The Prokaryotes Domains Bacteria and Archaea Flashcards

Question

What occurs in the genera for Thiobacillus? What different forms of this genera are there? What important cycle is it important for?

Answer 1

Betaproteobacteria (class) -Thiobaciluus (acidi-, Halo- and Thermi- ) (beta and gamma) -Oxidized reduced sulfur for energy and fix Co2 (obligate anaerobes) -Convert hydrogen sulfide (H2S) or elemental sulfure ito sulfates (SO4^2-) -Important in the Sulfur cycle

Answer 2

Sulfur Cycle: process: 1. Burining of fossil fuels leads to production of SO2. 2. SO2 will be released and react with air to produce H2 SO3 3. microbial oxidation will also occur and SO2-^4 will be reduced to H2S through decomposition by microbes (dissimilatory) - H2S will then be converted to elemental oxygen (S^0) elemental oxygen can be converted back to organic sulfur and animals can consume this organic sulfur through their food -purple and green phototropic bacteria that gets energy from light (that is found in water) and will have source of electrons to make NADPH and fix CO2

Answer 3

Genera: Burkholderia, Bordetella and Neisseria

Answer 4

Betaproteobacteria (class) Burkholderia : reclassified from Pseudomonas *rod-shaped bacteria found in soil *single polar flagella or tuft of flagella - B. cepacia: ("cepia" is latin for ONION) -First discovered as the cause of onion skin rot, then as human pathogen -Problematic contaminant of hospital equipment and drugs (can degrade >100 different organic molecules and able to grown in disinfectant solutions) -Opportunistic pathogen that infects the respiratory tract of Cystic fibrosis patients (metabolizes respiratory secretions) - B. pseudomallei: *the cause of Severe disease (melioidosis)that is endemic in SE (south eastern) Asia and N. Australia

Answer 5

Betaproteobacteria (class) *Genera that include Pathogenic species* - Bordetella: - B. pertussis - nonmotile rods/coccobailli -adhere to cilia of bronchial epithelium -causative agent of pertussis/WHOOPING COUGH/100 day-cough -Neisseria -diplococci -Use fimbriae to attach to mucous membranes in mammals N. meningitides: meningococcal meningitis N. gonorrhoeae: gonorrhoeae.

Answer 6

Gammproteobacteria (class) characteristics: -The LARGEST Subgroup of Proteobacteria -Encompass a wide variety of physiological types that live in diverse environments: soil, water, mammalian hosts Orders covered: -Thiotrichales -Pseudomonadales -Vibrionales -Enterobacteriales -Pasteurellales

Answer 7

Order Thiotrichales -Thiomargarita namibiensis ("sulfur pearl of Nambia") -Largest known bacterium (100-300 um in diameter) -Found in seafloor sediments of coastal waters off Namibia -An interior membrane-bound vacuole filled with nitrate, occupies 98% of cell volume -Oxidizes H2S and used the stored nitrate as an Anaerobic electron acceptor. -Elemental sulfur accumulates in the cell when H2S is oxidized How does massive bacterium circumvent bacterial size limitations? A surface to cytoplasm ratios is Not that big? (REVIEW this question)

Answer 8

Sulfur granules scatter incident light, lending the cell the pearly lustre. Thiomargarita namibiensis is visible without additional magnification

Answer 9

Gammaproteobacteria (class) Order Pseudomonadales has genera: Pseudomonas, Acinetobacter, Moraxella, Azotobacter and Azomonas.

