microbiology of GU tract

Question 1

common bacterial STIs and their pathogens

Answer 1

chlamydia (chlamydia trachomatis)
gonorrhoea (neisseria gonorrhoeae)
syphilis (treponema pallidum)

Question 2

common viral STIs and their pathogens

Answer 2

genital warts (HPV)
genital herpes (herpes simplex virus)
hepatitis
HIV

Question 3

common parasitic STIs and their pathogens

Answer 3

trichomonas vaginalis
pubic lice (phthirus pubis)
scabies

Question 4

normal vaginal flora

Answer 4

lactobacillus spp.
+/- strep viridans
+/- group B beta-haemolytic strep
+/- candida spp (small numbers)

Question 5

what do lactobacillus spp. produce

Answer 5

lactic acid (suppress growth of other bacteria)
\+/- H2O2

Question 6

describe the discharge present in BV

Answer 6

homogenous

may contain bubbles

Question 7

what is the whiff test

Answer 7

add potassium hydroxide to discharge

if elicits a fishy odour the test is +ve for BV

Question 8

what is cause BV

Answer 8

replacement of lactobacili with coccobacilli

Question 9

what do large number of leukocytes in the wet mount of a patient with BV suggest

Answer 9

coincident infection

Question 10

risks of BV

Answer 10

increased rate of upper tract infection
premature rupture of the membrane and preterm delivery
may have increased risk for the acquisition of HIV

Question 11

what is the commonest STI in the UK

Answer 11

chlamydia

Question 12

where does chlamydia infect

Answer 12

urethra
rectum
throat 
eyes 
endocervix

Question 13

what type of reproduction does chlamydia trachomatis display

Answer 13

obligate intracellular bacteria –> reproduces inside a host cell

Question 14

is chlamydia gram +ve or -ve

Answer 14

TRICK Q

does not gram stain as has no peptidoglycan in the cell wall

Question 15

what are the serological groupings of chlamydia

Answer 15

serovars A-C = trachoma (not an STI)
serovars D-K = genital infection
serovars L1-L3 = lymphogranuloma venereum

Question 16

treatment of chlamydia

Answer 16

7 days doxycycline 100 mg BD

Question 17

diagnosis of chlamydia and gonorrhoea

Answer 17

combine nucleic acid amplification tests (NAATs)

PCR test

Question 18

treatment of gonorrhoea

Answer 18

IM ceftriaxone

Question 19

how many stages are there of syphilis infection

Answer 19

4

Question 20

what is the first stage of syphilis infection

Answer 20

primary lesion (chancre)
organism multiplies at inoculation isle and gets into bloodstream
chancre will heal without treatment

Question 21

what is the second stage of syphilis infection

Answer 21

large numbers of bacteria circulate in the blood with multiple manifestation at different sites
snail-track mouth ulcers, generalised rash, flu-like symptoms

Question 22

what is the third stage of syphilis infection

Answer 22

latent stage
no symptoms
low level multiplication of spirochaete in intimate of small blood vessels

Question 23

what is the final stage of syphilis infection

Answer 23

cardiovascular or neuromuscular complications many years after initial infection

Question 24

what are non-specific serological tests

Answer 24

VDRL

RPR (rapid plasma reagin)

Question 25

when might non-specific serological tests be helpful

Answer 25

useful for monitoring response to therapy

usually become negative after successful treatment

Question 26

what do non-specific serological tests indicate

Answer 26

tissue inflammation

Question 27

cons of non-specific serological tests

Answer 27

may be falsely positive eg in SLE, malaria, pregnancy

Question 28

which types of HSV cause genital herpes

Answer 28

types 1 and 2

Question 29

where does the herpes virus migrate to and lie dormant

Answer 29

sacral root ganglion

Question 30

which types of nerve endings does the herpes virus infect

Answer 30

sensory

autonomic

Question 31

diagnosis of genital herpes

Answer 31

swab in virus transport medium of deroofed blister for PCR test

Question 32

treatment of genital herpes

Answer 32

acyclovir may be helpful if taken early

pain relief

Question 33

what is trichomonas vaginalis

Answer 33

single celled protozoal parasite

Question 34

symptoms of trichomonas vaginalis infection

Answer 34

vaginal discharge and irritation

Question 35

diagnosis of trichomonas vaginalis

Answer 35

high vaginal swab for microscopy

Question 36

treatment of trichomonas vaginalis

Answer 36

oral metronidazole

Question 37

treatment of pubic lice

Answer 37

malathion lotion

Question 38

female presentation of chlamydia

Answer 38

post coital ot intermenstrual bleeding
lower abdominal pain
dyspareunia
mucopurulent cervictis

Question 39

male presentation of chlamydia

Answer 39

urethral discharge 
dysuria 
urethritis 
epididymis-orchitis 
proctitis (LGV)

Question 40

complications of chlamydia

Answer 40

PID
tubal damage 
chronic pelvic pain
transmission to neonate 
adult conjunctivitis 
reiter's syndrome

Question 41

LGV is caused by which serovars of chlamydia

Answer 41

L1-L3

Question 42

symptoms of LGV

Answer 42

rectal pain
discharge
bleeding

Question 43

male presentation of gonorrhoea

Answer 43

urethral discharge
dysuria
pharyngeal/rectal infections are mostly asymptomatic

Question 44

female presentation of gonorrhoea

Answer 44

increased/altered vaginal discharge
dysuria
pelvic pain
pharyngeal and rectal infection are mostly asymptomatic

Question 45

are chancres painful

Answer 45

nope