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Updated: Jul 29, 2025

Preparation, Imaging, and Quantification of Bacterial Surface Motility Assays
Published on: April 7, 2015
Genomes comparison of two Proteus mirabilis clones showing varied swarming ability
Dawid Gmiter1, Ilona Pacak2, Sylwia Nawrot2
1Department of Microbiology, Institute of Biology, Faculty of Natural Sciences, Jan Kochanowski University in Kielce, Kielce, Poland. dawid.gmiter@ujk.edu.pl.
Background:
Proteus mirabilis is a Gram-negative bacteria most noted for its involvement with catheter-associated urinary tract infections. It is also known for its multicellular migration over solid surfaces, referred to as 'swarming motility'. Here we analyzed the genomic sequences of two P. mirabilis isolates, designated K38 and K39, which exhibit varied swarming ability.
Methods And Results:
The isolates genomes were sequenced using Illumina NextSeq sequencer, resulting in about 3.94 Mbp, with a GC content of 38.6%, genomes. Genomes were subjected for in silico comparative investigation. We revealed that, despite a difference in swarming motility, the isolates showed high genomic relatedness (up to 100% ANI similarity), suggesting that one of the isolates probably originated from the other.
Conclusions:
The genomic sequences will allow us to investigate the mechanism driving this intriguing phenotypic heterogeneity between closely related P. mirabilis isolates. Phenotypic heterogeneity is an adaptive strategy of bacterial cells to several environmental pressures. It is also an important factor related to their pathogenesis. Therefore, the availability of these genomic sequences will facilitate studies that focus on the host-pathogen interactions during catheter-associated urinary tract infections.
Insights
Genomic sequencing of Proteus mirabilis isolates K38 and K39 revealed high similarity despite differing swarming abilities. This suggests a shared origin and provides a basis for studying phenotypic heterogeneity in these bacteria.
Area of Science:
- Microbiology
- Genomics
- Bacterial Pathogenesis
Background:
- Proteus mirabilis is a Gram-negative bacterium associated with catheter-associated urinary tract infections.
- It exhibits a unique multicellular behavior known as swarming motility.
- This study focuses on two P. mirabilis isolates with distinct swarming capabilities.
Purpose of the Study:
- To analyze and compare the genomic sequences of two P. mirabilis isolates (K38 and K39) with varied swarming motility.
- To investigate the genetic basis for phenotypic heterogeneity in closely related bacterial strains.
- To facilitate research on host-pathogen interactions in urinary tract infections.
Main Methods:
- Whole-genome sequencing of P. mirabilis isolates K38 and K39 using Illumina NextSeq.
- In silico comparative genomic analysis.
- Assessment of Average Nucleotide Identity (ANI) for genomic relatedness.
Main Results:
- Genome size of approximately 3.94 Mbp with 38.6% GC content for both isolates.
- High genomic relatedness (up to 100% ANI similarity) between the two isolates.
- Despite genomic similarity, the isolates displayed differences in swarming motility.
Conclusions:
- The genomic data supports the hypothesis that one isolate may have originated from the other.
- Phenotypic heterogeneity is an adaptive bacterial strategy and crucial for pathogenesis.
- The generated genomic sequences will aid in understanding host-pathogen interactions in P. mirabilis-associated UTIs.

