Mycoplasmosis - are infectious diseases caused by mycoplasma, characterized by polymorphism of clinical manifestations, mainly affecting the respiratory, urogenital and central nervous system.
etiology. Mycoplasmas are the smallest free-living prokaryotes, capable of autonomous growth and reproduction, occupy an intermediate position between viruses, rickettsia, bacteria and protozoa.They are Mycoplasmatacae family, which includes two kinds - Ureaplasma and Mycoplasma.Mycoplasmas are small gram-negative microorganisms polymorphic size from 0.1 to 10 microns, contain RNA and DNA movable.
The unique properties of mycoplasmas are the absence of cell wall (instead have a three-layer membrane), the lowest for prokaryotic genome size (500-1000 MD), the presence of a minimum number of organelles, membrane parasitism.The latter property is due to the inability of mycoplasma synthesize cholesterol, which causes them to use the plastic material of the host cell.Attachment to cell surface occurs due aktinopodo
to human pathogens 16 species of mycoplasmas..pneumoniae is the causative agent of respiratory mycoplasmosis, U. urealyticum, M. hominis and M. genitalium - diseases of the urogenital tract, M. incognitis - generalized mycoplasma, M. orale and M. salivamm - periodontitis, pulpitis, stomatitis, osteomyelitis, M. artritidis and M. fermentas - arthritis.
Mycoplasma unstable in the environment, are killed under the influence of low and high temperatures, changing the pH of, the action of ultrasound, UFO, standard disinfectants, detergents.Sensitive to macrolides, tetracyclines, fluoroquinolones are resistant to penicillin and other (3-lactams, cephalosporins, carbapenems, sulfonamides.
Epidemiology. Mycoplasma take 4-6 place in the etiological structure of acute respiratory infections. They are the etiological agents 5-30% of acute respiratory infections and 6-25% of pneumonia. (during the epidemic rise - 30-60%)
source patients are symptomatic and subclinical forms mikopdazmoza Isolation of mycoplasma convalescents lasts for several weeks
Transduction -.. air-kapelny, sexual and vertical. Given the low stability of mycoplasma in the environment airborne route is implemented only in close contact, so the foci of the disease are recorded in the family, enclosed and semi-collectives (kindergartens and schools, dormitories, barracks and other.).
for respiratory mycoplasmosis characteristic of the autumn-winter-spring season.Epidemic rise observed once in 4-8 years.More common in schoolchildren (11-15 years) and young people.Post-infectious immunity lasts for 5-10 years, so there may be recurrent disease.
pathogenesis. in the pathogenesis of mycoplasmosis distinguish several stages.
1. The introduction and proliferation at the site of the entrance gate.Gateway for.pneumoniae is mucosa of the respiratory tract, for U. urealiticum, M. hominis and M. genitalium - mucosa of the urogenital tract, for M. orale and M. salivarum - oral mucosa.In place of the entrance gate agents multiplication occurs on the cell surface, and inside them.
2. Dissemination.As a result of accumulation of mycoplasma and their toxins into the blood.Dissemination pathogens also occurs as a part of infected macrophages and neutrophils.There direct defeat of various organs -. The central nervous system, heart, liver, kidneys, joints, etc. In addition, the adverse effect is allocated Mycoplasma toxins.Hemolysin damages cells ciliated epithelium, causing hemolysis, impaired microcirculation, the development of vasculitis and thrombosis.Neurotoxin has a toxic effect on the central nervous system and cardiovascular system, increases the permeability of the blood-brain barrier.They have toxic properties of hydrogen peroxide and ammonia, which is isolated mycoplasmas.
3. Development of serous inflammation.Adhesion of mycoplasmas to the target cells leads to disruption of tissue architectonics, cell-cell contacts, cell metabolism and cell membrane structure.The result is a degeneration, metaplasia, epithelial desquamation and destruction, violation of microcirculation, increased exudation, necrosis, in infants - hyaline membrane.The genesis of cell damage in the early stages of infection leading role played by direct action tsitodestruktivnoe mycoplasmas.Subsequently joins the immune inflammation component associated with deposition of immune complexes and tissue infiltration of cells involved in immune response.Formed peribronchial, perivascular and interstitial infiltration of affected tissues by lymphocytes, plasma cells, histiocytes, macrophages, monocytes and neutrophils isolated.In addition, a value close contact with mycoplasma cell membrane under conditions which respond defense reactions inevitably lead to cell damage.With 5-6-th week of the disease to the forefront autoimmune mechanism of inflammation, which plays a particularly important role in chronic mycoplasma.
