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Microbiology of the Spirochetosis (the syphilis, borreliosis and leptospirosis).

What are morphological and tinctorial features of genus Treponema? They are slender spirals measuring about 0.2 μm in width and 5-15 μm in length have 10-12 wave curls and actively move. The spiral coils are regularly spaced at a distance of 1 μm from one another. They are not stain well with aniline dyes, but they can be seen in tissues when stained by a silver impregnation method.
What diseases are caused by Treponema? Treponema pallidum subsp. pallidum causes syphilis Treponema pallidum subsp. perteinue causes yaws Treponema pallidum subsp. endemicum causes endemic syphilis Treponema carateum causes pinta.
How is Treponema pallidum cultivated? It has never been cultivated on artificial media. Treponema is micoaerophilic, cultivated in eggs and tissue culture.
What is the antigenic structure of the Treponema? Somatic O-antigen is presented by peptidoglycan - cytoplasm membrane complex. There are more than 100 protein antigens. Flagella H-antigen is presented by three core proteins, which are homologous of other bacterial flagellin protein.
Pathogenesis of the syphilis Infection is usually transmitted by sexual contact. T. pallidum may penetrate the intact mucous membranes or it can enter through a break in the epidermis. Spirochetes multiply locally at the site of entry, and some spread to nearby lymph nodes and then reach the blood stream. In 2-10 weeks after infection, at the site of infection an ulcer forms with clean, hard base (hard chancre). It always heals spontaneously, but 2-10 weeks later, the secondary lesions appear. These consist of a red maculopapular rash anywhere on the body and moist, pale papules (condylomas) in anogenital region, axillas, and mouth. There may also be syphilitic meningitis, chorioretinitis, hepatitis, nephritis, and periostitis. The secondary lesions subside spontaneously. Without treatment the disease progressed to the tertiary stage, characterized by the development of granulomatous lesions (gummas) of the skin, bones, liver; degenerative changes in the central nervous system or cardiovascular lesions. Pregnant syphilitic women can transmit T. pallidum to the fetus through the pacenta beginin in 10th-15th weeks of gestation. The infected fetus may be born with congenital syphilis and have such signs: interstitial keratitis, Hutchinson’s teeth, and saddle nose, periostitis and central nervous system anomalies.
Source of infection of the syphilis It is deseased people.
Factors of pathogenicity of T. pallidum They are factors of adhesion and colonization, hyaluronidase, components of the cell wall.
Method of microbiological diagnosis of syphilis. Microscopic, biological and serological.
Material, which is taken from a patient with syphilis. Tissue fluid expressed from early surface lesions for demonstration of spirochetes, serum for serologic test.
What serological tests are used to diagnose syphilis? Venereal disease research laboratory (VDRL) or rapid plasma Reagan (RPR) Wassermann’s test Treponemal antibody tests (fluorescent treponemal antibody tests, Treponema pallidum hemagglutination and microhemagglutination-T pallidum test, TPI-test).
What is the immunity of a patient who had suffered from syphilis? Humoral, unintense, non-protective, cellular delayed.
Treatment Penicillin, Bismuth sulphate
Morphological, physiological and tinctorial features of Leptospirae The leptospirae are characterized by very thin cell structure. It forms 12-18 irregular coils, shaping small primary spirals. One end of the organism is often the bent, forming the hook. It has no flagella. Gram-negative bacteria (they do not stain by Gram method). Special method of staining is Giemsa’s stain, silver impregnation.
Which of the bacteria from the family Leptospirae is the most valueable for men? Leptospirae interrogans.
Cultural features of Leptospirae Leptospirae grow best in aerobic conditions at 28-30 °Ñ in protein-rich semisolid media (Fletcher), where they produce round colonies 1-3 mm in diameter in 6-10 days. Leptospirae also grow on chorioallantoic membranes of chicken embryo.
Antigens of Leptospirae It has complicated antigenic structure composed of lipopolisaccharide and proteins.
Source of infection of leptospirosis Animals (mice, dogs, rodents water, swine, rats)
Pathogenesis Human infection results usually from ingestion of water or food contaminated with leptospirae. After an incubation period of 1-2 weeks, there is a variable febrile onset during which spirochetes are present in the blood-stream. They then establish themselves in the parenchymatous organs, producing haemorrhage and necrosis of tissue and resulting in dysfunction of those organs. The illness is often biphasic. Second phase manifests as “aseptic meningitis”. There may be nephritis, hepatitis, skin, muscle and eye lesions.
Factors of pathogenicity of Leptospirae Plasmocoagulase, cytotoxin, fibrinolysin, lipase, haemolysin
Method of microbiological Diagnosis of leptospirosis Microscopic, bacteriological, biological and serological methods.
Material, which is taken from a patient with leptospirosis Blood, spinal fluid, urine.
Immunity Humoral type is specific.
Features of environment of liquid media The media do not change.
Treatment Antibiotics
Prevention Killed leptospirosis vaccine by epidemiological indications
What diseases are caused by borrelia? Borrelia recurrentis causes epidemic relapsing fever. Borelia persica and Borelia duttoni cause endemic relapsing fever. Borelia burgdorferi causes Lyme disease.
Morphological, physiological and tinctorial features of borrelia They are purple irregular spirals of 10-30 μm long and 0.3 am wide. The distance between turns varies from 2 to 4 μm. Gram-negative bacteria (they do not stain by Gram’s method). Special method of staining is Giemsa’s stain, silver impregnation.
Cultural characteristics of borrelia Borrelia can grow in anaerobic conditions at 28-30 °Ñ in liquid media, containing blood, serum, or tissue. They also grow on chorioallantoic membranes of chicken embryo.
Source of infection of borreliosis Epidemic relapsing fever - patient, carrier- louse; endemic relapsing fever - animals (rodents, ticks), carrier- ticks, Lyme disease - animals (mice), carrier- ticks.
Pathogenesis of epidemic relapsing fever The bacteria enter the human body when they scratch the bite place and rub the lymph of the crashed louse. After an incubation period of 3-10 days the temperature rises. During this time spirochetes abound in the blood. The fewer persist 3-5 days and then decline. The febrile period lasts 4-10 days and is followed by a second attack of chills, fever, intense headache, malaise. There are formed three to ten such recurrences, generally of diminishing severity.
Pathogenesis of Lyme disease. The transmission of B. burgdorferi to human is by injection of the organism in tick saliva or by regurgitation of the ticks mid gut contents. After that borrelia migrates out from site and produces the characteristic skin lesion. Dissemination occurs by lymphatic or blood to other skin and musculoskeletal sites and to many other organs. The initial stage is called erythematic chronic migrants, begins 3 days to 4 weeks after tick bite. It is a flat reddened area near the tick bite. It slowly expands, with central clearing. With the skin lesion is often flu like illness with fever, chills, myalgia, and headache. The second stage occurs weeks to months later and includes artralgia and arthritis, neurologic manifestations and cardiac disease. The third stage begins months to years later with chronic skin, nervous system, or joint involvement.
Methods of microbiological diagnostic of borreliosis They are microscopical and serological methods and rarely bacteriological, biological.
Material, which is taken from a patient with relapsing fever It is blood.
Material, which is taken from a patient with Lyme disease It is blood, spinal fluid, exudates from skin lesions.
Immunity It is humoral type specific.
Treatment Antibiotics

Addition 2



Microbiological research of the Syphilis


Date: 2016-01-14; view: 202


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