Antivenom production in chicken against Sind krait (Bungarus sindanus) venom and its efficacy assessment using different immunoassays

Abstract

Present study aimed for detection, purification, quantification of Sind Krait (Bungarus sindanus) antivenom from chicken eggs and to determine extracted antivenom efficacy in mice. Hens’ three groups were immunized by sub-lethal doses of Sind Krait venom with adjuvant paraffin oil+lecithin. Booster doses were injected subcutaneously on pectorals muscles at multiple sites after every two weeks upto eight weeks. Antibodies-IgY produced against Sind Krait venom was purified form eggs’ yolk by precipitation method with PEG-6000. Purified antivenom-IgY protein contents were quantified by Nanodrop-photometer, purity accessed by SDS-PAGE, specificity checked by Ochterloneys method and titer estimated by indirect ELISA. Antivenom efficacy was assessed in albino mice. Purified antivnom-IgY exhibited single protein band 180-190 kDa on SDS-PAGE under non-reduced condition and two-bands 63 - 65 kDa and 22 - 25 kDa correspondingly under-reduced condition. Immunodiffusion exhibited sharp precipitation lines of immune-complex (venom and extracted-IgY). In all groups (G1, G2 and G3) antivenom level sharply increase from 3rd to 4th week and maintained thereafter. G2 and G3 presented high titer upto 1:2048 dilutions, while G1 showed upto 1:1024 dilutions, as tested by indirect ELISA. In neutralization assay ED50 dose of G2 and G3 obtained antivenom was 400.23 µg/mice for more than twofold LD50 dose of venom and 100% protection was at 508.84 µg/mice that completely neutralized highly lethal dose of venom. But G1 ED50 was 405.66 µg/mice and provides 100% protection at 554.21 µg/mice. Extracted antivenom, against Sind Krait venom were highly pure, and with high neutralization capacity were produced successfully from eggs yolk first time in Pakistan.