bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Bacterial Flora of Diphtheria Carriers, Diphtheria Patients, and Normal School Children
Authors: Harvey William Clunie
Published: May 2009

During a recent investigation on the carrier problem as it occurs in diphtheria, which was carried out (under the auspices of the Scientific Advisory Committee of the Metropolitan Asylums Board) at the Northern Group Laboratory, North-Eastern Hospital, one of the first subjects considered was that of the bacterial flora of the carriers under examination, and of an adequate series of controls. It was suggested that possibly the flora of the carriers might differ (apart altogether from the presence of the Klebs-Loeffler bacillus) from that found in non-carrier persons of the same age. It was thought that some pathogenic organism might be found to be constantly present in the nose or throat flora of carriers and not in controls, and that this might be exerting an influence on the Klebs-Loeffler bacillus by allowing it to survive in the infected region for prolonged periods. If such were the case it was hoped that an elimination of the organism or organisms concerned would go a long way towards clearing up the carrier condition.
A Statistical Analysis of Age Distribution of Asthmatics
Authors: Harvey W. F. , Kermack W. O. , Lyon D. M. , McKendrick A. G.
Published: May 2009

A statistical analysis has been made of the figures collected during the last eight years in the Edinburgh area, relating to asthmatic patients who presented themselves for examination in certain departments of the Edinburgh Royal Infirmary. The figures for males and females are considered separately, and refer to the numbers of individuals who presented themselves at various, ages, and in whom the disease first manifested itself at various earlier ages. In all, complete records were obtained of 193 males and 167 females. For convenience the ages are grouped in five-year periods.

It has been shown that the figures in the case of females agree well with the assumption that asthmatics, no matter at what age they are first affected, gradually cease to suffer from the disease, or at least fail to report for examination, at a rate which is constant and independent of age. In the case of males the agreement between theory and observation is not as good as in the case of the females, but much of the discrepancy results from two or three obviously aberrant figures. Of every 100 asthmatics at any age it would appear that approximately 7 females, or 8 males as the case may be, are transferred to a non-complaining category every year. The absence of complaint may be due to death from asthma, or recovery, or to some other cause, as for example, that by repeated experience the individual learns how to avoid conditions which precipitate an attack.

On this assumption the relative rates of incidence (P) of the disease at various ages have been calculated for males and for females. Both curves fall during adolescence, rise to a maximum, and then gradually fall, but the male curve lags behind the female curve. From these figures the rates of attack amongst the potential asthmatics (p) have been calculated both for males and for females. The curves fall during adolescence, then rise, remaining practically constant until about 45 years of age, when a rise occurs towards unity. For the further analysis of these curves larger numbers of figures will be necessary, in order that confidence may be placed in the results.
The Spermicidal Powers of Chemical Contraceptives: II. Pure Substances
Authors: Baker John R.
Published: May 2009

1. A technique for comparing the spermicidal powers of pure substances is described in detail. It is hoped that this may be accepted as the standard technique for the purpose.

2. The killing concentration of each substance is determined by this technique. The killing concentration is defined as the lowest concentration, in the series 2, 1, ½, ¼ per cent., etc., which suffices to kill every guinea-pig sperm suspended in glucose-saline solution in half an hour at the temperature of the body in four consecutive experiments, the majority of the control sperms being moderately or very active.

3. 36 substances have been graded by this technique.

4. Mercuric chloride and formaldehyde were found to be the most spermicidal substances. The killing concentration of each per cent.

5. Hexyl resorcin kills at per cent., soaps at per cent.

6. Formaldehyde and hexyl resorcin, among other substances, seem likely to be useful as contraceptives.

7. The significance of the high spermicidal power of soaps is discussed.

8. Quinine bisulphate and chinosol, which are perhaps more commonly used as contraceptives than any other substances, only kill at ½ per cent.

9. Certain very poisonous substances have very slight spermicidal powers. This applies to potassium cyanide, prussic acid and strychnine hydrochloride.

10. Foaming mixtures, consisting of acids and sodium bicarbonate, could probably be used alone as contraceptives.

11. The acrosome is the part of the sperm most vulnerable to spermicides. It tends to swell up and burst.

12. Sperms are very susceptible to changes in osmotic pressure.

13. It is the hydrogen ions and not the anions of acids that kill sperms.

14. The suggestion that tribasic acids would be found to be more spermicidal than dibasic, and dibasic than monobasic, is not substantiated.

