Pengimunan Protein Rekombinan SAG2 Eimeria tenella Melindungi Ayam terhadap Kesan Penyakit Koksidiosis

Sue-Kim Ho, Mandeepal Singh Atar Singh, Sheila Nathan, Kiew-Lian Wan
2020 Sains Malaysiana  
ABSTRAK Pengawalan penyakit koksidiosis ayam yang disebabkan oleh jangkitan parasit Eimeria melibatkan penggunaan vaksin hidup. Namun, kaedah ini mempunyai batasan disebabkan kos pengeluarannya yang tinggi secara relatif dan hanya memberikan perlindungan yang terhad disebabkan oleh sifat Eimeria yang khusus-hos. Justeru, vaksin rekombinan diperkenalkan sebagai strategi alternatif. Antigen permukaan-2 (SAG2) Eimeria tenella telah dikenal pasti berupaya merangsang gerak balas imun ayam berikutan
more » ... mun ayam berikutan jangkitan. Oleh itu, dalam kajian ini, protein rekombinan SAG2 terlarut telah dihasil dan digunakan dalam pengimunan ayam. Hasil ELISA menggunakan sampel ayam terimun menunjukkan bahawa program pengimunan berjaya merangsang penghasilan antibodi-khusus SAG2 pada ayam terimun. Antibodi IgG, IgM dan IgA khusus-SAG2 pada serum ayam berjaya dikesan selepas suntikan perangsang yang pertama, manakala IgA rembesan khusus-SAG2 dikesan pada sampel kandungan mukosa ayam yang telah melengkapkan keseluruhan program pengimunan. Ayam seterusnya telah diberikan jangkitan cabaran oosista tersporulasi E. tenella. Hasil menunjukkan bahawa ayam terimun menghasilkan bilangan oosista yang lebih rendah berbanding dengan ayam tidak terimun (p<0.05) dan ini mencadangkan keupayaan protein rekombinan SAG2 untuk melindungi ayam terhadap kesan jangkitan E. tenella. Secara keseluruhannya, hasil kajian ini menunjukkan kesesuaian protein rekombinan SAG2 E. tenella sebagai calon vaksin rekombinan bagi penyakit koksidiosis. Kata kunci: Antigen permukaan-2; ELISA; vaksin rekombinan ABSTRAcT The control of avian coccidiosis caused by Eimeria parasites involves the use of live vaccines. However, this method has its limits due to relatively high production cost and restricted protection because of the host-specific characteristic of Eimeria. Hence, recombinant vaccines were introduced as an alternative strategy. The surface antigen-2 (SAG2) of Eimeria tenella has been shown to be able to stimulate the chicken immune response upon infection. Therefore, in this study, purified soluble recombinant proteins of SAG2 were produced and used to immunise chickens. The results obtained by ELISA through the use of samples from immunised chickens indicated that the immunisation programme was successful in inducing the production of SAG2-specific antibodies in immunised chickens. SAG2-specific IgG, IgM, and IgA antibodies were detected in the sera of immunised chickens after the first boosting injection, while SAG2specific secretory IgA was detected in mucosal samples of the chickens that completed the immunisation program. The chickens were subsequently given a challenge dose of sporulated oocysts of E. tenella. Results indicated that the immunised chickens produced a significantly lower number of oocysts compared to their non-immunised counterparts (p<0.05), suggesting the ability of the recombinant protein SAG2 to protect chickens against the effects of E. tenella infection. Overall, the results of this study indicate the suitability of the E. tenella SAG2 recombinant protein as a recombinant vaccine candidate for coccidiosis.
doi:10.17576/jsm-2020-4905-01 fatcat:c5s6sjhkbnhjlceth72nnbkxbq