title: Prevalence, antimicrobial resistance and genetic lineages of Enterococcus spp. from vegetable food, soil and irrigation water in farm environments in Tunisia.
abstract: BACKGROUND
  The objective of this study was to determine the species, clonal diversity, antibiotic resistance and virulence of enterococci in different environments. Seventy-one samples of farm origin (34 of food vegetables, 27 of soil and ten of irrigation water) and 19 samples of vegetables from five markets, were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery.
  
  
  RESULTS
  Enterococci were obtained from 72.2% of tested samples in SB media (food vegetables from farms, 88.2%; soil and irrigation water, 51%; food vegetables from markets, 84.2%), and 65 enterococcal isolates were obtained. Enterococcus faecium was the most prevalent species (52.3%), followed by E. hirae (35.4%), E. faecalis (6.15%), and E. casseliflavus (6.15%). Antibiotic resistance detected among these enterococci was as follows (percentage/detected gene): ciprofloxacin (60%), erythromycin (18.4%/erm(B)), tetracycline (15.4%/tet(M)-tet(L)), kanamycin (15.4%/aph(3')-III), chloramphenicol (7.7%), streptomycin (3%/ant(6)), vancomycin (6.15%/vanC2)), teicoplanin (0%) and ampicillin (0%). High-level gentamicin-resistant (HLR-G) enterococci were detected in SB-Gen plates in 14 of 90 tested samples (15.5%), and 15 isolates were characterized: ten E. faecalis, four E. faecium and one E. hirae. All HLR-G enterococci carried the aac(6')-aph(2″), erm(B) and tet(M) genes, among other resistance genes. The HLR-G isolates showed high genetic diversity (ten different PFGE profiles), and were ascribed to the sequence types ST2, ST16, ST28 and new ST528 (in E. faecalis), and ST56, new ST885 and new ST886 (in E. faecium).
  
  
  CONCLUSIONS
  Food vegetables in the farm or market settings are frequently contaminated by HLR-G enterococci, and these microorganisms could reach the human intestine through the food chain, if hygienic conditions are not followed. © 2015 Society of Chemical Industry.
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Said
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.
authors.forename: Naouel
authors.initials: N
authors.lastname: Klibi
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.
authors.forename: Raoudha
authors.initials: R
authors.lastname: Dziri
authors.affiliation: Department of Health Sciences, Università degli Studi di Milano, I-20142, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Borgo
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Boudabous
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.|Institut Supérieur des Sciences Biologiques Appliquées de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.
authors.forename: Karim
authors.initials: K
authors.lastname: Ben Slama
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, E-26006, Logroño, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D057914:Agricultural Irrigation; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D005516:Food Microbiology; D012988:Soil Microbiology; D014416:Tunisia; D014675:Vegetables / Q000382:microbiology*; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: Tunisia; antibiotic resistance; enterococci; irrigation water; resistance genes; soil; vegetables; virulence