Chapter 11- Prokaryotes (EXAM 2) Flashcards by Amreen Patel

Classification in Carl Woese’s Three Domain System

Dr. King Phillip Came Over From Great Spain

Domain, Kingdom, Phylym, Class, Order, Family, Genus, Species

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which of the three domains does not have kingdom?

bacteria and archae

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Bergey’s Manual of Systematics of Archaea and Bacteria

Since 2015 Bergey’s Manual of Systematics of Archaea
and Bacteria has been published and updated (4x/yr)
online. The past five years, over 100 genera and six
hundred new species have been added to the manual
each year.
The new edition replaces and expands upon the second
edition of Bergey’s Manual of Systematic Bacteriology, a 5-volume set completed in 2012.

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The (2nd) edition of Bergey’s Manual of Systematic

Bacteriology (2001-12) recognizes ____ phyla of Bacteria and ___ phyla of Archaea

24; 2

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_____ are based on rRNA sequences. Considerable phenotypic diversity remains among the members of some _____.

phyla; phyla

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Largest taxonomic group of bacteria containing
mostly chemoheterotrophic bacteria that are all
Gram-negative

Phylum Proteobacteria

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Named after Proteus, a greek god of the sea, who
could assume many shapes (a great diversity of
forms is found in this phylum)

Phylum Proteobacteria

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proteobacteria are said to have arisen from what common ancestor?

Proposed to have arisen from a common
photosynthetic ancestor, although few are now
photosynthetic.

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what are the five classes of proteobacteria?

alpha, beta, gamma, delta, & epsilon proteobacteria

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bacterium of the sea

pelagibacter (alphaproteobacteria)

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A single marine species, ___________ ( derived from “ubiquitous”) has been isolated
One of most abundant microbes on Earth. Accounts for ___% of ocean bacteria and combined weight > all the fish.
One of the smallest (___ µm diameter), simplest (_______ genes) autonomously replicating cells
- shortest ________ spaces, no duplicate gene copies, viral genes, or junk DNA
Survives in a _____ nutrient environment (minimal genome and small size provide it a competitive advantage) gains energy by respiring _______ _______ or using a light driven proton pump. (don’t fix C- inorganic)

P. ubique; 25; 0.3; 1354; intergenic; low; organic carbon (Pelagibacter- alphaproteobacteria)

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Why is a small cell size a competitive advantagous?

a higher surface area or volume allows the cell to move materials in and out more efficiently. A smaller cell has a higher surface are to volume ratio.

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Caulobacter and Hyphomicrobium are part of which phylum?

alphaproteobacteria

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found in low-nutrient aquatic environments (i.e. lakes),
produce prominent prostheca (cytoplasmic extrusion bounded by the cell wall [i.e. hypha or stalk.]) and have a dimorphic cycle

Caulobacter and Hyphomicrobium (alphaproteobacteria)

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produce stalks for anchoring to surfaces and
increasing surface-to-volume ratios (both facilitate nutrient uptake. Stalk sizes increase when nutrient concentrations drop.

Caulobacter (alphaproteobacteria)

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a type of alphaproteobacteria that replicates by binary fission

caulobacter (alphaproteobacteria)

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a type of alphaproteobacteria that replicate by budding at

hyphal tips

Hyphomicrobium (alphaproteobacteria)

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In the ______ life cycle, morphogenic events are an intrinsic part of the _________ cell cycle/

Caulobacter; Caulobacter

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is motile for part of its life, then the flagella is lost,

and a stalk is formed

caulobacter

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In Caulobacter, what happens after surface attachement?

Following surface attachment, reproduction can

occur, resulting in one stalked cell and one flagellated swarmer cell.

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Describe the Caulobacter life cycle

flagellated swarmer cell that can’t replicate
the flagellum is lost
stalk begins to form when the organism attached to a surface
stalk elongates
division begins, flagellul forms on new cell
new cell with flagellum swims off as swarmer cell, and the stalked cell initiates a new round of replication

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What does the life cycle of hyphomicrobium look like?

the hypha starts forms
new nucleoid moves into the hypha
a young bud forms
the bud develops
swarmer cell with subpolar to lateral flagellum made (1-3)
Now the hypha lengthens as low nutrient conditions increase and it produces another bud

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A ___________ cell adheres to surfaces via a polar holdfast opposite the hypha

hyphomicrobium

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forms hyphae-like, cytoplasm-filled prostheca with end bud

hyphomicrobium

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Of the alphaproteobacteria, which are nitrogen-fixing?

Rhizobium Azospirillum agrobacterium acetobacter and gluconobacter

- enter the roots of leguminous plants (beans, peas, clover) and form nodules • Fix N2 in a symbiotic relationship with the plant • cannot independently fix nitrogen

Rhizobium (+ 4 other genera, (i.e. Bradyrhizobium) • commonly called rhizobia (Alphaproteobacteria)

* A free-living, plant root surface colonizing soil bacterium commonly found on tropical grasses and sugar cane * use nutrients excreted by plants and fixes nitrogen in return

Azospirillum (alphaproteobacteria)

prefix Azo, means ________ ______. Thus, nitrogen became associated with term “Azo”, which is frequently used in the names of nitrogen-fixing genera

without life

plant pathogens | invade plant cells but do not induce nodules or fix nitrogen

agrobacterium (alphaproteobacteria)

induces crown gall disease in plants through the insertion of the Ti plasmid into the plants genome.

