Microbiology 1 Flashcards
Is urine normally sterile ?
Yes! - apart from in the lower end of the urethra
Define what a UTI is
It is the presence of micro-organisms in the urinary tract that are causing clinical infection
Define what a lower UTI is
Infection confined to the bladder (cystitis)
Define what an upper UTI is
Infection involving the ureters +/- the kidneys (pyelonephritis)
Define what is meant by a complicated UTI
UTI complicated by systemic sepsis or urinary structural abnormality or stones
Define what is meant by bacteriuria
- This is presence of bacteria in the urine - note this does not necessarily mean infection e.g. in elderly people it is common
- Significant bacteruria - is >105 orgs/mL
Define cystitis
Inflammation of the bladder
Who most commonly gets UTI’s?
- Women - due to shoter, wider urethras
- Catheterised patients
- Patients with abnormalities of the urinary tract – may have family history of UTI’s
Describe the 2 main routes of how the urinary tract can become infected ?
- Ascending infection - essentially bacteria from the bowel works its way up the urinary tract starting at the lower end of the urethra
OR
- From the bloodstream
What is the most common way in which the urinary tract becomes infected ?
From ascending infection
What is the classification of Coliiformes (talking about there gram stain etc) ?
They are aerobic gram negative bacilli
What are the common organisms which cause urinary tract infections ?
Coliiforms:
- E.coli
- Klebsiella sp.
- Enterobacter sp. (referring to enterococcus types)
- Proteus sp.
Staphylococcus saphrophyticus
Pseudomonas aeruginosa
Staph.aureus - but this is usually in bacteraemia
What is the most common bacteria to cause UTI’s?
E.coli
What bacteria which causes UTI’s is associated with producing renal stones ?
Proteus sp.
What bacteria causing UTI’s is often described as having a very foul smell ?
Proteus sp.
