Module 2: Fundamentals of Microbiology Flashcards
Binomial Naming System
- Scientific name
- in honour of the microbiologist who discovered the microorganism
- may designate a characteristic of the microbe, a location where it is found or a disease it causes
Scientific name
- genus species
- written underlined
- typed italicized
Where are Prokaryotic cells found?
bacteria
Where are Eukaryotic cells found?
animals, plants, fungi, and protozoa
Prokaryotic vs Eukaryotic
- Nucleus
Prokaryotic - no nuclear membrane or nucleoli
Eukaryotic - true nucleus, consisting of nuclear membrane and nucleoli
Prokaryotic vs Eukaryotic
- Membrane Enclosed Organelles
Prokaryotic - absent
Eukaryotic - present; examples include lysosomes, Golgi complex, endoplasmic reticulum, mitochondria, and chloroplasts
Prokaryotic vs Eukaryotic
- Cell Wall
Prokaryotic - usually present; chemically complex (typical bacterial cell wall includes peptidoglycan)
Eukaryotic - when present chemically simple (includes cellulose and chitin)
Essential Nutrients
CHONPS
- carbon
- hydrogen
- oxygen
- nitrogen
- phosphate
- sulfer
transported into the cell by passive or active transport
Environmental Factors - Temperature
most medically significant bacteria are mesophiles
Environmental Factors - Gases
- oxygen and carbon dioxide
- different oxygen requirments
- capnophiles grow best at higher CO2 concentrations
Environmental Factors - Oxygen Use
oxygen can be a powerful oxidizing agents that exists in many toxic forms
Aerobe
can use oxygen
Obligate Aerobe
cannot grow without oxygen
Microaerophile
don’t grow at atmospheric concentrations of oxygen, but require a small amount
Anaerobe
doesn’t require oxygen for growth
Facultative Anaerobe
doesn’t require oxygen, but will use if present
Obligate Anaerobe
will die in the presence of oxygen
Aerotolerant Anaerobe
don’t utilize oxygen, but can still grow to a limited extent in it’s presence
Environmental Factors - 7
- pH (most grow best at pH 6-8)
- osmotic pressure
- salinity
- atmospheric pressure
- other organisms
- temperature
- gases
Five I’s
Inoculate
Incubate
Isolate
Inspect
Identify
Inoculate
introduce a small amount of sample (inoculum) into a container of nutrient medium
5 kinds of media
- liquid, semi-solid, solid
- chemicals defined or complex
- enriched medium
- selective medium
- differential medium
Enriched Medium
contains complex organic substances: blood, hemoglobin, or special growth factors
Selective Media
- contains one or more agents that inhibit the growth of a certain microbe, but not others
- speed up isolation by suppressing the unwanted background organisms and favours the growth of desired ones
Differentail Media
- allow multiple types of organisms to grow, but are designed to display visible difference among their colonies
- variations come from the way the microbes react to chemicals in the media
Incubate
placed in a temperature-controlled chamber to encourage multiplication
Isolate
- turbid broth
- colonies on a plate
Inspect- 4 methods
- phenotypic
- genotypic
- immunologic
- antimicrobic sensitivity tests
Phenotypic Methods
based on what we can see
Genotypic Methods
analyze the genetic material (DNA or RNA)
Immunologic Methods
use antibodies to determine what is in sample
Antimicrobic Sensitivity Tests
test sensitivity to antibiotics
Identify
species level
