The following is a summary of “A new method for the detection of Mycobacterium tuberculosis based on the CRISPR/Cas system,” published in the October 2023 issue of Infectious Disease by Zhang et al.
Researchers started a retrospective study to develop efficient, specific, convenient, and inexpensive Mycobacterium tuberculosis (MTB) assays for preventing and controlling Tuberculosis (TB).
They established a specific detection method for MTB by employing the Clustered Regularly Interspersed Short Palindromic Repeats (CRISPR) system, coupled with recombinase-mediated isothermal nucleic acid amplification (RAA) to enhance the detection system’s sensitivity and achieve a “two-level” signal amplification. RAA combined with CRISPR/Cas has high sensitivity and specificity for detecting TB.TB-CRISPR was compared to the gold standard BACTEC 960 culture for MTB detection in 504 suspected TB patients.
The results showed that the CRISPR-Cas12a system targeting IS6110 could detect MTB H37Ra at concentrations as low as 3.13 CFU/mL. When compared to the BACTEC960 culture (120 positives and 384 negatives), the TB-CRISPR technique exhibited a sensitivity of 0.883 (95% CI: 0.809–0.932) and a specificity of 0.940 (95% CI: 0.910–0.961). The receiver operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.944 (95% CI: 0.914–0.975). The positive likelihood ratio (PLR) was 14.747 (95% CI: 9.870–22.035), and the negative likelihood ratio (NLR) was 0.124 (95% CI: 0.076–0.203). Additionally, the positive predictive value (PPV) was 0.822 (95% CI: 0.742–0.881), and the negative predictive value (NPV) was 0.963 (95% CI: 0.937–0.979).
They concluded that TB-CRISPR provides a rapid, easy, and accessible molecular diagnosis of TB within 1.5 hours.
Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-023-08656-4