Development and Validation of a Pilot Scale Enhanced Biosafety Level Two Containment for Performance Evaluation of Produce Disinfection Technologies

Abstract

The development and validation of the Biosafety Level 2 (BSL-2) enhanced containment system located at the produce pilot plant facility of the U.S. Department of Agriculture—Eastern Regional Research Center is presented here. This multi-purpose containment is used to enclose pilot and pilot scale washing and sanitizing equipment for fruits and vegetables, or other decontamination equipment where aerosol generation is likely, and complete protection is required for researchers. This containment is operated under a negative pressure with all exhausted air (approximately eight containment air exchanges per hour) being passed in parallel through two hydrophobic HEPA filters. During operation, personnel are excluded from the containment, materials are introduced into and removed from the containment via pass-throughs, and equipment is operated via computer control and glove ports.

At the completion of any series of processing trials, vegetative bacterial cells remaining within the containment, and in the processing water, are inactivated by raising the internal temperature of the containment, and all contents, including equipment, processing water and waste water to sufficiently inactivate all bacterial cells, except spore formers, using industrial steam at atmospheric pressure. We have demonstrated the feasibility and safety of conducting multiple trials using pathogenic bacteria with pilot scale processing equipment within the containment, and then inactivating surviving vegetative bacterial cells with the steam-in-place process. Furthermore, we validated pilot-scale surface pasteurization processing equipment capable of significantly reducing cell densities (in excess of 5 logs) of Salmonella on inoculated cantaloupes, using this BSL-2 enhanced containment system.

References

Annous

B. A.

, Sapers

G. M.

, Jones

D. M.

, & Burke

(2005a). Improved recovery procedure for evaluation of sanitizer efficacy in disinfecting contaminated cantaloupes. Journal of Food Science, 70(4), M242–M247.

Annous

B. A.

, Solomon

E. B.

, Cooke

P. H.

, & Burke

(2005b). Biofilm formation by Salmonella spp. on cantaloupe melons. Journal of Food Safety, 25(4), 276–287.

Annous

B. A.

, Burke

, & Sites

J. E.

(2004). Surface pasteurization of whole fresh cantaloupes inoculated with Salmonella Poona or Escherichia coli. Journal of Food Protection, 67(9), 1876–1885.

Biosafety in Microbiological and Biomedical Laboratories (BMBL). (1999). U.S. Department of Human Health and Human Services Public Health Service, Centers for Disease Control and Prevention, and National Institutes of Health, (4th ed.).

Buck

J. W.

, Walcott

, & Beuchat

L. R.

(2003). Recent trends in microbiological safety of fruits and vegetables. Available at: www.apsnet.org/online/feature/safety/. Accessed November 6, 2006.

Eblen

D. R.

, Annous

B. A.

, & Sapers

G. M.

(2005). Studies to select an appropriate nonpathogenic surrogate Escherichia coli strains for potential use in place of Escherichia coli O157:H7 and Salmonella in pilot plant studies. Journal of Food Protection, 68(2), 282–291.

Economic Research Service (ERS). (2004). Food consumption (per capita) data system. Available at: www.ers.usda.gov/Data/FoodConsumption. Accessed November 6, 2006.

International Fresh-cut Produce Association (IFPA). (2004). Fresh-cut facts. Available at: http://fresh-cuts.org/index.php?page=103. Accessed November 6, 2006.

Sivapalasingam

, Friedman

C. R.

, Cohen

, & Tauxe

R. V.

(2004). Fresh produce: A growing cause of outbreaks of food-borne illness in the United States, 1973 through 1997. Journal of Food Protection, 67(10), 2342–2353.

10.

Solomon

E. B.

, Huang

, Sites

J. E.

, & Annous

B. A.

(2006). Thermal inactivation of Salmonella on cantaloupes using hot water. Journal of Food Science, 71(2), M25–M30.

11.

U.S. Food and Drug Administration (USFDA). (2004). Produce safety from production to consumption: 2004 action plan to minimize foodborne illness associated with fresh produce consumption. Available at: www.cfsan.fda.gov/_dms/prodpla2.html. Accessed November 6, 2005.