Silence as a way of niche adaptation: mecC-MRSA with variations in the accessory gene regulator (agr) functionality express kaleidoscopic phenotypes

ABSTRACT: Functionality of the accessory gene regulator (agr) quorum sensing system is an important switch promoting either acute or chronic infections, mediated by the notorious opportunistic human and veterinary pathogen Staphylococcus aureus. Spontaneous alterations of the agr system are known to frequently occur in human healthcare-associated S. aureus lineages. However, data on agr integrity and function are sparse regarding other major lineages. Here we report on the agr system functionality and activity level in mecC-carrying methicillin resistant S. aureus (MRSA) of various animal origins (n=33) in Europe together with closely related isolates of human patients (n=12). Whole genome analysis assigned all isolates to four clonal complexes (CC) with distinct agr types (CC599 agr I, CC49 agr II, CC130 agr III and CC1943 agr IV). Different levels of agr functionality were detected by use of different phenotype assays and proteomics for isolates of each CC, including completely non-functional variants. Genomic comparison of the agr I-IV encoding regions revealed that variants of AgrA and AgrC were associated with these phenotype changes, especially among the isolates of pet- and wild animal origin. Since a role in adaptation is most likely when genomic changes occur independently in divergent lineages, agr variation might foster viability and niche adjustment capacities of rare MRSA lineages.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Staphylococcus Aureus

SUBMITTER: Joerg Doellinger  

LAB HEAD: Peter Lasch

PROVIDER: PXD016486 | Pride | 2021-09-09

REPOSITORIES: Pride