bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enumeration of micro-organisms in food: a comparative study of five methods
Authors: Kramer J. M. , Gilbert R. J. 
Published: May 2009

SUMMARYFive methods for the enumeration of micro-organisms in food (pour plate, surface spread plate, surface drop, agar droplet, and microdilution) were used in parallel to examine 100 samples selected from a wide range of food products.Statistical analyses of the results showed that the regression and correlation coefficients between the methods were highly significant; the lowest correlation coefficient derived for any pair of methods was 0·979. A variation in count between the methods of less than 0·5 log10cycles was given by 98% of the samples.Analysis of the operation times and material requirements of each method showed that substantial savings in cost, time, space and support labour were achieved with the microdilution and agar droplet techniques as compared with the conventional pour plate and spread plate methods.
Bacteriological evaluation of a mobile laminar cross-flow unit for surgery, under laboratory circumstances
Authors: van der Waaij D. , Wiegersma N. , Dankert J. 
Published: May 2009

SUMMARYA mobile laminar cross-flow unit for surgery has been evaluated by the use of an experimental bacterial aerosol of Escherichia coli in different concentrations, generated at several different sites. A separate ventilation system, mounted underneath the table, produced an almost downward directed curtain of sterile air along both sides of the table. When the velocity of the air stream, discharged by the cross-flow unit, was adjusted at 0·50 m./sec. at 2 m. from the filter face (at the head end of the operation table), the surface of the table could be maintained free of bacterial settling, even after aerosolization of heavily concentrated suspensions of 108 bacteria/ml. at different sites outside the enclosure and underneath the table as well.
The antibacterial activity of chloroxylenol in combination with ethylenediaminetetra-acetic acid
Authors: Dankert J. , Schut I. K. 
Published: May 2009

SUMMARYThe bactericidal activity of RBA 777 has been found to vary with both the cultural and environmental test conditions againstPseudomonas aeruginosaand to a lesser extent againstStaphylococcus aureus.These variations may explain certain anomalies in earlier work regarding the activity of chloroxylenol-based products. The addition of EDTA to RBA 777 has brought about an improvement in the performance againstP. aeruginosaand this activity is confirmedin vivo.Previous reports have already illustrated this potential and the evaluations of the new antibacterial agent DA 136 confirms and extends these results to its performance under adverse conditions, often associated with the hospital environment.
Specific immunoglobulins in infants with the congenital rubella syndrome
Authors: Cradock-Watson J. E. , Ridehalgh Margaret K. S. , Chantler Shireen 
Published: May 2009

SUMMARYThe indirect immunofluorescent technique has been used to detect and titrate the specific immunoglobulins in serum specimens from 154 infants with confirmed or suspected congenital rubella. IgM antibody was stained more efficiently in sucrose density gradient fractions than in whole serum and was detected in this way in 27 out of 40 patients with confirmed congenital rubella at ages ranging from birth to 2 years. It was present in 48 out of 50 serum specimens during the first 6 months of life and in 11 out of 38 specimens obtained at ages between 6½ months and 2 years. IgM antibody was therefore estimated to persist for about 6 months in the majority of cases and up to 2 years in a few individuals. IgM antibody was also detected by this method in 11 out of 114 infants with suspected but unconfirmed congenital rubella at ages up to 5 months. The total concentrations of IgM were above the normal range in nearly all sera taken from confirmed cases during the first 3 months of life and in half the specimens obtained between the ages of 3 and 6 months.IgG antibody was detected by fluorescent staining of whole serum in all patients with congenital rubella. Geometric mean titres increased during the first 3 months of life and then declined slowly. IgA antibody was not detected, except in two patients in whom traces were present at the age of 6 months, and the total concentrations of IgA were usually within normal limits.Fluorescent staining of fractions showed that the sedimentation characteristics of rubella IgG and IgM antibodies were the same in infants as in adults. The peak IgM fractions never contained IgG antibody, and the presence of specific IgM in these fractions could usually have been safely inferred from their HAI titres. Fluorescent staining, however, was more sensitive and frequently detected IgM antibody in fractions which had no definite HAI activity.Fluorescent staining of whole serum for IgM antibody was less distinct, and often unsuccessful, even in specimens in which specific IgM was detected in the fractions. The addition of IgG- to IgM-containing fractions caused depression of IgM staining and suggested that failure to detect IgM antibody in whole serum was partly due to competitive inhibition by specific IgG.
The behaviour of porcine cytomegalovirus in commercial pig herds
Authors: Plowright W. , Edington N. , Watt R. G. 
Published: May 2009

