bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies in the dynamics of disinfection. XI. The effect of lethal temperatures on standard cultures ofBact. coli. IV. An investigation of that portion of the population which survives prolonged exposure atpH 7·0
Authors: Jordan R. C. , Jacobs S. E. , Davies H. E. F.
Published: May 2009

1. An attempt has been made to discover the origin and nature of the small proportion of the cells in standard cultures ofBact. coliwhich is able to withstand, apparently indefinitely, exposure to temperatures of 49, 51 and 53° C.

2. The method adopted was to allow these survivors to generate fresh cultures in the same flask merely by reducing the temperature to 35° C. and to subject the resulting cultures in turn to heat treatment. Only one process of regeneration and subsequent disinfection was carried out at 49 and 53° C., but at 51° C. the process was repeated four times. The disinfection curve was determined on each occasion and the permanent population allowed to become established.

3. Changes in the heat resistance of the cultures were judged by (a) the disinfection times (99·99 % mortality), (b) the maximum death-rates, (c) the levels of the surviving populations and (d) the variations in death-rate with time during each disinfection.

4. Marked fluctuation in numbers of viable cells was observed during each of the phases of permanent surviving population. The exact levels of survivors were therefore uncertain, but after exposure to 49° C. the mean values were not higher than when 53° C. was used, nor was there an increase in the mean numbers of survivors in the successively regenerated cultures.

5. The survivors did not grow when inoculated into either nutrient agar plates or tubes of broth held at the respective high temperatures, although they remained alive and developed readily on being transferred to 35° C.

6. The maximum death-rate decreased and the disinfection time increased markedly after one regeneration of the cultures. The increase in the latter was not wholly due to the decrease in the former, as the death-rates throughout the disinfection of the regenerated culture were lower.

7. After the second regeneration (at 51° C.) the maximum death-rate declined and the disinfection time rose still higher, but the process was reversed after the third and fourth regenerations.

8. The shape of the graph of log survivors against time altered markedly after the second regeneration at 51° C. The initial death-rate was higher but fell sharply to a minimum before rising again to the final maximum.

9. The experimental findings are discussed. An increase in the general heat resistance of these cultures may have occurred as a result of one regeneration, but the technique employed permitted the gradual alteration of the environmental conditions, and this appears to have exerted complex effects on the cultures so that the results of further regenerations are inconclusive.
The effect of phagocytosis on the growth and survival of avian tubercle bacilli in embryonic chicken tissue cultivatedin vitro
Authors: Fell Honor B. , Brieger E. M.
Published: May 2009

1. Explants of embryonic chick tissue were infected with avian tubercle bacilli of different degrees of virulence to study (a) some of the factors on which control of infection in tissue cultures depends and (b) the viability of bacilli ingested by wandering cells.

2. Embryonic lung cultures could control infection for 2–3 weeks owing to the intense phagocytic activity of the many wandering cells which they contained. The tissue appeared unharmed by infection with bacilli of either virulent or avirulent strains.

3. The wandering cells largely protected the much less phagocytic fibroblasts from intracellular infection.

4. This protective action of wandering cells towards less phagocytic cell types was limited by three factors: (1) the density of the infection relative to the volume of the explant, (2) the growth-rate of the infecting strain and (3) the proportion of wandering cells which the tissue contained.

5. Even under the most favourable conditions control of bacillary growth in the tissue was only temporary, largely owing to the gradual disappearance of the wandering cells during repeated subcultivation.

6. As control of bacillary growth was lost, the lung fibroblasts became packed with bacteria, but they appeared undamaged and might even undergo normal mitotic division. Eventually the ingested bacilli seemed to kill the cells by proliferating until they burst the cytoplasm.

7. Embryonic avian tissue cultures though infected with a highly virulent strain never showed the rapid, widespread necrosis observed by Maximow in cultures of adult rabbit tissue infected with a virulent bovine strain. Possible explanations of this disparity are discussed.

8. A special method was devised for testing the viability of bacilli phagocyted by macrophages. It showed that phagocyted bacilli, whether virulent or avirulent, survived for at least 21 days; when the host wandering cells were killed the ingested organisms were capable of immediate and profuse growth on suitable nutritive medium.
The conglutination phenomenon. III. The conglutinating complement absorption test in experimental glanders
Authors: Hole N. H. , Coombs R. R. A.
Published: May 2009

1. Observations on the sera of ponies, taken at frequent intervals for 321 days after oral administration ofP. mallei, are described.

2. It was found that the conglutinating complement absorption test was more sensitive than the haemolytic complement fixation test as a means of diagnosis. It detected the antibodies earlier in the course of the disease and demonstrated their presence over a longer period of time.

