AUTHOR=Rondón Liliana , Urdániz Estefanía , Latini Cecilia , Payaslian Florencia , Matteo Mario , Sosa Ezequiel J. , Do Porto Darío F. , Turjanski Adrian G. , Nemirovsky Sergio , Hatfull Graham F. , Poggi Susana , Piuri Mariana 

TITLE=Fluoromycobacteriophages Can Detect Viable Mycobacterium tuberculosis and Determine Phenotypic Rifampicin Resistance in 3–5 Days From Sputum Collection

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01471

DOI=10.3389/fmicb.2018.01471

ISSN=1664-302X

ABSTRACT=<p>The World Health Organization (WHO) estimates that 40% of tuberculosis (TB) cases are not diagnosed and treated correctly. Even though there are several diagnostic tests available in the market, rapid, easy, inexpensive detection, and drug susceptibility testing (DST) of <italic>Mycobacterium tuberculosis</italic> is still of critical importance specially in low and middle-income countries with high incidence of the disease. In this work, we have developed a microscopy-based methodology using the reporter mycobacteriophage <italic>mCherry<sub>bomb</sub></italic>ϕ for detection of <italic>Mycobacterium spp.</italic> and phenotypic determination of rifampicin resistance within just days from sputum sample collection. Fluoromycobacteriophage methodology is compatible with regularly used protocols in clinical laboratories for TB diagnosis and paraformaldehyde fixation after infection reduces biohazard risks with sample analysis by fluorescence microscopy. We have also set up conditions for discrimination between <italic>M. tuberculosis</italic> complex (MTBC) and non-tuberculous mycobacteria (NTM) strains by addition of <italic>p</italic>-nitrobenzoic acid (PNB) during the assay. Using clinical isolates of pre-XDR and XDR-TB strains from this study, we tested <italic>mCherry<sub>bomb</sub></italic>Φ for extended DST and we compared the antibiotic resistance profile with those predicted by whole genome sequencing. Our results emphasize the utility of a phenotypic test for <italic>M. tuberculosis</italic> extended DST. The many attributes of <italic>mCherry<sub>bomb</sub></italic>Φ suggests this could be a useful component of clinical microbiological laboratories for TB diagnosis and since only viable cells are detected this could be a useful tool for monitoring patient response to treatment.</p>