Microbiology

Question 1

Produced by the commensal bacteria in the vagina to suppress the growth of other bacteria

Answer 1

Lactobacillus spp. produces lactic acid (+/- hydrogen peroxide)

Question 2

Organism that is the cause of meningitis in neonates and can also be a commensal organism in the vagina

Answer 2

Group B beta-haemolytic streptococcus

Question 3

Main organism that makes up the normal vaginal flora

Answer 3

Lactobacillus spp.

Question 4

Name the predisposing factors for candida infection

Answer 4

Recent antibiotic therapy
High oestrogen levels (pregnancy, contraception)
Poorly controlled diabetes
Immunocompromised patients

Question 5

Why does poorly controlled blood sugar within diabetes cause thrush?

Answer 5

High sugar levels encourage bacterial growth

Question 6

Intensely itchy thick, white vaginal discharge - diagnosis?

Answer 6

Candid infection (vaginal thrush)

Question 7

Treatment for candid infection (vaginal thrush)

Answer 7

Topical clotrimazole pessary or cream - put inside the vagina
Oral fluconazole

Question 8

What is the typical appearance of candida infection on the male?

Answer 8

Spotty appearance

Question 9

Thin, watery, fishy-smelling vaginal discharge (sometimes brown in colour) and a raised vaginal pH - diagnosis?

Answer 9

Bacterial vaginosis (BV)

Question 10

Bacterial vaginosis is commonly caused by which organisms?

Answer 10

Anaerobes - Gardnerella vaginalis/Mobiluncus sp.

Question 11

Treatment for Bacterial vaginosis?

Answer 11

Oral metronidazole (5 day course)

Question 12

Laboratory testing that can be done for BV?

Answer 12

High vaginal swab (HVS) to look for the presence of clue cells

Question 13

How may acute bacterial prostatitis present?

Answer 13

Symptoms of UTI; lower abdominal/back/perineal/penile pain; tender prostate on examination

Question 14

Treatment for acute bacterial prostatitis?

Answer 14

Ciprofloxacin for 28 days (altered depending on culture result)
Trimethoprim if high C.diff risk (elderly)

Question 15

Bacteria that causes Chlamydia?

Answer 15

Chlamydia tracahomatis

Question 16

Sites where the chlamydia can infect

Answer 16

Urethra, rectum, throat and eyes

Endocervix (females)

Question 17

Treatment for Chlamydia?

Answer 17

Azithomycin (1g oral dose)

Question 18

How long after unprotected sex will chlamydia be detectable?

Answer 18

48hrs

Question 19

Which is more common - chlamydia or gonorrhoea?

Answer 19

Chlamydia

Question 20

Sites where gonorrhoea can infect

Answer 20

Urethra, rectum, throat and eyes

Endocervix (females)

Question 21

Describe the morphology of Neisseria gonorrhoeae

Answer 21

Gram negative diplococcus: looks like two kidney beans facing each other

Question 22

Which tests are used to diagnose chlamydia AND gonorrhoea?

Answer 22

Nucleic acid amplification tests (NAATs) or polymerase chain reaction test (PCR)

Question 23

Which samples are taken for gonorrhoea and chlamydia testing?

Answer 23

Male patients - first pass urine sample
Female patients - HVS or VVS
Rectal and throat swabs
Eye swabs

Question 24

What are the advantages of NAATs/PCR tests over culture?

Answer 24

Much less invasive
Much more sensitive
Will be positive even if organisms have died in transit
Takes hours not days

Question 25

What are the disadvantages of PCR/NAATs tests?

Answer 25

Cannot test antibiotic sensitivities | Will detect dead organisms - not a test of cure

Question 26

Recommended treatment for gonorrhoea in the UK?

Answer 26

IM ceftriaxone and oral azithromycin

Question 27

Which STI should be tested for cure due to high numbers of resistant strains?

Answer 27

Gonorrhoea

Question 28

Name the organism that causes syphilis

Answer 28

Treponema Pallidum

Question 29

What testing cannot be done on syphilis?

Answer 29

Cannot be grown in culture medium - diagnosis relies on PCR test or serological tests

Question 30

Describe the first stage of the syphilis illness

Answer 30

Organism multiplies at the inoculation site and get into bloodstream. Chancre will heal without treatment.

Question 31

Describe the second stage of syphilis illness

Answer 31

Large numbers of bacteria circulate in the blood with multiple manifestations at different sites (snail-track mouth ulcers, generalised rash (palms of hands and soles of feet - copper colour), flu-like symptoms)

Question 32

Describe the latent stage of syphilis

Answer 32

Patient will be asymptomatic. Low level of multiplication of the spirochaete in the small blood vessels

Question 33

Describe late stage syphilis

Answer 33

``` Cardiovascular or neurovascular complications Aortic aneurysm (commonly in the ascending or the arch) Proprioception difficulty, difficulty focusing eyes, grandiose delusions) ```

Question 34

What is the treatment for syphilis?

Answer 34

Injectable long-acting preparations of penicillin

Question 35

Name the organism that causes genital warts

Answer 35

Human Papilloma Virus, types 6 &11

Question 36

Which type of HPV is associated with an increased risk of cervical cancer?

Answer 36

Types 16 & 18

Question 37

What is the treatment for genital warts?

Answer 37

Cryotherapy | Podophyllotoxin cream/lotion

Question 38

What types of HPV does the vaccination immunise against?

Answer 38

6, 11, 16 and 18

Question 39

Which type of herpes simplex virus causes both genital herpes and cold sores?

Answer 39

Type 1

Question 40

How are genital herpes spread?

Answer 40

Via genital/genital or oropharyngeal/genital contact

Question 41

How are genital warts spread?

Answer 41

Via genital-genital contact

Question 42

Describe the appearance of genital warts

Answer 42

They are often whiter than the surrounding skin and the surrounding skin is rough

Question 43

How is genital herpes diagnosed?

Answer 43

Deroof blisters and swab for PCR testing

Question 44

What is the treatment for genital herpes?

Answer 44

Aciclovir if early enough, can also give pain relief

Question 45

How is Trichomona Vaginalis diagnosed?

Answer 45

High vaginal swab | PCR can be done but not in Tayside - no good test for males.

Question 46

Likely diagnosis in a women with multiple small painful ulcers on her genitalia and a flu-like illness. She is unable to urinate due to the discomfort.

Answer 46

Herpes Simplex

Question 47

Likely diagnosis in a non-sexually active woman who presents with a frothy brownish vaginal discharge which has an offensive smell.

Answer 47

Bacterial vaginosis

Question 48

Likely diagnosis in a women who presents with vulval irritation and a white discharge

Answer 48

Candida albicans

Question 49

What is the most commonly reported STI in sexual health clinics?

Answer 49

Chlamydia

Question 50

Which form of HSV has a higher rate of viral shedding?

Answer 50

HSV 2

Question 51

How is a pregnant mother who is infected with a primary infection of HSV during the third trimester managed?

Answer 51

Mother will have no antibodies developed already and so no protection for foetus. Give IV acyclovir before delivery and then give dose to baby after birth.

Question 52

What is the incubation period of HPV?

Answer 52

Ranges from 3 weeks to 9 months - average about 3 months

Question 53

Which STI is known as the "great imitator" because its symptoms resemble those of other infections?

Answer 53

Syphilis