Food Microbiology Flashcards

PH04-05

1
Q

name the foodborne bacterial pathogen

most frequent cause of foodborne outbreaks; highest number of cases & hospitalisations

(eggs, egg products, mixed foods)

A

Salmonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

name the foodborne bacterial pathogen

most frequently reported zoonosis;
most commonly reported GI pathogen in UK

(meat from chickens and turkeys)

A

Campylobacter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

name the foodborne bacterial pathogen

most deaths

(dairy, meat products, fish)

A

Listeria monocytogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

name the foodborne bacterial pathogen

(pork products, unoasteurised milk)

A

Yersinia enterocolotica

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

name the foodborne bacterial pathogen

(minced meat, unpasteruised milk, leafy greens, bean sprouts, water)

A

Shiga toxin-producing E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

name the 5 most common foodborne bacterial pathogens in the EU

A
  1. Salmonella
  2. Campylobacter
  3. Listeria monocytogenes
  4. Yersinia enterocolitica
  5. Shiga toxin-producing E. coli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

name the 3 important EU food safety legislations

A
  1. Regulation (EC) 852/2004 article 4
  2. Reguation (EC) 2073/2005
  3. Regulation (EU) 2017/625
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

name the safe food legislation

gives defined limits on presence or number of microbes or their metabolites in food;
ensures food is produced hygienically and is safe for the consumer BUT cannot guarantee food safety

A

Microbiological Criteria for Foodstuffs

Regulation (EC) 2073/2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

name the 2 types of criteria established in Regulation 2073/2005 (microbiological criteria for foodstuffs)

A
  1. process hygiene criteria
  2. food safety criteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what happens when a food safety criterion is not met?

A

batch of food should be removed from and not placed on market

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

name the criteria established in Regulation 2073/2005

purpose for testing against this criteria is NOT to assess the fitness of individual carcases or processed meat for human consumption BUT to provide an indication of performance and control of the slaughter, dressing and production hygienic process at time of sampling;
applies to:
1. carcases
2. minced meat
3. meat preparations
4. mechanically separated met

A

process hygiene criteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

this is a measure of bacteria in the sample that can survive in the conditions on the surface of carcases or in processed meat;
includes bacteria arising both from animals and from the slaughterhouse or meat processing environment

(requirement of process hygiene criteria)

A

Aerobic Colony Count (ACC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

this is a grouping of bacteria that live in the intestines of animals and the environment
(includes E. coli and Salmonella)

A

Enterobacteriaceae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

name the criteria established in Regulation 2073/2005

these have been set out for fresh poultry meat, minced meat, meat preparations, meat products and mechanically separated meat;
if criteria are exceeded, the batch tested is unsatisfactory and should be removed from the market (or not placed on the market)

A

Food safety criteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

demonstration of compliance with food safety criteria for meat and processed meat is required by the absence of Listeria monocytogenes in …

A

ALL ready-to-eat foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

demonstration of compliance with food safety criteria for meat and processed meat is required by the absence of Salmonella in …

A

carcases/meat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the only compulsory test for working surfaces when making ready-to-eat products under food safety criteria

A

for Listeria monocytogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what species of Campylobacter is responsible for 90% of human enteric illness

A

C. jejuni

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

name 5 conditions that Campylobacter is susceptible to

A
  1. low oxygen
  2. dessication
  3. freezing
  4. low pH
  5. high temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the biggest reservoir of Campylobacter causing human infections

A

poultry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

name 4 ways to control Campylobacter on-farm

A
  1. improved biosecurity and hygiene
  2. simple modification of diet (add organic acids or probiotics)
  3. reduce slaughter age (33-35d)
  4. discontinue thinning
22
Q

name 3 ways to control Campylobacter in the slaughter house

A
  1. cleanliness of birds
  2. good hygienic practices & HACCP throughout
  3. accurate evisceration
23
Q

what is the most common species of Salmonella causing gastroenteritis

A

Salmonella enterica

24
Q

name 3 serovars of Salmonella enterica that cause disease

A
  1. Typhimurium
  2. Enteritidis
  3. Newport
25
Q

name the type of salmonellosis

nausea, vomiting, abdominal cramps, diarrhoea, fever, headache

A

enteric salmonellosis

26
Q

name the type of salmonellosis

septicaemia;
endemic to Africa, Asia, Central and South America;
more a disease of poverty and poor hygiene conditions

A

Typhoidal salmonellosis

27
Q

what is the most common source of enteric salmonellosis infection?

