general overview of spirochaetales n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
General Overview of Spirochaetales PowerPoint Presentation
Download Presentation
General Overview of Spirochaetales

Loading in 2 Seconds...

play fullscreen
1 / 42

General Overview of Spirochaetales - PowerPoint PPT Presentation


  • 86 Views
  • Uploaded on

General Overview of Spirochaetales. Gram-negative spirochetes Spirochete from Greek for “coiled hair” Extremely thin and can be very long Tightly coiled helical cells with tapered ends Motile by Periplasmic flagella (axial fibrils or endoflegalla). Human pathogen. Treponema

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'General Overview of Spirochaetales' - fadhila


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
general overview of spirochaetales
General Overview of Spirochaetales
  • Gram-negative spirochetes
  • Spirochete from Greek for “coiled hair”
  • Extremely thin and can be very long
  • Tightly coiled helical cells with tapered ends
  • Motile by Periplasmic flagella (axial fibrils or endoflegalla)

Dr.T.V.Rao MD

human pathogen
Human pathogen

Treponema

Borreilia

Leptospira

treponema pallidum
Treponema pallidum

Morphology

  • Motile, sluggish in viscous environments
  • Size: 5 to 20 μm in length & 0.09 to 0.5 μm in diameter, with tapered ends
  • Can be seen on fresh primary or secondary lesions by dark field microscopy or fluorescent antibody techniques
staining with special stains
Staining with special stains

Staining by Giemsa and Fontana

cultivation of
Cultivation of .. ?

Treponemescannot be cultivated in laboratory media and are maintained by subculture in susceptible animals.

diagnosis of syphilis
Diagnosis of syphilis

A. Direct detection of spirochetes :

Darkfield microscopy

Silver stain

B. Culture : not used

C. Serology: non-specific and specific tests

rapid plasma reagin test rpr
Rapid Plasma Reagin Test - RPR

- General screening test, can be adapted to automation.

- CANNOT be performed on CSF.

  • Antigen
    • VDRL cardiolipin antigen is modified with choline chloride to make it more stable
    • attached to charcoal particles to allow macroscopic reading
    • antigen comes prepared and is very stable.
  • Serum or plasma may be used for testing, serum is not heated.
treponema pallidum haemagglutination tpha
Treponema pallidum haemagglutination (TPHA)
  • Adapted to micro techniques (MHA-TP)
  • Tanned sheep RBCs are coated with T. pallidum antigen from Nichol’s strain.
  • Agglutination of the RBCs is a positive result.
serologic tests
Serologic Tests

All positive nontreponemal test results should be confirmed with a specific treponemal test

b burgdorferi
B. burgdorferi

- Causes Lyme disease, transmitted by the bite of Ixodid ticks (deer tick)

- Diagnosis– serological tests

slide25

Diagnosis

  • - serum antibodies toB. burgdorferi
  • laboratory strains grow extremely slowly tissue
  • culture media not bacteriological media.
  • patient body fluids/tissue sample almost never
  • grow

25

leptospira
Leptospira

- Very thin, delicate spirochetes with hooked ends

- 2 species are recognised:

  • L. interrogans– pathogenic to human (rats are the reservoir)
  • L. biflexa – saprophytic, mainly found in surface water.
diagnosis
Diagnosis

- Examination of blood – 1st week only

- Urine– 2nd week of disease, should be examined immediately after voiding

- Serology– Abs appear by the end of 1st week & increase till 4th week of disease.

microbiology
Microbiology
  • Obligatory intracellular bacteria
  • Infect columnar epithelial cells
  • Survive by replication that results in the death of the cell
  • Takes on two forms in its life cycle:
    • Elementary body (EB)
    • Reticulate body (RB)
culture
Culture

- Historically the “gold standard”

- Variable sensitivity (50%-80%)

- High specificity

- Use in legal investigations

- Not suitable for widespread screening

naats
NAATs

- NAATs amplify and detect organism-specific genomic or plasmid DNA or rRNA

- Significantly more sensitivity than other tests

non amplication tests
Non-Amplication Tests

- Direct fluorescent antibody (DFA)

- Detects intact bacteria with a fluorescent antibody

- Variety of specimen sites

- Enzyme immunoassay (EIA)

- Detects bacterial antigens with an enzyme-labeled antibody

- Nucleic acid hybridization (NA probe)

- Detects specific DNA or RNA sequences of C. trachomatis and N. gonorrhoeae

why screen for chlamydia
Why Screen for Chlamydia?

- Screening can reduce the incidence of PID by more than 50%.

- Most infections are asymptomatic.

- Screening decreases the prevalence of infection in the population and reduces the transmission of disease.