The antigenic structure of Salmonellas obtained from domestic animals and birds in South Africa

The articles have been scanned in colour with a HP Scanjet 5590: 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Rockefeller Foundatio

Calf paratyphoid I. A general discussion of the disease in relation to animals and man

1. The incidence of calf paratyphoid in various countries and its relationship to disease in adult cattle, in other species of animals, and in human beings are reviewed. 2. The isolation of 507 strains of Salmonella from outbreaks of paratyphoid in calves is reported. Of these 491 were identified as S. dublin, eleven as S. typhi-murium, four as S. enteritidis, and one as S. bovis-morbificans. In addition the isolation of twelve further strains of S. dublin from adult cattle is recorded. 3. The significance of Salmonella dublin as an etiological agent in paratyphoid of cattle, particularly calves, is discussed. 4. For the detection of S. dublin or other forms of Salmonella infection either faeces, bile, blood or liver, and spleen cultures were made, and the suspected sera tested for "0 " and "H" agglutinins. In some cases only one of these tests was possible, but at other times two or more were performed. In. addition a pathological study of the liver and spleen was made whenever possible. With very few exceptions the results obtained from a pathological examination of suspected organs corresponded to the results of the bacteriological study. But in many positive cases of calf paratyphoid faeces and blood cultures were negative and a negative agglutination test was obtained. Sometimes faeces cultures were positive when the serological test was negative or vice versa. In other cases the presence of a carrier was spotted first by a positive agglutination test. For the detection of carriers, therefore, both faeces cultures and serological tests should be performed. 5. The agglutinogenic response of infected, carrier, or immunized animals generally resulted in the production of practically only "H" agglutinins. "0" agglutinins were seldom present in significant amounts, and when they were present the titre was generally extremely low in comparison with that of the "H" . These results do not agree with the previous observations of Henning and his co-workers (1939, 1946, 1942). These workers found that the sera of birds acting as carriers of S. typhi-murium or of horses affected with a latent or chronic S. abortus-equi infection responded chiefly to "0" agglutination, and that the "H" agglutination was either poor or entirely absent. 6. The role played by rodents and the so-called Rat "Viruses" in the dissemination of Salmonella infection is discussed. 7. The significance of S. dublin as an etiological agent of food infection in human beings is discussed.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Calf paratyphoid III. The transmission of anti-bodies to newly-born calves

1. In a study of the transmission of anti-bodies from immunized pregnant cows to the colostrum and to their progeny it was noticed that the agglutinin titre of the colostral whey and of the calf's serum might be several times that of the dam. At the time of birth hardly any agglutinins, or no agglutinins at all, could be detected in the calf's serum, but the titre suddenly rose to this high level within 24 hours after the first suckle. The calf's titre remained high for two weeks or more, and then gradually declined; but it remained at a significant level for about three months. 2. When newly-born calves from immunized or unimmunized mothers were fed on hyperimmune serum before the first suckle large amounts of agglutinins could be detected in their sera twelve hours later. These agglutinins persisted, though in progressively decreasing titre, for at least three months. 3. When the calves from immunized cows were inoculated with S. dublin vaccine one, two or three weeks after a colostral feed, no rise could be effected in the agglutinin titre and no difference could be detected in the titre whether the calves had been inoculated or not. The immunity was apparently completely blocked by the anti-bodies absorbed from the colostrum. 4. When the colostral immunity was challenged with virulent milk cultures given by the mouth the calves exhibited a fair degree of resistance, and it was extremely difficult to produce typical symptoms of paratyphoid in them. It is believed that this immunity is sufficient to protect young calves against natural exposure to paratyphoid. The immunization of pregnant cows as a means of protecting new-born calves against paratyphoid is, therefore, recommended as an additional method of combating the disease. But as hyperimmune sera, when given before the first suckle, can also transmit anti-bodies to new-born calves the use of immune sera is advised in cases where immune colostrum is not available.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Calf paratyphoid II. Artificial immunization