SUMMARYA longitudinal, virological and serological study of pigs in two herds with respiratory disease showed that infection by porcine cytomegalovirus (PCMV) was universal in both.Virus excretion usually began when piglets were between 3 and 6 weeks of age and reached a maximum between 5 and 8 weeks; it was usually no longer detectable at 11–12 weeks. Antibody demonstrable in indirect immunofluorescence (IIF) tests was present to moderate or high titre in all piglets at 2–3 weeks. This was presumed to be maternal in origin as it declined in titre between 2–3 and 5–6 weeks. After this fall the majority of piglets showed seroconversion as a result of virus infection. One group of 12 pigs in which infection occurred earlier than usual showed a very poor antibody response, which, nevertheless, persisted through to week 27.The findings are discussed with relation to porcine atrophic rhinitis and cytomegalovirus infection in other species.
Antibiotics and the Aberdeen typhoid outbreak in 1964
Authors: Brodie J. 
Published: May 2009

SUMMARYThis paper gives an abbreviated account of part of a research programme which followed the Aberdeen typhoid outbreak of 1964. Chloramphenicol, the main antibiotic used in treatment, was shown to have a minimum inhibitory concentration (MIC) of between 5 and 2.5 μg./ml. for the S. typhi phage type 34 of the outbreak. The MIC for methacycline was between 2.5 and 2 μg./ml. Whereas the deep and shallow broth techniques used gave similar results with these antibiotics, the MIC for ampicillin, and also cephaloridine, was less in the deep than in the shallow broths.Serum assays in patients given ampicillin or cephaloridine yielded abnormally high concentrations of both antibiotics when S. typhi phage type 34 was the test organism whereas, with other test organisms, the concentrations were within expectation. These abnormally high values fell within expected values when the sera under investigation had first been heated to 56° C. for 30 min. before assay against the S. typhi of the outbreak.The findings with ampicillin suggested that dosages given were satisfactory. With cephaloridine the concentrations found in patients' sera seemed to show that twice daily doses of 0.5 g. fell short of adequacy.
A preliminary study of the effect of contact with environmental mycobacteria on the pattern of sensitivity to a range of new Tuberculins amongst Ugandan adults
Authors: Stanford J. L. , Paul R. C. , Penketh Andrea , Thurlow Susan , Carswell J. W. , Barker D. J. P. , Barot Saroj 
Published: May 2009

SUMMARYA range of new Tubercul ns prepared from extracts of living organisms belonging to 12 mycobacterial species has been used to assess the effect of BCG immunization and contact with environmental mycobacteria on Ugandan adults. A total of 2,456 tests were carried out on 562 people, 86% of whom came from three areas selected for special study. These areas were chosen on the basis of occurrence of leprosy andM. ulceransinfection and on data concerning the distribution of environmental mycobacteria. It was found that the effect of BCG was small compared with that previously observed amongst Kenyan schoolchildren, but that the effect of geographical origin was considerable. There was some correlation between the percentages of reactivity to the reagents and the frequency of mycobacteria in the environment.
The importance of agglutinin production in mice in the determination of the definitive serotype ofBordetella pertussis
Authors: Bronne–Shanbury Caroline J. 
Published: May 2009

SUMMARYA schedule for the routine serotyping of strains ofBordetella pertussisbased on agglutinin production in mice to the K-antigens has been worked out. Mice have been found as satisfactory as rabbits but far more economical for the production of the very small volumes of serum which are required. Agglutinin production, used in conjunction with direct agglutination, provides definitive information about serotype.
The hamster as a secondary reservoir host of lymphocytic choriomeningitis virus
Authors: Skinner H. H. , Knight E. H. , Buckley L. S. 
Published: May 2009

