bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Studies on the Sampling and Investigation of Microbial Contamination of Surfaces by the Contact Plate and Swab Methods
Authors: NISKANEN A. , POHJA M. S.
Published: March 2008

In this study a comparison was made of recovering bacteria from stainless steel, plastic, wood, agar and meat surfaces. Sampling was performed using the agar contact and swab methods. The results indicated that for a flat, firm surface the contact plate method was more suitable, considering both recovery and repeatability. Swabbing was, by contrast, better for flexible and uneven surfaces and for heavily contaminated surfaces. Bacteriological guidelines are suggested for the hygienic evaluation of surface contamination of meat carcasses and for working surfaces in meat processing plates.
The Use of an Escherichia coli Lys‐ Auxotroph to Assay Nutritionally Available Lysine in Biological Materials
Authors: PAYNE J. W. , BELL G. , HIGGINS C. F.
Published: March 2008

A new bacterial method for determining amino acids in protein foods is described. Instead of the ‘natural’microbial auxotrophs e.g. Tetrahymena, Streptococcus, and Leuconostoc, currently used for such assays, an ‘artificial’mutant is used, viz. an auxotroph of Escherichia coli. Test proteins (Bovine serum albumin, legume and maize meals) were predigested with a mixture of pronase and intestinal peptidases, the efficiency and extent of proteolysis being monitored by pH stat titration. Final digests were examined by Sephadex gel filtration to ensure that all protein cleavage products were small enough to pass through the E. coli cell wall and to reach its cyto‐plasmic amino acid and peptide permeases. The lysine content of the meals, as determined from the growth of an E. coli lysine auxotroph upon the digests, was found to be greater than 90° of the lysine determined chemically in acid hydrolysates. Practical and theoretical advantages of using this latter type of bacterium rather than the fastidious species are discussed. In addition, the particular value of using an intestinal bacterium like E. coli to assay nutritional availability of amino acids is considered in relation to its normal utilization of digested protein foods in vivo, and the similarities between its amino acid and peptide permeases and those of the intestine.
The Cell Wall Composition and Distribution of Free Mycolic Acids in Named Strains of Coryneform Bacteria and in Isolates from Various Natural Sources
Authors: KEDDIE R. M. , CURE G. L.
Published: March 2008

The major cell wall amino acids and sugars in 177 strains of coryneform bacteria were determined using a ‘rapid’method. Representatives were examined for free mycolic acids and the oxygen requirements of all strains were determined. Included were named strains, most of which were labelled Arthrobacter, Brevibacterium, Cellulomonas, Corynebacterium or Microbacterium, and a similar number of unnamed isolates from various natural sources. Strains which contained meso‐diaminopimelic acid (DAP) were divided into four groups according to their oxygen requirements, the wall sugars and the occurrence and nature of free mycolic acids. Group 1 strains were mainly facultatively anaerobic and contained arabinose and mycolic acids of the Corynebacterium type. They were considered to be members of Corynebacterium sensu stricto and included Cor. diphtheriae and related animal parasites, Microbact. flavum, and Cor. glutamicum and similar species. Group 2 strains were aerobic, contained arabinose and mycolic acids of the ‘rhodochrous’type and were considered members of the ‘rhodochrous’complex. Group 3 strains were aerobic, contained ribose and no mycolic acids. Most were Br. linens strains from cheese but a few, possibly related strains, were from other habitats. Group 4 strains were aerobic and contained neither a pentose sugar nor mycolic acids and were of unknown taxonomic status. Most remaining strains contained lysine or ornithine in the wall and smaller numbers contained L‐DAP or diaminobutyric acid; none contained mycolic acids. The chemotaxonomic data are discussed in relation to recent numerical taxonomic studies of coryneform bacteria.
Micro‐organisms Associated with Cassava Fermentation for Garri Production
Authors: OKAFOR NDUKA
Published: March 2008

The predominant micro‐organisms isolated from de‐watered cassava pulp fermenting for garri production over a six‐day period were mainly Leuconostoc and, to a lesser extent, yeasts.

Corynebacterium sp. which had been implicated by earlier workers as the bacterium fermenting cassava was present in low numbers only.

It is suggested that although the predominant bacteria would be expected to produce lactice acid from the free sugar of the cassava, the breakdown of the cassava glucoside linamanin is probably accomplished more by the endogenous enzyme linamarase than by bacterial activity.
Antibiotic Resistance among Escherichia coli O‐serotypes from the Gut and Carcasses of Commercially Slaughtered Broiler Chickens: a Potential Public Health Hazard
Authors: LINTON A. H. , HOWE KATHERINE , HARTLEY CHRISTINE L. , CLEMENTS HELEN M. , RICHMOND M. H. , OSBORNE A. D.
Published: March 2008

Presumptive coliform counts and the distribution of Escherichia coli O‐serotypes were investigated in chicken rectal contents (175) abdominal cavities (152) and on the carcasses of 44 which had been commercially raised, slaughtered and prepared for sale. Large numbers of E. coli resistant to at least one antibacterial agent were found at each site; comparison of the O‐serotypes suggested heavy contamination of the carcass with strains from the gut. The range of O‐serotypes was similar to that found in man and some public health implications of cross‐infection particularly by handling uncooked birds in the kitchen, are discussed.
Effects of Composition of Substrate and Inoculation Technique on Plate Counts of Bacteria in the Northern Baltic Sea
Authors: VÄÄTÄNEN P.
Published: March 2008

Medium V has been developed for the enumeration of total colony forming units (TCFU) of heterotrophic bacteria in coastal waters of the Northern Baltic Sea.

