Impact of diet change on the gut microbiome of common marmosets (Callithrix jacchus).

Gastrointestinal diseases are the most frequently reported clinical problems in captive common marmosets (Callithrix jacchus), often affecting the health and welfare of the animal and ultimately their use as a research subject. The microbiome has been shown to be intimately connected to diet and gastrointestinal health. Here, we use shotgun metagenomics and untargeted metabolomics in fecal samples of common marmosets collected before, during, and after a dietary transition from a biscuit to a gel diet. The overall health of marmosets, measured as weight recovery and reproductive outcome, improved after the diet transition. Moreover, each marmoset pair had significant shifts in the microbiome and metabolome after the diet transition. In general, we saw a decrease in Escherichia coli and Prevotella species and an increase in Bifidobacterium species. Untargeted metabolic profiles indicated that polyamine levels, specifically cadaverine and putrescine, were high after diet transition, suggesting either an increase in excretion or a decrease in intestinal reabsorption at the intestinal level. In conclusion, our data suggest that Bifidobacterium species could potentially be useful as probiotic supplements to the laboratory marmoset diet. Future studies with a larger sample size will be beneficial to show that this is consistent with the diet change. IMPORTANCE: Appropriate diet and health of the common marmoset in captivity are essential both for the welfare of the animal and to improve experimental outcomes. Our study shows that a gel diet compared to a biscuit diet improves the health of a marmoset colony, is linked to increases in Bifidobacterium species, and increases the removal of molecules associated with disease. The diet transition had an influence on the molecular changes at both the pair and time point group levels, but only at the pair level for the microbial changes. It appears to be more important which genes and functions present changed rather than specific microbes. Further studies are needed to identify specific components that should be considered when choosing an appropriate diet and additional supplementary foods, as well as to validate the benefits of providing probiotics. Probiotics containing Bifidobacterium species appear to be useful as probiotic supplements to the laboratory marmoset diet, but additional work is needed to validate these findings.

N-acetylcysteine lock solution prevents catheter-associated bacteremia in rabbits.

PURPOSE: Indwelling vascular catheters are the most common cause of nosocomial bloodstream infections. One approach to infection prevention is the use of antimicrobial catheter lock solutions, although their widespread use is limited due to concern regarding the emergence of antimicrobial resistance. The primary purpose of this study was to determine the efficacy of N-acetylcysteine (NAC) lock solution in preventing peripheral bacteremia using an in vivo model of catheter-associated infection. METHODS: Twenty-four hours after inoculating a clinical isolate of Staphylococcus aureus into the lumen of tunneled external jugular catheters in rabbits, a catheter lock solution that contained NAC vs. heparinized saline alone was allowed to dwell for two consecutive periods of 72 hours. Surveillance peripheral and centrally collected blood cultures were obtained. Distal intravascular segments of the catheters were removed at day 7 and cultured using a sonication method. RESULTS: At 7 days after catheter insertion, none of the NAC-treated rabbits (0/8) developed peripheral bacteremia with S. aureus whereas 4/7 controls did (p=0.026). The bacterial yield from catheter tip cultures was not statistically different between the two arms. CONCLUSIONS: These promising data encourage further clinical evaluation of an NAC lock solution for prevention of catheter-associated bacteremia in patients.

Dermatophytosis in three colony-born spotted hyenas.

An adult female hyena and her two 4-month-old cubs were found to have multifocal areas of alopecia and dermatitis. Dermatophyte culture of hair and skin samples collected from the lesions yielded Trichophyton mentagrophytes. None of 10 other animals in the colony that were tested were found to have dermatophytes. Lesions were treated twice, at 3-week intervals, with thorough cleansing with chlorhexidine scrub followed by topical application of antifungal agents. Lesions resolved, and dermatophyte culture of samples collected 6 weeks after the initiation of treatment did not yield growth.