Evaluation of the Decontamination Power of Aqueous and Gaseous Ozone on Various Contaminated Surfaces with Cattle Manure containing Salmonella

Abstract

Despite using ozone (O 3) as an attractive alternative disinfectant for more than a century, little is known about the killing capacity of O 3 against Salmonella contaminated different surfaces in dairy operations. Accordingly, our objective was to characterize the killing capacity of aqueous and gaseous O 3 at different operational conditions on Salmonella Typhimurium and Salmonella Choleraesuis (aSTC) contaminated plastic, metal, nylon, rubber, and wood surfaces. In a crossover design, 14 strips of each material were randomly assigned between 3 groups, treatment (n=6), positive-control (n=6), and negative-control (n=2). The strips were loaded with aSTC (10 7-10 8) and exposed to aqueous O 3 of 2, 4, and 9 ppm for 4 minutes, and gaseous O 3 of 1 and 9 ppm for 30, 60, and 120 minutes. Plastic and metal surfaces were most effectively decontaminated, an aqueous O 3 of 4 ppm reduced aSTC by 6.7 and 5.2log 10 , respectively, and 9 ppm resulted in no detectable aSTC. On nylon and rubber, aqueous O 3 of 9 ppm reduced aSTC population to a safe level (5.8 and 5.1-log 10). On wood, both aqueous and gaseous O 3 at up to 9 ppm were unable to reduce aSTC to undetectable limit. Interestingly, aSTC load and sequential washing showed same impacts on the reduction rate of aSTC on complex surfaces. Our findings strongly indicate that aqueous O 3 of 9 ppm for 4 minutes exposure is an effective means to clear smooth surfaces of a high Salmonella load. However, sequential washing or decrease the bacterial load is needed to effectively decontaminate complex surfaces.

Comparative study on the efficacy of sodium hypochlorite, aqueous ozone, and peracetic acid in the elimination of Salmonella from cattle manure contaminated various surfaces supported by Bayesian analysis

“…The materials were selected for their degree of surface roughness: plastic (smooth or simple), nylon and rubber (intermediate), and wood (rough or complex). Fourteen strips (7.5 X 2.5 cm) of each material were prepared as described elsewhere [19, 20]. The thickness of plastic strips was 1.0 mm, 1.0 cm for nylon strips, 2.0 mm for rubber and wood strips.…”

“…Avirulent live Salmonella Typhimurium-Choleraesuis vaccine (Enterisol Salmonella T/C vaccine; Boehringer Ingelheim Vetmedica, St. Joseph, Missouri, USA) was used in the present study as a source of Salmonella pathogen. The Salmonella pathogen was revitalized and activated to contaminate the sterile feces as described elsewhere [20, 21]. Briefly, approximately 100 g of freshly voided feces was collected from a tie stall barn for fresh cows at the University of Illinois Dairy Research Farm.…”

“…The concentration of NaOCl was determined based several earlier studies [22–24], and this concentration is commonly used in practice. For aqueous-O 3 , the dissolved O 3 in water with concentrations from 1 to 10 ppm was obtained using OOG1X0 O 3 generator manufactured by Origin, Inc. (Princeton, NJ, USA) as described elsewhere [19, 20]. For PAA, 400 ppm was prepared using concentrated (32 wt.…”

“…The material’s strips were immersed in the fresh aSTC-fecal mixture for 60 minutes at room temperature of 18–21°C and relative humidity of 55–60%, then removed aseptically and hung on for 60 minutes to dry as described elsewhere [19, 20]. This time period of soaking and drying is sufficient for attachment (reversible and irreversible) of planktonic, free-swimming aSTC, to surfaces of strip but not for replication [28–29].…”

Antimicrobial Efficacy of Aqueous Ozone and Ozone–Lactic Acid Blend on Salmonella-Contaminated Chicken Drumsticks Using Multiple Sequential Soaking and Spraying Approaches

“…Currently, bacterial contamination is removed or controlled during the carcass processing using a combination of thermal treatment, water, and chemical antimicrobials, such as peracetic acid (PAA) ( Northcutt et al, 2005 ; Dittoe et al, 2019 ). However, these chemical antimicrobials are faced with challenges including last for several hours, and most of them can be toxic before and after the breakdown ( Megahed et al, 2018a , b , 2019 ). Additionally, these chemical antimicrobials can produce undesired color and texture effects and development of off-flavors ( Qiao et al, 2002 ).…”