Micro Exam 1

About how many bacterial types do we now think are normally found in the mouth?

~ 600

3 multiple choice options

What Gram positive bacteria are important colonizers of the gingival pocket in both health and disease?

A. Treptonema

B. Streptococcus

C. Actinomyces

D. Prevotella

E. B and C

E. B and C

3 multiple choice options

Which of this is not a valid theory about how periodontal disease occurs?

A. plaque of any kind is a contributor

B. Red Complex bacteria have a central role in disease

C. aerobic bacteria outgrow and dominate the gingival crevice

D. host factors and bacterial factors are both involved, adding complexity

E. Porphyromonas gingivalis is not abundant, but important in disease

C. aerobic bacteria outgrow and dominate the gingival crevice

3 multiple choice options

Periodontitis is different than other diseases that are now being associated with the gut microbiota, as studies are finding more diversity of species in disease than in health.

True

1 multiple choice option

Streptocccus pneumoniae is a potentially dangerous bacteria tha normally resides in the

upper respiratory tract (mouth, nose , throat, etc).

3 multiple choice options

Which of these is NOT a normal resident of the oral microbiota?

Staphylococcus aureus

3 multiple choice options

Moraxella are an odd coccus shaped Gram negative bacteria. What other genus of Gram negative coccus normally inhabits in the same body site?

Neisseria

3 multiple choice options

Most or all abundant oral bacteria have been proposed to play a role in periodontal disease.

True

1 multiple choice option

Is there a vaccine for Cholera?

Yes, it's a live strain of Vibrio

3 multiple choice options

What is the Vi capsule that is important in Typhoid Fever?

a. capsule seen only on S. Typhi bacteria

b. important in using live Salmonella as a vaccine

c. it is antiphagocytic

d. all of these

d. all of these

3 multiple choice options

Which is NOT a toxin E. coli can acquire by horizontal gene exchange and become dangerous?

a. shiga toxin

b. heat stable toxin

c. heat liable toxin

d. LPS endotoxin

e. all of these are E. coli toxins

e. all of these are E. coli toxins

3 multiple choice options

What is distinct about Shigella among the other Enterobacteriaceae?

It is intracellular, invading epithelial cells

3 multiple choice options

What is the difference between the 'O antigen' and Lipid A in Gram negative LPS?

A. Neisseria LPS lacks the O-antigen

B. The O antigen is used in strain typing differences among the same species

C. Haemophillus lacks the O antigen

D. All of these

D. All of these

3 multiple choice options

Which of these is NOT a Bordetella toxin?

A. Pertussis toxin (PT)

B. Adenylate cyclase toxin

C. Tracheal toxin

D. SPE superantigen

D. SPE superantigen

3 multiple choice options

Which of these bacteria is NOT a major cause of meningitis?

A. Staph Auerus

B. Strep Pneumoniae

C. Neisseria Meningitides

D. all of these cause meningitis

Staph auerus

3 multiple choice options

Which of these are true about Haemophilus influenza?

A. It is a major cause of ear infections from the throat

B. The vaccine is a protein conjugated capsule antigen

C. Can cause pneumonia

D. all of these

all of these

3 multiple choice options

Which of these Gram positive rods form spores?

- Listeria

- Bacillus

- Corynebacterium

- Clostridium

- Mycobacterium

- Lactobacillus

- Clostridium

- Bacillus

3 multiple choice options

Which of these is a strict anaerobe?

Clostridium

3 multiple choice options

Teichoic acids are always inflammatory

False

1 multiple choice option

Which of these are intracellular bacteria?

- Bacillus Anthracis

- Listeria monocytogenes

- Clostridium perfringes

- Lactobacillus acidophilus

- Mycobacterium tuberculosis

- Bacillus Anthracis

- Listeria monocytogenes

- Mycobacterium tuberculosis

Which is correct in terms of the relative pathogenic potential of S. pneumoniae and S. oralis?

A. S. Oralis can cause heart valve infections

B. S. pneumoniae can cause heart valve infections

C. S. pneumoniae is able to cause many diseases

D. All of the above

D. All of the above

3 multiple choice options

What is the simplest way to definitive identify Streptococcus pneumoniae causing characteristic disease?

distinct cell shape and arrangement

3 multiple choice options

The pneumococcus is alpha hemolytic unless

grown anerobically

3 multiple choice options

Which pair of infectious diseases caused by S. pneumoniae are caused as frequently by other bacteria?

A. endocarditis and arthritis

B. meningitis and ear infection

C. bacteriemia and impetigo

D. all of these

D. all of these

3 multiple choice options

What is the difference between greek and roman/latin letter (A, B, etc.) designations for groups of streptococci?

A. greek indicated different species in the genus

B. roman indicate different serotypes

C. greek indicate different hemolysis patterns

D. B and C

D. B and C

3 multiple choice options

What are the important post-infection Sequelae in Streptococcus pyogenes (G.A.S.) disease?

