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Title: Antimicrobial Effect of An Essential Oil Blend on Surface-attached Salmonella on Polyvinyl Chloride

item SONG, SANGYOON - University Of Georgia
item ALALI, WALID - University Of Georgia
item FRANK, JOSEPH - University Of Georgia
item Berrang, Mark
item HOFACRE, CHARLES - University Of Georgia

Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2014
Publication Date: 1/26/2015
Citation: Song, S., Alali, W., Frank, J., Berrang, M.E., Hofacre, C. 2015. Antimicrobial Effect of An Essential Oil Blend on Surface-attached Salmonella on Polyvinyl Chloride. International Poultry Scientific Forum. January 26-27, 2015. Atlanta, Georgia.

Interpretive Summary:

Technical Abstract: Polyvinyl chloride (PVC) is basic material for drinking water lines for chickens. Inner surface of PVC pipe can be susceptible to surface-attachment of Salmonella, the 1st stage of biofilm development. Biofilm which can cause Salmonella infection to chickens are known to have great resistance against antimicrobials. Chlorine is used to control the biofilm, but it cannot efficiently decrease the Salmonella cells of internal organs of chickens by intake. However, essential oils are proven they can reduce the Salmonella cells of internal organs of chickens. Hence, efficacy of essential oils (EO) to prevent the slime formation can be tested. The objective was to compare the efficacy of an essential oil blend to reduce attached Salmonella cells on PVC with chlorinated water and untreated control. PVC coupons (n=30) sanitized with ethanol were prepared and 3.0 × 107 CFU/mL of Salmonella cocktail (Enteritidis, Heidelberg, and Typhimurium) were incubated with the coupons in 30mL TSB per sample for 96h at 37°C with 100 rpm to develop the attachment. Antimicrobial treatments were performed for coupons (n=10/group) with EO (500 µg/mL), sodium hypochlorite (5 µg/mL), or sterile deionized water, and they were incubated at 25°C for 24 h with 100 rpm. The surfaces of the coupons after rinsing with PBS were swabbed with sterile sponges and stomached in 50mLs of D/E neutralizing broth. Next, enumeration with XLT-4 and enrichment with BPW and TT was conducted. Furthermore, pHs of the antimicrobials were measured at three different conditions (without Salmonella cells, before the treatment, and after the treatment). Average log10 CFU/cm2 (± standard error) of EO treated group and sodium hypochlorite treated group were 0.19 ± 0.13 and 0.86 ± 0.22 respectively. On the other hand, the control group showed 3.87 ± 0.054 indicating statistically significant reduction of Salmonella cells by two antimicrobials. The number of Salmonella positive samples per group was 2 (EO), 9 (chlorine), and 20 (sterile deionized water) out of total 20 samples per group, indicating statistically significant difference among the three groups. Finally, EO group did not show remarkable changes in pH showing around pH 3.6~3.7. However, chlorine group showed different pH depending on the timing; pH 8.00 when no Salmonella cells existed, pH 6.96 before the treatment and pH 6.38 after the treatment. Sterile deionized treated group showed consistent pH value no matter when the measurement timing was, indicating pH around 6~6.3. The potential of EO to substitute chlorine to both prevent biofilm and control Salmonella cells in chicken internal organs was verified.