Introduction to bacteriology Flashcards
What are bacteria?
definition
Single cell organisms known as prokaryotes which have no chlorophyll and multiply by simple division
How many genes do bacteria have approximately?
between 2000-6000
What is the size range of bacteria?
0.1-0.2um to >50um
What is the average size of E.coli?
1x3 um
What are some bacteria that live in respiratory habitats?
Mycobacterium, Haemophilus
What are some bacteria that live in intestinal habitats?
Salmonella, E.Coli, Yersinia
What are some bacteria that live on the skin?
staphylococcus aureus
What are some bacteria that are systemic?
Streptococcus suis, Salmonella
What are some examples of bacteria in agriculture?
Nitrogen fixation
Nutrient cycling
Animal husbandry
What are some examples of using bacteria for Energy/ The Environment?
Biofuels (methane)
Bioremediation
Microbial Mining
What are some examples of using bacteria for disease?
Identifying new diseases
Treatment
Prophylaxis
What are some examples of using bacteria for food?
Food preservation
Fermented foods
Food additives
What are some examples of using bacteria for biotechnology?
Genetically modified organisms
Production of pharmaceuticals
Gene therapy for diseases
What are some types of bacteria?
Gram +/-
Rod, Cocci, Comma, Spiral, Filamentous
Aerobic, Anaerobic, Microaerophiic
Commensal, Pathogenic
What are some identifiers of Gram Positive bacteria?
Thicker Cell Wall
Lacking Cell envelope
Teichoic acid
What are some identifiers of Gram Negative bacteria?
Thin Cell Wall
Cell Envelope
Do not have Teichoic acid
What two bacteria are exceptions to the gram positive/ negative rule?
Mycobacteria- are gram positive but do not stain well
Spirochaetes- Gram negative but do not stain well
What are some key points of Mycoplasma?
- Very small bacteria that lack a cell wall
- Many antibiotics are ineffective against them
- Causes disease in humans and animals
*arthritis, abortion, pneumonia, infertility, meningitis, mastitis *
What are spores?
“mummified bacteria” that can be dormant for a long time
Why do birds have fewer bacteria than other animals?
Their body temperature is around 42 degrees which prevents bacteria from growing
What is the approx doubling time for E.Coli?
20 minutes
What is the approx doubling time for Mycobacterium tuberculosis?
20 hours
What is the process that bacteria use to duplicate themselves?
Binary Fission
What is needed to culture bacteria in a laboratory?
- Nutrients (broth/agar plate)
- Warmth (28-42 degrees)
- Oxygen or lack of oxygen
- Selective media (use of antibiotics or additives to remove unwanted bacteria
What are some factors that influence infection?
- Diversity, pathogenic determinants, Genetic exchange
- Survival, Amplification, Transmission routes, Interventions
- Susceptability, Dose response, Latency, Immunity
What is the definition of an infectious disease?
A disease caused by a microorganism and therefore potentially transferable to new individuals
What is the definition of a contagious disease?
A disease capable of spreading rapidly from one individual to another by contact or close proximity
What is the definition of a communicable disease?
an infectious disease that is contagious and which can be transmitted from one source to another
What is a non-contagious infectious disease?
An infectious disease that is not transmitted by direct contact or exposure to a contaminated environment
What is a primary pathogen?
Can cause a disease in a healthy host, e.g Bovine TB, Salmonella, Anthrax
What is horizontal route of transmission
When there is transmission between the same or a different generation
What is the vertical route of transmission?
When transmission is through a different generation
What are some examples of indirect transmission
Contaminated food/ water, air borne, vectors, environment, contaminated equipment
What is the definition of one health?
Recognises the interrelationship between animal, human and environmental health
What is the definition of an infectious disease?
A disease caused by a microorganism and therefore potentially
transferable to new individuals. May or may not be communicable/contagious.
What is the definition of a contagious disease?
A disease capable of spreading rapidly from one individual to another
by contact or close proximity – Parvo, MRSA.
What is the definition of a communicable disease?
An infectious disease that is contagious and which can be
transmitted from one source to another (same as contagious, but used more in human
medicine).
What is a definition of a non-contagious infectious disease
An infectious disease that is not transmitted by direct
contact or exposure to contaminated environment – Blue tongue, Malaria, Lyme disease.
What is the definition of a primary pathogen?
Can cause a disease in a healthy host. E.g.
Bovine TB, Salmonella, Anthrax.
What is the difference between a primary and opportunistic pathogen?
opportunistic pathogens can only cause disease in already susceptible/ immunocompromised pathogens
What is the definition of an opportunistic pathogen?
Cause disease in the presence of or
following a predisposing factor – e.g. Avian colibacillosis.
