Download bacteria and archae of interest

Bacteria and Archaea of Interest
I. Domain: Bacteria
A. Taxonomic Classification
1. Bacteria are classified according to
rRNA similarities
morphological similarities
biochemical similarities
DNA similarities
II. Phylum: Proteobacteria
-largest taxonomic group
-all are gram negative bacteria
-divided into five classes
A. Class: Alpha Proteobacteria
1. Rickettsia
a. non-motile obligate intracellular parasite
b. can be cocci ,bacilli or threadlike- highly pleiomorphic
c. many members belong to the spotted fever group of diseases
d. damage the permeability of capillaries
e. pathogens are transmitted by arthropod vectors
g. R. typhi- causes typhus and is transmitted by the rat flea vector
h. R. rickettsii- causes Rocky Mountain spotted fever, is the most
dangerous Rickettsia pathogen and transmitted by the ticks, Dermacentor
variabilis and Dermacentor andersoni
i. R. prowazekii- causes epidemic typhus is transmitted by the lice vector,
and is the closest known relative to mitochondria through genome
sequencing
Tick vectors for Rocky Mountain spotted fever- Dermacentor variabilis
and Dermacentor andersoni
American dog tick
Rocky Mountain wood tick
Genetic analysis indicates that the mitochondrial genome is most closely
related to Rickettsia
Mitochondrion
Rickettsia
Rickettsias are small encapsulated bacteria that are intracellular obligate
parasites
Damage to the permeability of capillaries is demonstrated with Rocky
Mountain spotted fever
Dr. Howard Taylor Ricketts
-when researching the characteristics of Rickettsias, Ricketts injected
himself with R. rickettsii in order to measure its effects
-later when studying the disease typhus, he ultimately died from
this disease
Dr. Stanislaus von Prowazek
-von Prowazek’s study of typhus led to his dead also
-R. prowazekii was named in his honor
2. Agrobacterium tumefaciens
a. plant pathogen that causes crown gall disease (plant cancer)
b. bacteria contains the Ti plasmid
c. Ti plasmid has a T (tumor) gene for inducing crown gall in plants
d. makes a protein called opines
Crown gall in tomato plant stems
Crown gall in the roots of a plant
A. tumefaciens invading plant cells
Ti plasmid with the T-DNA gene
- tumors are inserted by the conjugative transfer of a DNA segment
(T-DNA)
3. Azospirillum
a. grow in soil, using nutrients
excreted by plants
b. fix nitrogen for green plants
4. Rhizobium
a. fix nitrogen and form nodules in the
roots of plants
Rhizobium forming root nodules
4. Rhodopseudomonas palustris
a. purple non sulfur bacteria
b. can grow with or without oxygen; it can use light, inorganic
c. compounds, or organic compounds for energy; it can acquire carbon
from either carbon dioxide fixation or green plant-derived compounds;
and it also fixes nitrogen
B. Class: Beta Proteobacteria
1. Neisseria
N. meningitidis causes
a. meningococcal meningitis, is an inflammation of the meninges
b. approximately 2500 to 3500 cases of meningitis infection occur annually
in the United States
c. lipopolysaccharide (LPS) of the cell wall acts as a powerful endotoxin
N. gonorrhoeae
a. sexually transmitted disease that causes gonorrhoea
b. transmitted via sexual contact
c. sometimes called "the clap"
N. gonorrhoeae attacking human tissue
C. Class: Gamma Proteobacteria
-largest subgroup of Proteobacteria
-includes the bacteria (enterics) that inhabit the intestine
1. Psuedomonas aeruginosa
a. opportunistic microbe responsible for many nosocomial infections
b. causes septicemia, meningitis, infections of urinary system, burn
infections, and wound infections
c. genome contains many novel genes not found in other bacteria
d. produce enzymes digest pesticides, oil, soap residues, antiseptics
e. can reside in soap residues, cap liner adhesive and some antiseptics
f. show a great deal of resistance to antibiotics
g. secretes a blue water soluble pigment
h. spoils refrigerated foods
