Urethral microbiota: a better understanding of male urinary tract infections
Urethritis is generally caused by well-known bacteria. These include gonococci, responsible for the dreaded “clap.” However, the urinary tract has its own microbiota which has yet to be explored! This is how researchers discovered1 other bacteria potentially involved in this urinary tract infection in men, which differ according to sexual orientation.
About this article
Urethritis is an inflammation of the (sidenote: Urethra The tube that carries urine from the bladder and out of the person’s body. ) , the tube through which urine leaves the bladder. In men, it manifests as a burning sensation on urination, with itching and abnormal discharge. It can be caused by a sexually transmitted infection (STI) triggered by a bacterium, usually Neisseria gonorrhoeae (gonococcus), and sometimes Chlamydia trachomatis or Mycoplasma genitalium, or less commonly by viruses such as herpes. However, up to half of cases of non-gonococcal urethritis are considered “idiopathic,” meaning we do not know what caused them. Either the urethritis is not infectious, which is rare, or the pathogen responsible is not identified. If in doubt, doctors usually prescribe an antibiotic. But this type of non-targeted approach can result in inadequate or excessive treatment, which can in turn alter the microbiota.
Close-up on the urethral microbiota of men with idiopathic urethritis
Recent studies also suggest that the infectious agents responsible for non-gonococcal urethritis in men who have sex with women (MSW) are not the same as in those who have sex with men (MSM). Australian researchers therefore sought to determine which bacteria, apart from those already known, might contribute to infection in humans, taking into account their sexual practices. To do so, they analyzed the urethral and urinary microbiota of around one hundred men (MSW and MSM) with symptoms of idiopathic urethritis and compared them to around one hundred men without urethritis, as “control” subjects.
What is non-gonococcal urethritis?
Non-gonococcal urethritis is a sexually transmitted infection (STI). It is characterized by inflammation of the urethra with symptoms that include burning sensations on urination, itching, and abnormal discharge from the penis. The infection can be caused by a variety of bacteria, and less commonly by viruses. Non-gonococcal urethritis is not caused by gonorrhea.2
(Bacterial) genus and sexual orientation issues
Scientists found that the bacterium Haemophilus influenzae, which naturally colonizes the microbiota of the nasopharynx (in other words, the nose and throat), was more abundant in the urethral microbiota of MSM with idiopathic urethritis. The researchers believe that this infection may be transmitted by the act of having oral sex without a condom. The scientists found more of the bacterial genus Corynebacterium in affected MSW, which was surprising because it is considered normal in male genital microbiota. The authors suggest that some of these species may become pathogenic on multiplying. Other bacterial genera such as Ureaplasma, Escherichia, some streptococci and a staphylococcus were also more abundant in the urinary and urethral microbiota of the affected men. The scientists believe they may also promote urethritis.
Hope for more targeted treatments for male urethritis
The discovery of these new bacteria brings hope for patients. Thanks to these new bacteria, researchers can now identify possible causes of non-gonococcal infectious urethritis based on the sexual orientation of patients. If these results are confirmed, doctors could offer their patients more targeted treatments. A small step for science, a giant leap for sexually transmitted infections (STIs)?