bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the lytic activity of bacteriophages of Leuconostoc oenos isolated from wine
Authors: Henick‐Kling T. , Lee T. H. , Nicholas D. J. D.
Published: March 2008

Two phage species (sl. ls and lco23) of Leuconostoc oenos, isolated in Switzerland and in Australia, were compared for their ability to inhibit growth of L. oenos in wine. The effect of pH, ethanol, SO2, temperature and time of infection on phage activity was evaluated in synthetic media and in wine. The phages differed in their response to pH in that the activity of phage sl.ls was highest at low pH (3.5), while that of phage lco23 was highest at a high pH (5.5). The phages were not inhibited by low temperature (15°C) or by 50 mg/l SO2. Both phages were inhibited by ethanol at a concentration greater than 5% (v/v). In a white and a red wine tested, the red wine partially inhibited and the white wine completely inhibited phage activity. When phage infection at pH 3.5 occurred during the exponential phase of growth, the bacteria outgrew the phage. Phage‐resistant mutants developed between 3 and 35 d after phage infection, depending on pH and temperature. Recommendations for the use of starter cultures of L. oenos in the wine industry are given.
Numerical taxonomy of α‐amylase producing Bacillus species
Authors: Pretorius I. S. , Kock M. J. de , Britz T. J. , Potgieter H. J. , Lategan P. M.
Published: March 2008

A total of 134 α‐amylase producing Bacillus isolates and 21 reference strains were divided into 12 groups according to their similarities (% SSM). Phenotypic characteristics determined by the API 20E and API 50CHB galleries, other biochemical tests and morphological characteristics were used for the numerical analysis. The API Computer Service identified 45% of the isolates. The amylase yields of 16 α‐amylase hyperproducing (AHP) isolates were compared with those of seven amylolytic reference and type strains. The AHP isolates were related to Bacillus subtilis, B. licheniformis and ‘B. amyloliquefaciens’.
Growth of salmonellas in different enrichment media
Authors: Patil M. D. , Parhad N. M.
Published: March 2008

The usefulness‐of selenite‐F (S‐F), tetrathionate (MKT) and Rappaport‐10 (R‐10) broths as enrichment media to support growth of salmonellas either alone or in the presence of other competing organisms was studied. Their ability to support the growth of stressed salmonellas from water was also investigated. It was observed that R‐10 was more inhibitory to competing organisms than MKT and S‐F. It strongly inhibited the growth of Pseudomonas aeruginosa, Citrobacter freundii and Proteus vulgaris though not of Escherichia coli and Enterobacter aerogenes. It was more toxic, however, to small numbers of salmonellas than MKT and S‐F. Tetrathionate was strongly inhibitory for E. coli and Ent. aerogenes but much less so for Proteus and Pseudomonas species. Selenite‐F was much less inhibitory than MKT to Ps. aeruginosa and it did not inhibit growth of E. coli and Ent. aerogenes as much as MKT. Salmonellas were inhibited by all three enrichment media and none of them is ideally suited for direct use. Of the three media, R‐10 was much more inhibitory to stressed organisms than S‐F or MKT.
Bactericidal activity of alkaline glutaraldehyde solution against a number of atypical mycobacterial species
Authors: Collins F. M.
Published: March 2008

The mycobactericidal activity of 2% alkaline glutaraldehyde solution was determined using standardized suspensions of 10 species of atypical mycobacteria and compared with that for virulent Mycobacterium tuberculosis. Suspensions of M. avium, M. intracellulare and M. gordonae were more resistant to disinfection by the glutaraldehyde than were virulent tubercle bacilli while M. kansasii, M. scrofulaceum and M. szulgae were somewhat more susceptible. Mycobacterium marinum, M. smegmatis and M. fortuitum were highly sensitive to the disinfectant action of the alkaline glutaraldehyde solution. This variation in sensitivity shown by apparently closely related strains of mycobacteria to this disinfectant has important practical implications.
Inhibition of bacterial growth and malolactic fermentation in wine by bacteriophage
Authors: Henick‐Kling T. , Lee T. H. , Nicholas D. J. D.
Published: March 2008

Bacteriophage present in wine can attack bacterial starter cultures and inhibit the malolactic fermentation. The possibility of starter culture failure due to phage attack was studied in a commercial dry red wine of pH 3·23, inoculated with a multiple strain starter culture. During two stages of malolactic fermentation, bacterial growth and malate degradation in the wine were inhibited. A phage capable of lysing isolates of Leuconostoc oenos was isolated from the wine. The isolated phage had an icosahedral head of 42–45 nm diameter and a flexible, regularly cross‐striated tail 197–207 nm long with a small baseplate. The results confirm that phage can attack bacterial starter cultures in wine at low pH.
The destruction of Salmonella typhimurium in chicken exudate by different freeze‐thaw treatments
Authors: Obafemi A. , Davies R.
Published: March 2008

Antibacterial treatments for frozen poultry, including holding at ‐5°C and slow thawing at 4°C to which exponential phase cells of Salmonella typhimurium were susceptible, were found to be relatively ineffective against stationary phase cells. Exposure of the latter, however, to a pre‐freezing triple stress treatment of cold‐shock exposure at 5°C to a solution containing 5 mg/l of free available chlorine in 1% succinic acid (pH 2.5) for 20 min substantially lowered the resistance of the cells to subsequent freezing, storage and thawing in poultry flesh exudate. Cell survival was further decreased by storage of exudate at ‐ 18°C for 28 d and this reduced the proportion of stationary phase cells to less than 1% of initial numbers, with a concomitant increase in sensitivity to deoxycholate. Such a combined pre‐treatment may have practical potential for salmonella decontamination in the production of frozen poultry.
Identification and distribution of Pseudomonas stutzeri in clinical material
Authors: Holmes B.
Published: March 2008

