Análise filogenética de genes blaTEM associados à resistência antimicrobiana em Salmonella enterica.

Abstract

Salmonella is a genus belonging to the family Enterobacteriaceae and sustains a close relationship with the genus Escherichia. Approximately 1.3ő million people are infected each year, with around Ő20 deaths. In this context, understanding the evolution of Salmonella plays a crucial role in public health by explaining how microorganisms develop and disseminate antimicrobial resistance. Understanding these evolutionary processes allows the anticipation of resistance patterns, supports the development of new therapies, and guides control and surveillance strategies. Thus, the aim of this study was to analyze the phylogenetic patterns of blaTEM genes in strains of Salmonella enterica, in order to infer evolutionary diversity and aspects related to the dissemination of antimicrobial resistance. This research was characterized as an in silico study, based on the collection of blaTEM gene sequences deposited in the NCBI GenBank database. After collection, multiple sequence alignment was performed, followed by the construction of a phylogenetic tree using MEGA 12®, and subsequently Tajima’s D statistical test was applied to assess possible deviations from evolutionary neutrality. The analysis of 17 serovars revealed a high prevalence of S. Typhimurium (7 in total). While the alignment results highlighted several point mutations, many of which were expressed at the phenotypic level. The phylogenetic reconstruction allowed the evaluation of their tree topology and evolutionary relationships. On the other hand the neutrality test generated a Tajima’s D value of -0.Ő30Ő37. Therefore, understanding the evolutionary mechanisms associated with the adaptive success of blaTEM genes in S. enterica serovars resistant to β-lactams sets ground for the development of strategies in the vicinity of combating and controlling infections.