The jejunal and stool flora of children with gastroenteritis in London and in Jamaica was examined. Although bacterial colonization of the small bowel was commonly detected, it was unusual to find the same serotype of E. coli in both jejunum and stool, and none of the jejunal strains of E. coli produced either heat-labile or heat-stable enterotoxin. Some strains of E. coli causing infant gastroenteritis are neither toxigenic nor invasive, and other mechanisms must be sought to account for their pathogenicity.

“Health is more affected by atmospheric conditions than by any other influence. From the moment the new born child utters its first cry, until life finally ceases, he is directly and immediately dependent on the atmosphere he breathes for continued existence. Records of sickness and of mortality clearly show that the nearer atmospheric conditions are to those of the open country, the better is the health of the population, and that the more these conditions are modified owing to urbanisation and industrialisation, the more pronounced is the ill-effect upon general health” (1).

A computer program was written to analyse oligonucleotide patterns displayed by gel electrophoresis following restriction endonuclease digestion of human cytomegaloviral DNA, and was applied to an epidemiological study of the transmission of infection in a hospital special care baby unit, with regard to infant-to-infant and mother-to-infant transmission.

The program calculates the molecular weight of oligonucleotides from their mobilities, using a cubic spline curve based on the mobilities of oligonucleotides from the AD169 strain. A matching algorithm then calculates the number of unmatched fragments for each pair of viral isolates. This was used as a similarity measure which successfully distinguished mother and infant isolate pairs from epidemiologically unrelated pairs.

The program is not intended to provide fully automatic matching, but could be recommended as a screening device to pick out pairs of strains which are sufficiently similar to suggest a common source of infection, and which may warrant closer comparison. Other applications are discussed, and the possible use of densitometers to automate data entry is considered.

1. We have investigated bacteriologically the conditions in a central meals kitchen from which about 3000 meals were issued daily to some 65 departments.

2. Plate counts showed that the containers in which the meals were sent out contained large numbers of organisms, from several thousand to several hundred thousand per container.

3. Counts of this order were obtained both before and after the routine method of washing.

4. These counts were reduced to the order of a few hundred or less per container by steam sterilization.

5. Exposure for 2–3 min. to steam from a simple jet sterilizer was effective for all except large insulated lids which required at least 5 min.

6. Treatment for 5 min. in a chamber filled with steam from a boiler was effective with all types of containers and lids tested.

7. If containers are to be sterilized at all they must be sterilized each time they are to be used.

8. A great improvement in the bacteriological counts can be achieved by attention to the hygiene of washing, e.g. by the use of plenty of hot water with soap and soda or perhaps preferably with detergents, with a second sink of very hot water for rinsing, and by using fresh sterilized dish-cloths each time the washing water is changed.

9. Counts almost as good as those given by steam sterilization were obtained by washing with soap and water at 48–50° C., wiping with a sterilized dish-cloth and then rinsing in a second sink of water at 75–80° C.

10. The arguments for and against steam sterilization are discussed.

This investigation was greatly helped by the co-operation of the Leicester Education Department.

(1) Killed agglutinable broth cultures of the various dysentery bacilli may be prepared by the formalin and cold storage process and may be standardized by the method elaborated by Prof. Dreyer for the typhoid and paratyphoid bacilli.

(2) Since formalin (0·1 %) usually causes a gradual loss of sensitiveness to agglutination during the early life of the emulsion, a certain period (two months) must be allowed to elapse before the emulsion can be used as standard.

(3) After such a period the sensitiveness of the emulsions remains unaltered for at least ten months, and probably much longer.

(4) By none of the other methods of preparation investigated could satisfactory standard agglutinable cultures be made.

Sub-lethal exposure of Aspergillus fumigatus spore suspensions to formalin resulted in prolongation by 1–22 days of the period of less than one day normally needed by spores to produce visible growth in Sabouraud's liquid medium at 37° C.; the degree of delay depended on the concentration of formalin and the duration of exposure, and was due to an increase in the germination-time of spores. The formalin concentration could be adjusted so as to affect the germination-time of almost all spores in a suspension without reducing viability. The effect on germination was not abolished by thorough washing or treatment with sodium sulphite. The spores of four different strains of A. fumigatus and of cultures aged 3 to 14 days reacted similarly to formalin treatment. Although of greatly reduced virulence for mice, affected viable spores were still capable of producing infection and death following intravenous inoculation, provided they were not eliminated by the host before germination occurred.

Four antigenic variants of the neuraminidase (NA) of A/Texas/77 (H3N2) virus were selected using monoclonal antibody at a frequency of one variant in 105 parental virions. The antigenic variants failed to react serologically with the monoclonal antibody used for their selection in vitro. The antigenic variants failed also to react serologically with a proportion of sera from children and adults although all of the sera reacted with the parental A/Texas/77 virus. Thus, certain human sera have a restricted antibody repertoire to influenza NA antigen which might enable virus antigenic variants to avoid anti-NA antibody-mediated neutralization in nature.

