Bacteriology

Question 1

What is the range of the size of a typical bacterial cell?

Answer 1

1µm - 10µm

Question 2

Bacterial cells…..

• are usually eukaryotic
• never have a cell wall
• usually possess a single chromosome
• may contain extrachromosomal DNA
• are always diploid

Answer 2

• Usually possess a single chromosome

- May contrain extrachromosomal DNA

Question 3

All bacteria…..

• reproduce by binary fission
• multiply by formation of endospores
• contain DNA
• are dependent on free oxygen for their survival
• have extracellular pili or fimbriae which are responsible for the motility

Answer 3

• Reproduce by binary fission

- Contain DNA

Question 4

All bacteria possess…..

• ribosomems in the cytoplasm
• a cell membrane
• a nucleus in the cytoplasm
• a nucleoid in the cytoplasm
• a flagellum

Answer 4

• Ribosomems in the cytoplasm
• A cell membrane
• A Nucleoid in the cytoplasm

Question 5

Gram negative bacteria usually possess…..

• lipopolysaccharide
• an inner and an outer membrane
• mitochrondries in the cytoplasm
• several chromosomes in the cytoplasm
• peptidoglycan in the cell wall

Answer 5

• Lipopolysaccharide
• An inner and an outer membrane
• Peptidoglycan in the cell wall

Question 6

Gram positive bacteria…..

• do not possess a cytoplasmic lipid membrane
• have a thick layer of peptidoglycan in the cell wall
• never have teichoic acid attached to the cell wall
• are red when stained by Gram’s method
• often have a polysaccharide capsule

Answer 6

• Have a thick layer of peptidoglycan in the cell wall

- Often have a polysaccharide capsule

Question 7

The human micro biome…..

• displays the harmful microbes associated with humans disease
• displays the interaction between human host cells and bacteria
• include bacteria, fungi and archaea
• displays the variation in human somatic cells
• resides on the surface and in deep layers of skin, in the saliva and oral mucosa, in the conjunctiva, and in the gastrointestinal tracts

Answer 7

• Include bacteria, fungi and archaea
• Resides on the surface and in deep layers of skin, in the saliva and oral mucosa, in the conjunctiva, and in the gastrointestinal tracts

Question 8

The number of bacteria humans carries in the colon intestines is estimated to be in the range?

Answer 8

10^10 - 10^12 CFU per gram

Question 9

The total number of bacterial species humans carries in their intestine is in the range?

Answer 9

500-1000

Question 10

The number of genes of the gut micro biome outnumber the number of genes in the human genome by how many times?

Answer 10

100 times

Question 11

The protective function of the commensal microbiota involves which of following?

• Production of oxygen by anaerobic metabolism
• Nutrient competition
• Production of organic acids by fermentation
• Production of anti-microbial substances
• Receptor competition and pathogen displacement

Answer 11

• Nutrient competition
• Production of anti-microbial substances
• Receptor competition and pathogen displacement

Question 12

The term commensal bacteria ‘‘means’’?

Answer 12

Bacteria with a non-harmful coexistence with the host

Question 13

Antibiotic-associated diarrhea (AAD),

• is treated by increasing the dose of the used antibiotics
• is a state of serve intestinal dysbiosis
• is caused by antibiotic therapy
• involves overgrowth of potentially pathogenic organisms
• is caused by the bacterial species Escherichia coil

Answer 13

• is a state of serve intestinal dysbiosis
• is caused by antibiotic therapy
• involves overgrowth of potentially pathogenic organisms

Question 14

Clostridium difficile

• causes an increasing number of infections in Denmark
• infections are preventable by vaccination
• infections often occur in otherwise healthy individuals
• is an aerobic intestinal bacterium
• infections is mainly a problem at hospitals

Answer 14

• causes an increasing number of infections in Denmark

- infections is mainly a problem at hospitals

Question 15

The gut microbiota has a beneficial affect on the health, which 3?

Answer 15

• By generation of fermentation products which act as an extra source of energy
• By synthesis of essential vitamins
• By stimulation of epithelial development

Question 16

Probiotics:

Answer 16

Are preparations of live microorganisms that provide health benefits when consumed.

• Used for manipulation of the composition of the intestinal microbiota was suggested more than 100 years ago

Question 17

Human milk

Answer 17

• Contains substances which have an important function as probiotics for the breastfed infant
• Contains oligosaccharides that infants lack the enzymatic capabilities to digest
• Oligosaccharides are fermented by highly specialized bacteria in the infant intestine

Question 18

Prebiotics

Answer 18

• Contains components which humans lack the enzymatic capabilities to digest
• Is food ingredients that affect the host by stimulating the growth of beneficial bacteria in the colon
• Induce the growth and/or activity of commensal microorganisms.

Question 19

Dysbiosis refers to:

Answer 19

Microbial imbalance on or inside the body