Microbiology Lec 1

Question 1

infectious diseases are caused by…

Answer 1

pathogens (disease-causing). Prokaryotes (some bacteria/not archaea); Eukaryotes (protist - protozoa (parasitic), worms - helminths, anthropods/ectoparasites (insects & more)); Acellular infectious agents (viruses, viroids, prions)

Question 2

What is public health?

Answer 2

• the science of protecting and improving the health of populations
• through: education, promotion of healthy lifestyles, research, and detecting/preventing/responding to disease
• careers/roles: developing plans/strategies to respond to outbreaks; implement vaccine programs; designing public health policy

Question 3

Types of microbes/microorganisms

Answer 3

• include atoms, molecules, ribosomes/mitochondria, proteins/lipids, viruses, bacteria, parasites, eukaryotic cells, etc
• subject to evolution
• prokaryotic microbes (bacteria, archaea)
• eukaryotic microbes (algae, fungi, protozoa, helminths, arthropods)
• acellular infectious agents (viruses, viroids, prions)

Question 4

The scope of public health microbiology & the role of microorganisms in the environment and public health

Answer 4

understanding types of microbes and their impact (pathogenic, non-pathogenic) on environment and humans, understanding transmission, understanding solutions (vaccines, policy, sanitation)

Question 5

Important milestones in the history of public health microbiology

Answer 5

• records in the Bible, Greeks and Romans: believing disease was caused by bad air, Rome’s aqueduct and sewer system likely prevented water-borne outbreaks
• Bubonic plague
• People and their discoveries
• Era of Sanitation (mid 1800s): beginning of efforts to prevent spread of disease (antiseptic surgery, pasteurization of milk, sewage treatment/water purification)
• Germ Theory of Disease (mid 1800s): idea that germs can invade other organisms and cause disease; not widely accepted, believed in abiogenesis (microoragnisms arise out of nonliving things/spontaneously) VS biogenesis (Redi = maggots, Pasteur = sterilizing liquid)
• Culturings vs isolating microbes (needed solid culture to isolate indivdiual w/ petri dishes/agar)
• Koch’s Postulates (late 1800s) – demonstrating that a disease is caused by a microorganism
• Era of Establishing Etiology/causation of Viral Diseases Begins (early 1800s) – immunological postulates formulated, viral agents of many diseases identified
• Era of Vector Control Begins (late 1800s) – public health strategies to address impact of disease (swamp drainage, insecticides, vaccines)
• Era of Vaccines Begins (late 1800s) – smallpox vaccination, development of first toxoid
• Global outbreaks (map)

Question 6

People in the history of public health microbiology

Answer 6

• Hippocrates: proposed disease was caused within patients or came from the environment
• Thucydides: observed survivors did not get re-infected
• Marcus Terentius Varro: things we cannot see can cause disease
• Van Leeuwenhoek: discovers microorganisms (bacteria, protozoans, fungi, algae) with small microscopes
• John Snow: birth of epidemiology (mapped cases of cholera in London)

Question 7

Transmission of disease

Answer 7

• animal to human (zoonotic)
• human to human (primarily occurs via respiratory droplets)