Table 1.
Classification of pathogenic clostridia by toxin(s) produced, the disease they cause, current protective method(s), and recombinant vaccine research.
| Pathogenic Strain | Type | Toxin | Disease | Commercial Toxoid or Bacterin-Toxoid Vaccine | Recombinant Vaccine Research |
|---|---|---|---|---|---|
| C. botulinum | Group I | BoNT serotypes A, B, E, and F | Botulism (human and animal) | Pentavalent BoNT/A–E toxoids (for people at high risk or exposed to the toxin). Discontinued. BoNT/B toxoid (horses) |
rBV A/B Withdrawn from human clinical trial. rHC BoNT/A/B/E |
| Group II | BoNT serotypes B, E, and F | Botulism (human and animal) | - | - | |
| Group III | BoNT serotypes C and D | Botulism (human and animal) | Bivalent BoNT/C-D toxoids (livestock) | rHC BoNT/C | |
| C. tetani | - | TeNT | Tetanus (human and animal) | TeNT toxoid (human and animal) | TeNT-HC |
| C. perfringens | Type A | CPA | CPA: Myonecrosis (human and animal). | Monovalent CPA toxoid vaccine (cattle and poultry). | rCPA |
| Type B | CPA, CPB, ETX | CPB: Necrohemorrhagic enteritis (animal) ETX: Dysentery (lambs) and enterotoxemia or pulpy kidney (domestic ruminants) |
CPB and ETX toxoid(s) or bacterin-toxoid(s) vaccine (animal) | rCPB rETX r- fused ETX-CPB vaccine |
|
| Type C | CPA, CPB, | CPB: Enteritis necroticans or pigbel (human) and necrotic enteritis, enterotoxemia (animal) | Experimental CPB toxoid vaccine (for people in Papua New Guinea). Discontinued. CPB toxoid or bacterin-toxoid (animals) |
rCPB | |
| Type D | CPA, ETX, | ETX: Enterotoxemia or pulpy kidney (domestic ruminants) | ETX toxoid or bacterin-toxoid (animal) | rETX | |
| Type E | CPA, ITX, | ITX: Hemorrhagic enteritis (ruminants) and enterotoxemia (rabbits). Not confirmed. |
- | - | |
| Type F | CPA, CPE | CPE: food poisoning, antibiotic-associated diarrhea, sporadic diarrhea, and sudden infant death syndrome (SIDS) (humans), and gastrointestinal disease (animals) |
- | rC-terminal CPE r-fused C-terminal CPE with Shiga toxin B subunit |
|
| Type G | CPA, NetB | NetB: Necrotic enteritis (poultry) |
- | rNetB | |
| C. chauvoei | - | CctA | Blackleg (cattle, sheep, and other small ruminants) | Bacterin-toxoid vaccine (animal) | rCctA |
| C. septicum | - | ATX | Spontaneous myonecrosis (human) Braxy (sheep and calves) Malignant edema (ruminants) Gangrenous dermatitis (poultry) |
Toxoid or bacterin-toxoid vaccine (animal) | rATX |
| C. novyi | A | TcnA | Myonecrosis (human and animal) | - | - |
| B | Beta toxin | Black disease (ruminants, pigs, and horses) | Toxoid vaccine (animal) | - | |
| C. hemolyticum | - | Beta toxin | Bacillary hemoglobinuria (cattle and occasionally in sheep and goats) | Bacterin-toxoid vaccine (animal) | r-beta toxin |
BoNT: botulinum neurotoxin. TeNT: tetanus neurotoxin. CPA: C. perfringens Alpha toxin. CPB: C. perfringens Beta toxin. ETX: C. perfringens Epsilon toxin. ITX: C. perfringens Iota toxin. NetB: Necrotic enteritis Beta-like toxin. CPE: C. perfringens Enterotoxin. CctA: C. chauvoei toxin A. ATX: C. septicum lethal Alpha toxin. TcnA: C. novyi Alpha toxin. r-: recombinant. HC: Heavy chain. rBV: recombinant botulinum vaccine. rHC: recombinant heavy chain.