That nasal passage infections have been an important area of research for ENT specialists is no secret. Research in morphology and bacteria have recently yielded some crucial research in infections that originate in the nasal passage ways. Some animals are physically shaped by their environment in whole, not just in part. For example, earthworms are entirely slender so that they can weave in and out of narrow spaces in the ground. Evolution plays a key role in such benefits. But does that hold for all things big and microscopic? Interestingly, bacteria come in two shapes: there’s the spherical bacterium (coccus) and the stick-shaped (bacillus)?

Biologists and morphologists wonder if there’s a reason behind why one is spherical and the other slender-shaped. After analyzing pathogenic bacteria living in the nasopharynx, the upper part of the nose, questions of shape have been answered. These bacteria have changed over time, evolving from bacillus to coccus. In an article published in the journal PLOS Genetics, Professor Frédéric Veyrier, of INRS-Institut Armand-Frappier Research Centre, along with his colleagues, demonstrated that the change may have occurred to allow bacteria to pass through the defenses of their host’s immune system.

Respiratory infections are the number three cause of death worldwide. So understanding how these bacteria, or pathogens, make it into the upper respiratory passage way is critical. These pathogens are highly evolved, some so well that bacteria like Neisseria meningitidis and Moraxella catharralis can sometimes cause severe infections in humans. Genetic analysis of the ancestors of these bacteria pinpointed a key gene: yacF. The absence of this gene makes it possible for the shape of these bacteria to evolve. The N. meningitidis and M. catharralis found today in humans are spherical and missing the yacF gene.

The bacteria’s changing from stick-shaped to spherical has allowed the composition of certain molecules on their surface to transform. These molecules, peptidoglycans, play a vital role in how the immune system recognizes bacteria.

“We have long believed that the shape of bacteria was a fixed variable,” noted Professor Veyrier. “We even use it as a way to classify bacteria. Some mystery remains as to how the various species regulate their shape. This research demonstrates that the environment in which the bacteria evolve has an impact on their morphology. These are exciting results because we were able to identify the same change in two different species–and therefore its impact could be a key aspect in the specific way these pathogens are adapting to the human nasopharynx.”

By deepening our understanding of the evolution of bacteria, researchers believe they’ll be able to create new tactics that will prevent severe infections, even those related to sinus infections. This research about bacteria evolving over time could lead to preventing and treating such nasal passage infections that attack more than your head and sinuses, but your entire body.