Enterococcus species diversity in fecal samples of wild marine species as determined by real-time PCR.

Abstract

Analyses using culture-independent molecular techniques have improved our understanding of microbial composition. The aim of this work was to identify and quantify enterococci in fecal samples of wild marine species using real-time quantitative PCR. Seven Enterococcus species were examined in fecal DNA of South American fur seals (Arctocephalus australis), Subantarctic fur seals (Arctocephalus tropicalis), green turtles (Chelonia mydas), Magellanic penguins (Spheniscus magellanicus), snowy-crowned tern (Sterna trudeaui), white-backed stilt (Himantopus melanurus), white-chinned petrels (Procellaria aequinoctialis), red knot (Calidris canutus), and black-browed albatross (Thalassarche melanophris). All Enterococcus species evaluated were detected in all fecal samples of wild marine species, with a concentration ranging between 106 and 1012 copies/ng of total DNA. Differences in the enterococci distribution were observed. Enterococcus faecalis and Enterococcus mundtii were most abundant in marine mammals. Enterococcus faecalis was frequent in green turtle, Magellanic penguin, snowy-crowned tern, red knot, and black-browed albatross. Enterococcus hirae and Enterococcus gallinarum showed elevated occurrence in white-backed stilt, and Enterococcus faecium in white-chinned petrel. This study showed highest diversity of enterococci in feces of wild marine species than currently available data, and reinforced the use of culture-independent analysis to help us to enhance our understanding of enterococci in gastrointestinal tracts of wild marine species.