Understanding and managing the microbial communities associated with animals (including humans) and the environments they inhabit is increasingly recognized as important to optimizing health and welfare.1,2 The planned movement of a mature male whale from one large public display aquarium habitat to another provided an opportunity to monitor host associated microbial community structure changes occurring during the move. Samples of habitat water, three sites from the whale (skin, “chuff” and feces) and food fish were collected prior to and after the move. To evaluate food independently from other effects; food fishes at the site of origin were sent along with the animal and were fed as the exclusive ration until one week following the move at which time the animal was transitioned to the food fishes from the receiving location. All samples were processed onsite through our nucleic acid extraction, library preparation and 16S rRNA community analysis workflow enabling comparison of bacterial diversity, richness, and relative abundance between and within all samples and sites. Measures of beta diversity between chuff, feces and water revealed a strong clustering by body site regardless of the animal’s location. Water samples in contrast are more dissimilar. In addition, paired sera from the animal prior to and following translocation were submitted for cytokine profiling under development at the USDA to survey for potential changes in immunocompetency.3 Following 5 hours of mitogen stimulation, expression of one cytokine (IL-12p40) was significantly elevated and one (TLR-4) significantly decreased when compared to levels pre-transport. Expression levels of 5 cytokines differed post-transport while the animal was consuming the ration from origin and while consuming the new ration (IF-1α, IL-6, TLR-4, CXCR4 and IFN-γ). At 18 hours of mitogen stimulation, expression of 4 cytokines (IL-12 p40, IL-6, IL-1β, and IFN-γ) were increased compared to pre-transport and one was decreased (TLR-4) while levels of 4 paired between rations (Cox-2, IL-6, IL-1β, and TLR-4). These data add substantially to the understanding of the source of animal associated microbes and the influence of changes in environment.
We thank the husbandry and transport logistics teams of both Shedd and Georgia Aquarium for providing exceptional animal care and sample collection during this study. Drs. Randy Sacco and Amelia Hofstetter of USDA are thanked for the cytokine assays.
1. Van Bonn W, LaPointe A, Gibbons S, Frazier A, Hampton-Marcell J, Gilbert J. 2015 Aquarium microbiome response to ninety-percent system water change: Clues to microbiome management. Zoo Biol 34: 360–367.
2. Cardona C, Lax S, Larsen P, Stephens B, Hampton-Marcell J, Edwardson C, Henry C, Van Bonn B, Gilbert J. 2018. Environmental sources of bacteria differentially influence host-associated microbial dynamics. mSystems 3: 1–18.
3. Hofstetter AR, Van Bonn W, Sacco R. 2018. Immunomediator gene transcription profiling in beluga (Delphinapterus leucas) clinical cases. In Review, J Zoo and Wild Med.