A comparative study of the fecal microbiota of gray seal pups and yearlings ‐ a marine mammal sentinel species

Abstract

Gray seals ( Halichoerus grypus ) can act as sentinel species reflecting the condition of the environment they inhabit. Our previous research identified strains of pathogenic Campylobacter and Salmonella , originating from both human and agricultural animal hosts, on rectal swabs from live gray seal ( H. grypus ) pups and yearlings on the Isle of May, Scotland, UK. We examined rectal swabs from the same pup ( n = 90) and yearling ( n = 19) gray seals to gain further understanding into the effects of age‐related changes (pup vs. yearling) and three different natal terrestrial habitats on seal pup fecal microbiota. DNA was extracted from a subset of rectal swabs (pups n = 23, yearlings n = 9) using an optimized procedure, and the V4 region of the 16S ribosomal RNA gene was sequenced to identify each individual's microbiota. Diversity in pup samples was lower (3.92 ± 0.19) than yearlings (4.66 ± 0.39) although not significant at the p = 0.05 level ( p = 0.062) but differences in the composition of the microbiota were ( p < 0.001). Similarly, differences between the composition of the microbiota from pups from three different terrestrial habitats (Pilgrim's Haven [PH], Rona Rocks [RR], and Tarbet Slope [TS]) were highly significant ( p < 0.001). Pairwise tests showed significant differences between all three habitats: PH versus TS ( p = 0.019), PH versus RR ( p = 0.042) and TS versus RR ( p = 0.020). This preliminary study suggests a general trend, that seal microbiomes are modified by both age and, in pups, different terrestrial habitats. Furthermore, knowledge of the microbiota species present has the potential to be used in determining the environmental quality index.

Convergent evolution of the gut microbiome in marine carnivores

“…16S rRNA gene data of the gut microbiome of the nine species ( Cuon alpinus [Wu et al, 2016 ], Canis lupus [Wu et al, 2017 ], Vulpes Vulpes [Wang, Shang, Wei, et al, 2022 ; Wang, Shang, Wu, et al, 2022 ; Wang, Wu, et al, 2022 ], V. Corsac [Wang, Shang, Wei, et al, 2022 ; Wang, Shang, Wu, et al, 2022 ; Wang, Wu, et al, 2022 ], Cervus elaphus [Wang et al, 2019 ], Ovis musimon [Sun et al, 2019 ], Pantholops hodgsonii [Wang, Shang, Wei, et al, 2022 ; Wang, Shang, Wu, et al, 2022 ; Wang, Wu, et al, 2022 ], Pseudois nayaur [Wang, Shang, Wei, et al, 2022 ; Wang, Shang, Wu, et al, 2022 ; Wang, Wu, et al, 2022 ], and Bos grunniens [Wang, Shang, Wei, et al, 2022 ; Wang, Shang, Wu, et al, 2022 ; Wang, Wu, et al, 2022 ]) were obtained by sequencing in our laboratory. Other 16S rRNA gene data ( C. Nippon [Guan et al, 2017 ], Moschus chrysogaster [Sun et al, 2020 ], Halichoerus grypus [Watkins et al, 2022 ], Nyctereutes procyonoides [Ishida‐Kuroki et al, 2020 ], Enhydra lutris nereis [Dudek et al, 2022 ], Balaenoptera physalus , and Physeter microcephalus [Glaeser et al, 2022 ]) were downloaded from the NCBI SRA database ( www.ncbi.nlm.nih.gov ). The 16S rRNA gene sequences are listed in Appendix S1 .…”

“…Moschus chrysogaster [Sun et al, 2020], Halichoerus grypus [Watkins et al, 2022], Nyctereutes procyonoides [Ishida-Kuroki et al, 2020],…”

Common core respiratory bacteriome of the blue whaleBalaenoptera musculus, in the Gulf of California

“…The advent of modern technologies that allow identification of all bacteria present in environmental or clinical samples (Haegeman et al, 2013;Salter et al, 2014;Rhodes et al, 2022) has led to a myriad of studies on the abundance, diversity and structure of the microbiome of different species (Nelson et al, 2015;Watkins et al, 2022). One of the reasons why it is paramount to increase our knowledge about the microbiome of a given species is because the microbial communities associated with a particular organ can impact the host's physiology (Foster et al, 2017), and even play an important role in its health status (Zaura et al, 2009;Huse et al, 2012;Chaban et al, 2013;Huang et al, 2016;Bierlich et al, 2018;Watkins et al, 2022). For example, respiratory infections can occur when opportunistic microorganisms, which are normally part of the microbiome of a healthy respiratory tract, preferentially flourish under certain conditions (Hilty et al, 2010;Dickson et al, 2016;Rhodes et al, 2022), and de novo infections may occur if individuals are exposed to pathogens.…”