R. Lovell

Studies on the survival of Johne's bacilli

Summary (1) Cultures of Johnes bacilli remain alive in sterilised water for upwards of nine months. (2) Intestinal scrapings from cases of Johnes disease may contain viable Johnes bacilli for upwards of 163 days after mixing with unsterilised river water. (3) Naturally infected faeces, when left exposed to atmospheric conditions, may contain viable Johnes bacilli as long as 246 days after exposure, and these findings have been correlated with the rainfall and atmospheric temperatures. (4) The practical application of these results to the control of Johnes disease has been discussed.

Diseases of Young Calves: A Bacteriological Examination of 100 Cases

Summary (1) One hundred calves dying within the first few months after birth were examined, and an attempt has been made to classify on an aetiological basis the diseases of calves occurring in this country. (2) In 69 cases it was possible to isolate and identify the associated organism or organisms. (3) Pure infections with Bact. coli accounted for 37 cases, C. pyogenes for 12, haemolytic coccobacilli for six, Salmonella typhi-murium for two and Pasteurella for one. (4) Mixed bacterial infections accounted for 11 cases, such organisms as Staph. aureus and Ps. pyocyonea being present in addition to certain of those encountered in pure infections. (5) In the remaining 31 cases the aetiology was doubtful, indicated causes not considered bacterial, or associated with bacteria which could not be identified with any known species.

Studies On Corynebacterium Renale: II. The Experimental Pathogenicity for Mice

Summary The sequence of events occurring in the kidneys which follows the intravenous inoculation of mice with C. renale has been studied histologically and bacteriologically. It has been shown that given in adequate dosage C. renale may cause the death of a proportion of mice and induce a pyelonephritis. Similar lesions may be found in some mice which survive. The changes in the kidneys are associated with actual multiplication of bacteria in the kidney tissue and the typical lesion occurs most frequently in the mice inoculated intravenously. Other routes of injection were tried and lesions were found in one only of those mice inoculated intraperitoneally, in one only given C. renale per vaginam, and in none of those inoculated subcutaneously. Although it is not suggested that these phenomena are peculiar to C. renale, these studies should form a useful basis for an extended investigation into C. renale and the disease it produces. A brief record is given of the effect C. renale produces after intravenous inoculation of guinea-pigs and rabbits and of the reaction in the developing egg.

Studies on Corynebacterium renale; a systematic study of a number of strains.

Summary C. renale is a large Gram-positive diphtheroid, possessing metachromatic granules. It grows readily in broth and on agar with cream to yellow colonies. When grown on 10 per cent. milk agar colonies of C. renale are surrounded by a halo or zone of clearing. This reaction is of great value when isolating C. renale from animal tissue. C. renale produces a characteristic alkaline change in litmus milk; splits urea, ferments glucose and gives positive M.R. and V.P. reactions. Most of the strains of C. renale tested appear to be serologically related as judged by the precipitin test. C. renale is pathogenic for mice, provided an adequate amount is given intravenously and the organism may be isolated from the kidneys and bladder of a high proportion of those which die and those which survive for seven days.

The nutritive value of colostrum for the calf. VIII. The performance of Friesian and Shorthorn calves deprived of colostrum.

Summary Twelve Shorthorn and twelve British Friesian bull calves were deprived of colostrum and reared for 3 weeks on a standard diet based on dried skim milk. Eleven calves of each breed died. There were no differences between the two breeds in the mean age of the calves at death or in their performance.

Field trials with Corynebacterium Pyogenes alum-precipitated toxoid.

Summary During the summer months of 1942-45, field trials were made in Ulster in order to assess the prophylactic value of C. pyogenes alum-precipitated toxoid against summer mastitis. There were 40 cases of infection in 2123 immunised cattle and 47 in a control series of 2022; percentages of 1·9 and 2·3 respectively. As judged by the time distribution of the cases and the antitoxin responses, there is need for a study to be made of the general problem of antibody response to non-living vaccines in cattle.

Studies on Corynebacterium Renale: III: Penicillin Treatment of Experimentally Infected Mice

Summary Strains of C. renale vary in their sensitivity in vitro to penicillin. Penicillin is of value in the treatment of experimentally produced C. renale pyelonephritis in mice when given early in the disease.

Food poisoning in man, with special reference to meat and meat products.

MAN acquires food by &dquo; gathering &dquo; or by &dquo; production.&dquo; Food gathering may ~YJL still be practised by primitive people but the greater number depend upon food which is produced, which implies an effective agriculture and animal industry. There have always been hazards associated with food consumption and they vary in their incidence and cause and are linked with the social history of a people. The daily life of the inhabitants of a land in past ages is the material whereby a picture can be

Studies on Corynebacterium renale. IV. Renal lesions in mice produced by other bacteria.

Summary The intravenous injection of mice with living suspensions of C. ovis, C. pyogenes, Bact. equirulis, Bact. colt and Staph. aureus produced renal lesions in a variable proportion of animals. These lesions differed in distribution from those which were observed after the similar administration of living suspensions of C. renale , as they were not confined to the medulla but were found also in the cortex. It is therefore concluded that, as far as our observations extend, the distribution of the lesions produced by C. renale are specific for that bacterium.