A

poultry

(both meat and eggs)

29
Q

name 2 important aspects of control of Samonella

A
  1. vaccine
  2. Red Lion Code
30
Q

this is a notorious strain of shiga toxin-producing E. coli (STEC);
causes mild diarrhoea to haemorrhagic colitis, haemolytic uraemic syndrome (HUS), thrombocytopaenia purpura

A

E. coli O157:H7

31
Q

what is the main reservoir for STEC;
they are asymptomatic, super shedder individuals

32
Q

name 5 clinical signs of listerosis in humans

A
  1. bacteraemia
  2. septicaemia
  3. meningitis, encephalitis
  4. miscarriage
  5. neonatal disease
33
Q

name the zoonotic foodborne virus
(most foodborne viruses are not zoonotic)

A

Hepatitis E

34
Q

name the foodborne virus

most common cause of infectious intestinal disease in the UK;
highly infectious and easily transmissible;
can be transmitted through food, BUT majority of cases NOT foodborne;
symptoms: vomiting, diarrhoea, headaches, abdominal pain, fever

35
Q

name the type of hepatitis virus

those that are parenterally transmitted

A

‘serum’ hepatitis

36
Q

name the type of hepatitis virus

those transmitted through the faecal-oral route i.e. “enteric” hepatitis

A

“infectious” hepatitis

37
Q

name the 2 types of hepatitis virus that cause “enteric” hepatitis

A
  1. Hepatitis A
  2. Hepatitis E
38
Q

what animal is the biggest reservoir for Hepatitis E

39
Q

name the method for bacterial food testing

methods based on detection, isolation, characterisation and identification of microbes

A

qualitative methods

40
Q

name the method for bacterial food testing

methods based on the detection & enumeration of microbes (usually in liquid and/or agar material)

A

quantitative methods

41
Q

name the 5 steps of qualitative lab culture methods

A
  1. sample collection
  2. culture of samples in enriched broth
  3. culture on selective media
  4. confirmatory tests
  5. examine identification tables
42
Q

name the type of bacteriological agar

non-selective, non chromogenic;
most bacteria appear similar (white colonies)

A

Luria-Bertani Agar / Nutrient Agar

43
Q

name the type of bacteriological agar

non-selective;
used for assessment of haemolysis (Clostridium perfringens);
can grow a large variety of other more fastidious organisms

A

blood agar (sheep, horse)

44
Q

name the type of bacteriological agar

semi-selective;
used for Salmonella and Shigella isolation;
some Salmonella can metabolise thiosulphate - produces hydrogen sulphite and colonies turn black in the centre

A

xylose lysine deoxycholate (XLD) agar

45
Q

name the type of bacteriological agar

selective for enterobacteriaceae (due to bile salts);
chromogenic: lactose fermenters appear pink/red (E. coli), non-fermenters appear white (Salmonella)

A

MacConkey agar

46
Q

name the type of bacteriological agar

selective for Campylobacter;
have to be incubated in reduced oxygen (5%)

A

charcoal-cefoperazone-deoxycholate agar (CCDA)

47
Q

name the rapid method of detection

used to separate & concentrate target organism;
10 min procedure;
specific Ab fixed on paramagnetic beads added to broth;
binding of pathogen to Ab, magnet used to immobilise pathogen, removal of remainder

A

immunomagnetic separaton (IMS)

48
Q

name the rapid method of detection

firefly luciferin-luciferase;
two-step biochemical reaction takes place, which produces light;
most widely used for monitoring cleaned surfaces

A

ATP bioluminescence

49
Q

name the rapid method of detection

widely used in food testing;
sensitivity varies;
can be specific for pathogen at species and subspecies/strain level;
can also detect toxins and allergens

A

ELISA
(Enzyme Linked Immunosorbent Assay)

50
Q

name the rapid method of detection

can be very specific;
can identify pathogen strain;
multiple primers can be used at once to specifically ID more than one bacterial strain;
degenerate primers can be used to ID multiple strains of same species but additional confirmatory tests needed afterwards

A

Specific Nucleic Acid Amplification / Detection
(PCR)

51
Q

name the rapid method of detection

serum from immunised animals provides fast (2 min) and specific detection;
bacterial cells cross link via surface antigens bound to antibodies in the sera;
easily used for Salmonella type identification

A

serum agglutination