58 terms

7-3 Sexually Transmitted Diseases Microbiology


Terms in this set (...)

Sexually Transmitted Bacterial Diseases examples
Gonorrhea is caused by
Neisseria gonorrheae
A gram negative diplococci
Gonorrhea grows on
Thayer Martin agar
Gonorrhea is very sensitive to
Gonorrhea affects what creatures?
Strictly humans
What are the characteristics of the discharge in Gonorrhoea?
Thick and creamy urethral discharge
Gonorrhoea infections are acquired through
direct inculcation of mucus
Gonorrhoea in males cause
urethritis leading to a
Type of discharge thick creamy urethral
Gonorrhoea in males if not treated can then cause
prostatitis - leading to secondary infertility

It will disseminate and cause very severe arthritis (inflammation of the large joints like the knees )
with septicemia

(and The arthritis is aseptic arthritis. Why aseptic? Coz its arthritis precipitated by the DNA antigens of the bacteria that invaded the joints not the actual bacteria.)
Gonorrhoea in females cause
Vaginal discharge, Urethritis,
Endometritis, Salpingitis (inflammation of the fallopian tubes), Pelvic inflammatory disease, sever pharyngitis, Proctitis, and Disseminated infection with arthritis
Gonorrhoea symptoms in females
about 80 percent of women may have the disease but have no symptoms. A source of infection to males.
Gonorrhoea symptoms in newborns
Infects the eye causing
sever conjunctivitis.
May lead to blindness.
Can also cause disseminated infection
Laboratory diagnosis of gonorrhea
Urethral, vaginal, rectal and other swabs for Gonococcus culture
should be transported and cultured in the laboratory with two hours of
Direct gram stain from discharge (Gram Negative intercellular
Characteristic appearance of its morphology
Remember : needs to be transported to special transport media coz of its sensitivity to drying
Culture on Thayer Martin agar (selective agar with antibiotics).
Done to look resistant strains
Colons appear after 48hrs of incubation as small transparent colons.
PCR is now available for detection of Gonococcus
Culturing is done today because of the large number of resistant gonorrhea esp.
in endemic areas where sexual practicing is common. Before in time , the
pencillin was just given used without culturing coz we took it for granted that the
pencillin was bacteriacidal
treatment of gonorrhea
Antibiotic sensitivity testing should be perfumed in all
isolates to assess treatment.

Penicillin resistance has been frequently reported due to
Beta-lactamase production. (not the drug of choice anymore)

Other antibiotic resistance has also been reported: Ciprofloxacin, spectinomycin, and cephalosporins
What are some of the most common causes of Non-Specific Urethritis (NSU)?
Chlamydia, Mycoplasma, Uroplasma
Non-specific urethritis is defined as
any urethritis that is not caused by gonorrhoea
Chlamydia trachomatis serotypes that cause a sexually transmitted disease are
Chlamydia trachomatis serotypes that cause trachoma (infection of the eye) are
Chlamydia trachomatis Causes urethritis characterized by
thin colorless discharge
Also it is very minimal in amount (compared to the thick creamy discharge in gonorrhea)
What is more common Chlamydia trachomatis or gonorrhea?
Chlamydia is regarded the most common STD in the west because it may be asymptomatic hence it's more common
Chlamydia trachomatis symptoms in males
urethritis with minor symptoms
but If not treated will lead to prostatitis, epididymitis.
Chlamydia trachomatis causes which syndrome as a complication of untreated infection in males?
Reiter's syndrome: urithiritis, arithiritis, conjunctivitis
Chlamydia trachomatis symptoms in females
Large number of asymptomatic carriers
Starts by urethritis . If not treated can lead to bartholinitis (inflammation of one or both of the two Bartholin's glands, which are located one on either side of the opening of the vagina, behind the labia) and pelvic inflammatory disease.
Chlamydia trachomatis symptoms in newborns
Can be transmitted to newborn babies during birth leading to conjunctivitis
What is the characteristic of the discharge in chlamydia trachomatis?
Thin and colorless discharge (v. Minimal compared to gonorrhea)
Most common causes of secondary infertility in males?
- Chlamydia Uroplasma and mycoplasma
Syphilis is caused by
Treponema palladium
Treponema palladium (syphilis) characteristics
A spiral shaped bacteria
belong to the spirochete family.