A. tumefaciens (Agrobacterium, alphaproteobacteria)

• called acetic acid bacteria • Industrially important aerobic organisms that oxidize ethanol to acetic acid (vinegar) • Thus, found in environments where ethanol is formed from the fermentation of sugars to ethanol

Acetobacter and Gluconobacter (alphaproteobacteria)

prefer ethanol as carbon | source, while Gluconobacter prefers sugar

acetobacter

Of the alphaproteobacteria, which are nitrifying bacteria?

Nitrobacter and Nitrosomonas

Chemoautotrophic

oxidize nitrogen for energy and fix CO2

which bacteria: NH4+ ---> NO2-

Nitrosomonas

which bacteria: NO2- ------> NO3-

Nitrobacter

What is nitrification?

the process in which bacteria in the soil use oxygen to change compounds of nitrogen in dead plant material into nitrates which plants can then absorb as food

Why is nitrate production important for the environment?

Nitrate production is critical for the environment and agriculture because they are more easily absorbed from the soil by plants than either nitrite or ammonium ions

a member of the Beta proteobacteria class

Nitrosomonas

Of the alphaproteobacteria's, which is a facultative intracellular parasite?

Bartonella | Brucella

``` bacillus that inhabits the interior of some cat red blood cells (cats are not sick) primary mode of transmission to humans is infected flea feces by a cat scratch, bite etc.: causes cat-scratch disease/fever (more common than lyme disease in the U.S.). ```

B. henselae

In Bartonella several members are _______ ________

human pathogens

What is a facultative intracellular parasite?

Facultative intracellular parasites are capable of living and reproducing either inside or outside cells.

What disease does Brucella cause?

causes Brucellosis

disease of ruminants that also affects humans

Brucellosis

how is brucellosis spread?

spreads to humans by ingestion of undercooked | meat or unpasteurized dairy products - species have different affinities for host mammals.

How is Brucella able to survive phagocytosis?

After phagocytosis by macrophages, able to survive in phagosomes by blocking lysosomal fusion.

What is an obligate intracellular parasite?

cannot reproduce outside their host cell, meaning that the parasite's reproduction is entirely reliant on intracellular resources.

Of the alphaproteobacteria's, which are obligate intracellular parasite?

Rickettsia, Ehrlichia

highly pleomorphic bacteria (rods or coccobacilli) - preferentially infect endothelial cells lining the small blood vessels by inducing phagocytosis. They escape the phagosome and enter the cytosol where they replicate

Rickettsia

transmitted to humans by insect and tick bites | - cause a number of diseases known as the spotted fever group

Rickettsia

lice---> Epidemic typhus

R. prowazekii

rat fleas ---> Endemic murine typhus

R. typhi

ticks -----> Rocky Mountain spotted fever

R. rickettsii

rickettsia-like bacteria - transmitted by ticks to humans

Ehrlichia

Disease caused by Ehrlichia

ehrlichiosis

How is Ehrlichia able to survive in phagosomes after phagocytosis by macrophages?

After phagocytosis by macrophages, able to survive in | phagosomes by blocking lysosomal fusion.

Of the alphaproteobacteria's which are endosymbionts?

Wolbachia

``` Although not human pathogens, they may be the most common infectious bacterial genus on earth (infecting over a million species) ```

Wolbachia

Wolbachia lives as an endosymbiont in the cells of what?

insects and other invertebrates

What percentage of insects are infected with Wolbachia?

20-75%

How is Wolbachia's relationship with its hosts complicated?

its interactions with its hosts | are often complex, and in some cases have evolved to symbiotic rather than parasitic

Why is Wolbachia interesting?

Much interest due to its ubiquitous distribution, many different evolutionary interactions, and potential for pest control

wolbachia is essential in which organism?

nematodes

pea aphids gain resistance to parasitic ________ | - harmless to aphids but kill ______ larvae

wasps

some pathogenic “_________” Wolbachia strains cause host cells to lyse or “_____”, eventually kills insect

popcorn; pop

Since __________ are only transferred from mother to offspring, some species alter host reproductive capabilities in different ways to increase its own transmission. What are the two mechanisms by which it accomplishes this?

Wolbachia; 1) males killed during larval development which increases the female to male ratio 2) infected males develop as females or infertile pseudo-females.

Where would Paelagibacter be placed in the alphaproteobacteria dichotomus key?

Echo slide 26

Chemoautotrophs and chemoheterotrophs that often use nutrients that diffuse away from the anaerobic decomposition of organic material (hydrogen gas, ammonia, methane). All are aerobic.

Betaproteobacteria

relatively large cell bodies that twist like a spiral - motile due to bipolar tufts of flagella - habitat is mainly fresh water

Genera Spirillum (Betaproteobacteria)

How long are spirillum?

