Readable documentation excerpt. Open the original PDF for all tables, figures and complete instructions.
Page 1
IMPROVED METHOD FOR BIOPSY INTRODUCTION
Microbial infections in prosthetic joint infections(PJIs) present
HOMOGENISATION AND RAPID
significant diagnostic challenges. This study explores two
homogenization techniques combined with isothermal
microcalorimetry (IMC), for detecting microbial infections.
DETECTION OF INFECTIONS »› OBJECTIVE
• To evaluate the impact of homogenisation technique on
recovery rate and detection speed depending on
homogenisation techniques combined with an IMC
readout.
JOSEFIN LARSSON1,2, KARIN LIDEROT3, MARTA VESES GARCIA1, • To assess the potential of these methods in a clinical
CHAITANYA TELLAPRAGADA2, WILHELM PAULANDER1, CHRISTIAN GISKE2 workflow, compared to standa
Page 1
otential of these methods in a clinical
CHAITANYA TELLAPRAGADA2, WILHELM PAULANDER1, CHRISTIAN GISKE2 workflow, compared to standard hospital techniques.
1 Symcel AB, Stockholm, Sweden
2 Karolinska Institute, Sweden
3 Karolinska University Hospital
METHODS
1 2 IN VIVO EXPERIMENT
IN VITRO EXPERIMENT
Standard
Bead-based microbiology
homogenisation methods
volume 100-500ul
rapid infection detection and
estimation of bacterial load
Bead-based/stone-milling IMC and plating
homogenisation
Alternative Method
RESULTS
COMPARING THE IMPACT ON DETECTION TIME AND MICROBIAL APPLYING OUR WORKFLOW (HOMOGENISATION + IMC READOUT)
RECOVERY OF HOMOGENISATION TECHNIQUE DIRECTLY ON LIQUID
Page 1
ROBIAL APPLYING OUR WORKFLOW (HOMOGENISATION + IMC READOUT)
RECOVERY OF HOMOGENISATION TECHNIQUE DIRECTLY ON LIQUID TO CLINICAL SAMPLES COMPARED TO STANDARD WORKFLOW
S. aureus CULTURES
50% faster detection of S. aureus (<2 h) after 5 times higher microbial recovery using alternative 48 patient samples from 22 PJI patients. Two homogenisation
homogenisation
Rapid withof
detection alternative
S.aureus homogenisation homogenisation methods (2 min interval) than the standard methods with IMC based readout and hospital standard method
method with IMC
infection compared
directly on to standard method.
homogenate homogenisation method. were compared.
Metabolic 150 Recovery (%) alternative homogeniser
activity alternative homogeniser standard homogeniser
(uW) (hospital)
Heat flow (µW)
100 hospital homogeniser
Majority of sample goes for hospital
50
workflow leaving less biopsy
Time to
material for the tested workflow.
Detection
Creating a bias, possibly leading to
Page 1
Creating a bias, possibly leading to
false negatives.*
0
Time (h) 4 6 8 10 Homogenisation interval
Time (h)
RECOVERY OF OXYGEN SENSITIVE C. acnes FROM SPIKED PIG In two polymicrobial samples the standard
TISSUE AFTER HOMOGENISATION homogenisation + IMC missed detection of
S. aureus or E. cloacae complex,
respectively.
Two to 2.5 x higher In three polymicrobial
recovery of C. acnes (6.15 to samples E. faecalis
7.6*104 cells) depending on and C. acnes were not
homogenisation interval with detected in standard
alternative method compared
Page 1
detected in standard
alternative method compared workflow.
standard method in the clinics
(2.75 – 3.3*104 cells).
WHAT´S
% of 105 C. acnes cells that were used to spike
NEXT?
*Four samples (not shown) of the homegenisation+IMC procedure were false negative
the tissue. compared to hospital procedure which can be explained using less biopsy material.
In an ongoing study we
expand the study
group to 120 PJI
patients allowing to
Page 1
patients allowing to
determine infection
detection speed with
CONCLUSION SIGNIFICANCE the use of IMC.
The alternative homogenisation method (SpinAX/ProbeAX Evolution, A semiautomated workflow combining an improved
Axonlab AG, Germany) shows to be less harsh on bacteria homogenisation technique, for higher recovery rates and speed in
compared to standard homogenisation method (Bullet Blender combination with a sensitive IMC-based readout, are promising as a
50DX. Next Advance, USA), allowing for faster and higher recovery, less invasive and more efficient alternative to the current
ultimately increasing accuracy and speed. clinical standard.
Using IMC for semi-automated readout, provides microbial
detection within hours as compared to days with standard
microbiology methods. CONTACT With funding from:
Increased detection of sensitive C. acnes with the alternative
homogenization method is promising. Confirmation of these
findings in a larger study group is necessary
wilhelm.paulander@symcel.com
Page 1
wilhelm.paulander@symcel.com