Correction: Khan et al. Oral Immunization of Chickens with Probiotic Lactobacillus crispatus Constitutively Expressing the α-ß2-ε-ß1 Toxoids to Induce Protective Immunity. Vaccines 2022, 10, 698.

The authors would like to make the following corrections to this published paper [...].

Oral Immunization of Chickens with Probiotic Lactobacillus crispatus Constitutively Expressing the α-ß2-ε-ß1 Toxoids to Induce Protective Immunity.

Clostridium perfringens (C. perfringens) is a bacterium that commonly causes zoonotic disease. The pathogenicity of C. perfringens is a result of the combined action of α, ß, and ε exotoxins. In this study, Lactobacillus crispatus (pPG-T7g10/L. crispatus) expressing the main toxoids of C. perfringens, α, ε, ß1, and ß2, with EGFP-labeling, was constructed, and the protective effect was estimated in chickens. The α-ß2-ε-ß1 toxoid was constitutively expressed for confirmation by laser confocal microscopy and western blotting, and its immunogenicity was analyzed by enzyme-linked immunosorbent assay (ELISA) and immunohistochemical assays. After booster immunization, the probiotic vaccine group showed significantly higher levels (p < 0.05) of specific secretory IgA (sIgA) and IgY antibodies in the serum and intestinal mucus. Furthermore, the levels of cytokines, including interferon (IFN)-γ, interleukin (lL)-2, IL-4, IL-10, IL-12, and IL-17, and the proliferation of spleen lymphocytes in chickens orally immunized with pPG-E-α-ß2-ε-ß1/L. crispatus increased significantly. Histopathological observations showed that the intestinal pathological changes in chickens immunized with pPG-E-α-ß2ε-ß1/L. crispatus were significantly alleviated. These data reveal that the probiotic vaccine could stimulate mucosal, cellular, and humoral immunity and provide an active defense against the toxins of C. perfringens, suggesting a promising candidate for oral vaccines against C. perfringens.