Time to detection of Mycobacterium tuberculosis using culture filtrate H37rv supplementation on MGIT 960 System

Abstract

Background: The fundamental priority program for controlling Tuberculosis (TB) is accurate and rapid diagnosis. Variable Mycobacterium tuberculosis (MTB) phenotypes were discovered in sputum samples from pulmonary TB (PTB) patients. Active replicating bacteria and differentially culturable tubercle bacteria (DCTB) are present in the sputum. Differentially culturable tubercle bacilli did not grow on the standard medium. Culture filtrate (CF) H37Rv supplementation containing resuscitation-promoting factors (Rpfs) has the potential to increase sensitivity and reduce time to detection (TTD) on culture-based diagnostics. Methods: This study was a true experimental laboratory. A clinical sample was taken from the sputum of 15 PTB patients, which was "MTB detected" by Xpert MTB/RIF assay. Sputum samples were divided into two groups and inoculated on MGIT 960 in one group with CF-H37Rv supplementation and without in the other as standard MGIT medium. Results: On both standard MGIT medium and MGIT+CF H37Rv, the recovery rate was 100%. Seven samples (47%) show a growth promotion effect with CF H37Rv supplementation (ΔTTD > 10 hours), while eight samples (53%) show no change in TTD (ΔTTD < 10 hours). There is no evidence that CF H37Rv supplementation inhibits growth. Six of the seven samples with ΔTTD > 10 jam (85,7%) were dominated by samples with acid-fast bacilli (AFB) grading 1+, which could be an assumption related to re-treatment PTB cases, chronic cases, treatment stages, TB-HIV, or follow up of treatments. Conclusion: There was no difference in recovery rate or TTD between standard MGIT medium and MGIT+CF H37Rv. The supplementation of culture filtrate H37Rv has a greater advantage on samples with low bacterial load (AFB 1+).