Unveiling a specific immunogen protein in A. baumannii

Acinetobacter baumannii is a Gram-negative, non-motile aerobic bacterium known as a nosocomial pathogen resisting often to broad range of antibiotics. The pathogen is a serious agent of mortality and morbidity in hospital particularly among immunocompromise patients. Treatment and control of its infections is complicated owing to its high antibiotic resistance, survival in various environmental conditions and utilization of wide range of nutrient sources. Early detection of the pathogen in established infections is pivotal for controlling the infections. Culture and biochemical test are current methods for detection of the bacterium taking 2-5 days time. Hence, a new rapid specific affordable diagnostic test is needed. Development of such test depends on a suitable biomarker without any cross reactivity with other bacteria. Accordingly, aim of the study is to unveil of a 34.4 KDa outer membrane protein (OMP) introduced by Islam et al. in A. baumannii ATCC19606. In the current study, we harnessed various bioinformatic servers to screen whole proteome of the bacterium. Properties critical to the screening include: molecular weight, localization, topology, homology, antigenicity and allergenicity of proteins. Three proteins were found as suitable candidate molecular weight as well as localization points of view. BLAST searches, antigen probability predictions and other analyses led to selection of one protein as the best specific antigen of A. baumannii. The in silico analyses unveiled the best candidate protein vide accession number ZP_05827218.1.