POLYMERASE CHAIN-REACTION FOR DETECTION OF CLOSTRIDIUM-BOTULINUM TYPE-A, TYPE-B AND TYPE-E IN FOOD, SOIL AND INFANT FECES

The application of the polymerase chain reaction (PCR) for detection o f Clostridium botulinum types A, B and E in foods, environmental and c linical samples was evaluated and compared to the mouse bioassay. Samp les inoculated with 10, 100 and 1000 spores of CI. botulinum types A a nd B included pasteurized milk, UHT milk, infant formula, infant faece s, meat juice, canned tuna, mushrooms, blood sausage and soil. Clostri dium botulinum type E spores were inoculated into fish eggs, canned tu na, picked herring, raw fish and soil at similar levels. Spores were a dded to 2.5 g of each sample with the exception of soil which was inoc ulated in 10 g samples. The presence of CI. botulinum in sample enrich ments was determined by both PCR and the bioassay. An overall correlat ion of 95.6% was observed between PCR results and the mouse bioassay. Of the total of 114 samples tested there was disparity between the mou se bioassay and the PCR in three samples of soil inoculated with 100 t ype A or E spores and 10 type B spores per 10 g, respectively, and two samples of infant faeces inoculated with 10 type A or B spores per 2. 5 g. All of these samples gave negative animal results and positive PC R results.