Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING LLC
RANDOX LABORATORIES
FOCUS DIAGNOSTICS, INC.

Molecular Immunoassay Diagnoses Melioidosis

By Labmedica International staff writers
Posted on 18 Feb 2013
Image: Burkholderia pseudomallei (Photo courtesy US Centers of Disease Control.
Image: Burkholderia pseudomallei (Photo courtesy US Centers of Disease Control.
Melioidosis is caused by the Gram-negative bacterium Burkholderia pseudomallei for which the standard test growing it on microbiological culture media, which requires at least 3 to 4 days to obtain a result, hindering successful treatment of acute disease.

Where the seroprevalence of antibodies to B. pseudomallei is relatively low, serology is a potentially advantageous addition to culture in the diagnosis of melioidosis and serology would be very effective in diagnosing travelers and military personnel returning from endemic tropical areas.

Scientists at James Cook University (Douglas, Australia) developed an enzyme-linked immunosorbent assay (ELISA) and a quantitative immunopolymerase chain reaction (PCR) assay capable of detecting melioidosis-specific antibodies. They demonstrated their validity with indirect haemagglutination assay (IHA)-negative sera from patients with melioidosis. A total of 10 serum samples from three IHA-positive and three IHA-negative melioidosis patients were tested along with sera from six healthy controls.

To verify the assays, the scientists used various techniques including immunoblotting, indirect peroxidase-conjugated protein G ELISA, and indirect terminus utilization substance (Tus) - DNA replication terminator sites (Ter)-lock immuno-PCR. Both the latter systems Both systems were based on the detection of immunoglobulin G (IgG) by protein G conjugated to a signal generation system consisting of either the enzymatic activity of peroxidase or a quantitative PCR (qIPCR) read-out in the case of Tus and the TT-lock-T DNA probe. All patient sera, including that collected at presentation and in subsequent follow-up collections, reacted against the B. pseudomallei antigenic fraction in both the G-peroxidase ELISA and TT-lock qIPCR format. Individual negative control sera from six healthy controls did not react against the B. pseudomallei antigenic fraction in either assay.


The authors concluded that although the indirect TT-lock qIPCR system is slightly slower than the ELISA format, it requires the least amount of serum and would be advantageous when multiple testing is required for the confirmation of disease. The ability to detect antibodies in patient sera that were persistently IHA negative is very promising, indicating that both immunoassay formats will be ideal for the rapid and reliable diagnosis of melioidosis in patients in nonendemic regions. The study was published in the February 2013 edition of the journal Diagnostic Microbiology and Infectious Disease.

Related Links:

James Cook University



DIASYS DIAGNOSTIC SYSTEMS
KARL HECHT GMBH & CO KG
77 ELEKTRONIKA

Channels

Genetic Tests

view channel

Padlock Probe Assay Rapidly Detects Cardiac Disease Gene Mutations

A recent paper described a novel next generation sequencing (NGS) assay for detecting cardiac disease gene mutations with improved accuracy, flexibility, turnaround time, and cost. By using double-stranded DNA probes (complementary long "padlock" probes or cLPPs), investigators at Stanford University (Palo Alto, CA,... Read more

Hematology

view channel
Image: Immunochemistry of bone marrow biopsy from an acute myeloid leukemia patient showing sheets of CD34 positive cells; corresponding bone marrow aspirate showed only 20% blasts (Photo courtesy of All India Institute of Medical Sciences).

Immunohistochemistry Assesses Early Response in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with respect to prognosis and early response assessment has an established role as predictor of remission rate, and overall and disease-free survival.... Read more

Industry News

view channel

Distribution Agreement to Improve Automated Hemostasis Diagnostics

A new, exclusive-distributer agreement will lead to creating a unique high-performance hemostatis work cell by connecting a laboratory automation system (LAS) from Thermo Fisher Scientific (Waltham, MA, USA) with a hemostasis testing LAS from Instrumentation Laboratory (IL; Bedford, MA, USA). The agreement between IL... Read more
 
Copyright © 2000-2015 Globetech Media. All rights reserved.