Term
| The Five I's of Culturing Microbes |
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Definition
Inoculation
Incubation
Isolation
Inspection
Identification |
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Definition
| introduction of a sample into a sterile media |
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Definition
| provides conditions for optimal growth |
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Definition
| getting a pure culture of the microbe |
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Definition
| looking at colonies and microscopic characteristics |
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Definition
| testing samples to ID the microbe |
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Term
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Definition
Physical-Liquid,Semisolid,Solid
Chemical-Synthetic/Nonsynthetic
Function-General purpose, enriched, selective, differential, anaerobic growth, transport, assay, enumeration
Selective
Differential |
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Definition
| contains pure organic & inorganic compounds in an exact chemical formula |
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Term
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Definition
| contains at least one ingredient that is not chemically definable – organic extracts(blood agar) |
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Definition
| grows a broad range of microbes, usually non-synthetic |
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Definition
| contains complex organic substances such as blood, serum, hemoglobin or special growth factors required by fastidious microbes |
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Definition
| contains one or more agents that inhibit growth of some microbes and encourage growth of the desired microbes |
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Definition
| allows growth of several types of microbes and displays visible differences among desired and undesired microbes. |
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Term
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Definition
a thick, homogenous sheath of peptidoglycan 20-80 nm thick
tightly bound acidic polysaccharides, including teichoic acid and lipoteichoic acid & surface proteins.
inner cytoplasmic membrane
Retain crystal violet and stain PURPLE |
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Term
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Definition
an outer membrane is an a symmeteric bilayer in which the outer most layer is composed of lipopolysaccharide (LPS)
periplasmic space.
thin shell of peptidoglycan
Inner cytoplasmic membrane
Lose crystal violet and stain RED from safranin counter-stain |
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Term
| Structure of Peptidoglycan |
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Definition
long gylcan chains cross-linked by short peptide fragments
polymer of alternating N-acetyl glucosamine(G) & N-acetyl muramic acid (M) cross-linked by a short peptide bridge
Several types of antibiotics are effective because they target the peptide cross-links , thereby disrupting the integrity of the cell wall. Specifically penicillins and cephalosporins |
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Term
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Definition
Single, circular, double-stranded DNA molecule that contains all the genetic information required by a cell.
DNA is tightly coiled around a protein, aggregated in a dense area called the nucleoid. |
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Term
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Definition
Small circular, double-stranded DNA
Duplicated and passed on to offspring
Not essential to bacterial growth and metabolism.
May encode antibiotic resistance, tolerance to toxic metals, enzymes & toxins.
Used in genetic engineering- readily manipulated & transferred from cell to cell |
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Term
| Methods in bacterial identification |
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Definition
1.Macroscopic morphology – colony appearance
2.Microscopic morphology
3.Physiological / biochemical characteristics
4.Chemical analysis
5.Serological analysis
6.Genetic & molecular analysis
-G + C base composition
-DNA analysis using genetic probes
-Nucleic acid sequencing & rRNA analysis |
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Term
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Definition
Cocci - spherical
Bacilli - rod
Spiral - helical, comma, twisted rod, spirochete
Look at slide #25 |
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Term
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Definition
Fixation -> Crystal Violet -> Iodine Tx
-> Decolorization -> Counter Stain(Safarin)
Gram +ve = PURPLE
Gram -ve = RED |
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Term
| Unusual Forms of Bacteria |
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Definition
Obligate Intracellular Parasites
cannot survive or multiply outside of a host cell
cannot carry out metabolism on their own
ie-Rickettsias,Chlamydia
Bacteria without a Cell Wall
is Mycoplasma |
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Term
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Definition
Obligate intracellular parasites
Very tiny, gram-negative bacteria
Most are pathogens that alternate between mammals and fleas, lice or ticks |
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Term
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Definition
| Rocky Mountain Spotted Fever |
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Definition
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Definition
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Definition
Obligate intracellular parasites
Tiny bacteria – once considered a virus
Not transmitted by arthropods |
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Definition
| severe eye infection and one of the most common sexually transmitted diseases |
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Definition
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Definition
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Definition
Naturally lack a cell wall
Stabilized by sterols, resistant to lysis
Extremely small
Range in shape from filamentous to coccus or doughnut shaped |
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Definition
atypical pneumonia in humans.
Walking Pneumonia |
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Term
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Definition
100,000 species divided into 2 groups:
macroscopic fungi (mushrooms, puffballs, gill fungi)
microscopic fungi (molds, yeasts)
Majority are unicellular or colonial, a few have cellular specialization |
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Definition
Exist in 2 morphologies
Yeasts – round ovoid shape, asexual reproduction
Hyphae – long filamentous fungi or molds
Some exist in both forms – dimorphic – characteristic of pathogens |
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Definition
4 Main Divisions based on Spore Type:
Zygomycota
Ascomycota
Basidiomycota
Deuteromycota – no sexual spores |
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Term
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Definition
65,000 species
most are unicellular, colonies are rare
most have locomotor structures – flagella, cilia, or pseudopods
vary in shape
lack a cell wall & chloroplasts
can exist in 2 stages
Trophozoite – motile feeding stage
cyst – a dormant resistant stage |
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Term
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Definition
Based on locomotion & reproduction
Mastigophora – flagellates
Sarcodina – amebas
Ciliophora – ciliates
Apicomplexa – sporozoas
all parasites
motility not well developed; produce unique reproductive structures |
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Term
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Definition
About 50 species of helminths parasitize humans worldwide.