Psuedomonas aeruginosa and the characteristic blue, water soluble pigment
it producers
P. aeruginosa is an opportunistic pathogen
2. Moraxella
a. Moraxella lacunata
can cause conjunctivitis or pink eye
b. Moraxella catarrhalis
fastidious, nonmotile, diplococcus that can cause infections of the
respiratory system, middle ear, eye, central nervous system, and joints
3. Legionella pneumophili
a. sometimes called Legion Fever
b. the disease caused by Legionella is called legionellosis, a
pneumonia-like condition
c. first identified during a flu-like outbreak at a convention attended by
the Legionaires (USA war veterans) in Philadelphia on July 1977
d. 221 Legionaires were hospitalized and 34 died
e. finally isolated with buffered charcoal-yeast extract agar
f. colonizes cooling towers of conditioning systems and hot air lines in
buildings
Legionella pneumophili
4. Vibrio
a. V. cholerae causes cholera
b. transmission occurs primarily by drinking water or eating food that has
been contaminated by the feces of an infected person
c. the severity of the diarrhea and vomiting can lead to rapid dehydration
and electrolyte imbalance, and death in some cases
Individual suffering with V. cholerae
5. Yersinia pestis
a. discovered in 1894 by Alexandre Yersin
b. infection takes three main forms: pneumonic, septicemic and bubonic plague
c. high-mortality rates from all three forms- 30% to 60% lethality rate
d. without treatment, the bubonic plague kills about two thirds of infected
humans within 4 days.
e. bubonic plague is responsible for the death of 1/3 of the population of
Europe between 1347 and 1353 and is spread between rodents and fleas
Oriental rat flea, Xenopsylla cheopsis, the vector for bubonic plague
Yersinia pestis
Medieval scene of the bubonic plague
Enterobacteriales
 somewhere between 300 and 1000 different species of bacteria live in the
gut
 99% of the bacteria come from about 30 or 40 species
 facultative anaerobe inhabit intestine permanently by mutualism,
commensalism, or as pathogens
 all have fimbriae that helps them adhere to cell surface
 produce bacteriocins that cause the lysis of other bacteria
 coliforms are enterics that metabolize lactose, E. coli is a coliform bacteria
 coliforms are commonly used bacterial indicators of sanitary quality of
foods and water
 coliforms are abundant in the feces of warm-blooded animals, but can
also be found in the aquatic environment, in soil and on vegetation
 they are easy to culture and their presence is used to indicate that
pathogenic organisms of fecal origin may be present
7. Escherichia coli
a. one of the most common human intestinal symbiotic bacteria and
the most studied bacteria
b. its presence in food and water is an indicator of fecal
contamination
c. not usually pathogenic but can cause urinary infections
d. O157:H7 strain is a source of dangerous food poisoning
8. Salmonella
a. Daniel Salmon first to identify salmonella
b. all considered pathogenic
c. inhabits intestinal tract of poultry, cattle, and humans
d. all Salmonella species are classified as S. enterica
e. S. enterica is divided into 2400 serovars
f. S. typhi causes typhoid fever
g. S. typhimurium used by researchers in the Ames assay
Common foods harboring Salmoella
Mary Mallon- Carried the distinction of being the first “healthy carrier” of
Typhoid Fever discovered in the US
9. Shigella
a. causes bacillary dysentery
10. Klebsiella
a. K. pneumoniae
capsulated bacteria that causes pneumonia
11. Serratia
-produces an orange-red pigment called prodigiosin
-can cause urinary, respiratory, wound and eye infections
12. Proteus
-P. vulgaris are opportunistic microorganisms that can cause urinary and wound
infections
-peritrichous flagela make them highly motile bacteria
13. Enterobacter
a. E. cloacae
-sometimes associated with urinary tract and respiratory infections
14. Erwinia
D. Class: Delta Proteobacteria
1. Bdellovibrio
a. lives in the periplasmic space of gram negative bacteria and causes
