Chlamydia pneumoniae is a gram-negative bacterium that infects the humanrespiratory tract. It causes acute pneumonia and has been linked to... Show moreChlamydia pneumoniae is a gram-negative bacterium that infects the humanrespiratory tract. It causes acute pneumonia and has been linked to several chronic
diseases including cardiovascular disease, asthma, and some neurological diseases. C.
pneumoniae primarily exists in two forms, the elementary body (EB) and the reticulate
body (RB). The EB infects host cells and the RB replicates inside them. In order to
survive in and out of the host, it was thought that C. pneumoniae RBs obtain host ATP to
use for energy, making it an “energy parasite.” However, genomic analysis indicated that
it was also possible for C. pneumoniae to create ATP from its own respiratory chain
using the Na + pump NADH Ubiquinone Oxidoreductase (Na + -NQR). Neither the details of
the energy parasite theory nor the possibility of C. pneumoniae creating its own energy
had been experimentally explored. This project used a pharmacological approach to
explore C. pneumoniae host energy consumption at various developmental stages,
examine a mechanism that the bacterium could use to produce its own energy, and assess
the importance of a balanced Na + /H + gradient for energy production and maintaining
homeostasis. Based on the genomic analysis, it was thought that C. pneumoniae would
rely heavily on host ATP in the EB form but not the RB form, that inhibiting Na + -NQR
would slow bacterial growth, particularly in RBs, and that disrupting the Na + /H + gradient
would significantly reduce RB infection. The results indicate that in the EB form, C.
pneumoniae relies on host ATP and requires a balanced Na + /H + gradient, but disrupting
Na + -NQR does not hinder its growth. In the RB form, C. pneumoniae is not dependent on
host ATP, nor on its own respiratory chain ATP, and is not impacted by an unbalanced
Na + /H + gradient. Therefore, the energy parasite hypothesis appears to apply to C.
pneumoniae EBs but not RBs. Furthermore, established C. pneumoniae infections are
excellent at compensating for various environmental conditions and sources of energy,
which proves challenging for drug design against C. pneumoniae. Show less