Introduction to Microbiology: Then and Now

Flashcards covering key concepts, pioneers, microbial diversity, microbiomes, methods, infectious disease challenges, and global health topics from the lecture notes.

What term refers to organisms that are microscopic or too small to be seen with the naked eye, including bacteria, archaea, fungi, algae, protozoa, and viruses?

Microorganisms (microbes).

Microorganisms account for over what percentage of biomass on Earth?

Over 50%.

What are two major ecological roles of aquatic microbes?

They produce oxygen (via marine plankton) and drive nutrient and mineral recycling.

Name two key ecological roles of terrestrial microbes.

Recycle carbon and other nutrients; Decomposers.

Name two food-related or industrial uses of microbes.

Fermentation for foods (yogurt, bread) and production of medicines/antibiotics.

What is the human microbiome?

Endogenous microbes—the collective microbial community associated with the human body.

What factors cause variation in the human microbiome among people?

Physiological differences, age, diet, and geographic location.

How are newborns colonized by microbes?

During the birthing process and through environmental contact.

What term describes microbes that are present temporarily in the human body?

Transient microbiota (transients).

Who published Micrographia in 1665 and what did it describe?

Robert Hooke; described the cork as made up of cells, opening the world of the cell.

Which scientist observed living organisms called 'animalcules' in lake water and expanded the microbial world?

Antoni van Leeuwenhoek.

What biogenesis concept did Pasteur validate in 1861?

Biogenesis — life arises from life.

What theory did Pasteur formulate in 1862?

Germ theory of disease.

What are Koch's four postulates?

1) Suspected microbe is associated with disease and present in all cases; 2) Microbe isolated in pure culture; 3) Pure culture inoculated into healthy, susceptible animals; 4) Same disease observed and microbe reisolated.

What solidifying agent did Fanny Hesse introduce to replace gelatin in 1882?

Agar.

Who developed the culture plate (Petri dish) in 1887?

Julius Petri.

Which diseases did Koch identify causative agents for?

Tuberculosis (1882) and cholera (1883).

What public health practice did Ignaz Semmelweis promote to reduce puerperal fever?

Handwashing with chlorine (chlorinated water).

Name the six major groups used to categorize the microbial world as listed.

Bacteriology, Virology, Mycology, Phycology, Protozoology, Parasitology.

What are the essential features common to all living things that microorganisms share?

Hereditary material; complex biochemical patterns; reproduction; response to stimuli; evolutionary adaptations.

What are the two domains of prokaryotes?

Bacteria and Archaea.

Name three roles of bacteria.

Pathogens, decomposers, and useful in the food industry (some photosynthesize).

Where do Archaea commonly live, and are any known to be pathogenic?

Extreme environments (hot springs, Dead Sea, acid mine drainage); none known to be pathogenic.

What do protists include and what are some clinically important pathogens?

Protozoa and single-celled algae; examples include malaria, sleeping sickness, Giardia.

How many fungal species have been described, and what is their ecological role?

About 125,000 described; many more exist; nonphotosynthetic decomposers; some produce antibiotics.

What are the basic features of viruses?

Not cells; contain DNA or RNA (not both); protein coat; must infect a host to replicate; only a fraction are human pathogens.

What is the global health concern summarized by infectious disease data (mortality, emergencies, outbreaks)?

Global mortality from infectious diseases (~15 million deaths annually); 16% of all deaths; WHO emergencies since 2010.

What drives antibiotic resistance in bacteria?

Mutations and acquisition of resistance genes; inappropriate use leading to superbugs; few new drugs.

What is the difference between emerging and reemerging diseases?

Emerging diseases arise for the first time in humans; reemerging diseases had been controlled but are resurfacing, often due to resistance or range expansion.

What is bioterrorism in the context of microbiology?

Intentional or threatened use of biological agents to cause fear or disease; agents include bacteria, viruses, and toxins; early detection and protection.

How might climate change affect the spread of infectious diseases?

Temperature and rainfall shifts can alter disease frequency and distribution; mosquito-borne diseases may expand; warming oceans can increase waterborne diseases.