Electrostatic Space Charge System Research Articles

Use of Negative Air Ionization for Reducing Bacterial Pathogens and Spores on Stainless Steel Surfaces

The use of chemicals in food plant sanitation for removing and killing microorganisms could be reduced by the use of alternative nonchemical interventions. Supercharged negative air ionizers have shown potential to effectively reduce airborne and surface microorganisms. In our earlier studies, a small chamber, controlled at 85% relative humidity and supercharged with a −25 kV electrostatic space charge system (ESCS), was used to transfer a strong negative charge to bacteria on stainless steel surfaces. The ESCS treatment caused the levels of biofilm bacteria from chicken carcass rinses to be significantly decreased with 99.8% efficiency at a distance of 18 cm with ion densities of 106 negative ions/cm3 or more. In the present study, effects of the −25 kV charge of ESCS on specific pathogens important for food safety were studied. Treatment of Campylobacter jejuni, Escherichia coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus achieved up to a 4 log reduction with 99.9% reduction efficiency in 3 h. Treatment of bacterial spores of Bacillus stearothermophilus achieved up to a 3 log reduction with a 99.8% reduction efficiency in 3 h. These significant reductions for 5 species of pathogenic bacteria and bacterial spores suggest that the ESCS is a promising alternative treatment for reduction of microbial load in a food-processing facility with the potential to reduce the amount of antimicrobials used.

APPLICATION OF AN ELECTROSTATIC SPACE CHARGE SYSTEM FOR DUST, AMMONIA, AND PATHOGEN REDUCTION IN A BROILER BREEDER HOUSE

Airborne dust in poultry housing is known to be one of the primary means by which disease-causing organismsare spread throughout a house. An electrostatic space charge system (ESCS) was used to reduce airborne dust in a small-scalebroiler breeder house. The system used ceiling fans to distribute negatively charged air throughout the room and to movenegatively charged dust downward toward the grounded litter where most of it would be captured. The system significantly(P < 0.0001) reduced airborne dust by an average of 61%, ammonia by an average of 56% (P < 0.0001), and airbornebacteria by 67% (P < 0.0001). Earlier studies with an ESCS have resulted in significant reductions of airborne dust, bacteria,and airborne transmission of disease in poultry hatching cabinets, caged layer rooms, and in controlled environment diseasetransmission cabinets. The ESCS was shown to be a reliable and easily maintained system for reducing airborne dust,ammonia, and bacteria in a small broiler breeder house. Results of this study combined with the results of related ESCS studiessuggest that the system could probably be scaled up to full-sized production houses for poultry or other animals for dustreduction, pathogen reduction, and possibly ammonia reduction. All of the applications have potential for improving humanhealth as well as animal health.

Reducing Airborne Pathogens and Dust in Commercial Hatching Cabinets with an Electrostatic Space Charge System

Commercial hatcheries typically infuse hydrogen peroxide or formaldehyde gas into hatching cabinets to reduce airborne pathogens that may lead to disease transmission during the hatch. A nonchemical option, an electrostatic space charge system (ESCS), was customized for full-sized commercial hatching cabinets and was tested extensively in broiler hatcheries. The ESCS cleans air by transferring a strong negative electrostatic charge to dust and microorganisms that are aerosolized during the hatch and collecting the charged particles on grounded plates or surfaces. In studies with three poultry companies, the ESCS resulted in significant (P < 0.0001) reductions of airborne dust of 77%-79%, in Enterobacteriaceae and fungus levels not significantly different (P > or = 0.05) from those with formaldehyde, and in 93%-96% lower Enterobacteriaceae than with no treatment or with hydrogen peroxide treatment (P < 0.01). The ESCS significantly (P < 0.05) reduced airborne Salmonella by 33%-83% compared with no treatment or hydrogen peroxide treatment. Results of this study suggest that the ESCS is a viable alternative to chemical treatment for reducing airborne pathogens in full-sized commercial hatchers, and it also provides dust control and containment, which should be helpful in reducing cross contamination and loading of ventilation ducts within different areas of the hatchery.

