bluuebunny/crossref_metadata_2025_split huggingface dataset:
The egg yolk reaction ofStaphylococcus aureusisolated from burns
Authors: Lowbury E. J. L. , Collins B. J. 
Published: May 2009

Staph. aureusfrom burns of in-patients were tested for egg yolk reaction during three periods; in 1958 and in 1960 approximately 80 % of the strains gave a negative reaction (EY-), but in 1962 only 36 % of the strains were egg yolk negative.Staphylococci of phage group III were more commonly EY- than those of other groups isolated from burns. Within each of groups I and III, however, there were patterns predominantly EY- and others predominantly egg yolk positive (EY+); in group I the majority of strains isolated in 1960 were of phage type 52 and EY-, while those isolated in 1962 were predominantly of phage type 80 or related patterns which were always EY+.Most of the staphylococci in burns were resistant to penicillin, tetracycline and erythromycin; within groups I and III, the staphylococci which were EY- were also more commonly resistant than EY+ strains to these three antibiotics.Most of the staphylococci from burns were mercuric chloride resistant (presumptive epidemic strains); of the mercuric chloride sensitive staphylococci, the proportion of EY+ strains was greater than that of EY- strains.
A rapid immunofluorescence technique for detecting salmonellae in raw meat
Authors: Georgala D. L. , Boothroyd Margery 
Published: May 2009

A rapid 18 hr. technique has been developed for detecting salmonella contaminated carcass and boneless meats. It is based on 43° C. selenite enrichment of samples, followed by immunofluorescent detection of salmonella cells in the enrichment. In tests with 286 meat samples the rapid and conventional techniques agreed in the detection of 93 positive and 149 negative samples. The two tests failed to agree for the remaining 44 samples. The rapid technique thus lacks precision, but could be used as a rapid ‘presumptive’ salmonella test, so that contaminated material could be prevented from reaching the processing lines of food factories.We thank Dr Betty Hobbs of the Food Hygiene Laboratory for kindly sup plying the meat samples used in this investigation, Dr Patricia Bradstreet of the Standards Laboratory for Serological Reagents for the salmonella diagnostic antisera and Mr R. Kenworthy for performing the goat injections.
Experiments on the spread of colds: 1. Laboratory studies on the dispersal of nasal secretion
Authors: Buckland F. E. , Tyrrell D. A. J. 
Published: May 2009

An attempt has been made to study quantitatively the mechanisms by which infectious materials may enter the body by the upper respiratory tract and be shed during a cold.The rapid clearance of tracers, spores of B. mycoides and bacteriophage type T3, has been measured after adding them in small drops to the nose, conjunctiva and mouth.Tracers placed in the nose pass rapidly down the throat, but are found in only small amounts in the saliva. They are dispersed by blowing the nose and, more efficiently, by sneezing. Nearly all are shed as coarse droplets. About 0·1% are shed in droplets small enough to remain airborne and just over half of these are in the size range likely to be trapped in the upper respiratory tract. The droplets are apparently formed mainly in the nose. The larger amounts of droplets formed in the mouth carried relatively few infectious particles.Testing by experiments in a model system it was concluded that most of the coarse droplets produced by a sneeze or by an experimental spray fall rapidly to the floor. A few of the larger droplets were trapped on a moistened microscope slide intended to mimic the possible trapping of droplets on the conjunctive. The spores in these represented only a small proportion of those found in droplets which remained airborne and were collected by an air sampler.We wish to thank Miss P. D. Ball for technical assistance and Dr J. E. Lovelock for helpful discussion in the early stages of this work. We are also grateful to Sir Victor Negus and Dr B. Wyke for discussing the physiology of the nose with us, and to Mr K. R. May for his advice on methods of air sampling. The air samplers were loaned by the Microbiological Research Establishment, Porton, and the photographs taken by the Chemical Defence Experimental Establishment, Porton.
The incidence of the serological groups ofCandida albicansin southern England
Authors: Stallybrass F. C. 
Published: May 2009

