Isolation and characterization of Brucella from the lungworms of a harbor porpoise (Phocoena phocoena).

Adult female nematodes identified as Pseudalius inflexus were collected from the lungs of a juvenile male harbor porpoise (Phocoena phocoena) found dead on a beach in Cornwall, UK. Classic and molecular typing methods, immunologic and electron microscopy immunolabeling techniques, provided evidence of Brucella sp. infection within the uterine tissue of nematodes of this marine mammal. This finding presents further evidence to suggest parasites should be considered as a potential means of transfer of bacterial infection in marine mammals and highlights the zoonotic implications for humans exposed to marine mammals through occupation or leisure.

Studies of embryo transfer from cattle clinically affected by bovine spongiform encephalopathy (BSE).

Semen from 13 bulls, eight with clinical bovine spongiform encephalopathy (BSE), was used to artificially inseminate (AI) 167 cows with clinical BSE, and their resultant embryos were collected non-surgically seven days after AI. The viable and non-viable embryos with intact zonae pellucidae were washed 10 times (as recommended by the International Embryo Transfer Society) then frozen. Later, 587 of the viable embryos were transferred singly into 347 recipient heifers imported from New Zealand, and 266 live offspring were born of which 54.1 per cent had a BSE-positive sire and a BSE-positive dam. The recipients were monitored for clinical signs of BSE for seven years after the transfer, and the offspring were monitored for seven years after birth. Twenty-seven of the recipients and 20 offspring died while being monitored but none showed signs of BSE. Their brains, and the brains of the recipients and offspring killed after seven years, were examined for BSE by histopathology, PrP immunohistochemistry, and by electron microscopy for scrapie-associated fibrils. They were all negative. In addition, 1020 non-viable embryos were sonicated and injected intracerebrally into susceptible mice (20 embryos per mouse) which were monitored for up to 700 days, after which their brains were examined for spongiform lesions. They were all negative. It is concluded that embryos are unlikely to carry BSE infectivity even if they have been collected at the end-stage of the disease, when the risk of maternal transmission is believed to be highest.

Evaluation of a rapid western immunoblotting procedure for the diagnosis of bovine spongiform encephalopathy (BSE) in the UK.

Bovine brain tissue samples from 625 UK cattle, clinically suspected as bovine spongiform encephalopathy (BSE) cases, were used in a blind analysis to assess a rapid Western immunoblotting technique (Prionics Check; Prionics AG, Zurich), which detects bovine disease-specific protease-resistant prion protein (PrP(Sc)). By means of statutory histopathological examination, 599 of the 625 cattle were confirmed as BSE cases by the demonstration of spongiform encephalopathy, the remaining 26 being classified as negative. Duplicate samples from the same animals were also examined by electron microscopy for the presence of abnormal brain fibrils (scrapie-associated fibrils; SAFs). The Prionics technique showed a high sensitivity, particularly when compared with the fibril detection test; the detection rates were 99.3% and 92.0% respectively, with histopathology being used as the "gold standard". The false negative results by the Prionics test were possibly related to the sampling procedure. Analysis of 50 BSE-positive samples revealed similar glycoprofiles, the majority of PrP(Sc)isoforms being di-glycosylated protein. The Prionics test also detected PrP(Sc)in the four brain samples from the 26 histopathologically negative animals, apparently reducing the specificity of the test to 84.6%; however, confirmatory positive results in these samples were obtained by demonstrating SAF or by immunohistochemical examination, or both. It was concluded that the Prionics test detected PrP(Sc)in a small percentage (0.64%) of clinically suspected BSE cases showing no spongiform change. Since January 2000, the Prionics Western blot test has been introduced as one of the statutory tests for the diagnosis of clinically suspected BSE and scrapie cases in the UK.