3. The possibility of another practical use of this reaction as an adjunct to the allergic test is considered. Ten days after an intradermo-palpebral test a pony, which had been previously sensitized and whose serum antibody titre at that time was below 10, developed a serum titre of over 160 as demonstrated by the conglutinating complement absorption test. Under similar circumstances 11 unsensitized ponies developed no detectable serum antibodies.
The measurement of domestic ventilation: An experimental and theoretical investigation with particular reference to the use of carbon dioxide as a tracer substance
Authors: Renbourn E. T. , Angus T. C. , Ellison J. McK. , Croton L. M. , Jones Merlin Stephens
Published: May 2009

The post-war need for large numbers of dwellings has promoted renewed inquiry into the basic criteria by which good practice in the design and construction of buildings may be judged. More emphasis than ever before is now being put upon the functional characteristics of buildings regarded as living-spaces rather than as structures.
A tellurite medium for the identification and isolation of corynebacterium diphtheriae
Authors: Handley W. R. C.
Published: May 2009

1. The preparation and characteristics of a tellurite medium, containing, in addition to a peptone and Lemco agar base, a tryptie hydrolysate of casein, sodium lactate, L-cystine, sheep serum, an extract of sheep red blood corpuscles and 0·01% potassium tellurite, is described for use in the identification and isolation of Corynebacterium diphtheriae.

2. The colonial appearances of the three types of C. diphtheriae on the medium are described, and the distinguishing features between these and the colonial appearances of diphtheroids and other organisms liable to occur on pathological material are indicated.

3. Recommendations are made concerning what has so far proved to be the most suitable manner of inoculation of pathological material on to the medium.

The author would like to express his thanks to Prof. F. C. Happold for suggesting the problem, to Dr R. E. Jones for encouragement during the course of the work, to Miss K. Gilliver, M.A., for assistance in the preparation of the manuscript and to Miss G. M. Jenkins for technical assistance.
The occurrence of natural antibodies in rabbit sera in relation to the paracolon group of organisms
Authors: Schwabacher Herta
Published: May 2009

1. Naturally occurring agglutinins to paracolon bacilli have been found in seven out of ten sera from non-immunized rabbits and in one anti-Salmonellaand two anti-paracolon immune rabbits' sera after complete absorption with the immunizing strain.

2. The a antigen of Stamp & Stone, which is known to occur as a natural agglutinin, has been demonstrated in one out of nine paracolon bacilli.

3. Rabbits which before immunization show agglutinins to the immunizing strain or to an α antigen should not be used for the preparation of diagnostic antisera for intestinal Gram-negative bacilli.
The nuclear cycle in bacteria
Authors: Bisset K. A.
Published: May 2009

1. Strains ofBact. coliand related bacteria possess a life cycle resembling that of Myxobacteria. The vesicular, resting nucleus is contained in a microcyst, which is formed by a process suggestive of sexual conjugation.

2. The microcyst germinates by the transformation of the resting nucleus into the chromosome-like bodies typical of active, vegetative cultures. These may be analogous to the chromosome complexes of yeasts. The period of germination of microcysts corresponds to the lag phase of cultures.

3. The nucleus remains permanently in the mitotic condition during the active, vegetative phase of growth, and reproduces by an asexual and a sexual method.

4. Older cultures may be transformed directly into microcysts or may first adopt a secondary, vegetative phase, in which the nucleus is in the form of a single, central body.

5. Microcyst formation differs from spore formation in that it lacks the obvious reduction processes associated with spore formation, upon which a few original observations are included.
An evaluation of Richardson's verification test in the sero-diagnosis of syphilis
Authors: Roberts G. Fulton , Swale J.
Published: May 2009

The importance of the accuracy of serological tests for syphilis has become more than ever emphasized by widespread testing and more efficient therapy. The problems are reviewed in the light of present knowledge of the specificity and sensitivity of standard serological tests for syphilis. Richardson's modification of the Wassermann reaction is described. The results of this test when applied to ninety-two cases giving doubtful or discrepant reactions by routine tests are presented and classified. The cases were followed up clinically. The results indicate that this simple test is a reliable and valuable adjunct to routine methods, and should be employed widely as a verification procedure.
The effect of radiation from the surroundings on subjective impressions of freshness
Authors: Munro A. F. , Chrenko F. A.
Published: May 2009

The effects of radiation from the surroundings on the impressions of freshness of 106 men and 39 women members of the staff of the Building Research Station were investigated during the first 6 months of 1948. Subjects were exposed to three types of environment: (1) where the walls were cooler than the air, (2) where the walls and air were at the same temperature, and (3) where the walls were warmer than the air. The tests were carried out in calm air.

It was found that the difference between the mean radiant temperature and the air temperature affected freshness impressions, but the effect was relatively slight. Environments which felt cool tended to feel fresh, yet a rise in the mean radiant temperature—which would increase the warmth of the environment—tended to produce an impression of greater freshness. At a given equivalent temperature, environments with the surroundings warmer than the air were found to be definitely fresher than cold- and neutral-wall environments. This was thought to be mainly due to the fact that the humidity of the air in the warm-wall environment was lower than that in the other two environments. Changes in humidity insufficient to affect sensations of warmth affect impressions of freshness. Under the conditions of these experiments, and to keep freshness impressions constant, a rise of 1° F. in the temperature of calm air must be compensated by a fall of about 5% in the relative humidity.

The subjects had a distinct preference for the warm-wall environment; 73% of them found it pleasanter than either the cold- or the neutral-wall environment.

