Exam 3

chemotherapy

use of drugs to treat a disease

antimicrobial drug

interfere with the grwoth of microbes within a host

antibiotic

A substance produced by a microbe that, in small amounts, inhibits another microbe

Selective toxicity

A drug that kills harmful microbes without damaging host cells

Alexander Fleming

discoverd penicillin

Howard Florey and Ernst Chain

first clinical trials of penicillin

Almost all antibiotic-producing microbes (T/F)

True

Broad spectrum

wide range of bacteria against which
drug is useful

Narrow spectrum

small range of microbes against which
drug is useful

Superinfection

1. killing normal microbiota (aka normal flora) along with pathogens,
leaving room for opportunistic pathogens to fluorish
2. killing drug-sensitive pathogen cells, but not killing drug-resistant
cells

Actions of Antimicrobials

inhibtion of cell wall synthesis
inhibtion of protien synthesis
inhibtion of nucleic acid replication and transcription
injury to plasma membrane
inhibition of sytheis of essential metabolites

β-lactams(Monobactams Cephalosporins), Glycopeptide antibiotics, Mycobacterium (sometimes)

cell wall synthsis inhibitor

Chloramphenicol, Aminoglycosides, Tetracyclines, Macrolides

protien synthesis inhibitor

Lipopeptides

Injury to cytoplasmic membrane

Rifamycin

Nucleic acid synthesis inhibitors

Quinolones and fluoroquinolones

Nucleic acid synthesis inhibitors

Sulfonamides

Inhibition of metabolism

Antifungal drugs common target

Ergosterol synthesis

Flucytosine

Inhibits protein synthesis (Funigi)

Antiviral drugs

Viruses hijack the cell’s machinery to replicate so, you cannot stop their replication without harming host cells!

viral thymidine kinase

Cells infected with virus have a it, which can
be tricked into producing false nucleotides.

“E-test”

Uses a strip with antibiotic gradient (epsilometer)
Helps to find the minimum inhibitory concentration

How does a bacterium become resistant to an antibiotic?

– Destroy drug enzymatically (e.g. β-lactamases)
– Prevent the drug from penetrating
– Alter drug’s target site (e.g. rRNA seqs)
– Eject drug from cell (efflux pumps)

Taxonomy

science of categorizing names

Systematics (aka phylogeny)

study of evolutionary history of organisms

Carolus Linnaeus

Proposed a formal system for naming microbes/Divided all organisms into Plantae and Animalia

Woese

proposed Domain system used today

difference in Eukaryotes and Prokaryotes (A,B,E)

binomial nomenclature

genus + specific epithet

Taxonomic hierarchy

Domain
Kingdom (not applicable for prokaryotes)
Phylum
Class
Order
Family
Genus
Species
Subspecies
Strain
Serovar (same species but different outside markers)
Pathovar (species but some isolets cause disease but others don't)
Sequivar (phenotype is the same, but phenotype is not)

Animalia

Multicellular; no cell walls; chemoheterotrophic

Plantae

Multicellular; cellulose cell walls; usually
photoautotrophic

Fungi

Chemoheterotrophic; unicellular or multicellular; cell
walls of chitin; develop from spores or hyphal fragments

Protista

A catchall kingdom for eukaryotic organisms that
do not fit other kingdoms

Viral species

population of viruses with similar
characteristics that occupies a particular ecological niche

Prokaryotic species

A population of cells with similar
characteristics

Eukaryotic species

A group of closely related organisms that
breed among themselves

ELISA

enzyme-linked immunosorbent assay

antibody shape

Y

antigen-antibody test

fast results, but only looks for one thing

Phylum Proteobacteria

Named for the Greek god Proteus
All are Gram-negative
Vast majority are chemoheterotrophic

Phylum Proteobacteria broken into 5 classes

– Alphaproteobacteria
– Betaproteobacteria
– Gammaproteobacteria
– Deltaproteobacteria
– Epsilonproteobacteria

Caulobacter (Alphaprotobacteria)

stalked and swarming

Hyphomicrobium (Alphaprotobacteria)

budding

Brucella, Erlichia and Rickettsia (Alphaprotobacteria)

intracellular

Rickettsia (Alphaprotobacteria)

arthropod-borne

Wolbachia (Betaproteobacteria)

live inside of insects and other animals

Burkholderia (Betaproteobacteria)

Nosocomial infections are common

Bordetella pertusis (Betaproteobacteria)

whooping cough

Neisseria (Betaproteobacteria)

common pathogens

Pseudomonas (Gammaproteobacteria)

just know its in the genus

Legionella (Gammaproteobacteria)

causes legionaire's disease

coxiella (Gammaproteobacteria)

endospore-like body

Vibrio (Gammaproteobacteria)

common pathogens

Enterobacteriales (Gammaproteobacteria)

many are pathogens

Escherichia (most are NOT pathogens)

Enterobacteriales

Salmonella

Enterobacteriales

Shigella

Enterobacteriales

Enterobacter

Enterobacteriales

klebsiella

Enterobacteriales

Serratia

Enterobacteriales

Proteus (swarming colonies)

Enterobacteriales

Yersinia (plague)

Enterobacteriales, praire dogs (southwest flare ups)

Erwinia

Enterobacteriales, plant pathogens

Pasteurella

Pasteurellales (Gammaproteobacteria)

Haemophilus

Pasteurellales (Gammaproteobacteria)

Myxococcus

sporangioles and myxospores (Deltaproteobacteria)

Campylobacter and Helicobacter

Epsilonproteobacteria

Cyanobacteria

OXYGENIC PHOTOSYNTHESIS

Chlorobi

ANOXYGENIC

Bacteriodes

bacteroidetes most common bacterium in human intestines

Fusobacterium

Fusobacteria (fusiform/spindle)

low G-C (30s)

Phylum Firmicutes

high G-C (70s)

Phylum Actinobacterium

clostridium

Clostirdiales, obligate anaerobes, endospore forming

Epulopiscium

Clostridiales HUGE bacterium

Firmicutes

Clostridiales, Bacilliales, Lactobaciallales, Mycoplasmatales

Bacillus

Bacillales, aerobes, endospores

Staphylococcus

Bacillales

Lactobacillus

aerotolerant anaerobes, Lactobacillales

Streptococcus

lactobacillales

alpha
beta
gamma

partial
complete
not at all

Mycoplasmatales

no cell wall, have sterols

Mycobacteriam

Acid fast (antinobacteria)

corynebacterium

club shaped cells (actinobacteria)

Streptomyces

produce lots of antibiotics (actinobacteria) smells like rain

Actinomyces

Arthric( filaments can break apart and disperse) (Actinobacteria)

Plantomycetes

gram -, gemmata (nucleus ish)

Chlamydiae

Direct human to human contact (elementary bodies= infect and Reticulate bodies= replicates and becomes elementary bodies)

Spirochaetes

Sheathed, and flagella that wrap around cell (axial filaments)

Treponema and Borrelia

Spirochaetes

Archea were ancesteral to Bacteria

NOOOOO

Archea are all extremophiles

NOOOOO

Archaea are hard to grow in lab

NOOOOO

Archaea are rare and pretty unimportant

NOOOOO

Hyperthermophiles

Grow at 80+ temps
oceans and hot springs

methanogens

turn CO2 into CH4
some humans

Halophiles

LOTS OF SALT
great salt lake and solar salt ponds

Virion

complete infectious viral particle

What is a virion composed of

Nucleic acid, capsid(protien coat composed of capsomeres)
some have envelope
some have spikes for attachment