Answer 10

Order pseudomonadales: Pseudomonas (Genus): - 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 numerous enzymes to catabolize a wide variety of substrates (beneficial for decomposing uncommon chemicals present in the soil but problematic in hospitals) -generally antibiotic resistant due to several efficient efflux pumps -many species excrete water soluble pigments -some species moved to Burkholderia (genus) based on rRNA studies

Answer 11

Other Pseudomonadales (Order) genera; Acinetobacter (genus); "nonmotile rod" -aerobic rods, found naturally in soil and water A. baumanii (species) *Opportunisitic pathogen found in hospital settings that is primarily a respiratory pathogen, but also infects skin, soft tissues and wounds *garnered media attention due to an outbreak among wounded soldiers in Iraq and Afghanistan that contracted it during the evacuation chain Concerns: -rapidly becomes resistant to antibiotics such that some strains are resistant to most available antibiotics -Difficult to Eliminate once established in the hospital because it survives on dry surfaces for weeks and is resistant to varies of disinfectants

Answer 12

Gammaproteobacteria (class) Other important Pseudomondales genera: Moraxella -aerobic coccobacilli M. lacunata (species) : * One of several bacteria (and viruses) that can cause conjunctivitis (pink eye): inflammation of the outermost layer of the eye and the inner surface of the eyelids *

Answer 13

Other imprint Pseudomonales (order) genera: Azotobacter ("nitrogen fixation") and Azomonas (monas= unicellular organism) Azomonas: Large ovoid heavily capsulated bacteria Azobacter: Free living soil bacteria that fix nitrogen (obtain energy from organic sources in soil)

Answer 14

Order Legionellales (contains 2 aerobic families ) Legionella (genus) -found in streams, warm-water pipes, HVAC cooling towers *Facultative intracellular parasites found in the environment either free-living or within aquatic amoeba - The amoeba shelter Legionella, protecting them from chemical disinfectants, drying ad heat -Humans are accidental hosts by inhalation of water droplets containing free-living Legionella, which are engulfed by pulmonary macrophages. -They prevent phage-lysosomal fusion, and multiply *L. pnuemophilia -Legionnaires Disease (pneuomia) (first identified during 1976 outbreak) (29 of 82 died)

Answer 15

Gammaproteobacteria (Class) Order Legnionellales Coxiella (genus) C. burnetti -Originally grouped with rickettsia (obligate intracellular parasites) but NOT transmitted among humans by insect or tick bites -Wild and domestic animals are reservoirs for the rod-shaped organism. Highly infectious, transmitted to humans via INHALATION of animal derived (urine, feces, etc) dusts, aerosols, or contaminated milk -Causes flu-like pneumonia called Q fever (named Q for query when causative-agent was unknown) -highly resistant to environmental stresses such as heat and drying; perhaps due to an endospore-like body in the cell

Answer 16

Order Vibrionales Vibrio (genus) -Facultatively Anaerobic curved rods that are mostly found in aquatic environments -Vibrio cholera -found in water/foods contaminated with feces from a person infected with V. cholerae -causes cholera, characterized by profuse watery diarrhea V. parahaemolyticus *gastroenteritis from eating raw or undercooked shellfish

Answer 17

Order Enterobacteriales (SEVEN families in 2021) Family: Enterobacteriaceae -also called enterics (inhabit intestinal tracts of humans and mammals) -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

Answer 18

Gammaproteobacteria (Class) Order Enterobacteriales Escherichia (genus) E. coli *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 *usually NOT pathogenic, but can cause urinary infections and certain strains produce Shiga toxin or ENTEROTOXINS* that cause traveler's diarrhea or food borne disease * its presence in food or water, indicates fecal contamination (the exotoxin acts on intestinal wall)

Answer 19

Gammaproteobacteria Order Enterobacteriales Family: Enterobacteriaceae Salmonella (genus) -ALL members are potentially pathogenic -common inhabitants of many animals, especially poultry and cattle -can contaminate food under unsanitary conditions

Answer 20

Nomenclature of genus Salmonella (changed and restructured several times) -Only Two species recognized *Salmonella enterica *Salmonella bongori ("cold blooded" animal resident) -These 2 strains are sub classified into 2,400 serovars -Most of these serovars (1,521) belong to Salmonella enteric and cause more than 99% of the diseases in humans *Salmonella enterica serovar Typhimirium" is generally written as you would a species, S. typhimirium *S. typhoid causes typhoid fever (A less severe gastrointestinal disease, Salmonellosis is caused by other Salmonella)

