* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download T pallidum
Toxoplasmosis wikipedia , lookup
Marburg virus disease wikipedia , lookup
Cysticercosis wikipedia , lookup
Onchocerciasis wikipedia , lookup
Middle East respiratory syndrome wikipedia , lookup
Trichinosis wikipedia , lookup
Human cytomegalovirus wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Eradication of infectious diseases wikipedia , lookup
Hepatitis B wikipedia , lookup
Hepatitis C wikipedia , lookup
Coccidioidomycosis wikipedia , lookup
Neonatal infection wikipedia , lookup
Diagnosis of HIV/AIDS wikipedia , lookup
Leptospirosis wikipedia , lookup
Sarcocystis wikipedia , lookup
Schistosomiasis wikipedia , lookup
Dirofilaria immitis wikipedia , lookup
Visceral leishmaniasis wikipedia , lookup
African trypanosomiasis wikipedia , lookup
Sexually transmitted infection wikipedia , lookup
Fasciolosis wikipedia , lookup
Oesophagostomum wikipedia , lookup
Epidemiology of syphilis wikipedia , lookup
Spirochetes (Spiral bacteria) 1 8/1/2017 Classification Domain: Bacteria Family : Spirochetaceae (free living spirochetes) Treponemataceae (human pathogens) Genus: Treponema Borrelia leptospira 2 8/1/2017 General Features All spirochetes have similar morphological appearance They are all long slender, helically coiled (spiral) gram negative bacilli around 5-250 µm in length Obligate intracellular parasites Contain axial filament (endoflagella) which begins at each end of the organism and wind around it, extending and overlapping at the mid point 3 8/1/2017 General Features Axial filament runs between the bacterial inner and outer membranes in the periplasmic space 4 Very actively motile Reproduce by traverse binary fission 8/1/2017 Genus : Tryponema 4 spp (subspecies) T pallidum subspecies pallidum (T pallidum) Syphilis T pallidum subspecies pertenue (T pertenue) Yaws T pallidum subspecies endemicum (T endemicum) Endemic syphilis (bejel) T carateum 5 Pinta 8/1/2017 T pallidum subspecies pallidum Morphology Small , about 5-15 µm in length, slender gram negative spiral bacilli Actively motile So thin (very difficult to be seen by gram stain) Can only be seen using dark field illumination or immuno-fluorescent stain 6 8/1/2017 Growth and cultural characteristics Microaerophilic organisms , survives best in 1-4 % O2 Never been cultured on artificial growth media or tissue culture. Obligate intracellular parasites and therefore cant be transmitted by public surfaces because of its narrow temperature and pH ranges (can not survive in temperature higher than 42 C and their optimal pH range is 7.2 - 7.4) 7 8/1/2017 Growth and cultural characteristics Exposure to air, antiseptic or sunlight kill it Invivo generation time very long about 30 hours All spp sensitive to penicillin 8 8/1/2017 Antigenic structures - - 9 Not widely characterized more than 100 protein antigens - Outer membrane lipoproteins - Endoflagellar antigens 8/1/2017 Pathogenesis, pathology and clinical findings - T pallidum infection is limited to human host (animals can only be infected experimentally) - Infection with T pallidum cause a disease called Syphilis - Syphilis can be divided into two main types Acquired syphilis Congenital syphilis 10 8/1/2017 Pathogenesis, pathology and clinical findings Acquired syphilis - Transmitted by sexual intercourse - 3 stages Primary stage - Multiply locally at the site of entry - Painless chancre lesion (painless ulcer) on skin and mucous membrane of external genetalia 11 8/1/2017 Pathogenesis, pathology and clinical findings - 10-20% of cases the 1ry lesion is intra-rectal or peri-anal or oral - Lasts for 2-6 weeks and then recede even without treatment (you should treat it!!!!) - Highly infectious spirochetes 12 stage and lesion rich in 8/1/2017 Pathogenesis, pathology and clinical findings Secondary stage - Develop 2-10 weeks after the infection - None specific symptoms maculo-papular rash, fatigue, fever sore throat headaches , loss of appetite and lymphadenopathy - Also subsides spontaneously - Like 1ry stage, 2ry lesions are rich in spirochetes and highly contagious 13 8/1/2017 Pathogenesis, pathology and clinical findings Tertiary stage - 30 % of patents with syphilis progress to complete cure even without treatment - Another 30% of patents , untreated infections