Download PSEUDOMONAS AERUGINOSA Daniel C. Ostberg , Hunter J. Sismaet , Ashley J. Lockwood

Undergraduate
Category: Engineering and Technology
Degree Level: BS
Abstract ID# 1062
University Scholar: Daniel C. Ostberg
RAPID DETECTION OF PSEUDOMONAS AERUGINOSA IN ANIMAL CLINICAL SAMPLES USING ELECTROCHEMICAL SENSORS
Daniel C.
1
Ostberg ,
Hunter J.
1
Sismaet ,
Ashley J.
2
Lockwood ,
Virginia B.
2
Sinnott ,
and Edgar D.
1
Goluch
1Department
of Chemical Engineering, Northeastern University, Boston, MA, 02115
2Department of Emergency and Critical Care, Angell Animal Medical Center, Boston, MA, 02130
Abstract
Materials and Methods
A significant limitation to antibiotic
stewardship and improved patient care is the
delay between the obtainment of a biological
sample and its bacterial identification from
culture results. Here, we report the use of
electrochemical sensors as a rapid test for
detecting Pseudomonas aeruginosa in animal
clinical samples.
 Swabs obtained from animals with
clinical infections at Angell Animal
Medical Center were inoculated in
thioglycollate (thio) broth for growth.
 22 animal samples were tested, with
species varying from dogs, cats, birds,
and rabbits. Swab collection areas
varied from skin lesions, ear canal,
nasal, ulcers, and surgical sites.
 Overnight thio liquid cultures were
pipetted onto an electrochemical
sensor and square-wave voltammetry
was used to determine the presence or
absence of pyocyanin in the samples.
 The electrochemical results were
compared against TREK Sensititre®, an
automated identification system used
in Angell Animal Medical Center.
Introduction
 It takes over 24-48 hours to receive a
positive identification using plate cultures,
the gold standard in animal clinical care.1
 Pseudomonas aeruginosa is a common
bacterium that can cause skin infections
and colonize in the ears of dogs, cats, and
exotic animals.2,3
How it Works
Electrochemical Sensor Results
Figure 1. (Top) Detection scheme for
pyocyanin production by Pseudomonas
aeruginosa in animal clinical samples. A swab
is taken from an animal, cultured, and placed
onto an electrochemical sensor. The presence
(peak, red dashed line) or absence (no peak,
black line) of pyocyanin indicates whether P.
aeruginosa is in the sample.
(Bottom) Pyocyanin is a redox-active, quorum
sensing molecule uniquely secreted by P.
aeruginosa. Because it is redox-active, we can
detect it electrochemically.4
“There is a huge need and market for
point-of-care infectious disease identification
technology in the veterinary diagnostic space.”
- Associate Dean Joe McManus,
Tufts Veterinary Hospital
Figures of Merit
Conclusions
 While P. aeruginosa infections are commonly associated with
hospital-acquired infections in humans,5 they also can be
found in animal healthcare.2,3
 The electrochemical sensor results for P. aeruginosa
detection compared favorably to an automated microbial
identification system, the gold standard for determining
clinical infections.
 From 22 animal samples, the sensor correctly identified the 3
true positives and the 19 true negatives.
 This study validates the use of an electrochemical sensor for
point-of-care applications in the clinical veterinary market.
Figure 3. (Left) Figures of merit for our electrochemical sensor, where we
correctly identified 3 positive P. aeruginosa samples out of 22 samples.
(Right) Important insight: Multiple electrochemical scans are needed (at least 3)
to remove false positives.
Applications and Future Research
 This study aims to continue collecting more animal samples,
with a focus on testing more animal samples with positive
Pseudomonas aeruginosa infections.
Figure 2. Detecting Pseudomonas aeruginosa in a
sample from a swab of (Top) pericardial fluid obtained
from a canine and (Bottom) nasal fluid obtained from a
rabbit. The concentration of pyocyanin (µM) in the
sample can be calculated from the peak current (µA).
Acknowledgements
This material is based upon work supported by
the NSF I-Corps Grant #1542812 and a
Northeastern University TIER 1 Seed Grant.
References
1.
2.
3.
4.
5.
Cai, H.Y., et al., Veterinary Pathology, 2014, 51(2), 341-350.
Nuttall, T., et al., Veterinary Dermatology, 2007, 18(2), 69-77.
Foti, M., et al., Journal of Exotic Pet Medicine, 2013, 22(3), 270-274.
Sismaet, H.J., et al., Analyst, 2014, 139(17), 4241-4246.
Boucher, H.W., et al., Clinical Infectious Diseases, 2009, 48(1), 1-12.