bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkali-dissolved diphtheria toxoid-antitoxin floccules adsorbed on aluminium carriers. Preparation, and immunity experiments in animals
Authors: Mason J. H. , Robinson Mary 
Published: May 2009

Since the introduction of toxoid-antitoxin floccules by Glenny & Pope (1927) little has been done to improve their value as an antigen. Watson, Taggart & Shaw (1941) and Barr (1949) confirmed the work of these investigators in showing that heating at 80° C. increased their antigenic value.It has been shown in this article that about 80% of the toxoid contained in floccules may be recovered if they are dissolved inn/20-NaOH, the alkali being allowed to act for 1 hr. before being neutralized with acid. A purity of between 0·002 and 0·0025 mg. N/Lf is obtained regularly. Such a dissolved floccule solution is a relatively poor antigen when tested in guinea-pigs, but may be rendered highly antigenic when precipitated with alum or adsorbed on AIPO4.The method has the advantage of simplicity. It would appear that any medium capable of yielding a toxin convertible into flucculable toxoid may be used, thus doing away with cumbersome media-making methods. However, for the best results in terms of both recovery and purity, a high-value, quickly flocculating, toxoid should be used. Further, the choice of antitoxin appears to be important where recovery is concerned. With most of the antitoxins used, recoveries of between 70 and 90 % were got, although with that used, for most of the work recorded here, the recoveries were much lower.It is not yet established which is the antigen of choice—alum-precipitated (P.D.F.) or AIPO4-adsorbed (A.D.F.) dissolved floccules. A.D.F. has the advantage of ease of preparation and of constant mineral carrier content, but further work is necessary to establish the optimum amount of carrier before a definite answer can be given. A paper on immunity responses in man will be published shortly in theLancet.
The detection of streptococci in air
Authors: Williams R. E. O. , Hirch Ann 
Published: May 2009

To estimate the number of viable streptococci present in the air of occupied places, airborne bacteria were collected in a slit-sampler on a nutrient agar medium containing 5% sucrose, 5% horse serum, 0·25 mg./100 ml. crystal violet, and 1·0/100 ml. potassium tellurite. This medium inhibits the great majority of the staphylococci and micrococci found in the air. On it colonies ofStrep. salivariusare readily recognized by their mucoid form. The number of other streptococci was estimated by picking and examining a random sample of the colonies.Streptococci were recognized in the sample by three different methods: (1) by microscopic examination of a nigrosin film made from the original colony; (2) by examination of a nigrosin film and also subculturing the colony to a ditch plate having blood agar on one side and serum agar containing 40% or bile on the other; or (3) by subculture to bile-agar ditch plates alone, the bile agar in this case containing aesculin and ferric citrate. By method (1) streptococci could be distinguished from micrococci; by methods (2) and (3) this distinction could be made with more confidence, and in addition enterococci could be distinguished from other streptococci.A number of tests of the efficiency of the method were carried out, and it was concluded that some 20–40% of the viable streptococci in the air were missed.The standard errors of the mean of a number of streptococcal counts in schoolrooms were calculated and found to be of the order of 14% of the mean when our standard routine was followed; increasing the size of the sample of colonies picked for examination by 30% would probably have had only a trivial effect on the standard error of the mean, since the greater part of the variation was due to differences between the counts in different rooms.
The behaviour of rats and mice feeding on whole grains
Authors: Spencer Mary M. 
Published: May 2009

The way in which rats and mice eat whole grains of wheat, barley, oats and maize has been studied.Rats (Rattus norvegicusandR. rattus) hold grains with the long axis parallel to that of the body and eat the germ end of the grain in preference to the rest.Mice (Mus musculus) hold grains with the long axis at right angles to that of the body and attack first the cheeks of all grains except maize, of which only the germ and scutellum are eaten.It is suggested that texture is in the main responsible for the selection of a particular part of a grain.
Differentiation of sero-fermentative types inBacterium coliO Group 55
Authors: Wright Joyce , Villanueva Regina 
Published: May 2009

