We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App




Events

09 Apr 2024 - 12 Apr 2024
15 Apr 2024 - 17 Apr 2024
23 Apr 2024 - 26 Apr 2024

Sequencing Shows Promise for Diagnosing Prosthetic Joint Infections

By LabMedica International staff writers
Posted on 07 May 2019
Print article
Image: The MinION is the only portable real-time device for DNA and RNA sequencing (Photo courtesy of Oxford Nanopore).
Image: The MinION is the only portable real-time device for DNA and RNA sequencing (Photo courtesy of Oxford Nanopore).
A method is being developed for diagnosing infections associated with prosthetic joint implants that promises to provide results in a matter of hours as opposed to a week or more. The current gold standard is bacterial culture from periprosthetic tissue samples collected during surgery, although another option is culturing from sonicated explanted prostheses in saline.

Of approximately 113,000 total knee replacement surgeries performed in the UK in 2017, 6,500, or about 6%, were revision surgeries, and nearly a quarter of those surgeries took place because of an infection or suspicion of infection. Elbow replacement surgeries showed similar rates of infection-related revision surgeries, while shoulder and hip replacements were around 17%and 16% respectively.

A team of scientists associated with the University of Oxford (Oxford, UK) devised a workflow involved removing a prosthetic device during surgery then placing it in saline and sonicating it to obtain approximately 40 mL of sonication fluid, which is essentially the largest volume they can easily handle in the laboratory, which is allowed them to maximize the number of cells they can extract DNA from. The sonication step potentially increases the number of bacterial cells available in the sample because it disrupts the bacterial biofilm. The DNA is extracted from the sonicated samples, cleaned, and prepared into libraries, which are then sequenced. The work leveraged Oxford Nanopore sequencing technologies.

Teresa Street, PhD, a postdoctoral research student at Nuffield Department of Clinical Medicine (Oxford, UK) and a co-author of the study said, discussed her group's attempts to validate the technology as part of a completely culture-free method for diagnosing prosthetic joint implant infections. She said “That the current gold standard is bacterial culture from periprosthetic tissue samples collected during surgery, although another option is culturing from sonicated explanted prostheses in saline. However, culture from tissue samples is relatively insensitive, with detection rates around 65% and is a very busy process with many steps.”

Their analyses using this improved protocol have a high degree of concordance with culture testing, and in fact they have been able to detect positives for certain species that were culture-negative. In addition, in a few Staphylococcus-positive cases so far they have been able to identify antimicrobial resistance genes. In one sample, they were able to detect two different Staphylococcus organisms, one of which they could identify (S. haemolyticus) and one of which they could not.

They later used MALDI-ToF mass spectrometry to identify this organism as S. caprae, and realized they couldn't initially detect it because it was not in their reference database, underscoring the fact that metagenomic sequencing is only as good as the reference database being used. The study was presented at the European Congress of Clinical Microbiology and Infectious Diseases held April 13-16, 2019, in Amsterdam, The Netherlands.

Related Links:
University of Oxford
Nuffield Department of Clinical Medicine

Platinum Member
COVID-19 Rapid Test
OSOM COVID-19 Antigen Rapid Test
One Step HbA1c Measuring System
GREENCARE A1c
Anti-Cyclic Citrullinated Peptide Test
GPP-100 Anti-CCP Kit
New
Gold Member
Fully Automated Cell Density/Viability Analyzer
BioProfile FAST CDV

Print article

Channels

Clinical Chemistry

view channel
Image: Reaching speeds up to 6,000 RPM, this centrifuge forms the basis for a new type of inexpensive, POC biomedical test (Photo courtesy of Duke University)

POC Biomedical Test Spins Water Droplet Using Sound Waves for Cancer Detection

Exosomes, tiny cellular bioparticles carrying a specific set of proteins, lipids, and genetic materials, play a crucial role in cell communication and hold promise for non-invasive diagnostics.... Read more

Molecular Diagnostics

view channel
Image: MOF materials efficiently enrich cfDNA and cfRNA in blood through simple operational process (Photo courtesy of Science China Press)

Blood Circulating Nucleic Acid Enrichment Technique Enables Non-Invasive Liver Cancer Diagnosis

The ability to diagnose diseases early can significantly enhance the effectiveness of clinical treatments and improve survival rates. One promising approach for non-invasive early diagnosis is the use... Read more

Hematology

view channel
Image: The low-cost portable device rapidly identifies chemotherapy patients at risk of sepsis (Photo courtesy of 52North Health)

POC Finger-Prick Blood Test Determines Risk of Neutropenic Sepsis in Patients Undergoing Chemotherapy

Neutropenia, a decrease in neutrophils (a type of white blood cell crucial for fighting infections), is a frequent side effect of certain cancer treatments. This condition elevates the risk of infections,... Read more

Pathology

view channel
Image: The OvaCis Rapid Test discriminates benign from malignant epithelial ovarian cysts (Photo courtesy of INEX)

Intra-Operative POC Device Distinguishes Between Benign and Malignant Ovarian Cysts within 15 Minutes

Ovarian cysts represent a significant health issue for women globally, with up to 10% experiencing this condition at some point in their lives. These cysts form when fluid collects within a thin membrane... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.