In April, 1917, while examining some rats (probably M. decumanus) in company with Mr L. D. Cleare, Jnr., my assistant, for external and internal parasites, the lungs of a male specimen were observed to be in a highly diseased condition.

The sera of 200 Chinese adults recently immigrated to Canada from Hong Kong were examined for antibodies to Toxoplasma gondii by the indirect fluorescent antibody technique. It was found that the total incidence was 18·0%. This is significantly lower than that of the indigenous population of the same age groups in this area.

The list of bacteria recorded as causative agents in enteric fever and “food-poisoning” increases steadily, and the proved pathogens already number eleven types, of which three have been found in both continued fever and food-poisoning, three in continued fever alone, and five in food-poisoning alone. This list will undoubtedly be added to when cultural methods for the diagnosis of these conditions are more widely employed, especially in the tropics.

1. A quantitative study has been made of the activity of C′1, C′2 and C′4 in the complements of the horse, cat, pig, man, guinea-pig and rabbit.

2. Evidence is presented which suggests that either there may be two types of C′4, the one haemolytic and the other conglutinating, or else that the manifestation of this complement component varies under conditions not yet understood.

3. In certain complements it appears that the serum proteins functioning as C′1 with the bovine anti-sheep red cell antibody are distinct from those functioning as C′1 with an antibody of similar specificity from an immune rabbit serum.

A retrospective cohort study was performed following several reported cases of gastrointestinal illness after a catered event. The attack rate was 45/77 (58·4%) by clinical case definition, with four individuals confirmed to have Campylobacter. There was near universal exposure to most foodstuffs served; consumption of duck liver pâté [relative risk (RR) 2·53, 95% confidence interval (CI) 1·05–6·10], mixed leaf salad (RR 2·91, 95% CI 1·22–6·92) and table water (RR undefined, P < 0·01) were associated with illness in univariate analysis, with only the latter associated in the final multivariable model (P < 0·001). Samples of cooked duck liver pâté subsequently prepared using identical methods at the venue were contaminated with Campylobacter jejuni and C. coli; water sampling was negative. Making inferences about causation in the presence of near universal exposures in this study required consideration of the limitations of statistical analysis, with the most compelling evidence of the causal role of inadequately prepared duck liver pâté provided by environmental investigation.

“White Australia,” the pleasant dream of a peculiar political party, is a subject on which a few years ago it would have been inadvisable if not unsafe to venture too unrestrained opinions. There was a time when in certain quarters the euphonious phrase was almost tantamount to a war cry. To some political dreamers it may even have been a perennial dream, full of visions of whiteness and purity, just as to us in England the mention of the “Pearly Pacific” conjures up vistas of prattling palms, wimpling waters and silvery strands. The dream is a pretty one, fitting theme for the poet and artist; Samoa and R. L. Stevenson, what a perfect juxtaposition! What delectable tales our romance weavers indulge us with! The gorgeous colouring, the wondrous life, the glorious moon, the ocean's unceasing sigh—all fine, all beautiful, all seeming perfect—but all superficial or tempered with prosaic features which mar the picture.

The experiments here described proved that preparations made from widely different classes of bacteria are capable of inducing immunity in mice against pneumococci. The success of these preparations was found to depend on the differential separation of an active immunizing antigen from another bacterial constituent—an ‘opposition factor’—which interferes with immunization. Further investigation and comparison depend largely on the discovery of a really effective method for the isolation and purification of the active antigen. Until its chemical nature is determined, the identity of the pneumococcal species antigen with similarly acting substances found in other bacteria remains unproved.

Pathogenic bacteria depend for their virulence and invasiveness on certain products individual to the species or type, and specific immunity is due to the development of the appropriate antibodies. But chemotherapy, as in the case of the sulphonamides, interferes with a less specialized metabolic process of the microbes and is neither species nor type specific in action. It is reasonable to infer that bacteria may possess in common a vital process associated with the presence of a common constituent which may be antigenic. ‘Species antigen’ may be a substance of this nature.

In view of the wide distribution of ‘species antigen’ among bacteria generally, it is probable that this constituent has already been separated and named in accordance with its presence in a particular species, but irrespective of its potential immunizing capacity.

So far as pneumococci are concerned, there is good evidence that species antigen may be identical with the species C carbohydrate. Tillett (1927) found that rabbits injected with successive courses of heat-killed pneumococci, whether of types I, II, III or of avirulent rough strains, developed an equal increase of resistance to infection by type III Pneumococcus. In 1936 Enders, Wu & Shaffer varied the procedure, and by injections of rough pneumococci prepared an antiserum which gave passive protection to rabbits against infection by type III Pneumococcus. This antiserum lost its protective power after absorption with the species C carbohydrate.

1. The bacteriological problems involved in the production of meat and fish pastes in sealed glass jars have been studied.

