Flashcards in Introduction to microbiology Deck (15)
categories of micro-organisms that cause infection
common specimen types collected for culture, sterile sites.
common specimen types collected for culture, non-sterile sites.
diagnosis of bacterial infections using microscopy
Light microscopy can be used, stain varies:
-no stain to see pus cells or parasites
-Gram stain to see bacteria and yeast/fungi
-ZN or Auramine stain for mycobactria
Pros and cons of gram stain microscopy for bacterial identification.
cons: not sensitive, can't usually identify particular species
Pros and cons of bacterial culture for identification.
selective bacterial growth media
only grows a specific bacteria or doesn't grow some species of bacteria
non-selective bacterial growth media
grows all bacteria
methods for identification of bacterial species
use observable characteristics:
-morphological (shape) using miscroscopy
-physiological (normal functions of the bacteria)
-biochemical (chemicals within and excreted by cells)
DNA based tests
site in body that should normally not contain microorgansims
site in the body that normally contains micro-organisms
Methods for detecting viruses
-molecular methods, real time PCR
-serology to determine immunity
diagnostic principles in parasitology
-microscopy, looking for parasites, cysts and ova in faeces. Blood films for malaria.
-culture rarely possible
-serology sometimes useful
basic infection control measures
-wash hands before and after patient contact aswell as contact with patient's immediate environment.
-swab stethoscope between patients
-isolation of patients, barrier nursing or source isolation