Quiz 1 (1/20) Flashcards
Microbiology is the study of…..
Bacteria, Archaea, Fungi, Algae, Protozoa, Helminths, Viruses, Prions
first person to describe “animalcules”
also created a tiny microscope
Anton von Leeuwenhoek
father of epidemiology
John Snow
formed the first germ theory
-discovered lactic acid in wine
-harmful pathogens can change (attenuation)
Louis Pasteur
made a competing germ theory
-grew bacteria in a pure culture
-didn’t believe in attenuation (bacteria changing)
Robert Koch
Koch’s 4 Postulates
1) the same bacteria are present in every case of the disease
2) bacteria get isolated from dead animal tissue
3) bacteria from the pure culture are inoculated into a healthy animal
4) the same bacteria must be then isolated from the newly infected animal
discovered Penicillium (accidentally) which led to the creation of penicillin
Alexander Flemming
Reasons drug resistant pathogens have developed
- overuse of antibiotics
- 80% of all antibiotics are used in animals
- growing range of mosquitos spreads mosquito borne disease
- warming ocean temps spread water borne disease
Three domains of Classification (based on DNA):
1) Bacteria
2) Archaea
3) Eukarya
Type of Phyla
-largest and most diverse species
-E coli, salmonella, enterica
Proteobacteria
Type of Phyla
-many gram positive species
-Bacillis anthracis, Clostridium difficile, Staphylococcus aureus, and Streptococcus pyogenes.
Firmicutes
Type of Phyla
-include Streptomyces, the genus that produces the antibiotic streptomycin, vancomycin, etc.
Actinobacteria
Type of Phyla
-extremely small mostly pathogenic
Chlamydiae
Type of Phyla
- live in the mouth, and water. Some cause STD’s like syphilis or systemic diseases like Lyme disease
Spirochaetes
Cell wall function:
maintain structure, prevent cell from bursting
gram positive cell wall features
-thick peptidoglycan layer
- penicillin can only destroy gram positive cells
gram negative cell wall features
- peptidoglycan between outer membrane and plasma membrane
-outer layer contains lipopolysaccharides (toxic to human on their own)
enzyme that links two or more amino acids in the cell wall
transpeptidase
external cell structure see mostly in gram positive cells that helps bacteria attach to surfaces and aids in conjugation.
Pili
external cell structure that acts like a motor on bacteria, rotating to propel the cells
Flagella
type of flagella that’s inside the cell. Seen in spirochete cells. Often allows cells to travel through mucus membranes
Endoflagella
sticky layer of polysaccharides and small proteins that forms an extracellular barrier between cells and the environment
the Glycocalyx
functions of the glycocalyx
protect the pathogen!
allow it to stick to surfaces
repel immune cells
formation of biofilms
organelle that is nucleus like, but is not encased by a membrane. Contains DNA in a single, double-stranded loop
Nucleiod
