The sigma factor RpoS in environmental isolates of the genus Kluyvera

• Grant number: 22/02115-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2022
• End date: December 31, 2022
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Beny Spira
• Grantee: Vinícius Freitas de Oliveira
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The rpoS gene encodes the RNA polymerase factor Ãs, responsible for the transcription of genes related to adaptive functions such as resistance to global stress (eg, pH extremes, osmolarity, dehydration, oxidation), biofilm formation, and virulence. important for the survival of bacteria under non-ideal growth conditions. Some enterobacteria are opportunistic pathogens and the ability of these bacteria to survive in constantly changing environments is essential for the virulence process. Kluyvera is a genus of the Enterobacteriaceae family. Some species of this genus can cause diseases in humans, but even so, they are poorly studied. In this project, we isolated 21 Kluyvera strains from a polluted urban stream and preliminarily characterized these strains as to the intrinsic level of RpoS in each of them. The present study aims to validate the RpoS levels of 21 Kluyvera strains through RpoS-dependent phenotypic analyses. For this, isolates with high levels of this protein will have the rpoS locus deleted, while strains with low levels of RpoS will be transformed with rpoS+ plasmids to increase the expression of this protein. The natural isolates, as well as the recombinant strains, will then be tested for several characteristics such as sensitivity to environmental stresses and capacity to grow with alternative carbon sources. Another objective will be to assess the sensitivity of these bacteria to antibiotics and observe biofilm production. Antibiotic sensitivity and biofilm formation data will be correlated with the RpoS levels of the strains.(AU)