[Is BC-GN applicable for analysis of strains and urine/sputum specimens?]

Abstract

As the reagent that can simultaneously detect bacterial nucleic acid/drug-resistant genes from the culture-positive liquid of blood cultures, Verigene^® system includes the Verigene^® Gram-Positive Blood Culture test (BC-GP) and the Verigene^® Gram Negative Blood Culture test (BC-GN). This study used BC-GN to identify the names of bacteria from stock strains, urine samples, and sputum specimens and detect drug-resistant genes. The stock strains included 28 clinical isolates, 9 urine samples in which the target bacterial strain grew to 106CFU/ml or more in culture, and 9 sputum specimens in which the target bacterial strain grew to 105CFU/ml or more in culture. The bacterial identification and detection of drug-resistant genes used quality Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) analysis and conventional PCR method, respectively, followed in comparison with the results of Verigene^®. As a result, the measurement results of Verigene^® for the stock strains and urine samples had a high concordance rate with MALDI-TOF MS analysis and PCR method. On the other hand, the concordance rate of the sputum specimens with the Verigene^® measurement results was only 40% (4 out of 10 specimens). These results suggest that BC‒GN can be an effective tool for AMR rapid diagnosis if the measurement target includes not only bacterial strains in the culture-positive liquid of blood cultures, but also other bacterial strains and urine.