---
title: "Genome-wide CRISPRi reveals pneumococcal genes for attachment and intracellular survival, reshaped"
id: "biorxiv-5-genome-wide-crispri-maps-pneumococcal-attachment-and-intracellular-survival"
canonical_url: "https://medichelpline.com/clinical-feed/biorxiv-5-genome-wide-crispri-maps-pneumococcal-attachment-and-intracellular-survival"
content_type: "clinical_feed_article"
specialty: "Infectious Disease"
source_name: "bioRxiv (Biomedical Preprints)"
source_url: "https://www.biorxiv.org/content/10.64898/2026.09.18.752567v1?rss=1"
published_at: "2026-09-21T12:00:00.000Z"
evidence_level: "Verified Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Genome-wide CRISPRi reveals pneumococcal genes for attachment and intracellular survival, reshaped
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/biorxiv-5-genome-wide-crispri-maps-pneumococcal-attachment-and-intracellular-survival
- **Specialty:** [Infectious Disease](https://medichelpline.com/clinical-feed/infectious-disease.md)
- **Primary Source:** bioRxiv (Biomedical Preprints)
- **Source URL:** [Original Journal Publication](https://www.biorxiv.org/content/10.64898/2026.09.18.752567v1?rss=1)
- **Published At:** 2026-09-21T12:00:00.000Z
- **Evidence Rating:** Verified Feed
## Executive GIST (TL;DR)
- The study used an inducible genome-wide **CRISPRi** library to map genetic determinants of Streptococcus pneumoniae fitness during epithelial attachment and intracellular survival in macrophages under single infection and Influenza A virus (IAV) co-infection. - Screens across multiple host cell types and viral strains identified 42 genes that affect **host-cell attachment** and 63 genes that influence **intracellular survival**. - Overall gene-fitness patterns were largely conserved between single infection and co-infection, but co-infection increased the importance of genes involved in **cell envelope biogenesis**, notably the undecaprenyl pyrophosphate phosphatase **uppP**. - Pharmacological inhibition of **cell wall biosynthesis** reproduced several genetic phenotypes and showed increased bacterial sensitivity to **bacitracin** in virally altered host environments. - Untargeted metabolomics integrated with CRISPRi screening revealed broad remodeling of **nucleotide metabolism** during infection. - Disruption of **nucleoside transport** changed bacterial fitness, cell morphology, capsule expression, and host-cell attachment, linking metabolic pathways to virulence traits. - **Uridine** availability was identified as a central regulator connecting metabolic adaptation with virulence-associated phenotypes, indicating a trade-off between growth and adherence. - The work provides a genome-scale resource of pneumococcal fitness determinants during infection and suggests **cell envelope homeostasis** and **nucleotide metabolism** as potential targets for antimicrobial or anti-virulence strategies. - The article is a preprint and has not been peer reviewed; details beyond the abstract (experimental parameters, full data, and quantitative metrics) were not reported in the source provided.
## Clinical Analysis & Structured Key Points
Genome-wide CRISPRi maps pneumococcal attachment and intracellular survival during single infection and Influenza co-infection | bioRxiv Skip to main content New Results Genome-wide CRISPRi maps pneumococcal attachment and intracellular survival during single infection and Influenza co-infection Philipp DK Walch , Petr Broz , View ORCID Profile Jan-Willem Veening doi: https://doi.org/10.64898/2026.09.18.752567 Philipp DK Walch Universite de Lausanne Find this author on Google Scholar Find this author on PubMed Search for this author on this site Petr Broz Universite de Lausanne Find this author on Google Scholar Find this author on PubMed Search for this author on this site Jan-Willem Veening Universite de Lausanne Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Jan-Willem Veening For correspondence: jan-willem.veening{at}unil.ch Abstract Info/History Metrics Preview PDF Abstract Streptococcus pneumoniae remains a leading cause of bacterial pneumonia and frequently causes severe secondary infections following influenza A virus (IAV) infection. Yet, the genetic requirements underlying pneumococcal pathogenicity during viral co-infection remain incompletely understood. Here, we employed an inducible genome-wide CRISPR interference (CRISPRi) library to systematically investigate pneumococcal gene fitness during epithelial attachment and intracellular survival in macrophages under both single-infection and IAV co-infection conditions. Screening across multiple host cell types and viral strains identified 42 pneumococcal genes affecting host-cell attachment and 63 genes influencing intracellular survival. While global patterns of gene fitness were largely conserved between single infection and co-infection, genes involved in cell envelope biogenesis, including the undecaprenyl pyrophosphate phosphatase uppP , became increasingly important during co-infection. Pharmacological inhibition of cell wall biosynthesis recapitulated several genetic phenotypes and revealed enhanced sensitivity to bacitracin in virally altered host environments. Integration of CRISPRi screening with untargeted metabolomics uncovered extensive remodeling of nucleotide metabolism during infection. Disruption of nucleoside transport altered bacterial fitness, morphology, capsule expression, and host-cell attachment. Uridine availability emerged as a key regulator linking metabolic adaptation to virulence-associated traits, highlighting a trade-off between bacterial growth and adherence. Taken together, our study provides a genome-scale resource of pneumococcal fitness determinants during infection and demonstrates that influenza co-infection selectively reshapes bacterial genetic dependencies rather than globally altering pathogenicity programs. These findings identify cell envelope homeostasis and nucleotide metabolism as central regulators of pneumococcal virulence and reveal potential targets for future antimicrobial and anti-virulence strategies. Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-ND 4.0 International license . Back to top Previous Next Posted September 21, 2026. Download PDF Email Thank you for your interest in spreading the word about bioRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. 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Share Genome-wide CRISPRi maps pneumococcal attachment and intracellular survival during single infection and Influenza co-infection Philipp DK Walch , Petr Broz , Jan-Willem Veening bioRxiv 2026.09.18.752567; doi: https://doi.org/10.64898/2026.09.18.752567 Share This Article: Copy Citation Tools Genome-wide CRISPRi maps pneumococcal attachment and intracellular survival during single infection and Influenza co-infection Philipp DK Walch , Petr Broz , Jan-Willem Veening bioRxiv 2026.09.18.752567; doi: https://doi.org/10.64898/2026.09.18.752567 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Areas All Articles Animal Behavior and Cognition (8018) Biochemistry (18744) Bioengineering (14893) Bioinformatics (44459) Biophysics (22612) Cancer Biology (19728) Cell Biology (26906) Clinical Trials (138) Developmental Biology (13972) Ecology (21008) Epidemiology (2067) Evolutionary Biology (25457) Genetics (16173) Genomics (23520) Immunology (18717) Microbiology (42520) Molecular Biology (18065) Neuroscience (93528) Paleontology (700) Pathology (2982) Pharmacology and Toxicology (5100) Physiology (8120) Plant Biology (16000) Scientific Communication and Education (2095) Synthetic Biology (4560) Systems Biology (10237) Zoology (2391)
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