Development of specific nano-antibody for application in selective and rapid environmental diagnoses of salmonella arizonae

Abstract

Treatment of human and animals for protection from pathogens infection has significant economic value, especially with the harmful Salmonella arizonae. Beneficial cameloid heavy-chain antibodies as single-domain antigen-binding fragments known as VHHs or nano-bodies may be the acceptable option for producing the treatment and/or diagnostic agents. In the current study, we developed a sandwich ELISA based nano-body towards S. arizonae as the first report for the treatment of S. arizonae. using the cDNA synthesized from immunized camels RNA to isolate 700 bp DNA fragment, which contains all VH domains of IgG2 and IgG3 isotypes followed by the second amplification VHH PCR with amplified fragments at 450 bp. The final PCR products were cloned into the phagemid vector pMECS then via phage display technique. Nano-antibodies protein was purified and separated under non-denaturing conditions by SDS-PAGE. The reactivity of each VHH of the selected clones was analyzed by Western blot assay. The isolated nano-antibodies showed binding not only to S. arizonae, but also to other bacterial strains, indicating that these nano-antibodies can be used in treatment but cannot use in diagnostic.