Diagnostic accuracy and usefulness of the Genotype MTBDRplus assay in diagnosing multidrug-resistant tuberculosis in Cameroon: a cross-sectional study

Abanda, Ngu Njei; Djieugoué, Josiane Yvonne; Lim, Eunjung; Pefura-Yone, E.W.; Mbacham, Wilfred Fon; Vernet, Guy; Penlap, Véronique; Eyangoh, Sara; Taylor, Diane Wallace; Leke, Rose G. F.

doi:10.1186/s12879-017-2489-3

Cited by 24 publications

(24 citation statements)

References 22 publications

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“…17 African countries are not among the top three countries associated with over half the global burden of MDR tuberculosis. 18 The MDR tuberculosis rates from this region have varied, with a range of rates reported: 4.5% from Chad, 19 12.0% from Benin, 20 5.1% from Mozambique, 21 18% from Cameroon, 22 11.5% from Djibouti, 23 and 1.2% and 3.37% from Ethiopia, 24,25 which are generally higher than the rate observed in this study. In addition to country and regional variations, the rate of MDR tuberculosis is also related to exposure of patients to tuberculosis drugs.…”

Section: Discussioncontrasting

confidence: 66%

Multi-drug resistant Mycobacterium tuberculosis in Port Harcourt, Nigeria

Otokunefor

Omakwele

2018

African Journal of Laboratory Medicine

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BackgroundIn past years, much focus has been on tackling the scourge and spread of tuberculosis worldwide. The recent emergence of multi-drug resistant (MDR) tuberculosis has, however, negatively threatened progress made so far. Nigeria ranks fourth out of the 22 high tuberculosis burden countries in the world and has the highest burden of tuberculosis in Africa. It is therefore necessary to monitor the MDR tuberculosis situation in the country.ObjectivesThis study set out to assess the proportions of MDR tuberculosis in patients attending six directly observed treatment short-course centres in Port Harcourt, Nigeria, from October 2015 to October 2016.MethodsSix hundred and nine participants between the ages of 18 and 75 years were enrolled in this study and comprised suspected and newly diagnosed tuberculosis cases. Sputum samples obtained from the participants were screened for the presence of Mycobacterium tuberculosis using standard culture and phenotypic biochemical techniques, and drug susceptibility testing was carried out using the 1% proportion conventional method.ResultsOf the 609 participants enrolled, 30 (4.9%) were confirmed as M. tuberculosis-positive cases. A high prevalence of drug resistant tuberculosis was noted in this study (14/30, 46.7%), with 26.7% of isolates resistant to streptomycin. MDR tuberculosis, defined as being resistant to isoniazid and rifampicin, was detected in only one case (3.3%).ConclusionThis study reports a low rate of MDR tuberculosis and contributes to the sparse data on drug resistant tuberculosis in Nigeria.

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Section: Discussioncontrasting

confidence: 66%

Multi-drug resistant Mycobacterium tuberculosis in Port Harcourt, Nigeria

Otokunefor

Omakwele

2018

African Journal of Laboratory Medicine

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“…A previous report found a high prevalence of the katG S315T gene mutation among HR-TB/MDR-TB/XDR-TB strains (58.7%-68.6%) in Thailand. 16,17 The prevalence of katG S315T varied according to the geographic region: Southeast Asia (78.4%), 18 Vietnam (85.3%), 19 Myanmar (61.2%), 20 Taiwan (29.3%), 6 Japan (25%), 10 India (67.6%), 21 Sri Lanka (67.8%), 22 Romania (52.8%), 23 Cameroon (64%), 24 and the United States (38%). 8 The different ranges of MIC found for each mutation gene can be explained by gene variation.…”

Section: Discussionmentioning

confidence: 99%

<p>Association Between the Phenotype and Genotype of Isoniazid Resistance Among <em>Mycobacterium tuberculosis</em> Isolates in Thailand</p>