15. Substances which reduce surface tension are often effective spermicides.

16. The characters of the ideal chemical contraceptive are discussed.

17. The need for co-operation in research in chemical contraception is stressed.
Milk epidemic of angina, originating from a Cow with mastitis and due to Streptococcus pyogenes (Lancefield group A)
Authors: Henningsen E. Juel , Ernst J.
Published: May 2009

A report is given of a milk epidemic of septic sore throat, comprising about 100 cases.

The epidemic originated from a cow with a slight degree of mastitis, produced by a Streptococcus pyogenes (Lancefield's group A).

The same Streptococcus (which we did not succeed in typing) was isolated from 74% of the patients examined and from three persons who were handling the milk.

It seems reasonable to assume that the cow was infected from the milkers. Owing to particular conditions in the distribution of the raw milk, it is possible that the milk delivered raw in the village involved on one day a massive contamination.

The epidemic is characterized as moderately severe. No case terminated fatally.
The bacterial content of ice-cream in relation to manufacture, storage and standards of purity
Authors: Bardsley Doris A.
Published: May 2009

Ice-Cream has occasionally been proved to be the carrier of disease, and therefore a study of the ingredients used, the processes of manufacture and the bacterial content of the final product is an important branch of modern hygiene.
Studies on the type division of the typhoid and paratyphoid B bacilli by fermentation
Authors: Kristensen Martin
Published: May 2009

No case of transformation (in vivo) of the “xylose-positive” typhoid bacillus to the “xylose-negative”, or vice versa, has been observed in any of the material dealt with at the State Serum Institute, Copenhagen.

On the other hand, the types of paratyphoid B bacilli that can be established on the basis of their relation to rhamnose and inositol did not prove to be absolutely constant; actual or apparent transformation of one type to the other having been observed in several cases.

In this connexion the suggestion is made that Bitter's rhamnose reaction be omitted; the distinction between types R1 and R2 would thus disappear.

Patients with symptoms of diseases of the liver and biliary system and also chronic carriers were represented in greater numbers for type R3I1 than for type R2I1, but it is doubtful whether this observation can be taken as a general one. Apart from this, the behaviour of these two types was very uniform as to the clinical course of the infections they produced. The cases of infection with the rarer types, also, did not seem to vary clinically from those with the more frequent types. On the other hand, the difference between the clinical course of paratyphoid B and the infection with Salmonella typhi murium was very marked.
The Eijkman test for faecal coli in the bacteriological examination of water supplies
Authors: Batty-Smith C. G.
Published: May 2009

1. A historical survey is given of work upon the Eijkman method.

2. A total of 104 water samples were examined by methods I and III. These yielded 602 cultures obtained from the 44 and 37° C. presumptive series, and of these 357 were 44° C.-positive. The only types capable of fermenting lactose at 44° C. wereBact. colitype I and Irregular type II, with the addition of three cultures of intermediate type I and two ofaerogenestype I.

3. The relative efficiencies in the detection ofBact. coliof the 44° C. method by direct inoculation and of the 37° C. presumptive test with plating and differentiation were compared. Out of 104 samples, sixty-eight were shown to contain faecalBact. coli, and in 19% of these the 44° C. method detectedBact. coliwhen it was not recovered at 37° C. The converse was true in only 13% of samples.

4. The results obtained by other workers in regard to the specificity of incubation at 44° C. and to the various methods hitherto proposed for employing it have been collected and discussed; technical advantages and disadvantages have also been considered.

5. It is concluded: (1) That false positives at 44° C. are a negligible quantity for practical purposes. (2) That the best all-round method to use is Wilson's method IV. (3) That 48 hr. incubation should be given, but that 24 hr. is sufficient when rapidity is desired. (4) That the test should be officially recognized and standards laid down for use with it.

6. Cellobiose was found to be inferior to citrate for the identification of the I.A.C. group.
A small outbreak of diarrhoea associated with the paracolon bacillus
Authors: Rhodes A. J.
Published: May 2009

A small outbreak of diarrhoea is reported which involved five patients in a mental hospital. An organism showing the characteristics of the paracolon bacillus was isolated from all these cases. Agglutinins to this organism were present to significant titre in the sera of all the patients, suggesting that this race of the paracolon bacillus was the aetiological agent in this outbreak.
The serological grouping ofStreptococcus lactis(group N) and its relationship toStreptococcus faecalis
Authors: Shattock P. M. F. , Mattick A. T. R.
Published: May 2009

1. It has been shown on serological and biochemical grounds thatStr. faecalisfalls into Lancefield's group D.Str. liquefaciensis considered to be a variety ofStr. faecalis, andStr. glycerinaceus(Orla Jensen) has insufficient claim to a separate name.

