Toxin-neutralizing antibodies protect against Clostridium perfringens-induced necrosis in an intestinal loop model for bovine necrohemorrhagic enteritis

Table 2 In vitro neutralization of biological activities of alpha toxin and perfringolysin O. Calves were immunized with either a C. perfringens toxin preparation (native toxins), L-lysine protected, formaldehyde inactivated C. perfringens toxins (L-lysine/formaldehyde toxoid) or a commercial multivalent formaldehyde inactivated clostridial vaccine

	Inhibitory capacity (Mean ± SEM)
Antiserum	Alpha toxin activity^a	PFO activity^b
Native toxins	409.8 ± 5.75	48.0 ± 0.0
L-lysine/formaldehyde toxoid	80.47 ± 46.93	72.0 ± 24.0
Commercial formaldehyde vaccine	22.39 ± 2.17	18.0 ± 6.0

^aNeutralization of 10 μg/ml alpha toxin. The inhibitory capacity of the antiserum is expressed as the dilution that gives 50 % inhibition of the alpha toxin activity
^bNeutralization of 2 μg/ml perfringolysin O. The inhibitory capacity of the antiserum is expressed as the highest dilution that inhibited perfringolysin O-induced hemolysis
Alpha toxin activity was determined by measuring its lecithinase activity on egg yolk lipoproteins. Perfringolysin O (PFO) activity was determined by measuring the hemolysis of horse erythrocytes

ISSN: 1746-6148