Mycoplasma vs. Ureaplasma

What's the Difference?

Mycoplasma and Ureaplasma are both types of bacteria that belong to the class Mollicutes. However, they differ in some key aspects. Mycoplasma is a genus of bacteria that can cause various infections in humans, such as pneumonia, urinary tract infections, and genital infections. It has a cell wall but lacks a cell membrane, making it resistant to many antibiotics. On the other hand, Ureaplasma is a genus of bacteria that primarily colonizes the urogenital tract and can cause infections such as urethritis and pelvic inflammatory disease. Unlike Mycoplasma, Ureaplasma lacks a cell wall and is highly susceptible to antibiotics. Both bacteria can be sexually transmitted and can cause similar symptoms, but their treatment approaches differ due to their different cell wall structures.


Cell WallAbsentAbsent
Size0.2-0.8 μm0.15-0.3 μm
PathogenicityCan cause various diseasesCan cause urinary tract infections
Resistant to AntibioticsSome strainsSome strains
Urease ProductionNot producedProduced

Further Detail


Mycoplasma and Ureaplasma are two types of bacteria that belong to the class Mollicutes. These bacteria are unique in that they lack a cell wall, making them the smallest self-replicating organisms known. Despite their similarities, there are distinct differences between Mycoplasma and Ureaplasma in terms of their characteristics, pathogenicity, and clinical significance.


Mycoplasma and Ureaplasma share several common characteristics. Both bacteria are pleomorphic, meaning they can take on various shapes, including cocci and filamentous forms. They are also facultative anaerobes, capable of surviving in both aerobic and anaerobic environments. Additionally, both Mycoplasma and Ureaplasma lack a cell wall, which makes them resistant to many antibiotics that target cell wall synthesis.

However, there are notable differences in their characteristics. Mycoplasma species are typically larger in size, ranging from 0.2 to 0.8 micrometers, while Ureaplasma species are smaller, measuring around 0.15 to 0.3 micrometers. Furthermore, Mycoplasma species possess a sterol-rich plasma membrane, which provides stability and resistance to osmotic stress. In contrast, Ureaplasma species lack this sterol-rich membrane and are more susceptible to osmotic changes.


Both Mycoplasma and Ureaplasma can cause infections in humans, but their pathogenicity differs. Mycoplasma species are known to be opportunistic pathogens, causing a wide range of infections in various body systems. For example, Mycoplasma pneumoniae is a common cause of community-acquired pneumonia, while Mycoplasma genitalium is associated with sexually transmitted infections.

On the other hand, Ureaplasma species are primarily associated with infections of the urogenital tract, particularly in newborns and individuals with compromised immune systems. Ureaplasma urealyticum and Ureaplasma parvum are the two main species that can cause urethritis, cervicitis, and other urogenital infections.

Clinical Significance

Both Mycoplasma and Ureaplasma have clinical significance, but their impact on human health varies. Mycoplasma infections are more prevalent and have been extensively studied. Mycoplasma pneumoniae, for instance, is a leading cause of atypical pneumonia worldwide, especially in children and young adults. It can also cause extrapulmonary manifestations, such as skin rashes and neurological complications.

Ureaplasma infections, on the other hand, are less well understood and have received less attention. However, they have been implicated in adverse pregnancy outcomes, including preterm birth, chorioamnionitis, and neonatal respiratory distress syndrome. Ureaplasma species have also been associated with infertility and pelvic inflammatory disease in women.


The diagnosis of Mycoplasma and Ureaplasma infections relies on various laboratory methods. Culturing these bacteria can be challenging due to their fastidious nature and slow growth. However, specialized culture media and techniques, such as broth enrichment and PCR-based assays, have improved the detection rates.

Additionally, serological tests, such as enzyme-linked immunosorbent assays (ELISA), can detect specific antibodies against Mycoplasma and Ureaplasma species. Molecular methods, such as polymerase chain reaction (PCR), are also commonly used to identify and differentiate between different species and strains of these bacteria.

Treatment and Prevention

The treatment of Mycoplasma and Ureaplasma infections often involves antibiotics, although their susceptibility patterns can vary. Mycoplasma species are generally susceptible to macrolides, tetracyclines, and fluoroquinolones. However, the emergence of antibiotic resistance, particularly in Mycoplasma genitalium, poses a challenge in the management of these infections.

Ureaplasma species, on the other hand, are inherently resistant to beta-lactam antibiotics due to the absence of a cell wall. They are typically susceptible to macrolides, tetracyclines, and fluoroquinolones. However, resistance to these antibiotics has also been reported, emphasizing the need for appropriate antibiotic stewardship and surveillance.

Prevention of Mycoplasma and Ureaplasma infections involves practicing safe sex, using barrier methods, and maintaining good hygiene. In the case of Ureaplasma infections in newborns, screening and appropriate antibiotic prophylaxis may be recommended to prevent adverse outcomes.


Mycoplasma and Ureaplasma are unique bacteria that share some similarities but also have distinct differences in their characteristics, pathogenicity, and clinical significance. Understanding these attributes is crucial for accurate diagnosis, appropriate treatment, and prevention of infections caused by these bacteria. Further research is needed to unravel the complexities of these microorganisms and their impact on human health.

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