Answer 21

Kauffamn-White Salmonella Serovar Reporting Scheme: Defined by the antigenic expression, O and H that relate to variant lipopolysaccharides and flagellin, respectively Within chart you have serovar type, O antigens, Phase 1 H antigen and Phase 2 H antigens -Antigenic formulas are used for Unamed Salmonella serotypes format: -Salmonella (species) serotype (O antigen): (H1 antigen) : (H2 antigen) ex: Salmonella enterica serotype Typhimurium= Salmonella enterica serotype 1, 4, 5, 12: i: 1, 2

Answer 22

Salmonella change between H1 and H2. (you are switching the flagella protein ) REVIEW slide 44

Answer 23

Gammaproteobacteria (Class) Order Enterobacteriales Family: Enterobacteriaceae (gram negative) -Shigella -all 4 species are responsible for shigellosis/bacillary dysentery -The most extreme S. dysenterie, causes deadly epidemics, but is Least common species in U.S -only found inhumane (No other natural animal reservoirs have been proven) -Klebsiella (genus) -common in soil and water -many isolates can fix nitrogen -K. pneumoniae can cause a serious form of pneumonia

Answer 24

Gammaproteobacteria (Class) Order Enterobacteriales Family: Enterobacteriaceae Proteus Opportunistic pathogens if they enter the urinary tract or wound. Unique multicellular behavior: A proteus 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 if repeated (Example of species: Proteus mirabillis) A swimmer cells changes to a swarmer: due to a 20-40 fold Increase in cell length and flagella number

Answer 25

Proteus (genus) swimmer: shorter cell length and small amount flagella (4-10) swarmer: have longer cell length (>10 um long) and greater amount of flagella (500-5000) swarming colony on agar plate can form concentric rings

Answer 26

Gammaproteobacteria (Class) Order Enterobacteriales Family: Enterobacteriaceae Enterobacter(genus) -Two species are known to cause disease. E. cloacae and E. aerogenes *Their presence in the intestinal tracts of animals results in their wide distribution in soil, water, and sewage *Both can cause urinary and hospital acquired infections

Answer 27

Gammaproteobacteria (class) Order Enterobacteriales Family; Yersiniaceae Yersina (genus) Y. pestis causes plague (Black Death of medieval Europe) ( In an 5 year span in 1300's, 35% of Europe's population was killed) *Urban rates 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 *Inhalations of respiratory droplets from infected animals or people can lead to infection

Answer 28

There was an average of 7 cases of Human plague per year (miscellaneous info 1 dot placed randomly in mostly likely county of exposures for each confirmed plaque case. )

Answer 29

Gammaproteobacteria (Class) Order Enterobacteriales Family: Yersiniaceae Serratia (genus) S. marcescens is distinguished by production a RED PIGMENT *intially considered completely harmless, now recognized as an opportunistic pathogen found to cause many hospital acquired urinary, respiratory and wound infections. Likely because it is found in solutions in hospitals that should be sterile (ex, catheters, saline solutions)

Answer 30

Gammaproteonbacteria (Class) Order: Pasteurellales -Pasteurella (Genus) -primarily pathogens of domestic animals Best known species is P. multocida , which can be transmitted to humans via dog and cat bites. It presents as an infection that complicated 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)

Answer 31

Gammaproteobacteria Order pasteurellales Haemophilus (genus) -pathogens that inhabit the mouth, upper respiratory tract, intestinal tract and vagina -named for their blood requirement in culture media (hemo= blood) (philus= liking) *Their requirements for X (heme from hemoglobin) and V (NAD+ or NADP+) factors can be used to differentiate species H. influenzae -mistakenly considered to be the cause of influenza until 1933 -Causative agent of meningitis, earaches, bronchitis, pneumonia and septic arthritis H. ducreyi -causes the sexually transmitted disease chancroid (causes genital ulcers) (H influenza growth only around disc impregnated with BOTH X and V factors)

Answer 32

Deltaproteobacteria (class); Anaerobic: OR Aerobic: Desulfovibrio Predator---> bdellovibrio Gliding---> Mycococcus

