Trusted Dairy Laboratory Services for more than 75 years
MASTITIS DNA SCREENING
Short Reference Guide
Eurofins DQCI
5205 Quincy Street, Mounds View, MN 55112
P: 763-785-0484 F: 763-785-0584 E: DQCIinfo@eurofinsUS.com
www.eurofinsus.com/MastitisTesting
Full Panel 16 Test Screen
(Bulk Tank Screening & cows/strings/pens)
Staphylococcus aureus
Staphylococcus spp.
(including all major coagulase-negative Staphylococci)
Streptococcus agalactiae
Streptococcus dysgalactiae
Streptococcus uberis
Escherichia coli
Enterococcus spp.
(including E. faecalis and E. faecium)
Klebsiella spp.
(including K. oxytoca and K. pneumoniae)
Serratia marcescens
Corynebacterium bovis
Arcanobacter pyogenes and Peptoniphilus (Peptostreptococcus) indolicus
Mycoplasma bovis
Mycoplasma spp.
Yeast
Prototheca spp.
Staphylococcal ß-lactamase gene
(penicillin-resistance gene)
Panel 4 Test Screen
(Bulk Tank Screening & cows/strings/pens)
Mycoplasma bovis
Staphylococcus aureus
Streptococcus agalactiae
Streptococcus uberis
Test Results
Results for each organism will be noted as
1. High (Strong Positive)
2. Moderate (Positive)
3. Low (Marginally Positive - Low Quantity)
4. Not Found
PG 1
Example Report
16 Test Screen
Corporation/Plant
ATTN: Producer
2200 Rittenhouse Street
Des Moines, IA 50321
Date sample
is collected
Date samples
are received
E
L
P
Producer name
or number
Cow ID,
Quarter ID.
Bulk tank
would be
marked TANK.
Date samples
are tested
E
M
A
X
PG 2
Example Report
4 Test Screen
Corporation/Plant
ATTN: Producer
2200 Rittenhouse Street
Des Moines, IA 50321
Date samples
are received
E
L
P
Producer name
or number
Cow ID,
Quarter ID.
Bulk tank
would be
marked TANK.
M
A
X
E
PG 3
Date sample
is collected
Date samples
are tested
Introduction
Eurofins DQCI now offers mastitis DNA/PCR screening. PCR (polymerase chain
reaction) is a technique that can identify mastitis causing microorganisms based
on the detection of their DNA. The method can detect pathogens associated
with both clinical and subclinical mastitis and is a revolutionary bovine
mastitis screening test that offers significant time savings over conventional
bacterial culture, which typically takes 48 hours to complete or even 7 days for
Mycoplasma spp.
The mastitis DNA/PCR screening can be used for different sample types:
• Cow milk samples - Test selected cows
• Bulk tank milk samples - Testing bulk tank milk samples to
screen the entire herd for mastitis causing bacteria
When collecting samples we recommend following the procedures for Collecting
Milk Samples - Follow Microbiological Procedures for the Diagnosis of Bovine
Udder Infection and Determination of Milk Quality. [NMC publication; 2004]
www.nmconline.org/sampling.htm
We also recommend that test results are reviewed with your veterinarian to
establish the appropriate treatment protocol for your herd.
Advantages of Mastitis DNA/PCR Screening
1. Test time takes 1-2 days from when samples are received by our laboratory
2.
Identify up to 15 mastitis causing microorganisms plus the Staphylococcal
β-lactamase penicillin resistance gene
3.
Can be used on treated cows since antibiotics don’t interfere with testing
4.
Works on both preserved and non-preserved milk samples
5.
Simultaneously detects all targeted bacteria species, thus overcoming the
common problem of “mixed growth” results from bacterial culture
6.
High sensitivity – can detect organisms that are present but not recoverable
by conventional culture methods
PG 4
Whole Herd Mastitis Screening
Bulk Tank Milk (BTM)
Step 1
Identify high somatic cell count herds
Step 2
Screen Bulk Tank to identify prevalence of mastitis causing organisms:
Full 16 screen for both contagious and environmental or the 4 panel that
focus on the contagious organisms. If positives in BTM, consider running
a BTM full screen second day to confirm/compare samples to minimize
possibility of sampling procedure contamination. It is recommend to
monitor BTM at least quarterly.
Step 3
Screen herd (all milking cows) for high somatic cell cows, if not already
done monthly. It is recommended that the bovine veterinarian becomes
engaged.
Step 4
Run Mastitis DNA test on high cell cows. Perform contagious screen or
full screen depending on bulk tank prevalence. It can be a 4-quarter
comingled milk sample (Quarter sampling will identify specific infected
quarters if chosen).
As a broad guide, at a BTSCC of 200,000 cells/ml, up to 15% of cows will
be infected in one or more quarters (3, 6). Each additional increase in
BTSCC of 100,000 cells/ml indicates a further increase in infection rate of
8% to 10%. At 400,000 cells/ml, perhaps one-third of cows contributing
milk to the supply will be infected, and at 700,000 cells/ml, some twothirds of the cows will be infected (3, 6) and contributing abnormal milk
to the supply.
PG 5
Bulk Tank Milk (BTM) Testing
Bulk tank milk testing should only be done if the practitioner is aware of
the pitfalls associated with this procedure:
1. BTM culturing/PCR can supply two important types of data:
a. Presence or absence of a bacterial group
b. Identification of predominant bacterial groups in BTM.
Beyond this data, assumptions must be made as to the
relevance of information gained.
2.
Bulk tank milk testing is more useful in monitoring concurrent
changes in conditions than as a tool to diagnose what
conditions have previously changed. Many changes in
management (good and bad) will be reflected by BTM cultures.
Increasing frequency in which samples are taken will increase
the probability of detecting these changes. Implementing
changes in management based upon findings from BTM
cultures should be based upon a thorough knowledge of the
ecology of bacteria and supplemented with information from
other records such as somatic cell counts,
preliminary incubation counts, clinical mastitis incidence, etc.
3.
Most important- BTM cultures are never substitutes for quarter
milk samples. BTM testing cannot be used for indicators of IMI
(Intramammary Infection) prevalence in a herd. BTM testing can be valuable supplements to quarter milk samples, but
never a substitute for determining IMI incidence and
prevalence based on quarter milk samples.
Sources 1-3 above: Adapted from “Using Bulk Tank Milk Cultures in a Dairy Practice National Mastitis Council factsheet” www.nmconline.org/articles/bulktank.htm
PG 6
Sample Submission
Since the technology is DNA based samples can be preserved, frozen, or
non-preserved. There are three options:
1. Send in a regular raw milk sample. The samples have to be cold
and shipped on ice. The samples cannot be stored for longer
time before you send it to the laboratory.
2. The samples can be frozen and stored at the point of collection
and then shipped later on ice to us (frozen)
3. Preservative must be added at the point of collection. Can then
be stored for a period and then shipped to the lab (no ice
needed)
For both 2 and 3 it is important that the raw sample is not stored for a
longer time before frozen/preservative added.
We only need a small amount of sample to conduct the test but we
encourage clients to send a typical two ounce milk sample vial.
Eurofins DQCI
5205 Quincy Street, Mounds View, MN 55112
P: 763-785-0484 F: 763-785-0584 E: DQCIinfo@eurofinsUS.com
www.eurofinsus.com/MastitisTesting