L. 19 Microbiology and One Health Flashcards
L.O
- Define the five major types of microbes (viruses, bacteria, fungi, protists, algae)
- Describe key inventions and ideas in microbiology:
- Microscopy
- Agar plates
- Spontaneous generation
- Germ theory
- Koch’s postulates
- Penicillin
- Discuss difference between normal flora & pathogens
- Explain the concept of ‘One Health’
- Describe one major problematic infectious disease
Different microorganisms
- Virus
- Bacteria
- Fungi
- Protists
- Algae
Viruses
- Smallest and simplest entities
- Acellular
- DNA/ RNA in protein shell
- Depend on host cell for replication and metabolism
- Small genome
Bacteria
- Unicellular
- Prokaryotic
- Smallest cellular organisms
- Binary fission
- Have own metabolism
Fungi
- Large complex cells, Eukaryotes
- Membrane bound nucleus
- Unicellular = Yeast
- Multicellular = Mushrooms
- Microscopic & macroscopic
Protists
- Eukaryotes
- “other” type of organism due to diversity
- Membrane bound nucleus
- Heterotrophs anf autotrophs
- Predatory = Protazoa
Algae
- Euk & prokaryotes
- Photosynthetic
- Complex cellular structures
History of cells
- Robert Hooke discovered in 1664
- 30x mag (~4x today)
- Came up with ‘cells’
History of bacteria and protists
- ‘Father of biology’ Antonie in 1684
- 300x (~40x today)
- First evidence of protists and bacteria everywhere
Louise Pastuer
Swan neck experiment with flask to allow air in but also keep free of organisms
Led to:
- Vaccines
- Fermentation
- Pasteurisation
Proved life does not come from non-life
- Disproved spontaneous generation in 1850s
Spontaneous Generation
- 1700s John Needham
- Lazzaru Spallanzani supported with repeated experiment with sealed lid. Creating an anaerobic environment.
Robert Koch
- Staining methods in microscopy
- Germ theory of disease
- Use of agar plates to isolate colonies.
Identified bacteria causing:
- Tuberculosis
- Cholera
- Anthrax
Germ theory of disease
- 1880s by Robert Koch
- Microbes are the cause of disease
- Koch Postulates went with Pastuers findings.
Kochs Postulates
4 Steps:
- An organism that causes disease must:
1. Be found in all cases of disease
2. be isolated from host in pure culture
3. Produce same disease in experimental infected host
4. Be re-isolated from experiment host
Penecillin
- 1928 by Alexander Fleming
- Accidentally found in agar plate that it was killing bacteria
Penecillin mass production
- 1935-19945 Howard Florey and Ernst Chain.
- First effective antibiotic that helped soldiers in WW2
Normal Flora
- Microbes that live in and on us
Microbiota:
- Specific site
- Specialised to cite
- Mostly bacteria
- Aquired at birth
Benefits of microbiota
- Primes immune system
- Nutritional benefits
- Compete with pathogens
Microbiota disadvantages
- Disease when in wrong location (eg. stephlococcus)
- Changed conditions result in incorrect functions of bacteria
Pathogens
- Disease causing microorganism
- Microbes can also have pathogens
Obligate = Always cause disease
Opportunistic = Certain conditions
Opportunistic pathogens
Cause disease in certain conditions
- Abnormally high cell numbers
- Wrong location
- Hosts health poor
- Antibiotic resistance
One Health
Consider animals, plants and envrionment when managing disease.
Zoonosis = animal cross infection
- Environmental origins
- Antimicrobes in agriculture
- Urbanisation
- Climate change
- etc
Mycobacterium Tuberculosis
Tuberculosis
- Caused by baterium
- Spreads from person to person by airborne droplets
- Infects lungs
- Respiratory disease
Tuberculosis difficulties
- Can be latent for years
- Symptoms are non-specific and hard to diagnose
- Approx 1/3 earth pop is infected
- Africa and SE asia high due to poor medical facilities
- Very good at drug resistance and antibiotics