Answer 33

Deltaporoteobacteria (class) -Genus Bdellovibrio -bdella= leech attaches tightly to other gram-negative bacteria (like E. coli) 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 ex: B. bacteriovirus attacks a bacteria cell

Answer 34

No since bdellovibrio does not attack gram-positive bacteria ? (staphylococcus aureus is gram-positive) REVIEW THIS ANSWER (Slide 57)

Answer 35

Deltaproteobacteria (class) -Members of the Order Desulfovibrioniales are... -Sulfur reducing bacteria that play a key role in the sulfur cycle -Use oxidized S (ex> S^0, SO4^2-) instead of O2 as final electron acceptor and produce reduced H2S -Desulfovibrio (Best studied genus) *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.

Answer 36

Deltaproteobacteria (class) Order Myxococcales -illustrate the most Complex life cycle of bacteria (part predatory upon other bacteria) - Myxococcus *myxo= nasal mucus *vegetative cells move by gliding motility and leave a slime trail , obtain nutrient from bacteria they encounter and enzymatically lyse *cooperative predation is accomplished by secretion antibiotics and lytic compounds that immobilize and degrade prey organisms, thereby creating a public pool f nutrients

Answer 37

Myxococcus xanthin preying on an E. coli colony (7 days real time)

Answer 38

Life cycle of Order Myxococcales: 1. Myxospores are resistant resting cells released from sporangiospores upon favorable conditions 2. Germination: myxosproes germinate and form gram-Negative vegetative 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 sensing, forming an aggregation 5 Mounding: Aggregations of cells heap up into the mound, an early fruiting body 6. Mounds of mycobacteria differentiate into mature fruiting body, which produces myxospores packed within sporiangoles (about 100,000 cells)

Answer 39

Epsilonproteobacteria (Class) -Slender rods that are helical or curved. Two medically important genera. Both are microaerophilic and motile by means of flagella Campylobacter (genus) -SINGLE polar flagella -C. jejune is leading cause of foodborne gastroenteritis -C. fetus causes spontaneous abortion in domestic animals Helicobacter -MULTIPLE flagella -H. pylori can infect the lining of the stomach. Most common cause of peptic ulcers (not thought to have a microbial cause prior to 1982) and associated with the development stomach cancers

Answer 40

Proteobacteria: contains all gram-NEGATIVE bacteria Nonproteobacteria: contains Both gram-negative and gram-positive bacteria

Answer 41

Nonproteobacteria Gram-Negative Phyla: Cyanobacteria, Planctomycetes, Chlamydiae, Spirochetes, Bacteroides, Fusobacteria, Deinoccoccu thermius (review), Gram Positive Phyla: Firmicutes, Tenericutes, Actinobacteria

Answer 42

Nonproteobacteria Gram-negative bacteria Phylum Cyanobacteria -Oxygenic Photosynthesis (chlorophyll a, like algae and plants) -Named for characteristic blue-green (cyan) pigmentation and once called "blue green algae"---They are NOT eukaryotic algae -believed to have generated most of the Earth's atmospheric O2 millions of years ago (0.1%--> 10% when plants arrive) Morphologically varied: Unicellular: divide by binary fission -Colonial: Multiple fission (parent divides multiple times by mitosis, producing several nucleotides; Cytoplasm then separates creating multiple daughter cells at once) -Filamentous: fragmentation -Many filamentous cyanobacteria fix nitrogen in specialized cells called Heterocysts (filamentous cyanobacteria can have heterocyst) (unicellular non filamentous cyanobacterium) held together by mucopolysaccharides)

Answer 43

Nonproteobacteria, Gram Negative Bacteria Anoxygenic Photosynthetic Bacteria -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) -morphollogically diverse (spiral, rods, cocci and budding forms) *Taxonomically confusing *Green non sulfur bacteria- Phylum Chloroflexi *Green Sulfur bacteria- phylum Chlorobi *Purple non sulfur bacteria - Phylum Proteobacteria (gamma) *Purple Sulfur bacteria -Phylum Proteobacteria (alpha) -Not necessarily colored green or purple *purple bacteria have various carotenoids, which give them colors raging between purple, red, brown, and orange *Most green sulfur bacteria are green but some have a brown tint

