Chlamydia's Persistent Hold on Health: Challenges in Elimination
Sexually transmitted infections, specifically by Chlamydia, are the most prevalent amongst the population, particularly affecting the youth, according to the Federal Centre for Health Education (BZgA). A recent study provides evidence that these bacterial pathogens can survive in the body by utilizing certain niches within the gastrointestinal tract.
Consequently, repeated infections in various tissues, including the genital tract, may occur, as explained by the research team led by Thomas Rudel from the University of Würzburg in the journal "PLoS Pathogens".
Bacterial Hibernation
The existing knowledge on this hypothesis mainly stems from mouse studies, which carry limited relevance to humans, the authors caution. Therefore, it remains uncertain if the human gastrointestinal tract can indeed serve as a site for persistent Chlamydia infections, acting as a reservoir for subsequent genital tract infections.
Persistence is a state in which bacteria continue to exist but are no longer replicating. Many bacteria enter this dormant phase in response to unfavorable environmental conditions and return to their regular growth cycle under more favorable conditions. Due to the minimal replication of bacteria, few or no symptoms emerge during the persistence phase, making persistent infections challenging to treat with antibiotics.
Experiments on Engineered Mini-Organs
The researchers led by Rudel used organoids, or three-dimensional engineered mini-organs, initiated from human gastrointestinal tract cells as their base. Epithelial cells from the stomach, small intestine, and colon were cultured on a nutrient medium to form a single-cell layer and infected with Chlamydia trachomatis.
Chlamydia can penetrate cells via specific mechanisms and subsequently develop into either regular or persistence-like growth forms. Healthy, intact epithelium appears to be resistant to C. trachomatis infections, the researchers propose. The epithelial barrier likely needs to be damaged, for instance through inflammation, proliferation, or microlesions on the mucous membrane, to allow an infection.
The team acknowledges that the model used lacks significant features, including natural microbial colonization and a functional immune system.
Infertility as a Potential Consequence
Chlamydia trachomatis is a human-specific bacterial pathogen, ranking as one of the leading causes of sexually transmitted infections (STIs) globally. Often, infections do not cause observable symptoms, although symptoms such as discharge, burning sensation during urination, or pain during sex may be experienced. Symptoms can resolve on their own or completely, as per BZgA.
However, an ongoing Chlamydia infection can still persist in the body, spreading further, as BZgA highlights. Untreated, it may result in inflammation of the reproductive organs, which can gradually lead to infertility in both men and women. When identified early, antibiotics can usually cure the infection promptly and effectively.
The recently conducted study suggests that Chlamydia, a bacterial pathogen, can survive in the human gastrointestinal tract by utilizing specific niches, potentially serving as a reservoir for future genital tract infections. During the persistence phase, many bacteria, including Chlamydia, enter a dormant state in response to unfavorable conditions, minimizing replication and often causing few or no symptoms, making persistent infections difficult to treat with antibiotics.
