title: Diversity of enterococcal species and characterization of high-level aminoglycoside resistant enterococci of samples of wastewater and surface water in Tunisia.
abstract: One hundred-fourteen samples of wastewater (n=64) and surface-water (n=50) were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 75% of tested samples in SB media (72% in wastewater; 78% in surface-water), and 85 enterococcal isolates (one/positive-sample) were obtained. Enterococcus faecium was the most prevalent species (63.5%), followed by Enterococcus faecalis (20%), Enterococcus hirae (9.4%), Enterococcus casseliflavus (4.7%), and Enterococcus gallinarum/Enterococcus durans (2.4%). Antibiotic resistance detected among these enterococci was as follows [percentage/detected gene (number isolates)]: kanamycin [29%/aph(3')-IIIa (n=22)], streptomycin [8%/ant(6)-Ia (n=4)], erythromycin [44%/erm(B) (n=34)], tetracycline [18%/tet(M) (n=6)/tet(M)-tet(L) (n=9)], chloramphenicol [2%/cat(A) (n=1)], ciprofloxacin [7%] and trimethoprim-sulfamethoxazole [94%]. High-level-gentamicin resistant (HLR-G) enterococci were recovered from 15 samples in SB-Gen or SB plates [12/64 samples of wastewater (19%) and 3/50 samples of surface-water (6%)]; HLR-G isolates were identified as E. faecium (n=7), E. faecalis (n=6), and E. casseliflavus (n=2). These HLR-G enterococci carried the aac(6')-Ie-aph(2")-Ia and erm(B) genes, in addition to aph(3')-IIIa (n=10), ant(6)-Ia (n=9), tet(M) (n=13), tet(L) (n=8) and cat(A) genes (n=2). Three HLR-G enterococci carried the esp virulence gene. Sequence-types detected among HLR-G enterococci were as follows: E. faecalis (ST480, ST314, ST202, ST55, and the new ones ST531 and ST532) and E. faecium (ST327, ST12, ST296, and the new ones ST985 and ST986). Thirty-two different PFGE patterns were detected among 36 high-level-aminoglycoside-resistant enterococci recovered in water samples. Diverse genetic lineages of HLR-G enterococci were detected in wastewater and surface-water in Tunisia. Water can represent an important source for the dissemination of these antibiotic resistant microorganisms to other environments.
authors.affiliation: Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Said
authors.affiliation: Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisia.
authors.forename: Naouel
authors.initials: N
authors.lastname: Klibi
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, 26006 Logroño, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Lozano
authors.affiliation: Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisia.
authors.forename: Raoudha
authors.initials: R
authors.lastname: Dziri
authors.affiliation: Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire, 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: Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisia.
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Boudabous
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, 26006 Logroño, Spain. Electronic address: carmen.torres@unirioja.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D000617:Aminoglycosides; D000818:Animals; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016983:Enterococcus / Q000145:classification / Q000502:physiology*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000382:microbiology; D005798:Genes, Bacterial; D014644:Genetic Variation; D014416:Tunisia; D062065:Wastewater / Q000382:microbiology*; D014871:Water Microbiology
chemical_list: D000617:Aminoglycosides; D062065:Wastewater
keywords: Antibiotic resistance; Enterococci; Surface water; Tunisia; Virulence; Wastewater