bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity of methicillin‐resistant Staphylococcus aureus strains to some antibiotics, antiseptics and disinfectants
Authors: Al‐Masaudi Saad B. , Day M.J. , Russell A.D.
Published: March 2008

The effects of antibiotics, antiseptics and disinfectants against some methicillin resistant (MRSA) and methicillin‐sensitive (MSSA) Staphylococcus aureus strains have been studied. The MRSA and MSSA strains were equally sensitive to phenols, esters of para(4)‐hydroxybenzoit acid and chlorhexidine but MRSA strains were slightly more resistant to quaternary ammonium compounds and considerably more so to dibromopropamidine isothionate. Some MRSA strains were also resistant to phenylmercuric nitrate (but not another organomercurial, thiomersal), mercuric chloride and cadmium chloride. All MRSA strains produced β‐lactamase. Strains from the Royal Free Hospital, London were highly resistant to β‐lactam antibiotics, erythromycin, trimethoprim and tetracyctines but were sensitive to other antibiotics. One strain from the University Hospital of Wales, Cardiff was resistant to gentamicin but sensitive to tetracycline and trimethoprim.
Further development of simple tests to differentiate the legionellas
Authors: Vesey G. , Dennis P.J. , Lee J.V. , Westy A.A.
Published: March 2008

Current methods for the identification of the Legionellaceae to species level are suitable only for the specialist or research laboratory. As part of a continuing taxonomic study 42 simple biochemical tests were screened for their ability to differentiate species of Legionella. Only 23 of these were of practical use. These tests are able to differentiate 21 of 23 recognized species of Legionella and six new species. Phenotypic screening with these tests may prove useful to the routine microbiologist and be a viable alternative to identification techniques currently employed.
Seasonal distribution of Aeromonas hydrophila in river water and isolation from river fish
Authors: Pathak S.P. , Bhattacherjee J.W. , Kalra N. , Chandra S.
Published: March 2008

The seasonal distribution of Aeromonas hydrophila in water and recovery rate from live river fish was investigated. The highest isolation rates of A. hydrophila occurred in water during the late winter followed by a progressive decline in density during the summer and monsoon seasons. The organism was recovered from fish throughout the period from which it was concluded that they form a reservoir which is unrelated to their density in water. The enterotoxigenicity of some environmental strains was tested in suckling mice and rabbit ileal loop.
Detection of hydrogen peroxide produced by meat lactic starter cultures
Authors: Juven B.J. , Weisslowicz H. , Harel S.
Published: March 2008

Twelve strains of meat lactic starter cultures (Pediococcus spp. and Lactobacillus plantarum) were found to produce hydrogen peroxide in vitro. The (cumulative) amounts of H2O2 produced were measured through the peroxidative action of catalase on H2O2 and oxidation of added formate to CO2 by the H2O2‐catalase complex formed. There was a problem in building a calibration curve for converting values of formate oxidation into amounts of H2O2, either by adding H2O2 directly to the assay mixture or having it produced via a glucose‐glucose oxidase system.
Purification and characterization of extracellular proteinases excreted by a strain of Bacillus subtilis BS2, isolated from fermented African locust bean ‘iru’
Authors: Aderibigbe E.Y. , Odunfa S.A.
Published: March 2008

Proteinases were excreted by strains of Bacillus subtilis during fermentation of African locust bean cotyledons. Those excreted by one strain were purified and characterized by ammonium sulphate precipitation, ion‐exchange chromatography (IEC), gel filtration, inhibition tests and polyacrylamide gel electrophoresis (PAGE). Three proteinases and an esterase without proteolytic activity were identified. A serine proteinase which showed a high degree of hydrophobicity and a neutral proteinase were present. The third proteinase showed both proteolytic and esterolytic activities, and had multiple electrophoretic mobilities on polyacrylamide gel.
Bacteriophage tracer experiments in groundwater
Authors: Skilton Helen , Wheeler D.
Published: March 2008

Three tracer experiments employing three different bacteriophage were performed at one groundwater site near Beverley, Humberside. In two of the experiments the bacteriophage were injected into the aquifer by a borehole at a distance of 366 m from the pumping borehole. In the other experiment they were injected at a distance of 122 m. Regular samples were taken of water abstracted at the pumping boreholes as well as from the injection boreholes. The objectives were to: (1) investigate the pattern of bacteriophage recovery from the aquifer; (2) calculate the total number of bacteriophage recovered and the rate of their migration; and (3) detect any differences in bacteriophage behaviour which could be directly related to the morphology of the three bacteriophage. In all experiments the pattern of recovery was similar, exhibiting a peak of high numbers reaching the pumping borehole soon after injection. The highest percentage of original inoculum recovered was 1.9%. In the majority of cases, however, recovery was usually one log10 lower than this. The fastest migration rates were very rapid, reaching 2.8 cm/s in one experiment. No variation in percentage recovery or transit time could be directly attributed to morphology of bacteriophage. The most important factor governing the pattern of migration was undoubtedly the hydrogeological conditions.
Polygalacturonase biosynthesis by Lactobacillus plantarum: effect of cultural conditions on enzyme production
Authors: Sakellaris G. , Nikolaropoulos S. , Evangelopoulos A.E.
Published: March 2008

