UTIs Flashcards
What classifies a UTI as being hospital acquired?
elements of a case not present on admission but on the third calendar day of admission
What classifies a UTI as being recurrent?
3 or more episodes symptomatic bacteriuria w/in 1 yr
Under what conditions are UTIs considered complicated?
Diabetes Pregnancy History of acute pyelonephritis in past year Symptoms of >7 days before seeking care Broad-spectrum antimicrobial resistant uropathogen Hospital (healthcare) acquired infection Renal failure BEING MALE
Except for one organism, what is the primary source of microbes that cause UTIs? What is the exception?
GI tract; Staphylococcus saprophyticus - CoNS can also be transient skin flora
When is the only time the prevalence of male UTI is higher than female? When does it pretty much equal out?
Prior to one month of age; age 50 due to BPH
2 predisposing factors in PGN women leads to reflux and UTI. What are they?
expanding uterus blocks ureters, Progesterone muscle tone reduction
How does menstruation predispose women to UTIs?
Loss of vaginal and uro- epithelia + normal flora
Increased risk for E. coli and S. saprophyticus UTIs
How does BPH lead to UTIs?
causes stasis and reflux
Which VF is responsible for colonizing lower UTI and causing acute cystitis with E. Coli?
Mannose-sensitive fimbria – FimH protein
What is the VF responsible for pyelonephritis?
P fimbriae- binds to P blood group antigen on uroepithelial cells and RBCs
Enhances persistence of infection & inflammation in UT
How is hemolysin used as a VF?
causes hemolysis
What is the primary VF in p mirabilis and s sapro? What does it do?
Urease; increases pH and forms struvite crystals
What effect does endotoxin have as a VF?
causes systemic sepsis
How does aerobactin act as a VF?
scavenges Fe
What are some microbes that use polysaccharides to form biofilms?
E. coli; Proteus mirabilis; Klebsiella pneumoniae
S. epidermidis; Enterococcus faecalis
Pseudomonas aeruginosa
Which microbe has a K antigen responsible for virulence? What does K signify?
UPEC; CAPSULAR PRESENCE
What are the three most common causes of descending pyelonephritis?
S. aureus
Mycobacterium tuberculosis
Candida albicans
What is urethritis often associated with in males? Females?
Prostatitis; cystitis
What are the common STD agents causing urethritis?
Chlamydia trachomatis, Neisseria gonorrhoeae,
and Trichomonas vaginalis
What amount of bacteria is considered significant and to be diagnostic for cystitis?
10^5 CFU
What are patients at risk for if they have bacteruria with no sx?
Upper UTI
In whom do you need to tx asymptomatic bacteriuria especially?
Pregnant women – lower infant birth weight
Preschool children – renal scarring
also elderly men who undergo prostatic surgery or some other UT procedure. You need to treat before any one of these! All it takes is a minor microabrasion for septic effects!
A pt has acute sx and pyuria. What amount of bacteria is needed to diagnose as UTI?
10^2 CFU, otherwise 10^5
What diagnostic tests can you run on urine to check for UTI?
Urine culture with sensitivity info
UA
What agars are used for urine cultures?
MacConkey; CLED; Eosin-Methylene Blue; Hektoen Enteric
What is the Kirby-Bauer agar used for?
To check sensitivity from a pure culture
What species contain nitrites?
E. coli, Proteus and Klebsiella
How long do you treat pyelonephritis for? Cystitis?
10 days; 3 days
What mechanism leads to UTIs in PGN? Post menopausal?
Stasis and reflux; STASIS ONLY
