Beta-lactam antibiotics induced bacteriolysis on LSPR sensors for assessment of antimicrobial resistance and quantification of antibiotics

Antimicrobial resistance affecting humans is fueled by empirical infection diagnostics and continuous unintended antibiotics exposure. A localized surface plasmon resonance (LSPR) based optical fiber biosensor for capture of bacteria followed by antibiotic mediated lysis has been demonstrated for quick drug susceptibility testing. The concept has been proven with P. aeruginosa and E. coli suspended in simulated human urine for potential drug susceptibility testing for urinary tract infections. P. aeruginosa RS1 was found to be selectively sensitive to commonly used third generation cephalosporins ceftazidime, ceftriaxone and cefotaxime. Hence, in an alternate scheme, bacteriolysis signatures of P. aeruginosa immobilized on gold nanoparticles modified optical fibers was used for quantification of third generation cephalosporins over a linear range of 0.01 to 1 μg/ml, R² = 0.985, in water. Further, this principle was established for therapeutic drug monitoring (TDM) of the said antibiotics in real human serum in the therapeutic relevant range of 0.5 to 10 μg /mL (R² = 0.987). This sensor provides a quick alternative to cumbersome Kirby-Bauer disk diffusion tests, practiced in most community health settings and tertiary care hospitals for drug susceptibility testing. The sensor also provides an alternative to chromatography coupled mass spectroscopic techniques for quicker, affordable and possibly point of care antibiotic quantification with applications in environmental and therapeutic monitoring.