bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification and distribution ofFlavobacterium meningosepticumin clinical material
Authors: Holmes B.
Published: March 2008

During the 19 year period ending December 1984, 82 (1.7%) of 4840 strains of Gram‐negative non‐fermentative bacteria submitted to the National Collection of Type Cultures (NCTC) for computer‐assisted identification wereFlavobacterium meningosepticum.These figures suggest either thatF. meningosepticumoccurs only rarely in clinical material in the UK, or that when it does occur it is not always recognized. The sources from which the NCTC strains were isolated are reported and also the characteristics by which the species may be identified. The clinical significance ofF. meningosepticumis reviewed, particularly its role in neonatal meningitis, of which there have been but two reported cases in the UK, both imported. The susceptibility of the species to antimicrobial agents is discussed and also antimicrobial therapy of neonatal meningitis due to this species.
The growth and nutrition of Clostridium sporogenes NCIB 8053 in defined media
Authors: Lovitt R. W. , Morris J. G. , Kell D. B.
Published: March 2008

Various defined and minimal media are described for the growth of Clostridium sporogenes NCIB 8053. The organism requires 10 amino acids and one vitamin for growth, whilst three other vitamins are growth stimulatory. L‐α‐hydroxy acid analogues can replace eight, and fatty acid analogues four, of these amino acids. The organism may generate free energy by a variety of Stickland reactions. Most Stickland acceptors, but not glycine, stimulate the growth of this organism on glucose. Nonetheless, cells grown in the presence of glycine will reductively deaminate it. The media described support the growth of several other strains of this species. The simplified growth media which we have developed permit quantitative studies of the physiology of this organism.
The physiology of Clostridium sporogenes NCIB 8053 growing in defined media
Authors: Lovitt R. W. , Kell D. B. , Morris J. G.
Published: March 2008

The physiology of Clostridium sporogenes was investigated in defined, minimal media. In batch culture, the major end products of glucose dissimilation were acetate, ethanol and formate. When L‐proline was present as an electron acceptor, acetate production was strongly enhanced at the expense of ethanol. As judged by assay of the relevant enzymes, glucose was metabolized via the Embden‐Meyerhof‐Parnas pathway. The growth energetics of Cl. sporogenes were investigated in glucose‐ or L‐valine‐limited chemostat cultures. In the former case, the addition of L‐proline to the medium caused a significant increase in the molar growth yield (as calculated by extrapolation to infinite dilution rate). This finding adds weight to the view that the reduction of L‐proline by Cl. sporogenes is coupled to the conservation of free energy.
A bacterium yielding a polysaccharide with unusual properties
Authors: Anson Avril , Fisher P. J. , Kennedy A. F. D. , Sutherland I. W.
Published: March 2008

A yellow‐pigmented bacterium, isolated in Czapek‐Dox medium, yielded copious quantities of extracellular polysaccharide. Liquid cultures became bright yellow and increasingly viscous after incubation for 4–6 d. Characterization tests indicate that it is a starch‐negative (amylase‐negative), gelatinase‐positive strain of Pseudomonas paucimobilis, closely resembling an organism previously described as Pseudomonas elodea. The polysaccharide contained L‐rhamnose and D‐glucose in a molar ratio of 0.66 : 1.0, together with 16% D‐glucuronic acid and 10.4% acetate. Solutions of the polysaccharide were highly viscous: certain ions tended to cause gelation of aqueous solutions. After deacetylation with mild alkali the polymer at a concentration of 0.8% yielded a strong gel.
A study of thermophilic campylobacters in a river system
Authors: Bolton F. J. , Coates D. , Hutchinson D. N. , Godfree A. F.
Published: March 2008

Fifteen kilometres of a river system traversing rural and urban areas and subject to sewage works effluent discharge was studied during a 12 1/2 month period. A total of 312 samples was collected from 12 sites at 14 d intervals and tested by a glass microfibre filtration method and a most probable number (MPN) method. Campylobacters were found in 43% of samples by the filtration method and 21% by the MPN method. The lowest frequency of isolation and lowest counts (<10 campylobacters/100 ml) were associated with samples collected from rural sites and fast‐flowing stretches of river. The greatest frequency of isolation and highest counts (< 10–230 campylobacters/100 ml) were associated with sites adjacent to or downstream of sewage works. There was an obvious seasonal trend; most isolations and highest counts were obtained in late autumn and winter, and fewest isolations and lowest counts in spring and summer. Surface water run‐off from adjacent farmland following heavy rainfall also increased the counts of campylobacters in the river system. Biotyping of isolates demonstrated that the most prevalent Campylobacter sp. was Campylobacter jejuni but C. coli, C. laridis and a previously unrecognized group of campylobacters were also isolated. Serotyping differentiated 14 serotypes of C. jejuni, 11 of C. coli and two of C. laridis. Furthermore, serotypes of C. jejuni commonly isolated from enteritis in man were frequently found in river water tested during this study.
A note on the use of the Catalasemetre in assessing the quality of milk
Authors: Phillips J. D. , Griffiths M. W.
Published: March 2008

