Unit 1 Lecture 1 Notes: Unseen Worlds — Microbes and You

Unit 1 Lecture 1 Notes: Unseen Worlds — Microbes and You

Learning Objectives (Page 2)

  • After attending the lecture and completing readings/videos, the student will:

    • Define terms from terminology list.

    • Explain the 7 Microbe Facts discussed.

    • Describe at least five ways microbes matter in the environment and to society (refer to Why Microbes Matter slides and assigned video).

    • List WHO Top 10 Threats to Global Health (2019) related to microbes.

    • Communicate how sustainability and global systems/problems relate to microbiology.

    • Identify 9 challenges facing microbiology today.

What is Microbiology? (Page 3)

  • Etymology: “Micro” + “Biology”

    • Literal: Study of small living things.

    • Scientific: Study of microbes (microorganisms and viruses).

  • Major groups covered in introductory microbiology:

    • Bacteria

    • Fungi (yeast and mold)

    • Viruses

    • Helminths

    • Protists (protozoa and algae)

How Small is Small? (Page 4)

  • Size relationships:

    • 1 mm = 1000 μm

    • 1 μm = 1 micron

    • Red blood cell width ≈ 6–8 μm6–8\,\mu\mathrm{m}

  • Source note: Foundations in Microbiology (Talaro & Talaro, 2001), Edition 4.

Microbes Are Everywhere in Nature (Page 5)

  • Microbes are abundant in nature and can be found:

    • In air, soil, water, vegetation, etc.

    • In or on things we rely on daily: food we eat, water we drink, air we breathe, surfaces we touch.

  • Visual cue: Microbes and their viruses are ubiquitous on Earth.

Scope of Microbiology (Page 6)

  • Sub-disciplines:

    • Bacteriology: study of bacteria

    • Mycology: study of yeasts and molds

    • Protozoology: study of protozoa

    • Phycology: study of algae

    • Parasitology: study of parasites (protozoa and helminths)

    • Virology: study of viruses

Microbes and You (Page 7)

  • Microbes are not only pathogens; only a minority cause disease.

  • Majority are harmless or helpful.

  • This section underscores a balanced view of the microbial world and its relationship to human health.

7 Microbe Facts (Page 8)

  • Core ideas about microbes (title suggests 7 facts, but the slide lists several key points):
    1) They are small – mostly.
    2) They are not simple.
    3) There are no good or bad microbes.
    4) Their only goal is to survive and reproduce.
    5) Although microbes are everywhere, no one kind of microbe is everywhere.
    6) Each microbe has a preferred environment.
    7) The importance of microbes can be underappreciated or oversold.

  • Additional points from the slide:

    • There are likely hundreds of millions of microbial species on the planet.

    • There are more and more microbes being discovered.

    • Microbes are critical to our past, present, and future.

  • Source note: Adapted from http://www.microbe.net/2014/12/31/11-things-everyone-needs-to-know-about-microbes/

Why Microbes Matter: Global Ecosystems (Page 9)

  • Most microbes are beneficial to the environment:

    • Photosynthesis by cyanobacteria generates approximately 50%50\% of Earth’s O2.

    • Many microbes are decomposers that recycle nutrients.

Why Microbes Matter: Agriculture (Page 10)

  • On the farm:

    • Essential in the gut of ruminant animals (e.g., cows) for digestion of grasses.

    • Nitrogen fixation for soil/plant health.

Why Microbes Matter: Food Production/Food Safety (Page 11)

  • Microbial roles in foods/meals:

    • Microbial fermentation processes.

    • Food and product additives, flavors, and aromas.

    • Examples: sausages, sauerkraut, beer.

Why Microbes Matter: Natural Resources In the Environment (Page 12)

  • Environmental applications:

    • Bioremediation (use of microorganisms to clean air, water, and soils).

    • Sewage treatment processes.

