Ultrasmall epibiont Nanosynbacter lyticus strain TM7x and host bacteria transcriptional activity after initial host parasitism

ABSTRACT

Background

Oral Saccharibacteria Nanosynbacter lyticus strain TM7× lives as an ultrasmall epibiont on the surface of its host, Schaalia odontolytica strain XH001. Establishing this interaction is a poorly understood multi-step process. The recovery phase marks a shift in the TM7×/host interaction, switching from the early killing phase, with extensive host cell death, to a stable symbiosis phase where the host and epibiont can grow together.

Results

Transcriptomes of TM7× and host, XH001, were captured during the recovery phase and compared to uninfected host and the early host/epibiont interaction (initial encounter). XH001 showed increased expression for rhamnose cell wall components and for the precursor to peptidoglycan while TM7× showed increases in the peptidoglycan pathway. Transporter expression was generally increased for both organisms during recovery compared to the initial encounter, though, XH001 showed lower amino acid transporter expression. Consistent with host parasitism, XH001 showed increased expression of various stress-related genes during recovery while TM7× showed reduced stress. TM7× displayed higher expression of type IV pili, consistent with increased attachment to new hosts.

Conclusion

As TM7× is a member of the broadly distributed Candidate Phyla Radiation with small genomes lacking numerous biosynthetic pathways, this study provides further insights into how these epibionts interact and modulate their host bacteria.

KEYWORDS:

• Transcriptome
• RNAseq
• oral
• Saccharibacteria
• epibiont
• parasitism

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Author contributions statement

E. Hendrickson contributed to conception, design, data acquisition and interpretation, drafted and carefully revised the manuscript; BBor contributed to conception, design, data acquisition and interpretation, and critically revised the manuscript; K Kerns contributed to data acquisition and interpretation, performed statistical analyses, and critically revised the manuscript; L Cen contributed to data acquisition; W Shi contributed to data interpretation and critically revised the manuscript; X He contributed to conception, design, and critically revised the manuscript; J McLean contributed to conception, design and interpretation, drafted and carefully revised the manuscript. All authors had access to the study data and reviewed and approved the final manuscript.

Data availability statement

The data discussed in this publication have been deposited in NCBI’s Gene Expression Omnibus [22] and are accessible through GEO Series accession number GSE196744 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE196744). Supplemental tables at (https://github.com/mcleanlab/TM7x_Host_Association_Study).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/20002297.2023.2287349

Additional information

Funding

This research was supported by grants from the National Institute of Dental and Craniofacial Research of the National Institutes of Health under Awards K99DE027719–01 (BB); KL2TR000421 (KAK); R01DE023810 (XH, WS and JSM); R21DE032890 (JSM).