Lactobacillus plantarum was found to produce extracellular polygalacturonase (EC 3.2.1.15.). Maximum enzyme production was obtained in a medium containing 0.5% glucose and 1.5% low methyl‐pectin as inducer at 27°C at an initial pH of 6.8. Enzyme production was strongly inhibited by 5 μmol/l NiCl2, 5 μmol/l CoCl2, 5 μmol/l CuSO4, and 10 μmol/l ZnCl2. MnSO4 and MgSO4 at 200 μmol/l and 50 μmol/l respectively seemed to enhance enzyme biosynthesis. The optimal pH and temperature for enzyme activity were 4.5 and 30°C respectively. Enzyme production in batch culture accompanied growth.
Cross protection between an encapsulated strain of Staphylococcus hyicus and encapsulated strains of Staphylococcus aureus
Authors: Yoshida K. , Ichiman Y. , Umeda A.
Published: March 2008

Strain ST67P of Staphylococcus hyicus grew diffusely in regular serum‐soft agar. With the addition of rabbit antisera prepared with Staph. aureus strains, Smith, NS58D or NS41D, capsular type A, B or C, respectively, the organisms converted to compact type growth. Mice immunized with heat‐killed vaccine of strain ST67P showed significant resistance against either homologous or heterologous strains, Smith, NS58D and NS41D. Passive protective activities in rabbit antisera prepared with strains Smith, NS58D and NS41D were absorbed out with either homologous cell surface polysaccharide fraction or cell surface polysaccharide fraction extracted from strain ST67P. Well‐defined large capsules were observed in ultra‐thin sections treated with rabbit antiserum prepared with homologous strain conjugated with ferritin. Also, the capsule surrounded by ferritin granules was shown in ultra‐thin sections treated with ferritin conjugated with antisera prepared with those heterologous strains although the capsular size was significantly smaller than those observed by homologous antiserum.
Numerical analysis of electrophoretic protein patterns of Providencia alcalifaciens strains from human faeces and veterinary specimens
Authors: Holmes B. , Costas M. , Sloss L. L.
Published: March 2008

Twenty‐five strains of Providencia alcalifaciens from various countries have been characterized by one‐dimensional SDS‐PAGE of cellular proteins. They comprised 15 from human faeces, one from duck faeces, one from a guinea‐pig eye and eight from unknown sources. Also included, for reference purposes, were the type strains of three other Providencia species. The protein patterns, which contained 45–50 discrete bands, were highly reproducible and were used as the basis for two numerical analyses. In the first, in which the principal protein bands (in the 33–40 kD range) were excluded, the 25 Prov. alcalifaciens strains formed, at the 83% S level, a single cluster whilst the three Providencia reference strains remained unclustered. In the second, which included all the protein bands, the 25 Prov. alcalifaciens strains formed 10 clusters at the 85% S level. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of Prov, alcalifaciens. Reference strains of each of the 10 PAGE types identified are available from NCTC for inclusion in future studies.
Investigation of spore surface antigens in the genus Bacillus by the use of polyclonal antibodies in immunofluorescence tests
Authors: Phillips A. P. , Martin K. L.
Published: March 2008

Fluorescein‐conjugated rabbit antibodies to formalized spores of Bacillus anthracis were tested against strains of B. anthracis and other Bacillus species in a subjective immunofluorescence test. The lack of reaction of B. anthracis Vollum spores with conjugated antibody raised against B. anthracis Sterne spores indicated that spores of the Vollum strain lacked a major surface antigen present in most of the other anthrax strains tested, including the non‐encapsulated strains Sterne and the Soviet ST1, variants cured of the pX01 plasmid that codes for the toxin, and several virulent strains. Four other antibody preparations, raised against B, anthracis Vollum, New Hampshire, Ames and Strain 15, reacted to an approximately similar degree with spores of all four strains and of Sterne, indicating that Vollum has at least one spore antigen in common with these other strains. The anti‐Sterne and anti‐Vollum conjugates both displayed cross‐reactions with spores of strains of B. cereus, B. coagulans, B. subtilis, B. megaterium, B. polymyxa, B. pumilus and B. thuringiensis. Absorption of the anti‐anthrax conjugates with B. cereus NCTC 8035 and NCTC 10320 removed all these cross‐reactions, demonstrating the existence of spore antigens specific for anthrax.
Reproducibility of pyrolysis mass spectrometry: effect of growth medium and instrument stability on the differentiation of selected Bacillus species
Authors: Shute L. A. , Gutteridge C. S. , Norris J. R. , Berkeley R. C. W.
Published: March 2008

The discrimination of a set of 53 strains, taken from four closely related Bacillus species (Bacillus subtilis, B. pumilus, B. licheniformis and B. amyloliquefaciens), was examined using pyrolysis mass spectrometry. Strains were grown on six different media to examine the effect of media variation, especially batch‐to‐batch variation of a single medium, on the pyrolysis mass spectra and strain discrimination achieved. Long‐term reproducibility over a period of 14 months was also examined. It was shown that batch‐to‐batch media variation is insufficient to affect spectra and strain discrimination significantly, but different media types do affect this. It was shown that species groups could still be recovered from the data, however, with an appropriate data‐handling system. It was not possible to directly compare spectra produced 14 months apart, but the strain and species discrimination achieved using each data‐set were highly comparable.
Synergistic effect of relative humidity and temperature on the survival of rhizobia in inoculant carrier
Authors: Juwarkar Asha , Rewari R.B.
Published: March 2008