60 microns

filamentous sheathed bacteria found in slow moving fresh water streams and sewage - the tube-like sheath protects the cells from drying and aids in surface attachment - Individual mature cells swarm out of the protective tube to colonize new sites

Genera Sphaerotilus (Betaproteobacteria)

Obligate aerobe betaproteobacteria

thiobacilus

Oxidize reduced sulfur for energy and fix CO2. Convert hydrogen sulfide (H2S) or elemental sulfur into sulfates (SO4^2-). Important in the sulfur cycle

thiobacilus

Which of the betaproteobacteria genera include pathogenic species?

burkholderia (B. cepacia, and b. pseudomallei), Bordetella, Neisseria

reclassified from Pseudomonas * rod-shaped bacteria found in soil * single flagella or tuft of flagella

Burkholderia (Betaproteobacteria)

can degrade >100 different organic molecules - problematic contaminant of hospital equipment and drugs (can even grow in disinfectant solutions) - opportunistic pathogen that infects the respiratory tract of cystic fibrosis patients (metabolizes respiratory secretions)

B. cepacia: (“cepia” is latin for onion) (Burkholderia)- Betaproteobacteria

the cause of a severe disease (melioidosis) that is endemic in SE Asia and N. Australia.

B. pseudomallei (Burkholderia) (Betaproteobacteria)

nonmotile rods/coccobacilli * adhere to cilia of bronchial epithelium * causitive agent of pertussis or whooping cough

• Bordetella: - B. pertussis Betaproteobacteria

- diplococci - Use fimbriae to attach to the mucous membranes of urethra in mammals

Neisseria; Betaproteobacteria

meningococcal meningitis

*N. meningitidis (Neisseria- Betaproteobacteria)

gonorrhoeae

N. gonorrhoeae (Neisseria- Betaproteobacteria)

The largest subgroup of Proteobacteria. Encompass a wide variety physiological types that live in diverse environments: soil, water, mammalian hosts

gammaproteobacteria

Gammaproteobacteria orders

- Pseudomonas - Legionellales - Vibrionales - Enterobacteriales - Pasteurellales

Genera in Order Pseudomonadales

Gammaproteobacteria: Generas in Order Pseudomonadales- - Pseudomonas - Acinetobacter - Moraxella - Azotobacter and Azomonas

Genera in Order Legionellales

Gammaproteobacteria: Generas in Order Legionellales- contains 2 aerobic families - Legionella - Coxiella

Genera in Order Vibrionales

Gammaproteobacteria: | Generas in Order Vibrio

Genera and Family in Order Enterobacteriales

Gammaproteobacteria: Generas in Order Enterobacteriales- - Escherichia - Salmonella - Shigella - Klebsiella - Serratia - Proteus - Yersinia - Enterobacter Family: Enterobacteriaceae

Genera in Order Pasteurellales

Gammaproteobacteria: Generas in Order Pasteurellales- - Pasteurella - Haemophilus

- Aerobic rods - Common in soil - Polar flagella (single or tufts) - Opportunistic pathogens * infect urinary tract, burns and wounds in a weakened host - Many can grow at refrigerator temperatures (food spoilage) - Have a large genetic capacity (≈yeast) for expression of a large amount of enzymes that catabolize a wide variety of substrates (beneficial for decomposing uncommon chemicals in the soil but problematic in hospitals) - generally antibiotic resistant: large genome codes for several efficient efflux pumps - many species excrete water soluble pigments - some species moved to Burkholderia based on rRNA studies

Pseudomonas

Name means “nonmotile rod”, but morphology species can be pleomorphic (rods to cocci) - aerobic and found naturally in soil and water

Acinetobacter

* opportunistic pathogen found in hospital settings * primarily respiratory pathogen, but also infects skin, soft tissues and wounds * concerns: - rapidly becomes resistant to antibiotics such that some strains are resistant to most available antibiotics. - difficult to eliminate once established in a hospital because it survives on artificial surfaces and resists desiccation

A. baumanii Acinetobacter Pseudomondales Gammaproteobacteria

aerobic coccobacilli of gammaproteobacteria

Moraxella

One of several bacteria that can cause conjunctivitis (pink eye): inflammation of the outermost layer of the eye and the inner surface of the eyelids

M. lacunata Moraxella Pseudomondales Gammaproteobacteria

large ovoid heavily capsulated bacteria | - free living soil bacteria that fix nitrogen (obtain energy from organic sources in the soil).

Azotobacter and Azomonas (monas= unicellular organism) Pseudomondales Gammaproteobacteria

Found in streams, warm-water pipes, HVAC cooling towers - Facultative intracellular parasites found in the environment either free-living or within amoeba. Found in pulmonary macrophages in humans.

Legionella

The amobea shelter ___________, protecting them from chemical disinfectants, drying and heat - Humans are accidental hosts by inhalation of water droplets

legionella

(first identified during | 1976 outbreak) (29 of 182 died)

L. pneumophilia: Legionnaires Disease (pneumonia) Legionella Legionellales Gammaproteobacteria

Originally grouped with rickettsia (obligate intracellular parasites) but NOT transmitted among humans by insect or tick bites - Wild & domestic animals are reservoirs for the rod-shaped organism. Transmitted to humans via inhalation of animalderived dusts and aerosols (urine, feces etc.) or contaminated milk - Causes flu-like pneumonia called Q fever (named Q for query when causitive agent was unknown) - highly resistant to environmental stresses such as heat and drying; perhaps due to an endospore-like body in the cell.

