Mycobacterium avium complex (MAC) species constitute most mycobacteria infections in persons with cystic fibrosis (CF) in the United States, but little is known about their genomic diversity or transmission. During 2016–2020, we performed whole-genome sequencing on 364 MAC isolates from 186 persons with CF from 42 cystic fibrosis care centers (CFCCs) across 23 states. We compared isolate genomes to identify instances of shared strains between persons with CF. Among persons with multiple isolates sequenced, 15/56 (27%) had >1 MAC strain type. Genomic comparisons revealed 18 clusters of highly similar isolates; 8 of these clusters had patients who shared CFCCs, which included 27/186 (15%) persons with CF. We provide genomic evidence of highly similar MAC strains shared among patients at the same CFCCs. Polyclonal infections and high genetic similarity between MAC isolates are consistent with multiple modes of acquisition for persons with CF to acquire MAC infections.

鸟分枝杆菌复杂 (MAC) 物种构成了美国囊性纤维化 (CF) 患者的大多数分枝杆菌感染，但对其基因组多样性或传播知之甚少。在 2016-2020 年期间，我们对来自 23 个州的 42 个囊性纤维化护理中心 (CFCC) 的 186 名 CF 患者的 364 个 MAC 分离株进行了全基因组测序。我们比较了分离基因组，以确定 CF 患者之间共享菌株的实例。在对多个分离株进行测序的人中，15/56 (27%) 的 MAC 菌株类型大于 1。基因组比较揭示了 18 个高度相似的分离群；其中 8 个集群有共享 CFCC 的患者，其中包括 27/186 (15%) CF 患者。我们提供了在相同 CFCC 的患者之间共享的高度相似的 MAC 菌株的基因组证据。