Desenvolvimento de vacina contra o patógeno emergente Serratia marcescens utilizando análises bioinformáticas de vacinologia reversa

Abstract

Serratia marcescens is a nosocomial opportunistic gram-negative bacterium with intrinsic and acquired resistance to several antibiotic classes. Vaccines are an efficient, fast way to improve public health with a great cost-benefit. Reverse Vaccinology allows the identification of potential vaccine targets through computational analysis, reducing time and money spent in vaccine development. In this study, Reverse Vaccinology and Subtractive Proteomics were utilized to identify potential vaccine targets of 49 S. marcescens proteomes recovered from NCBI. Five proteins were conserved between strains and were associated with essential, resistance or virulence functions. Those proteins were present in the extracellular environment and were antigenic. A total of 7, 16 and 12 MHC-I, MHC-II and B cell epitopes, respectively, were identified from those 5 proteins. These epitopes were antigenic, immunogenic, conserved, hydrophilic, nontoxic, and non-allergenic. The MHC-I epitopes, 12 MHC-II epitopes and 12 B cell epitopes were conjugated among themselves and with adjuvants with the help of linkers, creating four vaccine constructs. The secondary and tertiary structure of the vaccine constructs were analyzed, along with their antigenicity, toxicity, allergenicity and hydropathicity. All the four models were docked Against TLR4-MD2 complex and the SMV4 model, which had the 50s ribosomal protein L7/L12 had the better binding affinity. The protein was in silico reverse-translated and was codon adapted to E. coli K12. The protein was also in silico cloned in the vector pET-28a (+). Although SMV4 is a promising vaccine candidate, further experimental validation is necessary to confirm its safety and efficacy.

Reverse vaccinology