During the 19 year period ending December 1984, 114 (2.4%) of 4840 strains of Gram‐negative non‐fermentative bacteria submitted, mainly by laboratories in the UK, to the National Collection of Type Cultures for computer‐assisted identification were strains of Pseudomonas stutzeri. These figures suggest that Ps. stutzeri is a relatively uncommon species in clinical material in the UK but that when it does occur laboratories have difficulty in identifying it. The sources from which the strains were isolated and also characteristics of the species by which it may be recognized are reported. The clinical significance of Ps. stutzeri is discussed and also the susceptibility of this species to antimicrobial agents.
Changes in the plasmid profile of Lactobacillus plantarum obtained from commercial meat starter cultures
Authors: Von Husby K. O. , Nes I. F.
Published: March 2008

The stability of plasmids in Lactobacillus plantarum used commercially as a starter culture in the production of dry sausage was studied. Individual isolates of one strain taken from the starter culture produced over a period of 10 years were examined, and certain changes in the plasmid profiles identified. From molecular sizing and restriction enzyme analysis it appeared that two of the six plasmids became fused over this period of time to give one new, larger plasmid. The other plasmids remained unchanged.
Amylase from Lactobacillus cellobiosus D‐39 isolated from vegetable wastes: Purification and characterization
Authors: Sen Sribir , Chakrabarty S. L.
Published: March 2008

An organism producing α‐amylase and identified as Lactobacillus cellobiosus D‐39 was recently isolated from vegetable wastes. Its amylase was purified by (NH4)2SO4 precipitation and DEAE cellulose column chromatography and was obtained in crystalline form. It was fairly stable at a broadly neutral pH range and maximally active at 50°C. The molecular weight was 22 500 daltons as determined by SDS gel electrophoresis.
Antibiotic resistant bacteria in Windermere and two remote upland tarns in the English Lake District
Authors: Jones J. G. , Gardener S. , Simon B. M. , Pickup R. W.
Published: March 2008

The incidence of antibiotic resistance was determined in over 2000 bacteria which were divided into the following groups: faecal streptococci, coliforms (excluding Escherichia coli), E. coli, Pseudomonas spp. and aquatic bacteria (i.e. bacteria predominant in the lake water which were excluded from the previous four categories). The isolates were obtained from the water of Windermere (English Lake District) and from a sewage effluent which entered the lake. With the exception of the faecal streptococci, the incidence of antibiotic resistance was higher in the bacteria isolated from the lake water than in those from the effluent, and ranked according to groups Pseudomonas spp. > E. coli > aquatic bacteria > coliforms > faecal streptococci. The highest incidence of multiple resistance was found among the pseudomonads. When corrected for the relative size of each population the pool of antibiotic resistance in the aquatic bacteria was by far the largest. The incidence of antibiotic resistance in aquatic bacteria isolated from Windermere was, however, lower than in those isolated from two remote upland tarns. This finding may have been due to differences in the species composition of the three sites except that the same results were obtained when only fluorescent pseudomonads were tested. The upland tarns were not totally isolated from man and other animals but did not receive any sewage or other effluents and therefore the results were surprising. Possible explanations include a lack of susceptibility in aquatic bacteria and increased resistance associated with growth in nutrient poor environments.
Effect of medium supplements, illumination and superoxide dismutase on the production of coccoid forms of Campylobacter jejuni ATCC 29428
Authors: Moran A. P. , Upton Mary E.
Published: March 2008

Factors influencing the production of coccoid forms in cultures and suspensions of a strain of the enteric pathogen Campylobacter jejuni during storage in air were investigated. Addition of blood or a supplement containing ferrous sulphate, sodium metabisulphite and sodium pyruvate minimized conversion of rods to coccoid forms in cultures. Exposure of cultures to light during storage in air increased the rate of production of coccoid forms. Ultraviolet radiation was shown to effect the viability of cells in suspensions but the increase in production of coccoid forms was low after irradiation. The presence of hydrogen peroxide and its dissociation products in bacterial suspensions increased conversion to coccoid forms. Addition of active superoxide dismutase, a superoxide anion scavenging enzyme, minimized production of coccoid forms in suspensions stored in air. Coccoid forms contained a lower level of superoxide dismutase than rods. It is deduced that a decreased level of the enzyme in cells is linked with production of coccoid forms.
Relation of the heat resistance of bacterial spores to chemical composition and structure I. Relation to core components
Authors: Mallidis C. G. , Scholefield J.
Published: March 2008

The relation between heat resistance characteristics and the composition of the bacterial spores was studied in five strains of Bacillus stearothermophilus. A relationship was found to exist between the dipicolinic acid (Dpa) and calcium content of the spore and the heat resistance characteristics. The stability of the Dpa chelates was also significantly related to heat resistance.
The effect of nitrogen and carbon sources on proteinase production by Pseudomonas fluorescens
Authors: Fairbairn D. J. , Law B. A.
Published: March 2008

