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Biomedical subjects

W A Ellis

Publications and source records attributed to W A Ellis.

At least 91 records · Page 5Linked to original sources
PubMed1981

Role of cattle in the maintenance of Leptospira interrogans serotype hardjo infection in Northern Ireland.

Kidneys of cattle, mice and badgers were cultured for leptospires in an attempt to evaluate the relative importance of these species in the epidemiology of bovine leptospirosis caused by the Hebdomadis serogroup. Leptospires closely related to serotype hardjo were recovered from 57 (28.5 per cent) of 200 cattle examined but no evidence of infection was found in either badgers or mice, indicating that cattle act as the maintenance host for serotype hardjo. Many cattle were seronegative carriers.

Animals↗
PubMed1981

Leptospira parva sp.npv.: some morphological and biological characters.

Two lines of a spirochete were isolated as contaminants in a culture of a leptospire and from a bottle of uninoculated medium. Studies on morphological and biological characters led to the conclusion that these lines represent a new species of the genes Leptospira, Leptospira parva sp. nov. The morphology of the cells was rather similar to that of previously examined leptospires, but the cells were shorter and had a shorter wavelength (more tightly wound). Furthermore, the surface layer of cells of L. parva formed numerous small blebs with no apparent substructure when detached during preparation for negative staining, while the surface layer of previously studied leptospires formed cross-striated tubules under similar conditions. L. parva shows biological characteristics of both parasitic and saprophytic leptospires. The deoxyribonucleic acid base composition of cells of this organism differed from that found in leptospires, as well as from that found in cells of Leptonema illini.

Base Composition↗
PubMed1979

Toxoplasmosis in a calf.

Gross post mortem and histopathological changes are described in a calf with toxoplasmosis. The major pathological changes were restricted to the lungs and kidneys and comprised interstitial pneumonia with multifocal necrosis, and glomerular necrosis. Many pseudocysts were present in both organs. The calf had been in close contact with young cats, one of which was killed and examined and shown to have a high antibody titre to Toxoplasma gondii, although there was little histological evidence of infection. No antibodies to toxoplasma were detected in serum from the dam of the calf, and accordingly, it is suggested that the cat was the source of infection for the calf.

Animals↗
PubMed1978

Antibodies to Leptospira in the sera of aborted bovine fetuses.

Antibodies to Leptospira serotypes were detected in sera from 15 (6.9 per cent) of 218 aborted fetuses, but were not detected in the sera from 196 non-aborted fetuses. Fourteen (6.4 per cent) sera from the aborted fetuses had antibodies to strains belonging to the Hebdomadis serogroup and 1 (0.5 per cent) had antibodies to a strain belonging to the Icterohaemorrhagiae serogroup. These antibodies were predominantly immunoglobulin M whereas in the dams, antibodies belonged to both immunoglobulin M and G classes.

Abortion, Veterinary↗
PubMed1978

Serum immunoglobulins in aborted and non-aborted bovine foetuses.

The concentration of immunoglobulin classes G, M and A (IgG, IgM and IgA) in the sera of 233 aborted and 201 non-aborted foetuses was measured. IgM was first detected in a foetus at day 90 of gestation while IgG and IgA were first detected on day 111 of gestation. Immunoglobulins were detected in 81.5% of aborted foetuses and 32.8% of non-aborted foetuses. Total immunoglobulin concentrations of 20 mg/100 ml or greater were found in 35.2% of aborted foetuses but only in 4.5% of non-aborted foetuses. It is suggested that factors resulting in antigenic stimulation of the foetus may play an important part in bovine abortion.

Abortion, Veterinary↗
PubMed1978

The biochemical characteristics of Campylobacter-like organisms from cattle and pigs.

Examination of catalase-positive Campylobacter-like organisms from cattle and pig abortions, indicated the existence of two distinct biochemical groups. The group 1 strains, predominantly of intestinal origin, were identified as C fetus subspecies intestinalis whereas the group 2 strains appeared similar but not identical to C fetus subspecies venerealis. This second group of organisms was recovered from fetal and placental tissue of animals which aborted, however, the majority of strains were isolated only at 30 degrees C in media not generally employed for Campylobacter isolation. All of the strains from group 2 became aerotolerant on subculture.

Abortion, Veterinary↗
PubMed1977

Bovine leptospirosis: experimental infection of pregnant heifers with a strain belonging to the Hebdomadis serogroup.

Twenty pregnant heifers were inoculated with a leptospire of the Hebdomadis serogroup. Leptospiraemia was accompanied by pyrexia which lasted from one to five days. Sixteen animals had relapses of fever. One of these aborted and two produced weak calves, one of which was premature. In the heifers, leptospires localised in the placentae, where they were demonstrable for 14-60 days after inoculation, and in the renal tubules for as long as 174 days. They were also demonstrated in liver, kidney and lung from the aborted fetus. Antibodies were detected in susceptible heifers six days after inoculation and maximum titres of up to 1:100,000 developed between 11 and 21 days. A titre of 1:10 was demonstrated in the serum of a premature live calf. These findings indicated that leptospires of the Hebdomadis group were capable of causing abortion in cattle.

Abortion, Veterinary↗
PubMed1976

Bovine leptospirosis: infection by the Hebdomadis serogroup and abortion-A herd study.

A possible relationship is demonstrated between infection of cattle by the Hebdomadis serogroup of Leptospira and abortion of undiagnosed aetiology. This association is based on (1) The occurrence of a much higher incidence of antibodies to serotype sejroe in herds with a history of undiagnosed abortion than in other groups of cattle tested. (2) A relationship between the incidence of cows with antibody titres to sejroe and the incidence of abortion of unknown aetiology in 29 herds during an 18 month model period.

Abortion, Veterinary↗