The Catalasemetre, for assessing the quality of raw and pasteurized milk, has been studied. No correlation was found between catalase activity and bacterial counts for farm bulk tank milks within the range 5.2 ± 102‐5.4 ± 105 cfu/ml. Similarly, no relation was observed between catalase activity and somatic cell counts of milk (range of counts from 0.08 to 3.5). However, the catalase activity and bacterial count of pasteurized milks which had been pre‐incubated at 21.C for 25 h in the presence of crystal violet‐penicillin‐nisin to inhibit Gram‐positive bacterial growth were significantly related. Thus, the use of this pre‐incubation procedure coupled with the Catalasemetre to estimate bacterial growth, has potential in assessing the keeping quality of pasteurized milk samples within 25.5 h of production. Results on the thermostability of native milk catalase are also presented.
Comparison of populations of human faecal bacteria before and after in vitro incubation with plant cell wall substrates
Authors: Slade Annette P. , Wyatt G. M. , Bayliss Catherine E. , Waites W. M.
Published: March 2008

Human faecal slurries were incubated anaerobically with larchwood xylan, oat spelt xylan, wheat bran, apple cell walls or sugar beet pulp as sole carbon sources. The populations which developed during incubation were different from the inoculum, the most marked changes being an increase in the number of Bacteroides species and a decrease in the number of Fusobacterium species for all carbon sources tested. With a water‐soluble preparation of larchwood xylan the population was dominated by species able to ferment this substrate, in contrast to the population which developed with the insoluble substrates. The ability to use one plant cell wall substrate appeared to be related to the ability to use others. Strains capable of using plant cell wall substrates included Bacteroides spp., Clostridium clostridiiforme, Bifidobacterium longum, Fusobacterium spp. and Escherichia coli. When incubation with two contrasting substrates (bran and larchwood xylan) was replicated, the populations which developed were reproducibly different from the inoculum and from each other.
Multi‐stage chemostat investigation of interspecies interactions in a hexanoate‐catabolizing microbial association isolated from anoxic landfill
Authors: Coutts D. A. P. , Senior E. , Balba M. T. M.
Published: March 2008

Spatial separations of physico‐chemical environments (habitat domains) with maintenance of overlapping zones of influence (activity domains) with multi‐stage chemostat models were used to facilitate examination of interspecies interactions within a hexanoate‐catabolizing microbial association isolated from anoxic landfill. Under a constant dilution rate regime, in the presence of 1.4 and 5 mmol/l influent sulphate, consolidation of the major metabolic events of hexanoate catabolism, sulphate reduction, acetogenesis and methanogenesis took place in the first vessel of a five‐vessel array suggesting considerable overlap of activity domains or localization around the habitat domains. Evidence of partial competitive displacement was not apparent until 10 mmol/l of sulphate was used. Introduction of a non‐constant dilution rate regime to a three‐vessel model, subjected to an influent sulphate concentration of 1.4 mmol/l, effected the displacement of the methanogenic species and, as a consequence, in the presence of sulphate limitation, CO2 reduction became the major sink for excess electrons generated from hexanoate oxidation. A hypothetical scheme of anaerobic hexanoate catabolism by the interacting microbial association was developed.
Factors affecting the germination of spores of Bacillus anthracis
Authors: Titball R. W. , Manchee R. J.
Published: March 2008

Spores of Bacillus anthracis germinated poorly at high cell densities unless the alanine racemase inhibitor O‐carbamyl‐D‐serine was added to the germination medium. Spores derived from a variety of strains of B. anthracis germinated optimally at 22°C. No correlation was found between rate of spore germination and virulence or between susceptibility of animal species to anthrax and spore germination rate using sera from those animals as the germination medium.
Ampicillin‐dextrin agar medium for the enumeration of Aeromonas species in water by membrane filtration
Authors: Havelaar A. H. , During M. , Versteegh J. F. M.
Published: March 2008

Published selective media were evaluated for the isolation of Aeromonas spp. from environmental samples by membrane filtration. Satisfactory recoveries were obtained only with mA agar (Rippey & Cabelli) and dextrin‐fuchsin‐sulphite agar (Schubert), but neither was sufficiently selective. The positive aspects of these two media were combined in a new medium, ampicillin‐dextrin agar. Recovery from pure cultures and environmental samples was optimal at an ampicillin concentration of 10 mg/l and incubation for 24 h at 30°C under aerobic conditions, and specificity was high (i.e. confirmation rate usually <90%, no false negative colonies encountered). The medium can also be used for isolation of Aeromonas spp. from sea water provided that the vibriostatic agent 0/129 is added at 50 mg/1.
Mutual and self‐sensitivity among antibiotically active mutant derivatives from the inactive degenerate Aspergillus versicolor N5
Authors: Basu S. , Majumdar S. , Das S. K. , Bose S. K.
Published: March 2008

Antibiotically active producer mutants derived from the spontaneous degenerate parent Aspergillus versicolor N5 possessed not only mutual but also self‐sensitive activity. The producer mutants, like the inactive parent, were only 3·5‐fold less sensitive than the most sensitive unrelated organism, Trichophyton rubrum. The germination of spores is generally more sensitive than growth of vegetative cells. The antifungal spectrum of these mutual and self‐sensitive mutants was fairly wide, unlike the host range specificity of bacteriocinogenic strains acting on organisms closely related to the producers. The self and mutual growth inhibitory principle was finally identified as the antibiotics mycoversilin and versilin in the case of producer mutants (N5)17 and N5T10(7), respectively, or Vx, an antibiotic of unknown molecular species, in the case of another producer mutant N5T10(8). Thus self‐sensitivity, instead of self‐resistance, of these antibiotically active mutant derivatives is a unique property among filamentous fungi in having simultaneously expressed two loci of contradictory functions, one for synthesis of, and the other for sensitivity towards, the same or related antibiotics.
Pathogenicity of soft rot erwinias to potato plants in Scotland and Israel
Authors: Pérombelon M. C. M. , Lumb V. M. , Zutra D.
Published: March 2008

