Clinical Study
Saccharomyces boulardii probiotic-associated fungemia: questioning the safety of this preventive probiotic's use

https://doi.org/10.1016/j.diagmicrobio.2016.12.004Get rights and content

Highlights

  • Documenting a fungemia case in an immunocompetent patient after administration of probiotic.

  • Concluding the Saccharomyces yeast causing the patient bloodstream infection was indeed from the probiotic capsule.

  • Demonstrating the usefulness and feasibility of the two commercial-available strain-typing methods: DivsersiLab and MALDI-TOF MS.

  • Questioning the safety of this preventative biotherapy in clinical use.

Abstract

We report a case of fungemia in an immunocompetent patient after administration of probiotic containing Saccharomyces boulardii. We demonstrated the strain relatedness of the yeast from the probiotic capsule and the yeast causing fungal infection using genomic and proteomic typing methods. Our study questions the safety of this preventative biotherapy.

Section snippets

Case Summary

A 60-year-old man with a history of hyperlipidemia, paraplegia due to a remote motor vehicle accident, methicillin-resistant Staphylococcus aureus (MRSA) cellulitis, and recurrent urinary tract infections (UTIs) presented to the Emergency Department with abdominal pain. The status of the patient's gastrointestinal tract (GI), evidence of bowel obstruction or GI bleeding, evidence of diverticular disease, and record of colorectal cancer screening are not stated in his chart. He was found to be

Methods

A Florastor probiotic capsule was sent to the medical mycology laboratory for comparison of its contents with the patient's Saccharomyces cerevisiae blood isolate. Both isolates were grown on Sabouraud agar for initial identification. Macroscopic and microscopic examination were performed as well as gene sequencing of the ITS region and the D1/D2 region of the 28S ribosome (Applied Biosystems, Foster City, CA). Strain comparison was then performed using two methods: genetic analysis with the

Results

Both the probiotic isolate and the patient blood isolate were morphologically identical and sequence-identified as S. cerevisiae by ITS and D1/D2 ribosomal DNA sequencing with 100% sequence homology.

The DiversiLab® software-generated report (assay time ~ 4 hours) showed an overall similarity of greater than 95% between the probiotic and patient blood isolates. There was also an overall relatedness, albeit less strong to the 3 other clinical samples included (Fig. 1A).

Similarly, the dendrogram

Discussion

Fungemia is an unusual complication of probiotic use for which patients with CVC are known to be at increased risk. (Hempel et al., 2011) Indeed, Florastor's package insert lists the presence of a CVC line as a contraindication for use. Although this patient's CVC placed him at increased risk of developing fungemia, it remains unclear whether this case represents line colonization or true infection with S. cerevisiae. However, the time of blood culture draw correlated with a worsening of the

Acknowledgements

Financial support: None.

Potential conflicts of interest: All authors report no conflicts of interest relevant to this article.

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Authors contributed equally to this work.

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