Microbiology π¦ Flashcards
classification of genital system infections
- Venereal disease: Transmitted by sexual intercourse
- Non-venereal disease: Not transmitted by sexual intercourse
what are bacteria causes of venereal diseases of genital system?
- Gonorrhea β± Neisseria gonorrhea.
- Syphilis β± T. pallidum
- Lympho-granuloma venereumβ± Chlamydia
- Non-gonococcal urethritis (NGU)β± Chlamydia
- Soft sore β± Hemophilus ducrii
what are viral causes of venereal diseases of genital system?
- Herpes Simplex type 2
- HPV (Human Papilloma virus)
- HIV
- HBV
Non-venereal diseases of male and its causes
Prostatitis and urethritis may be due to:
- Staphylococcus aureus
- Proteus.
- Streptococcus pyogenes
- Mycoplasma.
Non-venereal diseases of female and its causes
Salpingitis, oophoritis and endometritis are due to:
- Staphylococcus aureus
- Proteus.
- Streptococcus pyogenes
- E. coli
Morphology of Neisseria gonorrhea
what are the Virulence factors of Neisseria gonorrhea?
- Pili (fimbriae) and outer membrane proteins: adhesion.
- IgA proteases: inactivate human IgA.
what are the diseases caused by Neisseria gonorrhea?
Gonorrhea
clinical picture of Gonorrhea in males
Acute urethritis: characterized by profuse purulent discharge
clinical picture of Gonorrhea in females
Cervicitis: characterized by profuse vaginal mucopurulent discharge & sometimes acute urethritis & dysuria
clinical picture of Gonorrhea in newborns
Ophthalmia neonatorum:
- occur in newborns who are exposed to infected secretions in the birth canal.
Specimens for diagnosis of N. gonorrhea
Direct film stained by Gram stain For the diagnosis of N. gonorrhea
Detection of intracellular and extracellular Gram-negative diplococci is diagnostic.
culture of N. gonorrhea
identification of colonies of N. gonorrhea
a) Film stained by Gram stain to show characteristic morphology.
b) Biochemical reactions:
* Ferments Glucose with acid production only.
* Oxidase test: positive.
shape of Treponema pallidum
Slender, Spiral filaments with regular coils (coils are small and large in numbers).
what are special contents of Treponema pallidum?
The cells have a high lipid content (cardiolipin, cholesterol), which is unusual for most bacteria.
staining of Treponema pallidum
- Stained by Giemsa and Fontana stains
- not by Gram stain,
- In tissues can be visualized by silver impregnation methods
Treponema pallidum microscopy
- Cannot be seen by light microscopy
- Can be seen unstained by dark-field microscopy (motile).
motility of Treponema pallidum
- Have axial filaments, which are otherwise similar to bacterial flagella.
Diseases caused by Treponema pallidum
Syphilis
what is the mode of transmission of syphilis?
by sexual contact:
- Organisms penetrate mucous membranes or enter minute breaks in the skin.
- Less than 10 organisms are capable of producing infection.
clinical picture of syphilis
The disease passes into 3 clinical stages:
1- Primary Syphilis: chancre
2- Secondary Syphilis:
- mucous patches on mucous membranes
- Wart-like lesions called βcondylomataβ in moist intertriginous areas.
3- Tertiary syphilis:
- gumma (granulomatous-like lesion),
- cardiovascular and neurosyphilis.
Can affect all areas of the body and be fatal.
specimens for diagnosis of syphilis
Exudate from chancre, mucous patches, blood for serology.
Direct smear for diagnosis of syphilis
Examined by:
- Dark ground microscope for motile treponemes.
- Fluorescent microscope for smears stained with fluorescein-labelled anti-treponemal antibodies
Sirological tests for the diagnosis of Syphilis
A. Non treponemal antigen tests: directed against lipid antigens, principally cardiolipin).
B. Treponemal antigen tests: detect specific antibodies directed against protein constituents of T -pallidum.
compare between Non-treponemal antigen tests & Treponemal antigen tests in terms of:
- Antigen
- Examples
- Effect of treatment and recovery
treatment of syphilis
Penicillin is the drug of choice in the treatment of syphilis.
morphology, and the characters of Chlamydia trachomatis
- Obligate intracellular bacteria
- Elementary body/reticulate body
- Not seen by Gram stain
- Cannot make ATP
- Cell wall lacks muramic acid
what properties of bacteria do Chlamydia trachomatis show?
- They contain both DNA and RNA.
- They have Gram negative cell wall.
- They contain prokaryotic ribosomes.
- They multiply by binary fission.
- They are susceptible to many antibiotic
what are the diseases caused by Chlamydia trachomatis?
Lymphogranuloma venereum: is a venereal disease spread sexually characterized by genital lesions and regional lymph node involvement (buboes).
Non gonococcal urethritis: in men and acute salpingitis and cervicitis in women.
Life cycle of Chlamydia trachomatis
specimen (Laboratory Diagnosis of Chlamydia)
- Scrapping from the urogenital tract.
- Urethral or Cervical exudates.
microscopic examination (Laboratory Diagnosis of Chlamydia)
Inclusion bodies in scraped tissue cells are detected by staining with:
β Giemsa
β iodine.
β fluorescent monoclonal antibodies staining
Culture (Laboratory Diagnosis of Chlamydia)
On McCoy cells:
- After incubation, typical cytoplasmic inclusions are seen:
Yolk sac of embryonated egg:
- Have been used to isolate Chlamydia.
Serological tests (Laboratory Diagnosis of Chlamydia)
Detection of chlamydial antigen:
- Directly in specimens by using specific immunofluorescent antibodies prepared against C- trachomatis.
Detection of anti-Chlamydia antibodies:
- in sera from infected humans by the complement fixation or micro immunofluorescence tests.
Molecular techniques (Laboratory Diagnosis of Chlamydia)
DNA probes:
- It is possible to diagnose C. trachomatis in tissue specimens by hybridization with a specific DNA probe.
- PCR.
Treatment of Chlamydia
- Tetracycline and Erythromycin is the drug of choice.
- No role for penicillin
what are viral infections that affect the Genital system?
- herpes viruses
- Human papilloma viruses
what are the species of Herpes viruses?
- Eight human Herpes virus species are known.
what can Herpes viruses enter?
- All can enter a latent state following primary infection and to be reactivated later
Structure of Herpes viruses
Virion: Icosahedral
Genome: ds DNA, Linear
Envelope: with glycoprotein spikes.
what are types of herpes simplex virus?
- There are 2 distinct herpes simplex viruses (HSV-1 and HSV-2)
- The two viruses cross-react serologically but some unique proteins exist for each type.
compare between HSV-1 & HSV-2 in terms of:
- Terms of transmission
- Multiplication
- Site of lesion
what does primary infection with HSV-1 cause?
- Acute gingivostomatitis.
- Herpes libialis (cold sores)
- Herptic whitlow: is a pustular lesion of the skin of finger or hand of medical personnel.
- Keratoconjunctivitis, encephalitis.
- Disseminated infections, such as pneumonia in immuno-compromised.
where does HSV-1 rest in its latent phase?
- Trigeminal ganglia