Medium V gave higher counts than ZoBell's medium 2216 E with samples taken over six months. The difference between counts for the inshore samples was significant.

A comparison of ‘spread’and ‘pour’plates suggested that the former was superior, especially for the enumeration of TCFU of psychrophiles.

‘Spread’plating should be used for samples whose natural temperature would suggest the presence of psychrophiles.
Incidence and Spoilage Potential of Isolates from Vacuum‐packaged Meat of High pH Value
Authors: PATTERSON J. T. , GIBBS P. A.
Published: March 2008

Meat of high pH value (6·6) showing dark‐cutting characteristics was vacuum‐packaged and stored for up to 8 weeks at 0–2°C. ‘Off’‐odours were detected on opening the packages after 6 weeks of storage. Total counts at this stage were ca. 107/cm2 of which lactobacilli were the major component, with ca. 106/cm2 Gram negative organisms. Psychrotrophic Enterobacteriaceae represented a major proportion of the microflora only after the full 8 weeks of storage and were not detected previously. Aerobic storage of steaks cut from the vacuum packaged meat stored for 8 weeks resulted in a predominantly Gram negative spoilage flora.

Inoculation studies on meat of normal pH value (5·4) and appearance using representative isolates from the vacuum‐packaged meat microflora indicated that most of the test organisms were capable of causing spoilage under aerobic conditions but few under vacuum‐packaging when incubated at 4°C. On meat of higher pH value (6·15) many of the Gram negative isolates did not grow as well, whereas the Gram positive isolates grew better than on meat of normal pH value when held under aerobic conditions. Under vacuum‐packaging all but one isolate grew as well or better on meat of high pH value than on normal meat at 4°C and objectionable odours were more marked.
The Delineation of a Point Source Plume by the Study of Bacterial Populations
Authors: RAO S. S. , BUKATA R. P.
Published: March 2008

Recent point source microbiological studies, using radial grid sampling stations, have indicated the potential of using bacterial populations to delineate mixing zones and identify the plumes. The discharge from the Niagara River into Lake Ontario was studied and microbiological data from the main plume area (impact zone), zone of minor influence of the plume, and the non‐plume lake waters are presented. The microbiological observations were found to agree with thermal observations of the plume area made by remote sensing scanning techniques.
A Quantitative Evaluation of the Antifungal Properties of Glutaraldehyde
Authors: GORMAN S. P. , SCOTT E. M.
Published: March 2008

Fungistatic data were obtained from measurements of mycelial growth of several fungal species in the presence of acid or alkaline glutaraldehyde. Alkaline glutaraldehyde in concentrations > 0·1% (w/v) prevented growth of all species examined while 0·5% (w/v) acid glutaraldehyde was necessary to achieve this effect. Further fungistatic data were obtained using a Coulter Counter method to measure spore swelling. Fungicidal determinations resulted in a 99·99% reduction in viable count after 90 min contact with 0·5% (w/v) alkaline glutaraldehyde. A considerable drop in spore production was also observed after treatment with alkaline glutaraldehyde.
Effect of Some Unicellular Algae on Escherichia coli Populations in Sea Water and Oysters
Authors: BROWN R. K. , McMEEKIN T. A. , BALIS C.
Published: March 2008

Acrylic acid was detected in sea water in which oysters had been maintained and was shown to be derived from unicellular algae containing dimethyl‐β‐propiothetin (DMPT). Anticoliform activity was noted in samples containing acrylic acid. Intensification of the effect was achieved in laboratory studies and Phaeodactylum tricornutum (DMPT present) caused a rapid decline of Escherichia coli populations in sea water and in oysters which had been fed this alga. Pavlova lutheri (DMPT absent) was ineffective against E. coli.
A Comparative Investigation of the Bactericidal and Fungicidal Effects of Three Phenolic Disinfectants
Authors: HEGNA IDA K.
Published: March 2008

Two methods, a capacity use‐dilution test and another employing geometrical dilution, are used when comparing the bactericidal and fungicidal effects of a phenolic disinfectant containing 45% (w/w) o‐phenylphenol in an aqueous soap solution of linseed oil (soap content 6·5% w/v) with the corresponding effects of the same phenolic compound in an aqueous soya oil soap solution (soap content 3·5% w/v). The soya oil soap did not change the disinfectant capacity on the different test organisms used. For the most resistant strain (Staphylococcus aureus) the usedilution concentration was evaluated to be slightly above 1%, i.e. 2%, which is much lower than the recommended use‐dilution concentration. However, using the same method and test organisms the capacity use‐dilution testing of a third phenolic disinfectant, containing p‐chloro‐m‐cresol and o‐benzyl‐p‐chlorophenol with a total of 9·2 (w/w) phenols in a detergent system, indicated that the recommended use‐dilution concentration should be doubled.
Use of Response Surface Methodology for the Rapid Optimization of Microbiological Media
Authors: MADDOX I. S. , RICHERT S. H.
Published: March 2008

The application of response surface methodology to microbiological medium‐screening has been investigated. Using an example of gibberellic acid production on a basal medium of whey filtrate, the methodology has been shown to be useful for the rapid optimization of supplementary nutrient concentrations in the medium.
Quality Assurance of Sterilized Products: Verification of a Model Relating Frequency of Contaminated Items and Increasing Radiation Dose
Authors: KHAN A. A. , TALLENTIRE A. , DWYER J.
Published: March 2008