Six strains of Rhizobium, three temperature‐tolerant (U1, C13 and A19) and three temperature‐sensitive strains (U10, C10 and A4) selected on the basis of previous study were used to screen the synergestic effect of different relative humidities (r.h. 50%, 65% and 90%) and temperatures (28°, 35°, 40° and 45°C) on the survival of rhizobia in inoculant carrier. At a particular temperature all the three r.h.'s were maintained. At a storage temperature of 28° and 35°C, the r.h. had little effect on the population of any of the rhizobial strains tested, but at 40° and 45°C, marked differences were observed and it was concluded that higher r.h. in conjunction with higher temperature resulted in low viable counts. The effect was similar but less obvious with the temperature‐tolerant strains. It was found that 50% r.h. at different storage temperatures extended shelf life of rhizobial strains of blackgram, cowpea and arhar crops which were tested in this study in inoculant carrier.
Survival of Staphylococcus epidermidis on the skin of patients of lepromatous leprosy
Authors: Kumar B. , Khanna V. , Saxena M. , Sharma Saroj
Published: March 2008

The effect of hydration on Staphylococcus epidermidis, the predominant resident bacterial flora, was studied on skin affected by leprosy and known to have impaired sweating. Normal areas served as control. Significantly higher bacterial counts were observed in affected areas compared with normal‐looking skin in 16/19 of the patients. Artificial application of Staph. epidermidis on leprosy‐affected and unaffected areas, however, showed equivocal results, as in only 50% of the patients were higher counts obtained in affected compared with unaffected sites. The possible responsible factors for the present observation are discussed.
Production of antibody to lipopolysaccharide (LPS) after immunization with a LPS‐polymyxin B‐agarose immunogen
Authors: Ryan Lisa K. , Karol Meryl H.
Published: March 2008

A method was devised to produce antibodies to lipopolysaccharide (LPS) in guineapigs following a single immunization, The antigen was prepared by mixing polymyxin B‐agarose with LPS from Escherichia coli O55:B5. Use of the agarose support allowed purification of the complex by simple washing procedures. Twenty‐nine days after a single injection of the immunogen mixed with Freund complete adjuvant all animals demonstrated antibody to the LPS portion of the complex. No antibodies were detected to the polymyxin B component. Typical titres of LPS as measured by ELISA were 211. After, a booster immunization, titres of LPS antibody were further inceased and a greater avidity was noted. In contrast to other methods which have been employed for production of antibody to LPS, use of the polymyxin B‐agarose complex has the following advantages: ease of antigen preparation, ready purification of the complex, potent immunostimulation, and under the conditions employed here, LPS‐specific antibody production, without accompanying antibody to polymyxin B.
Factors affecting growth and lipase production by meat lactobacilli strains and Brochothrix thermosphacta
Authors: PAPON MARTINE , TALON RÉGINE
Published: March 2008

Lipolytic activity of lactobacilli strains and Brochothrix thermosphacta was cellrelated; no significant activity was found in the supernatant fluids. Most lipase was produced during the logarithmic phase of growth and was greatly affected by growth conditions. The optimal temperatures for growth and lipase production were respectively 24°C for B. thermosphacta and 30°C for lactobacilli. For all strains, an initial pH of around 7‐0 for the medium and low glucose concentration stimulated lipase production. Tributyrin inhibited both growth and lipase production at a concentration of 0‐1% for B. thermosphacta or 1% for lactobacilli. Butyric acid (0‐1%) and anaerobic culture inhibited lipase production by B. thermosphacta while these two factors had no effect on enzyme production by lactobacilli.
Response of populations of human faecal bacteria to viscosity in vitro
Authors: Wyatt G.M. , Archer D.B.
Published: March 2008

The effects of viscosity on cultures of human faecal bacteria in vitro were studied. The composition of the microbial populations which developed during in vitro incubation were affected by viscosity. The proportion of Bacteroides species was decreased at high viscosities and it is concluded that the ‘viscotolerance’ of a bacterial population contributes towards its composition. Viscosity alters the enzyme activity of cultures. Cell‐associated total, and specific, β‐galactosidase activities of cultures of human faecal bacteria were decreased at high viscosity.
Infiltration of Pseudomonas putida cells, strain 48, into xylem vessels of cut Rosa cv. ‘Sonia’
Authors: Put Henriëtte M.C. , van der Meyden T.
Published: March 2008

Pseudomonas putida cells were unable to pass the inter‐vessel pit membranes of the xylem system of cut roses (Rosa hybrida cv. ‘Sonia’). It was further shown that (1) the number of bacteria which infiltrated into the xylem vessels decreased with increased distance between the cutting point and sampling point; (2) the number of bacteria which infiltrated into the open xylem vessels increased with time and with increasing numbers of pseudomonas cells; (3) only a minor part of the pseudomonas cells homogeneously suspended in the vase solution was able to infiltrate into the xylem vessels of the cut roses up to a distance from the cutting point of > 1 cm; and (4) even low levels of infiltrated pseudomonas cells could be demonstrated by measurements of the water conductivity of stem segments. More research is needed to reveal which mechanisms (e.g. gumnosis) might have contributed, directly or indirectly, to the prevention of further infiltration of bacterial particles into the cut open vascular system of the Rosa cultivar.
Characterization of Bacillus cereus strains isolated from drugs and evaluation of their toxins
Authors: Arribas M. Luisa García , Plaza Carlos J. , de la Rosa M. Carmen , Mosso M. Angeles
Published: March 2008

The microbial contamination of 68 samples of topical and 324 samples of oral medicaments has been studied. The most common group of contaminants was members of the genus Bacillus (34.4%). Because of the pathogenic significance of B. cereus, 39 strains were characterized by morphology and biochemical properties. All except three showed most of the characteristics of the type strain. They were highly resistant to lincomycin, polymyxin B and penicillin G‐cephalosporin and were susceptible to streptomycin, erythromycin and chloramphenicol. Enterotoxin, phospholipase C and haemolysin production were also studied: 33 strains gave a positive vascular permeability reaction, four of them causing necrosis, and 24 showed positive mouse lethal tests. All the strains had phospholipase activity. The majority also exhibited differing degrees of haemolysis. Permeability factor was related to mouse lethality and haemolytic activity. Phospholipase C was not related to any of the above activities.
The effects of temperature and pH on the growth of yeast species during the fermentation of grape juice
Authors: Heard G.M. , Fleet G.H.
Published: March 2008

