bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Antibiotic Tolerance of Vibrio cholerae
Authors: Naha P. M. 
Published: March 2008

SummaryPenicillin G, dihydrostreptomycin, chloramphenicol and chlortetracycline inhibited the growth of a strain of Vibrio cholerae in vitro, in that order of increasing effectiveness, except that at low concentrations dihydrostreptomycin was less effective than penicillin G. The amount of growth made in the presence of an antibiotic, relative to that in an antibiotic free control, as judged turbidimetrically, was a linear function of the concentration and the slopes of the regression lines differed significantly.Strains resistant to each of the four antibiotics were developed. The culture resistant to chlortetracycline was also relatively resistant to the other three antibiotics, but those which resisted the other antibiotics were greatly affected by chlortetracycline. The relationships between relative growth and concentration were not, however, obviously linear.
Observations on Lysogeny in the Plant Pathogens Pseudomonas mors‐prunorum and Ps. syringae
Authors: Garrett Constance M. E. , Crosse J. E. 
Published: March 2008

SummaryPhages were detected in 23 out of 56 cultures of Ps. mors‐prunorum, the organism causing the bacterial canker of cherry and plum in south‐east England, but not in 9 cultures of Ps. syringae from diseased pear trees. Attempts to free cultures from phage by repeated subculture from single colonies were in most cases unsuccessful, i.e. the majority of them were lysogenic and not carrier strains. This was confirmed for one strain by plating it with a suitable indicator strain, when a ratio of colonies to plaques slightly greater than 1:1 was observed. Lysogeny was encountered more frequently among the cherry than among the plum strains of Ps. mors‐prunorum. In typing experiments with 13 phages isolated from lysogenic cultures, the nonlysogenic cherry strains reacted more frequently than the lysogenic strains. No such relationship was observed among the plum strains, many of the nonlysogenic forms being immune to all the phages. Phage resistance in the cherry strains could be attributed to the presence of an homologous or closely related prophage, but it apparently had a different basis in the plum strains. The results confirmed the dissimilarity in the phage relationships between plum and cherry strains, previously observed with mainly virulent phages isolated from soils.
Salt Tolerance and Nitrate Reduction by Micrococci from Fresh Pork, Curing Pickles and Bacon
Authors: Patterson J. T. 
Published: March 2008

SummaryThe majority of 164 strains of micrococci and staphylococci isolated from fresh pork, curing pickle and maturing bacon were able to grow at 4°. Greater proportions of strains from brine and bacon tolerated high salt concentrations than did strains from pork. Added nitrate seemed to have a protective or stimulative effect, increasing tolerance. The proportion of the strains able to reduce nitrate to nitrite was large; but it decreased with increasing salt concentration and it is doubtful whether these organisms can reduce nitrate in curing pickles under curing conditions. Strains from all three sources survived incubation in high salt broths and curing pickles much better at 2–3° than at 30°, and there is little doubt that many of the original contaminants of the pork sides could survive the curing process.
Studies of Enzyme Changes During Sporulation in Bacillus cereus, Using Starch Gel Electrophoresis
Authors: Baillie Ann , Norris J. R. 
Published: March 2008

SummaryStarch gel electrophoresis showed that Bacillus cereus esterase and catalase are not single enzymes but multimolecular species and that they undergo changes during sporulation. Heat resistant spore catalase was detected in vegetative cells before mature spores were present.
Some Investigations on the Growth of Dialister pneumosintes
Authors: Chen Chien‐Ching , Cleverdon R. C. 
Published: March 2008

SummaryA convenient double bottle vessel is described for the culture of strictly anaerobic bacteria. With D. pneumosintes, about 90 mg dry weight of cells accumulated in about 80 h at 37°; in such conditions the generation time as assessed both by decimal dilution counts and by accumulation of deoxyribonucleic acid was about 2 h.
The Value of Phage Sensitivity Tests for the Identification of Phytopathogenic Pseudomonas Spp.
Authors: Billing Eve 
Published: March 2008

