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
                                            Hume, Michaelitem
                                            Poole, Toniitem
                                            PULTZ, NICOLE - L STOKES CLEV VAMCitem
                                            HANRAHAN, JENNIFER - METROHEALTH MED CENTERitem
                                            DONSKEY, CURTIS - L STOKES CLEV VAMC
  Submitted to: Letters in Applied Microbiology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 9/3/2003
                                    Publication  Date: 7/1/2004
                                    Citation: Hume, M.E., Poole, T.L., Pultz, N.J., Hanrahan, J.A., Donskey, C.J. 2004. Inhibition of vancomycin-resistant enterococcus by continuous-flow cultures of human stool microflora with and without anaerobic gas supplementation. Current Microbiology. 48:364-367.Interpretive Summary: Human stool bacteria were used to examine whether growing the bacteria in a gas environment free of oxygen is necessary for the bacteria to maintain their ability to inhibit the growth of the human intestinal pathogen vancomycin-resistant Enterococcus faecium (VRE).  Human stool bacteria were grown under a continuous supply of nitrogen gas, with no supply of gas, or with continuous supply of room air.  Supplying the bacteria with either no gas or with nitrogen gas supported the growth of bacteria that grow only when oxygen is not present and supported the growth inhibition and elimination by these bacteria of VRE added to the container.  Supplying the bacteria with room air resulted in a decrease in the numbers of bacteria that only grow when oxygen is not present and resulted in VRE not being eliminated when added to the container.  The ability of the bacteria to eliminate VRE when gas was not supplied is likely the result of oxygen-using bacteria present in the stool rapidly using any harmful oxygen that may enter the system.  The conclusion is that supplying the human stool bacteria with nitrogen gas is not necessary for maintenance of the ability to eliminate VRE.  The results indicate a more cost-effective method for the maintenance of these human stool bacteria that competitively exclude VRE.
                                Technical Abstract: 

Aims:  An in vitro continuous-flow competitive exclusion (CFCE) culture model of human stool microflora was used to examine whether supplemental anaerobic gas is necessary for maintenance of anaerobes and inhibition of vancomycin-resistant Enterococcus (VRE).    
Methods and Results:  CFCE cultures of human stool microflora were maintained with supplemental nitrogen, without supplemental nitrogen, or with percolated room air.  Cultures with or without supplemental nitrogen maintained >9 log10 CFU ml-1 of obligate anaerobes and eliminated 106 CFU ml-1 of VRE.  When room air was percolated into the culture, anaerobes were detected at <2 log10 CFU ml-1 and the same VRE inoculum was not eliminated (P < 0.001).   
Conclusions:  Supplemental nitrogen gas was not necessary for maintenance of anaerobes or inhibition of VRE.
Significance and Impact of the Study:  These data suggest that anaerobic gas is not necessary for in vitro efficacy of CFCE cultures of human stool microflora, and that obligate anaerobes are the component of the intestinal microflora that inhibit VRE.


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