1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation prepared by Christine L. Case Microbiology AN INTRODUCTION EIGHTH EDITION TORTORA FUNKE CASE Chapter 22, part B Microbial Diseases of the Nervous System

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Clostridium botulinum Gram-positive, endospore-forming, obligate anaerobe Intoxication due to ingesting botulinal toxin Botulinal toxin blocks release of neurotransmitter causing flaccid paralysis Prevention: –Proper canning –Nitrites prevent endospore germination in sausages Botulism

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Treatment: supportive care and antitoxin Infant botulism results from C. botulinum growing in intestines Wound botulism results from growth of C. botulinum in wounds. Botulism

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Type A –60-70% fatality –Found in CA, WA, CO, OR, NM Type B –25% fatality –Europe and eastern U.S. Type E –Found in marine and lake sediments –Pacific Northwest, Alaska, Great Lakes area Botulism

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Diagnosis Figure 22.7

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mycobacterium leprae Acid-fast rod that grows best at 30°C Grows in peripheral nerves and skin cells Transmission requires prolonged contact with an infected person Tuberculoid (neural) form: Loss of sensation in skin areas; positive lepromin test Lepromatous (progressive) form: Disfiguring nodules over body; negative lepromin test Leprosy

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Leprosy Figure 22.8

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Poliovirus Transmitted by ingestion Initial symptoms: sore throat and nausea Viremia may occur; if persistent, virus can enter the CNS; destruction of motor cells and paralysis occurs in <1% of cases Prevention is by vaccination (enhanced- inactivated polio vaccine) Poliomyelitis

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Poliomyelitis Figure 22.10

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Salk IPV compared to Sabin OPV http://microbiology.columbia.edu/pico/Chapters/Epidemiology.html http://www.brown.edu/Courses/Bio_160/Projects1999/polio/vac.html http://americanhistory.si.edu/polio/virusvaccine/vacraces2.htm

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Transmitted by animal bite Virus multiplies in skeletal muscles, then brain cells causing encephalitis Initial symptoms may include muscle spasms of the mouth and pharynx and hydrophobia Furious rabies: animals are restless then highly excitable Paralytic rabies: animals seem unaware of surroundings Preexposure prophylaxis: Infection of human diploid cells vaccine Postexposure treatment: Vaccine + immune globulin Rabies virus (Rhabdovirus)

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rabies virus (Rhabdovirus) Figure 22.11

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rabies virus (Rhabdovirus) Figure 22.12

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Arboviruses are arthropod-borne viruses that belong to several families. Prevention is by controlling mosquitoes Arboviral Encephalitis

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Soil fungus associated with pigeon and chicken dropping Transmitted by the respiratory route; spreads through blood to the CNS Mortality up to 30% Treatment: amphotericin B and flucytosine Cryptococcus neoformans Meningitis (Cryptococcosis)

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cryptococcus neoformans Meningitis (Cryptococcosis) Figure 22.14

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Trypanosoma brucei gambiense infection is chronic (2 to 4 years) T. b. rhodesiense infection is more acute (few months) Transmitted from animals to humans by tsetse fly Prevention: elimination of the vector Treatment: Eflornithine blocks an enzyme necessary for the parasite Parasite evades the antibodies through antigenic variation African Trypanosomiasis

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings African Trypanosomiasis Figure 22.15

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Protozoan infects nasal mucosa from swimming water Naegleria fowleri Figure 22.16

20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Caused by prions –Sheep scrapie –Creutzfeldt-Jakob disease –Kuru –Bovine spongiform encephalopathy Transmitted by ingestion or transplant or inherited Chronic, fatal Transmissible Spongiform Encephalopathies

21. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Transmissible Spongiform Encephalopathies Figure 22.17a