MASTITIS DNA SCREENING

Transcription

1 Trusted Dairy Laboratory Services for more than 75 years MASTITIS DNA SCREENING Short Reference Guide Eurofins DQCI 5205 Quincy Street, Mounds View, MN P: F: E:

2 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) 1. High (Strong Positive) 2. Moderate (Positive) 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 3. Low (Marginally Positive - Low Quantity) 4. Not Found PG 1

3 Example Report 16 Test Screen Corporation/Plant ATTN: Producer 2200 Rittenhouse Street Des Moines, IA Date sample is collected Date samples are received Cow ID, Quarter ID. Bulk tank would be marked TANK. Producer name or number EXAMPLE Date samples are tested PG 2

4 Example Report 4 Test Screen Corporation/Plant ATTN: Producer 2200 Rittenhouse Street Des Moines, IA Date sample is collected Date samples are received Cow ID, Quarter ID. Bulk tank would be marked TANK. Producer name or number Date samples EXAMPLEare tested PG 3

5 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] 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

6 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

7 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 PG 6

8 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 P: F: E: DQCIinfo@eurofinsUS.com