Characterizing the diversity and commensal origins of mosaicism in the genus .

Mosaic alleles formed through horizontal gene transfer (HGT) have been instrumental to the rising incidence of ceftriaxone-resistant gonococcal infections. Although interspecies HGT of regions of the gene between and commensal species has been described, knowledge concerning which species are the most common contributors to mosaic alleles is limited, with most studies examining only a small number of alleles. Here, we investigated the origins of recombinant alleles through analyses that incorporated 1700 alleles from 35 513 isolates, comprising 15 different species. We identified and as the most common source of recombinant sequences in . This contrasted with , for which the primary source of recombinant DNA was other meningococci, followed by . Additionally, we described the distribution of polymorphisms implicated in antimicrobial resistance in , and found that these are present across the genus. These results provide insight into resistance-related changes in the gene across human-associated species, illustrating the importance of genomic surveillance of not only the pathogenic , but also of the oral niche-associated commensals from which these pathogens are sourcing key genetic variation.