The pathogenicity of Erwinia carotovora pv. carotovora, E. carotovora pv. atroseptica and E. chrysanthemi to potato plants was examined in experimental and commercial crops in Scotland and Israel in 1983 and 1984. Symptoms caused by the three erwinias tended to be different depending on when they were expressed during the different growing seasons. Field symptoms were grouped into four types based on the origin and extent of stem rot and of leaf desiccation. Most were reproduced on inoculated potted plants held under different combinations of relative humidities (ca 70 and ca 100%) and temperatures (17° and 30°C). In plots planted with seed inoculated with E. c. atroseptica alone or together with E. c. carotovora or E. chrysanthemi (in Israel only), stem rot symptoms developed throughout the growing season in Scotland (Invergowrie) but only before May in February‐sown crops and after November in September‐sown crops in Israel (Negev). In contrast, E. chrysanthemi alone or together with one or the other erwinias in Israel caused extensive leaf desiccation with no stem rot only in May and before December in the spring‐and autumn‐sown growing seasons, respectively. None of 13 E. c. carotovora strains inoculated into erwinia‐free tubers was pathogenic in the spring growing season in Israel. More than one erwinia type was frequently present in both healthy and diseased stems, usually the same bacteria which were inoculated in ihe seed tubers. Isolations made from diseased stems showed that the temporal patterns of detection frequency of E. c. atroseptica and E. chrysanthemi in stem rots and in plants with leaf desiccation symptoms were similar to those for expression of the two symptom types. Erwinia carotovora pv. carotovora alone was never found in diseased stems although it could be isolated together with the other erwinias in both Scotland and Israel. Similar results were obtained when diseased stems from commercial potato fields were examined, except that E. c. carotovora was the sole erwinia present in aerial stem rots. The patterns observed in the pathogenicity of three erwinias were tentatively explained in terms of temperature changes during the growing season, the transition points being in the region of 20°C for maximum soil temperature at tuber depth or 25°C for maximum air temperature above which E. c. atroseptica and below which E. chrysanthemi were not apparently pathogenic.
Design and performance of a new medium for the quantitative recovery of Staphylococcus aureus from recreational waters
Authors: Borrego J. J. , Florido J. A. , Mrocek P. R. , Romero P.
Published: March 2008

Several reports have suggested that staphylococci, and especially Staphylococcus aureus, are useful indicators of pollution of recreational waters. The lack of a selective, accurate and reliable recovery system for the quantification of Staph. aureus from water has been the principal obstacle to the evaluation of their use as indicators. In this study, several inhibitory substances and different nutrient sources have been evaluated for the formulation of a new selective medium. The medium designed, BFR‐0 agar, recovers more than 75% of staphylococci and allows Staph. aureus to be identified.
Isolation ofYersinia enterocoliticafrom the faeces of diarrhoeic swine
Authors: Zheng X. B.
Published: March 2008

In April and May 1983, a total of 124 samples of faeces from 124 swine was examined for the presence ofYersinia enterocoliticaby a variety of isolation procedures. The organisms were recovered from 48˙4% of the swine, which all had diarrhoea. The strain belonged to serotypes 0: 3 and 0: 9 which are considered to be pathogenic for humans.
A note on hydrolysis of tributyrin by Branhamella and Neisseria
Authors: Riley T. V.
Published: March 2008

Sixty‐three strains of Branhamella and Neisseria were tested by two methods for their ability to hydrolyse glycerol tributyrate. After the conventional plate test, gas liquid chromatographical (GLC) analysis of the agar medium was carried out to detect the hydrolysis product, butyric acid, and other volatile fatty acids. All strains of Branhamella catarrhalis, Neisseria caviae, N. cuniculi and N. ovis but no other Neisseria spp. gave positive results with the conventional test. With GLC, however, most strains of Branhamella and Neisseria were shown to liberate butyric acid. In addition, some strains liberated acetic and isovaleric acids. Greater amounts of butyric acid were produced by clinical strains, in particular B. catarrhalis, compared with reference strains. It was concluded that the conventional plate test for tributyrin hydrolysis differentiates B. catarrhalis, N. caviae, N. cuniculi and N. ovis from other Neisseria.
A modified Kelsey‐Sykes method for testing disinfectants with 2,3,5‐triphenyltetrazolium chloride reduction as an indicator of bacterial growth
Authors: Mattila T.
Published: March 2008

Different dilutions of chlorhexidine gluconate were tested by the Kelsey‐Sykes procedure. The method was further modified on microtitration plates using 2,3,5‐triphenyltetrazolium chloride (TTC) reduction as an indicator of bacterial growth. There was a good correlation with the results based on TTC reduction and the conventional method based on turbidity changes caused by bacterial growth. Furthermore, the modified method using TTC reduction is more rapid and can be read by the naked eye because of the red colour.
Proficiency testing of water microbiology laboratories in The Netherlands
Authors: Havelaar A. H. , Hogeboom W. M. , Sekhuis V. M. , VAN Erne E. H. W.
Published: March 2008

