The Role of Glutamate Dehydrogenase (GDH) Testing Assay in the Diagnosis of Clostridium difficile Infections: A High Sensitive Screening Test and an Essential Step in the Proposed Laboratory Diagnosis Workflow for Developing Countries like China

PLoS One. 2015 Dec 11;10(12):e0144604. doi: 10.1371/journal.pone.0144604. eCollection 2015.

Abstract

The incidence and severity of Clostridium difficile infection (CDI) in North America and Europe has increased significantly since the 2000s. However, CDI is not widely recognized in China and other developing countries due to limited laboratory diagnostic capacity and low awareness. Most published studies on laboratory workflows for CDI diagnosis are from developed countries, and thus may not be suitable for most developing countries. Therefore, an alternative strategy for developing countries is needed. In this study, we evaluated the performance of the Glutamate Dehydrogenase (GDH) test and its associated workflow on 416 fecal specimens from suspected CDI cases. The assay exhibited excellent sensitivity (100.0%) and specificity (92.8%), compared to culture based method, and thus could be a good screening marker for C. difficile but not for indication of toxin production. The VIDAS CDAB assay, which can detect toxin A/B directly from fecal specimens, showed good specificity (99.7%) and positive predictive value (97.2%), but low sensitivity (45.0%) and negative predictive value (88.3%), compared with PCR-based toxin gene detection. Therefore, we propose a practical and efficient GDH test based workflow strategy for the laboratory diagnosis of CDI in developing countries like China. By applying this new workflow, the CDI laboratory diagnosis rate was notably improved in our center, yet the increasing cost was kept at a minimum level. Furthermore, to gain some insights into the genetic population structure of C. difficile isolates from our hospital, we performed MLST and PCR toxin gene typing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bacterial Proteins / analysis*
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Toxins / analysis*
  • Bacterial Toxins / biosynthesis
  • Bacterial Typing Techniques / methods*
  • Bacterial Typing Techniques / standards
  • Biological Assay*
  • Child
  • Child, Preschool
  • China
  • Clostridioides difficile / genetics
  • Clostridioides difficile / isolation & purification*
  • Clostridioides difficile / metabolism
  • Developing Countries
  • Enterocolitis, Pseudomembranous / diagnosis*
  • Enterocolitis, Pseudomembranous / microbiology
  • Feces / microbiology
  • Female
  • Glutamate Dehydrogenase / analysis*
  • Glutamate Dehydrogenase / biosynthesis
  • Glutamate Dehydrogenase / genetics
  • Humans
  • Male
  • Middle Aged
  • Multilocus Sequence Typing
  • Polymerase Chain Reaction
  • Sensitivity and Specificity

Substances

  • Bacterial Proteins
  • Bacterial Toxins
  • Glutamate Dehydrogenase

Grants and funding

This study was financially supported by a National Natural Science Foundation of China (grant number 81501807) and National Research Special Fund for Public Welfare Industry of Health of China (grant number 201402001). Website: http://www.nhfpc.gov.cn/zwgkzt/pkjjy1/201302/9cb220c8a5704c0a9ebf5ef65a337544.shtml. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.