SUMMARYExposure of weaned hamsters to an environment contaminated with LCM virus shed by tolerantly infected mice led to short subclinical infections. If infection occurred in early pregnancy, the young appeared normal at birth but their tissues were highly infective. For two to three months their bites and urine were also highly infective. A viraemia did not persist long enough for successive vertical transmissions of the infection to be likely. However, the viruria persisted in most prenatally infected hamsters for at least eight months and under simulated field conditions was a potent virus source for contact infections, leading to further generations of prenatally infected young. In the absence of the natural reservoir host, such long-term carriers could have been a major factor in causing the build-up of infection in colonies of hamsters which, when purchased as household pets, led to a recent spate of human clinical infections in Germany and the U.S.A.
Isolation of salmonellas and Shigella sonnei from a laboratory bench
Authors: Price T. H. 
Published: May 2009

SUMMARYAn area of the laboratory bench on which slide agglutinations were performed in the diagnosis of salmonella and shigella infection was examined for these organisms. Impression plates and broth-moistened swabs were used for sampling. Both techniques gave satisfactory results, but the contact plates provided positive results a day earlier than the swabs. Suitable precautions to minimize contamination of the bench surface are discussed.
Bacterial dispersion in relation to operating room clothing
Authors: Whyte W. , Vesley D. , Hodgson R. 
Published: May 2009

SUMMARYThe effect of operating clothing on the dispersal of bacterial particles from the wearers was studied in a dispersal chamber. A comparison was made of six gowns as well as four types of trousers. The gowns were of three basic types, namely a conventional cotton type, disposable types made of non-woven fabric and those of the total-body exhaust system (Charnley type). The dispersal chamber could simulate conditions as expected both in down-flow unidirectional ultra-clean systems and in a conventional turbulent plenum-ventilated system. It was found that the disposable gowns would reduce the dispersal rate by about 30% in the simulated conventionally ventilated system and about 65% in the laminar flow system. The total-body exhaust system (Charnley) would reduce the count by 10-fold in the conventional ventilated system and by 66-fold in the laminar-flow system.The poor performance of the gowns in conventionally ventilated systems was caused by the dispersal of bacterial particles from underneath the gown (about 80%). This was not reduced by the disposable gown and only partially by the Charnley type. This small drop would be further decreased in a conventionally ventilated operating-room as only scrubbed staff would wear the gown. In order to overcome this poor performance in conventionally ventilated operating-rooms impervious trousers would be required. Four types were studied and it was demonstrated that those made either from Ventile or non-woven fabric would reduce the bacterial dispersion fourfold.As these tests had been carried out in an artificial environment checks were carried out in the unidirectional-flow operating-room during total-hip arthroplasty. This was done by comparing conventional cotton gowns with non-woven gowns and total-body exhaust gowns. The results showed good correlation between the operating room and the chamber with the non-woven fabric gown but the total-body exhaust system did not perform as well in the operating room (12-fold compared to 66-fold) the difference being possibly due to the contribution from the patient. However, as this comparison was that which would be most open to influence from other variables confidence could be placed on the chamber test results.Values were also obtained for the total number of bacterial particles dispersed by persons during a standard exercise wearing different clothing. This count was dependent on the clothing worn but a median count of between 1000 and 1500 peatorial particlos/min. would be expected when conventional clothing was worn, with a range of between 300 and 19,000. This count could be reduced to about 100/min. if a total-body exhaust suit was worn (range 30–400).
Factors affecting the sensitivity of replicating McCoy cells in the isolation and growth of chlamydia A (TRIC agents)
Authors: Johnson F. W. A. , Hobson D. 
Published: May 2009

SUMMARYNormal non-irradiated McCoy cell cultures provide a sensitive and reproducible method for the isolation of oculo-genital strains of chlamydia A directly from human secretions and for laboratory studies with these agents. Since September 1973, chlamydia have been isolated from 175 of 562 women (32·1%) attending venereal disease clinics. Freshly isolated and low passage strains have been used to determine the importance of centrifugation, constitution and pH of the tissue culture medium, and the temperature of incubation in controlling the efficiency of plating in the method.
Prevention of low temperature denaturation injury in T4Bo phage by low concentrations of traditional cryoprotective additives
Authors: Steele P. R. M. 
Published: May 2009