4. The development of the immune response, induction of IDS and autoimmune reactions.The factors involved antimikoplazmennoy protection innate resistance (mucociliary clearance, neutrophils, macrophages, complement, interferons) and cellular immune response (CE) of 8-lymphocytes) and humoral type (antibody classes IgM, IgA, IgG).Mycoplasma effectively resist protective reactions of microorganism.They paralyze the movement of the cilia of the ciliated epithelium.The close relationship with the cells and the antigenic mimicry leads to disruption of mycoplasma detection by macrophages.Pathogens infect macrophages and neutrophils, thereby inducing incomplete phagocytosis.Furthermore, this leads to disruption of cell cooperation involved in the immune response by the humoral and cell types.The development of secondary IDS promotes the formation of mixed infection with chlamydia, bacteria, viruses, fungi and protozoa.In recent years proven to direct activating effect on mycoplasma replication of HIV, and oncogenic viruses. In has now been found that Mycoplasma cause polyclonal activation of T and B lymphocytes, which in combination with the presence of antigens cross lung tissue, brain, liver, pancreascancer, smooth muscle, lymphocytes and red blood cells leads to development of autoimmune reactions.
5. Outcomes.The outcomes of primary infection, taking into account the state of the immune system are healing, the transition to a chronic or latent form.In the normal state of the immune status of the organism occurs reorganization of mycoplasmas.Patients with IDS develops the latent form of mycoplasmosis in which pathogens are stored in the body for a long time.There is a shutdown of the gene encoding the protein synthesis of P (adhesin), which allows mycoplasma to evade the immune response.In the context of immunosuppression pathogen again it begins to multiply.With deep IDS mycoplasmosis becomes chronic with localized inflammation at the site of the entrance gate and / or the formation of a wide range of diseases - rheumatoid arthritis, asthma, chronic interstitial pulmonary fibrosis, immune cytopenias and other
Classification..APKazantsev (1997) identifies the following clinical forms mycoplasmosis:
The incubation period is 3-11 days.
clinical forms are rhinitis, pharyngitis, laryngotracheitis, bronchitis, otitis media, miringit, evstaheit, sinusitis.The most common mycoplasmal pharyngitis.Disease begins acutely or gradually.The body temperature is normal, or low-grade febrile.
symptoms intoxication expressed moderately.Characteristic complaints of dry, scratchy and sore throat, dry cough, nasal congestion.Less common cold, conjunctivitis, scleritis, facial flushing.When pharyngoscope detect diffuse hyperemia and granularity of the posterior pharyngeal wall.During favorable disease.Fever docked, usually 3-5 days, however, low-grade fever may persist for 1-2 weeks.Catarrhal symptoms disappear after 7 to 10 days.The most common complication is otitis media, rarer miringit, evstaheit and sinusitis.
mycoplasma laryngitis appears barking cough, hoarseness, sometimes joined by inspiratory dyspnea.A typical symptom is a dry compulsive tracheobronchitis paroxysmal cough without reprise, which is accompanied by pain in the chest and abdomen, sometimes ends up vomiting.The cough may persist for several weeks or even months.Sometimes patients develop bronchitis bronchial obstruction.
Mycoplasma pneumonia along with chlamydial pneumonia and refers to a group of atypical pneumonia, which are characterized by the absence of severe fever and clear physical findings, paroxysmal cough, presence of interstitial lesions on chest radiograph.
Mycoplasma pneumonia etiology occurs in 9-22% of children and 6% of adults.The disease most often occurs in children older than 7 years of life.The incubation period is 8-40 days.Mycoplasma pneumonia often begins gradually (75% of patients), rarely - acute.The initial period lasts from 2 to 12 days.It appears symptoms of lesions of the upper respiratory tract (pharyngitis, conjunctivitis, rhinitis).The body temperature of low-grade, less normal or febrile, symptoms of intoxication are mild.
Deterioration celebrated on 3-4th day of illness in acute or within 7-12 days with a gradual onset of the disease.Body temperature rises to 39-40 ° C.Symptoms of moderate intoxication, do not comply with fever, but may be severe (anorexia, headache, myalgia, repeated vomiting, lethargy).Febrile fever persists for 2-12 days, then transferred to a long low-grade fever (up to 1-7 weeks).Characterized by compulsive dry paroxysmal cough without reprise, there may be chest pain.Later the cough becomes productive, followed by separation of viscous sputum.It can persist for a long time, for 6-8 weeks, even after the disappearance of physical changes.Respiratory failure is most often absent.Physical findings scarce - against the backdrop of a rigid or a weakened respiratory listen to dry and wet wheezing, marked blunting of pulmonary sound.In 10-20% of patients, especially in adolescents, there is a "silent pneumonia."Physical findings may persist for 30-50 days.As a result, the development of secondary IDS quite often mixed infection with chlamydia, bacteria, respiratory viruses, herpes viruses, fungi.