C. burnetti Coxiella Legionellales Gammaproteobacteria

facultatively anaerobic curved rods that are mostly | found in aquatic environments

Gammaproteobacteria Order Vibrionales Vibrio

* causes cholera, characterized by profuse, | watery diarrhea

vibrio cholerae Gammaproteobacteria Order Vibrionales Vibrio

* gastroenteritis from eating raw or undercooked shellfish

V. parahaemolyticus Gammaproteobacteria Order Vibrionales Vibrio

inhabit intestinal tracts of | humans and mammals

enterics

``` - enterics – facultatively anaerobic rods – Most ferment glucose and other sugars – if motile, have peritrichous flagella – Fimbriae to aid with adhesion – Sex pili for exchange of genetic material— frequently confer antibiotic resistance ```

Gammaproteobacteria • Order Enterobacteriales (only one family: Enterobacteriaceae)

* common inhabitant of human intestinal tract but not most abundant (0.1% of gut flora) * a great deal is known about its biochemistry and genetics * not usually pathogenic but can cause urinary infections and certain strains produce enterotoxins that cause traveler’s diarrhea or foodborne disease * presence in food or water indicates fecal contamination

Gammaproteobacteria Order Enterobacteriales • Escherichia - E. coli

all members are potentially pathogenic - common inhabitants of many animals, especially poultry and cattle - can contaminate food under unsanitary conditions

Gammaproteobacteria Order Enterobacteriales • Salmonella

What two species are recognized in the genus Salmonella?

* Salmonella enterica | * Salmonella bongori (“cold blooded” animal resident)

* Salmonella enterica * Salmonella bongori (“cold blooded” animal resident) • These 2 strains are subclassified into ______ serovars

2400

Most of these serovars (______) belong to ________ ______, and cause more than 99% of the diseases in humans

1531; Salmonella enterica

"Salmonella enterica serovar Typhimirium” is | generally written as what?

a species, S. typhimirium

causes typhoid fever (Salmonellosis is a less | severe gastrointestinal disease caused by other Salmonella)

S. typhoid

•Defined by the antigenic expression, O and H, that relate to variant lipopolysaccharides and flagella, respectively

Kauffmann-White Salmonella Serovar Reporting Scheme

________ formulas are used for unnamed Salmonella serotypes

antigenic

Salmonella (_______); ________ (O antigen) : (____antigen) : (_____ antigen)

species; serotype

Salmonella enterica serotype Typhimurium = Salmonella enterica serotype _____________

1, 4, 5, 12 : i : 1, 2 (slide 46)

What is the disease caused by Shigella, and how many species cause it?

all 4 species are responsible for shigellosis

although ___________ causes deadly epidemics, not prevalent in U.S - only found in humans (No other natural reservoirs have been proven)

S. dysenteria Gammaproteobacteria Order Enterobacteriales • Shigella

common in soil and water - many isolates can fix nitrogen - ___________ can cause a serious form of pneumonia

K. pneumoniae Klebsiella Gammaproteobacteria Order Enterobacteriales

__________ is the primary pathogenic species and is distinguished by production of a red pigment * causes hospital many urinary and respiratory infections. Likely because it is found in hospital solutions in hospitals that should be sterile (i.e. cathetors, saline solutions)

S. marcescens Gammaproteobacteria Order Enterobacteriales Serratia

Genus can become pathogenic if it enters the urinary tract or a wound. - Unique multicellular behavior: a ________ colony on agar exhibits a distinctive series of concentric rings due to swarming growth. 1) On the edge of the colony, “swarmer” cells with many flagella move outward 2) they then revert to normal, less motile cells, with few flagella, “swimming” state 3) new generations of swarmer cells periodically develop, and the process is repeated

Gammaproteobacteria Order Enterobacteriales • Proteus

What occurs to the cell to permit swarming?

20-40 fold increase in both cell length and flagella number

________ causes plague (black death of medieval Europe) (In a 5 yr. span in 1300’s, 35% of Europe’s population was killed) * Urban rats in some parts of the world and squirrels and prairie dogs in Southwest U.S. carry the bacteria. * fleas bites generally transmit bacteria from animals to humans - inhalation of respiratory droplets from infected animals or people can also lead to infection

Y. pestis Gammaproteobacteria Order Enterobacteriales • Yersinia

What are the two known species of Enterobacter that cause disease?

Two species are known to cause disease, E. cloacae (klōā’kē) | and E. aerogenes (ā-rä’jen-ēz).

Their presence in the intestinal tracts of animals results in their wide distribution in soil, water, and sewage. * both can both cause urinary and hospital acquired infections

Gammaproteobacteria Order Enterobacteriales Enterobacter E. cloacae E. aerogenes

pathogens of domestic animals - Best know species is ___________, which can be transmitted to humans via dog and cat bites. It presents as an infection that complicates the animal bite or injury. * an especially virulent strain is present in Komodo dragon saliva and is introduced into its more mobile prey by a bite (kills in several days)

P. multocida Gammaproteobacteria Order Pasteurellales • Pasteurella

- pathogens that inhabit the mucus membranes of the upper respiratory tract, mouth, vagina and intestinal tract - named for their blood requirement in culture media

Haemophilus Gammaproteobacteria Order Pasteurellales

hemo

blood

philus

liking

clinical labs use their requirements for ___ (heme from hemoglobin) and ___ (NAD+ or NADP+) factors to I.D

X; V