SUMMARYThe well known cryoprotective additives glucose, sucrose, glycerol, dimethyl sulphoxide, polyvinylpyrrolidone, dextran and ammonium acetate have been found to prevent inactivation of T4Bo phage frozen in sodium bromide solutions. Their protective effects in this experimental system could not be accounted for by a colligative mechanism. It is proposed that they may act by modifying the structure of the unfrozen aqueous phase rather than by direct interaction with the phage.
A modified haemagglutination inhibition test for rubella antibodies, using standardized, freeze-dried reagents. Report of a comparative multi-centre trial
Authors: van Weemen Bauke K. , Kacaki Jovan 
Published: May 2009

SUMMARYA modified haemagglutination inhibition test for rubella antibodies, using standardized freeze-dried reagents, was developed and compared with haemagglutination inhibition tests using fresh erythrocytes. This comparison was made in collaboration with six European laboratories. A total of 4205 serum samples were tested. The results show that:(1) Sensitivity and reliability of the modified test are good;(2) the modified test can be performed in glass tubes as well as in polystyrene microtitration plates.
Salmonellosis in wild mammals
Authors: Jones P. W. , Twigg G. I. 
Published: May 2009

SUMMARYOne thousand two hundred and sixty-nine freeliving, wild mammals, representative of 16 species from estates in Berkshire, Oxfordshire and Surrey, were examined for the presence of salmonellas. Salmonella typhimurium was isolated from 1 and S. dublin from 7 house mice (Mus musculus). There were no isolations from the other species examined. It was concluded that the house-mice infected with S. dublin acquired the organism from experimentally infected cattle.The wild mammal population does not at present appear to constitute a reservoir for infection of domestic animals.
A comparative field trial, conducted without pre-treatment census baiting, of the rodenticides zinc phosphide, thallium sulphate and gophacide against Rattus norvegicus
Authors: Rennison B. D. 
Published: May 2009

SUMMARYThe effectiveness of the single-dose poison treatments of farm rat infestations, analysed by comparing the weights of the post-treatment census bait takes in covariance with the weights of the prebait takes, showed that treatments with 2·5% zinc phosphide, 0·3% thallium sulphate or 0·3% gophacide were equally effective and significantly better than were treatments with 1% zinc phosphide or 0·1% thallium sulphate. The methodology and sensitivity of different analyses are also considered.
Intravenous infusion bottle plugs as a source of microbial contamination
Authors: Holmes C. J. , Allwood M. O. 
Published: May 2009

SUMMARYA technique was described for the artificial contamination of the upper surface of intravenous infusion container plugs with viable micro-organisms. This technique was employed to assess the adequacy of decontamination of two designs of plug by the use of antiseptic swabbing. Results indicated that the MRO plug surface was more difficult to sterilize than that of the Tra venol plug. The possibility of contamination of the infusion fluid during insertion of the giving-set needle was examined. Results indicated that there was a risk of contamination through the administration-set port of the MRC plug if swabbing was inadequate.
The effect of colostrum-derived antibody on louping -ill virus infection in lambs
Authors: Reid H. W. , Boyce J. B. 
Published: May 2009

SUMMARYThe influence of colostrum-derived antibody to louping-ill virus on the course of experimental infection was investigated in lambs. Lambs that had high titres of antibody were refractory to infection. Lambs that had low titres of antibody did not develop a viraemia but either showed an antibody reaction or were sensitized as judged by the immune response, which was typical of an anamnestic response, after rechallenge. Animals that had no antibody 34–20 days before challenge had either no or very slight viraemia, but did develop an antibody response with titres as high as those of control lambs by day 21. Lambs that had been negative for longer periods responded in a similar fashion to controls.These findings are discussed in relation to the occurrence of disease in lambs kept in louping-ill endemic areas. It is concluded that in such areas infections of lambs are likely to be of minor importance as a cause of mortality and of little epidemiological significance.
Salmonella crossness– a new serotype containing a new somatic (O) antigen, 67
Authors: Rowe B. , Hall Mary L. M. , McCoy J. H. 
Published: May 2009

