgare L.) roots on seedling growth
Authors: Lynch J.M. , Clark Sarah J.
Published: March 2008

Lynch J.M. & Clark Sarah J. 1984. Ejects of microbial colonization of barley (Hordeum vulgare L.) roots on seedling growth. Journal of Applied Bacteriology56, 47–52.

A range of micro‐organisms, particularly pseudomonads, was isolated from seed, rhizosphere soil and straw. Their colonization and effects on the growth of barley seedlings in gnotobiotic culture were studied. The colonization potentials of the different species were between 004 and 47 times 106 viable cells/mg dry root. Some organisms stimulated root and shoot extension and dry matter production while others were inhibitory; these effects were not directly related to the colonization potentials.
Effects of the resistance plasmid R124 on the level of the OmpF outer membrane protein and on the response of Escherichia coli to environmental agents
Authors: Rossouw F.T. , Rowbury R. J.
Published: March 2008

Rossouw F.T. & Rowbury R.J.1984. Effects of the resistance plasmid R124 on the level of the OmpF outer membrane protein and on the response of Escherichia coli to environmental agents. Journal of Applied Bacteriology, 56, 63–79.

The introduction of the F‐like resistance plasmid R124 into an ompC mutant of Escherichia coli K12 conferred altered sensitivity to a wide range of inhibitory agents. Sensitivity to ampicillin, chloramphenicol, ethionine, copper ions, deoxycholate, two fatty acids and colicins L and M was decreased by the plasmid. In contrast the plasmid‐bearing ompC derivatives were more sensitive than the plasmid‐free ompC mutant to erythromycin, cetyltrimethylammonium bromide and phenol. Introduction of R124 into the ompC strain also decreased the level of the OmpF protein and some (but not all) of the changed sensitivities listed above clearly resulted from this outer membrane protein deficiency. The presence in the ompC mutant of R124 (rather than the more efficient introduction of the plasmid into variants of the ompC strain) led to at least most of the changes described above because those tested were accentuated by the presence of a copy mutant of R124 and reversed by plasmid curing.
Hydrogen‐using bacteria in a methanogenic acetate enrichment culture
Authors: Archer D.B.
Published: March 2008

Archer, D.B. 1984. Hydrogen‐using bacteria in a methanogenic acetate enrichment culture. Journal of Applied Bacteriology56, 125–129.

In a study of the anaerobic utilization of acetate, an enrichment culture of sewage sludge organisms was initiated with calcium acetate as the sole carbon and energy source. A mixed bacterial population became established from which 14 anaerobic species were isolated. Two of the isolates were methanogenic bacteria but only one of these, Methanosarcina barkeri, utilised acetate as an energy source in axenic culture. The other methanogenic isolate, a Methanobacterium sp., utilised H2/CO2 but not acetate. A third methanogen, which was morphologically identical to Methanothrix soehngenii, was detected in the enrichment but was not obtained in monoculture. 2‐Bromoethanesulphonate, a specific inhibitor of methanogenesis. completely inhibited the enrichment at a concentration of 10 μmol/1. Addition of H2 formate or methanol to the enrichment did not affect the rate of methanogenesis. An H2‐utilizing Desulfovibrio sp. was also isolated from the enrichment.
Competition studies with Rhizobium trifolii in a field experiment
Authors: McLloughlin T.J. , Bordeleau L.M. , Dunican L.K.
Published: March 2008

McLoughlin, T.J. Bordeleau L.M. & Dunican, L.K. 1984. Competition studies with Rhizobium trifolii in a field experiment. Journal of Applied Bacteriology56, 131–135.

Competition studies were carried out in a field experiment by comparing the ability of antibiotic marked Rhizobium strains inoculated at three inoculum levels in forming nodules against an effective indigenous Rhizobium population of 1.5 times 105/g. Three inoculum strains were assessed. It was seen that by increasing the level of inoculum there was a corresponding increase in the number of nodules formed by the introduced strains. G1067 formed a high proportion (85%) at the highest level, whereas the other two inoculum strains occupied less than 50% of the nodules at the same level. Persistence of the inoculum strain was measured into the second season; G1032 could not be detected, G1006 (another ‘foreign’ strain) formed 43% and G1067 formed 97% of the nodules sampled. The indigenous Rhizobium population isolated from nodules was shown to be heterogenous, and 15 different intrinsic antibiotic resistance patterns were found. Fifty per cent of the isolates fell in the same group which showed a similar pattern to that of the inoculum strain G1067.
Glycerol utilization by Brochothrix thermosphacta*
Authors: Macaskie Lynne E. , Sheard A.G. , Dainty R.H. , Henderson P.J.F.
Published: March 2008

Macaskie, Lynne E. Sheard, A.G.M. Dainty, R.H. Henderson, P.J.F.1984. Glycerol utilization by Brochothrix thermosphacta. Journal of Applied Bacteriology56, 137–143.

Growth of the meat spoilage organism, Brochothrix thermosphacta, was supported by either glucose or glycerol with acetoin production. Similar yields of bacteria were obtained at growth‐limiting concentrations of either substrate. The rate of uptake of each substrate was similar but glycerol supported higher rates of respiration than glucose. These findings are discussed in relation to metabolism of glycerol and the use of glycerol for meat storage.