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Updated: Aug 11, 2026
Establishment and Characterization of UTI and CAUTI in a Mouse Model
Published on: June 23, 2015
Molecular cloning of Proteus mirabilis uroepithelial cell adherence (uca) genes
Abstract:
Proteus mirabilis bacteria are a common cause of hospital-acquired urinary tract infection. In a previous study, we described a P. mirabilis fimbrial protein, UCA, that adhered to human uroepithelial cells. Genes sufficient for expression of UCA adherence were cloned into Escherichia coli K-12. E. coli bacteria that contained the uca recombinant plasmid adhered to human uroepithelial cells. In addition, the ucaA gene encoding the structural component of UCA pili was subcloned, and its DNA sequence was determined. Amino acid sequence homology (30 to 50%) was found between mature UcaA protein and pilins from pathogenic bacteria representing several genera, including E. coli F17, G, and type 1C pilins, Haemophilus M43 pilin, and a Bordetella pilin.
Insights
Proteus mirabilis UCA fimbrial protein aids bacterial adherence to urinary tract cells. Cloning the UCA adherence genes into E. coli demonstrated its function, revealing sequence similarities to other pathogenic bacterial pilins.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Proteus mirabilis is a frequent cause of hospital-acquired urinary tract infections.
- A previously identified P. mirabilis fimbrial protein, UCA, exhibits adherence to human uroepithelial cells.
Purpose of the Study:
- To clone and express genes responsible for UCA-mediated adherence in a heterologous host.
- To determine the DNA sequence of the ucaA gene, encoding the UCA pilin structural component.
- To analyze the amino acid sequence homology of UcaA with other bacterial pilins.
Main Methods:
- Genes for UCA adherence were cloned into Escherichia coli K-12.
- The ucaA gene was subcloned and its DNA sequence determined.
- Bioinformatic analysis was performed to compare UcaA amino acid sequence with known pilins.
Main Results:
- Recombinant E. coli expressing the uca genes successfully adhered to human uroepithelial cells.
- The DNA sequence of ucaA was determined.
- UcaA showed 30-50% amino acid sequence homology to pilins from various pathogenic genera, including E. coli, Haemophilus, and Bordetella.
Conclusions:
- The cloned UCA genes confer adherence properties to E. coli, confirming their role in P. mirabilis virulence.
- The UcaA protein shares structural similarities with pilins from other important human pathogens, suggesting conserved mechanisms of adherence.
