Microbiological criteria

Question 1

what is a microbial criterion

Answer 1

defines the acceptability of aproduct/batch or process based on the amount (or absence) of a MO/quant of the toxins/metabolites or mass/vol…

Question 2

bw what food safety objective control points are MC undertaken

Answer 2

between the PC and PO, and the PO and FSO of the food safety policy flow chart

Question 3

why is MO criteria different to the FSO or PO?

Answer 3

FSO and PO only have limits, but MO criteria has more aspects - different MO with different limits, sampling plans, type of food stuff and analytical method varies

Question 4

name thew 2 types of MC in the EU

Answer 4

1. food safety criteria

2. process hygiene criteria

Question 5

desc what the food safety criteria is

Answer 5

defines the acceptability of a product at retail. this test will be the reason for product recalls.

Question 6

desc the process hygiene criteria

Answer 6

acceptable functioning of the production process. sets a contamination value, above which correcve actions must be taken

Question 7

what are MO criteria used for

Answer 7

validation and verification of HACCP processes
assess acceptability of a batch
used in legislation to communicate the level of hazard control required
assurance

Question 8

what is the difference bw MO testing and criteria

Answer 8

testing is part of the criteria, but is looking fot presence, not the amount/level

Question 9

what are the basic criteria involved

Answer 9

• type of hazard
• food category
• production stages
• sampling plans
• interpretation

Question 10

which organisms are tested for?

Answer 10

indicatory organisms = total aerobic count or aerobic colony count
faecal coliforms
pathogens = salm, listeria, staphy a

Question 11

desc the basic difference bw 2 and 3-class sampling plan

Answer 11

• 2-class: pathogens, presence and absence only.
  n (no samples), m (mas acceptable no bacteria/gram), and c (max no of samples that can exceed m).
  classes: satis, unsatisf.
• 3-class: indicator organisms usually.
  n, c (no samples giving a figure between m and M), m and M. acceptable values are below m, but it is allowed if SOME (c/n) are bw m and M.
  classes = satisfactory; acceptable; unsatisfactory

Question 12

name the pathogens which are considered a mod risk

Answer 12

s aureus toxin, vibrio parahaemolyticus, b cereus, cl perfringens

Question 13

name the path considered a serious risk

Answer 13

salmonella, shigella, listeria

Question 14

name the path considered a severe risk

Answer 14

EHEC (STEC and ETEC), vibrio cholera, cl botulinum, EPEC, cronocbacer and listeria (for immune comp population)

Question 15

name a few different types of samples

Answer 15

excision of the skin square (carcasses)
wet/dry swab
direct contact with agar medium

rinses - poultry
retail meat sample
batch sample

Question 16

name the basic steps in sample processing

Answer 16

sample
get to lab (accredited)
remove bacteria from sample - make into a broth and then dilute
examine sample for target org
confirm suspected coolonies
calc and report

Question 17

name the best sites for sample cattle (and sheep) carcasses for enterobacteriaceae and total aerobic counts

Answer 17

rump
flank
brisket (or lat flank in sheep)
neck

area of 20cm (destructive) or 100cm (non-dest) shoul dbe sampled

Question 18

name the best sites for sampling pig carcases for enterobacteriaceae and total aerobic counts

Answer 18

ham
belly
back
jowl - drips down and collects

Question 19

describe the swabbing method for salmonella

Answer 19

an S-like wiggle to include rump, belly and jowl/brisket

area of 400cm^2 shoud be sampled

Question 20

how often should red meat carcasses be sampled

Answer 20

5 individuals, weekly

Question 21

what temp should samples be transported at

Answer 21

<4degrees (unless frozen or canned - <40)

Question 22

name some conformational tests for ID path

Answer 22

gramstain
catalase, oxidase, CHO fermentation, urease, methyl red
API commercial biochem kit
latex agglutination (e coli and s aureus)
serology (salmonella spp ID)

Question 23

what is cfu/g

Answer 23

colony forming units per gram

Question 24

what is the satisfactory level of TAC and ENT log for excision and swabbing cultures for non-poultry carcasses

Answer 24

excision - 3.5 (4 - pigs)

swab - 2.8 (3.3 pigs)

Question 25

what are the max log culture for salmonella swab sampels

Answer 25

salmonella swab - 2/50 (3/50 in pigs)