What Are Mycoplasmas and How Do They Impact Human Health?
Mycoplasmas are a unique group of pathogenic microorganisms that stand out due to their distinct biological structure. Unlike typical bacteria, mycoplasmas lack a rigid cell wall, which gives them a high degree of flexibility in shape. This structural feature allows them to appear in various forms—ranging from spherical and filamentous to rod-like and branched—and enables them to pass through bacterial filters that normally trap conventional microbes.
Why the Absence of a Cell Wall Matters
The absence of a cell wall is a defining characteristic of mycoplasmas and plays a crucial role in how they interact with their environment. Because they don't have this protective outer layer, they are more vulnerable to external stressors compared to other bacteria. This makes them particularly sensitive to common chemical disinfectants, including alcohol-based solutions and oxidizing agents.
However, this same trait also renders certain antibiotics ineffective. Penicillin and cephalosporins, for example, work by disrupting the synthesis of bacterial cell walls—a mechanism that has no effect on mycoplasmas since they lack this structure entirely. As a result, these widely used antibiotics cannot treat infections caused by mycoplasma species.
Common Mycoplasma Species Linked to Human Infections
While there are over 100 known species of mycoplasmas, only a few are associated with human diseases. Among the most clinically significant are Mycoplasma pneumoniae and Ureaplasma urealyticum.
Mycoplasma Pneumoniae: A Cause of Respiratory Illness
Mycoplasma pneumoniae is a leading cause of atypical pneumonia, often referred to as "walking pneumonia." It primarily affects children and young adults and spreads through respiratory droplets. Symptoms may include persistent dry cough, low-grade fever, fatigue, and sore throat. While usually mild, infections can sometimes lead to complications such as bronchitis, ear infections, or even neurological issues in rare cases.
Ureaplasma and Genitourinary Tract Infections
Ureaplasma urealyticum and related species are commonly found in the urogenital tract and can contribute to conditions like urethritis, bacterial vaginosis, and prostatitis. In pregnant women, these organisms may be linked to preterm birth, low birth weight, and other reproductive complications. Their role in chronic pelvic pain and infertility is still under investigation, but growing evidence suggests they may play a part in certain unexplained cases.
Diagnosis and Treatment Challenges
Diagnosing mycoplasma infections can be difficult because they do not grow on standard culture media used for typical bacteria. Instead, specialized techniques such as PCR (polymerase chain reaction) testing or serological assays are required for accurate detection.
When treatment is necessary, healthcare providers typically prescribe antibiotics that target protein synthesis rather than cell wall formation. Macrolides (like azithromycin), tetracyclines (such as doxycycline), and fluoroquinolones are commonly used and effective options. Early diagnosis and appropriate antimicrobial therapy are key to preventing prolonged illness or transmission.
Prevention and Public Awareness
Given their mode of transmission—especially through close contact and respiratory secretions—basic hygiene practices such as handwashing, covering coughs, and avoiding close contact with infected individuals can help reduce the spread. In healthcare settings, proper sterilization protocols are essential, especially since mycoplasmas can contaminate cell cultures and medical equipment.
As awareness grows about these unconventional pathogens, ongoing research continues to shed light on their role in chronic and emerging diseases. Understanding mycoplasmas not only improves clinical outcomes but also enhances our broader knowledge of microbial diversity and infection control.