Freshness impressions are considered to be related to transient fluctuations in the rate of heat loss from the head.
Effect of treatment at the sewage works on the numbers and types of bacteria in sewage
Authors: Allen L. A. , Brooks Eileen , Williams Irene L.
Published: May 2009

Over a period of about 10 months samples were taken at frequent intervals from various stages of treatment at two sewage works; one of these was a small rural works treating only domestic sewage, and the other treated the sewage of an industrial town. These samples were submitted to bacteriological and to chemical examination.

The total plate counts, the counts ofcoli-aerogenesbacteria, and the counts ofStreptococcus faecalisin settled sewage were higher in the warmer than in the colder months of the year.

Though the average total numbers of bacteria in the sewage containing trade wastes were appreciably higher than that of the domestic sewage the counts of faecal organisms were somewhat lower.

Treatment at the works considerably reduced not only the polluting strength of the sewage but also the numbers of bacteria. At the works receiving sewage from an industrial town an average of about 80% of bacteria in settled sewage were removed by treatment in the bio-aeration plant, percolating filters, and humus tanks, and a further 8–10% were removed by subsequent treatment in pressure sand or anthracite filters. At the small rural works, where the rate of treatment was much lower, rather more than 90% of the bacteria were, on the average, removed by treatment in percolating filters and humus tanks, and a further 6% by subsequent passage through shallow gravity sand filters.

The final effluents discharged from the works still contained large numbers of bacteria. Their effect on the bacterial content of the streams to which they are discharged may be gauged from the fact that, in the effluent from the small rural sewage works, which was of consistently good quality when judged by chemical criteria, there were on the average about 160,000 cells of faecalBacterium coliand about 20,000 faecal streptococci per 100 ml. Numbers in the effluent from the works in the industrial town were even higher. Sand filters of the type investigated here could therefore not be relied upon to produce an effluent of good bacterial quality.

The 44°C. test in MacConkey broth, prescribed by the Ministry of Health (1939) for examination of water, was found, when applied to samples of sewage or sewage effluent, to be almost specific forBacterium coli, type I. Growth with formation of acid in sodium azide broth incubated at 45° C. was found to be an almost specific test forStreptococcus faecalis.
OnStreptobacillus moniliformisand the filtrability of its L-form
Authors: klieneberger-Nobel Emmy
Published: May 2009

It has been shown that the L-form ofStreptobacillus moniliformisis filerable through gradocol membranes which retain the bacillary A-form completely. From the filtration analysis carried out as described it would appear that the particle size of the L-form ofStrep. monilifprmisranges with the larger viruses while the bacillary A-form ranges withBact. prodigiosum.
Measurements of rate of mutation of flagellar antigenic phase inSalmonella typhi-murium
Authors: Stocker B. A. D.
Published: May 2009

Change of flagellar antigenic phase in the Salmonellas is considered as resulting from the mutation and back mutation.

A rapid method of determining the phase of numerous colonies ofSalmonella typhi-muriumis described; melted sloppy agar containing antibody for one phase is layered on tplates on which colonies have grown. On brief incubation, colonies of the agglutinated phase produce narrow dense sharp edged zones of opacity, while colonies of the other phase wide diffuse zones of swarming organisms.

A theoretical analysis shows that if the growth rates of the phases are equal the proportion of cells of ‘mutant’ phase in a culture initially all in one phase and maintained in continuous logarithmic growth will (at first) increase linearly with the number of generations at a rate proportional to the mutation rate. In one strain ofSalm, typhi-muriumexperiments showed the rates of growth of the phases to be equal; the proportion of cells of mutant phase in cultures of this strain during long periods of continuous growth has been measured; linear rates of increase were found, and the mutation rates are calculated.

The variance in proportion of cells of mutant phase in replicate cultures has been measured; the findings are correlated with theoretical considerations.

Certain anomalous decrease in proportion of cells of mutant phase during prolonged growth are described, and a possible explanation is proposed.

Eight further strains have been investigated by the same methods; in the nine strains, the rates of mutation from group to specific phase range from 10-4to 4.7 X 10-3per bacterial generation cycle, and the rates of the reverse mutation from 10-5to 8.6 X 10-4. In all the strains, including two of varietybinns, the rate of mutation from group to specific is higher than the rate of the reverse change; it is shown theoretically that such strains will tend towards an equilibrium composition in which the specific phase will predominate; in one rapidly mutating strain such an equilibrium has been demonstrated.

In a limited experiment, alteration of medium and of temperature of incubation caused to detectable alteration of rate of mutation per bacterial generation.

Stable O mutants, and poorly flagellated mutants which back-mutate to the fully motile form, are described.

The experimental findings are compared with reports in the literature on the phase ofSalm. typhi muriumas isolated. The behavior of strains of varietybinnsis discussed, and it is suggested that this description should not now be applied to strains in which a specific phase can be demonstrated. The biological funtion of mutablility of phase is discussed.
A search for bacteriophages active upon bacteria of the Brucella genus
Authors: Williams Smith H.
Published: May 2009

1. None of forty-eight strans of Brucella abortus, ten of Br. melitensis and seven or Br.suis were shown to be lysogenic.

