Fluorescein diacetate and rapid molecular testing for the early identification of rifampicin resistance in Mali

Bassirou Diarra*, T. Decroo, A. Somboro, G. Coulibaly, M. Tolofoudie, M. Kone, B. Degoga, F. Diallo, A. C.G. Togo, M. Sanogo, Y. S. Sarro, A. B. Cisse, O. Kodio, B. Baya, A. Kone, M. Maiga, S. Dao, I. I. Maiga, R. L. Murphy, S. SiddiquiY. Toloba, B. Konate, M. Diakite, S. Doumbia, A. Van Deun, L. Rigouts, S. Diallo, B. C. De Jong

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

Abstract

BACKGROUND: Non-conversion on auramine smear microscopy indicates a lack of treatment response, possibly associated with initial rifampicin-resistant tuberculosis (RR-TB). However, dead bacteria still stain positive and may be detected. Fluorescein diacetate smear microscopy (FDA) shows live mycobacteria only. Therefore, we studied the potential of 2-month (2M) FDA for the identification of initial RRTB. METHODS: Between 2015 and 2018, we enrolled new smear-positive pulmonary TB patients from five local centres in Bamako, Mali. After baseline screening, sputum samples were collected at 1M, 2M, 5M and 18M. We used rpoB sequencing to identify initial RRTB. RESULTS: Of 1359 patients enrolled, 1019 (75%) had rpoB sequencing results. Twenty-six (2.6%, 95%CI: 1.7a-3.7) had mutations conferring rifampicin resistance. Most frequent rpoB mutations were located at the codons Asp435Val (42.4%) and Ser450Leu (34.7%). Among patients with initial RR-TB, 72.2% were FDAnegative at 2M (P Â 0.2). The positive and negative predictive value of 5M FDA for culture-based failure was respectively 20.0% and 94.7%. CONCLUSION: FDA did not identify the majority of patients with initial RR-TB or culture-based failure. As the full spectrum of mutations identified on sequencing was identified using Xpert, our data support its rapid universal implementation in Mali.

Original languageEnglish (US)
Pages (from-to)763-769
Number of pages7
JournalInternational Journal of Tuberculosis and Lung Disease
Volume24
Issue number8
DOIs
StatePublished - Aug 1 2020
Externally publishedYes

Keywords

  • FDA
  • Mali
  • rpoB
  • sequencing

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Fluorescein diacetate and rapid molecular testing for the early identification of rifampicin resistance in Mali'. Together they form a unique fingerprint.

Cite this