U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Food and Feed Safety Research: College Station, TX
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area College Station, Texas Southern Plains Agricultural Research Center Food and Feed Safety Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            MIN, B.R. - TAES,VERNON,TXitem
                                            PINCHAK, W.E. - TAES, VERNON,TXitem
                                            MERKEL, R. - INST GOAT RES,LANGSTON,OKitem
                                            WALKER, S. - INST GOAT RES,LANGSTON,OKitem
                                            TOMITA, G. - UNIV OF MONTREAL, QUEBECitem
                                            Anderson, Robin
  Submitted to: Scientific Research and Essays
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 2/19/2007
                                    Publication  Date: 2/1/2008
                                    Citation: Min, B., Pinchak, W., Merkel, R., Walker, S., Tomita, G., Anderson, R.C. 2008. Comparative antimicrobial activity of tannin extracts from perennial plants on mastitis pathogens. Scientific Research and Essays. 3(2):66-73.Interpretive Summary: Certain strains of Staphylococcus aureus and Escherichia coli can cause economically important disease in dairy cattle and can be found as contaminants in unpasteurized milk.  This study was conducted to test the antimicrobial effectiveness of a specific class of naturally occurring chemicals called tannins, found in certain plants, against these pathogenic bacteria.  We found that tannin chemicals extracted from Shinnery oak, Post oak, Locust, Blackjack oak, Skunk bush, Sericea lespedeza, commercial Quebracho, Sumac, and Plum plants inhibited the growth of Staphylococcus aureus, with effectiveness being best with tannins from Shinnery oak and Post oak.  When chemical components of the tannin extracts were separated based on their chemical properties and tested individually against Staphylococcus aureus and Escherichia coli, we found that the antimicrobial activity was greatest for compounds classified as catechins and less for compounds classified as ellagetannins, tannic acid, epi-catechin, and gallotannins.  These findings indicate that source, concentration, and chemical properties are important factors that influence antimicrobial activity of tannin extracts.  Our results also revealed that some of the plant tannin extracts were highly effective against these pathogens, inhibiting their growth as much or better than that of the common antibiotic Penicillin, which suggests that they may be useful alternatives to conventional antimicrobial feed additives.  Ultimately, these results may provide farmers with additional tools to control infections in their cattle so they can continue to produce wholesome, high quality food products for the American consumer.
                                Technical Abstract: Three strains of pathogenic bacteria were treated with condensed tannins (CT) purified from eight different woody plant species to investigate their inhibition effect on the growth of these bacteria in vitro.  Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were tested against low (0, 2, 4 and 8 mg CT/ml) and high dose levels (0, 50, and 100 mg CT /ml) of CT extracted from different plant species.  When exposed to purified tannin extracts at 4 mg extract/ml dosage, growth inhibition of S. aureus was dose dependent and observed in the following order: Shinnery oak greater than Post oak greater than Locust greater than Blackjack oak greater than or equal to Skunk bush greater than Sericea lespedeza greater than commercial Quebracho greater than or equal to Sumac greater than Plum.  The extracts from Shinnery and Post oaks were particularly inhibitory against S. aureus, having growth inhibition zones exceeding 23 mm at 8 mg tannin extract/ml.  Staphylococcus aureus and E. coli exhibited dose dependent susceptibility (P less than 0.01) when exposed to greater than or equal to 4 mg/ml of the following tannin monomers with inhibitory activity  observed in the following order: catechin greater than ellagetannin greater than or equal to tannic acid greater than or equal to epi-catechin greater than or equal to gallotannin.  In the presence of high dose levels at 0, 50, and 100 mg tannin extract/ml, inhibition zones of growth were varied among plant species.  The findings indicated that source and concentration are important factors that influence antimicrobial activity of tannins.  Because some of the plant tannin extracts are highly inhibitory to selected pathogens, they may provide alternatives to conventional antimicrobial feed additives.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov