Fatmata Bintu Barrie

Conference 2023 Presentation

Project title

A comparison Between the Phenotypic and Genotypic Drug Susceptibility Testing of 1st line Anti TB Drugs

Authors and Affiliations

Fatmata Bintu Barrie1

1. College of Medicine and Allied Health Sciences Freetown, Sierra Leone



Tuberculosis (TB) continues to claim the lives of several people in low- and middle-income countries. The continuing spread of multi-drug resistant tuberculosis (MDRTB) is alarming and a major public health threat. Sierra Leone is one of the countries with a high TB burden and factors such as drug availability and incomplete dosage treatment continues to cause a rise in MDRTB. Understanding phenotypic and genotypic drug susceptibility and adequate testing is crucial in combating MDRTB. The proper testing will enable quick treatment and prevent the spread of MDRTB.


This was a comparative study between the phenotypic and genotypic drug susceptibility testing
(DST) for first line anti-tuberculosis drugs for multi-drug resistant TB (MDRTB) patients. We compared the performance of two testing procedures,LPA (Line Probe Assay) and Bactec MGIT (Microbial Growth
Indicator Tube) 960 Testing Platforms for susceptibility testing of Tuberculosis to first-line drugs: rifampicin (RIF), and isoniazid (INH). Thirty-seven (n=37) consecutive Mycobacterium tuberculosis cultures were tested with DST (Drug Susceptibility Testing). Bactec MGIT 960 were also processed with Genotype MTBDR-Plus for this study.


Our study shows that, it is important for TB testing to be both accurate and reliable. Hence, we recommend that health facilities in Sierra Leone have both tests available (LPA and Bactec MGIT) with LPA being the first testing platform followed by MGIT for confirmation following the establishment of genotypic DST results. This will complement the antimicrobial susceptibility testing profile for patients. Also, since it has already been seen that the genotypic method i.e LPA is better in performance than the MGIT DST methods, it would be necessary that more genotypic methods be employed like the next generation sequencing methods so that Loci of strains of TB and their prevalence will be studied and established. We are hopeful that this will help reduce MDRTB spread in Sierra Leone.


This study showed that LPA was more sensitive than MGIT for the diagnosis of MDR-TB and
early detection of possible XDR-TB. (Extra Drug Resistance TB)