Analysis of Discordance between Genotypic and Phenotypic Assays for Rifampicin-Resistant Mycobacterium tuberculosis Isolated from Healthcare Facilities in Mthatha
- Bokop, Carine, Faye, M Lindiwe, Apalata, Teke
- Authors: Bokop, Carine , Faye, M Lindiwe , Apalata, Teke
- Date: 2023/07
- Subjects: Xpert MTB/RIF , Line probe assay , MGIT 960 system , Mycobacterium tuburculosis , Discrepant results
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/11260/13652 , vital:78963 , DOI: https://doi.org/10.3390/pathogens12070909
- Description: The study sought to determine the rate of discordant results between genotypic and phenotypic tests for the diagnosis of drug-resistant tuberculosis (DR-TB). Sputum samples and cultured isolates from suspected DR-TB patients were, respectively, analyzed for Mycobacterium tuberculosis by Xpert® MTB/RIF (Cepheid, Sunnyvale, CA, USA) and line probe assays (LPA) (Hain, Nehren, Germany). Discrepant rifampicin (RMP)-resistant results were confirmed using BACTEC MGIT960 (BD, New York, NY, USA). Of the 224 RMP-resistant results obtained by Xpert MTB/RIF, 5.4% were susceptible to RMP by LPA. MGIT960 showed a 75% agreement with LPA. The discrepancy was attributed to either heteroresistance or DNA contamination during LPA testing in 58.3% of cases. In 25% of the samples showing agreement in RMP resistance between Xpert MTB/RIF and MGIT960, the discrepancy was attributed to laboratory errors causing false RMP susceptible results with LPA. In 16.7% of the cases, the discrepancy was attributed to false RMP susceptible results with Xpert MTB/RIF. Out of the 224 isolates, susceptibility to isoniazid (INH) by LPA was performed in 73.7% RMP-resistant isolates, of which, 80.6% were resistant. All RMP-resistant isolates by Xpert MTB/RIF were confirmed in 98.5% by LPA if TB isolates were resistant to INH, but were only confirmed in 81.3% if TB isolates were susceptible to INH....
- Full Text:
- Date Issued: 2023/07
- Authors: Bokop, Carine , Faye, M Lindiwe , Apalata, Teke
- Date: 2023/07
- Subjects: Xpert MTB/RIF , Line probe assay , MGIT 960 system , Mycobacterium tuburculosis , Discrepant results
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/11260/13652 , vital:78963 , DOI: https://doi.org/10.3390/pathogens12070909
- Description: The study sought to determine the rate of discordant results between genotypic and phenotypic tests for the diagnosis of drug-resistant tuberculosis (DR-TB). Sputum samples and cultured isolates from suspected DR-TB patients were, respectively, analyzed for Mycobacterium tuberculosis by Xpert® MTB/RIF (Cepheid, Sunnyvale, CA, USA) and line probe assays (LPA) (Hain, Nehren, Germany). Discrepant rifampicin (RMP)-resistant results were confirmed using BACTEC MGIT960 (BD, New York, NY, USA). Of the 224 RMP-resistant results obtained by Xpert MTB/RIF, 5.4% were susceptible to RMP by LPA. MGIT960 showed a 75% agreement with LPA. The discrepancy was attributed to either heteroresistance or DNA contamination during LPA testing in 58.3% of cases. In 25% of the samples showing agreement in RMP resistance between Xpert MTB/RIF and MGIT960, the discrepancy was attributed to laboratory errors causing false RMP susceptible results with LPA. In 16.7% of the cases, the discrepancy was attributed to false RMP susceptible results with Xpert MTB/RIF. Out of the 224 isolates, susceptibility to isoniazid (INH) by LPA was performed in 73.7% RMP-resistant isolates, of which, 80.6% were resistant. All RMP-resistant isolates by Xpert MTB/RIF were confirmed in 98.5% by LPA if TB isolates were resistant to INH, but were only confirmed in 81.3% if TB isolates were susceptible to INH....
- Full Text:
- Date Issued: 2023/07
Prolongation of Acid-Fast Bacilli Sputum Smear Positivity in Patients with Multidrug Pulmonary Tuberculosis
- Mvo, Sidwell, Bokop, Carine, Longo-Mbenza, Benjamin, Vasaikar, D Sandeep, Apalata, Teke
- Authors: Mvo, Sidwell , Bokop, Carine , Longo-Mbenza, Benjamin , Vasaikar, D Sandeep , Apalata, Teke
- Date: 2023
- Subjects: MDR-TB , HIV status , Time to sputum microscopy conversion , Smear positivity
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/11260/13621 , vital:78968 , DOI: https://doi.org/10.3390/pathogens12091133
- Description: The study sought to determine factors associated with prolonged smear positivity in multidrug-resistant tuberculosis (MDR-TB) patients following appropriate management. Newly diagnosed patients were enrolled between June 2017 and May 2018. Sputum samples were collected for Xpert® MTB/RIF and line probe assays (LiPAs). Microscopic tests were performed at baseline and 4, 8, and 12 weeks post-anti-TB therapy. Of the 200 patients, 114 (57%) were HIV-positive. After 12 weeks of treatment, there was a significant microscopy conversion rate among DS-TB patients compared to MDR-TB patients irrespective of their HIV status (p = 0.0013). All MDR-TB patients who had a baseline smear grade ranging from scanty to +1 converted negative, while 25% ranging from +2 to +3 remained positive until the end of 12 weeks (p = 0.014)…
- Full Text:
- Date Issued: 2023
- Authors: Mvo, Sidwell , Bokop, Carine , Longo-Mbenza, Benjamin , Vasaikar, D Sandeep , Apalata, Teke
- Date: 2023
- Subjects: MDR-TB , HIV status , Time to sputum microscopy conversion , Smear positivity
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/11260/13621 , vital:78968 , DOI: https://doi.org/10.3390/pathogens12091133
- Description: The study sought to determine factors associated with prolonged smear positivity in multidrug-resistant tuberculosis (MDR-TB) patients following appropriate management. Newly diagnosed patients were enrolled between June 2017 and May 2018. Sputum samples were collected for Xpert® MTB/RIF and line probe assays (LiPAs). Microscopic tests were performed at baseline and 4, 8, and 12 weeks post-anti-TB therapy. Of the 200 patients, 114 (57%) were HIV-positive. After 12 weeks of treatment, there was a significant microscopy conversion rate among DS-TB patients compared to MDR-TB patients irrespective of their HIV status (p = 0.0013). All MDR-TB patients who had a baseline smear grade ranging from scanty to +1 converted negative, while 25% ranging from +2 to +3 remained positive until the end of 12 weeks (p = 0.014)…
- Full Text:
- Date Issued: 2023
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