PubMed Health⌕ Search

Biomedical subjects

A J Wilsmore

Publications and source records attributed to A J Wilsmore.

At least 19 recordsLinked to original sources

Detection of peste des petits ruminants virus antigen in conjunctival smears of goats by indirect immunofluorescence.

Peste des petits ruminants virus (PPRV) antigen was detected in conjunctival epithelial cells obtained from goats in the early or late stage of the disease by the use of a specific monoclonal antibody (mAb) to PPRV in an immunofluorescent antibody test (IFAT). The affected goats were sampled during an outbreak of peste des petits ruminants in Eritrea. Syncytia were also observed in some smears, consistent with a morbillivirus infection, but the IFAT was more sensitive than staining for syncytia in the detection of viral antigen, the two tests giving 63 per cent and 40 per cent of animals, respectively, with positive tests. Positive immunofluorescence was observed in samples from goats in the early and late stages of the disease, but was not observed with a specific rinderpest mAb or with conjunctival smears from uninfected animals. It is concluded that preparation of conjunctival smears for staining for syncytia is a simple procedure which can be applied in the field, and by use of a specific mAb PPRV infection can be rapidly confirmed and differentiated from rinderpest.

Animals↗

'Stupid calves'.

Explore the source record for details and available documents.

Animals↗

In vitro survival of the BS isolate of Chlamydia psittaci (ovis) in ruminal and abomasal contents.

The ability of the pathogenic BS isolate of Chlamydia psittaci (ovis) to survive after inoculation into ruminal or abomasal contents, and chlamydial transport medium held at 39 degrees C, was assessed by taking hourly samples which were cultured in mitomycin-treated McCoy cells. The chlamydiae survived for nine hours in the ruminal contents, eight hours in the abomasal contents and for 12 hours in transport medium, when the experiment was concluded. There was a steady decrease in the numbers of the organism in the ruminal and abomasal contents as their pH decreased, but the numbers in the transport medium also decreased without a corresponding change in pH. It is therefore possible that ewes may become infected with C psittaci (ovis) orally via the gastrointestinal tract.

Abomasum↗

Experimental infections of pregnant sows with ovine Chlamydia psittaci strains.

Four sows were experimentally inoculated at 42 days pregnancy, with the BS isolate of Chlamydia psittaci from aborted ewes. Their body temperature and health were monitored until 30 days after farrowing. The sows seroconverted but their reproductive performance was not impaired. Chlamydiae were identified in the afterbirths from two sows with normal litters using stained smears, "Clearview" and "IDEIA" ELISA antigen detection tests. The presence of inclusion bodies was detected in sections of the infected fetal membranes after staining with haematoxylin and eosin, methylene blue and Streptavidin-Biotin using an anti-Chlamydia monoclonal antibody.

Animals↗

Preparation and use of a monoclonal antibody to detect Chlamydia psittaci antigen in paraffin-embedded tissue sections.

A murine monoclonal antibody prepared against an ovine abortion isolate of Chlamydia psittaci (A22/Teramo) revealed specific binding to a 57 kDa chlamydial antigen in immunoblotting studies. The monoclonal antibody was able to detect intracytoplasmic chlamydial inclusions and scattered elementary bodies in infected McCoy cell culture, and on formalin-fixed paraffin-embedded tissue sections both from experimentally infected mice and from fetal membranes of cases of ovine enzootic abortion.

Animals↗

Comparison of the calf suckling technique and milk oxytocin test for estimation of milk yields.

The calf suckling technique and milk oxytocin test were compared as methods to quantify lactation yields in Sanga-type cows in the multi-purpose livestock sector of central Zambia. There was no significant difference between the overall means derived from 154 observations. The oxytocin method interferes less with the multi-purpose system of management, is less time consuming and does not require expensive calf weight scales.

Analysis of Variance↗

Effect of dry season supplementation of Sanga cattle in Zambia.

Supplementation of lactating Sanga cows in central Zambia with low cost crop residues and urea-mineral licks resulted in significant increases in milk offtake (79%), total daily milk (86%), and daily liveweight gain of their calves (86%). At 1988 market prices the value of the additional milk (ZK54.00) and of liveweight of both cow and calf (ZK189.00) over the 13 weeks exceeded the estimated costs of inputs by ZK180.00.

Animal Feed↗

The use of fluorescein-conjugated monoclonal antibodies, cell culture and transmission electron microscopy to detect Chlamydia psittaci and associated lesions in experimentally infected mice.

