title: Foods confiscated from non-EU flights as a neglected route of potential methicillin-resistant Staphylococcus aureus transmission.
abstract: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in food-producing animals has provoked a great concern in the presence of MRSA in associated foodstuff. In this study, we have assessed for the first time the presence of MRSA in food confiscated from non-EU flights. We performed a search for MRSA among 195 food samples confiscated from passengers on flights from twenty-one non-EU countries in 2012 and 2013. One hundred and seventeen meat samples of diverse animal origin (including antelope, beef, chicken, duck, guinea pig, pork, rodents, and turkey), 75 dairy products (74 cheeses and 1 butter) and 3 eggs were analyzed. All S. aureus were studied by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. MRSA isolates were further characterized by multilocus sequence typing (MLST), SCCmec typing, and tested for the presence of Panton-Valentine leukocidin (PVL) virulence factors. Overall, 66 food samples were positive for S. aureus (33.9%). Six S. aureus strains were MRSA (9.1%), all of them in flights from Bolivia (and 5 from the same passenger). Among methicillin-sensitive S. aureus (MSSA) (60 out of 66S. aureus strains), 44.1% were resistant to penicillin, 10.2% to tetracycline, 8.5% were resistant to aminoglycosides (amikacin and tobramycin) and 3.4% exhibited the M phenotype. MRSA isolates were sensitive to all non-β-lactam antibiotics tested. SmaI-PFGE analysis provided 40 genotypes among the S. aureus isolates (three genotypes among the six MRSA). Five MRSA isolates belonged to ST8 and harboured SCCmec type IVc as well as PVL genes. One isolate belonged to ST1649, harboured SCCmec type IVc and tested negative for the presence of the PVL genes. In conclusion, in this study, we report for the first time the presence of CA-MRSA in food confiscated from non-EU flights: ST8/ST1649-MRSA-IV. These results confirm the illegal entrance of food as a neglected route of transmission as well as the dissemination of successful CA-MRSA lineages among countries via illegal foods. As a result, illegally imported food could play a role in the prevalence and evolution of MRSA clones in the community.
authors.affiliation: InstitutoTecnológicoAgrario de Castilla y León (ITACyL), Valladolid, Spain; Microbiology Section, Faculty of Sciences, University of Burgos, Burgos, Spain. Electronic address: rodlazda@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Rodríguez-Lázaro
authors.affiliation: InstitutoTecnológicoAgrario de Castilla y León (ITACyL), Valladolid, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Ariza-Miguel
authors.affiliation: Department of Food Science and Biotechnology, Faculty of Sciences, University of Burgos, Burgos, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Diez-Valcarce
authors.affiliation: Complejo Asistencial Universitario de León, León, Spain; Institute of Biomedicine (IBIOMED), University of León, León, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Fernández-Natal
authors.affiliation: InstitutoTecnológicoAgrario de Castilla y León (ITACyL), Valladolid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Hernández
authors.affiliation: Department of Food Science and Biotechnology, Faculty of Sciences, University of Burgos, Burgos, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Rovira
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016521:Electrophoresis, Gel, Pulsed-Field; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D018570:Risk Assessment; D013203:Staphylococcal Infections / Q000382:microbiology / Q000635:transmission; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D037521:Virulence Factors
keywords: CA-MRSA; Food; Methicillin-resistant Staphylococcus aureus; Neglected route of transmission