The role of aerosols in transmission of microorganisms (including Listeria) to ready-to-eat meat/poultry products

This study demonstrated that aerosol particle size, relative humidity and distance from the air handling unit impacted settling rate and potential that exposed ready-to-eat products may become contaminated.

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Objectives

The objectives of this study were to investigate the potential of using Jonesia denitrificans as a surrogate for aerosol studies of L. monocytogenes and to study the role of aerosol in transmission of microorganisms (including L. monocytogenes) to ready-to-eat meat/poultry products in a bioaerosol containment chamber as well as in a small-scale poultry deboning room (J. denitrificans only).

Conclusions

The settling rates of aerosol-borne L. monocytogenes and J. denitrificans were similar and both dependant on particle size and relative humidity of the environment.  Studies on the survival and growth of J. denitrificans and L. monocytogenes on non-cured turkey meat with no preservatives at 4 and 12ºC with and without vacuum packaging revealed that J. denitrificans is not a suitable surrogate for L. monocytogenes for persistence and growth studies. Also, swab sampling of environmental surfaces of the deboning room immediately after aerosolizing J. denitrificans yielded negative results; indicating J. denitrificans is not a good environmental survivor.

Deliverable

Jonesia denitrificans is not a good surrogate for aerosol studies of L. monocytogenes.  Other surrogate organisms should be identified.