2.Str. lactishas, on biochemical and serological grounds, been clearly differentiated fromStr. faecalisand the other members of group D.

3. Reasons are given for assigningStr. lactisto a new serological group ‘N’ into whichStr. cremorisalso falls.
The bacteriology of activated sludge
Authors: Allen L. A.
Published: May 2009

Homogenization of activated sludge greatly increased the apparent bacterial count obtained by plating on a solid medium, and for this reason facilitated the isolation of the predominant flora by liberating the bacteria from the interior of the sludge flocs. The ordinary domestic cream-making machine was found to be quite effective for this purpose.

The high counts obtained indicated that there are probably several hundred thousand million bacteria per gram of dry matter in activated sludge.

Aeration of sewage was found to result in an increase in the total count of bacteria, and a high count was maintained for a considerable time. After aeration for several days fairly rapid and apparently fairly complete separation of the sludge occurred on allowing the liquid to stand, but the supernatant liquor contained large numbers of bacteria. When a fresh quantity of sewage was added to the small quantity of sludge which settled and a second period of aeration commenced, the bacteria were found to associate more quickly with the sludge than they had during the first aeration. Coliform bacteria and spore-forming aerobes formed only a small fraction of the total number of micro-organisms concerned in these changes, and moulds and yeasts never accounted for a large proportion. The predominant bacteria did not produce acid from glucose.

Various media were tested in investigating the bacteriology of activated sludge. None showed any superiority to nutrient agar. Coliform bacteria and aerobic spore-formers were encountered in negligible numbers. The morphological and physiological characters of seventy-one strains of the predominant bacteria were determined. The majority were Gram-negative rods with no action on carbohydrates and were members of the generaAchromobacterium, Chromobacterium,andPseudomonas.Those isolated from activated sludge soon after its formation from aerated sewage were found to be non-proteolytic, but a proteolytic flora was established after the sludge had been built up for a period of 4 weeks. The characters of the predominant bacteria indicate that they are water types derived from the water supply or the drainage water which enters sewage. Intestinal bacteria appear to be unimportant.

The experiments described in this paper were carried out as part of the programme of the Water Pollution Research Board of the Department of Scientific and Industrial Research, and the results are published by permission of the Department.
Susceptibility of vitamin A-deficient and starved rats and mice to a peroral infection withSalmonella typhi-murium
Authors: Kligler I. J. , Guggenheim K. , Henig E.
Published: May 2009

Green & Mellanby (1928, 1930) were the first to direct attention to a specific relationship between vitamin A deficiency and infection. They studied the occurrence of spontaneous infections in vitamin A-deficient rats and concluded that animals fed on a diet deficient in vitamin A, but complete in all other respects, develop multiple infective lesions and die. Since then vitamin A has become known as the ‘anti-infective’ vitamin.
Mode of origin of sulphonamide-resistant strains inB. dysenteriaeFlexner
Authors: Stewart F. H.
Published: May 2009

The change by which a strain ofB. dysenteriaeFlexner becomes resistant to sulphonamides is similar in character to the change inB. coli mutabilefrom white (non-lactose-fermenting) to red (lactosefermenting).

The highest proportion of variants are found in papillae, while no variants are found in the growing margin of colonies.

Reversion does not take place during growth on sulphonamide-free media.

The variation is a direct and heritable response to a chemical stimulus and in adaptation to this part of the environment.

The variation described by Reiner Müller ofB. typhosuson rhamnose and of certain coliform bacteria on arabinose may also be of the same nature.

Strains ofB. dysenteriaeFlexner resistant to sulphanilamide or sulphaguanidine 1/10,000 are only partially resistant to sulphathiazole 1/100,000 and to sodium sulphapyridine 1/10,000.

Technique. The size of (uncrowded) colonies on a plate containing 1/10,000 sulphanilamide or sodium sulphacetamide is a useful criterion of resistance or non-resistance, but a resistant strain must be able to grow on 1/5000 Sa and will not grow on 1/5000 Ssac.

The best culture medium for these tests is Lab. Lemco bouillon with agar, but without peptone.

In concluding I wish to express my thanks for their help to Prof. H. R. Dean, Prof. C. H. Browning, Drs E. T. C. Spooner, A. MacDonald, J. E. McCartney and R. D. Stuart. The sulphonamides I received through the kindness of the British Pharmacopoeial Commission and of Messrs May and Baker.
The bacteriology of dehydrated vegetables
Authors: Rishbeth J.
Published: May 2009

Considerable errors arose when the plate count method was used to determine the number of bacteria on dehydrated vegetables. Bacteria probably occurred on the surface of the vegetables only.