The general analysis of blood reveal leukocytosis, neutrophilia with a left shift, increased ESR.When X-ray reveals interstitial changes: increased vascular and bronchopulmonary drawing, fine linear or infiltrates petlistogo nature, interstitial edema, atelectasis.In infants bilateral pneumonia, in adolescents - often one-sided (right).One-third of patients diagnosed with focal, segmental and lobar pneumonia.Possible involvement in the pathological process of the pleura.
evidence of the systemic nature of the disease are ekstrares-piratornye symptoms.Half of the patients reveal hepatomegaly in 25% - splenomegaly, 15% - polymorphic exanthema (punctate, roseolous, blotchy or maculopapular).By ekstrarespirator nym manifestations include lymphadenopathy (usually increased perednesheynye lymph nodes), liver pathology (hepatitis, focal necrosis), the heart (myocarditis, focal necrosis, pericarditis), joints (arthritis, arthritis), kidneys (nephritis), blood (hemolytic anemia,platelet-topeniya), nervous system (meningitis, meningoencephalitis, poliradiku-loneyropatiya), pancreas (pancreatitis), the eye (uveitis), skin changes (erythema nodosum, erythema multiforme, Stevens-Johnson syndrome), dyspeptic syndrome (nausea, vomiting, abdominal pain, diarrhea), Reiter's syndrome.
pathology of the nervous system occurs infrequently.The symptoms of meningitis or meningoencephalitis serous appear simultaneously with respiratory lesions or earlier.Mycoplasma may be the cause of myelopathy and polyradiculoneuropathy.
Mycoplasma cause urethritis, prostatitis, vulvovaginitis, obesity, cervicitis, metroendometrity, salpingoophoritis, epididymitis, cystitis and pyelonephritis.Pathology of the urogenital tract is more common in sexually active adolescents.
incidence of urogenital mycoplasmosis women of childbearing age is 13.3%, in the presence of chronic urogenital pathology - 23,6-37,9%.During pregnancy, infection with Mycoplasma increases by 1.5-2 times (40-50%).The risk of vertical transmission, according to different authors, ranges from 3.5 to 96%.Prenatal mycoplasmosis diagnosed in 5,5-23% of newborns.The most common etiologic agent is M. hominis.
Infection may occur in the ante- and intrapartum periods.Antenatal infection hematogenous realized, ascending, descending, transplacental pathways, aspiration of infected amniotic fluid.In addition to direct damaging effect of mycoplasma cause chromosomal aberrations in cells of the fetus.They induce the production of prostaglandins that lead to a reduction in uterine and abortion.In addition, unfavorable role called mycoplasma spasm of blood vessels of the umbilical cord, the impact of harmful products of metabolism and hyperthermia, which leads to fetal hypoxia and fetal growth retardation.Intrapartum infection occurs through contact of the mucous membranes of the child with birth mother's ways and aspiration of amniotic fluid.
In the absence of pathognomonic symptoms essential for timely diagnosis acquires analysis of obstetrical and gynecological mother's medical history - the presence of vaginitis, vulvovaginitis, cervicitis, endometritis, salpingoooforita, urethritis, cystitis, pyelonephritis, infertility, recurrent miscarriage, placentation anomalies, premature detachmentplacenta, threatening miscarriage, late gestosis, polyhydramnios, horionamini-Onita, premature discharge of amniotic fluid, preterm labor, postpartum endometritis, sepsis.
While infecting antenatal clinical symptoms occurs at birth - congenital develops mycoplasmosis.Infection in the first two weeks of pregnancy leads to blastopatii - the death of the embryo or the formation of systemic pathology similar to genetic diseases.When infected in 15-75 days gestation occurs embriopaty - true malformations at the organ or cellular level, in the 76-180 days of gestation - early fetopathy (false malformations associated with cystic sclerotic bodies deformation).A feature inherent mycoplasma is relatively high frequency of malformations of various organs (CNS, cardiovascular, respiratory, urinary system, musculoskeletal system, etc.), Which are recorded in 63.4% of children.
infection during gestation more than 180 days, leading to the development of generalized congenital mycoplasma.Quite often there are prematurity, intrauterine growth retardation, hypoxic-traumatic CNS, asphyxia.Symptoms occur at birth or appear in the next few hours after birth.There are clinical lesions respiratory, cardiovascular, CNS, hemorrhagic and lymphoproliferative syndrome.There have shortness of breath with auxiliary muscles, pale gray skin color, cyanosis, half of the children - foam bleeding from the mouth.Auscultation listen finely rales and crepitation.On radiographs reveal the expansion of the lungs of the roots, pneumonic lesions, atelectasis, emphysema.