Preservation of sputum samples with cetylpyridinium chloride (CPC) for tuberculosis cultures and Xpert MTB/RIF in a low-income country

BMC Infectious Diseases

Research Article

Hellen Hiza¹  Lujeko Kamwela¹  Klaus Reither²  Francis Mhimbira²  Levan Jugheli²  Mohamed Sasamalo²  Jerry Hella²  Lukas Fenner³  Basra Doulla⁴  Sebastien Gagneux⁵ 

[1] Ifakara Health Institute, Bagamoyo, Tanzania;Ifakara Health Institute, Bagamoyo, Tanzania;Swiss Tropical and Public Health Institute, Basel, Switzerland;University of Basel, Basel, Switzerland;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;National Tuberculosis and Leprosy Programme, Dar es Salaam, Tanzania;Swiss Tropical and Public Health Institute, Basel, Switzerland;University of Basel, Basel, Switzerland;

关键词: Mycobacterium tuberculosis;    Tuberculosis;    Cetylpyridinium chloride;    CPC;    Sample transport;    Preservation;    Contamination;    Culture;    Sputum;    Recovery;    Tuberculosis;    Low-income country;   

DOI  :  10.1186/s12879-017-2642-z

 received in 2016-09-30, accepted in 2017-07-26,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundCulture 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.MethodsConsecutive 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.ResultsCPC 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.ConclusionsCPC increases culture yield, decreases the proportion of contamination, and does not alter the performance of Xpert MTB/RIF.

【 授权许可】

CC BY   
© The Author(s). 2017