Immunization of turkeys with < i > Clostridium septicum < /i > alpha toxin-based recombinant subunit proteins can confer protection against experimental Clostridial dermatitis

by Feba Ann John, Valeria Criollo, Carissa Gaghan, Abigail Armwood, Jennifer Holmes, Anil J. Thachil, Rocio Crespo, Raveendra R. Kulkarni Clostridial dermatitis (CD), caused byClostridium septicum, is an emerging disease of increasing economic importance in turkeys. Currently, there are no effective vaccines for CD control. Here, two non-toxic domains ofC.septicum alpha toxin, namely ntATX-D1 and ntATX-D2, were identified, cloned, and expressed inEscherichia coli as recombinant subunit proteins to investigate their use as potential vaccine candidates. Experimental groups consisted of a Negative control (NCx) that did not receiveC.septicum challenge, while the adjuvant-only Positive control (PCx), ntATX-D1 immunization (D1) and ntATX-D2 immunization (D2) groups receivedC.septicum challenge. Turkeys were immunized subcutaneously with 100 μg of protein at 7, 8 and 9 weeks of age along with an oil-in-water nano-emulsion adjuvant, followed byC.septicum challenge at 11 weeks of age. Results showed that while 46.2% of birds in the PCx group died post-challenge, the rate of mortality in D1- or D2-immunization groups was 13.3%. The gross and histopathological lesions in the skin, muscle and spleen showed that the disease severity was highest in PCx group, while the D2-immunized birds had significantly lower lesion scores when compared to PCx. Gene expression analysis revealed that PCx birds had significantly higher expression of pro-inflammatory cytokine genes in the skin, muscle an...
Source: PLoS One - Category: Biomedical Science Authors: Source Type: research