Identification of Gram-Negative Bacteria and Genetic Resistance Determinants from Positive Blood Culture Broths by Use of the Verigene Gram-Negative Blood Culture Multiplex Microarray-Based Molecular Assay. J Clin Microbiol 2015 Aug;53(8):2460-72
Date
05/23/2015Pubmed ID
25994165Pubmed Central ID
PMC4508435DOI
10.1128/JCM.00581-15Scopus ID
2-s2.0-84938118582 (requires institutional sign-in at Scopus site) 118 CitationsAbstract
Bloodstream infection is a serious condition associated with significant morbidity and mortality. The outcome of these infections can be positively affected by the early implementation of effective antibiotic therapy based on the identification of the infecting organism and genetic markers associated with antibiotic resistance. In this study, we evaluated the microarray-based Verigene Gram-negative blood culture (BC-GN) assay in the identification of 8 genus or species targets and 6 genetic resistance determinants in positive blood culture broths. A total of 1,847 blood cultures containing Gram-negative organisms were tested using the BC-GN assay. This comprised 729 prospective fresh, 781 prospective or retrospective frozen, and 337 simulated cultures representing 7 types of aerobic culture media. The results were compared to those with standard bacterial culture and biochemical identification with nucleic acid sequence confirmation of the resistance determinants. Among monomicrobial cultures, the positive percent agreement (PPA) of the BC-GN assay with the reference method was as follows; Escherichia coli, 100%; Klebsiella pneumoniae, 92.9%; Klebsiella oxytoca, 95.5%; Enterobacter spp., 99.3%; Pseudomonas aeruginosa, 98.9%; Proteus spp., 100%; Acinetobacter spp., 98.4%; and Citrobacter spp., 100%. All organism identification targets demonstrated >99.5% negative percent agreement (NPA) with the reference method. Of note, 25/26 cultures containing K. pneumoniae that were reported as not detected by the BC-GN assay were subsequently identified as Klebsiella variicola. The PPA for identification of resistance determinants was as follows; blaCTX-M, 98.9%; blaKPC, 100%; blaNDM, 96.2%; blaOXA, 94.3%; blaVIM, 100%; and blaIMP, 100%. All resistance determinant targets demonstrated >99.9% NPA. Among polymicrobial specimens, the BC-GN assay correctly identified at least one organism in 95.4% of the broths and correctly identified all organisms present in 54.5% of the broths. The sample-to-result processing and automated reading of the detection microarray results enables results within 2 h of culture positivity.
Author List
Ledeboer NA, Lopansri BK, Dhiman N, Cavagnolo R, Carroll KC, Granato P, Thomson R Jr, Butler-Wu SM, Berger H, Samuel L, Pancholi P, Swyers L, Hansen GT, Tran NK, Polage CR, Thomson KS, Hanson ND, Winegar R, Buchan BWAuthors
Blake W. Buchan PhD Professor in the Pathology department at Medical College of WisconsinNathan A. Ledeboer PhD Vice Chair, Professor in the Pathology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
BacteremiaBacteriological Techniques
Drug Resistance, Bacterial
Gram-Negative Bacteria
Gram-Negative Bacterial Infections
Humans
Microarray Analysis
Molecular Diagnostic Techniques
Prospective Studies
Retrospective Studies
Time Factors