Biochemical and serological investigations were made uponBact. coliO 55 B 5 strains isolated from infants with diarrhoea and vomiting. On the basis of their reactions with six fermentable substances and of their H antigen types, the strains could be differentiated into three sero-fermentative types, I, II and III, which comprised, respectively, those having H6, H2 and H7 antigens.We wish to acknowledge our thanks and indebtedness to the following: the Chairman and Members of the Tottenham Group Hospital Management Committee, and Dr T. H. C. Benians, Dr W. I. Leslie and Dr R. Swyer, for facilities for research in the laboratory and wards of St Ann's General Hospital; Mr L. G. C. Maslen for most valuable advice and assistance; the entire laboratory staff for their willing and efficient help.
The influence of atmospheric drying on the survival of wound flora
Authors: Lowbury E. J. L. , Fox Jean 
Published: May 2009

Suspensions ofStrep. pyogenes, Staph. aureus, Ps. pyocyaneaand micrococci in serum, distilled water, saline and oleic acid solution were allowed to dry on cover-slips. The numbers of bacteria surviving after periods of exposure were estimated from viable counts of extracted cover-slips.All the organisms tested showed after drying a fall in viable count that was absent in aqueous suspensions not allowed to dry.Ps. pyocyaneawas shown to have a lower survival rate on drying than the other organisms.Serum afforded moderate protection to the suspended organisms during the period of drying.0·1 mg./ml. oleic acid caused a rapid destruction ofStrep. pyogenesand a significant destruction ofPs. pyocyaneaas well as ofStaph. aureusand micrococci in drying films of these organisms. The similarity of the fate ofStaph. aureusand micrococci during drying in low concentrations of oleic acid is in contrast to the previously reported greater sensitivity ofStaph. aureusto higher concentrations of oleic acid (1–10 mg./ml.) in the test-tube.The implications of these findings are discussed in relation to skin and wound flora, and to environmental hygiene.
The Proportion of Viable Bacilli in Agar Cultures ofB. aertrycke(Mutton), with special reference to the change in size of the Organisms during growth, and in the Opacity to which they give rise
Authors: Wilson G. S. 
Published: May 2009

1. Working with agar cultures of a strain ofB. aertrycke(mutton) it was found that the number of organisms requisite to cause a given opacity was five times as great in a 26-hour as in a 4-hour culture.2. This difference is probably explicable by the fact that bacilli from young cultures are larger than those from old ones.3. Evidence is produced which suggests that the opacity method gives a measure not of the number of organisms, but of the total quantity of bacterial protoplasm in the suspension. It should therefore be of special value in the standardisation of vaccines.4. It is pointed out that the opacity method when used for the enumeration of bacteria is subject to a considerable error, and is hence unsuitable for accurate work.5. A technique is described for the estimation of the proportion of viable to total organisms in an agar culture.6. The results obtained are closely similar to those already described for broth cultures.7. The maximum proportion of living bacilli is reached at the end of the logarithmic phase of growth, when about 80 per cent, of the organisms are alive and capable of reproduction.8. It seems probable that there is a mortality amongst the bacilli that are generated in the early stages of growth, the least resistant organisms failing to divide.
The Relation of the Composition of the Culture Medium to the Formation of Endospores by Aerobic Bacilli
Authors: Tarr H. L. A. 
Published: May 2009

