Testing strains of Clostridium perfringens type A isolated from diarrhoeic piglets for the presence of the enterotoxin gene.

A diarrhoeic syndrome in piglets has been linked to Clostridium perfringens type A because this organism has been isolated in large numbers from all cases. The strains isolated from these cases and strains isolated from healthy piglets were screened for the enterotoxin gene of C perfringens by DNA-hybridisation. Using two different synthetic DNA-probes, none of the strains isolated from diseased pigs was positive in this reaction, indicating that the enterotoxin of C perfringens is not involved in the syndrome.

Synthetic DNA probes for detection of enterotoxigenic Clostridium perfringens strains isolated from outbreaks of food poisoning.

Four synthetic oligonucleotides encoding different parts of the Clostridium perfringens enterotoxin gene were used to test the enterotoxigenicity of C. perfringens strains isolated from confirmed outbreaks of food poisoning. Of the 245 strains isolated from food and feces originating from 186 separate outbreaks, 145 (59%) gave hybridization reactions with each of the four DNA probes used, while 104 strains did not hybridize with any of the probes.

Cloning and sequencing of the Clostridium perfringens enterotoxin gene.

Several gene banks of Clostridium perfringens in E. coli were constructed. Using a mixture of synthetic 29-mer DNA probes clones were selected containing inserts from the C.

Failure of E. coli K-12 to transport PhoE-LacZ hybrid proteins out of the cytoplasm.

A phoE-lacZ hybrid gene encoding the N-terminal 300 amino acid residues of pre-PhoE protein, fused to an almost complete beta-galactosidase molecule was constructed in vitro. Cell fractionation experiments suggested that the hybrid gene product is transported to the outer membrane. However, by using immuno-cytochemical labelling on ultra-thin cryosections it was shown that the hybrid protein accumulated in the cytoplasm.