Plate counts tended to be greater when suspensions were prepared at higher temperatures over the range 10–40° C. Counts often increased by 20% and sometimes by 50% in the short period allowed in the standard procedure (25 min.), probably owing to multiplication of bacteria. Changes in the volume of suspensions, caused by rehydration of vegetables, led to small errors for which allowance could be made. Larger variations in count arose from sampling errors through differences in the number of bacteria on individual strips and, to a lesser extent, through imperfect distribution of bacteria in suspensions. The relation of plate counts to the actual number of bacteria on the vegetables was uncertain.

However, the error in counting a single sample (— 65% to + 150%) was appreciably smaller than that in counting successive samples from the same factory (about fivefold) and this in turn was less than the variation between different factories (up to a thousandfold). The plate count could therefore be used with some confidence as a general guide to the state of factory hygiene.

The author is grateful for assistance given by Dr M. Stephenson, F.R.S., of the Biochemical Laboratory, Cambridge, and by Dr M. Ingram, Dr H. G. Wager and others of the Low Temperature Research Station, Cambridge.
Studies in the dynamics of disinfection IX. The effect of lethal temperatures on standard cultures of Bact. Coli. I. The nature of the probit-log survival-time relationship at pH 7·0
Authors: Jordan R. C. , Jacobs S. E. , Davies H. E. F.
Published: May 2009

1. A study has been made of the probit-log survival-time relationship in a number of experiments in which whole standard cultures of Bact. coli were subjected to heat at temperatures ranging from 47 to 55° C.

2. It is concluded that the whole mortality up to 99·99 % could not be covered by a single straightline relationship since the graphs are curves concave upwards and to the left.

3. Between 95 and 99·99 % mortality the relationship approximated closely to linearity.

4. Several individual experiments showed ‘humps’ in their curves. These, although always occurring at the same stage in time in the disinfections, varied in their probit levels.

5. By combining the data for all experiments, an idealized probit-log survival-time curve was obtained in which the changes of slope were less marked than in the curve representing the disinfection of similar cultures by phenol.

The authors wish to express their gratitude to Messrs I.C.I. (Pharmaceuticals) Ltd. for their valuable financial assistance, which has enabled one of us (H. E. F. D.) to devote his full time to this work.
The housing of laboratory animals
Authors: Jones J. I. M. , Wood E. C.
Published: May 2009

A survey of both the prevailing and the desirable conditions for housing small laboratory animals, with particular reference to rats and mice, is described. The data surveyed are confined to laboratories in Great Britain and include requirements of space, heating, ventilation and building construction, with such accessories as cages, feeding devices and other equipment.
Post-partum breeding in the guinea-pig
Authors: Rowlands I. W.
Published: May 2009

Information relating to post-partum mating has been described in guinea-pigs kept in six small colonies containing variable numbers of the sexes running together continuously in floor pens of standard size. Litters were born on the floor and rearing was communal (Method 1). Three other like colonies were similarly maintained, except that the females in late pregnancy were separated from the male to avoid post-partum mating (Method 2). The conditions of farrowing and rearing were similar to those of Method 1. The data given by thirty-four sows of a closely recorded (stock) colony bred in units of six females and one boar, but in which every litter was born and reared under ‘cage’ conditions (Method 3), were used for comparative purposes only.

Post-partum mating was considered to have occurred only when the interval between the births of any two consecutive litters of the same sow did not exceed 70 days. Of litters born under Method 1, 80% were conceived at post-partum oestrus; the mean gestation period was 68 days. The average inter-parturition interval of all sows breeding under Methods 1 and 2 was 74 and 118 days respectively. The optimal ratio of the sexes in a colony breeding by both methods was judged to be twelve females to one male.

Litter size varied between 3·98 (Method 1) and 3·69 (Method 3) and by all three breeding methods, the proportion of young already dead or that died at birth was about 5%. Deaths were more common in summer months when litter size was maximal.

The post-natal death-rate during the first 28 days of life among young reared communally (Methods 1 and 2) was 10% and was fivefold that observed in litters reared separately by their mothers (Method 3). This death-rate was highest during the winter months due to the difficulty of providing adequate amounts of fresh green vegetables.

The annual output of young guinea-pigs from colonies bred under Method 1 was 62% greater than that from other colonies bred by Method 2. The more rapid sequence of littering did not affect the quality (body weight) of the young at birth or at weaning.

