In silico investigation and expression analysis of two-component regulatory systems in Proteus mirabilis

Proteus mirabilis (P. mirabilis), a Gram-negative bacterium from the Morganellaceae family, exists in various habitats, ranging from natural environmental sources to animal and human host. Two-component systems (TCSs) are involved in sensing various types of stimuli present in the environment, including antimicrobial chemotherapeutics. Moreover, TCSs regulate bacterial virulence. The 16 sets of genes encoding TCSs proteins have been identified in genome of P. mirabilis HI4320 reference strain, but their role remains understudied.

In the presented work, a comparative in silico analysis of TCSs proteins encoded by the genome sequences of P. mirabilis strains obtained from public databases was performed. Additionally, the expression of genes encoding regulatory proteins in response to polymyxin B and H₂O₂ was analyzed using RT-qPCR. The obtained results revealed a relative conservatism of TCSs among P. mirabilis isolates, indicating, however, differences that might result in strains phenotypic diversity. Moreover, constitutive expression of genes coding regulatory proteins from studied TCSs was observed under laboratory conditions.

Presented study shed light on the role of TCSs in P. mirabilis. Further deepen research in this area might provide more effective means for controlling P. mirabilis infections.