Abstract
The worldwide emergence and spread of antimicrobial resistance is accelerated by irrational administration and use of empiric antibiotics. A key point to the crisis is a lack of rapid diagnostic protocols for antimicrobial susceptibility testing (AST), which is crucial for a timely and rational antibiotic prescription. Here, a recombinant bacteriophage tail fiber protein (TFP) was functionalized on magnetic particles to specifically capture Pseudomonas aeruginosa, while fluorescein isothiocyanate-labeled-magainin II was utilized as the indicator. For solving the magnetic particles’ blocking effects, a reverse assaying protocol based on TFP recognition was developed to investigate the feasibility of detection and AST of P. aeruginosa. P. aeruginosa can be rapidly, sensitively and specifically detected within 1.5 h with a linear range of 1.0 × 102 to 1.0 × 106 colony forming units (CFU)⋅mL−1 and a detection limit of 3.3 × 10 CFU⋅mL−1. Subsequently, AST results, which were consistent with broth dilution results, can be obtained within 3.5 h. Due to the high specificity of the TFP, AST can actually be conducted without the need for bacterial isolation and identification. Based on the proof-of-principle work, the detection and AST of other pathogens can be extended by expressing the TFPs of their bacteriophages.
Highlights
The worldwide emergence and spread of antimicrobial resistance is accelerated by irrational administration and use of empiric antibiotics
fluorescein isothiocyanate (FITC) labeled magainin II anchoring on the cytoplasmic membrane of both Gram-positive and Gram-negative bacteria through electrostatic and hydrophobic interactions was utilized as the fluorescent t racer[26,27]
When P. aeruginosa was captured by the TFPfunctionalized magnetic particles (MPs) to form a bacteria-MPs complex, quantitative excess FITC labeled magainin II was added to this complex
Summary
The worldwide emergence and spread of antimicrobial resistance is accelerated by irrational administration and use of empiric antibiotics. Some other bacterial growth-based protocols are reported to aim at shortening the time of AST, such as microscopy detection[9,10,11], electrochemical s ensor[12,13,14], phase-shift spectroscopy detection[15], fluorescent detection[16], microfluidic devices based on the slipchip technique[17], and surface-enhanced raman scattering[18]. Due to their lack of capacity of identifying the given bacterial species, they require time-consuming pretreatment procedures for bacterial culturing, isolation and identification. Just like the bacteriophage entity as a whole, the endolysin and TSP both have an inherent lytic activity which could be unfavorable for bacterial capture and sample manipulation
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