Answer 44

Phototrophic reactions: -Oxygenic photosynthesis Cyanobacteria: 2 H2O + CO2 , use light -------> (CH2O) + H2O + O2 -Anoygenic Photosynthesis Purple green Sulfur bacteria: 2 H2S + CO2 use light-------> (CH2O) + H2O + 2 S^0 Purple/Green NON-Sulfur bacteria: photoheterotrophs that use organic compounds (acids and carbohydrates) for their sources of carbon

Answer 45

Nonproteobacteria, Gram Negative bacteria Phylum Planctomycetes -May blur the definition of bacteria -Bacterial rRNA gene sequence -Members displayed number of unusual properties Genus Planctomyces -Aquatic budding bacteria that produce Stalks like Caulobacter -initially thought to lack peptidoglycan cell walls, but later disproved Gemmata obscuriglobus -may be a model for the origin of the eukaryotic nucleus -Double internal membrane around DNA, like a nuclear membrane (newer findings challenge the idea of eukaryotic ancestry of the phylum) (planctomyces have buds at Endosymbiotic of hypha, holdfasts and stalks)

Answer 46

Nonproteobacteria, Gram Negative Bacteria Phylum Chlamydiae Remarkably diverse phylum, but our discussion will be limited to only two genera: chlamydia and Chlamydophila *Obligate intracellular parasites *Direct Transmission: interpersonal contact or aerosols (not by ticks, etc) -Lab cultivation is difficult; must be cultivated in lab animals, cell culture or yolk sac of embryonate chicken eggs

Answer 47

Medically important species: Chlamydia trachomatis; Different Servers are responsible for different diseases: 1) Trachoma (leading cause of blindness in developing countries) Sexually transmitted diseases 2) nongonococcal urethritis (most coming BACTERIAL STD in U.S 3) lymphogranuloma centrum Chalymdophila pneumoniae -mild form of pneumonia Chlamydophila psittaci Respiratory disease psittacosis (infection caused by psittaci that is transmitted from infected bird to humans)

Answer 48

Life Cycle of the chlamydias (Chlaymydia and Chlamydophila) 1. The bacterium's infectious form, the elementary body attaches to a host cell(contains nucleus) 2. The host cell phagocytizes the elementary body, housing it in a vacuole 3. The elementary body reorganizes to form a Reticulate form (REPLICATING form) 4. The reticulate body divides successively, producing multiple reticulate bodies 5. The reticulate bodies begin to convert back into elementary bodies 6. The elementary bodes are released form the host cell. Elementary body (NON-REPLICATING with rigid outer membrane)

Answer 49

Elementary body: NON-replicating with rigid outer membrane reticulate body (Replicating form)

Answer 50

Life cycle of Chlamydias, takes about 48 hours to complete Chlamydia has two developmental stages- the elementary body (EB) and the reticulate body (RB) Chlamydias induces its own phagocytosis via contact with host epithelial and endothelial cells.

Answer 51

Nonproteobacteria, Gram Negative Bacteria Phylum Spirochaetes -Name is derived from their coiled morphology -Motile bacteria (rotating axial filaments) -Many inhabit the human oral and vaginal cavities Most important pathogenic genera/species: -Borrelia burgdorferi: causavtive agent of LYME DISEASE; transmission from ticks or lice to humans -Leptospira: Lesptospirosis, transmission from animals to humans through contaminated water. -Treponema pallidum: causative agent of SYPHILLIS

Answer 52

Spirochetes -Motile bacteria: utilized two or more axial filaments (endoflagella) -Allows the cell to to rotate like a corkscrew, easily cutting thought liquids

Answer 53

Spirochetes -Motile bacteria: utilized two or more axial filaments (endoflagella) -Allows the cell to to rotate like a corkscrew, easily cutting thought liquids

Answer 54

Spirochetes -Motile bacteria: utilized two or more axial filaments (endoflagella) -Allows the cell to to rotate like a corkscrew, easily cutting thought liquids

