Kidney and Bladder Infections Flashcards
Cystitis and pyelonpehritis mechanisms
Cystitis - pathogenic bacteria colonize the vagina…bacteria ascend from vagina to bladder…bacteria remain in bladder
Pyelo - start with cystitis then bacteria ascend from bladder to kidneys
Normal host defense
Normal flora compete with pathogenic bacteria - help maintain acidic pH..also secretory IgA
Eliminate bacteria that do not get into bladder by normal voiding and bactericidal components
Risk facotrs for bacterial cytisis
Anything that increase colonization, ascent, or decreases eliminaton
Pt risk factors for colonization
Genetic - epithelial glycoproteins
Dec normal flora - dec estrogen after menopause, spermicide, coitus, ABs
Increased vaginal contact iwth feces
Bacteria ascend into bladder
Can be spontenaous
Pt risk factors - coitus and urehtral instrumentation and catheters
DEc eliminatioin from bladder
Abnormal voiding
Diabetes - dec immune function in diabets…glucose in urine is energy for bacteria
Immunosuppression
Pt risk for bacterial pyelonephritis
Any of the cystitis risk factors
Increased ascent is BY far the mst fcommon mech…vesicouretral reflux, stasis of urine (pregnancy)
bacteremia due to IV drug use, infected central line, etc.
Type 1 E coli pili
FimH adhesion protein binds to mannose residues on luminal bladder surface
Free floating mannose inhibits this binding so oral mannose can dec UTI frwquency
Bac risk factor for pyelonephritis
P pili with papG adhesion protein..allows ascension into the kidneys
PapG
Binds glycolipid moiety on P blood group antigens…all the way up to kidneys
Mannose resistant
Gene is PAP operon for pyeloneprhitis associated pili
Female urethral diverticulum
Outpuching or urethra fills as pt urinartes…stagnant urine —-infections and some urine dribbles out
DDD - dysuria, dyspareunia, dribbling
Dx - tender mass and MRI
Asx bactriuria
No sx or PE
Urinalysis shows nitrites and/or bact
Urinalysis relevant to infection
Chemstrip - nitrites and leukocyte esterase
Microscope - WBCs and bacteria
Nitrites
Many gram neg bacteria…turns bind
Gram + do NOT do this conversion…neg nitrites does NOT rule out bacteria
Leukocyte esterase
Enzyme in granulocytes catalyzes color change to purple
When to tx asx bacteriuria
Tx if preg or planning surgery and need sterile urine
Comm acquired bac cystitis
Not recently in healthy care facility
Acute dysuria..no fever and not il
No angle tenderness, bladder may be tender
Urinalysis - Positive LE< WBC, nitrites or bact
US - acute dysuria UA and LE but no nitrites
Pseudomonas - nitrite neg
Staph - nitrite neg
Enterococcus - nitrtie neg
Tx of comm acquired cystitis
Tx based on scenario
Empiric tx for cystitis
Oral ABs - E coli or staph
Oral phenaopyrdine for the sx - analgesic to bladder and turns urine orange
Cystitis expected outcome with AB
Usually resolves in 1-3 days
If does not resolve, then may be resistant or not from a UTI in the first place…send a urine culture
Urine culture report
No growth - usually means no infection
Bacteria name with# CFU
Mixed flora - genital skin bacteria included in urine specimen
Usual urine collection methods
Midstream clean catch - could include bacteria
IN and out cath - pure urine and no skin flora
If clean cathc mixed flora- need to do a catheter
Recurrent UTI
More than 1 in 6 mos or 2 in 12
Change contraception
Vaginal estrogen in post menopausal
Oral d-mannose
Oral methenamine
Vaginal estorgen
After menopause, vaginal pH increase…normal lactobacillus dec…easier for uropathogens to colonize…estrogen reverses
Oral mannose
Binds pili so they can’t bidn to urothelium
Methenamine
Antiseptic…decomposes to formaldehyde and ammonia
No resistance
Contraindiciated if hepatic insuffiencet or renal
Comm acquired pyelo
Flank pain, fever, malaise, may or may not have dysuria
WIll have fever/CVAT
Labs - high WBC, may have high BUN/Cr
Usually positive as for cystitis
Tx of comm acq pyelo - outpatient
Okay to tx outpatient if comm, not preg, spetic, and compliant
Outpatient choices - cipro, bactrim PLUS cef or amino
NOT NITROfurantoin
Pyelo inpatient
Cephalo 3rd gen with AG OR carbapenem
Change to oral drug when stable —-continue 10-14 days
Expected pyelo outcome with AB
Temp should dec 1 degree a day
If fever does NOT dec….ureteral obsruction - lifethreatneing and get a CT scan!!!!!!!
Others - areas doesn’t penetrate, resistat
INfection with ureteral obstruction
MUST rule out the obstruction…get CT scan
CLinical scenario of obstruction plus infection
Same as pyelo but more severe
Relevant med hx with risk of obstruction - hx of stones, diabetes, radiation
Renal and perinephric abscess
Renal - within kidney parenchyma
Perineprhic - more severe and can airse from source adjacent to kidne y
Renal and perineprhic mechs
Starts as pyelo but not completely cleared
Seeding from bacteremia, usually gram+ from skin source or IV drug users
Presents like pyelo but does not improve…if you suspect a stone, get CT>..CT shows abscesses
Pyoneprhosis and XGP
Pyo - end stage hydroneprhotic kdiney with no functiong parenchyma
XGP - nonfuncitong enlarged kidney with stones and inflammatory phlegmon…lipid-laden macrophages
Dx process similar…get CT
Renal TB
If immunocompetent- —long latency
Often go down itno bladder and lead to scarring
Renal TB dx
Sx may be minimal
Urinalysis - WBC but no growht…sterile pyuria
Skin and blood tests don’t prove renal involvement
Best is 1st morning voided urine for acid-fast for 3-5 consecutive days
Renal Tb imaging
Ureter scarring - adjacent to bladder is classic…dilated ureter proximal to stricture
Kdiney - hydroneprhosis due to dilated ureter
Individual calyces idlated due to scarred infundibulae, parenchymal destruction, severe autoneprhectomy
Pseudomonas
Nitrite negative
Difficult to tx…maybe FQs?
Ciommon in bioflms on urinary catheters…secrete PSs and antibiotics can’t penetrate biofilms
Proteus
Has urease enzyme that converts urine urea to ammonia
Alkaline urine pH
Enterococcus
Gram+ so + LE and neg nitrites
Some resistant to vanc…all sensitive to linezolid