lysis of host bacteria
E. Class: Epsilon Proteobacteria
1. Helicobacter pylori
a. identified in 1982 by Barry Marshall and Robin Warren, who found
that it was present in patients with chronic gastritis and gastric
ulcers
b. H. pylori weakens the protective mucous coating of the stomach and
duodenum, which allows acid to get through to the sensitive lining
beneath
c. both the acid and bacteria irritate the lining and cause a sore, or
ulcer
d. H. pylori is able to survive in stomach acid because it secretes enzymes
that neutralize the acid allowing it to make its way to the protective
mucous linings
Helicobacter pylori
III. Nonproteobacteria
1. Cyanobacteria (blue-green algae)
-photosynthetic oxygenic bacteria
a. Anabaena
-filamentous cyanobacteria
b. Gleocapsa
-colonial cyanobacteria
Oscillatoria and a cyanobacteria “mat”
Rise in oxygen amounts in the ocean over time
IV. Chlamydiae
1. Chlamydia
a. C.trachomatis
b. C. pneumoniae
V. Spirochaetes
-move by axial filaments
1. Borrelia burgdorferi causes Lyme disease
a. predominant in North America, but also exists in Europe, and is the agent
of Lyme disease
b. it is a vector borne disease transmitted by the deer tick
Familiar “bulls eye” characteristic of Lyme disease and the deer tick vector
2. Treponema pallidum
a. is a motile spirochete that causes syphilis
b. it is generally acquired by close sexual contact
Primary syphilis
Secondary syphilis
VI. Phylum: Firmicutes
-low guanine-cytosine ratio
-gram-positive
1. Clostridium
-Clostridia are anaerobic, spore-forming rods
-produce powerful exotoxins
a. C. tetani
-usually enters a host through a wound to the skin
-produces the exotoxin, tetanospasmin
-the genes that produce the toxins are encoded on a plasmid
-tetanospasmin is a neurotoxin that causes the clinical manifestations of
tetanus
b. C. botulinum
-tolerate very small traces of oxygen due to the enzyme superoxide
dimutase (SOD) which is an important antioxidant defense when exposed
to oxygen
-C. botulinum is normally harmless to humans, but it can become infected
by a virus and become dangerous
-the virus DNA gets integrated into the bacterial genome, causing
C. botulinum to produce the neurotoxin, botulinum, the most toxic
exotoxin known
Botox is produced from botulism
c. C. perfringens
-can cause food poisoning
-is the most common bacterial agent for gas gangrene
-gas gangrene is necrosis and putrefaction of tissues
-the toxin involved in gas gangrene is known as alpha toxin which inserts into
the plasma membrane of cells, producing gaps in the membrane that disrupt
normal cellular function
-gas production forms bubbles of gas in muscle (crepitus)
-after rapid and destructive local spread (which can take hours), systemic
spread of bacteria and bacterial toxins may result in death
Gas gangrene
d. C. difficile (C. diff)
-causes the most severe diarrhea when gut flora have been wiped out by
antibiotics (broad spectrum)
-can lead to pseudomembranous colitis, a severe inflammation of the colon
-relapses of C. difficile in up to 20% of cases
-transmitted from person to person by the fecal-oral
-once spores are ingested by a patient, they pass through the stomach and
germinate into vegetative cells in the colon upon exposure to bile acids,
and multiply
C. difficile
Pseudomembranous colitis
2. Mycoplasma
-Mycoplasma pneumoniae
-extremely small, pleimorphic bacteria
-atypical pneumonia
-0.1 – 0.24 um
3. Staphylococcus
-S. aureus
-can live at 60 degrees Celsius for one hour
-lives 10 to 46 degrees Celsius
-live in extreme pH environments
-facultative halophile
-very resistant to antibiotics
-31 species
-80,000 deaths per year in the US
-produce many enterotoxins
-produce biofilms
-can cause food poisoning
-commonly lives on the skin and mucous
membrane
Methicillin Resistant Staphylococcus aureus (MRSA)
 In simple terms it is a staph infection that has morphed over time
making it resistant to the most used antibiotics.
