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8 Cards in this Set
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Chlamydiae - Small, obligate intracellular bacteria unable to synthesize ATP
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- Unable to synthesize ATP = "energy parasites"
- Cell walls = no peptidoglycan, other than this they're similar to Gram negative organisms - Extracellular infectious form is called elementary body is believe to be inert, attaches to host cells via adhesins and is phagocytosed - Elementary body prevents fuision of phagosome with lysosome, reorganizes into a larger reticulate body which divides repeatedly through binary fission to form an inclusion - Reticulate bodies condense to form elementary bodies released by death and lysis of host cells |
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Chlamydia Trachomatis - Has glycogen for iodine staining, SWAB VIGOROUSLY FOR SAMPLE, need alot of epithelial cells for isolation and staining, fluorescent antibody testing
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- Characterized by glycogen inclusions (iodine staining)
- Diff erotypes cause diff disease syndromes - Serotypes A, B, Ba, C = trachoma, keratoconjunctivitis most prevalent in poverty areas. Important cause of blindness resulting from corneal abrasion by eyelashes turned inward (trichiasis) due to conjunctival scarring after many yeras of infection. - Spread via eye/hand/eye contact - Serotypes D to K (DICK) cause STI's, DICK CAUSES STI's such as non gonococcal urethritis (NGU), cervicitis (can be PID), proctitis, neonatal inclusion conjunctivitis (vertical transmission) - Serotypes L1, L2, L3 : Cause lymphogranuloma venereum (LGV), STI relatively uncommon in canada that can be divided into 3 stages - Stage 1 = primary lesion stage, quickly healing, sometimes associated with constituitional symptoms - stage 2 = inguinal syndrome stage, inguinal lymphadenopathy (Groove sign) - stage 3 = genitoanorectal syndrome, primarily in women + male homos |
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Chlamydia Psittaci - doesn'th ave glycogen for iodine staining
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- causes ornithosis, acute generalized infection with fever, splenomegaly, headache, resp symptoms
- acquired by inhalation from dessicated droppings or secretions of infected brids, not person to person - WBC + ESR = not elevated, diagnosis = serology |
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Chlamydophila Pneuomniae - diagnostic tests not routinely available
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- causes outbreaks of pneumonia with normal WBC + ESR, spread person to person, as common as viral pneumonia but not as common as mycoplasma infections (esp in young + healthy)
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Mycoplasmas - family Mollicutes, bacteria without cell walls, smallest free living microorganisms
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- related to clostridia (anaerobic spore forming gram positive rods) + lack ytochromes, tricarboxylic acid cycle, and portions of hexose monophosphate shunt
- only prokaryotes to contain sterols in cell membrane but cannot synthesize the sterol ring, so they require an external cholsterol source - widely distributed in nature |
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Mycoplasma pneumoniae
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- One of three most common community aquired pneumonia causes (20%) along with Strep Pneumoniae and Haemophilus influenzae even though only 3% of cases manifest to pneumonia (77% tracheobronchitis, 20% asymptomatic)
- Not hard to isolate, requires 8-15 days to grow = Growth detected by acidification of liquir medium OR observation of fried egg or mulberry colonies on solid medium - Hemadsorption and pinpoint hemolysis confirm identification in resp isolates - Disease largely due to hosts immune response, summer disease in temperate climates |
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Genital Mycoplasmas (M. Hominis, Ureaplasma Urealyticum)
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- Organisms associated with non gonoccocal urethritis (NGU) but chlamydia trachomatis = much more common cause
- Interpretation of positive cultures is difficult because of high carrier rate of genital mycoplasmas in healthy individuals of both sexes (up to 70%) - Mycoplasma hominis = also causes post partum sepsis |
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AIDS related Mycoplasmas - cofactors to HIV virus to produce AIDS
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- Original: Mycoplasma incognitus
- Now mycoplasma fermentans (also called Lo organism after founder) - Other species = M. genitalium, M. pirum, M. penetrans - Organisms act synergistically with HIV to cause cell damage, found in many organs of AIDS patients |
