MBIO Exam #4

Alphaproteobacteria (General)

Grows in low nutrients; Important for nitrogen in agriculture (Nitrogen fixation).

Alphaproteobacteria (Species)

Rickettsia, Rhizobium, Agrobacterium tumefaciens, Caulobacter, Brucella, Bartonella.

Rickettsia rickettsii

Disease: Rocky Mountain Spotted Fever.

Agrobacterium tumefaciens

Disease: Causes Crown Gall in plants.

Bartonella henselae

Disease: Cat Scratch Disease.

Brucella / Brucellosis

Disease: Brucellosis (often from unpasteurized dairy).

Betaproteobacteria (General)

Often use methane, ammonia, or hydrogen gas; very similar to Alpha.

Betaproteobacteria (Species)

Neisseria, Bordetella, Burkholderia.

Neisseria species

N. meningitidis (Meningitis) and N. gonorrhoeae (Gonorrhea).

Bordetella pertussis

Disease: Whooping Cough.

Gammaproteobacteria (General)

Largest group of Proteobacteria; Includes the "Enterics" (Enterobacteriales).

Pseudomonas aeruginosa

Gammaproteobacteria; Causes UTIs, burn infections, and nosocomial infections.

Moraxella lacunata

Gammaproteobacteria; Disease: Conjunctivitis (pink eye).

Legionella pneumophilia

Gammaproteobacteria; Disease: Legionnaires' Disease (Legionellosis).

Coxiella burnetii

Gammaproteobacteria; Disease: Q Fever (Query Fever).

Vibrio cholerae

Gammaproteobacteria; Disease: Cholera.

Vibrio vulnificus / parahaemolyticus

Gastroenteritis from raw/undercooked shellfish; "Flesh-eating" bacteria.

Escherichia coli (E. coli)

Gammaproteobacteria; Common enteric; indicator of fecal contamination.

Salmonella species

S. enterica, S. bongori, S. typhimurium (Salmonellosis), S. typhi (Typhoid Fever).

Shigella flexneri

Gammaproteobacteria; Disease: Bacillary Dysentery.

Yersinia pestis

Gammaproteobacteria; Disease: Black Plague (transmitted by fleas).

Deltaproteobacteria

Characteristics: Attacks other bacteria (predatory) and important to the sulfur cycle.

Deltaproteobacteria (Species)

Bdellovibrio (predator), Desulfovibrionales (sulfur reducer).

Epsilonproteobacteria

Slender G- rods; vibrio or helical; microaerophilic; have flagella.

Campylobacter (C. jejuni / C. fetus)

Epsilonproteobacteria; Disease: Gastroenteritis and spontaneous abortion.

Helicobacter pylori

Epsilonproteobacteria; Disease: Stomach ulcers and stomach cancer.

Cyanobacteria

Nonproteobacteria G-; Blue-green; gliding motility; oxygenic photosynthesis (oxygen on Earth).

Purple and Green Photosynthetic Bacteria

Characteristics: Anoxygenic photosynthetic bacteria.

Firmicutes (Low G+C)

Gram-Positive; Examples: Clostridium, Bacillus, Staphylococcus, Streptococcus, Listeria.

Clostridium (tetani, botulinum, difficile)

Low G+C; Obligate anaerobes; endospore-forming; Tetanus, Botulism, C. diff.

Bacillus (anthracis, cereus)

Low G+C; Aerobic; endospore-forming; Anthrax, food poisoning.

Staphylococcus aureus

Low G+C; Gram-positive cocci; common cause of skin infections and food poisoning.

Listeria monocytogenes

Low G+C; Survives refrigeration; causes Listeriosis (dangerous in pregnancy).

Actinobacteria (High G+C)

Gram-Positive; Examples: Streptomyces, Mycobacterium, Mycoplasma.

Mycobacterium (tuberculosis, leprae)

High G+C; Acid-fast rods (mycolic acid); Tuberculosis and Leprosy.

Planctomycetes (Gemmata)

G- budding bacteria; aquatic; has a nucleus-like organelle; resembles Archaea cell wall.

Chlamydias

G- coccoid; no peptidoglycan; intracellular; Trachoma, Psittacosis, STDs.

Spirochetes

Spiral-shaped; move by axial filaments (endoflagella); Treponema (Syphilis), Borrelia (Lyme).

Bacteroidetes & Fusobacteria

Anaerobes; Bacteroidetes (intestines); Fusobacteria (mouth/periodontal disease).

Eukaryotic Kingdoms (Microscopic)

Fungi, Protista (Algae/Protozoa), Animalia (Helminths).

Yeast

Unicellular fungi; oval; non-filamentous; reproduce by budding.

Hyphae / Mycelium

Hyphae: fungal filaments. Mycelium: a mass/mat of hyphae.

Septate vs. Coenocytic Hyphae

Septate: have cross-walls (septa). Coenocytic: no septa; long continuous cells.

Fungal Dimorphism

Ability to grow in two forms (Yeast at 37°C, Mold at 25°C).

Plasmogamy (Fungal Sexual Cycle)

Haploid donor (+) nucleus penetrates cytoplasm of recipient (-) cell.

Karyogamy (Fungal Sexual Cycle)

The (+) and (-) nuclei fuse to form a diploid zygote nucleus.

