Chlamydia Has Found a New Place To Hide

The bacteria that causes chlamydia, a common sexually transmitted infection, may lurk elsewhere in the body other than just the genitals.
Chlamydia trachomatis, the species of bacteria responsible for the STI, may hide out in our guts, according to a new study in the journal PLOS Pathogens.
These hidden bacteria may then migrate back to the genitals, and cause recurring infections.
This discovery could result in different types of antibiotics being prescribed for infections to truly eradicate all of the bacteria in the body, the researchers suggest.
Chlamydia is transmitted through vaginal, anal or oral sex with someone who is infected, and can also be passed from an infected mother to her baby during childbirth. According to the World Health Organization, there were 128.5 million new chlamydia infections in people aged between 15 and 49 in 2020 worldwide.
Symptoms in women may include abnormal vaginal discharge, burning sensation during urination, pelvic pain, pain during intercourse and bleeding between periods or after sex. Men may experience discharge from the penis, burning sensation during urination and pain or swelling in one or both testicles. However, most people infected with chlamydia don’t experience noticeable symptoms.
If left untreated, chlamydia can lead to serious health complications, including pelvic inflammatory disease (PID) in women, which can cause permanent damage to the reproductive system, leading to infertility or ectopic pregnancy.
There have been numerous studies into chlamydia infecting the gut of other animals, including mice, but this new paper shows that it may also be found in the guts of humans.
“Increasing evidence suggests that the mucosa of the GI tract provides a niche for persistent C. trachomatis infections in the human body and can potentially cause repeated infections in other tissues, including the genital tract. Nevertheless, there is only a limited number of studies on the pathogenesis of C. trachomatis in human GI cells,” the researchers wrote in the paper.
The researchers discovered that cells of the gut are resistant to infection by chlamydia on their apical membrane, or the “top” of the cells facing into the gut, but also found that the bacteria could infect the cells via the basolateral membrane, surrounding the sides and bottom of gut cells that are in contact with other cells.
“We show that GI cells are resistant to apical infection and C. trachomatis needs access to the basolateral membrane to establish an infection,” the researchers wrote.
The researchers aren’t entirely sure how the bacteria reach this area of the cell membrane, with more research needing to be done to find out if the bacteria enter via tiny cuts or from the bloodstream.
The scientists also found that the chlamydia bacteria living in gut cells can make their way back to the genitals and cause reinfection.
“We think that more attention should be paid to the possibility that during the regular treatment of genital infections, especially in patients with recurrent infections, chlamydia might not be completely eliminated from the body,” study co-author Thomas Rudel, a microbiologist at the University of Würzburg in Germany, told Fierce Biotech. “Due to the varying susceptibility of the different anatomical regions to antibiotics, this could also have implications for the choice and the duration of the antibiotic therapy.”
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Hovhannisyan, P., Stelzner, K., Keicher, M., Paprotka, K., Neyazi, M., Pauzuolis, M., Ali, W. M., Rajeeve, K., Bartfeld, S., & Rudel, T. (2024). Infection of human organoids supports an intestinal niche for Chlamydia trachomatis. PLOS Pathogens, 20(8). https://doi.org/10.1371/journal.ppat.1012144