1. Spore formation in eight typical members of the genusBacillushas been studied.2. Three of these strains, including one species ofB. anthracis, have been found to be practically asporogenous under the experimental conditions. In general the following statements hold good for the sporogenous races studied.3. Spore formation is almost, or entirely, inhibited by cultivation on media rich in amino acids, such as tryptic digests of casein or meat. Similar inhibition results following cultivation on a medium containing reasonably high concentrations of a mixture of amino acids and asparagine.4. When such media are suitably diluted with standard inorganic salt solutions the percentage of spores formed is greatly increased, and frequently at least 99 per cent. of spores are formed if the dilution is sufficiently high.5. When simple nitrogenous compounds such as amino acids are added to a dilute casein digest medium in which sporulation is almost complete, a definite decrease in the percentage of spores present is observed. Asparagine, which is probably readily assimilated, apparently completely hinders spore formation in most cases. Other amino acids do not exert so pronounced an effect, and ammonium phosphate does not appreciably inhibit the formation of spores.6. The fact that the addition of glycine suppresses growth markedly when it is added to a dilute casein digest medium, but does not appreciably hinder sporulation, suggests that the formation of spores is not due to any toxic effect of added compounds, or compounds already present in the medium.7. Sporulation is almost complete in a “synthetic” medium in which low concentrations of ammonium phosphate and sucrose represent the sources of nitrogen and carbon, respectively. However, frequent transfers in such a medium may inhibit spore formation partially or entirely in certain instances. This effect probably depends upon the enhanced ability of the culture in question to utilise sucrose as a source of carbon when cultivated constantly in its presence.8. It is concluded, from the above data, that endospore formation in aerobic bacilli bears an inverse relationship to the amount of available nutrient material present in the culture medium.I am indebted to Prof. Sir F. G. Hopkins and Miss M. Stephenson for their constant encouragement during the progress of this work. My thanks are due to Mr Pirie of this Department who kindly furnished me with several of the amino acids employed, and to Dr Miles of the Department of Pathology for his kindness in supplying me with certain of the cultures.
Observations on the Bacterial Flora of Some Slaughter-houses
Authors: Haines R. B. 
Published: May 2009

1. A preliminary survey of the bacterial flora of some different types of slaughterhouse indicates the sources from which heaviest contamination with bacteria is likely to occur.2. Cleaner working conditions are shown to lead to a diminution in the numbers of organisms present in the air, swabbing water, etc., and in a reduction in the proportion of certain types of organism.
Studies in the dynamics of disinfection: VII. The reaction between phenol andBact. coli:the effect of temperature on the usually accepted concentration exponent and the calculation of a more satisfactory exponent based on theoretical considerations
Authors: Jordan R. C. , Jacobs S. E. 
Published: May 2009

1. Calculated values of the virtual sterilization time(v.s.t.)have been used in an analysis of the effect of temperature on the concentration exponent of the reaction between phenol andBact. colicultures under rigidly standardized conditions.2. Within the experimental range of temperature and concentration employed, the exponent calculated from the formulaCn×t=Kwas satisfactorily constant from 20° to 35° C., but it apparently increased at 39° C.3. This formula is unsatisfactory in that it cannot apply to concentrations near the threshold value without a change in the value ofn.Accordingly, a new method of treating these data has been suggested which makes allowance for this threshold or minimum concentration. A corresponding ‘maximum’ concentration has been arbitrarily fixed at which thev.s.t.is 10 min. and the value of (v.s.t.– 10) thus varies from infinity to zero between these concentration limits.4. Sigmoid curves asymptotic to ordinates at the minimum and maximum concentrations must be obtained when log (v.s.t.– 10) is plotted against concentration and the equation of the Pearl-Verhulst logistic curve, which is of the required type, has been used successfully to express the relationship betweenv.s.t.and concentration at constant temperature.5. One of the constants of this formula partakes of the nature of a concentration exponent and this may be constant over the full effective concentration range and for all temperatures.6. The logistic formula relatingv.s.t.to concentration at constant temperature is closely related to that connectingv.s.t.with temperature at constant concentration. The two formulae become interconvertible if certain assumptions are made concerning the relationships between the minimum and maximum concentrations and temperature.
Laboratory findings in enteric group fevers in the Middle East forces
Authors: Dick John C. 
Published: May 2009

1. The laboratory findings in a series of 215 cases of enteric fever are described and discussed, with special reference to early diagnosis.2. In the majority of the cases reviewed, the leucocyte count was about the lower level of normal limits, though considerable variation both upwards and downwards occurred.3. Blood culture was a very satisfactory and early method of diagnosis; the method used is described fully.4. Certain variations from normal in the behaviour of the organisms were encountered and are described.5. Bact. faecalis alkaligenes was isolated from blood culture in five cases in which enteric group organisms were also isolated from blood, faeces or urine and in three which were clinically enteric fever. The relation of these observations to the possibility of primary Bact. faecalis alkaligenes septicaemia is noted.6. Seventeen cases were fatal. The causes of death are described.
Group D streptococci in the faeces of healthy infants and of infants with neonatal diarrhora
Authors: Sharpe M. Elisabeth 
Published: May 2009

