| Abstract | Enterococcus faecalis is part of the human intestinal microbiota and an important nosocomial pathogen. It can be found in the marine environment, where it is also employed as a fecal indicator. To assess the pathogenic potential of marine E. faecalis, four strains isolated from marine sediment were analyzed for their ability to survive in human macrophages. Escherichia coli DH5α was used as a negative control. The number of adherent and intracellular bacteria was determined 2.5 h after the infection (T0) and after further 24h (T24) by CFU and qPCR counts. At T24 adherent and intracellular enterococcal CFU counts were increased for all strains, the increment in intracellular bacteria being particularly marked. No CFU of E. coli DH5α were detected. In contrast, qPCR counts of intracellular enterococcal and E. coli bacteria were similar at both time points. These findings suggest that whereas E. coli was killed within macrophages (no CFU, positive qPCR), the E. faecalis isolates not only escaped killing, but actually multiplied, as demonstrated by the increase in the viable cell population. These findings support earlier data by our group, further documenting that marine sediment can be a reservoir of pathogenic enterococci. |
| Text | 366497 2015 10.1016/j.micinf.2015.06.001 Scopus 2 s2.0 84940452011 ISI Web of Science WOS 000361264500007 Adhesion Enterococcus faecalis Internalization Macrophages Adherence and intracellular survival within human macrophages of Enterococcus faecalis isolates from coastal marine sediment Sabatino R.; Di Cesare A.; Pasquaroli S.; Vignaroli C.; Citterio B.; Amiri M.; Rossi L.; Magnani M.; Mauro A.; Biavasco F. Department of Biomolecular Sciences, Section of Biochemistry and Molecular Biology, Universita degli Studi Carlo Bo, via A. Saffi 2, Urbino, 61029, Italy; Istituto Auxologico Italiano, Neurobiology Laboratory, Strada Cadorna 90, Piancavallo di Oggebbio, 28824, Italy; Department of Life and Environmental Sciences, Universita Politecnica delle Marche, via Brecce Bianche, Ancona, 60131, Italy; Institute of Ecosystem Study ISE , Microbial Ecology Group MEG , Consiglio Nazionale delle ricerche CNR , largo V. Tonolli 50, Verbania, 28922, Italy; Section of Toxicological, Hygienistic and Environmental Sciences, Universita degli Studi Carlo Bo, via A. Saffi 2, Urbino, 61029, Italy Enterococcus faecalis is part of the human intestinal microbiota and an important nosocomial pathogen. It can be found in the marine environment, where it is also employed as a fecal indicator. To assess the pathogenic potential of marine E. faecalis, four strains isolated from marine sediment were analyzed for their ability to survive in human macrophages. Escherichia coli DH5α was used as a negative control. The number of adherent and intracellular bacteria was determined 2.5 h after the infection T0 and after further 24h T24 by CFU and qPCR counts. At T24 adherent and intracellular enterococcal CFU counts were increased for all strains, the increment in intracellular bacteria being particularly marked. No CFU of E. coli DH5α were detected. In contrast, qPCR counts of intracellular enterococcal and E. coli bacteria were similar at both time points. These findings suggest that whereas E. coli was killed within macrophages no CFU, positive qPCR , the E. faecalis isolates not only escaped killing, but actually multiplied, as demonstrated by the increase in the viable cell population. These findings support earlier data by our group, further documenting that marine sediment can be a reservoir of pathogenic enterococci. 17 Published version http //www.scopus.com/inward/record.url eid=2 s2.0 84940452011 partnerID=q2rCbXpz Articolo 2015_Microbes_and_Infection_17_660_664.pdf Articolo in rivista Ed. Elsevier 1286 4579 Microbes and infection Microbes and infection Microbes infect. Microbes and infection. andrea.dicesare DI CESARE ANDREA |