Some factors influencing the production of an extracellular proteinase by Pseudomonas fluorescens NCDO 2085 were studied. Proteinase production was optimal at 20C and pH 69 in static culture when calcium was included in the medium. Proteinase was not detectable in basal medium but could be induced by organic nitrogen compounds. The proteinase was produced in the exponential phase of growth on protein substrates but not until early stationary phase during growth on amino acids. The organism did not utilize lactose, the most abundant carbohydrate in milk. Citrate was readily utilized as an energy source but had a strong repressive effect on proteinase production. A medium containing sodium caseinate and pyruvate supported good growth and enzyme production. All the amino acids utilized as a sole carbon source, with the exception of serine, could induce proteinase production. Asparagine was the most effective amino acid inducer. Particular combinations of amino acids could induce or repress proteinase production. The regulation of proteinase production by Ps. fluorescens NCDO 2085 appears to be based on a balance between induction by low concentrations of low molecular weight degradation products and sensitivity to end product catabolite repression. The results suggest that the function of the proteinase is to ensure a supply of carbon rather than amino acids for protein synthesis.
A note on the isoprenoid quinone content of Bordetella avium and related species
Authors: Fletcher Mary T. , Blackall P. J. , Doheny Catherine M.
Published: March 2008

The isoprenoid quinone content of isolates of Bordetella avium (four strains), Alcaligenes faecalis (one strain), Bordetella bronchiseptica (one strain) and a Bordetella avium‐like organism (four strains) was determined by reverse‐phase high‐performance liquid chromatography. All the isolates contained ubiquinones with eight isoprene units as the major component. No menaquinones were detected.
Salmonella and campylobacter contamination of broiler chicken carcasses and scald tank water: the influence of water pH
Authors: Humphrey T. J. , Lanning D. G.
Published: March 2008

Scalding at 50°± 0.5°C, in water maintained at pH 9.0 ± 0.2 by the addition of sodium hydroxide, had no effect on the incidence of salmonella or campylobacter contamination of chicken carcasses. There were significant reductions, however, in the numbers of these organisms in the water itself.
The use of rats associated with a human faecal flora as a model for studying the effects of diet on the human gut microflora
Authors: Mallett A. K. , Bearne C. A. , Rowland I. R. , Farthing M. J. G. , Cole C. B. , Fuller R.
Published: March 2008

The activities of four bacterial biotransformation enzymes (β‐glucosidase, β‐glucuronidase, nitrate reductase and nitroreductase) were measured in the caecal contents of conventional flora rats or germ‐free rats contaminated with a mixed, human faecal flora and compared with activities present in a fresh human stool preparation. Both the conventional flora rats and the rats inoculated with a human flora exhibited an enzyme profile generally similar to that of human faeces, although the conventional rat flora exhibited negligible nitrate reductase activity. The enzyme profile remained essentially unaltered in both human flora preparations following supplementation of the diet with pectin, whereas the conventional rat flora responded to this plant cell wall carbohydrate with a significant increase in nitrate reductase activity. The results demonstrate that enzymic activities of the human faecal microflora can be simulated in rats associated with a mixed population of human intestinal bacteria.
A note on adhesion of bacteria to chicken muscle connective tissue
Authors: Campbell S. , Duckworth S. , Thomas C. J. , McMeekin T. A.
Published: March 2008

Laboratory cultures of bacteria were tested for the ability to attach to collagen fibres of intact chicken muscle connective tissue. All salmonellas, fimbriate strains ofEscherichia coliand a strain ofCampylobacter coliwere able to attach to tissue only when suspended in distilled water. Prior immersion of tissue in sterile water for 20 min or extended immersion in these bacterial suspensions was a prerequisite for adhesion. Attachment could be prevented by the addition of physiological levels of sodium chloride to the attachment medium.
Cell surface proteins of encapsulated Streptococcus cremoris: identification and immunochemical characterization
Authors: Kontusaari Sirpa , Forsen Raili
Published: March 2008

Cell surface proteins of two slime‐forming, encapsulated Streptococcus cremoris strains, MLS96 and T5 from the fermented milk product viili, were extracted with the non‐ionic detergent Triton X‐100. The isolated protein antigens were characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immuno‐blotting with antisera produced against whole Strep. cremoris cells. When protein profiles of these strains were compared, seven prominent polypeptides were found common to both and were recognized by both antisera. Five of these polypeptides with molecular weights of 70000, 54000, 50000, 47000 and 40000 were identified as cell wall components. The remaining two polypeptides with molecular weights of 42000 and 26000 are being studied further in connection with slime formation for which modified Triton X‐100 extraction provides a suitable method for isolation of the surface‐associated antigens of lactic streptococci.
Production and specificity of monoclonal antibodies and polyclonal antibodies to Escherichia coli
Authors: Kaspar C. W. , Hartman P. A.
Published: March 2008

Monoclonal antibodies were produced to whole cells of heat‐treated Escherichia coli. Balb/c mice were immunized with a pool of five strains of heat‐treated E. coli, and the resulting hybridomas were screened by indirect immunoassay. E. coli strains other than those used for immunization were used for screening to detect hybridomas producing antibody that reacted with a large number of E. coli strains. Of 864 hybridomas, 32 reacted strongly with either two or all three of the strains used for screening; 15 were successfully cloned. Antibody from hybridoma 6H2 reacted with 35 of 68 (51%) E. coli; of 13 non‐E. coli tested, only Enterobacter agglomerans was weakly positive. Hybridoma 9B12 antibody reacted with all six E. coli tested. Hybridoma 9B12, however, stopped producing antibody. Five hybridomas produced antibody which reacted with a majority of the bacteria tested whereas antibodies from two other hybridomas reacted with several E. coli and non‐E. coli. Polyclonal antibodies produced to two strains of E. coli varied in the numbers of E. coli with which they reacted; both antisera cross‐reacted with several non‐E. coli.
Ecophysiological grouping of Antarctic environmental bacteria by API 20 NE and fatty acid fingerprints
Authors: Tearle P. V. , Richard K. J.
Published: March 2008