``` * mistakenly considered to be the cause of influenza until 1933 * Causative agent of meningitis, earaches, bronchitis, pneumonia and septic arthritis ```

H. influenzae Haemophilus Gammaproteobacteria Order Pasteurellales

causes the sexually transmitted | disease chancroid

H. ducreyi Haemophilus Gammaproteobacteria Order Pasteurellales

When is there H. influenza growth on a culture media plate?

only around disc | impregnated with both X and V factors

type of deltaproteobacteria that is anaerobic?

desulfovirbrio

types of deltaproteobacteria that is aerobic?

predator and gliding Predator: Bdellovibrio Gliding: Mycococcus

bdella

leech

``` attaches tightly to other gram-negative bacteria, penetrates the outer layer and enters the periplasm - It breaks down the host cell molecules, which it uses to elongate and form a filament. - filament fragments into several individual flagellated cells that are released by cell lysis ```

Deltaproteobacteria | • Genus Bdellovibrio

Would B. bacteriovirus attack S. aureus?

slide 57

Sulfur reducing bacteria that play a key role in the sulfur cycle • Use oxidized S (i.e. S0, SO4 2- ) instead of O2 as final electron acceptor and produce reduced H2S

Deltaproteobacteria | Members of the order Desulfovibrionales

``` * obligate anaerobes found in sediments and intestinal tracts of humans and animals * use organic compounds such as lactate, ethanol or fatty acids as electron donors * black color of many sediments/sludge is due to H2S reacting with iron to form insoluble FeS ```

Desulfovibrio (best studied genus) Deltaproteobacteria Members of the order Desulfovibrionales

Illustrate the most complex life cycle of bacteria (part predatory upon other bacteria)

Deltaproteobacteria | Order Myxococcales

myxo

nasal mucus

* vegetative cells move by gliding motility and leave a slime trail * obtain nutrition from bacteria they encounter and enzymatically lyse. * cooperative predation is accomplished by secretion of antibiotics and lytic compounds that immobilize and degrade prey organisms, thereby creating a public pool of nutrients

Myxococcus Deltaproteobacteria Order Myxococcales

Describe the life cycle of Order Myxococcales

1. Myxospores: Myxospores are resistant resting cells released from sporangioles upon favorable conditions 2. Germination: myxospores germinate and form gram-negative vegetabtive cells, which divide to reproduce 3. Vegetative growth cycle: vegetative myxobacteria are motile by gliding, forming visible slime trails 4. Aggregation: under low nutrient conditions, the vegetative cells swarm to central locations by quorum sensisng, forming and aggregation 5. Mounding: aggregations of cells heap up into a mound, an early fruiting body 6. Mounds of myxobacteria differentiate into a mature fruting body, which produces myxospores packed within sporangioles

How many cells are in a myxobacteria fruiting body?

About 100,000 cells

``` __________ are formed within a cell, whereas __________ are formed when the entire cell differentiates into a spore ```

endospores; myoxospores

Slender rods that are helical or curved. Are microaerophilic and motile by means of flagella

Epsilonproteobacteria

What are the two genera of Epsilonproteobacteria?

Campylobacter | Helicobacter

_______________ – Single polar flagella – ________ is a leading cause of foodborne gastroenteritis – ________ causes spontaneous abortion in domestic animals

Campylobacter C. jejuni C. fetus

``` __________________ Multiple flagella ________ is the most common cause of peptic ulcers (prior to 1982 not thought to have a microbial cause) and also a cause of Stomach cancer ```

Helicobacter; | H. pylori

Oxygenic Photosynthetic Bacteria (_________)

chlorophyll a

– Named for characteristic blue-green pigmentation and also called “blue-green algae” – Are bacteria— NOT eukaryotic algae, although they resemble them, use chlorophyll and share same ecological niches – believed to have generated most of the Earths atmospheric O2 millions of years ago (0.1%è10% when plants arrived)

Photosynthetic, Gram Negative Bacteria • Phylum Cyanobacteria Oxygenic Photosynthetic Bacteria (chlorophyll a)

What are the different types of morphology found in cyanobacteria?

Unicellular: divide by binary fission • Colonial: multiple fission (parent divides multiple times by mitosis, producing several nucleoids. Cytoplasm then separates creating multiple daughter cells at once) • Filamentous: fragmentation

Many filamentous cyanobacteria fix nitrogen in specialized cells called _________

heterocysts

Unicellular nonfilamentous Cyanobacterium (binary fission) held together by __________________

mucopolysacchariades

• Are generally anaerobic • grow at great aquatic depths and use bacteriochlorophyll (utilizes a portion of the light spectrum not intercepted by organisms at higher levels). • morphologically diverse (spiral, rods, cocci and budding forms)

Anoxygenic Photosynthetic Bacteria Nonproteobacteria, Gram Negative Bacteria

green nonsulfur bacteria

Phylum Chloroflexi

green sulfur bacteria

Phylum Chlorobi

purple nonsulfur bacteria

Phylum Proteobacteria (gamma)

purple sulfur bacteria

– Phylum Proteobacteria (alpha)

purple bacteria have various _________, which give them colors ranging between purple, red, brown, and orange

carotenoids

most green sulfur bacteria are green | but some have a ______ tint.

brown

Oxygenic photosynthesis

Cyanobacteria: 2H2O + CO2 light--------->(CH2O) + H2O + O2

Anoxygenic photosynthesis

Purple/ Green Sulfur Bacteria: 2H2S + CO2 light---------> (CH2O) + H2O + 2S0

Photoautotrophs that use organic compounds (acids and carbohydrates) for the photosynthetic reduction of CO2

Purple/Green NON-Sulfur Bacteria

How are gram positive bacteria classified?

