Microbiology Chapter 3

        Test Notes

71 cards   |   Total Attempts: 188
  

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The Five I’s:
•Inoculation –Addition of microorganism to supporting medium •Incubation –Proper growth temperature and time •Isolation –Creating pure culture from a mixed population •Inspection –Macroscopic and microscopic observations •Identification
How do you culture a microorganism?
•To identify the agent that causes a specific disease requires that microorganisms be isolated and cultivated or cultured
Step 1 to cultivate microorganism
–Inoculum (sample to be cultured)•Environmental specimens (water, air, soil)•Clinical specimens (obtained from patient)•Stored specimens (previously cultured)
Step 2 to cultivate microorganism
–Medium(collection of nutrients allowing growth of inoculum)•Liquid broth •Solid media
Step 3 to cultivate microorganism
–Incubation (placing inoculated media at proper temperature for specific period of time)•Observable growth appears in or on medium after incubation is known as a culture
Clinical Specimens:
•A clinical specimen is a sample of human material to be examined or tested for the presence of a pathogen
How do you properly handle a clinical specimen? (3 Steps)
•Must take care not to contaminate the sample with organisms from the environment or other region’s of the patients body •Must be labeled properly •Must be transported quickly to the lab to avoid death of microbe and minimize growth of normal microbiota
•Obtaining Pure Cultures:
–Technique for isolating the suspected pathogen from normal microbiota in a culture
Pure culture :
–refers to a cultures composed of cells arising from a single progenitor (parent or original cell) •Progenitor is termed a CFU (colony forming unit)
Aseptic technique:
Refers to a set of instructions used to prevent further contamination by microbes
Two common pure culture isolation techniques:
•Streak plates •Pour plates
•Culture Media:
–Used to support the growth of microorganism or as a means of identification
–3 Physical States of Media
•Liquid •Semi solid •Solid
6 types of general culture media:
•Defined media •Complex media •Selective media •Differential media •Anaerobic media •Transport media
Physical States of Media •Liquid:
–Water-based solution –Growth appears as cloudiness or turbidity