Microbiology Flashcards
What normally cause UTIs?
coliforms and enterococci
Urine is normally not sterile where?
urethra
What may an upper UTI lead to?
pylonephritis
Does bacteria in the urine always mean a UTI?
no
What is a complicated UTI?
UTI with systemic sepsis/urinary structural abnormality or stones
Why are UTIs more common in women?
proximity of urethra to anus
short wide urethra
pregnancy/common after sexual activity
What congenital condition may cause increased UTI risk?
posterior urethral valces
Most common route of infection?
ascending (bowel-perianal-urinary tract)
What other route of infection exists?
bloodstream
What bacteria causes 70% of UTIs?
E.coli
Which bacteria causing UTIs is associated with stones and is very foul smelling?
proteus sp
How does proteus sp lead to stones?
produces urease, breaks down urea, increasing the pH and leading to precipitation of salts and therefore stones
Which enterococci is sensitive to antibiotics, faecalis or faecalum?
faecalis
In whom is staph saphrophytis a causal organism of UTI?
young women
What antibiotic should be used for pseudomonas aeruginosa?
ciprofloxacin
What is pseudomonas related to in terms of UTIs?
catheters
Is pseudomonas a coliform?
no
Give 3 symptoms of a UTI.
frequency
dysuria
haematuria
How should a urine specimen be collected?
mid stream specimen - as first urine past wille contaminated with other bacteria from urethra
In whome may you need to use a bag to catch the urine and is this reliable?
babies
less reliable as other bacteria are likely to be present, so more useful if negative result to rule out UTI
In whom may suprapubic aspiration be used?
babies/young kids
What type of container is recommended to collect urine samples?
boricon
What in urinalysis indicates WBCs?
leukocyte enterase
What are nitrites useful to point out in urinalysis?
mainly coliforms
What type of bacteria does not give a positive nitrite result on urinalysis?
enterococci
What should be looked for in microscopy and in whom is microscopy done?
urgent case of UTI
look for pus cells
Are UTIs in non catheterised patients usually caused by one or more organisms?
one
Which antibiotic resistant bacteria is becoming more common due to imported chicken?
ESBL
Which antibiotic resistant bacteria is linked to travel to India?
CPE
How many days should antibiotics be given for a female with uncomplicated UTI?
3
How many days should antibiotics be given for a male with uncomplicated UTI?
7
Is trimethoprim safe in pregnancy?
not in first trimester
Which antibiotic used for UTIs is linked to Steven-Jonson syndrome?
trimethoprim
When is nitrofurantoin not used?
late pregnancy
to treat pylonephritis
Is gentamycin safe in pregnancy?
NO
What is first choice antibiotic when there is urosepsis?
gentamicin
Which antibiotic prevents supercoiling and inhibits DNA gyrase?
ciprofloxacin
What treatment should be given to a female with uncomplicated UTI?
3 days of trimethoprim OR nitrofurantoin
What treatment should be given to a male with uncomplicated UTI?
7 days of trimethoprim OR nitrofurantoin
What treatment should be given to a patient with a complicated UTI?
co-amoxiclav/cotrimoxazole (14 days)
What treatment should be given to a UTI patient in hospital?
Amoxicillin AND gentamicin IV 3 days ONLY
then step down
What should be used instead of amoxicillin if penicillin allergic?
cotrimoxazole
What is asymptomatic bacteruria?
patient has no symptoms but bacteria present
No Pus Cells
Are antbiotics normally given for asymptomatic bacteruria?
No - only in pregnancy
Why are antibiotics given in pregnancy/screened for asymptomatic bacteruria?
if untreated can lead to:
- pyelonephritis (20-30%)
- premature labour and intra unterine growth retardation
What is abacterial cystitis?
symptoms of UTI but no signifigant bacterial growth
Pus cells ARE present
What may cause abacterial cystitis?
- early UTI
- urethral trauma caused by honeymoon cystitis
- urethritis caused by chlamydia/gonorrhea
What may help in abacterial cystitis?
alkanising urine - eg bicarbonate sachets
What is one of the most common causes of hospital acquired infection?
UTI in catheterized patients
Why should you only give antibiotics if patient has symptoms of UTI?
- antibiotic resistance
- C.Diff
Is the bladder normally sterile?
Yes
In which case other than in hospital may you need to consider giving IV antibiotics?
if patient is vomiting
Why is erythromycin not used in penicillin allergic patients?
likely organisms are resistant and NOT excreted in urine
do NOT prescribe erythromycin/clarithromycin for a UTI
