Weissella confusa: problems with identification of an opportunistic pathogen that has been found in fermented foods

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Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS
06:34

Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS

Published on: July 11, 2016

17.1K

Marilynn R Fairfax1, Paul R Lephart2, Hossein Salimnia1

  • 1Department of Pathology, Wayne State University School of Medicine Detroit, MI, USA ; Clinical Microbiology Division, Detroit Medical Center University Laboratories Detroit, MI, USA.

Frontiers in Microbiology
|June 28, 2014
PubMed

Insights

Weissella confusa, a bacterium in fermented foods, can cause severe infections. Commercial identification systems often fail to detect it, potentially underestimating its role as a pathogen.

Area of Science:

  • Medical microbiology
  • Clinical diagnostics
  • Bacterial pathogenesis

Background:

  • Weissella confusa is present in fermented foods and explored as a probiotic.
  • This bacterium is also an opportunistic pathogen causing serious infections in humans and animals.
  • Underdiagnosis of W. confusa infections occurs due to misidentification with other bacteria and limitations in commercial identification systems.

Purpose of the Study:

  • To investigate the identification challenges of Weissella confusa in clinical settings.
  • To report clinical cases of sepsis caused by W. confusa in immunocompromised patients.
  • To evaluate the performance of different commercial identification systems for W. confusa.

Main Methods:

  • Isolation and identification of W. confusa from two immunocompromised patients with sepsis.
  • Testing identification by MicroScan gram-positive panels.
  • Evaluating the RapID™ Str panel (Remel) for W. confusa identification.
  • Confirmation using 16S rDNA sequencing and Maldi-Tof mass spectrometry.

Main Results:

  • MicroScan panels failed to identify W. confusa but did not provide false identifications.
  • The RapID™ Str panel yielded incorrect high-probability identifications for W. confusa.
  • 16S rDNA sequencing and Maldi-Tof correctly identified the isolates as W. confusa.

Conclusions:

  • Commercial identification systems exhibit limitations in accurately identifying Weissella confusa.
  • The potential of W. confusa as an opportunistic pathogen necessitates cautious use as a probiotic.
  • Accurate diagnostics are crucial for recognizing and managing W. confusa infections.
Keywords:
16S rDNA sequenceMALDI-TOF mass spectrometryWeissella confusa bacteremiaWeissella confusa identificationWeissella confusa susceptibiliy testing

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