Their G/C content in their genetic material

Which Phylum of gram positive bacteria has a low GC content?

Phylum Firmicutes

Which Phylum of gram positive bacteria has a high GC content?

Phylum Actinobacteria

Draw the dichotomous key for Firmicutes

slide 68

* common in soil * endospore forming * obligate anaerobes * rod shaped, often distended due to presence of endospores

Clostridium Firmicutes Order: Clostridiales

``` special resistant, dormant structure formed within a cell that protects a bacterium from adverse environmental conditions. Capable of withstanding extreme heat, lack of water, exposure to toxic chemicals ```

endospore

GI tract infections

Clostridium difficile Clostridium Firmicutes Order: Clostridiales

food poisoning

C. botulinum Clostridium Firmicutes Order: Clostridiales

tetanus

C. tetani Clostridium Firmicutes Order: Clostridiales

foodborne diarrhea

C. perfringens Clostridium Firmicutes Order: Clostridiales

lives symbiotically in the gut of a Red Sea surgeon fish (1985) - Considered too large to be a bacterium (visible by naked eye), it seems to break the known rules of size/diffusion limitation * Its cell wall contains many folds that increase surface area and the organism is literally bathed in undigested food * Doesn’t rely on diffusion to distribute nutrients because it synthesizes macromolecules where needed.

Epulopiscium Firmicutes Order: Clostridiales

Why was Epulopiscium initially classified as a protozoan, and then reclassified as bacterial?

``` * lack of membrane enclosed nucleus * structures resembling protozoan cilia were actually bacterial flagella * analysis of rRNA ```

How much larger in volume is Epulopiscium than E.coli?

``` E. coli (1 µm x 2 µm) Epulopiscium (80µm x 600 µm) 1 million times larger volume ```

__________ daughter cells grow within the mother cell | until they fill the cell and burst the cell wall

Epulopiscium

How many daughter cells are released from the mother cell in Epulopiscium?

1 to 7

How much larger is the Epulopiscium genome than the human cell?

25X

How many copies of its genome are found in Epulopiscium?

contains tens of thousands of copies of its genome | which may allow it to overcome diffusion constraints.

- Endospore–forming rods - obligate aerobes or facultative anaerobes - Common in soil and often forms chains in culture - several species produce antibiotics - only a few pathogenic to humans

Bacillus Firmicutes Order: Bacillales

``` - disease of cattle, sheep and horses that can be transmitted to humans (linked with bioterrorism) ```

Bacillus anthracis: Bacillus Firmicutes Order: Bacillales

- agriculturally important insect pathogen used as a pesticide

Bacillus thuringiensis: Bacillus Firmicutes Order: Bacillales

- associated with food poisoning, typically through infection of starchy foods (i.e. rice)

Bacillus cereus: Bacillus Firmicutes Order: Bacillales

What differentiates Bacillus anthracis, Bacillus thuringiensis, Bacillus cereus from each other?

These 3 species are considered to be variants of the same species differing only by virulence genes carried on plasmids easily transferred one to another

Typically arrange themselves in grape-like clusters § Considered part of our normal flora § Grow well in high osmotic pressure, low moisture conditions (nasal passages and on skin) § Facultative anaerobic, cocci bacteria

Staphylococcus

``` § Golden in color (may protect from antimicrobial effects of sunlight) § Produce many exotoxins that aid in pathogenicity (allow invasion or damage tissues) § Commonly infect surgical wounds § Develops drug resistance quickly § Infections differ by anatomic region: - Vaginal tract: toxic shock syndrome - GI tract: food poisoning - Respiratory tract: sinus infections ```

Staphylococcus aureus Staphylococcus Firmicutes Order: Bacillales

What are the genus found in Bacillales?

Bacillus and Staphylococcus

What are the Orders found in Phylum Firmicutes

Clostridiales Bacillales Lactobacillales Mycoplasmatales

What are the genus found in Lactobacillales?

Lactobacillus Streptococcus Enterococcus Listeria (named after Joseph Lister)

What are the genus found in Mycoplasmatales?

Mycoplasmas

- Generally aerotolerant anaerobes - In humans, can be found in oral cavity, vaginal and GI tracts - Commercially important in pickle, yogurt, sauerkraut and buttermilk production Most lack an electron-transport chain

Lactobacillus Order: Lactobacillales Firmicutes

Why is it bad that lactobacillus doesn't have an ETC?

inefficient metabolism; can’t utilize oxygen as e-acceptor | grow poorly compared to oxygen utilizing bacteria

Why is it beneficial that lactobacillus doesn't have an ETC?

they generate lactic acid from simple carbohydrates and the low pH inhibits the growth of competing organisms.

