P072

1:National Reference Laboratory for Mycobacteria, Department of Infectious Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal; 2:Genomics and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal

Mycobacterium abscessus complex (Mab) is an emerging multidrug-resistant nontuberculous mycobacteria, responsible for a wide spectrum of infections. Recently, dominant circulating clones (DCC) have been identified as clusters of strains associated with increased virulence, worse clinical outcomes and higher levels of antimicrobial resistance (AMR). To implement a genomic based surveillance system for Mab, we adapted the recently published SeqSphere+ cgMLST and agMLST schemas into a dynamic wgMLST schema for chewBBACA. Thirty Mab Portuguese strains were integrated into a public dataset of 6974 genomes and stability analysis was performed using ReporTree. DCC classification could be obtained at 250 allelic differences and was able to classify 12 Portuguese isolates as belonging to distinct DCC. Dynamic wgMLST analysis of 7003 genomes revealed that, at a 100 AD threshold, 24 Portuguese genomes were integrated in eleven distinct clusters, two of which were composed exclusively by Portuguese isolates. AMR results showed that most isolates presented resistance to at least two antibiotics (23/30). Twenty eight of the thirty isolates presented the macrolide AMR-associated mutation T28 in erm41, while just one isolate had the aminoglycoside AMR-associated mutation A1408G in rrs. Whole genome analysis allowed us to screen for additional known AMR markers, thus allowing a more complete resistance profile of the strains. This study highlights the genetic diversity of circulating MAB isolates in Portugal and their association with AMR, while standing as the first step towards the implementation of a genomic-based surveillance system for MAB at the Portuguese National Institute of Health.