Lecture 1 Flashcards
Who made the first recorded observations of micro-organisms?
Antonie van Leeuwenhoek
What century was the first microscope invented?
16th century
How was spontaneous generation disproved for macro-organisms?
Demonstration that maggots will not arise from rotting meat, if covered by a muslin cloth so that flies can not access it.
What century was the spontaneous generation theory disproved for macro-organisms?
17th century
Describe Schwann’s experiment
He heat treated the meat broth in a flask, then kept the flame playing on the mouth of the flask. The meat broth did not spoil whilst the flames was alight.
What did many chemists argue about Schwann’s experiment?
That it did not disprove spontaneous generation as the flame killed vital elements required for spontaneous generation.
Describe pasteur’s experiment which disproved spontaneous generation.
Swan-necked flask in which the heat-treated meat broth would never spoil. If the flask was tilted the broth spoilt within a matter of days, the shape of the neck prevented airborne dust and micro-organisms reaching the liquid.
What are the 5 stages of scientific development?
Hypothesis Experiment Observation Interpretation Refinement
What are 3 of the symptoms of the bubonic plague?
Buboe
Capillary damage
Gangrene
What was Girolano Fracastro’s theory of infectious diseases?
He believed that disease could be passed from one object to another by seeds. This could be done by direct contact, indirect transmission or transmission at a distance
What animal did bassi notice a fungal infection?
Silk worms
What did Ignaz Semmelweiss implement to reduce childbed fever in Vienna?
He instituted mandatory hand washing in chlorine solution
Give 3 examples of milk-borne diseases, prevented by pasteurisation
TB
Brucellosis
Listeriosis
What did Lister introduce to hospitals?
That all surgical tools should be treated with carbolic acid
What was the first microorganism proved to cause human disease?
Bacillus anthracis
What did Robert Koch do?
Developed methods for growing pure cultures
Which 2 bacterias did Koch identify?
Tb and cholera
What are Koch’s postulates?
There are 5
Agent must be present in every case of the disease
The agent must be isolated and cultured in vitro
The disease must be reproduced when a pure culture is inoculated into a susceptible host
The agent must be recoverable from the experimentally-infected host
What are the three methods of growing pure cultures?
Micro-manipulation
Extinction dilution
Streaking out on a solid media
What does MacConkey agar contain?
Lactose and bile salts
What is a defined medium?
Inorganic salts plus organic carbon source and distilled water
What does a complex nutrient media contain?
Beef extract
Yeast extract
Hydrolysed milk proteins
What conditions do thermophiles like?
Heat
What conditions do Psychrophiles like?
Cold
What conditions do alkaliphiles like?
Alkaline
What conditions do acidiphiles like?
Acidic
What conditions do Halophiles like?
Salt loving
What conditions do aerobes need?
Oxygen
What environment do anaerobes need?
An oxygen feee atmosphere
What conditions do Piezophiles like?
High pressure
What conditions do xerophiles like?
Dry conditions
Where do heterotrophs get their carbon from?
Organic compounds
Where do autotrophs get their carbon from?
Carbon dioxide
Where do phototrophs get their energy from?
Light
Where what are the 4 phases of a microbial culture?
Lag phase
Exponential phase
Stationary phase
Death
What happens during the lag phase?
Preparation for active growth
What happens during the exponential growth phase?
Maximal metabolism and growth
What happens during the stationary phase of growth?
Nutrient depletion and accumulation of toxic compounds
How long does it typically take for a generation of bacteria to develop?
20minutes to 20hours
What are the methods of identifying microorganisms
Colony morphology Cell morphology Growth requirements Presence of metabolites Molecular composition Serology PCR
What is the best method of identification of microorganisms?
PCR
What is variolation?
The method first used to immunize and individual against small pox
