bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical analysis of electrophoretic protein patterns of Group EF‐4 bacteria, predominantly from dog‐bite wounds of humans
Authors: Holmes B. , Costas M. , Wood A.C.
Published: March 2008

Thirty‐seven strains of Group EF‐4 bacteria (from various countries) were characterized by one‐dimensional SDS‐PAGE of cellular proteins. They comprised 21 from dog‐bite wounds of humans, three from cat‐bite wounds of humans and five from human limb wounds which may have been inflicted by dogs or cats; there was also one each from a pet monkey, a tiger lung (fatal), a dog tonsil, a mouse, a cat liver, a wallaby mandible, a human vagina and one from a human limb wound which was apparently not inflicted by an animal. The protein patterns, which contained 45 to 50 discrete bands, were highly reproducible and were used as the basis for three numerical analyses. In the first, in which the principal protein bands (in the 34.8 to 41.3 kD range) were excluded, the 37 Group EF‐4 strains formed, at the 62% S level, two major clusters corresponding to strains producing a dihydrolase for arginine and those not doing so. In the second analysis, which included all the protein bands and which was performed only on the 22 arginine‐positive strains, two phenons formed (one of which could be further divided into two sub‐phenons) at the 56% S level. The third analysis, also based on all the protein bands, divided the 15 arginine‐negative strains into three clusters at the 56% S level. We conclude that high resolution PAGE combined with computerised analysis of protein patterns correlates exactly with the separation of Group EF‐4 into two biovars (also with the distinction of the biovars on the basis of G+C content). Reference strains of each of the PAGE types identified are available from the NCTC for inclusion in future studies.
Characterization and distribution of lactic acid bacteria in cassava fermentation during fufu production
Authors: Oyewole O.B. , Odunfa S.A.
Published: March 2008

One hundred and thirty four lactic acid bacterial strains isolated during the 96‐h period of cassava fermentation for fufu production were identified. The spectrum and proportion of the strains include Lactobacillus plantarum, 81%; Leuconostoc mesenteroides, 16%; Lact. cellobiosus, 15%; Lact. brevis, 9%; Lact, coprophilus, 5%; Lact. lactis, 4%; Leuc. lactis, 3% and Lact. bulgaricus, 1%. The isolates were characterized into strains. The succession among the lactic isolates was established. Lactobacillus plantarum was identified as the most dominant lactic acid bacterial strain involved in the fermentation.
The incidence of Listeria spp. in soft cheeses, butter and raw milk in the province of Bologna
Authors: Massa S. , Cesaroni Daniela , Poda G. , Trovatelli L.D.
Published: March 2008

Samples of soft cheese, butter and raw milk were examined for Listeria species. Listeria monocytogenes (serotype 1, haemolytic and virulent for mice) and L. innocua (the only other Listeria sp. isolated) were each found in 2/21 (1.6%) of soft cheese samples. Five per cent of butter samples were contaminated with L. innocua. No Listeria spp. were detected in 40 raw milk samples. The results were compared with similar studies in Italy and abroad. and accepted 14 June 1989
Rapid detection of salmonellas in raw meats using a fluorescent antibody‐microcolony technique
Authors: Rodrigues Ubaldina M. , Kroll R.G.
Published: March 2008

A fluorescent antibody‐microcolony technique was developed for the rapid detection of salmonellas in pure cultures. Examination of microcolonies made the detection of salmonellas by epifluorescence microscopy easier and more reliable than using fluorescent antibody and single cells. After a study of the most effective selective enrichment media for increasing the number of salmonellas, the technique was examined with various samples of raw meats. It was able to detect salmonellas in 24 h and appeared to be as sensitive as conventional cultural techniques. Of the 101 samples studied, complete agreement was obtained with conventional methods for 94 but six apparently false positive results and one false negative result occurred. and accepted 22 June 1989
Ethanol fermentation by nystatin‐resistant strains of Saccharomyces cerevisiae
Authors: Grunwald‐raij H. , Margalith P.
Published: March 2008

Nystatin‐resistant mutants of haploid and polyploid strains of Saccharomyces cerevisiae were isolated by plating on gradient plates with increasing nystatin concentrations (60–3000 U/ml). Some of the mutants were defective in ergosterol biosynthesis, and produced zymosterol and cholestatetraenol‐like sterols. Those mutants which do not form ergosterol produce less ethanol than the parent strains. They also had lower viability during fermentation of glucose solutions (8–13% vs. 33–47%). This became more pronounced in fermentations of higher concentrations of glucose. A nystatin‐resistant but ergosterol‐forming mutant had a similar fermentation capacity to the parent strain.
Hemicellulases of Bacillus species: preliminary comparative studies on production and properties of mannanases and galactanases
Authors: Araujo A. , Ward O.P.
Published: March 2008

