Biomedical subjects
I M Smith
Publications and source records attributed to I M Smith.
Immunisation of pigs against experimental infection with Bordetella bronchiseptica.
During pregnancy seven minimum-disease sows (group A) were infected intranasally with Bordetella bronchiseptica, fed with the killed bacterium periodically and inoculated parenterally with a dead vaccine eight, six and two weeks before parturition. Groups B and C, isolated from A until farrowing, contained respectively six sows given the vaccine parenterally and eight control sows. At parturition, group A had much higher average agglutinin titres in the serum and colostrum than B or C. Group A sows gave their piglets a better passive protection against infection with B bronchiseptica strain 293 and its effects in the respiratory tract during the first eight weeks of life, especially in those exposed to spontaneous infection with bordetellae from a littermate deliberately inoculated intranasally 24 hours after birth. Passive antibody strongly affected the capacity of piglets to respond actively to parenteral vaccination (when seven and 28 days old), marked humoral responses being noted only in those from group C sows. Vaccination of piglets exposed to infection by contact reduced neither the prevalence or intensity of the nasal infection, the amount of turbinate atrophy or pneumonia nor significantly improved weight gain compared with unvaccinated littermates. Unlike their eight-week-old littermates there was little hypoplasia and no pneumonia in infected pigs (whether vaccinated or not) when they reached five months of age.
Alkaline phosphatase activity in the turbinates of pigs infected with Bordetella bronchiseptica.
Explore the source record for details and available documents.
Immunogenicity of killed Bordetella bronchiseptica vaccines in the mouse.
Two intramuscular injections (two weeks apart of graded doses of killed strains of Bordetella bronchiseptica from the pig (OLN 14 or LBF 1) or the dog (D1) had produced in mice circulating agglutinins ranging in mean titre (log2) per group from about 3.3 to 10.2 two weeks later. These levels depended partly on vaccinal strains and dose, and partly on the strain used as agglutinogen. Other such mice were challenged intraperitoneally with about 50 LD50 (approximately or equal to 10(7.4) viable bacteria) of two pig strains, one (293) from a British case of atrophic rhinitis and the other (N) from an American herd. Against challenge vaccinal strain OLN 14 was about 10 and LBF 1 about 100 times more immunogenic than vaccinal strain D1. In a separate experiment mice given intramuscularly amounts of LBF 1 or D1 vaccine estimated as being immunogenically equivalent were challenged intraperitoneally with one or other of seven pig or seven dog strains. On aggregate each vaccine protected to about the same extent against challenge by the pig strains, although LBF 1 vaccine was less effective than D1 vaccine against a strain of Danish origin. Both vaccines also protected more mice against challenge by the dog than the pig strans but LBF 1 vaccine was somewhat less effective than D1 vaccine, especially when challenged by strain D1.
Ultrastructural changes in the nasal turbinate bones of pigs in early infection with Bordetella bronchiseptica.
The ultrastructural changes in the turbinates of young pigs killed four, seven, 14 and 28 days after intranasal inoculation (dpi) with Bordetella bronchiseptica were restricted to osteoblasts. In a few cells irregularities and evagination of the nuclear membrane were associated with enlargement of the Golgi apparatus at four dpi. By seven dpi many osteoblasts had these changes and also a dilatation of the endoplasmic reticulum while mitochondria retained normal definition: an amorphous degeneration occurred within the enlarged Golgi apparatus. These features had progressed at 14 and 28 dpi to produce shrunken osteoblasts with small, irregular nuclei, a grossly distended endoplasmic reticulum, absent or degenerate Golgi apparatus, but apparently intact mitochondria. At this stage the numbers of osteoid fibres were greatly reduced and macroscopic hypoplasia of the turbinates was observed.
Treatment of experimental Bordetella bronchiseptica infection in young pigs with potentiated sulphonamide in the drinking water.
Bordetella bronchiseptica was eliminated from the nasal cavity of experimentally infected piglets after about three weeks by trimethoprim and sulphadiazine (potentiated sulphonamide) in the drinking water in two experiments (at levels of 13.3 and 66.7 micrograms per ml, respectively). The rhinitis and turbinate damage associated with the infection was significantly less when the animals were examined at seven weeks of age but daily weight gain was not improved to a significant extent compared with controls. Smaller quantities of potentiated sulphonamide were less active but no amount induced resistance in the bordetellae during the one month period of treatment.
Acute referral hospital care in geriatric internal medicine.
Explore the source record for details and available documents.
Atrophic rhinitis in Southern England.
Explore the source record for details and available documents.
The prevalence of Brodetella bronchiseptica and turbinate (conchal) atrophy in English pig herds in 1978-79.
Examination of pigs (eight to 10 per farm) slaughtered between December 1978 and March 1979 at abattoirs in southern England indicated that infection with Bordetella bronchiseptica was widespread. The organism was recovered from the nasal cavity of 424 out of 844 (50 per cent) of such pigs and these were distributed among 79 out of 86 (91 per cent) of the herds submitting animals. The sensitivity to sulphonamide or potentiated sulphonamide of 255 of these strains was determined: in 20 out of 70 (25 per cent) herds there was partial or complete resistance to the former drug and, in 16 out of 79 (20 per cent), to the latter also. Despite this general level of infection and bacterial resistance the prevalence and severity of turbinate atrophy was less than in a survey undertaken by others in 1974. Thus about 74 per cent of pigs had no or minor atrophy only and about 10 per cent severe lesions. Some 10 per cent of the farms sent groups in which the majority of the pigs had severe atrophy.