Gas liquid chromatography and a commercially available strip of 20 conventional biochemical tests were used for the rapid sorting of strains of environmental bacterial isolates into similar ecophysiological groups. This combination is appropriate for studies with organisms that do not conform to described species because of the constraints imposed upon them by their habitats.
The ligules of green leaves of cock's‐foot grass, Dactylis glomerata L., are a micro‐habitat for bacteria and fungi
Authors: Birkby K. M. , Preece T. F.
Published: March 2008

Microbial populations on the ligule and leaf blade of cock's‐foot grass, Dactylis glomerata L., were examined by three different methods. The ligule was identified as an important microbial niche for both bacteria and fungi. Microbial populations on the ligule increased after emergence and declined again as it approached senescence. The area of leaf blade adjacent to the ligule also had a rich microbial flora. This contrasts with the remainder of the leaf blade which is sparsely populated. However, the tip can also support a rich microbial population.
Co‐metabolism of citrate and glucose by Leuconostoc spp.: effects on growth, substrates and products
Authors: Cogan T. M.
Published: March 2008

Growth, substrate utilization and product formation from glucose, citrate and a mixture of both substrates were studied in four strains of Leuconostoc spp. Citrate was not used as an energy source but was rapidly metabolized when glucose was present. The predictable amounts of D‐lactate and ethanol were produced from glucose, although strains X2 and 7–1 gave lower yields of ethanol. In strains NCW1, S3 and X2, co‐metabolism of both glucose and citrate resulted in stimulation of growth, decreased uptake of glucose, increased acetate and D‐lactate production and lack of ethanol production compared with that obtained with glucose alone. Strain 7–1 showed only growth stimulation and increased acetate production. Diacetyl, acetoin or 2, 3‐butylene glycol were not detected. In strain NCW1 citrate had a slightly inhibitory effect on the enzymes of the ‘ethanol’ leg of glucose metabolism. Except for strain 7–1, these observations are consistent with a switch in glucose metabolism from ethanol to acetate production.
Utility of subtilisin GX as a detergent additive
Authors: Durham D.R.
Published: March 2008

Subtilisin GX, purified from alkalophilic Bacillus sp. GX6644 (ATCC 53441), was assessed for its ability to augment detergencies of commercial laundry products. The addition of the alkaline protease to detergent compositions resulted in significant increases in the removal of proteinaceous stains from a standard soiled fabric during Tergotometer wash tests. The enzyme was effective in liquid and powdered detergent formulations and functional over a wide pH and temperature range. The results indicate that the alkaline protease from Bacillus sp. GX6644 possesses properties suitable as a detergent additive.
Antibody response to bacterial antigens covalently bound to biodegradable polymerized serum albumin beads
Authors: Lanchein C. , Newman J.F.E.
Published: March 2008

Model vaccines have been made by covalently linking Clostridium botulinum type D toxin and Klebsiella pneumoniae capsular polysaccharide antigen to polymerized rabbit serum albumin beads. When injected into rabbits these bead vaccines induced an enhanced production of specific humoral antibody without causing adverse reactions. The adjuvant effect is due to a slow release from the bead structure and offers an alternative to oil emulsions and mineral salt adsorbents.
Comparative study of Agrobacterium biotypes 1, 2 and 3 by electrophoresis and serological methods
Authors: Alarcon B. , Lopez M. M. , Cambra M. , Ortiz J.
Published: March 2008

A comparative study by electrophoresis and serology of strains representing the three Agrobacterium biotypes was carried out. Thirteen Spanish isolates and strains from international collections were included. Ten antisera were prepared by using strains from the three biotypes and different types of antigens. The strains were studied by immunodiffusion, indirect immunofluorescence and indirect ELISA. Serological relationship among all the strains was observed, although serological heterogeneity within each of the biotypes occurred. Biotype 3 appears as serologically related to biotypes 1 and 2, having an intermediate position. This observation is in agreement with their biochemical characteristics. Electrophoretic analysis of the three biotypes showed that there was high variability. Three main bands appeared in the six strains studied. One specific band occurred in the biotype 1 strains and another in the biotype 3 strains.
The occurrence of Campylobacter jejuni in raw cows' milk
Authors: BEUMER R.R. , CRUYSEN J.J.M. , BIRTANTIE I.R.K.
Published: March 2008

Faeces and raw milk from individual cows were examined for the presence of Campylobacter jejuni. After drawing milk, the lactoperoxidase system was inactivated by raising the pH to 7.5. The organism was isolated from 22% of 904 faecal samples and from 4.5% of 904 milk samples. From laboratory experiments it could be concluded that inactivation of the lactoperoxidase system resulted in a better isolation of C. jejuni from raw cows' milk.
Comparative studies of selective media for recovery of Staphylococcus aureus from natural waters
Authors: Borrego J.J. , Florido J.A. , MartÍAnez‐Manzanares E. , Romero P.
Published: March 2008