Values of the y‐radiation resistance parameters (k and n of the ‘multi‐hit’ expression) for Bacillus pumilus E601 spores and Serratia marcescens cells have been determined and the constancy of values for a given test condition demonstrated. These organisms, differing by a factor of about 50 in k value, have been included in a laboratory test system for use in verification of a model describing the dependence of the proportion of contaminated items in a population of items on radiation dose. The proportions of contaminated units of the test system at various y‐radiation doses have been measured for different initial numbers and types of organisms present in units either singly or together. Using the model, the probabilities of contaminated units for corresponding sets of conditions have been evaluated together with associated variances. Measured proportions and predicted probabilities agree well, showing that the model holds in a laboratory contrived situation.
The Effect of Water Activity and aw‐Controlling Solute on Sporulation of Bacillus cereus
Authors: JAKOBSEN T M. , MURRELL W. G.
Published: March 2008

The influence of water activity (aw) on the formation of phase bright, heat stable, and dipicoiir.ic acid‐containing spores of Bacillus cereus T from stage III to stage IV forespores has beer. investigated. Decreasing aw levels reduced the rate of sporulation and the number of forespores which lysed was determined by the aw‐controlling solute used. The limiting aw value for ir.e formation of mature spores was about 0·95 for glucose, sorbitol and NaCl whereas it was about 0·91 for glycerol. The development of refractility. the synthesis of dipicolinic acid, and acquisition of heat stability were affected equally by decrease in aw during sporulation. With the range of aw value where spores could be formed NaCl and glycerol had no signifcant: influence on the D value of the resulting spores whereas at all aw levels, when sorbitol was use: as the aw‐controlling solute, the heat resistance was greater than in the basal medium. It Is suggested that the aw of the sporulation medium determines the quantity of spores rather than. the spore properties.
The Antibacterial Activity of a New Chloroxylenol Preparation Containing Ethylenediamine Tetraacetic Acid
Authors: RUSSELL A. D. , FURR J. R.
Published: March 2008

A new chloroxylenol preparation (DC) containing ethylenediamine tetraacetic acid (EDTA). has been shown to be an effective bactericidal agent against various Gram positive and Gram negative bacteria. It possessed significant and rapid activity against two strains of Pseudomonas aeruginosa as well as against chlorhexidine‐and chloroxylenol‐resistant derivatives of these strains. DC showed high activity at 20° and 30 °C, and (unlike chlorhexidine) when prepared in hard water or when used in the presence of organic matter. Repeated challenge testing at 20 °C of DC (but not of chloroxylenol) with Ps. aeuruginosa indicated that contamination of DC will not prove to be a problem in practice and that the activity of solutions will be retained during storage.
Escherichia coli in the Faecal Flora of Man
Authors: HARTLEY CHRISTINE L. , CLEMENTS HELEN M. , LINTON K. B.
Published: March 2008

The predominant Escherichia coli faecal flora of healthy individuals was studied over a period of several weeks. E. coli in the intestine showed a spectrum of persistence. The concept of ‘resident’and ‘transient’strains is discussed and a clarification of nomenclature is suggested.
Improvement of Carob Pods as Feed by Solid‐substrate Fermentation
Authors: KOKKE R.
Published: March 2008

Chopped carob pods were autoclaved in an ammonium salt solution. The solution was absorbed by the pods during autoclaving. The material was inoculated with either Rhizopus oligosporus or Monascus ruber and incubated for 3 d at 30 °C. The growing mycelium penetrated the particles to form a cake‐like structure containing ca. 7% protein. The fermentation product contained 73–83% of the original carob sugars, whereas the amount of tannins was considerably lower than in the pods.
Studies on the Defaunation of the Ovine Rumen Using Dioctyl Sodium Sulphosuccinate
Authors: ORPIN C. G.
Published: March 2008

The lethal concentrations of dioctyl sodium Sulphosuccinate (DSS) to nine species of rumen ciliate protozoa were determined. The quantity of DSS required to remove these protozoa from the rumen of sheep was approximately 30 times the lethal concentration. This was caused by interaction of the DSS with rumen particulate material, and the protozoa were killed only after the particulate fraction was saturated with DSS. Defaunation was conducted most efficiently after withdrawal of food for 24 h followed by a period (1–4 d) of reduced food intake by the host animal. In toxic concentrations of DSS the cilia of both holotrich and entodiniomorphid protozoa became detached, followed by leakage of the cell contents via the gullet or anus (in the entodiniomorphids) or at variable points in the cell wall (in the holotrichs). The population densities of most of the other rumen micro‐organisms examined decreased during defaunation, but regained their original population density within 11–21 d. After this time the population densities of these organisms exceeded that shown before defaunation, with the exception of Oscillospira guilliermondii which was eliminated.
Sodium Dodecyl Sulphate‐Polyacrylamide Gel Electrophoresis of Polypeptides from Bacteraides melaninogenicus
Authors: SWINDLEHURST C.A. , SHAH H. N. , PARR C. W. , WILLIAMS R. A. D.
Published: March 2008

Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis has been applied to proteins extracted from 32 strains of Bacteroides melaninogenicus.

Strains of subspecies melaninogenicus gave similar electrophoretic patterns which differed from those of strains outside the subspecies.

Strains of subspecies intermedius serotype C were similar to one another in electrophoretic pattern, and were different from strains outside the subspecies and from one strain of subspecies intermedius of serotype C1.

Greater variation was observed between asaccharolytic than between saccharolytic strains.

The group within subspecies asaccharolyticus with low G + C content stained poorly and showed few bands.

