T.Pallidum
i) Name serological test: CAT (cardiolipin) & TAT (treponemal) . BOTH USE FOR diagnosis and monitoring treatment and follow up.
Importance of CAT :
· +ve 10-14 days after appearance of chancre
· -ve in early primary syphilis
· +ve screening test so..should be confirmed with TAT…and repeating the CAT
· Quantitative (gradual increase with progress of disease)
· Can be used to follow therapy
· False +ve result
False +ve: malaria
: measles
: Infectious mononucleosis
: leprosy
: collagen vascular disease ( SLE )
: drug addiction
TAT -FTA Abs : most sensitive,1st become +ve in early..remain +ve for many years..
Disadvantages : cannot be used to judge efficacy of treatment
-TP-PA : performed in microdilution plate.
ii) Test use to diagnose 1ry stage
§ Dark ground microscopy - for motility
§ Flourescein labeled anti treponemal serum - for antigen
§ NA probes and PCR – for DNA
§ CAT –ve but TAT +ve
iii) Differences HARD and SOFT chancre.
HARD | SOFT |
Produce by T.Pallidum | Produce by H.Ducreyi |
Never be culture on culture media. | Grow on choc agar. |
iv)Specime collection for EVERY STAGES.>
1ry STAGE | -Exudate from chancre (squeezed gently using gloves) BLEEDING should be avoided (RBC mask the spirochetes) |
2ry STAGE | -Exudate from skin lesions, mucous patches or condyloma lata |
LATENT SYPHILIS | -Serum sample |
LATE SYPHILIS | -Serum sample -CSF sample (active neurosyphilis) |
N.GONORRHOEA
i) Selective media used : THAYER MARTIN > consists of VCN
v Vancomycin - Gram +ve bact
v Colistin - Gram -ve bacilli
v Nystatin - Fungi
ii) Specimen collection ( acute/chronic in males and females )
ACUTE | CHRONIC (org. very few in no. / totally absent) |
Urethral discharge from men | Morning urethral drop Prostatic secretion |
Urethral discharge from female Cervical secretion | Swab from cervix uteri |
iii) Culture done in acute stages
ü Confirm the diagnosis
ü Isolate the organism to determine its sensitivity to different antibiotics
ü Medico-legal proceeding
Repeated gonococcal infection common
ü Protective immunity to reinfection does not appear
ü Antigenic variation
MYCOPLASMA
i) General character:
Ø Smallest – so can pass through bact filters
Ø Lack of rigid wall, bounded by triple layered membrane
Ø Complete resistant to penicillin, so inhibited by tetracycline or erythromycin
Ø Reproduce in cell free media – grow on agar rich sterols
Ø Inhibited by specific Ab
Ø Do not revert to, or originate from bact parental forms
Ø Affinity to mammalian cell membrane by special terminal adhesion proteins
ii) What are genital mycoplasma (urogenital mycoplasma) : Mycoplasma Hominis
: Ureaplasma urealyticum
Iii) Disease caused by genital mycoplasma
Mycoplasma Hominis | Ureaplasma urealyticum |
In females: 3P - Pyelonephritis - Post abortal or Post partum fever - Pelvic inflammatory disease - Salphingitis In male not causing any.. | In males : non gonococcal urethritis (10%) In females : lung disease in premature, low birth weight infants |
iv) Differentiate urogenital mycoplasma from others :
GROWTH INHIBITORS with specific antisera BUT differentiate ureaplasma urealyticum to M.Hominis by UREASE TEST (+ve in ureaplasma –ve in Hominis)
v) Specimen collection in urogenital mycoplasma affection
o ONLY UPPER GENITOURINARY specimens are value – because both species frequently colonize the lower genitourinary of both sexes.
o Urethral swabs or urine after prostatic massage in males.
o Fetal membrane swabs and semen – part of investigation infertility
ALL SPECIMENS….put in STUART’s TRANSPORT MEDIUM & sent to lab.
CHLAMYDIAE
i) General properties :
§ Coccoid shape
§ Obligatory intracellular – deficiency in energy producing metabolic pathways
§ Types of NA DNA & RNA
§ Resemble cell wall Gram –ve bact, but no peptidoglycan layer
§ Complicated life cycle of reproduction by fission
§ Sensitive to sulphonamides
§ Contain ribosome and metabolic enzymes
§ Lack mechanism for metabolic energy production
ii) Classification & disease caused
Sites of infection | Disease | Organism ( serovars ) |
Eyes | Trachoma Adult & neonatal conjunctivitis | C.T (A,B,Ba,C) C.T (D-K) |
Genital tracts | Male Female LGV | C.T (D-K) C.T (D-K) C.T ( L1-L3) |
Respiratory | Pneumonitis of infants Pharyngitis, pneumonia Psittacosis Pneumonia | C.T (D-K) C.Pneumonia C.Psittaci (avian) C.Psittaci (ovine) |
iii) Modes of transmission
Trachoma : eye to eye, droplet, hands, contaminated cloth and flies
Adult inclusion conjunctivitis: anto-inoculation of genital secretion or oral- genital contact (sexually active)
Neonatal conjunctivitis (ophthalmia nenonatorum) : passage through infected maternal birth canal.
C.psittaci from bird to human : Inhalation of dried birds faeces or feathers
TWAR strain C.pneumoniae : human contact
P/s : what we've study in practical class shoulh be read...hopefully this time would get us easily get 15/15...
