Exam Three Flashcards by Claire Sholar

Bacteria lacking peptidoglycan

Mycoplasma, chlamydiae (obligate intercellular)

How well did you know this?

Not at all

Perfectly

Bacteria with complex cell wall

Mycobacterium species (TB, para TB), thick waxy layer of mycolic acids, IDed with acid fast stain

How well did you know this?

Not at all

Perfectly

Temperature to autoclave spores at

121 C

How well did you know this?

Not at all

Perfectly

Most pathogenic bacteria are ________, but certain food borne pathogens are __________ (listeria monocytogenes)

Mesophiles(30-37C), Psychrophiles(10-15C)

How well did you know this?

Not at all

Perfectly

What is a siderophore and what is their most relevant function

Small, molecular weight molecules secreted by bacteria.
Bind iron

How well did you know this?

Not at all

Perfectly

List the shape, mode of transmission, and systems that disease from Leptospira impact

Spirochete
Contact with infected animal urine
Liver, renal, reproductive failure (also hemolysis)

How well did you know this?

Not at all

Perfectly

Bacteria that is gram negative, rod shaped, and highly associated with foot rot

Fusobacterium necrophorum

How well did you know this?

Not at all

Perfectly

Sulfa drugs are structural analogues of ____________ acid which bacteria use along with glutamic acid to make their own ________ acid

p-aminobenzoic, Folic acid

How well did you know this?

Not at all

Perfectly

List the three bacterial cell structures

Cytoplasm, cell envelope, surface structures

How well did you know this?

Not at all

Perfectly

List the three general aspects of cytoplasm

Genome (organized into nucleoid)
Plasmids (autonomously replicating, HGT)
Cytoskeleton (during cell division, MreB is an actin homolog, scaffold for Z ring)

How well did you know this?

Not at all

Perfectly

Talking about the cytoplasmic membrane, what effect does saturated va unsaturated fatty acids have on rigidity

Saturated FAs = increased rigidity
Unsaturated FAs (esp cis) = increased fluidity (double bonds)

How well did you know this?

Not at all

Perfectly

Most forms of life desaturate FAs (make C=C bonds) to modulate fluidity. What type of bacteria do not and what do they do instead

Low GC Gram positive bacteria
Use branched chain AAs to make branched chain FAs

How well did you know this?

Not at all

Perfectly

Beta lactam antibiotics target what cell structure

Cell wall (peptidoglycan)

How well did you know this?

Not at all

Perfectly

Capsules are __ antigens while Flagella are ___ antigens

K, H

How well did you know this?

Not at all

Perfectly

Sex Pilli mediates ____ (donor cell has plasmid)
Type IV Pili allow _______ motility

Conjugation
Twitching

How well did you know this?

Not at all

Perfectly

Type 3 secretion system is characteristic of what bacteria? The SCV stands for what and is made during T3SS -1 or T3SS-2

Salmonella enterica
T3SS1 = early invasion and salmonella containing vacuole (T3SS-2 = SCV trafficking, systemic infection)

How well did you know this?

Not at all

Perfectly

T6SS use kin recognition systems for ________-________ killing.
In culture, _______’s phenomenon illustrates the black lines of intense competition.
Strains with T6SS cannot kill each other

Contact-dependent
Diene’s

How well did you know this?

Not at all

Perfectly

DNA has a ____to _____ polarity (replication and transcription occur in this order) and the phosphodiester backbone has a net _____ charge

5’ to 3’
Negative

How well did you know this?

Not at all

Perfectly

At the origin of replication :
DNA _______ unwinds
DNA ________ replicates
DNA _______ uncoils (tension from supercoiling)

Helicase
Polymerase
Gyrase

How well did you know this?

Not at all

Perfectly

Quinolone antibiotics inhibit DNA _____

Gyrase

How well did you know this?

Not at all

Perfectly

Bacterial genes are organized into operons. _____ factor of RNA polymerase binds to _____ and ______ regions in promoters

Sigma
-35, -10

How well did you know this?

Not at all

Perfectly

RNA _________ co-transcribes operonic genes

Polymerase

How well did you know this?

Not at all

Perfectly

Two Component Systems : external signals to internal changes.
1) Membrane-bound _________ _______ senses signal
2) ____________ itself then _______ regulator
3) Phosphorylated RR activates genes for response to signal
4) Regulate MANY different processes!