2. It was not possible to ‘adapt’ bacteriophages that were active upon other species of bacteria to lyse brucellas.

3. Thirty samples of faeces, mainly from cows, four sewage samples, twelve specimens of uterine fluid from cows that had aborted, and twenty samples of bulk milk failed to yield bacteriophages active upon brucellas.
The survival of bacteria in dust. III. The effect of light on the survival of bacteria in dust
Authors: Lidwell O. M. , Lowbury E. J.
Published: May 2009

The effects of daylight, low-intensity ultra-violet radiation, fluorescent lighting, and tungsten-filament lighting on the survival of dust flora have been studied, at room humidities of about 60% and under dry conditions. The first three radiations all cause a significantly enhanced death-rate at room humidities for all the groups of organisms studied. The effect appears to be limited in extent and to be complete in about 10 days. The action of the radiations is much slower under dry conditions.
Static pressure and ventilation rates in rooms
Authors: Black Flora W.
Published: May 2009

The British Standard Code of Practice and other authoritative guides, recommend minimum rates of ventilation related to the size and use of rooms, and structural means for providing them. But the difficulty of measuring actual ventilation rates suggests that it is seldom done.
The formation of precipitates on mixing anti-horse sera
Authors: Naylor G. R. E.
Published: May 2009

1. Five anto-horse sera which did not contain antibodies for horse-serum crystalbumin have been shown by absorption experiments to contain horse-serum crystalbumin.

2. All five sera precipitated when mixes with other anti-horse sera containing anti-crystalbumin, precipitation being due to the presence of horse-serum crystalbumin in one antiserum and of anti-crystalbumin in the other.

3. Antigen and its homologous antibody were never found together in the serum of an animal, and contradictory results in other experiments are probably due to impure multiple antigens.

4. It is concluded that anti-horse sera may contain some of the antigenic components of injected horse serum together with antibodies to other antigens of the horse serum, but not homologous antigen and antibody. Consequently, the ‘mutual’ precipitation of anti-horse sera is due to the presence of a number of antigens in horse serum, one or more of which, present in one anti-horse serum, in the absence of its homologous antibody, may precipitate when mixed with another anti-horse serum which contains the homologous antibody.

5. The use in these experiments of a single α-procedure optimum as the indicator of an antigen-antibody reaction illustrates a method enabling the investigation of problems involving single antigen-antibody reactions, even though the available reagents consist of mistures of antigens and mixtures of antibodies.
The conglutination phenomenon. IV. An experimental investigation of the factors determining the adsorption of complement by an antigne-antiserum mixture
Authors: Blomfield A. M. , Coombs R. R. A. , Hole N. H.
Published: May 2009

1. Salmonella antisera from a number of animals, including man, have been examined by conglutinating complement-absorption and haemolytic complement-fixation tests for the presence of anitbodies. Both a soluble antigen and a particulate antigen of washed suspended orgainsms have been used. The behavior of the antisera was comparable with that previously recorded with the mallein antimallein system, in so far as the reactions obtained with the different complements followed the same general pattern.

2. Two factors were found to explain the failure of certain antisera, in conjunction with the antigen, to adsorb certain complements. On the one hand, a few antibodies themselves appeared incapable of fixing a particular complement. On the other hand, although some antisera failed to fix specific complements, their antibodies, isolated from the serum, were able to fix the complements concerned. In these cases it appeared that the heated serum contained a non-specific factor that prevented the adsorption of the complements.

3. The existence of such non-specific factors in certain heat-inactivated sera is illustrated in Figs. 11–14. An examination of the mechanism involved does not appear to implicate the procomplementary effect of sera, although this effect in itself is a complex problem requiring further elucidation. The few experiments carried out indicate that the factor in the inactivated serum does not come into play and inhibit the adsorption of complement by an antigen-antibody complex without the initial intervention of some component of complement. Only after this has occurred is the inhibitory factor able to block any further complement adsorption.

4. We have discussed the implications of these experiments and their possible relationships to the complementoid phenomena described by previous workers.
Strains of the virus of foot-and-mouth disease showing natural adaptation to swine
Authors: Brooksby J. B.
Published: May 2009

An account is given of the behaviour of two porcine field strains of the virus of foot-and-mouth disease, with evidence of their adaptation to swine, based on experiments on infection by contact.
Methods of estimating the LD 50 in quantal response data
Authors: Armitage P. , Allen Irene
Published: May 2009

A quantal response is one in which a certain event either happens or does not happen. If, in an animal experiment, we record merely whether or not the animal dies, we are measuring a quantal response. The type of data with which we are concerned here is familiar to all workers in biological assay, and occurs constantly in bacteriological and immunological experiments. A number of animals is divided randomly into several groups, and all the animals in each group are treated with the same dose of a certain substance. The doses differ from group to group, and are frequently arranged so that successive doses differ by a common dilution factor. At each dose the numbers of animals which respond positively and negatively are recorded. The potency of the substance may be measured by that dose which would in the long run produce a positive response in exactly 50 % of the animals, and the main statistical problem is how to estimate this dose (the LD 50) from the available data. It is assumed that any inaccuracies in measuring the doses are negligible in comparison with the sampling errors due to the inevitable differences between experimental animals.
A comparative study of tuberculosis mortality rates
Authors: Springett V. H.
Published: May 2009

