BACKGROUND Mycobacterium porcinum is a non-tuberculous mycobacterium (NTM) identified in potable water. The identification and clinical impact of M. porcinum in patients with cystic fibrosis (CF) has not been described. In our institution, M. porcinum was isolated exclusively during hospitalization in a cluster of patients with CF. METHODS Patients with CF who were hospitalized between September 2016 and September 2018 and could expectorate sputum were included, and samples were processed per institutional guidelines. Post-hospitalization and one-year clinical outcomes on those who isolated M. porcinum in respiratory cultures were reviewed. Whole genome sequencing was performed on M. porcinum isolates obtained from patients and environmental sources to identify source of acquisition. RESULTS Review of 14 CF patients with 16 M. porcinum isolates revealed rapid time to culture positivity within 0.8 (0.04-8.0) days after admission. M. porcinum was isolated in teenagers and adults irrespective of baseline pulmonary function, body mass index, or CF genotype. Whole genome sequencing suggested all isolates belong to the same M. porcinum strain and confirmed the source of acquisition to the ice machine. Review of patients' clinical course, including three patients who underwent lung transplantation, suggested a pseudo-outbreak with minimal clinical impact. CONCLUSIONS NTM, including M. porcinum, are ubiquitous in potable water and institutional water reservoirs. Our findings suggest M. porcinum is a transient colonizer rather than a pathogen. Challenges exist in discerning the role of NTM as a contributor of pulmonary morbidity in patients with CF, and adherence to established guidelines regarding NTM related pulmonary disease remains important.

中文翻译：

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在囊性纤维化患者中鉴定猪分枝杆菌：病原体还是污染物？

背景猪分枝杆菌是在饮用水中鉴定的非结核分枝杆菌(NTM)。尚未描述 M. porcinum 对囊性纤维化 (CF) 患者的鉴定和临床影响。在我们的机构中​​，猪支原体仅在住院期间在一组 CF 患者中分离出来。方法 纳入 2016 年 9 月至 2018 年 9 月期间住院并可能咳出痰的 CF 患者，并按照机构指南处理样本。回顾了那些在呼吸道培养物中分离出猪支原体的患者的住院后和一年的临床结果。对从患者和环境来源获得的 M. porcinum 分离株进行全基因组测序，以确定获取来源。结果回顾了 14 名 CF 患者，其中 16 M。猪分离株显示在入院后 0.8 (0.04-8.0) 天内培养阳性的时间很快。无论基线肺功能、体重指数或 CF 基因型如何，在青少年和成人中均分离到 M. porcinum。全基因组测序表明所有分离株都属于同一 M. porcinum 菌株，并证实了制冰机的获取来源。对患者临床病程的回顾，包括三名接受肺移植的患者，提示为具有最小临床影响的假性爆发。结论 NTM，包括 M. porcinum，在饮用水和机构水库中无处不在。我们的研究结果表明 M. porcinum 是一种短暂的殖民者而不是病原体。在识别 NTM 作为 CF 患者肺部发病率的贡献者方面存在挑战，