In a 3‐year period, four series of simulated water samples containing selected test strains were distributed to more than 50 laboratories in The Netherlands for bacteriological testing. Participating laboratories examined the samples by enrichment or membrane filtration methods, or both, for total coliform organisms, thermotol‐erant coliform organisms, faecal streptococci and standard plate counts (37˙ and 22˙C) according to Dutch standard methods. The results were quantitatively satisfactory: the distribution of positive and negative results with subsamples conformed to stochastic variation; the standard deviation of membrane or plate counts was usually in the range which may be expected from a Poisson distribution, and there was good correspondence between average counts in participating laboratories and those expected from controls in the organizing laboratory. Problems of a qualitative nature were frequently encountered, however. Among them were a false positive response with a strain of Enterobacter cloacae in the thermotolerant coliform test; a false positive result with Clostridium perfringens in enrichment tests for total or thermotolerant coliform organisms and false positive results with Micrococcus varians in the faecal streptococcus test by membrane filtration. It is concluded that quality assessment should be a consistent activity in water microbiology laboratories. For this purpose, stable and well characterized reference materials are needed.
Enrichment of an alkaline‐adapted association of streptococci and lactobacilli
Authors: Suhaimi M. , Bruyneel B. , Verstraete W.
Published: March 2008

By gradually increasing the starting pH during subsequent enrichment test runs, an association of lactic acid bacteria adapted readily to alkaline pH values. An association of homofermentative lactobacilli and streptococci capable of initiating growth at pH 10˙0 and rapidly producing lactic acid (3˙11 g/l/d) down to a final pH of ca 4˙0 was thus obtained. The streptococci present in the enriched association were capable of growing at pH 9˙5, whereas the lactobacilli were only capable of surviving at such high pH values.
Ensilage of ammonia‐treated straw in combination with whey by means of alkaline‐adapted lactic acid bacteria
Authors: Suhaimi M. , Bruyneel B. , Verstraete W.
Published: March 2008

A lactic acid‐producing bacterial association, adapted to alkaline conditions up to pH 10˙0, was tested for its effectiveness as an inoculum for ammonia‐treated straw combined with whey. The association proved capable of lowering the pH from 8˙0 to 5˙0 within 2 d, as opposed to about 4 d by the individual populations. In the silage inoculated with the association, the lactic acid content was 98 mg/g dry matter (DM) and no butyric acid was formed. In the non‐inoculated control, only 40 mg lactic acid/g DM was formed but the butyric acid amounted to 45˙5 mg/g DM. The association appeared to counteract clostridial growth effectively.
Influence of continuous challenge via the feed on competitive exclusion of salmonellas from broiler chicks
Authors: Impey C. S. , Mead G. C. , Hinton M.
Published: March 2008

In three replicate trials, chicks were treated orally with a culture of caecal contents from an adult hen and then exposed to continuous challenge from a strain of Salmonella kedougou incorporated in feed at a level of ca 102/g. The contaminated feed was introduced at intervals from 0 to 48 h after treatment. Under these conditions, only one of 119 chicks in 12 separate groups was salmonella‐positive at 7 d, compared with 36 of 119 controls, but thereafter protection was less consistent and in some cases the subsequent incidence of infected birds increased during the 3‐week rearing period. At 21 d, 14 of 60 treated chicks were positive and 32 of 59 controls. Protection was more evident in chicks challenged 24 or 48 h after treatment than in those groups which received the salmonella‐contaminated feed at 0 or 5 h and even untreated, control chicks showed greater resistance to salmonella infection from 24 h onwards. In some control and treated groups containing salmonella‐positive birds, contamination of the litter reached ca 106 salmonellas/g, thus providing a considerable secondary challenge. Introduction of salmonellas via contaminated feed probably reduces the efficacy of protective treatment under field conditions and helps to explain the more limited success in commeicial use.
On the statistical evaluation of adherence assays
Authors: Woolfson A. D. , Gorman S. P. , Mccafferty D. F. , Jones D. S.
Published: March 2008

Parametric (unpaired t‐test) and non‐parametric (Mann‐Whitney U‐test) methods have been used in the evaluation of adherence assays on the non‐antibiotic antimicrobial agent, Taurolin. In all but one case, where the anti‐adherence effect was known to be marginal, both statistical methods gave similar results although there were some minor differences in the levels of significance achieved. The effect of the agent on the deviation of adherence data from normality was quantified by calculation of the skewness coefficient for each data set. A significant anti‐adherence effect appears to result in a decrease in the skewness of the adherence assay data. It was concluded that either parametric or non‐parametric statistical evaluation of adherence assay data is valid for large numbers of observations. In future studies of this type it is suggested that attention should also be given to the effect of the anti‐adherence agent on the deviation of adherence data from normality as denoted by the skewness coefficient.
Protective antibodies in human sera against encapsulated strains of Staphylococcus epidermidis
Authors: Ichiman Y. , Yamada T. , Yoshida K.
Published: March 2008