Summary: To study the value of phage sensitivity tests for the identification of phytopathogenic pseudomonads, 284 isolates from various sources were examined for their sensitivity to 9 phages. Phages came from infected plants (4), meat (2), manure (2) and from a culture of Ps. mors‐prunorum, P27 (1). The main part of the study was concerned with isolates of Ps. syringae from lilac (6), stone fruits (22), pear (46), Ps. mors‐prunorum (17), Ps. phaseolicola (16) and Ps. lachrymans (11), but single isolates of other phytopathogenic Pseudomonas spp. (30) were also examined. Strains of Ps. aeruginosa (5) and pseudomonads from soil, water and chicken meat (151) were included for comparison. Three of the phages 2, 12B and 33 from plant sources showed a high degree of specificity for Ps. phaseolicola, Ps. syringae (pear isolates) and Ps. syringae (lilac isolates), respectively, but in no case was this absolute. Most isolates of the 4 species studied in detail showed characteristic but not specific patterns with phages 12S, 15 and 21. Many of the phytopathogens were sensitive to phage 12S, but pseudomonads from soil, water and chicken meat were not lyzed by this phage. Of this latter group 44% were lyzed by one or more of the phages from meat or manure (14, 15, 20 and 21). Ps. aeruginosa was not lyzed by any of the phages. The ninth phage, P27, lyzed a proportion of Ps. syringae isolates from pear but none of the other pseudomonads tested.Tests for oxidase, sucrose oxidation, gelatinase and lecithinase activity were found useful in conjunction with lesion tests for screening purposes. Many of the phytopathogens, especially those having affinities with Ps. syringae, were oxidase negative.From these results and those of other workers it is concluded that phage sensitivity tests can play a useful part in the identification of phytopathogenic pseudomonads, if used in conjunction with other tests. The importance of the host in connection with phage sensitivity patterns is emphasized; also the fact that isolates from a wide geographical area and saprophytes from the vicinity of the host plant need to be examined if an adequate assessment of the value of a phage is to be obtained.
The Examination of Foods for Enterobacteriaceae using a Test of the Type Generally Adopted for the Detection of Salmonellae
Authors: Mossel D. A. A. , Visser M. , Cornelissen A. M. R. 
Published: March 2008

Summary: In countries that have recently increased their bacteriological inspection of foods, many products have shown considerable improvement in microbiological quality; simultaneously, however, discrepancies between salmonella and coli‐aerogenes tests, especially on dehydrated and frozen foods, have tended to become more frequent. These discrepancies have been eliminated by applying the following measures: incorporating glucose in culture media so as to reveal all Enterobacteriaceae; placing reliance on growth rather than gas formation so as to avoid missing anaerogenic organisms, and, especially, examining quantities of foods commensurate with those used in salmonella tests.For this purpose a procedure is recommended in which 10 g of well homogenized food are enriched in 100 ml of buffered brilliant green‐bile‐glucose broth, with no attention being paid to gas formation; the enrichment cultures are then streaked on to MacConkey's glucose agar. Single colonies so obtained are tested for fermentative attack on glucose and may be further examined for other characteristics. The same enrichment fluid can be used for the so‐called ‘nonselective pre‐enrichment’ of samples of food containing salmonellae impaired by periods spent in conditions of low water activity, low pH, etc.
A Spot Test for Catechol 2:3‐Oxygenase in Bacteria
Authors: Pankhurst Eileen S. 
Published: March 2008

A simple and quickly performed colour test is described, in which organisms containing catechol 2:3‐oxygenase (meta‐pyrocatechase) produce from catechol a yellow coloured intermediate, α‐hydroxymuconic semialdehyde. The yellow colour is produced most consistently, rapidly and intensely by 2–4 day old cultures from 2·7–27 mM solutions of catechol. The purple‐brown colour produced by some organisms is discussed.Using growth from nutrient agar plates, the test was applied to cultures of 239 Gram negative bacteria; all of the 64 cultures which gave a positive result had been in contact previously with aromatic substrates and many of them could oxidize phenol. The significance of a positive reaction is discussed briefly.
Sporicidal Properties of Some Halogens
Authors: Cousins Christina M. , Allan Christine D. 
Published: March 2008

Summary. Sodium hypochlorite, sodium dichloroisocyanurate, dichlorodimethyl hydantoin, dibromodimethyl hydantoin and an iodophor have been examined for disinfectant activity against spores of Bacillus cereus. Under the test conditions used sodium hypochlorite was the most effective compound and dibromodimethyl hydantoin was least affected by increase in pH from 6.5 to 8; the activity of the iodophor was unaffected in the pH range 2.3–6.5. Bacillus subtilis spores were much more resistant to the disinfectants than were B. cereus spores. The addition of KBr to solutions of sodium dichloroisoyanurate enhanced its activity at pH 9 but not at pH 7 or 8.Mixtures of 1.5–4% of NaOH with NaOCl (200 p of available chlorine/m) were much more rapidly sporicidal than either NaOH or NaOCl (pH 9 and above) alone.
A Medium to Suppress the Swarming of Proteus Species
Authors: Alwen J. , Smith D. G. 
Published: March 2008

