The performance of the BD geneOhm MRSA™ assay for MRSA isolated from clinical patients in Japan, including the effects of specimen contamination and ways to improve it.
The BD geneOhm MRSA™ assay has been increasingly used in recent years, and it is possible to use it to screen and detect methicillin-resistant Staphylococcus aureus (MRSA) from a specimen within 2 h. The purpose of the present study was to evaluate the performance, i.e., the specificity and sensitivity, of the BD geneOhm MRSA™ assay to detect MRSA. Its specificity was assessed to be 100% compared to bacterial culture methods, which are commonly used in medical laboratories. Its bacterial limit of detection was over 10 colony-forming units (cfu) per reaction, although MRSA was detected at a cfu below 10 per reaction in a few samples. Additionally, the effect of MRSA isolate contamination was examined. While contamination with protein or other bacteria did not affect the outcome, contamination with a high concentration of blood resulted in an unresolved outcome. To inactivate polymerase chain reaction (PCR) inhibitors, the DNA samples were freeze-thawed prior to the BD geneOhm MRSA™ assay, which led to the sensitivity of the assay increasing. In summary, the BD geneOhm MRSA™ assay is rapid and shows high specificity and sensitivity of cultured MRSA isolates. It will, therefore, be a valuable diagnostic tool for detecting MRSA in specimens from clinical patients.
Ishikawa
Hiroki
H
Department of Microbiology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan. hiroki01@tokyo-med.ac.jp
Kutsukake
Etsuko
E
Chiba
Katsumi
K
Fukui
Toshie
T
Matsumoto
Tetsuya
T
D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D004340:Drug Contamination; D006801:Humans; D007564:Japan; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology
D003470:Culture Media; D004269:DNA, Bacterial; D011933:Reagent Kits, Diagnostic