Effect of an Electrostatic Space Charge System on Airborne Dust and Subsequent Potential Transmission of Microorganisms to Broiler Breeder Pullets by Airborne Dust

High levels of dust and microorganisms are known to be associated with animal confinement rearing facilities. Many of the microorganisms are carried by dust particles, thus providing an excellent vector for horizontal disease transmission between birds. Two environmentally controlled rooms containing female broiler breeder pullets (n = 300) were used to evaluate the effectiveness of an electrostatic space charge system (ESCS) in reducing airborne dust and gram-negative bacteria levels over an 8-wk period (starting when the birds were 10 wk old). The ESCS was used to evaluate the effectiveness of reducing airborne microorganism levels by charging airborne dust particles and causing the particles to be attracted to grounded surfaces (i.e., walls, floor, equipment). The use of the ESCS resulted in a 64% mean reduction in gram-negative bacteria. Airborne dust levels were reduced an average of 37% over a 1-wk period in the experimental room compared with the control room on the basis of samples taken every 10 min. The reductions of airborne dust and bacteria in this study are comparable with earlier results obtained with the ESCS in commercial hatching cabinets and experimental caged layer rooms, suggesting the system could also be applied to other types of enclosed animal housing.

Use of Negative Air Ionization for Reducing Microbial Contamination on Stainless Steel Surfaces

Microbiological concerns in food plant sanitation that relies heavily on physical and chemical methods for removing and killing bacteria could be reduced by the use of non-chemical intervention methods. This initial work on the effects of electrostatic space charge on biofilms shows promise as a viable intervention option for reducing bacterial contamination on surfaces. Natural bacterial populations from a poultry processing facility were collected, allowed to multiply and form biofilms, and assessed for susceptibility to negative air ionization. A small chamber with an electrostatic space charge system was used to treat the mixed bacterial populations that were grown on stainless steel coupons (1 × 4 cm). The object of the system was to transfer a strong negative electrostatic charge to bacteria that were attached to coupons at the base of the chamber. The system effectively decreased the survival levels of bacteria on the stainless steel, with a reduction efficiency of 99.8%. All of the swab samples taken from coupons were culture positive for bacteria, and the bacterial counts from the ionized surfaces were significantly less than for the non-ionized surfaces (P < 0.01). These results demonstrate the potential efficacy of negative air ionization against bacterial contamination on surfaces in the poultry processing environment.

Reducing Airborne Pathogens, Dust and Salmonella Transmission in Experimental Hatching Cabinets Using an Electrostatic Space Charge System

Electrostatic charging of particles in enclosed spaces has been shown to be an effective means of reducing airborne dust. Dust generated during the hatching process has been strongly implicated in Salmonella transmission, which complicates the cleaning and disinfecting processes for hatchers. Following two preliminary trials in which dust reduction was measured, four trials were conducted to evaluate the effectiveness of an electrostatic space charge system (ESCS) on the levels of total aerobic bacteria (TPC), enterobacteriaceae (ENT), and Salmonella within an experimental hatching cabinet. The ESCS was placed in a hatching cabinet that was approximately 50% full of 18-d-old broiler hatching eggs. The ESCS operated continuously to generate a strong negative electrostatic charge throughout the cabinet through hatching, and dust was collected in grounded trays containing water and a degreaser. An adjacent hatching cabinet served as an untreated control. Air samples from hatchers were collected daily, and sample chicks from each hatcher were grown out to 7 d of age for cecal analysis in three of the trials. The ESCS significantly (P < 0.05) reduced TPC and ENT by 85 to 93%. Dust concentration was significantly reduced (P < 0.0001) during the preliminary trials with an average reduction of 93.6%. The number of Salmonella per gram of cecal contents in birds grown to 7 d of age was significantly (P < 0.001) reduced by an average log10 3.4 cfu/g. This ionization technology is relatively inexpensive and could be used to reduce airborne bacteria and dust within the hatching cabinet.

Reducing Dust in a Caged Layer Room: An Electrostatic Space Charge System

Dust has been shown to be an important mechanism for airborne transmission of disease-causing agents. Although there are a variety of treatments that can reduce airborne dust, most of them are not practical in areas such as caged layer rooms where dust levels can be relatively high. In this study, an electrostatic space charge system was shown to be very effective on both artificial and naturally generated dust in a caged layer room. Duplicated trials of the system showed a reduction in average concentration of artificially generated dust ranging from 72 to 91% by ionizer treatment - depending on the initial concentration. The treatment reduced concentration of naturally generated dust from mature White Leghorn chickens in cages by an average of 52%. These results show that use of an electrostatic space charge system can significantly reduce dust in caged layer areas, resulting in a lower potential for respiratory problems of workers as well as chickens in these areas.