microbiology of GU tract Flashcards
common bacterial STIs and their pathogens
chlamydia (chlamydia trachomatis)
gonorrhoea (neisseria gonorrhoeae)
syphilis (treponema pallidum)
common viral STIs and their pathogens
genital warts (HPV)
genital herpes (herpes simplex virus)
hepatitis
HIV
common parasitic STIs and their pathogens
trichomonas vaginalis
pubic lice (phthirus pubis)
scabies
normal vaginal flora
lactobacillus spp.
+/- strep viridans
+/- group B beta-haemolytic strep
+/- candida spp (small numbers)
what do lactobacillus spp. produce
lactic acid (suppress growth of other bacteria) \+/- H2O2
describe the discharge present in BV
homogenous
may contain bubbles
what is the whiff test
add potassium hydroxide to discharge
if elicits a fishy odour the test is +ve for BV
what is cause BV
replacement of lactobacili with coccobacilli
what do large number of leukocytes in the wet mount of a patient with BV suggest
coincident infection
risks of BV
increased rate of upper tract infection
premature rupture of the membrane and preterm delivery
may have increased risk for the acquisition of HIV
what is the commonest STI in the UK
chlamydia
where does chlamydia infect
urethra rectum throat eyes endocervix
what type of reproduction does chlamydia trachomatis display
obligate intracellular bacteria –> reproduces inside a host cell
is chlamydia gram +ve or -ve
TRICK Q
does not gram stain as has no peptidoglycan in the cell wall
what are the serological groupings of chlamydia
serovars A-C = trachoma (not an STI)
serovars D-K = genital infection
serovars L1-L3 = lymphogranuloma venereum
treatment of chlamydia
7 days doxycycline 100 mg BD
diagnosis of chlamydia and gonorrhoea
combine nucleic acid amplification tests (NAATs)
PCR test
treatment of gonorrhoea
IM ceftriaxone
how many stages are there of syphilis infection
4
what is the first stage of syphilis infection
primary lesion (chancre) organism multiplies at inoculation isle and gets into bloodstream chancre will heal without treatment
what is the second stage of syphilis infection
large numbers of bacteria circulate in the blood with multiple manifestation at different sites
snail-track mouth ulcers, generalised rash, flu-like symptoms
what is the third stage of syphilis infection
latent stage
no symptoms
low level multiplication of spirochaete in intimate of small blood vessels
what is the final stage of syphilis infection
cardiovascular or neuromuscular complications many years after initial infection
what are non-specific serological tests
VDRL
RPR (rapid plasma reagin)
when might non-specific serological tests be helpful
useful for monitoring response to therapy
usually become negative after successful treatment
what do non-specific serological tests indicate
tissue inflammation
cons of non-specific serological tests
may be falsely positive eg in SLE, malaria, pregnancy
which types of HSV cause genital herpes
types 1 and 2
where does the herpes virus migrate to and lie dormant
sacral root ganglion
which types of nerve endings does the herpes virus infect
sensory
autonomic
diagnosis of genital herpes
swab in virus transport medium of deroofed blister for PCR test
treatment of genital herpes
acyclovir may be helpful if taken early
pain relief
what is trichomonas vaginalis
single celled protozoal parasite
symptoms of trichomonas vaginalis infection
vaginal discharge and irritation
diagnosis of trichomonas vaginalis
high vaginal swab for microscopy
treatment of trichomonas vaginalis
oral metronidazole
treatment of pubic lice
malathion lotion
female presentation of chlamydia
post coital ot intermenstrual bleeding
lower abdominal pain
dyspareunia
mucopurulent cervictis
male presentation of chlamydia
urethral discharge dysuria urethritis epididymis-orchitis proctitis (LGV)
complications of chlamydia
PID tubal damage chronic pelvic pain transmission to neonate adult conjunctivitis reiter's syndrome
LGV is caused by which serovars of chlamydia
L1-L3
symptoms of LGV
rectal pain
discharge
bleeding
male presentation of gonorrhoea
urethral discharge
dysuria
pharyngeal/rectal infections are mostly asymptomatic
female presentation of gonorrhoea
increased/altered vaginal discharge
dysuria
pelvic pain
pharyngeal and rectal infection are mostly asymptomatic
are chancres painful
nope
