Health benefits of first and second extraction drum-dried pitted olive pomace.

Olive pomace (OP) is the main by-product of olive oil extraction. After pit and skin removal, OP pulp has high concentrations of dietary fiber and phenolics with high antioxidant capacity. This study evaluated mice health benefits of drum-dried pitted OP pulp obtained after first and second oil extraction. Fresh OP was steam blanched, then pits and skins separated in a pulper/finisher, and pulp drum-dried and milled. OP was characterized by proximate analysis, total soluble phenolics (TSP), individual phenolics, and dietary fiber. Drum-dried pitted OP from first and second extraction was formulated at 10% and 20% in a high fat mice diet. Low fat (5%) and high fat (18%) control diets were also used for comparison. First extraction OP had higher TSP than OP from second extraction. Hydroxytyrosol was the main phenolic in OP. Mice weight gain was lower for the four OP diets compared to high and low-fat control diets. Fecal protein was high for all OP diets, indicating poor protein retention in mice, possibly by phenolics binding of protein and enzymes. Liver weight and adipose tissue were lower in mice consuming the four high fat OP diets compared to high fat control diet. Also, there was no effect on blood glucose by OP in diets. Mice gut microbiota analysis indicated that Actinobacteria decreased in the OP diets compared to the two control diets while Bacteroidetes increased, indicating a positive correlation with reduced body fat and weight. Drum-dried pitted OP is a novel agricultural by-product with its bioactive compounds having the potential to be incorporated in feeds and foods providing health benefits. PRACTICAL APPLICATION: Drum-dried pitted olive pomace can be produced from first or second olive oil extraction byproducts to be used as a shelf-stable healthy food or feed supplement.

Endogenous Enterobacteriaceae underlie variation in susceptibility to Salmonella infection.

Lack of reproducibility is a prominent problem in biomedical research. An important source of variation in animal experiments is the microbiome, but little is known about specific changes in the microbiota composition that cause phenotypic differences. Here, we show that genetically similar laboratory mice obtained from four different commercial vendors exhibited marked phenotypic variation in their susceptibility to Salmonella infection. Faecal microbiota transplant into germ-free mice replicated donor susceptibility, revealing that variability was due to changes in the gut microbiota composition. Co-housing of mice only partially transferred protection against Salmonella infection, suggesting that minority species within the gut microbiota might confer this trait. Consistent with this idea, we identified endogenous Enterobacteriaceae, a low-abundance taxon, as a keystone species responsible for variation in the susceptibility to Salmonella infection. Protection conferred by endogenous Enterobacteriaceae could be modelled by inoculating mice with probiotic Escherichia coli, which conferred resistance by using its aerobic metabolism to compete with Salmonella for resources. We conclude that a mechanistic understanding of phenotypic variation can accelerate development of strategies for enhancing the reproducibility of animal experiments.

Characterization of a highly pathogenic molecular clone of feline immunodeficiency virus clade C.

We have derived and characterized a highly pathogenic molecular isolate of feline immunodeficiency virus subtype C (FIV-C) CABCpady00C. Clone FIV-C36 was obtained by lambda cloning from cats that developed severe immunodeficiency disease when infected with CABCpady00C (Abbotsford, British Columbia, Canada). Clone FIV-C36 Env is 96% identical to the noninfectious FIV-C isolate sequence deposited in GenBank (FIV-Cgb; GenBank accession number AF474246) (A. Harmache et al.) but is much more divergent in Env when compared to the subgroup A clones Petaluma (34TF10) and FIV-PPR (76 and 78% divergence, respectively). Clone FIV-C36 was able to infect freshly isolated feline peripheral blood mononuclear cells and primary T-cell lines but failed to productively infect CrFK cells, as is typical of FIV field isolates. Two-week-old specific-pathogen-free cats infected with FIV-C36 tissue culture supernatant became PCR positive and developed severe acute immunodeficiency disease similar to that caused by the uncloned CABCpady00C parent. At 4 to 5 weeks postinfection (PI), 3 of 4 animals developed CD4(+)-T-cell depletion, fever, weight loss, diarrhea, and opportunistic infections, including ulcerative stomatitis and tonsillitis associated with abundant bacterial growth, pneumonia, and pyelonephritis, requiring euthanasia. Histopathology confirmed severe thymic and systemic lymphoid depletion. Interestingly, the dam also became infected with a high viral load at 5 weeks PI of the kittens and developed a similar disease syndrome, requiring euthanasia at 11 weeks PI of the kittens. This constitutes the first report of a replication-competent, infectious, and pathogenic molecular clone of FIV-C. Clone FIV-C36 will facilitate dissection of the pathogenic determinants of FIV.