SUMMARYMedia containing activated charcoal inhibited the swarming but not the growth of Proteus mirabilis and P. vulgaris. The suppression of swarming depended on the presence of the charcoal in the medium: media pretreated with charcoal gave normal swarming. Charcoal does not interfere with the production of flagella as do some other substances used for the suppression of swarming. Starch and albumin at similar concentrations to the charcoal had no effect on swarming. Charcoal agar does not interfere with the growth of organisms other than Proteus and so facilitates the isolation of organisms contaminated with Proteus spp.
Relationship between Environmental Temperature and Optimum Temperature of Bacteria along a Hot Spring Thermal Gradient
Authors: Brock T. D. , Brock M. Louise 
Published: March 2008

SUMMARYThe temperature optima of bacteria occurring at various temperatures along the thermal gradient of a hot spring in Yellowstone Park was studied directly in nature by measuring the rate of incorporation in the dark of [14C]glucose or 14CO2. Bacteria found at environmental temperatures over the range 35‐70° were studied. For each temperature, the optimum for glucose and CO2 incorporation was similar to the environmental temperature.
Studies on the Growth of Group D and other Streptococci in Different Media
Authors: Ramadan F. M. 
Published: March 2008

SUMMARYGrowth obtained from pure cultures of 9 Streptococcus spp. in media containing different added chemicals revealed that thallium acetate was the least harmful to the generation rate of all test species. Sodium azide follows in that respect except for Strep. uberis. Potassium tellurite tends to produce marked reductions in the generation rate of some species and completely inhibits the log phase in others. The tellurite tolerant species include Strep. faecalis var. zymogenes, Strep. faecalis var. liquefaciens, Strep. pyogenes, Strep. agalactiae and Strep. uberis. The tested Strep. faecalis strain demonstrated an inhibition of the log phase at tellurite concentrations between 0.05 and 0.7%. Sensitive species failing to proceed in a log phase of growth in the presence of 0.01% tellurite concentration include Strep. durans, Strep. lactis and Strep. bovis. The highest number of cell recoveries from the sensitive species may be made at 6 h incubation.
Changes in the pH Activity Profile of the Lysine Decarboxylase during Incubation of Escherichia coli
Authors: Cheeseman G. C. , Fuller R. 
Published: March 2008

SUMMARYDuring prolonged incubation of cultures of Escherichia coli there is a change in the pH of optimum activity of the lysine decarboxylase. The change, which occurs after completion of the logarithmic phase of growth but before any loss of viability, is from an optimum activity at pH 4.0‐4.5 in cultures 24 h old to an optimum activity at pH 6.0‐6.5 in cultures 48 h old. Possible explanations for the phenomenon are a change in enzyme characteristics or in permeability of the cell membrane. Differences in the times of onset of these changes in different strains of E. coli result in lysine decarboxylases of apparently different pH optima, depending on the period of incubation.
Some Factors Influencing the Growth and Survival of Root Nodule Bacteria in Peat Culture
Authors: Roughley R. J. 
Published: March 2008

SUMMARYThe growth and survival in peat culture of Rhizobium spp. from 3 inoculation groups was markedly affected by the gas exchange properties of the container. Complete restriction of aeration caused rapid reduction in numbers after only 1 week. Low moisture contents restricted growth but higher levels up to 60% (on a wet weight basis) favoured survival. Within the range tested the size of the inoculum was unimportant in determining the number of rhizobia in sterilized peat provided sufficient time elapsed for multiplication. Storage temperatures between 4° and 26° affected the rate of growth but not survival of rhizobia in pure culture for periods up to 26 weeks provided moisture was not limiting.
Incidence of Clostridium botulinum in Bottom Deposits in British Coastal Waters
Authors: Cann D. C. , Wilson Baebaka B. , Hobbs G. 
Published: March 2008

SUMMARYBottom deposits collected from British coastal waters were examined for the presence of Clostridium botulinum. Cl. botulinum type B was demonstrated in 15 of 429 samples examined. Other types of Cl. botulinum were not found.
Factors Affecting Production of Staphylococcal Lipase
Authors: Vadehra D. V. , Harmon L. G. 
Published: March 2008