A range of Bacillus subtilis strains and other Bacillus species were screened for mannanase, β‐mannosidase and galactanase activities. Maximum mannanase activity, 106.2 units/ml, was produced by B. subtilis NRRL 356. β‐Mannosidase and galactanase activities from all strains were relatively low. The effect of carbon and nitrogen source on mannanase and galactanase production by B. brevis ATCC 8186, B. licheniformis ATCC 27811, B. polymyxa NRRL 842 and B. subtilis NRRL 356 was investigated. Highest mannanase production was observed in the four strains tested when the mannan substrate, locust bean gum, was used as carbon source. Induction was most dramatic in the case of B. subtilis NRRL 356 where only basal enzyme levels were produced in the presence of other carbon sources. β‐Mannosidase was induced in the four Bacillus cultures by locust bean gum. Results indicated that galactose acted as an inducer for production of galactanase. Organic and inorganic nitrogen sources resulted in induction of high mannanase titres in B. subtilis. Highest galactanase activity was produced by each organism in media containing sodium nitrate as nitrogen source. Mannanases from B. brevis, B. licheniformis, B. polymyxa and B. subtilis retained 100% residual activity after a 3 h incubation at 65°C, 65°C, 60°C and 55°C respectively. Galactanases retained more than 95% activity at 55°C after 3 h. The pH optima of mannanases ranged from 6.5–6.8 whereas galactanases ranged from 5.1 in the case of B. brevis to 7.0 for B. polymyxa.
Investigations of the effectiveness of detergent washing, drying and chemical disinfection on contamination of cleaning cloths
Authors: Scott Elizabeth , Bloomfield Sally F.
Published: March 2008

Detergent washing, drying and chemical disinfection for decontamination of cleaning cloths was investigated with cloths contaminated by use in the domestic environment. Detergent washing produced only limited reductions in microbial contamination and cloths then stored at room temperature for 24 h showed increases in contamination due to multiplication of residual survivors. For effective and consistent decontamination of cloths, detergent washing followed by drying at 80°C for 2h was required. Hypochlorite and phenolic disinfectants produced significant reductions in contamination, but chemical disinfection may be unreliable where cloths are heavily contaminated.
A note on Aeromonas spp. from chickens as possible food‐borne pathogens
Authors: Kirov S.M. , Anderson M.J. , McMeekin T.A.
Published: March 2008

The possible role of Aeromonas spp. as potential food‐borne psychrotrophic pathogens was investigated by examining organisms isolated from processed raw chicken for their biochemical characteristics, ability to produce exotoxins and to grow at chill temperatures. These strains, in particular A. sobria, with identical characteristics to human diarrhoea‐associated aeromonads were readily found. Chicken, and human and environmental (water) strains characterized in a previous study, were investigated for their ability to grow at refrigeration temperatures (5 ± 2°C) and, for selected strains, the theoretical minimum temperature for growth (Tmin) was determined from the growth pattern in a temperature gradient incubator. All enterotoxigenic chicken strains tested were typical mesophiles, with an optimal growth temperature of ˜37°C and Tmin values ˜4.5°C. They were rapidly outgrown by a psychrotrophic Pseudomonas sp. typical of spoilage biota found on food. Enterotoxin was not produced below 15°C by any of the toxigenic food strains tested. The Aeromonas strains isolated from chickens in this study seem unlikely therefore to be a significant health risk, provided the chickens are properly stored and cooked. This would appear to be substantiated by the lack of reports of food‐associated outbreaks of illness from these sources.
The aerobic psychrotrophic populations on meat and meat contact surfaces in a meat production system and on meat stored at chill temperatures
Authors: Nortjé G.L. , Nel Linda , Jordaan Erika , Badenhorst Karin , Goedhart Erna , Holzapfel W.H.
Published: March 2008

At a city abattoir, a wholesaler and 10 different supermarkets, surface microbiological samples were taken of carcasses, hands and apron fronts of members of staff and equipment (mincers and saws). In addition, minced meat, packaged and displayed in chilled cabinets, was also sampled. Carcasses, personnel surfaces and equipment were monitored by a modified agar sausage technique. From each of the highest dilution psychrotrophic plate counts, five colonies were selected randomly, isolated and identified (1265 in total). Microbes developing on chilled meat were also isolated from other surfaces in the production chain. On chilled meat (51%) and at the abattoir (36%) pseudomonads were the predominant organisms followed by the Gram‐positive cocci on chilled meat and by Acinetobacter, Moraxella and Alcaligenes spp. at the abattoir. At the wholesaler Gram‐positive cocci (32%) predominated, followed by Alcaligenes, Moraxella and Alcaligenes spp. Pseudomonas, Alcaligenes, Neisseriaceae and related genera, Gram‐positive cocci, species from the coryneform groups of bacteria and yeasts were identified from all the surfaces monitored. Identification with the API NE20 was unsatisfactory. Enterbacteriaceae, lactobacilli and endospore‐forming bacteria were identified occasionally, but their significance as contaminating organisms seems low. No Salmonella spp. were identified. and accepted 25 July 1989
Intracellular X‐prolyl dipeptidyl peptidase from Lactococcus lactis spp. lactis: purification and properties
Authors: Zevaco C. , Monnet Véronique , Gripon J.‐C.
Published: March 2008

An X‐prolyl dipeptidyl peptidase (EC 3.4.14.5) has been purified from a crude intracellular extract from Lactococcus lactis spp. lactis NCDO 763 by ion‐exchange chromatography and gel filtration. One protein band was detected after electrophoresis of the purified enzyme in the presence or absence of sodium dodecyl sulphate. The enzyme is a 190 kDa dimer composed of identical subunits. Optimal activity occurs at pH 8.5 and 40–45°C and the enzyme is inhibited by reagents specific for serine proteases, such as diisopropylfluorophosphate. The enzyme hydrolyzes p‐nitroanilide‐ or β‐naphthylamide‐substituted X‐Pro dipeptides, as well as β‐casomorphin.
Differentiation of three serovars of Malassezia furfur
Authors: Cunningham Anne C. , Leeming J.P. , Ingham Eileen , Gowland G.
Published: March 2008