An immunofluorescence test based on a monoclonal antibody (mAb) was used to demonstrate chlamydiae in formalin-fixed and paraffin wax-embedded tissues from 10 adult mice experimentally infected by the oral route with Chlamydia psittaci isolated from the fetal membranes of an aborted ovine fetus. Samples of lung, jejunum and spleen were examined by bright-field microscopy, immunofluorescence and transmission electron microscopy, and were cultured for chlamydia in McCoy cells. These tissues were compared with those of two control mice. All infected mice had splenic hyperplasia and two had pneumonia. The lung appeared to be the target organ for C. psittaci administered by the oral route. Chlamydiae were identified in the lungs of five mice by immunofluorescence, bright-field and transmission electron microscopy. Chlamydiae were cultured from the jejunum of two mice and the spleen of one, but could not be identified at these sites by other methods. Immunofluorescence with an anti-chlamydia mAb was useful for detecting chlamydial antigen in formalin-fixed paraffin wax-embedded samples.

Animals↗

Experimental conjunctival infection of lambs with a strain of Chlamydia psittaci isolated from the eyes of a sheep naturally affected with keratoconjunctivitis.

Five ram-lambs were inoculated into the left conjunctival sac with the 15R isolate of Chlamydia psittaci, recovered from a sheep with keratoconjunctivitis. A sixth ram-lamb was kept in contact with them. The five lambs developed varying degrees of acute conjunctivitis and 14 days later C psittaci could be recovered from the inoculated eyes, from which Branhamella ovis was also isolated. The eyes were examined regularly for four months; C psittaci could not be re-isolated but the eyes developed varying degrees of follicular conjunctivitis. After four months the sheep were treated with corticosteroids in an attempt to reactivate a latent chlamydial infection but no chlamydiae could be isolated. Five months after the start of the experiment the six lambs were inoculated with 15R into the left conjunctival sacs. Acute conjunctivitis developed which was not as severe as after the first inoculation, but C psittaci could only be recovered from the left eyes of three sheep three days after inoculation. The eyes remained chronically affected by follicular conjunctivitis. Six months after the start of the experiment the left eyes were again inoculated with 15R; on this occasion acute conjunctivitis did not develop and chlamydiae could not be isolated. Chronic follicular conjunctivitis persisted until the experiment was terminated three months later.

Animals↗

A simple staining method for the identification of chlamydial elementary bodies in the fetal membranes of sheep affected by ovine enzootic abortion.

A dark-ground methylene blue (DGMB) staining method was used to demonstrate chlamydial elementary bodies in fetal membranes of sheep affected by Chlamydia psittaci. Before evaluation on material from clinically affected animals, the DGMB method was compared with modified Ziehl-Neelsen (MZN) and dark-ground Giemsa (DGG) staining methods for its ability to demonstrate chlamydial elementary bodies in hens' eggs which had been experimentally infected with C. psittaci. DGMB was more specific in its staining of chlamydial elementary bodies than DGG or MZN. The DGMB method was found to be a more reliable technique for the examination of fetal membranes from sheep affected with C. psittaci than DGG or MZN. Those samples diagnosed as positive using the DGMB showed a good correlation with those diagnosed as positive on macroscopic examination.

Abortion, Veterinary↗

Delayed-type hypersensitivity test for assessing tick-immune status of cattle in Zambia.

Delayed-type hypersensitivity skin reactions were used to assess the tick resistance status of Tonga calves in Zambia. The antigen used in the tests was a homogenate of unfed nymphal Rhipicephalus appendiculatus which had been shown to give protective immunity in guinea pigs to adult female R appendiculatus. There was a significant negative correlation between the intensity of the reactions and the total number of ticks (Amblyomma variegatum, R appendiculatus, Hyalomma truncatum, Boophilus decoloratus and Rhipicephalus species) on the animals.

Animals↗

Enzyme-linked immunosorbent assays for the measurement of specific antibodies in experimentally induced ovine toxoplasmosis.

Tachyzoites of the RH strain of Toxoplasma gondii were inoculated intravenously into sheep following which serum samples were collected at approximately weekly intervals for 9 months. The sera were examined by the toxoplasma dye test and two enzyme-linked immunosorbent assays (ELISA) specifically developed for investigations of ovine toxoplasmosis. One was an antibody class capture assay for the detection of anti-toxoplasma specific IgM, the other an indirect assay which detected anti-toxoplasma IgG. Some of the sheep had antibodies to toxoplasma prior to inoculation but none had specific IgM. Sera collected 17 days after inoculation showed that all had raised specific antibody levels but the only sheep that produced specific antitoxoplasma IgM were those that were initially without any antibody. Specific IgM could be detected in all these particular sheep for at least 1 month after infection and up to 3 months in some. Specific IgG persisted at high levels for at least 3 months and could still be detected at moderate levels for at least 9 months. The ELISA methods described are simple to perform and could clearly distinguish between previous infection and this experimental infection with Toxoplasma gondii.

Animals↗