Leon the Milkman

When there is a chance of antibiotic residues passing into milk it is important to be able to test for it quickly, since milk is a highly perishable product, so action is needed quickly.  Milk can also not be worked into value added products like, yoghurt or cheese when it contains antibiotics, since the added lactic acid bacteria(LAB) will not grow in the presence of antibiotics.   So for the producer of these products it not only limits the possibilities for the raw milk, but in case they miss the presence of the antibiotics, it could mean big losses.

It is thus of vital importance to be able to test for antibiotics as quickly as possible – even before the milk tanker is off loaded at the factory.   When antibiotic milk received from one farmer is mixed with the mikl of other producers in the bulk tank, they will hold that farmer responsible for the loss of the entire bulk tank.  It is thus in the interest of farmers to make sure that they do not supply antibiotic containing milk.   This can easily happen through mis-management on the farm, in the case where a long-acting antibiotic is given in palce of a short acting antibiotic.  The cow will be placed back into the milking sequence before all the antibiotic is out of the system and it will contaminate the entire batch.

Twinsensor that could test for tetracyclines and beta-lactames has evolved into the Trisensor.

Trisensor is brought to you by Unisensor Germany and is the latest rapid test that tests for Beta-Lactam, Sulfamides and Tetracycline in milk. This rapid test tests for 3 different families of antibiotics mainly used by farmers to control or prevent animal bacterial diseases.

Due to their human harmfulness and in respect to EU regulations, efficient controls of these antibiotics residues in food and especially in milk are needed.

The Trisensor test kit provides a multiplex dipstick test (Lateral Flow (LF) assay) that uses specific receptors and generic monoclonal antibodies. The results are visualized at the 3 specific capture lines by the use of colloidal gold-conjugates.

In this final version of the test, a fourth reagent line has been added to the dipstick, known  as a “dynamic control line”. The intensity signal of this control line will proportionally increase with the sample/reagent flow migration. Therefore it reflects the correct use of the test, excludes potential invalid results and serves also to establish a threshold value limit for each test line result interpretation.

The test takes 6 minutes to run and does not require any cleaning or sample preparation. It is able to detect Limit of Detection(LoD) the 3 antibiotics at concentrations near their respective Maximum Residue Limit (MRL) values.

The results can be interpreted either through direct visual observation of the test and control or for a more “MRL-suitable” observation and result, an optical reader (Readsensor) can be used that suppresses any subjectivity from the operator and doesn’t need any calibration.

What makes this test different from the others is that it tests for Sulfamides. When ingested by humans side effects can include dizziness, drowsiness, nausea, vomiting, difficulty breathing etc. Unfortunately many South African farmers do not test for Sulfamides in milk samples and conform to EU principles regarding Sulfamides.