Microbiology Final Chapters 10-13

question

What is the utility of preforming an rRNA analysis on different organisms?
answer

• The discovery of three cell types was based on the observations that ribosome’s are not the same in all cells. Ribosomes provide a method of comparing cells because ribosomes are present in all cells. Comparing the sequences of nucleotides in ribosomal RNA from different kinds of cells shows that there are three distinctly different kinds of cell groups; the eukaryotes and two different types of prokaryotes—the bacteria and the archaea. In addition to the differences in rRNA, the three domains differ in membrane lipid structure, transfer RNA molecules and sensitivity to antibiotics.
question

What is the point of using bacteriaphages to type bacteria?
answer

• Phage typing is a test for determining which phages a bacterium is susceptible to. Bacteriophages are bacterial viruses and that they usually cause lysis of the bacterial cells they infect. They are highly specialized, in the fact that they usually infect only members of a particular species, or even particular strains within a species. The source of food-associated infections can be traced by phage typing. Phages are able to infect and lyses the bacterial cells, clearing in bacterial growth, used in plaque assay.
question

What does DNA fingerprinting tell you?
answer

• The use of restriction enzymes enables researchers to compare the base sequences of different organisms. Restriction enzymes cut a molecule of DNA everywhere a specific base sequence appears, producing restriction fragments. A comparison of the number and size of restriction fragments that are produced from different organisms provides information about their genetic similarities and differences; the more similar the patterns, or DNA fingerprints, the more closely the organisms are expected to be. DNA fingerprinting is used to determine the source of hospital- acquired infections. However, it is currently unpractical for laboratory identification because of the great amount of time required.
question

Taxonomic profression
answer

i. Domain (DUMB)
ii. Kingdom (KING)
iii. Phylum (PHIL)
iv. Class (CAME)
v. Order (OVER)
vi. Family (FROM)
vii. Genus (GERMANY)
viii. Species (SHIT!)
question

Prokaryotic species
answer

a population of cells that share certain rRNA sequences; in conventional biochemical testing, it is a population of cells with similar characteristics.
question

Clone
answer

a population of cells arising from a single parent cell
question

Strain
answer

genetically different cells with in a clone
question

cladogram
answer

A dichotomous phylogenetic tree that branches repeatedly, suggesting the classification of organisms based on the time sequence in which evolutionary branches arose
question

clade
answer

a group of genetically related organisms
question

Fungi
answer

(mycology = study of fungi)
-All types of fungi are multicellular except for yeasts.
– Cellular arrangement: Unicellular, filamentous, fleshy
– growth: body consists of long filaments of cells joined together (called hyphae).
Yeasts:
i. Cellular Arrangement: nonfilamentous; unicellular
question

Algae
answer

(Protists) Lack the tissues of plants
– Some are multicellular
– Unicellular, colonial, filamentous; tissues
Dinoflagellates (plankton). Unicellular, stores starch, neurotoxins cause paralytic shellfish poisoning
question

Protozoa
answer

– None of the organisms are multicellular
– Unicellular cellular arrangement
question

Helminths
answer

– All are multicellular
– Cellular arrangement consists of tissues and organs
question

With the fungi, some can cause disease, but they are at a minority. Many species are beneficial.
answer

• Fungi decompose dead plant matter; primary decomposers of plants that cannot be digested by animals.
– Dimorphism: two forms of growth of fungi. Such fungi can either grow as mold or as yeast. Moldlike forms produce vegetative and aerial hyphae while yeastlike forms reproduce through budding. This sensation is temperature dependent in pathogenic fungi, It is yeastlike at 37 degrees and moldlike at 25.
question

Beneficial Fungi
answer

– Saccharomyces cerevisiae: bread, wine, HBV vaccine
– Trichoderma: Cellulase
– Taxomyces: taxol
– Entomophaga: Biocontrol of the gypsy moth
– Paecilomyces: kills termites
question

What is the structural arrangement of lichens, especially the interaction of the fungus and the green algae?
answer

