Ureaplasma

Detailed article on Ureaplasma for medical students

Introduction

Ureaplasma is a genus of bacteria belonging to the family Mycoplasmataceae. These bacteria are unique in that they lack a cell wall, which makes them resistant to many common antibiotics such as penicillin that target cell wall synthesis. Ureaplasma species are part of the normal flora of the human urogenital tract but can also be associated with various infections and complications, particularly in immunocompromised individuals and neonates.

Taxonomy and Classification

Ureaplasma is classified under the class Mollicutes, which includes other genera such as Mycoplasma. The genus Ureaplasma is further divided into several species, with the most clinically significant being Ureaplasma urealyticum and Ureaplasma parvum.

Morphology and Physiology

Ureaplasma species are among the smallest free-living organisms, typically measuring 0.2 to 0.3 micrometers in diameter. They are pleomorphic, meaning they can change shape, and are characterized by their lack of a cell wall. This feature contributes to their resistance to antibiotics that target cell wall synthesis. Ureaplasma species are facultative anaerobes and require urea for growth, which they hydrolyze to produce ammonia, a process that can be detected in laboratory cultures.

Pathogenesis

While Ureaplasma species are often part of the normal flora, they can become pathogenic under certain conditions. They are implicated in a variety of urogenital infections, including urethritis, bacterial vaginosis, and pelvic inflammatory disease. In pregnant women, Ureaplasma infections have been associated with adverse outcomes such as preterm birth and chorioamnionitis. In neonates, particularly those born prematurely, Ureaplasma can cause respiratory distress syndrome and other complications.

Diagnosis

Diagnosis of Ureaplasma infections typically involves the collection of clinical specimens such as urine, swabs from the urogenital tract, or amniotic fluid. Laboratory identification is based on culture techniques that detect the hydrolysis of urea, as well as molecular methods such as polymerase chain reaction (PCR) that can identify Ureaplasma DNA.

Treatment

Treatment of Ureaplasma infections can be challenging due to their intrinsic resistance to antibiotics that target cell walls. Effective antibiotics include macrolides, tetracyclines, and fluoroquinolones. The choice of antibiotic may depend on the site of infection, patient characteristics, and local resistance patterns.

Epidemiology

Ureaplasma species are widespread and can be found in a significant proportion of sexually active adults. Transmission occurs primarily through sexual contact, but vertical transmission from mother to child during birth is also possible. The prevalence of Ureaplasma colonization and infection varies by population and geographic region.

Also see

• Mycoplasma
• Bacterial vaginosis
• Urethritis
• Pelvic inflammatory disease
• Preterm birth