Malassezia furfur strains were isolated from the clinically normal skin of 10 volunteers by swabbing four different sites (forehead, ear, back and chest). The strains could be divided into three basic groups on the basis of cultural characteristics. Both unabsorbed and absorbed specific rabbit antisera were prepared against nine of the strains, and both species and group specific antigens could be demonstrated. Serologically, three group specific surface antigens could be identified which corresponded to the three groups identifiable on cultural characteristics. The relevance of these findings to previous in vitro results is discussed.
A convenient microtitre tray procedure for yeast identification
Authors: Heard G.M. , Fleet G.H.
Published: March 2008

Media for yeast identification tests were incorporated into the wells of a microtitre tray. The tests included fermentation and assimilation of carbohydrates, assimilation of nitrogen compounds, growth in vitamin‐free medium, resistance to cycloheximide, and observations for cell morphology and sporulation. Results of tests conducted in the trays showed very good agreement with those obtained by conventional methods. Eighteen reference yeasts were correctly identified from tests conducted in the trays. The trays of media could be stored, and provided a convenient system for yeast identification.
Importance of ultrasonication conditions in recovery of microbial contamination from material surfaces
Authors: Jeng D.K. , Lin L.I. , Hervey L. V.
Published: March 2008

The conditions of ultrasonication to recover micro‐organisms from material surfaces are not standardized and often not validated. This leads to discrepancies in experimental results which can affect the sterilization dose setting, cycle development and process validation, and can have an impact on sterilization processing economics and product sterile quality. The sample loading pattern, species of micro‐organism, materials and configurations of sample containers were examined under defined conditions. All of these were found to be important factors contributing to the efficiency of microbial recovery from material surfaces by ultrasonication. Validation of sonication conditions in routine laboratory operations is therefore important for an accurate estimate of the surface contamination to assure the medical device processing and the product sterile quality.
Numerical analysis of electrophoretic protein patterns of Providencia stuartii strains from urine, wound and other clinical sources
Authors: Costas M. , Holmes B. , Wood A.C.
Published: March 2008

Eighty‐six strains of Providencia stuartii (mainly of human origin) were characterized by one‐dimensional SDS‐PAGE of cellular proteins. The strains came from various countries; 52 were from urine, 11 from wounds, five from blood (one of these also from urine), four from ear infections, two each from faeces and sputum, one from ‘alimentation’and nine from unknown sources. The protein patterns, which contained 45 to 50 discrete bands, were highly reproducible. The patterns of 46 Prov, stuartii strains (selected to represent the full range of protein pattern diversity) plus those of the type strains of the four other Providencia species were used as the basis for two numerical analyses. In the first, which included all the protein bands, the Prov. stuartii strains formed 13 clusters at the 88% S level. In the second analysis, in which the principal protein bands (in the 33.8–40.7 kDa range) were excluded, 45 of the 46 Prov. stuartii strains formed a single cluster at the 82% S level, whilst the four Providencia reference strains remained unclustered. The 40 strains of Prov. stuartii not included in the cluster analysis were assigned to a protein type by calculating their similarity with the strains in the database used for the cluster analysis. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of Prov. stuartii. Reference strains of each of the 13 PAGE types identified are available from NCTC for inclusion in future studies.
The effect of withdrawal of morpholine from the influent and its reinstatement on the performance and microbial ecology of a model activated sludge plant treating a morpholine‐containing influent
Authors: Brown V. R. , Knapp J. S.
Published: March 2008

An activated sludge plant was established which was capable of treating an influent containing morpholine. When this compound was deleted from the influent the ability of the activated sludge to degrade morpholine was reduced. This reduction took the form of an increase in the length of the lag period before morpholine degradation was detected in a die‐away test from 0 to ca 1000 h. The decreased ability of the activated sludge to degrade morpholine was accounted for by a decline in the specific population of morpholine‐degrading microbes. In this activated sludge all morpholine degraders were Mycobacterium spp. In the absence of morpholine in the influent most mycobacteria in the activated sludge retained their morpholine‐degrading phenotypes. This is despite the fact that some of these organisms can lose this phenotype when grown under non‐selective conditions. These results are discussed in relation to other work on the degradation of morpholine and to problems in the treatment of xenobiotic compounds in industrial effluents.
The effect of pH, salt concentration and temperature on the survival and growth of Listeria monocytogenes
Authors: Cole M. B. , Jones M. V. , Holyoak C.
Published: March 2008

Factorially designed experiments have been used to study the growth and survival of Listeria monocytogenes in different combinations of pH and salt concentrations at ambient and chill temperatures. Survival at low pH and high salt concentration was strongly temperature dependent. The minimum pH values that allowed survival after 4 weeks from an initial 104 cells were 4·66 at 30†C, 4·36 at 10†C and 4·19 at 5†C. These limits were salt dependent, low (4–6%) salt concentrations improved and higher concentrations reduced survival at limiting pH values. The lowest pH that allowed a 100‐fold increase in cell numbers within 60 d was 4·66 at 30†C but this was increased to 4·83 at 10†C. At 5†C growth occurred at pH 7·0 but not at pH 5·13. Simple predictive models describing the effect of hydrogen‐ion and salt concentration on the time for at least a 100‐fold increase in numbers at 10†C and 30†C were constructed after analysis of the results for a least squares fit to a quadratic model. The interactions between salt and hydrogen‐ion concentration on growth were found to be purely additive.
Iron complexation as a tool to direct mixed clostridia—lactobacilli fermentations
Authors: Bruyneel B. , Woestyne M. Vande , Verstraete W.
Published: March 2008

