Certain vaginal bacteria may be linked with increased risk of chlamydia

September 25, 2017, British Medical Journal
Chlamydia trachomatis inclusion bodies (brown) in a McCoy cell culture. Credit: public domain

The presence of specific types of vaginal bacteria may be associated with an increased risk for chlamydia infection, finds a small, but well powered study published online in Sexually Transmitted Infections.

Chlamydia trachomatis is the most common sexually transmitted infection (STI) in . It usually causes no symptoms, but can increase the risk of HIV infection and lead to long-term complications in such as , ectopic pregnancy and infertility.

A range of microbes (microbiota) found naturally in the vagina are thought to help protect against infections, but their exact role remains uncertain.

Previous studies have shown that the vaginal microbiota of women infected with chlamydia was depleted of Lactobacillus species (a group of bacteria that live harmlessly in the urinary, digestive and genital tracts).

So a team of researchers set out to compare the composition and structure of vaginal microbiota prior to in women who subsequently acquired the infection and in women who did not.

The study involved 122 healthy women aged between 16 and 29 years old attending a STI outpatient clinic in The Netherlands. Vaginal swab samples were collected at their first visit when all women were still free of infection. These swabs were used to unravel the structure and composition of the vaginal microbiota. One year later, these women got tested for chlamydia again, 61 tested positive.

Sociodemographic information and sexual risk behaviour was recorded and cases were matched to controls according to age and ethnicity.

The researchers found that having a microbiota dominated by a particular strain of Lactobacillus (Lactobacillus iners) was associated with an increased risk for chlamydia infection.

They point out that this is an observational study, so no firm conclusions can be drawn about cause and effect, and they outline some limitations that may have introduced bias.

The exact mechanism behind this still needs to be unravelled, they say. Nevertheless, they suggest that "specific signatures of vaginal microbiota could be indicative of increased host predisposition to acquiring STIs."

And they add that "specific species or possibly even strain of Lactobacillus is of great importance to determine whether the vaginal microbiota can contribute to susceptibility to or protection against STIs."

Explore further: Vaginal bacteria alter sexual transmission of Zika and herpes simplex virus-2

More information: Lactobacillus iners-dominated vaginal microbiota is associated with increased susceptibility to Chlamydia trachomatis infection in Dutch women: a case- control study , Sexually Transmitted Infections (2017). sti.bmj.com/lookup/doi/10.1136 … sextrans-2017-053133

Related Stories

Vaginal bacteria alter sexual transmission of Zika and herpes simplex virus-2

June 5, 2017
Bacteria in the vagina can inhibit sexually transmitted Zika virus and herpes simplex virus-2 in women, according to a new study from The University of Texas Medical Branch at Galveston. The findings were discussed at the ...

Oral probiotics have no impact on vaginal health in pregnancy

November 1, 2016
(HealthDay)—For pregnant women, probiotics have no effect on vaginal health, according to a study published in the November issue of the American Journal of Obstetrics & Gynecology.

Women's wellness: vaginal yeast infections

November 25, 2016
A vaginal yeast infection is a fungal infection that causes irritation, discharge and intense itchiness of the vagina and the vulva - the tissues at the vaginal opening. It's a type of vaginitis, or inflammation of the vagina. ...

2.5 million U.S. women have condition that can cause infertility

February 3, 2017
(HealthDay)—About 2.5 million American women have had pelvic inflammatory disease, an often-symptomless infection of the reproductive tract that can cause infertility and lasting abdominal pain, a new U.S. government report ...

Chlamydia more common in New Zealand than thought

May 30, 2017
One in three New Zealand women have had the sexually transmitted infection (STI) chlamydia by the age of 38 as have one in five men, based on estimates from a new study.

Why do certain hormonal contraceptives increase the risk of HIV?

September 1, 2015
In recent years, evidence has been building that injectable contraceptive depot medroxyprogesterone acetate (Depo-Provera or DMPA) is associated with an increased risk of HIV infection. Now a study published in the September ...

Recommended for you

Research finds new mechanism that can cause the spread of deadly infection

April 20, 2018
Scientists at the University of Birmingham have discovered a unique mechanism that drives the spread of a deadly infection.

Selection of a pyrethroid metabolic enzyme CYP9K1 by malaria control activities

April 20, 2018
Researchers from LSTM, with partners from a number of international institutions, have shown the rapid selection of a novel P450 enzyme leading to insecticide resistance in a major malaria vector.

Study predicts 2018 flu vaccine will have 20 percent efficacy

April 19, 2018
A Rice University study predicts that this fall's flu vaccine—a new H3N2 formulation for the first time since 2015—will likely have the same reduced efficacy against the dominant circulating strain of influenza A as the ...

Low-cost anti-hookworm drug boosts female farmers' physical fitness

April 19, 2018
Impoverished female farm workers infected with intestinal parasites known as hookworms saw significant improvements in physical fitness when they were treated with a low-cost deworming drug. The benefits were seen even in ...

Zika presents hot spots in brains of chicken embryos

April 19, 2018
Zika prefers certain "hot spots" in the brains of chicken embryos, offering insight into how brain development is affected by the virus.

Super-superbug clones invade Gulf States

April 18, 2018
A new wave of highly antibiotic resistant superbugs has been found in the Middle East Gulf States, discovered by University of Queensland researchers.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.