Evaluation of the impact of refrigeration on next generation sequencing-based assessment of the canine and feline fecal microbiota

BACKGROUND: Evaluation of factors that might impact microbiota assessment is important to avoid spurious results, particularly in field and multicenter studies where sample collection may occur distant from the laboratory. This study evaluated the impact of refrigeration on next generation sequence-based assessment of the canine and feline fecal microbiota. Fecal samples were collected from seven dogs and ten cats, and analysed at baseline and after 3, 7, 10 and 14 days of storage at 4°C. RESULTS: There were no differences in community membership or population structure between timepoints for either dogs or cats, nor were there any differences in richness, diversity and evenness. There were few differences in relative abundance of phyla or predominant genera, with the only differences being significant increases in Actinobacteria between Days 0-14 (P = 0.0184) and 1-14 (P = 0.0182) for canine samples, and a decrease in Erysipelotrichaceae incertae sedis between Day 0 and Day 7 (median 4.9 vs 2.2%, P = 0.046) in feline samples. Linear discriminant analysis effect size and indicator analysis identified a small number of genera that were over-represented in, or defining characteristics of, Day 14 samples. These were predominantly Proteobacteria and Actinobacteria, with Psychrobacter and Arthrobacter enriched in both canine and feline Day 14 samples. CONCLUSIONS: Storage for at least 14 days at 4°C has limited impact on culture-independent assessment of the canine and feline fecal microbiota, although changes in some individual groups may occur.