``` Spherical bacteria that typically grow in chains – responsible for more illnesses and greater number of diseases than any other genus – Express and secrete a number of substances that aid in its survival and pathogenicity • Proteins to kill phagocytic cells • Enzymes that help spread infection - digesting host connective tissues which may also cause tissue destruction - destroying fibrin, a component of blood clots ```

Streptococcus Order: Lactobacillales Firmicutes

classified based upon their colony | appearance on blood agar medium

Streptococci

express hemolysin that lyses red blood | cells, leaving a clear zone around the colony

Beta-hemolytic species

species partially degrade red blood cells (due to hydrogen peroxide production only in the presence of oxygen) and their colonies are surrounded by a distinctive greening

Alpha-hemolytic species

species do not affect red blood cells

Gamma (non-hemolytic) species

(Beta-hemolytic Group A Strep): causative agent of Scarlet | and Rheumatic Fever

S. pyogenes

Beta-hemolytic Group B Strep: neonatal sepsis

S. agalactiae

cause of pneumococcal pneumonia

S. pneumoniae (alpha hemolytic)

primary cause of dental caries

S. mutans (alpha hemolytic)

a non-Linnaenan term for a large group of normal | microbiotia streptococcal bacteria that are either α-hemolytic or nonhemolytic

viridans

``` Part of our normal intestinal flora that occasionally cause urinary tract infections and sepsis – Adapted to nutrient rich but low oxygen body regions - GI tract - oral cavity - vagina – Major cause of hospital-acquired infections because they persist on inanimate objects for long periods of time and have high resistance to most antibiotics ```

Enterococcus Order: Lactobacillales Firmicutes

________ and _______, are responsible for most | surgical wound and urinary tract infections

E. faecalis and E. faecium Enterococcus Order: Lactobacillales Firmicutes

usually the causative agent of listerosis, a serious infection caused by eating food contaminated with the bacteria. § one of the most virulent foodborne pathogens (20-30% of clinical infections result in death) - a 2011 Listerosis outbreak from contaminated cantaloupe sickened 147 people and killed 33 § Can survive within phagocytic cells and infection of pregnant women poses risk to developing fetus § Capable of growth at refrigeration temperatures

L. monocytogenes Listeria Order: Lactobacillales Firmicutes

Lack a cell wall; pleomorphic as a result named because they can produce filaments that resemble those associated with fungi Are very small (0.1 - 0.24 µm) and originally classified as viruses • May be the smallest, self-replicating, free-living life form • Analysis of their DNA suggests they were once closely related to other families but lost genes over time

• Mycoplasmas Order: Mycoplasmatales Firmicutes

is the most significant species of "mykes", causing a mild | pneumonia

M. pneumoniae • Mycoplasmas Order: Mycoplasmatales Firmicutes

mykes

fungus

plasma

formed

High G + C and Gram-positive

Actinobacteria

Genera found in the Phylum Actinobacteria

``` Nocardia Frankia Streptomyces Actinomyces Mycobacterium Corynebacterium Propionibacterium ```

How are genera classified in the Dichotomous key for Actinobacteria?

genera appear to radiate due to the number of branching filaments associated with them

Draw the dichotomous key for Actinobacteria

slide 82

Some are highly pleomorphic in morphology and others | grow only as extended, often branching filaments

actinobacteria

actinobacteria have high _____ content

The genera ___________ in actinobacteria is pleomorphic

Corynebacterium

Filamentous genera resemble fungi but are __________. Some, like fungi, carry external spores for reproduction and are common inhabitants of soil.

prokaryotes

Why is the filamentous design of some actinobacteria advantageous?

- organism can bridge a water-free gap to a new nutritional site - increased surface area for greater nutrient absorption

The genus __________ is one of the most common soil isolates. Strict aerobes. Produce a gaseous compound, _________, that gives soil its musty odor • Valuable because they produce most of our commercial antibiotics

Streptomyces; geosmin

Reproductive asexual spores (____________) form at the end of the coiled aerial filaments that can germinate into a new colony if released into proper conditions

conidiospores

not Gram positive Aerobic, non-spore forming rods _______= Fungus-like; so named because they occasionally exhibit filamentous growth - Cell wall is similar to gram negative bacteria but the outermost lipopolysaccharide layer of their cell wall is replaced by _______ acids, giving them a waxy, water resistant layer. This results in: * Acid-fast staining * blocked entry of antimicrobial compounds * resistance to environmental stressors like drying * reduced nutrient uptake and growth rate

MYCOBACTERIUM | myco; mycolic;

Important members of mycobacterium

M. tuberculosis and M. leprae, | causative agents of tuberculosis and leprosy, respectively

``` Facultative anaerobes, branched filaments that replicate by fragmentation • Common in soil and animal microbiota, present in the mouth and throat of humans • Causative agents of _____________, a tissue destroying disease affecting the head, neck or lungs ```

actinomycosis; Genus Actinomyces: actinobacteria

• Morphologically similar to ____________ and also replicate by fragmentation • Aerobic, acid-fast bacteria (not gram positive) • Common in soil

actinomyces; genus nocardia; actinobacteria

can causes a chronic pulmonary infection and is also the cause of mycetoma, a localized, infection affecting feet and hands

nocardia asteroides genus nocardia actinobacteria

coryne

club-shaped

Genus __________ pleomorphic, morphology often changes with age • ___________ is the causative agents of diphteria

Genus Corynebacterium: C. diphtheriae i Actinobacteria

Genus ______________ named for ability to form ________ acid • some species important in the formation of Swiss cheese • ________ are commonly found on human skin and implicated as the primary bacterial cause of acne

Genus Propionibacterium; propanoic acid; P. acnes Actinobacteria

Genus _____________: causes nitrogen-fixing nodules to form on alder tree roots

Frankia | Actinobacteria