The group within subspecies asaccharolyticus with high G + C content showed interstrain differences but none would be confused with strains of the saccharolytic subspecies. The strain that did not react with type B antiserum was electrophoretically different from those strains that did.

The asaccharolytic Lev type strains form a separate group based on both electrophoretic and physiological criteria.
An Improved Medium for the Enumeration of Chromobacterium in Soil and Water
Authors: KEEBLE J. R. , CROSS T.
Published: March 2008

Bennett's agar, containing (μg/ml): neomycin, 50; cycloheximide, 50; and nystatin, 50; gave higher counts of Chromobacterium from soil and water samples than did the selective medium of Ryall & Moss (1975).

Colonies on the modified Bennett's agar were usually large, deep purple and easily recognized.

The strains isolated were identified as Chromobacterium lividum.
A Taxonomic Study of Flavobacteria and Related Gram Negative Yellow Pigmented Rods
Authors: HAYES P. R.
Published: March 2008

One hundred and seventy‐nine yellow pigmented Gram negative rods, including 170 new isolates obtained from a variety of habitats, were investigated and the results analysed by computer. Nine phena, embracing 146 strains, were distinguished. Five of these comprised 88 of the 109 non‐motile, aflagellate strains (i.e. ‘atypical cytophagas’) and they should be assigned to a re‐defined genus Flavobacterium. A separate phenon containing 41 of the gliding isolates was delineated which should be ascribed provisionally to the genus Flexibacter. Only low G + C contents have been recorded for representative strains from these six phena but one strain (which would have been ascribed to Flavobacterium) had a high G + C content; such organisms (both peritrichous and non‐motile) should comprise a separate genus Empedobacter (Brisou). The remaining three phena respectively comprised strains of Erwinia herbicola, pseudomonads and unclassified aflagellate isolates; their taxonomic position is discussed.
The Isolation and Some Characteristics of Photosynthetic Bacteria (Chromatiaceae and Chlorobiaceae) from Antarctic Marine Sediments
Authors: HERBERT R. A. , TANNER A. C.
Published: March 2008

Sediment samples taken at depths from 5 to 50 m in Borge Bay, Signy Island, Antarctica yielded purple (Chromatiaceae) and green (Chlorobiaceae) phototrophic bacteria when inoculated into Winogradsky columns or directly into Pfennig's medium. Pure cultures of Thiocapsa roseopersicina (2 strains), Thiocapsa pfennigii, Chromatium gracile, Chromatium vinosum, Thiocystis violaceae, Chlorobium limicola, Chlorobium vibrioforme and Prostaecochloris aestuarii were subsequently isolated from these enrichments. Thiocapsa roseopersicina and Chromatium vinosum were the species isolated most commonly. None of the isolates showed evidence of temperature adaptation; optimum growth was achieved between 25–30°C but all grew readily at low white light levels (spectral irradiance 160 μW/cm2) with mean generation times ranging from 8·9 to 14·2 h at 23°C depending upon the isolate. The green phototrophs grew readily in blue light (440–510 nm) of low irradiance (126 μW/cm2) which penetrates to a depth of 40–50 m in coastal waters surrounding Signy Island. Under these conditions Chlorobium limicola and Chlorobium vibrioforme had mean generation times of 22 and 12·2 h respectively compared with 10·3 and 8·9 when grown in white light of similar total irradiance. None of the purple phototrophs grew under blue light but they grew under yellow light (peak transmission 590 nm, irradiance 137 μW/cm2). Chromatium gracile and Thiocapsa roseopersicina had mean generation times of 22·3 and 18·3 h respectively compared with 14·2 and 12·3 h in white light of similar total irradiance.
A Rapid Microbiological Assay for Nystatin Using Rt+ Enriched Yeast Cells
Authors: COSGROVE R. F.
Published: March 2008

A simple, rapid (30 min) microbiological assay for nystatin is discussed. It is based on the efflux of Rb+ ions from nystatin treated yeast cells which had been grown in a medium enriched with this element. Results obtained with this method and the conventional agar diffusion method for nystatin in raw materials and finished products compare favourably both in accuracy and reproducibility. For simplicity and reproducibility, a cryogenically‐stored inoculum is advocated; its use gives a confidence interval (P= 0·05) on six results of < 5%.
Influence of the Growth Phase and Fimbriae on the Gradient Elution of Salmonella typhimurium from DEAE‐cellulose
Authors: HALL A. N. , HOGG S. D. , PHILLIPS G. O.
Published: March 2008

Initial investigations showed that certain populations of Sytyphimurium cells could be resolved into three fractions by eluting the cells from DEAE‐cellulose with a NaCl gradient in 0·05 Mphosphate buffer (pH 6·0). The three fractions were eluted with 0, 60 and 190 mmol/l NaCl. The results obtained with two strains indicate that non‐fimbriate, exponential phase cells; fimbriate, stationary phase cells; and non‐fimbriate, stationary phase cells are eluted with 0, 60 and 190 mmol/l NaCl in 0·05 M‐phosphate buffer (pH 6·0), respectively. These conclusions appear to be consistent with current views on the effects of fimbriae and the exponential growth phase in reducing the electrical charge carried by bacterial cells.
Isolation of Salmonellae from Sewage with a New Procedure of Enrichment
Authors: VASSILIADIS P. , TRICHOPOULOS D. , KALANDIDI A. , XIROUCHAKI E.
Published: March 2008