Why Microbes Matter: Industry (Page 13)

  • Pharmaceutical/Biotechnology implications:

    • Pharmaceutical products derived from manipulating bacteria (e.g., insulin, growth hormone).

    • Vaccine manufacture (e.g., Hepatitis B, cervical cancer).

Why Microbes Matter: Human Health (Page 14)

  • Human microbiota:

    • The human microbiota at 18 different locations; each person has a unique microbial community.

  • Pathogenicity stats:

    • Infectious agents < 1%1\% of bacteria are pathogenic for humans.

    • Infectious agents < 0.2%0.2\% of fungi are pathogenic for humans.

  • Microbes as therapy:

    • Probiotics

    • Vaccines

    • Gene therapy

Childhood Mortality & Infectious Disease (Page 15)

  • Global context:

    • Conditions related to neonatal mortality and infectious diseases account for most under-five deaths worldwide.

  • Estimated distribution (percentages shown on slide, listed in order):

    • Prematurity – 14%14\%

    • Lower respiratory infections (pneumonia) – 0.2%0.2\%

    • Birth asphyxia/trauma – 1%1\%

    • Malaria – 2%2\%

    • Diarrhoea – 2%2\%

    • Congenital anomalies – 3%3\%

    • Injuries – 3%3\%

    • Sepsis – 5%5\%

    • Tuberculosis – 8%8\%

    • Measles – 18%18\%

    • Meningitis/encephalitis – 9%9\%

    • HIV/AIDS – 9%9\%

    • Tetanus – 12%12\%

    • Other under-five deaths – 14%14\%

  • Source: UNICEF Child Mortality data (2023)

WHO: Top 10 Threats to Global Health (Page 16)

  • The 10 biggest threats (2019) as ranked by WHO:
    1) Air pollution and climate change
    2) Noncommunicable diseases
    3) Global influenza pandemic
    4) Fragile and vulnerable settings
    5) Antimicrobial resistance
    6) Ebola and other high-threat pathogens
    7) Weak primary healthcare
    8) Vaccine hesitancy
    9) Dengue fever
    10) HIV

Applied Microbiology (Page 17)

  • Subfields include:

    • Biotechnology: recombinant DNA technology or genetic engineering

    • Medical microbiology: study of pathogenic microbes and their role in illness

    • Pharmaceutical microbiology: microbes related to production of antibiotics, enzymes, vitamins, vaccines

    • Industrial microbiology: exploitation of microbes for industrial processes

    • Food microbiology: study of microbes causing food spoilage and foodborne illness

    • Agricultural microbiology: study of agriculturally relevant microorganisms

    • Plant microbiology and plant pathology

    • Soil microbiology

    • Environmental microbiology: study of microbes in natural environments; includes microbial ecology

    • Bioremediation: use of microorganisms to clean air, water, and soils

Microbes: Integral to One Health (Page 18)

  • One Health concept:

    • An integrated, unifying approach to sustainably balance and optimize the health of people, animals, and ecosystems.

    • Global collaborators include:

    • WHO, UN, FAO, OIE (global level)

    • At home collaborators include:

    • CDC, USDA, etc.

    • Emphasizes interconnected health across species and environments.

UN Sustainable Development Goals (2015–2030) (Page 19)

  • 17 goals aimed at addressing poverty, hunger, disease, illiteracy, environmental degradation, and gender discrimination.

  • Achieving these goals requires changes in global systems and is essential for sustainability.

  • Microbes impact many goals (directly or indirectly): 1, 2, 3, 6, 7, 8, 12, 13, 14, 15; with indirect relevance to 4, 5, 8, 9, 10, and 11.

