title: Prevalence, antibiotic resistance, virulence traits and genetic lineages of Staphylococcus aureus in healthy sheep in Tunisia.
abstract: Nasal swabs of 163 healthy sheep were obtained from two farms and one abattoir in Tunisia during 2010. Samples were inoculated in Baird Parker agar and ORSAB medium for Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) recovery, respectively. MRSA was detected in 5 of these 163 samples (3%) in ORSAB medium, and one isolate per sample was further studied. MRSA isolates were mecA-positive, typed as ST153-CC80-t044-agrIII, and contained blaZ, ant(6)-Ia, aph(3')-IIIa, erm(C), tet(K), and fusB genes encoding penicillin, streptomycin, kanamycin, erythromycin, tetracycline and fusidic acid resistance, respectively. These MRSA isolates showed indistinguishable or closely related PFGE-patterns and harboured the lukF/lukS gene encoding the Panton-Valentine leukocidin and the luk-ED, hla, hld, and hlg(v) genes. Methicillin-susceptible S. aureus (MSSA) were recovered in 68 of the 163 samples (41.7%) and one isolate per sample was characterized. Most of MSSA (82.4%) showed susceptibility to the tested antibiotics with exceptions: penicillin (6%, carrying blaZ gene), tetracycline (19%, carrying tet(K) gene) and fusidic acid (9%). The following toxin-genes were identified among MSSA: tst (53 isolates), luk-M (52), luk-ED, hla, hlb, hld and hlg(v) (67), hlg (1), sec (49), sel (52), and the egc-cluster-like sen-sem-sei-seo-seg (1). Ten spa-types (two of them new ones) and nine sequence types (six new ones) were detected among the 73 S. aureus isolates, and they were ascribed to agr types I and III. All MRSA and MSSA isolates were able to coagulate bovine plasma and MRSA harboured the immune-evasion-gene-cluster type E. Conclusions. Nares of healthy sheep could be a reservoir of PVL-positive community-associated-MRSA and also of TSST-positive S. aureus isolates, with potential implications in public health.
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université Tunis-El Manar, 2092 Tunis, Tunisia.
authors.forename: Haythem
authors.initials: H
authors.lastname: Gharsa
authors.forename: Karim
authors.initials: K
authors.lastname: Ben Slama
authors.forename: Carmen
authors.initials: C
authors.lastname: Lozano
authors.forename: Elena
authors.initials: E
authors.lastname: Gómez-Sanz
authors.forename: Naouel
authors.initials: N
authors.lastname: Klibi
authors.forename: Rym
authors.initials: R
authors.lastname: Ben Sallem
authors.forename: Paula
authors.initials: P
authors.lastname: Gómez
authors.forename: Myriam
authors.initials: M
authors.lastname: Zarazaga
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Boudabous
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D016521:Electrophoresis, Gel, Pulsed-Field; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D009666:Nose / Q000382:microbiology; D015995:Prevalence; D012756:Sheep / Q000382:microbiology; D012757:Sheep Diseases / Q000453:epidemiology / Q000382:microbiology*; D034561:Sheep, Domestic / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D014416:Tunisia / Q000453:epidemiology; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents