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
Abbott Diagnostics

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.
23 Jan 2021 - 27 Jan 2021
Virtual Venue
24 Feb 2021 - 28 Feb 2021
Virtual Venue

Serological Dipstick Assay Developed for Melioidosis

By LabMedica International staff writers
Posted on 05 Aug 2020
Print article
Image: The Melioidosis DS assay principle: A dipstick is placed into a well containing patient serum diluted in dipstick master mix (running buffer, detection antibody and control reagent) (Photo courtesy of Medical University of Graz).
Image: The Melioidosis DS assay principle: A dipstick is placed into a well containing patient serum diluted in dipstick master mix (running buffer, detection antibody and control reagent) (Photo courtesy of Medical University of Graz).
The Gram-negative environmental pathogen Burkholderia pseudomallei, causes the severe disease melioidosis. It is highly endemic in southeast Asia and northern Australia, but recent studies suggest that it is also present in many other parts of the world where it is severely underreported.

The underreporting results from the extremely variable and non-specific clinical manifestations of the disease, lack of clinical recognition, and the global scarcity of good quality laboratories to allow diagnosis from microbiological culture. Early diagnosis of the disease is indispensable for an effective therapy, since B. pseudomallei is intrinsically resistant to many antibiotics used for empirical treatment in endemic areas.

Medical microbiologists at the Medical University of Graz (Graz, Austria) and their international colleagues developed a dipstick assay, which was based on the detection of serum antibodies against four B. pseudomallei specific protein antigens. They evaluated their Melioidosis DS rapid test by using the same set of human serum samples that were previously characterized. The serum collection consisted of 75 sera from culture-confirmed melioidosis patients upon admission and 100 healthy controls. They also tested another 95 samples from Thailand on their dipsticks. These sera were previously classified as 55 false-negative or 40 false-positive on a heme carrier protein 1 (Hcp1) based lateral flow assay. Twenty-eight of the false-positive sera were drawn from healthy individuals and 12 from patients suffering from other kinds of infections.

The investigators reported that their 4-plex dipstick was validated with sera from 75 patients on admission plus control groups, achieving 92% sensitivity and 97% to 100% specificity. They then re-evaluated melioidosis sera with the 4-plex assay that were previously misclassified by the monoplex Hcp1 rapid test. They found that 12/55 (21.8%) false-negative samples were positive in the new dipstick assay. Among those, four sera (7.3%) were Hcp1 positive, whereas eight (14.5%) sera remained Hcp1 negative but gave a positive reaction with their additional antigens.

The authors concluded that the dipstick rapid test represents an inexpensive, standardized and simple diagnostic tool with an improved serodiagnostic performance due to multiplex detection. Each additional band on the test strip makes a false-positive result more unlikely, contributing to its reliability. The study was published on July 13, 2020 in the journal PLOS Neglected Tropical Diseases.

Related Links:
Medical University of Graz

Print article


Molecular Diagnostics

view channel
Image: Schematic representation of Chiari malformation type 1; it involves the lower part of the cerebellum known as tonsils, but not the brain stem (Photo courtesy of Healthline).

Common Brain Malformation Traced to Its Genetic Roots

About one in 100 children has a common brain disorder called Chiari 1 malformation, but most of the time such children grow up normally and no one suspects a problem. However about one in 10 of those children,... Read more


view channel
Image: uPath HER2 Dual ISH image analysis for breast cancer (Photo courtesy of Roche)

Roche Launches Digital Pathology Image Analysis Algorithms for Precision Patient Diagnosis in Breast Cancer

Roche (Basel, Switzerland) has announced the CE-IVD launch of its automated digital pathology algorithms, uPath HER2 (4B5) image analysis and uPath Dual ISH image analysis for breast cancer to help determine... Read more
Copyright © 2000-2021 Globetech Media. All rights reserved.