Session 9

Question 1

What colour do gram -ive bacteria stain?

Answer 1

Red

Question 2

What colour do gram +ive bacteria stain?

Answer 2

Blue

Question 3

What is the most common bacteria in the GI tract?

Answer 3

Bacteroides fragilis (An obligate anaerobe, gram -ive bacillus

Question 4

What gram -ive faculative anaerobe is in the GI tract?

Answer 4

E. coli

Question 5

What are the main anaerobic zones of the GI tract?

Answer 5

Some parts of the mouth/tongue
Small bowel
Colon

Question 6

How does the natural flora of the colon help humans?

Answer 6

They prevent colonisation by pathogens and synthesise vitamins sich as K, B2
Aid immune system as lack of them = poor immunity
Colonic mucus protects the person from them

Question 7

What bacteria can make endospores?

Answer 7

Clostridium difficilie
Clostridium tetani
Makes spores when in an uninhabitable environment

Question 8

What bacteria from our natural flora can cause issues with heart valves?

Answer 8

Staphylococcus epidermis

Makes biofilm on the valve so very hard to remove

Question 9

What are some of the key gram +ive aerobic cocci?

Answer 9

Staphylococci
Streptococci
Enterococci

Question 10

What are some of the key gram -ive aerobic cocci?

Answer 10

Nisseria meningitidis (Carried in the mouth)
Nisseria gonorrhoea

Question 11

What are some of the key gram +ive aerobic enteric bacilli?

Answer 11

E. coli
Pseudomonas
Salmonella
Shigella
Campylobacter
Helicobacter pylori

Question 12

What are the key gram -ive anaerobic enteric bacilli?

Answer 12

Bacteroides

Question 13

What are the key gram -ive aerobic non enteric bacilli?

Answer 13

Haemophilus influenzae
Brucella
Bordetella pertussis

Question 14

What are some of the microbes in the mouth?

Answer 14

Streptococci
Staphylococci
Lactobacillus
Entercoccus
Candida (Fungus)

Question 15

When can the natural flora of the mouth cause tissue damage?

Answer 15

When the person is dehydrated
Immunocompromised
Malnourished

Question 16

What can cause oral thrust?

Answer 16

Candida (A fungus in the natural flora of the mouth)

Especially if the patient is taking antibiotics, diabetic, on inhaled steroids or immune deficient

Question 17

What can cause Parotitis?

Answer 17

Staphylococcus aureus

Question 18

Why do you swab the nose when looking for MRSA?

Answer 18

Because Staphylococcus and Streptococcus are in the natural flora of the nose

Question 19

What throat commensal can get stuck to prosthetics in the body?

Answer 19

Streptococcus viridans

Enters via the teeth and blood stream and sticks to prosthetics eg heart valves

Question 20

What is bacteraemia?

Answer 20

Where bacteria invade the blood, but are cleared

Different to septicemia as they multiply and the body cannot control them

Question 21

Why are there lots of lymph nodes in the neck?

Answer 21

So the body can monitor the throat and mouth commensals

Question 22

How does the body help prevent infections in the mouth/throat?

Answer 22

Natural flora
Many lymph nodes in the area
Saliva contains antibodies and has alkaline pH

Question 23

What percentage of tonsilitis is viral/bacterial?

Answer 23

70% viral adenovirus or rhinovirus
30% bacterial
Viral will NOT respond to antibiotics

Question 24

What is a Quinsy?

Answer 24

An abscess on an infected tonsil

Question 25

How does Clostridium transfer from one person to another?

Answer 25

Spore when leave the GI tract to survive the hostile environment
Vegetative state once again when enters the GI system
Oral - fecal route

Question 26

Why do you give patients prophylactic treatment when they are going for GI surgery?

Answer 26

The surgery involves lots of bacteria so give antibiotics to cover anaerobes, -ive bacilli and +ive cocci

Question 27

What drug is often used in GI prophylaxis?

Answer 27

Metroniadazole (Anaerobes) and Gentomicin/Cephalosporin (Broad spectrum)

Question 28

What alternative drug can you use in GI prophylaxis?

Answer 28

Co-Amoxiclav (Brand name Augmentin)

Cannot give to patients with Penicillin allergies

Question 29

How do surgeons try to prevent resistance from prophylaxis?

Answer 29

Variation of the prophylactic regime

Question 30

What is Fecal peritonitis?

Answer 30

Feces in the peritoneal cavity cause inflammation. Usually due to knife wounds perforating the bowel and leads to rapid septicaemia

Question 31

How do perianal abscesses occur?

Answer 31

Blockage of one of the anal glands that make lubricant

Question 32

What colonic bacteria can leave the colon and travel to the perineal skin?

Answer 32

E. coli
Enterococcus faecalis
Lactobacillus
Bacteriodes are obligate anaerobes so would die

Question 33

What is the benefit of Lactobacillus being a normal vaginal commensal?

Answer 33

Convderts glycogen to lactic acid making the environment acidic. This prevents Candida from growing)
Antibiotics can cause vaginal thrush due to the candida being able to grow

Question 34

What are the main bacteria that can cause UTIs?

Answer 34

E. Coli (Gram -ive bacilli)
Enterococcus faecalis (Gram +ive cocci)

Question 35

What bacteria can colonise the skin?

Answer 35

Pseudomonas aeruginosa (Loves fluid/moisture)

Question 36

What causes gas gangrene? (Also known as wet gangrene)

Answer 36

An anaerobic bacterium called Perfringens

Proliferates and digests muscle causing contraction. Can lead to heart attacks

Question 37

What bacterium can cause tetanus?

Answer 37

Clostridia tetani

Opistholamus - All muscles contracting

Question 38

What bacterium can cause pseudomembranous colitis?

Answer 38

Clostridia difficile