50 millions cases per year in North America alone.
Helminths are classified by size, shape, development of organs, presence of hooks, suckers, and the appearance of their eggs and larvae
Flatworms & Roundworm |
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Term
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Definition
flat, no definite body cavity; digestive tract a blind pouch; simple excretory & nervous systems
cestodes (tapeworms)
trematodes (flukes) |
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Term
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Definition
| round, a complete digestive tract; a protective surface cuticle; spines & hooks on mouth; excretory & nervous systems poorly developed |
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Term
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Definition
Unique group of tiny infectious particles that are obligate intracellular parasites.
Do not exhibit the characteristics of life, but can regulate the functions of host cells.
Infect all groups of living things and cause many diseases – serious medical impact.
Are genetic parasites that take over the host’s cells metabolism.
May persist in cells, leading to progressive diseases and cancer. |
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Term
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Definition
No taxa above Family (no kingdom, phylum, etc)
19 families of animal viruses
Six DNA families; 13 RNA families
Family name ends in -viridae, Herpesviridae
Genus name ends in -virus, Simplex virus
Herpes simplex virus I (HSV-I) |
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Term
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Definition
The virus particle is made up of only 2 components – the central core and the covering.
Central core – nucleic acid molecule (DNA or RNA) and matrix proteins (enzymes)
Covering – Capsid and some viruses have envelopes |
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Term
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Definition
All viruses have capsids - protein coats that enclose & protect their nucleic acid
Each capsid is constructed from identical subunits called capsomers made of proteins
2 types:
helical
Iscosahedral
Some viruses have an “envelope” around the capsid |
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Term
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Definition
Adsorption – attachment to cell surface receptors
Penetration/Uncoating of Genome – nucleic acid is released
Duplication/Synthesis – cell synthesizes the basic components of new viruses
Assembly – nucleocapsid and envelope are formed
Release – viruses bud off of the membrane; virion is ready to infect other cells |
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Term
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Definition
Cytopathic effects are virus-induced damage to host cells.
changes in size & shape
cytoplasmic inclusion bodies
nuclear inclusion bodies
cells fuse to form multinucleated cells
cell lysis
alter DNA
transform cells into cancerous cells |
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Term
| Other noncellular infectious agents |
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Definition
Prions - misfolded proteins, contain no nucleic acid
cause spongiform encephalopathies – holes in the brain
common in animals
bovine spongiform encephalopathies (BSE), aka mad cow disease
humans – Creutzfeldt-Jakob Disease
Viroids - short pieces of RNA, no protein coat
only been identified in plants, so far |
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Term
| Elements of Microbial Growth |
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Definition
Factors that effect microbial growth –
Nutrients
Temperature
pH and the presence of water
Atmospheric gases (O2 ,CO2 ,N 2)
Light
Atmospheric pressure |
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Term
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Definition
Lag Phase
Exponential Growth Phase
Stationary Phase
Death Phase |
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Term
| Antibiotics that affect gene expression |
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Definition
Rifamycin – binds to RNA polymerase
Actinomycin D – binds to DNA & halts mRNA chain elongation
Erythromycin & spectinomycin – interfere with attachment of mRNA to ribosomes
Chloramphenicol, linomycin & tetracycline – bind to ribosome and block elongation
Streptomycin – inhibits peptide initiation & elongation |
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Term
| Mutations Changes in the DNA |
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Definition
Point mutation – addition, deletion or substitution of a few bases
Mis-sense mutation – causes change in a single amino acid
Nonsense mutation – changes a normal codon into a stop codon
Silent mutation – alters a base but does not change the amino acid |
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Term
| Enzymes for dicing, splicing, & reversing nucleic acids |
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Definition
Restriction endonucleases – recognize specific sequences of DNA & break phosphodiester bonds
Ligase – rejoins phosphate-sugar bonds cut by endonucleases
Reverse transcriptase – makes a DNA copy of RNA - cDNA |
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Term
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Definition
Gel electrophoresis – separates DNA fragments based on size
Nucleic acid hybridization & probes – probes base pair with complementary sequences; used to detect specific sequences
DNA Sequencing – reading the sequence of nucleotides in a stretch of DNA
Polymerase Chain Reaction – way to amplify DNA |
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Term
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Definition
| – “flat” period of adjustment, enlargement; little growth |
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Term
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Definition
| a period of maximum growth will continue as long as cells have adequate nutrients & a favorable environment |
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Term
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Definition
| rate of cell growth equals rate of cell death cause by depleted nutrients & O2, excretion of organic acids & pollutants |
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Definition
| as limiting factors intensify, cells die exponentially in their own wastes |
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