Cultures ofC. albicanshave been classified into two groups by means of a double diffusion precipitin test employing rabbit antisera and polysaccharide extracts. In the present series it has been found that 75% of cultures belong to group A and 25% to group B, and it is suggested that the higher incidence of group B strains occurring in the sputum of hospital in-patients with chest disease may be the result of reinfection by attenuated forms which persist in the environment.My thanks are due to many colleagues who provided me with the strains ofC. albicans, and to Prof. H. Hare for helpful criticism in the preparation of this paper.
Tests on self-disinfecting surfaces
Authors: Kingston D. , Noble W. C. 
Published: May 2009

A variety of surfaces was tested for self-disinfecting action againstStaph. aureusandEsch. coliat a humidity of 42%. Surfaces which had been treated with disinfectants sometimes reduced the survival when the organisms were applied subsequently in drops of broth, but the reduction was very small unless the surface was able to absorb appreciable amounts of disinfectant and the drop of inoculum spread. When the inoculum was applied dried in cotton dust, only surfaces which evolved formaldehyde showed any activity against the bacteria. These surfaces also reduced the survival of bacteria in liquid inocula.We would like to record our thanks to Dr O. M. Lidwell for much helpful advice.
A study of polio vaccination in infancy: excretion following challenge with live virus by children given killed or living poliovaccine
Authors: Henry J. L. , Jaikaran E. S. , Davies Joan R. , Tomlinson A. J. H. , Mason P. J. , Barnes Joan M. , Beale A. J. 
Published: May 2009

Quadruple vaccine containing 75 D antigen units of killed type 1 poliovirus was given to children at ages 2, 3 and 4 months followed by a booster dose at 15 months.The serological response to the primary course was difficult to assess owing to maternal antibody. Antibody titres to the type 1 component after the booster dose were very satisfactory and about 10 times higher than those observed in a similar group of children given attenuated vaccine. Response to the poliovirus types 2 and 3 in the quadruple vaccine was less satisfactory.Graded doses of attenuated poliovirus type 1 were fed to the children 2 months after the primary course and 1 month after the booster dose. Children who had received no poliovaccine and children immunized with attenuated vaccine were included for comparison.Immunization with killed vaccine did not greatly affect the size of the minimal infecting dose of live virus but reduced both the duration of the subsequent infection and the titre of virus in the faeces.The epidemiological significance of these findings is discussed.
Staphylococcal infection in thoracic surgery: experience in a subdivided ward
Authors: Lidwell O. M. , Polakoff Sheila , Jevons M. Patricia , Parker M. T. , Shooter R. A. , French Valentine I. , Dunkerley D. R. 
Published: May 2009

We studied the incidence of staphylococcal infection in a thoracic surgery ward which consisted of a number of separate rooms, and inquired whether the subdivision of the ward was responsible for the unusually low sepsis-rate.The airborne dissemination of Staphylococcus aureus from one room to another appeared to be little less than that in an open ward; but the total number of Staph. aureus in the air was very low.Most of the patients received prophylactic antibiotics. The nasal carrier-rate of Staph. aureus by patients fell greatly during their stay in the ward. There was a progressive disappearance of sensitive organisms and little acquisition of multiple-resistant organisms.When there are urgent clinical grounds for the lavish use of antibiotics, the dangers appear to be reduced by effective segregation of the patients from each other.
The survival ofToxoplasmain infected mosquitoes
Authors: Chapman Jennifer M. , Ormerod W. E. 
Published: May 2009

1. An incomplete field study in Lincolnshire, England, suggested that toxoplasmosis might be transmitted from pig to man by mosquitoes. Although the results were inconclusive they suggested the experimental work recorded in this paper.2. Trophozoites of the Beverley strain were obtained in increased yield from the peritoneal fluid ofMastomystreated with hydrocortisone. Cysts were obtained in increased yield by passage of the brain ofSigmodoninto laboratory mice.3. Four species of mosquitoes were fed through a membrane or on sucrose solution on media containing either cysts or trophozoites ofToxoplasma gondii. In some experiments blood was added to ensure passage of the feed to the mosquito stomach, in others it was excluded so that at least part would pass to the crop.4. A spurious ‘cyst’ resembling but distinguishable fromToxoplasmawas noted in the homogenate of mouse brain.5. In no instance did mosquitoes retain infectivity as demonstrated by injection into mice, beyond the third day, but since experiments were not carried on beyond the fourteenth day the existence of an occult form cannot be excluded.
A whey complement fixation test. Its relation to whey agglutination and isolation of Brucella abortus from the milk of individual cows
Authors: Farrell I. D. , Robertson L. 
Published: May 2009

