BackgroundMycobacterium abscessus complex (MABC), an opportunistic nontuberculous mycobacteria, can lead to poor clinical outcomes in pulmonary infections. Conflicting data exist on person-to-person transmission of MABC within and across health care facilities. To investigate further, a comprehensive retrospective study across 5 health care institutions on the Island of Montréal was undertaken.MethodsWe analyzed the genomes of 221 MABC isolates obtained from 115 individuals (2010–2018) to identify possible links. Genetic similarity, defined as ≤25 single-nucleotide polymorphisms (SNPs), was investigated through a blinded epidemiological inquiry.ResultsBioinformatics analyses identified 28 sequence types, including globally observed dominant circulating clones (DCCs). Further analysis revealed 210 isolate pairs within the SNP threshold. Among these pairs, there was 1 possible laboratory contamination where isolates from different patients processed in the same laboratory differed by only 2 SNPs. There were 37 isolate pairs from patients who had provided specimens from the same hospital; however, epidemiological analysis found no evidence of health care-associated person-to-person transmission between these patients. Additionally, pangenome analysis showed higher discriminatory power than core genome analysis for examining genomic similarity.ConclusionsGenomics alone is insufficient to establish MABC transmission, particularly considering the genetic similarity and wide distribution of DCCs, although pangenome analysis has the potential to add further insight. Our findings indicate that MABC infections in Montréal are unlikely attributable to health care-associated person-to-person transmission.

中文翻译：

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蒙特利尔岛上脓肿分枝杆菌的基因组流行病学不提示与医疗保健相关的人际传播


背景脓肿分枝杆菌复合体 （MABC） 是一种机会性非结核分枝杆菌，可导致肺部感染的不良临床结局。关于医疗保健机构内部和医疗保健机构之间的 MABC 人际传播存在相互矛盾的数据。为了进一步调查，对蒙特利尔岛上的 5 家医疗保健机构进行了全面的回顾性研究。方法我们分析了从 115 个个体 （2010-2018） 获得的 221 个 MABC 分离株的基因组，以确定可能的联系。遗传相似性，定义为 ≤25 个单核苷酸多态性 （SNP），通过盲法流行病学调查进行调查。结果生物信息学分析确定了 28 种序列类型，包括全球观察到的显性循环克隆 （DCC）。进一步分析显示 SNP 阈值内有 210 个分离株对。在这些对中，有 1 个可能的实验室污染，其中在同一实验室处理的不同患者的分离株仅相差 2 个 SNP。有 37 对分离物来自提供来自同一家医院的标本的患者;然而，流行病学分析发现，没有证据表明这些患者之间存在与医疗保健相关的人际传播。此外，泛基因组分析在检查基因组相似性方面显示出比核心基因组分析更高的鉴别能力。结论仅靠基因组学不足以确定 MABC 传播，特别是考虑到 DCC 的遗传相似性和广泛分布，尽管泛基因组分析有可能增加进一步的见解。我们的研究结果表明，蒙特利尔的 MABC 感染不太可能归因于与医疗保健相关的人际传播。