Different levels of genetic homogeneity in vancomycin-resistant and -susceptible Enterococcus faecium isolates from different human and animal sources analyzed by amplified-fragment length polymorphism.

The genetic relationship among fecal vancomycin-resistant Enterococcus faecium (VREF) and vancomycin-susceptible E. faecium (VSEF) isolates (n = 178) from the same populations of pigs, human healthy volunteers, and hospitalized patients (from The Netherlands) and chickens (from The Netherlands and Greece) was studied by amplified-fragment length polymorphism (AFLP). The majority of VREF isolates from pigs, healthy volunteers, and hospitalized patients grouped together (genetic similarity, >or=65%). In a previous AFLP study by our group the VREF isolates from hospitalized patients grouped separately, most likely because these were clinical and not fecal isolates as in the present study. Furthermore, VSEF isolates from humans and pigs were found much more genetically diverse than VREF isolates, whereas VREF and VSEF isolates from chickens clustered together in a separate genogroup (genetic similarity, >or=65%), a pattern clearly distinct from the patterns for human and pig isolates. The present study suggests that pigs are a more important source of VREF for humans than chickens and that human- and pig-derived VSEF isolates seem much more heterogeneous than VREF isolates.

Persistent rat cytomegalovirus (RCMV) infection of the salivary glands contributes to the anti-RCMV humoral immune response.

The salivary glands are the major sites of persistent replication of rat cytomegalovirus (RCMV). At several months post infection (pi), infectious RCMV is usually still produced in the salivary glands but not in any other organ or tissue of the rat. To investigate whether the persistence of RCMV in the salivary glands is crucial to the pathogenesis of viral infection, we monitored the progression of RCMV-induced disease in rats from which the salivary glands had been surgically removed (desalivated) as well as in sham-operated rats, both after a lethal and sublethal challenge with RCMV. Desalivation did not have a significant effect on either RCMV-induced morbidity or mortality. As expected, at 1 year pi, relatively high levels of infectious virus were detected in the salivary glands of sham-operated rats, whereas neither infectious virus nor RCMV DNA could be detected in liver, spleen and lungs of these animals. Infectious virus and viral DNA were also undetectable in organs from desalivated animals at 1 year pi. Surprisingly, a difference was found between desalivated and sham-operated rats in the titers of anti-RCMV IgG antibodies, which were significantly higher in sham-operated rats than in desalivated animals at 183, 295 and 365 days pi. This finding indicates that the persistence of RCMV in the salivary glands may contribute significantly to the anti-RCMV humoral immunity of infected rats.

Effect of dietary inulin supplementation on inflammation of pouch mucosa in patients with an ileal pouch-anal anastomosis.

PURPOSE: Inflammation is a constant finding in the ileal reservoir of patients with an ileal pouch-anal anastomosis and is associated with decreased fecal concentrations of the short chain fatty acid butyrate, increased fecal pH, changes in fecal flora, and increased concentrations of secondary bile acids. In healthy subjects, inulin, a dietary fiber, is fermented to short chain fatty acids and leads to a lower pH and potentially beneficial changes in fecal flora. The aim of the present study was to investigate the effect of enteral supplementation of inulin on inflammation of the ileal reservoir. METHODS: Twenty patients received 24 g of inulin or placebo daily during three weeks in a randomized, double-blind, crossover design. Stools were analyzed after each test period for pH, short chain fatty acids, microflora, and bile acids. Inflammation was assessed endoscopically, histologically, and clinically. RESULTS: Compared with placebo, three weeks of dietary supplementation with 24 g of inulin increased butyrate concentrations, lowered pH, decreased numbers of Bacteroides fragilis, and diminished concentrations of secondary bile acids in feces. This was endoscopically and histologically accompanied by a reduction of inflammation of the mucosa of the ileal reservoir. CONCLUSION: Enteral inulin supplementation leads to a decrease of inflammation-associated factors and to a reduction of inflammation of pouch mucosa.