Iron complexation was investigated as a possible tool to give lactobacilli a competitive advantage over clostridia. The iron complexing substance tested, i.e. 2,2′‐dipy‐ridyl, was not toxic itself for clostridia, but its addition to a mixed culture of lactobacilli and clostridia resulted in a strong ecological advantage of the lactobacilli.
Lectin of Sclerotium rolfsii: its purification and possible function in fungal‐fungal interaction
Authors: Barak R. , Chet I.
Published: March 2008

The soil‐borne plant pathogenic fungus, Sclerotium rolfsii, produces a lectin which is strongly associated with the fungal β‐1,3‐glucan. The chitin synthetase inhibitors, polyoxin D and nikkomycin decrease the production of β‐1,3‐glucan by the fungus but increase the titre of the excreted lectin. On the other hand, the competitive inhibitor of glucose, 2‐deoxyglucose, decreases the production of both β‐1,3‐glucan and the lectin. The inhibition of glucan synthesis by polyoxin D was used for separation of the lectin from the glucan. For purification, the fungus was grown in synthetic medium supplemented with 5 × 10−6 mol/l polyoxin D and the crude lectin was puried on a column of Sephadex G‐75. SDS‐PAGE of the purified lectin showed two protein bands with the molecular weights of 55 000 and 60 000. The location of the lectin on S. rolfsii hyphae and its adsorption to conidia of Tri‐choderma were determined by indirect imrnunofluorescence, with antiserum raised against the purified lectin. The possible role of this lectin in S. rolfsii‐Trichoderma cell interaction is discussed.
Factors affecting production and activity of phospholipase C by Yersinia enterocotttica
Authors: Toora S. , Singh G.
Published: March 2008

The production of phospholipase C by Yersinia enterocolitica strain SG was optimum at 37†C at pH 6·5. No enzyme activity could be detected when the organism was grown at extreme pH values (pH > 8·5 or <5·0). The enzyme production was maximum when the organism was grown under static conditions in TSB medium. All solvents and salts inhibited the enzyme activity, whereas loss of activity was 95% in presence of methanol (20%) and 99% in presence of sodium azide (0·2 mol/l). The enzyme activity was increased twofold in the presence of cyste‐ine and decreased by 98% in the presence of sodium perchlorate (0·2 mol/1).
Thermal inactivation of Listeria monocytogenes during a process simulating temperatures achieved during microwave heating
Authors: Coote P.J. , Holyoak C.D. , Cole M.B.
Published: March 2008

Conventional heating was used to expose cells of Listeria monocytogenes, either in broth or in situ on chicken skin, to the mean times and temperatures that are achieved during a 28 min period of microwave cooking of a whole chicken. Heating L. monocytogenes by this method in culture broth resulted in a reduction in viable cell numbers by a factor of greater than 106 upon reaching 70°C. Simulated microwave cooking of L. monocytogenes in situ, on chicken skin, resulted in more variability in the numbers of survivors. Heating for the full cook time of 28 min, however, resulted in a mean measured temperature of 85°C and no surviving listerias were detected. This indicated a reduction in viable numbers of greater than 106. To reduce temperature variation, cells were heated on skin in a submerged system in which exposure to 70°C for 2 min resulted in a reduction in viable cell numbers of all strains of listerias tested of between 106 and 108. These results show that when a temperature of 70°C is reached and maintained for at least 2 min throughout a food there is a substantial reduction in the numbers of L. monocytogenes. The survival of this organism during microwave heating when temperatures of over 70°C are reported is probably due to uneven heating by microwave ovens resulting in the presence of cold spots in the product. The heat resistance of L. monocytogenes is comparable with that of many other non‐sporing mesophilic bacteria.
A note on the isolation of psychrotrophic coliform organisms from faecal‐polluted environments
Authors: Rivilla R. , González Carmen C.
Published: March 2008

The Simmons citrate salicin (SCS) medium was developed for the enrichment and isolation of presumptive psychrotrophic coliforms from polluted environments. The selectivity and resolution of the medium were tested with pure and mixed laboratory cultures. A procedure for the isolation of psychrotrophic coliforms from polluted environments using a lactose‐bile broth and SCS medium is presented.
Physiological and biochemical characteristics of fast‐and slow‐growing Rhizobium sp. pigeonpea (Cajanus cajan)
Authors: Anand R.C. , Dogra B.C.
Published: March 2008

Thirty‐two of 38 cultures isolated from the nodules of pigeonpea plants were rapid growers. The generation time of rapid growers varied from 0·71 to 1·31 h and slow growers from 7·7 to 9·9 h. Rapid growers oxidized pentoses, hexoses, polyhydric alcohols (except dulcitol), tricarboxylic acid cycle intermediates (except citrate) and disaccharides more rapidly than slow growers; disaccharides were not oxidized by any of the slow growers. The Embden‐Meyerhof‐Parnas and Entner‐Doudoroff pathways and the tricarboxylic acid cycle were present in both rapid and slow growers, whereas the pentose‐phosphate pathway was present only in rapid growers.
Streptomycin and tetracycline resistance plasmids in Staphylococcus hyicus and other staphylococci
Authors: Rahman Mary , Kent Louise , Noble W.C.
Published: March 2008

Plasmids associated with resistance to streptomycin, to streptomycin plus chloramphenicol or to tetracycline in Staphylococcus hyicus isolated from the skin of pigs have been compared, by restriction endonuclease digest patterns, with similar staphylococci from human sources and with published DNA base sequences. Several plasmids from Staph. hyicus have proved to have a very similar structure to those described from Staph. aureus but others appeared very dissimilar. This confirms the opinion that staphylococci from animal skin share a pool of plasmids with those from human skin but may also possess some of quite different structure.
Calmodulin antagonists inhibit germination of Bacillus cereus T spores
Authors: Shyu Y.T. , Foegeding P.M.
Published: March 2008

