Micro Test 1 : Chapter 4 Continue Prokaryotes

Question 1

Non-proteobacteria G- phototrophic bacteria

Answer 1

Not all gram negative fall into proteobacteria phylum

Important

Chlamydia (blindness)

Spirochetes

Cytophaga, fusobacterium, bacterioides

Plantomycetes

Phototrophic bacteria

Question 2

Chlamydia

Answer 2

Chlamydia is very similar to the alphaproteobacteria, but different enough to not correctly fall into that group

Obligate intracellular parasite

Highly resistant to immune system defenses

Forms spore like stricter called elementary bodies that enter epithelia cells of host

Germinate into reticulate bodies inside host cell and consume ATP

Most common and leading cause of infectious blindness and most common STD

Chlamydia trachomatis can cause a sexually transmitted disease that can affect fertility if untreated, and increase the incidence of ectopic pregnancy

It can also cause blindness (Trachoma) when it infects the ocular conjunctiva

Question 3

Spirochetes

Answer 3

Spirochetes are long, thin G- bacteria with a spiral-shaped body

Are motile via the axial filament, a flagella-like structure that lies between the inner and outer cell membrane

Clinically relevant spirochetes:

Treponema pallidum subspecies: Syphillis, bejel, yaws

Borrelia burgdorferi, B. recurrens, others: Lyme disease, relapsing fever

Leptospira interrogans: Leptospirosis

Question 4

Phototrophic bacteria

Answer 4

Group contains both proteobacteria and nonproteobacteria

ATP synthesis by sunlight

Oxygenic and nonoxygenic photosynthesis

• Sulfur and nonsulfur bacteria
• Have a variety of bacteriochlorophylls that absorb different wavelengths
• Nonoxygenic photosynthesis possible, unlike plants

Question 5

Phototrophic bacteria types sulfur

Answer 5

Sulfur bacteria: Use sulfites/sulfides as electron donors, release free elemental sulfur

• Purple sulfur bacteria: Uses sulfides. CO2 is only carbon source. Produces sulfur and sulfuric acid
• Green sulfur bacteria: Uses sulfides. Most use only CO2 as carbon source. Can fix N into methane

Purple / Green Nonsulfur bacteria: Use H2 as electron donor, release H+ into various molecules

Question 6

Cyanobacteria

Answer 6

Have a blue-green (cyan) color

Carry out oxygenic photosynthesis

Produce massive amounts of oxygen

Very adaptable; found in a wide variety of environments

Question 7

Gram positive bacteria groups

Answer 7

High G+C
- gram positive bacteria
- High G+C means more than 50% of the microbial genome is made up of G+C complementary base pairs

Low G+C
- gram positive bacteria
- Low G+C means less than 50% of the microbial genome is made up of G+C complementary base pairs

Question 8

Class Actinobacteria: The High G+C bacteria

Answer 8

Diverse morphologies, from long, thin, branching bacilli to coccobacillary form

Mycobacterium is a bacillus that has mycolic acid in its peptidoglycan
M. tuberculosis

Question 9

Class actinobacteria high GC ; Gardenerella vaginalis

Answer 9

bacterial vaginosis, can cause complications in pregnancy

Question 10

Class actinobacteria high GC ; Bifidobacterium

Answer 10

Probiotic

Question 11

Class actinobacteria high GC ; Micrococcus

Answer 11

normal human skin flora

Question 12

Class actinobacteria high GC ;
Nocardia

Answer 12

pneumonia and skin infection

Question 13

Class actinobacteria high GC ; Propionibacterium acnes

Answer 13

associated with human cystic acne

Question 14

Class actinobacteria high GC ; Streptomyces

Answer 14

huge genera of soil decomposers; useful as a source of many antibiotics

Question 15

Low GC bacteria ; Class Clostridia

Answer 15

A large A large class of anaerobic, spore forming bacteria
Genus Clostridium has four important pathogens:

Clostridium tetani – Tetanus (contractile paralysis)

Clostridium perfringens – gas gangrene, food poisoning

Clostridium difficile – nosocomial colitis

Clostridium botulinum – Botulism (flaccid paralysis, floppy baby syndrome)

Question 16

Low G+C bacteria; Order Lactobacillales
Important members:

Answer 16

Lactobacillus – probiotic, common in yogurt

Leuconostoc – probiotic, fermenter used in dairy products

Enterococcus – E. faecalis, E. faecium can cause a variety of infections, including UTI’s, bacteremia, and endocarditis

Streptococcus – causes a wide range of disease in humans

Question 17

Streptococcus
Gram positive

Answer 17

Classified by serotype and blood hemolysis capability

Streptococcus pyogenes

Bacterial pharyngitis (strep throat)

Skin infections (Impetigo, erisypelas)

Streptococcal toxic shock syndrome
Necrotizing fasciitis

Strep throat -> Scarlet fever -> rheumatic fever (heart, NS, joint damage, death)

Question 18

Class Bacilli
Gram positive

Answer 18

Genus Bacillus – facultative anaerobes, spore-formers, used in some biotechnology applications (antibiotic, enzyme, and detergent production, insect control)

Bacillus anthracis – Causes the disease zoonotic disease Anthrax (cutaneous infection, enterocolitis, pneumonia, brain damage)

Bacillus cereus – food poisoning. Preformed emetic toxin is not heat inactivated.

Genus Staphylococcus – facultative anaerobes, halophilic

Staphylococcus epidermidis – normal skin flora, but can be opportunistically pathogenic in hospital settings – UTI, surgical wound infection

Staphylococcus aureus – causes a wide variety of infection in humans
Skin: Boils, carbuncles, cellulitis, impetigo, Staphylococcal Scalded Skin Syndrome (SSSS)

Staphylococcal food poisoning: projectile vomiting

Toxic Shock Syndrome
Resistant to methicillin, some resistant to vancomycin