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Dual-site recognition of Pseudomonas aeruginosa using polymyxin B and bacteriophage tail fiber protein
Yanli Shi1, Yong He2, Lvxia Zhang1
1Key Laboratory of Luminescence Analysis and Molecular Sensing (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
Abstract:
As one of the top three opportunistic pathogens, Pseudomonas aeruginosa (P. aeruginosa) has long accounted for hospital-acquired infections with high risk of death. In this work, a fluorescent method based on a dual-site recognition mode was developed for rapid assay of P. aeruginosa. Employing its strong binding capability towards lipid A on the outer membrane of Gram-negative bacteria, polymyxin B acted as one recognition element for P. aeruginosa. To overcome the poor binding specificity of polymyxin B, a recombinant bacteriophage tail fiber protein was expressed and employed as a species-specific recognition element for the target pathogen. Thus a dual-site recognition mode was developed for specific assay of P. aeruginosa species by using fluorescein isothiocyanate as a fluorescent probe. The target pathogen can be assayed within a broad dynamic range from 2.0 × 103 CFU mL-1 to 2.0 × 107 CFU mL-1. Due to the ideal specificity of tail fiber protein, the method is capable of excluding the interference from other Gram-negative bacteria and all Gram-positive bacteria. It has been employed for assaying P. aeruginosa in various types of sample matrixes inclusive of lake water, physiological saline injection, human urine and milk. The acceptable assay results demonstrate its promising prospect for practical application in various areas such as environmental hygiene, medical diagnosis, as well as drug and food safety.
Insights
A new fluorescent assay rapidly detects Pseudomonas aeruginosa (P. aeruginosa), a dangerous opportunistic pathogen. This dual-site method uses polymyxin B and bacteriophage tail fiber protein for high specificity in various samples.
Area of Science:
- Microbiology
- Biotechnology
- Analytical Chemistry
Background:
- Pseudomonas aeruginosa (P. aeruginosa) is a leading cause of hospital-acquired infections and mortality.
- Accurate and rapid detection methods for P. aeruginosa are crucial for clinical and environmental monitoring.
- Existing detection methods may lack specificity or speed.
Purpose of the Study:
- To develop a rapid and highly specific fluorescent assay for detecting P. aeruginosa.
- To utilize a dual-site recognition strategy for enhanced pathogen identification.
- To validate the assay's performance in diverse sample matrices.
Main Methods:
- A dual-site recognition assay was designed using polymyxin B and a recombinant bacteriophage tail fiber protein.
- Polymyxin B targets lipid A on the bacterial outer membrane.
- Fluorescein isothiocyanate served as the fluorescent probe for detection.
Main Results:
- The assay demonstrated high specificity for P. aeruginosa, distinguishing it from other Gram-negative and Gram-positive bacteria.
- A broad dynamic detection range was achieved, from 2.0 × 10^3 to 2.0 × 10^7 CFU mL^-1.
- The method was successfully applied to various sample types, including water, saline, urine, and milk.
Conclusions:
- The developed fluorescent assay offers a rapid, specific, and sensitive method for P. aeruginosa detection.
- The dual-site recognition approach enhances accuracy and minimizes interference.
- This assay shows significant potential for applications in environmental monitoring, medical diagnostics, and food/drug safety.