Passive protective antibodies in 100 samples of normal human sera against challenge with three representative capsular type strains of Staphylococcus epidermidis in mice were examined. Six of them passively protected mice against capsular type I; 17 protected against capsular type II; one against capsular type III; and one against both capsular types I and II. The activities were sensitive to 2‐mercaptoethanol and were absorbed out either with rabbit anti‐human IgG serum, rabbit anti‐human IgA serum or rabbit anti‐human IgM serum. Also, the sera activities absorbed out with cell surface polysaccharide extracted from three representative capsular type strains. These results indicate that the protective activities were specifically related to three major immunoglobulins against the above cell surface polysaccharides.
Effects of pCO2 on the growth and metabolism of Clostridium sporogenes NCIB 8053 in defined media
Authors: Dixon N. M. , Lovitt R. W. , Kell D. B. , Morris J. G.
Published: March 2008

The effects of the partial pressure of carbon dioxide (pCO2) on the growth rate of Clostridium sporogenes NCIB 8053 in batch culture were investigated in defined minimal media. Depending upon the growth medium, CO2 was stimulatory or inhibitory to growth. The absolute CO2 requirement for growth displayed by Cl. sporogenes in certain media was shown to be due to the involvement of CO2 in the synthesis of branched‐chain amino acids. High concentrations of CO2 were growth inhibitory except in complex media. In media where an optimal pCO2 was observed it was approximately 0˙45 atm. The pattern of fermentation end‐products displayed by this organism was also modified by the pCO2. The equilibria of the different species of ‘CO2’ present in microbiological media are described. Finally, the metabolic control theory of Kacser, Burns, Heinrich and Rapoport has been applied to the results obtained, to provide a quantitative description of the effects of pCO2 on the growth rate of Cl. sporogenes.
Frequency of Erwinia carotovora in the Alyth Burn in eastern Scotland and the sources of the bacterium
Authors: Perombelon M. C. M. , Hyman L. J.
Published: March 2008

Contamination of the Alyth Burn by Erwinia carotovora was monitored monthly over 2 years at nine sites spread over a distance of ca 20 km. The bacterium was detected only once in the upper reaches of the river where it flows in uninhabited moorland but frequency of detection and contamination level tended to increase progressively as the river flowed through the middle reaches mostly in grassland to the lower reaches in arable land where the bacterium was almost always present. Erwinia populations rose from < 102 cells/1 before May to frequently > 103 but < 104 cells/l thereafter at sites in the arable land zone. A similar pattern was found in the grassland zone except that erwinia numbers were lower. Erwinia numbers at one site in the arable land zone were positively and negatively correlated with the river water temperature and flow rate respectively when there was a 1 month lag between the environmental data and the population recorded. More than 80% of isolates tested were E. carotovora subsp. carotovora.

Water from field drains in arable fields, especially those recently planted with potatoes, was frequently contaminated by E.c. carotovora, with numbers and a temporal pattern similar to those of the Alyth Burn. Drainage water from non‐arable fields was rarely contaminated. Infected and rotting potatoes deposited in rivers temporarily contaminated the water. Survival of E. carotovora in dilute phosphate buffer was greater at pH 5˙7 than at pH 7˙7 and they survived for at least 10 d in river water.
Some modification to the media for rapid automated detection of salmonellas by conductance measurement
Authors: Gibson D. M.
Published: March 2008

A selenite medium for the automated detection of salmonellas by conductance measurements has been modified to eliminate the negative results given by some dulcitol‐negative strains. The dulcitol is replaced with mannitol and pre‐enrichment is best done in buffered peptone water containing mannitol and dimethylsulphoxide. It is suggested that both versions of the selenite medium be used initially.
Acetogenesis and acetotrophy in a hexanoate‐catabolizing microbial association isolated from anoxic landfill
Authors: Coutts D. A. P. , Balba M. T. M. , Senior E.
Published: March 2008

Metabolism of the key intermediates, acetate and hydrogen, in anaerobic hexanoate catabolism by an interacting microbial association isolated from a landfill was examined in the presence of sulphate. Hydrogen (the β‐oxidation product of hexanoate and butyrate), was competitively utilized by the component sulphate‐reducing bacteria whereas in the absence of sulphate an interaction between H2‐utilizing acetogenic and methanogenic bacteria facilitated H2 removal, with acetate catabolism restricted to methanogenic bacteria. A possible mechanism for energy conservation was suggested in which excess electrons were stored as acetate for subsequent usage as an energy source.
Serological and biochemical variation among potato strains of Erwinia carotovora subsp. atroseptica and their taxonomic relationship to other E. carotovora strains
Authors: Boer S. H. De , Verdonck L. , Vruggink H. , Harju P. , Bång H. O. , Ley J. De
Published: March 2008

The serological and biochemical characteristics of 32 Erwinia carotovora subsp. atroseptica strains from potato were compared with 48 other pectolytic Erwinia strains. Biochemical characteristics were examined by the API 20E and API 50CHE systems. Numerical analysis using the Euclidean distance coefficients and clustering by the unweighted average pair group method indicated that these E. carotovora subsp. atroseptica strains formed a distinct cluster (subphenon A1) that could be differentiated from other E. carotovora strains. Three non‐potato strains also belonged to this group; two of these were from tomato and the other from Chinese cabbage. Named E. carotovora subsp. atroseptica strains from other hosts clustered into other phenons. Sixty‐three per cent of subphenon A1 strains tested in this study typed into serogroup I. One potato strain in another phenon also typed into this serogroup. The subphenon A1 strains that did not type into serogroup I typed into serogroups XVIII, XX, or XXII. Many of these strains, however, expressed several different O antigens which were also expressed by E. carotovora strains in other phenons.
Mutagenesis of Clostridium butyricum
Authors: Carrasco Alicia , Soto C.
Published: March 2008

