A livestock-associated, multidrug-resistant, methicillin-resistant Staphylococcus aureus Clonal Complex 97 lineage spreading in dairy cattle and pigs in Italy
Applied and Environmental Microbiology publica este artículo de investigación
1 de febrero de 2016
Pandemic methicillin-resistant S. aureus (MRSA) Clonal Complex (CC)97 MRSA lineages originated from livestock-to-human host jumps. In recent years CC97 has become one of the major MRSA lineages detected in Italian farmed animals. The aim of the study was to characterize and analyze differences of MRSA and methicillin-susceptible S. aureus (MSSA) mainly of swine and bovine origin. Forty-seven CC97 isolates, 35 MRSA and 6 MSSA from different Italian pig and cattle holdings, 5 pig MRSA from Germany, one human MSSA from Spain, were characterized by macro-restriction-PFGE analysis, MLST, spa-typing, SCCmec typing, antimicrobial resistance pattern. Virulence and resistance genes were investigated by PCR and microarray. Most of isolates were SCCmec V, except two German MRSA (SCCmec III). Five main clusters were identified by PFGE, with the German isolates (cluster I and II) showing 60.5%, similarity with the Italian isolates, which mostly (68.1%) grouped in cluster V. All CC97 were PVL-negative and few (n=7) tested positive for sak or scn. All MRSA were multidrug resistant (MDR), and the main features were: erm(B)- or erm(C)-mediated (n=18) macrolide-lincosamide-streptogramin B and vga(A)-mediated (n=37) pleuromutilin resistance; fluoroquinolone resistance (n=33); tet(K) in 32/37 tet(M)-positive isolates, and BlaZ in almost all MRSA. Few host-associated differences were detected among CC97 MRSA: its extensive MDR nature both in pigs and dairy cattle may be a consequence of a spill-back from pigs of a MRSA lineage originated in cattle as MSSA, and needs further investigation. Measures should be implemented at farm level to prevent spill-over to humans in intensive farming areas
Feltrin F., Alba A., Kraushaar B., Ianzano A., Arqudin MA., Di Matteo P., Porrero MC., Aarestrup F., Butaye P., Franco A. y Battisti A.
 | Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana (IZSLT). |
 | Federal Institute for Risk Assessment (BfR). |
| Veterinary and Agrochemical Research Centre (CODA_CERVA). | |
 | Servicio de Zoonosis de Transmisión Alimentaria y Resistencia a Antimicrobianos (ZTA). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
 | Department of Biosciences. School of Veterinary Medicine. Ross University. |
 | Department of Pathology, Bacteriology, and Poultry Diseases. Faculty of Veterinary Medicine. University of Ghent (UGENT). |
| National Reference Centre – Staphylococcus aureus, Department of Microbiology. Hopital Erasme. Free University of Brussels (VUB). | |
