Microorganisms Flashcards
Examples of Viruses
- HIV
- bacteriophage T2
- adenovirus
- rabies virus
- influenza virus
Viruses
- acellular
- obligate intracellular parasite
- RNA or DNA
- presence or absent of lipid envelope
Prion
misfolded protein that perpetuates itself
Examples of Diseases Caused by Prions
- scrapie
- chronic wasting disease
- kuru
- Creutzfeldt-Jakob disease
- bovine spongiorm encephalopathy
Bacteria (Prokaryotes)
- self-replicating microorganism lacking a true nucleus
- most have rigid cell wall with peptidoglycan
Fungi
- eukaryotic
- cell wall of chitin (polymer of N-acetylglucosamine)
- grow as molds (cooler temps) and yeast (body temp)
Protozoa
unicellular eukaryotes with complex life cycles
4 Divisions of Pathogenic Protozoans
- Amoebae
- Flagellates
- Ciliates
- Sporozoa
Amoebae
cause diarrhea, dysentery
Flagellates
Giardia, Trichomonas
Ciliates
few cause human diseases
Sporozoa
- Plasmodium (malaria)
- Cryptosporidium (GI/diarrhea)
Helminths
- multicellular “worms”
- 3 classes: cestodes (tape worms), nematodes, trematodes (flukes)
Staphylococcus
- clusters of cocci
- G+
Neisseria
-pairs of cocci (diplococci)
Vibrio cholerae
- comma shaped
- contain 2 chromosomes
Bacteroides
-irregular rod shape
Mycoplasma
- lack peptidoglycan
- amorphous shapes
Bordetella pertussis
- fragment of peptidoglycan with toxic activity (tracheal cytotoxin/TCT)
- causes pertussis (whooping cough)
Hemophilus influenzae
- G-
- coccal-bacilli
Clostridium perfringens
- G+ rod
- old cultures stain variably
- gas gangrene, wound infections, food intoxication
- endospores
Streptococcus mutans
- cause of dental caries
- capsule
Bacillus anthracis
- G+ rod
- capsule made of polypeptides
- endospores
Streptococcus pneumoniae
-protective vaccine against it is composed of a polyvalent mixture of different antigenic types of pneumococcal capsules
Pattern Molecule that Elicits Immune Response
- peptidoglycan
- Lipid A
- Flagellin
- some pili
Borrelia burgdorferi
- bacterial genome is linear
- causes Lyme disease
- spirochete
Escherichia coli
-G- rod
Treponema pallidum
- spirochete
- causes syphilis
- axial filament (polar flagella encased within periplasm)
- corkscrew motion
Gonococcus
-can vary the immunogenicity of its pili
Endospores
- survival mechanism used by some bacteria
- heat-, drying-, and UV-resistant
- in 2 G+ spore-forming genera: Clostridium (ex: C. tetani, C. difficile), Bacillus (B. anthracis)