Mutagenesis of Clostridium butyricum ATCC 19398 was best accomplished by u. v. irradiation (254 nm) and methyl methane sulphonate. Nitrosoguanidine was only slightly mutagenic for this organism. Procedures are described which yielded a variety of auxotrophic and antibiotic‐resistant mutant strains.
Effect of the method of preparation of Bacille Calmette‐Guérin (BCG) vaccine on the properties of four daughter strains
Authors: Abou‐Zeid C. , Rook G.A.W. , Minnikin D.E. , Parlett J.H. , Osbornt T.W. , Grangets J.M.
Published: March 2008

Samples of Bacille Calmette‐Guerin (BCG) vaccines from four collaborating production laboratories, each of which had prepared vaccine from four different daughter strains of BCG, had previously been monitored for changes in colony morphology and the present study was undertaken to determine whether the changes observed were reflected in the patterns of protein secretion and lipid content. In the samples examined there was evidence for a correlation between colony morphology and the presence or absence of mycoside B. As the components of BCG that determine virulence and protective immunity are unknown, care must be taken to ensure constancy of the strains during the manufacture of vaccines.
Comparison of in vitro activity of niridazole, metronidazole and tetracycline against subgingival bacteria in chronic periodontitis
Authors: Wade W.G. , Addy M.
Published: March 2008

Niridazole, metronidazole and tetracycline were compared for their activity against subgingival bacteria from patients with chronic periodontitis. Niridazole was consistently more effective than the other drugs against obligate anaerobes and exhibited some activity against facultative organisms. It was concluded that niridazole has potential for topical use in chronic periodontitis.
Affinity purification of tetanus toxin using polyclonal and monoclonal antibody immunoadsorbents
Authors: Sheppard A. J. , Hughes M. , Stephen J.
Published: March 2008

Tetanus toxin has been immunopurified on immunoadsorbent columns derived from equine polyclonal antitoxin coupled to cyanogen bromide‐activated Sepharose CL4B. Desorption of bound toxin in active form was achieved only when the immunoadsorbent was mixed with Sephadex G15 and this mixture overlaid on a further volume of Sephadex G15. With equine antibody, 64% of adsorbed toxin was recovered with a specific activity of 2400 limiting flocculation units (Lf)/mg protein N (1.2 × 108 minimum lethal doses (MLD)/mg protein N). Similarly prepared immunoadsorbent derived from murine monoclonal antitoxin of low affinity had improved desorption with less acidic desorbents, without the requirement for Sephadex G15; greater than 80% of adsorbed toxin was recovered with a specific activity of 3000 Lf/mg protein N (1.6 × 108 MLD/mg protein N).
Use of iso‐osmolality plots to characterize yeast fermentative performance
Authors: Jones R. P.
Published: March 2008

Yeast fermentation data (ethanol product, P, vs glucose substrate, S) can be plotted on a graph showing lines of equivalent osmolality or water activity. Comparison of such plots for different strains and for single strains under different environmental conditions shows the conditions for optimum performance. With these plots the product/substrate yield coefficient (Yp/s) can be shown to vary with time, contrary to its usually assumed constant value. Under conditions of optimum environment and nutrition, five of the yeast strains tested ceased growing at a characteristic value of solution osmolality, indicating that the inhibitory effects of ethanol and glucose, to a first approximation, are the result of their molar contribution to water activity rather than due to any specific cellular effect. In one yeast strain this characteristic behaviour was not affected by temperature variations between 30° and 36°C.
A comparative study of the formation of extracellular proteins byAeromonas salmonicidaat two different temperatures
Authors: Fyfe Lorna , Coleman G. , Munro A. L. S.
Published: March 2008

Aeromonas salmonicidawas grown in a supplemented 3% (w/v) tryptone soya broth medium at 10°C, a temperature at the lower end of the range over which furunculosis has been observed to occur in the field, and 25°C, the optimum temperature for growth. Similar bacterial densities in the range 2.35 × 0.05 mg dry wt/ml were achieved in the two cultures at the beginning of the stationary phase of the growth cycle, after 125 h at 10°C and 18 h at 25°C. At this point, at the higher temperature 1.5 times more exoprotein was formed, 80 × 2.8 μg/ml compared with 54 × 1.7 μg/ml. Exoprotein contained the same proportion of haemolysin at both temperatures and twice as much protease at the higher temperature. The most marked difference was in an unidentified 100 kD protein which was formed in a 10‐fold greater amount at 10°C.
Cell surface characteristics of some phage‐resistant strains of Lactobacillus casei
Authors: Watanabe K. , Ishibashi K. , Iki K. , Nakashima Y. , Hayashida M. , Amako K.
Published: March 2008

The cell surface characteristics of two types of PL‐1 phage‐resistant strains of Lactobacillus casei: K‐12, which does not permit adsorption of the phage; and YIT 9021, which permits phage adsorption but not genome injection, were compared with those of the parent strain. There were no differences in the electron microscopic features of the cell surface. However, both the phage‐resistant strains were more hydrophobic than the parent strain as judged by hydrocarbon affinity test. A colloid titration test showed that these mutant strains were less negatively charged than the parent one. They differed in the composition of the polysaccharide of their cell walls, which were all free from teichoic acids.
Relation of the heat resistance of bacterial spores to chemical composition and structure II. Relation to cortex and structure
Authors: Mallidis C. G. , Scholefield J.
Published: March 2008

