UTI

Question 1

Usual bacteria

Answer 1

UPEC/ ExPEC
Enterococcus spp.
Proteus mirabilis
Staphylococcus saprophyticus

Question 2

Entry for UPEC

Answer 2

• Type I/P Fimbriae
• Flagella
• Lipopolysaccharide and capsular polysaccharide
• Toxins: hemolysin, aerobactin and protease

Question 3

Host factor for entry

Answer 3

• length of urethra
• mechanical factors: intercourse, diaphragm contraceptive, catheters, trauma
• genetic
• hormone
• underlying diseases

Question 4

Host factor for spread

Answer 4

• immunocompromised
• obstruction (calculi)
• Dilatation and reduced peristalsis of ureter e.g. in pregnancy
• incomplete emptying: neurogenic bladder
• reflux: incompetent vesicoureteral valve
• nidus for persistence: urethral catheter

Question 5

Bacterial factor for damage

Answer 5

Hemolysin: tissue damage
Lipopolysaccharide: inflammation
Polysacharide: prevent phagocytosis
Urease: stone formation (break urea into NH3, raised pH and ppt)

Question 6

Treatment for uncomplicated cystitis

Answer 6

First line: nitrofurantoin, co-amoxiclav

Second line: fluoroquinolones, cefuroxime, Sulfamethoxazole-trimethoprim

Question 7

Treatment for uncomplicated UTI in children

Answer 7

Co-trimethoxazole, cefuroxime

avoid co-trimethoxazole, nitrofurantoin in <3 months

Question 8

Treatment for pyelonephritis

Answer 8

IV co-amoxiclav or piperacillin-tazobactam

Question 9

Treatment for enterobacter clocae

Answer 9

PO/IV fluoroquinolone
IV cefepime
IV piperacillin-tazobactam

Question 10

Treatment for ESBL-E Coli

Answer 10

Fosfomycin trometamol (act like beta lactam)

Question 11

Treatment for symptomatic candida cystitis

Answer 11

Oral fluconazole for susceptible

Resistance: Amphotericin B deoxycholate or flucytosine

Question 12

Treatment for symptomatic ascending candida pyelonephritis

Answer 12

Oral fluconazole

Resistant: AmB deoxycholate with or without flucytosine

Question 13

Fungus ball

Answer 13

surgical intervention + antifungal treatment

Question 14

Chlamydial infection (urethritis/ cervititis)

Answer 14

• azithromycin (oral, use in case of pregnancy)
• doxycycline (oral)
• erythromycin or tetracycline or ofloxacin

Question 15

Gonococcal infection (urethritis or cervititis)

Answer 15

• one single IM ceftriaxone plus one oral dose of azithromycin

Question 16

Prostatitis

Answer 16

• quinolones is the treatment of choice (have anti-inflammatory and neuropathic effect)
• can also use azithromycin or doxycycline

Question 17

Antifolate mechanism of action

Answer 17

trimethoprim and sulfamethoxazole are structurally similar to folate intermediate of DNA synthesis thus compete with them to inhibit. Bacteriostatic.

Question 18

Antifolate formula and Cons

Answer 18

1:5 trimethoprim: sulfamethoxazole

skin rashes, hemolytic anemia in G6PD deciency

Question 19

Mechanism of DNA synthesis inhibitors

Answer 19

metronidazole: diffuse and metabolised in cell, form unstable complex with DNA, break
rapid bactericidal effect
effective against anaerobes

Question 20

Nitrofurantoin

Answer 20

• concentrated in urine but not blood, low tissue penetration, not use for pyelonephritis
• brown harmless urine
• reduced by nitrofuran reductase to form reactive electrophilic intermediate that attack DNA, ribosome, macromolecules, respiration
• can be used for prophylaxis

Question 21

Mechanism of fosfomycin

Answer 21

• phosphoenolpyruvate (PEP) analogue
• irreversibly inhibits enolpyruvate transferase (MurA)
• inhibits the synthesis of NAM