A. Scarlet fever

B. Rheumatic fever

C. Glomerulonephritis

D. B and C

E. all of these

D. B and C

3 multiple choice options

What are the secreted damaging enzymes causing hemolysis on blood agar generically called?

Streptolysins

3 multiple choice options

The two major type of pathogenic staphylococci are readily distinguished by

A. production of white or yellow pigment

B. production of coagulase

C. production of catalase

D. cell shape and arrangement

E. all except C and D

E. all except C and D

3 multiple choice options

Which of these staphylococcal virulence factors would be most important for growth in the bloodstream and sepicemia?

presence of a polysaccharide capsule

3 multiple choice options

Which of these is not a disease frequently associated with staphylococci?

- meningitis

- bone infection

- impetigo

- sinusitis

- endocarditis

- arthritis

meningitis

3 multiple choice options

What is the staphylococcal A protein

surface molecule that binds to antibodies non-specifically

3 multiple choice options

Clinical dentistry indicates the use of antibiotics in all of these situations. Choose the one where antibiotics are not routine:

a. anaerobic soft tissue abscess in a healthy patient

b. oral infection with elevated temperature or swollen lymph node

c. recognized named clinical infection syndrome or lesion type

d. otherwise fragile or patient with multiple co-morbidities

e. soil in a oral wound

anaerobic soft tissue abscess in a healthy patient

3 multiple choice options

Guidelines on the prophylatic use of antibiotics in routine dental procedures have changed through the years, resulting in confusion about this. Indicate which of these REMAINS on of the instances where antibiotics are used prior to invasive dental procedures

history of infective endocarditis

3 multiple choice options

Metronidizole is a very useful drug with low resistance because of its mechanism of action. Which is a limitation of its use?

A. it only works on aerobic infections that are not abscesses

B. it only works on microbes growing anaerobically

C. It is not compatible with patients unlikely to comply with instructions not to mix with drinking

D. B and C

E. None of these

D. B and C

3 multiple choice options

B-lactams are simply never an option when it comes to someone indicating they may have had an allergy to penicillin as a child.

False

1 multiple choice option

Which of these is among the main reason the community acquired resistant bacterial infections are increasing?

use in farming, and unregulated disposal of excess drugs

3 multiple choice options

What are antibiotics as found in Nature?

A. bacterial signal molecules

B. bacterial secondary metabolites

C. produced by fungi and soil bacteria

D. all of these

all of these

3 multiple choice options

What is clavulanic acid?

inhibitor of beta lactamase

What is homologous recombination?

recombination between two DNA helixes that are aligned over shared sequence (>400 bp)

3 multiple choice options

Which one of these is NOT a bacterial genetic element?

ribosome

3 multiple choice options

What is unique about bacterial genes or transcription units compared to those of eukaryotes?

They can have more than one protein coding region

3 multiple choice options

What additional capabilities do temperate (or "lysogenic") bacteriophages have compared to lytic phages?

ability to do specialized transduction

3 multiple choice options

What is the distinction in how the bacterial terms "cell wall" and "envelope" are commonly used?

wall for Gram positives, envelope for Gram negatives

3 multiple choice options

Why are Gram positive bacteria typically more sensitive to widely used antibiotics like beta lactams ?

The peptidoglycan target is on the outside of the bacteria

3 multiple choice options

What is the most significant function of a capsule for a pathogenic bacteria?

they can block phagocytosis by immune cells

3 multiple choice options

Which of these features of bacterial walls and envelopes are specific to Gram negative bacteria?

A. teichoic acids

B. capsules

C. LPS - lipolysacharide

D. flagella

E. fimbriae

C. LPS - lipolysacharide

3 multiple choice options

Bacterial in nature are often growing exponentially.

False

1 multiple choice option

Where does most of the material go when you are composting garabage?

into the air as carbon dioxide

3 multiple choice options

Which physiological process provides bacteria more energy as ATP than fermentation?

A. aerobic respiration

B. anaerobic respiration

C. A & B

D. none of these do

C. A & B

3 multiple choice options

Which of these is not an intracellular bacteria?

A. Streptococcus mutans

B. Chlamydia

C. Rickettsiae

D. Mycoplasma

Streptococcus mutans

3 multiple choice options

Why is it possible to identify many important bacteria simply by shape and Gram stain type?

Only a few are able to cause common human infections

3 multiple choice options

A bacterial virulence factor is

A. Flagella

B. Reactive cell wall lipid

C. Ability to grow in mucus

D. all of these

D. all of these

3 multiple choice options

What is the difference between a bacterial species, and a strain?

a strain is any isolate

3 multiple choice options

What is the modern defining characteristic now used to define different types of bacteria?

16S ribosomal sequence

3 multiple choice options

What is the size of the smallest moving object a person can see?

0.1 mm

3 multiple choice options

Which of these are benefits that bacteria can provide to the hosts they colonize?