Forty samples of sewage on Moore's swabs were examined for the presence of salmonellae. They were first pre‐enriched in buffered peptone water. From each pre‐enrichment, three enrichments were made: (1) in a new, considerably modified, formula of Rappaport medium (R 10) incubated at 43 °C (R 10/43 °C), (2) in the usual formula (R25) of the same medium at 37 °C (R25/37 °C) and (3) in Muller‐Kauffmann's tetrathionate broth at 43 °C (MK/43 °C). Practically the same numbers of swabs were found positive by the first two enrichment procedures, 38 and 39 respectively, while only 17 were found positive by the MK procedure. The R10/43 °C method was superior to the two other procedures; it yielded 103 strains of salmonellae as against 82 with the second Rappaport procedure, and only 25 with the MK/43 °C technique. A similar observation was made concerning the frequency of isolation of different serotypes by the three procedures; the number of the isolated serotypes was 24, 19 and 11, respectively. The new R 10/43 °C method of enrichment had also a much stronger inhibitory effect on the competing bacteria than the two other procedures of enrichment used.
A Survey of Argentine and Lebanese Bone for Salmonellas with Particular Reference to the Isolation of Salmonella typhimurium
Authors: HARVEY R. W. S. , PRICE T. H.
Published: March 2008

The incidence of Salmonella typhimurium in imported bone meal may be underestimated by conventional isolation techniques because of the presence of other salmonella serotypes. A method was developed with a serological bias towards recovery of serotypes with ‘i’as H phase 1 antigen. By this technique, 44 strains of S. typhimurium were isolated from Argentinian bone meal compared with nine strains cultured by the unbiased method. The technique was less successful with Lebanese bone. The serological technique was most effective when several salmonella serotypes not possessing the ‘i’antigen were present in a sample. S. kentucky (8, 20:i:z6), like S. typhimurium was also efficiently isolated by the serological method. In 12 specimens both S. typhimurium and S. kentucky were present. The two serotypes were easily separated by examining four 25 g sub‐samples of the specimen.
Streptococci Isolated from Dental Plaque of Animals
Authors: DENT V. E. , HARDIE J. M. , BOWDEN G. H.
Published: March 2008

Streptococci were isolated from dental plaque samples collected from 25 animals representing 18 species. Strains were characterized by biochemical, physiological and serological tests. Extracellular polysaccharide‐producing strains of Streptococcus mutans, Str. sanguis and Str. salivarius were found to be confined mainly to primate species. Streptococcus mutans was not widely distributed, being isolated from 2 of 18 animal species. Enterococci were isolated from the mouths of about one‐third of the animals, whilst Str. bovis was found mainly in the herbivores. Strains resembling Str. mitior were isolated from most animals. Of 271 strains. 34 could not be allocated to any known species. Streptococci known to be associated with diseases of animals, especially those belonging to Lancefield group C, were not isolated. A few strains representing Lancefield groups D, L, G and M were found, but with low frequency.
The Occurrence of Aeromonads in Activated Sludge: Isolation of Aeromonas sobria and its Possible Confusion with Escherichia coli
Authors: NEILSON A. H.
Published: March 2008

Strains of Aeromonas have been isolated in high numbers from several activated sludge samples. Immediately after isolation, some displayed only weak or negative oxidase activity, produced both acid and gas from lactose, formed ‘metallic’colonies on Endo agar, and had IMViC reactions which were identical with those of Escherichia coli. Although such strains could have been readily confused with E. coli, further biochemical characterization showed that these belonged to the recently‐described A. sobria. Nitrogenase activity was absent in all strains of both A. hydrophila and A. sobria. Almost all strains of both taxa were resistant to ampicillin and penicillin V and 67% of both were bete‐hemolytic.
A Simple Method for Storage of Bacteria at — 76°C
Authors: FELTHAM R. K. A. , POWER ANNETTE K. , PELL PATRICIA A. , SNEATH P. H. A.
Published: March 2008

A safe, reliable and simple procedure for storing bacteria on beads at –76 °C is described.

The most suitable cryoprotectant for a wide variety of bacteria appears to be 10–15% (v/v) glycerol.
Partial Characterization of a Bacteriophage of Lactobacillus bulgaricus Isolated from Yoghurt
Authors: PEAKE SALLY E. , STANLEY G.
Published: March 2008

Bacteriophage plaques have been obtained for a phage of Lactobacillus bulgaricus isolated from commercial yoghurt.

Electron microscopy has shown that the hexagonal head has a diameter of approximately 60 nm and the tail a length of approx. 210 nm. The tail is intersected at intervals by cross‐bar structures, the number (and positioning) on each tail being variable, up to a total of ten.
Bacterial Degradation Products of the lxodicide Amitraz
Authors: ALLCOCK E. R. , WOODS D. R. , RIVETT D. E.A.
Published: March 2008

The nature and order of appearance of the degradation products of amitraz by mixed bacterial cultures were investigated. The primary pathway involves the conversion of amitraz to 2,4‐dimethylaniline. A slower secondary pathway involves the conversion of amitraz to 2,4‐dimethylaniline via the intermediates N‐2, 4‐dimethylphenyl‐N′‐methylformamidine and 2, 4‐dimethylformanilide. The bacterial degradation pathway of amitraz differs from that found in plants and animals.
The Distribution of Staphylococcus aureus in a Poultry Processing Plant
Authors: GIBBS P. A. , PATTERSON J. T. , THOMPSON J. K.
Published: March 2008

