Sakanashi Daisuke, Kawachi Makoto, Uozumi Yuki, Nishio Mitsuru, Hara Yuki, Suematsu Hiroyuki, Hagihara Mao, Nishiyama Naoya, Asai Nobuhiro, Koizumi Yusuke, Yamagishi Yuka, Mikamo Hiroshige
Department of Infection Control and Prevention, Aichi Medical University Hospital, Aichi, Japan.
Department of Clinical Laboratory, Konan Kosei Hospital, Aichi, Japan.
J Infect Chemother. 2017 Jul;23(7):474-480. doi: 10.1016/j.jiac.2017.04.003. Epub 2017 Apr 26.
This study was designed to evaluate the sodium mercaptoacetic acid double disk synergy test (SMA-DDST), the Etest metallo-β-lactamase (MBL) MP/MPI (Etest MP/MPI), and the Mastdiscs ID Carbapenemase Detection Disc Set (MAST-CDS) for the detection of MBL-producing Enterobacteriaceae isolates in Japan.
Fifty-one clinical isolates and four reference strains were tested. These isolates included 40, 4, and 11 IMP-, New Delhi MBL (NDM)-, and non-MBL-producers, respectively. SMA-DDST was performed with meropenem (MEPM)-containing disks.
Sensitivities were 38/44 (86%), 40/44 (91%), and 15/44 (34%), and the cost ratio was 1:9.4:3.8 for MEPM-SMA-DDST:Etest MP/MPI:MAST-CDS, respectively. The specificity was 11/11 (100%) for all assays. MEPM-SMA-DDST detected IMP-producing isolates with high sensitivity (38/40; 95%), but the assay was inadequate for NDM-producing isolates (0/4; 0%). The Etest MP/MPI detected both IMP- (36/40; 90%) and NDM-producing isolates (4/4; 100%), but was the most expensive. MAST-CDS detected IMP-producing isolates with low sensitivity (11/40; 28%), but the assay worked well for NDM-producing isolates (4/4; 100%).
Our results indicated that MEPM-SMA-DDST was the most cost-effective assay for the detection of IMP-producing isolates. Therefore, we conclude that MEPM-SMA-DDST is the optimal available assay for clinical first-line screening in IMP-endemic areas such as Japan. However, this assay could not detect NDM-producing isolates, whereas the Etest MP/MPI and MAST-CDS could. When MEPM-SMA-DDST is negative, the Etest MP/MPI and MAST-CDS could be used to obtain supportive data and prevent detection failure for NDM-producing isolates.
本研究旨在评估巯基乙酸钠双纸片协同试验（SMA-DDST）、Etest金属β-内酰胺酶（MBL）MP/MPI（Etest MP/MPI）以及Mastdiscs ID碳青霉烯酶检测纸片组（MAST-CDS）用于检测日本产MBL的肠杆菌科分离株的效果。
对51株临床分离株和4株参考菌株进行检测。这些分离株分别包括40株产IMP、4株产新德里金属β-内酰胺酶（NDM）以及11株不产MBL的菌株。使用含美罗培南（MEPM）的纸片进行SMA-DDST。
MEPM-SMA-DDST、Etest MP/MPI和MAST-CDS的敏感性分别为38/44（86%）、40/44（91%）和15/44（3），成本比分别为1:9.4:3.8。所有检测方法的特异性均为11/11（100%）。MEPM-SMA-DDST对产IMP的分离株检测敏感性较高（38/40；95%），但对产NDM的分离株检测效果不佳（0/4；0%）。Etest MP/MPI对产IMP（36/40；90%）和产NDM的分离株（4/4；100%）均能检测，但成本最高。MAST-CDS对产IMP的分离株检测敏感性较低（11/40；28%），但对产NDM的分离株检测效果良好（4/4；100%）。
我们的结果表明，MEPM-SMA-DDST是检测产IMP分离株最具成本效益的检测方法。因此，我们得出结论，MEPM-SMA-DDST是日本等IMP流行地区临床一线筛查的最佳可用检测方法。然而，该检测方法无法检测出产NDM的分离株，而Etest MP/MPI和MAST-CDS可以。当MEPM-SMA-DDST为阴性时，可使用Etest MP/MPI和MAST-CDS获取支持性数据，防止产NDM分离株检测失败。
