Evidence map›Paper›PMID 24959661›Full record

ArticlePloS one2014

A modified Janus cassette (Sweet Janus) to improve allelic replacement efficiency by high-stringency negative selection in Streptococcus pneumoniae.

Yuan Li, Claudette M Thompson, Marc Lipsitch

Open access · goldAbstract read
In one paragraph

Article in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 39 papers.

0numbers the graph read from it
0cells of the map it votes in
39citing papers in PubMed
1.1field-weighted citation impact, top 23% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

39 citing papers in PubMed, 59 citations in OpenAlex.

  1. Article
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  3. Article
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  6. Article
  7. Review
  8. Article
  9. Article
  10. Streamlining marker-less allelic replacement inApplied and environmental microbiology · 2024
    Article
  11. Article
  12. Article
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  14. Influence of glycan structure on the colonization ofProceedings of the National Academy of Sciences of the United States of America · 2023
    Article
  15. Article
  16. Article
  17. Article
  18. The bacterial tyrosine kinase system CpsBCD governs the length of capsule polymers.Proceedings of the National Academy of Sciences of the United States of America · 2021
    Article
  19. Biochemical reconstitution defines new functions for membrane-bound glycosidases in assembly of the bacterial cell wall.Proceedings of the National Academy of Sciences of the United States of America · 2021
    Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors at 1 institution in 1 country.

Yuan LiDepartment of Epidemiology and Department of Immunology & Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America.
Claudette M ThompsonDepartment of Epidemiology and Department of Immunology & Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America.
Marc LipsitchDepartment of Epidemiology and Department of Immunology & Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America.
Harvard University · US

Funding

VACCINATION AND THE EVOLUTIONARY DYNAMICS OF PNEUMOCOCCIR01AI048935 · NIAID · HARVARD UNIVERSITY (SCH OF PUBLIC HLTH) · PI LIPSITCH, MARC · 2001 to 2016
$8.8M
NIAID NIH HHS 5R01AI048935-12NIAID NIH HHS R01 AI048935
6 · The paper itself

Abstract

The Janus cassette permits marker-free allelic replacement or knockout in streptomycin-resistant Streptococcus pneumoniae (pneumococcus) through sequential positive and negative selection. Spontaneous revertants of Janus can lead to high level of false-positives during negative selection, which necessitate a time-consuming post-selection screening process. We hypothesized that an additional counter-selectable marker in Janus would decrease the revertant frequency and reduce false-positives, since simultaneous reversion of both counter-selectable makers is much less likely. Here we report a modified cassette, Sweet Janus (SJ), in which the sacB gene from Bacillus subtilis conferring sucrose sensitivity is added to Janus. By using streptomycin and sucrose simultaneously as selective agents, the frequency of SJ double revertants was about 105-fold lower than the frequency of Janus revertants. Accordingly, the frequency of false-positives in the SJ-mediated negative selection was about 100-fold lower than what was seen for Janus. Thus, SJ enhances negative selection stringency and can accelerate allelic replacement in pneumococcus, especially when transformation frequency is low due to strain background or suboptimal transformation conditions. Results also suggested the sacB gene alone can function as a counter-selectable marker in the Gram-positive pneumococcus, which will have the advantage of not requiring a streptomycin-resistant strain for allelic replacement.

Indexed as

AllelesQuantitative Trait LociRecombination, GeneticSelection, GeneticGene OrderPlasmidsStreptococcus pneumoniaeTransformation, Bacterial

Identifiers

PMID24959661
PMCPMC4068995
OpenAlexW2048570423

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.