Several selective media currently used for the enumeration of Staphylococcus aureus from different sources were evaluated in order to establish their quantitative recovery, specificity and degree of selectivity, using different types of water samples. The highest selectivity and reliability in the enumeration of Staph. aureus from the samples was obtained on Borrego‐Florido‐Romero‐0 (BFR‐0) and KRANEP agars. The method that produced the highest recovery of Staph. aureus was BFR‐0 agar with membrane filter and incubation at 36°C for 48–72 h.
Effects of sewage treatment on the removal of Listeria monocytogenes
Authors: Al‐Ghazali M.R. , Al‐Azawi Salwa K.
Published: March 2008

Two sewage treatment plants in Baghdad, Iraq, were investigated to assess the effects of the different treatment stages on the removal of Listeria monocytogenes. The bacteria were severely affected after the activation and digestion stages at both plants. A dramatic decrease in numbers of listerias after each of these two stages was noticed during the cold months (September‐January). The organisms were able to survive these treatments and were present in the final effluent and even in low numbers in the sewage sludge cake. Sufficient dewatering of sewage sludge is recommended to obtain sewage free of listerias. Improvements in the isolation procedure of L. monocytogenes from such heavily contaminated material is also discussed.
The use of bacteriophage as tracers of aerosols liberated by sludge suction appliances
Authors: Wheeler D. , Skilton Helen E. , Carroll R.F.
Published: March 2008

Three bacteriophage tracers were added to 600–1 containers of water and simulated latrine sludge to provide high titres of tracer in aqueous and semi‐aqueous media. After a period of mixing and stabilization, media were removed from the containers with suction hoses coupled to the vacuum pump of one of two sludge suction tankers. Exhaust air from the appliances was sampled by cyclone sampler and assayed for the presence of tracer organisms carried over during the emptying process. In the experiments the appliances were operated at different vacuum pump speeds, drawing both aqueous and semi‐aqueous (simulated sludge) media. Air around one tanker was also sampled during the emptying, under pressure, of the vacuum vessel. The degree of aerosolization and expulsion of tracer bacteriophage by the vacuum appliances was consistently low, regardless of medium and pump air flow. In contrast, the proportion of tracer retained within the appliances was very high, exceeding the proportion expelled by a minimum of 8log10 orders of magnitude and a maximum of greater than 11log10 orders. The highest total of tracer bacteriophage was recovered during the pressure emptying of the vacuum vessel of one tanker. The results may be used for assessing and comparing potential public health hazards associated with the handling of wastewater sludge by vacuum appliances.
Serological diversity within the species Legionella spiritensis
Authors: Harrison T. G. , Saunders N. A. , Doshi Nivedita , Wait R. , Taylor A. G.
Published: March 2008

A strain of Legionella isolated from the environment which could not initially be identified was shown by restriction fragment length polymorphisms to be a Legionella spiritensis. This was confirmed by DNA homology studies, cell wall fatty acid composition and isoprenoid quinone analysis. This strain, which is only the second reported representative of the species, was shown to be serologically distinct from the type strain of L. spiritensis and all other serogroups of Legionella.
A medium for the detection of Lancefield Group D cocci in skimmed milk powder by measurement of conductivity changes
Authors: Neaves P. , Waddell M.J. , Prentice G.A.
Published: March 2008

A selective medium for the detection of Lancefield Group D cocci in skimmed milk powder by conductivity measurements was developed and evaluated using the Bactometer M123 and Malthus 128H systems. This medium promoted large changes in conductance and capacitance. The calibration curve of detection times vs concentration of Lancefield Group D cocci showed a linear correlation coefficient of 0.93 and the method gave comparable results in both conductivity instruments. Naturally contaminated samples containing c. 103 cfu/g of Lancefield Group D cocci gave detection times within 16–18 h which was sufficiently rapid for the medium to be used for the routine screening of skimmed milk powder.
Rapid selective enumeration of bacteria in foods using a microcolony epifluorescence microscopy technique
Authors: Rodrigues Ubaldina M. , Kroll R. G.
Published: March 2008

The growth patterns of macrocolonies of 59 different pure cultures were studied on eight selective solid media. A method of growing microcolonies on the surface of polycarbonate membrane filters, placed on the selective agar media, followed by staining and examination by epifluorescent microscopy was developed. The patterns of growth of the pure cultures as microcolonies were studied on the eight selective media. Only four media proved to be reliable for this purpose and the relationship between the microcolony count and plate count was studied on these media together with nutrient agar. Microcolony counts using three of these media (enriched lauryl sulphate aniline blue, pseudomonas selective agar (C‐F‐C) and Baird‐Parker medium) were capable of giving reliable estimates of coliforms (r = 0·89), pseudomonads (r = 0·93) and staphylococci (r = 0·92) after incubation at 30°C for 3 or 6 h (staphylococci) at contamination levels of above 103 bacteria/g in a variety of foods. The results are available within a working day and should allow the more efficient management of food supplies.
The infiltration ability of micro‐organisms Bacillus, Fusarium, Kluyveromyces and Pseudomonas spp. into xylem vessels of Gerbera cv. ‘Fleur’and Rosa cv. ‘Sonia’cut flowers: a scanning electron microscope study
Authors: Put Henriëtte M.C. , Clerkx Anke C.M.
Published: March 2008

Scanning electron microscope (SEM) observations have been made of transverse and longitudinal sections of xylem vessels of cut flowers of Gerbera cv. ‘Fleur’and cut Rosa cv. ‘Sonia’after a maximum of 24 h vase life. Vase waters used were: sterile tap water; sterile tap water plus suspensions of single pure cultures of Bacillus polymyxa, B. subtilis, Fusarium oxysporum microspores, segments of young mycelium of F. oxysporum, Kluyveromyces marxianus, or Pseudomonas putida, up to a maximum of 106 and 5×107 cells/ml of vase water.

