78. Genus Chlamydia (habitat, morphology, staining). Human pathogenic Chlamydia species.

Question 1

General features?

Answer 1

General features (Bacterium or virus?)
- both types of nucleic acids (RNA, DNA)
- replication with binary fission
- cell wall
- metabolic enzymes
- susceptibility to antibiotics
- obligate intracellular bacteria (propagate 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

Question 2

Habitat and Morphology?

Answer 2

Habitat
• mucous membranes (gut, genitals, respiratory tract) (persistent –
subclinical infection)
Morphology
• 0.2-0.4 µm, coccoid rod
• propagation:

Question 3

Staining?

Answer 3

Staining: Gr–, Stamp-staining, Giemsa

• Fixation (over the Bunsen burner flame)
• Stamp fuchsin (5-8 min)
• 1% acetic acid treatment
• Rinsing with tapwater
• 3% diluted malachite-green (0.5-1 min)
• Rinsing, drying

Question 4

Species?

Answer 4

Species:
• genus Chlamydia
•C. trachomatis
•C. psittaci
•C. abortus
•C. felis
•C. pecorum
•C. pneumoniae

Question 5

Chlamydia Trachomatis?

Answer 5

Species:
Chlamydia trachomatis: human only,
- trachoma: chronic purulent conjunctivitis
- lymphogranuloma venereum: inflammation
of urethra, vaginitis, enlargement of reg. lymph
nodes

Question 6

Chlamydia psittaci?

Answer 6

• Chlamydia psittaci: psittacosis or ornithosis (parrot disease,
parrot fever) more than 130 bird sp. (57 parrot-sp.), lots of mammals,
human (conjunctivitis, diarrhoea, respiratory infection): parrot, pigeon, hen,
turkey, duck, goose,
human: influenza-like symptoms, headache, pneumonia,
occupational disease: pigeon-keepers, slaughterho

Question 7

C.pneumoniae?

Answer 7

• C. pneumoniae: human pneumonia