A set of phages previously isolated from poultry strains of Staphylococcus aureus was used to type such isolates from poultry before, during and after processing in a poultry plant. Certain poultry phage types were found to be associated with the live birds rather than the processed carcases. Strains lysed by phages from this group may represent a specific ‘poultry’biotype. A site of cross‐contamination within the plant was discovered.
Adenosine Triphosphate and Deoxyribonucleic Acid in the Alimentary Tract of Cattle Fed Different Nitrogen Sources
Authors: WOLSTRUP J. , JENSEN K.
Published: March 2008

Total microbial cell counts and the content of deoxyribonucleic acid (DNA) and adenosine triphosphate (ATP) were determined in ruminal and abomasal digesta and in faeces from heifers fed a basal diet of barley and straw supplemented with urea, casein, soybean‐protein concentrate or feather meal. The concentration of ATP in the rumen content varied independently of the DNA content and total cell count, but dependently upon the nitrogen sources, the highest ATP/DNA ratio being obtained with casein. The ATP/DNA ratio in faeces was only one‐tenth of that found in the digesta of the rumen and abomasum, indicating either an extremely low level of activity of the microbial cells or more probably a very large number of dead organisms. It is suggested that DNA and ATP might be useful indices of the microbial status in terms of biomass and metabolic activity. The total cell count should still be included in routine studies to determine the proportion of protozoa to bacteria.
Sources of Psychrotrophic Bacteria on Meat at the Abattoir
Authors: NEWTON K. G. , HARRISON J. C. L. , WAUTERS A. M.
Published: March 2008

An export abattoir was examined to determine the sources and types of psychrotrophic bacteria which gain access to meat. Gram negative psychrotrophs were recovered from the hides, from structural and work surfaces within the abattoir, and from carcasses and meat at all stages of processing. Microbacterium thermosphactum was recovered intermittently at all sampling sites. Psychrotrophic and total counts and the incidence of M. thermosphactum on carcasses and meat increased during processing through the abattoir. Structural and work surfaces may be as important as the hide as sources of bacterial contaminants on meat. Seasonal variation was observed in psychrotrophic counts which correlated positively with rainfall and negatively with temperature.
A Soil Flavobacterium sp. that Degrades Sulphanilamide and Asulam
Authors: WALKER N.
Published: March 2008

A Flavobacterium sp. which grows with either sulphanilamide or asulam as carbon and energy source has been isolated from asulam‐treated soil and characterized. Growth on sulphanilamide induces an enzyme system which oxidatively degrades sulphanilamide and asulam.
The Maceration of Linen Flax under Anaerobic Conditions
Authors: CHESSON A.
Published: March 2008

Ret tanks of 350 1 capacity, loaded with 14 kg of flax straw and maintained at 32°C. were sampled at regular intervals for 90 h. Total numbers of bacteria and viable anaerobes increased rapidly during the initial 16 h, reached a maximum at 22 h and then remained constant in the ret liquor. They continued to increase at a reduced rate within the flax straw. Dissolved oxygen content and pH of the ret liquor fell rapidly over the initial period while volatile fatty acids, ammonia and methanol accumulated. Xylanolytic and cellulolytic bacteria were detected in increasing numbers after 40 h. Pectinesterase (PE.EC. 3.1.1.11) was restricted largely to the flax straw where activity developed in parallel with microbial growth, reached a maximum at 22 h and rapidly declined thereafter. Polygalacturonase (PG.EC. 3.2.1.15/40) and pectate lyase (PAL.EC.4.2.2.1/2) activities developed after 16 h when soluble carbohydrates had been depleted. Higher levels of both activities were associated with the flax straw than with the ret liquor. PG predominated over PAL activity throughout. Other glycan hydrolyase activities were not detected. Fractionation and analysis of straw samples showed that 83% of pectic polyuronide present at the start of the ret was degraded by 70 h, whereas 16% of the hemicellulose and none of the cellulose was lost over the same period.
Attempts to Displace the Indigenous Antibiotic Resistant Gut Flora of Chicken by Feeding Sensitive Strains of Escherichia coli Prior to Slaughter
Authors: LINTON A. H. , HOWE KATHERINE , RICHMOND M. H. , CLEMENTS HELEN M. , OSBORNE A. D. , HANDLEY BARBARA
Published: March 2008

Attempts to limit the use of antibiotics have not, in general, resulted in the gut flora in farm animals becoming predominantly sensitive. Partial success has been demonstrated, however, by feeding chickens with antibiotic sensitive Escherichia coli known to be good colonizers of the chicken gut. Where feeding was done prior to slaughter a corresponding reduction in carcass contamination by resistant E. coli was observed.
A Comparison of Membrane Filters for Counting Thermoactinomyces Endospores in Spore Suspensions and River Water
Authors: AL‐DIWANY LAMYA J. , UNSWORTH BRIDGET A. , CROSS T.
Published: March 2008

Ten types of membrane filter, most with a nominal pore size of 0.45 μm, were compared for their efficiency in recovering Thermoactinomyces endospores from water samples and yielding colonies for viable counts. The endospores were in laboratory‐prepared suspensions from two strains and in river water containing a natural population of actinomycetes and bacteria. There were significant differences in recovery efficiency between membranes used with river water samples; black Sartorius membranes (SM 13006) gave highest colony counts when incubated on selective agar. All membranes except Nuclepore gave good recovery from the spore suspensions but some differences were noted in their ability to recover the two strains. Thus it is inadvisable to use the results of trials on pure cultures prepared in the laboratory to predict the performance of membranes for use with natural water samples. Czapek‐Dox agar with added yeast extract and Casamino acids (CYC) was a superior recovery medium to Trypticase Soy agar (TSA). The efficiency of green Gelman membranes was improved if they were boiled in distilled water before use; in contrast, boiled Oxoid membranes (original type) carried fewer colonies.
Hydrolytic and Fermentative Properties of Clostridium Species Isolated from Digesting Sludge
Authors: COX D. J.
Published: March 2008

