A potential in silico antibody-antigen based diagnostic test for precise identification of Acinetobacter baumannii

Acinetobacter baumannii is a problematic nosocomial pathogen. The resistance to a wide range of antimicrobial agents, attributable to its biofilm phenotype, makes the treatment very difficult. Biofilm is a common feature of most pathogens. Biofilm associated proteins (Bap) are cellular surface components directly involved in biofilm formation process. The dearth of a fast precise diagnostic test and versatility of Bap sequences in A. baumannii were intuitions to design this study. In silico analysis is a reliable alternative to laborious experimental work in this connection. Databases were searched for an antigenic conserved region of Bap specific to A. baumannii. The region was selected based on alignments and propensity scales. Tertiary structure for this region was built and predicted B-cell epitopes were mapped on the surface of the built model. Our protein subunit was found to be a potential antigen, possessing several antigenic determinants, eliciting antibody. Hence this subunit could be used as a suitable agent for antibody-antigen based diagnostic test. This specific antigen can minimize laboratory errors in identification of A. baumannii and thus help clinicians to quick and precise diagnosis of the bacteria and initiatives to the treatment of the infection. Antigenicity of the region could also be explored for elicitation of antibody to protect the individuals exposed to A. baumannii.