Micro Test 1 : Chapter 4 Continue Prokaryotes Flashcards
Non-proteobacteria G- phototrophic bacteria
Not all gram negative fall into proteobacteria phylum
Important
Chlamydia (blindness)
Spirochetes
Cytophaga, fusobacterium, bacterioides
Plantomycetes
Phototrophic bacteria
Chlamydia
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
Spirochetes
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
Phototrophic bacteria
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
Phototrophic bacteria types sulfur
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
Cyanobacteria
Have a blue-green (cyan) color
Carry out oxygenic photosynthesis
Produce massive amounts of oxygen
Very adaptable; found in a wide variety of environments
Gram positive bacteria groups
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
Class Actinobacteria: The High G+C bacteria
Diverse morphologies, from long, thin, branching bacilli to coccobacillary form
Mycobacterium is a bacillus that has mycolic acid in its peptidoglycan
M. tuberculosis
Class actinobacteria high GC ; Gardenerella vaginalis
bacterial vaginosis, can cause complications in pregnancy
Class actinobacteria high GC ; Bifidobacterium
Probiotic
Class actinobacteria high GC ; Micrococcus
normal human skin flora
Class actinobacteria high GC ;
Nocardia
pneumonia and skin infection
Class actinobacteria high GC ; Propionibacterium acnes
associated with human cystic acne
Class actinobacteria high GC ; Streptomyces
huge genera of soil decomposers; useful as a source of many antibiotics
Low GC bacteria ; Class Clostridia
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)
Low G+C bacteria; Order Lactobacillales
Important members:
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
Streptococcus
Gram positive
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)
Class Bacilli
Gram positive
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
