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
INTEGRA BIOSCIENCES AG

Download Mobile App




Events

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

Simple Test Could Improve TB Diagnosis in Developing Countries

By LabMedica International staff writers
Posted on 29 Aug 2016
Print article
Image: In an innovative new diagnostic test for tuberculosis (TB), a green glow highlights live TB bacteria cells against a field of other debris in a saliva sample (Photo courtesy of Prof. CR Bertozzi, Stanford University).
Image: In an innovative new diagnostic test for tuberculosis (TB), a green glow highlights live TB bacteria cells against a field of other debris in a saliva sample (Photo courtesy of Prof. CR Bertozzi, Stanford University).
Researchers have developed an innovative diagnostic assay for tuberculosis (TB) that may replace the complicated error-prone test often used in resource-limited areas. Field trials of the experimental new test began in June 2016 in South Africa, which has a high incidence of TB.

The researchers, led by Prof. Carolyn R. Bertozzi, PhD, Stanford University (Stanford, CA, USA), presented their work at the American Chemical Society’s (ACS; Washington, DC, USA) 252nd National Meeting & Exposition, held August 21-25 in Philadelphia, PA, USA.

In wealthier countries, a patient suspected of having TB can be examined with a chest X-ray or a patient sputum or saliva sample can be tested by modern techniques such PCR. But in developing nations with limited resources and spotty access to electricity, samples are often checked for TB with the Ziehl-Neelsen (ZN) test, developed in the 1880s. The procedure takes several hours and is even not very sensitive, missing some TB cases and resulting in many false positives.

Years ago the researchers began investigating bacterial cell wall glycolipids involved in causing TB. Each glycolipid consists of the sugar trehalose linked to a lipid. They discovered that if they provided slightly modified forms of trehalose to the bacteria, the microbes would metabolize and integrate them into their glycolipids. Other researchers showed that the bacteria can take up forms of trehalose attached to a fluorescent dye molecule. A cell that picks up these sugars glows green. “We thought we could use this to detect the bacteria in sputum samples,” said Prof. Bertozzi. Unfortunately, the other researchers’ dye also sticks to other components in saliva, making it difficult to distinguish the bacteria.

The team solved this problem by attaching trehalose to a “solvatochromic” dye that doesn’t glow until it’s incorporated into the cell walls. As a result, there is no background glow. In addition, the procedure is relatively simple: the technician takes a sputum sample, squirts a small amount of dye mixture onto it, and after an hour examines it under a microscope. Even better, whereas the ZN test dyes label both live and dead cells, the new test labels only live cells as it depends on the bacterial cells metabolizing & integrating the trehalose. Since the ZN test cannot determine whether the number of live cells is decreasing, it cannot be used to monitor treatment effectiveness. “If the drugs aren’t working, you want to switch the patient to the next treatment as quickly as possible so you don’t contribute to drug resistance,” said Prof. Bertozzi.

Prof. Bertozzi’s team is also studying other fluorescent dyes that may work even better, and using their current trehalose/dye molecule to explore the structure and properties of the TB bacteria’s cell wall.

Related Links:
Stanford University
American Chemical Society
Platinum Member
COVID-19 Rapid Test
OSOM COVID-19 Antigen Rapid Test
HLX
Anti-Cyclic Citrullinated Peptide Test
GPP-100 Anti-CCP Kit
Gold Member
Real-time PCR System
GentierX3 Series

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.