Histidine Kinase
Phosphorylates
Response

How well did you know this?

Not at all

Perfectly

mRNA ________ bind ligands to regulate gene expression

riboswitches

How well did you know this?

Not at all

Perfectly

What is transformation? A bacteria capable of being transformed is called _____

Taking up DNA from environment Competent

______ genetic elements = "jumping genes" What is a major concern?

Transposable Can encode antibiotic resistance

List the 5 main aspects of bacterial physiology that antibiotics target

1) Cell Wall (peptidoglycan, lipid membrane) 2) DNA synthesis 3) Transcription 4) Translation 5) Folate metabolism

Bacteriophages are obligate _______ parasites. Name the two types and if they are virulent or not.

intracellular 1) Lytic - virulent 2) Lysogenic - avirulent

CRISPER used for bacterial ______ immunity. Needs ___ sequence to cut

adaptive PAM

Name one major pro to Phage therapy

Most phages are specific to one strain, and the limited host range allows the pathogen to be killed and the microbiome to be spared

CRISPR phages target _____ and remove _____ modules

plasmids lysogeny

The central dogma of molecular biology says ...

DNA to RNA to protein

Morphology bacterial classification: Measurement : ________ Resolution : ________

microscopy (flow cytometry) low

Pathogenicity bacterial classification : explain the difference between primary and opportunistic pathogens. Measurement : __________ Resolution : __________

Primary : will cause disease if they get a foothold in host Opportunistic : may be commensal at times, but will take advantage of chances to become pathogenic Measurement : patient symptoms Resolution : variable

Metabolism bacterial classification: Measurement : _________ Resolution : _________

M : culture R : low-moderate

List 5 different Metabolic classes

1) aerobes/anaerobes/facultative anaerobes 2) Fermenters/respirers 3) Lactic acid producers 4) Sulfer reducers 5) Methane producers (methanogens)

Cell structure bacterial classification : Measurement : _____________ Resolution : ____________

microscopy (+ staining), motility tests, proteomics Low to high

Structural Classes of bacteria : 1) flagella/no flagella 2) Gram +/Gram - cell wall 3) _______________ 4) Pilus presence and type 5) Vacuoles 6) ____________

S-layer on cell surface Magnetosomes

Genetics and Genomics bacterial classification : Measurement : _____________ Resolution : _____________

DNA sequencing (marker gene(s), whole genome) moderate to very high

King Philip Came Over For Good Spaghetti

Kingdom Phylum Class Order Family Genus Species (strain sometimes)

In subspecies taxonomy. Serovars = differing _____ ______ ______

antigenic surface proteins

Testing for bacterial growth in defined conditions = ________ _____

Selective culture

Microscopy cannot resolve beyond the _____ level

Species

_______ content : Mass-spec comparison to a reference database ("_____-____"). Resolution limited beyond ________ level

Protein MALDI-TOF Species

Targeted Genes : testing for the presence of a characteristic gene sequence using _____. No resolution beyond species level if using a _____ sequencing technique.

PCR 16S

Whole genome sequencing depended on ________ _____. Max resolution : provable that two isolates are related within X generations

Successful Culture

"Is this infection caused by pathogen A or B?" Answered by :

Selective culture for A/B

"Is this outbreak connected to that previous outbreak?" Answered by :

Whole genome sequencing

List the 5 characteristics used to organize bacteria into groups

1) Morphology 2) pathogenicity 3) metabolism 4) cell structure 5) genome

List 5 bacterial ID methods

1) Selective culture 2) Microscopy 3) Protein Content 4) Targeted Genes 5) Whole Genome Sequencing

Sequence-based measurements : 1) A microbial census : marker gene + metagenomic sequencing 2) _______ sequencing : all microbes in community 3) ______-_____ sequencing : example) 16s rRNA in everything 4) _______ sequencing : tons of dashes everywhere

community marker-gene shotgun

When present, a healthy microbiome restricts _________ + ______ to invading pathogens

physical space + nutrients

"germ-free" animals have (increased/decreased) long-term susceptibility to various kinds of infection

increased

What bacteria is the #1 hospital-acquired infection and why does it become a problem?

