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Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability

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DOI

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Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability. / Mtafya, Bariki; Sabiiti, Wilber; Sabi, Issa; John, Joseph; Sichone, Emanuel; Ntinginya, Nyanda E.; Gillespie, Stephen H.

In: Journal of Clinical Microbiology, Vol. 57, e01992-18, 25.06.2019.

Research output: Contribution to journalArticle

Harvard

Mtafya, B, Sabiiti, W, Sabi, I, John, J, Sichone, E, Ntinginya, NE & Gillespie, SH 2019, 'Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability', Journal of Clinical Microbiology, vol. 57, e01992-18. https://doi.org/10.1128/JCM.01992-18

APA

Mtafya, B., Sabiiti, W., Sabi, I., John, J., Sichone, E., Ntinginya, N. E., & Gillespie, S. H. (2019). Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability. Journal of Clinical Microbiology, 57, [e01992-18]. https://doi.org/10.1128/JCM.01992-18

Vancouver

Mtafya B, Sabiiti W, Sabi I, John J, Sichone E, Ntinginya NE et al. Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability. Journal of Clinical Microbiology. 2019 Jun 25;57. e01992-18. https://doi.org/10.1128/JCM.01992-18

Author

Mtafya, Bariki ; Sabiiti, Wilber ; Sabi, Issa ; John, Joseph ; Sichone, Emanuel ; Ntinginya, Nyanda E. ; Gillespie, Stephen H. / Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability. In: Journal of Clinical Microbiology. 2019 ; Vol. 57.

Bibtex - Download

@article{7da6c22f5b794a17a116e4d25cc3c539,
title = "Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability",
abstract = "Effective methods to detect viable Mycobacterium tuberculosis (Mtb), the main causative agent of tuberculosis (TB) are urgently needed. To date, cultivation of Mtb is the gold standard which depends on initial sample processing with N-Acetyl-L-Cysteine/Sodium hydroxide (NALC/NaOH), chemicals that compromise Mtb viability and, consequently the performance of downstream tests. We applied culture and the novel Molecular bacterial load assay (MBLA) to measure the loss of Mtb viability following NALC/NaOH treatment of Mtb H37Rv pure culture and clinical sputa from pulmonary TB patients. Compared to untreated controls, NALC/NaOH treatment of Mtb, reduced MBLA detectable bacillary load (estimated colony forming units/milliliter (eCFU/mL) by 0.66±0.21log10- at 23°C (P=0.018) and 0.72±0.08log10- at 30°C (P=0.013). Likewise, NALC/NaOH treatment reduced viable count on solid culture by 0.84±0.02log10- at 23°C (P<0.001) and 0.85±0.01log10- CFU/mL at 30°C (P<0.001) respectively. The reduction in viable count was reflected by a corresponding increase in time to positivity of MGIT liquid culture, 1.2 days at 23°C (P<0.001), and 1.1 days at 30°C (P<0.001). This NaOH-induced Mtb viability loss was replicated in clinical sputum samples, with bacterial load dropping by 0.65±0.17log10 from 5.36±0.24log10- to 4.71±0.16log10- eCFU/mL for untreated and treated sputa respectively. Applying the Bowness et al model, revealed that the treated MGIT time to culture positivity of 142hrs was equivalent to 4.86±0.28log10CFU, consistent with MBLA-measured bacterial load. Our study confirms the contribution of NALC/NaOH treatment to loss of viable bacterial count. Tests that obviate the need of decontamination may offer alternative option for accurate detection of viable Mtb and treatment response monitoring.",
author = "Bariki Mtafya and Wilber Sabiiti and Issa Sabi and Joseph John and Emanuel Sichone and Ntinginya, {Nyanda E.} and Gillespie, {Stephen H.}",
note = "This work was supported by the commonwealth studentship award for Bariki Mtafya at University of St Andrews in UK and European and Developing Countries Clinical Trials Partnership (EDCTP) through TWENDE and PanACEA II grants.",
year = "2019",
month = "6",
day = "25",
doi = "10.1128/JCM.01992-18",
language = "English",
volume = "57",
journal = "Journal of Clinical Microbiology",
issn = "0095-1137",
publisher = "American Society for Microbiology",

}

RIS (suitable for import to EndNote) - Download

TY - JOUR

T1 - Molecular bacterial load assay (MBLA) concurs with culture on the NaOH-induced Mycobacterium tuberculosis loss of viability

AU - Mtafya, Bariki

AU - Sabiiti, Wilber

AU - Sabi, Issa

AU - John, Joseph

AU - Sichone, Emanuel

AU - Ntinginya, Nyanda E.

