Evaluation of the performance of Acuitas® ResistomeTest and the Acuitas Lighthouse® Software for the detection of β-lactamase producing microorganisms

Abstract Objectives Given the international spread of multidrug resistant (MDR) Gram negative bacteria the need for prompt and precise characterization of underlying resistance traits has evolved into the cornerstone of infection control strategies. Novel commercial molecular tests enable rapid simultaneous testing for multiple resistance genes. We aimed to evaluate the performance of OpGen’s Acuitas® Resistome Test and the Acuitas Lighthouse® Software. Methods The test is tailored towards detecting 46 β-lactamase genes (SHV and TEM variants associated with wild-type penicillin resistance, ESBLs, acquired AmpCs and carbapenemases) via a microfluidic PCR array. In total 118 isolates part of the collection of the Bacteriology Laboratory of the Hellenic Pasteur Institute, specifically 96 enterobacterial isolates and 21 Acinetobacter baumannii, of divergent origins, with previously characterized β-lactamase content,were tested. Results In the enterobacterial group all 69carbapenemase genes of the KPC, VIM, NDM and OXA-48 types were correctly identified (sensitivity, specificity, PPV and NPV of 100%).Non-ESBL SHV enzymes, ESBLs (CTX-M, GES, VEB-types) and acquired AmpC enzymes were also correctly characterized. Of the 35 SHV-ESBLs harboured, correct identification was possible in 32/35 isolates, with overall sensitivity, specificity, PPV and NPV for the K. pneumoniae group of 89.29%, 100%, 100% and 91.18% respectively.For the A. baumannii group the test exhibited an overall sensitivity for carbapenemase detection of 96.55% and 100% PPV. Conclusions The OpGenAcuitas® Resistome Test is an efficient molecular tool that can identify resistance threats in health care institutions with high diagnostic accuracy and be integrated into targeted surveillance protocols.