Microbiology Flashcards
What bacterial species predominates in healthy vaginal flora?
Lactobacillus spp.
What does Lactobacillus spp. produce and what is the effect of these products?
Lactic acid +/- hydrogen peroxide
Suppresses growth of other bacteria
List some bacteria other than Lactobacillus spp. that can be part of the normal vaginal flora
Strep viridans
Group B Strep
Candida spp. (small numbers)
What are the 3 main non-sexually-transmitted genital tract infections?
Vaginal thrush
Bacterial vaginosis
Prostatitis
Which bacteria causes vaginal thrush?
Candida (usually albicans)
The presence of Candida on vaginal swab indicates vaginal thrush. True/False?
False
30% of females are colonised by small numbers of Candida as part of normal flora
List some predisposing factors to developing Candida infection
Recent antibiotic therapy
High oestrogen levels (pregnant, contraceptives)
Poorly controlled diabetes
Severely immunocompromised
Describe clinical presentation of vaginal thrush
Intensely itchy
White vaginal discharge “like cottage cheese”
How is the diagnosis of vaginal thrush made?
Clinical diagnosis/appearance
Vaginal swab to culture for C. albicans
How is vaginal thrush treated?
Topical clotrimazole
Oral fluconazole if no response
What is characteristic of Candida albicans on gram film?
Appearance of budding
Who typically gets other forms of Candida infection (other than albicans)?
Poorly controlled diabetics (C. balanitis)
Immunosuppressed
Which organisms are the main causes of bacterial vaginosis?
Gardnerella vaginalis
Mobiluncus sp.
Other anaerobes
Describe clinical presentation of bacterial vaginosis
Thin, watery, fish-smelling discharge that reeeeaally stinks
How is a diagnosis of bacterial vaginosis made?
Clinical diagnosis/examination
Raised vaginal pH greater than 4.5
The presence of what cells on microscopy suggest bacterial vaginosis?
Clue cells
How is bacterial vaginosis treated?
Oral metronidazole
Describe the clinical presentation of acute bacterial prostatitis
UTI-like
Abdominal/back/perineal/penile pain
Tender prostate
A mid-stream sample of urine is required to test for urethral infection in acute bacterial prostatitis. True/False?
False
Mid-stream for upper UTI, first-pass for lower UTI
How is acute bacterial prostatitis treated?
Ciprofloxacin for 28 days
Trimethoprim if high C. diff risk
List the 3 main sexually-transmitted bacterial infections
Chlamydia
Gonorrhoea
Syphilis
What is the commonest bacterial STI in the UK? What organism causes it?
Chlamydia, caused by Chlamydia trachomatis
What areas of the body can chlamydia infect?
Eyes Throat Rectum Urethra Cervix
Chlamydia reproduces both in and out -side the host cell. True/False?
False
Obligate bacteria that only reproduces inside the host
Does chlamydia stain with Gram stain?
No because no peptidoglycan in cell wall
What are the 3 serological groupings of chlamydia and their respective infections?
Serovars A-C = trachoma/eye infection
Serovars D-K = genital infection
Serovars L1-L3 = lymphogranuloma venereum