Bacteriophage-mediated identification of bacteria using photoacoustic flow cytometry.

Robert H Edgar,Austin Minard,John A Viator,John D Hempel,Andrea Sajewski,Cierra Noel,Rachel Fernandez,Justin Cook,John A Kellum,Matthew Fitzpatrick

doi:10.1117/1.jbo.24.11.115003

Robert H Edgar, Austin Minard + Show 8 more

Open Access

https://doi.org/10.1117/1.jbo.24.11.115003

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Abstract

.Infection with resistant bacteria has become an ever increasing problem in modern medical practice. Currently, broad spectrum antibiotics are prescribed until bacteria can be identified through blood cultures, a process that can take two to three days and is unable to provide quantitative information. To detect and quantify bacteria rapidly in blood samples, we designed a method using labeled bacteriophage in conjunction with photoacoustic flow cytometry (PAFC). PAFC is the generation of ultrasonic waves created by the absorption of laser light in particles under flow. Bacteriophage is a virus that infects bacteria and possesses the ability to discriminate bacterial surface antigens, allowing the bacteriophage to bind only to their target bacteria. Bacteria can be tagged with dyed phage and processed through a photoacoustic flow cytometer where they are detected by the acoustic response. We demonstrate that E. coli can be detected and discriminated from Salmonella using this method. Our goal is to develop a method to determine bacterial content in blood samples. We hope to develop this technology into future clinical use and decrease the time required to identify bacterial species from 3 to 4 days to less than 1 hour.

Highlights

Bacterial infections that may lead to sepsis in patients is a major problem in many aspects of hospital care, including emergency medicine, transplant surgery, and intensive care.[1]
Bacterial cultures are still the gold standard for identification of blood stream infections,[3] though there is a critical need to develop early detection and identification methods for bacterial pathogens that avoid the requirement of bacterial culture, obviate the need for broad spectrum antibiotics, and improve patient outcomes.[4]
Bacteriophage buffer was run through the photoacoustic flow cytometry (PAFC) system to demonstrate a level of background detection and any variability with PBS

Summary

Introduction

Bacterial infections that may lead to sepsis in patients is a major problem in many aspects of hospital care, including emergency medicine, transplant surgery, and intensive care.[1] To combat these infections, current medical practice calls for the use of broad spectrum antibiotics until bacterial cultures can identify specific pathogens. Because of the doubling time of bacteria, this process may take 48 to 96 h. Bacterial cultures are still the gold standard for identification of blood stream infections,[3] though there is a critical need to develop early detection and identification methods for bacterial pathogens that avoid the requirement of bacterial culture, obviate the need for broad spectrum antibiotics, and improve patient outcomes.[4]

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