Nephro/Uro Microbiology

Gram-positive bacteria

Staphylococcus saprophyticus, Enterococcus spp.

Gram-negative bacteria

UPEC, Proteus spp., Klebsiella spp., Pseudomonas aeruginosa

Trematode

Schistosoma haemotobium

Novobiocin resistant

Staphylococcus saprophyticus

Normal flora of female perineum and vagina

Staphylococcus saprophyticus

Normal floral of colon that can ascend the urethra

Escherichia, Klebsiella, Proteus, Enterobacter, Enterococcus

2nd most common cause of uncomplicated cystitis in young, sexually-active women

Staphylococcus saprophyticus

Nitrate negative on UA

Staphylococcus saprophyticus

Adhesins bind to uroepithelial cells

Staphylococcus saprophyticus

#1 cause of community-acquired UTIs

Uropathogenic Escherichia coli (UPEC)

Type 1 fimbriae binds to mannose on bladder epithelial cells

Uropathogenic Escherichia coli (UPEC)

P fimbriae binds to glycolipids on kidney cells

Uropathogenic Escherichia coli (UPEC)

Nitrite positive on UA

Uropathogenic Escherichia coli (UPEC)

Urease positive

Proteus species

Swarming motility

Proteus species

Causes formation of struvite stones

Proteus species

Causes very alkaline pH

Proteus

Intermediate host is freshwater snails with humans as definitive host

Shistosoma species

Humans infected with cercariae penetrate the skin

Schistosoma spp.

Eggs shed in urine (diagnostic)

Schistosoma spp.

Endemic in Africa, Middle-East near rivers

Schistosoma spp.

Pruritic rash at site of cercariae penetration

Schistosoma spp.

Swimmer's itch

Schistosoma spp.

Terminal hematuria with acute infection

Schistosoma spp.

Squamous cell carcinoma of the bladder is complication of chronic infection

Schistosoma spp.

Treated with Praziquantel

Schistosoma spp.

Only treat if pregnant or about to undergo invasive GU surgery

Asymptomatic bacteriuria

Diagnosed using clean-catch mid stream urine specimen

Bacteriuria

Bacteriuria + symptoms reflecting lower/upper infection

Urinary tract infection

Elderly may only present with delirium

Urinary tract infection

Dysuria, urinary frequency, urinary urgency +/- suprapubic tenderness

Cystitis

Flank pain, +/- dysuria, frequency, urgency

Acute pyelonephritis

WBC casts may be present in urine

Acute pyelonephritis

Infection confined to the bladder in afebrile women or men

Uncomplicated UTI

10 WBCs / microscope field

Pyuria

Evidence of UTI in association with signs of sepsis (fever, tachycardia, tachypnea,

leukocytosis)

Urosepsis

Managed with blood cultures, IV broad-spectrum empiric antibiotics

Urosepsos

≥ 3 infections in 12 months

Recurrent infections

Hospital-acquired UTIs and antibiotic resistance

Pseudomonas, Proteus

Transmission associated with water/equipment contaminants in the hospital setting

Pseudomonas

May use prophylactic low dose TMP/SMX, nitrofurantoin, or cephalexin nightly

Recurrent UTIs

Associated with catheter use, GU surgery

Enterococcus spp.

Biofilm-mediated

Catheter-associated UTIs

May be caused by Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, or Enterococcus spp.

Catheter-associated UTIs

First line treatments include TMP-SMX, nitrofurantoin, or fosfomycin

Uncomplicated cystitis

Outpatient treatment with oral Ciprofloxacin x 5-7 days if mild

Pyelonephritis

May be treated with amoxicillin-clavulanate, cephalexin, fosfomycin, TMP-SMX, or nitrofurantoin depending on trimester

Asymptomatic bactiuria in pregnancy

Screened for at 12-16 weeks gestation

Asymptomatic bactiuria in pregnancy

Contamination of urine sample

Epithelial cells