 Most people who contract MRSA do so in the hospital. This is because
people in the hospital have weak immune systems from being sick and
or they have open wounds which allow the bacteria to get in their body.
It is also a problem in other confined setting such as prisons, daycare
centers, nurseries and also in athletes who share locker rooms and gyms.
 MRSA is highly contagious and can cause severe health problems and
even death if not treated in time.
 MRSA is a type of bacteria that causes a variety of infections that belong
to the Staphylococcus family.
 Although the bacteria are resistant to most antibiotics it does respond to
vancomycin and some other antibiotics.
MRSA Infection
Osteomyelitis
Infective endocarditis
inflammation of the innermost surface of the heart
Toxic shock syndrome (TSS)
-is a very rare but potentially fatal illness caused by a bacterial toxin
-different toxins may cause toxic shock syndrome
-it is generally caused by Staphylococcus aureus bacteria and has
been associated with the use of tampons which has since been taken off
the market
-Streptococcus pyogenes can also cause this illness
Carbuncles and Furuncles
-carbuncles are large, contagious
abscesses with one or more
openings draining pus
-furuncles are boils on the skin that are
smaller
4. Streptococcus
-Rebecca Lancefield identified 17
different types of streptococci
(ABC….)
-S. pyogenes is a very dangerous
member of this group
Classification of Streptococcus by Rebecca Lancefield
 Group A - Streptococcus pyogenes
 Group B - Streptococcus agalactiae
 Group C - Streptococcus equisimilis, Streptococcus equi, Streptococcus
zooepidemicus, Streptococcus dysgalactiae
 Group D – Enterococci, Streptococcus bovis
 Group E - Streptococcus milleri and mutans
 Group F - Streptococcus anginosus
 Group G - Streptococcus canis and Streptococcus dysgalactiae
 Group H - Streptococcus sanguis
 Group L - Streptococcus dysgalactiae
 Group N - Lactococcus lactis
 Group R&S - Streptococcus suis
 other Streptococcus species are classified as non-Lancefield Streptococci
Streptococcus pyogenes and advanced flesh-eating disease
Impetigo
Strep throat
Scarlet fever
5. Bacillus
endospore producers
endospores in particular are highly resilient, surviving
extremes of temperature, low-nutrient environments, and
harsh chemical treatment over decades or centuries.
a. B. anthracis
capsulated
causes anthrax
B. subtilis
B. cereus
B. polymyxa
B. megaterium
6. Listeria monocytogenes
-commonly found in soil, streams, sewage, plants, and food
-listeriosis is a lethal food-borne infection (25% fatal)
-vegetables can become contaminated from the soil, and animals can also be
carriers. Listeria has been found in uncooked meats, uncooked vegetables,
unpasteurized milk, foods made from unpasteurized milk, and processed foods
-Listeria induces macrophage phagocytic uptake but escapes the destruction
by lysing the vacuole
VII. Phylum: Actinobacteria
-high guanine-cytosine ratio, gram
positive
1. Gardnerella vaginalis
-pleomorphic
-cause vaginitis
2. Mycobacterium
-M. tuberculosis
-acid fast bacteria that causes tuberculosis
-M. leprae
causes leprosy
M. leprae and leprosy
VIII. Microbial Diversity
A. Thiomargarita namibiensis - the largest bacteria (750 um)
B. Nanobes (nanobacteria)
-tiny filamentus structures first found in some rocks and sediments
-smallest form of life, 1/10th the size of the smallest known bacteria
-no conclusive evidence exists for whether these structures are, or are
not, living organisms, and their classification is controversial
-0.02 um in size
IX. Domain Archaea
A. Phylum: Crenarchaeota
1. Sulfolobolus
-hyperthermophiles
B. Phylum: Euryarchaeota
1. Methanobacterium
-methanogens
- inhabit the gut of humans and aid in the
digestion of food
2. Halobacterium
-extreme halophiles
Methanogens