Document Detail

Ecology of Enterococcus faecalis and niche-adapted or non-niche-adapted Enterococcus faecium in continuous-flow anaerobic cultures.
MedLine Citation:
PMID:  19737066     Owner:  NLM     Status:  MEDLINE    
An anaerobic continuous-flow culture of chicken gastrointestinal microflora (CCF) and pure cultures of Enterococcus faecalis I.2 were used for survivability studies of niche-adapted and non-niche-adapted Enterococcus faecium isolates. CCF eliminated non-CCF niche-adapted glycopeptide-resistant E. faecium 47 (GRE47) at a rate of 1.01 log(10) cfu/mL/day, whereas CCF niche-adapted E. faecium I.3(rif) survived in CCF at 4.5-6.5 log(10) cfu/mL. In continuous-flow monocultures of GRE47 (8.93 log(10) cfu/mL), the addition of 100 mL (9.5% total volume) of CCF resulted in the displacement of GRE47 in 14 days at a rate of 0.66 log(10) cfu/mL/day. Pure continuous-flow cocultures were used to assess a direct inhibitory effect of E. faecalis I.2 on E. faecium isolates. In cocultures of E. faecalis I.2 and GRE47, GRE47 was eliminated from the culture at a rate of 1.24 log(10) cfu/mL/day. In cocultures of E. faecalis I.2 and E. faecium I.3(rif), the E. faecium I.3(rif) population fluctuated, but was 6.86 log(10) CFU/mL on day 21. A fit subset of the E. faecium I.3(rif) population survived in CCF and with E. faecalis I.2 alone. No subset of the non-niche-adapted E. faecium GRE47 was able to survive under the same conditions. The mechanism by which E. faecium I.3(rif) is tolerant in CCF, and in E. faecalis coculture is unknown. E. faecium I.3(rif) and GRE47 possessed the cell wall adhesion factor efaAfm. E. faecalis I.2 was positive by polymerase chain reaction for gelE, efaAfs, cad, ccf, cdp, and cob, but not the cytolysin-associated gene cylMAB, suggesting that the mechanism of activity against E. faecium strains was due to factors other than the two-component cytolysin.
Toni L Poole; J Allen Byrd; Todd R Callaway; David J Nisbet
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Foodborne pathogens and disease     Volume:  6     ISSN:  1556-7125     ISO Abbreviation:  Foodborne Pathog. Dis.     Publication Date:  2009 Sep 
Date Detail:
Created Date:  2009-09-09     Completed Date:  2009-12-11     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101120121     Medline TA:  Foodborne Pathog Dis     Country:  United States    
Other Details:
Languages:  eng     Pagination:  901-6     Citation Subset:  IM    
Southern Plains Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, College Station, Texas 77845, USA.
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MeSH Terms
Adaptation, Physiological*
Cecum / microbiology*
Chickens / microbiology*
Colony Count, Microbial
Enterococcus faecalis / genetics,  growth & development*,  isolation & purification,  metabolism
Enterococcus faecium / genetics,  growth & development*,  isolation & purification,  metabolism
Microbial Interactions
Microbial Viability
Polymerase Chain Reaction
Regression Analysis
Species Specificity
Time Factors
Virulence Factors / genetics,  metabolism
Reg. No./Substance:
0/Virulence Factors

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