The effects of two calmodulin antagonists, trifluoperazine (TFP) and N‐(6‐aminohexyl)‐5‐chloro‐1‐naphthalene sulphonamide hydrochloride (W‐7) on L‐alanine‐induced germination of Bacillus cereus T spores were examined by measuring commitment to germination, decrease in optical density at 660 nm and phase‐contrast microscopy. The kinetics of optical density decrease suggested competitive inhibition of TFP or W‐7 with both L‐alanine and D‐alanine (L‐alanine analogue and germination inhibitor) as determined by Lineweaver‐Burk and Schild plots, respectively. Germination inhibition was pH‐dependent. The I50 values for maximum decreasing rate of optical density in 10 mmol/l L‐alanine plus 5 mmol/l adenosine at pH 6·4 were 0·21 and 0·74 mmol/l for TFP and W‐7, respectively. Much less effect of N‐(6‐aminohexyl)‐l‐naphthalene sulphonamide hydrochloride than W‐7 lends support to the specificity of W‐7. The calmodulin antagonists were effective at a step in germination after commitment and loss of heat resistance. It is postulated that this process is necessary in the germination of B. cereus T spores to convert phase‐bright spores to phase‐dark spores and to cause a decrease in optical density.
Applicability of the Davey (linear Arrhenius) predictive model to the lag phase of microbial growth
Authors: Davey K.R.
Published: March 2008

The empirical and quantitative (linear Arrhenius) model of Davey (1989a) was assessed against a range of published lag phase data, some of which included combined temperature—water activity as influencing factors while others had temperature as the sole influencing factor. For two large (n≧ 27) sets of combined temperature and water activity data, the model explained 74·2 and 86·4% of the variation in results, and for eight wide ranging data sets with temperature as the sole factor, it explained between 80·8 and 99·7% of the variation in results, with an overall mean of 95·7%. These published data included both Gram‐positive and Gram‐negative bacteria and a spore former. The model has four coefficients which can be obtained by relatively unsophisticated users with linear regression analyses on most desk top calculators or personal computers.
Sunlight and the survival of enteric bacteria in natural waters
Authors: Davies Cheryl M. , Evison Lilian M.
Published: March 2008

Escherichia coli and some salmonellas were exposed in seawater and freshwater to natural sunlight, visible light of comparable intensity, and light containing a similar proportion of u.v. as natural sunlight but of a much lower intensity. Direct viable bacterial counts and culturable counts on selective and non‐selective media were made at intervals. The rate of decrease in numbers of culturable bacteria was significantly faster in seawater than in freshwater when exposed to natural sunlight. No significant difference was found between the rates of decrease in numbers of culturable bacteria in seawater and those in freshwater when bacteria were exposed to light with a small u.v. component of similar intensity. The effect of salinity on loss of culturability is, therefore, more significant in the presence of u.v. radiation. Direct counts by the acridine orange direct viable count method decreased much more slowly than the culturable counts in seawater but comparably with culturable counts in freshwater in natural sunlight. Direct viable counts and culturable counts decreased at a similar rate in seawater and in freshwater in visible light. This may signify the evolution of enteric bacteria towards a viable but non‐culturable form in seawater when exposed to natural sunlight. The presence of humic acids significantly reduced loss of culturability but only in low salinity conditions. Salinity appears to be an important factor influencing culturability in bacteria exposed to sunlight.
In‐vitro bacteriocin‐mediated antagonism by oral streptococci against human carrier strains of staphylococci
Authors: Tzannetis S. E. , Bigis Athena , Konidaris N. , Ioannidis Helen , Genimatas Vassiliki , Papavassiliou J.
Published: March 2008

All strains of oral streptococci tested and specially those of Streptococcus mutans, Strep. sanguis and Strep. minor produced more than one distinct bacteriocin‐like substance with variable inhibitory activity on 20 indicator staphylococci. Inhibitory activity was comparatively higher on nasal strains of Staph. aureus and Staph. epidermidis than on strains of both species isolated from the mouth. Nineteen of 20 staphylococcal indicators were inhibited by 1–12 of the 12 effector streptococci. Sensitivity of nasal staphylococci to bacteriocins (frequency of positive inhibitory tests and total inhibition zone diameters) was significantly higher (P < 0·001, χ2 test and P < 0·05, t test respectively) than that of oral ones. The sensitivity of nasal over oral Staph. aureus (P < 0·001 and P < 0·01) and of oral Staph. epidermidis over oral Staph. aureus (P < 0·01 and P < 0·05) was also significantly higher. The evaluation of variability of inhibitory patterns of bacteriocins produced by streptococci (p‐typing), of sensitivity patterns of staphylococci to bacteriocins (s‐typing) and of the significantly higher sensitivity of nasal over oral staphylococci to bacteriocins from the epidemiological and ecological veiwpoints are discussed.
A numerical taxonomic study of lactic acid bacteria isolated from irradiated pork and chicken packaged under various gas atmospheres
Authors: Grant Irene R. , Patterson Margaret F.
Published: March 2008