Fifty cultures belonging to the genus Clostridium were isolated from digesting sewage sludge and some of their hydrolytic and fermentative properties studied. The isolates could be divided into four loosely defined groups. Organisms belonging to the first group possessed little or no hydrolytic properties but produced acetic and iso‐valeric acids in media containing minimal amounts of carbohydrate. The second (largest) group produced butyric acid in carbohydrate and non‐carbohydrate media and were able to hydrolyse starch. The third group comprised non‐hydrolytic strains which fermented carbohydrate to butyric acid; acetic, iso‐butyric and iso‐valeric acids were produced in media containing no additional carbohydrate. The final group, proteolytic organisms, produced very large quantities of several iso‐acids in non‐carbohydrate media. It is suggested that these organisms fulfil an important role in the ecosystem and that the properties described help to define that role.
Optimum Levels of Sulphate and Iron for the Cultivation of Pure Cultures of Methanogens in Synthetic Media*
Authors: PATEL G. B. , KHAN A. W. , ROTH L. A.
Published: March 2008

Experiments on the effects, of sulphate and iron content of medium on the growth of Methanobacterium strain M.O.H., Methanospirllum hungatii GPI, and an unidentified strain similar in characteristics to Methanobacterium formicicum, indicated that the 4.0 mM of sulphate normally incorporated into laboratory media was above the optimum level, while the iron content normally incorporated (0.01–0.08 mM) was below the optimum requirement of these methanogens. The tests were made in synthetic media containing acetate, carbon dioxide and hydrogen as carbon and energy sources, and a cysteine‐sodium sulphide solution as a reducing agent. The optimum sulphate requirement for Methanobacterium strain M.O.H., M. hungatii, and the unidentified methanogen was in the range of 0.16–0.52 mM. An absence of sulphate in the medium decreased significantly (95% confidence level) the growth of these cultures. The optimum requirement of Fe++ was in the range of 0.3–0.9 mM. Addition of Fe+++ greater than 0.10 mM to pre‐reduced medium, or the addition of greater than 0.15 mM during preparation of medium resulted in precipitation of iron. A method for the preparation of medium without formation of precipitate is described and its contribution to improving growth and methanogenesis discussed.
Epithelial Attachment and Other Factors Controlling the Colonization of the Intestine of the Gnotobiotic Chicken by Lactobacilli
Authors: FULLER R.
Published: March 2008

Four strains of lactobacilli with different abilities to adhere to chicken crop epithelial cells in vitro were administered to germfree chickens and their colonization of the intestine compared. Ability to colonize the gut effectively was related to adhesion index and, in the absence of adhesive ability, to growth rate. Tolerance of low pH was also a factor in determining good colonization of the small intestine. With only one strain did diet appear to affect colonization.
Synergism between Chlorhexidine and Sulphadiazine
Authors: QUESNEL L. B. , AL‐NAJJAR A. R. , BUDDHAVUDHIKRAI P.
Published: March 2008

Chlorhexidine and sulphadiazine react synergistically against strains of Pseudomonas. Proteus and Staphylococcus, with high factors of synergy. The impermeability of these strains to sulphadiazine is destroyed by low concentrations of chlorhexidine, permitting the accumulation of sulphadiazine which then inhibits protein synthesis. The combination of these drugs is bactericidal.
Streptococcus uberis: an Approach to its Classification
Authors: GARVIE ELLEN I. , BRAMLEY A. J.
Published: March 2008

Thirty‐one strains of streptococci, selected because they were considered to be or were similar to Streptococcus uberis, were examined by physiological tests and for properties of their lactate dehydrogenases (LDHs) and deoxyribonucleic acid (DNA). Twenty‐nine of the 31 strains fell into two main genotypes as judged by DNA/DNA hybridization. One genotype (Group I) included the type strain of Strep. uberis and most other strains in this group were physiologically similar to it and had the same percent guanine + cytosine (%GC) in their DNA. The other genotype (Group II) contained strains which were more variable physiologically and had DNA of a lower % GC than the type strain. The European strains examined contained two distinct LDH types, one being associated with the Group I and the other with Group II strains. Three American strains examined however had LDH's which were unlike those of the European strains.
The Influence of Specific Bacteria and a Filterable Agent on the Growth of Gnotobiotic Chicks
Authors: FULLER R. , COATES M. E. , HARRISON G. F.
Published: March 2008

Growth depression was induced in chicks and a collection of aerobic and anaerobic bacteria was isolated from the crop and caecum. The collection of bacteria was tested in gnotobiotic chickens for its ability to depress growth with and without a bacteria‐free faecal filtrate. None of the anaerobic bacteria depressed growth. Aerobic bacteria always depressed growth but only in the case of Streptococcus faecium was this statistically significant. The faecal filtrate also depressed growth. A statistically significant effect was obtained when faecal filtrate was combined with any of the following treatments: (a) the total collection of bacteria, (b) the aerobic group, (c) the anaerobic group, (d) Strep. faecalis var. liquefaciens, (e) Strep, faecium, (f) the unclassified streptococci, and (g) a group containing the lactobacilli and coliform organisms. The largest growth depression was obtained in chickens dosed with Strep, faecium and faecal filtrate.
Extracellular Peptidases in Group N Streptococci used as Cheese Starters
Authors: LAW B. A.
Published: March 2008