SUMMARYA new salmonella subgenus I serotype is described. Strain C.S. 1608/73, serotype 67: r: 1, 2, was isolated from activated sewage sludge and was assigned the nameS. crossness. The serotype is biochemically atypical in its ability to utilize sucrose and this ability appears to be controlled by a transferable plasmid.
Quality control of the isolation rate of pathogens in medical microbiology laboratories
Authors: Tillett Hilary E. , Crone P. B. 
Published: May 2009

SUMMARYTwo statistical analyses are suggested to compare the success rates in isolating and identifying pathogenic organisms from specimens achieved by different laboratories participating in a quality control scheme. An example is given in which the analyses are applied to 25 laboratories that received 30 simulated specimens.
Trials of the anticoagulant rodenticide WBA 8119 against confined colonies of warfarin-resistant house mice (Mus musculus L.)
Authors: Rowe F. P. , Bradfield A. 
Published: May 2009

SUMMARYThe efficacy of the newly developed anticoagulant rodenticide WBA 8119 was evaluated against the house mouse (Mus musculus L.) using individual and family groups of warfarin-resistant animals. WBA 8119 at 0·002 %, O % and 0.01 % in pinhead oatmeal bait gave complete kills of mice in ‘no-choice’ feeding tests carried out in cages and small pens. In replicated 21-day treatments on families of mice confined in larger pens and conditioned to feeding on plain foods, the overall mortalities obtained using the three formulated poison baits were 71/72, 62/63 and 57/57 respectively.The results of the WBA 8119 toxicity tests are considered in relation to previous findings on other anticoagulant rodenticides, particularly difenacoum. In equivalent tests, WBA 8119 performed better than difenacoum. The data thus support the laboratory findings that WBA 8119 is the most active anticoagulant so far tested for the control of warfarin-resistant house mice.
Incidence of salmonella infection in animals in England and Wales, 1968–1974
Authors: Sojka W. J. , Wray C. , Shreeve Jean , Benson A. J. 
Published: May 2009

SUMMARYOf a total of 23,609 incidents of salmonella infection reported during the period 1968–74, 20,326 occurred in cattle, 1744 in poultry and other birds, 675 in sheep, 558 in pigs and 306 in other species of animals.Despite the large number of serotypes isolated (153), 88% of incidents were due to only two serotypes: S. dublin (15,929 incidents of which 15,446 occurred in cattle) and S. typhimurium (4842 incidents of which 3785 occurred in cattle and 732 in birds).S. choleraesuis was the third (314 incidents which with only 5 exceptions occurred in pigs) and S. abortusovis (243 incidents all in sheep) was the fourth most commonly isolated serotype. The following six serotypes were each recorded in more than 100 incidents: S. newport (177), S. agona (170), S. virchow (169), S. anatum (152), S. enteritidis (150) and S. montevideo (111). The other 143 serotypes accounted for only 5·8% of total incidents.The trends of annual incidence of salmonella infection in cattle, sheep, pigs, poultry and other birds during the 17-year period 1958–74 and the distribution of the main serotypes in the individual species of animals from 1968 to 1974 are discussed.
Neutralization kinetics studies with type SAT 2 foot-and-mouth disease virus strains. 1. Factors that influence the rate and pattern of neutralization
Authors: Rweyemamu M. M. , Booth J. C. , Pay T. W. F. 
Published: May 2009

SUMMARYA study of the kinetics of inactivation of foot-and-mouth disease virus type SAT 2 strains revealed that in most cases the rate of neutralization was not rectilinear. Deviations from first-order kinetics observed represented biphasic or parabolic and stepwise reactions. The initial rate was rapid and showed no lag phase or shoulder. The effects of deviations from linearity could be minimized by dilution of antiserum to a suitable extent. Treatment of virus–antibody mixtures with anti-species globulin resulted in enhancement of the rate of neutralization of homologous and heterologous reactions without significantly altering the relation between the two. This treatment also considerably reduced the amount of the persistent fraction. In attempt to disaggregate virus it was observed that sodium dodecyl sulphate inhibited neutralization of virus by specific antiserum.