Improvement ofNeisseria gonorrhoeaeculture media to enable growth without CO₂

Abstract

Bacterial culture is the crucial step in diagnosingNeisseria gonorrhoeaeinfections and is the gold standard for determining their antimicrobial resistance profile. However, culture ofNeisseriaspp. can be challenging in resource poor areas, relying on specialist incubators supplying 5% CO2for growth of the bacteria. Even when such incubators are available, the CO2to run them may be scarce; there were CO2shortages during the COVID-19 pandemic, for example. Although culture jars with gas packs or candles can be used, these are inefficient in terms of use of incubator space and researcher time. To achieve simplicity in culturing ofN. gonorrhoeae, the standard Oxoid GC base medium, made with the Kellogg’s glucose and iron supplements was improved with the addition of 0.75 g/L sodium bicarbonate (NaHCO3), which is inexpensive and really available. This improved media was able to sustain gonococcal growth as well as standard GC media in 5% CO2. Chocolate agar and Thayer-Martin agar with sodium bicarbonate was also developed, with all showing good growth ofN. gonorrhoeaewithout the need for atmospheric CO2.

Gonorrhoeae must Compete with the Naturally Inhabitant of Microbial Community Right at the Outer Mucosal Surface to Authorize Infection

“…In laboratory culture milieu, N. gonorrhoeae actually need a complex nutrient related media requirements and with specific handling [55,80]. Specifically, for the growth medium, bacteria cannot grow in culture without a supplemented fountain of sufficient glutamine, glucose, iron, thiamine, phosphate and even carbon dioxide [55,81]. "Moreover, outside the laboratory atmosphere, in natural conditions in its predilection niche, in order to meet its nutritional requirements, N. gonorrhoeae must interact and possibly compete with resident microbiota for available nutrients.…”