No abstract

Aims: A mouse model of vancomycin‐resistant enterococcus (VRE) stool colonization was used to study the effect of Bacillus coagulans, a biotherapeutic agent, on the density of colonization. Methods and Results: VRE‐colonized mice received orally administered B. coagulans (107 cfu) or saline daily for four days. For one VRE strain, the density of VRE at one and four days after treatment was 1·4 log10cfu g−1 lower in experimental vs. control mice (P=0·03), and 35% of experimental vs. 0% of control mice had no detectable VRE four days after treatment (P=0·03). For two additional strains, there was no statistically significant reduction of VRE density in the B. coagulans groups. Conclusions: B. coagulans therapy reduced the density of colonization for one of three VRE strains tested. Significance and Impact of the Study: This study suggests a potential role for biotherapeutic agents as a means to reduce the density of VRE intestinal colonization.

Antibiotic therapy may be associated with recurrent high-density VRE stool colonization in many patients who have previously had three consecutive negative stool cultures. These patients should be screened for recurrent stool colonization when antibiotic therapy is administered.

An in vitro anaerobic continuous-flow competitive exclusion (CFCE) culture model was used to study the ability of human stool flora to inhibit the growth of vancomycin-resistant (VR) enterococci (VRE). The CFCE culture was established from a stool sample obtained from a healthy adult. When 10(3) or 10(6) cfu/mL of VR Enterococcus faecium were added to the CFCE culture, the VRE were eliminated within 6 or 9 days, respectively. When 10(7) cfu/mL of the CFCE culture was added to a continuous-flow culture that contained 10(7) cfu/mL of VRE, the density of VRE was reduced but not eliminated. These data support the hypothesis that the indigenous intestinal flora inhibit growth of VRE and suggest that CFCE cultures may be a useful means to study interactions between the indigenous flora and VRE.

We examined the point prevalence of undetected vancomycin-resistant Enterococcus (VRE) stool colonization in an institution that screens stool samples submitted for Clostridium difficile testing. Of 112 patients not known to be colonized, 10 (9%) had rectal VRE colonization. A prospective algorithm was effective for identification of colonized patients.