评估用于从痰液样本中回收结核分枝杆菌的氢氧化钠-N-乙酰-L-半胱氨酸和0.7%氯己定去污方法：一项比较分析（冈比亚经验）

Evaluation of sodium hydroxide-N-acetyl-l-cysteine and 0.7% chlorhexidine decontamination methods for recovering Mycobacterium tuberculosis from sputum samples: A comparative analysis (The Gambia Experience).

作者信息

Gitteh Ensa, Kweku Otu Jacob, Jobarteh Tijan, Mendy Francis, Faal-Jawara Isatou Tutty, Ofori-Anyinam Nana Boatema, Ayorinde Abigail, Secka Ousman, Gehre Florian

机构信息

Medical Research Council Unit, The Gambia.

出版信息

Int J Mycobacteriol. 2016 Dec;5 Suppl 1:S167-S168. doi: 10.1016/j.ijmyco.2016.09.020. Epub 2016 Oct 28.

DOI:10.1016/j.ijmyco.2016.09.020

PMID:28043532

Abstract

OBJECTIVE/BACKGROUND: To determine the culture yield and time to detection of mycobacterial growth between samples decontaminated using 0.7% chlorhexidine and sodium hydroxide-N-acetyl-l-cysteine (NaOH-NALC) and cultured on the Löwenstein-Jensen (LJ) medium. We also aimed to determine the contamination rate between the 0.7% chlorhexidine and NaOH-NALC decontamination methods.

METHODS

The study was carried out on 68 sputa samples (42 smear positives and 26 smear negatives). Of these 68 samples, 46 were collected from men and 26 from women with an approximate average age of 27years. All the sputum samples were decontaminated using the standard NaOH-NALC and 0.7% chlorhexidine methods. The concentrates were cultured in parallel on LJ media in which reading of the slope for mycobacterial growth was obtained daily for the first 2weeks and then weekly until week 8. The mycobacterial recovery rate, time to detection, and contamination rate were then compared.

RESULTS

The overall recovery rate of mycobacterial growth on samples treated with both decontamination methods inoculated on LJ media is 51.5% (35/68). Specifically, mycobacterial growth rates on samples treated with 0.7% chlorhexidine and standard NaOH-NALC on LJ media were 61.8% (42/68) and 54.4% (37/68), respectively. However, the growth of Mycobacterium tuberculosis complex was faster on samples treated with 0.7% chlorhexidine than those treated with NaOH-NALC (average, 32±5days vs. 33±5.2days, respectively). The contamination rate on samples treated with 0.7% chlorhexidine was 1.5% (1/68), whereas on those treated with NaOH-NALC, the rate was 4.4% (3/68).

CONCLUSION

The 0.7% chlorhexidine decontamination method is rapid and has less contamination rate in terms of mycobacterial recovery compared with the standard NaOH-NALC method. Therefore, the 0.7% chlorhexidine decontamination method would be an ideal alternative option for decontamination of sputum samples and recovery/isolation of M. tuberculosis in resource-poor countries.

摘要

目的/背景：确定使用0.7%洗必泰与氢氧化钠- N -乙酰- L -半胱氨酸（NaOH-NALC）对样本进行去污处理后，在罗-琴（LJ）培养基上培养的分枝杆菌生长培养产量及检测所需时间。我们还旨在确定0.7%洗必泰与NaOH-NALC去污方法之间的污染率。

方法

对68份痰液样本（42份涂片阳性和26份涂片阴性）进行研究。在这68份样本中，46份来自男性，26份来自女性，平均年龄约为27岁。所有痰液样本均采用标准的NaOH-NALC和0.7%洗必泰方法进行去污处理。将浓缩物平行接种于LJ培养基上培养，在最初2周内每天观察斜面以检测分枝杆菌生长情况，之后每周观察一次，直至第8周。然后比较分枝杆菌回收率、检测时间和污染率。

结果

两种去污方法处理后接种于LJ培养基上的样本中，分枝杆菌生长的总体回收率为51.5%（35/68）。具体而言，0.7%洗必泰处理的样本在LJ培养基上的分枝杆菌生长率为61.8%（42/68），标准NaOH-NALC处理样本的生长率为54.4%（37/68）。然而，结核分枝杆菌复合群在0.7%洗必泰处理的样本上生长速度比NaOH-NALC处理的样本更快（平均分别为32±5天和33±5.2天）。0.7%洗必泰处理样本的污染率为1.5%（1/68），而NaOH-NALC处理样本的污染率为4.4%（3/68）。