Characterization of the cluster MabR prophages of Mycobacterium abscessus and Mycobacterium chelonae

Abstract

Mycobacterium abscessus is an emerging pathogen of concern in cystic fibrosis and immunocompromised patients and is considered one of the most drug-resistant mycobacteria. The majority of clinical M. abscessus isolates carry one or more prophages that are hypothesized to contribute to virulence and bacterial fitness. The prophage McProf was identified in the genome of the Bergey strain of M. chelonae, and is distinct from previously described prophages of M. abscessus. The McProf genome increases intrinsic antibiotic resistance of M. chelonae and drives expression of the intrinsic antibiotic resistance gene, whiB7, when superinfected by a second phage. The prevalence of McProf-like genomes was determined in sequenced mycobacterial genomes. Related prophage genomes were identified in the genomes of 25 clinical isolates of M. abscessus and assigned to the novel cluster, MabR. The MabR genomes share less than 10% gene content with previously described prophages; however, share features typical of prophages, including polymorphic toxin immunity (PT-Imm) systems.