remain latent (evident by positive serological reactions) - About 40 % of patients progress to tertiary syphilis 14 8/1/2017 Pathogenesis, pathology and clinical findings Tertiary stage - Granulmatous lesions (GUMMAS) in skin , bones, joints and liver - Degenerative changes in CNS including syphilitic meningitis, paralysis , difficulties in movements, stroke, numbness and gradual blindness - Cardiovascular syphilitic lesions (aortitis, aneurysm an aortic valve insufficiencies 15 aortic - Not infectious stage, tryponema very rarely isolated and lesions are attributed to hypersensitivity to organism 8/1/2017 Pathogenesis, pathology and clinical findings Congenital syphilis - From pregnant woman to fetus through placenta - Usually begins in the 10th to 15th weeks of gestation 16 - Consequences • Some of the infected fetuses die and abortion result • Some are stillbirth at delivery 8/1/2017 Pathogenesis, pathology and clinical findings Congenital syphilis • Some fetuses born life but die soon after birth • Some fetuses born life but develop signs of congenital syphilis in childhood, these include 17 Varity of CNS anomalies Deafness Teeth deformities Saddle nose 8/1/2017 Laboratory Diagnosis • Specimen - Tissue fluid expressed from early surface lesions for identification of spirochetes - Blood or serum for serology • Direct testing - Dark - field examination (should be before the starting of antibiotic treatment) - IF 18 8/1/2017 Laboratory Diagnosis • Serology - Two types : - None treponemal serological tests (detect none trponemal antigens or antibodies) - Treponemal serological tests (detect treponemal antigens or antibodies) 19 8/1/2017 Laboratory Diagnosis None treponemal serological tests - None specific tests - Used for screening - Look for cardiolipins (Indirect indications of the infection with T pallidum - Cardiolipin shares some antigenic determinants with T pallidum 20 - They indicate either active infection or healed but not treated infection 8/1/2017 Laboratory Diagnosis - Two types VDRL (Venereal Disease Research Laboratory) test RPR (Rapid Plasma Reagin) test - The only difference between the two the later does not need a microscope to read the result 21 8/1/2017 Laboratory Diagnosis - Ve VDRL test + Ve VDRL test - Positive test is indicated by the formation of clusters - If positive, go with treponemal serological tests 22 8/1/2017 Laboratory Diagnosis Disadvantages of None treponemal serology - Not specific (false positive can occur with other conditions such us pregnancy , HIV, TB, and rheumatoid arthritis - Not very sensitive in early syphilis, specially in the first 2-3 weeks after the infection (false negative) 23 8/1/2017 Disadvantages of None treponemal serology - Not specific (false positive can occur with other conditions such us pregnancy , HIV, TB, rheumatoid arthritis - Not very sensitive in early syphilis, specially in the first 2-3 weeks after the infection (false negative) 24 8/1/2017 Laboratory Diagnosis Treponemal serological tests - Indicated if non treponemal serological tests are positive - Detect treponemal antigens or antibodies - Remains positive for life (not useful for screening) - Many types: Fluorescent treponemal antibody (FTA) Treponema pallidum particle agglutination ELISA 25 8/1/2017 Treatment and Immunity 26 - Sensitive to penicillin ( treatment of choice) - If patient is allergic, tetracycline and erythromycin can be substituted but they are generally less effective than penicillin - No permanent immunity. If the disease is treated, the individual again becomes fully susceptible to re-infection 8/1/2017 Other Treponema subspecies • T pallidum subspecies pertenue • T pallidum subspecies endimicum Yaws Bejel - Non sexually transmitted diseases - Affect children in hot tropical countries - 1ry lesion is an ulcerating macule or papule on arms and legs. Complications rare - Yaws is a variant of syphilis (????) - Sensitive to penicillin ( treatment of choice) 27 8/1/2017 Other Treponema subspecies • T carateum Pinta - Non sexually transmitted disease - Affect all age groups in Mexico and South America (restricted to dark skinned people) - 1ry lesion is non ulcerating macule on exposed areas changes later on to hyperpigmented lesions. Complications rare - Diagnosis and treatment like syphilis 28 8/1/2017