Biomedical subjects
Publications and source records attributed to W A Ellis.
Leptospira interrogans serovar bratislava was recovered from 2 of 10 sows examined from an Iowa slaughterhouse. Isolations were made from the kidney and genital tract of each sow. Serovar bratislava is not included in vaccines because it has not been previously isolated in the United States.
Leptospira interrogans serovar hardjo was recovered from 5 of 11 nonpregnant cows chosen at random from an Iowa slaughterhouse. Isolations were made from the kidney in each instance, the genital tract of 3 cows: uterus from 1 cow, oviduct of another, and oviduct and uterus of a 3rd cow.
During an investigation of natural in utero infection of cattle by Leptospira interrogans strains, infection (almost entirely caused by serovar hardjo) was diagnosed in 57 per cent of 505 calves (472 aborted fetuses, 20 stillborn calves and 13 perinatal deaths) examined over a six-year period. The prevalence of leptospire-infected fetuses showed a seasonal increase in September, October and December and was significantly higher in fetuses aborted by dairy cows than in fetuses aborted by beef cows. The majority of infected fetuses were aborted from the sixth month of gestation onwards. Cows which aborted infected fetuses had not previously exhibited overt signs of agalactia. There was an association between leptospiral infection and retention of fetal membranes.
Explore the source record for details and available documents.
Ten non-pregnant heifers, experimentally infected with Leptospira interrogans serovar hardjo, were each given an intramuscular injection of dihydrostreptomycin at a dose rate of 25 mg kg-1. In five of these animals this treatment was repeated after 14 days. Treatment failed to remove established genital or renal infection in seven of the 10 heifers, although the number of organisms persisting was apparently reduced in these animals. Serovar hardjo infection persisted for at least 83 days in the oviduct and uterus and these tissues may be as important carrier sites for serovar hardjo as bovine kidney tissue.
Leptospira interrogans serovar hardjo was demonstrated in the vaginal discharges of 12 experimentally infected heifers for up to eight days after abortion or calving. Organisms were recovered from the oviducts of heifers examined at slaughter eight to 22 days after calving or 32 to 91 days after infection. They were also recovered from the uteri of four heifers eight to 22 days after calving.
Malignant melanoma can involve any organ of the body and commonly involves the gastrointestinal tract. The first case of melanoma in the world's literature involving the cystic duct and the first in the English literature involving the common bile duct is described. This case is compared with the two cases in the world's literature with common duct involvement.
The first isolations of Leptospira interrogans serovar hardjo from pigs are recorded. Evidence that hardjo may be a sporadic cause of porcine reproductive disease is presented.
Using culture, immunofluorescence and fetal serology, leptospiral infection was demonstrated in aborted, stillborn and weak lambs from nine out of 42 flocks investigated during the 1980 and 1981 lambing seasons. Three serogroups of leptospira, namely the Hebdomadis, Australis and Pomona serogroups, were implicated.
A total of 15 cultures of Leptospira were examined for aminopeptidase activity using 22 aminoacyl-beta-naphthylamde substrates. Activity was demonstrated in each of the cultures. Extracts from serovars of Leptospira interrogans preferentially hydrolysed the same range of substrates. The level of hydrolysis of the preferred substrates for the seven strains of L. interrogans was distinctively higher than that demonstrated for the six Leptospira biflexa strains. Extracts from cultures of Leptospira illini and Leptospira parva sp. nov. exhibited profiles different to those demonstrated for the other 13 leptospiral cultures examined.
Thirteen strains of pathogenic leptospires were isolated from 12 of 91 horses; seven strains belonged to the Australis serogroup (serotype bratislava) with three, two and one strains belonging to the Icterohaemorrhagiae, Hebdomadis (serotype hardjo) and Autumnalis serogroups respectively. Using leptospires isolated from horses and others representing the known parasitic Leptospira serogroups, a sample of 650 mares' sera was tested for agglutinating antibodies. Antibodies were found in 89.1 per cent of sera. The predominant reaction was to serotype bratislava, strain S/1334/79, isolated in this study, antibodies to which were detected in 81.8 per cent of sera. It is suggested that serotype bratislava may be adapted to, and maintained by, the horse population in Northern Ireland.
During an investigation of equine abortion, leptospiral infection was demonstrated in nine out of 22 foetuses examined by immunofluorescence and culture. Strains belonging to four serogroups (Australis, Pomona, Hebdomadis and Icterohaemorrhagiae) were isolated. The age of leptospira infected foetuses ranged from six months to term.
Eighteen isolates from the Australis serogroup from free-living and domestic animals were identified using the cross agglutination absorption test. Serovar muenchen was found only in England and Wales in wood mice, short tailed and bank voles, a grey squirrel and a pig. Serovar bratislava was found in hedgehogs in England, Wales and Northern Ireland and also in a brown rat from Northern Ireland. Serovar bratislava was isolated from sheep in both England and Northern Ireland and from horses in Northern Ireland. The distribution of these serovars in relation to possible maintenance hosts is discussed.
The morphology of freshly isolated strains of Leptospira interrogans serovar hardjo was studied by electron microscopy and was compared to that of established laboratory strains of the same serovar and to some other serovars within the Hebdomadis serogroup. Changes in the morphology of freshly isolated strains of serovar hardjo were observed when the isolates were subcultured in the laboratory. Cells of strains subcultured more than 20 times were longer and had longer wavelengths, and electron lucent inclusions were observed less frequently than in cells of strains subcultured less than 10 times. Upon hamster passage, cells subcultured 40 and 50 times became more similar to cells of low passage number than to those of the inoculate. The results are discussed and the importance of environmental factors for the growth of leptospires is emphasized.
Leptospires were demonstrated by a combination of the direct fluorescent antibody technique and culture in six (4.6 per cent) of 130 fetuses from apparently normal uteri collected at an abattoir. Fetal ages ranged from the fifth to the seventh months. In addition, leptospires were isolated from the oviducts of two uteri whose fetuses were not infected. All the strains isolated were similar antigenically to serovar hardjo. Leptospiral antibodies were not detected in any of the fetuses.
The antibody titres of 149 cows aborting leptospire infected fetuses and 156 cows aborting fetuses not apparently infected with leptospires were determined by the microscopic agglutination (MA) test. There were differences in the distribution patterns of MA titres between the two groups of cows but these differences would only be of very limited value in the diagnosis of leptospiral abortion. Although 81.2 per cent of aborting cows which had a titre of 1:1000 or greater had leptospire infected fetuses, they represented 46.3 per cent of cows aborting leptospire infected fetuses. Among cows which aborted infected fetuses, 22.8 per cent had no detectable antibodies. The complement fixation and plate agglutination tests were of less value than the MA test.
Leptospiral infection was diagnosed in 41.6 per cent of 245 randomly selected aborted bovine fetuses and 68.9 per cent of 103 aborted fetuses from farms with abortion problems. Diagnosis was based on combined leptospiral isolates from fetal kidney and eye, and fetal serology and immunofluorescence. Fifty-six of the 58 strains of leptospira isolated belonged to the Hebdomadis serogroup and were similar to serovar hardjo while one of the remaining two strains belonged to the Icterohaemorrhagiae serogroup and the other to the Canicola serogroup. These findings indicate that serovar hardjo infection is a major factor in the aetiology of bovine abortion and that it is possible to isolate this organism from fetal kidney by the careful application of dilution culture technique.
Explore the source record for details and available documents.