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Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291
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Published on: December 10, 2016

Pseudomembranous colitis caused by toxin A-negative/toxin B-positive variant strain of Clostridium difficile

Masahiro Toyokawa1, Akiko Ueda, Hisako Tsukamoto

  • 1Laboratory for Clinical Investigation, Osaka University Hospital, Osaka University, 2-15 Yamadaoka, Suita, 565-0871 Osaka, Japan. toyokawa@hp-lab.med.osaka-u.ac.jp

Journal of Infection and Chemotherapy : Official Journal of the Japan Society of Chemotherapy
|December 24, 2003
PubMed

Insights

A new Clostridium difficile strain causing pseudomembranous colitis (PMC) was found in Japan. This toxin A-negative, toxin B-positive strain is missed by standard toxin A tests, requiring PCR for accurate diagnosis.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Gastroenterology

Background:

  • Clostridium difficile is a common cause of antibiotic-associated diarrhea and colitis.
  • Pseudomembranous colitis (PMC) is a severe form of C. difficile infection.
  • Current diagnostic methods primarily rely on detecting C. difficile toxins.

Observation:

  • A case of PMC in Japan was caused by a novel strain of C. difficile.
  • This strain was characterized as toxin A-negative and toxin B-positive, referred to as a toxin A variant strain.
  • The patient presented with symptoms consistent with PMC.

Findings:

  • The identified C. difficile toxin A variant strain is capable of causing PMC.
  • Standard clinical laboratory immunoassays detecting only toxin A fail to identify this specific strain.
  • This highlights a limitation in current diagnostic approaches for C. difficile infections.

Implications:

  • Clinical laboratories using toxin A immunoassays may miss cases caused by this variant strain.
  • Healthcare providers should consider the possibility of toxin A variant strains if C. difficile-associated diarrhea is suspected but toxin A is negative.
  • Further diagnostic testing, such as polymerase chain reaction (PCR) for C. difficile toxin genes, is recommended for definitive diagnosis in such cases.

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