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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety & Processing Research » Research » Publications at this Location » Publication #310531

Research Project: Pathogen Reduction and Processing Parameters in Poultry Processing Systems

Location: Poultry Microbiological Safety & Processing Research

Title: Use of Extract of Citrus sinensis as an antimicrobial agent for foodborne zoonotic pathogens and spoilage bacteria

Author
item Hassan, Hazem - Tuskegee University
item Amit, Tiwari - Tuskegee University
item Min, Byungjin - Tuskegee University
item Reddy, Gopal - Tuskegee University
item Hinton, Jr, Arthur
item Abdela, Woubit - Tuskegee University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/11/2014
Publication Date: 9/18/2014
Citation: Hassan, H., Amit, T., Min, B., Reddy, G., Hinton Jr, A., Abdela, W. 2014. Use of Extract of Citrus sinensis as an antimicrobial agent for foodborne zoonotic pathogens and spoilage bacteria. Annual Biomedical Research Conference for Minority Students. 20.

Interpretive Summary: Foodborne pathogens remain global health problems despite concerted efforts to control the transmission of these microorganisms through food. The resurgence of drug resistant bacteria has renewed interest in developing and testing new sources of antimicrobial agents to control foodborne illness. This study was conducted to determine the antimicrobial activity of extract of Citrus sinensis (sweet orange) against some foodborne pathogenic bacteria such as, Methicillin-resistant Staphylococcus aureus (MRSA), Listeria monocytogenes, Salmonella Typhimurium, E. coli, and the food spoilage bacteria, Pseudomonas fluorescens. The antimicrobial activity of C. sinensis extracts was determined using the agar diffusion method and minimum inhibitory concentration (MIC) of the extract was performed using the Bioscreen C Microbiology Reader. Additionally, antibacterial activity of extract was evaluated on spiked chicken skin using changes in bacterial load and scanning electron microscopy (SEM). The results showed that the average diameter of zones of inhibition of bacteria by C. sinensis extract at a concentration of 100 mg/ml for MRSA, L. monocytogenes, S. Typhimurium, E. coli, and P. fluorescens were 13.8 mm, 25.56 mm, 12.1, 7.8 mm, and 24.3 mm respectively. At a concentration of 10 mg/ml, the average zone of inhibition was 10 mm, 20.96 mm, 8.6 mm, 0 mm, and 20.3 mm for MRSA, L. monocytogenes, S. Typhimurium, E. coli, and P. fluorescens, respectively. However, solutions of 1 mg/ml of extract produced no zones of inhibition against MRSA, S. Typhimurium or E. coli. The MIC concentrations of the extract were 5 mg/ml, 1.25 mg/ml and 1.25 mg/ml for MRSA, L. monocytogenes, and P. fluorescens, respectively. MIC for S. Typhimurium and E. coli was =10 mg/ml. The bacterial population for MRSA, L. monocytogenes, and P. fluorescens recovered from rinsates of inoculated chicken skin treated with a solution of 5 mg of extract/ml were reduced from 8 log CFU/ml to 4.5~4.7 log CFU/ml while there was only a 1.1 log CFU/ml reduction in the number of Salmonella and E. coli recovered from the treated skin. Abnormalities of the bacterial cell morphology were detected by SEM as indication of antimicrobial activity of C. sinensis. This study shows the potential of a natural plant extract for use as a sanitizer to control foodborne pathogens in vitro and on poultry skin.

Technical Abstract: Foodborne pathogens remain global health problems despite concerted efforts to control the transmission of these microorganisms through food. The resurgence of drug resistant bacteria has renewed interest in developing and testing new sources of antimicrobial agents to control foodborne illness. This study was conducted to determine the antimicrobial activity of extract of Citrus sinensis (sweet orange) against some foodborne pathogenic bacteria such as, Methicillin-resistant Staphylococcus aureus (MRSA), Listeria monocytogenes, Salmonella Typhimurium, E. coli, and the food spoilage bacteria, Pseudomonas fluorescens. The antimicrobial activity of C. sinensis extracts was determined using the agar diffusion method and minimum inhibitory concentration (MIC) of the extract was performed using the Bioscreen C Microbiology Reader. Additionally, antibacterial activity of extract was evaluated on spiked chicken skin using changes in bacterial load and scanning electron microscopy (SEM). The results showed that the average diameter of zones of inhibition of bacteria by C. sinensis extract at a concentration of 100 mg/ml for MRSA, L. monocytogenes, S. Typhimurium, E. coli, and P. fluorescens were 13.8 mm, 25.56 mm, 12.1, 7.8 mm, and 24.3 mm respectively. At a concentration of 10 mg/ml, the average zone of inhibition was 10 mm, 20.96 mm, 8.6 mm, 0 mm, and 20.3 mm for MRSA, L. monocytogenes, S. Typhimurium, E. coli, and P. fluorescens, respectively. However, solutions of 1 mg/ml of extract produced no zones of inhibition against MRSA, S. Typhimurium or E. coli. The MIC concentrations of the extract were 5 mg/ml, 1.25 mg/ml and 1.25 mg/ml for MRSA, L. monocytogenes, and P. fluorescens, respectively. MIC for S. Typhimurium and E. coli was =10 mg/ml. The bacterial population for MRSA, L. monocytogenes, and P. fluorescens recovered from rinsates of inoculated chicken skin treated with a solution of 5 mg of extract/ml were reduced from 8 log CFU/ml to 4.5~4.7 log CFU/ml while there was only a 1.1 log CFU/ml reduction in the number of Salmonella and E. coli recovered from the treated skin. Abnormalities of the bacterial cell morphology were detected by SEM as indication of antimicrobial activity of C. sinensis. This study shows the potential of a natural plant extract for use as a sanitizer to control foodborne pathogens in vitro and on poultry skin.