Epidemiology and transmission routes
An infected person is the sole source of urogenital mycoplasmoses. In the vast majority of cases, microorganisms are transmitted sexually.
However, for certain species (M. hominis and U. urealyticum), which can be part of the normal vaginal microflora, a vertical mechanism of transmission is also characteristic. This means microorganisms can infect the fetus directly as it passes through the mother's infected birth canal. In such cases, infection can lead to the development of pneumonia in newborns.
Clinical manifestations and pathogenesis
Symptoms and the localization of the inflammatory process directly depend on the specific type of pathogen and the patient's sex.
- M. genitalium: in men, this microorganism causes non-gonococcal urethritis. In women, the infection involves the internal genital organs, leading to cervicitis, endometritis, and salpingitis.
- U. urealyticum: this pathogen is associated with non-gonococcal urethritis in men (according to statistics, it is detected in approximately 10% of such urethritis cases).
- M. hominis: the clinical significance of this species is especially high for women. The infection is closely associated with the development of salpingitis. Furthermore, the presence of this pathogen is linked to postpartum and post-abortion fever.
Immune features
One of the key characteristics of urogenital mycoplasmoses is the lack of robust protection following the disease. Post-infection immunity is not formed.
Although specific humoral antibodies are produced in the infected person's body, they are present in extremely low titers. These antibodies do not possess protective properties and cannot prevent reinfection.
Laboratory diagnostics
To detect pathogens, various clinical specimens are sent to the laboratory: scrapings from the urethral mucosa, vaginal discharge, or urine portions.
Key point in test interpretation: Since M. hominis and U. urealyticum are often an integral part of the normal urogenital microflora, the mere fact of their detection in a biomaterial is entirely insufficient for diagnosis. The main pathogenicity criterion is a strictly quantitative indicator (titer) — it must be higher than $10^4$ CFU/mL.
Identification methods: Specialized test systems are used to determine the exact species of the microorganism and its titer. Biochemical differentiation of pathogens based on their enzymatic activity plays an important role:
- M. hominis — metabolizes the amino acid arginine.
- U. urealyticum — exhibits pronounced urease activity (capable of splitting urea).
Briefly: answers to topical questions
Which antibiotic groups are used for etiotropic treatment of urogenital mycoplasmoses?
For etiotropic treatment of mycoplasmoses, antibiotics acting intracellularly or targeting protein and DNA synthesis are used, since the pathogens lack a cell wall. The following drug groups are used:
- Macrolides — prescribed selectively (azithromycin, clarithromycin, roxithromycin, spiramycin, midecamycin, erythromycin).
- Tetracyclines — broad-spectrum drugs with intracellular penetration.
- Fluoroquinolones — drugs of choice affecting DNA synthesis.
- Lincosamides — used as part of etiotropic antibacterial therapy.
Which culture media are used for bacteriological inoculation of urogenital mycoplasmoses?
Complex culture media are used for mycoplasma bacteriological culture, as these microorganisms are fastidious. The media composition includes:
- Medium base — heart and brain extracts, yeast extract, and serum.
- Cholesterol — an essential additive required for cell membrane construction.
- Urea — a specific additive required for ureaplasma growth.
What pathogenicity factors are characteristic of Ureaplasma urealyticum?
The following factors and features are characteristic of Ureaplasma urealyticum:
- Urease — an enzyme that hydrolyzes urea to form ammonia and carbon dioxide; these products are toxic to tissues.
- Hydrogen peroxide — a mycoplasma metabolic product.
- Hemolysins — substances causing erythrocyte lysis.
- Urease activity is a differential feature; urea is required for ureaplasma growth.
Biochemical properties are easy to remember: UREaplasma splits UREa.
Class and exam questions
Is a qualitative PCR test sufficient to confirm a disease caused by U. urealyticum?
No. Since this microorganism can be part of the normal flora, the diagnosis is confirmed only at a quantitative titer above 10⁴ CFU/mL.
Is a person protected from reinfection after successful treatment?
No, post-infection immunity to mycoplasmoses is not formed, and the antibodies produced do not serve a protective function.
Can a mother's mycoplasmosis harm her child?
Yes, by passing through an infected birth canal, the fetus can become infected with M. hominis or U. urealyticum, which can cause pneumonia in the newborn.
What else to study on this topic
- Mechanisms of mycoplasma adhesion to the urogenital tract epithelium
- Specifics of clinical specimen collection in men and women
- Principles of test systems for quantitative determination of CFU/mL
- Differential diagnosis of non-gonococcal urethritides
Study the full topic in the «Microbiology» course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Urogenital mycoplasmoses" and 4,383 other subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 141 video lectures on the subject
Other topics in the "Mycoplasmas" section
The entire "Mycoplasmas" sectionFree video lessons: microbiologyShort lessons with study notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.