Ninety‐four Gram‐positive, catalase‐negative bacteria, isolated from pork and chicken that had been packed in modified atmospheres and irradiated to 1·75 and 2·5 kGy respectively, were studied. The majority of the strains were Lactobacillus saké. Numerical taxonomy, with the group average clustering strategy, revealed the existence of six clusters at the 85% similarity level. The largest, Cluster 1, contained 78 (83%) of the test strains along with three Lact. saké strains. Cluster 2 contained three test strains and the type strains of Carnobacterium piscicola and Carn. divergens. Cluster 3 contained two chicken strains and Lact. curvatus. Cluster 4 contained a pork strain and Leuconostoc dextranicum. Clusters 5 and 6 contained four pork and two chicken strains respectively and no type strains. Four test strains remained unclustered as did the other reference strains included in the study.
Polymer production by Lactobacillus delbrueckii ssp. bulgaricus
Authors: Garcia‐Garibay M. , Marshall V. M. E.
Published: March 2008

A polymer‐forming strain of Lactobacillus delbrueckii ssp. bulgaricus was grown under differing conditions. It was found that at higher temperatures and slower growth the production of the polymer per cell was greater. Polymer‐producing ability seems to be unstable with cells losing the phenotype faster at 48 than at 40°C. Specific production of polymer was increased in the presence of hydrolysed casein early in the growth phase when growing in milk, but production of polymer in MRS broth + lactose was reduced compared with milk. Furthermore, addition of hydrolysed casein to MRS did not increase specific production of polymer. Preliminary results suggest that the polymer is a glycoprotein, although the protein may be loosely associated with the carbohydrate.
Growth of Bacillus cereus in fermenting tempeh made from various beans and its inhibition by Lactobacillus plantarum
Authors: Ashenafi M. , Busse M.
Published: March 2008

Counts of Bacillus cereus reached ca 108 cfu/g within 40 h in fermenting unacidified horsebean tempeh and resulted in complete spoilage of the product. In fermenting unacidified pea, chickpea and soybean tempeh, B. cereus counts reached 106–107 cfu/g, although the products were not spoiled. Inoculation of these unacidified beans with Lactobacillus plantarum decreased the final count of B. cereus by 2 log units, but had no effect on its growth in unacidified horsebean tempeh and its subsequent spoilage. Acidification of the beans during soaking resulted in a lower rate of B. cereus growth during fermentation. Inoculation of acidified beans with Lact. plantarum resulted in a markedly lower growth rate of B. cereus. In an associative broth culture study, B. cereus was completely inhibited by Lact. plantarum at pH values of about 5·5. Lactobacillus plantarum may be used to control the growth of B. cereus during tempeh production.
Differentiation of the genus Listeria from other Gram‐positive species based on low molecular weight (LMW) RNA profiles
Authors: Slade P. J. , Collins‐Thompson D. L.
Published: March 2008

Low molecular weight RNA (LMW RNA; 5S rRNA and tRNAs) profiles of several Gram‐positive species were generated on 9% denaturing polyacrylamide gels. The profiles of five Listeria spp. (L. innocua, L. ivanovii, L. monocytogenes, L. seeligeri and L. welshimeri) were identical when cultured in three different media (APT, BHI and TSBYE), either shaken or statically, both at 30 and 37°C. Twenty‐six strains from 15 other species representing seven different genera were also compared. Each species exhibited a characteristic profile. Strain variants of the same species gave identical profiles. The technique represents a simple, reproducible approach to the identification of species and possibly of relationships between species. The taxonomic and phylogenetic implications, particularly with respect to Listeria spp., Brochothrix thermosphacta and the lactic acid bacteria, are considered.
Effect of fermentation on crude protein and fat contents of crushed grains of maize and sorghum
Authors: Abasiekong S.F.
Published: March 2008

Cereal grains are conventional energy sources in livestock and poultry rations, while the requisite protein is often supplied by richer sources. Possibilities for the production of crude protein by growing micro‐organism on crushed cereal grains was investigated with the aim of obtaining protein‐enriched grains for providing both energy and protein in farm animal diets.

Samples of white maize and sorghum were crushed, wetted with distilled water and fermented by Fibrobacter succinogenes, Lactobacillus brevis and a mixed culture of both micro‐organisms. Crude protein and either extract values increased with increasing fermentation period. Peak values of both fat and protein were obtained in the fourth week for all fermentations. Highest values of protein were 30·1 and 24·2% respectively for heat‐treated sorghum and maize which were both fermented by F. succinogenes. Highest values of fat were 13·1 and 10·6% for maize and sorghum respectively and were obtained from fermentation of heat‐treated grains using Lact. brevis. Heat treatment of grains encouraged microbial protein production.
A rapid fluorogenic method for the detection ofEscherichia coliby the production of β‐glucuronidase
Authors: Sarhan H.R. , Foster H.A.
Published: March 2008

A medium containing the fluorogenic substrate 4‐methylumbelliferyl‐β‐d‐glucuronide was developed for the isolation and identification ofEscherichia coliwithin 7·5 h and was based on the detection of β‐glucuronidase. Optimum conditions for the rapid development of fluorescent colonies were determined. The optimum temperature was 41·5°C. Development of fluorescence was delayed when carbohydrates were incorporated into the medium. Water samples were used to evaluate the medium by surface plating and membrane filtration. The frequency of false‐negative results was 6·1% and false‐positives were 3·7% for freshwater samples. The false‐positive organisms were identified asKlebsiellaspp. andShigella sonnei.The potential applications of the medium are discussed.
Toxicity of medium chain fatty acids to Penicillium crustosum Thom and their detoxification to methyl ketones
Authors: Hatton P.V. , Kinderlerer Judith L.
Published: March 2008