The recorded mortality from tuberculosis has fallen greatly in England and Wales since the middle of the nineteenth century when records were first available. The fall in rate has not occurred uniformly in all age groups however, and one result of this is that the maximum mortality rate in males is now occurring at a much later period of life than formerly.
An experimental study of haemolytic disease of the newborn due to isoimmunization of pregnancy. II. Report of an attempt to produce anti-red cell isoantibodies in guinea-pigs, together with a note on the blood picture of one-day-old guinea-pigs
Authors: Mynors L. S. , Heard D. H. , Coombs R. R. A.
Published: May 2009

1. Repeated inoculation of thirty-six guinea-pig does with random blood of guinea-pig bucks failed to produce any demonstrable anti-red cell isoantibodies.

2. A note is included on the blood picture of a small series of newborn guinea-pigs aged between 12 and 24 hr.
Infantile gastro-enteritis with special reference to the specific serological type O55 B5 H6 (Betatype) ofBacterium coli
Authors: Smith J. , Galloway W. H. , Speirs A. L.
Published: May 2009

1. An account is given of the relationship ofBact. colitype O55 B5 H6 to cases of infantile gastro-enteritis.

2. In Aberdeen this organism has now largely replaced the O111 variety (alpha) which had been the prevalent type during 1947 and 1948 in its association with the disease.

3. A brief description has been given of the clinical findings, which show no marked deviation from those found in similar cases elsewhere. The actual severity of the illness as judged by the mortality rate has been greatly lessened.

4. The value of medication with chloromycetin in a small number of cases has been discussed. It is believed that the use of the drug eliminates the organism from the bowel in certain cases and helps to reduce the number of cross-infections even in a cubicle ward. The average weekly weight increase of children on chloromycetin was almost double that of a group of healthy, untreated children.

5. Several small outbreaks of infantile diarrhoea associated with the O55 B5 H6 type in wards and institutions have been recorded. In some the numbers of symtomless carriers of the O55 type have exceeded those of clinical cases also harbouring the same organism.

6. ‘O’ and ‘H’ agglutination tests made with suspensions of the prevalent strain ofBact. colion sera from cases examined early in the disease were mostly negative. Such positive titres as were obtained were low. Examination of paired acute and convalescent sera from 29 cases gave some evidence of increasing titre during the course of the disease in eight cases, but such increase was of low order.

7. The present bacteriological evidence suggests that further specific types ofBact. coliwill be found to be associated with the disease.
The pathogenicity of the spores of Clostridium botulinum
Authors: Keppie J.
Published: May 2009

1. The injection of mice with botulinum spores, freed from all traces of superficial toxin, can cause death but only if a very large number is given. This number was found in the case of a highly toxic strain to be of the order of 20 million spores given intramuscularly. This dose was fatal in the absence of spore germination.

2. In human botulism it is concluded that the spores of Clostridium botulinum persent in spoiled foodstuffs are not of importance compared with the toxin produced by the initial growth of the contaminating organisms.

3. Toxin could be demonstrated in the cytoplasm of botulinum spores when these were disintegreted by mechanical means. This is of theoretical interest as the toxin within the spores is more heat-stable than the extracellular form.

4. A local anaerobic myositis could be produced in mice by the intramuscular injection of spores plus 2·5% CaCl2. The number of viable spores in the LD50 was of the order of 50,000.

5. Calcium chloride solution in the commonly used strength of 2·5% was shown regularly to cause a drop in the number of botulinum spores in a given suspersion of some 40% and a parallel loss of viability of about 60%.
Phage typing of Staphylococcus aureus
Authors: Hood A. M.
Published: May 2009

Phage adsorption by resistant staphylococci was studied.

Staphylococcal cultures previously allowed to adsorb phage to which they were resistant remained as sensitive to their appropriate phages as normal cultures of the same strains.

When pooled related and unrelated phages were incubated with their propagating strains, the results resembled those obtained when these phages were incubated separately with the same strains.

The lytic effects of thirty-two phages at test dilutions were tested singly and when pooled into five mixtures. All the phage-propagating strains and over 500 strains received for typing were tested. The results were in agreement.

Thirty-two phages at their test dilution in nutrient broth remained stable, whether pooled or not, at 0 to + 5° C. for various times. Briefly summarized, serological group A phages were stable for at least 1 month, and group B phages were stable for only 2–3 weeks.

Broth cultures of staphylococci incubated for 18 hr. at 30° C. were as phage-sensitive as the same cultures when left at room temperature for 24 hr.