The effects of temperature and pH on the survival and growth of Saccharomyces cerevisiae, Kloeckera apiculata, Candida stellata, Candida krusei, Candida pulcherrima and Hansenula anomala were examined during mixed culture in grape juice. At 25°C, pH 3.0 and pH 3.5, S. cerevisiae dominated the fermentation and the other species died off before fermentation was completed. Saccharomyces cerevisiae also dominated the fermentation at 20°C but there was increased growth and survival of the other species. At 10°C the fermentation was dominated by the growth of both S. cerevisiae and K. apiculata and there was extended growth and survival of C. stellata and C. krusei. Juices fermented at 10°C exhibited ethanol concentrations between 7.4 and 13.4% and populations of K. apiculata, C. stellata and C. krusei in the range 106‐108 cells/ml. However, these species produced maximum ethanol concentrations in the range 2.7–6.6% when grown as single cultures in grape juice.
Staphylococcus aureus, thermostable nuclease and staphylococcal enterotoxins in raw ewes' milk Manchego cheese
Authors: Nuñez M. , Bautista Lydia , Medina Margarita , Gaya Pilar
Published: March 2008

Growth and survival of two enterotoxigenic strains of Staphylococcus aureus were studied during manufacture and ripening of eight batches of raw ewes' milk Manchego cheese. Only 2–3 generations of Staph. aureus occurred in the vat and during pressing. The death rate of Staph. aureus (mean decrease in log cfu/g/week of ripening) from day 1 to day 60 was 0.421 in cheese made with 1%Streptococcus lactis starter and 0.404 in cheese made without starter. Thermostable nuclease was produced in the vat by growing Staph. aureus cells; it was inactivated by rennet during the first 24 h and synthesized again by surviving cells of Staph. aureus from day 1 to day 60. Staphylococcal enterotoxins A, B, C and D were not detected in any batches of cheese, even though Staph. aureus counts exceeded 107 cfu/g.
Electropositively charged filters for the recovery of yeasts and bacteria from beverages
Authors: Thomas D. Susan
Published: March 2008

The ability of electropositively charged filters to recover yeasts and lactic acid bacteria from a variety of beverages was evaluated. Filtration through ‘Zeta plus’, grade OSS, filters recovered nearly all of the yeast contaminants from table wines, sherry and port. Recovery of yeasts from cream liqueurs and egg‐based beverages was also good but it was not possible to filter drinks containing orange juice, even through filters with nominal pore sizes of 2 to 10 μm. Lactic acid bacteria proved more difficult to recover than yeasts, even though smaller pore‐sized filters (1 to 4 μm) were employed. However, a sufficiently high percentage of bacteria were recovered to justify use of these filters for quality assurance. The advantage of concentrating contaminants by using charged filters, and the influence of product composition on the efficiency of microbial adsorption are discussed. The growth of wine‐spoiling yeasts and lactic acid bacteria were not inhibited by water‐ or ethanol‐soluble extracts of the filter material.
Metabolism and some characteristics of lactobacilli isolated from the rumen of young calves
Authors: Marounek M. , Jehlickova Katerina , Kmet V.
Published: March 2008

Fourteen strains of lactobacilli isolated from the rumen of young calves were studied to determine their biochemical characteristics, growth parameters, metabolism on lactose and sensitivity to 28 antimicrobial agents. Thirteen homofermentative strains belonged to Lactobacillus acidophilus and one heterofermentative strain resembled Lact. fermentum. The relevance of rumen lactobacilli to the nutrition of calves is discussed.
Presumptive identification of nocardias in a clinical laboratory
Authors: Collins C.H. , Yates M.D. , Uttley Anne H.C.
Published: March 2008

One hundred and thirty‐six cultures of aerobic streptomycetes were examined by simple cultural and microscopical methods. Nocardia spp. were recognized by their resistance to lysozyme and identified to the three important species by casein, xanthine and tyrosine hydrolysis tests.
Numerical analysis of electrophoretic protein patterns of Campylobacter laridis and allied thermophilic campylobacters from the natural environment
Authors: Owen R.J. , Costas M. , Sloss Lesley , Bolton† F.J.
Published: March 2008

Twenty‐one strains comprising Campylobacter laridis (nine), nalidixic acid sensitive campylobacters (NASC) (four), and urease‐positive thermophilic campylobacters (UPTC) (eight) were characterized by one‐dimensional SDS‐PAGE of cellular proteins. The UPTC and NASC strains included six from river water, two from mussels and four from sea water. The type strains of three other Campylobacter species were included for reference. The protein patterns, which contained 45–50 discrete bands, were highly reproducible and were used as the basis for two numerical analyses. In the first, which included all the protein bands, the 21 strains formed nine clusters at the 80% similarity (S) level. The typical C. laridis strains were restricted to two phenons (2 and 5); the atypical strains being distributed among the remaining phenons. In the second analysis, which excluded the principal protein bands (40–48.5 kD range), the 21 strains formed five clusters at the 80% S level. The typical C. laridis strains were relatively homogeneous and fell into a single phenon (2) within which two subgroups were discernable. The atypical strains were more heterogeneous with respect to background protein pattern, with representatives appearing in all five phenons. An electropherotyping scheme comprising six electropherotypes, and based on both analyses is proposed. The high within‐group S level and separation from reference strains of Campylobacter in the second analysis, suggested that UPTC and NASC strains belonged within C. laridis possibly as biovars.
Some important parameters in the evaluation of herbicide toxicity in diazotrophic cyanobacteria
Authors: Singh Laisram J. , Tiwari D.N.
Published: March 2008