A. provide vitamins

B. stimulate the immune system

C. increase inflammation

D. A & B

D. A & B

3 multiple choice options

What was Anthony Leeuwenhoek's nationality?

Dutch

3 multiple choice options

What is a "microbiome?"

Complete set of microbes in a niche

3 multiple choice options

Which Mutans streptococcus contributes to caries by producing water insoluble glycans and acid?

Strep sobrinus

3 multiple choice options

Which of these is a proven contributor to dental caries?

A. saliva flow rates

B. local pH

C. strep mutans

D. sucrose

E. enamel composition

F. all of these

all of these

3 multiple choice options

Which of these is NOT a known way to reduce caries?

A. fluoride

B. reduce frequency of sucrose intake

C. probiotics (e.g. lactobacillus)

D. plaque removal

probiotics (e.g. lactobacillus)

How many bacteria types are in the gut? the mouth?

300-400 in gut

400-600 in mouth

3 multiple choice options

Who was the first person to take scrapings from gingival area, isolate the DNA, and do parallel sequencing on it using a primer?

Zaura, 2009

What was the point of scraping gingival material, extracting the DNA, and doing parallel sequencing?

to determine the different bacterial in different people

True or false: Prokaryotes (bacteria) lack membrane bound organelles

True

1 multiple choice option

Strain

Any isolated colony

Gram stain steps

Step 1: prepare a heat fixed film of bacteria on a glass slide

Step 2: stain with crystal violet (cationic) for 1 min and rinse with water

Step 3: treat with grams iodine for 1 min and rinse with water

Step 4: briefly decolorize with acetone or ethanol (a few seconds depending on thickness of film) and rinse with water

Step 5: counterstain with basic fuchsin or safranin (pink dye) for 1 min and rinse with water

Step 6: blot dry and view under oil immersion

What does iodine help with in gram staining?

helps binding to peptidoglycan

after rinsing with ethanol, gram + will _____ _______ and gram - will _______ ______

gram +: stays purple (thicker peptidoglycan)

gram -: becomes clear

Anaerobic

uses inorganic molecules or carbon dioxide

Fermentation

conversion of the products of glycolysis to other forms without additional ATP gains

discovered archaea?? go back

What is the most basic step of glycolysis?

lactic acid

in lactic acid fermentation, pyruvate is converted into lactic acid producing how many NAD+?

1 NAD

What are the two ways to regenerate NAD?

1. Oxygen present

2. Fermentatioin

Anaerobic respiration

Have enzyme reductase in membrane other than oxygen reductase

What enzyme reductases are present in anaerobic respiration? (final electron acceptors)

carbonate, sulfur, nitrate reductases

Some bacteria are almost virus like, they can't make anything (NAD or ATP) so they take it from where?

host cell

Examples of the "virus like" bacteria

- genus mycoplasma

- genus chlamydiae

Genus Mycoplasma

- exceptional in lacking peptidoglycan, and small size and genome

- these cause pneumonia and contribute to pelvic inflammatory disease

- tiny bacteria that can go through a filter

Nathalie Balabans experiment found what?

bacteria that were not growing initially are now growing after the rest had been killed off by ampicillin

Persisters

randomly non-dividing / resting cells that are resistant

Antibiotic resistance can occur by __________, which is a phenotypically resting cell in a population

persister

True or false: staphylococcus has a thick peptidoglycan

true

1 multiple choice option

What diseases are caused by biofilms or surface growth of bacteria?

- dental caries

- periodontitis

- otitis media

- musculoskeletal infections

- necrotizing fasciitis

- UTIs, prostatitis

- endocarditis

Common biofilm bacteria

- acidogenic streptococci (S. mutans)

- anaerobic gram negative bacteria

(non-typeable H. influenzae, Moraxella, staphylococci, s. pyrogenes, e. coli, viridans streptococci)

True or false: Water DOES go through a lipid bilayer membranes

True

1 multiple choice option

Gram - bacteria (like E. coli) have a more complex _______ ______ or "envelope"

cell wall

Do gram - or gram + have an extra permeability barrier, bioactive compound called LPS?

Gram -

3 multiple choice options

Mycolic acid

waxy cell wall that resists decolorization

Two parts of the structure of lipopolysaccharide (only in gram -)

1. O-antigen

2. Lipid A

Lipid A

- bioactive component

- Immune notices this right away through toll receptors

- on outside of outer membrane

What blocks phagocytosis?

Capsule (gram - / +)

What is a capsule important for?

bacteria to survive in the blood stream at any time

example of protein carbohydrate conjugate vaccine

Haemophilus conjugate vaccine

- stuck a protein on there for meningitis

HOK

H = flagella

O = O antigen of LPS

K = capsule

Spirochetes

treptonema spp important in mouth / dental field

Spirochetes

Specific type of spiral shaped, gram negative bacteria known for unique structure and movement

Transposons are also called

jumping genes

Transposons cannot move on their own, so they get help from

recombinase