Diagnosis of botulism in mammals aided by toxin ELISA and C and D gene RT-PCRs with an emphasis on farm animals.

Animal welfare and ethical considerations limit the use of the mouse lethality bioassay for the detection of botulinum toxins. This study assessed an ELISA and RT-PCRs to detect toxin types C and D in samples from mammals with flaccid paralysis or weakness. DNA/RNA tightly bound to the toxin molecules were used as surrogates for the presence of toxin.

Confirmation of botulism diagnosis in Australian bird samples by ELISA and RT rtPCR.

We developed a sandwich ELISA that detects C and D toxins and reverse-transcription real-time PCRs (RT-rtPCRs) that detect botulinum C and D toxin genes, respectively, to replace the mouse bioassay. The toxin genes were closely associated with the toxin molecules and used as surrogates for the presence of toxin. Samples (638) from 103 clinical cases of birds (302) with suspected botulinum toxicity came from wild birds and poultry (9 cases).

Assessing the risk of residues of the toxin indospicine in bovine muscle and liver from north-west Australia.

Indospicine is a natural toxin occurring only in Indigofera plant species, including the Australian native species I. linnaei. These perennial legumes are resistant to drought and palatable to grazing livestock including cattle.

Characterisation of an extracellular serine protease gene (nasp gene) from Dermatophilus congolensis.

A partial amino acid sequence of a serine protease from Dermatophilus congolensis allowed the design of oligonucleotide primers that were complemented with additional ones from previously published partial sequences of the gene encoding the enzyme. The polymerase chain reaction (PCR), using combinations of specific and degenerate oligonucleotide primers, allowed the amplification of a 1738-bp internal fragment of the gene, which was finally characterised by inverse PCR as the first full-length sequenced serine protease gene (nasp) from Dermatophilus congolensis. The deduced amino acid sequence of this enzyme, probably involved in the pathogenesis of dermatophilosis, links it to the subtilisin family of proteases.