García-Arata M I, Gerner-Smidt P, Baquero F, Ibrahim A
Department of Microbiology, Hospital Ramón y Cajal, Madrid.
Res Microbiol. 1997 Dec;148(9):777-84. doi: 10.1016/s0923-2508(97)82453-9.
The genus Acinetobacter is phenotypically rather homogeneous, but genotypically heterogeneous. In this study, a simple method based on restriction analysis of a PCR-amplified large fragment (4.5 kb) of most of the ribosomal operon (16S and 23S ribosomal genes and the spacer in-between) was investigated. Sixty-seven collection strains belonging to the 20 DNA groups proposed until 1993 were studied. Using the enzyme Sau3AI, 25 DNA profiles were obtained. Strains belonging to DNA groups 1, 3, 6, TU13 and TU15 showed two profiles each, and DNA groups 4, 5 and 7 showed profiles with variants showing less intensive additional bands. The remaining 12 groups showed 12 different profiles. The profiles obtained were DNA-group-specific except for one profile which was shared between the unnamed DNA group 3 and a rarely encountered genotypically related DNA group. These two DNA groups could be separated by using the enzyme Hinf1. Twenty-five additional clinical isolates previously characterized by standard DNA-DNA hybridization were selected in a double-blind fashion for identification at the DNA group level to check the reliability of the assay. All strains were correctly identified at the DNA group level. PCR-amplified 16S and 23S rDNA restriction analysis is both an accurate and rapid method for the identification of Acinetobacter at the DNA group level.
不动杆菌属在表型上相当一致，但在基因型上具有异质性。在本研究中，研究了一种基于对核糖体操纵子大部分区域（16S和23S核糖体基因及两者之间的间隔区）的PCR扩增大片段（4.5 kb）进行限制性分析的简单方法。对属于截至1993年提出的20个DNA组的67株收集菌株进行了研究。使用Sau3AI酶，获得了25种DNA图谱。属于DNA组1、3、6、TU13和TU15的菌株各显示两种图谱，DNA组4、5和7显示的图谱带有强度较低的额外条带变体。其余12个组显示出12种不同的图谱。除了未命名的DNA组3和一个很少遇到的基因型相关DNA组共有一种图谱外，所获得的图谱具有DNA组特异性。使用Hinf1酶可将这两个DNA组区分开。以双盲方式选择了另外25株先前通过标准DNA-DNA杂交鉴定的临床分离株，用于DNA组水平的鉴定，以检验该检测方法的可靠性。所有菌株在DNA组水平上均被正确鉴定。PCR扩增的16S和23S rDNA限制性分析是在DNA组水平上鉴定不动杆菌的一种准确且快速的方法。
