Nephritis
Infection in the kidneys
Pyelonephritis
Ascending UTI
Cystitis
Bladder infection
Urethritis
Urethral infection
Prostatitis
Prostate infection
Symptoms of urethritis and cystitis
Dysuria
Frequency/urgency
Tender over bladder
Positive urine culture
Symptoms of prostatitis
Pain in lower back, perirectal, and testicles
Fever, chills
Positive urine culture
Symptoms of pyelonephritis
Pain in flanks of body
Fever
Severe - diarrhea, vomiting, tachycardia
Can cause premature birth
Positive urine culture
UTI diagnosis
Symptoms and urine examination
Collection of clean, midstream urine
Pyuria most common (>10 WBC per cubic mm of urine)
Increased risks for UTIs
Women (shorter urethra)
Kidney surgery
Catheterization
Most common cause of UTIs
Normal fecal flora
Enterics
Enterics
Facultative anaerobes
LPS
Enterobacteriaceae family
Largest group of Gram-negative rods
Normal fecal flora in most animals
Ferment glucose, reduce nitrite, catalase positive, oxidase negative
Enterobacteriaceae virulence factors
Endotoxin
Capsule
K and H Ag variation
T3SS
Growth factors
Resistance to serum killing
Antimicrobial resistance
E. coli features
Normal fecal flora
Virulence variability based on acquisition of plasmids
Fimbriae or pili
Ferment lactose
E. coli UTI virulence
Adhesins - bind to bladder cells
Hemolysin - induce inflammation
Endotoxin - inflammation
Type I pili
Most E. coli express this
Binds to the mannose residues commonly present on epithelial surfaces
P pili
Subpopulations of E. coli express this
Binds to sugar residues specifically on uroepithelial cells
Staphylococci features
Gram-positive, facultative anaerobe, in clusters
Catalase positive
Non-motile, non-spore forming
Two groups of Staphylococci
S. aureus (coagulase positive)
Coagulase negative Staph. (CoNS)
CoNS features
Form biofilms to enhance survival
S. epidermidis
S. saprophyticus
S. saprophyticus
Normally in GI tract
Causes UTIs
Resistant to novobiocin (unlike other CoNS)
S. saprophyticus commonly causes?
Cystitis in young, sexually active women
Which causes of UTIs are frequent community acquired?
E. coli
CoNS
Which causes of UTIs are frequent hospital acquired?
Proteus, Pseudomonas, Klebsiella
Proteus mirabilis features
Gram-negative enteric
Common in catheterized patients
Produce biofilms
Proteus virulence
Produce a potent urease Alkalizes urine (converts urea into ammonia)
Results in formation of renal calculi (kidney stones)
Symptoms of renal calculi
Sudden onset of severe pain
Treatment of Proteus species
Trimethoprim- Sulfamethoxazole
Pseudomonas aeruginosa features
Gram-negative, aerobic, motile rod
Oxidase positive
Wide temperature range with minimal nutrition
Nosocomial infection
Opportunistic pathogen
P. aeruginosa UTI cause and treatment
Common in long-term catheterization
Treat with multiple courses of antibiotics against resistant strains
Enterococcus features
Gram-positive cocci
Catalase negative
Group D carbohydrate
What other bacteria is enterococcus similar to, and how do you distinguish?
S. pneumoniae
Enterococcus tolerates high salt and bile concentrations, and is not sensitive to optochin
Common Enterococcus species that cause UTIs
Enterococcus faecalis
Entercoccus faecium
Risk factors for Enterococcus infection
Prolonged hospitalization and treatment with broad-spectrum antibiotics
Enterococcus - UTI
Hospitalized patients with long-term catheter receiving broad-spectrum antibiotics
Enterococcus - peritonitis
Abdominal swelling/tenderness after abdominal trauma or surgery
Bacteremia
Enterococcus - endocarditis
Infection of heart endothelium or valves
Associated with persistent bacteremia
Asymptomatic bacteriuria diagnosis
Significant bacteriuria on two successive cultures (women) or one (men)
Common in elderly
Treatment for asymptomatic bacteriuria
Only in pregnant women, prior to urologic surgery, and after renal transplantation
Treatment for uncomplicated cystitis
Trimethoprim-sulfamethoxazole
Treatment for pyelonephritis
Aggressive antimicrobial treatment
Fluoroquinolones for Gram-negatives
Amoxicillin for Gram-positives
Treatment for asymptomatic bacteriuria
No treatment (unless indicated) Amoxicillin, cephalexin, or nitrofurantoin