Toxins and Microbiology

Question 1

What are the most common worms in the UK?

Answer 1

Pinworms

Tiny, sit on anus, very itchy

Question 2

What is lactoperoxidase?

Answer 2

An antimicrobial present in breast milk

Question 3

Which bacteria causes parotitis?

Answer 3

Staph aureus

Question 4

What is achlorhydria?

Answer 4

Don’t produce enough gastric acid

More susceptible to certain infections

Question 5

Name some microorganisms that are resistant to stomach acid

Answer 5

Mycobacterium tuberculosis
Hep A
Polio
Coxsackie

Question 6

Does the small bowel usually contain bacteria?

Answer 6

No

It is normally sterile

Question 7

What is the main role of the colon?

Answer 7

Water recovery

Question 8

What do eosinophil granules contain?

Answer 8

Peroxidases
Cationic proteins
Major basic protein

Question 9

Eosinophilia only occurs in which conditions?

Answer 9

Asthma
Hay fever
Parasitic infection

Question 10

How do we treat roundworms?

Answer 10

Can operate to remove
In poorer countries cannot operate as people are malnourished
Give them a drug to kill the roundworm
Expelled from anus

Question 11

Where is the guinea worm most prevalent?

Answer 11

Ghana

Sudan

Question 12

How does the guinea worm spread?

Answer 12

Ingested by humans from fresh water ponds
Flies ingest ovum
Flies protect ovum to the human duodenum where the worm burrows through the retroperitoneum
Moves down to the feet and expelled at a large ulcer
Moves subcutaneously
Intensely painful

Question 13

What are basophils?

Answer 13

Mast cells in the blood

Question 14

In cholera, the losses of water can be up to …

Answer 14

1 L/hr

Question 15

What is the mortality of cholera if untreated?

Answer 15

60%

Question 16

Where are the majority of macrophages in the body?

Answer 16

Liver

Question 17

What are the 3 main sites for macrophages?

Answer 17

Liver
Lungs
Spleen

Question 18

How many portal systems are there in the human body and name them?

Answer 18

2
Hepatic
Hypothalamus-hypophyseal

Question 19

What is a portal system?

Answer 19

One capillary system flowing into another capillary system

Question 20

Where are sinusoids present?

Answer 20

Liver
Spleen
Bone marrow

Question 21

Give some causes of liver failure

Answer 21

Viral hepatitis 
Alcohol 
Drugs 
Industrial solvents 
Mushroom poisoning

Question 22

What types of infection are more likely to occur during liver failure?

Answer 22

Bacterial

Fungal

Question 23

How does hepatic encephalopathy occur in liver failure?

Answer 23

Failure of urea cycle
Increased plasma ammonia
Moves through BBB
Toxic to the brain

Question 24

What are the consequences at porto-systemic shunts of portal hypertension?

Answer 24

Oesophageal varices
Haemorrhoids
Caput medusae

Question 25

What does MALT stand for?

Answer 25

Mucosal associated lymphoid tissue

Question 26

What does GALT stand for?

Answer 26

Gut associated lymphoid tissue

Question 27

GALT is nodular in which 3 locations?

Answer 27

Tonsils Peyer's patches Appendix

Question 28

What are the 3 types of tonsils?

Answer 28

Palatine (normal) Lingual (back of tongue) Nasopharyngeal

Question 29

Where do the tonsils drain into?

Answer 29

Cervical lymph nodes

Question 30

Why do we need ileocaecal lymphatic tissue?

Answer 30

In case of reflux of large bowel contents into the ileum

Question 31

Describe how typhoid fever affects the gut

Answer 31

Inflamed Peyer's patches in terminal ileum | Can perforate and kill patients

Question 32

Where are there unsafe levels of arsenic?

