Campylobacter

Question 1

most common bacterial cause of

Answer 1

infectious intestinal disease in England and Wales.

about three times more common than Salmonella

Question 2

Most infections are caused by two species

Answer 2

C. jejuni ; C. coli

Question 3

symptom

Answer 3

abdominal pain

Mild watery diarrhoea
– mainly seen in people in developing countries

Severe diarrhoea with inflammation of the gut
– mainly seen in industrialized nations

Question 4

a bacterial pathogen causing foodborne illness without

Answer 4

multiplying within the food

Question 5

how many cases reported in 2009

Answer 5

58,000 reported
Real number may be as high as 450,000 due to
under-reporting. 80 deaths

Question 6

Characteristics of the family with ______

Answer 6

sequence similarity of their ribosomal RNA molecules

• small curved or spiral rods
  – microaerophilic
  – do not metabolise carbohydrates
  – adapted to live in mucus lining of the intestines

Question 7

can Subdivided into two families

Answer 7

– Campylobacter, Arcobacter

– Helicobacter, Wolinella, Flexispira

Question 8

Species of Campylobacter

Answer 8

15 species including:

• C. jejuni -major human enteric pathogen worldwide (80-95% of cases)
• C. coli - (often associated with pigs) (5-20% of cases)
• C. fetus -major veterinary pathogen (

Question 9

Properties of Campylobacter species

Answer 9

• Gram-negative, curved or spiral rods
• Small size
• Rapid ‘darting’ corkscrew motility - long polar flagella

Question 10

Grow best with [gas]

Answer 10

reduced oxygen (~5%) and increased CO2 (5-10%)

Question 11

Optimum & minimum temperature for growth

Answer 11

about 42°C (body temperature of birds)

Minimum growth temperature about 30°C (cannot
normally grow in foods)

Question 12

Growth condition and nutrient

Answer 12

•Do not metabolize sugars
•Have small genome with few stress response regulons
•Sensitive to heating, freezing, drying, acid, etc.
•Form coccoid cells in old cultures or when exposed to
oxygen (some people think this is a survival mechanism)

Question 13

Campylobacter infection

Answer 13

• Mainly present in chicken
• Contamination of aqauatic reservoirs
• Present in milk
• Contamination through pets

Question 14

Infective dose

Answer 14

Infective dose is low
– less than 1,000 cells needed
– children and young adults susceptible

Question 15

severe type of infection incubation time

Answer 15

usually 2- 5 days, sometimes up to 10 days

Question 16

severe type of infection Symptoms

Answer 16

• Often starts with fever and headache (50% of people)
• Abdominal pain and diarrhoea (profuse, bloody, mucus)
• Self-limiting (10 days max.). May continue to shed
organisms in faeces without showing symptoms
• Vomiting is uncommon
• Rarely causes death

Question 17

Complications

Answer 17

Reactive arthritis
– inflammation of the joints
– usually lasts 2-3 weeks but sometimes much
longer
– disease mechanism not fully understood

• Guillain-Barré syndrome
– occurs 1-3 weeks after onset of enteritis
– immune attack on myelin sheaths of nerve cells
– can lead to paralysis
– occurs in 1 in 1,000 infections

Question 18

Treatment

Answer 18

• Usually no special treatment is necessary
– diarrhoea lasts for 2-3 days
– abdominal pain lasts longer
– usually clears up within 10 days but sometimes
longer
– faeces remain positive for 2-7 wks

• Severe cases
– antibiotics (fluoroquinolones, erythromycin)
– rehydration with fluids

Question 19

Mechanisms

Answer 19

Still poorly understood

– many factors likely to be involved but conclusive
evidence is hard to obtain
– sequence genome to look for genes associated with
virulence in other organisms
– examine behaviour of mutants with particular genes
knocked out
– no suitable animal model available
– can test colonization of chickens, but Campylobacter
lives as harmless commensal in poultry – colonizes
caecum but rarely causes disease
– tissue culture experiments are an alternative

Question 20

Adaptation to living in gut

Answer 20

Microaerophilic metabolism
– Low oxygen levels near to gut epithelial cells (but not
anaerobic)

Cell shape and motility
– ability to penetrate viscous mucus lining of gut

Iron acquisition

Question 21

Iron acquisition for Adaptation to living in gut

Answer 21

– intense competition for iron in the gut
– Campylobacter can acquire iron from iron-containing molecules
obtained from the host e.g. haemin or haemoglobin
– siderophores are high affinity iron-binding molecules
– Campylobacter can make use of siderophores such as
enterochelin produced by other bacteria in the gut

Question 22

Mechanisms for Adaptation to living in gut

Answer 22

Chemotaxis
– attracted towards fucose (a sugar component of mucin)
and serine; repelled by bile acids

• Motility
– long polar flagella and spiral shape help cells to burrow into mucus layer

• Adhesion
– fimbriae similar to those in E. coli have been reported in Campylobacter and may be involved in adhesion

• Invasion
– the ability to invade human cells varies widely between strains

• Toxins
– Campylobacter produce a toxin which does not seem to be a unique characteristic of pathogenic strains.

Question 23

infections source

Answer 23

• Poultry meat believed to be important
• Unpasteurized milk
• Water
• Domestic pets

Question 24

Campylobacter in humans

Answer 24

• Most cases are sporadic (scattered with no
obvious pattern)
• Few large outbreaks from a common source

Question 25

Campylobacter in animals

Answer 25

• Found in poultry, wild birds, cattle, pigs, domestic pets, faecal material in environment
• Well adapted to live in the gut of wild and domestic birds
• Does not cause disease under natural conditions

• Broiler chickens become colonized within 2-3 weeks of life and remain colonized until
slaughter

Question 26

In 2008, UK has % of broiler chicken sample contained

Campylobacter

Answer 26

In the UK 42% of samples contained less that 100
Campylobacter per gram (cfu/g) and 27% contained
more than 1,000 Campylobacter per gram (cfu/g)

The counts of Campylobacter on broiler carcasses
varied widely between samples

Question 27

Campylobacter in poultry at slaughter

Answer 27

19

Question 28

Campylobacter in poultry bought from supermarkets and shops

Answer 28

20

Question 29

Factors leading to infection

Answer 29

• Consumption of undercooked meats (e.g. BBQ)
• Cross contamination in the kitchen
• Contaminated milk
• Contaminated water
• Occasional faecal-oral route (children and pets)

Question 30

infection Incidents and consequences

Answer 30

• Free (unpasteurised) milk at a primary school
• Bird-pecked bottles at a day nursery
• Canteen in UK University serving cooked chicken

•Large economic cost of disease - sick days, loss of
production, etc.

Question 31

Controlling Campylobacter

Answer 31

• FSA has agreed new targets with industry
stakeholders to cut Campylobacter levels in chicken

• Three categories of contamination: (1,000 cfu/g)

• The agreed target is to reduce bird levels in the
highest contamination category from 27% to 10% by
2015, which the FSA says could reduce
Campylobacter cases by up to 30%.

Question 32

How many chicken slaughtered in UK each year.

Answer 32

About 850m

Question 33

How to cut Campylobacter?

Answer 33

• Modified atmosphere packaging
• Better farm hygiene
• Hot water treatment or steaming chicken carcasses
• Use of electrolysed water
• Anti-microbial washes such as lactic acid (requires EU approval)
• Better farm hygiene

Question 34

How to improve farm hygiene

Answer 34

• Hygiene barrier (footwear)
• Hygiene barrier (outside of farm)
• Financial incentives for producers
• Vaccination
• Fly Control
• Earlier Slaughter Age
• UV Water Treatment
• Thinning