Microbiology Flashcards
Who is more susceptible to UTI’s and why?
- Females: shortened urethra + proximity to anus
- Increased incidence with age
- Post-menopausal women: hormone + microflora changes
- Prostrate issues in men: growth/obstruction of urethra by prostate
Describe the structure of the urinary tract
Kindeys -> Ureter -> Bladder -> Urethra
What are the methods of entry for microbes into the urinary tract?
- Enter renal tract via renal artery - pyelonephritis = bacteria enter blood via renal vein = bacteraemia or sepsis
- Incompetence of cyst-ureteric valves = organisms. enter upper UT
What are the presenting symptoms of Cystitis?
- increased urinary urgency and frequency
- dysuria = painful urination
- lower abd pain
- WBC’s + bacteria in urine
- raised temp
What are the presenting symptoms of Pyelonephritis?
- same as cystitis
- flank pain
- high fever
- malaise
- confusion/restlessness
- nausea
How are UTI’s diagnosed?
- urinalysis
- urine culture
- sensitivity testing
What bacteria most commonly causes UTI’s?
E.coli = gram -ve
UPEC = uropathogenic E.coli
How are UTI’s treated?
- uncomplicated = empirical treatment (look at local guidance + resistance patterns)
- recurrent/complicated = culture + assess sensitivity to guide treatment
How does UPEC cause UTI’s?
- transferred from gut to flora
- express pili = attachment + microbe can ascend UT
- invade + destroy bladder cells to obtain/release nutrients
What are obligate pathogens? Give an example.
= organisms not part of normal microflora
e.g. STI’s
Describe some virulence factors
- Adhesion - pili
- Invasion - haemolysin
- Motility - flagella
- Biofilm formation
What organism causes Chlamydia?
- Chalmydia trachomatis
- Gram -ve
- Non-motile
- More common in females
Describe the life cycle of Chlamydia within epithelial cells
- Elementary bodies attach to enter cell
- Phagosome fusion
- Converts to reticulate body = reproductive form
- Multiplication
- Mature to elementary bodies = released
What are the symptoms of Chlamydia?
- Can be asymptomatic
- Males: urethritis, proctitis, epididymitis
- Females: urethritis, cervicitis
- New-born: conjunctivitis, pneumonia
- Key cause of PID
What organism causes Gonorrhoea?
- Gram -ve
- Diplococci bacteria
- Capsulated
- More common in men