Attention has been drawn to a possible deleterious effect of intensive breeding to the health of the females and their lessened resistance to infection. It has been suggested that, for this reason, the breeding life of the sows should be limited to 1 year.
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.
A Note on some Attempts to cause the Formation of Cytolysins and Precipitins in Certain Invertebrates
Authors: Drew G. Harold
Published: May 2009

The results obtained in these investigations were negative throughout, but perhaps are worth recording as tending to show that the formation of such ‘anti-bodies’ as cytolysins and precipitins is not a necessary reaction on the part of any living organism to the presence of foreign cells or substances.
The Sand Filtration and Purification of Chalk Waters
Authors: Nankivell A. T.
Published: May 2009

Some deep wells in the chalk are liable to contamination. The pollution may gain access to the wells by means of fissures or “swallow-holes” in the water-bearing stratum, and, through these defects, micro-organisms and organic matter may find their way into the water supply of a town from points many miles distant. The risk of chalk waters becoming contaminated is daily growing more probable: quick and cheap transit is responsible for an exodus from the town to the country which serves as a gathering ground for water supplies; and the chalk uplands and countryside, which formerly were sparsely populated, are in many places becoming covered with collections of houses and small villages, whose only method of sewage disposal is by means of cesspools into the chalk on which the houses are built. If the chalk is sound and unfissured, this method of sewage disposal is not harmful to distant water supplies; but, given a fissure or swallow-hole, the intestinal micro-organisms and organic matter from some outlying village, may make the water from a deep well some miles away unfit to drink. I know at present of five important wells in the chalk in different parts of England, which are, in this manner, liable to intermittent and undoubted faecal contamination; but, in only two of these places are means taken to purify the water before it is distributed to the consumers. A typhoid carrier or a case of enteric fever might distribute bacilli to a distant town through some imperfection in the stratum, and the consequences, without doubt, would be very disastrous; yet probably there are many towns in the country which take the risk of such an epidemic.
An Examination of some Factors influencing the Rate of Infant Mortality
Authors: Greenwood M. , Brown J. W.
Published: May 2009

In all countries which make statistical returns, attention has been directed to the large proportion of children failing to complete one year of life. Even the most highly civilised races lose in this way more than ten per cent, of their potential citizens as will appear from the data contained in the following table (Deutsche Sterbetafeln, 1910).
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.
Cereal Food Poisoning and its Relation to the Etiology of Pellagra
Authors: Stockman Ralph , Johnston J. M.
Published: May 2009

Pellagra is a comparatively modern disease. The first account of it dates from 1735 when under the namemal de la rosait was very fully described by Gaspar Casal who at that time practised at Oviedo and found it endemic among the Asturian peasantry. In Lombardy it was recognised about 1730 and only much later (1771) was systematically described by Frapolli as pellagra (rough skin), but Strambio, who was physician to a special hospital for pellagrins at Legnano, states (1784) that many of his patients told him that their fathers and grandfathers had suffered from the disease. Early in the nineteenth century it was comparatively common in Gascony and about 1836 it was beginning to be recognised in Roumania. In the United States sporadic cases seem to have been noticed in 1864, and since 1907 it has increased to an extent which has seriously disquieted the public health authorities. In Egypt, Turkey, Mexico, the Balkans, Brazil, the West Indies and other countries it is common and well known. Wherever it has appeared endemically it has followed on the introduction of maize as a field-crop and its adoption (by the rural population especially) as a chief and staple article of diet.
Experimental Evidence of a Heat-Resistant Gastro-Intestinal Irritant produced by Bacilli of the Salmonella Group
Authors: Savage William G.
Published: May 2009

The Salmonella group contains the organisms which are mainly responsible for outbreaks of food poisoning and the possibility of the production by these strains of bodies which are toxic, or which act as gastro-intestinal irritants, when administered by the oral route, is of practical as well as theoretical interest. This is especially the case if it can be shown that these irritant substances are heat resistant.
Analysis of meals served in Surrey school canteens
Authors: Kerly Margaret , Morkam Florence , Magill Kathleen
Published: May 2009

The enormous increase in the number of children* eating their mid-day dinners at school canteens came at a time when enlargement of school buildings was impossible and when equipment was difficult to obtain. The following report on meals served in nine canteens illustrates the success that has been achieved in providing adequate meals in spite of great difficulties of preparation and service. The schools were chosen to represent different conditions of environment and type of canteen. Sample meals were analysed and an attempt was made to assess the home food of the children.
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.