What are possible infecting agents?
What are the two areas of the body in terms of organisms?
Sterile and non-sterile
What is a sterile site?
One which normally does not have infection
What is a non-sterile sites?
One which has some degree of harmless infection, usually associated with the outside world
What are examples of sterile sites?
Cerebrospinal fluid (CSF)
What are examples of non-sterile sites?
Which kind of sites is easier to diagnose a harmful infection?
Sterile sites because you are not expecting to find anything there
What are some common speciments collected for bacterial culture?
Mid-stream urine (urinary tract infection)
Sputum (chest infection)
Throat swab (tonsillitis)
Swab or pus (wound or site of infection)
Blood culture (bacteraemia)
Cerebro-spinal fluid (meningitis)
What are different ways of looking for pathogens?
Gram stain and microscopy
In what site does microscopy work well?
Sterile sites but not non-sterile sites
What can microscopes not see?
Viruses, they are too small
What can unstained microscopy see?
Pus cells (in urine)
Parasites (in faeces)
What is stained microscopy used to see?
How can flourescent bacteria be seen?
By using flourescent staining such as auramine. such as for mycobacteria
What does gram staining identify?
Whether the bacteria is gram negative or gram positive
How does gram negative bacteria appear when gram staining?
How does gram positive appear when gram staining?
What is an advantage of microscopy?
It is quick
What can gram staining not identify?
The specific speices present
What does gram staining not being 'sensitive' mean?
There needs to be lots of bacteria present for it to work
What are properties of bacterial culture?
It is slow
It is sensitive (do not need lots of bacteria)
What can be changed in a bacterial culture?
Culture conditions to promote the growth of certain species
What are things that can be controlled in a bacterial culture?
Type of media (selective/non-selective)
Duration of incubation
What are observable characteristics that can be used to identify a species?
What distinguishes strains within a species?
How can viral infections be diagnosed?
Molecular methods (such as real time PCR)
Cell or tissue culture
What is not really used now for detecting viruses?
Cell or tissue culture
What is serology?
Detecting antibodies that the patient has produced against the virus
What are the 3 classes of parasites?
What are examples of protozoa?