Nonspecific toxicites in the mouse assay test for botulinum toxin.

In inoculated pack experiments on Clostridium botulinum type E, unirradiated and 0.1-Mrad irradiated haddock fillets often gave nonspecific toxicities by the mouse assay test for botulinum toxin. Samples given 0.2-Mrad radiation failed to produce nonspecific reactions. Nonspecific deaths sometimes occurred within 24 hr after injection, although deaths between 24 and 48 hr were more common. The symptoms and the pattern of these deaths suggested a septicemia. Heart-blood cultured from mice showing nonspecific symptoms indicated an infectious process. Among 23 isolates from the blood, eight were identified as Proteus vulgaris, two P. morganii, one P. rettgeri, one Providence subgroup B, two Aerobacter aerogenes, one Actinobacillus, three enterococci, one Alcaligenes marshalli, and four Erysipelothrix insidiosa. The E. insidiosa, Aerobacter, Providence group, and most of the Proteus isolates were infectious for mice when injected by the intraperitoneal route. But the enterococci, Alcaligenes, and Actinobacillus isolates were not infectious and probably represent secondary invaders. The cultural characteristics of the E. insidiosa isolates conform to those described in the literature, with the exception that the four strains grew in the temperature range 50 F (10 C) to 40 F (4.4 C). Nonspecific toxicities were avoided in assays for botulinum toxin by the protection of mice with chloramphenicol and oxytetracycline.