SUMMARYTwo hundred and ninety-three milk ring test-positive individual milk samples were examined by whey complement fixation and agglutination tests and the results were compared with the isolation of B. abortus by cultures made from the milk.There was a closer correlation between whey CF tests and isolation of the organism than between whey AG tests and isolation. Brucella organisms were not isolated from 116 MRT-positive milk samples when the whey CF titre was < 1/10; whereas 9/104 (9%) isolations were made from milk when the whey AG titre was < 1/20.Because of its closer correlation with culture results it is suggested that the whey CF test would be valuable in an eradication programme for the detection of infected udders.The limitations of the milk ring test for the examination of individual milk samples are emphasized and it should be used only as a preliminary screening test. In the individual milk samples examined, 32% of the MRT-positives showed no evidence of infection by either the whey AG, whey CF, or culture tests.
The immunogenicity of heat-inactivated vaccinia virus in rabbits
Authors: Madeley C. R. 
Published: May 2009

SUMMARYRabbits were immunized by multiple intradermal injections followed by six intravenous doses of vaccinia virus inactivated by heating to 65° C. Particular attention was paid to confirming that the virus used was fully inactivated and incapable of reactivation. The immunized rabbits developed neutralizing and other antibodies to a titre comparable with those developed in response to live virus, but multiple intravenous injections were required to elicit a maximum titre. A qualitatively different response was seen only in immunodiffusion tests in agar gel where two or three fewer lines developed with antisera to heated virus than with those to live virus. The rabbits were subsequently challenged intradermally either with vaccinia and cowpox or with rabbitpox. They showed some immunity to vaccinia and cowpox, compared with normal controls, but less than that elicited by live virus. Their resistance to lethal doses of rabbitpox was life-saving though some rabbits did develop lesions. Later rechallenge of the rabbits showed that they had not developed further immunity, in distinction from the normal controls. The implications of these findings are discussed.I wish to thank the National Fund for Research into Poliomyelitis and Other Crippling Diseases for their generous support in providing a Research Fellowship during which this work was done. I wish to thank also Professor A. W. Downie F.R.S. and the Staff of the Department of Bacteriology, University of Liverpool, for their encouragement and assistance respectively.
Studies on the inhibitory properties of sodium thioglycollate on the germination of wet spores of clostridia
Authors: Mossel D. A. A. , Beerens H. 
Published: May 2009

SUMMARYWet spores of fourteen strains ofClostridium, representing eight species, were enumerated in four different types of thioglycollate agar and in a similar medium in which thioglycollate was replaced by cysteine-HCl. Thioglycollate appeared to be toxic, in principle, to almost all strains tested, although the degree of toxicity was influenced by other components of the medium. These experiments entirely confirm earlier observations and must lead to the conclusion that the use of thioglycollate in sterility test media should be discontinued and that cysteine-HCl should be used as the redox potential reducing compound instead.
Sources of salmonellas in market swine
Authors: Williams L. P. , Newell K. W. 
Published: May 2009

