Salmonella Prevention Techniques

To tackle Salmonella  diagnosis, Dr. Goodman and her team developed a workflow for testing veterinary matrices, including enteric and cloacal tissues (mostly from cows, but also from alpaca, chicken, clouded leopard, deer, duck, gazelle, goat, goose, hooded crane, horse, rabbit, raccoon, and turtle species), feces (from cows, dogs, and horses), and feed, plus environmental samples, by using real-time polymerase chain reaction after selective enrichment in Rappaport-Vassiliadis soya medium.

The study was funded by and performed in collaboration with the FDA’s Veterinary Laboratory Investigation and Response Network.

Dr. Goodman says that the new method to detect Salmonella is now available as an environmental testing program for animal facilities through Cornell’s Animal Health Diagnostic Center (AHDC). “The test covers all S. enterica subspecies and serotypes and offers next-day results,” she relates.

Stakeholders throughout the country can access the testing on a fee for service basis by shipping samples to the AHDC. “Instructions are available on our website,” Dr. Goodman says.

“Salmonella  biosurveillance in veterinary facilities and on farms is critical because animals can shed the bacteria without showing clinical disease signs,” Dr. Thompson emphasizes. “Thanks to the 24-hour turnaround time with the new test, infected animals in a hospital or clinic setting or on a farm can be quarantined, and contaminated environments can be identified to ensure other animals are not being exposed to  Salmonella Dublin.”

The AHDC environmental test for Salmonella is applicable to poultry farms, Dr. Goodman notes, although the new rapid method is not a National Poultry Improvement Plan (NPIP) test. “We would encourage this testing in addition to NPIP testing if poultry producers wanted to monitor for any Salmonella, not specifically Enteritidis,” she advises.

Dr. Goodman says that, while the AHDC Salmonella testing protocol is potentially applicable to food manufacturing plants and food besides raw milk, and could be adopted by other labs, the AHDC does not test human food products.

Dry Surrogate Organisms

Based in historic Dijon, France, birthplace of the famous mustard and just 30 miles from the birthplace of Louis Pasteur, a company called Novolyze is making an international name for itself that would surely make the “Father of Microbiology” proud.

Novolyze is a developer and manufacturer of dry, ready-to-use surrogate microorganisms that mimic the behavior of foodborne pathogens, and thus make it possible for food companies to perform in-plant preventive control validations.

While Novolyze has developed a full range of surrogate microorganisms qualified for different kinds of food products, target pathogens, and kill steps, the firm’s signature product is a patented dry Salmonella surrogate marketed under the trade name SurroNov.

“Our surrogate products are non-pathogenic, so food manufacturers can validate their processes right in their own production lines,” says Karim-Frank Khinouche, the firm’s founder and CEO. “SurroNov surrogates validate such products as spices, nuts, cocoa, pet food, powders, cereals, pasta, flour, cookie dough, and baked goods; and they can be used in extruder, steam pasteurizer, oven, and dryer applications.”

Khinouche explains that SurroNov surrogates are formulated with food-grade ingredients to stabilize them, while ensuring initial inoculation levels and their thermal behaviors remain the same. All SurroNov surrogates are Biosafety Level 1 microorganisms.

“SurroNov’s high-volume production capability enables a manufacturer to inoculate multiple tons of product, which is important, for example, if an extruder is producing 300 pounds of product per minute,” Khinouche notes. “Another benefit is being able to run validation/challenge studies in-house, rather than incurring the expense of third party laboratories.”

The patented SurroNov surrogates are available in unit pouches ranging from 25 grams to 1 kilogram, Khinouche relates. They can also be acquired pre-inoculated with a food ingredient, packed in bulk pouches, or in thermally-resistant bags or thermal balls for a faster and easier in-plant use.