Which of the following organism has a strict requirement for CO in order to grow?
a. Neisseria gonorrhoeae
b. Moraxella catarrhalis
c. Neisseria meningitidis
d. Commensal Neisseria spp.
The correct answer and explanation is:
The correct answer is a. Neisseria gonorrhoeae.
Neisseria gonorrhoeae, the bacterium responsible for the sexually transmitted infection gonorrhea, has a strict requirement for carbon monoxide (CO) in its growth. This organism is known to exhibit a unique metabolic dependency on CO, which is crucial for the synthesis of certain enzymes, particularly those involved in electron transport. The presence of CO helps the bacteria thrive in conditions where other organisms may not be able to survive. It is thought that CO acts by stabilizing specific enzymes, such as cytochrome c oxidase, which are involved in the electron transport chain, playing a key role in cellular respiration.
The requirement for CO in the growth of Neisseria gonorrhoeae is a distinctive feature that sets it apart from other Neisseria species, such as Neisseria meningitidis or Moraxella catarrhalis. Although these organisms can grow in a variety of environments and have different metabolic profiles, they do not have the same strict dependency on CO for growth. This CO requirement is one of the factors that defines the unique physiology of N. gonorrhoeae and contributes to its ability to infect human mucosal surfaces.
In contrast, Moraxella catarrhalis and Neisseria meningitidis do not exhibit this strict CO requirement for growth. Commensal Neisseria spp., which are typically harmless and part of the normal flora of the human respiratory tract, also do not have a strict dependence on CO for growth.
Thus, Neisseria gonorrhoeae is the organism with the strictest requirement for CO among the options listed. This metabolic characteristic helps the organism adapt to its niche within the human body and may play a role in its virulence.