Strains of Streptococcus cremoris which utilized peptides had a mercaptoethanol‐sensitive, Mg2+‐activated dipeptidase which could be released from the cells by lysozyme. A similar enzyme was inferred to be present in Strep. lactis. An apparently cell wall‐bound peptidase was only found in Strep. lactis; this was also Mg2+‐activated but was insensitive to mercaptoethanol. The peptidase recovered from culture‐supernatants of Strep. cremoris and Strep. lactis was similar to one of the two EDTA‐sensitive intracellular dipeptidases present in both organisms, but was distinct from the lysozyme‐released enzymes. The significance of these cell‐bound extracellular peptidases in relation to peptide utilization is discussed.
The Occurrence and Survival of Coliforms and Salmonellas in Apple Juice and Cider
Authors: GOVERD K. A. , BEECH F. W. , HOBBS R. P. , SHANNON R.
Published: March 2008

Apples and juices from large and small cidermakers were examined for the presence of coliform organisms and salmonellas. Coliforms were found both on the fruit and in the juice, and salmonellas were isolated on more than one occasion from the flume water. Experiments showed that salmonellas could survive in apple juice for 30 d at a pH of 3·6.
A Note on the Preparation of Deoxyribonucleic Acid from Streptococcus bovis and Variations in the Melting Temperature of Different Preparations
Authors: GARVIE ELLEN I.
Published: March 2008

Deoxyribonucleic acid was prepared three times from Streptococcus bovis NCDO 597. The difference in % guanine and cytosine, estimated by melting temperature, was found to be 2·8%. Possible reasons for this large difference are discussed.
Streptococcus bovis—an Approach to its Classification and its Importance as a Cause of Bovine Mastitis
Authors: GARVIE ELLEN I. , BRAMLEY A. J.
Published: March 2008

Six streptococci isolated in high numbers from different mastitis samples have been identified as strains of Streptococcus bovis. The properties of the strains were compared with those strains of Strep, bovis from culture collections and also with those of two strains of Strep. mutans. Physiological properties, including ability to form capsules and dextran, the properties of the lactate dehydrogenases and hybridization between the deoxyribonucleic acid of the unknown strains and the reference strain of Strep. bovis were determined. It is concluded that Strep. bovis comprises strains with heterogeneous properties. No subgroups were apparent. The pathogenicity to the udder was determined for eight strains of Strep. bovis and one of Strep. mutans.
A Note on the Comparison of two Modifications of Rappaport's Medium with Selenite Broth in the Isolation of Salmonellas
Authors: VASSILIADIS P. , TRICHOPOULOS D. , PAPOUTSAKIS G. , PALLANDIOU E.
Published: March 2008

Two modified Rappaport's enrichment broths were compared with selenite broth in the isolation of salmonellas from pork sausages. It was found that: (1) both modifications of Rappaport's broth were significantly superior to selenite broth, and (2) one of the modifications (R10/43°C), had a remarkable inhibitory effect on the competing bacteria, including those which produce salmonella‐like colonies.
A Note on the Range of Escherichia coli O‐Serotypes Causing Clinical Bovine Mastitis and their Antibiotic Resistance Spectra*
Authors: LINTON A. H. , HOWE KATHERINE , SOJKA W. J. , MAFF C. WRAY
Published: March 2008

Sixty‐seven Escherichia coli O‐serotypes were found among 279 isolates from individual cows with clinical mastitis suggesting that coliform mastitis is a non‐specific infection. Sensitivity tests on all isolates were carried out in two laboratories and the results compared. A low incidence of antibiotic resistance was found.
A System for Setting Numerical Microbiological Specifications for Foods
Authors: KILSBY D. C. , ASPINALL L. J. , BAIRD‐PARKER A. C.
Published: March 2008

A scheme is described which can be applied to any numerical microbiological limit where the distribution of microorganism density is approximately log normal. The actual limits used, the degree of safety assurance required, the definition of an unsatisfactory batch and the number of units examined may be chosen to suit any particular requirement. The scheme's versatility and ability to operate with low sample numbers make it ideal for microbiological specifications. It is based on consideration of both safety and quality requirements and good manufacturing practice.
The Uptake and Utilization of Bacteria, Amino Acids and Nucleic Acid Components by the Rumen Ciliate Eudiplodinium maggii
Authors: COLEMAN G. S. , SANDFORD DEBORAH C.
Published: March 2008

Washed suspensions of the rumen ciliate protozoon Eudiplodinium maggii grown in vitro and incubated anaerobically engulfed all the bacteria tested except for Bacteroides ruminicola and Klebsiella aerogenes. There was considerable variation (160–9100 bacteria/h/protozoon at an external concentration of 1010 bacteria/ml) in the rate at which the bacteria were engulfed, but Eu. maggii showed some preference for bacteria of rumen origin. Some of the bacteria were digested with the release of soluble materials into the medium. Free amino acids were incorporated from an 0.1 mM solution at rates of 0.13 to 0.84 pmol/h/protozoon. Evidence is presented that Eu. maggii could obtain half the amino acids required for growth by the engulfment and digestion of bacteria and half by the uptake of free amino acids. Eudiplodinium maggii incorporated uridine 5' monophosphate and also hydrolysed this to uridine and then to uracil which was reduced to dihydrouracil. These products all appeared in the medium. Ribose was incorporated by the protozoon and appeared as glucose in protozoal and bacterial polysaccharide; none was incorporated as such into protozoal nucleic acid.