Transcript Chapter 18
TORTORA • FUNKE • CASE Microbiology AN INTRODUCTION B.E Pruitt & Jane J. Stein Chapter 18 Practical Applications of Immunology QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Vaccine History • Variolation: Inoculation of smallpox into skin (18th century) • Vaccination: Inoculation of cowpox into skin • Herd immunity results when most of a population is immune to a disease. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. • On 14th May 1796, Edward Jenner used cowpoxinfected material obtained from the hand of Sarah Nemes, a milkmaid from his home village of Berkley in Gloucestershire to successfully vaccinate 8 year old James Phipps. On 1st July 1796, Jenner challenged the boy by deliberately inoculating him with material from a real case of smallpox.He did not become infected! Jenner QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. How • Trigger your own immune response Vaccines work – Artificially acquired active immunity QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Virus, Bacterial or Toxins •Attenuated - no longer virulent •Inactivated or Killed - formalin, phenol or heat destroyed • Attenuated whole agent vaccines: – – – • Inactivated (killed) vaccines: – – – – • Types of Vaccines Live, attenuated (weakened) microbes - virus or bacteria Long term immunity May back mutate to virulent strain (rare) Killed by formalin, phenol or heat Toxoids Not as long lasting Safe Subunit vaccine: – Uses fragments from virus or bacteria • – – • QuickTime™ and a TIFF (Uncomp resse d) de com press or are nee ded to s ee this picture. QuickTime™ and a TIFF (Uncomp resse d) de com press or are nee ded to s ee this picture. Produced by recombinant methods Recombinvac Safe Clean Conjugated vaccines: – Bind to larger particle or protein to enhance antigenicity QuickTime™ and a TIFF (Uncomp resse d) de com press or are nee ded to s ee this picture. Principal Vaccines Used in the United States to Prevent Bacterial Diseases in • DTaP - Trivalent (threeHumans in one) – Diphtheria: Purified diphtheria toxoid – Pertussis: Acellular fragments of B. pertussis – Tetanus: Purified tetanus toxoid • Meningococcal meningitis: Purified polysaccharide from N. meningitidis • Haemophilus influenzae type b meningitis: Polysaccharides conjugated with protein • Pneumococcal conjugate vaccine: S. pneumoniae antigens conjugated with protein Vaccine Schedule • • • • • • • • • • Principal Vaccines Used in the United States to Prevent Viral Diseases in Smallpox: Live vaccinia virus Humans Poliomyelitis: Inactivated virus Rabies: Inactivated virus Hepatitis A: Inactivated virus Influenza: Inactivated or attenuated virus Measles: Attenuated virus Mumps: Attenuated virus Rubella: Attenuated virus Chickenpox: Attenuated virus Hepatitis B: Antigenic fragments (recombinant vaccine) Other Diagnostic Diagnostic Immunological tests: applications: Serological • Direct tests detect antigens (from Tests patient sample) • Indirect tests detect antibodies (in patient's serum) Diagnostic Immunology: Precipitation Reactions Precipitation Reactions: • Involve soluble antigens with antibodies • Precipitin Ring test Figure 18.3 Agglutination Reactions • Involve particulate antigens and antibodies • Antigens may be: • On a cell (direct agglutination) • Attached to latex spheres (indirect or passive agglutination) Figure 18.4 Hemagglutination • Hemagglutination involves agglutination of RBCs. Figure 18.7 • Antibodies help eliminate the harmful effect of a virus or Neutralization Reactions exotoxin • Viral hemagglutination inhibition tests for the presence of antibodies in a patients serum by the antibodies' ability to prevent viruses from agglutinating RBCs. Figure 18.8b Antibody Titer • Is the concentration of antibodies against a particular antigen Figure 18.5 Complement Fixation Figure 18.9.1 Complement Fixation Figure 18.9.2 Fluorescent Antibody Techniques (Direct) Figure 18.10a Fluorescent Antibody Techniques (Indirect) Figure 18.10b Enzyme-Linked Immunosorbent Assay(Direct ELISA) Figure 18.12a Enzyme-Linked Immunosorbent Assay (Indirect ELISA) Figure 18.12b Serological Tests Figure 18.13 Serological Tests: Summary • • • • • Precipitation: Soluble antigens Agglutination: Particulate antigens Hemagglutination: Agglutination of RBCs Neutralization (inhibition): Inactivates toxin or virus Fluorescent-antibody technique: Antibodies linked to fluorescent dye • Complement fixation: RBCs are indicator • ELISA: Enzyme linked to antibody amplifies results for easier visibility and more sensitivity.