Lecture 1 Flashcards
What is the ratio of bacteria in your body and your cells?
~2:1
How many human cells are there?
~7 trillion humans cells
How many bacterial cells are there?
~14 Trillion
How many human and bacterial genes make up the microbiome in the body?
~30,000 human genes
~3,000,000 bacterial genes
What is meant by disease is the exception?
This means most interactions between the host and microbe do not result in a disease. Most bacteria are harmless, and some are essential for good health.
How many bacterial species are known to cause disease in humans?
~1350
What are the benefits of microbe-host interactions (3 points)
- Help us digest out food
- Produce vitamins essential for life
- Educate out immense system to keep the bad microbes out and protect us against environmental insult
What is microbe-host interaction
Ways in which microbes and their hosts communicate and interact with each other. These interactions can be beneficial, harmful, or neutral, and can occur in almost all organisms.
How can you tell if something is a bacterial disease?
The germ theory of infectious disease (1800)
Who created the germ theory of infectious disease (1800)?
Louis Pasteur and Friedrich Gustav Henle (1800s)
What is the foundational germ theory?
Koch’s Postulates (1884 & 1890)
What is Koch’s Postulates?
Served as a guideline to establish a causal relationship between microbe and disease.
What are the original postulates? (4 points)
- The microbe must be associated with symptoms of the disease and must be present at the site of infection.
- The microbe must be isolated from the lesions of the disease and grown as a pure culture.
- A pure culture of the micorbe, when inoculated into a susceptible host, must reproduce the disease in the experimental host
- The microbe must be reisolated in pure culture from the experimentally infected host.
What is a potential issue with the germ theory?
- If you cant culture bacteria, it cannot be inoculated into a host and won’t be able to reproduce in the experimental host.
How are bacterial pathogens shown in the news?
1) Natural disasters
2) Hospital infections
3) Tainted food
4) Animals
What is an example of natural disasters and bacterial pathogens in the news?
The Haitian cholera epidemic following the earthquakes in 2010 where ~700,000 were sick and nearly 9,000 died
What is an example of hospital infections and bacterial pathogens in the news?
- The spread of antibiotic resistant superbugs like methicillin-resistant Staphylococcus aureus (MRSA)
- Secondary infections as complications in COVID-19
What is an example of tainted food and bacterial pathogens in the news?
Listeria infections linked to plant-based refrigerated beverages - an example is silk almond milk (recalled due to harmful bacteria)
What is an example of animals and bacterial pathogens in the news?
There were links of salmonella infections being linked to pet geckos. Many kids were hospitalized.
Why is vegetation more prone to being contaminated?
This is because it is not cooked/boiled to kill any bacteria. The outbreak of E. coli infections in 2018 was linked to romaine lettuce.
People typically associate such outbreaks with chicken but no one eats raw chicken and cooks it therefore the harmful bacteria dies.
How many people are infected by TB (Tuberculosis)
- 1/3 of the ENTIRE human population has been infected. This is a new infection every second
- linked to 1 million deaths globally each year
Who is most susceptible to infectious disease?
Very small children who are younger than 1-2 years old. Many die from infectious disease as their immune system is too weak to handle it.
What is a pathogen?
An organism that ca cause disease (damage the host)
Many pathogens are opportunistic
What does the infectious disease trifecta include?
- Host
- Microbe
- Environment
