Exam 1 Lecture 1 Flashcards
Robert Hooke
First to visualize “cells”
Antonie van Leeuwenhoek
First to visualize microbes
How far can we see with the unaided human eye?
40 micrometers (10^-6 m)
Which tools can we use to best visualize microbes?
light microscope, electron microscope, x-ray crystallography
Edward Jenner
reported cowpox vaccination against smallpox (one of the first successful vaccines)
Florence Nightingale
discovers that hygiene is the best way to prevent infection/illness
Louis Pasteur
pivotal in disproving spontaneous generation hypothesis, developed swan-necked flask experiment, shows microbes as causative agents of disease
Koch
formed Koch’s postulates to show microbes as causative agents of disease
Hans Christian Gram
developed gram stain, which is a key method to differentiate between gram-positive and gram-negative bacteria
Paul Ehrlich
discovered arsphenamine aka 606 or salvarsan, the first effective treatment for syphilis
Alexander Fleming
best known for discovering the world’s first broad antibiotic, penicillin
Ernst Chain and Howard Florey
successfully purified and concentrated penicillin, also played a role in increasing the production of penicillin
Gerhard Domagk
discovered sulfonamides as an effective treatment for bacterial infections
Avery, MacLeod, McCarty
discovered that DNA is the substance that leads to bacterial transformation - this was proved by injecting purified DNA from Streptococcus into harmless bacteria of a mouse. the bacteria became virulent
Watson, Crick, Rosalind Franklin
figured out the structure of DNA (helical)
Sanger
discovered protein sequencing and DNA sequencing
Rich Roberts
known for isolation of restriction enzymes, essential to cutting out specific regions of DNA
Herb Boyer, Stanley Cohen
made significant contributions to recombinant DNA technology
Kary Mullis
invented PCR, which is used to amplify a small sample of DNA
Next Gen Sequencing
developed in the 2000s, allows for rapid and cheap DNA/RNA sequencing
Cocci (coccus)
spherical
Bacilli (bacillus)
rod-shaped
Coccobacilli
intermediate between cocci and bacilli (short rods)
Fusiform (gram-neg)
spindle-like shape
Vibrio (gram-neg)
curved-rod shape
Spirilla (gram-neg)
corkscrew (spiral) shape, rigid, flagella on outside of cells, most are NOT pathogenic
Spirochetes (gram-neg)
corkscrew (spiral) shape, flexible, flagella is on the inside of cells in the periplasm, pathogenic (Lyme’s disease, syphilis)
What are the multi-cellular arrangements bacteria can take on?
diplococci, chains, clusters, tetrad, biofilms
What ribosomes do prokaryotes have?
70S
What does the 70S ribosome consist of?
5S, 16S, 23S rRNA sequences (16S critical to identify start codon!)
also over 50 proteins
Do prokaryotes contain sterols?
No - they contain hopanoids
What is significant about Mycoplasma?
They do not have a cell wall! Therefore do not contain structures that are common for GP and GN bacteria (ex: do not contain PG). They do, however, contain cytoplasmic membrane
Lipoteichoic acid
characteristic of Gram + bacteria, they are teichoic acids anchored to lipid membrane
Do all bacteria have capsule/slime layer?
No, it depends on the species of bacteria specifically within GP and GN
Do all bacteria have pili/flagella?
No, it depends on the species of bacteria specifically within GP and GN and if they have transformative/motility/adhesive properties
O-specific side chains of LPS are found in…
LPS of Gram negative bacteria
True or false: gram negative bacteria have outer membrane and inner membrane
True
What does Lipid A do?
It is endotoxin, and when cell is lysed, endotoxin is released and can overstimulate the immune response
What are functions of core polysaccharide of LPS?
- largely serve as disguise mechanisms to fool the immune system
- important for complement resistance
Bacterial structures provide 4 main things:
- staining differences
- triggers innate response
- triggers adaptive immune response
- targets for small molecules that we can antibiotics or antimicrobials
Framework for what is causing infection
Staining pattern, morphology, specimen site, patient history
True or false: we can use DNA sequences to identify bacteria
True - we can use this information to diagnose, come up with a treatment plan, administer the appropriate antibiotic to interrupt infection
How can we classify bacteria? (5 things)
- Taxonomy
- Phylogeny
- Phenotype
- Genotype
- Microbiome
Phenotype can tell us:
morphology, biochemical capabilities; fatty acid (membrane and by-products); mycolic acid analysis (found in the membrane of Mycobacteria)