Microbiology Today: Current/Future Challenges (Page 20)

  • Key challenges listed:

    • Food security

    • Access to clean water

    • Antibiotic stewardship

    • Antibiotic resistance

    • Climate change

    • Biodiversity loss

    • Emerging diseases/pandemics

    • Immunization/vaccine hesitancy

    • Bioterrorism

Terminology (Page 21)

  • Terms (as listed):

    • Microbiology

    • Micron

    • Bacteriology

    • Mycology

    • Protozoology

    • Phycology

    • Parasitology

    • Helminth

    • Virology

    • Pathogen

    • One Health

    • Bioremediation

    • Microbiota

    • Microbiome

    • Biotechnology

    • Medical microbiology

    • Pharmaceutical microbiology

    • Industrial microbiology

    • Food microbiology

    • Agricultural microbiology

    • Environmental microbiology

    • Sustainability

Summary and Connections

  • Microbiology is the study of small living things, spanning bacteria, fungi, viruses, helminths, and protists.

  • Size relations and measurement units help contextualize microbial scales (mm vs μm).

  • Microbes pervade environments and everyday life, yet their roles span from beneficial to pathogenic.

  • The field is diverse, with many sub-disciplines and applied areas (biotech, health, industry, environment).

  • The One Health framework emphasizes interdependence of human, animal, and environmental health.

  • Global health threats and development goals intersect with microbiology through infections, antimicrobial resistance, public health infrastructure, and sustainability.

  • Current challenges highlight the need for responsible stewardship, vaccine confidence, and resilience against emerging threats.

Key Formulas and Numerical References (selected)

  • Photosynthesis by cyanobacteria contributes about 50%50\% of Earth’s oxygen.

  • Size relationships: 1 mm=1000 μm1\ \text{mm} = 1000\ \mu\text{m}; 1 μm=1 micron1\ \mu\text{m} = 1\ \text{micron}.

  • Red blood cell width: 6∼8 μm6\sim 8\ \mu\text{m}.

  • Microbial species diversity: on the order of 108 to 10910^8\text{ to }10^9 microbial species on the planet.

  • Pathogen prevalence (as stated): infectious agents in humans among bacteria < 1%1\%; infectious agents in fungi < 0.2%0.2\%.

Notes for Exam Preparation

  • Be able to define each major sub-discipline and provide real-world examples (e.g., fermentation in food, nitrogen fixation in soil, antibiotics production, vaccines).

  • Explain the 7 Microbe Facts and how they influence our understanding of microbes (e.g., not all microbes are harmful; environment-specific prevalence).

  • List and describe the WHO Top 10 threats and discuss how antimicrobial resistance and vaccine hesitancy threaten public health.

  • Understand the One Health concept and give examples of how human, animal, and environmental health are interconnected.

  • Recall the UN SDGs related to health, environment, and poverty, and discuss how microbes influence several of these goals.

  • Be familiar with current/future challenges and potential microbiology solutions (e.g., bioremediation, vaccines, antibiotic stewardship).

Glossary (selected terms)

  • Microbiology: Science of microorganisms and their interactions with the environment and hosts.

  • Micron: Unit of length equal to one millionth of a meter (10^-6 m).

  • Bacteriology: Study of bacteria.

  • Mycology: Study of fungi (yeasts and molds).

  • Protozoology: Study of protozoa.

  • Phycology: Study of algae.

  • Parasitology: Study of parasites (protozoa and helminths).

  • Helminth: Parasitic worm (e.g., nematodes, cestodes, trematodes).

  • Virology: Study of viruses.

  • Pathogen: An organism that causes disease.

  • One Health: Integrated approach to health across humans, animals, and ecosystems.

  • Bioremediation: Use of microbes to clean contaminated environments.

  • Microbiota: Microbes living in a specific environment (e.g., human body).

  • Microbiome: Collective genomes of the microbiota in a site.

  • Biotechnology: Use of living systems to develop products.

  • Medical microbiology: Pathogenic microbes and disease.

  • Pharmaceutical/Industrial/Food/Agricultural/Environmental microbiology: Subfields focusing on microbes in manufacturing, health, agriculture, and ecosystems.

  • Sustainability: Meeting present needs without compromising the ability of future generations to meet theirs.