Lichen is a combination of green alga and a fungus. (considered to be part of the kingdom fungi). The two organisms exist in a mutualistic relationship (both benefit from each other) LICHEN NO LONGER EXISTS WHEN EITHER THE ALGA OR FUNGUS ARE SEPARATED AND GROW ALONE.
• When the algal partner is separated about 1% of the carbohydrates produced during photosynthesis are released into the culture medium.
• When together the algal plasma membrane is more permeable and up to 60% of the products of photosynthesis are released to the fungus or are found as end products of fungal metabolism. Alga receives protection from desiccation and attachment from the fungus.
question

What is the role of parasites?
answer

i. Vectors: To carry disease causing organisms from one host to another.
ii. The definitive host:(mosquito) an organism that harbors the adult, sexually mature form of a parasite. Look for intracellular intrusions.
iii. The intermediate host:(human) an organism that harbors the larval or asexual stage of a helminth or protozoan.
question

What would be the reason that gastrointestinal parasites lack a complete digestive sytem themselves?
answer

Gastrointestinal parasites lack a complete digestive system because they can absorb nutrients from the host’s food, body fluids, and tissues.
question

tick
answer

rocky mountain spotted fever, lyme disease, relapsing fever
question

human louse
answer

epidemic typhus
question

rat flea
answer

plague
question

mosquito
answer

malaria, dangue fever, yellow fever, heart worm, arboviral encvephalitis
question

tsetse fly
answer

african trypanosomiasis
question

kissing bug
answer

changas disease
question

deer fly
answer

tularemia
question

distinctions of Fungi v Yeast
answer

Fungi- chemoheterotrophs that require organic compounds for energy and carbon. Aerobic or facultatively anaerobic.
Yeast- nonfilamentous, unicellular and are typically spherical or oval
question

Bartonella
answer

gram negitive, human pathogen that causes cat scratch disease
question

Argobacterium
answer

invade plants causing crown gall which inserts a plasmid with bacterial genetic information into plants chromosomal DNA
question

Rhizobium
answer

infect plant induce root nodules, symbiotic relationship result in fixation of nitrogen plant for use
question

azosprillium
answer

soil bacteria, nitrogen fixing
question

acetobacter, gluconobacter
answer

makes vinegar
question

rickettsia, ehrlichia
answer

intercellular parasites, gram negitive, rod or coccobacilli, enter host cell by phagocytosis, are transmitted to humans by bites of insects and ticks
question

wolbachia
answer

only live inside host cell, most common infectious bacteria
question

nitrobacter, nitrosomonas
answer

chemoautotrophs, use inorganic compounds as energy and carbon dioxide as only source of carbon, reduce nitrogenous compounds
question

sprillium
answer

gram negitive aerobic, motile by polar flagella
question

bulkholderia
answer

gram negitive, aerobic, capable of degrading more than 100 different organic molecules, can grow disinfectants
question

francisella
answer

pleomorphic, growing only on selective media
question

moracella
answer

aerobic coccobacilli, causing inflamation of the eye
question

acinetobacter
answer

aerobic, and grows rapidly, becoming resistant to antibiotics, causing concern in hospitals
question

neissaira
answer

aerobic, gram negitive cocci, inhabit mucous membrane, causitive agent of gonorrhea
question

Bordetella
answer

nonmotile. aerobic, gram negitive rod causing whooping cough
question

zooglea
answer

form fluffy, slimy masses part of sewage treatment process
question

Pseudomonas
answer

aerobic, gram-negitive, polar flagella movement. some can glow under UV light, have as much genetic material as eukaryotes, grow in refrigerators causing food spoilage
question

azotobacter and azomonas
answer

nitrogen fixing
question

legionella
answer

liked to pneumonia, have the ability to survive and reproduce within aquatic amoebae (difficult to kill)
question

coxiella
answer

requires mammalian host cell to reproduce, transmitted by aerosois and contaminated milk, has high resistance of airborn transmission and heat tratment
question

vibrio
answer

slightly curved rods, transmitted by raw/ undercooked food causitive agents of vibrio cholera causing profuse and watery diarrhea
question

enterobacter
answer

gram negitive rods, facultatively anaerobic, have fibriae, active fermenters of glucose and produce bacteriocins
question

erwinia
answer

plant pathogen producing enzymes that hydrolyze pectin- splitting plants
question