SUMMARYA commercial swine fattening ration containing animal origin ingredients was shown to be related to the salmonella excretion of market pigs being sent to slaughter from a well-managed farm. When similar animals from this farm were fed a ration of much lower salmonella content, due to exclusion of ingredients of animal origin, their excretion declined as measured by both rectal and caecal swabs. When subsequent lots of pigs consumed a pelleted weaner ration and the special supplement only, before being exposed to a supplement containing the usual level of contamination, they seemed to be refractory to infection. Probably, this was a function of age at first exposure.With prospective methods it was possible to show that salmonellas from the abattoir environment could infect pigs, that they would excrete them within a very short time, and that organisms from this source could be demonstrated at slaughter and shown to be a cause of carcass contamination.While these findings support the view that the build-up of salmonellas hi pigs is by contact with a contaminated environment, they indicate that the primary source of the contamination is most probably the salmonella-excreting pig which has consumed contaminated feed ingredients on its farm of origin.If the great majority of pigs went to slaughter salmonella-free they would not serve as a source of infection to other pigs being sent to slaughter. Their intestinal contents could not contaminate carcass sides in the slaughtering process. This should help to prevent the contamination with salmonellas of the food preparation area of both homes and commercial eating establishments.
A modification of the growth-inhibition test and its use for detectingMycoplasma mycoidesvar.mycoides
Authors: Davies G. , Read W. C. S. 
Published: May 2009

SummaryA modification of the growth-inhibition test for identifyingMycoplasmaspecies is described. The modification simplifies the screening of a large number of strains for one species. Experiments showed that it was effective and specific when used to identifyM. mycoidesvar.mycoides. Its use in studying the epidemiology of contagious bovine pleuropneumonia is discussed.This work was financed in part by the United States of America Agency for International Development under the terms of the CCTA/AID Joint Project 16 for research on contagious bovine pleuropneumonia.We wish to thank Dr R. H. Leach for the various bovine mycoplasma cultures.
The hygiene of slicing machines, carving knives and can-openers
Authors: Gilbert R. J. , Maurer Isobel M. 
Published: May 2009

SummaryExperiments have been made in several supermarkets, shops and cafés to determine the bacterial counts on slicing machines, carving knives and can-openers after contact with various cooked and canned meats, and to find a simple, quick and effective cleaning method for such articles of equipment. The importance of personal effort in cleaning rather than a reliance on the known attributes of detergent/disinfectants is stressed. The methods available for testing the efficiency of cleaning procedures are outlined.In vitro tests have shown that the detergent/disinfectant used in the present study at a concentration of 0·75 % (w/v) was satisfactory. This concentration was the minimum inhibitory concentration for Salmonella paratyphi B, which was the most resistant of fifteen strains of bacteria studied.The design of slicing machines and can-openers is discussed in relation to safety in use and ease of cleaning. Recommendations concerning the necessity of regular and effective cleaning of food-handling equipment and storage of cooked and canned meats before and after slicing are given.
Live influenza B vaccine in volunteers
Authors: Beare A. S. , Tyrrell D. A. J. , Hobson D. , Howells C. H. L. , Pereira M. S. , Pollock T. M. , Tyler L. E. 
Published: May 2009

SUMMARYA trial of an experimental live influenza B vaccine has been described.The virus it contained was active and produced infections, antibody rises and clinical reactions.Second and third vaccinations had much less effect than the first. Resistance to revaccination was only partially reflected in the serological response.It seems that another factor, probably local antibody, exerts a considerable influence on resistance to infection with influenza viruses.We are greatly indebted to Dr P. G. Higgins of the Public Health Laboratory, Cirencester, who went to much trouble to provide us with specimens from patients with influenza; to Dr H. G. Pereira of the National Institute for Medical Research for the antigenic analysis of the vaccine virus; to Messrs Sankey Ltd., Bilston, Wolverhampton, for their unfailing courtesy and forbearance throughout the trial; to the volunteers for their enthusiastic co-operation in the face of some discom forts; and to Messrs Pfizer Ltd., Sandwich, for originally providing facilities for the preparation of the vaccine.In particular we wish to record our gratitude for the invaluable technical help of Miss Pamela Ball of the Common Cold Research Unit, Mrs Maria Gregory of the Bacteriology Department of Liverpool University, Mrs L. Johnson of the Virus Laboratory of New Cross Hospital, Wolverhampton, and Mr A. Westoby, an assistant in the practice of Dr Tyler.
Factors affecting lecithinase activity and production inClostridium welchii
Authors: Nakamura M. , Schulze Judith A. , Cross W. R. 
Published: May 2009

