Blanking on blanks: few insect microbiota studies control for contaminants

ABSTRACT Research on insect-microbe relationships is booming, with DNA sequencing being the most commonly used method to describe insect microbiota. However, sequencing is vulnerable to contamination, especially when the sample has low microbial biomass. Such low-biomass samples are common across in...

Full description

Saved in:
Bibliographic Details
Main Authors: Elisabeth M. Williamson, Tobin J. Hammer, Katja Hogendoorn, Raphael Eisenhofer
Format: Article
Language:English
Published: American Society for Microbiology 2025-04-01
Series:mBio
Subjects:
Online Access:https://journals.asm.org/doi/10.1128/mbio.02658-24
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850185450201808896
author Elisabeth M. Williamson
Tobin J. Hammer
Katja Hogendoorn
Raphael Eisenhofer
author_facet Elisabeth M. Williamson
Tobin J. Hammer
Katja Hogendoorn
Raphael Eisenhofer
author_sort Elisabeth M. Williamson
collection DOAJ
description ABSTRACT Research on insect-microbe relationships is booming, with DNA sequencing being the most commonly used method to describe insect microbiota. However, sequencing is vulnerable to contamination, especially when the sample has low microbial biomass. Such low-biomass samples are common across insect taxa, developmental stages, and tissue types. Identifying putative contaminants is essential to distinguish between true microbiota and introduced contaminant DNA. It is therefore important that studies control for contamination, but how often this is done is unknown. To investigate the status quo of contamination control, we undertook a systematic literature review to quantify the prevalence of negative control usage and contamination control across the literature on insect microbiota (specifically bacterial communities) over a 10 year period. Two-thirds of the 243 insect microbiota studies evaluated had not included blanks (negative controls), and only 13.6% of the studies sequenced these blanks and controlled for contamination in their samples. Our findings highlight a major lack of contamination control in the field of insect microbiota research. This result suggests that a number of microbes reported in the literature may be contaminants as opposed to insect-associated microbiota and that more rigorous contamination control is needed to improve research reliability, validity, and reproducibility. Based on our findings, we recommend the previously developed guidelines outlined in the RIDE checklist, with the addition of one more guideline. We refer to this as the RIDES checklist, which stands for Report methodology, Include negative controls, Determine the level of contamination, Explore contamination downstream, and State the amount of off-target amplification.IMPORTANCEOur systematic review reveals a major lack of methodological rigor within the field of research on insect-associated microbiota. The small percentage of studies that control for contamination suggests that an unknown but potentially considerable number of bacteria reported in the literature could be contaminants. The implication of this finding is that true microbiota may be masked or misrepresented, especially in insects with low microbial biomass.
format Article
id doaj-art-99f7a5c346da49bd937ef3421e62d9bc
institution OA Journals
issn 2150-7511
language English
publishDate 2025-04-01
publisher American Society for Microbiology
record_format Article
series mBio
spelling doaj-art-99f7a5c346da49bd937ef3421e62d9bc2025-08-20T02:16:44ZengAmerican Society for MicrobiologymBio2150-75112025-04-0116410.1128/mbio.02658-24Blanking on blanks: few insect microbiota studies control for contaminantsElisabeth M. Williamson0Tobin J. Hammer1Katja Hogendoorn2Raphael Eisenhofer3School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, AustraliaDepartment of Ecology and Evolutionary Biology, University of California, Irvine, California, USASchool of Agriculture, Food and Wine, The University of Adelaide, Adelaide, AustraliaCentre for Evolutionary Hologenomics, Globe Institute, The University of Copenhagen, Copenhagen, DenmarkABSTRACT Research on insect-microbe relationships is booming, with DNA sequencing being the most commonly used method to describe insect microbiota. However, sequencing is vulnerable to contamination, especially when the sample has low microbial biomass. Such low-biomass samples are common across insect taxa, developmental stages, and tissue types. Identifying putative contaminants is essential to distinguish between true microbiota and introduced contaminant DNA. It is therefore important that studies control for contamination, but how often this is done is unknown. To investigate the status quo of contamination control, we undertook a systematic literature review to quantify the prevalence of negative control usage and contamination control across the literature on insect microbiota (specifically bacterial communities) over a 10 year period. Two-thirds of the 243 insect microbiota studies evaluated had not included blanks (negative controls), and only 13.6% of the studies sequenced these blanks and controlled for contamination in their samples. Our findings highlight a major lack of contamination control in the field of insect microbiota research. This result suggests that a number of microbes reported in the literature may be contaminants as opposed to insect-associated microbiota and that more rigorous contamination control is needed to improve research reliability, validity, and reproducibility. Based on our findings, we recommend the previously developed guidelines outlined in the RIDE checklist, with the addition of one more guideline. We refer to this as the RIDES checklist, which stands for Report methodology, Include negative controls, Determine the level of contamination, Explore contamination downstream, and State the amount of off-target amplification.IMPORTANCEOur systematic review reveals a major lack of methodological rigor within the field of research on insect-associated microbiota. The small percentage of studies that control for contamination suggests that an unknown but potentially considerable number of bacteria reported in the literature could be contaminants. The implication of this finding is that true microbiota may be masked or misrepresented, especially in insects with low microbial biomass.https://journals.asm.org/doi/10.1128/mbio.02658-24microbiomesymbiontsbacteriakitome16Scontamination
spellingShingle Elisabeth M. Williamson
Tobin J. Hammer
Katja Hogendoorn
Raphael Eisenhofer
Blanking on blanks: few insect microbiota studies control for contaminants
mBio
microbiome
symbionts
bacteria
kitome
16S
contamination
title Blanking on blanks: few insect microbiota studies control for contaminants
title_full Blanking on blanks: few insect microbiota studies control for contaminants
title_fullStr Blanking on blanks: few insect microbiota studies control for contaminants
title_full_unstemmed Blanking on blanks: few insect microbiota studies control for contaminants
title_short Blanking on blanks: few insect microbiota studies control for contaminants
title_sort blanking on blanks few insect microbiota studies control for contaminants
topic microbiome
symbionts
bacteria
kitome
16S
contamination
url https://journals.asm.org/doi/10.1128/mbio.02658-24
work_keys_str_mv AT elisabethmwilliamson blankingonblanksfewinsectmicrobiotastudiescontrolforcontaminants
AT tobinjhammer blankingonblanksfewinsectmicrobiotastudiescontrolforcontaminants
AT katjahogendoorn blankingonblanksfewinsectmicrobiotastudiescontrolforcontaminants
AT raphaeleisenhofer blankingonblanksfewinsectmicrobiotastudiescontrolforcontaminants