The effect of different inocula sizes on the toxicity of the herbicides machete, basalin and propalin was tested. The inocula sizes gave differential response pattern towards a particular herbicide dose and, as such, the employment of a specific dose inoculum response is suggested. Furthermore, Gloeocapsa sp. showed remarkable herbicide resistance potential while Nostoc muscorum was quite susceptible to all the herbicides.
Serological studies on Listeria grayi and Listeria murrayi
Authors: Vazquez‐Boland J.A. , Rodriguez L. Dominguez , Garayzabal J.F. Fernandez , Cancelo J.L. Blanco , Gomez‐Lucia E. , Dieste V. Briones , Fernandez G. Suarez
Published: March 2008

A cross‐agglutination study between somatic antigens from reference strains of Listeria grayi and Listeria murrayi with rabbit antisera was done. L. murrayi antisera reacted, at low titres, with L. grayi but L. grayi antisera did not react with L. murrayi antigen. These results, together with agglutinin‐absorption tests, led to the conclusion that the serologic relationship between L. grayi and L. murrayi is not as close as is thought. The two species seem to differ in at least one somatic factor, that might be designated O‐XVI for L. grayi and O‐XVII for L. murrayi. The serologic relationship of L. grayi and L. murrayi with other serovars of Listeria is discussed. The agglutination titre of 180 healthy ruminants against O‐antigens of L. grayi and L. murrayi was also investigated; almost all the sera reacted with the antigens of these species, with similar titres (that reached 640) to those detected against O‐antigens of serogroups 1/2 and 4.
Post‐processing microflora and the shelf stability of gari marketed in Port Harcourt
Authors: Ofuya C.O. , Akpoti P.
Published: March 2008

Gari was examined for its post‐processing microbial content. Aerobic mesophilic bacteria and fungi were isolated from all samples. The total viable bacterial counts ranged from 2.0 × 102 to 8.0 × 104 cfu/g. Fungal counts ranged from 1.0 × 102 to 1.5 × 104 cfu/g. The total viable counts of fresh samples were much lower than those of market and packaged samples. Bacillus, Micrococcus and Proteus spp. were the bacteria isolated, Aspergillus niger, Aspergillus flavus and Penicillium spp. the fungi. Food borne parasites and pathogens such as Staph. aureus and Clostridium perfringens were not found. The gari samples were quite stable, having a shelf life of 3–6 months. The water activities of the samples ranged from 0.52 to 0.68. Based on the microbial counts of the samples, the critical upper limit for the safety of gari was set at 104 cfu/g dry sample.
Lactic acid bacteria in murcha and ragi
Authors: Hesseltine C.W. , Ray M.L.
Published: March 2008

Sixty‐nine strains of bacteria isolated from murcha and ragi (amylase starters) were studied. These came from 14 different amylase starters from Java, Bali, and Nepal and were isolated from dilution plates incubated under aerobic and anaerobic conditions. Most belonged to Pediococcus, probably P. pentosaceus, and to Streptococcus faecalis. None were able to attack starch although they are used in starch fermentations. When inoculated on rice as pure cultures most of them failed to show visible growth unless yeasts and moulds were added at the same time. The roles of these bacteria are unknown but they may produce secondary products from the glucose formed by the amylolytic yeasts and moulds always found in the starters.
Factors affecting the induction of malolactic fermentation in red wines with Leuconostoc oenos
Authors: Wibowo D. , Fleet G.H. , Lee T.H. , Eschenbruch R.E.
Published: March 2008

Malolactic fermentation was induced in red wines by inoculation with several strains of Leuconostoc oenos. The progress of Malolactic Fermentation was monitored by following the kinetics of bacterial growth and degradation of malic acid. These kinetics varied significantly depending on the strain of Leuc. oenos inoculated, the strain of Saccharomyces cerevisiae used to conduct the alcoholic fermentation, and the wine properties of pH and concentrations of ethanol and sulphur dioxide. Rapid, predictable malolactic fermentation was achieved by inoculating a high density (> 106 cfu/ml) of Leuc. oenos, whereby malic acid degradation was not connected to the growth of the bacterial cells. Wines after malolactic fermentation were not bacteriologically stable and supported the growth of Leuc. oenos inoculated into the wines.
Olaquindox resistance in the coliform flora of pigs and their environment: an ecological study
Authors: Hedges A.J. , Linton A.H.
Published: March 2008

Faecal samples were taken weekly from a chosen pen on each of four commercial pig farms, two of which used olaquindox as a feed additive. Coliform bacteria were isolated from the samples and the incidence and level of resistance to olaquindox and to four therapeutic antibiotics determined. The coliforms isolated were biotyped to follow the emergence of drug‐resistant sub‐populations. The results showed that the coliform flora was complex and that a turnover of biotypes was associated with changes in the occupancy of the pen and, possibly, diet. This turnover led to large fluctuations in both incidence and level of resistance to olaquindox and the antibiotics. Olaquindox resistance was not specifically linked with resistance to any therapeutic antibiotic, and the possible origin of olaquindox‐resistant strains is discussed in relation to the biotypes.
Regulation of isofunctional enzymes in Pseudomonas alcaligenes mutants defective in the gentisate pathway
Authors: Poh C.L. , Bayly R.C.
Published: March 2008

