Molecular Analysis of Resistance and Virulence in clinic isolates of multidrug-resistant Serratia marcescens and design of multiepitope vaccine against Enterobacter cloacae using Reverse Vaccinology

Abstract

In the past decades, the increasing quantity of multidrug-resistant (MDR) bacteria has reached an alarmin rhythm and is causing grave health issues around the world, as it has been accompanied by high morbidity and mortality rates. Studies about S. marcenscens, an opportunistic nosocomial pathogen, with intrinsical resistance to varied classes of antibiotics and a high potential for dissemination, are scarce. Therefore, the goal of our study is to analyze the presence of resistance genes, including efflux bombs, and virulence genes in S. marcescens isolated from clinical samples collected in ICU patients, utilizing PCR and then sequencing. Additionally, it is intended to find proteic targets that could be candidates for the production of vaccines, by bioinformatic analyses of their coding sequences in the Enterobacter cloacae genome, using the reverse vaccinology (RV) technique. Previous studies by our research group have found that most of the isolates samples of S. marcenscens utilized in this study are MDR with a high level of resistance to ²-lactams, aminoglycosides, quinolones, tigecycline, and colistin. Initial studies to verify the presence of beta-lactam resistance genes and other classes of antibacterial drugs are being realized, as well as the identification of virulence genes. Thus, the proposed study in this project may broaden our knowledge of S. marcescens opportunist strains that circulate in Brazil, allow us to understand its pathogenicity, and, in the future, assist in the development of new molecular diagnostic assays, new medicines, vaccines and, hence, in the control of nosocomial infections.Additionally, we propose the identification of targets that could be utilized as a multiepitope vaccine against Enterobacter cloacae, through the RV methodology, once in the past few years these bacterias have been reported as important opportunistic and multiresistant pathogens to human beings.As the bacterial resistance issue is global, the results of this study will be useful to predict nationally and internationally the emergence of new resistance problems, guide intervention strategies, and assist new and better treatment strategies. In the future, we intend to validate experimentally the vaccine candidate obtained to establish its potency, efficiency, and safety.