Protective Effect of Botulinum C/D Mosaic Toxoid against Avian Botulism

Abstract

ABSTRACT. Avian botulism is a paralytic disease caused by a toxin produced by Clostridium botulinum type C. Since type C isolates from cases of avian botulism produced a neurotoxin consisting of a mosaic form of parts of type C and D neurotoxins, we examined the antitoxin titers in the convalescent sera of botulism-affected birds which belonged to family Anatidae. ELISA using the C/D mosaic neurotoxin as an antigen revealed that the antibody was detected in the sera at 2 weeks, but not at 5 weeks after the onset, suggesting that the antibody only appeared for a short period in the convalescent phase. However, we failed to detect the antibody titers with antichicken IgG instead of anti-duck IgG. We therefore examine the immunological properties of IgG among different families and species. The results revealed that different species of IgG in the same family exhibited strong cross-reactivity. Ducks immunized once with the toxoid together with a commercial oil-adjuvanted vaccine were found to develop sufficient antibody to protect against a challenge with a lethal toxin dose. The ELISA titers did not correspond to the neutralization titers in the sera of immunized ducks at the early stage during immunization. These findings suggest that the neutralizing titer was more useful than the ELISA titer for evaluating the protection against the toxin, but the ELISA technique may be applicable for detecting the occurrence of botulism. KEY WORDS: avian botulism, C/D mosaic toxin, Clostridium botulinum, vaccination.

Management of Animal Botulism Outbreaks: From Clinical Suspicion to Practical Countermeasures to Prevent or Minimize Outbreaks

“…[10][11][12] Group IV, C. butyricum, and C. baratii produce type G, E, and F toxins, respectively. Some strains are also capable of producing 2 toxins simultaneously or may carry a second silent nonexpressed gene.…”

Protection with recombinant Clostridium botulinum C1 and D binding domain subunit (Hc) vaccines against C and D neurotoxins

“…Two cases of foodborne botulism linked to BoNT C and one case of infant botulism attributed to C. botulinum serotype C1 have been reported [8,9], and BoNT D organisms were found in tainted ham that caused mild botulism in several persons [9]. However, BoNT C1 and D are predominantly known for causing avian or mammalian botulism [10][11][12]. Limited stocks of anti-BoNT C1 and D veterinary vaccines are used to vaccinate cattle and other domestic animals, and they have been shown to be protective.…”

Multiplex Real-Time PCR for Detecting and Typing Clostridium botulinum Group III Organisms and Their Mosaic Variants

“…4,9,25,26 Among BoNT-producing clostridia strains, C. botulinum strains that produce types C, D, C/D, and D/C toxins (group III organisms) are the organisms mainly responsible for animal botulism outbreaks. 6,7 Rapid detection and typing of these organisms and their toxins are a prerequisite for a prompt diagnosis, for treatment of sick animals, and to prevent or minimize further cases. Moreover, the knowledge of toxin subtype is valuable, not only for epidemiologic reasons but also because the mosaic toxins have shown a higher toxic activity in animals compared to nonmosaic toxins.…”