The relation between the amount of cortex, measured as total hexosamine, as diaminopimelic acid and as muramic lactam, and the heat resistance of spores of five different strains of Bacillus stearothermophilus was studied. Electron micrographs of thin sections of the spores were made to relate the structure of the spores to chemical and thermal characteristics. It was found that the amount of the cortex was significantly related to heat resistance of the spores. Strains with more electron‐dense and better organized cortices were found to express higher heat resistance.
A note on shelf‐life extension of British fresh sausage by vacuum packing
Authors: Adams M. R. , Baker T. , Forrest C. L.
Published: March 2008

Vacuum packing of British fresh sausage in a low oxygen permeability film (Diolon) extended the product shelf‐life at 6°C to more than 20 d compared with 9–14 d in conventional packs. After 10 d storage, counts of key spoilage organisms such as yeasts and Brochothrix thermosphacta were generally 2 log cycles lower in vacuum packs. Vacuum‐packed sausages also displayed a slower rate of loss of free sulphite. Variations in pack permeability to SO2 were not responsible for this. Losses of free SO2 in stored sausages are largely due to the production of sulphite‐binding agents by yeasts. Selective enumeration of these yeasts showed them to be inhibited by conditions of vacuum packing. The extension of shelf‐life observed is ascribed to the reduction in growth rate of the spoilage flora in vacuum packs coupled with the consequent maintenance of inhibitory levels of sulphite for a longer period.
Component‐specific stimulation of cellulase secretion in Thermomonospora curvata by the surfactant Tween 80
Authors: Stutzenberger F. J.
Published: March 2008

The non‐ionic surfactant, Tween 80, stimulated the secretion of extracellular proteins by 35–140% in Thermomonospora curvata during growth on a variety of substrates. Cellulase secretion was also stimulated but fractionation of extracellular proteins by ion‐exchange high performance liquid chromatography showed that this stimulation was largely confined to a single enzymatic component (or group of closely related components) active against crystalline cellulose. The surfactant's effect was more pronounced during growth on cellobiose octaacetate than on the soluble sugar, cellobiose, or on crystalline cellulose.
Quantitative measurement of endotoxin in rainbow trout (Salmo gairdneri) serum by the chromogenic substrate method
Authors: Kodama H. , Yamada F. , Kurosawa T. , Mikami T. , Izawa H.
Published: March 2008

The amount of endotoxin in serum collected from normal rainbow trout (Salmo gairdneri) and trout inoculated with viable Vibrio anguillarum or lipopolysaccharide (LPS) extracted from bacteria was determined by the chromogenic substrate method. The mean values of endotoxin in four different groups of normal rainbow trout sera ranged from 31.9 to 65.3 pg/ml. When fish were inoculated with viable bacteria (1 × 108), they became septicaemic and a large amount of endotoxin (> 14 ng/ml) was detected in the sera. In fish inoculated with a smaller number of bacteria the amount of endotoxin was several times higher than that of normal fish in spite of failure of bacterial isolation. Although the endotoxin level in serum increased rapidly (> 100 ng/ml) after intraperitoneal inoculation with purified V. anguillarum LPS (540 μg), no fish died during the experiment. The high level of endotoxin in normal rainbow trout and the resistance of trout to endotoxin are in striking contrast to those of mammalian and avian species.
Fermentation products, amino acid utilization, maintenance energies and growth yields for the fibrillar Streptococcus salivarius HB and a non‐fibrillar mutant HB‐B grown in continuous culture under glucose limitation
Authors: HARTY D.W.S. , HANDLEY PAULINE S.
Published: March 2008

The fibrillar strain Streptococcus salivarius HB and a non‐fibrillar mutant, strain HB‐B, were grown in a defined medium under glucose limitation in a chemostat. Fermentation balances were produced for both strains in batch culture and at growth rates between 0.1/h and 1.1/h. In batch culture both strains fermented glucose to lactate, but in continuous culture glucose was fermented to formate, acetate and ethanol with increasing amounts of lactate as the growth rate was increased. Lactate never became the major fermentation product even at the highest growth rate. Amino acid analysis showed that only lysine was more than 50% utilized, while proline and tyrosine showed net production. The non‐fibrillar strain HB‐B showed, in general, a reduced utilization of amino acids compared with the fibrillar strain HB. Calculated growth yields and maintenance energies for the two strains showed that there was a reduction in the true growth yield and the maintenance energy coefficient of the non‐fibrillar strain HB‐B when compared with the fibrillar strain HB. The increase in the maintenance energy of the fibrillar strain HB (1.382 mmol/g/h) when compared with the non‐fibrillar strain HB‐B (0.546 mmol/g/h) of 153% is proposed to be the energy required for the maintenance of the fibrillar surface of the cell.
Avoparcin and vancomycin: useful antibiotics for the isolation of brewery lactic acid bacteria
Authors: Simpson W. J. , Hammond J. R. M. , Miller R. B.
Published: March 2008

