title: Epidemic Escherichia coli ST131 and Enterococcus faecium ST17 in coastal marine sediments from an Italian beach.
abstract: Fecal indicator bacteria (FIB) are used worldwide to assess water quality in coastal environments, but little is known about their genetic diversity and pathogenicity. This study examines the prevalence, antimicrobial resistance, virulence, and genetic diversity of FIB isolated from marine sediments from a central Adriatic seaside resort. FIB, recovered from 6 out of 7 sites, were significantly more abundant at sampling stations 300 m offshore than close to the shore. Escherichia coli accounted for 34.5% of fecal coliforms, and Enterococcus faecalis accounted for 32% of enterococci. Most isolates (27% of E. coli and 22% of enterococci) were recovered from the sediments that had the highest organic content. Multidrug-resistant E. coli (31%) and enterococci (22%) were found at nearly all sites, whereas 34.5% of E. coli and 28% of enterococci harboring multiple virulence factors were recovered from just two sites. Pulsed-field gel electrophoresis typing showed wide genetic diversity among isolates. Human epidemic clones ( E. coli ST131 and Enterococcus faecium ST17) were identified for the first time by multilocus sequence typing in an area where bathing had not been prohibited. These clones were from sites far removed from riverine inputs, suggesting a wide diffusion of pathogenic FIB in the coastal environment and a high public health risk.
authors.affiliation: Department of Life and Environmental Sciences, Polytechnic University of Marche , via Brecce Bianche, 60131 Ancona, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Vignaroli
authors.forename: G M
authors.initials: GM
authors.lastname: Luna
authors.forename: S
authors.initials: S
authors.lastname: Pasquaroli
authors.forename: A
authors.initials: A
authors.lastname: Di Cesare
authors.forename: R
authors.initials: R
authors.lastname: Petruzzella
authors.forename: P
authors.initials: P
authors.lastname: Paroncini
authors.forename: F
authors.initials: F
authors.lastname: Biavasco
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D017753:Ecosystem; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D014644:Genetic Variation; D019015:Geologic Sediments / Q000382:microbiology*; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D014774:Virulence / Q000187:drug effects / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000890:Anti-Infective Agents; D037521:Virulence Factors