1. The aerobic faecal flora of healthy infants was found to comprise coliform organisms, streptococci and occasionally yeast and spore-bearing organisms. Coliforms and streptococci occurred more frequently in the stools of artificially fed than of breast-fed infants in whom micrococci occurred more frequently.2. Of 191 strains of streptococci isolated from healthy infants' faeces and tested serologically, 8·90% fell into Lancefield's group D. Of the stools examined 93·7% contained group D streptococci.3. A comparison of the group D streptococcal flora of the faeces of healthy infants and of infants associated with outbreaks of neonatal diarrhoea showed that the percentage of these organisms found in the latter was much higher than in healthy infants, the modes being 90–100 and 10–20% respectively.4. The same species and varieties of group D streptococci were found in both healthy and sick infants. Streptococcus faecalis was the predominant species.5. Serological typing of strains of group D streptococci from healthy infants from three maternity hospitals showed that particular types tended to predominate in each maternity unit and to recur over a considerable period of time, in each instance suggesting a reservoir of dissemination to successive infants as they arrived. With artificial feeding an increased diversity of serological types was found.6. Serological types of group D streptococci isolated from sick infants during ten outbreaks of neonatal diarrhoea showed a considèerable variety. Apart from one outbreak (A), where type I was isolated with great frequency, one or two types tended to predominate in each outbreak, but not to any great extent, and not always the same one.7. Types 1, 5, 8 and 9 were the types of group D streptococci most commonly found in both healthy and sick infants, but type 1 occurred in a significantly greater percentage of sick than of healthy infants.8. Tyrosine decarboxylase activities of group D streptococci were usually associated with serological types. The distribution of activities of these organisms was similar in healthy and sick infants.9. The possibility that neonatal diarrhoea may consist of more than one syndrome is discussed, and several of the outbreaks described here are classified into two groups.The author wishes to thank Dr A. T. R. Mattick for his constant interest in this work; Dr P. M. P. Shattock for advice and many valuable suggestions; Dr E. F. Gale for advice and material; Dr E. H. Gillespie, Dr A. M. McFarlan and Dr J. Wright for material and clinical data; Dr P. White and Miss Z. D. Hosking for assistance with the statistical computations; Mr L. G. Newland for technical assistance; and to express her appreciation to the Medical Research Council for a grant which enabled this work to be carried out.
The antigenicity of sera of man and animals in relation to the preparation of specific precipitating antisera
Authors: Weitz Bernard 
Published: May 2009

Specific precipitating antisera can be prepared in rabbits by the repeated inoculation of alum-precipitated serum.High titre of sensitivity to the homologous serum is obtained only with a complete loss of specificity.By absorption of the non-specific antiserum with heterologous sera the specificity can be restored.Two types of reactions can be observed in such non-specific antisera: (1) the homologous reaction which occurs with the sera of closely related animals, and (2) the heterologous reaction which is attributed to the presence of antigens which are widespread among mammalian sera.Cross-immunization experiments have demonstrated the presence of specific antigenic material in the serum of indvidual species.A schematic representation of the antigenic arrangement of mammalian sera is suggested.I am indebted to the Colonial Medical Research Committee for their help in this investigation and for the financial help provided by the Colonial Office.I would like to acknowledge my indebtedness to Prof. P. A. Buxton, F.R.S., for his help and encouragement and in providing and housing the chimpanzee used in these experiments, to Dr C. H. N. Jackson and Mr W. A. Hilton for their valued help in the field in collecting a number of sera from East Africa, and also to Dr E. Hindle, F.R.S., for supplying me with materials from animals which had died at the Zoological Gardens, London. I wish to record my thanks to Mr E. Pope, for his valued technical assistance throughout these experiments.
Immune and allergic reactions to diphtheria toxin and toxoid in guinea-pigs
Authors: Long D. A. 
Published: May 2009