Charoenpak¹,

Santimaleeworagun²,

Suwanpimolkul³

et al. 2020

IDR

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Purpose: The emergence of isoniazid-resistant tuberculosis (HR-TB) is a global public health problem, causing treatment failure and high mortality rates. This study aimed to determine the minimal inhibitory concentration (MIC) of isoniazid and detect the gene mutation in HR-TB and any association between the level of isoniazid resistance and gene mutation. Methods: We collected 74 clinical HR-TB isolates from two tertiary-care centers in Thailand. MICs were established using broth macrodilution. A line probe assay (LPA) was used to detect gene mutations that confer resistance to isoniazid, rifampicin, aminoglycosides, and fluoroquinolones. Results: Sixty-one (82.4%) isolates were monoresistant to isoniazid and 44 (72.1%) were highly resistant to isoniazid. From the clinical isolates, the range of isoniazid MICs was 0.4-16 μg/mL. The katG S315T gene mutation was the prominent mutation in both isoniazid-monoresistant TB (70.5%) and multidrug-resistant TB (72.7%) isolates. The positive predictive value (PPV) of katG was 100% in detecting high levels of isoniazid resistance. The PPV of the inhA mutation was 93.8% in detecting low levels of isoniazid resistance. Five isolates (6.8%) exhibited low-level phenotypic resistance, whereas an LPA failed to detect an isoniazid gene mutation. Our study found one HR-TB isolate with a gyrA fluoroquinoloneresistant gene mutation. Conclusion: Most HR-TB isolates had high isoniazid-resistance levels associated with the katG gene mutation. High-dose isoniazid should be used with caution in patients with HR-TB. Early detection of drug resistance by genotypic assay can help determine an appropriate regimen.

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“…However, performance of genotypic/molecular DST has been shown to be comparable with that of phenotypic DST and is unlikely to be a major factor. [16,17,[43][44][45] We did not analyse second-line resistance and some of these isolates might have demonstrated resistance to second-line drugs, which would render them XDR-TB rather than MDR-TB isolates. Further research in this regard is recommended.…”

Section: Study Limitationsmentioning

confidence: 99%

Prevalence of isoniazid resistance-conferring mutations associated with multidrug-resistant tuberculosis in Free State Province, South Africa

2019

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Background. Multidrug-and extensively drug-resistant tuberculosis (MDR-TB and XDR-TB) threaten local and global control of the disease. The molecular line-probe assay (LPA) provides rapid diagnosis and early management of MDR-TB. The LPA detects mutations of katG and inhA genes associated with isoniazid (INH) resistance in Mycobacterium tuberculosis isolates. The katG and inhA genes are associated with high-and low-level INH resistance, respectively, as well as cross-resistance to ethionamide in the case of inhA gene mutations. Patients with MDR-TB due to an inhA mutation could benefit from the use of high-dose INH -instead of ethionamide -in their MDR-TB regimen. Objectives. To determine the frequencies of katG and inhA mutations that conferred INH resistance among MDR-TB isolates during 2014 -2016 in Free State (FS) Province of South Africa. Methods. We retrospectively reviewed MDR-TB isolates assayed with GenoType MTBDRplus (Hain Lifescience, Germany) (LPA) at the central TB laboratory of Universitas Academic Hospital, Bloemfontein, FS, and calculated the frequencies of katG and inhA mutations. Results. Among 918 MDR-TB isolates, the prevalence of katG, inhA and katG plus inhA mutations was 63.9%, 13.4% and 22.7%, respectively. Approximately 60% (n=536; 58.4%) of the isolates were obtained from male patients. The patients' ages ranged from 1 to 89 (median 37) years. The Xhariep district had the highest incidence of INH resistance-conferring mutations in the province. Conclusions. katG-associated mutations are the predominant INH resistance-conferring mechanism among MDR-TB isolates in the FS. Patients infected with isolates that harbour the katG mutation are unlikely to benefit from high-dose INH therapy in the bedaquiline (BDQ)-containing modified short MDR-TB regimen. They may, however, benefit from the inclusion of ethionamide in the regimen. Dual katG and inhA gene mutations make these patients unlikely to respond to either high-dose INH or ethionamide and should now be considered for either the BDQ-containing long MDR-TB regimen or an individualised treatment regimen, depending on fluoroquinolone susceptibility. Clinicians should familiarise themselves with interpreting various INH resistance-conferring mutation results and their implications for management of MDR-TB treatment.S Afr Med J 2019;109(9):659-664. https://doi.

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Diagnostic accuracy and usefulness of the Genotype MTBDRplus assay in diagnosing multidrug-resistant tuberculosis in Cameroon: a cross-sectional study

Cited by 24 publications

References 22 publications

Multi-drug resistant Mycobacterium tuberculosis in Port Harcourt, Nigeria

Multi-drug resistant Mycobacterium tuberculosis in Port Harcourt, Nigeria

<p>Association Between the Phenotype and Genotype of Isoniazid Resistance Among <em>Mycobacterium tuberculosis</em> Isolates in Thailand</p>

Prevalence of isoniazid resistance-conferring mutations associated with multidrug-resistant tuberculosis in Free State Province, South Africa

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