Detection of Antibiotic Residues inVinamilk

Kris FergusonRegional Sales Manager Food and Crop Protection APAC

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Why Test?

1.Example of a European milk qualitycontrol program

2.Problem of fast vs broad spectrumtests

3.Delvotest BLF how to use

4.Best practice when using Delvotest

Content

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Milk Residue Control : Example of the EU

Animal’s milk1-40 Liters

Farm’s tank>>1,000 Liters Truck

>>10,000 LitersSilo>>100,000 Liters

Consumer’s productsYoghurt, Cheese, etc

Dairy Factory

FARM

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DAIRYCONTROL

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Broad Spectrum test.Tests such as Delvotest SP NTor Delvotest T are capable ofdetecting all antibiotics in themilk in 2h30min to 3hours.

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Fast tests for -lactams.Tests such as Delvotest BLFare capable of detecting allantibiotics from the -lactamfamily in 5 minutes.

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Milk Residue Control : Example of the EU

Animal’s milk1-40 Liters

Farm’s tank>>1000 Liters Truck

>>10,000 LitersSilo>>100,000 Liters

Consumer’s productsYogurt, Cheese, etc

Dairy Factory

Laboratory>1,000 samples/day

Good milk quality starts at the farm. Farmers are responsiblefor the delivery of good milk (price increases with quality).

FARM

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DAIRYCONTROL

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Tank sample is takenby the truck andsent to the lab

Farms will befined ifantibioticsare detected.

Strong collaborationbetween Lab and Dairy.The Dairy organises andpays for the testing of themilk samples.

Fast test and broad spectrum testsThe problem

Broad Spectrum test.Tests such as Delvotest SP NTor Delvotest T are capable ofdetecting all antibiotics inmilk in 2h30min to 3hours.

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Fast tests for -lactams.Tests such as Delvotest BLFare capable of detecting allantibiotics from the -lactamfamily in 5 minutes.

Based on Bacillus bacteriaSensitivity depends on the way

antibiotics acts on the Bacillus.

Based on affinity of antibody or ingeneral proteins with the antibiotic

Sensitivity depends on theselectivity of the binding moleculeto the antibiotics.

Those are different targets withdifferent affinity for antibiotics

different sensitivity profiles

Delvotest BLF

IncubatorUse

Press Program to change timer:“T1 2” means timer 1 : 2minPress on Time Set x times to increase T1 ofx min.When time reached, long press on Time Setwill save the new time.

Press Program again to change timer 2:Same procedure as for T1.

Temperature set (63°C – 65°C):Press “Program” together with “Time Set”to increase temperature.Press “Program” together with “Start/Stop”to decrease temperature.

Press Program to change mode: Auto(Autoamtic switch off – no sound) or Snd(sound is played after incubation)Press on Program to select desired modeand long press on Program to save theselected program.

Time SetPress several times on Time Set to selectthe desired incubation time. (Time loops1:45 to 3:15)

Temperature set (63°C – 65°C):Press “Program” together with “Time Set”to increase temperature.Press “Program” together with “Start/Stop”to decrease temperature.Start /Stop

Power on: press I/O

Display: Display “PrE” “HEAt”“brd”

Display “64°C”and “cont”

T°=64°CStart count downDisplay remaining time

Display “64°C”and “Count”

T°=64°C

Start /Stop

Start count down (2min)Display remaining time

Time elapsed

Bip sound is played“StRp” is displayed

Start /Stop to start 3 min

Start count down (3min)Display remaining time

Time elapsed

Play Bip soundDisplay “REAd”

Start /Stop

Start

Stop5sec

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Display: Display “PrE” “HEAt”“FASt”

Press”I /O” and “Program”+ “I/O” toswitch from broad spectrum test mode

to fast test mode.

Start

Stop5sec

Start /Stop to stop bip soundPlay Bip sound*Display “Read”

AUTO Stop Heating**

Time elapsed

Start/Stop

Delvotest Step by Step

Take representative sample

Cut of or remove ampoulesfrom tray (!DO NOTDAMAGE OTHER PLATE’S orAMPOULE’S FOIL, ifdamaged, will be falsepositive!)

Make a hole (Not necessaryto remove foil forampoules)

Pipette milk (the correct volumeof milk is the one in the pipettetube, not its tank)

Add the milk to the testThe antibiotics is any willdiffuse in the agar gel

Incubate: the bacteriain the agar gel willgrow if no antibioticsin the milk

Read the test. POS or NEGdepending on colors(POS=Not good milk,NEG=Good milk)

Principle of Delvotest

Penicillin 4

Antibiotic freePOSITIVE RESULT

NEGATIVE RESULT

Sulfadiazine 100

Control TimeTime

Colo

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Control time versus fix reading time

Penicillin 4

Antibiotic freePOSITIVE RESULT

NEGATIVE RESULT

Sulfadiazine 100

Control TimeTime

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Fix timeFix time Test less sensitive than at control timeIf incubation time increases, the test sensitivity decreases

Delvotest Colors

Wrong color reading Wrong results!

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Delvotest Colorcards for improved reading

Systematically in each box of Delvotest T

On request

On request

On request

Delvotest: Storage and Sampling

Good practice in storage/handlingThe test is sensitive to LIGHT.

Store in the DARK (in original packaging).

The test is sensitive to TEMPERATURE.Store 4-8°C (in original packaging).Place ampoules in fridge directly after cutting out the

required number.

Test should not freeze even partially. (creates milk runnersand/or false positive, test can also become liquid)

Up to 4 days, test can be transported at max 30°C.

The test is sensitive to AIR.Test where foil is removed can dry. (False positive

/ dried test)

What if not stored correctly?Spores DIE (when freezing, agar gel looses structure)Test becomes slower and more sensitiveFalse positives

Thank You!