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931.
Naturally acquired Brucella abortus infections were studied during consecutive pregnancies in eight sheep and in their lambs over a period of 40 months to evaluate epizootiologic aspects of natural infection in sheep. Brucella abortus was isolated from the ewes following 16 of 26 natural terminations of pregnancy: from 5 of 6 ewes in the first year, from six of eight ewes in the second year, from two of six ewes in the third year, and from three of six ewes in the fourth year. Vaginal swab samples and milk samples were the most consistent source of the brucella organisms. Brucella abortus was isolated from three ewes when standard tube test seroagglutination titers were less than 1:100. In contrast, results of supplemental tests (card, 2-mercaptoethanol, complement-fixation, and Rivanol) remained positive during the study. During the 40 months, B abortus was isolated from 4 of 4 aborted fetuses, 2 of 5 stillborn lambs, 10 of 37 living lambs, and as an indicator of continuing infection, from 6 of 12 lambs born during the fourth year. Although B abortus has a definite host preference for cattle, this study demonstrated that under appropriate management conditions, sheep may be naturally infected and may remain infected for more than 40 months. Epizootiologic evaluation of all factors, including husbandry practices and exposure potential, should be utilized in determining the need to test other species that may have been exposed to cattle infected with B abortus. 相似文献
932.
P J Ihrke R M Schwartzman R E Halliwell 《American journal of veterinary research》1979,40(10):1495-1497
Quantitative and qualitative bacterial assays were performed on the skin of three dogs with endocrine-related primary metabolic seborrhea. After the dogs were treated (thyroid supplementation or castration, bacterial analyses were again performed on the same sites. Before therapy, the dogs had a cutaneous flora composed mainly of Staphylococcus aureus coagulase-positive organisms. After therapy, there was a significantly lower bacterial count, and two of the dogs had floras consisting mainly of coagulase-negative cocci. During the study, the two dogs that reverted bacteriologically to a normal cutaneous microenvironment became normal dermatologically. The third dog improved, but continued to have minor signs of seborrhea. 相似文献
933.
Silicified anthoecia (fertile le'mmas and paleas) of grasses (Berriochloa communis, Berriochloa primaeva, and Berriohldoa cf. nova) were found in, the oral cavity and rib cage articulated skeletons of Teleoceras major buried in late Clarendonian volcanic ash in. Nebraska The plant fossils, thought to be food residues, help clarify, the enigmatic paleobiological role, of Teleocears, which had hippotamus-like porportions but very high-crowned teeth. Telecoceras was probably amphbious, but siliceous grasses formed a significant portion of its diet. 相似文献
934.
Walsh J 《Science (New York, N.Y.)》1979,204(4395):815
935.
936.
L F Woodard H W Renshaw D Burger C S McCain R B Wilson 《American journal of veterinary research》1979,40(5):636-644
937.
938.
939.
940.
J M Bradbury 《Research in veterinary science》1979,27(3):386-387
Fifty-four strains of avian mycoplasma representing 11 species or serotypes were examined for their phosphatase activity using two different methods. Both methods gave similar results. All of four strains of Mycoplasma anatis and six of M meleagridis and the type strain of serotype L were phosphatase positive. The other species gave variable reactions between strains and on different occasions of testing. 相似文献