Slicers and Belts Increase Risk of Listeria Contamination, Says Study

Bread feeding machines, slicers, conveyor belts and water hoses increase the risk of contamination by Listeria monocytogenes, a study reveals.

A research team from the Institute of Food Safety and Hygiene in Zurich, Switzerland, said of the 86 strains 93% belonged to serotype 1/2a and genetic lineage II. Rep PCR and PFGE analysis yielded six profiles.

Nearly 78% of strains belonged to only one genotype, which was found in slicers, conveyor belts, tables, bread-feeding machines, spattles and air blow-guns.

The report said strains of this genotype persisted for more than nine months in slicers and conveyor belts due to the difficulty to clean and maintain them.

Air blow-guns and water hoses testing positive for strains of certain genotypes might indirectly contribute to the contamination of food products by the hands of employees, the report said.