Microbiology Flashcards
What is the normal vaginal flora?
Lactobacillus spp
Strep viridans
Group B beta-haemolytic streptococcus
Candida spp
What does Lactobacillus spp produce that suppresses growth of other bacteria?
Lactic acid
Hydrogen peroxide
What % of unselected females are colonised with small numbers of candida and have no symptoms?
30%
What are some predisposing factors for candida infection?
Recent antibiotic therapy
High oestrogen levels (pregnancy, some contraceptions)
Poorly controlled diabetes
Immunocompromised patients
What is the presentation of candida infection?
Intensely itchy white vaginal discharge
How is candida infection diagnosed?
Clinical diagnosis
High vaginal swab for culture- majority of cases C. albicans
What is the treatment for a candida infection?
Topical clotrimazole pessary or cream (OTC)
Oral fluconazole
What organisms are involved in bacterial vaginosis?
Gardnerella vaginalis
Mobiluncus sp.
Others incl. anaerobes
What are the predisposing factors for bacterial vaginosis?
Uncertain
What are the symptoms of bacterial vaginosis?
Thin, watery, fishy-smelling vaginal discharge
How is bacterial vaginosis diagnosed?
Clinical diagnosis
Raised vaginal pH >4.5
What laboratory testing can be carried out in bacterial vaginosis?
HVS sent to lab and examined microscopically to look for presence of clue cells
Subjective/inaccurate test
Hay-Ison scoring system estimates proportions of clue cells to epithelial cells and lactobacilli
What is the treatment for bacterial vaginosis?
Oral metronidazole
What are the 3 classes of prostatitis?
Acute bacterial
Chronic bacterial
Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)
What are the symptoms of acute bacterial prostatitis?
UTI symptoms
Lower abdo/back/perineal/penile pain and tender prostate on exam
What is acute bacterial prostatitis a rare complication of?
UTI
What organisms cause acute bacterial prostatitis?
Same as UTI- E. coli & other coliforms, enterococcus sp (check for STI in patients <35yo)
How is acute bacterial prostatitis diagnosed?
Clinical signs + MSSU for C&S (+- first pass urine for chlamydia/gonorrhoea)
How is acute bacterial prostatitis treated?
Ciprofloxacin for 28 days (depending on culture result)
Trimethoprim (28d) if high C. diff risk
What are some bacterial causes of STI?
Chlamydia trachomatis (chlamydia) Neisseria gonorrhoeae (gonorrhoea) Treponema pallidum (syphilis)
What are some viral causes of STI?
Human papilloma virus (genital warts)
Herpes simplex (genital herpes)
Hepatitis and HIV
What are some parasitic causes of STI?
Trichomonas vaginalis
Phthirus pubis (pubic lice or “crabs”)
Scabies
Where does chlamydia infect?
Urethra Rectum Throat Eyes Endocervix
What is Chlamydia trachomatis?
Obligate intracellular bacterial with biphasic life cycle (does not reproduce outside host cell or gram stain)
What are the 3 serological groupings of chlamydia trachomatis?
Serovars A-C = Trachoma (eye infection) (NOT an STI)
Serovars D-K = Genital infection
Serovars L1-L3 = Lymphogranuloma venereum
What is the treatment for uncomplicated chlamydia?
Azithromycin- 1g oral
What is the chlamydia infectious cycle?
Attachment and entry
2hrs: Migration to perinuclear area and EB>RB transition
8-24hrs: Inclusion biogenesis and bacterial replication
48hrs: RB>EB transition and cell lysis
Where does Neisseria gonorrhoeae infect?
Urethra Rectum Throat Eyes Endocervix