AU - Gillespie, Stephen H.

N1 - This work was supported by the commonwealth studentship award for Bariki Mtafya at University of St Andrews in UK and European and Developing Countries Clinical Trials Partnership (EDCTP) through TWENDE and PanACEA II grants.

PY - 2019/6/25

Y1 - 2019/6/25

N2 - Effective methods to detect viable Mycobacterium tuberculosis (Mtb), the main causative agent of tuberculosis (TB) are urgently needed. To date, cultivation of Mtb is the gold standard which depends on initial sample processing with N-Acetyl-L-Cysteine/Sodium hydroxide (NALC/NaOH), chemicals that compromise Mtb viability and, consequently the performance of downstream tests. We applied culture and the novel Molecular bacterial load assay (MBLA) to measure the loss of Mtb viability following NALC/NaOH treatment of Mtb H37Rv pure culture and clinical sputa from pulmonary TB patients. Compared to untreated controls, NALC/NaOH treatment of Mtb, reduced MBLA detectable bacillary load (estimated colony forming units/milliliter (eCFU/mL) by 0.66±0.21log10- at 23°C (P=0.018) and 0.72±0.08log10- at 30°C (P=0.013). Likewise, NALC/NaOH treatment reduced viable count on solid culture by 0.84±0.02log10- at 23°C (P<0.001) and 0.85±0.01log10- CFU/mL at 30°C (P<0.001) respectively. The reduction in viable count was reflected by a corresponding increase in time to positivity of MGIT liquid culture, 1.2 days at 23°C (P<0.001), and 1.1 days at 30°C (P<0.001). This NaOH-induced Mtb viability loss was replicated in clinical sputum samples, with bacterial load dropping by 0.65±0.17log10 from 5.36±0.24log10- to 4.71±0.16log10- eCFU/mL for untreated and treated sputa respectively. Applying the Bowness et al model, revealed that the treated MGIT time to culture positivity of 142hrs was equivalent to 4.86±0.28log10CFU, consistent with MBLA-measured bacterial load. Our study confirms the contribution of NALC/NaOH treatment to loss of viable bacterial count. Tests that obviate the need of decontamination may offer alternative option for accurate detection of viable Mtb and treatment response monitoring.

AB - Effective methods to detect viable Mycobacterium tuberculosis (Mtb), the main causative agent of tuberculosis (TB) are urgently needed. To date, cultivation of Mtb is the gold standard which depends on initial sample processing with N-Acetyl-L-Cysteine/Sodium hydroxide (NALC/NaOH), chemicals that compromise Mtb viability and, consequently the performance of downstream tests. We applied culture and the novel Molecular bacterial load assay (MBLA) to measure the loss of Mtb viability following NALC/NaOH treatment of Mtb H37Rv pure culture and clinical sputa from pulmonary TB patients. Compared to untreated controls, NALC/NaOH treatment of Mtb, reduced MBLA detectable bacillary load (estimated colony forming units/milliliter (eCFU/mL) by 0.66±0.21log10- at 23°C (P=0.018) and 0.72±0.08log10- at 30°C (P=0.013). Likewise, NALC/NaOH treatment reduced viable count on solid culture by 0.84±0.02log10- at 23°C (P<0.001) and 0.85±0.01log10- CFU/mL at 30°C (P<0.001) respectively. The reduction in viable count was reflected by a corresponding increase in time to positivity of MGIT liquid culture, 1.2 days at 23°C (P<0.001), and 1.1 days at 30°C (P<0.001). This NaOH-induced Mtb viability loss was replicated in clinical sputum samples, with bacterial load dropping by 0.65±0.17log10 from 5.36±0.24log10- to 4.71±0.16log10- eCFU/mL for untreated and treated sputa respectively. Applying the Bowness et al model, revealed that the treated MGIT time to culture positivity of 142hrs was equivalent to 4.86±0.28log10CFU, consistent with MBLA-measured bacterial load. Our study confirms the contribution of NALC/NaOH treatment to loss of viable bacterial count. Tests that obviate the need of decontamination may offer alternative option for accurate detection of viable Mtb and treatment response monitoring.

U2 - 10.1128/JCM.01992-18

DO - 10.1128/JCM.01992-18

M3 - Article

VL - 57

JO - Journal of Clinical Microbiology

JF - Journal of Clinical Microbiology

SN - 0095-1137

M1 - e01992-18

ER -

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