Download Chlamydiae

Chlamydiae
Chlamydiae
Chlamydiae are small gram- ne g ative
bacteria which obligate intracellular parasites
and multiply in the cytoplasm of their host
cell by a distinctive developmental cycle.
Classification
on the basis of antigen composition,
intracellular inclusion, sulfonamide
susceptibility and disease production,they
are divided into 4 species:
1.
2.
3.
4.
chlamydia trachomatis
chlamydia psittaci
chlamydia pneumeniae
chlamydia pecorum
Classification
C. trachomatis can be divided into three
biovars:
(1) Biovar trachoma
Serovars(serotype): A, B, Ba, C,D,Da,E,F,
G,H,I,Ia,J,and K 14 serotype.
A,B,Ba and C---trachoma
D～K---sexnaly transmitted infection
(2) Biovar lymphogranuloma venereum (LGV)
L1,L2,L2a and L3---LGV
(3) Biovar mouse
Characteristics
1. It differs from virus
(1) They possess both RNA and DNA
(2) Binary fission
(3) They have a rigid cell wall that resembles
a bacterial type cell wall(G-). It does not
have typical peptidoglycan layer and lacks
muramic acid.
Characteristics
(4) Ribosome
(5) They have a variety of metabolically active
enzymes, eg .they can librate CO2 from
glucose. Some can synthesize folates.
(6) Their growth can inhibited by many
antimicrobial drugs, especially tetracycline
and erythromycins.
Characteristics
2. development cycle
Two particles were found in infected cell.
(1) Elementary body (EB):
infectious particles, small (0.3µm in
diameter),with an electron-dense nucleoid.
A high affinity for host epithelial cells.
Characteristics
Characteristics
(2) Initial body(IB):
0.5～1 µm, binary(reticulate body)
fission→small particles (inclusion bodies)→
librated→other cell.
The developmental cycle takes 24-48 hrs.
Characteristics
3. antigens
(1) genus specific antigen:
It is shared by all chlamydiae.
Heat-stable lipopolysaccharide with 2keto-3-deoxyoctonic acid.
CF and immunofluorescence
Characteristics
(2) species-specific antigen.
Major outer membrane protein(MOMP)
Immunofluorescence
(3) Immunotype-specific antigen
MOMP
McAb
pathogenicity
1. pathogenic substances
endotoxin-like substance
MOMP
2. clinical finding
(1) trachoma
It is a chronic keratoconjunctivits that
begins with acute inflammatory changes in
the conjunctiva and cornea and rogresses
to scarring and blindness.
pathogenicity
Immunotypes: A,B,Ba,C
Transmission: eye→eye, eye→hand→eye.
C.trachomatis→eye→3～10 day→earliest
symptoms: lacrimation, mucopurulent
discharge, conjunctival hyperemia, follicular
hypertrophy→conjunctiva scar→trichiasis→
eyelashe sweeping corna→blindness.
pathogenicity
(2) Genital chlamydial infections
Immunotypes: D-K
Transmission: sexual contact
It is a promiment cause of nongonococcal
urethritis, epididymitis (in male),urethritis,
cervicitis,salpingitis and pelvic inflammatory
(in female), Up to 50% of nongonococcal or
postgonococcal urethritis or the urethral
syndrome is attributed to chlamydiae and
produces dysuria,nonpurulent discharge.
pathogenicity
Inclusion conjunctivitis:
Immunotype: B,Ba,D,Da,E,F,G,H,I,Ia,J and K
Newborn---infected birth canal
Adults---sexual contact
Inclusion conjunctivitis in adults results from
self-inoculation of genital secretion.
pathogenicity
(3) Lymphogranulom venereum(LGV)
LGV is a sexually transmitted disease
characterized by suppurative inguinal
adenitis.
L1-L3
pathogenicity
(4) psittacosis
psittacosis is a disease of birds that may be
transferred to humans. In human,the agent,
C. psittaci, produces a spectrum of clinical
manifestations ranging from severe
pneumonia and sepsis with a high mortality
rate to a mild inapparent infection.
pathogenicity
(5) C. Pneumoniae (TWAR)
TW-138
TWAR AR-39
Human to human
Respiratory infection→pnenmoniae
Laboratory liagnosis
1. cytolcgy
2. cuture
3. serology
ELISA
4. Nucleic acid probes: PCR, ligase chain
reaction(LCR)