Answer 32

``` Bangladesh India Nepal Pakistan (In wells) ```

Question 33

What are obligate aerobes and give 2 examples?

Answer 33

Must have oxygen to live | Pseudomonas and mycobacterium

Question 34

What are obligate anaerobes and give 2 examples?

Answer 34

Die in the presence of oxygen | Bacteroids and clostridial organisms

Question 35

What are facultative anaerobes and give 2 examples?

Answer 35

Prefer oxygen but can live without it Gram negative enteric bacteria (eg. Ecoli) Gram positive skin dwellers (staphylococcus)

Question 36

Where are the anaerobic zones in the GI tract?

Answer 36

Parts of the mouth - deep in taste buds, between teeth, peridontal pockets Small bowel Colon

Question 37

What are the positive effects of human colonic bacteria?

Answer 37

``` Synthesis and excrete vitamins Prevent colonisation by pathogens Kill non-indigenous bacteria Stimulate development of MALT Stimulate production of natural antibodies ```

Question 38

What are the consequences of being 'germ-free'?

Answer 38

Vitamin deficiencies Increased susceptibility to infectious disease Poorly developed immune system Lack of natural antibody

Question 39

Which bacteria notoriously forms endospores?

Answer 39

Clostridium tetani

Question 40

A classic sore throat is caused by ...

Answer 40

Strep viridans

Question 41

Can gonorrhoea cause UTIs?

Answer 41

No | Can cause inflammation of the urethra

Question 42

Describe the bacteria of the mouth

Answer 42

Lots of anaerobes Over 700 species Human bites can cause v nasty/fatal infections

Question 43

Give some risk factors for oral thrush

Answer 43

``` Newborns Diabetes Antibiotics Inhaled steroids Immune deficiency ```

Question 44

What is the treatment for oral thrush?

Answer 44

Amphotericin lozenges | Nystatin suspension

Question 45

What is Ludwig's angina?

Answer 45

Bugs at cervical lymph nodes in tissue of neck Usually streptococcal Need to act v quickly because can cause laryngeal oedema

Question 46

Where are the 3 sites that are swabbed for MRSA?

Answer 46

Nose Throat Perineum

Question 47

When is strep viridans likely to cause bacteriaemia?

Answer 47

Teeth brushing Dental procedures General anaesthesia

Question 48

Define bacteriaemia

Answer 48

Bacteria are rapidly cleared from the bloodstream | No symptoms

Question 49

Define septicaemia

Answer 49

Bacteria not cleared and multiply in the bloodstream | Sepsis symptoms develop

Question 50

Is tonsillitis usually viral or bacterial?

Answer 50

Viral

Question 51

What are the most common viral causes of tonsillitis?

Answer 51

Adenovirus Rhinovirus EBV

Question 52

What is the most common cause of bacterial tonsillitis?

Answer 52

Strep pyogenes

Question 53

What is quinsy?

Answer 53

Hugely inflamed tissue around the palatine tonsil Deviates the uvula Patient in absolute agony and struggling to breathe Stop eating because swallowing is too painful Treatment - to let the pus drain out

Question 54

Why is the treatment for quinsy very dangerous?

Answer 54

Cutting into tonsil to let the pus drain out | Very close to the internal carotid artery

Question 55

How many species of bacteria live in the colon?

Answer 55

> 100

Question 56

What particular species of bacteria are most common in the colon?

Answer 56

Bacteroides | Clostridia

Question 57

Name some bacteria always present in the colon

Answer 57

Bacteroides fragilis, bacteroides oralis, bacteroides melaninogenious E-coli Enterococcus faecalis

Question 58

How do we describe any gut surgery?

Answer 58

Dirty surgery

Question 59

How do we prevent surgical wound infections?

Answer 59

Prophylactic Abx Metronidazole + broad spec Abx Or Co-amoxiclav

Question 60

What is the purpose of anal glands?

Answer 60

Secrete mucus at dentate line to aid passage of faeces

Question 61

How do we get perianal abscesses?

Answer 61

Stasis in the anal glands | Blockage causing infection

Question 62

Describe lactobacillus and its useful effect

Answer 62

Normal vaginal commensal Converts glycogen to lactic acid - maintain acidic environment of vagina Prevents other bacteria and candida albicans form growing

Question 63

Why is vaginal thrush common on broad spec Abx?

Answer 63

Kill lactobacillus in vagina Acidic environment cannot be maintained Candida albicans can grow

Question 64

What is the commonest bacteria causing UTI?

Answer 64

E-coli

Question 65

What is the second commonest organism causing UTI?

Answer 65

Enterococcus faecalis

Question 66

What is crepitus of the skin?

Answer 66

Feeling air underneath the skin