escherichia
answer

most common in intestinal tract, produce exotoxins
question

klesiella
answer

found in soil and water, nitrogen fixation, cause pneumonia
question

proteus
answer

swaemer cells many flagella, distinctive appearance of concentric rings
question

salmonella
answer

in contaminate food, flagella capsules and cell walls serve as antigens that cause animal to form antibodies in blood
question

serratia
answer

produce red pigment, found on catheters causing urinary and respritory tract infections
question

yersinia
answer

cause plaque, common in rats and squirrels, fleas transmit as well as through respritory droplets transmission
question

haemophilus
answer

inhabit mucous membrane, reponsible for influenza, in blood and neeed heme group of the hemoglobin
question

haemophilus
answer

inhabit mucous membrane, reponsible for influenza, in blood and neeed heme group of the hemoglobin
question

pasteurella
answer

pathogen in domestic animals, can be transmitted to humans by dog/ cat bites
question

bdellovibrio
answer

gram negitive, attacks other gram negative bacteria causing host cells lyses
question

myxococcales
answer

most complex life cycle, vegetative cells, fruting and gliding bacteria, similar to slime molds
question

campylobacter
answer

microaerophilic vibrios, one polar flagella cause abortion and foodborn diseases
question

helicobacter
answer

microaerphilic curved rods, many flagella, cause peptic ulcers
question

the gamaproteobacteria
answer

beggiatoa alba (B. alba) is unusual because they grow in aquatic sediments between anerobic and aerobic layers. it uses hdrogen sulfide for energy and accumulates internal granules of sulfur. it produces slime which gives it the ability to move by gliding
question

helical virus
answer

a virual nucleic acid is found with in a hollow cylindrical capsid that has a helical structure
ex- ebola virus and rabies virus
question

polyhedral viruses
answer

many animal plant and bacterial viruses are polyhedral (or many sided virus) the capsomeres on each face from an equalateria triangle.
ex- adenovirus and poliovirus
question

enveloped viruses
answer

some capsids are covered by an envelope made up of combination of proteins, lipids and carbs
-some animal viruses released from host cell, use the host cells and cell plasma membrane to become the viral envelope. many cases envelope contains proteins determinded by viral nucleic acids and mature from normal host cell componets.
– many have spiked as means of attachment, idenity and ability to clump to RBCs (ex influenza)
question

hemagglutiation
answer

the use of the spikes to attach itself to RBCs and cause bridges
question

non enveloped viruses
answer

capsid has to protect nucleic acids from nuclease enzymes and promotes viruses attachment to host cells
question

host infected by a virus
answer

host immune system to produce antibodies, interaction between host antibodies and viruses should stop infection. however viruses can escape antibodies- by viruses and mutating their own surface proteins, so antibodies are unable to react with viruses. influenza, undergoes spike changes. this is why you can have the flu more than once, you may have antibodies to one influenza virus, but viruses can mutate and infect you agin
question

complex viruses
answer

complicated structure
bacteriaphage- have capsids with aditional structures attached (capsid head, dna, sheath, tail fier, base plate)
poxvirus- do not contain identifiable capsids, but have several coasts around the nucleic acid
question

group viruses by
answer

nucleic acid type
stratagy of replification
morphology
question

genus name
answer

virus
question

family names
answer

viribae
question

order name
answer

ales
question

viral species group (viruses sharing the same)
answer

genetic information
ecological niche (host range)
question

viral plaque
answer

-plaque method mixes bacteriophages with host bacteria and nutrient agar
-after several viral multiplication, cycles bacterial area surrounding the original viruses are destroyed, this area of lysis is called plaque
-each plaque originates with a single viral particle
-concentration of viruses is given as (PTU) plaque forming units
question

Prion
answer

“Proteinaceous Infectious particle”
-infectious agent in pure protein
– nine animal disases- spongiform encephanlopathies balck large vaculoles develope in the brain
-kuru
– creuizfeld jakob diseases
-gerstmann stanussler scheinker syndrome
-fatal faminial insomia
these diseases are caused by conversion of normal host glyroprotein called PrPc (cellular prion proteins) into infectious form called PrPsc (scabie proteins) PrPc is on chromosome 20 in humans and is involved in cell death

Get instant access to
all materials

Become a Member