Variation in supplemental carbon dioxide requirements defines lineage-specific antibiotic resistance acquisition in Neisseria gonorrhoeae

Abstract

The evolution of the obligate human pathogen Neisseria gonorrhoeae has been shaped by selective pressures from diverse host niche environments^1,2 as well as antibiotics^3,4. The varying prevalence of antibiotic resistance across N. gonorrhoeae lineages⁵ suggests that underlying metabolic differences may influence the likelihood of acquisition of specific resistance mutations^6,7. We hypothesized that the requirement for supplemental CO₂, present in approximately half of isolates⁸, reflects one such example of metabolic variation. Here, using a genome-wide association study and experimental investigations, we show that CO₂-dependence is attributable to a single substitution in a β-carbonic anhydrase, canB. CanB^19E is necessary and sufficient for growth in the absence of CO₂, and the hypomorphic CanB^19G variant confers CO₂-dependence. Furthermore, ciprofloxacin resistance is correlated with CanB^19G in clinical isolates, and the presence of CanB^19G increases the likelihood of acquisition of ciprofloxacin resistance. Together, our results suggest that metabolic variation has impacted the acquisition of fluoroquinolone resistance.