| dc.description.abstract | objectives Differences among Mycobacterium tuberculosis complex (MTC) species may predict
drug resistance or treatment success. Thus, we optimised and deployed the genotype MTBC assay
(gMTBC) to identify MTC to the species level, and then performed comparative genotypic drugsusceptibility testing to anti-tuberculosis drugs from direct sputum of patients with presumed
multidrug-resistant tuberculosis (MDR-TB) by the MTBDRplus/sl reference method.
methods Patients with positive Xpert MTB/RIF (Xpert) results were consented to provide earlymorning-sputum for testing by the gMTBC and the reference MTBDRplus/sl. Chi-square or Fisher’s
exact test compared proportions. Modified Poisson regression modelled detection of MTC by gMTBC.
results Among 73 patients, 53 (73%) were male and had a mean age of 43 (95% CI; 40–45)
years. In total, 34 (47%), 36 (49%) and 38 (55%) had positive gMTBC, culture and MTBDR
respectively. Forty patients (55%) had low quantity MTC by Xpert, including 31 (78%) with a
negative culture. gMTBC was more likely to be positive in patients with chest cavity 4.18 (1.31–
13.32, P = 0.016), high-quantity MTC by Xpert 3.03 (1.35–6.82, P = 0.007) and sputum smear
positivity 1.93 (1.19–3.14, P = 0.008). The accuracy of gMTBC in detecting MTC was 95% (95%
CI; 86–98; j = 0.89) compared to MTBDRplus/sl. All M. tuberculosis/canettii identified by gMTB
were susceptible to fluoroquinolone and aminoglycosides/capreomycin.
conclusions The concordance between the gMTBC assay and MTBDRplus/sl in detecting MTC
was high but lagged behind the yield of Xpert MTB/RIF. All M. tuberculosis/canettii were susceptible
to fluoroquinolones, a core drug in MDR-TB treatment regimens. | en_US |