Vancomycin (30 μg) and avoparcin (20 μg) have no effect on growth of hetero‐fermentative lactobacilli, mesophilic homofermentative lactobacilli, Lactobacillus salivarius and bacteria of the genera Leuconostoc and Pediococcus. The growth of thermophilic homofermentative lactobacilli (with the exception of Lacto salivarius), enteric and lactic streptococci and all other Gram‐positive bacteria encountered in breweries (and likely to be encountered in foods) is inhibited by these antibiotics. The recovery of sub‐lethally stressed cells is slightly reduced by the presence of either antibiotic. Vancomycin and avoparcin are useful selective agents for the detection of lactic acid bacteria in the brewing industry and may also be of use, for quality control purposes, in the distilling, wine, cider, dairy and meat industries. These antibiotics may also find applications in differentiation of pediococci from streptococci, and in rapid identification of lactobacilli.
Monitoring for the development of antimicrobial resistance during the use of olaquindox as a feed additive on commercial pig farms
Authors: Linton A. H. , Hedges A. J. , Bennett P. M.
Published: March 2008

Since 1982, when olaquindox was introduced as a pig‐feed additive in the UK, about 12 commercial farms in Suffolk have been monitored annually to check for the possible emergence of resistance to olaquindox and chloramphenicol among the coliform flora of the pigs and their environment. In spite of the sampling variability and the impossibility of controlling the use of feed additives and management on the farms, the overall results obtained were consistent and, it is suggested, the method is widely applicable. A steady, albeit low, increasing incidence and level of resistance to olaquindox was recorded (1982–1984) on farms using it and, to a lesser degree, on neighbouring farms that did not. No significant increase in the level of chloramphenicol resistance was observed. Genetical studies on a selection of olaquindox‐resistant isolates suggested that the genes determining resistance were likely to be borne on the chromosome.
Storage effects of sewage sludge cake on the survival of Listeria monocytogenes
Authors: Al‐Ghazali M.R. , Al‐Azawi Salwa K.
Published: March 2008

Sewage sludge cake is widely used as an agricultural fertilizer in Iraq. Listeria monocytogenes was shown to be present in small numbers in this material despite sewage treatments. In an attempt to reduce the numbers of this pathogen in this sewage end product, the survival of L. monocytogenes was monitored in a heap of sewage sludge cake stored for over 23 weeks on farm land. The organisms were reduced in numbers and eliminated to undetectable limits during 8 weeks of storage under subtropical weathering and did not recover even 2 months after disappearence. Dewatering processes seem to have some affect on the survival of the bacteria. Therefore, solar dewatering by heaping the sewage sludge cake and exposing it to sun for no less than 8 weeks is recommended to obtain a listeria‐free product.
Studies on the irradiation of toxins of Clostridium botulinum and Staphylococcus aureus
Authors: Rose Sally A. , Modi N.K. , Tranter H.S. , Bailey N.E. , Stringer M.F. , Hambleton P.
Published: March 2008

The effects of irradiation of Clostridium botulinum neurotoxin type A (BNTA) and staphylococcal enterotoxin A (SEA) in gelatin phosphate buffer and cooked mince beef slurries were investigated. Estimation of toxins by immunoassays showed that in buffer, toxins were destroyed by irradiation at 8.0 kGy; in mince slurries however, 45% of BTNA and 27–34% of SEA remained after this level of irradiation. At 23.7 kGy, over twice the dose of irradiation proposed for legal acceptance in the UK, 15% of BNTA and 16–26% of SEA still remained. Increasing concentrations of mince conferred increased protection against the effect of irradiation on both toxins. The biological activity of BNTA was more sensitive to irradiation than the immunological activity. Staphylococcal enterotoxin was more resistant to irradiation than BNTA. Irradiation should therefore only be used in conjunction with good manufacturing practices to prevent microbial proliferation and toxin production prior to irradiation.
Preliminary investigation of the influence of pH on the solid‐state refuse methanogenic fermentation
Authors: Kasali G.B. , Senior E. , Watson‐Craik Irene A.
Published: March 2008

Laboratory refuse columns and bottle cultures were used to examine the responses of the interrelated metabolic processes of acid metabolism, solvent metabolism and methanogenesis of the solid‐state refuse fermentation to single initial additions of exogenous buffering capacity. Refuse samples poised at neutral and alkaline pH values, by the addition of 0.2 mol/1 phosphate buffer, were found to promote acid‐ogenesis to such an extent that methanogenesis was inhibited. The same inhibition was also apparent in the presence of acid pH regimes which were initially characterized by the accumulation of solvents. The possible implications of controlling pH by adding buffer to promote and exploit the refuse fermentation are discussed.
A selective medium for detecting yeasts capable of spoiling wine
Authors: Thomas D. Susan , Ackerman Judith C.
Published: March 2008

By careful manipulation of nutrients, pH, and ethanol concentration, a medium has been developed which permits the growth of yeasts capable of spoiling table wines yet restricts growth of other contaminants. The selectivity of the broth was evaluated using yeasts which were known to spoil, or not spoil, a variety of table wines. All of the yeasts tested that were capable of spoiling wine grew in the broth within 72 h. Over 77% of the non‐spoilers failed to grow in the broth during the 3 d incubation.

A test, using this broth, has been introduced into several wine‐bottling plants in the UK, and is proving to be a useful predictor of yeast spoilage. A pre‐enrichment medium has been formulated which ensures that stressed cells are also detected. Automation of the test, by exploiting a robotic arm and suitable photometry, is discussed. If desired, a quicker detection of wine‐spoiling yeasts can be achieved by using the medium in conjunction with rapid methods such as ATP‐assay.