Free-Living Protozoa Found in Meat-Cutting Plants

They report their findings in the September 2008 issue of the journal Applied and Environmental Microbiology.

Protozoa are unicellular microorganisms that feed on bacteria. Sometimes the bacteria survive and replicate within the protozoa. Although bacterial presence in meat-processing environments has been previously examined, no studies of protozoan communities in these environments and their role in food contamination have been conducted.

In the study researchers used a series of methods to screen for protozoa in five meat-cutting plants and found communities of amoebae, ciliates, and flagellates to be present in all. Protozoa were detected in floor drains, standing water on the floor, soiled bars of cutting tables, plastic pallets and out-of-use hot water knife sanitizers. In addition, protozoa were identified on surfaces which come into direct contact with meat, such as conveyor belts, surfaces of cutting tables, and needles of meat tenderizers. Cultures were then refrigerated for seven days, after which protozoa were still detected in half of the samples. Through microscopic observations researchers identified up to 61 morphospecies.

"This survey showed that there is high protozoan species richness in meat-cutting plants and that the species included species related to known hosts of food-borne pathogens," say the researchers.-American Society for Microbiology