Development of loop-mediated isothermal amplification assays for genotyping of Type III Secretion System in
Unlabelled:
Pseudomonas aeruginosa is a well-known environmental bacterium capable of causing a variety of life-threatening human infections, with a Type III Secretion System (T3SS) as the most significant virulence determinant. P. aeruginosa strains exhibit unique T3SS virulence genotypes defined by the presence of either exoS or exoU. In this study, loop-mediated isothermal amplification (LAMP) assays for rapid detection of exoS and exoU in P. aeruginosa have been developed and evaluated. Set of four primers were designed for LAMP-based amplification of exoS and exoU respectively. The LAMP reactions were performed at 63°C for 40 min, with detection limits of 100 fg purified DNA. In 107 river water isolates, exoS and exoU were detected in 10 (9%) and 89 (83%) isolates, respectively, and in 38 soil isolates, they were detected in 7 (18%) and 31 (82%) cases respectively. In conclusion, the LAMP assays are rapid, simple and cost-effective tools for detection of the exoU- and exoS-types of P. aeruginosa strains.
Significance And Impact Of The Study:
This method can be used for the rapid, sensitive and low-cost detection of genes (exoS and exoU) encoding proteins that are part of Type III Secretion System of Pseudomonas aeruginosa. It can serve as an efficient method in outbreak situations or in routine surveillance studies to judge virulence potential and to investigate pathogenesis of P. aeruginosa.
Insights
New loop-mediated isothermal amplification (LAMP) assays rapidly detect exoS and exoU genes in Pseudomonas aeruginosa. These simple, cost-effective tools identify virulence types for outbreak surveillance and pathogenesis studies.
Area of Science:
- Microbiology
- Molecular Biology
- Biotechnology
Background:
- Pseudomonas aeruginosa is an environmental bacterium causing severe human infections.
- The Type III Secretion System (T3SS) is a key virulence factor in P. aeruginosa.
- Strains are classified by T3SS genotypes, specifically the presence of exoS or exoU.
Purpose of the Study:
- To develop and evaluate rapid loop-mediated isothermal amplification (LAMP) assays for detecting exoS and exoU genes in P. aeruginosa.
- To assess the prevalence of exoS and exoU genotypes in environmental isolates.
Main Methods:
- Design of specific primer sets for LAMP-based amplification of exoS and exoU.
- Optimization of LAMP reaction conditions (63°C for 40 min).
- Evaluation of assay sensitivity (100 fg purified DNA).
Main Results:
- LAMP assays demonstrated high sensitivity for detecting purified DNA.
- In river water isolates (n=107), exoS was found in 9% and exoU in 83%.
- In soil isolates (n=38), exoS was found in 18% and exoU in 82%.
Conclusions:
- Developed LAMP assays are rapid, simple, and cost-effective for identifying exoS and exoU genotypes of P. aeruginosa.
- These assays are suitable for outbreak situations and routine surveillance to assess virulence potential.
- The method aids in investigating the pathogenesis of P. aeruginosa strains.
