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Updated: Mar 8, 2026
Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing
Published on: October 15, 2019
Cerebrospinal Fluid in a Small Cohort of Patients with Multiple Sclerosis Was Generally Free of Microbial DNA
Juan Jovel1, Sandra O'keefe1, Jordan Patterson1
1Department of Medicine, University of Alberta Edmonton, AB, Canada.
Abstract:
Multiple sclerosis (MS) is a common cause of non-traumatic neurologic disability with high incidence in many developed countries. Although the etiology of the disease remains elusive, it is thought to entail genetic and environmental causes, and microbial pathogens have also been envisioned as contributors to the phenotype. We conducted a metagenomic survey in cerebrospinal fluid (CSF) from 28 MS patients and 15 patients suffering other type of neurological conditions. We detected bacterial reads in eight out of the 15 non-MS patients and in a single MS patient, at an abundance >1% of total classified reads. Two patients were of special interest: one non-MS patient harbored ~73% bacterial reads, while an MS patient had ~83% bacterial reads. In the former case, Veillonella parvula, a bacterium occasionally found associated with meningitis was the predominant species, whilst Kocuria flava, apparently an environmental bacterium, predominated in the latter case. Thirty-four out of 43 samples contained <1% bacterial reads, which we regard as cross- or environmental contamination. A few viral reads corresponding to Epstein-Barr virus, cytomegalovirus, and parvovirus were also identified. Our results suggest that CSF of MS patients is often (but not always) free of microbial DNA.
Insights
This study investigated microbial DNA in cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. Results indicate that MS patients
Area of Science:
- Neurology
- Microbiology
- Immunology
Background:
- Multiple sclerosis (MS) is a significant cause of non-traumatic neurologic disability.
- The etiology of MS is complex, involving genetic and environmental factors, with potential contributions from microbial pathogens.
- Understanding the role of microbes in neurological conditions like MS is crucial for developing effective treatments.
Purpose of the Study:
- To conduct a metagenomic survey of cerebrospinal fluid (CSF) from MS patients and patients with other neurological conditions.
- To identify and quantify bacterial and viral DNA in CSF samples.
- To explore potential correlations between microbial presence and MS.
Main Methods:
- Metagenomic sequencing of CSF samples from 28 MS patients and 15 patients with other neurological conditions.
- Bioinformatic analysis to identify and classify bacterial and viral reads.
- Quantification of microbial DNA abundance relative to total classified reads.
Main Results:
- Bacterial DNA was detected at >1% abundance in only one MS patient and eight non-MS patients.
- Two patients, one MS and one non-MS, showed exceptionally high bacterial loads (approx. 83% and 73%, respectively), dominated by *Kocuria flava* and *Veillonella parvula*.
- Viral reads (Epstein-Barr virus, cytomegalovirus, parvovirus) were also identified in a subset of samples.
Conclusions:
- The cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients is frequently devoid of detectable microbial DNA.
- The presence of specific bacteria like *Veillonella parvula* and *Kocuria flava* in CSF requires further investigation.
- These findings suggest that microbial involvement in MS may not be consistently detectable via metagenomic analysis of CSF.