The regulation of the inducible set of gentisate pathway enzymes used by Pseudomonas alcaligenes (P25X1) has been studied in strains derived from mutant strains of P25X1 that had lost the constitutive enzymes that degrade m–cresol, 2,5–xylenol and 3,5–xylenol. The enzyme, 3‐hydroxybenzoate 6‐hydroxylase II, that catalyzes the oxidation of 3‐hydroxybenzoate to gentisate is substrate‐ and product‐induced while gentisate dioxygenase II is substrate induced. Neither 3‐hydroxybenzoate nor gentisate could induce the synthesis of maleylpyruvate hydrolase II and fumarylpyruvate hydrolase II. The results suggest that the structural genes encoding these four inducible enzymes and maleylpyruvate hydrolase I (a constitutive enzyme) exist in at least four operons. There is strict induction specificity of expression of this inducible set of gentisate pathway enzymes. 3‐Hydroxy‐4‐methyl‐benzoate failed to induce whilst 3‐hydroxybenzoate and 3‐hydroxy‐5‐methylbenzoate served as inducers of 6‐hydroxylase II. Degradation of 2,5‐xylenol is mediated by constitutive enzymes whereas the inducible set of enzymes are responsible for the metabolism of m‐cresol and 3,5‐xylenol.
Postprandial variations in the activity of polysaccharide‐degrading enzymes in microbial populations from the digesta solids and liquor fractions of rumen contents
Authors: WILLIAMS A. G. , Withers Susan E. , Strachan N. H.
Published: March 2008

The diurnal variations in the specific activities of polysaccharide‐degrading enzymes after feeding were monitored in adherent and non‐adherent microbial populations separated from bovine rumen liquor and digesta solids. There were marked differences in the activity profiles of the enzymes within the subpopulations. Enzymes involved in the degradation of soluble carbohydrates were more active in the non‐adherent populations, and in the liquor phase subpopulation activities increased in the 1–2 h post‐feed period. The muralytic enzymes were most active in the adherent population. Specific activities increased by up to 20‐fold over the 24 h period, with an initial five‐fold increase occurring between 8 h and 12 h after feeding. Enzyme levels in the three non‐adherent populations were similar at the end of the postprandial period. In the population recovered from the liquid associated with the digesta particles, however, the activities did not increase until the latter stages of the period, whereas in the non‐adherent population from the digesta solids the activities varied little during the diurnal cycle. The numbers of micro‐organisms associated with the digesta solids were similar at 2 h and 20 h after feeding; the variations in enzyme levels did not occur as a result of a population increase but were due to increased activities in an established population. The plant cell wall structural polysaccharides were degraded at different rates. There was no appreciable cellulose digestion during the first 8 h of the postprandial period and although hemicellulosic constituents were removed continuously the rate of loss of both polymers was increased in the later stages of the diurnal cycle when enzyme activities were maximal.
A biotinylated DNA probe to detect bacterial cells in artificially contaminated foodstuffs
Authors: Dovey S. , Towner K. J.
Published: March 2008

A biotin‐labelled DNA probe was used in a dot‐blot hybridization test to demonstrate the presence of Escherichia coli in a variety of artificially contaminated foodstuffs. Positive hybridization was detected by using a streptavidine/polyalkaline phosphatase conjugate to generate an insoluble coloured precipitate in the presence of an appropriate dye. The colour intensity was measured with a computer‐controlled image analysis system which assessed objectively the hybridization signal produced by each sample. The method was capable of distinguishing positive hybridization at cell concentrations exceeding 104 cells/dot‐blot, equivalent to 2×107 cells/g food, and had none of the drawbacks normally associated with the use of radioactively labelled DNA in hybridization techniques. The procedure is highly specific and takes less than 30 h. Many samples can be screened simultaneously and the procedure can be used to detect any species for which a suitable DNA probe is available
Rapid radiometric detection of mycobacterial growth from smear‐positive tissue samples from pigs
Authors: Hoffner S.E. , Hahn K. , PEdersen A. , Sandstedt K.
Published: March 2008

Rapid demonstration of mycobacteria in slaughter pigs is important for medical, epidemiological and economic reasons. The Bactec radiometric system detected more mycobacteria in less time than conventional culture on solid medium.
Antimicrobial activity of clove oil dispersed in a concentrated sugar solution
Authors: Briozzo Jorge , Núncez Lidia , Chirife Jorge , Herszage León , D'aquino Miguel
Published: March 2008

Essential oil of clove, dispersed (0.4%v/v) in a concentrated sugar solution, had a marked germicidal effect against various bacteria and Candida albicans. Staphyloccus aureus (five strains), Klebsiella pneumoniae, Pseudomonas aeruginosa, Clostridium perfringens, and Escherichia coli inoculated at a level of 107 cfu/ml, and C. albicans (inoculum 4.0×105 cfu/ml) were killed (< 99.999%) after 2–7 min in a laboratory broth supplemented with 63% (v/w) of sugar, and containing 0.4% (v/w) of essential oil of clove. Added organic matter (i.e. human or bovine serum) did not impair its antimicrobial activity.

