title: Characterization of Staphylococcus aureus from Raw Meat Samples in Tunisia: Detection of Clonal Lineage ST398 from the African Continent.
abstract: Livestock-associated Staphylococcus aureus isolates, and especially those belonging to ST398, have been increasingly described in colonized and infected animals and humans, and also in food samples in several countries. The purpose of this study was to determine the frequency of S. aureus and methicillin-resistant S. aureus (MRSA) isolates in raw meat samples destined for food consumption in Tunisia, and to characterize the recovered isolates. One hundred sixty-nine food samples of animal origin were collected. Samples were inoculated onto selective mediums for S. aureus and MRSA recovery. Different molecular typing methods were implemented (pulsed-field gel electrophoresis [PFGE], multilocus sequence typing, spa-, agr-, and SCCmec typing). MRSA was detected in 2 of these 169 samples (1.2%), both of which were of chicken origin. The two MRSA isolates (one/sample) were typed as ST30-CC30-t012-agrIII-SCCmecV and ST398-CC398-t4358-agrI-SCCmecIVa. The MRSA ST398 strain presented resistance, in addition to β-lactams, to tetracycline (tet[M]) and erythromycin (erm[C]) and harbored the sen, hla, hlg, and hlgv virulence genes. Methicillin-susceptible S. aureus (MSSA) isolates were recovered from 42 of the 169 tested samples (24.8%). A high diversity of spa types (n=21) and SmaI-PFGE patterns (27 different profiles; 4 nontypeable) were detected among MSSA isolates. Four MSSA isolates were typed as ST398/CC398. The percentage of antimicrobial resistance and detected genes in MSSA isolates were as follows: tetracycline (28.6% tet[K] and tet[L]), kanamycin (9.5%, aph[3']-IIIa), tobramycin (2.4%, ant[4']-Ia), erythromycin (14.3%, erm[A], erm[C], msr[A]), and penicillin (95%). The genes lukS-lukF were detected in two MSSA isolates (4.5%), the gene tst in one isolate, and the gene eta in five isolates. To our knowledge, this is the first detection of MRSA and MSSA ST398 in food in an African country. The risk of transmission of S. aureus and MRSA carrying different antimicrobial resistance and virulence genes through the food chain cannot be ignored.
authors.affiliation: 1 Laboratoire de Microorganismes et Biomolécules Actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire , Tunis, Tunisia .
authors.forename: Sarra
authors.initials: S
authors.lastname: Chairat
authors.affiliation: 1 Laboratoire de Microorganismes et Biomolécules Actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire , Tunis, Tunisia .
authors.forename: Haythem
authors.initials: H
authors.lastname: Gharsa
authors.affiliation: 2 Área de Bioquímica y Biología Molecular, Universidad de La Rioja , Logroño, Spain .
authors.forename: Carmen
authors.initials: C
authors.lastname: Lozano
authors.affiliation: 2 Área de Bioquímica y Biología Molecular, Universidad de La Rioja , Logroño, Spain .|3 Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW) , Wädenswil, Switzerland .
authors.forename: Elena
authors.initials: E
authors.lastname: Gómez-Sanz
authors.affiliation: 2 Área de Bioquímica y Biología Molecular, Universidad de La Rioja , Logroño, Spain .
authors.forename: Paula
authors.initials: P
authors.lastname: Gómez
authors.affiliation: 2 Área de Bioquímica y Biología Molecular, Universidad de La Rioja , Logroño, Spain .
authors.forename: Myriam
authors.initials: M
authors.lastname: Zarazaga
authors.affiliation: 1 Laboratoire de Microorganismes et Biomolécules Actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire , Tunis, Tunisia .
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Boudabous
authors.affiliation: 2 Área de Bioquímica y Biología Molecular, Universidad de La Rioja , Logroño, Spain .
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
authors.affiliation: 1 Laboratoire de Microorganismes et Biomolécules Actives, Département de Biologie, Faculté de Sciences de Tunis, Campus Universitaire , Tunis, Tunisia .|4 Institut Supérieur des Sciences Biologiques Appliquées de Tunis, Université de Tunis El Manar , Tunis, Tunisia .
authors.forename: Karim
authors.initials: K
authors.lastname: Ben Slama
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005506:Food Contamination; D005516:Food Microbiology; D005798:Genes, Bacterial; D008460:Meat / Q000382:microbiology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D013752:Tetracycline / Q000494:pharmacology; D014416:Tunisia; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D047090:beta-Lactams; D013752:Tetracycline