BACKGROUND Heater-cooler units (HCUs) have been implicated in the recent global outbreak of invasive Mycobacterium chimaera infection among patients following cardiothoracic surgery. Because infected patients tend to remain asymptomatic for extended periods, detection of M. chimaera from HCUs in real time is essential to halting the ongoing M. chimaera HCU-associated outbreak. Sample collection protocols to evaluate the presence of M. chimaera offer conflicting recommendations regarding the addition of sodium thiosulfate (NaT) during the collection process. AIM To study the effect of NaT on M. chimaera recovery and culture contamination. METHODS Seventy-six paired HCU water samples (with and without NaT) were collected, processed and cultured simultaneously into Lowenstein-Jensen slants, Middlebrook 7H10 agar plates, and mycobacterial growth indicator tubes (MGITs), and incubated at 37°C. A subset of 31 paired samples was additionally cultured on MGITs and incubated at 30°C. FINDINGS Of 76 samples incubated at 37°C in each of the three media, with and without NaT, M. chimaera was identified in at least one aliquot of 21 samples. CONCLUSION The presence of NaT did not significantly increase the probability of recovering M. chimaera in a multi-variable conditional logistic model and culture contamination rates were similar between aliquots with and without NaT. In the subset of samples cultured on MGITs at both 30°C and 37°C, the presence of NaT again was not associated with M. chimaera recovery, but was significantly associated with reduced culture contamination.

中文翻译：

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硫代硫酸钠对从加热器-冷却器单元水样中回收分枝杆菌的影响。

背景技术在最近的心胸外科手术患者中，侵袭性分枝杆菌感染的全球爆发中已经涉及到加热器冷却器单元（HCU）。由于被感染的患者长期无症状，因此从HCU中实时检测M. chimaera对停止正在进行的M. chimaera HCU相关爆发至关重要。评估鼠疫支原体存在的样本收集方案对收集过程中添加硫代硫酸钠（NaT）提供了相互矛盾的建议。目的研究NaT对M. chimaera恢复和培养物污染的影响。方法收集，处理和同时培养76对成对的HCU水样品（含和不含NaT）到Lowenstein-Jensen斜面，Middlebrook 7H10琼脂平板中，和分枝杆菌生长指示器管（MGITs），并在37°C下孵育。31对配对样品的子集在MGIT上另外培养，并在30°C孵育。结果在37种培养基中，分别在37℃和37％的NaT或不加入NaT的条件下，在至少21个样品的等分试样中均鉴定出了X. chimaera。结论在多变量条件对数模型中，NaT的存在并没有显着增加回收嵌合体分枝杆菌的可能性，有和没有NaT的等分试样之间的培养物污染率相似。在30°C和37°C的MGITs上培养的样品子集中，NaT的存在与奇异分支杆菌的回收率无关，但与减少的培养物污染显着相关。31对配对样品的子集在MGIT上另外培养，并在30°C孵育。结果在37种培养基中，分别在37℃和37％的NaT或不加入NaT的条件下，在至少21个样品的等分试样中均鉴定出了X. chimaera。结论在多变量条件对数模型中，NaT的存在并没有显着增加回收嵌合体分枝杆菌的可能性，有和没有NaT的等分试样之间的培养物污染率相似。在30°C和37°C的MGITs上培养的样品子集中，NaT的存在与奇异分支杆菌的回收率无关，但与减少的培养物污染显着相关。31对配对样品的子集在MGIT上另外培养，并在30°C孵育。结果在37种培养基中，分别在37℃和37℃下，无论有无NaT，在至少21份样品中均鉴定到了X. chimaera。结论在多变量条件对数模型中，NaT的存在并没有显着增加回收嵌合体分枝杆菌的可能性，有和没有NaT的等分试样之间的培养物污染率相似。在30°C和37°C的MGITs上培养的样品子集中，NaT的存在再次不与希氏分枝杆菌回收相关，但与减少的培养物污染显着相关。至少在21个样本中有一个等份鉴定出了chimaera。结论在多变量条件对数模型中，NaT的存在并没有显着增加回收嵌合体分枝杆菌的可能性，有和没有NaT的等分试样之间的培养物污染率相似。在30°C和37°C的MGITs上培养的样品子集中，NaT的存在再次不与希氏分枝杆菌回收相关，但与减少的培养物污染显着相关。至少在21个样本中有一个等份鉴定出了chimaera。结论在多变量条件对数模型中，NaT的存在并没有显着增加回收嵌合体分枝杆菌的可能性，有和没有NaT的等分试样之间的培养物污染率相似。在30°C和37°C的MGITs上培养的样品子集中，NaT的存在再次不与希氏分枝杆菌回收相关，但与减少的培养物污染显着相关。