C. diff 2ndary bioacids that suppress C. diff spores are wiped out by antibiotics

in the rumen microbiome, methane is produced by _______ ________ inhabiting the rumen

archaean methanogen

List 5 examples of non-host-derived compounds

-rumen microbiome -secondary bile acids in gut -toxic byproducts of some chemotherapeutics -SCFA in gut -lactic acid in the vagina

Gut microbiome prevents pathogen ______

blooms

List the 7 steps in pathogenesis

1) exposure 2) adhesion 3) colonization 4) invasion 5) evasion of host defenses 6) damage to host tissue 7) +/- transmission

______ : organism that normally inhabits inanimate environments shared with animals (aka opportunistic)

Saprophyte

Products produces by the pathogen that facilitate pathogenesis

virulence factor

Virulence factors allow for 1) Colonization (ex : _______) 2) Invasion (ex: ________) 3) Evasion (ex: _______, ________) 4) Suppression (ex: _______, _______) 5) Acquisition (ex: _______) - gets nutrients

1) Colonization (ex : Adhesions) 2) Invasion (ex: invasins) 3) Evasion (ex: enzymes, toxic molecules) 4) Suppression (ex: enzymes, toxic molecules) 5) Acquisition (ex: siderophores)

Where are pathogenicity islands found? Where are Virulence plasmids found?

bacterial chromosomes plasmids in bacerial cytoplasm

Give two examples of Adhesins

Fimbrial proteins Pili

ETEC (enterotoxigenic E. coli) - have ______ adhesions - secrete ____ ____ (LT) and ____ _____ (ST) enterotoxins - FUNCTIONAL change ONLY (not structural)

fimbrial Heat Labile Heat Stable

What do LT and ST enterotoxins do? (ETEC) give physiological steps (4 steps)

disrupt function of cell membrane electrolyte/fluid transport 1)open Cl channels in enterocyte membranes 2) Cl moves to lumen 3) H2O follows 4) secretory diarrhea

Most relevant toxin to humans from Enterohemorrhagic E. coli (carried by cattle)

Shiga toxin (cook your burgers well!)

Bacterial mechanisms of spread (give 4)

1) direct 2) lymphatic/blood vessels 3) organ architecture (bronchial tree, bile ducts, nerves) 4) within phagocytes

The bacteria that is Gram-negative, aerobic, facultative intracellular rods that cause Glanders in equids

Burkholderia mallei

What is Glanders?

Systemic pyogranulomatous disease in equids

How is Burkholderia mallei spread?

via lymphatics within macrophages (can survive and replicate in cytosol)

Is Mycobacterium tuberculosis slow or fast growing and how does it evade the immune system

slow prevent phagosomal acidification and lysosomal function when phagocytized so they are NOT degraded

Listeria species are Gram -______, facultatively ________ rods, and grow at ____ temperatures

positive intracellular cooler (think poor quality silage : pH >5.5)

What 3 main issues can Listeria sp cause in ruminants?

septiciemia, encephalitis, abortion

Listeria enters _______ nerve endings, migrate to the CNS, and form _________

peripheral microabcesses

How can Listeria sp translocate the intestine

enter enterocytes and M cells --> escape phagosome --> use ActA to polymerize host actin to move in cell --> enter next cell via protrusion --> avoid immune response

Abscess = aggregate of live and dead ______, typically in response to __________ bacteria

neutrophils extracellular

Staphylococcus = Gram ____ cocci, facultative ______

positive anaerobes

_______-______ S. aureus (MRSA) common problem in hospitals. Chronic skin infection in _____

Methicillin-resistant dogs

S. _____ (humans/animals) S. ________ (dogs/cats)

S. aureus S. pseudintermedius

What is a granuloma?

focal aggregate of large, epithelioid macrophages (+/- multinucleated giant cells)

Granulomas typically cased by _____ bacteria, and ________ species

intracellular Mycobacterium

Johne's disease caused by Mycobacterium avium ssp. ________ and affects ______ _____ (villi damaged), leading to diarrhea

Paratuberculosis Small Intestine

What is described by an aggregate of microbes embedded within a self-produced matrix of extracellular polymeric substance

Biofilm

True/False Biofilms can only grow on living surfaces

FALSE can grow on living or nonliving can develop antibiotic resistance and pass it on :(

Which mechanism of immune evasion does Mycobacterium tuberculosis use?

Phagosomal maturation inhibition

How does Listeria spread from cell to cell while avoiding immune response?

Polymerizing host actin

Exam Three Flashcards

(87 cards)