UT1 Flashcards
How does an infection reach the urinary tract?
- Ascending route (most com)
- Haematogenous route.
most common bacterial infections acquired in the
community/hospitals
UTI
UTI is second most common cause of ___ in hospitalized patients
bacteremia
Who gets uncomplicated UTI?
Women with acute cystitis or acute pyelonephritis
Pregnant lady with UTI, which month determines if its complicated or not?
If she’s pregnant its COMPLICATED regardless of the month.
Biofilm formation can be formed by
S. epidermitis
Why are postmenopausal women prone to UTI?
high prevalence of cystocele
altered vaginal normal flora bc of estrogen lack
common organisms causing UTI
E. coli
Urinary tract normal flora
Gardnerella vaginalis
Alpha-hemolytic Streptococcus sp
When do we treat yeast?
If the patient is diabetic
most common UTI staph in hospital if the patient is on catheter
epidermitis
Most common UTI staph in the community if the
patient is a young sexually active female is
saprophyticus
Virulence factors of uropathogens
Adhesions
Enzymes
Toxins
Sidosphores
Sidosphores
iron acquisition
UPEC are different from other E. coli strains in
that it inhabits GI
Uropathogenic E. coli (UPEC) is characterized from other E.coli strains by
Biofilm formation
urothelial cell invasion a
What’s different if u can’t find pyuria ?
The diagnostic criteria changes
What specimens do we reject?
Leaking container
foley Cath. tip
bedpan urine
24-h urine (pooled urine)
+ abt suprapubic aspiration?
done for who?
Avoid contamination
pediatrics
Which urine collection method might introduce bacteria into the bladder ?
Single catheter
Single catheter used for
patients with quadraplagia
Most common urine collection method ?
midstream technique
urine from midstream technique might be contaminated by ___
commensal bacteria from distal urethra.
urine specimens must be CULTURED within ___
2 hrs unless refrigerated/preserved
NON-CULTURE METHODS FOR THE LABORATORY DIAGNOSIS OF UTI
Microscopy
chemical
What can be found in urine microscopy
Pus cells
RBC
Epithelial cells
Bacteria
Gram staining + and -?
+: immediate infooo
-: insensitive (requires specific concentration)
and tooo much work
conc. required for gram stain?
10^5
PYURIA
the presence of at least 10
leukocytes/mm3 of un-centrifuged urine
or 5-10 if centrifuged
When do UTI produce pyuria without bacteriuria?
TB
Chlamydia
Mycoplasma
bacteria produce ____ reducing enzyme
nitrAte
nitrite test is useless when
agent not a member of the family Enterobacteriaceae
nitrite test is tested when?
FIRST thing in the morningg
The main reason for esterase production?
neutrophils
Routine cultures include
sheep blood agar (SBA) and MacConkey’s agar(MAC)
Which culturing methods is used?
Semi-quantitative (Standard loop)
Blood agar gives a ___ measurement of bacteriuria
quantitative
MacConkey’s gives ____ of the bacteria
presumptive diagnosis
What to do if you found significant bacteriuria? and what’s the count?
antibiotics, more than 10^5
What to do if you found doubtful significance bacteriuria? the count?
another specimen, 10^4-10^5
When to treat non-significant bacteria growth and what’s the limit?
<10^3
pregnancy and cystitis
how does Proteus spp grow and where?
Swarming growth on blood agar
E coli grows on ___ and is oxidase pos/neg
lactose fermenter, negativve
pseudomonas is oxidase pos/neg
positive
Staphylococcus Saprophyticus is ___ resistant
novobiacin
False-negative results are due to
Recent antibiotic use
In which of the following patients, is treatment for UTI considered unnecessary?
A- E.coli
B- pseudomonas
C- A. Hemolytic streptococci D- klebsilla
C- A. Hemolytic streptococci
2- what is the most common cause of UTI in hospitalized patients ?
A- E.Coli
B- S.saprophyticus C- Pseudomonas D- S. Epidermitis
A- E.Coli
