Topic 1 LAB Flashcards
Identification of pathogenic based on phenotypic
Fermentation profiles for bacteria
Cytopathic effects in tissue culture for viral agents
Microscopic morphology for fungi or parasites
First tool to diagnose microbial disease is:
Microbial culture
Most common method to isolate individual cells and to produce a pure culture is:
To prepare a streak plate
Limitations of conventional methods:
Time
Risky
Viruses, fungi, parasites cant be cultured
Culture may be negative due to prior antimicrobial agents
Requires sophisticated labs (ex mycobacteria)
NON-Conventional lab methods:
Sero/Immunological identification of antibodies/antigens
Nucleic acid/molecular biology techniques
Biological signal:
signal generated when detecting material that can be differentiated from other substances in the sample
Key issues:
are distinguishing it from background noise and translating it to meaningful info
Direct detection:
Detection without use of culture: Microscopy + staining
Macroscopic antigen detection
Serology
Simplest method of microscope examination
Wet mount
Macroscopic antigen detection:
Latex agglutination
EIA
Serology:
used to determine if someone has a protective antibody level or is infected by a specific pathogen ex: Precipitation Agglutination Haemagglutination Haemagglutination inhibition Complement fixation test Fluorescent antibody test
Most widely used precipitation tests:
Ouchterlony and Mancini tests
Sensitive can detect as little as 1microgram of protein
ex VDLR test for syphilis
Causes of classic FUO
Infection Neoplasms Habitual hyperthermia Collagen vascular/Hypersensitivity diseases Granulomatous diseases Miscellaneous conditions Inherited and metabolic diseases Thermoregulatory disorders Factitous fevers
Infections
Appendicitis
Cat-Scratch disease