Answer 55

Spirochetes -Motile bacteria: utilized two or more axial filaments (endoflagella) -Allows the cell to to rotate like a corkscrew, easily cutting thought liquids. Structure: cell with Axial filaments, sheath

Answer 56

Nonproteobacteria, Gram Negative Bacteria Phylum Bacteroides -includes several genera of ANAEROBIC bacteria Genus Bacteroides -Rod-shaped, non-motile, non-endospore forming bacteria -Common inhabitants of the GI tract (predominant protein/30%) -Some species found in gingival crevice (between teeth and gums) -Cause infections at surgical sites, puncture wounds and through perforated bowel

Answer 57

Nonproteobacteria, Gram Negative Bacteria Phylum Fusobacteria -Anaerobic phylum -Often pleomorphic but may be spindle-shaped (fuso= spindle) Genus Fusobacterium: -Long, slender spindle-shaped rods with pointed ends -Primarily found in the mouth where it may be involved in dental diseases -Also identified as a pathogen in other parts of the body.

Answer 58

Phylum Deioncoccus-Thermus Although, they have a Thick cell wall that allows them to stain gram-positive, they also have an outer membrane, and so are closer in structure to GRAM-NEGATIVE cells *Deinococcus radiodurans - More resistant to radiation that endospores (survive a radiation exposure 1500x the dosage that would kill a human) -Resistance is due to rapid repair of radiation damage, which also extends to chemical mutagens (change in DNA) *Thermus aquaticus -Isolated from a Hot spring in Yellowstone National Park -Source of TAQ POLYMERASE

Answer 59

Gram positive bacteria can be divided based on the G/C content of their genetic material (G/C--> guanine/cytosine) -Phylum Firmicutes: LOW G/C content -Phylum Tenericutes: LOW G/C content Phylum Actinobacteria: HIGH G/C content

Answer 60

Dichotomous key for Firmicutes -Low G + C -Gram- positive Low G + C gram-positives: Tenericutes is placed into their own phylum Have cell walls: Produce endospores OR. NO endospores = Anaerobic OR Aerobic = Lactobacillale =Clostridiales & Fac Anaerobic --> Bacillales* This Dichotomous key is based on ORDERS

Answer 61

Firmicutes (phylum) Order: Clostridiales Clostridium (genus) Characteristics: -Common in soil -form endospores -obligate anaerobes -rod shaped, often distended due to presence of endospores 4 pathogens: C. difficile: GI tract infections C. botulinum: food poisoning C. tetani: tetanus C. perfringens: foodborne diarrhea

Answer 62

Firmicutes (Phylum) Order: Clostridiales Epulopiscium (guest at the banquet of a fish) -Nutritionally symbiotic in the digestive tract of surgeon fish (Tang) -Considered too LARGE to be a bacterium (visible by naked eye) and seems to break the known rules of size/diffusion limitation *its cell walls contains many folds that increase surface area and the organism is literally bathed In undigested food *Does NOT rely on diffusion to distribute nutrients because it synthesizes macromolecules where needed -Initially classified as a protozoan, reclassified as a bacterial based upon: *Lack of membrane enclosed nucleus *Analysis of rRNA

Answer 63

E. coli (1 um x 2 um) Epulopiscium (89 um x 600 um) Epulopiscium is LARGER 1 million times larger volume

Answer 64

Replication: Epulopisicum daughter cells grow within the mother cell until they fit the cell and burst the cell wall once offspring development is complete, the mother cell dies and releases offspring -1 to 7 cells are released -contains tens of thousands of copies of its genome, which may help it to overcome diffusion constraints

Answer 65

Firmicutes (Phylum) Order: Bacillales Bacillus (genus) -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 anthracis: -disease of cattle, sheep and horses that can be transmitted to humans (linked with bioterrorism) *Bacillus thuringiensis: -agriculturally important insect pathogen used as a pesticide *Bacillus cereus: associated with food poising, typically through infection of starchy foods (ex: rice) *These 3 species are considered variants of the Same species differing only by VIRULENCE genes carried on plasmids easily transferred to one another

