Evaluation of Omnigene-Sputum for Preservation of Sputum Samples for Diagnosis of <i>Mycobacterium tuberculosis</i>

In several low-income countries, the transport of sputa could take up to one week to reach the laboratories, resulting in increased contamination rates and a loss of growth. The aim of this study was to evaluate the effect of the OMNIgene-SPUTUM in preserving <i>Mycobacterium tuberculosis</...

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Bibliographic Details
Main Authors: Edson Mambuque, Belén Saavedra, Barbara Molina-Moya, Dinis Nguenha, Esther García-García, Silvia Blanco, Neide Gomes, Joanna Ehrlich, Helder Bulo, Shilzia Munguambe, Helio Chiconela, Sozinho Acacio, José Domínguez, Alberto L. García-Basteiro
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Tropical Medicine and Infectious Disease
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Online Access:https://www.mdpi.com/2414-6366/8/7/367
Description
Summary:In several low-income countries, the transport of sputa could take up to one week to reach the laboratories, resulting in increased contamination rates and a loss of growth. The aim of this study was to evaluate the effect of the OMNIgene-SPUTUM in preserving <i>Mycobacterium tuberculosis</i> on sputum samples simulating three hypothetical scenarios for conservation and/or decontamination: (1) sputum was mixed with OMN and conserved at room temperature for five days and then processed for culture (OMN); (2) sputum cultures followed the routine standing operating procedure at day 0 (STD); and (3) sputum samples were kept at room temperature for five days and mixed with the standard decontamination reagent (SDT5) and then processed for culture. The positivity rate based on smear microscopy was 36.4%, 29.1%, and 27.3% for STD, STD5, and OMN, respectively. The proportion of positive results by liquid culture (MGIT) was 39.1% (43/110) for STD, 26.4% (29/110) for STD5, and 20.0% for OMN (22/110). The overall concordance of liquid culture results was 51.8% (57/110): 37.3% (41/110) for negative results, 11.8% (13/110) for MTBC growth, and 2.7% (3/110) for contaminated results. The OMN arm showed better performance in solid culture than in liquid culture, with a notable reduction in contaminated results.
ISSN:2414-6366