Nanosphere's Verigene® Blood Culture Assay to Detect Multidrug-Resistant Gram-Negative Bacterial Outbreak: A Prospective Study on 79 Hematological Patients in a Country with High Prevalence of Antimicrobial Resistance

Abstract

Infections are a major cause of morbidity and mortality in hematological patients. We prospectively tested a new molecular assay (Verigene^®) in 79 consecutive hematological patients, with sepsis by gram-negative bacteria. A total of 82 gram-negative microorganisms were isolated by blood cultures, of which 76 cases were mono-microbial. Considering the bacteria detectable by the system, the concordance with standard blood cultures was 100%. Resistance genes were detected in 20 of the isolates and 100% were concordant with the phenotypic antibiotic resistance. Overall, this new assay correctly identified 66/82 of all the gram-negative pathogens, yielding a general sensitivity of 80.5%, and providing information on genetic antibiotic resistance in a few hours. This new molecular assay could ameliorate patient management, resulting in a more rational use of antibiotics.

Keywords: Carbapenem resistance; Hematological patients; Molecular diagnosis; Sepsis.

Figure 1

Potential clinical application of the Verigene test and its integration with standard blood culture assay for the management of febrile neutropenia in hematologic patients. The median time from blood sample collection to the blood culture positivity is 18 hours. In our organization, the Verigene test yielded results within a median of 2 hours from blood culture positivity. This represented a gain of a median of 20 hours, as compared to the standard blood cultures with antibiotic susceptibility, which required a median of 22 hours from blood culture positivity.