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Updated: Jul 6, 2026

Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing
Published on: December 23, 2022
Complete genome sequence of uropathogenic Proteus mirabilis, a master of both adherence and motility
Melanie M Pearson1, Mohammed Sebaihia, Carol Churcher
1Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109-0620, USA.
Abstract:
The gram-negative enteric bacterium Proteus mirabilis is a frequent cause of urinary tract infections in individuals with long-term indwelling catheters or with complicated urinary tracts (e.g., due to spinal cord injury or anatomic abnormality). P. mirabilis bacteriuria may lead to acute pyelonephritis, fever, and bacteremia. Most notoriously, this pathogen uses urease to catalyze the formation of kidney and bladder stones or to encrust or obstruct indwelling urinary catheters. Here we report the complete genome sequence of P. mirabilis HI4320, a representative strain cultured in our laboratory from the urine of a nursing home patient with a long-term (> or =30 days) indwelling urinary catheter. The genome is 4.063 Mb long and has a G+C content of 38.88%. There is a single plasmid consisting of 36,289 nucleotides. Annotation of the genome identified 3,685 coding sequences and seven rRNA loci. Analysis of the sequence confirmed the presence of previously identified virulence determinants, as well as a contiguous 54-kb flagellar regulon and 17 types of fimbriae. Genes encoding a potential type III secretion system were identified on a low-G+C-content genomic island containing 24 intact genes that appear to encode all components necessary to assemble a type III secretion system needle complex. In addition, the P. mirabilis HI4320 genome possesses four tandem copies of the zapE metalloprotease gene, genes encoding six putative autotransporters, an extension of the atf fimbrial operon to six genes, including an mrpJ homolog, and genes encoding at least five iron uptake mechanisms, two potential type IV secretion systems, and 16 two-component regulators.
Insights
Proteus mirabilis causes urinary tract infections and catheter issues due to urease. We sequenced the HI4320 strain genome, revealing virulence factors and secretion systems.
Area of Science:
- Microbiology
- Genomics
- Infectious Diseases
Background:
- Proteus mirabilis is a Gram-negative bacterium causing urinary tract infections (UTIs).
- It is notorious for urease production, leading to stones and catheter obstruction.
- UTIs caused by P. mirabilis can result in pyelonephritis, fever, and bacteremia.
Purpose of the Study:
- To report the complete genome sequence of Proteus mirabilis HI4320.
- To identify genetic determinants of virulence and pathogenicity in this strain.
Main Methods:
- Whole-genome sequencing of P. mirabilis HI4320.
- Bioinformatic analysis and annotation of the genome.
- Identification of virulence factors, secretion systems, and metabolic pathways.
Main Results:
- The P. mirabilis HI4320 genome is 4.063 Mb with 38.88% G+C content and a single plasmid.
- Genome annotation revealed 3,685 coding sequences and seven rRNA loci.
- Confirmed known virulence factors, flagellar regulon, 17 fimbriae types, a type III secretion system, and multiple iron uptake mechanisms.
Conclusions:
- The genome sequence provides a comprehensive resource for understanding P. mirabilis pathogenesis.
- Identified genetic elements, including secretion systems and fimbriae, are crucial for P. mirabilis virulence.
- This data facilitates the development of targeted interventions against P. mirabilis infections.
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