Answer 66

Firmicutes (Phylum) Order: Bacillales Staphylococcus: -Cocci bacteria that 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) Staphylococcus aureus: -GOLDEN in color ( may protect form antimicrobial effects of sunlight) -Produce many exotoxins to aid its pathogenicity (allow invasion or damage tissues) -Commonly infect surgical wounds -Develop drug resistance quickly -Infections differ by anatomic region: -Vaginal tract: toxic shock syndrome -GI tract: food poisoning -Respiratory tract: sinus infections

Answer 67

Firmicutes (phylum) Order: Lactobacillales Lactobacillus (species) -Commerically important in pickle, yogurt, sauerkraut, and buttermilk production -Generally aerotolerant anaerobes (they use fermentation to produce energy (ATP) -In humans, can be found in oral cavity, vaginal and GI tracts -Most lack an electron-transport chain What does this mean: Inefficient metabolism; can NOT utilize oxygen as electron acceptor. They grow poorly compared to oxygen utilizing bacteria -however, since they generate lactic acid from simple carbohydrates---- the Low pH inhibits the growth of competing organisms

Answer 68

Firmicutes (phylum) Order: Lactobacillales Streptococcus (genus) -Cocci bacteria that typically grow in chains *responsible for more illnesses and Greater variety of diseases than any other genus -Express and secrete substances that aid in its pathogenicity -Proteins to kill phagocytic cells -Enzymes that help spread infection: -digest host connective tissues which may also cause tissue destruction -destroy fibrin, a component of blood clot

Answer 69

Streptococci can be classified based upon their Colony Appearance on blood agar medium -Alpha-hemolytic species partially degrade red blood cells (due to hydrogen peroxide production) and their colonies are surrounded by a distinctive Greening -Beta-hemolytic species express hemolysin that lyses red blood cells, leaving a CLEAR Zone around the colony (yellow color) . S. pyogenes (Beta-hemolytic group A strep): causative agent of Scarlet and Rheumatic Fever - S. agalactiae (beta-hemolytic Group B Strep): neonatal sepsis -Gamma-hemolytic species DO NOT Affect red blood cells and are usually NOT pathogenic (hence red, regular blood agar color) -** The Beta group contains the most Virulent Streptococci and is divided into Lancefield antigenic groups (A-G) based on Streptococci cell wall carbohydrate antigens.

Answer 70

viridians streptococcus is a common name for a large group of normal microbiota streptococcal bacteria that are either alpha-hemolytic ("viridian's means green, hence the name) or nonhemolytic (on Beta hemolysis plate, appearance on blood agar play is yellow; on alpha hemolysis plate: appearance is green; on gamma hemolytic (RBCS not affected) , so not pathogenic (color is red)

Answer 71

Firmicutes (phylum) Order: Lactobacillales Enterococcus (Genus) -Part of our normal intestinal flora that occasionally cause urinary tract infections and sepsis -Adapted to nutrient rich, 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 -E. faecalis and E. faecium, are responsible for most surgical wound and urinary tract infections

Answer 72

Firmicutes (phylum) Order: Lactobacillus Listeria (named after Joseph Lister0 -L. monocytogenes is usually the causative agent of listeriosis, a serious infection caused by eating food contaminated with the bacteria _one of the most Virulent food borne pathogens (20-30%) of clinical infections result in death) * a 2011 Listerosis Outbreak from contaminated cantaloupe sickened 147 and killed 33. -facultative intracellular parasite that survives within phagocytic cells and infection of pregnant women -Capable of growth at refrigeration temperatures

Answer 73

Phylum Tenericutes Order: Mycoplasmas -lack a cell wall; pleomorpic as a result -Named ("mykes" = fungus and plasma= formed) because they produce filaments resembling those associated with fungi -Very small (0,1-0.25 um)and originally classified as viruses -May be the smallest, self-replicating, free living form -DNA analysis suggests once closely related to Bacillus, Lactobacillus, and streptococcus but LOST genes over time -M. pneumonia is the most signicant species, causing mild pneumonia

Answer 74

M. pneumonia have arrowheads, which indicate terminal structures that probably aid in attachment to eukaryotic cells, which then become infected. M. pneumonia also reproduces by fragmentation of the filaments at the bulges.