``` Phylum _____________: • Gram negative, budding bacteria • Blur the definition of bacteria – Bacterial rRNA gene sequence - Some have organelles resembling those of eukaryotic cells ```

Planctomycetes

Genus _____________: | – Aquatic bacteria that produce stalks like ___________

Planctomyces; caulobacter | Phylum Planctomycetes

- May be a model for the origin of the eukaryotic nucleus - Double internal membrane around DNA, like a nuclear membrane

Gemmata obscuriglobus genus planctomyces phylum planctomycetes

What was an important recent research finding about Chylmadia?

Historically it was believed that all Chlamydiae species had a peptidoglycan-free cell wall, but recent work demonstrated a detectable presence of peptidoglycan (2014 Nature paper detects peptidoglycan in Chylmadia!)

Phylum ____________: Grow intracellularly (obligate) within a eukaryotic host (like Rickettsiae) • Gram negative cocci. • Direct Transmission: interpersonal contact or aerosols (not by ticks etc) • Lab cultivation is difficult; must cultivate in lab animals, cell culture or the yolk sac of embryonated chicken eggs

Phylum Chlamydiae

___________: different serovars are responsible for different diseases 1) _________ (leading cause of blindness in developing countries) Sexually transmitted diseases 2) _________ ________ (most common STD in U.S.) 3) lymphogranuloma venerum

``` Chlamydia trachomatis: trachoma nongonococcal urethritis Genera: Chlamydia Phylum: Chlamydiae ```

mild form of pneumonia

Chlamydophila pneumoniae Genus: Chlamydophila Phylum: Chlamydiae

Respiratory disease | Psittacosis

Chlamydophila psittaci Genus: Chlamydophila Phylum: Chlamydiae

Describe the life cycle of the chlamydias

slide 93

Phylum ______________: • Name is derived from their coiled morphology • Motile bacteria (rotating axial filaments) • Many Inhabit the human oral and vaginal cavities

Phylum Spirochaetes

Most important pathogenic genera/species of spirochetes

Borrelia burgdorferi Leptospira: Treponema pallidum:

causative agent of Lyme disease; transmission from ticks or lice to humans

Borrelia burgdorferi | Phylum Spirochaetes

____________, transmission from animals to humans | through contaminated water

Leptospira: Leptospirosis Phylum Spirochaetes

causative agent of Syphillis

Treponema pallidum | Phylum Spirochaetes

``` Motile bacteria; utilize two or more axial filaments (endoflagella) Allows the cell to rotate like a corkscrew, easily cutting through liquids ```

spirochetes

§ Gram-negative, rod-shaped, non-motile, non-endospore forming bacteria § Common inhabitants of the GI tract (most substantial portion) § Some species found in gingival crevice § Cause infections at surgical sites, puncture wounds and through perforated bowel

Phylum Bacteroidetes | Genus Bacteroides

Gram negative non-motile rods present in the mouth and | known for creating periodontal and tooth problems

Genus Prevotella | Phylum Bacteroidetes

What is a unique characteristic about Phylum bacteroidetes, what the genus that are found in it?

Includes several genera of anaerobic bacteria Genus Bacteroides Genus Prevotella

* Anaerobic phylum | * Often pleiomorphic but may be spindle-shaped

Phylum Fusobacteria

fuso

spindle

``` – Long, slender spindle-shaped rods, pointed at the ends – Are found in the mouth – May be involved in dental diseases ```

Genus Fusobacterium | Phylum Fusobacteria

More resistant to radiation than are endospores (survive a radiation exposure 1500x the dosage that would kill a human) – Resistance to is due to rapid repair of radiation damage, which also extends to chemical mutagens

Deinococcus radiodurans | Phylum Deinococcus-Thermus

– Hot spring in Yellowstone National Park | – Source of Taq polymerase

Thermus aquaticus | Phylum Deinococcus-Thermus

Types of species found in Phylum Deinococcus-Thermus

Deinococcus radiodurans | Thermus aquaticus

Domain ________ Placed into 5 physiological (3) or nutritional (2) groups _____________: often conventional morphology but can be unusual

archae; extremophiles

high temperatures; >80 degrees

thermophiles

survive in extremely low pH and often high | temps

acidophiles

thrive in high salt concs

halophiles

oxidize ammonia for energy

nitrifying

anaerobic bacteria that generate | methane gas by combining CO2 and H2

methanogens

PCR indicates up to _________ different types of bacteria in a 1 gram soil sample. (_______ named thus far in Bergey’s) • Many bacteria have not been identified because they haven’t been cultured – Need special nutrients – Are a part of complex food chains requiring the products of other bacteria • Culturing is necessary to understand their metabolism and ecological role

10000, 15975

Chapter 11- Prokaryotes (EXAM 2) Flashcards

(263 cards)