Linking plasmid-based beta-lactamases to their bacterial hosts using single-cell fusion PCR
Abstract
The horizonal transfer of plasmid-encoded genes allows bacteria to adapt to constantly shifting environmental pressures, bestowing functional advantages to their bacterial hosts such as antibiotic resistance, metal resistance, virulence factors, and polysaccharide utilization. However, common molecular methods such as short- and long-read sequencing of microbiomes cannot associate extrachromosomal plasmids with the genome of the host bacterium. Alternative methods to link plasmids to host bacteria are either laborious, expensive or prone to contamination. Here we present the One-step Isolation and Lysis PCR (OIL-PCR) method, which molecularly links plasmid encoded genes with the bacterial 16S rRNA gene via fusion PCR performed within an emulsion. After validating this method, we apply it to identify the bacterial hosts of three clinically relevant beta-lactamases within the gut microbiomes of neutropenic patients, as they are particularly vulnerable multidrug-resistant infections. We successfully detect the known association of a multi-drug resistant plasmid with Klebsiella pneumoniae, as well as the novel associations of two low-abundance genera, Romboutsia and Agathobacter. Further investigation with OIL-PCR confirmed that our detection of Romboutsia is due to its physical association with Klebsiella as opposed to directly harboring the genes. Here we put forth a robust, accessible, and high-throughput platform for sensitively surveying the bacterial hosts of mobile genes, as well as detecting physical bacterial associations such as those occurring within biofilms and complex microbial communities.
Data availability
All fusion PCR amplicons are deposited in SRA under the accession number PRJNA701446. The metagenomic samples analyzed can be obtained through SRA with under the accession number PRJNA649316.
Article and author information
Author details
Funding
Centers for Disease Control and Prevention (OADS BAA 2016-N-17812)
- Michael J Satlin
- Ilana Brito
National Science Foundation (1661338)
- Ilana Brito
National Science Foundation (1650122)
- Ilana Brito
National Institutes of Health (K23 AI114994)
- Michael J Satlin
National Institutes of Health (1DP2HL141007-01)
- Ilana Brito
Pew Charitable Trusts
- Ilana Brito
Alfred P. Sloan Foundation
- Ilana Brito
David and Lucile Packard Foundation
- Ilana Brito
State University of New York
- Felicia N New
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: All human subjects research was approved by the Weill Cornell Medicine IRB (#1504016114) and Cornell University IRB (#1609006586). Informed consent and consent to publish were obtained from individuals receiving a hematopoietic stem cell transplant at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. Serial stool samples were obtained from consenting patients. Consent documents and procedures were approved by the Institutional Review Boards at Weill Cornell Medical College (#1504016114) and Cornell University (#1609006586).
Reviewing Editor
- Sophie Helaine, Harvard Medical School, United States
Publication history
- Received: January 22, 2021
- Preprint posted: January 23, 2021 (view preprint)
- Accepted: June 30, 2021
- Accepted Manuscript published: July 20, 2021 (version 1)
- Version of Record published: July 21, 2021 (version 2)
Copyright
© 2021, Diebold et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,803
- Page views
-
- 209
- Downloads
-
- 5
- Citations
Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Chromosomes and Gene Expression
- Genetics and Genomics
Heart development and rhythm control are highly Tbx5 dosage-sensitive. TBX5 haploinsufficiency causes congenital conduction disorders, whereas increased expression levels of TBX5 in human heart samples has been associated with atrial fibrillation (AF). We deleted the conserved mouse orthologues of two independent AF-associated genomic regions in the Tbx5 locus, one intronic (RE(int)) and one downstream (RE(down)) of Tbx5. In both lines we observed a modest (30%) increase of Tbx5 in the postnatal atria. To gain insight into the effects of slight dosage increase in vivo, we investigated the atrial transcriptional, epigenetic and electrophysiological properties of both lines. Increased atrial Tbx5 expression was associated with induction of genes involved in development, ion transport and conduction, with increased susceptibility to atrial arrhythmias, and increased action potential duration of atrial cardiomyocytes. We identified an AF-associated variant in the human RE(int) that increases its transcriptional activity. Expression of the AF-associated transcription factor Prrx1 was induced in Tbx5RE(int)KO cardiomyocytes. We found that some of the transcriptional and functional changes in the atria caused by increased Tbx5 expression were normalized when reducing cardiac Prrx1 expression in Tbx5RE(int)KO mice, indicating an interaction between these two AF genes. We conclude that modest increases in expression of dose-dependent transcription factors, caused by common regulatory variants, significantly impact on the cardiac gene regulatory network and disease susceptibility.
-
- Genetics and Genomics
- Microbiology and Infectious Disease
Adaptation to fluctuating environmental conditions is difficult to achieve. Phase variation mechanisms can overcome this difficulty by altering genomic architecture in a subset of individuals, creating a phenotypically heterogeneous population with subpopulations optimized to persist when conditions change, or are encountered, suddenly. We have identified a phase variation system in Burkholderia thailandensis that generates a genotypically and phenotypically heterogeneous population. Genetic analyses revealed that RecA-mediated homologous recombination between a pair of insertion sequence (IS) 2-like elements duplicates a 208.6 kb region that contains 157 coding sequences. RecA-mediated homologous recombination also resolves merodiploids, and hence copy number of the region is varied and dynamic within populations. We showed that the presence of two or more copies of the region is advantageous for growth in a biofilm, and a single copy is advantageous during planktonic growth. While IS elements are well-known to contribute to evolution through gene inactivation, polar effects on downstream genes, and altering genomic architecture, we believe that this system represents a rare example of IS element-mediated evolution in which the IS elements provide homologous sequences for amplification of a chromosomal region that provides a selective advantage under specific growth conditions, thereby expanding the lifestyle repertoire of the species.