Mycoplasma is the smallest microorganism living outside the cell, a class of prokaryotic cellular microorganisms lacking cell walls, generally between 0.3 and 0.5 um in size, highly polymorphic, with spherical, rod-shaped, filamentous, branched and other states. Unlike cells and viruses, it is diverse, widely distributed, and causes considerable harm, involving humans, animals, plants, and insects in many fields, bringing adverse effects to human health and scientific research. Of the 16 species of mycoplasma isolated from humans, 5 are pathogenic to humans, namely Mycoplasma pneumoniae, Mycoplasma urealyticum, Mycoplasma humanum, Mycoplasma reproductiveis and Mycoplasma fermentum urealyticum genus containing Mycoplasma urealyticum, Mycoplasma urealyticum and Mycoplasma humanum, etc. are pathogenic to humans. Common causes: Mycoplasma pneumoniae, Mycoplasma solani, Mycoplasma humanum, Mycoplasma genitalium, Mycoplasma fermentum urealyticum. Common symptoms: genitourinary tract infection, respiratory tract infection. Pathology and etiology: among the causative mycoplasmas, Mycoplasma pneumoniae starts pneumonia, Mycoplasma humanum, Mycoplasma solani and Mycoplasma genitalium mainly genitourinary tract infections. Mycoplasma pneumonia, also known as primary atypical pneumonia, mycoplasma pneumonia can develop throughout the year, more common in winter, can have a small epidemic, mycoplasma pneumonia is a common pneumonia in preschool children and young people, mycoplasma pneumonia mainly through droplet transmission, the incubation period is long, up to 2 to 3 weeks, mycoplasma pneumonia, although the course of the disease is long, heavy lung lesions, inflammation absorption is slow, but the vast majority of prognosis is good. The pathogen is Mycoplasma pneumoniae, a microorganism between bacteria and viruses, no cell wall structure, parthenogenic anaerobic, the smallest microorganism that can live independently. Healthy people are infected by inhaling the oral and nasal secretions emitted by the patient during coughing and sneezing. The pathogen usually exists between the ciliated epithelium of the respiratory tract and does not invade the lung parenchyma, but adsorbs to the surface of the host respiratory epithelial cells through neuraminic acid receptor sites on the cell membrane, inhibiting ciliary activity and destroying the epithelial cells. Mycoplasma genitalium infection is a newly identified sexually transmitted disease in recent years, mainly transmitted through sexual contact in adults, while newborns are infected by the mother’s genital tract during delivery, with adult males being infected in the urethral mucosa and females in the cervix, and newborns mainly causing conjunctivitis and pneumonia. Clinical manifestations 1, genitourinary tract infection Genitourinary tract infection: incubation period of 1 to 3 weeks, typical acute symptoms are similar to other non-gonorrheal genitourinary infections, manifested as urethral tingling, varying degrees of urinary urgency and frequency, stinging pain in urination, especially when the urine is more concentrated, the urethral orifice is mildly red and swollen, the discharge is thin, small, plasmacy or purulent, and requires forceful squeezing of the urethra to In the subacute stage, it is often combined with prostate infection. Patients often have perineal swelling and pain, lumbago, discomfort in the inner side of both femurs or a tingling sensation from the perineum to the inner side of the femur when doing anal lifting. When the infection spreads to the urethra, frequent and urgent urination is the main symptom that draws the patient’s attention. If the infection is confined to the cervix, the symptoms are increased leucorrhea, cloudiness, edema, congestion or surface erosion of the cervix, and if the infection spreads to the urethra, the urethral orifice is flushed and congested. Even if pregnancy occurs, it can easily lead to embryonic death, fetal death, spontaneous abortion, and low birth weight babies. Mycoplasma humanum infection in women can also cause pyelonephritis, pelvic inflammatory disease, postpartum fever, non-gonococcal urethritis and other diseases. 2, respiratory tract infections start slowly, incubation period 2 to 3 weeks, at the beginning of the disease, there is general malaise, weakness, headache. 2 to 3 days later, fever often reaches about 39 ℃, can last 1 to 3 weeks, may be accompanied by sore throat and muscle aches. 1.Blood tests The total number of peripheral blood leukocytes is normal or slightly increased, mainly neutrophils. 2.X-ray examination Mycoplasma pneumonia chest X-ray is non-specific, mostly unilateral infiltration of the lower lobe, showing segmental pneumonia, and in severe cases, extensive bilateral pneumonia. 3, pathogenic examination sputum, nose and throat swab culture for Mycoplasma pneumoniae. 4, serological examination serum pathogen antibody potency > 1:32, streptococcal MG agglutination test, potency ≥ 1:40 is positive, two consecutive 4-fold increase has diagnostic value. About 2 weeks after the onset of disease, about 2/3 of patients with positive condensation set test and titration potency >1:32, especially when the titer gradually increases, have diagnostic value. About half of the patients were positive for the streptococcal MG agglutination test. Further confirmation of the diagnosis depends on the determination of IgM antibodies to mycoplasma in the serum (enzyme-linked immunosorbent assay is the most sensitive, immunofluorescence is more specific, and indirect hemagglutination is more practical). Antigen detection can be used PCR method, but the reagent kit has to be improved to improve the sensitivity and specificity. 5, PCR technology Ordinary PCR technology to detect Chlamydia pneumoniae specific DNA, with the advantages of rapid, simple, specific, higher sensitivity than the cell isolation technique, with a set of PCR (nPCR) detection can significantly improve its sensitivity. Treatment Early use of appropriate antibacterial drugs can reduce symptoms and shorten the course of the disease. The disease is self-limiting and most cases can be cured spontaneously without treatment. Macrolide antibacterial drugs are preferred, such as erythromycin, roxithromycin and azithromycin. Fluoroquinolones such as levofloxacin, gatifloxacin and moxifloxacin, and tetracyclines are also used in the treatment of Mycoplasma pneumoniae pneumonia. The course of treatment is usually 2 to 3 weeks. Because Mycoplasma pneumoniae has no cell wall, antibacterial drugs such as penicillin or cephalosporins are ineffective. For those who choke violently, cough suppressants should be given appropriately. In case of secondary bacterial infection, targeted antibacterial drugs can be used for treatment according to sputum pathogenesis. The disease is self-limiting, most cases can be cured without treatment, the use of appropriate antibacterial drugs can reduce the symptoms and shorten the course of the disease. Erythromycin is preferred for treatment, and tetracyclic antibiotics can also be used. Early use of appropriate antibiotics can reduce the symptoms and shorten the course of the disease to 7-10 days.