FSIS Begins New Pork Screening Tests

The USDA’s Food Safety and Inspection Service has replaced the Fast Antimicrobial Screen test (FAST) with the Kidney Inhibition Swab (KIS) test for swine carcasses at processing establishments that slaughter both swine and cattle and where the KIS test is already in use for cattle, according to the American Meat Institute.

FSIS plans to replace FAST with the KIS test in all remaining establishments slaughtering swine during calendar year 2012. Carcasses for sampling and testing by the KIS test are selected in the same way as carcasses selected for FAST. Read the FSIS notice.

In addition, FSIS has updated the confirmation step used when a positive sample is identified. The new confirmation test is more specific and is able to confirm residues of a particular antibiotic. “FSIS has switched its procedure from a biological test to a chemical test for confirmation of a positive screening test for antibiotic residues,” says Paul Sundberg, DVM, vice president, science and technology for the National Pork Board. “The new confirmation step increases the ability to arrive at a definitive answer on violative residues in meat.”

According to Sundberg, occasional instances of residues resulting from procaine penicillin injections have been reported. “Based on FSIS tests, there have been reports of the detection of penicillin violations in cull sows,” he says. “Even if withdrawal times are strictly observed, there are situations that may arise that would require an extended withdrawal period.” NPB is currently conducting research to verify the potential for detecting penicillin residues.

It appears that the amount of penicillin administered into one injection site affects the potential of detecting residue violations in sows. The recommended withdrawal time for procaine penicillin is at least 15 days, according to Sundberg. “Our research is investigating if this will be sufficient even for our domestic markets given the likely uses of procaine penicillin on the farm and the sensitivity of the new tests.”

If a sow requires a penicillin injection, no more than 10 mL (10 cc) should be injected into one site. It is also important to select different injection sites if a sow requires more than one treatment, according to Sundberg. The issue has not been reported in finished slaughter hogs.

Antibiotic withdrawal times are established by the Food and Drug Administration prior to approval of products. The violative or non-violative residue issue in meat is not an antibiotic resistance issue. According to Sundberg, it is an important differentiation. “Antibiotic resistance is a very important issue and both veterinarians and pork producers are diligent when using antibiotics in preventing the issue,” he says. “However, antibiotic resistance is not related to potential violative residue issues in meat.”

[e-Letter editor’s note: Penicillin G Procaine is approved for use in swine only for the treatment of erysipelas at a dose of 3,000 units per pound of body (1 mL per 100 pounds). Administration should not exceed 10 mL at a single injection site. Use at a higher dosage or to treat other indications would be considered extra-label use and requires veterinary approval and an extended withdrawal period to comply with the requirements of AMDUCA.]

Porknetwork, September 19, 2011
By Rick Jordahl