Evaluation of an automated rapid diagnostic assay for detection of Gram-negative bacteria and their drug-resistance genes in positive blood cultures.
We evaluated the performance of the Verigene Gram-Negative Blood Culture Nucleic Acid Test (BC-GN; Nanosphere, Northbrook, IL, USA), an automated multiplex assay for rapid identification of positive blood cultures caused by 9 Gram-negative bacteria (GNB) and for detection of 9 genes associated with β-lactam resistance. The BC-GN assay can be performed directly from positive blood cultures with 5 minutes of hands-on and 2 hours of run time per sample. A total of 397 GNB positive blood cultures were analyzed using the BC-GN assay. Of the 397 samples, 295 were simulated samples prepared by inoculating GNB into blood culture bottles, and the remaining were clinical samples from 102 patients with positive blood cultures. Aliquots of the positive blood cultures were tested by the BC-GN assay. The results of bacterial identification between the BC-GN assay and standard laboratory methods were as follows: Acinetobacter spp. (39 isolates for the BC-GN assay/39 for the standard methods), Citrobacter spp. (7/7), Escherichia coli (87/87), Klebsiella oxytoca (13/13), and Proteus spp. (11/11); Enterobacter spp. (29/30); Klebsiella pneumoniae (62/72); Pseudomonas aeruginosa (124/125); and Serratia marcescens (18/21); respectively. From the 102 clinical samples, 104 bacterial species were identified with the BC-GN assay, whereas 110 were identified with the standard methods. The BC-GN assay also detected all β-lactam resistance genes tested (233 genes), including 54 bla(CTX-M), 119 bla(IMP), 8 bla(KPC), 16 bla(NDM), 24 bla(OXA-23), 1 bla(OXA-24/40), 1 bla(OXA-48), 4 bla(OXA-58), and 6 blaVIM. The data shows that the BC-GN assay provides rapid detection of GNB and β-lactam resistance genes in positive blood cultures and has the potential to contributing to optimal patient management by earlier detection of major antimicrobial resistance genes.
Disease Control and Prevention Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan; Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Masayoshi
M
Tojo
Department of Infectious Diseases, Tokyo Women's Medical University, Tokyo, Japan.
Takahiro
T
Fujita
Department of Infectious Diseases, Tokyo Women's Medical University, Tokyo, Japan.
Yusuke
Y
Ainoda
Disease Control and Prevention Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan; Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Maki
M
Nagamatsu
Disease Control and Prevention Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Kayoko
K
Hayakawa
Department of Clinical Laboratory, National Center for Global Health and Medicine, Tokyo, Japan.
Kazuhisa
K
Mezaki
Department of Pulmonary Medicine, Kohnodai Hospital, National Center for Global Health and Medicine, Chiba, Japan.
Aki
A
Sakurai
Department of Internal Medicine, Kohnodai Hospital, National Center for Global Health and Medicine, Chiba, Japan.
Yoshinori
Y
Masui
AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan.
Hirohisa
H
Yazaki
East-West Diagnostics/Theranostics, LLC, San Francisco, California, United States of America.
Hiroshi
H
Takahashi
Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Tohru
T
Miyoshi-Akiyama
Department of Infectious Diseases, Tokyo Women's Medical University, Tokyo, Japan.
Kyoichi
K
Totsuka
Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Teruo
T
Kirikae
Disease Control and Prevention Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Norio
N
Ohmagari
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D025202:Molecular Diagnostic Techniques / Q000379:methods*
D000900:Anti-Bacterial Agents