SummaryLipase production by the cells of Staphylococcus aureus is affected by aeration, agitation, age and pH value of the cultures during growth. At 37° the maximum production of both cells and lipase occurred within the pH range 6.5–9.0, with the optimum for cell production at pH 7.5–8.0 and the optimum for lipase production at pH 7.5–9.0. The presence of air was essential for lipase production, and the maximum lipase activity was produced in a culture incubated 5 days with agitation.
The Antagonism of Enterococci on Other Bacteria in Canned Hams
Authors: Kafel S. , Ayres J. C. 
Published: March 2008

SummaryEnterococci can act antagonistically on selected species of Clostridium, Bacillus and Lactobacillus in a canned ham environment. This phenomenon is a common feature of Streptococcus faecium, Strep, durans and Strep, faecalis. The antibacterial agent elaborated by these enterococci is probably a metabolite that diffuses into the medium or meat and may play a role in the preservation of commercial products.
A Study of Chromobacterium typhiflavum from the Rat
Authors: Lev M. , Alexander R. H. , Sobel H. J. 
Published: March 2008

SummaryTwo strains of an organism possessing unusual morphological features have been isolated from the rat. Aggregations of individual cells into discrete spherical ‘large bodies’ are found. These bodies appear in chain forms. The nature of the matrix binding the cells is not known. Individual young cells are motile by peritrichous flagella, swarm in soft agar and are Gram negative. Sections of cells show a typically Gram negative cell wall and mode of division. The cell surface appears convoluted in the Gram negative manner. Well defined buds continuous with the cell wall have been demonstrated and many cells contain crystalloid and peripheral bodies. The organisms ferment a wide variety of carbohydrates and are aerobic and facultative anaerobes. These organisms appear to fit the description of Chromobacterium typhiflavum; however the ability to form regular aggregates, containing cells distinct from the ‘vegetative’ form, and to form buds would indicate that this organism should be placed in a new genus.
Growth of Mycobacterium rhodochrous on n‐Decane: a New Growth Factor and Emulsifying Agent
Authors: Holdom R. S. , Turner A. G. 
Published: March 2008

SummaryDuring the study of the growth of Mycobacterium rhodochrous NCIB 9905 in a minimal medium with n‐decane as the sole carbon source, a growth factor and a hydrocarbon emulsifying factor were discovered. The factors were heat stable, were released from cells by autolysis or by physical disruption and functioned independently of one another. Inoculations of < 107 cells/ml of culture medium routinely failed to grow unless an autoclaved cell suspension or purified extract was added. This growth factor requirement was not satisfied by exogenous trace metals, vitamins, amino acids, intermediates of decane metabolism or Mycobactin, but was satisfied by an extract from cells of an unrelated species growing on n‐decane. The extract of strain 9905 did not satisfy the sideramine requirement of Arthrobacter JG9 and was not associated with ferric ions. Some evidence was obtained suggesting that the growth factor may be of a new type involving the chelation of calcium ions.
Effect of Irradiation Temperature on Inactivation of Clostridium botulinum Toxin Type E by Gamma Rays
Authors: Licciardello J. J. , Ribich C. A. , Goldblith S. A. 
Published: March 2008

SummaryAt an irradiation temperature of 32°F the inactivation curve for Clostridium botulinum type E toxin was characterized by an initial lag for the first 2 Mrad followed by an apparent linear portion represented by a D10 of 2.1 Mrad. The effect of irradiating at temperatures up to 117.5°F was only to shorten or eliminate the initial lag. A synergistic effect of irradiation temperature was indicated at 91.4 and 105.8°F, but at 117.5°F the toxin appeared more radioresistant.
Some Effects on the Rumen Micro‐organisms of Overfeeding a High Barley Ration
Authors: Mann S. O. 
Published: March 2008

Summary.When the barley ration fed to a heifer was increased from a steady rate of 3 × 1·7 kg/24 h to 10 kg within 7 h, the animal became lethargic and scoured, and rumen movement ceased. These clinical symptoms were accompanied by gross changes in the bacterial flora of the rumen. Lactobacilli increased from 1·3 × 104/ml to 1·96 × 109/ml and comprised 60–65% of the total viable count, displacing the usual ‘barley type organisms’ (bacteroides and Gram negative vibrio types) as the predominant organisms. At the same time rumen lactic acid concentration rose to 912 mg/100 ml and the pH value fell from 5·7 to 4·5. After recovery of the animal and reintroduction of restricted feeding the ration was slowly increased until it reached a daily level approximating to the amount taken during the period of rapid feeding. The ration of a second animal was similarly increased. The animals showed no ill effects; lactobacilli comprised only 0·19 and 1·17%, respectively, of the total viable counts, rumen lactic acid was < 5 mg/100 ml and the rumen pH values were 5·2 and 5·5 for the 2 animals. Bacteria of the genus Bacteroides predominated in both rumina.
The Growth of Salmonella choleraesuis in Various Enrichment Broths
Authors: Chung G. T. , Frost A. J. 
Published: March 2008

