Prototheca sp are colorless algae that are found in a variety of environmental sources and can cause chronic mastitis in cows. Currently, there is no effective treatment for protothecal mastitis, resulting in significant economic losses for producers.
File: CL-Res-62-Prototheca-Background-and-Control-1.pdfStaphylococcus aureus is a coagulase-positive bacteria, which is a general name for a class of bacteria that are small, round, and gram-positive. Staph. aureus is a contagious pathogen, which is transmitted from infected glands or teats during the milking process. It is a major cause of chronic or recurring clinical mastitis infections in dairy cattle and is believed to be the most significant contagious mastitis pathogen
File: CL-Res-63-Staphylococcus-aureus-1.pdfStreptococcus agalactiae is a gram-positive, chained coccus bacterium and the reservoir in which it is found is infected udders. Strep. ag. is an obligate pathogen of the udder of dairy cattle. The presence of Strep. ag. infections has been reduced by modern milking technologies. This bacterium still is a threat for all dairies that do not have a closed herd. Strep. ag. cannot persist very long outside of the mammary gland. Cattle infected by Strep. ag. often have more than one quarter infected.
File: CL-Res-65-Streptococcus-agalactiae-1.pdfStreptococcus dysgalactiae – This gram positive, beta-haemolytic, coccal bacterium can be spread from cow-to-cow or acquired from the environment. Good hygiene and mastitis control programs including post-milking teat disinfection, antibiotic dry cow therapy and maintaining a clean, dry environment will reduce infections caused by this pathogen.
Streptococcus uberis – This gram-positive bacterium is the most frequent cause of mastitis in lactating cows. It can be isolated from the udder, skin, lips, and genital area of dairy cows, but infections are typically acquired from the environment. This bacterium causes mastitis during the dry period and are isolated frequently from cows with clinical mastitis during early lactation. Good hygiene and mastitis control programs including post-milking teat disinfection, antibiotic dry cow therapy and maintaining a clean, dry environment will reduce infections caused by this pathogen.
Other Streptococcus species isolated less frequently include the following:
S. acidominimus, S. alactolyticus, S. canis, S. zooepidemicus, S. equi, S. equinus (formally S. bovis), and S. parauberis.
Enterococcus species – Enterococcus species are a gram-positive cocci and lactic acid bacteria. Species include E. durans, E. faecalis, E. faecium, and E. saccharoluticus. These bacteria cause clinical and subclinical mastitis infrequently. Cows are infected from environmental contamination. Effective mastitis control procedures as mentioned above will control these mastitis-causing pathogens.
File: CL-Res-57-Environmental-Streptococcus-species-15-05-06-1.pdfMicrobiology Media Order Form
File: FM-CL-ORD-4-MICROBIOLOGYMEDIAFORM-1.pdfMilk samples may be collected individually from each affected quarter (quarter milk samples) or combined from multiple quarters of a cow into one sample tube (composite milk samples). Composite milk samples are not recommended however, as cultures usually reveal growth of numerous different bacterial species, making it difficult, if not impossible, to determine which pathogens are causing mastitis and which are environmental contaminants. Isolation of contagious organisms, such as Staphylococcus aureus, Streptococcus agalactiae, or Mycoplasma sp., are indicators of true infections of the udder. Environmental organisms, such as Streptococcus spp., coliforms, Staphylococcus spp., (coagulase negative Staph.), Pseudomonas sp., Corynebacterium sp., yeast, and fungi, may be contaminants or true infections. Unless only screening for contagious pathogens, composite milk samples should be avoided.
Milk samples may become contaminated with bacteria from the hands of the sample collector, the environment, and the teat, skin or teat canal of the cow. It is important that proper sample collection techniques are used in order to avoid contamination of the milk sample.
Valuable diagnostic information can be gained from a quantitative interpretation of the Johne's ELISA. In general, the ELISA value is a measure of the concentration of serum antibodies to Mycobacterium avium subspecies paratuberculosis (MAP). Generally, serum antibody levels increase as the infection progresses. Animals with higher ELISA values are more likely to be shedding the bacterium in milk and colostrum and be heavy fecal shedders than lower scored animals. High ELISA scored animals are also at increased risk of developing clinical Johne's disease.
Currently, there are three, USDA-certified kits available in the U.S. for the diagnostic detection of MAP-specific antibodies. The VMRD Mycobacterium avium paratuberculosis, Zoetis Paratuberculosis SERELISA kit and the IDEXX Laboratories, Inc MAP Antibody ELISA. The WVDL is currently providing and is proficiency tested using the VMRD kits for the detection of MAP specific antibodies. WVDL does not currently use the Zoetis Paratuberculosis SERELISA kit or the IDEXX Laboratories, Inc MAP Antibody ELISA kits. It is important to remember that each kit manufacturer develops proprietary reagents such as antigen and conjugates (antibodies) that may not be the same. It is possible that one serum/plasma sample could test positive with one kit, but be negative with the other. This is because the antibody in the serum/plasma may only bind the one antigen or antigenic site from one kit manufacturer, but not the other kit manufacturer’s antigen. The only way to confirm if the animal is infected with MAP is to send a fecal sample for direct PCR or liquid culture.
Necropsy Submission Form
File: FM-CL-SUB-41-WVDLNecropsySubmissionForm.pdfBackground: Federal regulations and vendor policies exist prohibiting the use of barbiturates in euthanasia of animals disposed of by rendering or landfill.
Species affected and disposal options: The following species can be rendered, if not euthanized with barbiturates or diagnosed with a select agent: bovines <30 months of age (including fetuses), bovines > 30 months of age with brain and spinal cord removed, bovines > 30 months of age with a negative BSE test, small ruminants with a negative scrapie test, poultry, pigs, camelids, lagomorphs, and fish. In addition to animals euthanized with barbiturates or animals diagnosed with a select agent, the following species cannot be disposed of by rendering: cervids, horses, large wildlife and zoo animals. Incineration is a disposal option for domestic dogs and cats, mustelids, pocket pets, and small wildlife and zoo animals.
WVDL Zero Tolerance Barbiturate Policy
The best samples are collected within 4-8 hours of death, but it’s difficult to predict which cases will
be diagnostic. Please collect both fresh and formalin-fixed tissues from any organ that has gross
lesions.