Skip to main content
. 2020 Oct 9;2020:5185896. doi: 10.1155/2020/5185896

Table 2.

Phenotypic and genotypic drug susceptibility results.

Conventional drug susceptibility testing (DST) Genotypic drug susceptibility method Comparison of phenotypic and genotypic resistance (INHR/RIFR)
Studies included in the review Isolates (n) Susceptible for all first-line drugs INHR RIFR MDR Molecular assay Sample processing and DNA extraction Isolates (n)
Oudghiri et al. 2018 [26] 703 221 194 198 90 PCR and DNA sequencing (performed only for MDR: 90) DNA was prepared from scraped colonies suspended in distilled water, followed by heat inactivation 84 6 MDR isolates contained no mutations in the sequenced region (157 bp)
DNA was immediately used or stored at −20°C until use

Karimi et al. 2018 [27] 70 19 13 12 26 GenoType® MTBDRplus V2.0 (performed for all resistant strains: 51) The assay was applied on direct sputum specimens and on culture isolates 47 4 (1 INHR and 3 RIFR) phenotypically resistant strains did not exhibit any mutation using GenoType® MTBDRplus assay

Ennassiri et al. 2017 [28] 319 172 31 9 107 GenoType® MTBDRplus V2.0 (performed for RIFR and MDR: 116) The assay was performed on isolates after solid culture or directly on decontaminated sputum specimens 98 18 RIFR samples were missing wild-type probes with no gain in mutation probes

Bentaleb et al. 2017 [29] 67 22 45 qPCR-HRM (120 pb) (performed for RIFR strains: 45) DNA was extracted and purified using QIAamp DNA mini kit according to the manufacturer's protocol 40 5 RIFR strains contained no mutation in the rpoB amplified region and were classified as phenotypically RIF-resistant isolates
DNA was stored at −20°C until use

Chaoui et al. 2014 [24] 500 346 154 RIFO (performed for RIFR strains: 154) DNA was prepared from scraped colonies suspended in 1x TE buffer, followed by heat inactivation 140 14 RIFR isolates that were phenotypically resistant did not exhibit any point mutation in the hot-spot region of the rpoB gene
DNA was stored at −20°C until use

Zakham et al. 2013 [25] 133 94 10 18 11 PCR and DNA sequencing (performed for all resistant strains: 39) Specimens decontaminated by N-acetyl-l-cysteine were first thawed and centrifuged. For each specimen, the pellet was treated by heat shock 33 6 (3 INHR, 1 RIFR, and 2 MDR) strains did not exhibit any point mutation in the amplified regions (rpoB and katG genes and inhA promoter region)
DNA was immediately used or stored at −20°C until use

Total 1792 874 248 436 234 442 53 (4 INHR, 8 MDR, and 41 RIFR)

n: number; INHR: isoniazid resistant; RIFR: rifampicin resistant; RIFO: rifoligotyping; qPCR-HRM: quantitative polymerase chain reaction-high-resolution melting; MDR: multidrug resistant.