First bacteriostatic composition is not medicine.Resistance is so dangerous, because in the patient's survival environment to rely on the drug resistant strain failure.And antibacterial ingredients are not used as a drug, even if the tolerance of antibacterial ingredients, also won't have much impact.
Second, there is stress, can raise the tolerance.Stress is a choice.Under environmental stresses, especially lethal stress, such as antibiotics, although the pathogenic bacteria of survival rate is reduced, but the individual is more likely to have survived to this stress tolerance.Stress, the more intolerance strain of mortality is higher, the resistance strain of survival advantage is more obvious, the surviving strains will be obtained by genetic resistance gene.This tolerance is a gradual process, in repeated screening stress by the weak strong, repeated drug use is likely to stronger resistant strains screened out step by step.That is why antibiotics don't have, use is enough, not premature discontinuation, the purpose is to kill the pathogenic bacteria species, make sure not to leave the survivors.And antibacterial composition only inhibit the growth of microorganisms, microorganisms will not be killed, mostly of the resistance of the strains in the population does not have obvious advantages, thus in the subsequent populations to strengthen their own tolerance genes.So I think low resistance strains screened out opportunities.