GitHub

A reproducible workflow for bacterial whole genome sequencing (WGS) upstream analysis. This repository is aligned with the abstract workflow for Pseudomonas aeruginosa strain 2025SY-00129 (SRR33893847), using the Pseudomonas aeruginosa strain-2507 reference for quality control, trimming, mapping, variant calling, de novo assembly, assembly assessment, and annotation.


Project Structure

All scripts should be run from the base directory:

bacterial-upstream-analysis

Tools & Conda Environments

Each step requires a separate conda environment with the listed tool(s) installed using the Bioconda channel:

Step Tool(s) Conda Env Name
Download raw reads sra-tools ncbi-sra
Quality control fastqc fastqc
QC summary multiqc multiqc
Trimming trimmomatic trimmomatic
Mapping and variant calling bwa, samtools, freebayes, tabix, bcftools bwa-sam
Assembly spades spades
Assembly evaluation quast quast
Annotation prokka prokka

Setup Conda Environments

Create separate environments for each step/tool by running:

conda env create -f envs/ncbi-sra.yml
conda env create -f envs/fastqc.yml
conda env create -f envs/multiqc.yml
conda env create -f envs/trimmomatic.yml
conda env create -f envs/spades.yml
conda env create -f envs/quast.yml
conda env create -f envs/prokka.yml
conda env create -f envs/mapping.yml

Run a Script

./scripts/script_name.sh

Data Input

  • SRA accession list: data/accession.txt
  • Reference genome path: data/reference/reference.fasta
  • Active reference: NZ_CP141269.1 Pseudomonas aeruginosa strain 2507 chromosome, GI 2647842840

Script Execution

Run the scripts in this order:

  1. 00_download_sra.sh - Download raw reads from Sequence Read Archive
  2. 01_fastqc.sh - Run quality control on raw reads
  3. 02_multiqc.sh - Summarize QC reports
  4. 03_trimmomatic.sh - Trim low-quality reads
  5. 04_mapping.sh - Map trimmed paired reads to the Pseudomonas reference genome
  6. 05_variant_calling.sh - Call variants against the reference genome
  7. 06_assembly.sh - Perform de novo genome assembly
  8. 07_quast.sh - Evaluate the assembly
  9. 08_prokka.sh - Annotate the genome

Included Outputs

  • Dataset accession: SRR33893847
  • QUAST assembly report: results/quast/report.txt
  • Annotation summary: results/annotation/SRR33893847.txt
  • Variant calls: results/vcf/SRR33893847.vcf.gz
  • Assembly outputs: results/assembly/contigs.fasta and results/assembly/scaffolds.fasta
  • QC reports: results/qc/ and results/multiqc/multiqc_report.html

Access to Large Data Files

Due to GitHub's file size limits, raw FASTQ files, trimmed reads, and mapping output files such as .fastq, .bam, and .sam are hosted on Google Drive.

Access the large data files on Google Drive


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