Lab 10. Mycoplasm Flashcards
Chlamydia
- general features
Bacterium or virus?
- both types of nucleic acids (RNA, DNA)
- replication with binary fission
- cell wall
- metabolic enzymes
- susceptibility to anitbiotics
- obligate intracellular bacteria (propagata in the vacuoles of the cytoplasm of the host cell)
- propagation cycle is unique (–> elementary body - reticulate body)
- unable to produce ATP (energy-parasites)
- peptidoglycane layer is missing from the cell wall, but they have genus-specific LPS
Chlamydia
- habitat, morphology
Habitat:
- mucous membranes (gut, respiratory tract) (persistent-subclinical infection)
Morphology:
- 0.2-0.4 um coccoid rod
Chlamydia
- staining
Gram negative, Giemsa, Stamp-staining
Stamp-staining:
- stamp fuchsin (5-8 min)
- 1% acetic acid treatment
- rinsing with tapwater
- 3% diluted malachite-green (0.5-1 min)
- rinsing, drying
Chlamydia:
- culture, antigens, resistance
Culture:
- in living cells only: 5-7 old embryonated egg, tissue culture (McCoy, L929, BHK, Vero), animals
- replication in the vacuoles of the cells
Antigens:
- genus specific (heat resistant): LPS
- Species specific: Protein Ag-s
Resistance:
- week
- survives: faeces, fetal membranes, dust (1-3 weeks)
Chlamydia:
- species
Genus Chlamydia:
- C. trachomatis
- C. psittaci
- C. abortus
- C. felis
- C. pecorum
- C. pneumoniae
Chlamydia trachomatis
- human only
- trachoma: chronic purulent conjuctivitus. Leading infectious cause of preventable blindness.
- Lymphogranuloma venerum: inflammation of urethra, vaginitis, enlargement of regional lymph nodes.
Chlamydia psittaci
psittacosis or ornithosis:
- parrot disease, parrot fever, lots of mammals, human (conjunctivitis, diarrhea, respiratory infection): parrot, pigeon, hen, turkey, duck, goose
- human: influenza-like symptoms, headache, pneumonia
- Occupational disease: pigeon-keepers, slaughterhouse workers, Zoo-workers, veterinarians
C. abortus, C. felis, C. pecorum, C. pneumoniae:
- C. abortus: abortion (ewe, goat, cattle, swine)
- C. felis: cat conjunctivits (30% of the cases)
- C. pecorum: arthritis, pneumonia, encephalomyelitis in ruminants
- C. pneumoniae: human pneumonia
Systematics of Rickettsiales
Rickettsiaceae family (cell wall contains polypeptidoglycane layer)
- Coxiella genus: C. burnetii
- Ehrlichia: E. canis, E. ruminantium
- Rickettsia: R. rickettsii, R. prowazekii, R. sibirica, R. conorii
- Neorickettsia: N. risticii
Anaplasmatacea family (no cell wall)
Systematics of Rickettsiales:
- Anaplasmataceae family
Anaplasmataceae family (no cell wall, cytoplasma-membrane only)
Anaplasma:
- A. marginale
- A. centrale
- A. bovis
- A. ovis
- A. phagocytophilum
Rickettsiales
- Habitat, Morphology, Staining
Habitat:
- obligate cell parasites, arthropod vectors, small rodents
Morphology:
- 0.3-0.8 um coccoid rods, non motile
Staining:
- difficult
- Giemsa, Köster, Stamp
Rickettsiales:
- culture, classification, genera
Culture:
- living cells
- embyonated eggs, cell culture, animals
Classification:
- cell tropism
- intra or extra cellular propagation
Genera:
- Rickettsia, Coxiella: propagate in all cell types
- Ehrlichia, Neorickettsia: lymphoid cells, endothel cells
- Anaplasma: in or on eryhtrocytes, in lymphoid cells
Rickettsia genus
- habitat, pathogenicity
Habitat:
- reservoir: rodents and arthropods
Pathogenicity:
- R. prowazekii: epidemic typhus fever - louse
- R. rickettsii: Rocky Mountain spotted fever - ticks
- R. sibirica: North-asian tick-borne rickettsiosis - ticks
- R. conorii: Boutouneuse-fever - ticks
Coxiella genus
Derrik - 1937 slaughterhouse workers in Australia
Burnet - 1937 Australia
Cox - 1938 USA
C. burnetii:
- Culture: embryonated eggs
- Resistance: very good (in dust 50 days!)
- Pathogenicity: No vectors are needed (ticks), Q-fever (human, cattle, sheep, goat), worldwide
Ehrlichia and Neorickettsia genus:
- morhology, culture, pathogenicity
Morphology:
- coocid
Culture:
- tissue cultures
- cannot be cultured in embryonated eggs
Pathogenicity:
- E. canis: canine monocytic ehrlichiosis (fewer, generalised)
- E. ruminantium: heartwater of ruminats
- Neorickettsia risticii: Potomac horse fever (N-america, Europe)