背景:快速准确的微生物鉴定和抗菌药物敏感性测试(AST)对于及时使用适当的抗菌药物治疗血流感染至关重要。为了缩短从阳性血培养物中分离菌落的时间,开发了使用基质辅助激光解吸/电离飞行时间质谱(MALDI-TOFMS)系统直接鉴定的各种制备方法。这里,我们评估了SepsiPrep套件(ASTACorp.)用于使用MicroIDSysEliteMALDI-TOFMS系统从阳性血液培养物中直接鉴定微生物和AST(ASTACorp.)和VITEK-2系统(bioMérieux)。
方法:对于直接识别,共纳入124个前瞻性单抗微生物阳性血液培养瓶.为了直接识别,通过离心和洗涤两次制备沉淀。对于直接AST,将沉淀悬浮在0.45%盐水中并调节至McFarland0.5。将使用MicroIDSysElite和VITEK-2系统直接鉴定和AST的结果与在琼脂平板上继代培养的纯菌落进行的常规方法的结果进行了比较。
结果:与使用纯菌落的常规方法相比,57株革兰氏阳性菌株和67株革兰氏阴性菌株的正确率分别为96.5%和98.5%,分别。对于直接AST,在55株革兰氏阳性菌株中,葡萄球菌的分类协议(CA),链球菌,肠球菌占96.7%,98.4%,94.1%,分别。对于66个革兰氏阴性分离株,肠杆菌和非发酵革兰阴性杆菌的CA分别为99.0%和96.6%,分别。
结论:SepsiPrep试剂盒易于与MicroIDSysElite和VITEK-2系统结合使用,正确的鉴定和AST率很高。
BACKGROUND: Rapid and accurate microbial identification and antimicrobial susceptibility testing (AST) are essential for timely use of appropriate antimicrobial agents for bloodstream infection. To shorten the time for isolating colonies from the positive blood culture, various preparation methods for direct identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system were developed. Here, we evaluated the
SepsiPrep kit (ASTA Corp.) for direct identification of microorganisms and AST from positive blood cultures using MicroIDSys Elite MALDI-TOF MS system (ASTA Corp.) and VITEK-2 system (bioMérieux).
METHODS: For direct identification, a total of 124 prospective monomicrobial positive blood culture bottles were included. For direct identification, the pellet was prepared by centrifugation and washing twice. For direct AST, the pellet was suspended in 0.45% saline and adjusted to McFarland 0.5. The results from the direct identification and AST using MicroIDSys Elite and VITEK-2 system were compared to those from the conventional method performed with pure colony subcultured on agar plate.
RESULTS: Compared to the conventional method using pure colony, correct direct identification rate was 96.5% and 98.5% for 57 gram-positive isolates and 67 gram-negative isolates, respectively. For direct AST, among the 55 gram-positive isolates, the categorical agreement (CA) for staphylococci, streptococci, and enterococci was 96.7%, 98.4%, and 94.1%, respectively. For 66 gram-negative isolates, the CA for Enterobacterales and non-fermentative gram-negative rods was 99.0% and 96.6%, respectively.
CONCLUSIONS: The
SepsiPrep kit was easy to use combined with MicroIDSys Elite and VITEK-2 system and also, the correct identification and AST rate were very high.