Guinea-pigs immunized with alum-precipitated diphtheria toxoid (APT) become hypersensitive to diphtheria toxin and toxid. This hypersensitivity is probably due to a mixture of immediate (Arthus-type) reactions and delayed (tuberculin-type) reactions, the former increasing as the level of circulating precipitating antitoxin rose and tending to mask the latter. In a hyperimmune guinea-pig the residual damage following the intradermal injection of toxin is due, at least in part, to hypersensitivity to toxin; toxicity probably contributes relatively little to the extent of the lesion in animals with a high titre of antitoxin.The technical difficulties of proving the presence of a delayed allergic reaction in animals with an early allergic reaction are discussed.I am grateful to Dr C. G. Pope, who has been closely associated with this work, not only for providing highly purified materials, but also for his advice.
Staphylococcus aureus type 83A as a cause of hospital cross-infection
Authors: Martin T. D. M. 
Published: May 2009

1. A retrospective survey has been made to determine the amount of cross-infection caused by Staphylococcus aureus of one particular phage-type, 83 A, in four main hospitals of a provincial hospitals group, over a period of 2½ years.2. The total number of strains considered was 1131. Of these, 776 were resistant to tetracycline and therefore the most likely to be of significance in cross-infection. Of these 776 strains, about one-third belonged to phage-type 83 A. In the hospital where 83 A strains were most prevalent, they formed about one-half of the tetra cycline-resistant strains; in that where they were least prevalent, about one- quarter.The clinical sources of the tetracycline-resistant strains are described.3. It was found that type 83 A strains were the most likely to show resistance to erythromycin, chloramphenicol or novobiocin.Of a series of 214 type 83 A strains sensitivity tested against methicillin, using a disk-plate method, none was found to be resistant.My thanks are due to Prof. R. E. O. Williams, St Mary' Hospital Medical School, for his helpful criticism of this paper and, in his previous capacity as Director of the Staphylococcus Reference Laboratory, Central Public Health Laboratory, Colindale, to him and his staff for supplying me with typing phages, and instructing me in their use. I should also like to thank Dr M. T. Parker, Director of the Cross Infection Reference Laboratory, Colindale, for a continued supply of these phages; the Hon. the Viscount Waverley, F.R.C.P., for allowing me to quote from the case history of a patient under his care; and Mr K. Allen, F.I.M.L.T., and other members of my technical staff for their assistance.
A biochemical subdivision of one phage type ofSalmonella typhimurium
Authors: Lewis M. J. , Stocker B. A. D. 
Published: May 2009

SUMMARYA total of 1537 strains ofSalmonella typhimuriumbelonging to seven prevalent phage types were examined on solid media for their ability to ferment rhamnose, xylose and inositol, for colicine production and for nutritional requirements. Most of the strains in each phage type were almost completely homogeneous, especially in their sugar fermentation reactions. However, strains of phage type 1a/2 were not homogeneous, but could be assigned to one of four subgroups on the basis of ability to ferment inositol, inhibition of growth bymeso-tartrate and auxotrophy for nicotinic acid. The subdivision proved to have epidemiological value. The inhibition of growth bymeso-tartrate was observed on a denned medium containing citrate as the energy source. Inhibition did not occur if glucose, casein hydrolysate or aspartic acid were added to the medium.
An evaluation of strontium chloride, Rappaport and strontium selenite enrichment for the isolation of salmonellas from man, animals, meat products and abattoir effluents
Authors: Iveson J. B. , Mackay-Scollay E. M. 
Published: May 2009

SUMMARYStrontium chloride enrichment broth was found to be comparable to Rappaport broth for the recovery of a wide range ofSalmonellaserotypes from man, animals, meat products and effluents. With the exception of cloacal samples from reptiles, both procedures were superior to selenite F.The performance of strontium chloride M and selenite F enrichment was improved when effluent samples were incubated at 43° C.Strontium chloride M and Rappaport enrichment were superior to selenite F for the isolation ofArizonaspecies from reptiles.Strontium chloride B, strontium selenite and Rappaport broths were found suitable for the isolation of multipleSalmonellaserotypes from sea water contaminated with abattoir effluents. The strontium chloride B and strontium selenite enrichment media were superior to Rappaport broth when samples were incubated at 43° C.Modified bismuth sulphite agar was found superior to Salmonella-Shigella agar as a solid subculture medium.The investigation of a food poisoning outbreak due toSalmonella typhimuriumphage type 21 is reported.The significance of the choice of sampling and isolation techniques in salmon-ellosis in man and animals is discussed.