Clostridium botulinum type E in Bavarian fish

A quantitative PCR-detection method was used to determine the presence of C . botulinum type B and E spores in eighty-seven fish representing six diffe rent species from two fish farms and ten wild freshwater whitefish. Thirty percent (29/97) of the fish were positive for C. botulinum type E with no s erotype B spores being detected. The prevalence of type E in individual fis h species varied from 4 % to 100 %. Fifteen type E isolates from the PCR- p ositive samples from one of the fish Cans were characterized by pulsed-fiel d gel electrophoresis (PFGE), randomly amplified polymorphic DNA analysis a nd biochemical tests. Five different genotypes were observed, with 11 of th e isolates representing a predominant clone. The discriminatory power of PF GE was superior to that of RAPD and biochemical tests. Based on these resul ts, it was concluded that a survey of the prevalence of type E in German fi shery products is indicated in order to determine the public health risk.