A new method of phage typing staphylococci by means of phage pools, as satisfactory as the standard method, and less laborious, is described.
Bacteriophage inhibition by extracts from phage-insensitive bacteria of the genusPseudomonas
Authors: Mead T. H. , van den Ende M.
Published: May 2009

1. An electrophoretically homogeneous antigen preparation extracted from a strain (LII) ofPseudomonas aeruginosaby trichloracetic acid inhibits four phages active against this strain, and two phages (5 and 14) to which it is resistant but which attack a mutant strain LIII–3 bi.

2. An extract prepared in the same way from strain LIII–3 bi has no antigenic or inhibitory properties. Lysis of LIII–3 bi organisms by chloroform, however, yields a potent inhibitor active against several phages.

3. TCA extracts from immunologically distinctPs. strains AII, BII and GII also inhibit phages 5 and 14 to which these strains are resistant.

4. The effect of a third phage (13) onPs. LIII–3 bi is activated by the extract from strain LII which normally inhibits phages 5 and 14. Prolonged contact with very dilute solutions of the extract also causes activation of phage 5. Activation of phage 14 has not been observed.

5. The above findings are discussed in relation to current theories of phage action and phage inhibition.
The inhibition by various agents of the lysis ofBacterium coliby glycine
Authors: Gordon J. , Hall R. A. , Stickland L. H.
Published: May 2009

1. The lysis ofBact. coliby glycine is inhibited completely by various treatments: (a) by heating the bacteria at 65 or 100° C.; (b) by the action of Cr, Fe, and Al salts at concentrations which cause agglutination of the organisms, (c) by various heavy metals, including particularly Hg and Ag salts, at low concentrations (d) by lethal concentrations of formaldehyde and phenol.

2. The lysis is not inhibited by sodium fluoride, potassium cyanide, or sodium monoiodoacetate at concentrations which suppress the action of certain enzymes.

3. This evidence on the whole supports the rejection of the view that a simple physical process is responsible for lysis by glycine, but does not yet enable us to distinguish between the other possible mechanisms of the lysis because the treatments used might equally interfere either with the structural proteins of the bacteria, or with the hypothetical enzymes which might be concerned in producing the lysis.
Second attacks of typhoid fever
Authors: Marmion D. E. , Naylor G. R. E. , Stewart I. O.
Published: May 2009

1. Second attacks of typhoid fever are uncommon. In the literature this has been taken to imply that an attack of typhoid fever confers a high degree of immunity which, nevertheless, may be overcome by such factors as re-infection by a large dose, an organism of a different strain, or one of high virulence.

2. Two large outbreaks of typhoid fever in the same community within 5 months produced eleven examples of second attacks. Clinical descriptions of four of these are given.

3. Details are given of the population at risk and the attack rates in various groups.

4. The evidence of these facts and figures, though inconclusive, suggests that an attack of typhoid fever does not confer more than a moderate degree of specific immunity. The influence of chloramphenicol upon immunity remains sub judice.
Some effects of chloramphenicol in the gut
Authors: Gray J. D.
Published: May 2009

A method for the estimation of chloramphenicol in faeces and bile is described. It has been shown that the bile contains high concentrations of the antibiotic, but the faeces small amounts. It is considered that the faecal concentration is dependent on the biliary supply.

The action of chloramphenicol on the gut flora is described and the dominance of yeasts on complete suppression of the conforms is reported, drawing attention to the possibility of intestinal moniliasis following unrestricted use of the antibiotic.

An explanation of ‘relapses’ in the chloramphenicol treatment of typhoid fever is given, and the possible effect of chloramphenicol on immunity response is discussed.
Infection rates of Rattus norvegicus with Leptospira icterohaemorrhagiae in Great Britain: I. A Rural Area in Carmarthenshire, Wales
Authors: Broom J. C. , Gibson E. A.
Published: May 2009

A description is given of the topography, type of farming carried out, and the living conditions of the agricultural community of a district in South Wales where a survey was made of the infection rate of rats with Leptospira icterohaemorrhagiae.

Leptospires were seen in stained sections of the kidneys of eighty-two of the 357 rats examined (23%). With a single exception, all the infected rats were adult, but no difference in sex-incidence was found.

Weil's disease occurs in this area, but no cases in man or cattle had been reported from this particular locality. Blood samples taken from six persons living on two heavily infested farms contained no anti-leptospiral agglutinins.
An Outbreak of Poisoning from Infected Brawn
Authors: Savage William G. , Gunson C. Herbert
Published: May 2009

1. Eighteen persons after eating a certain batch of pork-cheese, or vegetables infected from it, suffered from severe illness and three died.

2. The illness was caused by a Gaertner bacillus of the Aertrycke sub-group isolated from one of the fatal cases.

3. This bacillus was contained in the meat used for the pork-cheeses (brawn), infection being antecedent to preparation.

4. Part of the meat was obtained from a pig suffering from local injury or disease of one leg and the bacilli were no doubt etiologically connected with this condition.