The results of the SEM observations showed that only a small fraction of the microbial cells entered into the vascular system with the normal intake of vase water; most microbial cells remained attached to the submerged cut surface while a small fraction of the initially attached microbes were sometimes liberated into the surrounding vase water. The SEM figures give the impression that adhesion on to the cut stem surfaces of the bacterial cells (Bacillus and Pseudomonas spp.) by their capsular materials may have occurred, although the cut surface possibly acted as a filter, trapping cells because of the upward pressure of the transpiration stream into the vessels. Few attached yeast cells were found, but Fusarium microconidia formed cell clusters on the cut surface, partially blocking the xylem vessel entrance; Fusarium mycelium covered the cut‐surfaces as another filter layer through which only small mycelial particles could enter the vascular system.

The extent of infiltration of microbial cells into the xylem vessel system depended upon the number of microbial cells/ml of vase water (up to a certain maximal number) and on the shape and size of the individual cells and the width of the xylem vessels. The end of the vase life of Gerbera and Rosa flowers was marked by an extensive water stress in the xylem vessels so that the water intake necessary for a normal flower development was insufficient and wilting ensued. The water deficit may have been enhanced by secondary biochemical and physiological interactions between the microbes and the plant tissues, which may also have affected the infiltration of micro‐organisms.
High‐performance liquid chromatographic analysis of demethylmenaquinone and menaquinone mixtures from bacteria
Authors: Hiraishi A.
Published: March 2008

Demethylmenaquinone and menaquinone mixtures from some species of enterobacteria were analysed by reverse‐phase partition high‐performance liquid chromatography. This method allowed clear separation and quantitative determination of these quinone components.
Plasmids in Staphylococcus hyicus
Authors: Noble W.C. , Rahman Mary , Lloyd D.H.
Published: March 2008

Fifty‐one strains of Staphylococcus hyicus and six of Staph, chromogenes were collected from porcine and bovine sources in England and Belgium. Antibiotic resistance and plasmid profiles were established. Plasmids associated with resistance to tetracycline, erythromycin and streptomycin were identified in many strains; these plasmids were about the same size as those mediating similar resistances in Staph. aureus of human origin. Many small cryptic plasmids were also seen.
Presence and population dynamics of Erwinia carotovora in irrigation water in south central Colorado
Authors: Maddox D.A. , Harrison M.D.
Published: March 2008

The presence of Erwinia carotovora in surface and underground (well) water was studied using filter concentration and anaerobic enrichment techniques. The organism was found in water samples collected at sites in mountainous (over 80 km from potato‐producing regions), transitional (upland) and arable regions every month in 1982 and 1983. Filter concentration and anaerobic enrichment of 3‐10 1 of water yielded E. carotovora from 82.8% of the water samples collected from streams, canals and lakes. The organism was detected by direct enrichment of 50 ml water samples in 56.3% of surface water samples collected. Erwinia carotovora subsp. carotovora was the predominant subspecies isolated. Of 1029 strains, 999 (97.1%) were identified as E. carotovora subsp. carotovora and 30 (2.9%) as E. carotovora subsp. atroseptica. Erwinia carotovora subsp. atroseptica was found primarily in water samples collected in arable regions during spring months. Erwinia chrysanthemi was never isolated. Quantitative bacteriological methods were used in 1982 and 1983 to monitor populations of E. carotovora in two streams in south central Colorado. These ranged from undetectable levels to 8.5 cfu/ml of water in Rio Grande River and Saguache Creek. Maximum populations were usually reached by August or September in both streams in both years. Erwinia carotovora was isolated from well water samples collected in the San Luis Valley, but only 15.6 and 15.4% of the samples yielded the organism during 1982 and 1983, respectively. Erwinia carotovora subsp. atroseptica was found only once, and E. carotovora subsp. carotovora was the predominant subspecies detected. Filter concentration of 3.4‐10.0 1 of water plus anaerobic enrichment of the samples was usually necessary to detect E. carotovora in well water.
The influence of pyrithione on the growth of micro‐organisms
Authors: Khattar M.M. , Salt W.G. , Stretton R.J.
Published: March 2008

Pyrithione was active against a range of micro‐organisms, the most resistant being Gram‐negative bacteria. The growth curves for Klebsiella pneumoniae and Bacillus licheniformis showed a drug‐dependent lag phase. Candida albicans grew with a drug‐dependent growth rate. EDTA antagonized the effects of pyrithione.
Use of a computer data file for storage of heat resistance data on bacterial spores
Authors: Brown K.L.
Published: March 2008

The use of a computer data file to compile published heat resistance data on bacterial spores is described. Information relating to sporulation, heating and recovery of the spores, in addition to decimal reduction times at different temperatures has been stored. The data file was constructed using Minitab and an indexer program on a VAX 11/750 computer operating on VMS. Storage of the data in this way enables rapid manipulation and analysis of large quantities of information relating to heat resistance of bacterial spores.
Methods used to investigate a possible environmental source of Mycobacterium avium‐intracellulare‐scrofulaceum (MAIS) infection in farmed deer
Authors: PROSSER B.A.
Published: March 2008

Currently used methods for the culture of mycobacteria from contaminated material were found to be unsatisfactory in an investigation of a possible environmental source of Mycobacterium avium‐intracellulare‐scrofulaceum (MAIS) infection in a New Zealand deer farm. Different combinations of established procedures were investigated using soil spiked with a laboratory strain of M. avium.

