Besides, the role of ClpP as a regulator essential for the expression of many virulence factors is established in a variety of bacterial species, and clpP deletion strains of many species were shown to be attenuated in the infection process (for reviews see Brötz-Oesterhelt and Sass, 2014; Frees at al., 2014; Culp and Wright, 2017; Bhandari et al., 2018; Moreno-Cinos et al., 2019b). This evidence concerns the gene CLPP and infection.