TY - JOUR AU - Wally, N. AU - Schneider, M. AU - Thannesberger, J. AU - Kastner, M. T. AU - Bakonyi, T. AU - Indik, S. AU - Rattei, T. AU - Bedarf, J. AU - Hildebrand, F. AU - Law, J. AU - Jovel, J. AU - Steininger, C. TI - Plasmid DNA contaminant in molecular reagents. JO - Scientific reports VL - 9 IS - 1 SN - 2045-2322 CY - [London] PB - Macmillan Publishers Limited, part of Springer Nature M1 - DZNE-2020-06797 SP - 1652 PY - 2019 AB - Background noise in metagenomic studies is often of high importance and its removal requires extensive post-analytic, bioinformatics filtering. This is relevant as significant signals may be lost due to a low signal-to-noise ratio. The presence of plasmid residues, that are frequently present in reagents as contaminants, has not been investigated so far, but may pose a substantial bias. Here we show that plasmid sequences from different sources are omnipresent in molecular biology reagents. Using a metagenomic approach, we identified the presence of the (pol) of equine infectious anemia virus in human samples and traced it back to the expression plasmid used for generation of a commercial reverse transcriptase. We found fragments of multiple other expression plasmids in human samples as well as commercial polymerase preparations. Plasmid contamination sources included production chain of molecular biology reagents as well as contamination of reagents from environment or human handling of samples and reagents. Retrospective analyses of published metagenomic studies revealed an inaccurate signal-to-noise differentiation. Hence, the plasmid sequences that seem to be omnipresent in molecular biology reagents may misguide conclusions derived from genomic/metagenomics datasets and thus also clinical interpretations. Critical appraisal of metagenomic data sets for the possibility of plasmid background noise is required to identify reliable and significant signals. KW - Computational Biology KW - DNA Contamination KW - DNA, Viral: analysis KW - DNA, Viral: genetics KW - Diagnostic Errors: prevention & control KW - Genes, pol: genetics KW - High-Throughput Nucleotide Sequencing KW - Humans KW - Indicators and Reagents: analysis KW - Infectious Anemia Virus, Equine: genetics KW - Metagenomics KW - Plasmids: analysis KW - Plasmids: genetics KW - Retrospective Studies KW - Sequence Analysis, DNA: methods LB - PUB:(DE-HGF)16 C6 - pmid:30733546 C2 - pmc:PMC6367390 DO - DOI:10.1038/s41598-019-38733-1 UR - https://pub.dzne.de/record/140475 ER -