5. The outbreak points to the need for a more complete and thorough veterinary inspection of meat before sale, and of the necessity for extended investigation into the diseases of animals used for human food caused by Gaertner bacilli.
Studies on Cider and Perry. No. I. Sulphite Preservatives
Authors: Durham Herbert E.
Published: May 2009

The practice of using preservatives in the process of making cider is very widely spread, and moreover is much encouraged by the makers of the preservatives.
On the Danysz Effect with reference to the Toxin-antitoxin Reaction
Authors: Craw J. A.
Published: May 2009

Svante Arrhenius (1908) has taken exception to my criticism (1907) of his interpretation of the Danysz Effect with reference to the Toxin-Antitoxin reaction. In this paper he has given an interesting but rather far-fetched analogy to the Danysz Effect, which is, according to him, purely chemical in character and subject to the laws of chemical mass action, and here marks in italics that “the opponents of the use of these laws have still given no explanation at all of the Danysz Effect, especially of the experiments cited in our memoir”.
An Anti-serum for Scorpion Venom
Authors: Todd Charles
Published: May 2009

Many deaths occur every year in Egypt as the result of scorpion sting. These deaths are practically confined to Cairo and Upper Egypt, and are almost entirely among children. Unfortunately, owing to local conditions, it is almost impossible to obtain really accurate figures for this mortality, but some idea may be formed from the statistics given below of some of the larger towns.
Multiplication of Bacteria and the Influence of Temperature and some other conditions thereon
Authors: Lane-Claypon Janet E.
Published: May 2009

The species of organisms used were B. coli, B. typhosus and B. enteritidis Gaertner. With these organisms:

(1) When a fresh broth culture is made with a small inoculation there is a period during which there is no increase in the number of bacteria present.

(2) When this period is over the bacteria commence to divide regularly; this is shown by the fact that the logarithms of the numbers plotted against time are found to fall on a straight line. This regular growth persists until (or nearly until) a maximum has been reached, after which the numbers remain more or less constant and then slowly decline.

The time necessary for a complete division to take place (generation time) was determined for various temperatures between 20°C. and 42°C.

(3) The effect of temperatures between 20° and 35.3°C. upon the rate of multiplication is in accordance with the Arrhenius-Van 't Hoff law; above this temperature the effect diminishes.
On Heterologous Agglutinins more particularly those present in the Blood Serum of Cerebro-Spinal Fever and Typhus Fever Cases
Authors: Wilson W. James
Published: May 2009

In previous papers Professor Symmers and myself have called attention to the presence of agglutinins for the typhoid bacillus, the colon bacillus, and a bacillus of the alcaligenes class in the blood serum of patients suffering from cerebro-spinal fever from whose lumbar puncture fluid and in some cases from whose blood theMicrococcus intracellularis meningitidis(Weichselbaum) had been cultivated.
A Comparison between the Germicidal Power of a Disinfectant in Solution and in the Emulsified State
Authors: Massey R. E.
Published: May 2009

In the Milroy Lectures of this year, Professor Hewlett stated:—“There is some evidence to show that the germicidal power of emulsified disinfectants is greater than can be accounted for by the activity of the active constituent and theoretically seems likely, but we want some reliable experimental work in confirmation. It is ture that Chick and Martin have compared the germicidal value of higher tar acids emulsified in water and dissolved in alcohol, their results showing that the emulsified form was much more active; but the reliability of this work is vitiated by the fact that they have entirely failed to take into account the influence of alcohol in decreasing germicidal activity; for example in the case of phenol, which I dealt with in my last lecture”.
On the Production of Antitoxin by the Injection of Filtrates of Cultures of Non-virulent Diphtheria Bacilli
Authors: Arkwright J. A.
Published: May 2009

We are still in doubt regarding the exact position of those bacilli which, morphologically and culturally, appear to be identical with the Klebs-Loeffler bacillus but which differ from it only in the absence of specific pathogenic power for laboratory animals. Most writers regard such non-virulent strains as true diphtheria bacilli which have lost their virulence and toxigenic power either temporarily or permanently. Others however are inclined to place them in a group allied to that of the genuine Klebs-Loeffler bacillus and express doubts as to whether they at any time possessed a claim to pathological significance (Graham Smith, 1904).
The Fleas Common on Rats in Different Parts of the World and the Readiness with which they Bite Man
Authors: Chick Harriette , Martin C. J.
Published: May 2009

(1) As far as is at present known, the great majority of the fleas infesting Mus rattus and Mus decumanus in different parts of the world, belong to either the species Xenopsylla cheopis, Ceratophyllus fasciatus, Ceratophyllus anisus, Ctenopsylla musculi or Ctenophthalmus agyrtes or are comprised of some admixture of these five species.

(2) Xenopsylla cheopis is the most prevalent in the tropics and sub-tropical regions and often occurs there to the almost complete exclusion of other species. It is common during summer and autumn in some of the warmer parts of the temperate zone, more especially in ports which have maritime intercourse with the tropics.

(3) In the cooler regions Ceratophyllus fasciatus is the most universally distributed flea and is associated with more or less of Ctenopsylla musculi and Ctenophthalmus agyrtes according to the locality and the habitat of the particular rats.

(4) In Japan Ceratophyllus fasciatus is replaced by Ceratophyllus anisus, a closely allied species.

(5) The numerous other fleas which have been captured off rats are only occasional visitors.

