1
|
Shinu P, Singh VA, Nair A, Venugopala KN, Akrawi SH. Papain-cetylpyridinium chloride and pepsin-cetylpyridinium chloride; two novel, highly sensitive, concentration, digestion and decontamination techniques for culturing mycobacteria from clinically suspected pulmonary tuberculosis cases. PLoS One 2020; 15:e0236700. [PMID: 32750088 PMCID: PMC7402486 DOI: 10.1371/journal.pone.0236700] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 07/12/2020] [Indexed: 11/18/2022] Open
Abstract
Mycobacterial culture remains the gold standard for the diagnosis of tuberculosis. However, an appropriate digestion and decontamination method (DDM) is essential for the effective recovery of tubercle bacilli in culture. Therefore, the current study was designed to compare the performance of papain-cetylpyridinium chloride [papain-CPC] and pepsin-cetylpyridinium chloride [pepsin-CPC] DDMs against N-acetyl L-Cysteine-sodium hydroxide (NALC-NaOH) DDM for recovery of mycobacteria from clinically suspected pulmonary tuberculosis cases. To evaluate papain-CPC, pepsin-CPC and NALC-NaOH DDMs, sputum samples (N = 1381) were cultured on Löwenstein-Jensen medium and the results were compared. The papain-CPC DDM showed sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 93.27%, 71.7%, and 100%, respectively as compared to NALC-NaOH DDM. Similarly, pepsin-CPC DDM demonstrated sensitivity, specificity, positive predictive value and negative predictive value of 98.94%, 94.7%, 76.11%, and 99.81%, respectively. In summary, both papain-CPC and pepsin-CPC DDMs are highly sensitive and specific techniques for recovery of mycobacteria as compared to NALC-NaOH DDM. However, when the overall performances of all DDMs compared, papain-CPC DDM isolated increased number of mycobacterial isolates with comparatively higher numbers of colonies on LJ media than both pepsin-CPC and NALC-NaOH DDMs, indicating its potential to replace the NALC-NaOH DDM for recovery of mycobacteria from sputum samples.
Collapse
Affiliation(s)
- Pottathil Shinu
- Department of Biomedical Sciences, College of Clinical Pharmacy, King Faisal University, Al Ahsa, Saudi Arabia
- * E-mail:
| | - Varsha A. Singh
- Department of Microbiology, M.M.I.M.S.R., M.M. Deemed to be University, Ambala, India
| | - Anroop Nair
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al Ahsa, Saudi Arabia
| | - Katharigatta N. Venugopala
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al Ahsa, Saudi Arabia
- Department of Biotechnology and Food Technology, Durban University of Technology, Durban, South Africa
| | - Sabah H. Akrawi
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al Ahsa, Saudi Arabia
| |
Collapse
|
2
|
Hiza H, Doulla B, Sasamalo M, Hella J, Kamwela L, Mhimbira F, Reither K, Gagneux S, Jugheli L, Fenner L. Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country. BMC Infect Dis 2017; 17:542. [PMID: 28778186 PMCID: PMC5543576 DOI: 10.1186/s12879-017-2642-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 07/26/2017] [Indexed: 11/10/2022] Open
Abstract
Background Culture contamination with environmental bacteria is a major challenge in tuberculosis (TB) laboratories in hot and humid climate zones. We studied the effect of cetylpyridinium chloride (CPC) preservation on culture results and performance of Xpert MTB/RIF. Methods Consecutive sputum samples from microscopy smear-positive TB patients were collected. Two-hundred samples were equally split in two aliquots, one aliquot was treated with CPC and stored at ambient temperature for 7 days. The second aliquot was immediately processed. Samples were decontaminated for 20, 15 or 10 min, and subsequently cultured on Löwenstein-Jensen medium. Furthermore, 50 samples were stored for 7, 14 and 21 days, and 100 CPC-pretreated samples tested by Xpert MTB/RIF. Results CPC pretreated samples showed a higher culture yield compared to non-treated sputum samples across all decontamination times: 94% vs. 73% at 10 min (p = 0.01), 94% vs. 64% at 15 min (p = 0.004), and 90% vs. 52% at 20 min (p < 0.001). The quantitative culture grading was consistently higher in CPC treated compared to non-CPC treated samples. The proportion of contaminated cultures was lower in CPC pretreated samples across all decontamination times (range 2-6%) compared to non-CPC treated samples (15-16%). For storage times of CPC treated samples of 7, 14, and 21 days, 84, 86, and 84% of the respective cultures were positive. Of 91 CPC treated samples with a positive culture, 90 were also Xpert MTB/RIF positive. Conclusions CPC increases culture yield, decreases the proportion of contamination, and does not alter the performance of Xpert MTB/RIF.
Collapse
Affiliation(s)
- Hellen Hiza
- Ifakara Health Institute, Bagamoyo, Tanzania
| | - Basra Doulla
- National Tuberculosis and Leprosy Programme, Dar es Salaam, Tanzania
| | - Mohamed Sasamalo
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Jerry Hella
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Francis Mhimbira
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Klaus Reither
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Sebastien Gagneux
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Levan Jugheli
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Lukas Fenner
- Ifakara Health Institute, Bagamoyo, Tanzania. .,Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
| |
Collapse
|