Sugar was not necessary for the antimicrobial activity of clove oil, but the concentrated sugar solution provided a good vehicle for obtaining an oil dispersion that is relatively stable for certain practical applications.
Impact of aeration on the metabolic end‐products formed from glucose and galactose by Streptococcus lactis
Authors: Cogan J.F. , Walsh D. , Condon S.
Published: March 2008

Compared with cultures grown aerobically in batch culture with glucose, aerated cultures of lactic streptococci had a less homolactic type of metabolism when galactose was the carbohydrate source in batch cultures, or when glucose was limiting in chemostat cultures. Differences in end‐products of sugar metabolism between aerated and unaerated cultures were observed. In addition to lactate, formate, acetate and ethanol were produced in anaerobic cultures, whereas acetate and acetoin were formed in aerated cultures. Acetate production in aerated cultures depended on lipoic acid, an essential cofactor of the pyruvate dehydrogenase complex. In a chemically defined medium with glucose as the energy substrate, lipoic acid (or acetate) was an essential growth factor. Formation of acetoin was inversely related to lipoic acid concentration in the growth medium. Although not observed in unaerated cultures, acetoin (and 2,3‐butanediol) was produced in unaerated buffered suspensions metabolizing pyruvate. Aeration caused a modest increase in the activities of aP‐acetolactate synthetase and phosphate acetyl trans‐ferase, but it is unlikely that the increases were sufficient to account for the changes in end‐products of sugar metabolism observed.
Enhanced resistance of anaerobic rumen fungi to the ionophores monensin and lasalocid in the presence of methanogenic bacteria
Authors: Stewart C. S. , Richardson A. J.
Published: March 2008

The presence of Methanobrevibacter smithii altered the susceptibility of the anaerobic fungi Neocallimastix frontalis and Piromonas communis to the carboxylic ionophores monensin and lasalocid. The ionophores depressed growth (measured by chitin accretion), the uptake of glucose and the production of H2, formate and acetate by the fungi growing axenically in semi‐solid medium. In the presence of M. smithii, the sensitivity of the fungi to monensin and lasalocid was decreased. For example, the uptake of glucose by N. frontalis strain RE1 in the culture was reduced to 50% of the control value by monensin at 0.5 mUg/ml. In the presence of M. smithii strain PS, approximately three tunes as much monensin was needed to bring about the same effect. In similar tests, the sensitivity of strain RE1 to lasalocid was decreased about nine‐fold in the presence of M. smithii. The effect was not observed if the methanogens were killed by autoclaving before inoculation. It is suggested that the enhanced resistance to ionophores in the presence of M. smithii is a consequence of changes in the energy metabolism of the fungi growing in co‐culture.
Physiological state of epiphytic bacteria on submerged stems of the reed Phragmites australis compared with planktonic bacteria in gravel‐pit ponds
Authors: Al‐hadithi S.A. , Goulder R.
Published: March 2008

Suspensions of epiphytic bacteria from submerged stems of Phragmites australis, collected from a gravel‐pit pond, were prepared by treatment in a stomacher and by brushing. The two procedures were equally successful in dislodging bacteria. These epiphytic bacteria were compared with planktonic bacteria in water samples from within the reed bed. Colony‐forming units (cfu) as a percentage of acridine‐orange direct counts (AODCs), percentage of cells capable of intracellular reduction of 2‐(p‐iodophenyl)‐3‐(p‐nitrophenyl)‐5‐phenyl tetrazolium chloride (INT) to INT‐formazan, percentage of cells able to form microcolonies, and cell length were all greater for epiphytic bacteria. Epiphytic bacteria of P. australis from six further gravel‐pit ponds were also compared with bacterioplankton; cfu as a percentage of AODCs, and percentage of cells capable of INT reduction were again greater for epiphytic bacteria. Because the epiphytic bacteria in these non‐organically‐enriched, gravel‐pit ponds were physiologically different from the planktonic bacteria it is suggested that there was not continual casual exchange, by largely identical bacterial cells, between the epiphytic and planktonic mode. Instead, epiphytic and planktonic populations were independent of each other and/or if there was exchange then bacteria were more successful while in the attached mode, perhaps because of greater organic‐nutrient availability at the stem surface.
Differentiation of Staphylococcus aureus from freshly slaughtered poultry and strains ‘endemic’to processing plants by biochemical and physiological tests
Authors: Mead G.C. , Norris A.P. , Bratchell N.
Published: March 2008

A comparison was made of 27 ‘endemic’ strains of Staphylococcus aureus and 35 strains from freshly slaughtered birds, isolated at five commercial slaughterhouses processing chickens or turkeys. Of 112 biochemical and physiological tests used, 74 gave results which differed among the strains. Cluster analysis revealed several distinct groupings which were influenced by strain type, processing plant and bird origin; these included a single group at the 72% level of similarity containing most of the ‘endemic’ strains. In comparison with strains from freshly slaughtered birds, a higher proportion of ‘endemic’ strains produced fibrinolysin, aP‐glucosidase and urease and were β‐haemolytic on sheep‐blood agar. The ‘endemic’ type also showed a greater tendency to coagulate human but not bovine plasma, and to produce mucoid growth and clumping. The last two properties, relevant to colonization of processing equipment, were less evident in heart infusion broth than in richer media or process water collected during defeathering of the birds.
A comparative study of the bactericidal and growth inhibitory activities of the bisbiguanides alexidine and chlorhexidine
Authors: CHAWNER JUDI A. , GILBERT P.
Published: March 2008

A comparative study of the growth inhibitory and bactericidal activities of two related bisbiguanide antiseptics, alexidine and chorhexidine is reported. Whilst overall bactericidal activities and MICs were similar, alexidine was more rapid in its action and it is suggested that (1) it might possess additional targets at the cell envelope to chlorhexidine, and (2) the nature of the interaction at the cytoplasmic membrane for the two compounds differs.
Bacterial overgrowth in the jejunum of ICR mice and Wistar rats orally administered with a single lethal dose of fusarenon‐X, a trichothecene mycotoxin
Authors: MORISHITA Y. , NAGASAWA K. , NAKANO NAOKO , SHIROMIZU KIMIKO
Published: March 2008