2. Data are presented showing the normal flora of the raw materials used. Particular attention is drawn to the anaerobic species present in seasoning materials.

3. Bacterial contamination due to manufacturing operations is discussed.

4. The requirements of a satisfactory heat treatment are outlined, together with experimental methods of study used to overcome possible causes of failure.

5. Bacteriological examinations of 14,365 samples of paste showed that 88% were sterile: the flora of the remainder was examined.

6. Experimental evidence is presented to show that certain anaerobic spore-forming bacilli are the main possible cause of spoilage, and the significance of aerobic spore-forming bacilli has been established. An extremely heat-resistant anaerobe was isolated.

7. Routine bacteriological control of the finished products is suggested.

8. A simple, inexpensive, and rapid method of detecting anaerobic species has been devised, which can also be applied to other foodstuffs. Data are presented from the examination of a further 6110 samples using this method.

1. One hundred lepers were examined by Browning, Cruickshank and McKenzie's modification of the Wassermann reaction with positive results in 22 cases. The amount of complement deviated was in some cases exceptionally large.

2. In a control group of 110 non-leprous persons there were 11 positive reactions.

3. In only one of the lepers was there visible evidence of former venereal disease but 33 of the lepers admitted that they had suffered from syphilis or from chancres, and of these 33, 13 reacted positively, while only nine of the remaining 66 gave positive reactions.

4. In the control group, 21 admitted former syphilitic infection and, of these, eight reacted positively; among the remaining 89, who denied syphilis, there were three positive reactions.

5. There were 12 positive reactions among 44 cases of tubercular leprosy and 10 positive reactions among 56 cases of the anaesthetic type.

6. The average duration of the disease, among the 22 lepers who reacted positively, was four years and eight months, as compared with an average of three years and eight months for the 78 patients who reacted negatively; but among the latter there were many old-standing cases.

7. Seventeen of the 22 positive cases were in an advanced stage of leprosy and in some of them the disease was progressing; but among those lepers who reacted negatively there were also many advanced and progressing cases.

8. Serum from the lesions in 10 of the lepers who reacted positively was examined by dark-ground illumination, but in no case was the Treponema pallidum found.

9. The luetin test was applied to 21 lepers, with negative results in every instance; 13 of these cases gave positive and eight gave negative Wassermann reactions. The test was also applied to a control group of non-leprous persons selected because they were likely to be latent syphilitics. In this group there were 11 positive luetin reactions.

Adult cockroaches were found to survive up to 22 weeks when provided with 1% Formalin (0·4% formaldehyde) in lieu of drinking water. Given 4% Formalin or 2% glutaraldehyde they survived up to 41 days. During the experiments eggs were laid and hatched and the offspring continued to grow. Combined with surface disinfection, this may hold out a simple method of rendering adult cockroaches gnotobiotic or even axenic.

1. The participation times of a series of mixtures of horse serum and a pool of rabbit antihorse serum have been determined. The results have been presented in a table and isochrones drawn. Four distinct α procedure optima were found, suggesting that there may be at least four different antigen-antibody reactions concerned when horse serum reacts with a rabbit antihorse serum.

2. The reaction between horse serum crystalbumin and the same pooled rabbit antihorse serum has been investigated, and recorded-similarly.

3. Inhibition of precipitation was found to be more marked in the region of antigen excess than in the region of antiserum excess. Evidence is presented in support of the view that the occurrence of multiple zones may obscure this observation.

4. The results are compatible with the view that the second stage of the precipitation reaction is specific.

5. The isochrones correspond with Boyd's R type.

The literature upon the presence of various ferments in milk is extremely large and dates back through many years. Up to the beginning of 1911, however, when the experiments described in this paper were undertaken, no observer had dealt with milk uncontaminated by bacteria.

This investigation was initiated when twelve miners who were working in a certain part of the Mill Close Lead Mine complained of smarting of the eyes associated with marked congestion of the conjunctivae. They also suffered from a stinging sensation in the nose and throat. The particular area in which they were working differed from other parts of the mine in that there was a strong smell of sulphuretted hydrogen present. After recovery, and when the ventilation had been improved, the men were able to continue working in that area without experiencing further discomfort. The interesting part of the investigation was tracing the origin of the sulphuretted hydrogen. The odour proceeded from collections of mine water which the miners very appropriately called “stink water”. In this there was a deposit of sulphur mixed with black sludge which also smelt strongly of H2S. The sludge consisted of slightly gelatinous black masses mixed with a whitish felt work of a filamentous organism. On microscopical examination the filaments were seen to contain sulphur globules, and often to arise from a mass of black material. This black material consisted of sulphur and inorganic salts in a slimy matrix, the black colour being due to the presence of ferrous sulphide. On further examination these masses were found to be teeming with other bacteria, Gram-negative bacilli and spirilla, both of which were motile, the spirilla being actively so.