1. Immunization experiments performed on mice with various vaccines prepared from S. dublin and other Salmonella species showed that a formalinized aluminium hydroxide precipitated vaccine gave the best protection against virulent cultures of S. dublin. The immunity produced gave only a partial or incomplete protection, yet when this vaccine was used for the routine immunization of calves on badly infected premises in different parts of the country a marked reduction in deaths from paratyphoid was effected. In a few outbreaks where the routine vaccine failed to prevent losses a vaccine made from a local strain of S. dublin invariably gave complete protection against natural exposure. But unless the vaccine was employed regularly and all the calves born on the farm were inoculated soon after birth, losses continued to occur. In a few cases where the use of the vaccine was discontinued fresh outbreaks of paratyphoid usually occurred. In spite of the excellent results obtained with vaccine in the field, it is admitted that the immunity produced is of a low grade and that it cannot be relied upon entirely to prevent symptoms or even death from paratyphoid. When the immunity in calves was challenged with fresh milk-cultures given by the mouth the majority of them reacted and developed symptoms of paratyphoid, although much less severely than the control calves. 2. The immunization of calves with routine S. dublin vaccine resulted in the production of "H" agglutinins almost exclusively. Whereas the "H" agglutinin titre of the serum of the vaccinated animals rose from 1:25 or less to 1:3,200 or more after immunization, there was hardly any perceptible "0" agglutinogenic response in the majority of these animals, and the "0" titre remained extremely low in all of them. When the immunity was boosted by means of a third injection of vaccine 30 days after the second a very marked rise in the "H" agglutinin titre resulted, but there was only a slight "0" agglutinogenic response in some of the animals and hardly any "0" agglutinins could be detected in the others. 3. An easy method of artificially infecting calves with fresh milk cultures of S. dublin is described. By the utilization of this method the pathogenesis and the course of the disease could be observed and treatment instituted. It was found that when calves manifesting typical symptoms of paratyphoid were treated with large doses of phthalylsulphathiazole by the mouth recovery supervened, whereas untreated calves, infected in the same way and left as controls, died. Phthalylsulphathiazole can, therefore, be regarded as an effective therapeutic agent for calf paratyphoid, and its employment can be recommended for the treatment of this disease. It was observed subsequently, however, that fresh milk-cultures of the same strain of S. dublin, grown under apparently identical conditions, might not always be equally pathogenic for calves. Sometimes an acute and fatal disease was set up, whereas, at other times, very much milder symptoms were produced. Although the cause of this variation is not known it is believed that some factor in the media is responsible.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Krimpsiekte

On reviewing the results of these experiments, there can be little doubt that the plant Cotyledon wallichii Harv. (kandelaar bos or bandjes bos) is at least one of the causes of the disease known as krimpsiekte in the western Karroo. The possibility of the parasitic nature of the disease can be completely ruled out for the following reasons: (1) Neither by inoculation nor by contact was it possible to transmit the disease. (2) In no instance on post-mortem was a parasitic organism found which might suggest a parasitic nature of the condition. (3) By sterilizing the plant, both by boiling and by autoclaving, the virulence of the plant was not appreciably reduced, as would be expected in the case of a parasitic organism. (4) Very large quantities of the meat of krimpsiekte animals were required to be fed to dogs in order to produce symptoms, since the toxin had apparently been considerably diluted as a result of its distribution through the tissues. If the disease were of a parasitic nature, considerably smaller doses would be expected to reproduce the malady. (5) Furthermore, since the toxin of this plant is apparently thermostabile, the meat and organs of a krimpsiekte animal cannot be considered safe for human consumption even after boiling or cooking. This conclusion, it will be observe, is contrary to popular belief.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.ab202

Serological variants of Salmonela typhi-murium isolated from South African animals

A number of epizootics in domestic animals caused by Loefflers Bacterium typhi-murium, containing both factors IV and V, have been described by Henning (1939). In the description given here we have confined ourselves mainly to the study of strains of typhi-murium lacking factor V. These were obtained from outbreaks of paratyphoid in pigeons, horses and cattle.The articles have been scanned in colour with a HP Scanjet 5590: 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Pasteurellosis: an outbreak amongst sheep

