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Unformatted text preview: Cultivating and Identifying
1. Choice of environmental sample
2. Analyzing the sample microscopically - Gram Stain
Liquid vs Solid
4. Isolating a pure culture – streak purification
5. Identifying the bacterium – DNA fingerprinting
6. Estimate recovery of microbial cells from a sample
WHY? Gram Stain Neisseria meningiditis • Figure legend:
Gram stain of liquor of a patient with meningococcal meningitis. Nuclei
and cell membrane outlines of many polymorphonuclear cells are seen
as well as intracellular gram-negative diplococci (Neisseria meningitidis).
(http://www.genomik.uni-wuerzburg.de/pathogenomik-plus_2006__2009/research_groups/cluster_2/) Liquid Versus Solid Medium DNA Fingerprinting
1. Isolate chromosomal DNA
2. Digest with a restriction enzyme
3. Separate DNA fragments with PFGE
cartoon animation PFGE
1, 6 & 10 = MW markers
2 = Nm case 1
3 = Nm case 2
4 = Nm case 3
5, 7-9 = control Nm For your amusement
Patterns on pulsed-field gel electrophoresis of Neisseria meningitidis restricted by SpeI.
Lanes 1, 6, 10: lambda ladder reference. Lanes 2, 3, 4: N meningitidis isolates from Cases 1,
2, and 3, respectively. Lanes 5, 7, 8, 9: N meningitidis control isolates from 1999.) The three
case patients had all been previously healthy and had not attended college. A search for a
common exposure among the three revealed that all had attended a party on May 14, 1999,
which was also attended by at least 80 other persons, most of whom were 18 to 24 years
old. At the party, a large number of persons reportedly smoked tobacco, smoked marijuana,
and/or drank alcohol. The only exposure common to all three patients was the party.
Although the patients in case 1 and case 2 were household roommates, the patient in case 3
had no contact with the other two, either before or after the party. Antimicrobial
chemoprophylaxis was recommended to a total of 83 party, work, and household contacts of
www.medscape.com/ viewarticle/423567_3 Viable Cell Count Direct Microscopic Cell Count ...
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This note was uploaded on 11/23/2009 for the course MIMG 101 taught by Professor Bradley during the Winter '08 term at UCLA.
- Winter '08