Division of Clinical Microbiology, HUSLAB, Helsinki University Hospital, Finland.
Clin Microbiol Infect. 2011 Feb;17(2):166-75. doi: 10.1111/j.1469-0691.2010.03221.x.
Clostridium difficile infection is most often induced by antibiotic treatment. Recently, morbidity and mortality resulting especially from C. difficile PCR ribotype 027 have increased significantly. In addition, more severe disease has been associated with C. difficile PCR ribotype 078 strains. Thus, reliable typing methods for epidemic control are needed. In the present study, we compared an automated repetitive extragenic palindromic sequence-based PCR (rep-PCR) method (DiversiLab; Bacterial Barcodes, Inc., Athens, GA, USA) to PCR ribotyping and pulsed-field gel electrophoresis (PFGE) typing using 205 isolates of C. difficile (including 24 previously characterized isolates). Among the 181 clinical isolates, a total of 31 different PCR ribotypes, 38 different PFGE types and subtypes and 28 different rep-PCR types were found. Six major rep-PCR groups (DL1-DL6) harboured 86% of the clinical isolates. All isolates belonging to PCR ribotypes 027 and 001 clustered in their own rep-PCR groups, enabling us to screen out the hypervirulent ribotype 027 strain. Within the PCR ribotype 001, four subgroups were found using rep-PCR. Overall, in 75% (135/181) of the isolates, the classification attributed following rep-PCR and PCR ribotyping was comparable. In conclusion, the automated rep-PCR-based typing method represents an option for first-line molecular typing in local clinical microbiology laboratories. The method was easy to use as well as rapid, requiring less hands-on time than PCR ribotyping or PFGE typing. The conventional PCR ribotyping or PFGE, however, are needed for confirmatory molecular epidemiology. In addition, more epidemiology-oriented studies are needed to examine the discriminatory power of automated rep-PCR with isolates collected from a larger geographical area and during a longer period of time.
艰难梭菌感染通常由抗生素治疗引起。最近，尤其是由艰难梭菌 PCR 核糖型 027 引起的发病率和死亡率显著增加。此外，更严重的疾病与艰难梭菌 PCR 核糖型 078 株有关。因此，需要可靠的用于流行控制的分型方法。在本研究中，我们比较了自动化重复外基因回文序列基序 PCR（rep-PCR）方法（DiversiLab；细菌条码公司，美国佐治亚州雅典）与 PCR 核糖分型和脉冲场凝胶电泳（PFGE）分型，使用了 205 株艰难梭菌（包括 24 株先前表征的菌株）。在 181 株临床分离株中，共发现了 31 种不同的 PCR 核糖型、38 种不同的 PFGE 型和亚型以及 28 种不同的 rep-PCR 型。6 个主要的 rep-PCR 组（DL1-DL6）包含了 86%的临床分离株。所有属于 PCR 核糖型 027 和 001 的分离株都聚集在自己的 rep-PCR 组中，使我们能够筛选出高毒力的核糖型 027 株。在 PCR 核糖型 001 中，通过 rep-PCR 发现了 4 个亚组。总体而言，在 75%（135/181）的分离株中，基于 rep-PCR 和 PCR 核糖分型的分类是可比的。总之，自动化基于 rep-PCR 的分型方法是当地临床微生物学实验室一线分子分型的一种选择。该方法易于使用，并且快速，与 PCR 核糖分型或 PFGE 分型相比，所需的手工时间更少。然而，对于确证分子流行病学，需要常规的 PCR 核糖分型或 PFGE。此外，需要进行更多以流行病学为导向的研究，以检查在更大地理区域和更长时间内收集的分离株的自动化 rep-PCR 的区分能力。
