The bacteria of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) are site-specific and distinct from freshwater environment

Abstract

Bacteria play an essential role in the health of marine mammals, and the bacteria of marine mammals are widely concerned, but less is known about freshwater mammals. In this study, we investigated the bacteria of various body sites of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) and analyzed their association with freshwater environmental bacteria. The bacterial community and function of Yangtze finless porpoise showed apparent site-specificity. Various body sites have distinct differences in bacteria and have their dominant bacteria. Romboutsia, Plesiomonas, Actinobacillus, Candidatus Arthromitus dominated in the intestine (fecal and rectal samples). Fusobacterium, Streptococcus, and Acinetobacter dominated in the oral. The dominant genera in the blowhole include Suttonella, Psychrobacter, and two uncultured genera. Psychrobacter, Flavobacterium, and Acinetobacter were dominant in the skin. The alpha diversity of intestinal (fecal and rectal) bacteria was the lowest, while that of skin was the highest. The oral and skin bacteria of Yangtze finless porpoise significantly differed between the natural and semi-natural conditions, but no sex difference was observed. A clear boundary was found between the animal and the freshwater environmental bacteria. Even the skin bacteria, which are more affected by the environment, are significantly different from the environmental bacteria and harbor indigenous bacteria. Our results provide a comprehensive preliminary exploration of the bacteria of Yangtze finless porpoise and its association with bacteria in the freshwater environment.

Fecal and skin microbiota of two rescued Mediterranean monk seal pups during rehabilitation

“…Cultured E. coli prevailed in the feces of stranded—but not diseased—harbor seal ( Phoca vitulina ) individuals at admission to rehabilitation compared to wild-caught ones ( 50 ), and this is a point of concern during rehabilitation, i.e., the transfer of microorganisms from humans to the hospitalized animals. Streptococcus is another potentially detrimental group of bacteria, but it has not been directly related to pathogenesis in marine mammals; it has been found in the oral cavity and intestine of the Yangtze finless porpoise ( Neophocaena asiaeorientalis ) ( 51 ) and sperm whales ( Physeter catodon ) ( 52 ). Enterococcus has been reported to be among the dominant fecal bacteria of captive or stranded but not diseased cetaceans ( 42 , 52 – 56 ).…”

“…The genus Fusobacterium had 10.3% relative abundance in this period. This genus has been found in the oral cavity ( 51 ), the genitals ( 64 ), and the fecal material of other cetaceans ( 52 , 65 ), as well. The phylum Fusobacteria has been found to be characteristic of marine carnivores when compared to terrestrial carnivores ( 29 ).…”

“…Of similar abundance was the genus Bacteroides whose abundance increased from 0.1% to 5.3% between the first and second periods. This genus has been found in the oral ( 51 ) and fecal ( 53 , 54 , 70 ) microbiome of cetaceans. In humans, it is considered one of the commensal bacteria that first colonize the gut after vaginal birth ( 71 ), and this could be also the case for the M. monachus pups.…”

“…Although Psychrobacter -related OTUs dominated in each sampling, their relative abundance decreased gradually during the rehabilitation period. This genus is common on the skin of marine mammals ( 51 , 72 – 74 ), reflecting its ubiquity in the marine environment ( 75 , 76 ). Although it remains unclear if some of its species could be true pathogens, an extensive comparative genomics study concluded that the genus’s strains belong to either the flexible ecotype, which can grow at warm temperatures, and so, it can colonize mammalian skin and other tissues, or the restricted ecotype, i.e., the pure psychrophiles, free-living, and generalist strains found in the world ocean.…”

Fecal and skin microbiota of two rescued Mediterranean monk seal pups during rehabilitation

“…the transfer of microorganisms from humans to the hospitalized animals. Streptococcus is another potentially detrimental group of bacteria but it has not been directly related to pathogenesis in marine mammals; it has been found in the oral cavity and intestine of the Yangtze finless porpoise (Neophocaena asiaeorientalis) (50) and sperm whales (Physeter catodon) (51). Enterococcus has been reported to be among the dominant fecal bacteria of captive or stranded but not diseased cetaceans (41,(51)(52)(53)(54)(55).…”