Answer 75

Actiobacteria (phylum) phylum name derived from the Greek "actino" meaning "ray"because above genera appear to radiate due to manmber of branching filament Dichotomous key for Actinobacteria -All have High G+ C and Gram-POSITIVE: Form filaments OR. have NO mycelia No condidospores OR Form Condidospores Acid-fast OR. Fix N2 Aerobic or Anaerobic Acid-fast--> Nocardia; Aerobic-->. Streptomyces Fix N2---> Frankia Anaerobic--> Actinomyces No mycelia---Acid Fast--> Mycobacterium No mycelia--> NOT Acid fast--> stain gram+------> Cause diphtheria--> Corynebacterium Or Not Aci-d Fast--> stain gram + ----> make propionic acid---> Propioinibacterium.

Answer 76

Actinobacteria; HIGH G/C content Some are Highly pleomorphic in morphology and others grown old as extend, often branching filaments -The genera Corynebacterium is pleomorphic -Filamentous genera resemble fungi but are PROKARYOTES *some, like fungi also carry external spores for reproduction *Common soil inhabitants *Advantages of filamentous design -organism can bridge a water-free gap to a new nutritional site -increased surface area for greater nutrient absorption

Answer 77

Actinobacteria -The genus Streptomycetes: -is one of the most common soil isolates -Reproductive asexual spores (Condidospores) form at the end of the coiled aerial filaments that can germinate into a new colony if released into proper conditions -Are strict aerobes -Produce a gaseous compound, geosmin, that gives soil its musty odor *Valuable because they produce most of our commercial antibiotics*

Answer 78

Actinobacteria Genus: Mycobacterium (NOT Gram POSITIVE) -Aerobic, non-spore forming rods -"Myco" = fungus-like; named because they occasionally exhibit filamentous growth -Cell wall is similar to gram negative bacteria, But the outermost lippopolysaccharde layer of their cell wall is replaced by mycolic acids, giving them a waxy, watery 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 *Important membrers include M. tuberculosis and M. leprae, causative agents of tuberculosis and leprosy, respectively

Answer 79

Genus Actinomyces: -Facultative anaerobes, branched filaments that replicate by Fragmentation - Common in soil and animal microbiota, present in the mouth and throat of humans -One species, A. Israeli, is the causative agent of actinomycosis, a tissue destroying disease affecting the head, neck, or lungs Genus Nocardia: -Morphologically similar to Actinomyces and also replicate by fragmentation Aerobic, acid-fast bacteria (NOT gram Positive) -Common in soil Nocardia asteroids can cause a chronic pulmonary infection and is also the cause of a mycetoma, a localized infection affecting feet and hands.

Answer 80

Actionbacteria Genus Corynebacterium: coryne= club-shaped -pleomorphic, morphology often changes with age -C. diphtheria ist he causative agent of diphteria Genus Propionibacterium: -named for ability to form propionic acid some species important in the formation of Swiss cheese (forming holes in the chess) P. acnes are commonly found on human skin and implicated as primary bacterial cause of acne Genus Frankia: causes nitrogen-fixing nodules to form on alder tree roots

Answer 81

Domain Archaea -Placed into 5 groups: (3) physiological and (2) nutritional Thermophiles: high temperatures: >80 degrees Acidophiles: survive in extremely low pH (and often high temps) Halophiles: thrive in high salt concentration Nitrifying: oxidize ammonia for energy Methanogens: anaerobic bacteria that generate methane gas by combining CO2 and H2 (nutritional groups are nitrify ing and methanogens)

Answer 82

Microbial Diversity -PCR indicates up to 10,000 different types of bacteria in 1 gram of soil -Many bacteria have NOT been identified because they have NOT 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