The most successful combination involved mixing the soil in nutrient broth (pH 8mD0) containing Tween 80, incubating at 37°C for 1 h to germinate sporing contaminants, treatment for 24 h with 1% cetylpyridinium chloride, followed by washing and culture on Lowenstein‐Jensen slopes and incubation at 37°C and 42°C in approximately 5% CO2 atmosphere. This procedure allowed good recovery of M. avium while successfully inhibiting saprophytic mycobacteria and other soil organisms, and was chosen to process the deer farm samples. No mycobacteria resembling the deer strains were found in these samples.
Partial immunological characterization of heat‐stable proteinases from Pseudomonas spp. of dairy origin
Authors: AZCONA J.I. , MARTÍN R. , HERNÁNDEZ P.E. , SANZ B.
Published: March 2008

A homogeneous extracellular heat‐stable proteinase from Pseudomonas fluorescens AH‐70 was used to prepare antiserum in rabbits. The rabbit antiserum was used to study the antigenic relationship of the proteinases from 26 psychrotrophic Pseudomonas spp. isolated from raw milk. The inhibition of the proteinases by the antiserum, the gel precipitin reactions and the use of a double‐antibody sandwich ELISA, revealed that proteinase AH‐70 is immunologically related to proteinases from 8/26 other Pseudomonas strains. These results also indicate that the immunological techniques for the detection of proteolytic enzymes in raw milk require antibody preparations of broader specificity.
Glutaraldehyde: its uptake by sporing and non‐sporing bacteria, rubber, plastic and an endoscope
Authors: Power E. G. M. , Russell A. D.
Published: March 2008

Uptake of glutaraldehyde to bacterial spores, germinating and outgrowing spores, vegetative cells (sporing and non‐sporing bacteria), various types of rubber, plastic and an endoscope was investigated. Escherichia coli NCTC 10418 exhibited greatest uptake, followed by Bacillus subtilis NCTC 8236 vegetative cells and Staphylococcus aureus NCTC 6571. Germinated and outgrowing B. subtilis spores adsorbed more glutaraldehyde than resting spores, but less than vegetative cells. Low concentrations of alkaline and acid glutaraldehyde increased the surface hydrophobicity and inhibited the germination of bacterial spores, the alkaline solution to a greater extent in both cases.

Rubbers exhibited varying degrees of uptake and are listed in decreasing order of uptake: red rubber, fluorinated rubber (Vinescol), silicone rubber (Silescol), butyl rubber (Butyl XX). Polypropylene, the only plastic examined, was found not to adsorb any glutaraldehyde. The endoscope adsorbed more glutaraldehyde (per gram) than fluorinated rubber but less than red rubber. No damage was observed.
Occurrence of Erysipelothrix rhusiopathiae on pork and in pig slurry, and the distribution of specific antibodies in abattoir workers
Authors: Molin G. , Söderlind O. , Ursing J. , Nørrung V. , Ternström A. , Löwenhielm C.
Published: March 2008

Strains of Erysipelothrix rhusiopathiae isolated at 19 pig farms serving a certain abattoir, and on pork and in workers of this abattoir were studied. Mouse‐pathogenic E. rhusiopathiae was found in pig slurry from two farms (11%). The strains belonged to serotypes 7 and 16 (both from the same farm) or were untypable. In pig slurry from the abattoir lairage only serotype 2 strains were found and all were pathogenic to mice. Mouse‐pathogenic E. rhusiopathiae strains of serotype 2 were also recovered from 25 pork loins (25%). A mouse‐pathogenic E. rhusiopathiae (serotype 2) strain was isolated from one of the 16 hand infections of slaughterhouse workers. The E. rhusiopathiae strains were phenotypically grouped by the API 50 CH system. Variations were demonstrated for the different serotypes. In 20 of 138 workers antibodies against E. rhusiopathiae were found; 14 had increased levels of IgG antibodies, seven had increased levels of IgM antibodies and one had an increased level of both.
A note on the isolation and propagation of lytic phages from Streptococcus uberis and their potential for strain typing
Authors: Hill A.W. , Brady C.A.
Published: March 2008

Thirty‐eight of 98 strains of Streptococcus uberis were shown to be carrying lysogenic phage. Although propagating strains were rare, host modification by field strains sensitive to phage was used to increase the lytic spectra. When 120 nationally‐collected strains were challenged with 25 phages, selected on the basis of differing lytic spectra and propagating strains, 30% were susceptible to at least one phage, increasing to 42% when 480 strains from a single farm were considered. A typing system based on susceptibility to lytic phage was considered feasible.
A procedure for urease and protein extraction from staphylococci
Authors: Sissons C.H. , Hancock E.M. , Perinpanayagam H.E.R. , Cutress T.W.
Published: March 2008