Summary.Salmonella choleraesuis was examined for growth in selenite, tetrathionate, brilliant green‐MacConkey and nutrient broths. Six strains of Salm. choleraesuis and 8 of Salm. choleraesuis var. kunzendorf were used. Selenite and tetrathionate broths failed to allow growth, especially when the inoculum was small. A modified tetrathionate broth in which half the normal amount of iodide was added was similar to nutrient broth, and brilliant green‐MacConkey broth was also highly effective. The number of organisms required to establish growth in selenite broth was 103−105.
Stimulation of Body Defence against Staphylococcus aureus by Norinyl
Authors: Yotis W. W. , Yotis Eleonora 
Published: March 2008

Summary.The spleens, kidneys and livers of mice that had received intraperitoneal doses of norethindrone and/or mestranol before intravenous injection with virulent Staphylococcus aureus contained fewer viable staphylococci than did the corresponding organs of control mice. Also, fewer hormone treated mice than control animals died during the 4 days after infection. Both groups survived better when penicillin was administered 12 h after infection. Thirteen serotypes of Staph. aureus grew better in sera of control rabbits than in sera of rabbits treated with both hormones. Rabbits treated with either hormone alone yielded sera that suppressed growth of most, but not all, serotypes. Coagulase, phosphatase, gelatinase, anaerobic and aerobic acid production were not affected by prior growth of staphylococci in the presence of hormones, but the haemolysin titres of staphylococci grown with the hormones were lower than those grown without them.
Dried Paper Discs for Serological Identification of Human Mycoplasmas
Authors: Dighero Mabel W. , Bradstreet C. M. Patricia , Andrews B. E. 
Published: March 2008

Summary.The preparation of antisera to human mycoplasmas and their use when dried on paper discs are described. The discs were tested in 6 diagnostic laboratories in parallel with locally prepared wet discs as controls. In all 138 mycoplasma strains were examined. Wet and dry discs gave essentially identical results in all but 5% of cases. The dried discs had a shelf life of at least 2 years.
Homofermentative Lactobacilli of Ciders including Lactobacillus mali nov. spec.
Authors: Carr J. G. , Davies Patricia A. 
Published: March 2008

Summary.This paper describes some homofermentative lactobacilli, found in freshly pressed apple juice, which can be divided into two groups. One of these consists of strains identified as Lactobacillus plantarum, of which nearly all can metabolize quinic acid. The other group, which consists mainly of catalase positive bacteria, is composed of strains alike enough to be grouped together but sufficiently different from other lactobacilli to be proposed as Lactobacillus mali nov. spec.
Bacteria Active in the Spoilage of Certain Sea Foods
Authors: Herbert R. A. , Hendrie Margaret S. , Gibson D. M. , Shewan J. M. 
Published: March 2008

Summary.Spoilage of certain sea foods is caused by the activities of some groups of Gram negative bacteria. The characteristic off odours and flavours of naturally spoiling cod and haddock have been reproduced in blocks of sterile cod muscle by organisms identified as Pseudomonas putida, Ps. fragi, Ps. putrefaciens and other Pseudomonas spp.
Microbiological and Chemical Changes in Lean Wiltshire Bacon During Aerobic Storage
Authors: Gardner G. A. 
Published: March 2008

Total microbial growth and chemical changes in aerobically stored bacon lean were found to fall into 2 phases. Phase 1: there was an increase in total microbial load to c. 109/g, during which most of the nitrate was broken down and there was an accumulation of nitrite. Phase 2: the microbial load increased further to c. 1010/g and during this time most of the accumulated nitrite was broken down to unknown products, so that at the end of the experiments most of the nitrate and nitrite had disappeared from the bacon.The most important types of micro‐organisms isolated from the bacons were Micrococcus, yeasts, Vibrio, Acinetobacter, Alcaligenes and Arthrobacter‐Corynebacterium. The latter 3 types appeared to be associated with phase 2 changes.