SUMMARYA variety of factors that affect lecithinase activity and lecithinase production byCl. welchiiwere studied. The lecithinase activity was time and temperature dependent. The optimum temperature varied from 30° to 46° C. according to the strain ofCl. welchiiemployed. Maximum lecithinase activity was produced after 12–60 hr. There was considerable strain variation. This could easily account for the differences in the published data.Commercial purified lecithinase was more readily destroyed by heat than the lecithinase produced byCl. welchiiin culture media. The enzyme inactivation pattern at 60° C. was similar to that at 90° C. This is not in agreement with the reports of others who found that less enzyme was inactivated at the higher temperatures.Acid pH values completely inactivated the enzyme. However, alkaline pH values did not significantly destroy the enzyme. The lecithovitellin reaction was completely inhibited at pH values of 1–5. The optimum pH for the reaction was around pH 7–8.The production of lecithinase was dependent upon the pH of the culture medium. One strain produced measurable lecithinase at pH values of 5·5–8·5, whereas another strain produced lecithinase only at pH values 6–5–7–5.Lecithin stimulated the production of lecithinase in a chemically defined medium.
An appraisal of sewage pollution along a section of the Natal coast
Authors: Livingstone D. J. 
Published: May 2009

SUMMARYA bacteriological survey was made on the distribution and occurrence of coliforms and pathogenic indicators of pollution within the surf-zone and near-shore waters along a section of the Natal Coast, prior to the use of submarine outfalls. The distance covered measured approximately 47 miles. The waters sampled and assessed ranged from ‘clean’ beaches to heavily polluted areas; a single short run off an Eastern Cape coastal region was included for comparative purposes. In all cases, the bacteriological picture was related to sanitary features on the shore. The method is based on Escherichia coli I counts, parasite units, staphylococci, salmonellas and salinity, and provides an objective approach to the assessment of any future changes in water quality consequent on development.
Air-movement control for treatment and isolation rooms
Authors: Baird G. , Whyte W. 
Published: May 2009

SUMMARYThe degree of protection provided by various air movement control systems, as applied to isolation and treatment rooms, has been assessed. The main factors influencing the efficiency of isolation were the air supply rate to the room and the time the door was left open. The effect of some other possible factors, such as temperature differences and method of air distribution, are discussed.The type of facilities provided must depend on the type of patient and economics, but prediction equations, which allow the assessment of positive, negative and balanced ventilation systems, are presented. The ventilation requirements for isolation rooms should be assessed individually, but for a treatment room a balanced system of ventilation with between 500 and 1000 ft.3/min. should be very effective. Precautions should be taken to ensure the air quantities are balanced and temperature differences are minimized. An air lock should not be necessary for balanced systems provided these rooms are in a mechanically ventilated ward.We thank Mr W. Carson and members of the Building Services Research Unit for their help and advice and Sister M. F. D. Muir and the staff of the experimental ward for their co-operation. This work was sponsored by the Nuffield Provincial Hospitals Trust.Requests for reprints, or a fuller description of the ward unit and test results, should be addressed to George Baird, Building Services Research Unit, 3 Lilybank Gardens, Glasgow, W. 2.
Dose-response relationships of lymphocytic choriomeningitis viruses in mice and L cell tube cultures
Authors: Lehmann-Grube F. 
Published: May 2009

SUMMARYThe dose—response relationships between two strains of lymphocytic choriomeningitis virus (WE3and Armstrong) and two hosts (mice and L cell tube cultures) were determined. The statistical analysis showed that, if infection was regarded as the response, and in the case of Armstrong virus in mice also death, the shapes of the empirical dose—response curves did not deviate from expectation which was based on the zero term of the Poisson distribution. Hence, the hypothesis that individual infectious units are capable of initiating infection and that co-operation is not required, was not contradicted. Furthermore, the units of assay were found to be equally susceptible under the experimental conditions applied.By way of contrast, the relationship between WE3virus and mice dying after intracerebral inoculations was found to be more complex. In this case the empirical curve did not run the expected sigmoid course at all, but rather was bell-shaped with a maximum of mortality (92%) at approximately 50 ID 50.The work was supported by a research grant from the Deutsche Forschungs-gemeinschaft.