Conversion of medium chain length fatty acids into methyl ketones by some filamentous fungi is important in the development of flavour in the blue mould‐ripened cheeses and in the promotion of ketonic rancidity in the lauric acid oils. The effect of fatty acid composition of single acid glycerides, pH, temperature and medium chain length fatty acids on conversion of fatty acids into methyl ketones has been studied with two strains of Penicillium crustosum Thom. Medium chain length fatty acids were fungitoxic. The minimum inhibitory concentration was 3776, 2884, 1723 and 3066 mg/l for the C6:0, 8:0, 10:0 and 12:0 acids, respectively, at pH 7·0 in liquid suspension culture. Evidence is provided to suggest that the cellular site for this conversion is the microbody. Growth of P. crustosum on single acid glycerides involves two distinct physiological processes; the first, a general inhibition of growth, and the second, a detoxification. The fatty acid composition and the slip point of the substrate are of paramount importance in these two processes.
Effect of avian intestinal microflora possessing adhering and hydrophobic properties on competitive exclusion of Salmonella typhimurium from chicks
Authors: Stavric S. , Gleeson T.M. , Blanchfield B.
Published: March 2008

The role of adherence and hydrophobic properties of native gut microflora in competitive exclusion of salmonellas from chicks is reported. Pure bacterial strains were isolated from washed caeca of 3‐d‐old chicks which had been treated on the day of hatch with a microflora from salmonella‐free adult birds. These strains, when added to known mixtures of pure cultures, improved the efficacy of the mixtures in protecting chicks against a challenge of 105 cfu of Salmonella typhimurium. Strains from washed caeca and from other sources were also screened for hydrophobic properties. Undefined microflora and strains freshly isolated from washed caeca and which were hydrophobic improved the efficacy of protective mixtures, while none of the combination of hydrophobic strains obtained from stored strains had any beneficial effect.
Effect of bacterial suspensions on vascular occlusion in stems of cut rose flowers
Authors: van Doorn W.G. , de Witte Y.
Published: March 2008

A suspension of Pseudomans aeruginosa at 5 × 109 cfu/ml was either left untreated, pasteurized (15 min, 70°C) or autoclaved (15 min, 121°C). Stems of cut rose flowers (Rosa hybrida L. cv. Sonia) placed in these solutions for 0·5–4·0 h showed decreased water uptake and a reduction of hydraulic conductance of the basal 5·0 cm stem segment. No difference was found between the treatments. When the pasteurized or autoclaved solutions were left at 4°C for 7 days, bacterial cells had autolyzed, and stems placed in these suspensions showed lower water uptake and hydraulic conductance than stems in freshly prepared solutions. The results show that living and non‐living bacteria have the same effect on vascular occlusion, and indicate that hydraulic conductance was more reduced when the average size of the particles was smaller than that of bacterial cells. Vascular blockage occurred within 30 min after the start of treatment, apparently due to a physical effect rather than a physiological response of the stem tissue.
Mode of action of pediocin AcH from Pediococcus acidilactici H on sensitive bacterial strains
Authors: Bhunia A.K. , Johnson M.C. , Ray B. , Kalchayanand N.
Published: March 2008

The peptide, pediocin AcH, from Pediococcus acidilactici H binds to the cell surface of Lactobacillus plantarum NCDO 955, its resistant mutant and several other sensitive and resistant Gram‐positive bacteria but not to Gram‐negative bacteria. Sensitive cells, following treatment with pediocin AcH, lost intracellular K ions, u.v.‐absorbing materials, became more permeable to ONPG and, in some strains, lysed. Binding of pediocin AcH was maximum at pH 6.0. Anions of several salts inhibited binding of pediocin AcH but this was overcome by increased concentrations of pediocin AcH. Treatment of sensitive cells with 1% SDS, 4 mol/1 guanidine‐HCl, several organic solvents and enzymes did not reduce subsequent binding of pediocin AcH. Partially purified cell wall from a sensitive strain was also able to bind pediocin AcH. However, treatment of the cell walls to remove lipoteichoic acid prevented binding. These molecules might, therefore, be one of the binding sites of pediocin AcH.
Induction of Bacillus brevis L‐forms
Authors: Strang J.A. , Allan E.J. , Seddon B. , Paton A.M.
Published: March 2008

L‐forms of Bacillus brevis were induced and maintained in L‐phase medium supplemented with inactivated horse serum with a combination of penicillin (80 u/ml) and cephalosporin (5 μg/ml) in liquid medium and penicillin (200 u/ml) in diphasic culture. These L‐forms failed to grow on solid media.
Elimination of Lactobacillus plantarum, Corynebacterium spp., Staphylococcus saprophyticus and Pseudomonas paucimobillis from micropropagated Hemerocallis, Choisya and Delphinium cultures using antibiotics
Authors: Leifert C. , Camotta Helen , Wright Sandra M. , Waites Barbara , Cheyne Valerie A. , Waites W.M.
Published: March 2008

C. LEIFERT, H. CAMOTTA, S.M. WRIGHT, B. WAITES, V.A. CHEYNE & W.M. WAITES. 1991. The antibiotic sensitivity patterns of bacterial contaminants isolated from micropropagated plant cultures were determined. Lactobacillus plantarum, Corynebacterium spp., Staphylococcus saprophyticus and Pseudomonas paucimobilis were eliminated from plant tissue cultures of Hemerocallis, Choisya and Delphinium by incorporating combinations of antibiotics into the plant growth medium. Elimination of contaminants resulted in increased growth rates of all plant cultures, except Choisya infected with Staph. saprophyticus. Pseudomonas maltophilia was not eliminated from Delphinium by any of the antibiotic treatments tested.
Applications of BLIS typing to studies of the survival on surfaces of salivary streptococci and staphylococci
Authors: Tagg J.R. , Ragland Nancy L.
Published: March 2008

