The Role of Molecular Testing in Identifying Carbapenemase Producing Organisms: Implications for Infection Control and Prevention Strategies

Abstract

<h3>Background</h3> As multi-drug resistance proliferates, healthcare institutions must implement antimicrobial stewardship processes to quickly identify and disarm the microscopic enemy. Infection control (IC) surveillance should consider incorporating molecular testing to rapidly identify resistance threats and implement appropriate infection control measures. <h3>Methods</h3> In 2014, a large metropolitan teaching hospital implemented gram-negative blood culture nucleic acid testing (BC-GN). A retrospective review by a multidisciplinary team consisting of an IC practitioner and an infectious disease (ID) pharmacist assessed timeliness of organism identification, the prevalence of Carbapenemase-producing (CP) markers and collaboration opportunities for improvement of antimicrobial stewardship efforts. <h3>Results</h3> BC-GN testing has increased the speed of identifying epidemiologically significant organisms by 81% from the time of laboratory receipt. Of identified Carbapenem-resistant isolates from blood cultures, 41% also expressed CP mechanisms. Additionally, 50% of patients identified with CP organisms had a previously confirmed Carbapenem-resistant isolate from non-blood specimens. In collaboration with ID pharmacist, specific types of CP mechanisms were found to be associated with specific antibiotic resistance patterns. <h3>Conclusions</h3> Implementation of molecular testing provides quick identification of isolates and epidemiologically significant genetic markers. Understanding the CP prevalence assists ID professionals with the information necessary to treat patients appropriately while enhancing antimicrobial stewardship efforts. Trending antibiotic resistance patterns in BC-GN specimens with confirmed CP mechanisms can aid in developing a proxy marker for non-blood specimens where molecular testing is not yet available.