Monitoring bacterial resistance using selected reaction monitoring

Antibiotic resistance among pathogenic bacteria continues to be a major growing public health problem worldwide. It is well documented that the overuse of antibiotics also leads to new resistant strains, thus decreasing the effectiveness of “front line” antibiotics. Therefore, the detection of the antibiotics to which a bacterium is resistant is critical in designing an effective medical treatment plan and in minimizing the chances of increasing antibiotic resistance. Clinical treatment of an infection with ineffective antibiotics can lead to increased pathogen growth and spread, and cause serious medical complications and death. For this reason, clinical laboratories often determine the susceptibility of the bacterial isolate to a number of different antibiotics in order to establish the most effective antibiotic for treatment. Unfortunately, current clinical procedures for antimicrobial susceptibility assays remain based on time consuming culturing methods. Since antibiotic resistance often involves the chemical modification of an antibiotic to an inactive form by a bacterial enzyme, selected reaction monitoring (SRM) has the ability to quickly monitor and identify these chemical changes in an unprecedented time scale. Because SRM is highly selective and can identify chemical changes in a multitude of antibiotics, SRM has the ability to detect organisms that are resistant to one or more antibiotics in a single assay. The use of SRM greatly reduces the time it takes to determine the susceptibility or resistance of an organism to many antibiotics by eliminating the time consuming process of current culturing methods.