J.R. TAGG AND N. L. RAGLAND. 1991. A typing scheme based on detection of the production of bacteriocin‐like inhibitory substances (BLIS) was a useful tool in a series of epidemiological studies of the spread and survival on surfaces of salivary streptococci and staphylococci. The organisms survived for longer periods on glass, plastic, stainless steel and latex surfaces than on unpainted wood or paper. The presence of saliva as a suspending medium prolonged the viability of Staphylococcus aureus C55 and Streptococcus pyogenes FF22 but not of Strep. salivarius Min 5. Young children were shown to carry Strep. salivarius of identical BLIS‐types on their fingers and in their saliva. BLIS typing of Strep. salivarius strains obtained from telephone mouthpieces and from the tongue‐sealed flap of envelopes was used as a method of tracing the human source of the salivary deposits.
Conversion of biological and immunological properties during a process of decapsulation in a strain of Staphylococcus hyicus
Authors: Yoshida E. , Ichiman Y. , Suganuma M. , Yoshida K.
Published: March 2008

E. YOSHIDA, Y. ICHIMAN, M. SUGANUMA AND K. YOSHIDA. 1991. Repeated subculture at 42°C of Staphylococcus hyicus strain ST67P, which exhibits streaming‐type growth in a soft‐agar medium, yielded three variants, ST67L, ST67S and ST67C, which had different colonial morphologies; small compact colonies possessing long and short tails and perfect compact colonies. The parent strain and ST67L respectively gave strong and weak positive intensity when stained by rabbit antisera prepared by capsular type I and II strains of Staph. epidermidis conjugated with fluorescein isothiocyanate. Variant ST67L gave a positive result with antiserum prepared by capsular type I strain and no staining was observed with variants ST67S and ST67C against these antisera preparations. Strain ST67C had the lowest virulence although no remarkable difference was shown between the parent strain and variants ST67L and ST67S. The cell volume index of the parent strain was 1.35, 2.43 and 3.71 times larger than those of ST67L, ST67S and ST67C, respectively. The converting activity of rabbit anti‐ST67P strain serum absorbed by strain ST67C required four times more of the organisms than strain ST67P, changing the colonial morphology of the strain from diffuse to compact type by the addition of antiserum to soft agar medium. Positive coagulase and false positive clumping factor reaction were shown in variants ST67C, but no remarkable alteration was observed with 19 biochemical properties determined by a conventional identification kit. In ulta‐thin sections of the parent strain labelled with rabbit anti‐strain ST67P serum conjugated with ferritin, large capsules surrounded by ferritin granules were demonstrated by electron microscopy. In variants ST67L and ST67S, but not ST67C medium size capsules surrounded by ferritin granules and only ferritin granules located around the cell wall, respectively, were observed.
Obituary
Authors: Lapage Stephen P.
Published: March 2008

Stephen Lapage was Curator of the National Collection of Type Cultures (NCTC), 1965–78. He took early retirement because of ill health; he made a good recovery from major surgery but sadly died in October 1990. He was a member of the Society for Applied Bacteriology from 1962 and served on its Committee, 1969–72. He had a national and international reputation for his energy and enthusiasm for various aspects of research and development in bacterial taxonomy and culture collections. Many will remember a colleague with very considerable organizational abilities, good humour and wide interests.
Microbiological exploitation of cardiac glycosides and alkaloids from Garcinia kola, Borreria ocymoides, Kola nitida and Citrus aurantifolia
Authors: Ebana R.U.B. , Madunagu B.E. , Ekpe E.D. , Otung I.N.
Published: March 2008

R.U.B. EBANA, B.E. MADUNAGU, E.D. EKPE AND I.N. OTUNG. 1991. The four medicinal plants, Garcinia kola (roots), Borreria ocymoides (leaves), Kola nitida (bark) and Citrus aurantifolia (roots) were screened for phytochemical components. They were found to contain tannins, phlobatannins, polyphenols, pydroxymethyl anthraquinones, glucides, saponins, alkaloids, cardiac glycosides, flavanoids and reducing compounds. The aqueous and alcoholic extracts as well as alkaloids and cardiac glycosides of the medicinal plants were tested on various pathogenic bacteria. They were found to inhibit such organisms as Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, β‐haemolytic streptococci, Escherichia coli and Neisseria gonorrhoeae. The usefulness of the phytochemical bases of these plants as potential sources of pharmaceutical drug preparation is discussed.
A dot‐immunobinding assay for the laboratory diagnosis of tuberculous meningitis and its comparison with enzyme‐linked immunosorbent assay
Authors: Radhakrishnan V. V. , Mathai A.
Published: March 2008

V.V. RADHAKRISHNAN AND A. MATHAI. 1991. In an attempt to establish an alternative to standard bacteriological methods in the laboratory diagnosis of tuberculous meningitis (TBM), a simple dot‐immunobinding assay (Dot‐Iba) was standardized to detect Mycobacterium tuberculosis antigen 5 and antimycobacterial antibody in cerebrospinal fluid (CSF) specimens of patients with TBM. Sensitivity and specificity of Dot‐Iba was compared with conventional enzyme‐linked immunosorbent assay (ELISA) and standard bacteriological techniques. The Dot‐Iba showed excellent correlation with indirect ELISA for the detection of antimycobacterial antibody in CSF and showed 60% sensitivity and 100% specificity in culture‐negative patients with TBM. However Dot‐Iba was less sensitive for the detection of antigen 5 in CSFs and showed false negative results (60%) in culture‐positive patients with TBM.