Can't be stained by gram stain (Coz covered by lipids and other constituents) however can be seen under dark field microscope using unstained wet preparation
is Treponema palladium (syphilis) only transmitted by sexual contact?
No, other Treponema can cause
endemic non-venereal treponematosis

So not all syphillis is Sexually transmitted. It can be endemic
Stages of Syphilis
primary, secondary, latent, tertiary or can be congenital
How is syphilis acquired?
Infection is acquired through direct inculcation of the skin and mucus membrane. Even direct skin contact just by touch ing Is enough to transmit the disease
Stage of syphilis characterized by a local lesion
The stage of syphilis that is characterized by a bacteria-filled chancre is
Primary syphilis
After penetration of the
characterized by hard
chancres around the genitalia
skin the bacteria multiply
at the site of entry and the
local lymph node
A hard painless chancre is
The fluid in side the chancre (of syphilis) contains
large numbers of spirochetes
most infectious stages of syphilis
primary and secondary
Secondary syphilis occurs after
two months from primary infection (If not treated it can disseminate to the body and cause very severe skin rash around the Occur two months from back, trunks , surfaces of the soles and palms primary infection of the hand)
The bacteria disseminate
to other parts of the body
and they and multiply
Secondary stage symptoms
Maculopapular rash occur
at different parts of the
Fever, sore throat, and
If blood is transfused to someone else and they develop syphilitic symptoms this means
they probably have secondary Syphilis.
Latent syphilis stage
the stage of syphilis where the chancres disappear and the patient become asymptomatic.
The bacteria become dormant and does not multiply.
Can stay up to 30 years without showing any symptoms.
Latent syphillis can be transmitted through
blood transfusions but not through sexual practic
Late syphilis
the fourth and final stage of syphilis, during which the disease does damage to major organs of the body such as the lungs, heart, or brain
The bacteria are re-activated and multiply at different sites.
Form granulomatous reaction. Can affect the skin and submucus
membranes, the bones, the cardiovascular system, and the central nervous system
Rates of neurosyphillis have increased now due to
higher HIV rates
a variation of syphilis that infects the nervous system. Causes asymptomatic meningitis, spinal
cord and cerebral damage.
Diagnosis of syphilis is usually made by
the MHA-TP test

Direct detection. At the primary stage the organism can be detected in the chancre by dark field microscopy or direct immunofluoresce
Diagnosis of syphilis
2. Indirect method Use of Serological antibodies
During infection the immune system will
produce two types of antibodies which can
be detected in the serum 1. Non-specific antibodies 2. specific Treponemal antibodies
During any disease our body reacts by producing two diff types of antibodies : Non- specific and specific (in wh ich case treponema antibodies)
Non-specific Treponemal Very antibodies
These antibodies can cross react with some human and animal
antigens like bovine cardiolipins
These antibodies can be present in other diseases and in normal
subjects (during pregnancy) The tests used for detecting non-specific antibodies :
They can be detected using agglutination test like Venereal disease
research laboratory (VDRL) test or raped plasma reagen (RPR) test
The results are usually reported as a semi-quantitative results (1:8)
Why do we use nonspecific antibodies and look for them ? Coz
They are useful for monitoring treatment (titer decreases with
successful treatment)
Specific Treponemal antibodies
Trichomonas vaginalis
parasite Motile with multiple
flagella Characteristic
GMSA stain is used , but their motility characterizes them
Trichomonas vaginalis symptoms in males
50% of males are asymptomatic,
but can cause urethritis with discharge
Trichomonas vaginalis symptoms in females
causes vaginal discharge with
foul smell, itching sensation, and
discomfort during urination
Trichomonas vaginalis diagnosis
by wet mount from vaginal or
urethral discharge
Trichomonas vaginalis treatment
Metronidazole (patient and partner)
bacterial that is known for its sensitivity to drying?
A 25 year old male patient present to ER complaining of urethral dischagre. The discharge was thick , creamy , and voluminous. The stain showed gram negative diplococci . What is the most likely diagnosis?
Which bacterial strains of Chlamydia can cause thin colorless discharge?
A 26 year old male patient presented to the clinic complaining of painless but hard ulceration around his genitals. The patient reported having unprotected sex with someone other than his partner. What is the diagnosis and stage of the disease ?
A patient was diagnosed with syphilis 30 years ago. He presented to ER with headache, neck stiffness , and fever. His symptoms were compatible with meningitis. What is the most likely cause of his meningitis.