Final answer:
Neisseria gonorrhoeae requires a CO2-enriched atmosphere for optimal growth because it is a capnophile, which means it thrives in higher CO2 concentrations similar to its natural habitat on mucosal surfaces.
Step-by-step explanation:
The instructions for the growth of Neisseria gonorrhoeae recommend a CO₂-enriched atmosphere because it is a capnophile. Capnophiles are bacteria that require increased concentrations of carbon dioxide for their optimal growth. This bacterium is fastidious and lives on mucosal surfaces of the human body, hence the need for environments similar to its natural habitat to thrive.
It is microaerophilic and requires low levels of oxygen, however, it is not classified as an aerobe, anaerobe, or phototroph that uses CO₂ in its metabolic processes. Thus, the correct answer to the student's question would be that Neisseria gonorrhoeae recommend a CO₂-enriched atmosphere because it is a capnophile (Option C).
The cultivation of Neisseria gonorrhoeae by use of fastidious broth (FB) was evaluated. FB was found to be able to support the growth of all N. gonorrhoeae strains tested in this study without a rapid decrease in the viable count after exponential growth. After 24 h of incubation at 35°C with 5% CO2, viable counts of all strains reached over 108 CFU/ml in FB. Similar growth of the wild-type strain and its target-altered quinolone-resistant derivatives was observed.
The susceptibilities of laboratory-adapted strains and clinical isolates to quinolones were tested by the microdilution method using FB. The MICs determined by microdilution were not significantly different from those determined by the agar dilution method recommended by the CLSI (formerly National Committee for Clinical Laboratory Standards).