Initial Recovery and Rebound of Type F Intestinal Colonization Botulism After Administration of Investigational Heptavalent Botulinum Antitoxin
ABSTRACT Investigational heptavalent botulinum antitoxin (HBAT) is now the primary antitoxin for US noninfant botulism patients. HBAT consists of equine Fab/F(ab')2 IgG fragments, which are cleared from circulation faster than whole immunoglobulins. Rebound botulism after antitoxin administration is not previously documented but occurred in our patient 10 days after HBAT administration.
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ABSTRACT: Background. Clostridium botulinum strain IBCA10-7060, isolated from a patient with infant botulism, produced botulinum neurotoxin type B (BoNT/B) and another BoNT that, by use of the standard mouse bioassay, could not be neutralized by any of the Centers for Disease Control and Prevention-provided monovalent polyclonal botulinum antitoxins raised against BoNT types A-G.Methods and Results. The combining of antitoxins to neutralize the toxicity of known bivalent C. botulinum strains Ab, Ba, Af, and Bf also failed to neutralize the second BoNT. Analysis of culture filtrate by double immunodiffusion yielded a single line of immunoprecipitate with anti-A, anti-B, and anti-F botulinum antitoxins but not with anti-E antitoxin. A heptavalent F(ab')2 botulinum antitoxin A-G obtained from the US Army also did not neutralize the second BoNT. An antitoxin raised against IBCA10-7060 toxoid protected mice against BoNT/B (Okra) and against the second BoNT but did not protect mice against BoNT/A (Hall) or BoNT/F (Langeland).Conclusions. The second BoNT thus fulfilled classic criteria for being designated BoNT/H. IBCA10-7060 is the first C. botulinum type Bh strain to be identified. BoNT/H is the first new botulinum toxin type to be recognized in >40 years, and its recognition could not have been accomplished without the availability of the mouse bioassay.The Journal of Infectious Diseases 10/2013; 209(2). DOI:10.1093/infdis/jit449 · 5.78 Impact Factor