From the three cases of pasteurellosis in sheep studied, five different strains of pasteurellae were obtained, 182 from ram 1, 181 from ram 2, and 247, 247a, and 247c from ram 3. Of these strains 182 and 247 were highly pathogenic for both sheep and guinea-pigs, and almost non-pathogenic for rabbits and pigeons. Both showed the same biochemical reactions and both produced similar pathological changes in experimental animals inoculated with live cultures. They resembled each other also in morphology, staining and cultural characteristics. Pasteurellae 182 and 247 can therefore be regarded either as identical or so closely related that they cannot be differentiated by the methods employed. Both these organisms have a predilection for pulmonary tissue and serous membranes and both produced lesions in experimental animals that could not be differentiated from those found in natural cases studied. These two organisms are considered to have been the cause of the mortality among the Ryeland sheep at the experimental farm of the University of Pretoria. An identical disease in experimental sheep was produced by the injection of organ emulsions and cultures made from the original cases from the University farm. Berkeveld filtrates of organ emulsions from natural cases did not produce the disease. So far no success has yet been attained with immunisation tests in laboratory animals and no properly controlled immunisation experiments have been carried out with sheep. The pathogenesis of the disease under natural conditions is still obscure. Pasteurellae 181 and 247a cannot be distinguished from each other by the tests employed; both are very slightly pathogenic for guinea-pigs and both have the same biochemical reactions, and they agree in morphology, cultural and staining characteristics. Both have originated from small colonies picked from primary cultures of pulmonary material. Pasteurella 247c does not resemble either of the two groups of organisms mentioned above. It is entirely non-pathogenic for laboratory animals. These results indicate: (1) that the small colonies picked from the primary growths on media seeded with material from affected lungs yielded cultures which were either non-pathogenic (247c) or only very slightly pathogenic (247a, 181); (2) that the large colonies obtained from similar growths gave rise to highly pathogenic cultures (182 and 247); (3) that when several colonies were picked from the same primary growth, highly pathogenic, slightly pathogenic and non-pathogenic cultures may be obtained e.g. cultures 247, 247a, and 247c); (4) that if only one colony is picked from the primary growth either a highly pathogenic culture (182) or one which is barely pathogenic (181) may result. It is possible that the non-pathogenic and slightly pathogenic pasteurellae occur as saprophytes in the respiratory passages of sheep in certain areas and that they invade the lungs only when the way has been paved for them by the entrance of pathogenic pasteurellae of the type 182 and 247. These latter enter the tissues and set up disease under conditions which have not yet been determined. In making a bacteriological study of a case of pasteurellosis, therefore, it is recommended that several colonies of different sizes be picked from the primary growth, and that the pathogenicity of each one be studied separately. Only in this way may the presence of pathogenic pasteurellae be determined.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Salmonella bovis-morbificans (Basenau) from an outbreak of food-poisoning in the Cape Province

The antigenic structure of the Salmonella isolated by Greenfield and Judd (1936) from an outbreak of food-poisoning at the Cape Peninsula is described. As its antigenic components were found to resemble those of bovis-morbificans the following antigenic factors should be assigned to it: Somatic "0'' antigen, VI, VIII; "H" (Specific) antigen, r; "H" (non-specific) antigen, 1, 3, 4, 5. The reason why Kunzendorf failed to absorb all the group agglutinins from this strain of bovis-morbificans and vice versa is still obscure.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Further studies on the antigenic structure of paratyphoid bacilli with special reference to three new species of Salmonella

Three new species of Salmonella are described. 1. S. durban was obtained from an adult native woman suffering from dysentery. The antigenic formula allocated to it was IX-a, enx. 2. S. reading var. kaapstad was isolated from the cerebrospinal fluid of a child suffering from meningitis. Its antigenic structure was found to be IV-eh: 1, 7. 3. Two unrelated organisms were isolated from one of a group of pigs affected with paratyphoid. The one turned out to be S. heidelberg, factors IV, V-r: 1.2, while the other was found to be a new species with the following antigenic structure: XI- k: 1,2. The latter was named S. pretoria. 4. The biochemical reaction of these organisms are given in Table 1.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Sleep and resting-state functional magnetic resonance imaging connectivity in middle-aged adults and the elderly: A population-based study

Sleep problems increase with ageing. Increasing evidence suggests that sleep problems are not only a consequence of age-related processes, but may independently contribute to developing vascular or neurodegenerative brain disease. Yet, it remains unclear what mechanisms underlie the impact sleep problems may have on brain health in the general middle-aged and elderly population. Here, we studied sleep's relation to brain functioning in 621 participants (median age 62 years, 55% women) from the population-based Rotterdam Study. We investigated cross-sectional associations of polysomnographic and subjectively measured aspects of sleep with intrinsic neural activity measured with resting-state functional magnetic resonance imaging on a different day. We investigated both functional connectivity between regions and brain activity (blood-oxygen-level-dependent signal amplitude) within regions, hierarchically towards smaller topographical levels. We found that longer polysomnographic total sleep time is associated with lower blood-oxygen-level-dependent signal amplitude in (pre)frontal regions. No objective or subjective sleep parameters were associated with functional connectivity between or within resting-state networks. The findings may indicate a pathway through which sleep, in a ‘real-life’ population setting, impacts brain activity or regional brain activity determines t