UTIs (Flemming)

How are UTIs classified?

By site of infection

Define UTI

presence of microbial pathogens within the urinary tract

UTI in urine

bacteriuria

UTI in bladder

cystitis (lower UTI)

What is the generally accepted threshold of bacteria in urinary tract?

10^5 bacteria/ml or more

UTI in kidney

pyelonephritis (upper)

UTI in prostate

prostatitis

What are the 2 ways bacteria can get into the urinary tract?

1. ascending route

2. hematogenous route

What is the ascending route?

bacterial colonization of urethra causes bacteria to multiply in bladder and ascend to ureters

Ascending route is primarily from colonization of vaginal area by _______

fecal flora

What is the hematogenous route?

dissemination of microorganisms in blood from distant sites of infection due to bacteremia

Which route is most common?

ascending

Signs and symptoms of lower UTI

• painful urination

• urgency and frequency

• suprapubic heaviness

• gross hematuria

Upper UTI symptoms and signs

• flank pain or CVA tenderness

• fever

• N?V

• chills, rigor, BP changes

• May or may not have s/s of cystitis concurrently

Does upper or lower UTI have more systemic symptoms?

upper

What are common laboratory tests for UTIs?

• urinalysis

• urine culture

• bacteriuria

What do you look for in an urinalysis?

• pyuria (pus in urine, WBCs)

  • WBC > 10 cells/mm³

• nitrite- positive

• leukocyte esterase positive (represents inflammation)

• epithelial cells <5

What does a urine culture report?

bacterial speciation and drug susceptibilities

Quality of the sample that was voided

What are the types of antibiotic therapies?

• empiric

• pathogen-directed

Empiric is based on _______ and pathogen-directed is based on ______

guideline recommendations; specific culture results

Should you treat asymptomatic bacteriuria? (even if culture isolates a pathogen)

no (2 exceptions though)

What are the 2 exceptions of treating asymptomatic bacteriuria?

1. pregnancy

2. patients undergoing transurethral resection of prostate (TURP) or urologic procedures where mucosal bleeding is anticipated

What are some causative pathogens related to UTIs?

• Mainly gram (-)

  • E. coli

  • Proteus mirabilis

  • Klebsiella pneumonia or oxytoca

  • Staph Saprophyticus (+)

  • Enterococcus sp.

How should we structure diagnosing UTIs?

1. Upper or lower?

2. Complicated or uncomplicated?

3. Severity of illness?

According to the new guidelines, what characterizes uncomplicated UTI?

infection confined to the bladder in afebrile women OR men

According to the new guidelines, what classifies complicated UTIs?

infection beyond bladder (systemic s/s)

What are the 1st line options for uUTI?

• nitrofurantoin 100mg BID x5 days (if CrCl>40-60ml/min)

• Bactrim DS tab PO BID x 3 days (if resistance in local area is <20%)

• Fosfomycin 3gm PO x 1 day (not highly stocked or tested)

• Pivmecillinam 200mg TID x 3-7 days *

What are some 2nd line agents for UTIs?

• FQs (lots of ADR, “collateral damage”)

  • Levo 750mg QD x 3 days

  • Cipro 500 BID x 3 days

• B-lactams for 5-7 days

  • Amox/Clav, Keflex, Cefpodoxime

  • Cefuroxime and cefixime

True or false: amox or ampicillin can be used alone empirically

false; due to resistance

Cons in nitrofurantoin

• cannot be used for pyelonephritis or bactermia

• CrCl < 40

Side effects of bactrim

• hyperkalemia

• sulfa rxn

• increased INR

Cons of fosfomycin

• cannot be used for pyelo or bacteremia

• more $$

Levo/Cipro ADR

• QT prolongation

• tendon rupture

• CNS

• lower seizure threshold

(shorter/longer) courses of B-lactams are needed?

Longer

Which 1st line agent has good urinary activity and post-antibiotic effect

FQ (levo/cipro)

What is the 4 step process to address cUTI?

1. assess severity

2. assess risk factors for drug resistant pathogens

3. evaluate patient specific considerations

4. use of antibiogram

Preferred therapy in patients with sepsis or septic shock

• 3rd or 4th cephalosporins

• piper/tazo

• FQs

• Carbapenems

Preferred therapy for patients without sepsis - IV therapy

• 3rd or 4th cephalosporins

• piper/tazo

• FQs

Preferred therapy for patients without sepsis - oral therapy

• FQs

• Bactrim

What are some alternative agents for cUTIs?

• new/novel BL/BLis

• cefiderocol

• plazomicin

• older AGs

• Amox/clav

• 1st or 2nd gen cephalosporins

For patients with cTUI, avoid using _____ in patients who have received this class in the last 12 months

FQs

In septic shock, choose an antibiotic with > /+ ____% susceptibility

90

In sepsis without shock, choose an antic with >/+ ____% susceptibility

80

Define sepsis

life-threatening organ dysfunction caused by dysregulated host response to infection

Define septic shock

subset of sepsis in which despite volume resuscitation, vasopressors are required to maintain blood pressure

This is the most common-health care associated infection worldwide

catheter-associated UTIs (CA-UTIs)

This drug is an orally bioavailable form of mecillinam, has specificity for urinary tract and newly approved for uUTI

Pivmecillinam

This agent inhibits 2 topoisomerase, is approved for the treatment of uUTI, and first in class triazaacenaphythylene antibiotic

Gepotidacin

Dosing recommendations for mecillinam

• 400mg BID X 3-7 days

• 200mg TID X 3-7 days

This is an oral carbapenem approved for uUTI in patients whom limited other options exists

Tebipenem