Various technical means are available for identifying the causative agents of microbial infections and for generating antibiotic susceptibility profiles, which can inform the suitable course of treatment (diagnostic routing). First, host factors, such as C-reactive protein (CRP), procalcitonin (PCT) and others are analysed to, for instance, distinguish viral from bacterial infection. Following the identification of the causative bacterial pathogen, antimicrobial susceptibility testing (AST) is the next step (except in some specific molecular tests) to generate an antibiotic susceptibility profile. AST ensures that suitable antibiotics are prescribed to a patient. Beyond the outlined routine diagnostic process, there is opportunity to follow up with fundamental research to analyse the presence of novel resistance markers (possibly identifying novel resistance mechanisms) and to determine the resistance levels to the antibiotic.