UTI Micro Flashcards by Keaton Joppru

What are the major defenses of the Urinary tract?

Chemistry
Flow
IgA (adaptive immune)
Different surface proteins of epithelial than GI tract

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What are the chemistry defenses of the urinary tract?

pH
Lysozyme- breaks down peptidoglycan
Lactoferrin– sequesters iron from bacteria

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What are the major threats to the urinary system?

Microorganisms
Blocked/decreased flow
Hematoganous threat from another anatomical location

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What is the cause of cloudy urine in a UTI?

WBC’s

Bacteria

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What are the Sings and sx’s of cystitis?

Sudden onset pain
Dysuria 
Frequency/urgency 
Cloudy urine
Orange or red urine
Fever/n
Back pain

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What is an uncomplicated UTI?

Structurally or Neurological normal urinary tract

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What are some examples of complicated UTI?

Persistent infections
Foreign bodies like calculi and catheters
Obstruction
Immunosuppression
Renal failure
Renal transplant
Urinary retention from neuro dz

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What are the bacterial causes of UTI’s?

E. Coli 80%
Staph saprophyticus 10%
- The rest are 10%:
3a. Enterococcus spp
3b. Klebsiella
3c. Citrobacter spp
3d. Proteus mirabilis

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Is the E. Coli that causes Bloody diarrhea and watery diarrhea cause UTI’s?

Those are EHEC and ETEC
UPEC is what causes UTI’s

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What does UPEC stand for?

Uropathogenic E. Coli

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What percent of women who get UTI’s have them reoccur?

25-30%

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What is the most common nosocomial infection?

Catheter related UTI’s

accounts for 40%

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Who is at less risk for UTI?

Children and men

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Why would a child get a UTI?

Sexual assault

Atomic or functional abnormalities

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Why would a man get a UTI?

Usually UT abnormality
Obstruction
Enlarged prostate

Can lead to prostitis or epidydimitis

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What the sx’s of pyelonephritis?

Flank pain
Fever
Nausea
Dysuria
Vomiting 
Malaise

1/4 mil cases/year

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Which patients have risk factors for papillary necrosis (complication of pyelonephritis)?

in DM pts
Obstruction
Sickle cell
Analgesic abuse (can happen without infection)

Necrotic tissue can slough off and block downstream

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What are some gross anomalies with pyelonephritis?

Enlarged
Discrete yellowish raised abscesses
Histo- Suppurative necrosis

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How does one diff between chronic glomerulonephritis and chronic pyelonephritis?

In Chronic pyelonephritis the kidneys are not scared evenly bilaterally.

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What is periglomerular fibrosis?

Concentric fibrosis about the parietal layer of the Bowman’s capsule

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What are some characteristics of pyelonephritis?

Colloid casts
Periglomerular fibrosis
Dilated tubules
Atrophy of endothelial lining
Parenchymal with interstitial fibrosis and inflammatory infiltrates

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Can one see necrotic papilla on a plain film?

Yes

Radiopague

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What is common sight of abscesses for pts with Staph Aureus endocarditis?

Kidneys
Via Hematogenous spread

Gram - rarely spreads this way

What do O K and H stand for in serotyping of bacteria?

O- Polysaccharide sugars
K- Capsule ag
H- Flagellar ag

Are the serotypes of E Coli that cause cystitis vs pyelonephritis the same?

Nope | Genetically distinct

What are some virulence factors for E coli?

``` Adherence Resistance K ag Siderophore receptor Toxins and factors ```

What is main virulence factor for E coli?

P Fimbriae - Binds to globoseries glycophingolipid found on uroepithelial cells - Resists neutrophil destruction

What does Type 1 fimbriae bind to?

mannose containing host epithelial receptors - Uroplankin 1 and 2 - however mannose sensitive because they bind so strongly to mannose that bacteria doesn't infect us with excess mannose in urine

What is needed in order for E coli to cause cystitis?

Type 1 Fimbriae

What is the MOA of Linezolid?

Binds to 23S subunit of the 50S subunit and inhibits protein synthesis

What are the 50S inhibitors?

``` CCEL= Sell C= Chloramphenicol and clindamycin E= Erythromycin (macrolides) L= Linezolid ``` All static but linezolid can be cidal

What are the 30 S inhibitors ?

AT A=Aminoglycosides (cidal) T= Tetracyclines (static)

What is the mnemonic for 30s and 50s inhibitors?

buy AT 30, CCEL (sell) at 50

What are the common nosocomial infections pathogens? Treatment?

1. E. Coli 2. K. pneumoniaie (Carbapenum resistant enterobacteriaceae (CRE) 3. VRE- vancomucin resistent enterococci Linezolid

What is needed for bacteriuria?

>10^5 colony forming units per ml

What is pyruia?

10 or more neutrophils per high power field of unspun, voided midstream urine

How does one diff between staph and enterococcus?

Catalase test Staph is positive

How does one diff between staph a and staph saprophyticus?

Coagulase test SS is negative

What is a positive catalase test?

Oxygen bubble production - Some bacteria protein H202 and O2- and thus need enzymes to break this down and protect themselves. - Catalase converts these reactive species to H20 and O2.

What is coagulase?

Free and bound | - causes bacteria to clump together with fibrinogen which results in a precipitation

How does one diff between staph epi and staph saprophyticus?

Novobiocin test Epi is sensitive Sapro is resistant

What does novobiocin do?

Inhibits bacterial DNA gyrase in susceptible organisms

What is unique about E coli in terms of Indole, citrate, MR and VP tests?

only enteric organisms that is both always Positive for indole and negative for citrate

What are the first line treatments for UTIs? Contraindicated?

1. Nitrofurantoin--> with suspected pyelonephritis as it has poor affect there 2. TMP-SMX--> >20% local resistance and used in last 3 months

What are the alternative treatments for UTIs?

1. Fluoroquinolones | 2. Amoxicillin/clavulanate (augmentin)

What is first line treatment for staph saprophyticus?

Augmentin

What is the MOA of Nitrofurantoin?

Inhibits bacterial acetyle-coenzyme A - interferes with organisms carb metabolism - disrupt cell wall formation too

How does nitrofurantoin get activated?

By bacteria flavoprotein Thus its a prodrug 30-40% excreted in urine unchanged

Can pregnant people take nitrofurantoin? Renal pts?

no - it crosses the placenta and distributed through breast milk - accumulates and can be toxic in renal pts

What do sulfonamides inhibit?

pteridine synthetase | - Inhibits Pteridine + PABA from forming into dihydropteroic acid

What does trimethoprim inhibit?

Dihydrofolate reductase | - inhibits production of tetrahydrofolic acid from dihydrofolic acid

What else can Bactrim be used for?

- Acute bronchitis - Otitis media - Pneumocystis jirovecii pneumonia - Traveler's diarrhea - Shigellosis - UTI

What does Bactrim interact with that could be fatally bad?

CYP450 and CYP2C9

What is the MOA of Quinolones?

Inhibits DNA gyranse and topo IV - contraindicated while using antiacids - contraindicated in people taking iron supplements

What is potent enough quinolone to fight again P aeruginosa?

Levofloxacin

What are the current uses of quinolones?

most active against aerobic gram-negative bacilli, particularly members of the family Enterobacteriaceae and Haemophilus spp., and against gram-negative cocci, such as Neisseria spp. and Moraxella (Branhamella) catarrhalis. Relative to nalidixic acid, the fluoroquinolones also have additional activity against gram-negative bacilli, such as P. aeruginosa and against staphylococci.