Pennsylvania Veterinary Laboratory

Tickborne disease testing

PVL recently introduced a duplex real-time PCR assay for the detection of Anaplasma phagocytophilum and Borrelia burgdorferi DNA in ticks. Test cost is $35/specimen for both agents.

• Borrelia burgdorferi, a tick transmitted spirochete, is the etiological agent of Lyme disease. The disease is transmitted by Ixodes spp. ticks (blacklegged or deer ticks). Specimens acceptable for PCR testing include the tick, a skin biopsy, synovial or cerebral spinal fluid, fresh tissue, formalin-fixed paraffin embedded (FFPE) tissue blocks or shavings.
• Anaplasma phagocytophilum is a rickettsial disease, also transmitted primarily by Ixodes ticks (blacklegged or deer ticks). A. phagocytophilum is the causative agent of granulocytic anaplasmosis (formerly granulocytic ehrlichiosis) in humans, dogs and horses. Common clinical signs of infection in horses include fever, decreased appetite, lethargy, petechiae, icterus, reluctance to move, ataxia, distal limb edema along with laboratory findings of thrombocytopenia and leukopenia. Most frequently reported clinical signs in dogs include lethargy, fever, lack of appetite and musculoskeletal signs. Laboratory abnormalities in dog include thrombocytopenia, anemia, lymphopenia, leukopenia and mildly elevated levels of hepatic enzymes. Specimens for PCR testing include the tick, EDTA blood (purple top) and tissue. Ticks for testing must be submitted in concurrence with a veterinarian’s referral in a tightly sealed plastic bag or container to the lab.

Brucella melitensis

Brucella melitensis primarily infects sheep and goats in which it is a significant cause of abortion. Brucellosis is also a serious zoonotic disease, causing undulant fever in humans. B. melitensis has not been found recently in the U.S. However, this test is frequently requested by countries importing sheep or goats from the U.S. PVL now offers the B. melitensis card test for $2 per animal.

Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS)

All three PADLS labs are now offering duplex real-time PCR for the detection of M. gallisepticum and M. synoviae in poultry. MG infections are particularly significant in commercial flocks, backyard flocks and even pet birds. This new assay is more sensitive and rapid than previous assays. Specimens that can be tested include swabs, aspirates, tissues, culture broth and plates. The fee is $40 per specimen.

Equine herpes virus (EHV)

EHV is a significant cause of abortion and neurological disease in equids. Besides providing rapid detection of EHV -1 by PCR, we can also distinguish between the wild- type EHV-1 and the neuropathogenic variant. For abortion cases, please submit a whole fetus with the placenta, if possible, to ensure a complete diagnostic work-up.

For antemortem testing, submit both whole blood and nasal swabs.

• Whole blood: collect a minimum of 15 cc of blood in two 10 cc EDTA (purple top) tubes.
• Nasal swabs: use a 5-6 inch long, plastic shaft, polyester tipped swab to gently rub the mucosa of the nasal cavity. Break the swab off into a sterile red top tube. No additives are suggested, although swabs in appropriate viral transport medium will be accepted.

MALDI-TOF (Matrix-assisted laser desorption ionization-Time of Flight)

PVL has started using the new MALDI-TOF for bacterial pathogen identification. Over 10,000 bacterial isolates have already been screened in last 3 years. The proteomics-based-approach has changed clinical microbiology. The main benefit to clients is rapid and accurate results. Using this methodology, when fresh and pure cultures are tested, identifications can be achieved in minutes.