What is the definition of Mycoplasma?

Mycoplasma is a microorganism unfamiliar to many people. In fact, its pathogenicity is relatively weak and not particularly severe; it typically does not invade the bloodstream. However, detection of mycoplasma during diagnostic testing should never be overlooked, as untreated infection may progress to Mycoplasma pneumoniae infection or other mycoplasma-related diseases—conditions requiring prolonged treatment for symptom relief.

What Is Mycoplasma?

Mycoplasma stains Gram-negative but is difficult to visualize with conventional Gram staining; Giemsa staining is therefore commonly used, yielding pale purple organisms. Reproduction occurs primarily by binary fission, though budding and branching—followed by fragmentation into coccobacillary particles—may also occur. Most mycoplasma species replicate more slowly than typical bacteria. Optimal growth occurs at 35°C and pH 7.8–8.0.

On solid culture media, mycoplasma forms characteristic “fried-egg”–like colonies. Mycoplasma exhibits low resistance to environmental stressors: it is sensitive to heat and desiccation, as well as to 75% ethanol and cresol soap solution. It is susceptible to antibiotics such as erythromycin, tetracycline, spiramycin, streptomycin, and kanamycin—but resistant to penicillin-class antibiotics.

Although mycoplasma possesses relatively low pathogenicity and generally does not enter the bloodstream, it can adhere to host cells and extract lipids and cholesterol from the cell membrane, thereby causing membrane damage. Ureaplasma urealyticum hydrolyzes urea to produce large amounts of ammonia, which exerts cytotoxic effects.

Mycoplasma pneumoniae

Mycoplasma pneumoniae is the causative agent of mycoplasma pneumonia, and may also cause upper respiratory tract infections and chronic bronchitis. Transmission occurs primarily via the respiratory route; infections can occur year-round but peak in late summer and early autumn. Incidence is highest among children and adolescents aged 1–15 years. Clinical manifestations are usually mild and include irregular fever, headache, and paroxysmal, irritative cough. While bronchopneumonia is common, some patients develop extrapulmonary complications—including skin rashes, cardiovascular involvement, and neurological symptoms. Diagnosis is typically confirmed via culture isolation and serological testing.

Other Mycoplasma Species

Ureaplasma urealyticum, Mycoplasma hominis, and Mycoplasma genitalium are pathogens responsible for human urogenital tract infections. These organisms are transmitted primarily through sexual contact, causing conditions such as urethritis and prostatitis. They may also cross the placenta, leading to preterm birth, spontaneous abortion, congenital anomalies, stillbirth, and infertility. Neonatal transmission during vaginal delivery can result in neonatal pneumonia or meningitis.

We hope the above information is helpful. Wishing you a happy and healthy life!