Infection diagnosis and antibiotic sensitivity testing are important aspects of clinical microbiology that are in dire need of improvement owing to the inadequate current standards in the early detection of bacterial response to antibiotics. The increasing antimicrobial resistance is a serious global threat to human health. Current resistance-detecting methods, using the phenotypic antibiotic sensitivity test, which measures bacterial growth as affected by antibiotics, have long analysis times. Therefore, new and rapid methods are needed to detect antibiotic resistance. Here, we review the methods used to detect antibiotic resistance in bacteria, including that caused by biofilm development, and we look at the development of rapid methods for evaluating antimicrobial resistance (AMR).