Ureaplasma is a genus of bacteria that does not have a cell wall and is characterized by hydrolyzing urea and growing in acidic media. They are known to infect humans and other mammals, including cattle, dogs, cats, sheep, goats, raccoons, monkeys, pigs and birds, including quail, domestic chickens and turkeys.

In humans, ureaplasma has been isolated from the genital tract of apparently healthy sexually active males and females, but has also been found in females with urethritis and in males with chorioamnionitis and puerperal fever.

The genus Eureaplasma includes six species: U. urealyticum, Yu. Diversum, Yu. Gallorel, Yu. Felinum, U. Katie, U.. But the most important species for humans is Ureaplasma urealyticum,  since the rest of the ureaplasma are found only in animals.

For example,  u. Diversum It is found in the respiratory and genital tracts of cattle and sheep; You. Gallorel conjunctiva, oropharynx, nasal cavity and upper and lower has been isolated from chickens and other poultry.

As long as it is,  u. felinum and A. sati is recovered from the respiratory tract of healthy domestic cats and U. Congenital It is found in the mouth, nose and foreskin of dogs.


The genus Ureaplasma is antigenically heterogeneous, that is, it has several serotypes and to date 14 have been described in total. These serotypes are classified into two subgroups or biovares.

Biovar 1 contains serotypes 1, 3, 6 and 14 that are characterized by small genomes. For this reason it is called Biovar 1 . Parvam , comes from the word parvo, which means small.

Similarly, biovar 2 includes 2, 4, 5, 7, 8, 9, 10, 11, 12 and 13 serotypes.

Ureaplasma urealyticum, as well as other microorganisms like Mycoplasma hominis and Chlamydia trachomatis,  are considered sexually transmitted bacteria.

It is intimately related to perinatal disorders and gynecological diseases and infertility.

Another important feature of this style is its ability to grow in vitro at a pH between 5.5 and 6.5.


Domain: Bacteria

Phylum: Firmicutes

Class: Molicutes

Order: Mycoplasmatalis

Family: Mycoplasmataceae

Genre: Ureaplasma

virulence factor

Specifically the species U. urealyticum It produces the phospholipase enzyme. These enzymes hydrolyze phospholipids with the libration of arachidonic acid.

The arachidonic acid released from the amniotic membrane can lead to the production of prostaglandins, leading to premature labor during pregnancy.

Similarly, while these may play a role in the lung disease of U. urealyticum reaches the respiratory tract of the fetus.


The genus Ureaplasma resemble the genus Mycoplasma in that they do not have a cell wall, but differ in that they produce urea, which is why they are able to split urea.

The colonies of the genus Ureaplasma are small and spherical and extend towards the interior of the agar.


In the case of Ureaplasma urealyticum it is spread by sexual contact. Vertical transmission can also be given from colonized mother to newborn or prey.


in human

in women

Some women can bother u. urealyticum in the vaginal fluid in relatively high concentrations due to a poor immune response. It can lead to ascending infections like descending or chronic endometritis, which can lead to infertility.

In the case of pregnancy, it can lead to complications such as chorioamnionitis and perinatal morbidity and mortality (miscarriage or premature birth, fetal death in utero), depending on the time of infection.

However, in some cases it is difficult to detect a pathology for ureaplasmas when they are isolated with other pathogens identified in the genital area. Neisseria gonorrhea, Chlamydia trachomatis and Streptococcus agalactiae .

Other times if its involvement as a pathogen is evident, for example, it has been isolated from U. urealyticum blood cultures in 10% of women with postpartum fever or miscarriage.

Similarly, the presence of Ureaplasma in urine cultures during the first trimester of pregnancy has been associated with the development of preeclampsia.

in newborns

Ureaplasma urealyticum  causes fetal death in many cases, or affects premature birth and low birth weight. The newborn is colonized with the microorganism through contact with the mother at birth.

Some may colonize even 3 months after birth and may not develop any disease, mainly conjugation and separation from the vaginal mucosa in the case of girls.

While colonic in the respiratory tract can develop chronic lung disease, bronchopulmonary dysplasia and systemic infection in premature infants of colonized mothers.

He has also recovered from CSF due to meningitis in the neonatal period.

among men

On the other hand, U. Urealyticum   has been linked as a causative agent of non-gonococcal and non-chlamydial urethritis in males.

While their role in male infertility is controversial.


Postpartum bacterial anemia is caused by overgrowth of microorganisms from the site of colonization in the vagina, where the organism causes endometritis.

Subsequently, infection of the placental membrane and amniotic fluid due to ureaplasma leads to premature rupture of the fetal membranes, before prolonged labor or delivery.

From these sites, microorganisms enter the bloodstream during vaginal or cesarean delivery.

It is also possible that there is a silent amniotic infection, that is, U. urealyticus is capable of initiating an acute inflammatory tissue response, without associated symptoms.

deformities in animals

On the other hand, at the veterinarian level, avian ureaplasmas appear to be non-pathogenic, although they have been associated with lesions and clinical signs including pneumonia, air sacculitis and peritonitis in chickens and turkeys.


There are currently semi-automatic detection methods that help in diagnosis.

Mycoplasma System Plus or AF The genitourinary system is useful in the identification of microorganisms isolated most often by vaginal swabs, among which ureaplasmas are found.

There are also serological tests that determine specific antibodies against the microorganism.

On the other hand, there are molecular tests that can also be used for this microorganism.


The ideal treatment is tetracycline, as it is effective not only against Ureaplasma urealyticum, but also against Chlamydia trachomatis .

However, some strains of Ureaplasma have shown resistance to this drug, in which case treatment with quinolones, azithromycin, minocycline or clindamycin is appropriate.

However there has also been a strain of Ureaplasma urealyticum with resistance to ofloxacin and clarithromycin.

As susceptibility patterns can change, it is important to maintain monitoring of the antimicrobial susceptibility of these microorganisms to control guidelines in the application of an adequate therapeutic.

It is important to remember that since Ureaplasma is a bacterium that lacks a cell wall, beta-lactam antibiotics and glycopeptides are not efficient for the treatment of this microorganism.

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