High prevalence of strains of Bordetella bronchiseptica resistant to potentiated sulphonamide in English pig herds in 1978-79.
Explore the source record for details and available documents.
Clinical bacteriological and epidemiological observations on infectious atrophic rhinitis of pigs in southern England.
Three distinct patterns of infection with Bordetella (Alcaligenes) bronchiseptica were found in groups of 12 to 24 pigs born in 1977-78 in 12 herds in southern England. In five of these, heavy bordetella infection of a substantial proportion of unweaned piglets persisted to a variable extent until slaughter. Clinical disease and severely atrophied turbinates were most marked in these groups. In three other herds the infection first appeared soon after weaning and occasionally persisted until slaughter. Clinical disease occurred in only one of these other groups and conchal atrophy at slaughter was moderate. In the groups of the four remaining herds there was no clinical disease and conchal atrophy at slaughter was slight, infection appearing only late in the weaning, or even the fattening, stages. These varying patterns suggest that immunological phenomena were involved in the infection in the least affected herds and that such responses might, if reproducible artificially, provide a better means of control of this disease in badly affected herds than the available forms of chemotherapy.
The effects of added dietary iron in various forms on mice inoculated with Salmonella typhimurium.
The susceptibility of mice to intraperitoneal infection with 10(4.8) living bacteria of three strains of Salmonella typhimurium was measured in groups fed either a basal, nutritionally adequate diet or the same diet to which had been added ferric iron in one of six forms: ferric sulphate or chloride (FeS), ferric ethylenediaminetetra-acetate (FeE), ferric nitrilotri-acetate (FeN), ferric fructose (FeF), ferric diethylenetriaminepenta-acetate (FeT) and ferric ethylenediamine di (O-hydroxyphenylacetate) (FeD). FeN and FeF significantly increased the survival rate of male but not female mice. This protective effect of FeN was not influenced by its concentration in the diet over the range tested, 25 to 800 mg of Fe per kg of diet. FeN had to be given a week before infection to produce the effect and it was associated with a reduced rate of multiplication of salmonellae. FeE significantly decreased the survival rate of both male and female mice, and greatly reduced the survival time of mice that died. The deleterious effect of FeE increased with its concentration in the diet and with the time for which it had been fed, and it was associated with very rapid bacterial multiplication. FeT gave results similar to those of FeE, while FeS and FeD had hardly any effect.
Common infections in the elderly diabetic.
Explore the source record for details and available documents.
Infective endocarditis with negative blood cultures. An analysis of 52 cases.
The clinical records of 52 patients who were diagnosed clinically as having had infective endocarditis despite negative blood cultures have been reviewed. They differed at presentation from patients with positive blood cultures in more frequent receipt of antibiotics prior to culture and more frequent signs of major systemic emboli and congestive heart failure. Response of culture-negative patients with fever to empiric antibiotic therapy was correlated with survival, in that 92 per cent of the patients who became afebrile within the first week of therapy liver, whereas only 50 per cent of those who did not become afebrile lived. Deaths resulted primarily from major systemic emboli and from uncontrollable congestive heart failure due to valvular insufficiency. In 25 cases, valvular tissue was examined histologically. In 15 cases, vegetations were seen and organisms identified; in six cases, only vegetations were seen; and in four cases (16 per cent), the clinical diagnosis of infective endocarditis was not substantiated in the pathologic report.
A selective medium facilitating the isolation and recognition of Bordetella bronchiseptica in pigs.
A medium was developed that in most instances allowed the isolation from pigs of Bordetella (Alcaligenes) bronchiseptica in pure, or virtually pure, culture from such sites as the nasal cavity, which contains many other bacteria. If not suppressed, some of the latter can inhibit, sometimes completely, the growth of the bordetellae on artificial media. Besides being markedly selective, the new medium is simple to prepare, reasonably cheap and practically noninhibitory to B bronchiseptica. This organism produces a distinctive colony that is easily differentiated on morphological grounds from the few other bacteria (such as Alcaligenes faecalis and Pseudomonas spp) which also grow on this medium. Parallel examination of specimens from the nasal cavities of 219 pigs in the field in southern England confirmed that this medium was better than hitherto recommended for the detection of B bronchiseptica. This was particularly true when the organism occurred in small numbers only and/or when bacteria little affected by the inhibitors in the previously recommended media were present in the nasal flora.
Serological evidence of infection with the virus of infectious bursal disease in wild and domestic birds in Nigeria.
Explore the source record for details and available documents.
Haematological, serological and pathological effects in chicks of one or more intravenous injections of Salmonella gallinarum endotoxin.
Abnormalities appeared a few hours after groups of 14-day-old chicks (Gallus domesticus) were injected intravenously with 15 mg/kg of endotoxin (LPS) from Salmonella gallinarum. Clinical illness without mortality was accompanied by significant (P less than 0.05) falls in body temperature, bursa weight, the main haematological parameters, serum iron (SI) and transferrin saturation (TS) and a significant increase in unsaturated iron-binding capacity. All responses, apart from bursa weight, SI values and total and differential white-cell counts, returned to normal within 24 to 48 h. LPS given daily for three consecutive days did not cause changes in the main haematological parameters during the 48 h period following the third injection. However body and bursa weight and heterophil counts were significantly depressed, whereas body temperature, SI and TS were affected biphasically, being first depressed and then raised above normal. Chicks injected with LPS daily for six consecutive days showed broadly similar responses but a persistent microcytosis was also present.