(6) Ceratophyllus fasciatus, like Xenopsylla cheopis, readily bites man. Out of 517 experiments 308 fed, or 59% were positive. In 101 experiments, under identical circumstances with a rat, 59, or 58.4% of the fleas fed.

(7) The experiments with Ceratophyllus fasciatus were made upon eight persons and evidence was obtained of preference on the part of the insects for particular individuals.

(8) 111 experiments were made with 46 specimens of Ctenopsylla musculi; only 4 fed=3.6% whereas 9 out of 11 fed on a mouse.

(9) 68 specimens of Ctenophthalmus agyrtes were tried, in some cases upon three persons. None fed, whereas 11 out of 19 of the same fleas fed on a rat under identical conditions.
A Diphtheria-Like Bacillus Causing Cellulitis in the Region of a Spontaneous Fracture in a Case of Tabes Dorsalis
Authors: Dudgeon Leonard S.
Published: May 2009

The interest of this case is due to the fact that the patient from whom this bacillus was isolated was a tabetic in whom a spontaneous fracture of his femur had occurred, and cellulitis developed at the level of the lesion due to a diphtheria-like bacillus. This organism was isolated and obtained in pure culture from the cellulitis and was found present in the films of the pus; also the patient's serum gave a complement fixation reaction with his own bacillus and for syphilis.
The Relation of the Reaction of the Culture Medium to the Production of Haemolysin
Authors: Atkin E. E.
Published: May 2009

Ever since artificial media have been used for the cultivation of micro-organisms, the question as to what is the best reaction—that is the degree of acidity or alkalinity—has been a moot point. It has been assumed gratuitously that there is an optimum reaction which is the same for all the common bacteria met with in the laboratory. In recent years however some attempts have been made to settle the question definitely, notably by Eyre and Deelemann. On enquiring what reaction of medium was adopted in six different London laboratories, Eyre found that very divergent standards were used, ranging from 20 units of acidity to 10 units of alkalinity on his scale. (20 units of acidity implies that 20 c.c. of normal alkali must be added to each litre to make it neutral to phenolphthalein. In the case of alkalinity the indicated number of c.c. of normal acid must be added.) The importance of having a definite reaction had until recently not impressed itself upon the majority of bacteriologists. The possibility that although many organisms may grow on media of comparatively widely differing reactions, yet only one of these reactions may be suitable for the growth of a more delicate kind, had been overlooked. Consequently they failed to grow bacteria which by careful adjusting of the reaction of the medium could be readily cultivated. Martin (1910), for example, has lately pointed out the ease with which gonococcus can be made to grow on serum agar if the reaction is carefully adjusted. In later years the subject has assumed still more importance in connection with the production of bacterial toxins, which have been submitted to a large amount of investigation. In the production of diphtheria toxin it was soon recognised that bouillon containing more alkali than is usually employed for ordinary bacteriological work, yielded the most toxin, and even various devices were invented to avoid the initial production of acid which usually takes place as the consequence of bacterial growth in a sugar-containing medium. Madsen (1896) has made a thorough examination of the factors governing the production of diphtheria toxin. By following the reaction of a growing culture from day to day he found two different types of growth occur,—one in which the medium increases in acidity without abatement, and such cultures are atoxic; in the other the primary increase in acidity is followed by a decrease, and subsequent increase in alkalinity. These cultures are sometimes toxic. The two conditions seemed to have relation to the amount of alkali added in the preparation of the bouillon, in that a strongly alkaline medium gave an alkaline end reaction while a less alkaline medium gave sometimes an acid and sometimes an alkaline end reaction.
Attempts to reproduce the Typhoid-carrier State in the Rabbit
Authors: Morgan H. de R.
Published: May 2009

Preliminary record of attempts to produce the typhoid-carrier state in the rabbit and to obtain evidence of the presence of this condition by bacteriological examination of the faeces.
The Action on Nitrates and Nitrites of Dysentery Organisms killed by various processes and of Filtrates from Fluid Cultures
Authors: Logie W. J.
Published: May 2009

The organisms examined have been killed, (a) by temperatures which should not have destroyed the reducing enzyme, (b) by sodium fluoride and four other antiseptics, derivatives of phenol, and (c) by acetone. In each case there has been total destruction of the reducing power, any apparent production of nitrite from nitrate being too slight to justify the assumption that it is due to anything more than experimental error. Filtrates of fluid cultures have also failed to reduce. The results may be summed up as follows:

(1) The reduction of nitrite by certain dysentery bacilli is not due to a soluble extra-cellular enzyme.

(2) Dysentery bacilli and B. coli killed by a minimal degree of heat have little if any effect in reducing nitrites.

(3) Organisms killed by antiseptics or by acetone do not reduce nitrates and nitrites.

(4) Even where all the organisms are not dead, reduction may be prevented by antiseptics.

(5) The high antiseptic value of tetrachlor-o-biphenol, tetrabrom-o-kresol, p-chlor-m-kresol and hexabrom-dioxy-diphenyl-carbinol has been established for the organisms of the dysentery group.