A single oral dose of fusarenon‐X (F‐X), a trichothecene mycotoxin, resulted in abnormal microflora in the jejunum in ICR mice and Wistar rats with some differences in dose response between the species. In the acute phase, enterobacteria, streptococci, Clostridium perfringens and bacteroides showed remarkably increased counts in the jejunum of mice and rats dosed with F‐X while lactobacilli showed a decrease in count. F‐X brought an invasion of Pseudomonas aeruginosa into the livers, lungs, kidneys and spleens of ICR mice. Changes in the jejunal microflora appeared after 7 h in ICR mice and after 24 h in Wistar rats after a single oral dose of F‐X of 7–5 and 4–0 mg/kg b.w., respectively, and the microflora returned to its normal state at 72 h in mice and 96 h in rats. The changes of intestinal microflora were followed by alterations in the growth curves of both animal species. The pH in the glandular stomach was also greatly enhanced before changes in the jejunal microflora. Acute F‐X intoxication may be an involved manifestation of essential cytotoxicity of F‐X mycotoxin alone and secondary bacterial overgrowth in the bowel.
Partial purification and characterization of phospholipase C from Yersinia enterocolitica
Authors: TOORA S. , SINGH GAGANDEEP , DHAR S. , SINGH A.D. , TIWARI R.P. , SINGH G.
Published: March 2008

About 34% of the strains of Yersinia enterocolitica isolated from raw milk were found to produce lecithinase. A selected strain produced phospholipase C at 22°C and 37°C; production was optimum at 37°C in the stationary phase (14–16 h). A decrease in phospholipase C activity at various storage temperatures (—5°C, 4°C, 37°C) was also observed, although the enzyme was active over a wide range of temperature (5–65°C) and pH (3mD5–7mD5). The phospholipase C was partially purified by ammonium sulphate precipitation and Sephadex column chromatography, and characterized.
Klebsiella pneumoniae haemolysin adsorption to red blood cells
Authors: Albesa Inés
Published: March 2008

It was necessary to incubate the Klebsiella pneumoniae haemolysin with erythrocytes at 37°C to produce the whole lytic action. The amount of attached klebolysin at 4°C increased as its concentration in the medium increased, until the erythrocyte surface was saturated. Treatment with 2‐mercaptoethanol was necessary to permit the adsorption; it was inhibited by low concentrations of cholesterol. Klebsolysin was immunogenic and its antiserum neutralized its own haemolytic effect and streptolysin O. Anti‐streptolysin serum also neutralized klebsolysin. Streptolysin O attachment to erythrocytes impeded the posterior klebolysin adsorption in the same way that klebsolysin adsorption interfered with streptolysin O attachment.
Production and characterization of a compound inhibitory to Vibrio parahaemolyticus from Proteus vulgaris
Authors: Gbejuade Carol M. , Upton Mary E. , Moran A. P.
Published: March 2008

The production and characteristics of a compound in Proteus vulgaris G cultures which was capable of inhibiting Vibrio parahaemolyticus and other food‐borne pathogens was investigated. Production was influenced by medium composition, pH and temperature but not by the extent of aeration. The compound was most inhibitory at the optimum temperature for growth of V. parahaemolyticus. The inhibitor was most stable at pH 7·0 and inhibition occurred even after heating at 70°C for 30 min and after autoclaving. Ultrafiltration showed that the inhibitor had a molecular weight less than 1000. Thin layer chromatography of filtrates and subsequent peptidase digestion indicated that it was at least in part a peptide. The inhibitor purified by Sephadex G‐15 gel filtration had a calculated molecular weight of 731 and contained only six amino acids.
The effects of chlorhexidine on the maximum specific growth rate, biomass and hydrolytic enzyme production of Bacteroides gingivalis grown in continuous culture
Authors: Minhas T. , Greenman J.
Published: March 2008

Bacteroides gingivalis was grown in continuous culture in the presence of chlorhexidine. Maximum specific growth rates and biomass levels initially increased but then decreased as the chlorhexidine level increased from 0 to 30 μg/ml. Total inhibition of growth occurred when the chlorhexidine concentration reached 60 μg/ml. The steady‐state levels of cell‐bound, extracellular vesicle and extracellular soluble enzymes, trypsin‐like protease, alkaline phosphatase and N‐acetyl‐β‐glucosaminidase were measured. With increasing sub‐lethal concentrations of chlorhexidine, levels of alkaline phosphatase increased noticeably in all three fractions of culture, whilst cell‐bound and extracellular vesicle levels of N‐acetyl‐β‐glucosaminidase remained approximately constant. Extracellular soluble levels of alkaline phosphatase and N‐acetyl‐β‐glucosaminidase increased with increasing levels of chlorhexidine. The levels of trypsin‐like protease decreased significantly in all fractions of the culture when cells were grown in the presence of chlorhexidine. Thus, chlorhexidine has a differential effect on the production of B. gingivalis hydrolytic enzymes.
Identification of psychrotrophic pseudomonads from goats’milk by computer‐assisted analysis of carbon source assimilation data
Authors: Cox J.M. , Rae I.C. Mac
Published: March 2008

The results of carbon source assimilation tests on a group of psychrotrophic pseudomonas were compared with published data for established Pseudomonas taxa, using computer‐assisted numerical taxonomic analysis and a modified diagnostic computer program. Several phenons were not grouped at the biovar level by numerical taxonomic analysis. Identification of strains by the diagnostic program revealed heterogeneity among those in the unassigned phenons, and supported a continuum concept among the fluorescent pseudomonads.