Staphylococcal cell protein and urease can be solubilized after growth in Todd‐Hewitt broth supplemented with 0.5% yeast extract by extraction for 18–24 h in phosphate buffer, pH 7.0. In general 20% (but up to 100%) of the urease present in the original cells could be solubilized. Less protein was solubilized. Species examined included coagulase‐negative staphylococci,Staphylococcus intermediusandStaph. aureus.Extracts ofStaph, epidermidisprepared by this procedure gave electrophoretic urease and protein patterns similar to those prepared by sonication. The procedure was simple and minimized handling of the cells.
Numerical analysis of electrophoretic protein patterns of Providencia rettgeri strains from human faeces, urine and other specimens
Authors: Costas M. , Holmes B. , Wood A.C. , On S.L.W.
Published: March 2008

Thirty‐one strains of Providencia rettgeri (mainly from humans) were characterized by one‐dimensional SDS‐PAGE of cellular proteins. The strains came from various countries and comprised 14 from urine, eight from faeces, two from bile (plus one from the liver of a sheep), two from sputum, one from an insect pupa and three the sources of which were unknown. Also included, for reference purposes, were the type strains of the four other Providencia species. The protein patterns, which contained 45–50 discrete bands, were highly reproducible and were used as the basis for two numerical analyses. In the first, which included all the protein bands, the 31 Prov. rettgeri strains formed 13 clusters at the 84% S level. In the second analysis, in which the principal protein bands (in the 33.3–41.3 kD range) were excluded, 29 of the 31 Prov. rettgeri strains formed a single cluster at the 81% S level, whilst the four Providencia reference strains remained unclustered. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of Prov. rettgeri. Reference strains of each of the 13 PAGE types identified are available from NCTC for inclusion in future studies.
The taxonomic relationship of certain environmental flavobacteria to the genus Weeksella
Authors: Botha W.C. , Jooste P.J. , Britz T.J.
Published: March 2008

Forty environmental strains and reference cultures of Flavobacterium, Cytophaga and Weeksella spp. were examined by numerical taxonomy. Twenty‐seven strains were recovered in four phena. Phena 1A and IB comprised 48% of the strains and were sufficiently similar to the genus Weeksella as to suggest possible inclusion in this genus. They could not be accommodated in the existing species W. virosa and W. zoohelcum. Strains from phenon 2 appear to belong neither in the Flavobacterium or the Weeksella genus. Although no reference strains were included in phena 3 and 4 they appear phenotypically to be most similar to F. breve and F. odoratum respectively.
Enumeration of some microbial groups in thermophilic poultry waste digesters and enrichment of a feather‐degrading culture
Authors: Williams C.M. , Shih J.C.H.
Published: March 2008

Methane‐producing, cellulolytic, feather‐degrading, and total anaerobic microbial populations were enumerated in four laboratory‐scale (l l) thermophilic (50°C) poultry waste digesters over a 40d period. Four different operation conditions were: 5 d retention time (RT), 6% volatile solids (VS); 5 d RT, 3% VS; 10 d RT, 6% VS; and 10 d RT, 3% VS. Laying hen manure was the sole source of substrate and micro‐organisms. At theoretical steady state (day 40) the biogas volumetric rate was near 3.0 l/l digester volume (l/l/d) in all but the 10 d RT, 3% VS digester which was 2 l/l/d. The total viable anaerobic population was > 106 cfu/ml digester fluid at the first sampling and stabilized at 107–108 cfu/ml between days 20 and 40 in all digesters. Methane‐producing bacteria increased from ≤ 10/ml early in the sampling period to 105/ml at steady state in all but the 5 d RT, 3% VS digester which was highest at 107/ml. Cellulolytic micro‐organisms were low throughout the 40 d, generally less than 10/ml. Feather‐degrading micro‐organisms ranged from near 102–105 at steady state and were decreasing in number near day 40 in all but the 10 d RT, 6% VS digester which maintained 105/ml after day 20. A feather‐degrading culture was enriched from this digester and subsequently adapted to grow in a medium with feather as the sole source of carbon. Results of this study provide information regarding potential biological upgrading of poultry waste digesters for increased operational efficiency and potential industrial application of a feather‐hydrolytic micro‐organism.
Rapid flow cytometric studies of Borrelia burgdorferi phagocytosis by human polymorphonuclear leukocytes
Authors: Banfi Elena , Cinco M. , Perticarari S. , Presani G.
Published: March 2008

The interactions between a strain of Borrelia burgdorferi and human polymorphonuclear leukocytes were studied by flow cytometry in the presence of specific or non‐specific opsonizing factors. The capacity of the borrelias to stimulate leukocyte metabolism was also investigated. The results indicated that a low phagocytosis by isolated purified polymorphonuclear leukocytes did occur in the presence or absence of specific antibodies. Within whole blood the percentages of phagocytosting leukocytes increased in the presence of non‐specific opsonizing factors. No stimulation of the oxidative metabolism stimulated by Borrelia was observed and PMA or zymosan stimulation of leukocytes was inhibited by the spirochaetes.
A note on the inhibition of cellulase binding to protein‐extracted lucerne fibre by denatured enzyme
Authors: Stutzenberger F.
Published: March 2008

Protein‐extracted lucerne fibre rapidly bound Trichoderma reesei cellulases. The presence of denatured cellulase proteins inhibited both the binding and catalysis by active enzyme. This inhibition indicates that accumulation of denatured cellulase during repeated recycling in biomass conversion processes would progressively diminish the ability of the fibre to recover active enzyme from the product stream.