Sunday January 19, 2020

Genomic Sequencing-based Test Detect Resistant Mutation In Tuberculosis

Indian firm develops a test to detect drug-resistant TB mutation

0
//
Tuberculosis
Doctors can use direct whole genome sequencing to get information on drug resistance mutations in TB. Pixabay

Genetic diagnostic and drug discovery research firm MedGeneome Labs on Thursday claimed to have developed the first whole genomic sequencing-based test to detect drug-resistant mutation in tuberculosis (TB) bacteria.

“The breakthrough DNA test will enable a doctor to correctly prescribe the most effective drug to a TB patient without a time-consuming trial and error process,” said the city-based clinical data-driven Labs.

Announcing its foray into infectious disease testing in TB, central nervous system (CNS), systemic and eye infections, the company said India had the largest number of multi-drug resistant (MDR) TB cases.

Tuberculosis detection
A breakthrough DNA test will enable doctors to correctly prescribe the most effective medicine to a TB patient. Pixabay

“India has the largest number of MDR-TB cases. Our spit sequence can be a boon for TB patients, clinicians and healthcare agencies to achieve the sustainable development goal of eliminating TB by 2025,” Labs Chief Operating Officer V.L. Ramprasad told reporters here.

“The test is based on the whole-genome sequencing of mycobacterium tuberculosis (MTB), the TB causing bacteria, to assess the mutations in bacteria’s genome and allows a clinician to determine which drug will work for a patient,” he said.

Mumbai-based P.D. Hinduja Hospital and Medical Research Centre head Camilla Rodrigues said the test was validated with 100 samples recording 100 per cent sensitivity and 98.04 per cent specificity compared with line probe assay technology.

tuberculosis
India had the largest number of multi-drug resistant (MDR) TB cases. Pixabay

“Of the 100 samples, 50 were tested in our hospital. The findings in the manuscript are under review for publication,” Rodrigues said on the occasion.

Noting that the process of analyzing the drug resistance was long, which is delaying early treatment for MDR-TB patient, Rodrigues said the current expertise allowed testing resistance only on 4 drugs, which makes the patient wait until testing on all possible drugs concluded.

Also Read: The Health Benefits of Testing Your Cortisol Levels

“Direct whole genome sequencing reveals information on drug resistance mutations for all anti-TB drugs in 10 days. Our testing will help to optimise the management of an MDR-TB patient”, she added. (IANS)

Next Story

Changing the Dose of TB Vaccination may Improve its Efficacy: Study

New approach improves efficacy of TB vaccine says a new study

0
TB vaccination
Tuberculosis (TB) is the leading infectious cause of death globally, yet the world's only licensed TB vaccine, Bacille Calmette-Guerin (BCG), was developed a century ago. Pixabay

Researchers have shown that simply changing the dose and route of administration from intradermal (ID) to intravenous (IV) greatly increases the vaccine’s ability to protect rhesus macaques from infection following exposure to Mycobacterium tuberculosis (Mtb), the bacterium that causes TB.

Tuberculosis (TB) is the leading infectious cause of death globally, yet the world’s only licensed TB vaccine, Bacille Calmette-Guerin (BCG), was developed a century ago.

Given to infants via a needle placed just under the skin, BCG protects babies from a form of the disease called disseminated TB but is far less effective at preventing pulmonary TB.

The findings from University of Pittsburgh in US, provide a new understanding of the mechanisms of BCG-elicited protection against tuberculosis infection and disease.

In addition, the finding, published in the journal Nature, supports investigation of IV BCG administration in clinical trials to determine whether this route improves its effectiveness in teens and adults.

According to the researchers, to control Mtb infection and prevent clinical disease, a TB vaccine must elicit strong, sustained responses from the immune system’s T cells, specifically those in the lungs. However, the standard, ID, route of BCG administration may not generate enough of these critical cells in the lungs.

TB
A TB vaccine must elicit strong, sustained responses from the immune system’s T cells, specifically those in the lungs. Pixabay

The research team hypothesized that administration of BCG by IV or aerosol (AE) routes would overcome this hurdle and thus confer substantially better protection from infection and disease in rhesus macaques following challenge with virulent Mtb. In their study, groups of animals received the BGC vaccine by ID, AE or IV routes.

The scientists assessed immune responses in blood and in fluid drawn from the lungs for a 24-week period following vaccination. IV BCG vaccination resulted in the highest durable levels of T cells in the blood and lungs.

Six months after vaccination, the researchers exposed groups of vaccinated rhesus macaques (immunized via ID, AE or IV routes) and a group of unvaccinated macaques to a virulent strain of Mtb by introducing the bacteria directly into the animals’ lungs. They then tracked the infection and disease development over three months.

Nine out of 10 animals vaccinated with IV BCG were highly protected; six showed no detectable infection in any tissue tested and three had only very low counts of Mtb bacteria in lung tissue.

Also Read- For Millennials, Owning a Car Means More Sex

All unvaccinated animals and those immunized via ID or AE routes showed signs of significantly greater infection.

The investigators concluded that IV BCG conferred an unprecedented degree of protection in an animal model of severe TB and ‘represents a major step forward in the field of TB vaccine research.’ (IANS)