Gene exchange between Neisseria meningitidis and Neisseria gonorrhoeae

(NG) has not been well studied. This study aimed to investigate evidence of genetic exchanges between these two species. All coincident paired NM and NG isolates cultured from pharyngeal swabs collected from a sexual health clinic in Sydney in 2021 underwent whole-genome sequencing. A gene-by-gene analysis of the 47 NM-NG pairs identified 184 instances where the ancestry of the gene revealed intermixing between the two species. Incorporating the gene phylogenies demonstrated that these events occurred across a wide range of timeframes. At the nucleotide level, 91 genes were found where paired isolates harboured identical sequences. Notably, one instance of unequivocal recent gene transfer events between the paired pharynx isolates was observed. This work provides new insights into the evolutionary dynamics of these bacteria and highlights the importance of genetic exchange in populations with high rates of pharyngeal gonorrhoea. The clinical implications of such exchanges call for continued vigilance and research to address the challenges posed by these bacteria.