Meiosis (Fungal Sexual Cycle)

Diploid nucleus produces haploid nuclei (sexual spores).

Zygomycota

"Bread mold" (Rhizopus); Coenocytic hyphae; Sexual: Zygospore; Asexual: Sporangiospore.

Ascomycota

"Sac fungi"; Septate hyphae; Sexual: Ascospore; Asexual: Conidiospore.

Basidiomycota

"Club fungi"; Septate hyphae; Sexual: Basidiospore; Asexual: Conidiospore.

Microsporidia

No mitochondria; obligate intracellular parasites; cause chronic diarrhea in AIDS patients.

Mycosis Classifications

Systemic (deep), Subcutaneous (under skin), Superficial (hair/surface), Opportunistic.

Histoplasma capsulatum

Fungal disease: Primary pulmonary infection (lung).

Candida albicans

Fungal disease: Yeast infection; part of normal flora; opportunistic.

Pneumocystis carinii

Unicellular fungus; causes pneumonia in AIDS patients.

Trichophyton spp.

Fungal disease: Tinea (Ringworm, Athlete's foot, Jock itch).

Lichen

Mutualism: Alga/Cyanobacterium + Fungus; Types: Crustose, Foliose, Fruticose.

Algae General Traits

Produce 80% of Earth's oxygen; mostly photoautotrophs.

Brown Algae (Phaeophyta)

Multicellular; produce Algin (thickener).

Red Algae (Rhodophyta)

Harvested for Agar and Carrageenan.

Diatoms

Silica cell walls; produce Domoic Acid (toxin in mussels/shellfish).

Dinoflagellates

Cause "Red Tides" (Gambierdiscus); cause Ciguatera disease from eating fish.

Protozoa: Trophozoite vs. Cyst

Trophozoite: Active feeding stage. Cyst: Survival stage for adverse conditions.

Schizogony

Asexual reproduction in protozoa by multiple fission.

Diplomonads (Giardia)

No mitochondria; multiple flagella; causes Giardiasis (diarrhea).

Amebae (Entamoeba histolytica)

Move by pseudopods; cause Amoebic Dysentery.

Apicomplexa (Plasmodium)

Nonmotile; intracellular parasites; causes Malaria.

Euglenozoa (Trypanosoma)

Flagellated; T. brucei (Sleeping Sickness), T. cruzi (Chagas Disease).

Definitive Host

The host where the parasite reaches sexual maturity and reproduces sexually.

Intermediate Host

The host where the parasite develops but does not reach sexual maturity.

Vector

A carrier (like a flea or tick) that transmits a pathogen from one host to another.

Complex Life Cycle

A life cycle involving multiple stages and requiring two or more different hosts.

Taxonomy vs. Phylogeny

Taxonomy: Science of classifying organisms; Phylogeny: Study of evolutionary history.

Taxon

A category of organisms showing similarities (e.g., Species, Genus, Family).

Bacteria Domain

Prokaryote; Peptidoglycan cell walls; rRNA has a "loop" sequence; Antibiotics are effective.

Archaea Domain

Prokaryote; Pseudomurein cell walls; Antibiotics NOT effective; No rRNA loop.

Eukarya Domain

Eukaryote; Contains carbohydrates; Antibiotics NOT effective; No rRNA loop.

Culture vs. Clone vs. Strain

Culture: Grown in lab media; Clone: Population from a single cell; Strain: Genetically different cells within a clone.

Eukaryotic Species

A group of closely related organisms that breed among themselves.

Prokaryotic Species

A population of cells with similar characteristics.

Viral Species

Population of viruses with similar characteristics occupying a specific ecological niche (same host).

Prokaryote Classification Difficulties

Simple morphology, rapid horizontal gene transfer, and inability to culture >99% of species.

Major ID Methods (5)

1. Serology, 2. Biochemical testing, 3. Morphology, 4. Staining, 5. Genetics.

Classification vs. Identification

Classification: Placing organisms into groups of related species; Identification: Matching an unknown to known lists.

Bergey’s Manual (Determinative)

Provides identification schemes (morphology, staining, biochemical tests) for bacteria and archaea.

Antiserum

A blood-derived fluid containing specific antibodies used in serological testing.

Serology / Serological Testing

Identifying proteins (antigens) on cell surfaces by testing their reaction with specific antibodies.

DNA Fingerprinting

Using electrophoresis to analyze restriction enzyme digests of DNA.

PCR (Polymerase Chain Reaction)

A technique to quickly amplify small samples of DNA to quantities large enough for analysis.

Dichotomous Key

A series of statements with two choices that lead a user to the correct identification of an organism.

Helminths (General)

Multicellular animals; Parasitic worms; Kingdom: Animalia.

Platyhelminthes

Flatworms; Examples: Taenia solium (pork tapeworm) and Paragonimus spp. (lung fluke).

Nematoda

Roundworms; Examples: Enterobius vermicularis (pinworm) and Dirofilaria immitis (heartworm).

Taenia solium

Platyhelminthes; Disease: Pork tapeworm infection.

Paragonimus spp.

Platyhelminthes; Disease: Lung fluke.

Enterobius vermicularis

Nematoda; Disease: Pinworm.

Dirofilaria immitis

Nematoda; Disease: Heartworm; Spread by mosquitoes.