[Interpretation of bacterial susceptibility/resistance to antibiotics].

Bacterial resistance may be defined from a microbiological, clinical and pharmacological perspective. Microbiological resistance refers to the presence of genetic information coding for the relevant mechanism of resistance of a bacterium to a particular antibiotic. In case of clinical interpretation, breakpoints are of key importance as their role is to distinguish bacterial pathogens in which successful therapy is highly probable from isolates with a high likelihood of failure. However, it is questionable whether this approach is suitable for all patients, particularly those receiving intensive care for life-threatening infections. A pharmacodynamic/pharmacokinetic definition of resistance may be understood as comprehensive since it allows consideration of all parameters, especially the patient's clinical condition, site of infection, minimum inhibitory concentration of a specific antimicrobial agent and its concentration in the relevant tissue. In that case, determination of bacterial susceptibility or resistance is more personalized and allows more targeted antibiotic therapy.