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Updated: Sep 6, 2025
Rapid and Specific Detection of Acinetobacter baumannii Infections Using a Recombinase Polymerase Amplification/Cas12a-based System
Published on: April 25, 2025
Engineering Phage Tail Fiber Protein as a Wide-Spectrum Probe for Acinetobacter baumannii Strains with a Recognition
Ying Chen1, Honglin Yang1, Shuai Luo1
1Key Laboratory of Luminescence Analysis and Molecular Sensing (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
Abstract:
As a multidrug-resistant pathogen, Acinetobacter baumannii has long been identified as one of the most common nosocomial bacteria. High-performance recognition probes for wide-spectrum detection of A. baumannii are highly desired to achieve efficient diagnosis and timely treatment of infectious diseases induced by this pathogen. An engineering tail fiber protein (ETFP) named as Gp50 encoded by lytic phage Abp9 was expressed in Escherichia coli and identified as a binding protein for A. baumannii. According to the results of genome sequencing of an A. baumannii wild strain and phage-resistant strains, the binding receptor of ETFP Gp50 is inferred to be a lipopolysaccharide distributed on the bacterial surface. The engineering protein did not show lytic activity to A. baumannii, which facilitates the development of reliable diagnosis kits and biosensors with high flexibility and low false-negative rate. The results of specificity study show that ETFP Gp50 is a species-specific binding protein with a recognition rate of 100% for all tested 77 A. baumannii strains, while that of the natural phage Abp9 is only 27.3%. With the engineering protein, a fluorescence method was developed to detect A. baumannii with a detection range of 2.0 × 102 to 2.0 × 108 cfu mL-1. The method has been used for the quantification of A. baumannii in a diverse sample matrix with acceptable reliability. The work demonstrates the application potential of ETFP Gp50 as an ideal recognition probe for rapid screening of A. baumannii strains in a complicated sample matrix.
Insights
A novel engineered tail fiber protein (ETFP) Gp50 specifically detects Acinetobacter baumannii. This protein enables a sensitive fluorescence assay for rapid bacterial screening in complex samples.
Area of Science:
- Microbiology
- Biotechnology
- Molecular Biology
Background:
- Acinetobacter baumannii is a multidrug-resistant nosocomial pathogen.
- Efficient detection methods for A. baumannii are crucial for timely diagnosis and treatment.
- Existing detection methods may lack specificity or sensitivity.
Purpose of the Study:
- To develop a high-performance recognition probe for wide-spectrum detection of A. baumannii.
- To engineer a tail fiber protein (ETFP) with specific binding capabilities.
- To establish a sensitive and reliable detection method for A. baumannii.
Main Methods:
- Expression of engineered tail fiber protein (ETFP) Gp50 from phage Abp9 in Escherichia coli.
- Genome sequencing of A. baumannii strains to infer the ETFP Gp50 binding receptor (lipopolysaccharide).
- Development of a fluorescence-based detection method using ETFP Gp50.
Main Results:
- ETFP Gp50 demonstrated specific binding to A. baumannii, with a 100% recognition rate across 77 strains.
- The engineered protein showed no lytic activity, reducing false negatives in diagnostics.
- A fluorescence assay detected A. baumannii from 2.0 × 10^2 to 2.0 × 10^8 cfu mL^-1.
Conclusions:
- ETFP Gp50 is a highly specific and sensitive probe for A. baumannii detection.
- The developed fluorescence method offers a reliable tool for rapid screening in diverse sample matrices.
- ETFP Gp50 holds significant potential for developing advanced diagnostics and biosensors for A. baumannii infections.
