Multiresistance in Gram-negative bacteria occurs through the accumulation of resistance plasmids or by horizontal gene transfer, associated with an outer membrane barrier of low permeability, with an efficient complex of efflux pumps (capable of pumping out of the bacteria more than one type of drug), combined with various specific mechanisms of resistance (Nikaido, 2009). In addition, the susceptibility of the bacterial cells to antibiotics can be affected by their physiological state. An important consequence of this phenomenon is the discovery of “persistent” cells, revealing that even high concentrations of antibiotics do not kill the whole bacterial population, leaving a resistant population that is genetically identical to the susceptible cells (Tikhonova et al., 2007).
We therefore conclude that the hydroalcoholic extract of P. cincinnata has potential as an antibacterial agent when combined with drugs that are little effective in the treatment of various human diseases but are often utilized by the public in general. Its profile of action is thereby altered by decreasing the MIC of conventional antibiotics, where this plant extract can be developed as a new therapeutic weapon, potentiating aminoglycosides and beta-lactams, which are not very effective in the treatment of infections caused by MRSA and ESBL strains.