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This study was undertaken to evaluate two monoclonal antibody-based sandwich ELISAs (sELISAs) for the detection of Clostridium botulinum neurotoxins (BoNTs) types C and D from culture-enriched intestinal content samples from cattle. To validate the diagnostic significance of the presence of cultivable, toxin-producing C botulinum in the intestines of cattle, samples from both suspect and non-suspect botulism cases were examined. BoNT was detected by both sELISAs in a greater number of suspect animals than by direct testing of uncultured samples by mouse bioassay. One sELISA detected two BoNT C and one BoNT Group III mosaic isoform in three animals that were missed by the other, and both sELISAs failed to identify samples from two mouse bioassay-positive BoNT C animals. BoNT D was also detected in one non-suspect sample by one of the sELISAs.

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Mycoplasma bovis became firmly established in NorthernIreland during 1993, following the relaxation of import controls within the European Union and the resulting extensive importation of cattle (Reilly and others 1993). At the time of its arrival, a monoclonal antibody-based sandwich ELISA developed at the Agri-Food and Biosciences Institute, Belfast, for the detection of M bovis (Ball and others 1994) was available for the diagnosis of the organism, and the routine application of this assay has enabled the continued subsequent recording of the incidence of M bovis in Northern Ireland. Brice and others (2000) reported the results of the first six years of monitoring, during which the majority of M bovis cases were associated with pneumonia in young cattle, but cases of bovine arthritis and mastitis also occurred. This short communication extends the review of the incidence of M bovis in Northern Ireland, to include the seven years from 1999 to 2005.The study was undertaken on samples from bovine pneumonia, arthritis and mastitis cases submitted to Veterinary Sciences Division laboratories at Stormont and Omagh for diagnostic examination.The sandwich ELISA used for the detection of M bovis was that described by Ball and others (1994) and Brice and others (2000). An ELISA plate was incubated over three days during the capture enrichment stage, after which a small sample (10 µl) was removed from the well of lowest titration without visible bacterial contamination and subcultured on to mycoplasma agar. In ELISA-positive cases where bacterial contamination was present in all sample wells, the original stored homogenised sample was passed through a 0·45 µm filter (Millipore) and the filtrate was retested. Mycoplasmas cultured from ELISA-negative samples were also retested by the assay. In some instances in which the colony growth was sparse, these cultures were found to be M bovis-positive from the second assay. They were considered to have been ELISA-negative from the first test because of poor enrichment growth, presumably because of inhibitory antibiotic levels in the tissue sample. Positive ELISA results were recorded only when confirmed by culture. Table 1 summarises the results of the testing of isolates for M bovis from pneumonia cases submitted for diagnostic examination for the seven years from 1999 to 2005. The total number of samples tested was 1328, with 282 (21·2 per cent) positive cases, from 214 farm outbreaks. The highest incidence occurred in 2003 and 2004, with 27 per cent of cases being M bovis-positive, and involving 40 and 45 farm outbreaks, respectively. The highest number of farm outbreaks, 48, was in 2005. Table 1 also includes the data from Brice and others (2000), and summarises the incidence of M bovis isolates over its 13-year presence in Northern Ireland. Compared with the six years from 1993 to 1998, the average annual percentage of cases in the more recent seven-year period rose from 15 to 21 per cent, but the total number of farm outbreaks dropped slightly from 226 to 214. Table 2 sh...

1The ability to accurately identify infected hosts is the cornerstone of effective disease control 1 2 and eradication programs. In the case of bovine tuberculosis, caused by infection with the 1 3pathogen Mycobacterium bovis, accurately identifying infected individual animals has been 1 4 challenging as all available tests exhibit less than 100% discriminatory ability. Here we 1 5 assess the utility of three serological tests and assess their performance relative to skin test where one test was used in conjunction with statutory testing. 9Serological tests using samples taken prior to SICCT disclosed low proportions of animals as with TB visible lesions (27%) or with laboratory confirmed infection (25%). As a result, 2 4 apparent sensitivities within this cohort was very low (≤15%), however the tests succeeded in 2 5 achieving very high specificities (96-100%). During the case-study, 7/670 (1.04%) samples 2 6 from SICCT negative animals from a large chronically infected herd were serology positive, 2 7 with a further 10 animals being borderline positive (17/670; 2.54%). 9/17 of these animals 2 8were voluntarily removed, none of which were found to be infected (-lesions/-bacteriology) 2 9 post-mortem; 1 serology test negative animal was subsequently lesion+ and M. bovis 3 0 confirmed at slaughter.